Science.gov

Sample records for ethyl radicals

  1. Dissociation of the Ethyl Radical: An Exercise in Computational Chemistry

    ERIC Educational Resources Information Center

    Nassabeh, Nahal; Tran, Mark; Fleming, Patrick E.

    2014-01-01

    A set of exercises for use in a typical physical chemistry laboratory course are described, modeling the unimolecular dissociation of the ethyl radical to form ethylene and atomic hydrogen. Students analyze the computational results both qualitatively and quantitatively. Qualitative structural changes are compared to approximate predicted values…

  2. Ethyl Radical Ejection During Photodecomposition of Butanone on TiO2(110)

    SciTech Connect

    Henderson, Michael A.

    2008-10-15

    The photodecomposition of acetone and butanone were examined on the (110) surface of rutile TiO2 using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). In both cases, photodecomposition was proceeded by a required thermal reaction between the adsorbed ketone and coadsorbed oxygen resulting in a diolate species. The diolate photodecomposed by ejection of an organic radical from the surface leaving behind a carboxylate species. In the acetone case, only methyl radical PSD was detected and acetate was left on the surface. In the butanone case there was a possibility of either methyl or ethyl radical ejection, with propionate or acetate left behind, respectively. However, only ethyl radical PSD was detected and the species left on the surface (acetate) was the same as in the acetone case. The preference for ethyl radical ejection is linked to the greater thermal stability of the ethyl radical over that of the methyl radical. Unlike in the acetone case, where the ejected methyl radicals did not participate in thermal chemistry on the TiO2(110) surface after photoactivation of the acetone diolate, ethyl radicals photodesorbing at 100 K from butanone diolate showed a preference for dehydrogenation to ethene through the influence of coadsorbed oxygen. These results reemphasize the mechanistic importance of organic radical production during photooxidation reactions on TiO2 surface.

  3. Ethyl Radical Ejection During Photodecomposition of Butanone on TiO2(110)

    SciTech Connect

    Henderson, Michael A.

    2008-10-15

    The photodecomposition of acetone and butanone were examined on the (110) surface of rutile TiO2 using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). In both cases, photodecomposition was proceeded by a required thermal reaction between the adsorbed ketone and coadsorbed oxygen resulting in a diolate species. The diolate photodecomposed by ejection of an organic radical from the surface leaving behind a carboxylate species. In the acetone case, only methyl radical PSD was detected and acetate was left on the surface. In the butanone case there was a possibility of either methyl or ethyl radical ejection, with propionate or acetate left behind, respectively. However, only ethyl radical PSD was detected and the species left on the surface (acetate) was the same as in the acetone case. The preference for ethyl radical ejection is linked to the greater thermal stability of the ethyl radical over that of the methyl radical. Unlike in the acetone case, where the ejected methyl radicals did not participate in thermal chemistry on the TiO2(110) surface after photoactivation of the acetone diolate, ethyl radicals photodesorbing at 100 K from butanone diolate showed a preference for dehydrogenation to ethene through the influence of coadsorbed oxygen. These results reemphasize the mechanistic importance of organic radical production during photooxidation reactions on TiO2 surface. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  4. Rapid syntheses of dehydrodiferulates via biomimetic radical coupling reactions of ethyl ferulate.

    PubMed

    Lu, Fachuang; Wei, Liping; Azarpira, Ali; Ralph, John

    2012-08-29

    Dehydrodimerization of ferulates in grass cell walls provides a pathway toward cross-linking polysaccharide chains limiting the digestibility of carbohydrates by ruminant bacteria and in general affecting the utilization of grass as a renewable bioresource. Analysis of dehydrodiferulates (henceforth termed diferulates) in plant cell walls is useful in the evaluation of the quality of dairy forages as animal feeds. Therefore, there has been considerable demand for quantities of diferulates as standards for such analyses. Described here are syntheses of diferulates from ethyl ferulate via biomimetic radical coupling reactions using the copper(II)-tetramethylethylenediamine [CuCl(OH)-TMEDA] complex as oxidant or catalyst. Although CuCl(OH)-TMEDA oxidation of ethyl ferulate in acetonitrile produced mixtures composed of 8-O-4-, 8-5-, 8-8- (cyclic and noncyclic), and 5-5-coupled diferulates, a catalyzed oxidation using CuCl(OH)-TMEDA as catalyst and oxygen as an oxidant resulted in better overall yields of such diferulates. Flash chromatographic fractionation allowed isolation of 8-8- and 5-5-coupled diferulates. 8-5-Diferulate coeluted with 8-O-4-diferulate but was separated from it via crystallization; the 8-O-4 diferulate left in the mother solution was isolated by rechromatography following a simple tetrabutylammonium fluoride treatment that converted 8-5-diferulate to another useful diferulate, 8-5-(noncyclic) diferulate. Therefore, six of the nine (5-5, 8-O-4, 8-5-c, 8-5-nc, 8-5-dc, 8-8-c, 8-8-nc, 8-8-THF, 4-O-5) diferulic acids that have to date been found in the alkaline hydrolysates of plant cell walls can be readily synthesized by the CuCl(OH)-TMEDA catalyzed aerobic oxidative coupling reaction and subsequent saponification described here. PMID:22846085

  5. The photodissociation dynamics of the ethyl radical, C{sub 2}H{sub 5}, investigated by velocity map imaging

    SciTech Connect

    Steinbauer, Michael; Giegerich, Jens; Fischer, Kathrin H.; Fischer, Ingo

    2012-07-07

    The photodissociation dynamics of the ethyl radical C{sub 2}H{sub 5} has been investigated by velocity map imaging. Ethyl was produced by flash pyrolysis from n-propyl nitrite and excited to the A {sup 2}A{sup Prime} (3s) Rydberg state around 250 nm. The energetically most favorable reaction channel in this wavelength region is dissociation to C{sub 2}H{sub 4} (ethene) + H. The H-atom dissociation products were ionized in a [1+1{sup Prime }] process via the 1s-2p transition. The observed translational energy distribution is bimodal: A contribution of slow H-atoms with an isotropic angular distribution peaks at low translational energies. An expectation value for the fraction of excess energy released into translation of = 0.19 is derived from the data, typical for statistical dissociation reactions. In addition, a fast H-atom channel is observed, peaking around 1.8 eV. The latter shows an anisotropic distribution with {beta}= 0.45. It originates from a direct dissociation process within less than a rotational period. Time-delay scans with varying extraction voltages indicate the presence of two rates for the formation of H-atoms. One rate with a sub-nanosecond time constant is associated with H-atoms with large translational energy; a second one with a time constant on the order of 100 ns is associated with H-atoms formed with low translational energy. The data confirm and extend those from previous experiments and remove some inconsistencies. Possible mechanisms for the dissociation are discussed in light of the new results as well as previous ones.

  6. Accurate Prediction of Hyperfine Coupling Constants in Muoniated and Hydrogenated Ethyl Radicals: Ab Initio Path Integral Simulation Study with Density Functional Theory Method.

    PubMed

    Yamada, Kenta; Kawashima, Yukio; Tachikawa, Masanori

    2014-05-13

    We performed ab initio path integral molecular dynamics (PIMD) simulations with a density functional theory (DFT) method to accurately predict hyperfine coupling constants (HFCCs) in the ethyl radical (CβH3-CαH2) and its Mu-substituted (muoniated) compound (CβH2Mu-CαH2). The substitution of a Mu atom, an ultralight isotope of the H atom, with larger nuclear quantum effect is expected to strongly affect the nature of the ethyl radical. The static conventional DFT calculations of CβH3-CαH2 find that the elongation of one Cβ-H bond causes a change in the shape of potential energy curve along the rotational angle via the imbalance of attractive and repulsive interactions between the methyl and methylene groups. Investigation of the methyl-group behavior including the nuclear quantum and thermal effects shows that an unbalanced CβH2Mu group with the elongated Cβ-Mu bond rotates around the Cβ-Cα bond in a muoniated ethyl radical, quite differently from the CβH3 group with the three equivalent Cβ-H bonds in the ethyl radical. These rotations couple with other molecular motions such as the methylene-group rocking motion (inversion), leading to difficulties in reproducing the corresponding barrier heights. Our PIMD simulations successfully predict the barrier heights to be close to the experimental values and provide a significant improvement in muon and proton HFCCs given by the static conventional DFT method. Further investigation reveals that the Cβ-Mu/H stretching motion, methyl-group rotation, methylene-group rocking motion, and HFCC values deeply intertwine with each other. Because these motions are different between the radicals, a proper description of the structural fluctuations reflecting the nuclear quantum and thermal effects is vital to evaluate HFCC values in theory to be comparable to the experimental ones. Accordingly, a fundamental difference in HFCC between the radicals arises from their intrinsic molecular motions at a finite temperature, in

  7. Kinetic study of the reaction of the hydroxyl radical (OH) with methyl ethyl ketone (2-butanone) and its deuterated isotopomers at low pressure

    NASA Astrophysics Data System (ADS)

    Liljegren, J. A.; Stevens, P. S.

    2012-12-01

    Methyl ethyl ketone (2-butanone) in the atmosphere comes from a variety of sources. It is produced commercially as an industrial ketone. It can be formed as a result of the OH or Cl-initiated oxidation of C4-C6 alkanes, primarily n-butane, or from the reaction of some alkenes with OH or O3. Biogenic sources include direct emissions from certain plants as well as emissions from decaying plant matter. Methyl ethyl ketone is removed from the atmosphere primarily by its reaction with OH. A product of this reaction includes acetaldehyde, which is a hazardous air pollutant, can further react to produce peroxy acetyl nitrate (PAN), and can be a significant source of free radicals to the atmosphere. The absolute rate constant for the reaction of OH with methyl ethyl ketone has been measured as a function of temperature at low pressure using discharge-flow techniques coupled with laser induced fluorescence (LIF) detection of OH. In addition, measurements of the rate constants for the reactions of OH with two deuterated isotopomers of methyl ethyl ketone, including CD3C(O)CH2CH3 and CH3C(O)CD2CD3, will be presented to gain a better understanding of the mechanism for this reaction. Theoretical studies of the potential energy surface for this reaction suggest that the reaction proceeds through the formation of a hydrogen-bonded pre-reactive complex, similar to that of several other atmospherically relevant oxygenated VOCs such as acetone, acetic acid, and hydroxyacetone.

  8. Rate laws and kinetic modeling of N-ethyl perfluorooctane sulfonamidoethanol (N-EtFOSE) transformation by hydroxyl radical in aqueous solution.

    PubMed

    Nguyen, Tung Viet; Reinhard, Martin; Gin, Karina Yew-Hoong

    2013-05-01

    The degradation of perfluorochemicals (PFCs) by hydroxyl radical ((·)OH) follows complex pathways resulting in stable products. Kinetic models are needed to predict the product distribution of (·)OH-initiated PFC degradation under environmental and treatment conditions. The bimolecular rate constants were measured in water for the reaction of (·)OH and N-ethyl perfluorooctane sulfonamidoethanol (N-EtFOSE), and intermediates, N-ethyl perfluorooctane sulfonamidoacetate (N-EtFOSAA), N-ethyl perfluorooctane sulfonamide (N-EtFOSA) and perfluorooctane sulfonamidoacetate (FOSAA). Under standard conditions (pH = 6, 25 ± 2 °C, Co PFC = 5-10 μg L(-1), Co H2O2 = 10 mM, irradiation intensity = 765 W m(-2)), the measured constants for N-EtFOSE, N-EtFOSAA, N-EtFOSA and FOSAA were (1.05 ± 0.12) × 10(9) M(-1) s(-1), (0.68 ± 0.05) × 10(9) M(-1) s(-1), (0.68 ± 0.05) × 10(9) M(-1) s(-1) and (0.53 ± 0.05) × 10(9) M(-1) s(-1), respectively. Constants in the pH range from 1 to 10 varied within a factor of 2-4 for most compounds. Over a period of 2-days, N-EtFOSE reacted directly (without forming long-lived intermediates) to perfluorooctane sulfonamide (FOSA) (18.8%) and perfluorooctanoic acid (PFOA) (39.1%). N-EtFOSE reacted via oxidation of the ethanolic hydroxyl group to N-EtFOSAA (12.4%) and N-dealkylation to N-EtFOSA (13.3%) and FOSAA (0.2%) and unknown intermediates. In sunlit surface waters, the (·)OH-induced transformation of N-substituted sulfonamide compounds to photostable products occurs on a time scale of days to weeks by model prediction.

  9. Synthesis of biomimetic poly[2-(methacryloyloxy)ethyl phosphorycholine]-coated magnetite nanoparticles via surface-initiated atom transfer radical polymerization.

    PubMed

    Sui, Jie-He; Cao, Chang-Yan; Cai, Wei

    2011-10-01

    Modification of magnetite nanoparticles with biomimetic poly[2-(methacryloyloxy)ethyl phosphorycholine] (poly(MPC)) via surface-initiated atom transfer radical polymerization (ATRP) was carried out. Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analyses (TGA) and zeta potential studies indicated that well defined poly (MPC) was successfully grafted on the surface of magnetite nanoparticles. X-ray diffraction results showed the structure of magnetite nanoparticles after surface modification was not changed. The poly (MPC)-coated magnetite nanoparticles had a mean transmission electron microscopy (TEM) diameter of 11 +/- 1.5 nm. The resulting nanomaterials were superparamagnetic at room temperature, exhibited good colloidal stability in aqueous media and good responsibility to magnetic field. Such magnetite nanoparticles with biomimetic surface have potential application in prolonging circulation time in vivo.

  10. Atom transfer radical addition (ATRA) catalyzed by copper complexes with tris[2-(dimethylamino)ethyl]amine (Me6TREN) ligand in the presence of free-radical diazo initiator AIBN.

    PubMed

    Eckenhoff, William T; Pintauer, Tomislav

    2011-05-14

    In this article, we focus on the evaluation of tris[2-(dimethylamino)ethyl]amine (Me(6)TREN) ligand in copper catalyzed ATRA in the presence of free-radical diazo initiator AIBN (2,2'-azobis(2-methylpropionitrile)). The addition of carbon tetrachloride to 1-hexene, 1-octene and cis-cyclooctene proceeded efficiently to yield 89, 85 and 85% of monoadduct, respectively, using the catalyst to alkene ratio of 1 : 2500. For alkenes that readily undergo free radical polymerization, such as methyl acrylate, catalyst loadings as high as 0.4 mol-% were required. Furthermore, modest yields of the monoadduct were obtained with less active alkyl halides (chloroform and bromoform) using 250 : 1 and 500 : 1 ratios of alkene to copper(II). Interestingly, the addition of carbon tetrachloride to cis-cyclooctene produced only 1-chloro-4-(trichloromethyl)-cyclooctene, while carbon tetrabromide yielded 1,2 and 1,4-regioisomers in 75 : 25 ratio. The activity of [Cu(II)(Me(6)TREN)X][X] (X = Br(-) and Cl(-)) complexes in ATRA in the presence of AIBN was additionally probed by adding excess free ligand, source of halide anions and triphenylphosphine. The results indicated that disproportionation is a likely cause for lower activity of Me(6)TREN as compared to TPMA (tris(2-pyridylmethyl)amine).

  11. Icosapent Ethyl

    MedlinePlus

    ... pharmacist if you are allergic to icosapent ethyl; fish, including shellfish (clams, scallops, shrimp, lobster, crayfish, crab, ... and ticlopidine (Ticlid); aspirin or aspirin-containing products; beta-blockers such as atenolol (Tenormin), labetalol (Normodyne), metoprolol ( ...

  12. Ethyl carbamate

    Integrated Risk Information System (IRIS)

    Ethyl carbamate ; CASRN 51 - 79 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  13. Ethyl ether

    Integrated Risk Information System (IRIS)

    Ethyl ether ; CASRN 60 - 29 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  14. Ethyl acetate

    Integrated Risk Information System (IRIS)

    Ethyl acetate ; CASRN 141 - 78 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  15. Ethyl chloride

    Integrated Risk Information System (IRIS)

    Ethyl chloride ; CASRN 75 - 00 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  16. Pulse radiolysis of aqueous solutions of ethyl acrylate and hydroxy ethyl acrylate

    NASA Astrophysics Data System (ADS)

    Safrany, A.; Biro, A.; Wojnarovits, L.

    1993-10-01

    Ethyl- and hydroxy ethyl acrylate show high reactivities with hydrated electron and hydroxyl radical intermediates of water radiolysis. The electron adduct reversibly protonate with pK values of 5.7 and 7.3. The adducts may take part in irreversible protonation at the β carbon atom forming α-carboxyl alkyl radicals. Same type of radical forms in reaction of acrylates with OH: at low concentration the adduct mainly disappear in self termination reactions. Above 5 mmol dm -1 the signals showed the startup of oligomerization.

  17. FTIR gas-phase kinetic study on the reactions of OH radicals and Cl atoms with unsaturated esters: Methyl-3,3-dimethyl acrylate, (E)-ethyl tiglate and methyl-3-butenoate

    NASA Astrophysics Data System (ADS)

    Colomer, Juan P.; Blanco, María B.; Peñéñory, Alicia B.; Barnes, Ian; Wiesen, Peter; Teruel, Mariano A.

    2013-11-01

    The relative-rate technique has been used to obtain rates coefficients for the reactions of the unsaturated esters methyl-3,3-dimethyl acrylate, (E)-ethyl tiglate and methyl-3-butenoate with OH radicals and chlorine atoms at (298 ± 2) K in synthetic air at a total pressure of (760 ± 10) Torr. The experiments were performed in an environmental chamber using in situ FTIR detection to monitor the decay of the esters relative to different reference compounds. The following room temperature rate coefficients (in units of cm3 molecule-1 s-1) were obtained: k1(OH + (CH3)2Cdbnd CHC(O)OCH3) = (4.46 ± 1.05) × 10-11, k2(Cl + (CH3)2Cdbnd CHC(O)OCH3) = (2.78 ± 0.46) × 10-10, k3(OH + CH3CHdbnd C(CH3)C(O)OCH2CH3) = (8.32 ± 1.93) × 10-11, k4(Cl + CH3CHdbnd C(CH3)C(O)OCH2CH3) = (2.53 ± 0.35) × 10-10, k5(OH + CH2dbnd CHCH2C(O)OCH3) = (3.16 ± 0.57) × 10-11, k4(Cl + CH2dbnd CHCH2C(O)OCH3) = (2.10 ± 0.35) × 10-10. With the exception of the reaction of Cl with methyl-3,3-dimethyl acrylate (k2), for which one determination exists in the literature, this study is the first kinetic study for these reactions under atmospheric pressure. Reactivity trends are discussed in terms of the effect of the alkyl and ester groups attached to the double bond on the overall rate coefficients towards OH radicals. The atmospheric implications of the reactions were assessed by the estimation of the tropospheric lifetimes of the title reactions.

  18. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ethyl alcohol containing ethyl acetate....

  19. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ethyl alcohol containing ethyl acetate....

  20. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ethyl alcohol containing ethyl acetate....

  1. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl alcohol containing ethyl acetate....

  2. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ethyl alcohol containing ethyl acetate....

  3. Ethyl alcohol production

    SciTech Connect

    Hofman, V.; Hauck, D.

    1980-11-01

    Recent price increases and temporary shortages of petroleum products have caused farmers to search for alternate sources of fuel. The production of ethyl alcohol from grain is described and the processes involved include saccharification, fermentation and distillation. The resulting stillage has potential as a livestock feed.

  4. Methyl ethyl ketone (MEK)

    Integrated Risk Information System (IRIS)

    Methyl ethyl ketone ( MEK ) ( CASRN 78 - 93 - 3 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonc

  5. Chlorimuron-ethyl

    Integrated Risk Information System (IRIS)

    Chlorimuron - ethyl ; CASRN 90982 - 32 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinog

  6. Atmospheric Oxidation Mechanisms for Diethyl Ether and its Oxidation Products, Ethyl Formate and Ethyl Acetate.

    NASA Astrophysics Data System (ADS)

    Orlando, J. J.; Tyndall, G. S.

    2006-12-01

    Carbon-containing compounds are present in the earth's atmosphere as the result of emissions from natural and anthropogenic sources. Their oxidation in the atmosphere, initiated by such oxidants as OH, ozone, and nitrate radicals, leads to potentially harmful secondary pollutants such as ozone, carbonyl species, organic acids and aerosols. Ethers and esters are two classes of compounds that contribute to the complex array of organic compounds found in anthropogenically-influenced air. Additional ester is present as a result of the oxidation of the ethers. In this paper, the oxidation of diethyl ether and its two main oxidation products, ethyl formate and ethyl acetate, are studied over ranges of temperature, oxygen partial pressure, and NOx concentration, using an environmental chamber / FTIR absorption technique. Major end-products (the esters from diethyl ether; organic acids and anhydrides from the esters) are quantified, and these data are interpreted in terms of the chemistry of the various alkoxy and peroxy radicals generated. Emphasis is placed on the effects of chemical activation on the behavior of the alkoxy radicals, as well as on a novel peroxy radical rearrangement that may contribute to the observed products of ether oxidation under some conditions. Finally, the data are used, in conjunction with data on similar species, to provide a general representation of ether and ester oxidation in the atmosphere.

  7. A Study on Spectro-Analytical Aspects, DNA - Interaction, Photo-Cleavage, Radical Scavenging, Cytotoxic Activities, Antibacterial and Docking Properties of 3 - (1 - (6 - methoxybenzo [d] thiazol - 2 - ylimino) ethyl) - 6 - methyl - 3H - pyran - 2, 4 - dione and its Metal Complexes.

    PubMed

    Ravi, Mudavath; Chennam, Kishan Prasad; Ushaiah, B; Eslavath, Ravi Kumar; Perugu, Shyam; Ajumeera, Rajanna; Devi, Ch Sarala

    2015-09-01

    The focus of the present work is on the design, synthesis, characterization, DNA-interaction, photo-cleavage, radical scavenging, in-vitro cytotoxicity, antimicrobial, docking and kinetic studies of Cu (II), Cd (II), Ce (IV) and Zr (IV) metal complexes of an imine derivative, 3 - (1 - (6 - methoxybenzo [d] thiazol - 2 - ylimino) ethyl) - 6 - methyl - 3H - pyran - 2, 4 - dione. The investigation of metal ligand interactions for the determination of composition of metal complexes, corresponding kinetic studies and antioxidant activity in solution was carried out by spectrophotometric methods. The synthesized metal complexes were characterized by EDX analysis, Mass, IR, (1)H-NMR, (13)C-NMR and UV-Visible spectra. DNA binding studies of metal complexes with Calf thymus (CT) DNA were carried out at room temperature by employing UV-Vis electron absorption, fluorescence emission and viscosity measurement techniques. The results revealed that these complexes interact with DNA through intercalation. The results of in vitro antibacterial studies showed the enhanced activity of chelating agent in metal chelated form and thus inferring scope for further development of new therapeutic drugs. Cell viability experiments indicated that all complexes showed significant dose dependent cytotoxicity in selected cell lines. The molecular modeling and docking studies were carried out with energy minimized structures of metal complexes to identify the receptor to metal interactions. PMID:26315729

  8. Reactivity of 2-ethyl-1-hexanol in the atmosphere.

    PubMed

    Gallego-Iniesta García, María Paz; Moreno Sanroma, Alberto; Martín Porrero, María Pilar; Tapia Valle, Araceli; Cabañas Galán, Beatriz; Salgado Muñoz, María Sagrario

    2010-04-01

    Rate coefficients at room temperature for the reaction of 2-ethyl-1-hexanol with OH and NO(3) radicals and with Cl atoms have been determined in a 150 L PTFE chamber using GC-FID/SPME and FTIR as detection systems. The rate coefficients k (in units of cm(3) molecule(-1) s(-1)) obtained were: (1.13 +/- 0.31) 10(-11) for the OH reaction, (2.93 +/- 0.92) 10(-15) for the NO(3) reaction and (1.88 +/- 0.25) 10(-10) for the Cl reaction. Despite the high concentrations of 2-ethyl-1-hexanol, especially in indoor air, this is the first kinetic study carried out to date for these reactions. The results are consistent with the expected reactivity given the chemical structure of 2-ethyl-1-hexanol. Calculated atmospheric lifetimes reveal that the dominant loss process for 2-ethyl-1-hexanol is clearly the daytime reaction with the hydroxyl radical. PMID:20237722

  9. Reactivity of 2-ethyl-1-hexanol in the atmosphere.

    PubMed

    Gallego-Iniesta García, María Paz; Moreno Sanroma, Alberto; Martín Porrero, María Pilar; Tapia Valle, Araceli; Cabañas Galán, Beatriz; Salgado Muñoz, María Sagrario

    2010-04-01

    Rate coefficients at room temperature for the reaction of 2-ethyl-1-hexanol with OH and NO(3) radicals and with Cl atoms have been determined in a 150 L PTFE chamber using GC-FID/SPME and FTIR as detection systems. The rate coefficients k (in units of cm(3) molecule(-1) s(-1)) obtained were: (1.13 +/- 0.31) 10(-11) for the OH reaction, (2.93 +/- 0.92) 10(-15) for the NO(3) reaction and (1.88 +/- 0.25) 10(-10) for the Cl reaction. Despite the high concentrations of 2-ethyl-1-hexanol, especially in indoor air, this is the first kinetic study carried out to date for these reactions. The results are consistent with the expected reactivity given the chemical structure of 2-ethyl-1-hexanol. Calculated atmospheric lifetimes reveal that the dominant loss process for 2-ethyl-1-hexanol is clearly the daytime reaction with the hydroxyl radical.

  10. EPA dashes ethyl`s hopes for MMT

    SciTech Connect

    Heller, K.

    1992-01-15

    Up until the Environmental Protection Agency (EPA; Washington) decided to deny Ethyl`s (Richmond, VA) petition to sell manganese-based gasoline additive MMT, many on Wall Street were bullish. Bets were that MMT sales could create an up to $200 million/year sales windfall for Ethyl with $60 million/year income, and push its near $26/share price up by at least 50 cts. But EPA ruled January 8 against MMT in unleaded gas due to its potential to increase hydrocarbon emissions. What kept analysts hoping is that octane enhancer MMT`s environmental impacts are mixed. An Ethyl spokesman says that MMT cut tailpipe emissions of nitrogen oxide by 20% and carbon monoxide by 7%. Ethyl also points out that MMT could save as much as 85,000 barrels/day of imported oil because of lower energy requirements in blending. And the product has sold for 13 years in Canada with no reported ill health effects. But, points out Smith, Barney (New York) analyst James Wilbur, Canada is not the congested Los Angeles basin, where the unknown effects of small amounts of heavy metal manganese would show up a lot faster if every car burnt MMT. For now, the financial effect of the decision is negligible, although at some point Ethyl may have to take a write-down on its Orangeburg, NC plant.

  11. Ethyl`s MMT ready to hit the road

    SciTech Connect

    Stringer, J.

    1996-01-03

    After spending two decades and about $30 million on the fight to sell the fuel octane booster methylcyclopentadienyl manganese tricarbonyl (MMT), Ethyl has started marketing the product. Ethyl president and chief operating officer Thomas Gottwald says he expects a profit from MMT from the outset. {open_quotes}MMT is a gangbuster new product,{close_quotes} says Paul Raman, an analyst with S.G. Warburg (New York), {open_quotes}and it will be very profitable for Ethyl.{close_quotes} Ethyl`s effort to bring MMT to market faced pressure from EPA and automakers. EPA says MMT should not be marketed until more research is done on health effects of the manganese-based additive. US automakers oppose MMT, fearing it will damage catalytic converters. Last October Ethyl won a federal appeals court decision compelling EPA to approve MMT use. Gottwald says the MMT fight has been well worth it: {open_quotes}We fought with our eye on the bottom line.{close_quotes}

  12. Radical Hysterectomy

    MedlinePlus

    ... the base of her partner’s penis during intercourse. Orgasm after radical hysterectomy Women who have had a ... the surgery will affect their ability to have orgasms. This has not been studied a great deal, ...

  13. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which are... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethyl acetate. 173.228 Section 173.228 Food and..., Lubricants, Release Agents and Related Substances § 173.228 Ethyl acetate. Ethyl acetate (CAS Reg. No....

  14. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which are... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl acetate. 173.228 Section 173.228 Food and..., Lubricants, Release Agents and Related Substances § 173.228 Ethyl acetate. Ethyl acetate (CAS Reg. No....

  15. S-Ethyl dipropylthiocarbamate (EPTC)

    Integrated Risk Information System (IRIS)

    S - Ethyl dipropylthiocarbamate ( EPTC ) ; CASRN 759 - 94 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessme

  16. Detection of interstellar ethyl cyanide

    NASA Technical Reports Server (NTRS)

    Johnson, D. R.; Lovas, F. J.; Gottlieb, C. A.; Gottlieb, E. W.; Litvak, M. M.; Thaddeus, P.; Guelin, M.

    1977-01-01

    Twenty-four millimeter-wave emission lines of ethyl cyanide (CH3CH2CN) have been detected in the Orion Nebula (OMC-1) and seven in Sgr B2. To derive precise radial velocities from the astronomical data, a laboratory measurement of the rotational spectrum of ethyl cyanide has been made at frequencies above 41 GHz. In OMC-1, the rotational temperature of ethyl cyanide is 90 K (in good agreement with other molecules), the local-standard-of-rest radial velocity is 4.5 + or - 1.0 km/s (versus 8.5 km/s for most molecules), and the column density is 1.8 by 10 to the 14th power per sq cm (a surprisingly high figure for a complicated molecule). The high abundance of ethyl cyanide in the Orion Nebula suggests that ethane and perhaps larger saturated hydrocarbons may be common constituents of molecular clouds and have escaped detection only because they are nonpolar or only weakly polar.

  17. 21 CFR 172.868 - Ethyl cellulose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethyl cellulose. 172.868 Section 172.868 Food and... Multipurpose Additives § 172.868 Ethyl cellulose. The food additive ethyl cellulose may be safely used in food in accordance with the following prescribed conditions: (a) The food additive is a cellulose...

  18. 21 CFR 172.868 - Ethyl cellulose.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethyl cellulose. 172.868 Section 172.868 Food and... Multipurpose Additives § 172.868 Ethyl cellulose. The food additive ethyl cellulose may be safely used in food in accordance with the following prescribed conditions: (a) The food additive is a cellulose...

  19. Effect of ethyl esterification of phenolic acids on low-density lipoprotein oxidation.

    PubMed

    Chalas, J; Claise, C; Edeas, M; Messaoudi, C; Vergnes, L; Abella, A; Lindenbaum, A

    2001-02-01

    Inhibition of copper-induced low-density lipoprotein (LDL) oxidation by phenolic acids and their ethyl esters was investigated. LDL oxidation was evaluated by the hydroperoxide concentration and the chromatographic pattern of apoprotein fractions after fast protein liquid chromatography (FPLC). Antiradical properties against 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical and 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) were also investigated, and lipophilicity determined by thin-layer chromatography. Caffeic acid at 5 microM and sinapic acid at 10 microM protected LDL against oxidation, inhibiting both hydroperoxide formation and the increase of apoprotein negative charge. Ferulic, gallic and p-hydroxy cinnamic acids were ineffective. Ethyl esterification increased the lipophilicity of the five acids, and enhanced the antioxidant properties of caffeic, sinapic and ferulic acids. Ethyl caffeate was protective at 1 microM. In contrast, gallic and p-hydroxy cinnamic ethyl esters were ineffective. Our results indicate that ethyl esterification of phenolic acids increases lipophilicity of their ethyl esters and may enable a better incorporation into the lipid layer of the LDL particle and the exertion of their antioxidant effect in the true site of lipoperoxidation. However, increasing lipophilicity is not the only mechanism able to potentiate preexisting antioxidant properties of molecules, and probably other mechanisms are implicated.

  20. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, Box... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and....1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH. (b) The ingredient meets...

  1. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  2. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  3. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  4. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  5. Characterization and Antioxidant Properties of Six Algerian Propolis Extracts: Ethyl Acetate Extracts Inhibit Myeloperoxidase Activity

    PubMed Central

    Boufadi, Yasmina Mokhtaria; Soubhye, Jalal; Riazi, Ali; Rousseau, Alexandre; Vanhaeverbeek, Michel; Nève, Jean; Boudjeltia, Karim Zouaoui; Van Antwerpen, Pierre

    2014-01-01

    Because propolis contains many types of antioxidant compounds such as polyphenols and flavonoids, it can be useful in preventing oxidative damages. Ethyl acetate extracts of propolis from several Algerian regions show high activity by scavenging free radicals, preventing lipid peroxidation and inhibiting myeloperoxidase (MPO). By fractioning and assaying ethyl acetate extracts, it was observed that both polyphenols and flavonoids contribute to these activities. A correlation was observed between the polyphenol content and the MPO inhibition. However, it seems that kaempferol, a flavonoid, contributes mainly to the MPO inhibition. This molecule is in a high amount in the ethyl acetate extract and demonstrates the best efficiency towards the enzyme with an inhibiting concentration at 50% of 4 ± 2 μM. PMID:24514562

  6. Wheat Seedlings as Food Supplement to Combat Free Radicals: An In Vitro Approach

    PubMed Central

    Ravikumar, P.; Shalini, G.; Jeyam, M.

    2015-01-01

    The present study was designed to evaluate the antioxidant activity of 5 organic solvent extracts (petroleum ether, n-hexane, chloroform, ethyl acetate and methanol) of wheat grains, 3, 5 and 7 days old wheat seedlings. To determine the antioxidant activity of five extracts of four different samples, 1,1-diphenyl-2-picrylhydrazyl and 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, total phenolic content and ferrous reducing power ability were carried out. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging effect of chloroform and ethyl acetate extracts of 3 days old wheat seedlings was higher than wheat grains. Chloroform, ethyl acetate and methanol extracts of 3 days old wheat seedlings exhibited higher 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging effcet than extracts of other samples. The phenolic content was high in chloroform, ethyl acetate and methanol extract of 5 days old wheat seedlings. When compared with wheat grain, reducing power ability was high in chloroform, ethyl acetate and methanol extract of wheat seedlings, especially in 3 and 5 days old wheat seedlings. From the above results, it was concluded that chloroform, ethyl acetate and methanol extract of 3, 5 and 7 days old wheat seedlings showed better antioxidant activity than the wheat grain extracts. Hence, the results of the present study suggest the intake of wheat seedlings as a food supplement to combat the diseases caused by free radicals. PMID:26798175

  7. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  8. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  9. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  10. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  11. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  12. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  13. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  14. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  15. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT....108 Ethyl ether. (a) Odor. Characteristic odor. (b) Specific gravity at 15.56 °/15.56 °C. Not...

  16. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT....108 Ethyl ether. (a) Odor. Characteristic odor. (b) Specific gravity at 15.56 °/15.56 °C. Not...

  17. Synthesis, Structural and Antioxidant Studies of Some Novel N-Ethyl Phthalimide Esters

    PubMed Central

    Chandraju, Siddegowda; Win, Yip-Foo; Tan, Weng Kang; Quah, Ching Kheng; Fun, Hoong-Kun

    2015-01-01

    A series of N-ethyl phthalimide esters 4(a-n) were synthesized and characterized by spectroscopic studies. Further, the molecular structure of majority of compounds were analysed by single crystal X-ray diffraction studies. The X-ray analysis revealed the importance of substituents on the crystal stability and molecular packing. All the synthesized compounds were tested for in vitro antioxidant activity by DPPH radical scavenging, FRAP and CUPRAC methods. Few of them have shown good antioxidant activity. PMID:25742494

  18. Radical addition-initiated domino reactions of conjugated oxime ethers.

    PubMed

    Ueda, Masafumi

    2014-01-01

    The application of conjugated oxime ethers to the synthesis of complex chemical scaffolds using domino radical reactions has been described in detail. The triethylborane-mediated hydroxysulfenylation reaction allows for the regioselective construction of a carbon-sulfur bond and a carbon-oxygen bond in a single operation for the formation of β-hydroxy sulfides. This reaction proceeds via a radical pathway involving regioselective thiyl addition and the subsequent trapping of the resulting α-imino radical with O₂, where the imino group enhances the stability of the intermediate radical. Hydroxyalkylation reactions that occur via a carbon radical addition reaction followed by the hydroxylation of the resulting N-borylenamine with O₂ have also been developed. We investigated sequential radical addition aldol-type reactions in detail to explore the novel domino reactions that occur via the generation of N-borylenamine. The radical reaction of a conjugated oxime ether with triethylborane in the presence of an aldehyde affords γ-butyrolactone via sequential processes including ethyl radical addition, the generation of N-borylenamine, an aldol-type reaction with an aldehyde, and a lactonization reaction. A novel domino reaction has also been developed involving the [3,3]-sigmatropic rearrangement of N-boryl-N-phenoxyenamine. The triethylborane-mediated domino reactions of O-phenyl-conjugated oxime ethers afforded the corresponding benzofuro[2,3-b]pyrrol-2-ones via a radical addition/[3,3]-sigmatropic rearrangement/cyclization/lactamization cascade.

  19. Rate Constant and Temperature Dependence for the Reaction of Hydroxyl Radicals with 2-Flouropropane (FC-281ea) and Comparison with an Estimated Rate Constant

    NASA Technical Reports Server (NTRS)

    DeMore, W.; Wilson, E., Jr.

    1998-01-01

    Relative rate experiments were used to measure the rate constant and temperature dependence of the reaction of OH radicals with 2-fluoropropane (HFC-281ea), using ethane, propane, ethyl chloride as reference standards.

  20. Process for the preparation of ethyl benzene

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1995-12-19

    Ethyl benzene is produced in a catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 50 C to 300 C, using as the catalyst a mole sieve characterized as acidic by feeding ethylene to the catalyst bed while benzene is conveniently added through the reflux to result in a molar excess present in the reactor to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene and diethyl benzene in the bottoms. The bottoms are fractionated, the ethyl benzene recovered and the bottoms are contacted with benzene in the liquid phase in a fixed bed straight pass reactor under conditions to transalkylate the benzene thereby converting most of the diethyl benzene to ethyl benzene which is again separated and recovered. 2 figs.

  1. Process for the preparation of ethyl benzene

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1995-01-01

    Ethyl benzene is produced in a catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 50.degree. C. to 300.degree. C., using as the catalyst a mole sieve characterized as acidic by feeding ethylene to the catalyst bed while benzene is conveniently added through the reflux to result in a molar excess present in the reactor to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene and diethyl benzene in the bottoms. The bottoms are fractionated, the ethyl benzene recovered and the bottoms are contacted with benzene in the liquid phase in a fixed bed straight pass reactor under conditions to transalkylate the benzene thereby converting most of the diethyl benzene to ethyl benzene which is again separated and recovered.

  2. Radical prostatectomy - discharge

    MedlinePlus

    ... prostatectomy - discharge; Laparoscopic radical prostatectomy - discharge; LRP - discharge; Robotic-assisted laparoscopic prostatectomy - discharge ; RALP - discharge; Pelvic lymphadenectomy - ...

  3. Antioxidant and protective effect of ethyl acetate extract of podophyllum hexandrum rhizome on carbon tetrachloride induced rat liver injury.

    PubMed

    Ganie, Showkat Ahmad; Haq, Ehtishamul; Masood, Akbar; Hamid, Abid; Zargar, Mohmmad Afzal

    2011-01-01

    The antioxidant and hepatoprotective activities of ethyl acetate extract was carefully investigated by the methods of DPPH radical scavenging activity, Hydroxyl radical scavenging activity, Superoxide radical scavenging activity, Hydrogen peroxide radical scavenging activity and its Reducing power ability. All these in vitro antioxidant activities were concentration dependent which were compared with standard antioxidants such as BHT, α-tocopherol. The hepatoprotective potential of Podophyllum hexandrum extract was also evaluated in male Wistar rats against carbon tetrachloride (CCl(4))-induced liver damage. Pre-treated rats were given ethyl acetate extract at 20, 30 and 50 mg/kg dose prior to CCl(4) administration (1 ml/kg, 1:1 in olive oil). Rats pre-treated with Podophyllum hexandrum extract remarkably prevented the elevation of serum AST, ALT, LDH and liver lipid peroxides in CCl(4)-treated rats. Hepatic glutathione levels were significantly increased by the treatment with the extract in all the experimental groups. The extract at the tested doses also restored the levels of liver homogenate enzymes (glutathione peroxidase, glutathione reductase, superoxide dismutase and glutathione-S- transferase) significantly. This study suggests that ethyl acetate extract of P. hexandrum has a liver protective effect against CCl(4)-induced hepatotoxicity and possess in vitro antioxidant activities.

  4. Antioxidant and Protective Effect of Ethyl Acetate Extract of Podophyllum Hexandrum Rhizome on Carbon Tetrachloride Induced Rat Liver Injury

    PubMed Central

    Ganie, Showkat Ahmad; Haq, Ehtishamul; Masood, Akbar; Hamid, Abid; Zargar, Mohmmad Afzal

    2011-01-01

    The antioxidant and hepatoprotective activities of ethyl acetate extract was carefully investigated by the methods of DPPH radical scavenging activity, Hydroxyl radical scavenging activity, Superoxide radical scavenging activity, Hydrogen peroxide radical scavenging activity and its Reducing power ability. All these in vitro antioxidant activities were concentration dependent which were compared with standard antioxidants such as BHT, α-tocopherol. The hepatoprotective potential of Podophyllum hexandrum extract was also evaluated in male Wistar rats against carbon tetrachloride (CCl4)-induced liver damage. Pre-treated rats were given ethyl acetate extract at 20, 30 and 50 mg/kg dose prior to CCl4 administration (1 ml/kg, 1:1 in olive oil). Rats pre-treated with Podophyllum hexandrum extract remarkably prevented the elevation of serum AST, ALT, LDH and liver lipid peroxides in CCl4-treated rats. Hepatic glutathione levels were significantly increased by the treatment with the extract in all the experimental groups. The extract at the tested doses also restored the levels of liver homogenate enzymes (glutathione peroxidase, glutathione reductase, superoxide dismutase and glutathione-S- transferase) significantly. This study suggests that ethyl acetate extract of P. hexandrum has a liver protective effect against CCl4-induced hepatotoxicity and possess in vitro antioxidant activities. PMID:21394192

  5. Decontamination of 2-Chloroethyl Ethyl Sulfide by Pulsed Corona Plasma

    NASA Astrophysics Data System (ADS)

    Li, Zhanguo; Hu, Zhen; Cao, Peng; Zhao, Hongjie

    2014-11-01

    Decontamination of 2-chloroethyl ethyl sulfide (2-CEES, CH3CH2SCH2CH2Cl) by pulsed corona plasma was investigated. The results show that 212.6 mg/m3 of 2-CEES, with the gas flow rate of 2 m3/h, can be decontaminated to 0.09 mg/m3. According to the variation of the inlet and outlet concentration of 2-CEES vapor with retention time, it is found that the reaction of 2-CEES in a pulsed corona plasma system follows the first order reaction, with the reaction rate constant of 0.463 s-1. The decontamination mechanism is discussed based on an analysis of the dissociation energy of chemical bonds and decontamination products. The C-S bond adjacent to the Cl atom will be destroyed firstly to form CH3CH2S· and ·CH2CH2Cl radicals. CH3CH2S· can be decomposed to ·C2H5 and ·S. ·S can be oxidized to SO2, while ·C2H5 can be finally oxidized to CO2 and H2O. The C-Cl bond in the ·CH2CH2Cl radical can be destroyed to form ·CH2CH2. and ·Cl, which can be mineralized to CO2, H2O and HCl. The H atom in the ·CH2CH2Cl radical can also be substituted by ·Cl to form CHCl2-CHCl2.

  6. Growing up Radical: Investigation of Benzyl-Like Radicals with Increasing Chain Lengths

    NASA Astrophysics Data System (ADS)

    Korn, Joseph A.; Jawad, Khadija M.; Hewett, Daniel M.; Zwier, Timothy S.

    2015-06-01

    Combustion processes involve complex chemistry including pathways leading to polyaromatic hydrocarbons (PAHs) from small molecule precursors. Resonance stabilized radicals (RSRs) likely play an important role in the pathways to PAHs due to their unusual stability. Benzyl radical is a prototypical RSR that is stabilized by conjugation with the phenyl ring. Earlier work on α-methyl benzyl radical showed perturbations to the spectroscopy due to a hindered methyl rotor. If the alkyl chain is lengthened then multiple conformations become possible. This talk will discuss the jet-cooled spectroscopy of α-ethyl benzyl radical and α-propyl benzyl radical produced from the discharge of 1-phenyl propanol and 1-phenyl butanol respectively. Electronic spectra were obtained via resonant two-photon ionization, and IR spectra were obtained by resonant ion-dip infrared spectroscopy. Kidwell, N. M.; Reilly, N. J.; Nebgen, B.; Mehta-Hurt, D. N.; Hoehn, R. D.; Kokkin, D. L.; McCarthy, M. C.; Slipchenko, L. V.; Zwier, T. S. The Journal of Physical Chemistry A 2013, 117, 13465.

  7. [Lavoisier and radicals].

    PubMed

    Lafont, Olivier

    2007-01-01

    Lavoisier and his co-workers (Guyton de Morveau, Bertholet, Fourcroy) considered that acids were constituted of oxygen and of something else that they called radicals. These radicals were known in some cases, i.e. nitrogen for nitrous acid, carbon for carbonic acid, phosphorus for phosphoric acid. In the case of sulfur, the sulfuric radical could be associated with different quantities of oxigen leading to sulfuric or sulfurous acids. In other cases radicals remained unknown at the time i.e. muriatic radical for muriatic acid, or benzoyl radical for benzoic acid. It is interesting to notice that Lavoisier evoked the case of compound radicals constituted of different substances such as carbon and hydrogen.

  8. Synthesis of functionalized 5-substituted thiazolidine-2-thiones via adscititious xanthate-promoted radical cyclization of allyl(alkyl/aryl)dithiocarbamates.

    PubMed

    Gao, Simiao; Zhang, Yu; Dong, Jun; Chen, Ning; Xu, Jiaxi

    2016-01-21

    Functionalized 5-substituted thiazolidine-2-thiones were synthesized efficiently from alkyl allyl(alkyl/aryl)-dithiocarbamates via radical cyclization with the corresponding S-alkyl O-ethyl xanthates as the adscititious radical precursors. The application of the adscititious radical precursors improves not only the yields, but also the efficiency in the radical cyclization reaction significantly. The current adscititious radical precursor method provides a new strategy for the achievement and improvement of some radical reactions which are hardly or difficultly realized by the traditional direct methods. PMID:26626401

  9. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  10. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  11. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  12. A Signature of Roaming Dynamics in the Thermal Decomposition of Ethyl Nitrite: Chirped-Pulse Rotational Spectroscopy and Kinetic Modeling.

    PubMed

    Prozument, Kirill; Suleimanov, Yury V; Buesser, Beat; Oldham, James M; Green, William H; Suits, Arthur G; Field, Robert W

    2014-11-01

    Chirped-pulse (CP) Fourier transform rotational spectroscopy is uniquely suited for near-universal quantitative detection and structural characterization of mixtures that contain multiple molecular and radical species. In this work, we employ CP spectroscopy to measure product branching and extract information about the reaction mechanism, guided by kinetic modeling. Pyrolysis of ethyl nitrite, CH3CH2ONO, is studied in a Chen type flash pyrolysis reactor at temperatures of 1000-1800 K. The branching between HNO, CH2O, and CH3CHO products is measured and compared to the kinetic models generated by the Reaction Mechanism Generator software. We find that roaming CH3CH2ONO → CH3CHO + HNO plays an important role in the thermal decomposition of ethyl nitrite, with its rate, at 1000 K, comparable to that of the radical elimination channel CH3CH2ONO → CH3CH2O + NO. HNO is a signature of roaming in this system.

  13. Forgotten radicals in biology.

    PubMed

    Luc, Rochette; Vergely, Catherine

    2008-12-01

    Redox reactions play key roles in intra- and inter-cellular signaling, and in adaptative processes of tissues towards stress. Among the major free radicals with essential functions in cells are reactive oxygen species (ROS) including superoxide anion (O2 (•-)), hydroxyl radical ((•)OH) and reactive nitrogen species (RNS) such as nitric oxide ((•)NO). In this article, we review the forgotten and new radicals with potential relevance to cardiovascular pathophysiology. Approximately 0.3% of O2 (•-) present in cytosol exists in its protonated form: hydroperoxyl radical (HO2 (•)). Water (H2O) can be split into two free radicals: (•)OH and hydrogen radical (H(•)). Several free radicals, including thiyl radicals (RS(•)) and nitrogen dioxide (NO2 (•)) are known to isomerize double bonds. In the omega-6 series of poly-unsaturated fatty acids (PUFAs), cis-trans isomerization of γ-linolenate and arachidonate catalyzed by RS(•) has been investigated. Evidence is emerging that hydrogen disulphide (H2S) is a signaling molecule in vivo which can be a source of free radicals. The Cu-Zn superoxide dismutase (SOD) enzyme can oxidize the ionized form of H2S to hydro-sulphide radical: HS(•). Recent studies suggest that H2S plays an important function in cardiovascular functions. Carbonate radical, which can be formed when (•)OH reacts with carbonate or bicarbonate ions, is also involved in the activity of Cu-Zn-SOD. Recently, it has been reported that carbonate anion were potentially relevant oxidants of nucleic acids in physiological environments. In conclusion, there is solid evidence supporting the formation of many free radicals by cells leading which may play an important role in their homeostasis. PMID:23675099

  14. Elastic electron scattering by ethyl vinyl ether

    NASA Astrophysics Data System (ADS)

    Khakoo, M. A.; Hong, L.; Kim, B.; Winstead, C.; McKoy, V.

    2010-02-01

    We report measured and calculated results for elastic scattering of low-energy electrons by ethyl vinyl ether (ethoxyethene), a prototype system for studying indirect dissociative attachment processes that may play a role in DNA damage. The integral cross section displays the expected π* shape resonance. The agreement between the calculated and measured cross sections is generally good.

  15. Manufacturing Ethyl Acetate From Fermentation Ethanol

    NASA Technical Reports Server (NTRS)

    Rohatgi, Naresh K.; Ingham, John D.

    1991-01-01

    Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.

  16. Ethyl p-nitrophenyl phenylphosphorothioate (EPN)

    Integrated Risk Information System (IRIS)

    Ethyl p - nitrophenyl phenylphosphorothioate ( EPN ) ; CASRN 2104 - 64 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Ha

  17. The photodissociation dynamics of alkyl radicals

    SciTech Connect

    Giegerich, Jens; Fischer, Ingo

    2015-01-28

    The photodisscociation dynamics of the alkyl radicals i-propyl (CH(CH{sub 3}){sub 2}) and t-butyl (C(CH{sub 3}){sub 3}) are investigated by H-atom photofragment imaging. While i-propyl is excited at 250 nm, the photodynamics of t-butyl are explored over a large energy range using excitation wavelengths between 347 nm and 233 nm. The results are compared to those obtained previously for ethyl, CH{sub 3}CH{sub 2}, and to those reported for t-butyl using 248 nm excitation. The translational energy (E{sub T}) distribution of the H-atom photofragments is bimodal and appears rather similar for all three radicals. The low E{sub T} part of the distribution shows an isotropic photofragment angular distribution, while the high E{sub T} part is associated with a considerable anisotropy. Thus, for t-butyl, two H-atom loss channels of roughly equal importance have been identified in addition to the CH{sub 3}-loss channel reported previously. A mechanism for the photodissociation of alkyl radicals is suggested that is based on interactions between Rydberg- and valence states.

  18. HOCO radical chemistry.

    PubMed

    Francisco, Joseph S; Muckerman, James T; Yu, Hua-Gen

    2010-12-21

    Free radicals are important species in atmospheric chemistry, combustion, plasma environments, interstellar clouds, and biochemistry. Therefore, researchers would like to understand the formation mechanism, structure, stability, reactivity, spectroscopy, and dynamics of these chemical species. However, due to the presence of one or more unpaired electrons, radicals are often very reactive and have short lifetimes, which makes it difficult to conduct experiments. The HOCO radical appears in the atmosphere as well as in combustion environments and plays an important role in the conversion of CO to CO(2). Through the interplay between theoretical and experimental investigations, researchers have only recently understood the chemical role of the HOCO radical. In this Account, we systematically describe the current state of knowledge of the HOCO radical based on recent theoretical and experimental studies. This radical's two stable conformers, trans- and cis-HOCO, have been identified by high-level ab initio calculations and experimental spectroscopy. trans-HOCO is more stable by approximately 1.8 kcal/mol. The heat of formation of HOCO (298 K) was determined to be -43.0 ± 0.5 kcal/mol, giving a potential well depth of 30.1 ± 0.5 kcal/mol relative to the asymptote of the reactants OH + CO. The HOCO radical is very reactive. In most reactions between the HOCO radical and atoms, the HOCO radical acts as a hydrogen donor to reaction partners. Generally, the hydrogen is transferred through the formation of an association intermediate, which then proceeds through a molecular elimination step to produce the reaction products. The reaction rates of HOCO with some small radicals fall in the range of 10(-11)-10(-10) cm(3) molecule(-1) s(-1). These results clearly illustrate important features in the reactivity of the HOCO radical with other molecules.

  19. Antifungal and antioxidant activity of Crassocephalum bauchiense (Hutch.) Milne-Redh ethyl acetate extract and fractions (Asteraceae)

    PubMed Central

    2014-01-01

    Background Crassocephalum bauchiense is a flowering plant, found in the West Region of Cameroon. Previous studied has highlighted the antibacterial and the dermal toxicological safety as well as the immunomodulatory activities of the ethyl acetate extract of its dry leaves. As an extension of the previous researches, the current work has been undertaken to evaluate the in vitro antifungal and antioxidant activities of C. bauchiense dried leaves ethyl acetate extract and fractions. Methods The extract was obtained by maceration in ethyl acetate and further fractionated into six fractions labeled F1 to F6 by flash chromatography. The antifungal activity of the extract and fractions against yeasts and dermatophytes was evaluated using broth microdilution method. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and β-carotene - linoleic acid assays. Results The extract (MIC = 0.125 - 4 mg/ml) was found to be more active on dermatophytes and yeasts compared to the fractions. The ethyl acetate extract and fractions exhibited strong scavenging activity on DPPH (CI50 = 28.57 - 389.38 μg/ml). The fractions F3 and F6 expressed best antioxidant activity on DPPH radicals compared to the crude extract. Conclusion The results of these findings clearly showed that C. bauchiense ethyl acetate extract has a significant antifungal and antioxidant activity. It is therefore a source of active compounds that might be used as antifungal and antioxidant agents. PMID:24742210

  20. 4-Alkyl radical extrusion in the cytochrome P-450-catalyzed oxidation of 4-alkyl-1,4-dihydropyridines

    SciTech Connect

    Lee, J.S.; Jacobsen, N.E.; Ortiz de Montellano, P.R. )

    1988-10-04

    Rat liver microsomal cytochrome P-450 oxidizes the 4-methyl, 4-ethyl (DDEP), and 4-isopropyl derivatives of 3,5-bis(carbethoxy)-2,6-dimethyl-1,4,-dihydropyridine to mixtures of the corresponding 4-alkyl and 4-dealkyl pyridines. A fraction of the total microsomal enzyme is destroyed in the process. The 4-dealkyl to 4-alkyl pyridine metabolite ratio, the extent of cytochrome P-450 destruction, and the rate of spin-trapped radical accumulation are correlated in a linear inverse manner with the homolytic or heterolytic bond energies of the 4-alkyl groups of the 4-alkyl-1,4-dihydropyridines. No isotope effects are observed on the pyridine matabolite ratio, the destruction of cytochrome P-450, or the formation of ethyl radicals when (4-{sup 2}H)DDEP is used instead of DDEP. N-Methyl- and N-ethyl-DDEP undergo N-dealkylation rather than aromatization but N-phenyl-DDEP is oxidized to a mixture of the 4-ethyl and 4-deethyl N-phenylpyridinium metabolites. In contrast to the absence of an isotope effect in the oxidation of DDEP, the 4-deethyl to 4-ethyl N-phenylpyridinium metabolite ratio increases 6-fold when N-phenyl(4-{sup 2}H)DDEP is used. The results support the hypothesis that cytochrome P-450 catalyzes the oxidation of dihydropyridines to radical cations and show that the radical cations decay to nonradical products by multiple, substituent-dependent, mechanisms.

  1. 21 CFR 172.872 - Methyl ethyl cellulose.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Methyl ethyl cellulose. 172.872 Section 172.872... Methyl ethyl cellulose. The food additive methyl ethyl cellulose may be safely used in food in accordance with the following prescribed conditions. (a) The additive is a cellulose ether having the...

  2. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  3. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  4. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  5. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  6. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  7. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  8. Theoretical calculations of hyperfine coupling constants for muoniated butyl radicals.

    PubMed

    Chen, Ya Kun; Fleming, Donald G; Wang, Yan Alexander

    2011-04-01

    The hyperfine coupling constants (HFCCs) of all the butyl radicals that can be produced by muonium (Mu) addition to butene isomers (1- and 2-butene and isobutene) have been calculated, to compare with the experimental results for the muon and proton HFFCs for these radicals reported in paper II (Fleming, D. G.; et al. J. Phys. Chem. A 2011, 10.1021/jp109676b) that follows. The equilibrium geometries and HFCCs of these muoniated butyl radicals as well as their unsubstituted isotopomers were treated at both the spin-unrestricted MP2/EPR-III and B3LYP/EPR-III levels of theory. Comparisons with calculations carried out for the EPR-II basis set have also been made. All calculations were carried out in vacuo at 0 K only. A C-Mu bond elongation scheme that lengthens the equilibrium C-H bond by a factor of 1.076, on the basis of recent quantum calculations of the muon HFCCs of the ethyl radical, has been exploited to determine the vibrationally corrected muon HFCCs. The sensitivity of the results to small variations around this scale factor was also investigated. The computational methodology employed was "benchmarked" in comparisons with the ethyl radical, both with higher level calculations and with experiment. For the β-HFCCs of interest, compared to B3LYP, the MP2 calculations agree better with higher level theories and with experiment in the case of the eclipsed C-Mu bond and are generally deemed to be more reliable in predicting the equilibrium conformations and muon HFCCs near 0 K, in the absence of environmental effects. In some cases though, the experimental results in paper II demonstrate that environmental effects enhance the muon HFCC in the solid phase, where much better agreement with the experimental muon HFCCs near 0 K is found from B3LYP than from MP2. This seemingly better level of agreement is probably fortuitous, due to error cancellations in the DFT calculations, which appear to mimic these environmental effects. For the staggered proton HFCCs of the

  9. Synthesis of Ethyl Salicylate Using Household Chemicals

    NASA Astrophysics Data System (ADS)

    Solomon, Sally; Hur, Chinhyu; Lee, Alan; Smith, Kurt

    1996-02-01

    Ethyl salicylate is synthesized, isolated, and characterized in a three-step process using simple equipment and household chemicals. First, acetylsalicylic acid is extracted from aspirin tablets with isopropyl alcohol, then hydrolyzed to salicylic acid with muriatic acid, and finally, the salicylic acid is esterified using ethanol and a boric acid catalyst. The experiment can be directed towards high school or university level students who have sufficient background in organic chemistry to recognize the structures and reactions that are involved.

  10. Production of ethyl alcohol from bananas

    SciTech Connect

    Jones, R.L.; Towns, T.

    1983-12-01

    The production of ethyl alcohol from waste bananas presents many special problems. During cooking, matting of the latex fibers from the banana peel recongeal when cooled and left untreated. This problem has been addressed by Alfaro by the use of CaC1/sub 2/. Separation of solids prior to distillation of the mashes in an economical fashion and use of the by product are also of concern to banana processors.

  11. Computer assisted modeling of ethyl sulfate pharmacokinetics.

    PubMed

    Schmitt, Georg; Halter, Claudia C; Aderjan, Rolf; Auwaerter, Volker; Weinmann, Wolfgang

    2010-01-30

    For 12 volunteers of a drinking experiment the concentration-time-courses of ethyl sulfate (EtS) and ethanol were simulated and fitted to the experimental data. The concentration-time-courses were described with the same mathematical model as previously used for ethyl glucuronide (EtG). The kinetic model based on the following assumptions and simplifications: a velocity constant k(form) for the first order formation of ethyl sulfate from ethanol and an exponential elimination constant k(el). The mean values (and standard deviations) obtained for k(form) and k(el) were 0.00052 h(-1) (0.00014) and 0.561 h(-1) (0.131), respectively. Using the ranges of these parameters it is possible to calculate minimum and maximum serum concentrations of EtS based on stated ethanol doses and drinking times. The comparison of calculated and measured concentrations can prove the plausibility of alleged ethanol consumption and add evidence to the retrospective calculation of ethanol concentrations based on EtG concentrations. PMID:19913378

  12. Chemical and thermochemical aspects of the ozonolysis of ethyl oleate: decomposition enthalpy of ethyl oleate ozonide.

    PubMed

    Cataldo, Franco

    2013-01-01

    Neat ethyl oleate was ozonized in a bubble reactor and the progress of the ozonolysis was followed by infrared (FT-IR) spectroscopy and by the differential scanning calorimetry (DSC). The ozonolysis was conducted till a molar ratio O3/C=C≈1 when the exothermal reaction spontaneously went to completion. A specific thermochemical calculation on ethyl oleate ozonation has been made to determine the theoretical heat of the ozonization reaction using the group increment approach. A linear relationship was found both in the integrated absorptivity of the ozonide infrared band at 1110 cm(-1) and the ozonolysis time as well as the thermal decomposition enthalpy of the ozonides and peroxides formed as a result of the ozonation. The DSC decomposition temperature of ozonated ethyl oleate occurs with an exothermal peak at about 150-155 °C with a decomposition enthalpy of 243.0 kJ/mol at molar ratio O3/C=C≈1. It is shown that the decomposition enthalpy of ozonized ethyl oleate is a constant value (≈243 kJ/mol) at any stage of the O3/C=C once an adequate normalization of the decomposition enthalpy for the amount of the adsorbed ozone is taken into consideration. The decomposition enthalpy of ozonized ethyl oleate was also calculated using a simplified thermochemical model, obtaining a result in reasonable agreement with the experimental value.

  13. Chemical and thermochemical aspects of the ozonolysis of ethyl oleate: decomposition enthalpy of ethyl oleate ozonide.

    PubMed

    Cataldo, Franco

    2013-01-01

    Neat ethyl oleate was ozonized in a bubble reactor and the progress of the ozonolysis was followed by infrared (FT-IR) spectroscopy and by the differential scanning calorimetry (DSC). The ozonolysis was conducted till a molar ratio O3/C=C≈1 when the exothermal reaction spontaneously went to completion. A specific thermochemical calculation on ethyl oleate ozonation has been made to determine the theoretical heat of the ozonization reaction using the group increment approach. A linear relationship was found both in the integrated absorptivity of the ozonide infrared band at 1110 cm(-1) and the ozonolysis time as well as the thermal decomposition enthalpy of the ozonides and peroxides formed as a result of the ozonation. The DSC decomposition temperature of ozonated ethyl oleate occurs with an exothermal peak at about 150-155 °C with a decomposition enthalpy of 243.0 kJ/mol at molar ratio O3/C=C≈1. It is shown that the decomposition enthalpy of ozonized ethyl oleate is a constant value (≈243 kJ/mol) at any stage of the O3/C=C once an adequate normalization of the decomposition enthalpy for the amount of the adsorbed ozone is taken into consideration. The decomposition enthalpy of ozonized ethyl oleate was also calculated using a simplified thermochemical model, obtaining a result in reasonable agreement with the experimental value. PMID:23969233

  14. 40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates (salts). 721.3152 Section 721... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

  15. Radical-Mediated Fluoroalkylations.

    PubMed

    Cho, Eun Jin

    2016-02-01

    Recently, the development of eco-friendly radical processes has become of great interest in synthetic chemistry. In particular, visible-light photocatalysis has drawn tremendous attention for its environmental compatibility and versatility in promoting many synthetically important reactions. In addition, inorganic electrides as electron donors have emerged as new eco-friendly tools for radical transformations since they consist of non-toxic and naturally abundant main metals such as calcium. The design of new fluoroalkylation reactions has benefited greatly from recent advances in visible-light photocatalysis and the chemistry of inorganic electrides. Since adding fluoroalkyl groups can dramatically change the physical and chemical properties of organic compounds, using these processes to promote eco-friendly radical fluoroalkylations will have a major impact in areas such as pharmaceuticals, agrochemicals, and material sciences. This Personal Account reviews radical-mediated fluoroalkylations, such as trifluoromethylations and difluoroalkylations, recently developed in our laboratory. PMID:26497950

  16. Hydroxyl radicals in indoor environments

    NASA Astrophysics Data System (ADS)

    Sarwar, Golam; Corsi, Richard; Kimura, Yosuke; Allen, David; Weschler, Charles J.

    Indoor hydroxyl radical concentrations were estimated using a new indoor air quality model which employs the SAPRC-99 atmospheric chemistry model to simulate indoor homogenous reactions. Model results indicate that typical indoor hydroxyl radical concentrations are lower than typical outdoor summertime urban hydroxyl radical levels of 5-10×10 6 molecules cm -3; however, indoor levels can be similar to or greater than typical nighttime outdoor hydroxyl radical levels of approximately 5×10 4 molecules cm -3. Effects of selected parameters on indoor hydroxyl radical concentrations are presented herein. Indoor hydroxyl radical concentrations are predicted to increase non-linearly with increasing outdoor ozone concentrations, indoor alkene emission rates, and air exchange rates. Indoor hydroxyl radical concentrations decrease with increasing outdoor nitric oxide concentrations. Indoor temperature and indoor light intensity have moderate impacts on indoor hydroxyl radical concentrations. Outdoor hydroxyl radical concentrations, outdoor nitrate (NO 3rad ) radical concentrations, outdoor hydroperoxy radical concentrations, and hydroxyl radical removal by indoor surfaces are predicted to have no appreciable impact on indoor hydroxyl radical concentrations. Production of hydroxyl radicals in indoor environments appears to be controlled primarily by reactions of alkenes with ozone, and nitric oxide with hydroperoxy radical. Estimated indoor hydroxyl radical levels may potentially affect indoor air quality. Two examples are presented in which reactions of d-limonene and α-pinene with indoor hydroxyl radicals produce aldehydes, which may be of greater concern than the original compounds.

  17. Electronic states of alkyl-radical-functionalized C20 fullerene using density functional theory

    NASA Astrophysics Data System (ADS)

    Abe, Shigeaki; Kawano, Shimpei; Toida, Yu; Nakamura, Mariko; Inoue, Satoshi; Sano, Hidehiko; Yoshida, Yasuhiro; Kawabata, Hiroshi; Tachikawa, Hiroto

    2016-03-01

    The structures and electronic states of alkyl-radical-functionalized C20 fullerenes (denoted by C20-R) have been investigated using density functional theory (DFT). The different alkyl radicals investigated were methyl, ethyl, propyl, and butyl radicals. The DFT calculation indicated that the alkyl radical binds to the carbon atom of C20 in the on-top site, thus forming a strong C-C single bond. The binding energies of the alkyl radicals to C20 were calculated to be 83.9-86.6 kcal/mol at the CAM-B3LYP/6-311G(d,p) level. The electronic states of the C20-R complex are discussed on the basis of the theoretical results.

  18. Theoretical study of the decomposition of ethyl and ethyl 3-phenyl glycidate.

    PubMed

    Josa, Daniela; Peña-Gallego, Angeles; Rodríguez-Otero, Jesús; Cabaleiro-Lago, Enrique M

    2013-01-01

    The mechanism of the decomposition of ethyl and ethyl 3-phenyl glycidate in gas phase was studied by density functional theory (DFT) and MP2 methods. A proposed mechanism for the reaction indicates that the ethyl side of the ester is eliminated as ethylene through a concerted six-membered cyclic transition state, and the unstable intermediate glycidic acid decarboxylates rapidly to give the corresponding aldehyde. Two possible pathways for glycidic acid decarboxylation were studied: one via a five-membered cyclic transition state, and the other via a four-membered cyclic transition state. The results of the calculations indicate that the decarboxylation reaction occurs via a mechanism with five-membered cyclic transition state.

  19. Free Radical Reactions in Food.

    ERIC Educational Resources Information Center

    Taub, Irwin A.

    1984-01-01

    Discusses reactions of free radicals that determine the chemistry of many fresh, processed, and stored foods. Focuses on reactions involving ascorbic acid, myoglobin, and palmitate radicals as representative radicals derived from a vitamin, metallo-protein, and saturated lipid. Basic concepts related to free radical structure, formation, and…

  20. Chemistry of carotenoid neutral radicals.

    PubMed

    Ligia Focsan, A; Magyar, Adam; Kispert, Lowell D

    2015-04-15

    Proton loss from the carotenoid radical cations (Car(+)) to form neutral radicals (#Car) was investigated by numerous electrochemical, EPR, ENDOR and DFT studies described herein. The radical cation and neutral radicals were formed in solution electrochemically and stabilized on solid silica-alumina and MCM-41 matrices. Carotenoid neutral radicals were recently identified in Arabidopsis thaliana plant and photosystem II samples. Deprotonation at the terminal ends of a zeaxanthin radical cation could provide a secondary photoprotection pathway which involves quenching excited state chlorophyll by the long-lived zeaxanthin neutral radicals formed. PMID:25687648

  1. Reactions of NO 3 with the man-made emissions 2-methylpent-2-ene, ( Z)-3-methylpent-2-ene, ethyl vinyl ether, and the stress-induced plant emission ethyl vinyl ketone

    NASA Astrophysics Data System (ADS)

    Pfrang, Christian; Tooze, Christopher; Nalty, Andrew; Canosa-Mas, Carlos E.; Wayne, Richard P.

    Rate coefficients for reactions of nitrate radicals (NO 3) with the anthropogenic emissions 2-methylpent-2-ene, ( Z)-3-methylpent-2-ene, ethyl vinyl ether, and the stress-induced plant emission ethyl vinyl ketone (pent-1-en-3-one) were determined to be (9.3±1.1)×10 -12, (9.3±3.2)×10 -12, (1.7±1.3)×10 -12 and (9.4±2.7)×10 -17 cm 3 molecule -1 s -1. We performed kinetic experiments at room temperature and atmospheric pressure using a relative-rate technique with GC-FID analysis. Experiments with ethyl vinyl ether required a modification of our established procedure that might introduce additional uncertainties, and the errors suggested reflect these difficulties. Rate coefficients are discussed in terms of electronic and steric influences. Atmospheric lifetimes with respect to important oxidants in the troposphere were calculated. NO 3-initiated oxidation is found to be the strongly dominating degradation route for 2-methylpent-2-ene, ( Z)-3-methylpent-2-ene and ethyl vinyl ether. Atmospheric concentrations of the alkenes and their relative contribution to the total NMHC emissions from trucks can be expected to increase if plans for the introduction of particle filters for diesel engines are implemented on a global scale. Thus more kinetic data are required to better evaluate the impact of these emissions.

  2. In vitro protection of biological macromolecules against oxidative stress and in vivo toxicity evaluation of Acacia nilotica (L.) and ethyl gallate in rats

    PubMed Central

    2014-01-01

    Background Recently, enormous research has been focused on natural bioactive compounds possessing potential antioxidant and anticancer properties using cell lines and animal models. Acacia nilotica (L.) is widely distributed in Asia, Africa, Australia and Kenya. The plant is traditionally used to treat mouth, ear and bone cancer. However, reports on Acacia nilotica (L.) Wild. Ex. Delile subsp. indica (Benth.) Brenan regarding its toxicity profile is limited. Hence in this study, we investigated the antioxidant capacity and acute toxicity of ethyl gallate, a phenolic antioxidant present in the A. nilotica (L.) leaf extract. Methods The antioxidant activity of ethyl gallate against Fenton’s system (Fe3+/H2O2/ascorbic acid) generated oxidative damage to pBR322 DNA and BSA was investigated. We also studied the interaction of ethyl gallate to CT-DNA by wave scan and FTIR analysis. The amount of ethyl gallate present in the A. nilotica (L.) leaf extract was calculated using HPLC and represented in gram equivalence of ethyl gallate. The acute toxicity profile of ethyl gallate in the A. nilotica (L.) leaf extract was analyzed in albino Wistar rats. Measurement of liver and kidney function markers, total proteins and glucose were determined in the serum. Statistical analysis was done using statistical package for social sciences (SPSS) tool version 16.0. Results Ethyl gallate was found to be effective at 100 μg/mL concentration by inhibiting the free radical mediated damage to BSA and pBR322 DNA. We also found that the interaction of ethyl gallate and A. nilotica (L.) leaf extract to CT-DNA occurs through intercalation. One gram of A. nilotica (L.) leaf extract was found to be equivalent to 20 mg of ethyl gallate through HPLC analysis. Based on the acute toxicity results, A. nilotica (L.) leaf extract and ethyl gallate as well was found to be non-toxic and safe. Conclusions Results revealed no mortality or abnormal biochemical changes in vivo and the protective effect

  3. Optimization of ethyl ester production assisted by ultrasonic irradiation.

    PubMed

    Noipin, K; Kumar, S

    2015-01-01

    This study presents the optimization of the continuous flow potassium hydroxide-catalyzed synthesis of ethyl ester from palm oil with ultrasonic assistance. The process was optimized by application of factorial design and response surface methodology. The independent variables considered were ethanol to oil molar ratio, catalyst concentration, reaction temperature and ultrasonic amplitude; and the response was ethyl ester yield. The results show that ethanol to oil molar ratio, catalyst concentration, and ultrasonic amplitude have positive effect on ethyl ester yield, whereas reaction temperature has negative influence on ethyl ester yield. Second-order models were developed to predict the responses analyzed as a function of these three variables, and the developed models predicts the results in the experimental ranges studied adequately. This study shows that ultrasonic irradiation improved the ethyl ester production process to achieve ethyl ester yields above 92%. PMID:25116594

  4. Comparison of Diffusion Coefficients of Aryl Carbonyls and Aryl Alcohols in Hydroxylic Solvents. Evidence that the Diffusion of Ketyl Radicals in Hydrogen-Bonding Solvents is Not Anomalous?

    SciTech Connect

    Autrey, S Thomas ); Camaioni, Donald M. ); Kandanarachchi, Pramod H.; Franz, James A. )

    2000-12-01

    The diffusion coefficients of a benzyl-, sec-phenethyl-, and diphenylmethyl alcohol and the corresponding aryl carbonyls (benzaldehyde, acetophenone and benzophenone) were measured by Taylor's dispersion method in both ethyl and isopropyl alcohol. The experimental values are compared to published transient grating measurements of the corresponding aryl ketyl radicals (benzyl-, sec-phenethyl-, and diphenylmethyl-ketyl radical). In general, the diffusion coefficient of the aryl alcohols and the corresponding aryl ketyl radicals are equivalent within experimental error. This work shows that the diffusion of ketyl radicals is not anomalously slow and that aryl alcohols are significantly better models than the corresponding aryl ketones for analyzing the diffusion of aryl ketyl radicals in both ethyl and isopropyl alcohol. Empirical estimates of the diffusion coefficients of aryl alcohols using the Spernol-Wirtz and Wilke-Chang modifications to the Stokes-Einstein diffusion equation do not adequately account for the interactions between the aryl ketyl radicals or aryl alcohols with the hydroxylic solvents ethyl and isopropyl alcohol. The excellent agreement between the experimental diffusion coefficients of the aryl alcohols and the corresponding ketyl radicals show that the transient grating method can provide accurate estimates for the diffusion coefficients of transient species. This is especially important when a stable model is not available, for example the pyranyl radical.

  5. 21 CFR 172.872 - Methyl ethyl cellulose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Methyl ethyl cellulose. 172.872 Section 172.872... CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the...

  6. 21 CFR 172.872 - Methyl ethyl cellulose.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Methyl ethyl cellulose. 172.872 Section 172.872... CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the...

  7. 21 CFR 172.872 - Methyl ethyl cellulose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Methyl ethyl cellulose. 172.872 Section 172.872... CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the...

  8. The thermal decomposition of the benzyl radical in a heated micro-reactor. I. Experimental findings

    NASA Astrophysics Data System (ADS)

    Buckingham, Grant T.; Ormond, Thomas K.; Porterfield, Jessica P.; Hemberger, Patrick; Kostko, Oleg; Ahmed, Musahid; Robichaud, David J.; Nimlos, Mark R.; Daily, John W.; Ellison, G. Barney

    2015-01-01

    The pyrolysis of the benzyl radical has been studied in a set of heated micro-reactors. A combination of photoionization mass spectrometry (PIMS) and matrix isolation infrared (IR) spectroscopy has been used to identify the decomposition products. Both benzyl bromide and ethyl benzene have been used as precursors of the parent species, C6H5CH2, as well as a set of isotopically labeled radicals: C6H5CD2, C6D5CH2, and C6H513CH2. The combination of PIMS and IR spectroscopy has been used to identify the earliest pyrolysis products from benzyl radical as: C5H4=C=CH2, H atom, C5H4—C ≡ CH, C5H5, HCCCH2, and HC ≡ CH. Pyrolysis of the C6H5CD2, C6D5CH2, and C6H513CH2 benzyl radicals produces a set of methyl radicals, cyclopentadienyl radicals, and benzynes that are not predicted by a fulvenallene pathway. Explicit PIMS searches for the cycloheptatrienyl radical were unsuccessful, there is no evidence for the isomerization of benzyl and cycloheptatrienyl radicals: C6H5CH2⇋C7H7. These labeling studies suggest that there must be other thermal decomposition routes for the C6H5CH2 radical that differ from the fulvenallene pathway.

  9. Ethyl Lithiodiazoacetate: Extremely Unstable Intermediate Handled Efficiently in Flow.

    PubMed

    Müller, Simon T R; Hokamp, Tobias; Ehrmann, Svenja; Hellier, Paul; Wirth, Thomas

    2016-08-16

    Ethyl diazoacetate (EDA) is one of the most prominent diazo reagents. It is frequently used in metal-carbene-type reactions. However, EDA can also be used as a nucleophile under base catalysis. Whilst the addition of EDA to aldehydes can be performed using organic bases, the addition of EDA to other carbonyl electrophiles requires the use of organometallics such as lithium diisopropylamide (LDA). The generated ethyl lithiodiazoacetate is highly reactive and decomposes rapidly, even at low temperatures. Herein, we report a continuous flow protocol that overcomes the problems associated with the instantaneous decomposition of ethyl lithiodiazoacetate. The addition of ethyl lithiodiazoacetate to ketones provides direct access to tertiary diazoalcohols in good yields.

  10. Testing for ethanol markers in hair: discrepancies after simultaneous quantification of ethyl glucuronide and fatty acid ethyl esters.

    PubMed

    Kintz, P; Nicholson, D

    2014-10-01

    The hair of 97 cases were analysed for ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEE, including ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) according to the Society of Hair Testing guidelines to examine the role of both tests in documenting chronic excessive alcohol drinking, particularly when the results are in contradiction. 27 (27.8%) results were EtG negative and FAEE positive, when applying the SoHT cut-offs, probably due to the use of alcohol-containing hair products. Four cases (4.1%) were EtG positive and FAEE negative that were attributed to the use of herbal lotions containing EtG. PMID:24794020

  11. Radical School Reform.

    ERIC Educational Resources Information Center

    Gross, Beatrice, Ed.; Gross, Ronald, Ed.

    This book provides a comprehensive examination of the nature of the school crisis and the ways in which radical thinkers and educators are dealing with it. Excerpts from the writings of Jonathan Kozol, John Holt, Kenneth Clark, and others are concerned with the realities of education in ghettos and suburbs. Paul Goodman, Marshall McLuhan, Sylvia…

  12. Tyrosyl Radicals in Dehaloperoxidase

    PubMed Central

    Dumarieh, Rania; D'Antonio, Jennifer; Deliz-Liang, Alexandria; Smirnova, Tatyana; Svistunenko, Dimitri A.; Ghiladi, Reza A.

    2013-01-01

    Dehaloperoxidase (DHP) from Amphitrite ornata, having been shown to catalyze the hydrogen peroxide-dependent oxidation of trihalophenols to dihaloquinones, is the first oxygen binding globin that possesses a biologically relevant peroxidase activity. The catalytically competent species in DHP appears to be Compound ES, a reactive intermediate that contains both a ferryl heme and a tyrosyl radical. By simulating the EPR spectra of DHP activated by H2O2, Thompson et al. (Thompson, M. K., Franzen, S., Ghiladi, R. A., Reeder, B. J., and Svistunenko, D. A. (2010) J. Am. Chem. Soc. 132, 17501–17510) proposed that two different radicals, depending on the pH, are formed, one located on either Tyr-34 or Tyr-28 and the other on Tyr-38. To provide additional support for these simulation-based assignments and to deduce the role(s) that tyrosyl radicals play in DHP, stopped-flow UV-visible and rapid-freeze-quench EPR spectroscopic methods were employed to study radical formation in DHP when three tyrosine residues, Tyr-28, Tyr-34, and Tyr-38, were replaced either individually or in combination with phenylalanines. The results indicate that radicals form on all three tyrosines in DHP. Evidence for the formation of DHP Compound I in several tyrosine mutants was obtained. Variants that formed Compound I showed an increase in the catalytic rate for substrate oxidation but also an increase in heme bleaching, suggesting that the tyrosines are necessary for protecting the enzyme from oxidizing itself. This protective role of tyrosines is likely an evolutionary adaptation allowing DHP to avoid self-inflicted damage in the oxidative environment. PMID:24100039

  13. Spectroscopy and Kinetics of Organic Peroxy Radicals Measured Using a Laser Photolysis / CW Cavity Ring-down Reactor

    NASA Astrophysics Data System (ADS)

    Atkinson, D. B.

    2001-12-01

    A new type of reactor system is used to examine the spectra and gas phase reaction kinetics of atmospherically relevant organic peroxy radicals (RO2). The reactor uses the recently developed continuous wave laser excitation cavity ring-down (CWCRD) spectroscopic technique to detect the near-infrared (NIR) absorptions of peroxy radicals produced by laser photolysis. Preliminary spectroscopic and kinetic results for the methyl peroxy (CH3O2) and ethyl peroxy (C2H5O2) radicals are presented. Organic peroxy radicals are formed as reaction intermediates in the atmospheric oxidation of biogenic and anthropogenic volatile organic compounds (VOCs). Peroxy radicals react with NO, NO2, HO2, or other organic peroxy radicals in the troposphere to produce a variety of atmospherically important products, including ozone. The reactor uses the conventional slow flow/photolysis approach and is capable of accessing pressures between 5 and 1000 torr and temperatures between 275 and 400 K. Methyl or ethyl radicals are generated from suitable precursors via 193nm laser photolysis, and are reacted with excess oxygen to form methyl peroxy or ethyl peroxy radicals respectively. The peroxy radical concentrations are then monitored by their NIR absorptions near 1.3μ m using CWCRD spectroscopy. The spectra are consistent with those originally published [Hunziker and Wendt, 1976] and with the more recently reported results implementing the pulsed cavity ring-down technique [Pushkarsky et al., 2000]. The kinetics of the radical's self-reactions, the oxidation reaction with nitric oxide, and the prototypical cross-reaction between methyl peroxy and ethyl peroxy will be presented. All rate coefficients obtained to date are in good agreement with recommended values, lending credence to the new methodology. Hunziker, H.E., and Wendt, H.R., Electronic Absorption Spectra of Organic Peroxy Radical in the Near-Infrared, J. Chem. Phys., 64, 3488-3490, 1976. Pushkarsky, M.B., Zalyubovsky, S.J., and

  14. Biological screening of 100 plant extracts for cosmetic use (II): anti-oxidative activity and free radical scavenging activity.

    PubMed

    Kim, B J; Kim, J H; Kim, H P; Heo, M Y

    1997-12-01

    Methanol aqueous extracts of 100 plants were screened for anti-oxidative activity using Fenton's reagent/ethyl linoleate system and for free radical scavenging activity using the 1,1-diphenyl-2-picryl hydrazyl free radical generating system. The results suggest that 14 plants - Alpinia officinarum, Areca catechu, Brassica alba, Cannabis sativa, Curcuma longa, Curcuma aromatica, Eugenia caryophyllata, Evodia officinalis, Paeonia suffruticosa, Rhaphanus sativus, Rheum palmatum, Rhus verniciflua, Trapa bispinosa, Zanthoxylum piperitum - may be potential sources of anti-oxidants. Eight plants - Citrus aurantium, Cornus officinalis, Gleditsia japonica, Lindera strychnifolia, Phragmites communis, Prunus mume, Schizandra chinensis, Terminalia chebula - may be the potential source of free radical scavengers from natural plant.

  15. Cognitive effects of creatine ethyl ester supplementation.

    PubMed

    Ling, Jonathan; Kritikos, Minos; Tiplady, Brian

    2009-12-01

    Supplementation with creatine-based substances as a means of enhancing athletic performance has become widespread. Until recently, however, the effects of creatine supplementation on cognitive performance has been given little attention. This study used a new form of creatine--creatine ethyl ester--to investigate whether supplementation would improve performance in five cognitive tasks, using a double-blind, placebo-controlled study. Creatine dosing led to an improvement over the placebo condition on several measures. Although creatine seems to facilitate cognition on some tasks, these results require replication using objective measures of compliance. The improvement is discussed in the context of research examining the influence of brain energy capacity on cognitive performance. PMID:19773644

  16. 21 CFR 172.872 - Methyl ethyl cellulose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose may be safely used in food in accordance with the following prescribed conditions. (a) The additive...

  17. IRIS TOXICOLOGICAL REVIEW OF METHYL ETHYL KETONE (2003 Final)

    EPA Science Inventory

    EPA is announcing the release of the final report, "Toxicological Review of Methyl Ethyl Ketone: in support of the Integrated Risk Information System (IRIS)". The updated Summary for Methyl Ethyl Ketone and accompanying Quickview have also been added to the IRIS Database.

  18. Electronic structure and normal vibrations of the 1-ethyl-3-methylimidazolium ethyl sulfate ion pair.

    PubMed

    Dhumal, Nilesh R; Kim, Hyung J; Kiefer, Johannes

    2011-04-21

    Electronic and structural properties of the ion pair 1-ethyl-3-methylimidazolium ethyl sulfate are studied using density functional methods. Three locally stable conformers of the ion pair complex are considered to analyze molecular interactions between its cation and anion. Manifestations of these interactions in the vibrational spectra are discussed and compared with experimental IR and Raman spectroscopy data. NBO analysis and difference electron density coupled with molecular electron density topography are used to interpret the frequency shifts of the normal vibrations of the ion pair, compared to the free anion and cation. Excitation energies of low-lying singlet excited states of the conformers are also studied. The density functional theory results are found to be in a reasonable agreement with experimental UV/vis absorption spectra.

  19. 40 CFR 180.483 - O-[2-(1,1-Dimethylethyl)-5-pyrimidinyl] O-ethyl-O-(1-methyl-ethyl) phosphorothioate; tolerances...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false O- O-ethyl-O-(1-methyl-ethyl... FOOD Specific Tolerances § 180.483 O- O-ethyl-O-(1-methyl-ethyl) phosphorothioate; tolerances for residues. Time-limited tolerances are established for residues of the insecticide O-...

  20. Spectroscopy reveals that ethyl esters interact with proteins in wine.

    PubMed

    Di Gaspero, Mattia; Ruzza, Paolo; Hussain, Rohanah; Vincenzi, Simone; Biondi, Barbara; Gazzola, Diana; Siligardi, Giuliano; Curioni, Andrea

    2017-02-15

    Impairment of wine aroma after vinification is frequently associated to bentonite treatments and this can be the result of protein removal, as recently demonstrated for ethyl esters. To evaluate the existence of an interaction between wine proteins and ethyl esters, the effects induced by these fermentative aroma compounds on the secondary structure and stability of VVTL1, a Thaumatin-like protein purified from wine, was analyzed by Synchrotron Radiation Circular Dichroism (SRCD) spectroscopy. The secondary structure of wine VVTL1 was not strongly affected by the presence of selected ethyl esters. In contrast, VVTL1 stability was slightly increased by the addition of ethyl-octanoate, -decanoate and -dodecanoate, but decreased by ethyl-hexanoate. This indicates the existence of an interaction between VVTL1 and at least some aroma compounds produced during fermentation. The data suggest that proteins removal from wine by bentonite can result in indirect removal of at least some aroma compounds associated with them. PMID:27664648

  1. Mechanistic insight into alkylation of the ethyl acetoacetate anion with different ethyl halides

    NASA Astrophysics Data System (ADS)

    Marković, S.; Đurđević, J.; Vukosavljević, M.; Petrović, Z.

    2013-12-01

    The alkylation reactions of the ambident ethyl acetoacetate anion with C2H5X (X = F, Cl, Br, and I) in the O2, C3, and O4 positions of the anion were investigated at the B3LYP/6-311+G( d,p) level of theory. It was found that the ethylation reaction does not occur in the position O4, as well as with ethyl fluoride in any position of the anion, due to very high activation energies and thermodynamic instability of the hypothetic products. The activation energies for the reactions in the position O2 are lower in comparison to the position C3, but the products of the reactions in the C3 position are more stable than those in the position O4, implying that the C/O products ratio is controlled by both thermodynamic and kinetic factors, leading to the O2-product with the chloride, and C3-product with the iodide as leaving group.

  2. Pickering emulsion templated interfacial atom transfer radical polymerization for microencapsulation.

    PubMed

    Li, Jian; Hitchcock, Adam P; Stöver, Harald D H

    2010-12-01

    This Article describes a new microencapsulation method based on a Pickering emulsion templated interfacial atom transfer radical polymerization (PETI-ATRP). Cationic LUDOX CL nanoparticles were coated electrostatically with an anionic polymeric ATRP initiator, poly(sodium styrene sulfonate-co-2-(2-bromoisobutyryloxy)ethyl methacrylate) (PSB), prepared by radical copolymerization of sodium styrene sulfonate and 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM). The resulting PSB-modified CL particles were surface active and could be used to stabilize oil-in-water Pickering emulsions. ATRP of water-soluble cross-linking monomers, confined to the oil-water interface by the surface-bound PSB, then led to nanoparticle/polymer composite shells. This method allowed encapsulation of core solvents (xylene, hexadecane, perfluoroheptane) with different solubility parameters. The microcapsule (MC) wall chemistry could accommodate different monomers, demonstrating the versatility of this method. Double-walled MCs were formed by sequentially carrying out PETI-ATRP and in situ polymerization of encapsulated monomers. The double-walled structure was verified by both transmission electron microscopy (TEM) and scanning transmission X-ray microscopy (STXM).

  3. Parameters Affecting Ethyl Ester Production by Saccharomyces cerevisiae during Fermentation▿

    PubMed Central

    Saerens, S. M. G.; Delvaux, F.; Verstrepen, K. J.; Van Dijck, P.; Thevelein, J. M.; Delvaux, F. R.

    2008-01-01

    Volatile esters are responsible for the fruity character of fermented beverages and thus constitute a vital group of aromatic compounds in beer and wine. Many fermentation parameters are known to affect volatile ester production. In order to obtain insight into the production of ethyl esters during fermentation, we investigated the influence of several fermentation variables. A higher level of unsaturated fatty acids in the fermentation medium resulted in a general decrease in ethyl ester production. On the other hand, a higher fermentation temperature resulted in greater ethyl octanoate and decanoate production, while a higher carbon or nitrogen content of the fermentation medium resulted in only moderate changes in ethyl ester production. Analysis of the expression of the ethyl ester biosynthesis genes EEB1 and EHT1 after addition of medium-chain fatty acid precursors suggested that the expression level is not the limiting factor for ethyl ester production, as opposed to acetate ester production. Together with the previous demonstration that provision of medium-chain fatty acids, which are the substrates for ethyl ester formation, to the fermentation medium causes a strong increase in the formation of the corresponding ethyl esters, this result further supports the hypothesis that precursor availability has an important role in ethyl ester production. We concluded that, at least in our fermentation conditions and with our yeast strain, the fatty acid precursor level rather than the activity of the biosynthetic enzymes is the major limiting factor for ethyl ester production. The expression level and activity of the fatty acid biosynthetic enzymes therefore appear to be prime targets for flavor modification by alteration of process parameters or through strain selection. PMID:17993562

  4. Trapping of neutral radicals by aromatic and heterocyclic cation radicals

    SciTech Connect

    Shine, H.J.; Soroka, M.

    1986-09-01

    A considerable amount of knowledge has been accrued during the last 15-20 years on the chemistry of polynuclear aromatic and heterocyclic cation radicals. For the most part, the reactions that have been studied have been of cation radicals with neutral and anionic nucleophiles which lead to addition or substitution products. Classic examples among these reactions are, for example, the reaction of water with the cation radical of 9,10-diphenylanthracene and perylene, and that of water with the thianthrene cation radical. Reactions such as these have been among foundation-establishing studies in the scope and mechanism of cation-radical reactions. Cation radicals can also undergo another type reaction with nucleophies, that is, electron transfer. This possibility leads to two far-reaching and connected questions: can addition and substitution reactions of aromatic cation radicals with nucleophiles be preceded by single electron transfer (SET).; and, can such cation radicals trap neutral radicals. These questions are also then related to another question having even greater impact on organic chemistry: can electrophilic aromatic substitution (ArH + E/sup +/ ..-->.. ArE + H/sup +/) be preceded by SET. The authors have been trying to answer the first two questions about SET and trapping of radicals by combining the two possibilities. That is, they have chosen the reaction of the thianthrene cation radical (represented by the symbol S/sup +./) with grignard reagents, for which two possible routes could be anticipated: either direct addition at sulfur or addition preceded by SET.

  5. Free radical explosive composition

    DOEpatents

    Walker, Franklin E.; Wasley, Richard J.

    1979-01-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a getter additive comprising a compound or mixture of compounds capable of capturing or deactivating free radicals or ions under mechanical or electrical shock conditions and which is not an explosive. Exemplary getter additives are isocyanates, olefins and iodine.

  6. Radicalism, Marxism, and medicine.

    PubMed

    Navarro, V

    1983-01-01

    This article presents a critique of recent radical interpretations of medicine and provides an alternative explanation of such interpretations. It analyzes 1) the articulation of medical practices, knowledge, and institutions within specific modes of production and social formations; 2) the dual functions of medicine within capitalist relations of production; 3) the reproduction of power within medicine; and 4) the meaning of capitalist, socialist, and communist medicine. The political practice derived from these analyses is also elaborated.

  7. THERMOCHEMISTRY OF HYDROCARBON RADICALS

    SciTech Connect

    Kent M. Ervin, Principal Investigator

    2004-08-17

    Gas phase negative ion chemistry methods are employed to determine enthalpies of formation of hydrocarbon radicals that are important in combustion processes and to investigate the dynamics of ion-molecule reactions. Using guided ion beam tandem mass spectrometry, we measure collisional threshold energies of endoergic proton transfer and hydrogen atom transfer reactions of hydrocarbon molecules with negative reagent ions. The measured reaction threshold energies for proton transfer yield the relative gas phase acidities. In an alternative methodology, competitive collision-induced dissociation of proton-bound ion-molecule complexes provides accurate gas phase acidities relative to a reference acid. Combined with the electron affinity of the R {center_dot} radical, the gas phase acidity yields the RH bond dissociation energy of the corresponding neutral molecule, or equivalently the enthalpy of formation of the R{center_dot} organic radical, using equation: D(R-H) = {Delta}{sub acid}H(RH) + EA(R) - IE(H). The threshold energy for hydrogen abstraction from a hydrocarbon molecule yields its hydrogen atom affinity relative to the reagent anion, providing the RH bond dissociation energy directly. Electronic structure calculations are used to evaluate the possibility of potential energy barriers or dynamical constrictions along the reaction path, and as input for RRKM and phase space theory calculations. In newer experiments, we have measured the product velocity distributions to obtain additional information on the energetics and dynamics of the reactions.

  8. Free radical propulsion concept

    NASA Technical Reports Server (NTRS)

    Hawkins, C. E.; Nakanishi, S.

    1981-01-01

    The concept of a free radical propulsion system, utilizing the recombination energy of dissociated low molecular weight gases to produce thrust, is analyzed. The system, operating at a theoretical impulse with hydrogen, as high as 2200 seconds at high thrust to power ratio, is hypothesized to bridge the gap between chemical and electrostatic propulsion capabilities. A comparative methodology is outlined by which characteristics of chemical and electric propulsion for orbit raising mission can be investigated. It is noted that free radicals proposed in rockets previously met with difficulty and complexity in terms of storage requirements; the present study proposes to eliminate the storage requirements by using electric energy to achieve a continuous-flow product of free radicals which are recombined to produce a high velocity propellant. Microwave energy used to dissociate a continuously flowing gas is transferred to the propellant via three-body-recombination for conversion to propellant kinetic energy. Microwave plasma discharge was found in excess of 90 percent over a broad range of pressure in preliminary experiments, and microwave heating compared to electrothermal heating showed much higher temperatures in gasdynamic equations.

  9. [Radical prostatectomy - pro robotic].

    PubMed

    Gillitzer, R

    2012-05-01

    Anatomical radical prostatectomy was introduced in the early 1980s by Walsh and Donker. Elucidation of key anatomical structures led to a significant reduction in the morbidity of this procedure. The strive to achieve similar oncological and functional results to this gold standard open procedure but with further reduction of morbidity through a minimally invasive access led to the establishment of laparoscopic prostatectomy. However, this procedure is complex and difficult and is associated with a long learning curve. The technical advantages of robotically assisted surgery coupled with the intuitive handling of the device led to increased precision and shortening of the learning curve. These main advantages, together with a massive internet presence and aggressive marketing, have resulted in a rapid dissemination of robotic radical prostatectomy and an increasing patient demand. However, superiority of robotic radical prostatectomy in comparison to the other surgical therapeutic options has not yet been proven on a scientific basis. Currently robotic-assisted surgery is an established technique and future technical improvements will certainly further define its role in urological surgery. In the end this technical innovation will have to be balanced against the very high purchase and running costs, which remain the main limitation of this technology.

  10. 40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ethanaminium, N-ethyl-2-hydroxy-N,N... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

  11. 40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethanaminium, N-ethyl-2-hydroxy-N,N... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

  12. Silicon based radicals, radical ions, diradicals and diradicaloids.

    PubMed

    Chandra Mondal, Kartik; Roy, Sudipta; Roesky, Herbert W

    2016-02-21

    Radicals are an important class of species which act as intermediates in numerous chemical and biological processes. Most of the radicals have short lifetimes. However, radicals with longer lifetimes can be isolated and stored in a pure form. They are called stable radicals. Over the last five decades, the syntheses of several stable radicals have been reported. Recently, highly unstable radicals have been successfully stabilized via strong σ-donation of singlet carbenes. Cyclic aklyl(amino) carbene (cAAC) is regarded as a stronger σ-donor and a better π-acceptor when compared with that of an N-heterocyclic carbene (NHC). In this article we review preferentially the results of our group to generate stable radical centers on the carbene carbon atoms by employing the so far hidden and unique ability of the cAACs. We focus on the development of new synthetic routes to stable and isolable radicals containing silicon atoms. All the compounds have been well characterized by single crystal X-ray analysis; the mono-radicals have been distinguished by EPR spectroscpy and the ground state of the diradicals has been studied by magnetic susceptibility measurements and theoretical calculations. Many of these compounds are studied by cyclic voltammetry and are often converted to their corresponding radical cations or radical anions via electron abstraction or addition processes. Some of them are stable, having long lifetimes and hence are isolated and characterized thoroughly. Not much information has been obtained on the short lived persistent radical species. Herein, we discuss some of the examples of such a type of species and focus on what kind of chemical reactions are initiated by these short-lived radical species in solution. We also briefly mention the syntheses and charaterization of the so far reported stable silicon centered radicals. PMID:26585359

  13. Graft copolymerization of ethyl acrylate onto tamarind kernel powder, and evaluation of its biodegradability.

    PubMed

    del Real, Alicia; Wallander, Daniela; Maciel, Alfredo; Cedillo, Gerardo; Loza, Herminia

    2015-03-01

    In the present study, tamarind kernel powder and ethyl acrylate were reacted by free radical polymerization to synthesize a grafted copolymer soluble in water. The grafted copolymer was analyzed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR); FTIR showed a shift of the vibration of R-CO-OR' from 1258 cm(-1) to 1253 cm(-1). This shift appeared because of the grafting copolymerization. Films were prepared to study the mechanical properties and the biodegradation of this material. The mechanical properties of the grafted copolymer were found to lie between those of the parent polymers, suitable for disposable products. The new grafted copolymer manifested a steady process of biodegradation under incubation with the bacterial strain Alicycliphilus sp. BQ1; this was proved by scanning electron microscopy (SEM) and near infrared spectroscopy (NIR).

  14. Poly(ethyl methacrylate) and poly(2-ethoxyethyl methacrylate) based polymer gel electrolytes

    NASA Astrophysics Data System (ADS)

    Reiter, Jakub; Michálek, Jiří; Vondrák, Jiří; Chmelíková, Dana; Přádný, Martin; Mička, Zdeněk

    New poly(ethyl methacrylate) and poly(2-ethoxyethyl methacrylate) gel electrolytes containing immobilised lithium perchlorate solution in propylene carbonate were prepared by UV radical polymerisation. Materials exhibit high ionic conductivity up to 0.23 mS cm -1 and long-term stability of chemical and mechanical properties. Both materials keep their suitable conductivity above -20 °C. The effect of material composition, temperature, cross-linking agent and salt concentration on the electrochemical and mechanical properties were studied using impedance spectroscopy and cyclic voltammetry. The accessible electrochemical window of both polymer electrolytes was estimated from -2.1 to 1.5 V versus Cd/Cd 2+. Impedance measurements showed almost one-order increase of conductivity when ethylene dimethacrylate was used as a cross-linking agent in comparison with the polymer electrolyte without agent.

  15. Graft copolymerization of ethyl acrylate onto tamarind kernel powder, and evaluation of its biodegradability.

    PubMed

    del Real, Alicia; Wallander, Daniela; Maciel, Alfredo; Cedillo, Gerardo; Loza, Herminia

    2015-03-01

    In the present study, tamarind kernel powder and ethyl acrylate were reacted by free radical polymerization to synthesize a grafted copolymer soluble in water. The grafted copolymer was analyzed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR); FTIR showed a shift of the vibration of R-CO-OR' from 1258 cm(-1) to 1253 cm(-1). This shift appeared because of the grafting copolymerization. Films were prepared to study the mechanical properties and the biodegradation of this material. The mechanical properties of the grafted copolymer were found to lie between those of the parent polymers, suitable for disposable products. The new grafted copolymer manifested a steady process of biodegradation under incubation with the bacterial strain Alicycliphilus sp. BQ1; this was proved by scanning electron microscopy (SEM) and near infrared spectroscopy (NIR). PMID:25498603

  16. Recyclable antibacterial magnetic nanoparticles grafted with quaternized poly(2-(dimethylamino)ethyl methacrylate) brushes.

    PubMed

    Dong, Hongchen; Huang, Jinyu; Koepsel, Richard R; Ye, Penglin; Russell, Alan J; Matyjaszewski, Krzysztof

    2011-04-11

    Highly efficient recyclable antibacterial magnetite nanoparticles consisting of a magnetic Fe(3)O(4) core with an antibacterial poly(quaternary ammonium) (PQA) coating were prepared in an efficient four-step process. The synthetic pathway included: (1) preparation of Fe(3)O(4) nanoparticles via coprecipitation of Fe(2+)/Fe(3+) in the presence of an alkaline solution; (2) attachment of an ATRP initiating functionality to the surface of the nanoparticles; (3) surface-initiated atom transfer radical polymerization (ATRP) of 2-(dimethylamino)ethyl methacrylate (DMAEMA); and (4) transformation of PDMAEMA brushes to PQA via quaternization with ethyl bromide. The success of the surface functionalization was confirmed by FT-IR, thermal gravimetric analysis (TGA), elemental analysis, and transmission electron microscopy (TEM). The PQA-modified magnetite nanoparticles were dispersed in water and exhibited a response to an external magnetic field, making the nanoparticles easy to remove from water after antibacterial tests. The PQA-modified magnetite nanoparticles retained 100% biocidal efficiency against E. coli (10(5) to 10(6)E. coli/mg nanoparticles) during eight exposure/collect/recycle procedures without washing with any solvents or water.

  17. Biodegradation of pyrazosulfuron-ethyl by Acinetobacter sp. CW17.

    PubMed

    Wang, Yanhui; Du, Liangwei; Chen, Yingxi; Liu, Xiaoliang; Zhou, Xiaomao; Tan, Huihua; Bai, Lianyang; Zeng, Dongqiang

    2012-03-01

    The pyrazosulfuron-ethyl-degrading bacterium, designated as CW17, was isolated from contaminated soil near the warehouse of the factory producing pyrazosulfuron-ethyl in Changsha city, China. The strain CW17 was identified as Acinetobacter sp. based on analyses of 94 carbon source utilization or chemical sensitivity in Biolog microplates, conventional phenotypic characteristics, and 16S rRNA gene sequencing. When pyrazosulfuron-ethyl was provided as the sole carbon source, the effects of pyrazosulfuron-ethyl concentration, pH, and temperature on biodegradation were examined. The degradation rates of pyrazosulfuron-ethyl at initial concentrations of 5.0, 20.0, and 50.0 mg/L were 48.0%, 77.0%, and 32.6%, respectively, after inoculation for 7 days. The growth of the strain was inhibited at low pH buffers. The chemical degradation occurs much faster at low pH than at neutral and basic pH conditions. The degradation rate of pyrazosulfuron-ethyl at 30°C was faster than those at 20 and 37°C by CW17 strains. Two metabolites of degradation were analyzed by liquid chromatography-mass spectroscopy (LC/MS). Based on the identified products, strain CW17 seemed to be able to degrade pyrazosulfuron-ethyl by cleavage of the sulfonylurea bridge. PMID:22388979

  18. Radical Cation/Radical Reactions: A Fourier Transform Ion Cyclotron Resonance Study of Allyl Radical Reacting with Aromatic Radical Cations

    PubMed Central

    Russell, Amber L.; Rohrs, Henry W.; Read, David; Giblin, Daryl E.; Gaspar, Peter P.; Gross, Michael L.

    2010-01-01

    A method for the study of reactions of open-shell neutrals (radicals) and radical cations is described. Pyrolysis (25–1500 °C) of thermally labile compounds, such as, 1,5-hexadiene via a Chen nozzle yields a seeded beam of reactive species in helium. The pyrolysis products are then analyzed by electron ionization (EI) or reacted with stored ions. Electron ionization of the pyrolysis products of 1,5-hexadiene shows that both the allyl radical and allene are generated. Reactions of benzene radical cations and the pyrolysis products of 1,5-hexadiene result in carbon-carbon bond formation. Those reactions of allyl radical with the benzene radical cation yield the C7H7+ ion of m/z 91, permitting an unusual entry into arenium ions. The reaction of allene with benzene radical cation in contrast yields C9H10+. and C9H9+. PMID:20401179

  19. Ethyl Esterification for MALDI-MS Analysis of Protein Glycosylation.

    PubMed

    Reiding, Karli R; Lonardi, Emanuela; Hipgrave Ederveen, Agnes L; Wuhrer, Manfred

    2016-01-01

    Ethyl esterification is a technique for the chemical modification of sialylated glycans, leading to enhanced stability when performing matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry (MS), as well as allowing the efficient detection of both sialylated and non-sialylated glycans in positive ion mode. In addition, the method shows specific reaction products for α2,3- and α2,6-linked sialic acids, leading to an MS distinguishable mass difference. Here, we describe the ethyl esterification protocol for 96 glycan samples, including enzymatic N-glycan release, the aforementioned ethyl esterification, glycan enrichment, MALDI target preparation, and the MS(/MS) measurement. PMID:26700047

  20. On the cause of low thermal stability of ethyl halodiazoacetates

    PubMed Central

    Mortén, Magnus; Hennum, Martin

    2016-01-01

    Summary Rates for the thermal decomposition of ethyl halodiazoacetates (halo = Cl, Br, I) have been obtained, and reported herein are their half-lives. The experimental results are supported by DFT calculations, and we provide a possible explanation for the reduced thermal stability of ethyl halodiazoacetates compared to ethyl diazoacetate and for the relative decomposition rates between the chloro, bromo and iodo analogs. We have also briefly studied the thermal, non-catalytic cyclopropanation of styrenes and compared the results to the analogous Rh(II)-catalyzed reactions. PMID:27559411

  1. a Free Radical

    NASA Astrophysics Data System (ADS)

    Carrington, Alan

    2001-10-01

    This chapter describes my research career, spanning the period from 1955 to 2000. My initial PhD work at the University of Southampton was concerned with the electronic structure and spectra of transition metal complexes and included studies of the electronic spin resonance (ESR) spectra of magnetically dilute single crystals. After a year at the University of Minnesota, I went to Cambridge University and for the next six years studied the ESR spectra of liquid phase organic free radicals. I commenced work on the microwave magnetic resonance (MMR) spectra of gaseous free radicals in 1965, and this work continued until 1975. I moved from Cambridge to Southampton in 1967. In 1975 I turned to the study of gas phase molecular ions, using ion beam methods. In the earlier years of this period I concentrated on simple fundamental species like H+2, HD+, and H+3. In the later years until my retirement in 1999, I concentrated on the observation and analysis of microwave spectra involving energy levels lying very close to a dissociation asymptote. DEDICATION This chapter is dedicated to the memory of Harry E. Radford, who died while it was being written. Harry was a quiet and shy man, who often worked alone and never indulged in self-promotion. So far as I know, he was never awarded any medals or prizes, nor elected to any academies or learned societies. Nevertheless he was an experimentalist of the highest originality and quality, a theorist of true intellectual depth, and a remarkable pioneer in many of the techniques of studying free radicals that are now commonplace.

  2. Catalysis of Radical Reactions: A Radical Chemistry Perspective.

    PubMed

    Studer, Armido; Curran, Dennis P

    2016-01-01

    The area of catalysis of radical reactions has recently flourished. Various reaction conditions have been discovered and explained in terms of catalytic cycles. These cycles rarely stand alone as unique paths from substrates to products. Instead, most radical reactions have innate chains which form products without any catalyst. How do we know if a species added in "catalytic amounts" is a catalyst, an initiator, or something else? Herein we critically address both catalyst-free and catalytic radical reactions through the lens of radical chemistry. Basic principles of kinetics and thermodynamics are used to address problems of initiation, propagation, and inhibition of radical chains. The catalysis of radical reactions differs from other areas of catalysis. Whereas efficient innate chain reactions are difficult to catalyze because individual steps are fast, both inefficient chain processes and non-chain processes afford diverse opportunities for catalysis, as illustrated with selected examples.

  3. Complications Following Radical Nephroureterectomy.

    PubMed

    Raman, Jay D; Jafri, Syed M

    2016-05-01

    Radical nephroureterectomy (RNU) is the gold standard treatment strategy for bulky, high-grade, or muscle-invasive upper tract urothelial carcinoma (UTUC). Many patients with UTUC who require RNU are elderly, comorbid, and at risk for perioperative complications. Recognition of likelihood and extent of such complications guides preoperative counseling, decision-making process for major surgery, and perioperative care. A critical review of such data is essential, given the inevitable impact of complications on hospital duration, need for readmission, resource utilization, and costs associated with management. PMID:26968416

  4. 46 CFR 151.50-42 - Ethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... shall be designed and tested to meet the rules of the American Bureau of Shipping for a head of water at... liquid. (g) Precautions shall be taken to prevent the contamination of ethyl ether by strong...

  5. Amphiphilic graft copolymers with ethyl cellulose backbone: Synthesis, self-assembly and tunable temperature-CO2 response.

    PubMed

    Yuan, Weizhong; Zou, Hui; Shen, Jin

    2016-01-20

    Amphiphilic ethyl cellulose-graft-poly(N,N-dimethylaminoethyl methacrylate) (EC-g-PDMAEMA) and ethyl cellulose-graft-poly(2-(2-methoxyethoxy)ethyl methacrylate-co-N,N-dimethylaminoethyl methacrylate) (EC-g-P(MEO2MA-co-DMAEMA)) graft copolymers were easily synthesized by atom transfer radical polymerization (ATRP). The micelles self-assembled from the copolymer presented switchable temperature-CO2 dually responsive properties. The value of lower critical solution temperature (LCST) for the copolymer micelle solutions could be adjusted by CO2/Ar. Moreover, due to the alteration of the ratio of DMAEMA to MEO2MA, the LCST values of the micelle solutions decreased with the increase of MEO2MA in copolymer. The temperature-CO2 dually responsive properties of the copolymer were reversible and could be accomplished through altering the temperature and bubbling CO2/Ar. The hydrodynamic radius (Rh) of the copolymer micelles was also influenced by the ratio of DMAEMA to MEO2MA and the stimuli of temperature and CO2/Ar. As a drug release system, the copolymer micelles could achieve the control release of doxorubicin (DOX) by changing the temperature and alternatively bubbling CO2/Ar.

  6. Bursectomy at radical gastrectomy

    PubMed Central

    Kayaalp, Cuneyt

    2015-01-01

    Radical gastrectomy with extended lymph node dissection and prophylactic resection of the omentum, peritoneum over the posterior lesser sac, pancreas and/or spleen was advocated at the beginning of the 1960s in Japan. In time, prophylactic routine resections of the pancreas and/or spleen were abandoned because of the high incidence of postoperative complications. However, omentectomy and bursectomy continued to be standard parts of traditional radical gastrectomy. The bursa omentalis was thought to be a natural barrier against invasion of cancer cells into the posterior part of the stomach. The theoretical rationale for bursectomy was to reduce the risk of peritoneal recurrences by eliminating the peritoneum over the lesser sac, which might include free cancer cells or micrometastases. Over time, the indication for bursectomy was gradually reduced to only patients with posterior gastric wall tumors penetrating the serosa. Despite its theoretical advantages, its benefit for recurrence or survival has not been proven yet. The possible reasons for this inconsistency are discussed in this review. In conclusion, the value of bursectomy in the treatment of gastric cancer is still under debate and large-scale randomized studies are necessary. Until clear evidence of patient benefit is obtained, its routine use cannot be recommended. PMID:26523213

  7. Bursectomy at radical gastrectomy.

    PubMed

    Kayaalp, Cuneyt

    2015-10-27

    Radical gastrectomy with extended lymph node dissection and prophylactic resection of the omentum, peritoneum over the posterior lesser sac, pancreas and/or spleen was advocated at the beginning of the 1960s in Japan. In time, prophylactic routine resections of the pancreas and/or spleen were abandoned because of the high incidence of postoperative complications. However, omentectomy and bursectomy continued to be standard parts of traditional radical gastrectomy. The bursa omentalis was thought to be a natural barrier against invasion of cancer cells into the posterior part of the stomach. The theoretical rationale for bursectomy was to reduce the risk of peritoneal recurrences by eliminating the peritoneum over the lesser sac, which might include free cancer cells or micrometastases. Over time, the indication for bursectomy was gradually reduced to only patients with posterior gastric wall tumors penetrating the serosa. Despite its theoretical advantages, its benefit for recurrence or survival has not been proven yet. The possible reasons for this inconsistency are discussed in this review. In conclusion, the value of bursectomy in the treatment of gastric cancer is still under debate and large-scale randomized studies are necessary. Until clear evidence of patient benefit is obtained, its routine use cannot be recommended. PMID:26523213

  8. Radically innovative steelmaking technologies

    NASA Astrophysics Data System (ADS)

    Szekely, Julian

    1980-09-01

    The steel industry is faced with serious problems caused by the increasing cost of energy, labor and capital and by tough overseas competition, employing new highly efficient process plants. The very high cost of capital and of capital equipment renders the construction of new green field site plants, exemplifying the best available technology economically unattractive. For this reason, over the long term the development radically innovative steelmaking technologies appears to be the only satisfactory resolution of this dilemma. The purpose of this article is to present a critical review of some of the radically innovative steelmaking technologies that have been proposed during the past few years and to develop the argument that these indeed do deserve serious consideration at the present time. It should be stressed, however, that these innovative technologies can be implemented only as part of a carefully conceived long range plan, which contains as a subset short term solutions, such as trigger prices improved investment credits, and so forth and intermediate term solutions, such as more extensive use of continuous casting, external desulfurization and selective modernization in general.

  9. Oligorotaxane Radicals under Orders

    PubMed Central

    2016-01-01

    A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components—namely oligoviologens—in which different numbers of 4,4′-bipyridinium (BIPY2+) subunits are linked by p-xylylene bridges, are shown to be capable of being threaded by cyclobis(paraquat-p-phenylene) (CBPQT4+) rings following the introduction of radical-pairing interactions under reducing conditions. UV/vis/NIR spectroscopic and electrochemical investigations suggest that the reduced oligopseudorotaxanes fold into highly ordered secondary structures as a result of the formation of BIPY•+ radical cation pairs. Furthermore, by installing bulky stoppers at each end of the oligopseudorotaxanes by means of Cu-free alkyne–azide cycloadditions, their analogous oligorotaxanes, which retain the same stoichiometries as their progenitors, can be prepared. Solution-state studies of the oligorotaxanes indicate that their mechanically interlocked structures lead to the enforced interactions between the dumbbell and ring components, allowing them to fold (contract) in their reduced states and unfold (expand) in their fully oxidized states as a result of Coulombic repulsions. This electrochemically controlled reversible folding and unfolding process, during which the oligorotaxanes experience length contractions and expansions, is reminiscent of the mechanisms of actuation associated with muscle fibers. PMID:27163033

  10. Radicals in flavoproteins.

    PubMed

    Schleicher, Erik; Weber, Stefan

    2012-01-01

    Current technical and methodical advances in electron paramagnetic resonance (EPR) spectroscopy have proven to be very beneficial for studies of stationary and short-lived paramagnetic states in proteins carrying organic cofactors. In particular, the large number of proteins with flavins as prosthetic groups can be examined splendidly by EPR in all its flavors. To understand how a flavin molecule can be fine-tuned for specific catalysis of different reactions, understanding of its electronic structure mediated by subtle protein-cofactor interactions is of utmost importance. The focus of this chapter is the description of recent research progress from our laboratory on EPR of photoactive flavoproteins. These catalyze a wide variety of important photobiological processes ranging from enzymatic DNA repair to plant phototropism and animal magnetoreception. Whereas increasing structural information on the principal architecture of photoactive flavoproteins is available to date, their primary photochemistry is still largely undetermined. Interestingly, although these proteins carry the same light-active flavin chromophore, their light-driven reactions differ significantly: Formations of photoexcited triplet states and short-lived radical pairs starting out from triplet or singlet-state precursors, as well as generation of stationary radicals have been reported recently. EPR spectroscopy is the method of choice to characterize such paramagnetic intermediates, and hence, to assist in unravelling the mechanisms of these inimitable proteins.

  11. Multidimensional chromatographic approach applied to the identification of novel aroma compounds in wine. Identification of ethyl cyclohexanoate, ethyl 2-hydroxy-3-methylbutyrate and ethyl 2-hydroxy-4-methylpentanoate.

    PubMed

    Campo, E; Cacho, J; Ferreira, V

    2006-12-29

    A multidimensional chromatographic strategy has been developed and optimized with the purpose of identifying different odorants potentially relevant to the aroma and flavor of aged wines from Madeira or Sherry. Different techniques of extraction and fractionation were studied in order to get clear olfactometric and spectrometric signals from the target odorants. The best results were obtained with a dynamic headspace extraction followed by a fractionation on a normal phase medium pressure liquid chromatography on a silicagel column. Large volumes (50 microl) of the concentrated fractions were further analyzed in a dual gas chromatography-mass spectrometric system (GC-MS) equipped with two olfactometric ports. The strategy made it possible to identify in wine by first time the presence of the powerful strawberry-smelling compound, ethyl cyclohexanoate, and of two other novel fruity esters, ethyl 2-hydroxy-3-methylbutyrate and ethyl 2-hydroxy-4-methylpentanoate. Some other unidentified odorants could be isolated and their mass spectra are given. PMID:17069823

  12. Radical-radical interactions among oxidized guanine bases including guanine radical cation and dehydrogenated guanine radicals.

    PubMed

    Zhao, Jing; Wang, Mei; Yang, Hongfang; Zhang, Meng; Liu, Ping; Bu, Yuxiang

    2013-09-19

    We present here a theoretical investigation of the structural and electronic properties of di-ionized GG base pairs (G(•+)G(•+),G(-H1)(•)G(•+), and G(-H1)(•)G(-H1)(•)) consisting of the guanine cation radical (G(•+)) and/or dehydrogenated guanine radical (G(-H1)(•)) using density functional theory calculations. Different coupling modes (Watson-Crick/WC, Hoogsteen/Hoog, and minor groove/min hydrogen bonding, and π-π stacking modes) are considered. We infer that a series of G(•+)G(•+) complexes can be formed by the high-energy radiation. On the basis of density functional theory and complete active space self-consistent (CASSCF) calculations, we reveal that in the H-bonded and N-N cross-linked modes, (G(•+)G(•+))WC, (G(-H1)(•)G(-H1)(•))WC, (G(-H1)(•)G(-H1)(•))minI, and (G(-H1)(•)G(-H1)(•))minIII have the triplet ground states; (G(•+)G(•+))HoogI, (G(-H1)(•)G(•+))WC, (G(-H1)(•)G(•+))HoogI, (G(-H1)(•)G(•+))minI, (G(-H1)(•)G(•+))minII, and (G(-H1)(•)G(-H1)(•))minII possess open-shell broken-symmetry diradical-characterized singlet ground states; and (G(•+)G(•+))HoogII, (G(•+)G(•+))minI, (G(•+)G(•+))minII, (G(•+)G(•+))minIII, (G(•+)G(•+))HoHo, (G(-H1)(•)G(•+))minIII, (G(-H1)(•)G(•+))HoHo, and (G(-H1)(•)G(-H1)(•))HoHo are the closed-shell systems. For these H-bonded diradical complexes, the magnetic interactions are weak, especially in the diradical G(•+)G(•+) series and G(-H1)(•)G(-H1)(•) series. The magnetic coupling interactions of the diradical systems are controlled by intermolecular interactions (H-bond, electrostatic repulsion, and radical coupling). The radical-radical interaction in the π-π stacked di-ionized GG base pairs ((G(•+)G(•+))ππ, (G(-H1)(•)G(•+))ππ, and (G(-H1)(•)G(-H1)(•))ππ) are also considered, and the magnetic coupling interactions in these π-π stacked base pairs are large. This is the first theoretical prediction that some di

  13. Residual behavior of quizalofop ethyl on onion (Allium cepa L.).

    PubMed

    Sahoo, S K; Mandal, Kousik; Singh, Gurmail; Kumar, Rajinder; Chahil, G S; Battu, R S; Singh, Balwinder

    2013-02-01

    Quizalofop ethyl, a phenoxy propionate herbicide, is used for postemergence control of annual and perennial grass weeds in broad-leaved crops in India. The experiments were designed to study the dissipation kinetics of quizalofop ethyl on onion for two seasons. A simple, rapid, and sensitive method for estimation of quizalofop ethyl residues in onion and soil was developed and validated. The recoveries of quizalofop ethyl residues from onion and soil at different spiking level range from 84.81 to 92.68 %. The limit of quantification of this method was found to be 0.01 μg g(-1). The risk assessment through consumption of the onion in comparison to its acceptable daily intake which is an important parameter for the safety of the consumer was also evaluated. Standardized methodology supported by recovery studies was adopted to estimate residues of quizalofop ethyl on onion and soil. The average initial deposits of quizalofop ethyl on onion were observed to be 0.25 and 0.33 mg kg(-1), following single application of the herbicide at 50 g active ingredient (a.i.) ha(-1) during 2009 and 2010, respectively. The half-life values (T (1/2)) of quizalofop ethyl on onion crop were worked out to be 0.85 and 0.79 days, respectively, during 2009 and 2010. At harvest time, the residues of quizalofop ethyl on onion and soil were found to be below the determination limit of 0.01 mg kg(-1) following single application of the herbicide at 50 and 100 g a.i. ha(-1) for both the periods.

  14. Glutathione S-transferase pi (GST-pi) inhibition and anti-inflammation activity of the ethyl acetate extract of Streptomyces sp. strain MJM 8637.

    PubMed

    Lee, Sung-Kwon; Lee, Dong-Ryung; Choi, Bong-Keun; Palaniyandi, Sasikumar Arunachalam; Yang, Seung Hwan; Suh, Joo-Won

    2015-11-01

    To investigate the anti-cancer properties of soil-borne actinobacteria, MJM 8637, the glutathione S-transferase pi (GST-pi) assay, anti-tumor necrosis factor (TNF)-α assay, the level of antioxidant potential by DPPH radical scavenging activity, NO scavenging activity, and ABTS radical scavenging activity in ethyl acetate extract were determined. The 16S rDNA sequencing analysis revealed that Streptomyces sp. strain MJM 8637, which was isolated from Hambak Mountain, Korea, has 99.5% similarity to Streptomyces atratus strain NBRC 3897. The physiological and the morphological characteristics of the strain MJM 8637 were also identified. The ethyl acetate extract of MJM 8637 inhibited TNF-α production approximately 61.8% at concentration 100 μg/ml. The IC50 value of the strain MJM 8637 extract on GST-pi was identified to be 120.2 ± 1.6 μg/ml. In DPPH, NO, and ABTS radical scavenging assays, the IC50 values of the strain MJM 8637 extract were found to be 977.2 μg/ml, 1143.7 μg/ml, and 454.4 μg/ml, respectively. The ethyl acetate extract of the strain MJM 8637 showed 97.2 ± 1.3% of cell viability at 100 μg/ml in RAW 264.7 cell viability assay. The results obtained from this study suggest that the ethyl acetate extract of Streptomyces sp. strain MJM 8637 could be considered as a potential source of drug for the cancers that have multidrug resistance with its GST-pi inhibition and anti-inflammation activities, and low cytotoxicity.

  15. Glutathione S-transferase pi (GST-pi) inhibition and anti-inflammation activity of the ethyl acetate extract of Streptomyces sp. strain MJM 8637

    PubMed Central

    Lee, Sung-Kwon; Lee, Dong-Ryung; Choi, Bong-Keun; Palaniyandi, Sasikumar Arunachalam; Yang, Seung Hwan; Suh, Joo-Won

    2015-01-01

    To investigate the anti-cancer properties of soil-borne actinobacteria, MJM 8637, the glutathione S-transferase pi (GST-pi) assay, anti-tumor necrosis factor (TNF)-α assay, the level of antioxidant potential by DPPH radical scavenging activity, NO scavenging activity, and ABTS radical scavenging activity in ethyl acetate extract were determined. The 16S rDNA sequencing analysis revealed that Streptomyces sp. strain MJM 8637, which was isolated from Hambak Mountain, Korea, has 99.5% similarity to Streptomyces atratus strain NBRC 3897. The physiological and the morphological characteristics of the strain MJM 8637 were also identified. The ethyl acetate extract of MJM 8637 inhibited TNF-α production approximately 61.8% at concentration 100 μg/ml. The IC50 value of the strain MJM 8637 extract on GST-pi was identified to be 120.2 ± 1.6 μg/ml. In DPPH, NO, and ABTS radical scavenging assays, the IC50 values of the strain MJM 8637 extract were found to be 977.2 μg/ml, 1143.7 μg/ml, and 454.4 μg/ml, respectively. The ethyl acetate extract of the strain MJM 8637 showed 97.2 ± 1.3% of cell viability at 100 μg/ml in RAW 264.7 cell viability assay. The results obtained from this study suggest that the ethyl acetate extract of Streptomyces sp. strain MJM 8637 could be considered as a potential source of drug for the cancers that have multidrug resistance with its GST-pi inhibition and anti-inflammation activities, and low cytotoxicity. PMID:26587003

  16. Icosapent ethyl: a review of its use in severe hypertriglyceridemia.

    PubMed

    Kim, Esther S; McCormack, Paul L

    2014-12-01

    Icosapent ethyl (Vascepa®) is a high-purity ethyl ester of eicosapentaenoic acid (EPA) that is de-esterified to EPA following oral administration. Both EPA and docosahexaenoic acid (DHA) are long-chain omega-3 fatty acids that have been associated with triglyceride (TG)-lowering. However, DHA has been associated with increased low-density lipoprotein cholesterol (LDL-C) levels. Icosapent ethyl contains ≥96 % of the EPA ethyl ester, does not contain DHA, and is approved in the USA for use as an adjunct to diet to lower TG levels in adult patients with severe (≥500 mg/dL [≥5.65 mmol/L]) hypertriglyceridemia. In a pivotal phase III trial, oral icosapent ethyl 4 g/day significantly decreased the placebo-corrected median TG levels by 33.1 %. It did not increase LDL-C, had favorable effects on other lipid parameters, and had a tolerability profile similar to that of placebo. Therefore, icosapent ethyl is an effective and well-tolerated agent for the treatment of severe hypertriglyceridemia in adults. PMID:25428605

  17. Phytochemical analysis, antimicrobial and radical-scavenging properties of Acalypha manniana leaves.

    PubMed

    Noumedem, Jaures Ak; Tamokou, Jean de Dieu; Teke, Gerald Ngo; Momo, Rosine Cd; Kuete, Victor; Kuiate, Jules Roger

    2013-01-01

    Acalypha manniana (Euphorbiaceae) is a plant popularly used in Cameroon and in several parts of Africa for the treatment of various microbial diseases like diarrhea and skin infections. The present study was designed to evaluate the phytochemical composition, antimicrobial and radical-scavenging activities of A. manniana methanol leaf extract and its fractions. The methanol extract was partitioned into hexane, ethyl acetate and residual fractions and phytochemical analysis was conducted using standard methods. The broth microdilution method was used to evaluate the antimicrobial activity against nine bacterial species and four dermatophyte species. The free radical scavenging activities of the methanol extract and its fractions were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The results obtained showed that A. manniana contains alkaloids, tannins, anthocyanins, flavonoids, phenols and steroids. The methanol extract as well as the hexane, ethyl acetate and residual fractions exhibited both antibacterial and antidermatophytic activities that varied between the microbial species (MIC = 0.12 - 2.04 mg/mL). These tested samples also showed high radical-scavenging activities (RaS50 = 3.34 - 4.80 μg/mL) when compared with vitamin C used as reference antioxidant (RaS50 = 1.74 μg/mL). These findings provide evidence that the studied plant possesses antimicrobial and antioxidant properties and may act as potential antioxidant for biological systems susceptible to free radical-mediated reactions.

  18. Isolation and Characterization of the 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) Radical Cation-Scavenging Reaction Products of Arbutin.

    PubMed

    Tai, Akihiro; Ohno, Asako; Ito, Hideyuki

    2016-09-28

    Arbutin, a glucoside of hydroquinone, has shown strong 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation-scavenging activity, especially in reaction stoichiometry. This study investigated the reaction mechanism of arbutin against ABTS radical cation that caused high stoichiometry of arbutin in an ABTS radical cation-scavenging assay. HPLC analysis of the reaction mixture of arbutin and ABTS radical cation indicated the existence of two reaction products. The two reaction products were purified and identified to be a covalent adduct of arbutin with an ABTS degradation fragment and 3-ethyl-6-sulfonate benzothiazolone. A time-course study of the radical-scavenging reactions of arbutin and the two reaction products suggested that one molecule of arbutin scavenges three ABTS radical cation molecules to generate an arbutin-ABTS fragment adduct as a final reaction product. The results suggest that one molecule of arbutin reduced two ABTS radical cation molecules to ABTS and then cleaved the third ABTS radical cation molecule to generate two products, an arbutin-ABTS fragment adduct and 3-ethyl-6-sulfonate benzothiazolone.

  19. Isolation and Characterization of the 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) Radical Cation-Scavenging Reaction Products of Arbutin.

    PubMed

    Tai, Akihiro; Ohno, Asako; Ito, Hideyuki

    2016-09-28

    Arbutin, a glucoside of hydroquinone, has shown strong 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation-scavenging activity, especially in reaction stoichiometry. This study investigated the reaction mechanism of arbutin against ABTS radical cation that caused high stoichiometry of arbutin in an ABTS radical cation-scavenging assay. HPLC analysis of the reaction mixture of arbutin and ABTS radical cation indicated the existence of two reaction products. The two reaction products were purified and identified to be a covalent adduct of arbutin with an ABTS degradation fragment and 3-ethyl-6-sulfonate benzothiazolone. A time-course study of the radical-scavenging reactions of arbutin and the two reaction products suggested that one molecule of arbutin scavenges three ABTS radical cation molecules to generate an arbutin-ABTS fragment adduct as a final reaction product. The results suggest that one molecule of arbutin reduced two ABTS radical cation molecules to ABTS and then cleaved the third ABTS radical cation molecule to generate two products, an arbutin-ABTS fragment adduct and 3-ethyl-6-sulfonate benzothiazolone. PMID:27607833

  20. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], and its metabolite, S-3153 acid-4-OH; -phenoxy]-acetic acid, free and conjugated, in or on...

  1. Radioprotection of Tendon Tissue via Crosslinking and Free Radical Scavenging

    PubMed Central

    Seto, Aaron; Gatt, Charles J.

    2008-01-01

    Ionizing radiation could supplement tissue bank screening to further reduce the probability of diseases transmitted by allografts if denaturation effects can be minimized. It is important, however, such sterilization procedures be nondetrimental to tissues. We compared crosslinking and free radical scavenging potential methods to accomplish this task in tendon tissue. In addition, two forms of ionizing irradiation, gamma and electron beam (e-beam), were also compared. Crosslinkers included 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and glucose, which were used to add exogenous crosslinks to collagen. Free radical scavengers included mannitol, ascorbate, and riboflavin. Radioprotective effects were assessed through tensile testing and collagenase resistance testing after irradiation at 25 kGy and 50 kGy. Gamma and e-beam irradiation produced similar degenerative effects. Crosslinkers had the highest strength at 50 kGy, EDC treated tendons had 54% and 49% higher strength than untreated, for gamma and e-beam irradiation respectively. Free radical scavengers showed protective effects up to 25 kGy, especially for ascorbate and riboflavin. Crosslinked samples had higher resistance to collagenase and over a wider dose range than scavenger-treated. Of the options studied, the data suggest EDC precrosslinking or glucose treatment provides the best maintenance of native tendon properties after exposure to ionizing irradiation. PMID:18512113

  2. Free radical propulsion concept

    NASA Technical Reports Server (NTRS)

    Hawkins, C. E.; Nakanishi, S.

    1981-01-01

    A free radical propulsion concept utilizing the recombination energy of dissociated low molecular weight gases to produce thrust was examined. The concept offered promise of a propulsion system operating at a theoretical impulse, with hydrogen, as high as 2200 seconds at high thrust to power ratio, thus filling the gas existing between chemical and electrostatic propulsion capabilities. Microwave energy used to dissociate a continuously flowing gas was transferred to the propellant via three body recombination for conversion to propellant kinetic energy. Power absorption by the microwave plasma discharge was in excess of 90 percent over a broad range of pressures. Gas temperatures inferred from gas dynamic equations showed much higher temperatures from microwave heating than from electrothermal heating. Spectroscopic analysis appeared to corroborate the inferred temperatures of one of the gases tested.

  3. Radicals in Berkeley?

    PubMed Central

    Linn, Stuart

    2015-01-01

    In a previous autobiographical sketch for DNA Repair (Linn, S. (2012) Life in the serendipitous lane: excitement and gratification in studying DNA repair. DNA Repair 11, 595–605), I wrote about my involvement in research on mechanisms of DNA repair. In this Reflections, I look back at how I became interested in free radical chemistry and biology and outline some of our bizarre (at the time) observations. Of course, these studies could never have succeeded without the exceptional aid of my mentors: my teachers; the undergraduate and graduate students, postdoctoral fellows, and senior lab visitors in my laboratory; and my faculty and staff colleagues here at Berkeley. I am so indebted to each and every one of these individuals for their efforts to overcome my ignorance and set me on the straight and narrow path to success in research. I regret that I cannot mention and thank each of these mentors individually. PMID:25713083

  4. Examination of sex differences in fatty acid ethyl ester and ethyl glucuronide hair analysis.

    PubMed

    Gareri, Joey; Rao, Chitra; Koren, Gideon

    2014-06-01

    Clinical studies examining performance of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in identifying excessive alcohol consumption have been primarily conducted in male populations. An impact of hair cosmetics in producing both false-negative EtG results and false-positive FAEE results has been demonstrated, suggesting a possible bias in female populations. This study evaluates FAEE-positive hair samples (>0.50 ng/mg) from n = 199 female and n = 73 male subjects for EtG. Higher FAEE/EtG concordance was observed amongst male over female subjects. Performance of multiple proposed EtG cut-off levels were assessed; amongst female samples, FAEE/EtG concordance was 36.2% (30 pg/mg), 36.7% (27 pg/mg), and 43.7% (20 pg/mg). Non-coloured hair demonstrated a two-fold increase in concordance (41.8 v. 20.8%) over coloured hair in the female cohort. FAEE levels did not differ between male and female subjects; however they were lower in coloured samples (p = 0.046). EtG was lower in female subjects (p = 0.019) and coloured samples (p = 0.026). A total of n = 111 female samples were discordant. Amongst discordant samples (EtG-negative), 26% had evidence of recent alcohol use including consultation histories (n = 20) and detectable cocaethylene (n = 9); 29% of discordant samples were coloured. False-negative risk with ethyl glucuronide analysis in females was mediated by cosmetic colouring. These findings suggest that combined analysis of FAEE and EtG is optimal when assessing a female population and an EtG cut-off of 20 pg/mg is warranted when using combined analysis. While concordant FAEE/EtG-positive findings constitute clear evidence, discordant FAEE/EtG findings should still be considered suggestive evidence of chronic excessive alcohol consumption. PMID:24817046

  5. Phytochemical Analysis and Free Radical Scavenging Activity of Medicinal Plants Gnidia glauca and Dioscorea bulbifera

    PubMed Central

    Ghosh, Sougata; Derle, Abhishek; Ahire, Mehul; More, Piyush; Jagtap, Soham; Phadatare, Suvarna D.; Patil, Ajay B.; Jabgunde, Amit M.; Sharma, Geeta K.; Shinde, Vaishali S.; Pardesi, Karishma; Dhavale, Dilip D.; Chopade, Balu A.

    2013-01-01

    Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS•+ and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS•+ radical with a second order rate constant of 2.33×106 and 1.72×106, respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48×106 and 4.46×106 were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C27H42O3) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants. PMID:24367520

  6. Studies of radiation-produced radicals and radical ions

    SciTech Connect

    Williams, T.F.

    1991-01-01

    The radiolytic oxidation of anti-5-methylbicyclo(2.1.0)pentane gives the 1-methylcyclopentene radical cation as the sole rearrangement product H migration whereas oxidation of its syn isomer results in the highly selective formation of the 3-methylcyclopentene radical cation by methyl group migration. Since exactly the same stereoselectivity of olefin formation was observed in corresponding PET (photosensitized electron transfer) studies in the liquid phase, it is concluded that the rearrangement in this case also occurs through the intermediacy of radical cations. Clearly, the radical cation rearrangement must occur very rapidly (10{sup {minus}8}--10{sup {minus}9}s) under liquid-phase conditions at room temperature to compete with back electron transfer, and therefore the hydrogen (or methyl) migration is a fast process under these conditions. An intramolecular cycloaddition reaction was demonstrated in the radical cation rearrangement of 4-vinylcyclohexene to bicyclo(3.2.1)oct-2-ene. ESR studies show that the radiolytic oxidation of quadricyclane in Freon matrices under conditions of high substrate dilution leads to the bicyclo(3.2.0)hepta-2,6-diene radical cation as well as the previously reported norbornadiene radical cation, the former species predominating at sufficiently low concentrations.

  7. Anti-genotoxic and free-radical scavenging activities of extracts from (Tunisian) Myrtus communis.

    PubMed

    Hayder, N; Abdelwahed, A; Kilani, S; Ammar, R Ben; Mahmoud, A; Ghedira, K; Chekir-Ghedira, L

    2004-11-14

    The effect of extracts from leaves of Myrtus communis on the SOS reponse induced by Aflatoxin B1 (AFB1) and Nifuroxazide was investigated in a bacterial assay system, i.e. the SOS chromotest with Escherichia coli PQ37. Aqueous extract, the total flavonoids oligomer fraction (TOF), hexane, chloroform, ethyl acetate and methanol extracts and essential oil obtained from M. communis significantly decreased the SOS response induced by AFB1 (10 microg/assay) and Nifuroxazide (20 microg/assay). Ethyl acetate and methanol extracts showed the strongest inhibition of the induction of the SOS response by the indirectly genotoxic AFB1. The methanol and aqueous extracts exhibited the highest level of protection towards the SOS-induced response by the directly genotoxic Nifuroxazide. In addition to anti-genotoxic activity, the aqueous extract, the TOF, and the ethyl acetate and methanol extracts showed an important free-radical scavenging activity towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. These results suggest the future utilization of these extracts as additives in chemoprevention studies. PMID:15474415

  8. Addition reaction of alkyl radical to C60 fullerene: Density functional theory study

    NASA Astrophysics Data System (ADS)

    Tachikawa, Hiroto; Kawabata, Hiroshi

    2016-02-01

    Functionalized fullerenes are known as a high-performance molecules. In this study, the alkyl-functionalized fullerenes (denoted by R-C60) have been investigated by means of the density functional theory (DFT) method to elucidate the effects of functionalization on the electronic states of fullerene. Also, the reaction mechanism of alkyl radicals with C60 was investigated. The methyl, ethyl, propyl, and butyl radicals (denoted by n = 1-4, where n means the number of carbon atoms in the alkyl radical) were examined as alkyl radicals. The DFT calculation showed that the alkyl radical binds to the carbon atom of C60 at the on-top site, and a strong C-C single bond is formed. The binding energies of alkyl radicals to C60 were distributed in the range of 31.8-35.1 kcal mol-1 at the CAM-B3LYP/6-311G(d,p) level. It was found that the activation barrier exists before alkyl addition, the barrier heights were calculated to be 2.1-2.8 kcal mol-1. The electronic states of R-C60 complexes were discussed on the basis of the theoretical results.

  9. Generation of Organic Radicals During Photocatalysis on TiO2

    NASA Astrophysics Data System (ADS)

    Henderson, Michael

    2008-03-01

    It is well-known that water-related radicals (such as OH. species) are produced by charge transfer events at UV-irradiated TiO2 surfaces. In contrast, organic radicals are generally viewed as being formed by reactions with OH. groups and not by direct charge transfer events. Using rutile TiO2(110) as a model photocatalyst, we show that organic radicals are generated in single-step charge transfer events during photodecomposition of adsorbed carboxylates and ketones. Some organic radicals (e.g., methyl) are ejected from the surface and, in high surface area catalysts, experience reactions away from the surface of origin. Other radicals (e.g., ethyl and t-butyl) have limited ability to escape the surface of origin without capture and subsequent thermal reactions. Understanding the chemistry associated with organic radical formation on TiO2 opens the door for more detailed examinations of charge transfer dynamics and energy redistribution during photon-initiated reactions important to heterogeneous photocatalysis.

  10. The thermal decomposition of the benzyl radical in a heated micro-reactor. I. Experimental findings

    SciTech Connect

    Buckingham, Grant T.; Ormond, Thomas K.; Porterfield, Jessica P.; Ellison, G. Barney; Hemberger, Patrick; Kostko, Oleg; Ahmed, Musahid; Robichaud, David J.; Nimlos, Mark R.; Daily, John W.

    2015-01-28

    The pyrolysis of the benzyl radical has been studied in a set of heated micro-reactors. A combination of photoionization mass spectrometry (PIMS) and matrix isolation infrared (IR) spectroscopy has been used to identify the decomposition products. Both benzyl bromide and ethyl benzene have been used as precursors of the parent species, C{sub 6}H{sub 5}CH{sub 2}, as well as a set of isotopically labeled radicals: C{sub 6}H{sub 5}CD{sub 2}, C{sub 6}D{sub 5}CH{sub 2}, and C{sub 6}H{sub 5}{sup 13}CH{sub 2}. The combination of PIMS and IR spectroscopy has been used to identify the earliest pyrolysis products from benzyl radical as: C{sub 5}H{sub 4}=C=CH{sub 2}, H atom, C{sub 5}H{sub 4}—C ≡ CH, C{sub 5}H{sub 5}, HCCCH{sub 2}, and HC ≡ CH. Pyrolysis of the C{sub 6}H{sub 5}CD{sub 2}, C{sub 6}D{sub 5}CH{sub 2}, and C{sub 6}H{sub 5}{sup 13}CH{sub 2} benzyl radicals produces a set of methyl radicals, cyclopentadienyl radicals, and benzynes that are not predicted by a fulvenallene pathway. Explicit PIMS searches for the cycloheptatrienyl radical were unsuccessful, there is no evidence for the isomerization of benzyl and cycloheptatrienyl radicals: C{sub 6}H{sub 5}CH{sub 2}⇋C{sub 7}H{sub 7}. These labeling studies suggest that there must be other thermal decomposition routes for the C{sub 6}H{sub 5}CH{sub 2} radical that differ from the fulvenallene pathway.

  11. Free radicals and male reproduction.

    PubMed

    Agarwal, Ashok; Allamaneni, Shyam S R

    2011-03-01

    Male factor accounts for almost 50% cases of infertility. The exact mechanism of sperm dysfunction is not known in many cases. Extensive research in the last decade has led to the identification of free radicals (reactive oxygen species) as mediators of sperm dysfunction in both specific diagnoses and idiopathic cases of male infertility. Elevated levels of reactive oxygen species are seen in up to 30-80% of men with male infertility. The role of free radicals has been studied extensively in the process of human reproduction. We know now that a certain level of free radicals is necessary for normal sperm function, whereas an excessive level of free radicals can cause detrimental effect on sperm function and subsequent fertilisation and offspring health. Oxidative stress develops when there is an imbalance between generation of free radicals and scavenging capacity of anti-oxidants in reproductive tract. Oxidative stress has been shown to affect both standard semen parameters and fertilising capacity. In addition, high levels of free radicals have been associated with lack of or poor fertility outcome after natural conception or assisted reproduction. Diagnostic techniques to quantify free radicals in infertile patients can assist physicians treating patients with infertility to plan for proper treatment strategies. In vivo anti-oxidants can be used against oxidative stress in male reproductive tract. Supplementation of in vitro anti-oxidants can help prevent the oxidative stress during sperm preparation techniques in assisted reproduction.

  12. Radical scavenging activity of lipophilized products from lipase-catalyzed transesterification of triolein with cinnamic and ferulic acids.

    PubMed

    Choo, Wee-Sim; Birch, Edward John

    2009-02-01

    Lipase-catalyzed transesterification of triolein with cinnamic and ferulic acids using an immobilized lipase from Candida antarctica (E.C. 3.1.1.3) was conducted to evaluate the antioxidant activity of the lipophilized products as model systems for enhanced protection of unsaturated oil. The lipophilized products were identified using ESI-MS. Free radical scavenging activity was determined using the DPPH radical method. The polarity of the solvents proved important in determining the radical scavenging activity of the substrates. Ferulic acid showed much higher radical scavenging activity than cinnamic acid, which has limited activity. The esterification of cinnamic acid and ferulic acid with triolein resulted in significant increase and decrease in the radical scavenging activity, respectively. These opposite effects were due to the effect of addition of electron-donating alkyl groups on the predominant mechanism of reaction (hydrogen atom transfer or electron transfer) of a species with DPPH. The effect of esterification of cinnamic acid was confirmed using ethyl cinnamate which greatly enhances the radical scavenging activity. Although, compared to the lipophilized cinnamic acid product, the activity was lower. The radical scavenging activity of the main component isolated from lipophilized cinnamic acid product using solid phase extraction, monocinnamoyl dioleoyl glycerol, was as good as the unseparated mixture of lipophilized product. Based on the ratio of a substrate to DPPH concentration, lipophilized ferulic acid was a much more efficient radical scavenger than lipophilized cinnamic acid.

  13. Radical scavenging activity of lipophilized products from transesterification of flaxseed oil with cinnamic acid or ferulic acid.

    PubMed

    Choo, Wee-Sim; Birch, Edward John; Stewart, Ian

    2009-09-01

    Lipase-catalyzed transesterification of flaxseed oil with cinnamic acid (CA) or ferulic acid (FA) using an immobilized lipase from Candida antarctica (E.C. 3.1.1.3) was conducted to evaluate whether the lipophilized products provided enhanced antioxidant activity in the oil. Lipase-catalyzed transesterification of flaxseed oil with CA or FA produced a variety of lipophilized products (identified using ESI-MS-MS) such as monocinnamoyl/feruloyl-diacylglycerol, dicinnamoyl-monoacylglycerol and monocinnamoyl-monoacylglycerol. The free radical scavenging activity of the lipophilized products of lipase-catalyzed transesterification of flaxseed oil with CA or FA toward 2,2-diphenyl-1-picrylhydrazyl radical (DPPH.) were both examined in ethanol and ethyl acetate. The polarity of the solvents proved important in determining the radical scavenging activity of the substrates. Unesterified FA showed the highest free radical scavenging activity among all substrates tested while CA had negligible activity. The esterification of CA or FA with flaxseed oil resulted in significant increase and decrease in the radical scavenging activity compared with the native phenolic acid, respectively. Based on the ratio of a substrate to DPPH. concentration, lipophilized FA was a much more efficient free radical scavenger compared to lipophilized CA and was able to provide enhanced antioxidant activity in the flaxseed oil. Lipophilized cinnamic acid did not provide enhanced radical scavenging activity in the flaxseed oil as the presence of natural hydrophilic antioxidants in the oil had much greater radical scavenging activity.

  14. Fragrance material review on ethyl phenyl carbinyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of ethyl phenyl carbinyl acetate when used as a fragrance ingredient is presented. Ethyl phenyl carbinyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for ethyl phenyl carbinyl acetate were evaluated, then summarized, and includes: physical properties; acute toxicity; skin irritation; and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  15. Fragrance material review on 2-(p-tolyloxy)ethyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-(p-tolyloxy)ethyl acetate when used as a fragrance ingredient is presented. 2-(p-tolyloxy)ethyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-(p-tolyloxy)ethyl acetate were evaluated, then summarized, and includes physical properties data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  16. Fragrance material review on 2-(p-tolyloxy)ethyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-(p-tolyloxy)ethyl acetate when used as a fragrance ingredient is presented. 2-(p-tolyloxy)ethyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-(p-tolyloxy)ethyl acetate were evaluated, then summarized, and includes physical properties data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414652

  17. NEW GROUND-STATE MEASUREMENTS OF ETHYL CYANIDE

    SciTech Connect

    Brauer, Carolyn S.; Pearson, John C.; Drouin, Brian J.; Yu, Shanshan

    2009-09-01

    The spectrum of ethyl cyanide, or propionitrile (CH{sub 3}CH{sub 2}CN), has been repeatedly observed in the interstellar medium with large column densities and surprisingly high temperatures in hot core sources. The construction of new, more sensitive, observatories accessing higher frequencies such as Herschel, ALMA, and SOFIA have made it important to extend the laboratory data for ethyl cyanide to coincide with the capabilities of the new instruments. We report extensions of the laboratory measurements of the rotational spectrum of ethyl cyanide in its ground vibrational state to 1.6 THz. A global analysis of the ground state, which includes all of the previous data and 3356 newly assigned transitions, has been fitted to within experimental error to J = 132, K = 36, using both Watson A-reduced and Watson S-reduced Hamiltonians.

  18. Peroxy radical partitioning during the AMMA radical intercomparison exercise

    NASA Astrophysics Data System (ADS)

    Andrés-Hernández, M. D.; Stone, D.; Brookes, D. M.; Commane, R.; Reeves, C. E.; Huntrieser, H.; Heard, D. E.; Monks, P. S.; Burrows, J. P.; Schlager, H.; Kartal, D.; Evans, M. J.; Floquet, C. F. A.; Ingham, T.; Methven, J.; Parker, A. E.

    2010-11-01

    Peroxy radicals were measured onboard two scientific aircrafts during the AMMA (African Monsoon Multidisciplinary Analysis) campaign in summer 2006. This paper reports results from the flight on 16 August 2006 during which measurements of HO2 by laser induced fluorescence spectroscopy at low pressure (LIF-FAGE) and total peroxy radicals (RO2* = HO2+ΣRO2, R = organic chain) by two similar instruments based on the peroxy radical chemical amplification (PeRCA) technique were subject of a blind intercomparison. The German DLR-Falcon and the British FAAM-BAe-146 flew wing tip to wing tip for about 30 min making concurrent measurements on 2 horizontal level runs at 697 and 485 hPa over the same geographical area in Burkina Faso. A full set of supporting measurements comprising photolysis frequencies, and relevant trace gases like CO, NO, NO2, NOy, O3 and a wider range of VOCs were collected simultaneously. Results are discussed on the basis of the characteristics and limitations of the different instruments used. Generally, no data bias are identified and the RO2* data available agree quite reasonably within the instrumental errors. The [RO2*]/[HO2] ratios, which vary between 1:1 and 3:1, as well as the peroxy radical variability, concur with variations in photolysis rates and in other potential radical precursors. Model results provide additional information about dominant radical formation and loss processes.

  19. Peroxy radical partitioning during the AMMA radical intercomparison exercise

    NASA Astrophysics Data System (ADS)

    Andrés-Hernández, M. D.; Stone, D.; Brookes, D. M.; Commane, R.; Reeves, C. E.; Huntrieser, H.; Heard, D. E.; Monks, P. S.; Burrows, J. P.; Schlager, H.; Kartal, D.; Evans, M. J.; Floquet, C. F. A.; Ingham, T.; Methven, J.; Parker, A. E.

    2010-04-01

    Peroxy radicals were measured onboard two scientific aircrafts during the AMMA (African Monsoon Multidisciplinary Analysis) campaign in summer 2006. This paper reports results from the flight on 16 August 2006 during which measurements of HO2 by laser induced fluorescence spectroscopy at low pressure (LIF-FAGE) and total peroxy radicals (RO2*=HO2+ΣRO2, R= organic chain) by two similar instruments based on the peroxy radical chemical amplification (PerCA) technique were subject of a blind intercomparison. The German DLR-Falcon and the British FAAM-BAe-146 flew wing tip to wing tip for about 30 min making concurrent measurements on 2 horizontal level runs at 697 and 485 hPa over the same geographical area in Burkina Faso. A full set of supporting measurements comprising photolysis frequencies, and relevant trace gases like CO, NO, NO2, NOy, O3 and a wider range of VOCs were collected simultaneously. Results are discussed on the basis of the characteristics and limitations of the different instruments used. Generally, no data bias are identified and the RO2* data available agree quite reasonably within the instrumental errors. The [RO2*]/[HO2] ratios, which vary between 1:1 and 3:1, as well as the peroxy radical variability, concur with variations in photolysis rates and in other potential radical precursors. Model results provide additional information about dominant radical formation and loss processes.

  20. Nitrosamine-induced carcinogenesis. The alkylation of N-7 of guanine of nucleic acids of the rat by diethylnitrosamine, N-ethyl-N-nitrosourea and ethyl methanesulphonate

    PubMed Central

    Swann, P. F.; Magee, P. N.

    1971-01-01

    1. The extent of ethylation of N-7 of guanine in the nucleic acids of rat tissue in vivo by diethylnitrosamine, N-ethyl-N-nitrosourea and ethyl methanesulphonate was measured. 2. All compounds produced measurable amounts of 7-ethyl-guanine. 3. A single dose of diethylnitrosamine or N-ethyl-N-nitrosourea produced tumours of the kidney in the rat. Three doses of ethyl methanesulphonate produced kidney tumours, but a single dose did not. 4. A single dose of diethylnitrosamine produced twice as much ethylation of N-7 of guanine in DNA of kidney as did N-ethyl-N-nitrosourea. A single dose of both compounds induced kidney tumours, although of a different histological type. 5. A single dose of ethyl methanesulphonate produced ten times as much ethylation of N-7 of guanine in kidney DNA as did N-ethyl-N-nitrosourea without producing tumours. 6. The relevance of these findings to the hypothesis that alkylation of a cellular component is the mechanism of induction of tumours by nitroso compounds is discussed. PMID:5145908

  1. Assistance of ethyl glucuronide and ethyl sulfate in the interpretation of postmortem ethanol findings.

    PubMed

    Krabseth, Hege; Mørland, Jørg; Høiseth, Gudrun

    2014-09-01

    Postmortem ethanol formation is a well-known problem in forensic toxicology. The aim of this study was to interpret findings of ethanol in blood, in a large collection of forensic autopsy cases, by use of the nonoxidative ethanol metabolites, ethyl glucuronide (EtG), and ethyl sulfate (EtS). In this study, according to previously published literature, antemortem ethanol ingestion was excluded in EtS-negative cases. Among 493 ethanol-positive forensic autopsy cases, collected during the study period, EtS was not detected in 60 (12 %) of the cases. Among cases with a blood alcohol concentration (BAC) of ≤ 0.54 g/kg, antemortem ethanol ingestion was excluded in 38 % of the cases, while among cases with a BAC of ≥ 0.55 g/kg, antemortem ethanol ingestion was excluded in 2.2 % of the cases. For all cases where ethanol was measured at a concentration >1.0 g/kg, EtS was detected. The highest blood ethanol concentration in which EtS was not detected was 1.0 g/kg. The median concentrations of EtG and EtS in blood were 9.5 μmol/L (range: not detected (n.d.) 618.1) and 9.2 μmol/L (range: n.d. 182.5), respectively. There was a statistically significant positive correlation between concentration levels of ethanol and of EtG (Spearman's rho=0.671, p<0.001) and EtS (Spearman's rho=0.670, p<0.001), respectively. In conclusion, this study showed that in a large number of ethanol-positive forensic autopsy cases, ethanol was not ingested before the time of death, particularly among cases where ethanol was present in lower blood concentrations. Routine measurement of EtG and EtS should therefore be recommended, especially in cases with BAC below 1 g/kg. PMID:24935750

  2. Blood kinetics of ethyl glucuronide and ethyl sulphate in heavy drinkers during alcohol detoxification.

    PubMed

    Høiseth, Gudrun; Morini, Luca; Polettini, Aldo; Christophersen, Asbjørg; Mørland, Jørg

    2009-07-01

    Studies of ethyl glucuronide (EtG) blood kinetics have so far been performed on healthy volunteers with ingestion of low to moderate doses of ethanol. These data are not necessarily transferable to heavy drinkers where the consumed doses of ethanol are much higher. The aim of this study was to investigate the pharmacokinetics of EtG and ethyl sulphate (EtS) in blood in heavy drinkers after termination of alcohol ingestion. Sixteen patients from an alcohol withdrawal clinic were included directly after admission. Time of end of drinking, estimated daily intake of ethanol (EDI) and medical history were recorded. Three to five blood samples over 20-43 h were collected from each patient subsequent to admission. The median EDI was 172 g (range 60-564). The first sample was collected median 2.5 h after end of drinking (range 0.5-23.5). Two patients had levels of EtG and EtS below LOQ in all samples, the first collected 19.25 and 23.5 h after cessation of drinking, respectively. Of the remaining 14 patients, one subject, suffering from both renal and hepatic disease, showed concentrations of EtG and EtS substantially higher than the rest of the material. This patient's initial value of EtG was 17.9 mg/L and of EtS 5.9 mg/L, with terminal elimination half lives of 11.9 h for EtG and 12.5 h for EtS. Among the remaining 13 patients, the initial median values were 0.7 g/L (range 0-3.7) for ethanol, 1.7 mg/L (range 0.1-5.9) for EtG and 0.9 mg/L (range 0.1-1.9) for EtS. Elimination occurred with a median half-life of 3.3 h for EtG (range 2.6-4.3) and 3.6 h for EtS (range 2.7-5.4). In conclusion, elimination of EtG in heavy drinkers did not significantly differ from healthy volunteers, and EtS appeared to have similar elimination rate. In the present work, there was one exception to this, and we propose that this could be explained by the patient's renal disease, which would delay excretion of these conjugated metabolites. PMID:19395207

  3. Conformation-specific spectroscopy of alkyl benzyl radicals: Effects of a radical center on the CH stretch infrared spectrum of an alkyl chain

    NASA Astrophysics Data System (ADS)

    Korn, Joseph A.; Tabor, Daniel P.; Sibert, Edwin L.; Zwier, Timothy S.

    2016-09-01

    An important initial step in the combustion of gasoline and diesel fuels is the abstraction of hydrogen from alkylbenzenes to form resonance-stabilized alkyl benzyl radicals. This work uses, for the first time, double resonance spectroscopy methods to explore the conformation-specific vibronic and infrared spectroscopy of the α-ethylbenzyl (αEtBz) and α-propylbenzyl (αPrBz) radicals. Local mode Hamiltonian modeling enables assignment of the alkyl CH stretch IR spectra, accounting for Fermi resonance that complicates aliphatic alkyl CH stretch IR spectroscopy. The ground state conformational preferences of the ethyl and propyl chains are changed from those in the alkylbenzenes themselves, with global minima occurring for an in-plane orientation of the alkyl chain (trans) about its first dihedral angle (ϕf123, numbers are alkyl C atoms. C1 is CH radical site). This in-plane structure is the only observed conformer for the α-EtBz radical, while two conformers, tt and tg' share this orientation at the first dihedral, but differ in the second (ϕ1234) for the αPrBz radical. The in-plane orientation lowers the local site frequencies of the CH2 group stretches immediately adjacent to the benzylic radical site by about 50 cm-1 relative to those in pure alkyl chains or alkylbenzenes. This effect of the radical site is localized on the first CH2 group, with little effect on subsequent members of the alkyl chain. In the D1 excited electronic state, an out-of-plane orientation is preferred for the alkyl chains, leading to torsional mode Franck-Condon activity in the D0-D1 spectra that is both conformer-specific and diagnostic of the conformational change.

  4. Redox Properties of Free Radicals.

    ERIC Educational Resources Information Center

    Neta, P.

    1981-01-01

    Describes pulse radiolysis as a useful means in studing one-electron redox potentials. This method allows the production of radicals and the determination of their concentration and rates of reaction. (CS)

  5. Ribonucleotide Reductase-- a Radical Enzyme

    NASA Astrophysics Data System (ADS)

    Reichard, Peter; Ehrenberg, Anders

    1983-08-01

    Ribonucleotide reductases catalyze the enzymatic formation of deoxyribonucleotides, an obligatory step in DNA synthesis. The native form of the enzyme from Escherichia coli or from mammalian sources contains as part of its polypeptide structure a free tyrosyl radical, stabilized by an iron center. The radical participates in all probability in the catalytic process during the substitution of the hydroxyl group at C-2 of ribose by a hydrogen atom. A second, inactive form of the E. coli reductase lacks the tyrosyl radical. Extracts from E. coli contain activities that interconvert the two forms. The tyrosyl radical is introduced in the presence of oxygen, while anaerobiosis favors its removal, suggesting a regulatory role in DNA synthesis for oxygen.

  6. Ethyl glucuronide and ethyl sulfate in meconium and hair-potential biomarkers of intrauterine exposure to ethanol.

    PubMed

    Morini, L; Marchei, E; Vagnarelli, F; Garcia Algar, O; Groppi, A; Mastrobattista, L; Pichini, S

    2010-03-20

    This study investigated ethyl glucuronide (EtG) and ethyl sulfate (EtS) concentration in meconium and in maternal and neonatal hair (HEtG and HFAEEs, respectively) as potential markers of intrauterine exposure to ethanol together with meconium fatty acid ethyl esters (FAEEs) in a cohort of 99 mother-infant dyads, 49 coming from the Arcispedale of Reggio Emilia (Italy) and 50 from the Hospital del Mar of Barcelona (Spain). FAEEs, EtG and EtS were measured in meconium samples using liquid chromatography-tandem mass spectrometry. A head space-solid phase microextraction-gas chromatography-mass spectrometry was used to test HEtG and HFAEEs in hair samples from mothers and their newborns. Eighty-two meconium samples (82.8%) tested positive for EtG, 19 (19.2%) for EtS while 22 (22.2%) showed FAEEs levels higher than 2 nmol/g, the cut-off used to differentiate daily maternal ethanol consumption during pregnancy from occasional or no use. Although EtG and EtS in meconium did not correlate with total FAEEs concentration, a good correlation between EtG, EtS and ethyl stearate was observed. Moreover, EtG correlated well with ethyl palmitoleate, while EtS with ethyl laurate, myristate and linolenate. Neither maternal nor neonatal hair appears as good predictors of gestational ethanol consumption and subsequent fetal exposure in these mother-infant dyads. In conclusion, these data show that meconium is so far the best matrix in evaluating intrauterine exposure to ethanol, with EtG and EtS being potentially good alternative biomarkers to FAEEs. PMID:20060246

  7. Antimutagenic and free radical scavenger effects of leaf extracts from Accacia salicina

    PubMed Central

    2011-01-01

    Background Three extracts were prepared from the leaves of Accacia salicina; ethyl acetate (EA), chloroform (Chl) and petroleum ether (PE) extracts and was designed to examine antimutagenic, antioxidant potenty and oxidative DNA damage protecting activity. Methods Antioxidant activity of A. salicina extracts was determined by the ability of each extract to protect against plasmid DNA strand scission induced by hydroxyl radicals. An assay for the ability of these extracts to prevent mutations induced by various oxidants in Salmonella typhimurium TA102 and TA 104 strains was conducted. In addition, nonenzymatic methods were employed to evaluate anti-oxidative effects of tested extracts. Results These extracts from leaf parts of A. salicina showed no mutagenicity either with or without the metabolic enzyme preparation (S9). The highest protections against methylmethanesulfonate induced mutagenicity were observed with all extracts and especially chloroform extract. This extract exhibited the highest inhibitiory level of the Ames response induced by the indirect mutagen 2- aminoanthracene. All extracts exhibited the highest ability to protect plasmid DNA against hydroxyl radicals induced DNA damages. The ethyl acetate (EA) and chloroform (Chl) extracts showed with high TEAC values radical of 0.95 and 0.81 mM respectively, against the ABTS.+. Conclusion The present study revealed the antimutagenic and antioxidant potenty of plant extract from Accacia salicina leaves. PMID:22132863

  8. Antioxidant potential and radical scavenging effects of various extracts from Abutilon indicum and Abutilon muticum.

    PubMed

    Yasmin, Sammia; Kashmiri, Muhammad Akram; Asghar, Muhammad Nadeem; Ahmad, Mushtaq; Mohy-ud-Din, Ayesha

    2010-03-01

    Abutilon indicum L. (Malvaceae) and Abutilon muticum DC. (Malvaceae) are traditional medicinal herbs used for analgesic, anthelmintic, hepatoprotective, and hypoglycemic properties. These effects may be correlated with the presence of antioxidant compounds. Extracts in organic solvents from the aerial parts and roots of both species were prepared and evaluated for their total antioxidant capacity (TAC), total phenolic content, and total flavonoid content. The Trolox equivalent antioxidant capacity (TEAC) of all the extracts of both plants was found, employing ABTS and FRAP assays. TEAC values ranged from 3.019 to 10.5 muM for n-hexane and butanol fractions of Abutilon indicum and from 2.247 to 14.208 muM for n-hexane and butanol fractions of Abutilon muticum, respectively, using the ABTS assay. The FRAP assay showed reducing powers of the fractions in the order of butanol > ethyl acetate > chloroform > n-hexane and butanol > chloroform > hexane > ethyl acetate for Abutilon indicum and Abutilon muticum, respectively. EC(50) and T(EC50) values for the extracts of both plants were determined using the DPPH free radical assay. The reaction kinetics with this free radical indicated the presence of both slow reacting and fast reacting antioxidant components in the extracts of both plants. The antioxidant/radical scavenging capacity of the extracts was found to be a dose-dependent activity. The results obtained in the present study indicate that both Abutilon species are potential sources of natural antioxidants. PMID:20645814

  9. 77 FR 12740 - Trinexapac-ethyl; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-02

    ... plant growth regulator, trinexapac-ethyl and its primary metabolite CGA-179500, in or on grass, forage... Tolerance In the Federal Register of August 4, 2010, (75 FR 46925) (FRL-8834- 9), EPA issued a notice... Order 12866, entitled Regulatory Planning and Review (58 FR 51735, October 4, 1993). Because this...

  10. Higher permeability for water than for ethyl alcohol in Nitella.

    PubMed

    OSTERHOUT, W J V

    1950-03-01

    If we apply water at one end of a Nitella cell, A, and place at the other end, B, a solution of a substance which does not penetrate, such as sucrose, water enters the cell at A, passes along inside the cell, and escapes at B. But if in place of sucrose we use a substance which penetrates such as ethyl alcohol the flow of water is lessened and this fact makes it possible to measure the amount of alcohol which enters. (An increase in the size of cells placed in solutions of alcohol does not necessarily indicate that the number of mols of alcohol entering is greater than the number of mols of water leaving the cell.) The permeability for water is more than 18 times as great as for ethyl alcohol. The behavior of the 2 substances was compared in the same individual cell with a driving force which at the start was the same for both substances. The number of mols entering per second per cm.(2) of surface with a driving force of 1 atmosphere at 25 degrees C. is 0.772 (10(-6)) for water and 0.042 (10(-6)) for ethyl alcohol. The experiments indicate that the non-aqueous substance at the surface of the protoplasm has a higher partition coefficient for water than for ethyl alcohol, although the protoplasmic surface is composed of materials not miscible with water.

  11. 76 FR 31479 - Pyraflufen-ethyl; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... Federal Register of June 23, 2010 (75 FR 35801) (FRL-8831- 3), EPA issued a notice pursuant to section 408...- ethyl. C. Revisions to Petitioned-for Tolerances In the Federal Register of December 8, 2010 (75 FR..., entitled Regulatory Planning and Review (58 FR 51735, ] October 4, 1993). Because this final rule has...

  12. 40 CFR 180.429 - Chlorimuron ethyl; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Chlorimuron ethyl; tolerances for residues. 180.429 Section 180.429 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED..., field, forage 0.5 Corn, field, grain 0.01 Corn, field, stover 2.0 Grain, aspirated fractions 3.0...

  13. Enantioselective Metabolism of Quizalofop-Ethyl in Rat

    PubMed Central

    Liang, Yiran; Wang, Peng; Liu, Donghui; Shen, Zhigang; Liu, Hui; Jia, Zhixin; Zhou, Zhiqiang

    2014-01-01

    The pharmacokinetic and distribution of the enantiomers of quizalofop-ethyl and its metabolite quizalofop-acid were studied in Sprague-Dawley male rats. The two pairs of enantiomers were determined using a validated chiral high-performance liquid chromatography method. Animals were administered quizalofop-ethyl at 10 mg kg−1 orally and intravenously. It was found high concentration of quizalofop-acid in the blood and tissues by both intragastric and intravenous administration, and quizalofop-ethyl could not be detected through the whole study which indicated a quick metabolism of quizalofop-ethyl to quizalofop-acid in vivo. In almost all the samples, the concentrations of (+)-quizalofop-acid exceeded those of (−)-quizalofop-acid. Quizalofop-acid could still be detected in the samples even at 120 h except in brain due to the function of blood-brain barrier. Based on a rough calculation, about 8.77% and 2.16% of quizalofop-acid were excreted through urine and feces after intragastric administration. The oral bioavailability of (+)-quizalofop-acid and (−)-quizalofop-acid were 72.8% and 83.6%. PMID:24964043

  14. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    ERIC Educational Resources Information Center

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

  15. 77 FR 41346 - Trinexapac-ethyl; Proposed Pesticide Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ...-ethyl in or on barley, bran; sugarcane, molasses; and wheat, bran under the Federal Food, Drug, and... affected by this action if you are an agricultural producer, food manufacturer, or pesticide manufacturer... production (NAICS code 112). Food manufacturing (NAICS code 311). Pesticide manufacturing (NAICS code...

  16. Synthesis of Ethyl Nalidixate: A Medicinal Chemistry Experiment

    ERIC Educational Resources Information Center

    Leslie, Ray; Leeb, Elaine; Smith, Robert B.

    2012-01-01

    A series of laboratory experiments that complement a medicinal chemistry lecture course in drug design and development have been developed. The synthesis of ethyl nalidixate covers three separate experimental procedures, all of which can be completed in three, standard three-hour lab classes and incorporate aspects of green chemistry such as…

  17. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... prescribed in paragraph (c)(2) of this section, when tested by the methods prescribed for polyethylene in... identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate... less than 0.920 nor more than 0.935, as determined by ASTM method D1505-68 (Reapproved 1979),...

  18. Crystalline bipyridinium radical complexes and uses thereof

    SciTech Connect

    Fahrenbach, Albert C.; Barnes, Jonathan C.; Li, Hao; Stoddart, J. Fraser; Basuray, Ashish Neil; Sampath, Srinivasan

    2015-09-01

    Described herein are methods of generating 4,4'-bipyridinium radical cations (BIPY.sup..cndot.+), and methods for utilizing the radical-radical interactions between two or more BIPY.sup..cndot.+ radical cations that ensue for the creation of novel materials for applications in nanotechnology. Synthetic methodologies, crystallographic engineering techniques, methods of physical characterization, and end uses are described.

  19. Social Radicalism as a Framework for Education.

    ERIC Educational Resources Information Center

    Nelson, Jack L.

    This paper examines the nature of radicalism, proposes definitions and dimensions, and suggests the dynamics of radical thoughts and their interrelation with schools. A radical idea is one which is highly divergent from the normative values, behaviors, ideals or traditions of a culture at a point in time. This paper views radical ideas as…

  20. Steric Effects in the Reaction of Aryl Radicals on Surfaces

    SciTech Connect

    Combellas, Catherine; Jiang, Deen; Kanoufi, Frederic; Pinson, Jean; Podvorica, Fetah

    2009-01-01

    Steric effects are investigated in the reaction of aryl radicals with surfaces. The electrochemical reduction of 2-, 3-, 4-methyl, 2-methoxy, 2-ethyl, 2,6-, 2,4-, and 3,5-dimethyl, 4-tert-butyl, 3,5-bis-tert-butyl benzenediazonium, 3,5-bis(trifluoromethyl), and pentafluoro benzenediazonium tetrafluoroborates is examined in acetonitrile solutions. It leads to the formation of grafted layers only if the steric hindrance at the 2- or 2,6-position(s) is small. When the 3,5-positions are crowded with tert-butyl groups, the growth of the organic layer is limited by steric effects and a monolayer is formed. The efficiency of the grafting process is assessed by cyclic voltammetry, X-ray photoelectron spectroscopy, infrared, and ellipsometry. These experiments, together with density functional computations of bonding energies of substituted phenyl groups on a copper surface, are discussed in terms of the reactivity of aryl radicals in the electrografting reaction and in the growth of the polyaryl layer.

  1. Synthesis and self-assembly of terpyridine end-capped poly(N-isopropylacrylamide)-block-poly(2-(dimethylamino)ethyl methacrylate) diblock copolymers.

    PubMed

    Brassinne, Jérémy; Poggi, Elio; Fustin, Charles-André; Gohy, Jean-François

    2015-04-01

    At the basis of smart self-assembled materials are lying small building blocks that can hierarchically assemble in response to stimuli, e.g., temperature or chemical species. In this context, the synthesis of terpyridine end-capped poly(2-(dimethylamino)ethyl methacrylate)-block-poly(N-isopropylacrylamide) diblock copolymers via controlled radical copolymerization is reported here. The self-assembly of those copolymers is investigated in dilute aqueous solutions while varying temperature or adding transition metal ions, respectively, leading to the formation of micellar nanostructures or metallosupramolecular triblock copolymers. PMID:25491079

  2. Possible mediators of the ``living'' radical polymerization

    NASA Astrophysics Data System (ADS)

    Motyakin, M. V.; Wasserman, A. M.; Stott, P. E.; Zaikov, G. E.

    2006-03-01

    The stable radicals derived from different compounds were detected in process of styrene autopolymerization. The nitroxide radicals are produced from nitrosocompound, hindered hydroxylamine, nitrophenols and nitroanisoles. The phenoxyl radicals are formed from quinine methides, and naphtoxyl radicals are generated from 2-nitro-1-naphtol. The radicals are identified, the kinetics of their formation and follow-up evolution are studied. These radicals can participate in process of living radical polymerization as the mediators and can effect significantly on kinetics of polymerization and structure of the resulting polymer.

  3. Standard Electrode Potentials Involving Radicals in Aqueous Solution: Inorganic Radicals

    SciTech Connect

    Armstrong, David A.; Huie, Robert E.; Koppenol, Willem H.; Lymar, Sergei V.; Merenyi, Gabor; Neta, Pedatsur; Ruscic, Branko; Stanbury, David M.; Steenken, Steen; Wardman, Peter

    2015-12-01

    Recommendations are made for standard potentials involving select inorganic radicals in aqueous solution at 25 °C. These recommendations are based on a critical and thorough literature review and also by performing derivations from various literature reports. The recommended data are summarized in tables of standard potentials, Gibbs energies of formation, radical pKa’s, and hemicolligation equilibrium constants. In all cases, current best estimates of the uncertainties are provided. An extensive set of Data Sheets is appended that provide original literature references, summarize the experimental results, and describe the decisions and procedures leading to each of the recommendations

  4. Mechanically Stabilized Tetrathiafulvalene Radical Dimers

    SciTech Connect

    Coskun, Ali; Spruell, Jason M.; Barin, Gokhan; Fahrenbach, Albert C.; Forgan, Ross S.; Colvin, Michael T.; Carmieli, Raanan; Benitez, Diego; Tkatchouk, Ekaterina; Friedman, Douglas C.; Sarjeant, Amy A.; Wasielewski, Michael R.; Goddard, William A.; Stoddart, J. Fraser

    2011-01-01

    Two donor-acceptor [3]catenanes—composed of a tetracationic molecular square, cyclobis(paraquat-4,4'-biphenylene), as the π-electron deficient ring and either two tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP) containing macrocycles or two TTF-butadiyne-containing macrocycles as the π-electron rich components—have been investigated in order to study their ability to form TTF radical dimers. It has been proven that the mechanically interlocked nature of the [3]catenanes facilitates the formation of the TTF radical dimers under redox control, allowing an investigation to be performed on these intermolecular interactions in a so-called “molecular flask” under ambient conditions in considerable detail. In addition, it has also been shown that the stability of the TTF radical-cation dimers can be tuned by varying the secondary binding motifs in the [3]catenanes. By replacing the DNP station with a butadiyne group, the distribution of the TTF radical-cation dimer can be changed from 60% to 100%. These findings have been established by several techniques including cyclic voltammetry, spectroelectrochemistry and UV-vis-NIR and EPR spectroscopies, as well as with X-ray diffraction analysis which has provided a range of solid-state crystal structures. The experimental data are also supported by high-level DFT calculations. The results contribute significantly to our fundamental understanding of the interactions within the TTF radical dimers.

  5. Antioxidant and antimicrobial activities of ethyl acetate extract, fractions and compounds from stem bark of Albizia adianthifolia (Mimosoideae)

    PubMed Central

    2012-01-01

    Background Albizia adianthifolia is used traditionally in Cameroon to treat several ailments, including infectious and associated diseases. This work was therefore designed to investigate the antioxidant and antimicrobial activities of ethyl acetate extract, fractions and compounds isolated from the stem bark of this plant. Methods The plant extract was prepared by maceration in ethyl acetate. Its fractionation was done by column chromatography and the structures of isolated compounds were elucidated using spectroscopic data in conjunction with literature data. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and trolox equivalent antioxidant capacity (TEAC) assays were used to detect the antioxidant activity. Broth micro-dilution method was used for antimicrobial test. Total phenol content was determined spectrophotometrically in the extracts by using Folin–Ciocalteu method. Results The fractionation of the extract afforded two known compounds: lupeol (1) and aurantiamide acetate (2) together with two mixtures of fatty acids: oleic acid and n-hexadecanoic acid (B1); n-hexadecanoic acid, octadecanoic acid and docosanoic acid (B2). Aurantiamide acetate was the most active compound. The total phenol concentration expressed as gallic acid equivalents (GAE) was found to vary from 1.50 to 13.49 μg/ml in the extracts. The antioxidant activities were well correlated with the total phenol content (R2 = 0.946 for the TEAC method and R2 = 0.980 for the DPPH free-radical scavenging assay). Conclusions Our results clearly reveal that the ethyl acetate extract from the stem bark of A. adianthifolia possesses antioxidant and antimicrobial principles. The antioxidant activity of this extract as well as that of compound 2 are being reported herein for the first time. These results provide promising baseline information for the potential use of this plant as well as compound 2 in the treatment of oxidative damage and infections associated with the studied microorganisms. PMID

  6. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ethyl silicate, reaction products with... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with...

  7. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethyl silicate, reaction products with... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with...

  8. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ethyl silicate, reaction products with... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with...

  9. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ethyl silicate, reaction products with... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with...

  10. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethyl silicate, reaction products with... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with...

  11. 40 CFR 721.10064 - 2-Propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2- ethyl ester. 721... Substances § 721.10064 2-Propenoic acid, 2- ethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2- ethyl ester (PMN...

  12. 40 CFR 721.10064 - 2-Propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propenoic acid, 2- ethyl ester. 721... Substances § 721.10064 2-Propenoic acid, 2- ethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2- ethyl ester (PMN...

  13. 40 CFR 721.10064 - 2-Propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 2-Propenoic acid, 2- ethyl ester. 721... Substances § 721.10064 2-Propenoic acid, 2- ethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2- ethyl ester (PMN...

  14. 40 CFR 721.10300 - Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-.alpha.-phenyl-, ethyl ester. 721.10300 Section 721.10300 Protection of Environment ENVIRONMENTAL....-phenyl-, ethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester (PMN...

  15. 40 CFR 721.10365 - Butanoic acid, 3-mercapto-2-methyl-, ethyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-, ethyl ester. 721.10365 Section 721.10365 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10365 Butanoic acid, 3-mercapto-2-methyl-, ethyl ester. (a) Chemical... acid, 3-mercapto-2-methyl-, ethyl ester (PMN P-10-56; CAS No. 888021-82-7) is subject to...

  16. 40 CFR 721.10365 - Butanoic acid, 3-mercapto-2-methyl-, ethyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-, ethyl ester. 721.10365 Section 721.10365 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10365 Butanoic acid, 3-mercapto-2-methyl-, ethyl ester. (a) Chemical... acid, 3-mercapto-2-methyl-, ethyl ester (PMN P-10-56; CAS No. 888021-82-7) is subject to...

  17. 40 CFR 721.7290 - Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to...

  18. 40 CFR 721.10300 - Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-.alpha.-phenyl-, ethyl ester. 721.10300 Section 721.10300 Protection of Environment ENVIRONMENTAL....-phenyl-, ethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester (PMN...

  19. 40 CFR 721.7290 - Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to...

  20. 40 CFR 721.7290 - Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to...

  1. 40 CFR 721.10064 - 2-Propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 2-Propenoic acid, 2- ethyl ester. 721... Substances § 721.10064 2-Propenoic acid, 2- ethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2- ethyl ester (PMN...

  2. 40 CFR 721.10365 - Butanoic acid, 3-mercapto-2-methyl-, ethyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-, ethyl ester. 721.10365 Section 721.10365 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10365 Butanoic acid, 3-mercapto-2-methyl-, ethyl ester. (a) Chemical... acid, 3-mercapto-2-methyl-, ethyl ester (PMN P-10-56; CAS No. 888021-82-7) is subject to...

  3. 40 CFR 721.7290 - Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to...

  4. 40 CFR 721.10300 - Benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-.alpha.-phenyl-, ethyl ester. 721.10300 Section 721.10300 Protection of Environment ENVIRONMENTAL....-phenyl-, ethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as benzeneacetic acid, .alpha.-chloro-.alpha.-phenyl-, ethyl ester (PMN...

  5. 40 CFR 721.7290 - Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to...

  6. 40 CFR 721.10064 - 2-Propenoic acid, 2-[2-(ethenyloxy)ethoxy]ethyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 2-Propenoic acid, 2- ethyl ester. 721... Substances § 721.10064 2-Propenoic acid, 2- ethyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2- ethyl ester (PMN...

  7. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  8. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  9. Radical-Mediated Enzymatic Polymerizations.

    PubMed

    Zavada, Scott R; Battsengel, Tsatsral; Scott, Timothy F

    2016-01-01

    Polymerization reactions are commonly effected by exposing monomer formulations to some initiation stimulus such as elevated temperature, light, or a chemical reactant. Increasingly, these polymerization reactions are mediated by enzymes--catalytic proteins--owing to their reaction efficiency under mild conditions as well as their environmental friendliness. The utilization of enzymes, particularly oxidases and peroxidases, for generating radicals via reduction-oxidation mechanisms is especially common for initiating radical-mediated polymerization reactions, including vinyl chain-growth polymerization, atom transfer radical polymerization, thiol-ene step-growth polymerization, and polymerization via oxidative coupling. While enzyme-mediated polymerization is useful for the production of materials intended for subsequent use, it is especially well-suited for in situ polymerizations, where the polymer is formed in the place where it will be utilized. Such polymerizations are especially useful for biomedical adhesives and for sensing applications. PMID:26848652

  10. Radical-Mediated Enzymatic Polymerizations

    PubMed Central

    Zavada, Scott R.; Battsengel, Tsatsral; Scott, Timothy F.

    2016-01-01

    Polymerization reactions are commonly effected by exposing monomer formulations to some initiation stimulus such as elevated temperature, light, or a chemical reactant. Increasingly, these polymerization reactions are mediated by enzymes―catalytic proteins―owing to their reaction efficiency under mild conditions as well as their environmental friendliness. The utilization of enzymes, particularly oxidases and peroxidases, for generating radicals via reduction-oxidation mechanisms is especially common for initiating radical-mediated polymerization reactions, including vinyl chain-growth polymerization, atom transfer radical polymerization, thiol–ene step-growth polymerization, and polymerization via oxidative coupling. While enzyme-mediated polymerization is useful for the production of materials intended for subsequent use, it is especially well-suited for in situ polymerizations, where the polymer is formed in the place where it will be utilized. Such polymerizations are especially useful for biomedical adhesives and for sensing applications. PMID:26848652

  11. Epistemological barriers to radical behaviorism

    PubMed Central

    O'Donohue, William T.; Callaghan, Glenn M.; Ruckstuhl, L. E.

    1998-01-01

    The historian and philosopher of science Gaston Bachelard proposed the concept of epistemological barriers to describe the intellectual challenges encountered by scientists in their work. In order to embrace novel ways of approaching a problem in science, scientists must overcome barriers or obstacles posed by their prior views. For example, Einsteinian physics presents scientists with claims that space is curved and that time and space are on the same continuum. We utilize Bachelard's concept of epistemological barriers to describe the differences between the intellectual journeys students pursuing advanced studies face when attempting to accept cognitive psychology or radical behaviorism. We contend that the folk psychological beliefs that students typically hold when entering these studies pose less challenge to cognitive psychology than to radical behaviorism. We also suggest that these barriers may also partly be involved in the problematic exegesis that has plagued radical behaviorism. In close, we offer some suggestions for dealing with these epistemological barriers. PMID:22478314

  12. Free radical scavenging activities measured by electron spin resonance spectroscopy and B16 cell antiproliferative behaviors of seven plants.

    PubMed

    Calliste, C A; Trouillas, P; Allais, D P; Simon, A; Duroux, J L

    2001-07-01

    In an effort to discover new antioxidant natural compounds, seven plants that grow in France (most of them in the Limousin countryside) were screened. Among these plants, was the extensively studied Vitis vinifera as reference. For each plant, sequential percolation was realized with five solvents of increasing polarities (hexane, chloroform, ethyl acetate, methanol, and water). Free radical scavenging activities were examined in different systems using electron spin resonance (ESR) spectroscopy. These assays were based on the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH), the hydroxyl radicals generated by a Fenton reaction, and the superoxide radicals generated by the X/XO system. Antiproliferative behavior was studied on B16 melanoma cells. ESR results showed that three plants (Castanea sativa, Filipendula ulmaria, and Betula pendula) possessed, for the most polar fractions (presence of phenolic compounds), high antioxidant activities in comparison with the Vitis vinifera reference. Gentiana lutea was the only one that presented a hydroxyl scavenging activity for the ethyl acetate and chloroform fractions. The antiproliferative test results showed that the same three plants are the most effective, but for the apolar fractions (chloroform and hexane).

  13. Microstructure determination of 2-hydroxy ethyl methacrylate and methyl acrylate copolymers by NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Brar, A. S.; Hooda, Sunita; Goyal, Ashok Kumar

    2007-02-01

    Copolymers of 2-Hydroxy ethyl methacrylate and methyl acrylate (H/M) of different compositions were synthesized by free radical bulk polymerization using azobisisobutyronitrile (AIBN) as an initiator under nitrogen atmosphere. The copolymers compositions were calculated from 1H NMR spectra. The reactivity ratios for H/M copolymers obtained from a linear Kelen-Tudos method (KT) and nonlinear error-in-variables method (EVM) are rH = 3.31 ± 0.08, rM = 0.23 ± 0.00 and rH = 3.32, rM = 0.23, respectively. The complete spectral assignment of methine, methylene, methyl and carbonyl carbon regions in terms of compositional and configurational sequences of H/M copolymers was done with the help of 13C{ 1H} NMR, distortionless enhancement by polarization transfer (DEPT), two-dimensional heteronuclear single quantum coherence (HSQC) along with total correlated spectroscopy (TOCSY). Further, the assignments of carbonyl region were made with the help of heteronuclear multiple bond coherence (HMBC) spectrum.

  14. UV spectroscopic characterization of dimethyl- and ethyl-substituted carbonyl oxides.

    PubMed

    Liu, Fang; Beames, Joseph M; Green, Amy M; Lester, Marsha I

    2014-03-27

    Dimethyl- and ethyl-substituted Criegee intermediates, (CH3)2COO and CH3CH2CHOO, are photolytically generated from diiodo precursors, detected by VUV photoionization at 118 nm, and spectroscopically characterized via UV-induced depletion of the m/z = 74 signals under jet-cooled conditions. In each case, UV excitation resonant with the B-X transition results in significant ground-state depletion, reflecting the large absorption cross section and rapid dynamics in the excited B state. The broad UV absorption spectra of both (CH3)2COO and CH3CH2CHOO peak at ~320 nm with absorption cross sections approaching ~4 × 10(-17) cm(2) molec(-1). The UV absorption spectra for (CH3)2COO and CH3CH2CHOO are similar to that reported previously for syn-CH3CHOO, suggesting analogous intramolecular interactions between the α-H and terminal O of the COO groups. Hydroxyl radical products generated concurrently with the Criegee intermediates are detected by 1 + 1' resonance enhanced multiphoton ionization. The OH signals, scaled relative to those for the Criegee intermediates, are compared with prior studies of OH yield from alkene ozonolysis. The stationary points along the reaction coordinates from the alkyl-substituted Criegee intermediates to vinyl hydroperoxides and OH products are also computed to provide insight on the OH yields.

  15. Ethyl ferulate, a component with anti-inflammatory properties for emulsion-based creams.

    PubMed

    Nazaré, Ana C; de Faria, Carolina M Q G; Chiari, Bruna G; Petrônio, Maicon S; Regasini, Luis O; Silva, Dulce H S; Corrêa, Marcos A; Isaac, Vera L B; da Fonseca, Luiz M; Ximenes, Valdecir F

    2014-06-17

    Ethyl ferulate (FAEE) has been widely studied due to its beneficial heath properties and, when incorporated in creams, shows a high sun protection capacity. Here we aimed to compare FAEE and its precursor, ferulic acid (FA), as free radical scavengers, inhibitors of oxidants produced by leukocytes and the alterations in rheological properties when incorporated in emulsion based creams. The cell-free antiradical capacity of FAEE was decreased compared to FA. However, FAEE was more effective regarding the scavenging of reactive oxygen species produced by activated leukocytes. Stress and frequency sweep tests showed that the formulations are more elastic than viscous. The viscoelastic features of the formulations were confirmed in the creep and recovery assay and showed that the FAEE formulation was less susceptive to deformation. Liberation experiments showed that the rate of FAEE release from the emulsion was slower compared to FA. In conclusion, FAEE is more effective than FA as a potential inhibitor of oxidative damage produced by oxidants generated by leukocytes. The rheological alterations caused by the addition of FAEE are indicative of lower spreadability, which could be useful for formulations used in restricted areas of the skin.

  16. A boron-boron coupling reaction between two ethyl cation analogues

    NASA Astrophysics Data System (ADS)

    Litters, Sebastian; Kaifer, Elisabeth; Enders, Markus; Himmel, Hans-Jörg

    2013-12-01

    The design of larger architectures from smaller molecular building blocks by element-element coupling reactions is one of the key concerns of synthetic chemistry, so a number of strategies were developed for this bottom-up approach. A general scheme is the coupling of two elements with opposing polarity or that of two radicals. Here, we show that a B-B coupling reaction is possible between two boron analogues of the ethyl cation, resulting in the formation of an unprecedented dicationic tetraborane. The bonding properties in the rhomboid B4 core of the product can be described as two B-B units connected by three-centre, two-electron bonds, sharing the short diagonal. Our discovery might lead the way to the long sought-after boron chain polymers with a structure similar to the silicon chains in β-SiB3. Moreover, the reaction is a prime textbook example of the influence of multiple-centre bonding on reactivity.

  17. Dual responsive pickering emulsion stabilized by poly[2-(dimethylamino)ethyl methacrylate] grafted cellulose nanocrystals.

    PubMed

    Tang, Juntao; Lee, Micky Fu Xiang; Zhang, Wei; Zhao, Boxin; Berry, Richard M; Tam, Kam C

    2014-08-11

    A weak polyelectrolyte, poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA), was grafted onto the surface of cellulose nanocrystals via free radical polymerization. The resultant suspension of PDMAEMA-grafted-cellulose nanocrystals (PDMAEMA-g-CNC) possessed pH-responsive properties. The grafting was confirmed by FTIR, potentiometric titration, elementary analysis, and thermogravimetric analysis (TGA); the surface and interfacial properties of the modified particles were characterized by surface tensiometer. Compared to pristine cellulose nanocrystals, modified CNC significantly reduced the surface and interfacial tensions. Stable heptane-in-water and toluene-in-water emulsions were prepared with PDMAEMA-g-CNC. Various factors, such as polarity of solvents, concentration of particles, electrolytes, and pH, on the properties of the emulsions were investigated. Using Nile Red as a florescence probe, the stability of the emulsions as a function of pH and temperature was elucidated. It was deduced that PDMAEMA chains promoted the stability of emulsion droplets and their chain conformation varied with pH and temperature to trigger the emulsification and demulsification of oil droplets. Interestingly, for heptane system, the macroscopic colors varied depending on the pH condition, while the color of the toluene system remained the same. Reversible emulsion systems that responded to pH were observed and a thermoresponsive Pickering emulsion system was demonstrated. PMID:24983405

  18. Vaginal radical trachelectomy: an update.

    PubMed

    Plante, Marie

    2008-11-01

    The vaginal radical trachelectomy has emerged as a valuable fertility-preserving treatment option for young women with early-stage disease. Cancer-related infertility is associated with feelings of depression, grief, stress, and sexual dysfunction. Data have shown that the overall oncological outcome is safe and that the obstetrical outcome is promising. In this article, we analyze the data on the vaginal radical trachelectomy published over the last 10 years in the context of what we have learned, what issues remain unclear, and what the future holds.

  19. Donor free radical explosive composition

    DOEpatents

    Walker, Franklin E. [15 Way Points Rd., Danville, CA 94526; Wasley, Richard J. [4290 Colgate Way, Livermore, CA 94550

    1980-04-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a donor additive comprising an organic compound or mixture of organic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and which is not an explosive, or an inorganic compound or mixture of inorganic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and selected from ammonium or alkali metal persulfates.

  20. [A study on the mechanism of reductive alkylation for preparing 3-(beta-hydroxy-ethyl-sulfonyl) N-ethyl aniline with HPLC/MS].

    PubMed

    Zhang, R; Wu, Z W; Lin, L S; Yang, H Y

    2000-11-01

    Hydrogenating 3-(beta-hydroxy-ethyl-sulfonyl)-aniline and acetaldehyde in the presence of Raney Nickel as a catalyst, 3-(beta-hydroxy-ethyl-sulfonyl)-N-ethyl-aniline was obtained with 98% conversion and 95% monoalkylation selectivity under optimum conditions. By using high performance liquid chromatography/mass selective detection technique to characterize the structures of the products, the mechanism of reductive alkylation is proposed. From the intermediates determined, it is shown that the reaction mechanism would go via an unstable N-alpha-hydroxyethylaniline derivative and Schiff base stage. After hydrogenation of Schiff base, finally the product 3-(beta-hydroxyethyl-sulfonyl)-N-ethyl aniline was formed.

  1. Elevated plasma creatinine due to creatine ethyl ester use.

    PubMed

    Velema, M S; de Ronde, W

    2011-02-01

    Creatine is a nutritional supplement widely used in sport, physical fitness training and bodybuilding. It is claimed to enhance performance. We describe a case in which serum creatinine is elevated due to the use of creatine ethyl esther. One week after withdrawal, the plasma creatinine had normalised. There are two types of creatine products available: creatine ethyl esther (CEE) and creatine monohydrate (CM). Plasma creatinine is not elevated in all creatine-using subjects. CEE , but not CM, is converted into creatinine in the gastrointestinal tract. As a result the use of CEE may be associated with elevated plasma creatinine levels. Since plasma creatinine is a widely used marker for renal function, the use of CEE may lead to a false assumption of renal failure.

  2. Effect of ethyl oleate on drying characteristics of mulberries.

    PubMed

    Doymaz, Ibrahim; Pala, Mehmet

    2003-10-01

    In this study, air-drying experiments in thin layers of mulberry grown in Istanbul, Turkey, were conducted. The effect of ethyl oleate solution on drying time of mulberry samples was investigated in a pilot air-dryer. When ethyl oleate was used as pretreatment solution, the drying time of samples was decreased. Drying curves were obtained using the Page model. The effective diffusivity varied from 2.326 x 10(-10) to 1.809 x 10(-9) m2/s the temperature range. The temperature dependence of the diffusivity coefficient was described by the Arrhenius type relationship. The activation energy for moisture diffusion was found to be 50.87 kJ/mol for treated samples and 51.85 kJ/mol for untreated samples. PMID:14609084

  3. [Influence of ethyl alcohol on diabetes pathogenesis type].

    PubMed

    Zasimowicz, Elzbieta; Wolszczak, Blanka; Zasimowicz, Barbara

    2014-03-01

    Relations between metabolism of carbohydrates and ethyl alcohol consumption became a subject of many research because they occur very frequently amongst alcoholics. One of the most often and dangerous effects of abusing ethanol is hypoglycemia. It is caused by hepatic gluconeogenesis disturbed by ethyl alcohol. Chronic result of abusing alcohol is chronic pancreas inflammation (PZT), what causes disorders of exo- and endocrine function of pancreas. Endocrine function is secretion of insulin and the glucagon what regulates metabolism of absorbed compounds. Failure of beta cells of Langerhans islets causes diabetes demanding insulin therapy. The ethanol can cause recurring diabetes resulting from damage of cells of Langerhans islets but can be also the risk factor of diabetes type 2.

  4. Structural analysis of 1-ethyl-3-methylimidazolium bifluoride melt

    NASA Astrophysics Data System (ADS)

    Matsumoto, Kazuhiko; Hagiwara, Rika; Ito, Yasuhiko; Kohara, Shinji; Suzuya, Kentaro

    2003-01-01

    The structure of 1-ethyl-3-methylimidazolium bifluoride (EMImF · HF) melt has been analyzed at 333 K by a high-energy synchrotron X-ray diffraction method. The total correlation function of the EMImF · HF melt was similar to that of the solid state, indicating that not only the short range but also the intermediate-range ordering in the solid are partially preserved in the liquid state. The intra-molecular F-F correlation in the anions clearly appears in the total correlation function of the EMImF · HF melt, whereas prominent peaks are not observed in the case of a room temperature molten salt, 1-ethyl-3-methylimidazolium fluorohydrogenate.

  5. Fragrance material review on 2-ethyl-1-butanol.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2010-07-01

    A toxicologic and dermatologic review of 2-ethyl-1-butanol when used as a fragrance ingredient is presented. 2-Ethyl-1-butanol is a member of the fragrance structural group branched chain saturated alcohols. The common characteristic structural elements of the alcohols with saturated branched chain are one hydroxyl group per molecule, and a C(4)-C(12) carbon chain with one or several methyl side chains. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. A safety assessment of the entire branched chain saturated alcohol group will be published simultaneously with this document; please refer to Belsito et al. (2010) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances.

  6. Fragrance material review on 2-ethyl-1-hexanol.

    PubMed

    McGinty, D; Scognamiglio, J; Letizia, C S; Api, A M

    2010-07-01

    A summary of the safety data available for 2-ethyl-1-hexanol when used as a fragrance ingredient is presented. 2-Ethyl-1-hexanol is a member of the fragrance structural group branched chain saturated alcohols in which the common characteristic structural element is one hydroxyl group per molecule, and a C(4) to C(12) carbon chain with one or several methyl side chains. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. A safety assessment of the entire branched chain saturated alcohol group will be published simultaneously with this document; please refer to Belsito et al. (2010) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances.

  7. Identification of an antioxidant, ethyl protocatechuate, in peanut seed testa.

    PubMed

    Huang, Shiow Chyn; Yen, Gow-Chin; Chang, Lee-Wen; Yen, Wen-Jye; Duh, Pin-Der

    2003-04-01

    The antioxidant activity and identification of the antioxidant component of peanut seed testa were investigated. The antioxidant activity of peanut seed testa was studied in the linoleic acid model system by using the ferric thiocyanate method. Among the five organic solvent extracts, the ethanolic extracts of peanut seed testa (EEPST) produced higher yields and stronger antioxidant activity than other organic solvent extracts. EEPST was separated into 17 fractions on silica gel column chromatography. Fraction 17, which showed the largest yield and significant antioxidant activity, was separated by thin-layer chromatography. Four major antioxidative subfractions were present. Subfraction 17-2 was found to be effective in preventing oxidation of linoleic acid. This subfraction was further fractionated and isolated and characterized by UV, MS, IR, and (1)H NMR techniques. The active compound was identified as ethyl protocatechuate (3,4-dihydroxybenzoic acid ethyl ester).

  8. Preparation of ethyl magnesium bromide for regiospecific analysis of triacylglycerols.

    PubMed

    Ando, Yasuhiro; Tomita, Yuki; Haba, Yusuke

    2008-01-01

    This paper presents a procedure for preparation of a Grignard reagent, ethyl magnesium bromide, used for partial deacylation of triacylglycerols (TAG) in their regiospecific analysis. Magnesium turnings were reacted with ethereal solution of bromoethane in a screw-capped test tube to synthesize 2 mL of 1 M ethyl magnesium bromide. Continuously stirred with a vortex mixer, the reaction smoothly proceeded at room temperature. Regiospecific analysis of 1,3-distearoyl-2-oleoylglycerol using this product showed that fatty acid compositions of the sn-1(3) and sn-2 positions were contaminated by less than 2 mol% of fatty acids migrated from isomeric positions. The analyses of lard and cod liver/mackerel oil TAG showed typical distribution patterns of 16:0, 22:5n-3 and 22:6n-3 in pig and fish depot TAG. These results confirmed the view that the freshly prepared reagent is usable for regiospecific analysis of TAG.

  9. Fragrance material review on 2-ethyl-1-hexanol.

    PubMed

    McGinty, D; Scognamiglio, J; Letizia, C S; Api, A M

    2010-07-01

    A summary of the safety data available for 2-ethyl-1-hexanol when used as a fragrance ingredient is presented. 2-Ethyl-1-hexanol is a member of the fragrance structural group branched chain saturated alcohols in which the common characteristic structural element is one hydroxyl group per molecule, and a C(4) to C(12) carbon chain with one or several methyl side chains. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. A safety assessment of the entire branched chain saturated alcohol group will be published simultaneously with this document; please refer to Belsito et al. (2010) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances. PMID:20659633

  10. Fragrance material review on 2-ethyl-1-butanol.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2010-07-01

    A toxicologic and dermatologic review of 2-ethyl-1-butanol when used as a fragrance ingredient is presented. 2-Ethyl-1-butanol is a member of the fragrance structural group branched chain saturated alcohols. The common characteristic structural elements of the alcohols with saturated branched chain are one hydroxyl group per molecule, and a C(4)-C(12) carbon chain with one or several methyl side chains. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. A safety assessment of the entire branched chain saturated alcohol group will be published simultaneously with this document; please refer to Belsito et al. (2010) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances. PMID:20659644

  11. Fatty acid ethyl esters: current facts and speculations.

    PubMed

    Laposata, M

    1999-01-01

    Increasing evidence indicates that fatty acid ethyl esters (FAEE) play a role in ethanol-induced organ damage and may serve as long-term markers of ethanol intake. This report summarizes the current knowledge on the toxicity of FAEE, the enzymes associated with FAEE synthesis, FAEE as fatty acid supplements, the in vivo degradation of orally ingested FAEE and FAEE as markers of ethanol intake. A list of major unanswered questions in each of these categories is also included.

  12. [Detection and application of ethyl glucuronide in forensic toxicology].

    PubMed

    Zhao, Hui; Zhuo, Xian-yi; Shen, Bao-hua

    2009-02-01

    Ethyl glucuronide is a specific metabolite of ethanol. There have been plenty of articles referring its pharmacokinetics, detection and application as a specific bio-marker of alcohol intake. This article reviews various analytical methods of EtG, relationship between EtG quantification and ethanol intake, and criteria for determining chronic alcohol abuse, and origin of ethanol found in the cadavers by EtG analysis. EtG has its potential application in forensic toxicology. PMID:19397218

  13. The interaction of ethyl alcohol and industrial chemicals.

    PubMed

    Hills, B W; Venable, H L

    1982-01-01

    A serious, relatively unrecognized, occupational health problem involves the interaction of ethyl alcohol and chemical agents used in industry. Workers who drink alcohol and are exposed to certain chemical agents may experience adverse health effects such as nausea, dizziness, headache, and liver damage. This report reviews the synergistic interactions of ethanol with compounds such as the thiurams, amides, oximes, halogenated hydrocarbons, and metals. Also discussed is the effect of ethanol as a cofactor with vinyl chloride in the etiology of cancer.

  14. Fragrance material review on ethyl phenyl carbinyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of ethyl phenyl carbinyl acetate when used as a fragrance ingredient is presented. Ethyl phenyl carbinyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for ethyl phenyl carbinyl acetate were evaluated, then summarized, and includes: physical properties; acute toxicity; skin irritation; and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22433983

  15. Sensory reception of the primer pheromone ethyl oleate

    NASA Astrophysics Data System (ADS)

    Muenz, Thomas S.; Maisonnasse, Alban; Plettner, Erika; Le Conte, Yves; Rössler, Wolfgang

    2012-05-01

    Social work force distribution in honeybee colonies critically depends on subtle adjustments of an age-related polyethism. Pheromones play a crucial role in adjusting physiological and behavioral maturation of nurse bees to foragers. In addition to primer effects of brood pheromone and queen mandibular pheromone—both were shown to influence onset of foraging—direct worker-worker interactions influence adult behavioral maturation. These interactions were narrowed down to the primer pheromone ethyl oleate, which is present at high concentrations in foragers, almost absent in young bees and was shown to delay the onset of foraging. Based on chemical analyses, physiological recordings from the antenna (electroantennograms) and the antennal lobe (calcium imaging), and behavioral assays (associative conditioning of the proboscis extension response), we present evidence that ethyl oleate is most abundant on the cuticle, received by olfactory receptors on the antenna, processed in glomeruli of the antennal lobe, and learned in olfactory centers of the brain. The results are highly suggestive that the primer pheromone ethyl oleate is transmitted and perceived between individuals via olfaction at close range.

  16. Physiologically based pharmacokinetic modeling of ethyl acetate and ethanol in rodents and humans.

    PubMed

    Crowell, S R; Smith, J N; Creim, J A; Faber, W; Teeguarden, J G

    2015-10-01

    A physiologically based pharmacokinetic (PBPK) model was developed and applied to a metabolic series approach for the ethyl series (i.e., ethyl acetate, ethanol, acetaldehyde, and acetate). This approach bases toxicity information on dosimetry analyses for metabolically linked compounds using pharmacokinetic data for each compound and toxicity data for parent or individual compounds. In vivo pharmacokinetic studies of ethyl acetate and ethanol were conducted in rats following IV and inhalation exposure. Regardless of route, ethyl acetate was rapidly converted to ethanol. Blood concentrations of ethyl acetate and ethanol following both IV bolus and infusion suggested linear kinetics across blood concentrations from 0.1 to 10 mM ethyl acetate and 0.01-0.8 mM ethanol. Metabolic parameters were optimized and evaluated based on available pharmacokinetic data. The respiratory bioavailability of ethyl acetate and ethanol were estimated from closed chamber inhalation studies and measured ventilation rates. The resulting ethyl series model successfully reproduces blood ethyl acetate and ethanol kinetics following IV administration and inhalation exposure in rats, and blood ethanol kinetics following inhalation exposure to ethanol in humans. The extrapolated human model was used to derive human equivalent concentrations for the occupational setting of 257-2120 ppm ethyl acetate and 72-517 ppm ethyl acetate for continuous exposure, corresponding to rat LOAELs of 350 and 1500 ppm.

  17. Physiologically based pharmacokinetic modeling of ethyl acetate and ethanol in rodents and humans.

    PubMed

    Crowell, S R; Smith, J N; Creim, J A; Faber, W; Teeguarden, J G

    2015-10-01

    A physiologically based pharmacokinetic (PBPK) model was developed and applied to a metabolic series approach for the ethyl series (i.e., ethyl acetate, ethanol, acetaldehyde, and acetate). This approach bases toxicity information on dosimetry analyses for metabolically linked compounds using pharmacokinetic data for each compound and toxicity data for parent or individual compounds. In vivo pharmacokinetic studies of ethyl acetate and ethanol were conducted in rats following IV and inhalation exposure. Regardless of route, ethyl acetate was rapidly converted to ethanol. Blood concentrations of ethyl acetate and ethanol following both IV bolus and infusion suggested linear kinetics across blood concentrations from 0.1 to 10 mM ethyl acetate and 0.01-0.8 mM ethanol. Metabolic parameters were optimized and evaluated based on available pharmacokinetic data. The respiratory bioavailability of ethyl acetate and ethanol were estimated from closed chamber inhalation studies and measured ventilation rates. The resulting ethyl series model successfully reproduces blood ethyl acetate and ethanol kinetics following IV administration and inhalation exposure in rats, and blood ethanol kinetics following inhalation exposure to ethanol in humans. The extrapolated human model was used to derive human equivalent concentrations for the occupational setting of 257-2120 ppm ethyl acetate and 72-517 ppm ethyl acetate for continuous exposure, corresponding to rat LOAELs of 350 and 1500 ppm. PMID:26297692

  18. Students' Ideas and Radical Constructivism

    ERIC Educational Resources Information Center

    Sánchez Gómez, Pedro J.

    2016-01-01

    In this article, I study, from the point of view of the analytic philosophy of mind, the compatibility of students' ideas studies (SIS) with radical constructivism (RC). I demonstrate that RC is based on a psychology of "narrow mental states"; that is, the idea that the mental content of an individual can be fully characterised without…

  19. Free radicals, antioxidants, and nutrition.

    PubMed

    Fang, Yun-Zhong; Yang, Sheng; Wu, Guoyao

    2002-10-01

    Radiation hazards in outer space present an enormous challenge for the biological safety of astronauts. A deleterious effect of radiation is the production of reactive oxygen species, which result in damage to biomolecules (e.g., lipid, protein, amino acids, and DNA). Understanding free radical biology is necessary for designing an optimal nutritional countermeasure against space radiation-induced cytotoxicity. Free radicals (e.g., superoxide, nitric oxide, and hydroxyl radicals) and other reactive species (e.g., hydrogen peroxide, peroxynitrite, and hypochlorous acid) are produced in the body, primarily as a result of aerobic metabolism. Antioxidants (e.g., glutathione, arginine, citrulline, taurine, creatine, selenium, zinc, vitamin E, vitamin C, vitamin A, and tea polyphenols) and antioxidant enzymes (e.g., superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidases) exert synergistic actions in scavenging free radicals. There has been growing evidence over the past three decades showing that malnutrition (e.g., dietary deficiencies of protein, selenium, and zinc) or excess of certain nutrients (e.g., iron and vitamin C) gives rise to the oxidation of biomolecules and cell injury. A large body of the literature supports the notion that dietary antioxidants are useful radioprotectors and play an important role in preventing many human diseases (e.g., cancer, atherosclerosis, stroke, rheumatoid arthritis, neurodegeneration, and diabetes). The knowledge of enzymatic and non-enzymatic oxidative defense mechanisms will serve as a guiding principle for establishing the most effective nutrition support to ensure the biological safety of manned space missions. PMID:12361782

  20. The Other Women: Radicalizing Feminism.

    ERIC Educational Resources Information Center

    Puigvert, Lidia; Darder, Antonia; Merrill, Barbara; de los Reyes, Eileen; Stromquist, Nelly

    A recent international symposium on radicalizing feminism explored ways of developing a dialogic feminism that emphasizes working in different settings under the common goal of including women who have been invisible in the dominant feminist literature by furthering theories and practices based on the principles of dialogic feminism. The seminar…

  1. Impact of Association Colloids on Lipid Oxidation in Triacylglycerols and Fatty Acid Ethyl Esters.

    PubMed

    Homma, Rika; Suzuki, Karin; Cui, Leqi; McClements, David Julian; Decker, Eric A

    2015-11-25

    The impact of association colloids on lipid oxidation in triacylglycerols and fatty acid ethyl esters was investigated. Association colloids did not affect lipid oxidation of high oleic safflower and high linoleic safflower triacylglycerols, but were prooxidative in fish triacylglycerols. Association colloids retarded aldehyde formation in stripped ethyl oleate, linoleate, and fish oil ethyl esters. Interfacial tension revealed that lipid hydroperoxides were surface active in the presence of the surfactants found in association colloids. The lipid hydroperoxides from ethyl esters were less surface active than triacylglycerol hydroperoxides. Stripping decreased iron and copper concentrations in all oils, but more so in fatty acid ethyl esters. The combination of lower hydroperoxide surface activity and low metal concentrations could explain why association colloids inhibited lipid oxidation in fatty acid ethyl esters. This research suggests that association colloids could be used as an antioxidant technology in fatty acid ethyl esters.

  2. Impact of Association Colloids on Lipid Oxidation in Triacylglycerols and Fatty Acid Ethyl Esters.

    PubMed

    Homma, Rika; Suzuki, Karin; Cui, Leqi; McClements, David Julian; Decker, Eric A

    2015-11-25

    The impact of association colloids on lipid oxidation in triacylglycerols and fatty acid ethyl esters was investigated. Association colloids did not affect lipid oxidation of high oleic safflower and high linoleic safflower triacylglycerols, but were prooxidative in fish triacylglycerols. Association colloids retarded aldehyde formation in stripped ethyl oleate, linoleate, and fish oil ethyl esters. Interfacial tension revealed that lipid hydroperoxides were surface active in the presence of the surfactants found in association colloids. The lipid hydroperoxides from ethyl esters were less surface active than triacylglycerol hydroperoxides. Stripping decreased iron and copper concentrations in all oils, but more so in fatty acid ethyl esters. The combination of lower hydroperoxide surface activity and low metal concentrations could explain why association colloids inhibited lipid oxidation in fatty acid ethyl esters. This research suggests that association colloids could be used as an antioxidant technology in fatty acid ethyl esters. PMID:26506263

  3. 1,1-Diphenyl-2-picrylhydrazyl radical-scavenging active compounds from greater cardamom (Amomum subulatum Roxb.).

    PubMed

    Kikuzaki, H; Kawai, Y; Nakatani, N

    2001-04-01

    Constituents of the fruits of greater cardamom (Amomum subulatum) were fractionated into three fractions, the dichloromethane extract, and the ethyl acetate-soluble and water-soluble fractions of the 70% aqueous acetone extract. The ethyl acetate-soluble fraction showed a high radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH). Four compounds were isolated from the ethyl acetate-soluble fraction, and their structures were ascribed to protocatechualdehyde (1), protocatechuic acid (2), 1,7-bis(3,4-dihydroxyphenyl)hepta-4E,6E-dien-3-one (3) and 2,3,7-trihydroxy-5-(3,4-dihydroxy-E-styryl)-6,7,8,9-tetrahydro-5H-benzocycloheptene (4) on the basis of spectroscopic evidence. This is the first isolation of these compounds from greater cardamom. In particular, 4 was a new type of cyclic diarylheptanoid. DPPH radical-scavenging activity of these compounds was measured by colorimetric analysis. Compounds 1 and 3 showed stronger activity than such natural antioxidants as alpha-tocopherol and L-ascorbic acid. Compounds 2 and 4 were comparable to alpha-tocopherol and L-ascorbic acid.

  4. Arene-thioether mixed complex radical cations

    SciTech Connect

    Werst, D.W.

    1994-03-01

    Studies of radiolytically generated radical cations in aromatic hydrocarbon solvents have led to the first direct characterization of monomeric thioether radical cations in liquid solution. Observation of these very reactive chemical intermediates is made possible by the great sensitivity of fluorescence-detected magnetic resonance (FDMR) and by solvent stabilization of the thioether radical cations via electron donation. Monomeric thioether radical cations in arene solvents such as toluene exist as arene-thioether mixed complex radical cations -- the first {pi}-lone pair mixed complex radical cations ever observed. Such orbital interactions are of fundamental importance for open-shell intermediates as they have consequences for both electronic structure and reactivity. Thioether radical cations provide a valuable test system to probe the chemical influence of orbital interactions that are generic to all {pi}-type and heteroatom-containing organic radical cations, and magnetic resonance provides unsurpassed structural resolution for condensed-phase paramagnetic intermediates.

  5. Radical Reactions of Alkyl 2-Bromo-2,2-difluoroacetates with Vinyl Ethers: "Omitted" Examples and Application for the Synthesis of 3,3-Difluoro-GABA.

    PubMed

    Kondratov, Ivan S; Bugera, Maksym Ya; Tolmachova, Nataliya A; Posternak, Ganna G; Daniliuc, Constantin G; Haufe, Günter

    2015-12-18

    Addition reactions of perfluoroalkyl radicals to ordinary or polyfluorinated alkenes have been frequently used to synthesize perfluoroalkylated organic compounds. Here ethyl/methyl 2-bromo-2,2-difluoroacetate, diethyl (bromodifluoromethyl)phosphonate, [(bromodifluoromethyl)sulfonyl]benzene, and ethyl 2-bromo-2-fluoroacetate were involved in Na2S2O4-mediated radical additions to vinyl ethers in the presence of alcohols to give difluoro or monofluoroacetyl-substituted acetals or corresponding difluoromethylphosphonate- and (difluoromethylphenyl)sulfonyl-substituted alkyl acetals. This methodology has also been applied as a key step in the synthesis of hitherto unknown 3,3-difluoro-GABA, completing the series of isomeric difluoro GABAs. Comparison of the pKa values of 3-fluoro- and 3,3-difluoro-GABA with that of the fluorine free parent compound showed that introduction of each fluorine lead to acidification of both the amino and the carboxyl functions by approximately one unit.

  6. Protective effect of the ethyl acetate fraction of Sargassum muticum against ultraviolet B-irradiated damage in human keratinocytes.

    PubMed

    Piao, Mei Jing; Yoon, Weon Jong; Kang, Hee Kyoung; Yoo, Eun Sook; Koh, Young Sang; Kim, Dong Sam; Lee, Nam Ho; Hyun, Jin Won

    2011-01-01

    The aim of this study was to investigate the cytoprotective properties of the ethyl acetate fraction of Sargassum muticum (SME) against ultraviolet B (UVB)-induced cell damage in human keratinocytes (HaCaT cells). SME exhibited scavenging activity toward the 1,1-diphenyl-2-picrylhydrazyl radicals and hydrogen peroxide (H(2)O(2)) and UVB-induced intracellular reactive oxygen species (ROS). SME also scavenged the hydroxyl radicals generated by the Fenton reaction (FeSO(4) + H(2)O(2)), which was detected using electron spin resonance spectrometry. In addition, SME decreased the level of lipid peroxidation that was increased by UVB radiation, and restored the level of protein expression and the activities of antioxidant enzymes that were decreased by UVB radiation. Furthermore, SME reduced UVB-induced apoptosis as shown by decreased DNA fragmentation and numbers of apoptotic bodies. These results suggest that SME protects human keratinocytes against UVB-induced oxidative stress by enhancing antioxidant activity in cells, thereby inhibiting apoptosis. PMID:22174656

  7. Gas chromatography-mass spectrometry of ethyl palmitate calibration and resolution with ethyl oleate as biomarker ethanol sub acute in urine application study

    NASA Astrophysics Data System (ADS)

    Suaniti, Ni Made; Manurung, Manuntun

    2016-03-01

    Gas Chromatography-Mass Spectrometry is used to separate two and more compounds and identify fragment ion specific of biomarker ethanol such as palmitic acid ethyl ester (PAEE), as one of the fatty acid ethyl esters as early detection through conyugated reaction. This study aims to calibrate ethyl palmitate and develop analysis with oleate acid. This methode can be used analysis ethanol and its chemistry biomarker in ethanol sub-acute consumption as analytical forensic toxicology. The result show that ethanol level in urine rats Wistar were 9.21 and decreased 6.59 ppm after 48 hours consumption. Calibration curve of ethyl palmitate was y = 0.2035 x + 1.0465 and R2 = 0.9886. Resolution between ethyl palmitate and oleate were >1.5 as good separation with fragment ion specific was 88 and the retention time was 18 minutes.

  8. Radical Puppets and the Language of Art

    ERIC Educational Resources Information Center

    Asher, Rikki

    2009-01-01

    Radical puppets are puppets with a social message. Radical puppets encourage creative ideas that lead toward understanding global and environmental aspects of society through the "art of the puppet," a phrase coined by American puppeteer Bill Baird (1965). There is a blending of performance and visual art in puppetry. Through radical puppetry,…

  9. Labeled 1,N6-ethenoadenosine and 3,N4-ethenocytidine in hepatic RNA of mice given[ethyl-1,2(-3)H or ethyl-1(-14)C]ethyl carbamate (urethan).

    PubMed

    Ribovich, M L; Miller, J A; Miller, E C; Timmins, L G

    1982-01-01

    Injection of a single dose of[ethyl-1,2(-3)H]or[ethyl-1(-14C]- ethyl carbamate into 12-day old male[C57BL/6 x C3H/He]F1 mice or of[ethyl-1,2(-3H]ethyl carbamate into adult male A/Jax mice resulted in the formation of labeled 1,N6-ethenoadenosine and 3,N4-ethenocytidine adducts in the hepatic RNA. These adducts were characterized by comigration on h.p.l.c. of 3H or 14C in enzymatic hydrolysates of the RNA with synthetic standards. Both the ethenoadenosine and ethenocytidine were further characterized by their conversion to acetylated products that comigrated with acetylated synthetic standards. The ethenoadenosine was also converted by anhydrous trifluoroacetic acid to a product that comigrated with synthetic 1,N6-ethenoadenine. The levels of adducts in the hepatic RNA 12 h after a single injection of 0.5-0.6 mg of ethyl carbamate/g body weight were 6-10 and 2-3 pmol/mg RNA of ethenoadenosine and ethenocytidine, respectively. No labeled ethenoadenosine or ethenocytidine could be detected in the hepatic RNA of mice given[1-14C]ethanol, an enzymatic hydrolysis product of ethyl carbamate. These data indicate that ethyl carbamate may be metabolically activated by dehydrogenation to vinyl carbamate and subsequent epoxidation of the latter compound as previously proposed. Vinyl carbamate epoxide may form etheno derivatives in a manner analogous to that demonstrated for chloroethylene oxide, an electrophilic metabolite of vinyl chloride. Vinyl carbamate has been shown to have the same spectrum of tumor induction as ethyl carbamate but to be much more active than the latter carcinogen. PMID:6178529

  10. [Free radicals and eye inflammations].

    PubMed

    Ianopol, N

    1998-01-01

    Free radicals (FR), mainly those oxygen derived (FRO) are considered to be inflammation's mediators. Produced either by photochemical reactions or by synthesis into active phagocytic cells (in the cellular time of inflammation), FRO can determine an inflammatory reaction or they can augment a pre-existed one. These phenomena are produced by synthesis of inflammation's mediators as: prostaglandines, prostaciclines, thromboxane and leucotrienes starting from arachidonic acid, by the generation of some compounds with chemotactic properties and by the activation of phagocytic cells, by the augmentation of the proteolytic activity due to natural protease inhibitors inactivation and, last but not least, by the directly destructive action against different tissue compounds. In the first part of this lecture I presented general data about FR, inflammation, photosensitive agents and radical reactions. In the second part, I presented the pathogenic relation between FR and ocular inflammations from two different point of view: that of inflammation generation by FR, and that of FR generation during a preexistent inflammation.

  11. [Nerve-sparing radical prostatectomy].

    PubMed

    Okada, K; Tada, M; Nakano, A; Konno, T

    1988-04-01

    The neuroanatomy of the pelvic space was studied in order to clarify the course of cavernous nerves responsible for erectile function. The cavernous nerves travel along the dorsolateral portion at the base toward the apex of the prostate, then penetrate urogenital diaphragm at the lateral aspect of the membranous urethra. According to the anatomical findings, nerve-sparing radical prostatectomy was performed through the antegrade approach in 28 patients with prostate cancer. No significant surgical complications were encountered in the present series. Of the 28, evaluable cases were limited to 22 in terms of erection. Fifteen patients (68%) recovered their erectile function after nerve-sparing surgery. Therefore, the present surgical technique seems to be effective for the preservation of male sexual function following radical pelvic surgery.

  12. Mutagenicity of Oxygen Free Radicals

    NASA Astrophysics Data System (ADS)

    Moody, Carmella S.; Hassan, Hosni M.

    1982-05-01

    Paraquat 1,1'-dimethyl-4,4'-bipyridinium dichloride) was used as an intracellular generator of oxygen free radicals and was found to be highly mutagenic for Salmonella typhimurium. It caused both base-pair substitution and frameshift mutations. Paraquat was much more toxic and mutagenic in a simple nutritionally restricted medium than in a rich complex medium. The mutagenicity of paraquat was dependent upon the presence of a supply of both electrons and oxygen. Cells containing high levels of superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) were more resistant to the toxicity and the mutagenicity of paraquat than were cells containing normal levels of this enzyme. The mutagenicity of paraquat thus appears to be due to its ability to exacerbate the intracellular production of superoxide radicals.

  13. [Laser spectroscopy of hydrocarbon radicals

    SciTech Connect

    Not Available

    1993-01-01

    Several hydrocarbon reactive intermediates (carbenes, biradicals, etc.) were prepared in a supersonic jet expansion. heats of formation were determined for the isosmeric C[sub 3]H[sub 2] carbenes. Fits were made to the photoelectron spectra of c-C[sub 3]H[sub 2] and c- C[sub 4]H[sub 4]. Resonant MPI (multi-photon ionization ) spectra were obtained for allyl radical and its deuterated isotopomers.

  14. [Laser spectroscopy of hydrocarbon radicals

    SciTech Connect

    Not Available

    1993-05-01

    Several hydrocarbon reactive intermediates (carbenes, biradicals, etc.) were prepared in a supersonic jet expansion. heats of formation were determined for the isosmeric C{sub 3}H{sub 2} carbenes. Fits were made to the photoelectron spectra of c-C{sub 3}H{sub 2} and c- C{sub 4}H{sub 4}. Resonant MPI (multi-photon ionization?) spectra were obtained for allyl radical and its deuterated isotopomers.

  15. Geoscientists and the Radical Middle

    NASA Astrophysics Data System (ADS)

    Tinker, S. W.

    2015-12-01

    Addressing the great challenges facing society requires industry, government, and academia to work together. I call this overlap space, where compromises are made and real solutions determined, the Radical Middle. Radical because it can appear at times as if the loudest and most publicly influential voices lie outside of the actual solution space, content to provoke but not problem-solve. One key area where geoscientists can play a lead role in the Radical Middle is in the overlap between energy, the environment, and the economy. Globally, fossil fuels still represent 85% of the aggregate energy mix. As existing conventional oil and natural-gas reservoir production continues to slowly decline, unconventional reservoirs, led today by shale and other more expensive resources, will represent a growing part of the oil and gas production mix. Many of these unconventional reservoirs require hydraulic fracturing. The positive economic impact of hydraulic fracturing and associated natural gas and oil production on the United States economy is well documented and undeniable. Yet there are environmental concerns about fracking, and some states and nations have imposed moratoria. This energy-environment-economy space is ideal for leadership from the geosciences. Another such overlap space is the potential for geoscience leadership in relations with China, whose economy and global presence continue to expand. Although China is building major hydropower and natural-gas power plants, as well as nuclear reactors, coal is still king—with the associated environmental impacts. Carbon sequestration—onshore in brine and to enhance oil recovery, as well as offshore—could prove viable. It is vital that educated and objective geoscientists from industry, government, and academia leave their corners and work together in the Radical Middle to educate the public and develop and deliver balanced, economically sensible energy and environmental strategies.

  16. A radical way to burn

    SciTech Connect

    Ashley, S.

    1996-08-01

    By manipulating chamber geometries as well as engine cycle pressures and timing, engineers are exploiting a long-obscure technology known as activated radical combustion. Piston-driven internal combustion engines generally come in two varieties: compression-ignited diesels and spark-ignited gasoline power plants. There, is however, a third way to initiate burning of the fuel-air mixture. The technique--variously called radical ignition (RI), activated radical (AR) combustion, Toyota-Soken combustion, and active thermo-atmosphere combustion--is not exactly new, but only recently have engineers begun to exploit the process in practical power plants. These new units include a lightweight two-stroke racing-motorcycle engine, truck diesels with reduced soot output, and lean-burn spark-ignited car engines. This long-obscure combustion process is based on a range of specialized chemical kinetic and physical acoustic techniques developed over decades. Engineers manipulate fundamental combustion parameter such as chamber geometries, valving and porting configurations, and engine cycle pressures and timing to foster the formation of certain highly reactive chemical species that lower the fuel-air mixture`s flash point so that even modest compression make sit self-ignite. These chemical initiators are then retained into the next cycle to start combustion, allowing the engineer to run stably with no spark.

  17. Radical scavengers from heavy hydrocarbons

    SciTech Connect

    Kubo, Junichi

    1996-10-01

    The hydrogen-donating properties of some hydrocarbons form the basis for processes such as coal liquefaction and heavy oil upgrading. However, these hydrocarbons have seldom been used for other purposes, because their potential applications have not been well recognized. Research has indicated that these hydrogen-donating hydrocarbons can be used in important reactions as radical scavengers and have properties particular to those of pure hydrocarbons without functional groups containing heteroatoms. Over years of study researchers have found that pure hydrocarbons with radical-scavenging effects nearly as high as those in conventional hindered phenolic antioxidants can be produced from petroleum, and these hydrogen-donating hydrocarbons exhibit such effects even in oxidative atmospheres (i.e., they function as antioxidants). He has also shown that these mixtures have some properties particular to pure hydrocarbons without functional groups containing heteroatoms, and they`ve seen that a mechanism based on the steric effects appears when these hydrocarbons are used in heavy oil hydroprocessing. Hydrogen-donating hydrocarbons should be a viable resource in many applications. In this article, he presents radical-scavenging abilities, characteristics as pure hydrocarbons, and applications on the basis of the studies.

  18. Influence of Gilbert's syndrome on the formation of ethyl glucuronide.

    PubMed

    Huppertz, Laura M; Gunsilius, Leonie; Lardi, Christelle; Weinmann, Wolfgang; Thierauf-Emberger, Annette

    2015-09-01

    A drinking experiment with participants suffering from Gilbert's syndrome was performed to study the possible influence of this glucuronidation disorder on the formation of ethyl glucuronide (EtG). Gilbert's syndrome is a rather common and, in most cases, asymptomatic congenital metabolic aberration with a prevalence of about 5 %. It is characterized by a reduction of the enzyme activity of the uridine diphosphate glucuronosyltransferase (UGT) isoform 1A1 up to 80 %. One of the glucuronidation products is EtG, which is formed in the organism following exposure to ethanol. EtG is used as a short-term marker for ethyl alcohol consumption to prove abstinence in various settings. After 2 days of abstinence from ethanol and giving a void urine sample, 30 study participants drank 0.1 L of sparkling wine (9 g ethanol). 3, 6, 12, and 24 h after drinking, urine samples were collected. 3 hours after drinking, an additional blood sample was taken, in which liver enzyme activities, ethanol, hematological parameters, and bilirubin were measured. EtG and ethyl sulfate (EtS), another short-term marker of ethanol consumption, were determined in the urine samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS); creatinine was measured photometrically. In all participants, EtG and EtS were detected in concentrations showing a wide range (EtG: 3 h sample 0.5-18.43 mg/L and 6 h sample 0.67-13.8 mg/L; EtS: 3 h sample 0.87-6.87 mg/L and 6 h sample 0.29-4.48 mg/L). No evidence of impaired EtG formation was found. Thus, EtG seems to be a suitable marker for ethanol consumption even in individuals with Gilbert's syndrome. PMID:25680552

  19. Preventive efficacy of hydroalcoholic extract of Cymbopogon citratus against radiation-induced DNA damage on V79 cells and free radical scavenging ability against radicals generated in vitro.

    PubMed

    Rao, B S S; Shanbhoge, R; Rao, B N; Adiga, S K; Upadhya, D; Aithal, B K; Kumar, M R S

    2009-04-01

    This study presents the findings of free radical scavenging and antigenotoxic effect of hydroalcoholic extract of Cymbopogon citratus (CCE). The CCE at a concentration of 60 microg/mL resulted in a significant scavenging ability of 2,2-diphenyl-2-picryl hydrazyl (DPPH; (85%), 2,2-azinobis (3-ethyl benzothiazoline-6-sulphonic acid) (ABTS; 77%), hydroxyl (70%), superoxide (76%), nitric oxide (78%) free radicals generated using in vitro and also a moderate anti-lipid peroxidative effect (57%). Further, the radiation-induced antigenotoxic potential of CCE was assessed in Chinese hamster lung fibroblast cells (V79) using micronucleus assay. The CCE resulted in a dose-dependent decrease in the yield of radiation-induced micronuclei, with a maximum effect at 125 microg/mL CCE for 1 h before 2 Gy of radiation. Similarly, there was a significant (P < 0.05-0.0001) decrease in percentage of micronuclei when V79 cells were treated with optimal dose of CCE (125 microg/mL) before exposure to different doses of gamma radiation, that is, 0.5-4 Gy, compared with radiation alone groups. The results of the micronucleus study indicated antigenotoxic effect demonstrating the radioprotective potential of CCE and, which may partly due to its and antioxidant capacity as it presented its ability to scavenge various free radicals in vitro and anti-lipid peroxidative potential. PMID:19734270

  20. Cytotoxic constituents of ethyl acetate fraction from Dianthus superbus.

    PubMed

    Ding, Chengli; Zhang, Wu; Li, Jie; Lei, Jiachuan; Yu, Jianqing

    2013-01-01

    The ethyl acetate fraction (EE-DS) from Dianthus superbus was found to possess the cytotoxic activity against cancer cells in previous study. To investigate cytotoxic constituents, the bioassay-guided isolation of compounds from EE-DS was performed. Two dianthramides (1 and 2), three flavonoids (3-5), two coumarins (6 and 7) and three other compounds (8-10) were obtained. Structures of isolated compounds were identified by spectroscopic analysis. Cytotoxicity of the compounds against HepG2 cells was evaluated. Compound 1 showed the strongest cytotoxicity, compounds 10, 4, 3 and 5 had moderate cytotoxicity.

  1. Ethyl alcohol boiling heat transfer on multilayer meshed surfaces

    NASA Astrophysics Data System (ADS)

    Dåbek, Lidia; Kapjor, Andrej; Orman, Łukasz J.

    2016-06-01

    The paper presents the problem of heat transfer enhancement with the application of multilayer metal mesh structures during boiling of ethyl alcohol at ambient pressure. The preparation of samples involved sintering fine copper meshes with the copper base in the reduction atmosphere in order to prevent oxidation of the samples. The experiments included testing up to 4 layers of copper meshes. Significant augmentation of boiling heat transfer is possible, however, considerable number of meshes actually hinders heat transfer conditions and leads to the reduction in the heat flux transferred from the heater surface.

  2. Radical scavengers as ribonucleotide reductase inhibitors.

    PubMed

    Basu, Arijit; Sinha, Barij Nayan

    2012-01-01

    This paper compiled all the previous reports on radical scavengers, an interesting class of ribonucleotide reductase inhibitors. We have highlighted three key research areas: chemical classification of radical scavengers, structural and functional aspects of the radical site, and progress in drug designing for radical scavengers. Under the chemical classification section, we have recorded the discovery of hydroxyurea followed by discussions on hydroxamic acids, amidoximes, hydroxyguanidines, and phenolic compounds. In the next section, we have compiled the structural information for the radical site obtained from different crystallographic and theoretical studies. Finally, we have included the reported ligand based and structure based drug-designing studies.

  3. Ethyl Pyruvate Combats Human Leukemia Cells but Spares Normal Blood Cells

    PubMed Central

    Kurz, Susanne; Bigl, Marina; Buchold, Martin; Thieme, Rene; Wichmann, Gunnar; Dehghani, Faramarz

    2016-01-01

    Ethyl pyruvate, a known ROS scavenger and anti-inflammatory drug was found to combat leukemia cells. Tumor cell killing was achieved by concerted action of necrosis/apoptosis induction, ATP depletion, and inhibition of glycolytic and para-glycolytic enzymes. Ethyl lactate was less harmful to leukemia cells but was found to arrest cell cycle in the G0/G1 phase. Both, ethyl pyruvate and ethyl lactate were identified as new inhibitors of GSK-3β. Despite the strong effect of ethyl pyruvate on leukemia cells, human cognate blood cells were only marginally affected. The data were compiled by immune blotting, flow cytometry, enzyme activity assay and gene array analysis. Our results inform new mechanisms of ethyl pyruvate-induced cell death, offering thereby a new treatment regime with a high therapeutic window for leukemic tumors. PMID:27579985

  4. Ethyl Pyruvate Combats Human Leukemia Cells but Spares Normal Blood Cells.

    PubMed

    Birkenmeier, Gerd; Hemdan, Nasr Y A; Kurz, Susanne; Bigl, Marina; Pieroh, Philipp; Debebe, Tewodros; Buchold, Martin; Thieme, Rene; Wichmann, Gunnar; Dehghani, Faramarz

    2016-01-01

    Ethyl pyruvate, a known ROS scavenger and anti-inflammatory drug was found to combat leukemia cells. Tumor cell killing was achieved by concerted action of necrosis/apoptosis induction, ATP depletion, and inhibition of glycolytic and para-glycolytic enzymes. Ethyl lactate was less harmful to leukemia cells but was found to arrest cell cycle in the G0/G1 phase. Both, ethyl pyruvate and ethyl lactate were identified as new inhibitors of GSK-3β. Despite the strong effect of ethyl pyruvate on leukemia cells, human cognate blood cells were only marginally affected. The data were compiled by immune blotting, flow cytometry, enzyme activity assay and gene array analysis. Our results inform new mechanisms of ethyl pyruvate-induced cell death, offering thereby a new treatment regime with a high therapeutic window for leukemic tumors. PMID:27579985

  5. Oxidative stress, free radicals and protein peroxides.

    PubMed

    Gebicki, Janusz M

    2016-04-01

    Primary free radicals generated under oxidative stress in cells and tissues produce a cascade of reactive secondary radicals, which attack biomolecules with efficiency determined by the reaction rate constants and target concentration. Proteins are prominent targets because they constitute the bulk of the organic content of cells and tissues and react readily with many of the secondary radicals. The reactions commonly lead to the formation of carbon-centered radicals, which generally convert in vivo to peroxyl radicals and finally to semistable hydroperoxides. All of these intermediates can initiate biological damage. This article outlines the advantages of the application of ionizing radiations to studies of radicals, with particular reference to the generation of desired radicals, studies of the kinetics of their reactions and correlating the results with events in biological systems. In one such application, formation of protein hydroperoxides in irradiated cells was inhibited by the intracellular ascorbate and glutathione.

  6. Extracts and constituents of Rubus chingii with 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity.

    PubMed

    Ding, Hsiou-Yu

    2011-01-01

    The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of the fruits of Rubus chingii was studied in vitro. Ethanolic extract, ethyl acetate and n-butanol fractions from dried R. chingii fruits revealed strong DPPH free radical scavenging activity with IC(50) values of 17.9, 3.4 and 4.0 μg/mL, respectively. The ethyl acetate and n-butanol fractions were further purified by a combination of silica gel chromatography, Lobar RP-8 chromatography, and high-pressure liquid chromatography (HPLC). Nine compounds were isolated, where methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), vanillic acid (5), kaempferol (7), and tiliroside (9) showed stronger DPPH free radical scavenging activity than that of ascorbic acid (131.8 μM) with IC(50) values of 45.2, 34.9, 78.5, and 13.7 μM, respectively. In addition, rubusine (1) is a new compound discovered in the present study and methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), methyl dioxindole-3-acetate (3), and 2-oxo-1,2-dihydroquinoline-4-carboxylic acid (4) were isolated from the fruits for the first time.

  7. Extracts and Constituents of Rubus chingii with 1,1-Diphenyl-2-picrylhydrazyl (DPPH) Free Radical Scavenging Activity

    PubMed Central

    Ding, Hsiou-Yu

    2011-01-01

    The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of the fruits of Rubus chingii was studied in vitro. Ethanolic extract, ethyl acetate and n-butanol fractions from dried R. chingii fruits revealed strong DPPH free radical scavenging activity with IC50 values of 17.9, 3.4 and 4.0 μg/mL, respectively. The ethyl acetate and n-butanol fractions were further purified by a combination of silica gel chromatography, Lobar RP-8 chromatography, and high-pressure liquid chromatography (HPLC). Nine compounds were isolated, where methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), vanillic acid (5), kaempferol (7), and tiliroside (9) showed stronger DPPH free radical scavenging activity than that of ascorbic acid (131.8 μM) with IC50 values of 45.2, 34.9, 78.5, and 13.7 μM, respectively. In addition, rubusine (1) is a new compound discovered in the present study and methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), methyl dioxindole-3-acetate (3), and 2-oxo-1,2-dihydroquinoline-4-carboxylic acid (4) were isolated from the fruits for the first time. PMID:21747716

  8. Highly active gold-based catalyst for the reaction of benzaldehyde with ethyl diazoacetate.

    PubMed

    Fructos, Manuel R; Díaz-Requejo, M Mar; Pérez, Pedro J

    2009-09-14

    The gold complex [IPrAu(NCMe)]BF(4) catalyzes the reaction of ethyl diazoacetate with benzaldehyde to give mixtures of ethyl 3-oxo-3-phenylpropanoate and ethyl 3-hydroxy-2-phenylacrylate in the first example of a group 11 metal-based catalyst for this transformation; the catalyst activity is improved by a factor of 2500 compared to those of previously reported iron-based catalysts.

  9. Transesterification process to manufacture ethyl ester of rape oil

    SciTech Connect

    Korus, R.A.; Hoffman, D.S.; Bam, N.; Peterson, C.L.; Drown, D.C.

    1993-12-31

    A process for the production of the ethyl ester of winter rape [EEWR] for use as a biodiesel fuel has been studied. The essential part of the process is the transesterification of rape oil with ethanol, in the presence of a catalyst, to yield the ethyl ester of rape oil as a product and glycerin as a by-product. Experiments have been performed to determine the optimum conditions for the preparation of EEWR. The process variables were: (1) temperature, (2) catalyst, (3) rate of agitation, (4) water content of the alcohol used, and (5) the amount of excess alcohol used. The optimum conditions were: (1) room temperature, (2) 0.5% sodium methoxide or 1% potassium hydroxide catalyst by weight of rapeseed oil, (3) extremely vigorous agitation with some splashing during the initial phase of the reaction and agitation was not necessary after the reaction mixture became homogeneous, (4) absolute ethanol was necessary for high conversion, and (5) 50% excess ethanol with NaOCH{sub 3} or 100% excess with KOH gave a maximum conversion. Viscosity, cloud point and pour point of the EEWR were measured. A preliminary break-even cost for the commercial production of EEWR was found to be $0.55/liter [$2.08/US gallon].

  10. Growth of glycine ethyl ester hydrochloride and its characterizations

    NASA Astrophysics Data System (ADS)

    Venkatesan, G.; Pari, S.

    2016-11-01

    Single crystal of glycine ethyl ester hydrochloride by slow evaporation method is reported. The grown crystal characterized by single crystal X-ray diffraction, FT-IR, UV-Vis-NIR and fluorescence spectroscopy. It is established that the crystal falls under the monoclinic system and space group P21/c with the cell parameters as: a=8.565 Å, b=12.943 Å, c=6.272 Å, α=γ=90°, β=103.630º. UV-Vis-NIR spectrum shows indirect allowed transition with a band gap of 5.21 eV and other optical properties are measured. The crystal is also shown to have a high transmittance in the visible region. The third order nonlinear property and optical limiting have been investigated using Z-Scan technique. Complex impedance spectrum measured at the dc conductivity. Dependence of dielectric constant, dielectric loss and ac conductivity on frequency at different temperature of applied ac field is analyzed. The mechanical behavior has been assessed by Vickers microhardness indenter. The thermal behavior of glycine ethyl ester hydrochloride was analyzed using TG/DTA thermal curves. From the thermal study, the material was found to possess thermal stability up to 174 °C. The predicted NLO properties, UV-Vis transmittance and Z-scan studies indicate that is an attractive material for photonics optical limiting applications.

  11. Detection of ethyl glucuronide in blood spotted on different surfaces.

    PubMed

    Winkler, M; Kaufmann, E; Thoma, D; Thierauf, A; Weinmann, W; Skopp, G; Alt, A

    2011-07-15

    This study aims to show that sensitive detection of ethyl glucuronide in dried blood spotted onto various surfaces after a period of 24h is feasible. At present, there is insufficient information how tightly ethyl glucuronide (EtG) binds to various materials and how easily it can be eluted. 4ml aliquots of blood samples obtained from seven volunteers after consumption of alcoholic beverages were applied to six different surfaces. After drying and a 24h-storage at 20±2°C the samples were re-dissolved in water, and EtG was subsequently analyzed by a LC-MS Paul-type ion trap. A comparison was made between dried and corresponding fluid samples. EtG was detectable in all subjects' samples following consumption of alcohol. EtG was also detectable after a storage time of four weeks at 4°C in whole blood that had been preserved with EDTA. EtG was detectable in all samples dried on different surfaces and its concentration remained relatively constant irrespective of the particular condition of the material. Detection of EtG in blood spots from the scene may indicate recent alcohol consumption in cases where collection of blood remained undone or could not be performed. PMID:21641739

  12. DISCOVERY OF METHYL ACETATE AND GAUCHE ETHYL FORMATE IN ORION

    SciTech Connect

    Tercero, B.; Cernicharo, J.; Lopez, A.; Caro, G. M. Munoz; Kleiner, I.; Nguyen, H. V. L. E-mail: jcernicharo@cab.inta-csic.es E-mail: munozcg@cab.inta-csic.es E-mail: nguyen@pc.rwth-aachen.de

    2013-06-10

    We report on the discovery of methyl acetate, CH{sub 3}COOCH{sub 3}, through the detection of a large number of rotational lines from each one of the spin states of the molecule: AA species (A{sub 1} or A{sub 2}), EA species (E{sub 1}), AE species (E{sub 2}), and EE species (E{sub 3} or E{sub 4}). We also report, for the first time in space, the detection of the gauche conformer of ethyl formate, CH{sub 3}CH{sub 2}OCOH, in the same source. The trans conformer is also detected for the first time outside the Galactic center source SgrB2. From the derived velocity of the emission of methyl acetate, we conclude that it arises mainly from the compact ridge region with a total column density of (4.2 {+-} 0.5) Multiplication-Sign 10{sup 15} cm{sup -2}. The derived rotational temperature is 150 K. The column density for each conformer of ethyl formate, trans and gauche, is (4.5 {+-} 1.0) Multiplication-Sign 10{sup 14} cm{sup -2}. Their abundance ratio indicates a kinetic temperature of 135 K for the emitting gas and suggests that gas-phase reactions could participate efficiently in the formation of both conformers in addition to cold ice mantle reactions on the surface of dust grains.

  13. Genotoxicity and cytotoxicity assessment of new ethyl-carbamates with ixodicidal activity.

    PubMed

    Prado-Ochoa, María Guadalupe; Muñoz-Guzmán, Marco Antonio; Vázquez-Valadez, Víctor Hugo; Velázquez-Sánchez, Ana María; Salazar, Ana María; Ramírez-Noguera, Patricia; Angeles, Enrique; Alba-Hurtado, Fernando

    2016-09-01

    The mammalian erythrocyte micronucleus test was used on the peripheral blood of Wistar rats exposed to two new ethyl-carbamates: ethyl-4-bromophenyl-carbamate (LQM 919) and ethyl-4-chlorophenyl-carbamate (LQM 996) to analyze their genotoxic potential. The mitotic index and cell proliferation kinetics in human lymphocyte cultures in the presence of these ethyl-carbamates were used to evaluate cytotoxicity and cytostaticity respectively. Exposure to greater acute doses (300mg/kg) and to all of the subchronic doses (12.5, 25 and 50mg/kg daily for 90 days) of these ethyl-carbamates induced an increased frequency (p<0.05) of micro-nucleated polychromatic erythrocytes (MN-PCE) compared with rats not exposed to the ethyl-carbamates. Increases in MN-PCE was higher in males than in females exposed to LQM 996 50mg/Kg (p<0.05). All observed changes in rats return 21days after suspending ethyl-carbamate exposure. The highest concentration (0.3mM) of both ethyl-carbamates in lymphocyte cultures increased the percentage of cells in first division metaphase and decreased the percentage of cells in third division metaphase, indicating an increase in cell cycle length or a possible cell cycle arrest in metaphase (cytostatic effect). The results of this study show that the evaluated ethyl-carbamates may induce genotoxic damage in rats and alterations in the human lymphocyte cell cycle. PMID:27542710

  14. Genotoxicity and cytotoxicity assessment of new ethyl-carbamates with ixodicidal activity.

    PubMed

    Prado-Ochoa, María Guadalupe; Muñoz-Guzmán, Marco Antonio; Vázquez-Valadez, Víctor Hugo; Velázquez-Sánchez, Ana María; Salazar, Ana María; Ramírez-Noguera, Patricia; Angeles, Enrique; Alba-Hurtado, Fernando

    2016-09-01

    The mammalian erythrocyte micronucleus test was used on the peripheral blood of Wistar rats exposed to two new ethyl-carbamates: ethyl-4-bromophenyl-carbamate (LQM 919) and ethyl-4-chlorophenyl-carbamate (LQM 996) to analyze their genotoxic potential. The mitotic index and cell proliferation kinetics in human lymphocyte cultures in the presence of these ethyl-carbamates were used to evaluate cytotoxicity and cytostaticity respectively. Exposure to greater acute doses (300mg/kg) and to all of the subchronic doses (12.5, 25 and 50mg/kg daily for 90 days) of these ethyl-carbamates induced an increased frequency (p<0.05) of micro-nucleated polychromatic erythrocytes (MN-PCE) compared with rats not exposed to the ethyl-carbamates. Increases in MN-PCE was higher in males than in females exposed to LQM 996 50mg/Kg (p<0.05). All observed changes in rats return 21days after suspending ethyl-carbamate exposure. The highest concentration (0.3mM) of both ethyl-carbamates in lymphocyte cultures increased the percentage of cells in first division metaphase and decreased the percentage of cells in third division metaphase, indicating an increase in cell cycle length or a possible cell cycle arrest in metaphase (cytostatic effect). The results of this study show that the evaluated ethyl-carbamates may induce genotoxic damage in rats and alterations in the human lymphocyte cell cycle.

  15. Effects of switching from omega-3-acid ethyl esters to icosapent ethyl in a statin-treated patient with elevated triglycerides.

    PubMed

    Kedia, Anurag W; Lynch, Erin

    2015-01-01

    In patients with dyslipidemia, elevated triglyceride (TG) levels, or TG-rich lipoproteins, and cardiovascular risk may remain despite statin therapy. Prescription omega-3 fatty acid formulations containing the ethyl esters of eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) (omega-3-acid ethyl esters; Lovaza®) or high-purity EPA ethyl ester (icosapent ethyl; Vascepa®) are TG-lowering treatments that may be administered in addition to statins. Here we describe the effects of switching from omega-3-acid ethyl esters to icosapent ethyl in a 44-year-old obese man with dyslipidemia, hypertension, and hypothyroidism. The patient was receiving stable treatment with medications, including atorvastatin 40 mg/day and extended-release niacin 1000 mg/day. Owing to persistently elevated TG levels and other cardiovascular risk factors, the patient was initiated on omega-3-acid ethyl esters 4 g/day. After approximately 2 years on omega-3-acid ethyl esters, his total cholesterol (TC) level was 184 mg/dL, low-density lipoprotein cholesterol (LDL-C) level was 81 mg/dL, TG level was elevated at 307 mg/dL despite statin therapy, and non-high-density lipoprotein cholesterol (non-HDL-C) level was 144 mg/dL. After the switch to icosapent ethyl, TC level decreased by 34% to 121 mg/dL, LDL-C level decreased by 28% to 58 mg/dL, TG level decreased by 41% to 180 mg/dL, and non-HDL-C level decreased by 44% to 81 mg/dL. Switching from omega-3-acid ethyl esters containing both EPA and DHA to icosapent ethyl containing high-purity EPA resulted in beneficial and substantial changes in the lipid profile with a notable reduction of TG levels along with additional reductions in LDL-C levels in a statin-treated obese patient with persistently high TG levels. Treatment with icosapent ethyl was well tolerated. PMID:26453247

  16. Section i: Thermodynamic Properties of Hydrocarbon Radicals, Peroxy Hydrocarbon and Peroxy Chlorohydrocarbon Molecules and Radicals. Section II. Kinetics and Reaction Mechanisms For: (1) Chloroform Pyrolysis and Oxidation; (2) Benzene and Toluene Oxidation Under Atmospheric Conditions.

    NASA Astrophysics Data System (ADS)

    Lay, Tsan-Horng

    1995-01-01

    Alkyl radicals are important active intermediates in gas phase photochemistry and combustion reaction systems. With the exception of a limited number of the most elementary radicals, accurate thermodynamic properties of alkyl radicals are either not available or only rough estimations exist. An H atom Bond Increment approach is developed and a data base is derived, for accurately estimating thermodynamic properties (Delta H_{f }^circ298, S ^circ298 and Cp(T)) for generic classes of hydrocarbon radical species. Reactions of alkyl radicals with molecular oxygen are one of the major reaction paths for these radicals in atmospheric photochemistry, oxidation of hydrocarbon liquids and combustion process. Alkyl hydroperoxides are subsequently formed through the alkyl peroxy radicals reactions with varied chemical species present in the reaction system. Thermodynamic properties of the alkyl hydroperoxides and related radicals are therefore frequently required in gas phase modeling and kinetic studies on these systems. The thermodynamic properties of alkyl hydroperoxides, alkyl peroxy radicals and hydroperoxyl-1-ethyl radicals including the species with fluorine and chlorine substituents on the alpha-carbon are evaluated using molecular orbital calculations. Chloroform is used as a model chlorocarbon system with high Cl/H ratio to investigate thermal decomposition processes of chlorocarbons in oxidative and pyrolytic reaction environments. A detailed reaction mechanism is developed to describe the important features of products and reagent loss and is shown to predict the experimental data well. Reaction pathways and rate constants are developed for CCl _3, CCl_2 and rm C_2Cl_3 radical addition to O_2 and combination with O, OH HO_2 and ClO. The reversible addition reaction of OH radical with benzene to form the hydroxyl-2,4-cyclohexadienyl (benzene -OH) adduct and the subsequent reactions of this benzene -OH adduct with O_2 are important initial steps for the

  17. Laser spectroscopy of hydrocarbon radicals

    SciTech Connect

    Chen, P.

    1993-12-01

    The author reports the application of supersonic jet flash pyrolysis to the specific preparation of a range of organic radicals, biradicals, and carbenes in a skimmed molecular beam. Each species was produced cleanly and specifically, with little or no secondary reactions by the thermal dissociation of appropriately designed and synthesized organic precursors. Photoelectron spectra of the three isomeric C{sub 3}H{sub 2} carbenes, ortho-benzyne, and the {alpha},3-dehydrotoluene biradical, were used to establish adiabatic ionization potentials for use in thermochemical determinations.

  18. Aromatic-radical oxidation chemistry

    SciTech Connect

    Glassman, I.; Brezinsky, K.

    1993-12-01

    The research effort has focussed on discovering an explanation for the anomalously high CO{sub 2} concentrations observed early in the reaction sequence of the oxidation of cyclopentadiene. To explain this observation, a number of plausible mechanisms have been developed which now await experimental verification. One experimental technique for verifying mechanisms is to probe the reacting system by perturbing the radical concentrations. Two forms of chemical perturbation of the oxidation of cyclopentadiene were begun during this past year--the addition of NO{sub 2} and CO to the reacting mixture.

  19. Neuroprotective strategies in radical prostatectomy.

    PubMed

    Schiff, Jonathan D; Mulhall, John P

    2005-01-01

    In this section, authors from New York give their views on the various neuroprotective strategies for patients having a radical prostatectomy, such as the use of nerve grafts and other approaches. A joint study from Korea, the USA, Canada and the UK is presented in a paper on the importance of patient perception in the clinical assessment and management of BPH. There is also a review of robotic urological surgery. Finally, authors from New York give a review on the life of Isaac Newton. This is a new historical review in the journal, but one that will be of general interest.

  20. Iron and iron derived radicals

    SciTech Connect

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

  1. Free radical kinetics of irradiated durum wheat

    NASA Astrophysics Data System (ADS)

    Korkmaz, M.; Polat, M.

    2000-04-01

    In the present work, a detailed ESR investigation of characteristic features and kinetic behaviors at three different temperatures of free radicals produced in a species of durum wheat cultivated in Turkey and irradiated at doses of up to 5 kGy by a γ source, is reported. Unirradiated wheat samples exhibit a weak, single-line ESR signal originating from a radical of unknown structure called radical III in this work. Irradiation produces two more radicals identified as hydroxyalkyl (I) and aldehydalkyl (II) radicals beside radical III. The radicals (I, II and III) follow complicated kinetics. Species I and II initially decay very fast after the irradiation followed by slower decay. Radical half-life times depend on whether they were induced in the crystalline or amorphous fractions of the wheat starch. Activation energy values of the radicals were found to follow the order Ea(III)> Ea(II)> Ea(I). ESR parameters of the radical species were determined by simulating experimental spectra recorded following the irradiation. Room temperature dose-response curves and variations of different spectral parameters between 120 and 390 K were also studied.

  2. Radical constructivism: Between realism and solipsism

    NASA Astrophysics Data System (ADS)

    Martínez-Delgado, Alberto

    2002-11-01

    This paper criticizes radical constructivism of the Glasersfeld type, pointing out some contradictions between the declared radical principles and their theoretical and practical development. These contradictions manifest themselves in a frequent oscillation between solipsism and realism, despite constructivist claims to be an anti-realist theory. The paper also points out the contradiction between the relativism of the radical constructivist principles and the constructivist exclusion of other epistemological or educational paradigms. It also disputes the originality and importance of the radical constructivist paradigm, suggesting the idea of an isomorphism between radical constructivist theory and contemplative realism. In addition, some pedagogical and scientific methodological aspects of the radical constructivist model are examined. Although radical constructivism claims to be a rational theory and advocates deductive thinking, it is argued that there is no logical deductive connection between the radical principles of constructivism and the radical constructivist ideas about scientific research and learning. The paper suggests the possibility of an ideological substratum in the construction and hegemonic success of subjective constructivism and, finally, briefly advances an alternative realist model to epistemological and educational radical constructivism.

  3. Quenching and radical formation in the reaction of photoexcited benzophenone with thiols and thioethers (sulfides). Nanosecond flash studies

    SciTech Connect

    Inbar, S.; Linschitz, H.; Cohen, S.G.

    1982-01-01

    Laser flash measurements have been made of rate constants and primary radical yields in the reactions of triplet benzophenone with aliphatic and aromatic thiols and with dialkyl and aryl alkyl sulfides. Reaction with n-pentylthiol in benzene leads mainly to quenching, with k/sub ir/ = 9 x 10/sup 6/ M/sup -1/ s/sup -1/ and radical yield (ketyl) = 0.14; with mesitylene-2 thiol in benzene k/sub ir/ = 7 x 10/sup 8/ M/sup -1/ s/sup -1/ and hydrogen transfer is efficient, radical yield (ketyl) approx. 1.0. In reactions with both p-chlorophenyl ethyl and diisopropyl sulfides, k/sub ir/ increases and radical yield (ketyl) decreases with increasing solvent polarity. Values of k/sub ir/ are higher and those of radical yield (ketyl) are lower for the dialkyl than for the aryl alkyl sulfide. Results are discussed in terms of rapid interaction of the triplet with S, followed by quenching and/or hydrogen transfer. Quenching without hydrogen transfer occurs to a much greater extent with sulfides and aliphatic thiols than with amines.

  4. Graphene oxide as a radical initiator: Free radical and controlled radical polymerization of sodium 4-vinylbenzenesulfonate with graphene oxide

    DOE PAGES

    Voylov, Dmitry N.; Saito, Tomonori; Lokitz, Bradley S.; Uhrig, David; Wang, Yangyang; Agapov, Alexander L.; Holt, Adam P.; Bocharova, Vera; Kisliuk, Alexander; Sokolov, Alexei P.

    2016-01-19

    The free radical and controlled radical polymerization of sodium 4-vinylbenzenesulfonate using graphene oxide as a radical initiator was studied. This work demonstrates that graphene oxide can initiate radical polymerization in an aqueous solution without any additional initiator. Poly(sodium 4-vinylbenzenesulfonate) obtained via reversible addition fragmentation chain transfer polymerization had a controlled molecular weight with a very narrow polydispersity ranging between 1.01 and 1.03. Furthermore, the reduction process of graphene oxide as well as the resulting composite material properties were analyzed in detail.

  5. Two mechanisms for toxic effects of hydroxylamines in human erythrocytes: involvement of free radicals and risk of potentiation.

    PubMed

    Evelo, C T; Spooren, A A; Bisschops, R A; Baars, L G; Neis, J M

    1998-09-01

    The toxic potency of three industrially used hydroxylamines was studied in human blood cells in vitro. The parent compound hydroxylamine and the O-ethyl derivative gave very similar results. Both compounds induced a high degree of methemoglobin formation and glutathione depletion. Cytotoxicity was visible as Heinz body formation and hemolysis. High levels of lipid peroxidation occurred, in this respect O-ethyl hydroxylamine was more active than hydroxylamine. In contrast H2O2 induced lipid peroxidation was lowered after O-ethyl hydroxylamine or hydroxylamine treatment, this is explained by the ferrohemoglobin dependence of H2O2 induced radical species formation. Glutathione S-transferase (GST) and NADPH methemoglobin reductase (NADPH-HbR) activities were also impaired, probably as a result of the radical stress occurring. The riboflavin availability was decreased. Other enzyme activities glutathione reductase (GR), glucose 6-phosphate dehydrogenase (G6PDH), glucose phosphate isomerase and NADH methemoglobin reductase, were not or only slightly impaired by hydroxylamine or O-ethyl hydroxylamine treatment. A different scheme of reactivity was found for N,O-dimethyl hydroxylamine. This compound gave much less methemoglobin formation and no hemolysis or Heinz body formation at concentrations up to and including 7 mM. Lipid peroxidase induction was not detectable, but could be induced by subsequent H2O2 treatment. GST and NADPH-HbR activities and riboflavin availability were not decreased. On the other hand GR and G6PDH activities were inhibited. These results combined with literature data indicate the existence of two different routes of hematotoxicity induced by hydroxylamines. Hydroxylamine as well as O-alkylated derivatives primarily induce methemoglobin, a process involving radical formation. The radical stress occurring is probably responsible for most other effects. N-alkylated species like N,O-dimethyl hydroxylamine primarily lead to inhibition of the protective

  6. Spectroscopic detection, characterization and dynamics of free radicals relevant to combustion processes

    SciTech Connect

    Miller, Terry

    2015-06-04

    Combustion chemistry is enormously complex. The chemical mechanisms involve a multitude of elementary reaction steps and a comparable number of reactive intermediates, many of which are free radicals. Computer simulations based upon these mechanisms are limited by the validity of the mechanisms and the parameters characterizing the properties of the intermediates and their reactivity. Spectroscopy can provide data for sensitive and selective diagnostics to follow their reactions. Spectroscopic analysis also provides detailed parameters characterizing the properties of these intermediates. These parameters serve as experimental gold standards to benchmark predictions of these properties from large-scale, electronic structure calculations. This work has demonstrated the unique capabilities of near-infrared cavity ringdown spectroscopy (NIR CRDS) to identify, characterize and monitor intermediates of key importance in complex chemical reactions. Our studies have focussed on the large family of organic peroxy radicals which are arguably themost important intermediates in combustion chemistry and many other reactions involving the oxidation of organic compounds. Our spectroscopic studies have shown that the NIR Ã - ˜X electronic spectra of the peroxy radicals allows one to differentiate among chemical species in the organic peroxy family and also determine their isomeric and conformic structure in many cases. We have clearly demonstrated this capability on saturated and unsaturated peroxy radicals and β-hydroxy peroxy radicals. In addition we have developed a unique dual wavelength CRDS apparatus specifically for the purpose of measuring absolute absorption cross section and following the reaction of chemical intermediates. The utility of the apparatus has been demonstrated by measuring the cross-section and self-reaction rate constant for ethyl peroxy.

  7. Quantitative determination of atmospheric hydroperoxyl radical

    DOEpatents

    Springston, Stephen R.; Lloyd, Judith; Zheng, Jun

    2007-10-23

    A method for the quantitative determination of atmospheric hydroperoxyl radical comprising: (a) contacting a liquid phase atmospheric sample with a chemiluminescent compound which luminesces on contact with hydroperoxyl radical; (b) determining luminescence intensity from the liquid phase atmospheric sample; and (c) comparing said luminescence intensity from the liquid phase atmospheric sample to a standard luminescence intensity for hydroperoxyl radical. An apparatus for automating the method is also included.

  8. Determination of Radical Scavenging Activity and Total Phenols of Wine and Spices: A Randomized Study

    PubMed Central

    Lugemwa, Fulgentius Nelson; Snyder, Amanda L.; Shaikh, Koonj

    2013-01-01

    Thirty eight bottles of red wine (Carbanet Sauvignon) were randomly selected based on vintage, region, price, and age (number of months in a barrel). The total phenolic content of each wine was determined using Folin-Ciocalteau assay. The radical scavenging activity was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. Apart from a few bottles that exhibited above average radical scavenging activity and phenolic content, there was no good correlation of those two quantities with region, price or vintage. The average phenolic amount was 2874 mg/L. The lowest phenolic content was found to be 1648 mg/L for an eight dollar wine. Wine with the highest amount of phenol of 4495 mg/L was a 2007, nine dollar bottle from South America. High amount of phenols did not translate into high radical scavenging activity. Barrel-aging did not increase the amount of phenols or the radical scavenging activity of wine. In order to discover new and potent sources of antioxidants from plants, the following spices were studied: ginger, cilantro, cumin, anise, linden, eucalyptus, marjoram, oregano, sage, thyme and rosemary. Whole spices were crushed and extracted for 96 h at room temperature using a combination of ethyl acetate, ethyl alcohol and water in the ratio of 4.5:4.5:1 (v/v/v). The radical scavenging activity of extracts was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. The total phenolic content of each spice was also determined using the Folin-Ciocalteau assay. Eucalyptus was found to be the most potent antioxidant with an LC50 of 324.1 mg of phenol/L, followed by marjoram with an LC50 of 407.5 mg of phenol/L, and rosemary with an LC50 of 414.0 mg/L. The least potent antioxidants were ginger and cilantro with LC50 of 7604 mg/L of phenol and 7876 mg of phenol/L, respectively. PMID:26784340

  9. Hydroxide as general base in the saponification of ethyl acetate.

    PubMed

    Mata-Segreda, Julio F

    2002-03-13

    The second-order rate constant for the saponification of ethyl acetate at 30.0 degrees C in H(2)O/D(2)O mixtures of deuterium atom fraction n (a proton inventory experiment) obeys the relation k(2)(n) = 0.122 s(-1) M(-1) (1 - n + 1.2n) (1 - n + 0.48n)/(1 - n + 1.4n) (1 - n + 0.68n)(3). This result is interpreted as a process where formation of the tetrahedral intermediate is the rate-determining step and the transition-state complex is formed via nucleophilic interaction of a water molecule with general-base assistance from hydroxide ion, opposite to the direct nucleophilic collision commonly accepted. This mechanistic picture agrees with previous heavy-atom kinetic isotope effect data of Marlier on the alkaline hydrolysis of methyl formate.

  10. Ethyl carbamate levels in selected fermented foods and beverages.

    PubMed

    Canas, B J; Havery, D C; Robinson, L R; Sullivan, M P; Joe, F L; Diachenko, G W

    1989-01-01

    Ethyl carbamate (EC), also known as urethane, is an animal carcinogen and a by-product of fermentation. Because EC has been found in distilled spirits and wines, a variety of fermented foods and beverages were analyzed to assess its occurrence in other products. Previously described methods using a gas chromatograph-thermal energy analyzer with a nitrogen converter were modified for each matrix and gave recoveries of greater than 80%, with a limit of detection in the 1-2 micrograms/kg (ppb) range. A total of 152 test samples were analyzed; EC levels ranged from none found to 3 ppb in 15 cheeses, 6 teas, 12 yogurts, and 8 ciders; from none found to 13 ppb in 30 breads and 69 malt beverages; and from none found to 84 ppb in 12 soy sauces. Gas chromatography/mass spectrometry/mass spectrometry was used to confirm EC identity and to quantitate EC in selected food extracts. PMID:2592308

  11. Interaction of Ethyl Alcohol Vapor with Sulfuric Acid Solutions

    NASA Technical Reports Server (NTRS)

    Leu, Ming-Taun

    2006-01-01

    We investigated the uptake of ethyl alcohol (ethanol) vapor by sulfuric acid solutions over the range approx.40 to approx.80 wt % H2SO4 and temperatures of 193-273 K. Laboratory studies used a fast flow-tube reactor coupled to an electron-impact ionization mass spectrometer for detection of ethanol and reaction products. The uptake coefficients ((gamma)) were measured and found to vary from 0.019 to 0.072, depending upon the acid composition and temperature. At concentrations greater than approx.70 wt % and in dilute solutions colder than 220 K, the values approached approx.0.07. We also determined the effective solubility constant of ethanol in approx.40 wt % H2SO4 in the temperature range 203-223 K. The potential implications to the budget of ethanol in the global troposphere are briefly discussed.

  12. Preoperative treatment of a parotid hemangioma with 100% ethyl alcohol

    PubMed Central

    Emsen, Ilteris Murat

    2008-01-01

    Hemangiomas are one of the most common childhood neoplasms, occurring in approximately 12% of infants younger than one year of age. The lesions typically appear shortly after birth, increase in size over the first year and characteristically regress over the next decade. Because hemangiomas can be visible during an important stage of a child’s social development, numerous authors have pursued alternative treatment strategies to avoid or reduce this lengthy involution process. Unfortunately, no effective medical treatment has been reported for children with large, deforming hemangiomas of the parotid gland and overlying cheek. In the present case, a patient with a large parotid hemangioma was treated preoperatively with an intralesional injection of 100% ethyl alcohol solution to reduce the size of the mass. The mass was removed 28 days later with no major postoperative complications. PMID:19949507

  13. Effects of acetone on methyl ethyl ketone peroxide runaway reaction.

    PubMed

    Lin, Yan-Fu; Tseng, Jo-Ming; Wu, Tsung-Chih; Shu, Chi-Min

    2008-05-30

    Runaway reactions by methyl ethyl ketone peroxide (MEKPO) are an important issue in Asia, due to its unstable structure and extensive heat release during upset situations. This study employed differential scanning calorimetry (DSC) to draw the experimental data for MEKPO 31 mass% and with acetone 99 mass% on three types of heating rate of 2, 4, and 10 degrees C/min; the kinetic and safety parameters were then evaluated via curve fitting. Through the reproducible tests in each condition, the results show that acetone is not a contaminant, because it could increase the activation energy (Ea) and onset temperature (To) when combined with MEKPO, which differs from the hazard information of the material safety data sheet (MSDS).

  14. Dynamics of Radical-Mediated Enzyme Catalyses

    NASA Astrophysics Data System (ADS)

    Warncke, Kurt

    1997-11-01

    An emergent class of enzymes harnesses the extreme reactivity of electron-deficient free radical species to perform some of the most difficult reactions in biology. The regio- and stereo-selectivity achieved by these enzymes defies long-held ideas that radical reactions are non-specific. The common primary step in these catalyses is metal- or metallocenter-assisted generation of an electron-deficient organic "initiator radical". The initiator radical abstracts a hydrogen atom from the substrate, opening a new reaction channel for rearrangement to the product. Our aim is to elucidate the detailed molecular mechanisms of the radical pair separation and radical rearrangement steps. Radical pair separation and substrate radical rearrangement are tracked by using time-resolved (10-7 to 10-3 s) techniques of pulsed-electron paramagnetic resonance spectroscopy (FT-EPR, ESEEM). Synchronous time-evolution of the reactions is attained by triggering with a visible laser pulse. Transient non-Boltzmann population of the states of the spin-coupled systems, and resultant electron spin polarization, facilitates study at or near room temperature under conditions where the enzymes are operative. The systems examined include ethanolamine deaminase, a vitamin B12 coenzyme-dependent enzyme, ribonucleotide reductase and photosynthetic reaction centers. The electronic and nuclear structural and kinetic information obtained from the pulsed-EPR studies is used to address how the initiator radicals are stabilized against deleterious recombination with the metal, and to distinguish the participation of concerted versus sequential rearrangement pathways.

  15. Physiological aspects of free-radical reactions.

    PubMed Central

    Yamazaki, I; Tamura, M; Nakajima, R; Nakamura, M

    1985-01-01

    Enzymes which catalyze the formation of free radicals in vitro will catalyze similar reactions in vivo. We believe that the formation of some kinds of free radicals has definite physiological meanings in metabolism. In this sense, the enzymes forming such free radicals are concluded to be in evolutionally advanced states. Elaborated structure and function of enzymes such as horseradish peroxidase and microsomal flavoproteins support the idea. Deleterious and side reactions caused by free radicals are assumed to be minimized in vivo by localizing the reactions, but this assumption should be verified by future studies. PMID:3007098

  16. Oxygen centered radicals in iodine chemical oscillators.

    PubMed

    Stanisavljev, Dragomir R; Milenković, Maja C; Mojović, Milos D; Popović-Bijelić, Ana D

    2011-07-14

    The existence of free radicals in iodine-based oscillatory systems has been debated for some time. Recently, we have reported the presence of reactive oxygen species (ROS) in the iodide-peroxide system in acidic medium, which is common to all iodine--based oscillatory systems ( J. Phys. Chem. A 2011 , 115 , 2247--2249 ). In this work, the goal was to identify the ROS produced in this system using an EPR spin trap which can distinguish between hydroxyl (HO(•)) and hydroperoxyl (HOO(•)) radicals. The formation of the hydroperoxyl radical was observed and a possible explanation for the low EPR signal of hydroxyl radical was proposed. PMID:21692499

  17. Inhibition of dual-specificity phosphatase 26 by ethyl-3,4-dephostatin: Ethyl-3,4-dephostatin as a multiphosphatase inhibitor.

    PubMed

    Seo, Huiyun; Cho, Sayeon

    2016-04-01

    Protein tyrosine phosphatases (PTPs) regulate protein function by dephosphorylating phosphorylated proteins in many signaling cascades and some of them have been targets for drug development against many human diseases. There have been many reports that some chemical inhibitors could regulate particular phosphatases. However, there was no extensive study on specificity of inhibitors towardss phosphatases. We investigated the effects of ethyl-3,4-dephostatin, a potent inhibitor of five PTPs including PTP-1B and Src homology-2-containing protein tyrosine phosphatase-1 (SHP-1), on thirteen other PTPs using in vitro phosphatase assays. Of them, dual-specificity protein phosphatase 26 (DUSP26), which inhibits mitogen-activated protein kinase (MAPK) and p53 tumor suppressor and is known to be overexpressed in anaplastic thyroid carcinoma, was inhibited by ethyl-3,4-dephostatin in a concentration-dependent manner. Kinetic studies with ethyl-3,4-dephostatin and DUSP26 revealed competitive inhibition, suggesting that ethyl-3,4-dephostatin binds to the catalytic site of DUSP26 like other substrate PTPs. Moreover, ethyl-3,4-dephostatin protects DUSP26-mediated dephosphorylation of p38, a member of the MAPK family, and p53. Taken together, these results suggest that ethyl-3,4-dephostatin functions as a multiphosphatase inhibitor and is useful as a therapeutic agent for cancers overexpressing DUSP26. PMID:27209699

  18. Continuous hot pressurized solvent extraction of 1,1-diphenyl-2-picrylhydrazyl free radical scavenging compounds from Taiwan yams (Dioscorea alata).

    PubMed

    Chen, Po-Yen; Tu, Yu-Xun; Wu, Cheng-Tar; Jong, Ting-Ting; Chang, Chieh-Ming J

    2004-04-01

    This study investigates a semicontinuous hot pressurized fluid extraction process and the scavenging activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical of the extract from Taiwan yams (Dioscorea alata). Liquid-liquid extractions were preliminarily employed to generate six fractions, initially extracted by ethanol. Then, the aqueous solution of dried crude ethanol extract was sequentially fractionated by hexane, chloroform, ethyl acetate, and n-butanol. The EC50 value was defined as the UV absorption of DPPH concentrations sufficiently decreased to 50% of the original value. It was found that all peel portions have a better effect on scavenging of the DPPH free radical than meat portions, especially for the ethyl acetate partition of the peel portion of Tainung #2 yam. Its EC50 value (14.5 microg mL(-1)) was even lower than that of ascorbic acid (21.4 microg mL(-1)). Furthermore, semicontinuous hot pressurized ethanol was superior to hot pressurized water in extracting the compound scavenging the DPPH radical from the Purpurea-Roxb peel. The recovery of four unknown compounds corresponded to the scavenging ratio of DPPH free radical in the hot pressurized ethanol extract. Finally, three-level and four-factor experimental design revealed that ethanol ratio and temperature were the most effective factors in order. Conditions of 80% of aqueous ethanol, 20.0 kg/kg solid ratio, 180 psig (1.342 MPa), and 100 degrees C were preferred to extract those antioxidants from the yam peel.

  19. 40 CFR 721.538 - Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenol, 4-(1,1-dimethyl- ethyl... Specific Chemical Substances § 721.538 Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  20. 40 CFR 721.538 - Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phenol, 4-(1,1-dimethyl- ethyl... Specific Chemical Substances § 721.538 Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  1. 75 FR 82069 - Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-29

    ... COMMISSION Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports AGENCY: United States.... This determination is to be used to establish the ``base quantity'' of imports of fuel ethyl alcohol... CBERA-beneficiary countries. The base quantity to be used by U.S. Customs and Border Protection in...

  2. 78 FR 9938 - Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-12

    ... recent previous determination for the 2012 amount in the Federal Register on December 30, 2011 (76 FR... COMMISSION Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports AGENCY: United States... is equal to 7 percent of the U.S. domestic market for fuel ethyl alcohol during the 12-month...

  3. 40 CFR 721.1085 - Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzenamine,4,4â²-methylenebis[N-ethyl-N-methyl-. 721.1085 Section 721.1085 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1085 Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-. (a)...

  4. 40 CFR 721.1085 - Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Benzenamine,4,4â²-methylenebis[N-ethyl-N-methyl-. 721.1085 Section 721.1085 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1085 Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-. (a)...

  5. 40 CFR 721.538 - Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenol, 4-(1,1-dimethyl- ethyl... Specific Chemical Substances § 721.538 Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  6. 40 CFR 721.445 - Substituted ethyl alken-a-mide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.445 Substituted ethyl alken-a-mide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted ethyl...

  7. 40 CFR 721.445 - Substituted ethyl alken-a-mide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.445 Substituted ethyl alken-a-mide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted ethyl...

  8. Novel in vivo active anti-malarials based on a hydroxy-ethyl-amine scaffold.

    PubMed

    Ciana, Claire-Lise; Siegrist, Romain; Aissaoui, Hamed; Marx, Léo; Racine, Sophie; Meyer, Solange; Binkert, Christoph; de Kanter, Ruben; Fischli, Christoph; Wittlin, Sergio; Boss, Christoph

    2013-02-01

    A novel series of anti-malarials, based on a hydroxy-ethyl-amine scaffold, initially identified as peptidomimetic protease inhibitors is described. Combination of the hydroxy-ethyl-amine anti-malarial phramacophore with the known Mannich base pharmacophore of amodiaquine (57) resulted in promising in vivo active novel derivatives. PMID:23260352

  9. Survey of ethyl carbamate in fermented foods sold in the United Kingdom in 2004.

    PubMed

    Hasnip, Sarah; Crews, Colin; Potter, Nicholas; Christy, Julie; Chan, Danny; Bondu, Thomas; Matthews, Wendy; Walters, Barry; Patel, Krishna

    2007-04-01

    Results are presented of a survey of fermented foods and beverages sold in the United Kingdom for levels of ethyl carbamate (urethane) carried out to expand the range of food types sold in the United Kingdom for which data regarding ethyl carbamate are available. Samples were analyzed by in-house validated methods, which included measurement uncertainty estimates. The samples comprised 75 fermented liquids (beers, wines, fortified wines, spirits, liqueurs, soy sauces, and vinegars) and 25 fermented solid foods (cheeses, yogurts, soybean products, sauerkraut, yeast extract, olives, and Christmas pudding). Ethyl carbamate was not detected in the beers or the cider. Wines contained between 11 and 24 microg/kg and sake between 81 and 164 microg/kg. Fortified wines contained ethyl carbamate at levels between 14 and 60 microg/kg. Only two of five liqueurs contained ethyl carbamate. Most soy sauces and vinegars did not contain ethyl carbamate. No ethyl carbamate was detected in cheeses, yogurts, olives, or soybean-based products. Single samples of sauerkraut, yeast extract, and Christmas pudding contained low levels (29, 41, and 20 microg/kg ethyl carbamate, respectively).

  10. Biomonitoring of N-ethyl-2-pyrrolidone in automobile varnishers.

    PubMed

    Koslitz, Stephan; Meier, Swetlana; Schindler, Birgit Karin; Weiss, Tobias; Koch, Holger Martin; Brüning, Thomas; Käfferlein, Heiko Udo

    2014-12-01

    N-alkyl-2-pyrrolidones are important organic solvents for varnishes in industry. This study investigates exposure to N-ethyl-2-pyrrolidone (NEP) in varnishing of hard plastic components in an automobile plant. Two specific biomarkers of exposure, 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI), were analyzed in urine samples of 14 workers. For this purpose, pre-shift, post-shift and next day pre-shift urine samples were collected midweek. Twelve workers performed regular work tasks (loading, wiping and packing), whereas two workers performed special work tasks including cleaning the sprayer system with organic solvents containing N-alkyl-2-pyrrolidones. Spot urine samples of nine non-exposed persons of the same plant served as controls. Median post-shift urinary levels of workers with regular work tasks (5-HNEP: 0.15 mg/L; 2-HESI: 0.19 mg/L) were ∼5-fold higher compared to the controls (0.03 mg/L each). Continuously increasing metabolite levels, from pre-shift via post-shift to pre-shift samples of the following day, were observed in particular for the two workers with the special working tasks. Maximum levels were 31.01 mg/L (5-HNEP) and 8.45 mg/L (2-HESI). No clear trend was evident for workers with regular working tasks. In summary, we were able to show that workers can be exposed to NEP during varnishing tasks in the automobile industry.

  11. Biomonitoring of N-ethyl-2-pyrrolidone in automobile varnishers.

    PubMed

    Koslitz, Stephan; Meier, Swetlana; Schindler, Birgit Karin; Weiss, Tobias; Koch, Holger Martin; Brüning, Thomas; Käfferlein, Heiko Udo

    2014-12-01

    N-alkyl-2-pyrrolidones are important organic solvents for varnishes in industry. This study investigates exposure to N-ethyl-2-pyrrolidone (NEP) in varnishing of hard plastic components in an automobile plant. Two specific biomarkers of exposure, 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI), were analyzed in urine samples of 14 workers. For this purpose, pre-shift, post-shift and next day pre-shift urine samples were collected midweek. Twelve workers performed regular work tasks (loading, wiping and packing), whereas two workers performed special work tasks including cleaning the sprayer system with organic solvents containing N-alkyl-2-pyrrolidones. Spot urine samples of nine non-exposed persons of the same plant served as controls. Median post-shift urinary levels of workers with regular work tasks (5-HNEP: 0.15 mg/L; 2-HESI: 0.19 mg/L) were ∼5-fold higher compared to the controls (0.03 mg/L each). Continuously increasing metabolite levels, from pre-shift via post-shift to pre-shift samples of the following day, were observed in particular for the two workers with the special working tasks. Maximum levels were 31.01 mg/L (5-HNEP) and 8.45 mg/L (2-HESI). No clear trend was evident for workers with regular working tasks. In summary, we were able to show that workers can be exposed to NEP during varnishing tasks in the automobile industry. PMID:25455446

  12. Effects of electron acceptors and radical scavengers on nonchain radical nucleophilic substitution reactions

    SciTech Connect

    Xianman Zhang; Dilun Yang; Youcheng Liu )

    1993-01-01

    The yields of reaction products from thermal nucleophilic substitution reactions in dimethyl sulfoxide (DMSO) of six o- and p-nitrohalobenzenes with the sodium salt of ethyl [alpha]-cyanoacetate carbanion [Na[sup +][sup [minus

  13. Echinochrome, a naturally occurring iron chelator and free radical scavenger in artificial and natural membrane systems.

    PubMed

    Lebedev, Alexander V; Ivanova, Marina V; Levitsky, Dmitri O

    2005-01-01

    Echinochrome, or 6-ethyl-2,3,5,7,8-pentahydroxy-1,4-naphthoquinone, possesses cardioprotective activity, and diminishes the myocardial ischemia/reperfusion injury that is known to be accompanied by free-radical oxidative damage and calcium overload. In this study, we investigated the lipophilicity of echinochrome, its ability to inhibit free-radical oxidation both in the bulk organic phase and in an artificial membrane system (liposomes), and to prevent the ferrous/ascorbate-induced leakage of calcium from the isolated sarcoplasmic reticulum (SR) of rabbit skeletal muscle. The experimentally-determined octanol/water partition coefficient (LogP) of echinochrome was +3.11, and the distribution coefficient (LogD) was +2.58 at pH 6.0 and -0.15 at pH 8.0. Echinochrome displayed high scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals with a stoichiometry of about 1:7. Echinochrome was more effective in inhibiting the phosphatidyl choline liposome peroxidation induced by Fe2+/ascorbate than that induced by hemin. The iron chelating ability of echinochrome was estimated spectrophotometrically. In isolated SR, echinochrome protected the ATP-dependent Ca2+-pump system from damage by Fe2+/ascorbate. It was concluded that iron chelation predominates in the overall antioxidant potential of echinochrome. PMID:15589964

  14. Radical-scavenging compounds from olive tree (Olea europaea L.) wood.

    PubMed

    Pérez-Bonilla, Mercedes; Salido, Sofía; van Beek, Teris A; Altarejos, Joaquín

    2014-01-01

    The purpose of this study was to complete knowledge on the chemical composition and radical-scavenging activity of olive tree wood. Two new monoterpene glycosides, (-)-oleuropeic acid 6'-O-α-D-glucopyranosyl ester (6a) and (-)-perillic acid 1'-O-β-D-primeverosyl ester (8), together with the known compounds (-)-oleuropeic acid (1), (-)-olivil (2), the aldehydic form of oleuropein aglycone (3), (+)-1-hydroxypinoresinol 1-O-β-D-glucopyranoside (4), (-)-oleuropeic acid 1'-O-β-D-glucopyranosyl ester (5), (-)-oleuropeic acid 6'-O-β-D-glucopyranosyl ester (6b), and (-)-olivil 4-O-β-D-glucopyranoside (7) were isolated from an ethyl acetate extract. The radical scavengers found (2-4 and 7) were detected and isolated with the help of the online HPLC-DAD-DPPH/ABTS technique. Compounds 2-4 and 7 displayed a higher antioxidative effect against the free radical DPPH than the reference BHT and lower than hydroxytyrosol, whereas compounds 1, 5, 6a, 6b, and 8 showed no activity.

  15. High-yield synthesis of bioactive ethyl cinnamate by enzymatic esterification of cinnamic acid.

    PubMed

    Wang, Yun; Zhang, Dong-Hao; Zhang, Jiang-Yan; Chen, Na; Zhi, Gao-Ying

    2016-01-01

    In this paper, Lipozyme TLIM-catalyzed synthesis of ethyl cinnamate through esterification of cinnamic acid with ethanol was studied. In order to increase the yield of ethyl cinnamate, several media, including acetone, isooctane, DMSO and solvent-free medium, were investigated in this reaction. The reaction showed a high yield by using isooctane as reaction medium, which was found to be much higher than the yields reported previously. Furthermore, several parameters such as shaking rate, water activity, reaction temperature, substrate molar ratio and enzyme loading had important influences on this reaction. For instance, when temperature increased from 10 to 50 °C, the initial reaction rate increased by 18 times and the yield of ethyl cinnamate increased by 6.2 times. Under the optimum conditions, lipase-catalyzed synthesis of ethyl cinnamate gave a maximum yield of 99%, which was of general interest for developing industrial processes for the preparation of ethyl cinnamate.

  16. Sexual dysfunction following radical prostatectomy.

    PubMed

    Benson, Cooper R; Serefoglu, Ege Can; Hellstrom, Wayne J G

    2012-01-01

    Prostate cancer is the most common solid cancer in men and the second leading cause of cancer death in men. A favored treatment option for organ-confined prostate cancer in a middle-aged healthy man is radical prostatectomy (RP). Despite advances in techniques for RP, there remain concerns among physicians and patients alike on its adverse effects on sexual function. Although post-RP erectile dysfunction has been extensively studied, little attention has been focused on the other domains of sexual function, namely loss of libido, ejaculatory dysfunction, orgasmic dysfunction, penile shortening, and Peyronie disease. The aim of this review is to discuss the most recent literature regarding post-RP sexual dysfunctions. PMID:22744864

  17. Students' Ideas and Radical Constructivism

    NASA Astrophysics Data System (ADS)

    Sánchez Gómez, Pedro J.

    2016-08-01

    In this article, I study, from the point of view of the analytic philosophy of mind, the compatibility of students' ideas studies (SIS) with radical constructivism (RC). I demonstrate that RC is based on a psychology of narrow mental states; that is, the idea that the mental content of an individual can be fully characterised without any reference external to her or him. I show that this fact imposes some severe restrictions to SIS to be incorporated into RC. In particular, I argue that only qualitative studies can comply with the requirement of narrowness. Nevertheless, I propose that quantitative works can be employed as sources of types in order to study token actual students. I use this type-token dichotomy to put forward an outline of a theory of the relation between school contents and mental contents. In this view, token mental contents regarding a given topic can be defined, and probed, only by resorting to typical school contents.

  18. Peroxy radical measurements with NCAR's chemical amplifier

    NASA Technical Reports Server (NTRS)

    Cantrell, Christopher; Shetter, Richard; Calvert, Jack G.

    1994-01-01

    The present NCAR instrument for HO2/RO2 measurements has been described previously. It is based on the reactions involving HO2, RO2, and HO radicals with CO and NO. Since (HO2) + (RO2) + (HO) is much greater than (HO) for most atmospheres, it is useful as a peroxy radical detector. Operation of the instrument depends on the creation of a chemical chain reaction which is initiated as HO2 and RO2 radicals in ambient air encounter added NO gas; this forms an NO2 molecule and an HO or RO radical: HO2(RO2) + NO yields HO(RO) + NO2. RO radicals react relatively efficiently with O2 to form an HO2 radical, and subsequently an HO-radical, by reaction with NO. CO gas added to the reaction chamber during part of the operating cycle, recycles the HO to HO2; HO + CO (+O2) yields HO2 + CO2. The reaction sequence may form several hundred NO2 molecules per HO2 (RO2) originally present, before chain termination occurs. The added CO is replaced by N2 addition periodically so that the chain reaction is suppressed, and a 'blank' signal resulting from NO2, O3 and possibly other NO2-forming species (non-chain processes) in ambient air is recorded. The difference between the signal with and without CO is proportional to the peroxy radical concentration. The NO2 produced is monitored using a sensitive luminol chemiluminescence detector system. In the NCAR instrument the length of the amplification chain is determined using a stable source of HO2 radicals (H2O2 thermal decomposition); the ratio of the signal seen with CO present to that with N2 present gives the sensitivity of the instrument to HO2 (molecules of NO2 formed/peroxy radical). The instrument is automated to carry out in hourly repeated cycles: (1) chain length determination; (2) NO2 calibration; and (3) linearity check on the response of signals. One minute averages of signals are normally recorded. The sensitivity of the instrument to detect peroxy radicals is in the pptv range. The present instrument has operated

  19. Distribution and organoleptic impact of ethyl 2-methylbutanoate enantiomers in wine.

    PubMed

    Lytra, Georgia; Tempere, Sophie; de Revel, Gilles; Barbe, Jean-Christophe

    2014-06-01

    The enantiomers of ethyl 2-methylbutanoate were assayed in several wines using chiral gas chromatography (β-cyclodextrin). Analyses of 37 commercial red wines from various vintages and origins revealed the almost exclusive presence of the S-enantiomeric form. The average concentration was ∼50 μg/L, but the oldest samples were found to contain higher ethyl 2-methylbutanoate levels than the youngest wines. The olfactory threshold of a racemic mixture of ethyl (2R)-2-methylbutanoate and ethyl (2S)-2-methylbutanoate (50:50, m/m) in dilute alcohol solution was 2.60 μg/L, almost twice that of the S-form, which was 1.53 μg/L. Ethyl (2S)-2-methylbutanoate and the racemic mixture of ethyl (2R)-2-methylbutanoate and ethyl (2S)-2-methylbutanoate had different aromatic nuances: the former was mainly defined by fruity descriptors, such as green apple (Granny Smith) and strawberry, whereas the latter had an unspecific, caustic, fruity, solvent odor. Sensory analysis revealed an enhancing effect of ethyl (2S)-2-methylbutanoate on the perception of fruity aromas in the matrices studied: the "olfactory threshold" of the fruity pool, consisting of esters found in red wines, in dilute alcohol solution alone was higher than that of the same mixture supplemented with 50 μg/L ethyl (2S)-2-methylbutanoate. The sensory profiles of these aromatic reconstitutions highlighted the contribution of ethyl (2S)-2-methylbutanoate to black-berry-fruit descriptors. PMID:24844693

  20. Crystal structure of (eth­oxy­ethyl­idene)di­methyl­aza­nium ethyl sulfate

    PubMed Central

    Tiritiris, Ioannis; Saur, Stefan; Kantlehner, Willi

    2015-01-01

    In the title salt, C6H14NO+·C2H5SO4 −, the C—N bond lengths in the cation are 1.2981 (14), 1.4658 (14) and 1.4707 (15) Å, indicating double- and single-bond character, respectively. The C—O bond length of 1.3157 (13) Å shows double-bond character, indicating charge delocalization within the NCO plane of the iminium ion. In the crystal, C—H⋯O hydrogen bonds between H atoms of the cations and O atoms of neighbouring ethyl sulfate anions are present, generating a three-dimensional network. PMID:26870525

  1. Urine tested positive for ethyl glucuronide and ethyl sulphate after the consumption of "non-alcoholic" beer.

    PubMed

    Thierauf, Annette; Gnann, Heike; Wohlfarth, Ariane; Auwärter, Volker; Perdekamp, Markus Grosse; Buttler, Klaus-Juergen; Wurst, Friedrich M; Weinmann, Wolfgang

    2010-10-10

    In abstinence maintenance programs, for reissuing the driving licence and in workplace monitoring programs abstinence from ethanol and its proof are demanded. Various monitoring programs that mainly use ethyl glucuronide (EtG) as alcohol consumption marker have been established. To abstain from ethanol, but not from the taste of alcoholic beverages, in particular non-alcoholic beer has become more and more popular. In Germany, these "alcohol-free" beverages may still have an ethanol content of up to 0.5vol.% without the duty of declaration. Due to severe negative consequences resulting from positive EtG tests, a drinking experiment with 2.5L of non-alcoholic beer per person was performed to address the question of measurable concentrations of the direct metabolites EtG and EtS (ethyl sulphate) in urine and blood. Both alcohol consumption markers - determined by LC-MS/MS - were found in high concentrations: maximum concentrations in urine found in three volunteers were EtG 0.30-0.87mg/L and EtS 0.04-0.07mg/L, i.e., above the often applied cut-off value for the proof of abstinence of 0.1mg EtG/L. In the urine samples of one further volunteer, EtG and EtS concentrations cumulated over-night and reached up to 14.1mg/L EtG and 16.1mg/L EtS in the next morning's urine. Ethanol concentrations in blood and urine samples were negative (determined by HS-GC-FID and by an ADH-based method). PMID:20457499

  2. Practical use of ethyl glucuronide and ethyl sulfate in postmortem cases as markers of antemortem alcohol ingestion.

    PubMed

    Høiseth, Gudrun; Karinen, Ritva; Christophersen, Asbjørg; Mørland, Jørg

    2010-03-01

    In postmortem toxicology, it could be difficult to determine whether a positive blood ethanol concentration reflects antemortem ingestion or postmortem synthesis of alcohol. Measurement of the nonoxidative ethanol metabolite ethyl glucuronide (EtG) has been suggested as a marker of antemortem ingestion of alcohol, but EtG might degrade postmortem which could make interpretation difficult. So far, the published articles concern EtG only. Another nonoxidative metabolite, ethyl sulfate (EtS), which is more stable, has therefore been included in this study. We present a material of 36 deaths where postmortem formation of ethanol was suspected and where both EtG and EtS were measured in blood and urine to assist the interpretation. In 19 cases, EtG and EtS were positive in the body fluids analyzed. The median concentration of EtG and EtS in blood was 0.4 (range 0.1-23.2) and 0.9 mg/L (range 0.04-7.9), respectively. The median concentration of EtG and EtS in urine was 35.9 (range 1.0-182) and 8.5 mg/L (range 0.3-99), respectively. In another 16 cases, there was no trace of EtG or EtS in the specimens analyzed. In one case, there was inconsistency between the results of EtG and EtS; they were both positive in urine, while only EtS was positive in blood. This study showed that, out of 36 cases, antemortem ingestion of alcohol was very likely in 19 and unlikely in 16, according to EtG and EtS results. In the last case, the interpretation was more difficult. One possible explanation would be postmortem degradation of EtG in blood. PMID:19937334

  3. Urine tested positive for ethyl glucuronide and ethyl sulphate after the consumption of "non-alcoholic" beer.

    PubMed

    Thierauf, Annette; Gnann, Heike; Wohlfarth, Ariane; Auwärter, Volker; Perdekamp, Markus Grosse; Buttler, Klaus-Juergen; Wurst, Friedrich M; Weinmann, Wolfgang

    2010-10-10

    In abstinence maintenance programs, for reissuing the driving licence and in workplace monitoring programs abstinence from ethanol and its proof are demanded. Various monitoring programs that mainly use ethyl glucuronide (EtG) as alcohol consumption marker have been established. To abstain from ethanol, but not from the taste of alcoholic beverages, in particular non-alcoholic beer has become more and more popular. In Germany, these "alcohol-free" beverages may still have an ethanol content of up to 0.5vol.% without the duty of declaration. Due to severe negative consequences resulting from positive EtG tests, a drinking experiment with 2.5L of non-alcoholic beer per person was performed to address the question of measurable concentrations of the direct metabolites EtG and EtS (ethyl sulphate) in urine and blood. Both alcohol consumption markers - determined by LC-MS/MS - were found in high concentrations: maximum concentrations in urine found in three volunteers were EtG 0.30-0.87mg/L and EtS 0.04-0.07mg/L, i.e., above the often applied cut-off value for the proof of abstinence of 0.1mg EtG/L. In the urine samples of one further volunteer, EtG and EtS concentrations cumulated over-night and reached up to 14.1mg/L EtG and 16.1mg/L EtS in the next morning's urine. Ethanol concentrations in blood and urine samples were negative (determined by HS-GC-FID and by an ADH-based method).

  4. Free Radical Mechanisms in Autoxidation Processes.

    ERIC Educational Resources Information Center

    Simic, Michael G.

    1981-01-01

    Discusses the use of steady-state radiation chemistry and pulse radiolysis for the generation of initial free radicals and formation of peroxy radicals in the autoxidation process. Provides information regarding the autoxidation process. Defines autoxidation reactions and antioxidant action. (CS)

  5. THE RADICAL OF A JORDAN ALGEBRA

    PubMed Central

    McCrimmon, Kevin

    1969-01-01

    In this paper we define a Jacobson radical for Jordan algebras analogous to that for associative algebras and show that it enjoys many of the properties of the associative radical. We then relate the corresponding notion of “semisimplicity” to the previously defined notion of “nondegeneracy” (Jacobson, N., these Proceedings, 55, 243-251 (1966)). PMID:16591736

  6. Ideals Adrift: An Educational Approach to Radicalization

    ERIC Educational Resources Information Center

    van San, Marion; Sieckelinck, Stijn; de Winter, Micha

    2013-01-01

    These days, the radicalization of young people is above all viewed as a security risk. Almost all research into this phenomenon has been carried out from a legal, criminological or socio-psychological perspective with a focus on detecting and containing the risks posed by radicalization. In the light of the political developments since September…

  7. Rearrangement of sulfonamidyl radicals with hydrogen migration

    SciTech Connect

    Troyanskii, E.I.; Lazareva, M.I.; Nikishin, G.I.

    1987-01-20

    One-step outlying oxidative chlorination of alkanesulfonamides by the action of the Na/sub 2/S/sub 2/O/sub 8/-CuCl/sub 2/ system via intermediate sulfonamidyl radicals gives 3- and 4-chloroalkanesulfonamides. Rearrangements of sulfonamidyl radicals with H atom migration from the sulfonyl segment predominates over rearrangement with H atom migration from the amide segment.

  8. Radical Behaviorism and Buddhism: Complementarities and Conflicts

    ERIC Educational Resources Information Center

    Diller, James W.; Lattal, Kennon A.

    2008-01-01

    Comparisons have been made between Buddhism and the philosophy of science in general, but there have been only a few attempts to draw comparisons directly with the philosophy of radical behaviorism. The present review therefore considers heretofore unconsidered points of comparison between Buddhism and radical behaviorism in terms of their…

  9. Victimology: A Consideration of the Radical Critique.

    ERIC Educational Resources Information Center

    Friedrichs, David O.

    1983-01-01

    Discusses the emergence of a new radical model in criminology and a new subdisciplinary area of concern, victimology, with roots in Marx and Engels' original formulations. Argues that the radical understanding of victimization provides an important corrective to mainstream approaches and broadens the focus of the concept of victimization. (JAC)

  10. Alex Bloom, Pioneer of Radical State Education

    ERIC Educational Resources Information Center

    Fielding, Michael

    2005-01-01

    Alex Bloom is one of the greatest figures of radical state education in England. His approach to "personalised learning" and the development of a negotiated curriculum was immeasurably more profound and more inspiring than anything to emerge thus far from the current DfES. His approach to student voice was much more radical than anything presently…

  11. Place of Schauta's radical vaginal hysterectomy.

    PubMed

    Roy, Michel; Plante, Marie

    2011-04-01

    Women affected by early stage invasive cancer of the cervix are usually treated by surgery. Radical abdominal hysterectomy with pelvic lymphadenectomy is the most widely used technique. Because the morbidity of the abdominal approach can be important, the radical vaginal hysterectomy has gained acceptance in gynaecologic oncology. New instrumentation in laparoscopy also opens the possibility of treating cervical cancer by laparoscopically assisted vaginal radical hysterectomy and also total laparoscopic radical hysterectomy. Before these techniques become widely accepted, it has to be shown that safety and efficacy are comparable with the 'standard' abdominal approach. In this chapter, we review the technique of radical vaginal hysterectomy with pelvic lymphadenectomy and evaluate results of published studies, comparing the abdominal, vaginal and laparoscopic approaches.

  12. 21 CFR 176.160 - Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Chromium (Cr III) complex of N-ethyl-N... § 176.160 Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine. The chromium (Cr III) complex of N-ethyl - N -heptadecylfluoro-octane sulfonyl glycine containing up to 20...

  13. 40 CFR 721.10074 - Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-dimethylcyclohexyl)ethyl ester. 721.10074 Section 721.10074 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10074 Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester. (a... acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester (PMN P-05-568; CAS No. 477218-59-0)...

  14. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-oxopropenyloxy)ethyl) ester . 721.1950 Section 721.1950 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  15. 40 CFR 721.10074 - Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-dimethylcyclohexyl)ethyl ester. 721.10074 Section 721.10074 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10074 Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester. (a... acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester (PMN P-05-568; CAS No. 477218-59-0)...

  16. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-oxopropenyloxy)ethyl) ester . 721.1950 Section 721.1950 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  17. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-oxopropenyloxy)ethyl) ester . 721.1950 Section 721.1950 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  18. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-oxopropenyloxy)ethyl) ester . 721.1950 Section 721.1950 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  19. 40 CFR 721.10074 - Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-dimethylcyclohexyl)ethyl ester. 721.10074 Section 721.10074 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10074 Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester. (a... acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester (PMN P-05-568; CAS No. 477218-59-0)...

  20. 40 CFR 721.10074 - Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-dimethylcyclohexyl)ethyl ester. 721.10074 Section 721.10074 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10074 Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester. (a... acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester (PMN P-05-568; CAS No. 477218-59-0)...

  1. 40 CFR 721.1950 - 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester .

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-oxopropenyloxy)ethyl) ester . 721.1950 Section 721.1950 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1950 2-Butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester . (a... 2-butenedioic acid (Z), mono(2-((1-oxopropenyloxy)ethyl) ester (PMN P-85-543) is subject...

  2. 40 CFR 721.10588 - Phenol, 2-[1-[[3-(1H-imidazol-1-yl)propyl]imino]ethyl]-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenol, 2- imino]ethyl]-. 721.10588... Substances § 721.10588 Phenol, 2- imino]ethyl]-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol, 2- imino]ethyl]- (PMN P-11-98; CAS No....

  3. 40 CFR 721.10588 - Phenol, 2-[1-[[3-(1H-imidazol-1-yl)propyl]imino]ethyl]-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phenol, 2- imino]ethyl]-. 721.10588... Substances § 721.10588 Phenol, 2- imino]ethyl]-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol, 2- imino]ethyl]- (PMN P-11-98; CAS No....

  4. 40 CFR 721.10243 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, bis(2-chloroethyl) ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphonic acid, P- ethyl]-, bis(2... Specific Chemical Substances § 721.10243 Phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester. (a... phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester (PMN P-09-193; CAS No. 55088-28-3) is subject...

  5. 40 CFR 721.10243 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, bis(2-chloroethyl) ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphonic acid, P- ethyl]-, bis(2... Specific Chemical Substances § 721.10243 Phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester. (a... phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester (PMN P-09-193; CAS No. 55088-28-3) is subject...

  6. 40 CFR 721.10243 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, bis(2-chloroethyl) ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphonic acid, P- ethyl]-, bis(2... Specific Chemical Substances § 721.10243 Phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester. (a... phosphonic acid, P- ethyl]-, bis(2-chloroethyl) ester (PMN P-09-193; CAS No. 55088-28-3) is subject...

  7. Pilot study of radical hysterectomy versus radical trachelectomy on sexual distress.

    PubMed

    Brotto, Lori A; Smith, Kelly B; Breckon, Erin; Plante, Marie

    2013-01-01

    Radical trachelectomy, which leaves the uterus intact, has emerged as a desirable surgical option for eligible women with early-stage cervical cancer who wish to preserve fertility. The available data suggest excellent obstetrical outcomes with radical trachelectomy, and no differences in sexual responding between radical trachelectomy and radical hysterectomy. There is a need to examine the effect of radical hysterectomy on sexual distress given that it is distinct from sexual function. Participants were 34 women diagnosed with early-stage cervical cancer. The authors report 1-month postsurgery data for 29 women (radical hysterectomy group: n = 17, M age = 41.8 years; radical trachelectomy group: n = 12, M age = 31.8 years), and 6-month follow-up data on 26 women. Whereas both groups experienced an increase in sex-related distress immediately after surgery, distress continued to increase 6 months after surgery for the radical hysterectomy group but decreased in the radical trachelectomy group. There were no between-group differences in mood, anxiety, or general measures of health. The decrease in sex-related distress in the radical trachelectomy but not in the radical hysterectomy group suggests that the preservation of fertility may have attenuated sex-related distress. Care providers should counsel women exploring surgical options for cervical cancer about potential sex distress-related sequelae.

  8. Quantification of lipid alkyl radicals trapped with nitroxyl radical via HPLC with postcolumn thermal decomposition.

    PubMed

    Koshiishi, Ichiro; Tsuchida, Kazunori; Takajo, Tokuko; Komatsu, Makiko

    2005-11-01

    Lipid alkyl radicals generated from polyunsaturated fatty acids via chemical or enzymatic H-abstraction have been a pathologically important target to quantify. In the present study, we established a novel method for the quantification of lipid alkyl radicals via nitroxyl radical spin-trapping. These labile lipid alkyl radicals were converted into nitroxyl radical-lipid alkyl radical adducts using 3-carbamoyl-2,2,5,5-tetramethyl-3-pyrroline-N-oxyl (CmdeltaP) (a partition coefficient between octanol and water is approximately 3) as a spin-trapping agent. The resulting CmdeltaP-lipid alkyl radical adducts were determined by HPLC with postcolumn online thermal decomposition, in which the adducts were degraded into nitroxyl radicals by heating at 100 degrees C for 2 min. The resulting nitroxyl radicals were selectively and sensitively detected by electrochemical detection. With the present method, we, for the first time, determined the lipid alkyl radicals generated from linoleic acid, linolenic acid, and arachidonic acid via soybean lipoxygenase-1 or the radical initiator 2,2'-azobis(2,4-dimethyl-valeronitrile).

  9. Healing mechanisms of the hydroalcoholic extract and ethyl acetate fraction of green tea (Camellia sinensis (L.) Kuntze) on chronic gastric ulcers.

    PubMed

    Borato, Débora Gasparin; Scoparo, Camila Toledo; Maria-Ferreira, Daniele; da Silva, Luísa Mota; de Souza, Lauro Mera; Iacomini, Marcello; Werner, Maria Fernanda de Paula; Baggio, Cristiane Hatsuko

    2016-03-01

    Green tea is an infusion of unfermented leaves of Camellia sinensis (L.) Kuntze (Theaceae), traditionally used for the treatment of obesity, hypercholesterolemia, and gastric complaints. This study evaluated the mechanisms involved in the gastric ulcer healing of the hydroalcoholic extract from green tea (GEt), its ethyl acetate fraction, (GEAc) and epigallocatechin gallate (EGCG) using the model of acetic acid-induced gastric ulcer in rats. The chronic gastric ulcer was induced by application of 80 % acetic acid on serosal mucosa of rats. After 7 days of oral treatment with GEt and GEAc, the ulcer area, mucin content, inflammatory parameters (MPO and NAG), and antioxidant system (GSH and LOOH levels, SOD and GST activities) were evaluated. In vitro, the scavenging activity of GEt and GEAc were also measured. The antisecretory action was studied on the pylorus ligature method in rats. Oral treatment with GEt and GEAc reduced significantly the gastric ulcer area induced by acetic acid. The gastric ulcer healing was accompanied by increasing of mucin content, restoration of GSH levels and SOD activity, and reduction of MPO and LOOH levels. In addition, GEt and GEAc reduced the DPPH free radicals in vitro. Furthermore, the oral treatment of animals with GEt and GEAc did not alter the gastric acid secretion or cause signs of toxicity. Collectively, these results showed that GEt had a pronounced antiulcer effect, possibly through maintenance of mucin content and reduction of inflammation and oxidative stress. In addition, the compounds present in its ethyl acetate fraction could be responsible for the extract activity.

  10. Amphiphilic poly(D- or L-lactide)-b-poly(N,N-dimethylamino-2-ethyl methacrylate) block copolymers: controlled synthesis, characterization, and stereocomplex formation.

    PubMed

    Spasova, Mariya; Mespouille, Laetitia; Coulembier, Olivier; Paneva, Dilyana; Manolova, Nevena; Rashkov, Iliya; Dubois, Philippe

    2009-05-11

    Novel well-defined amphiphilic poly(D-lactide)-b-poly(N,N-dimethylamino-2-ethyl methacrylate) (PDLA-b-PDMAEMA) and poly(L-lactide)-b-poly(N,N-dimethylamino-2-ethyl methacrylate) (PLLA-b-PDMAEMA) copolymers were obtained. The synthesis strategy consisted of a three-step procedure: (i) controlled ring-opening polymerization (ROP) of (D- or L-)lactide initiated by Al(O(i)Pr)(3), followed by (ii) quantitative conversion of the polylactide (PLA) hydroxyl end-groups with bromoisobutyryl bromide and (iii) atom transfer radical polymerization (ATRP) of DMAEMA. The PLA block molecular weight was kept below 5000 g/mol. The macromolecular parameters of the (co)polymers were determined by (1)H NMR spectroscopy and size exclusion chromatography (SEC). The stereocomplexes of PDLA-b-PDMAEMA/PLLA-b-PDMAEMA diblock copolymers were prepared via solvent casting. The stereocomplex formation was evidenced by differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses. The obtained stereocomplexes had melting temperature of about 65 degrees C above that of the individual copolymers and exhibited diffraction patterns assigned to the stereocomplex crystallites. In addition, for the first time it was shown that the replacement of one of the PLA partners with high molecular weight PLLA or PDLA did not hamper the stereocomplex formation. The presence of PDMAEMA blocks proved to impart hydrophilicity of the synthesized copolymers and related stereocomplexes, as determined by static water contact angle measurements. PMID:19331403

  11. Searching for trans ethyl methyl ether in Orion KL⋆

    NASA Astrophysics Data System (ADS)

    Tercero, B.; Cernicharo, J.; López, A.; Brouillet, N.; Kolesniková, L.; Motiyenko, R. A.; Margulès, L.; Alonso, J. L.; Guillemin, J.-C.

    2015-10-01

    We report on the tentative detection of trans ethyl methyl ether (tEME), t-CH3CH2OCH3, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for gauche-trans-n-propanol, Gt-n-CH3CH2CH2OH, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30 m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are ≤(4.0 ± 0.8) × 1015 cm-2 and ≤(1.0 ± 0.2) × 1015 cm-2 for tEME and Gt-n-propanol, respectively. The rotational temperature is ~100 K for both molecules. We also provide maps of CH3OCOH, CH3CH2OCOH, CH3OCH3, CH3OH, and CH3CH2OH to compare the distribution of these organic saturated O-bearing species containing methyl and ethyl groups in this region. Abundance ratios of related species and upper limits to the abundances of non-detected ethers are provided. We derive an abundance ratio N(CH3OCH3)/N(tEME) ≥ 150 in the compact ridge of Orion. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00009.SV. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan) with NRC (Canada), NSC, and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. This work was also based on observations carried out with the IRAM 30-m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).Appendix A is available in electronic form at http://www.aanda.org

  12. Subchronic inhalation neurotoxicity studies of ethyl acetate in rats.

    PubMed

    Christoph, Greg R; Hansen, John F; Leung, Hon-Wing

    2003-12-01

    Rats were exposed to 0, 350, 750 or 1500 ppm of ethyl acetate by inhalation for 6 h per day, 5 days per week for 13 weeks. Functional observational battery (FOB) and motor activity tests occurred on non-exposure days during weeks 4, 8 and 13, after which tissues were microscopically examined for neuropathology. A subset of rats was monitored during a 4-week recovery period. Exposure to 750 and 1500 ppm, diminished behavioral responses to unexpected auditory stimuli during the exposure session and appeared to be an acute sedative effect. There were no signs of acute intoxication 30 min after exposure sessions ended. Rats exposed to 750 and 1500 ppm had reduced body weight, body weight gain, feed consumption, and feed efficiency, which fully or partially recovered within 4 weeks. Reductions in body weight gain and feed efficiency were observed in male rats exposed to 350 ppm. The principal behavioral effect of subchronic exposure was reduced motor activity in the 1500 ppm females, an effect that was not present after the 4-week recovery period. All other FOB and motor activity parameters were unaffected, and no pathology was observed in nervous system tissues. Operant sessions were conducted in another set of male rats preconditioned to a stable operant baseline under a multiple fixed ratio-fixed interval (FR-FI) schedule of food reinforcement. FR response rate, FR post-reinforcement pause duration, and the pattern of FI responding were not affected during or after the exposure series. In contrast, within-group FI rate for the treatment groups increased over time whereas those of the controls decreased. A historical control group, however, also showed a similar pattern of increase, indicating that these changes did not clearly represent a treatment-related effect. Results from these studies indicate a LOEL of 350 ppm for systemic toxicity based on the decreased body weight gain in male rats, and a LOEL of 1500 ppm for neurotoxicity based on the transient reduction in

  13. Replication across Regioisomeric Ethylated Thymidine Lesions by Purified DNA Polymerases

    PubMed Central

    Andersen, Nisana; Wang, Pengcheng; Wang, Yinsheng

    2013-01-01

    Causal links exist between smoking cigarettes and cancer development. Some genotoxic agents in cigarette smoke are capable of alkylating nucleobases in DNA and higher levels of ethylated DNA lesions were observed in smokers than non-smokers. In this study, we examined comprehensively how the regioisomeric O2-, N3- and O4-ethylthymidine (O2-, N3- and O4-EtdT) perturb DNA replication mediated by purified human DNA polymerases (hPol) η, κ, and ι, yeast DNA polymerase ζ (yPol ζ), and the exonuclease-free Klenow fragment (Kf−) of Escherichia coli DNA polymerase I. Our results showed that hPol η and Kf− could bypass all three lesions and generate full-length replication products, whereas hPol ι stalled after inserting a single nucleotide opposite the lesions. Bypass carried out by hPol κ and yPol ζ differed markedly amongst the three lesions: Consistent with its known capability in bypassing efficiently the minor-groove N2-substituted 2′-deoxyguanosine lesions, hPol κ was able to bypass O2-EtdT, though it experienced great difficulty in bypassing N3-EtdT and O4-EtdT; yPol ζ was only modestly blocked by O4-EtdT, but the polymerase was highly hindered by O2-EtdT and N3-EtdT. LC-MS/MS analysis of the replication products revealed that DNA synthesis opposite O4-EtdT was highly error-prone, with dGMP being preferentially inserted, while the presence of O2-EtdT and N3-EtdT in template DNA directed substantial frequencies of misincorporation of dGMP and, for hPol ι and Kf−, dTMP. Thus, our results suggested that O2-EtdT and N3-EtdT may also contribute to the AT→TA and AT→GC mutations observed in cells and tissues of animals exposed to ethylating agents. PMID:24134187

  14. Radiolytic generation of radical cations in xenon matrices. Tetramethylcyclopropane radical cation and its transformations

    SciTech Connect

    Qin, X.Z.; Trifunac, A.D. )

    1990-04-05

    Radiolytic generation of radical cations in xenon matrices containing electron scavengers is illustrated by studying the 1,1,2,2-tetramethylcyclopropane radical cation. Dilute and concentrated solutions of tetramethylcyclopropane in xenon without electron scavengers and neat tetramethylcyclopropane yielded neutral radicals upon {gamma}-irradiation. Speculation on the mechanisms of radical formation is presented. The radical species observed in the {gamma}-irradiation of neat tetramethylcyclopropane appears to be identical with the paramagnetic species observed in CF{sub 2}ClCFCl{sub 2} above 120 K, suggesting that a neutral radical rather than the ring-opened distonic radical cation is observed in the CF{sub 2}ClCFCl{sub 2} matrix.

  15. Halogenated silanes, radicals, and cations

    NASA Astrophysics Data System (ADS)

    Wang, Liming; He, Yi-Liang

    2008-09-01

    Quantum chemistry study has been carried out on the structure and energetics of halogenated silanes, radicals, and cations (SiHxXy0,+1, X = F, Cl, Br; x + y = 1-4). The geometries are optimized at B3LYP/6-31+G(2df,p) level. The adiabatic ionization energiess (IEas), relative energetics of cations, proton affinities (PAs) of silanes, and the enthalpies of formation are predicted using G3(CC) model chemistry. Non-classical ion complex structures are found for hydrogenated cations and transition states connecting classical and non-classical structures are also located. The most stable cations for silylene and silyl radicals have their classical divalent and trivalent structures, and those for silanes have non-classical structures except for SiH3Br+ and SiH2Br2+. The non-classical structures for halosilane cations imply difficulty in experimentally measurement of the adiabatic ionization energies using photoionization or photoelectron studies. For SiH3X, SiH2X2, and SiHX3, the G3(CC) adiabatic IEas to classical ionic structures closest to their neutrals agree better with the photoelectron spectroscopic measurements. The transition states between classical and non-classical structures also hamper the photoionization determination of the appearance energies for silylene cations from silanes. The G3(CC) results for SiHx0,+1 agree excellently with the photoionization mass spectrometric study, and the results for fluorinated and chlorinated species also agree with the previous theoretical predictions at correlation levels from BAC-MP4 to CCSD(T)/CBS. The predicted enthalpy differences between SiH2Cl+, SiHCl2+, and SiCl3+ are also in accordance with previous kinetics study. The G3(CC) results show large discrepancies to the collision-induced charge transfer and/or dissociation reactions involving SiFx+ and SiClx+ ions, for which the G3(CC) enthalpies of formation are also significantly differed from the previous theoretical predictions, especially on SiFx+ (x = 2-4). The G3

  16. Ethyl-2-(3,5-Dihidroxyfenol): Phloroglucinol derivatives as potential anticancer material

    NASA Astrophysics Data System (ADS)

    Kusumaningsih, Triana; Firdaus, Maulidan; Widyo Wartono, Muhammad; Nur Artanti, Anif; Suci Handayani, Desi; Eryanto Putro, Angga

    2016-02-01

    Ethyl-2-(3,5-dihidroxyfenol) based phloroglucinol compounds have been synthesized. Ethyl-2-(3,5-dihidroksifenol) were synthesized by reacting phloroglucinol with ethyl 2-chloro acetate in excess. Phloroglucinol reaction using 2-chloro ethyl acetate was carried out under reflux for 24 hours at a temperature of 56 oC. The reaction products were identified by a thin layer chromatography and were characterized by melting point test. Analysis of the structure of the products was obtained by FTIR spectrophotometer, H-NMR, and 13C-NMR. The result of the reaction between phloroglucinol and 2-chloro ethyl acetate was brownish black solid, and has a melting point of 191 oC. Based on the structural analysis by FTIR, 1H-NMR and 13C-NMR, the reaction product was a mixture of compounds which is ethyl 2- (3,5-dihidroksifenol) acetate, ethyl-2-(2,4,6-trioxocyclohexyl) acetate, and the rest of phloroglucinol which can not react.

  17. Mechanism of quizalofop-ethyl selectivity in monocotyledonous and dicotyledonous species

    SciTech Connect

    Ruizzo, M.A.

    1986-01-01

    Cucumber (Cucumis sativus L.) susceptibility to quizalofop-ethyl herbicide was investigated under field and greenhouse conditions. Yield of cucumber cultivars was significantly reduced under field conditions with a single or repeat application of the ethyl ester of quizalofop at 0.14 or 0.28 kg ai/ha. Under greenhouse conditions, quialofop-ethyl significantly suppressed cucumber plant fresh weight with or without the presence of an adjuvant. Enhancement of herbicide activity was directly related to concentration of adjuvant. Microliter droplet application of quizalofop-ethyl at a 10/sup -3/ M concentration, inhibited the relative growth (RGR) and net assimilation rate (NAR) of the treated cucumber leaf 45% and 52%, respectively. Expression of herbicidal injury was localized on the treated leaf with no visible symptoms observed on adjacent leaves. Radiolabeled /sup 14/C-quizalofop-ethyl was applied to leaves of cucumber and corn (Zea mays L.) to compare translocation patterns between two susceptible plant species and relate this information to the observed selectivity of the herbicide. Cucumber autoradiographs showed minimal translocation of /sup 14/C-quizalofop-ethyl 192 hours after treatment. In contrast, corn autoradiographs showed both apoplastic and symplastic transport of quizalofop-ethyl 3 and 24 hours after treatment. Quantification of /sup 14/C in cucumber revealed 96% of absorbed /sup 14/C was confined to the treated leaf after 192h of exposure.

  18. Synthesis of zwitterionic polymer-based amphiphilic triblock copolymers by atom transfer radical polymerization for production of extremely stable nanoemlusions

    NASA Astrophysics Data System (ADS)

    Lee, Jin Yong; Kim, Ji Eun; Kim, Jin Woong

    2015-03-01

    In fields of soft matter, there have been growing interests in utilizing amphiphilic block copolymers due to their intriguing properties, such as surface activity as well as self-assembly. In this work, we synthesize a series of poly (2-(methacryloyloxy) ethyl phosphorylcholine)- b-poly (ɛ-caprolactone)- b-poly (2-(methacryloyloxy) ethyl phosphorylcholine) (PMPC- b-PCL- b-PMPC) triblock copolymers by using atom transfer radical polymerization (ATRP). We have a particular interest in using poly (2-(methacryloyloxy) ethyl phosphorylcholine) (PMPC) as a hydrophilic block, since it can have both electrostatic repulsion and steric repulsion in complex fluid systems. Assembling them at the oil-water interface by using the phase inversion method enables production of highly stable nanoemulsions. From the analyses of the crystallography and self-assembly behavior, we have found that the triblock copolymers assemble to form a flexible but tough molecular thin film at the interface, which is essential for the remarkable improvement in the emulsion stability.

  19. Characteristics of Radical Reactions, Spin Rules, and a Suggestion for the Consistent Use of a Dot on Radical Species

    ERIC Educational Resources Information Center

    Wojnarovits, Laszlo

    2011-01-01

    In many chemical reactions, reactive radicals have been shown to be transient intermediates. The free radical character of a chemical species is often, but not always, indicated by adding a superscript dot to the chemical formula. A consistent use of this radical symbol on all species that have radical character is suggested. Free radicals have a…

  20. [Preparation of a novel polymer monolith using atom transfer radical polymerization method for solid phase extraction].

    PubMed

    Shen, Ying; Qi, Li; Qiao, Juan; Mao, Lanqun; Chen, Yi

    2013-04-01

    In this study, a novel polymer monolith based solid phase extraction (SPE) material has been prepared by two-step atom transfer radical polymerization (ATRP) method. Firstly, employing ethylene glycol dimethacrylate (EDMA) as a cross-linker, a polymer monolith filled in a filter head has been in-situ prepared quickly under mild conditions. Then, the activators generated by electron transfer ATRP (ARGET ATRP) was used for the modification of poly(2-(dimethylamino)ethyl-methacrylate) (PDMAEMA) on the monolithic surface. Finally, this synthesized monolith for SPE was successfully applied in the extraction and enrichment of steroids. The results revealed that ATRP can be developed as a facile and effective method with mild reaction conditions for monolith construction and has the potential for preparing monolith in diverse devices.

  1. Surface-initiated atom transfer radical polymerization of methyl methacrylate from magnetite nanoparticles at ambient temperature.

    PubMed

    Raghuraman, G K; Dhamodharan, R

    2006-07-01

    The synthesis of methyl methacrylate (MMA) brush from the surface of magnetite nanoparticles (core-shell structure), from initiator moieties anchored covalently to the nanoparticles, via room temperature atom transfer radical polymerization (ATRP) is described. The surface-initiated polymerization was carried out from a surface-confined initiator containing a 2-bromoisobutyrate moiety with Cu(I)Br/PMDETA catalytic system. The initiator moiety was covalently anchored to the nanoparticles via a two step modification reaction scheme. Controlled polymerization was observed if ethyl-2-bromoisobutyrate (2-EiBrB) was added as a free/sacrificial initiator. A linear increase of molecular weight and a narrow molecular weight distribution of the PMMA formed in solution, provide evidence for a controlled surface-initiated polymerization, leading to surface-attached polymer brushes under mild conditions. The grafted PMMA provides good stability and dispersibility for the nanoparticles in organic solvents.

  2. Reactions of Ethyl Groups on a Model Chromia Surface: Ethyl Chloride on Stoichiometric Alpha-Cr2O3(1012)

    SciTech Connect

    Brooks, J.; Ma, Q; Cox, D

    2009-01-01

    The reaction of CH3CH2Cl over the nearly-stoichiometric ?-Cr2O3 (1 0 View the MathML source 2) surface yields gas phase CH2double bond; length as m-dashCH2, CH3CH3, H2 and surface chlorine adatoms. The decomposition reaction is initiated via C-Cl bond cleavage to give a surface ethyl (CH3CH2-) intermediate. A rate-limiting ?-hydride elimination from the surface ethyl species produces gas phase CH2double bond; length as m-dashCH2 and surface hydrogen atoms. Two parallel competing reactions form CH3CH3, via ?-hydride addition to remaining surface ethyl species (reductive elimination), and H2, via the combination of two surface hydrogen atoms. The chlorine freed from the dissociation of CH3CH2Cl binds at the five-coordinate surface Cr3+ sites on the stoichiometric surface and inhibits the surface chemistry via simple site blocking. No surface carbon deposition is observed from the thermal reaction of ethyl chloride, suggesting that ethyl intermediates are not primary coke forming intermediates in the dehydrogenation of ethane over (1 0 View the MathML source 2) facets of ?-Cr2O3.

  3. Quantification of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in meconium for detection of alcohol abuse during pregnancy: Correlation study between both biomarkers.

    PubMed

    Cabarcos, Pamela; Tabernero, María Jesús; Otero, José Luís; Míguez, Martha; Bermejo, Ana María; Martello, Simona; De Giovanni, Nadia; Chiarotti, Marcello

    2014-11-01

    This article presents results from 47 meconium samples, which were analyzed for fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) for detection of gestational alcohol consumption. A validated microwave assisted extraction (MAE) method in combination with GC-MS developed in the Institute of Forensic Science (Santiago de Compostela) was used for FAEE and the cumulative concentration of ethyl myristate, ethyl palmitate and ethyl stearate with a cut-off of 600ng/g was applied for interpretation. A simple method for identification and quantification of EtG has been evaluated by ultrasonication followed solid phase extraction (SPE). Successful validation parameters were obtained for both biochemical markers of alcohol intake. FAEE and EtG concentrations in meconium ranged between values lower than LOD and 32,892ng/g or 218ng/g respectively. We have analyzed FAEE and EtG in the same meconium aliquot, enabling comparison of the efficiency of gestational ethanol exposure detection. Certain agreement between the two biomarkers was found as they are both a very specific alcohol markers, making it a useful analysis for confirmation. PMID:25137651

  4. Degradation of methyl and ethyl mercury by singlet oxygen generated from sea water exposed to sunlight or ultraviolet light.

    PubMed

    Suda, I; Suda, M; Hirayama, K

    1993-01-01

    Photodegradation of methyl mercury (MeHg) and ethyl Hg (EtHg) in sea water was studied by sunlight or ultraviolet (UV) light exposure, and by determining inorganic Hg produced by degradation. Sea water containing 1 microM MeHg or EtHg was exposed to sunlight or UV light. N-Acetyl-L-cysteine was added to the solution for preventing Hg loss during the light exposure. MeHg and EtHg in sea water were degraded by sunlight (> 280 nm), UV light A (320-400 nm) and UV light B (280-320 nm), though the amounts of inorganic Hg produced from MeHg were 1/6th to 1/12th those from EtHg. Inorganic Hg production was greater with increasing concentration of sea water. Degradation of MeHg and EtHg by the UV light A exposure was inhibited by singlet oxygen (1O2) trappers such as NaN3, 1,4-diazabicyclo[2,2,2]octane, histidine, methionine and 2,5-dimethylfuran. On the other hand, inhibitors or scavengers of superoxide anion, hydrogen peroxide or hydroxyl radical did not inhibit the photodegradation of alkyl Hg. These results suggested that 1O2 generated from sea water exposed to sunlight, UV light A or UV light B was the reactive oxygen species mainly responsible for the degradation of MeHg and EtHg.

  5. Kinetics of Propargyl Radical Dissociation.

    PubMed

    Klippenstein, Stephen J; Miller, James A; Jasper, Ahren W

    2015-07-16

    Due to the prominent role of the propargyl radical for hydrocarbon growth within combustion environments, it is important to understand the kinetics of its formation and loss. The ab initio transition state theory-based master equation method is used to obtain theoretical kinetic predictions for the temperature and pressure dependence of the thermal decomposition of propargyl, which may be its primary loss channel under some conditions. The potential energy surface for the decomposition of propargyl is first mapped at a high level of theory with a combination of coupled cluster and multireference perturbation calculations. Variational transition state theory is then used to predict the microcanonical rate coefficients, which are subsequently implemented within the multiple-well multiple-channel master equation. A variety of energy transfer parameters are considered, and the sensitivity of the thermal rate predictions to these parameters is explored. The predictions for the thermal decomposition rate coefficient are found to be in good agreement with the limited experimental data. Modified Arrhenius representations of the rate constants are reported for utility in combustion modeling. PMID:25871530

  6. Kinetics of Propargyl Radical Dissociation.

    PubMed

    Klippenstein, Stephen J; Miller, James A; Jasper, Ahren W

    2015-07-16

    Due to the prominent role of the propargyl radical for hydrocarbon growth within combustion environments, it is important to understand the kinetics of its formation and loss. The ab initio transition state theory-based master equation method is used to obtain theoretical kinetic predictions for the temperature and pressure dependence of the thermal decomposition of propargyl, which may be its primary loss channel under some conditions. The potential energy surface for the decomposition of propargyl is first mapped at a high level of theory with a combination of coupled cluster and multireference perturbation calculations. Variational transition state theory is then used to predict the microcanonical rate coefficients, which are subsequently implemented within the multiple-well multiple-channel master equation. A variety of energy transfer parameters are considered, and the sensitivity of the thermal rate predictions to these parameters is explored. The predictions for the thermal decomposition rate coefficient are found to be in good agreement with the limited experimental data. Modified Arrhenius representations of the rate constants are reported for utility in combustion modeling.

  7. Functional polymer brushes via surface-initiated atom transfer radical graft polymerization for combating marine biofouling.

    PubMed

    Yang, Wen Jing; Neoh, Koon-Gee; Kang, En-Tang; Lee, Serina Siew Chen; Teo, Serena Lay-Ming; Rittschof, Daniel

    2012-01-01

    Dense and uniform polymer brush coatings were developed to combat marine biofouling. Nonionic hydrophilic, nonionic hydrophobic, cationic, anionic and zwitterionic polymer brush coatings were synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-hydroxyethyl methacrylate, 2,3,4,5,6-pentafluorostyrene, 2-(methacryloyloxy)ethyl trimethylammonium chloride, 4-styrenesulfonic acid sodium and N,N'-dimethyl-(methylmethacryloyl ethyl) ammonium propanesulfonate, respectively. The functionalized surfaces had different efficacies in preventing adsorption of bovine serum albumin (BSA), adhesion of the Gram-negative bacterium Pseudomonas sp. NCIMB 2021 and the Gram-positive Staphylococcus aureus, and settlement of cyprids of the barnacle Amphibalanus amphitrite (=Balanus amphitrite). The nonionic hydrophilic, anionic and zwitterionic polymer brushes resisted BSA adsorption during a 2 h exposure period. The nonionic hydrophilic, cationic and zwitterionic brushes exhibited resistance to bacterial fouling (24 h exposure) and cyprid settlement (24 and 48 h incubation). The hydrophobic brushes moderately reduced protein adsorption, and bacteria and cyprid settlement. The anionic brushes were least effective in preventing attachment of bacteria and barnacle cyprids. Thus, the best approach to combat biofouling involves a combination of nonionic hydrophilic and zwitterionic polymer brush coatings on material surfaces. PMID:22963034

  8. The synthesis and purification of aromatic hydrocarbons V : 1-ethyl-3-methylbenzene

    NASA Technical Reports Server (NTRS)

    Ebersole, Earl R

    1946-01-01

    The method used for the synthesis and purification of an 8-gallon quantity of 1-ethyl-3-methylbenzene from m-creosol consists in obtaining m-methylcyclohexanone from m-creosol by hydrogenation followed by oxidation, condensation of the ketone with ethylmagnesium bromide, dehydration of the tertiary alcohol obtained, and the dehydration of the olefins to 1-ethyl-3-methylbenzene. A yield of 28 percent of the theoretical was obtained from 98 percent commercial m-creosol. The physical properties of the 1-ethyl-3-methylbenzene are compared with selected values from the literature.

  9. The mode of action of ethyl lactate as a treatment for acne.

    PubMed

    Prottey, C; George, D; Leech, R W; Black, J G; Howes, D; Vickers, C F

    1984-04-01

    We have shown that an alcoholic lotion containing ethyl lactate when applied topically to rat skin under occlusion became localized in the follicles and sebaceous glands. When applied to human facial skin the ethyl lactate was hydrolysed to ethanol and lactic acid, and thereby lowered the skin pH. Under such conditions the growth of recoverable skin bacteria, in particular the anaerobe Propionibacterium acnes, was inhibited, and the hydrolysis of sebum to free fatty acids by lipase derived from the bacteria was greatly impaired. These effects of ethyl lactate would account for its observed clinical efficacy in acne vulgaris.

  10. Estimation of quizalofop ethyl residues in black gram (Vigna mungo L.) by gas liquid chromatography.

    PubMed

    Mandal, Kousik; Sahoo, Sanjay Kumar; Battu, R S; Singh, Balwinder

    2014-01-01

    Quizalofop ethyl, a phenoxy propionate herbicide is used for post emergence control of annual and perennial grass weeds in broad-leaved crops in India. The experiments were designed to study the harvest time residues of quizalofop ethyl in black gram for two seasons. At harvest time, the residues of quizalofop ethyl on black gram seed, foliage and soil were found to be below the determination limit of 0.01 mg kg(-1) following a single application of the herbicide at 50 and 100 g a.i. ha(-1) for both the periods. Application of the herbicide is quite safe from a consumer and environmental point of view.

  11. Essential Oil from Flowers and Leaves of Elaeagnus Angustifolia (Elaeagnaceae): Composition, Radical Scavenging and General Toxicity Activities

    PubMed Central

    Torbati, Mohammadali; Asnaashari, Solmaz; Heshmati Afshar, Fariba

    2016-01-01

    Purpose: The aim of this work was to identify the chemical composition of the essential oils obtained from the flowers and leaves of Elaeagnus angostifolia (Elaeagnaceae) along with evaluate the radical scavenging and general toxicity activities. Methods: A combination of GC-MS and GC-FID were utilized for analyzing the chemical profile of the essential oils extracted by hydro-distillation from the leaves and flowers of E. angustifolia. The essential oils were subjected to general toxicity and radical scavenging assays using brine shrimp lethality test and DPPH method, respectively. Results: In total, 53 and 25 components were identified and quantified in the essential oils of flowers and leaves, accounting for 96.59% and 98.97% of the oil, respectively. The both oils were observed to be rich in ester compounds. The most abundant components of the oil from flowers were E-ethyl cinnamate (60.00%), hexahydrofarnesyl acetone (9.99%), palmitic acid (5.20%) and phytol (3.29%). The major constituents of the oil from leaves were E-ethyl cinnamate (37.27%), phytol (12.08%), nonanal (10.74%) and Z-3-hexenyl benzoate (7.65%). Both oils showed moderate activity in DPPH assay; however, they exhibited potent tocixity in brine shrimp lethality test. Conclusion: The remarkable toxicity effects of the oils are worthy to further investigation to find the probable mechanisms of action accountable for the noticeable toxic effect of these essential oils. PMID:27478777

  12. Enhanced DPPH radical scavenging activity and DNA protection effect of litchi pericarp extract by Aspergillus awamori bioconversion

    PubMed Central

    2012-01-01

    Background Litchi (Litchi chinensis Sonn.) pericarp is a major byproduct which contains a significant amount of polyphenol. This study was designed to biotransformation litchi pericarp extract (LPE) by Aspergillus awamori to produce more bioactive compounds with stronger antioxidant activities. Results The study exhibited that the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities significantly (p < 0.05) increased from 15.53% to 18.23% in the water-extracted fraction and from 25.41% to 36.82% in the ethyl acetate-extracted fraction. Application of DNA cleavage assay further demonstrated the enhanced protection effect of the fermented phenolics on DNA damage. It is also noted that the water-extracted fraction of the fermented LPE possessed a much stronger capacity than the ethyl acetate-extracted fraction to prevent from damage of supercoiled DNA. Interestingly, it was found that some new compounds such as catechin and quercetin appeared after of A. awamori fermentation of LPE, which could account for the enhanced antioxidant activity. Conclusion The DPPH radical scavenging activity and DNA protection effect of LPE were increased by Aspergillus awamori bioconversion while some compounds responsible for the enhanced antioxidant activity were identified. This study provided an effective way of utilizing fruit pericarp as a readily accessible source of the natural antioxidants in food industry and, thus, extended the application area such as fruit by-products. PMID:23016522

  13. Analysis of the Cavity Ringdown Spectra of the Smallest Jet-Cooled Alkyl Peroxy Radicals Using a Evolutionary Algorithm

    NASA Astrophysics Data System (ADS)

    Just, Gabriel M. P.; Rupper, Patrick; Miller, Terry A.; Meerts, W. Leo

    2009-06-01

    Alkyl peroxy radicals long have been well known to bekey intermediates in atmospheric chemistry as well as in low temperature combustion. For the last several years, our group has generated a data set for these radicals using room temperature cavity ringdown spectroscopy. We have recently extended our investigations of these radicals to obtain a similar data set of spectra under jet cooled conditions using a quasi-Fourier-transform-limited laser source, a supersonic slit jet expansion, and a discharge. We were able to observe partially rotationally resolved spectra of isomers and conformers of several peroxy radicals such as methyl peroxy, CH_3O_2/CD_3O_2, ethyl peroxy, C_2H_5O_2 and C_2D_5O_2, propyl peroxy, C_3H_7O_2, and phenyl peroxy, C_6H_5O_2. To analyze our results we employed a new approach by using the evolutionary algorithm method, whereby we can effectively use both the frequency and the intensity information contained in the experimental spectra. This presentation will focus on the results from our fitted spectra which were obtained using this semi-automated method and will demonstrate the power of our technique .

  14. Successful topical dissolution of cholesterol gallbladder stones using ethyl propionate.

    PubMed

    Hofmann, A F; Amelsberg, A; Esch, O; Schteingart, C D; Lyche, K; Jinich, H; Vansonnenberg, E; D'Agostino, H B

    1997-06-01

    Topical dissolution of cholesterol gallbladder stones using methyl tert-butyl ether (MTBE) is useful in symptomatic patients judged too ill for surgery. Previous studies showed that ethyl propionate (EP), a C5 ester, dissolves cholesterol gallstones rapidly in vitro, but differs from MTBE in being eliminated so rapidly by the liver that blood levels remain undetectable. Our aim was to test EP as a topical dissolution agent for cholesterol gallbladder stones. Five high-risk patients underwent topical dissolution of gallbladder stones by EP. In three patients, the solvent was instilled via a cholecystostomy tube placed previously to treat acute cholecystitis; in two patients, a percutaneous transhepatic catheter was placed in the gallbladder electively. Gallstone dissolution was assessed by chromatography, by gravimetry, and by catheter cholecystography. Total dissolution of gallstones was obtained in four patients after 6-10 hr of lavage; in the fifth patient, partial gallstone dissolution facilitated basketing of the stones. In two patients, cholesterol dissolution was measured and averaged 30 mg/min. Side effects were limited to one episode of transient hypotension and pain at the infusion site; no patient developed somnolence or nausea. Gallstone elimination was associated with relief of symptoms. EP is an acceptable alternative to MTBE for topical dissolution of cholesterol gallbladder stones in high-risk patients. The lower volatility and rapid hepatic extraction of EP suggest that it may be preferable to MTBE in this investigational procedure.

  15. Determination of acetone and methyl ethyl ketone in water

    USGS Publications Warehouse

    Tai, D.Y.

    1978-01-01

    Analytical procedures for the determination of acetone and methyl ethyl ketone in water samples were developed. Concentrations in the milligram-per-liter range were determined by injecting an aqueous sample into the analysis system through an injection port, trapping the organics on Tenax-GC at room temperature, and thermally desorbing the organics into a gas chromatograph with a flame ionization detector for analysis. Concentrations in the microgram-per-liter range were determined by sweeping the headspace vapors over a water sample at 50C, trapping on Tenax-GC, and thermally desorbing the organics into the gas chromatograph. The precision for two operators of the milligram-per-liter concentration procedure, expressed as the coefficient of variation, was generally less than 2 percent for concentrations ranging from 16 to 160 milligrams per liter. The precision from two operators of the microgram-per-liter concentration procedure was between 2 and 4 percent for concentrations of 20 and 60 micrograms per liter. (Woodard-USGS)

  16. Ethyl carbamate levels resulting from azodicarbonamide use in bread.

    PubMed

    Cañas, B J; Diachenko, G W; Nyman, P J

    1997-01-01

    Azodicarbonamide (ADA), a dough conditioner, is an additive approved in the US up to a maximum of 45 mg/kg in flour. The addition of 45 mg/kg of ADA was investigated and found to increase the ethyl carbamate (EC) content of commercially prepared breads by 1-3 micrograms/kg. A similar increase in EC was observed in breads baked in the laboratory with a bread machine. The increase in EC levels appears to depend on a variety of factors, most notably the concentration of ADA added and the time of fermentation. The addition of 20 mg/kg ADA caused only a slight increase, if any, in commercial products but a 2.3 micrograms/kg increase of EC in breads baked with a bread machine. When 100 mg/kg of ascorbic acid was added along with ADA, smaller EC increases were observed. Addition of urea was also found to enhance the EC content of the bread. Toasting, which was previously shown to increase EC levels, caused even larger increases when ADA or urea had been added.

  17. Ethyl cellulose nanoparticles: clarithomycin encapsulation and eradication of H. pylori.

    PubMed

    Pan-In, Porntip; Banlunara, Wijit; Chaichanawongsaroj, Nuntaree; Wanichwecharungruang, Supason

    2014-08-30

    The extreme acidic environment of the stomach, its regular voidance of contents and the restricted access to the mucus covered habitat combined with the antibiotic resistance of the bacteria, all contribute to the poor success in the treatment of Helicobacter pylori gastric infections. Here, we demonstrate that by encapsulating clarithromycin into ethyl cellulose (EC) nanoparticles, the efficiency of H. pylori clearance in C57BL/6 mice infected with these bacteria was significantly improved. Clarithomycin-loaded EC nanoparticles were prepared via a simple yet effective anti-solvent particle induction method, to yield sub-micron sized particles with 22.3 ± 0.17% (w/w) clarithromycin loading at 86 ± 0.5% (w/w) encapsulation efficiency. The particles dispersed well in water and simulated gastric fluid and gave a minimum inhibitory concentration of 0.09-0.18 μg/ml against four strains of H. pylori. Encapsulation into EC particles not only enhanced the anti-adhesion activity of clarithromycin when tested with H. pylori and Hep-2 cells, but also gave significant enhancement of H. pylori clearance in the stomach of C57BL/6 mice infected with the bacteria.

  18. Gauche Ethyl Alcohol: Laboratory Assignments and Interstellar Identification

    NASA Technical Reports Server (NTRS)

    Pearson, J. C.; Sastry, K. V. L. N.; Herbst, Eric; DeLucia, Frank C.

    1997-01-01

    Ethyl alcohol (ethanol) is known to possess a pair of closely spaced excited torsional substates (gauche+, gauche-) at an energy of approximately 57 K above the ground (trans) torsional substate. We report an extended analysis of some gauche - gauche+ Q-branch ((Delta)J = 0) transitions with a three-substate fixed frame axis method (FFAM) Hamiltonian. Our approach accounts for complex trans-gauche interactions for the first time. In addition, we are able to obtain intensities for perturbed rotational transitions, and to determine the trans to gauche+ separation to be 1185399.1 MHz. A complete ground state rotational-torsional partition function accounting for the previously neglected gauche substates is presented. Based on our analysis, a total of 14 U lines obtained towards Orion KL can now be assigned to gauche substates of ethanol. Analysis of these lines yields a rotational temperature of 223 K and a total (trans + gauche) column density of 7.0 x 10(exp 15)/sq cm. The column density is in reasonable agreement with the recent value of 2-3 x 10(exp 15)/sq cm based on observations of trans-ethanol by Ohishi et al., although there is some disparity in the rotational temperatures. Eight additional U lines in the literature are assigned to transitions of gauche ethanol.

  19. The pharmacological actions of pempidine and its ethyl homologue

    PubMed Central

    Spinks, A.; Young, E. H. P.; Farrington, J. A.; Dunlop, D.

    1958-01-01

    Pempidine, and other highly active ganglion blocking agents of the polyalkylpiperidine series, were developed from tertiary alkylamines, themselves weakly active, on the hypothesis that high activity was conferred by the presence in the molecule of a sterically hindered secondary or tertiary nitrogen atom. Pempidine and its N-ethyl homologue (26539) resembled mecamylamine qualitatively. All three drugs blocked sympathetic and parasympathetic ganglia; this action was slow in onset and protracted. They blocked neuromuscular transmission, but only about one hundredth as powerfully as ganglionic transmission. They caused a fall in amplitude and rate of the isolated heart, and reduced coronary flow. They had local anaesthetic properties in one of four tests used. They caused tremor. All were well absorbed when administered orally. Pempidine was about twice as active as mecamylamine on ganglia, but only about one half to one quarter as toxic as judged by death, growth, induction of tremor, or cardiotoxicity. Compound 26539 was also quantitatively superior to mecamylamine in respect of these safety margins, but unlike pempidine or mecamylamine damaged the pituitary gland and testis when administered daily for several months. The mode of action of the three drugs is discussed: the results give tentative support for the hypothesis that their action is intracellular. PMID:13618559

  20. Reactions of ruthenium hydrides with ethyl-vinyl sulfide.

    PubMed

    Dahcheh, Fatme; Stephan, Douglas W

    2014-03-01

    The Ru-hydride precursors (Im(OMe)2)(PPh3)2RuHCl () and (Me2Im(OMe)2)(PPh3)2RuHCl () reacted with ethyl-vinyl-sulfide to give ((MeOCH2CH2)C3H2N2(CH2CH(OMe))RuCl(PPh3)2 () and ((MeOCH2CH2)C3Me2N2(CH2CH(OMe))RuCl(PPh3)2 (), respectively. Dissolution of () in C6D6 prompts formation of ((MeOCH2CH2)C5H6N2(CHCH)RuCl(PPh3)2 (). The analogous reactions of the bis-carbene Ru-hydride precursors (Im(OMe)2)(IMes)(PPh3)RuHCl (), (Im(OMe)2)(SIMes)(PPh3)RuHCl () and (Im(OMe)2)(IMes-Cl2)(PPh3)RuHCl () gave ((MeOCH2CH2)C3H2N2(CHCH)RuCl(PPh3)(NHC) (NHC = IMes (), SIMes (), IMes-Cl2 (), respectively. The formation of compounds () and () is thought to go through an initial insertion of the vinyl-fragment into the Ru-H prompting subsequent C-H activation and loss of diethyl sulfide. This yields () and (), while subsequent loss of methanol yields () and (-). PMID:24441082

  1. Involvement of free radicals in breast cancer.

    PubMed

    Ríos-Arrabal, Sandra; Artacho-Cordón, Francisco; León, Josefa; Román-Marinetto, Elisa; Del Mar Salinas-Asensio, María; Calvente, Irene; Núñez, Maria Isabel

    2013-08-27

    Researchers have recently shown an increased interest in free radicals and their role in the tumor microenvironment. Free radicals are molecules with high instability and reactivity due to the presence of an odd number of electrons in the outermost orbit of their atoms. Free radicals include reactive oxygen and nitrogen species, which are key players in the initiation and progression of tumor cells and enhance their metastatic potential. In fact, they are now considered a hallmark of cancer. However, both reactive species may contribute to improve the outcomes of radiotherapy in cancer patients. Besides, high levels of reactive oxygen species may be indicators of genotoxic damage in non-irradiated normal tissues. The purpose of this article is to review recent research on free radicals and carcinogenesis in order to understand the pathways that contribute to tumor malignancy. This review outlines the involvement of free radicals in relevant cellular events, including their effects on genetic instability through (growth factors and tumor suppressor genes, their enhancement of mitogenic signals, and their participation in cell remodeling, proliferation, senescence, apoptosis, and autophagy processes; the possible relationship between free radicals and inflammation is also explored. This knowledge is crucial for evaluating the relevance of free radicals as therapeutic targets in cancer.

  2. Free-radical scavengers and antioxidants from Peumus boldus Mol. ("Boldo").

    PubMed

    Schmeda-Hirschmann, G; Rodriguez, J A; Theoduloz, C; Astudillo, S L; Feresin, G E; Tapia, A

    2003-04-01

    The dry leaves of Peumus boldus (Monimiaceae) are used in infusion or decoction as a digestive and to improve hepatic complains. Preliminary assays showed free-radical scavenging activity in hot water extracts of boldo leaves, measured by the decoloration of a methanolic solution of the 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH). Assay-guided isolation led to the active compounds. Catechin proved to be the main free-radical scavenger of the extracts. Lipid peroxidation in erythrocytes was inhibited by boldo extracts and fractions at 500 microg/ml with higher effect for the ethyl acetate soluble and alkaloid fractions. The IC50 for catechin and boldine in the lipid peroxidation test were 75.6 and 12.5 microg/ml, respectively. On the basis of dry starting material the catechin content in the crude drug was 2.25% while the total alkaloid calculated as boldine was 0.06%. The activity of boldine was six times higher than catechin in the lipid peroxidation assay. However, the mean catechin:total alkaloid content ratio was 37:1. The relative concentration of alkaloids and phenolics in boldo leaves and their activity suggest that free-radical scavenging effect is mainly due to catechin and flavonoids and that antioxidant effect is mainly related with the catechin content The high catechin content of boldo leaves and its bioactivity suggest that quality control of Boldo folium has to combine the analysis of catechin as well as their characteristic aporphine alkaloids. PMID:12747739

  3. Radical Scavenging Activity of the Essential Oil of Silver Fir (Abies alba).

    PubMed

    Yang, Seun-Ah; Jeon, Sang-Kyung; Lee, Eun-Jung; Im, Nam-Kyung; Jhee, Kwang-Hwan; Lee, Sam-Pin; Lee, In-Seon

    2009-05-01

    The essential oil of silver fir (Abies alba) is known to help respiratory system and have easing and soothing effect for muscle. In the present study, we investigated the chemical composition, cytotoxicity and its biological activities of silver fir (Abies alba) essential oil. The composition of the oil was analyzed by GC-MS and bornyl acetate (30.31%), camphene (19.81%), 3-carene (13.85%), tricyclene (12.90%), dl-limonene (7.50%), alpha-pinene (2.87%), caryophyllene (2.18%), beta-phellandrene (2.13%), borneol (1.74%), bicyclo[2.2.1]hept-2-ene,2,3-dimethyl (1.64%) and alpha-terpinene (1.24%) were the major components in the oil. The results tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that the oil showed no cytotoxic effect, at concentrations of 1 and 5%, for as long as 24 and 3 h, respectively. The antiradical capacity was evaluated by measuring the scavenging activity of the essential oil on the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals. The oil was able to reduce the both radicals dose-dependently, and the concentration required for 50% reduction (RC(50)) against DPPH radicals (2.7 +/- 0.63%) was lower than ABTS radicals (8.5 +/- 0.27%). The antibacterial activity of the oil was also evaluated using disc diffusion method against Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Acinetobacter baumannii, Escherichia coli, and Vibrio parahaemolyticcus. The oil exhibited no antibacterial activity against all the bacterial strains tested except S. aureus of mild activity. PMID:19430614

  4. Radical Scavenging Activity of the Essential Oil of Silver Fir (Abies alba)

    PubMed Central

    Yang, Seun-Ah; Jeon, Sang-Kyung; Lee, Eun-Jung; Im, Nam-Kyung; Jhee, Kwang-Hwan; Lee, Sam-Pin; Lee, In-Seon

    2009-01-01

    The essential oil of silver fir (Abies alba) is known to help respiratory system and have easing and soothing effect for muscle. In the present study, we investigated the chemical composition, cytotoxicity and its biological activities of silver fir (Abies alba) essential oil. The composition of the oil was analyzed by GC-MS and bornyl acetate (30.31%), camphene (19.81%), 3-carene (13.85%), tricyclene (12.90%), dl-limonene (7.50%), α-pinene (2.87%), caryophyllene (2.18%), β-phellandrene (2.13%), borneol (1.74%), bicyclo[2.2.1]hept-2-ene,2,3-dimethyl (1.64%) and α-terpinene (1.24%) were the major components in the oil. The results tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that the oil showed no cytotoxic effect, at concentrations of 1 and 5%, for as long as 24 and 3 h, respectively. The antiradical capacity was evaluated by measuring the scavenging activity of the essential oil on the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals. The oil was able to reduce the both radicals dose-dependently, and the concentration required for 50% reduction (RC50) against DPPH radicals (2.7 ± 0.63%) was lower than ABTS radicals (8.5 ± 0.27%). The antibacterial activity of the oil was also evaluated using disc diffusion method against Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Acinetobacter baumannii, Escherichia coli, and Vibrio parahaemolyticcus. The oil exhibited no antibacterial activity against all the bacterial strains tested except S. aureus of mild activity. PMID:19430614

  5. Ethyl sulphate and ethyl glucuronide in vitreous humor as postmortem evidence marker for ethanol consumption prior to death.

    PubMed

    Thierauf, Annette; Kempf, Jürgen; Perdekamp, Markus Grosse; Auwärter, Volker; Gnann, Heike; Wohlfarth, Ariane; Weinmann, Wolfgang

    2011-07-15

    To clarify the circumstances of death, the degree of inebriation is of importance in many cases, but for several reasons the determination of the ethanol concentration in post-mortem samples can be challenging and the synopsis of ethanol and the direct consumption markers ethyl glucuronide (EtG) and ethyl sulphate (EtS) has proved to be useful. The use of a rather stable matrix like vitreous humor offers further advantages. The aim of this study was to determine the concentrations of ethanol and the biomarkers in the robust matrix of vitreous humor and to compare them with the respective levels in peripheral venous blood and urine. Samples of urine, blood from the femoral vein and vitreous humor were taken from 26 deceased with suspected ethanol consumption prior to death and analyzed for ethanol, EtS and EtG. In the urine samples creatinine was also determined. The personal data, the circumstances of death, the post-mortem interval and the information about ethanol consumption prior to death were recorded. EtG and EtS analysis in urine was performed by LC-ESI-MS/MS, creatinine concentration was determined using the Jaffé reaction and ethanol was detected by HS-GC-FID and by an ADH-based method. In general, the highest concentrations of the analytes were found in urine and showed statistical significance. The mean concentrations of EtG were 62.8mg/L (EtG100 206.5mg/L) in urine, 4.3mg/L in blood and 2.1mg/L in vitreous humor. EtS was found in the following mean concentrations: 54.6mg/L in urine (EtS100 123.1mg/L), 1.8mg/L in blood and 0.9mg/L in vitreous humor. Ethanol was detected in more vitreous humor samples (mean concentration 2.0g/kg) than in blood and urine (mean concentration 1.6g/kg and 2.1g/kg respectively). There was no correlation between the ethanol and the marker concentrations and no statistical conclusions could be drawn between the markers and matrices.

  6. Ethyl sulphate and ethyl glucuronide in vitreous humor as postmortem evidence marker for ethanol consumption prior to death.

    PubMed

    Thierauf, Annette; Kempf, Jürgen; Perdekamp, Markus Grosse; Auwärter, Volker; Gnann, Heike; Wohlfarth, Ariane; Weinmann, Wolfgang

    2011-07-15

    To clarify the circumstances of death, the degree of inebriation is of importance in many cases, but for several reasons the determination of the ethanol concentration in post-mortem samples can be challenging and the synopsis of ethanol and the direct consumption markers ethyl glucuronide (EtG) and ethyl sulphate (EtS) has proved to be useful. The use of a rather stable matrix like vitreous humor offers further advantages. The aim of this study was to determine the concentrations of ethanol and the biomarkers in the robust matrix of vitreous humor and to compare them with the respective levels in peripheral venous blood and urine. Samples of urine, blood from the femoral vein and vitreous humor were taken from 26 deceased with suspected ethanol consumption prior to death and analyzed for ethanol, EtS and EtG. In the urine samples creatinine was also determined. The personal data, the circumstances of death, the post-mortem interval and the information about ethanol consumption prior to death were recorded. EtG and EtS analysis in urine was performed by LC-ESI-MS/MS, creatinine concentration was determined using the Jaffé reaction and ethanol was detected by HS-GC-FID and by an ADH-based method. In general, the highest concentrations of the analytes were found in urine and showed statistical significance. The mean concentrations of EtG were 62.8mg/L (EtG100 206.5mg/L) in urine, 4.3mg/L in blood and 2.1mg/L in vitreous humor. EtS was found in the following mean concentrations: 54.6mg/L in urine (EtS100 123.1mg/L), 1.8mg/L in blood and 0.9mg/L in vitreous humor. Ethanol was detected in more vitreous humor samples (mean concentration 2.0g/kg) than in blood and urine (mean concentration 1.6g/kg and 2.1g/kg respectively). There was no correlation between the ethanol and the marker concentrations and no statistical conclusions could be drawn between the markers and matrices. PMID:21367549

  7. Combined use of fatty acid ethyl esters and ethyl glucuronide in hair for diagnosis of alcohol abuse: interpretation and advantages.

    PubMed

    Pragst, F; Rothe, M; Moench, B; Hastedt, M; Herre, S; Simmert, D

    2010-03-20

    In this study the combined use of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) for diagnoses of chronically excessive alcohol abuse is investigated at 174 hair samples from driving ability examination, workplace testing and child custody cases for family courts and evaluated with respect to the basics of interpretation. Using the cut-off values of 0.50 ng/mg for FAEE and 25 pg/mg for EtG, both markers were in agreement in 75% of the cases with 103 negative and 28 positive results and there were 30 cases with FAEE positive and EtG negative and 13 cases with FAEE negative and EtG positive. As the theoretical basis of interpretation, the pharmacokinetics of FAEE and EtG is reviewed for all steps between drinking of ethanol to incorporation in hair with particular attention to relationships between alcohol dose and concentrations in hair. It is shown that the concentrations of both markers are essentially determined by the area under the ethanol concentration in blood vs. time curve AUC(EtOH), despite large inter-individual variations. It is demonstrated by calculation of AUC(EtOH) on monthly basis for moderate, risky and heavy drinking that AUC(EtOH) increases very strongly in the range between 60 and 120 g ethanol per day. This specific feature which is caused by the zero-order elimination of ethanol is a favorable prerequisite for a high discrimination power of the hair testing for alcohol abuse. From the consideration of the different profiles of FAEE and EtG along the hair and in agreement with the literature survey, a standardized hair segment 0-3 cm is proposed with cut-off values of 0.5 ng/mg for FAEE and 30 pg/mg for EtG. This improves also the agreement between FAEE and EtG results in the cases of the present study. A scheme for combined interpretation of FAEE and EtG is proposed which uses the levels of abstinence and the double of the cut-off values as criteria in addition to the cut-off's. Considering the large variations in the relationship

  8. Generation of free radicals and messenger function.

    PubMed

    Carlson, J C; Sawada, M

    1995-09-01

    Free radicals are toxic agents that are produced as by-products of metabolic activity. A number of antioxidant mechanisms work to protect cells from damage. Recent evidence indicates, however, that free radicals and related oxidants such as hydrogen peroxide may also have a beneficial role, working as messengers to control cell function. These agents are generated in response to agonists, production is regulated by intracellular signal pathways, and they appear to be used to control particular cellular processes. Free radicals may perform these functions in a number of cell types. Also, they are produced in muscles and there is evidence that they may work as messengers in smooth muscle cells.

  9. Competition of charge- versus radical-directed fragmentation of gas-phase protonated cysteine sulfinyl radicals.

    PubMed

    Love, Chasity B; Tan, Lei; Francisco, Joseph S; Xia, Yu

    2013-04-24

    The fragmentation behavior of various cysteine sulfinyl ions (intact, N-acetylated, and O-methylated), new members of the gas-phase amino acid radical ion family, was investigated by low-energy collision-induced dissociation (CID). The dominant fragmentation channel for the protonated cysteine sulfinyl radicals ((SO•)Cys) was the radical-directed Cα-Cβ homolytic cleavage, resulting in the formation of glycyl radical ions and loss of CH2SO. This channel, however, was not observed for protonated N-acetylated cysteine sulfinyl radicals (Ac-(SO•)Cys); instead, charge-directed H2O loss followed immediately by SH loss prevailed. Counterintuitively, the H2O loss did not derive from the carboxyl group but involved the sulfinyl oxygen, a proton, and a Cβ hydrogen atom. Theoretical calculations suggested that N-acetylation significantly increases the barrier (~14 kcal mol(-1)) for the radical-directed fragmentation channel because of its reduced capability to stabilize the thus-formed glycyl radical ions via the captodative effect. N-Acetylation also assists in moving the proton to the sulfinyl site, which reduces the barrier for H2O loss. Our studies demonstrate that for cysteine sulfinyl radical ions, the stability of the product ions (glycyl radical ions) and the location of the charge (proton) can significantly modulate the competition between radical- and charge-directed fragmentation.

  10. Expanding Radical SAM Chemistry by Using Radical Addition Reactions and SAM Analogues.

    PubMed

    Ji, Xinjian; Li, Yongzhen; Xie, Liqi; Lu, Haojie; Ding, Wei; Zhang, Qi

    2016-09-19

    Radical S-adenosyl-l-methionine (SAM) enzymes utilize a [4Fe-4S] cluster to bind SAM and reductively cleave its carbon-sulfur bond to produce a highly reactive 5'-deoxyadenosyl (dAdo) radical. In almost all cases, the dAdo radical abstracts a hydrogen atom from the substrates or from enzymes, thereby initiating a highly diverse array of reactions. Herein, we report a change of the dAdo radical-based chemistry from hydrogen abstraction to radical addition in the reaction of the radical SAM enzyme NosL. This change was achieved by using a substrate analogue containing an olefin moiety. We also showed that two SAM analogues containing different nucleoside functionalities initiate the radical-based reactions with high efficiencies. The radical adduct with the olefin produced in the reaction was found to undergo two divergent reactions, and the mechanistic insights into this process were investigated in detail. Our study demonstrates a promising strategy in expanding radical SAM chemistry, providing an effective way to access nucleoside-containing compounds by using radical SAM-dependent reactions. PMID:27573794

  11. Expanding Radical SAM Chemistry by Using Radical Addition Reactions and SAM Analogues.

    PubMed

    Ji, Xinjian; Li, Yongzhen; Xie, Liqi; Lu, Haojie; Ding, Wei; Zhang, Qi

    2016-09-19

    Radical S-adenosyl-l-methionine (SAM) enzymes utilize a [4Fe-4S] cluster to bind SAM and reductively cleave its carbon-sulfur bond to produce a highly reactive 5'-deoxyadenosyl (dAdo) radical. In almost all cases, the dAdo radical abstracts a hydrogen atom from the substrates or from enzymes, thereby initiating a highly diverse array of reactions. Herein, we report a change of the dAdo radical-based chemistry from hydrogen abstraction to radical addition in the reaction of the radical SAM enzyme NosL. This change was achieved by using a substrate analogue containing an olefin moiety. We also showed that two SAM analogues containing different nucleoside functionalities initiate the radical-based reactions with high efficiencies. The radical adduct with the olefin produced in the reaction was found to undergo two divergent reactions, and the mechanistic insights into this process were investigated in detail. Our study demonstrates a promising strategy in expanding radical SAM chemistry, providing an effective way to access nucleoside-containing compounds by using radical SAM-dependent reactions.

  12. Biofiltration of ethyl acetate by Pseudomonas putida immobilized on walnut shell.

    PubMed

    Zare, Hossein; Najafpour, Ghasem; Rahimnejad, Mostafa; Tardast, Ali; Gilani, Saeedeh

    2012-11-01

    A biofilter packed with walnut shells was used to eliminate ethyl acetate from an air stream. The shells treated with NaOH were used as medium for immobilization of Pseudomonas putida PTCC 1694. At an empty bed residence time (EBRT) of 60s, a removal efficiency of 99% was achieved at inlet concentrations lower than 430ppm of ethyl acetate. The removal efficiency decreased below 80% with an increase in inlet concentration of ethyl acetate. When the EBRT was increased to 75 s, the removal efficiency remained above 80% even though the inlet loading rate was increased to 421g/m(3)h. Michaelis-Menten type and zero-order diffusion limited models were employed and the predicted data perfectly matched the experimental data. Thus P. putida immobilized on walnut shell has potential for the removal of ethyl acetate from air streams.

  13. Rapeseed ethyl ester as bio-lube in 2-cycle engine

    SciTech Connect

    1996-12-31

    The performance of four blends of gasoline with rapeseed ethyl ester (REE) and three commercial 2-cycle oils has been evaluated in engine tests by the University of Idaho. Details and results of the tests are given in the article.

  14. Biofiltration of ethyl acetate by Pseudomonas putida immobilized on walnut shell.

    PubMed

    Zare, Hossein; Najafpour, Ghasem; Rahimnejad, Mostafa; Tardast, Ali; Gilani, Saeedeh

    2012-11-01

    A biofilter packed with walnut shells was used to eliminate ethyl acetate from an air stream. The shells treated with NaOH were used as medium for immobilization of Pseudomonas putida PTCC 1694. At an empty bed residence time (EBRT) of 60s, a removal efficiency of 99% was achieved at inlet concentrations lower than 430ppm of ethyl acetate. The removal efficiency decreased below 80% with an increase in inlet concentration of ethyl acetate. When the EBRT was increased to 75 s, the removal efficiency remained above 80% even though the inlet loading rate was increased to 421g/m(3)h. Michaelis-Menten type and zero-order diffusion limited models were employed and the predicted data perfectly matched the experimental data. Thus P. putida immobilized on walnut shell has potential for the removal of ethyl acetate from air streams. PMID:22940351

  15. Base-switched annuloselectivity in the reactions of ethyl malonyl chloride and imines.

    PubMed

    Yang, Zhanhui; Li, Siqi; Zhang, Zhong; Xu, Jiaxi

    2014-12-28

    The base-switched annuloselectivity, namely [2 + 2] and [2 + 2 + 2] selectivity, in the reactions of ethyl malonyl chloride and imines is successfully realized. In the presence of the weak nucleophilic base 2-chloropyridine, the reactions deliver ethyl trans-β-lactam-3-carboxylates as the exclusive [2 + 2] products in up to 93% yields, while with the strong nucleophilic N-methylimidazole as the base, the reactions give rise to 2,3-dihydro-1,3-oxazin-4-one derivatives as the sole products in up to 99% yields via the formal [2 + 2 + 2] cycloaddition involving one molecule of the imine and two molecules of the ketene generated from malonyl chloride. Notably, ethyl trans-β-lactam-3-carboxylates are synthesized for the first time directly from the reactions of ethyl malonyl chloride and imines. Mechanistic discussions reveal that the annuloselectivity is controlled by the nucleophilicity of organic bases.

  16. Fast beam studies of free radical photodissociation

    SciTech Connect

    Neumark, D.M.

    1993-12-01

    The authors have developed a novel technique for studying the photodissociation spectroscopy and dynamics of free radicals. In these experiments, radicals are generated by laser photodetachment of a fast (6-8 keV) mass-selected negative ion beam. The resulting radicals are photodissociated with a second laser, and the photofragments are collected and detected with high efficiency using a microchannel plate detector. The overall process is: ABC{sup -} {yields} ABC + e{sup -} {yields} A + BC, AB + C. Two types of fragment detection schemes are used. To map out the photodissociation cross-section of the radical, the photodissociation laser is scanned and the total photofragment yield is measured as a function of wavelength. In other experiments, the photodissociation frequency is fixed and the photofragment masses, kinetic energy release, and scattering angle is determined for each photodissociation event.

  17. A Mechanochemical Switch to Control Radical Intermediates

    PubMed Central

    2015-01-01

    B12-dependent enzymes employ radical species with exceptional prowess to catalyze some of the most chemically challenging, thermodynamically unfavorable reactions. However, dealing with highly reactive intermediates is an extremely demanding task, requiring sophisticated control strategies to prevent unwanted side reactions. Using hybrid quantum mechanical/molecular mechanical simulations, we follow the full catalytic cycle of an AdoB12-dependent enzyme and present the details of a mechanism that utilizes a highly effective mechanochemical switch. When the switch is “off”, the 5′-deoxyadenosyl radical moiety is stabilized by releasing the internal strain of an enzyme-imposed conformation. Turning the switch “on,” the enzyme environment becomes the driving force to impose a distinct conformation of the 5′-deoxyadenosyl radical to avoid deleterious radical transfer. This mechanochemical switch illustrates the elaborate way in which enzymes attain selectivity of extremely chemically challenging reactions. PMID:24846280

  18. A mechanochemical switch to control radical intermediates.

    PubMed

    Brunk, Elizabeth; Kellett, Whitney F; Richards, Nigel G J; Rothlisberger, Ursula

    2014-06-17

    B₁₂-dependent enzymes employ radical species with exceptional prowess to catalyze some of the most chemically challenging, thermodynamically unfavorable reactions. However, dealing with highly reactive intermediates is an extremely demanding task, requiring sophisticated control strategies to prevent unwanted side reactions. Using hybrid quantum mechanical/molecular mechanical simulations, we follow the full catalytic cycle of an AdoB₁₂-dependent enzyme and present the details of a mechanism that utilizes a highly effective mechanochemical switch. When the switch is "off", the 5'-deoxyadenosyl radical moiety is stabilized by releasing the internal strain of an enzyme-imposed conformation. Turning the switch "on," the enzyme environment becomes the driving force to impose a distinct conformation of the 5'-deoxyadenosyl radical to avoid deleterious radical transfer. This mechanochemical switch illustrates the elaborate way in which enzymes attain selectivity of extremely chemically challenging reactions.

  19. (State resolved studies of the methyl radical)

    SciTech Connect

    Houston, P.L.

    1991-01-01

    Reactions of methyl radicals play a major role in the combustion of nearly all hydrocarbon fuels. During the past three years, the objectives of our DOE supported research have been (1) to examine photodissociations producing methyl radicals in order to learn the internal and translational energy distributions of the products, and (2) to develop a capability to investigate important combustion reactions using these methyl radicals as reagents are summarized. The sources for methyl (and other) radicals that have been examined in our laboratory, and our progress in constructing an apparatus to investigate their reactions. Our group has performed detailed examination of four methyl sources: methyl iodide, acetone, acetaldehyde, and nitromethane. 24 refs., 9 figs.

  20. RADICALLY CONTESTED ASSERTIONS IN ECOSYSTEM MANAGEMENT

    EPA Science Inventory

    Ecosystem management is a magnet for controversy, in part because some of its formulations rest on questionable assertions that are radically contested. These assertions are important to understanding much of the conflict surrounding ecosystem management and, therrefore, deserve...

  1. The Electronic Spectrum of the Fulvenallenyl Radical.

    PubMed

    Chakraborty, Arghya; Fulara, Jan; Maier, John P

    2016-01-01

    The fulvenallenyl radical was produced in 6 K neon matrices after mass-selective deposition of C7H5(-) and C7H5(+) generated from organic precursors in a hot cathode ion source. Absorption bands commencing at λ=401.3 nm were detected as a result of photodetachment of electrons from the deposited C7H5(-) and also by neutralization of C7H5(+) in the matrix. The absorption system is assigned to the 1 (2)B1 ←X (2)B1 transition of the fulvenallenyl radical on the basis of electronic excitation energies calculated with the MS-CASPT2 method. The vibrational excitation bands detected in the spectrum concur with the structure of the fulvenallenyl radical. Employing DFT calculations, it is found that the fulvenallenyl anion and its radical are the global minima on the potential energy surface among plausible structures of C7H5. PMID:26593635

  2. Radical formation in cytochrome c oxidase☆

    PubMed Central

    Yu, Michelle A.; Egawa, Tsuyoshi; Shinzawa-Itoh, Kyoko; Yoshikawa, Shinya; Yeh, Syun-Ru; Rousseau, Denis L.; Gerfen, Gary J.

    2015-01-01

    The formation of radicals in bovine cytochrome c oxidase (bCcO), during the O2 redox chemistry and proton translocation, is an unresolved controversial issue. To determine if radicals are formed in the catalytic reaction of bCcO under single turnover conditions, the reaction of O2 with the enzyme, reduced by either ascorbate or dithionite, was initiated in a custom-built rapid freeze quenching (RFQ) device and the products were trapped at 77 K at reaction times ranging from 50 µs to 6 ms. Additional samples were hand mixed to attain multiple turnover conditions and quenched with a reaction time of minutes. X-band (9 GHz) continuous wave electron paramagnetic resonance (CW-EPR) spectra of the reaction products revealed the formation of a narrow radical with both reductants. D-band (130 GHz) pulsed EPR spectra allowed for the determination of the g-tensor principal values and revealed that when ascorbate was used as the reductant the dominant radical species was localized on the ascorbyl moiety, and when dithionite was used as the reductant the radical was the SO2•− ion. When the contributions from the reductants are subtracted from the spectra, no evidence for a protein-based radical could be found in the reaction of O2 with reduced bCcO. As a surrogate for radicals formed on reaction intermediates, the reaction of hydrogen peroxide (H2O2) with oxidized bCcO was studied at pH 6 and pH 8 by trapping the products at 50 µs with the RFQ device to determine the initial reaction events. For comparison, radicals formed after several minutes of incubation were also examined, and X-band and D-band analysis led to the identification of radicals on Tyr-244 and Tyr-129. In the RFQ measurements, a peroxyl (R – O – O•) species was formed, presumably by the reaction between O2 and an amino acid-based radical. It is postulated that Tyr-129 may play a central role as a proton loading site during proton translocation by ejecting a proton upon formation of the radical

  3. Catalyst-free ethyl biodiesel production from rice bran under subcritical condition

    NASA Astrophysics Data System (ADS)

    Zullaikah, Siti; Afifudin, Riza; Amalia, Rizky

    2015-12-01

    In-situ ethyl biodiesel production from rice bran under subcritical water and ethanol with no catalyst was employed. This process is environmentally friendly and is very flexible in term of feedstock utilization since it can handle relatively high moisture and free fatty acids (FFAs) contents. In addition, the alcohol, i.e. bioethanol, is a non-toxic, biodegradable, and green raw material when produced from non-edible biomass residues, leading to a 100% renewable biodiesel. The fatty acid ethyl esters (FAEEs, ethyl biodiesel) are better than fatty acid methyl esters (FAMEs, methyl biodiesel) in terms of fuel properties, including cetane number, oxidation stability and cold flow properties. The influences of the operating variables such as reaction time (1 - 10 h), ethanol concentration (12.5 - 87.5%), and pressurizing gas (N2 and CO2) on the ethyl biodiesel yield and purity have been investigated systematically while the temperature and pressure were kept constant at 200 °C and 40 bar. The optimum results were obtained at 5 h reaction time and 75% ethanol concentration using CO2 as compressing gas. Ethyl biodiesel yield and purity of 58.78% and 61.35%, respectively, were obtained using rice bran with initial FFAs content of 37.64%. FFAs level was reduced to 14.22% with crude ethyl biodiesel recovery of 95.98%. Increasing the reaction time up to 10 h only increased the yield and purity by only about 3%. Under N2 atmosphere and at the same operating conditions (5h and 75% ethanol), ethyl biodiesel yield and purity decreased to 54.63% and 58.07%, respectively, while FFAs level was increased to 17.93% and crude ethyl biodiesel recovery decreased to 87.32%.

  4. Immunomodulating effect of ethyl pyruvate on nonsyngenic transplanted tumor in mice.

    PubMed

    Bogdanova, L A; Morozkova, T S; Kaledin, V I; Nikolin, V P; Popova, N A

    2013-10-01

    Indolamine-2,3-dioxygenase, a tryptophan-catabolizing enzyme, creates local conditions suppressing immune lymphocytes. Expression of this enzyme in tumors protects them from immune mechanisms, while its inhibition partially reduces tumor immunoresistance. This effect is attained by multiple subcutaneous or intraperitoneal injections of ethyl pyruvate, an indolamine-2,3-dioxygenase inhibitor. Experiments on mouse nonsyngenic tumor have demonstrated the immunomodulating effect of chronic oral ethyl pyruvate administered with drinking water.

  5. 2-cyano-5-(BETA-(trans-4-alkylcyclohexyl)ethyl)pyridines

    SciTech Connect

    Pavlyuchenko, A.I.; Korotkova, N.I.; Koshev, E.I.; Sergeeva, N.D.; Smirnova, N.I.; Titov, V.V.

    1986-10-01

    2-Methyl-5-((4-alkyl-1-hydroxycyclohexyl)ethynyl)pyridines were obtained by the reaction of the organomagnesium derivative of 2-metyl-5-ethynylpyridine with 4-alkylcyclohexanones. The hydrogenation of the products gave 2-methyl-5-((4alkyl-1-hydroxycyclohexyl)ethyl)pyridines, the dehydration of which and subsequent hydrogenation led to 2-methyl-5-((4-alkylcyclohexy)ethyl)pyridines; the methyl group was substituted by a nitrile group according to the usual scheme.

  6. Spin trapping endogenous radicals in MC-1010 cells: evidence for hydroxyl radical and carbon-centered ascorbyl radical adducts.

    PubMed

    Bernofsky, C; Bandara, B M

    1995-07-19

    Incubation of MC-1010 cells with the spin-trapping agent 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) followed by brief treatment with the solid oxidant lead dioxide (PbO2) yielded, after filtration, a cell-free solution that contained two nitroxyl adducts. The first was the hydroxyl radical adduct, 5,5-dimethyl-2-hydroxypyrrolidine-1-oxyl (DMPO-OH), which formed immediately upon PbO2 oxidation. The second had a 6-line EPR spectrum typical of a carbon-centered radical (AN = 15.9 G; AH = 22.4 G) and formed more slowly. No radical signals were detected in the absence of either cells or PbO2 treatment. The 6-line spectrum could be duplicated in model systems that contained ascorbate, DMPO and DMPO-OH, where the latter was formed from hydroxyl radicals generated by sonolysis or the cleavage of hydrogen peroxide with Fe2+ (Fenton reaction). In addition, enrichment of MC-1010 cells with ascorbate prior to spin trapping yielded the 6-line EPR spectrum as the principal adduct following PbO2 oxidation and filtration. These results suggest that ascorbate reacted with DMPO-OH to form a carbon-centered ascorbyl radical that was subsequently trapped by DMPO. The requirement for mild oxidation to detect the hydroxyl radical adduct suggests that DMPO-OH formed in the cells was reduced to an EPR-silent form (i.e., the hydroxylamine derivative). Alternatively, the hydroxylamine derivative was the species initially formed. The evidence for endogenous hydroxyl radical formation in unstimulated leukocytes may be relevant to the leukemic nature of the MC-1010 cell line. The spin trapping of the ascorbyl radical is the first report of formation of the carbon-centered ascorbyl radical by means other than pulse radiolysis. Unless it is spin trapped, the carbon-centered ascorbyl radical immediately rearranges to the more stable oxygen-centered species that is passive to spin trapping and characterized by the well-known EPR doublet of AH4 = 1.8 G.

  7. Hydroxyl radical generation by red tide algae.

    PubMed

    Oda, T; Akaike, T; Sato, K; Ishimatsu, A; Takeshita, S; Muramatsu, T; Maeda, H

    1992-04-01

    The unicellular marine phytoplankton Chattonella marina is known to have toxic effects against various living marine organisms, especially fishes. However, details of the mechanism of the toxicity of this plankton remain obscure. Here we demonstrate the generation of superoxide and hydroxyl radicals from a red tide unicellular organism, C. marina, by using ESR spectroscopy with the spin traps 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and N-t-butyl-alpha-phenylnitrone (PBN), and by using the luminol-enhanced chemiluminescence response. The spin-trapping assay revealed productions of spin adduct of superoxide anion (O2-) (DMPO-OOH) and that of hydroxyl radical (.OH) (DMPO-OH) in the algal suspension, which was not observed in the ultrasonic-ruptured suspension. The addition of superoxide dismutase (500 U/ml) almost completely inhibited the formation of both DMPO-OOH and DMPO-OH, and carbon-centered radicals were generated with the disappearance of DMPO-OH after addition of 5% dimethyl sulfoxide (Me2SO) and 5% ethanol. Furthermore, the generation of methyl and methoxyl radicals, which are thought to be produced by the reaction of hydroxyl radical and Me2SO under aerobic condition, was identified using spin trapping with a combination of PBN and Me2SO. Luminol-enhanced chemiluminescence assay also supported the above observations. These results clearly indicate that C. marina generates and releases the superoxide radical followed by the production of hydroxyl radical to the surrounding environment. The velocity of superoxide generation by C. marina was about 100 times faster than that by mammalian phagocytes per cell basis. The generation of oxygen radical is suggested to be a pathogenic principle in the toxication of red tide to susceptible aquaculture fishes and may be directly correlated with the coastal pollution by red tide.

  8. Catalytic Radical Domino Reactions in Organic Synthesis

    PubMed Central

    Sebren, Leanne J.; Devery, James J.; Stephenson, Corey R.J.

    2014-01-01

    Catalytic radical-based domino reactions represent important advances in synthetic organic chemistry. Their development benefits synthesis by providing atom- and step-economical methods to complex molecules. Intricate combinations of radical, cationic, anionic, oxidative/reductive, and transition metal mechanistic steps result in cyclizations, additions, fragmentations, ring-expansions, and rearrangements. This Perspective summarizes recent developments in the field of catalytic domino processes. PMID:24587964

  9. Radicals: Reactive Intermediates with Translational Potential

    PubMed Central

    2016-01-01

    This Perspective illustrates the defining characteristics of free radical chemistry, beginning with its rich and storied history. Studies from our laboratory are discussed along with recent developments emanating from others in this burgeoning area. The practicality and chemoselectivity of radical reactions enable rapid access to molecules of relevance to drug discovery, agrochemistry, material science, and other disciplines. Thus, these reactive intermediates possess inherent translational potential, as they can be widely used to expedite scientific endeavors for the betterment of humankind. PMID:27631602

  10. Lignin biodegradation and the production of ethyl alcohol from cellulose

    SciTech Connect

    Rosenberg, S.L.; Wilke, C.R.

    1981-02-01

    During the last few years our group has been engaged in developing a biochemical process for the conversion of lignocellulosic materials to ethyl alcohol. Lignin is a barrier to complete cellulose saccharification in this process, but chemical and physical delignification steps are too expensive to be used at the present time. An enzymatic delignification process might be attractive for several reasons: little energy would be expected to be needed, enzymes could be recovered and reused, and useful chemicals might be produced from dissolved lignin. A number of thermophilic and thermotolerant fungi were examined for the ability to rapidly degrade lignocellulose in order to find an organism whcih produced an active lignin-degrading enzyme system. Chryosporium pruinosum and Sporotrichum pulverulentum were found to be active lignocellulose degraders, and C. pruinosum was chosen for further study. Lignin and carbohydrate were degraded when the substrate remained moistened by, but not submerged in, the liquid medium. Attempts were made to demonstrate a cell-free lignin degrading system by both extraction and pressing of cultures grown on moist lignocellulose. Carbohydrate-degrading activity was found but not lignin-degrading activity. This led us to ask whether diffusible lignin-degrading activity could be demonstrated in this organism. The data indicate that the lignin degradation system, or one or more of its components, produced by this organism is either unstable, non-diffusible, or inactive at small distances (about 1 mm) from growing hyphae. At present, studies are being conducted using diffusion cultures to select mutants of C. pruinosum that do produce a diffusible lignin degradation system. We are also examining a number of mesophilic lignin-degrading molds for this ability.

  11. ETHYL CYANIDE ON TITAN: SPECTROSCOPIC DETECTION AND MAPPING USING ALMA

    SciTech Connect

    Cordiner, M. A.; Palmer, M. Y.; Nixon, C. A.; Charnley, S. B.; Mumma, M. J.; Serigano, J.; Irwin, P. G. J.; Teanby, N. A.; Kisiel, Z.; Wang, K.-S.

    2015-02-10

    We report the first spectroscopic detection of ethyl cyanide (C{sub 2}H{sub 5}CN) in Titan’s atmosphere, obtained using spectrally and spatially resolved observations of multiple emission lines with the Atacama Large Millimeter/submillimeter Array (ALMA). The presence of C{sub 2}H{sub 5}CN in Titan’s ionosphere was previously inferred from Cassini ion mass spectrometry measurements of C{sub 2}H{sub 5}CNH{sup +}. Here we report the detection of 27 rotational lines from C{sub 2}H{sub 5}CN (in 19 separate emission features detected at >3σ confidence) in the frequency range 222–241 GHz. Simultaneous detections of multiple emission lines from HC{sub 3}N, CH{sub 3}CN, and CH{sub 3}CCH were also obtained. In contrast to HC{sub 3}N, CH{sub 3}CN, and CH{sub 3}CCH, which peak in Titan’s northern (spring) hemisphere, the emission from C{sub 2}H{sub 5}CN is found to be concentrated in the southern (autumn) hemisphere, suggesting a distinctly different chemistry for this species, consistent with a relatively short chemical lifetime for C{sub 2}H{sub 5}CN. Radiative transfer models show that C{sub 2}H{sub 5}CN is most concentrated at altitudes ≳200 km, suggesting production predominantly in the stratosphere and above. Vertical column densities are found to be in the range (1–5) × 10{sup 14} cm{sup −2}.

  12. Environmental Fate of Chiral Herbicide Fenoxaprop-ethyl in Water-Sediment Microcosms

    NASA Astrophysics Data System (ADS)

    Jing, Xu; Yao, Guojun; Liu, Donghui; Liu, Mingke; Wang, Peng; Zhou, Zhiqiang

    2016-05-01

    The environmental fate of the herbicide fenoxaprop-ethyl (FE) in water, sediment and water-sediment microcosm was studied and degradation products fenoxaprop (FA), ethyl-2-(4-hydroxyphenoxy)propanoate (EHPP), 2-(4-hydroxyphenoxy)propanoic acid (HPPA) and 6-chloro-2,3-dihydrobenzoxazol-2-one (CDHB) were monitored. FE, FA, EHPP and HPPA were chiral and the environmental behavior was investigated on an enantiomeric level. In water, sediment and water-sediment microcosms, fenoxaprop-ethyl degraded very fast with half-lives less than 1 day and it was found the herbicidally inactive S-enantiomer degraded faster. Fenoxaprop was the main primary degradation product which was quickly formed and the further degradation was relatively slow with half-lives of 6.4-12.4 days, and the S-enantiomer degraded faster too. EHPP, HPPA and CDHB could be found and S-EHPP and S-HPPA were degraded preferentially. The effects of microorganism and water content were investigated and it was found that the enantioselectivity was attributed to microorganisms. In sediment, the main degradation pathway of fenoxaprop-ethyl was hydrolysis and the degradation rate of fenoxaprop-ethyl increased with water content. The degradation products and enantioselectivity should be considered for the impact of fenoxaprop-ethyl on the aquatic system.

  13. Environmental Fate of Chiral Herbicide Fenoxaprop-ethyl in Water-Sediment Microcosms

    NASA Astrophysics Data System (ADS)

    Jing, Xu; Yao, Guojun; Liu, Donghui; Liu, Mingke; Wang, Peng; Zhou, Zhiqiang

    2016-05-01

    The environmental fate of the herbicide fenoxaprop-ethyl (FE) in water, sediment and water-sediment microcosm was studied and degradation products fenoxaprop (FA), ethyl-2-(4-hydroxyphenoxy)propanoate (EHPP), 2-(4-hydroxyphenoxy)propanoic acid (HPPA) and 6-chloro-2,3-dihydrobenzoxazol-2-one (CDHB) were monitored. FE, FA, EHPP and HPPA were chiral and the environmental behavior was investigated on an enantiomeric level. In water, sediment and water-sediment microcosms, fenoxaprop-ethyl degraded very fast with half-lives less than 1 day and it was found the herbicidally inactive S-enantiomer degraded faster. Fenoxaprop was the main primary degradation product which was quickly formed and the further degradation was relatively slow with half-lives of 6.4–12.4 days, and the S-enantiomer degraded faster too. EHPP, HPPA and CDHB could be found and S-EHPP and S-HPPA were degraded preferentially. The effects of microorganism and water content were investigated and it was found that the enantioselectivity was attributed to microorganisms. In sediment, the main degradation pathway of fenoxaprop-ethyl was hydrolysis and the degradation rate of fenoxaprop-ethyl increased with water content. The degradation products and enantioselectivity should be considered for the impact of fenoxaprop-ethyl on the aquatic system.

  14. Environmental Fate of Chiral Herbicide Fenoxaprop-ethyl in Water-Sediment Microcosms

    PubMed Central

    Jing, Xu; Yao, Guojun; Liu, Donghui; Liu, Mingke; Wang, Peng; Zhou, Zhiqiang

    2016-01-01

    The environmental fate of the herbicide fenoxaprop-ethyl (FE) in water, sediment and water-sediment microcosm was studied and degradation products fenoxaprop (FA), ethyl-2-(4-hydroxyphenoxy)propanoate (EHPP), 2-(4-hydroxyphenoxy)propanoic acid (HPPA) and 6-chloro-2,3-dihydrobenzoxazol-2-one (CDHB) were monitored. FE, FA, EHPP and HPPA were chiral and the environmental behavior was investigated on an enantiomeric level. In water, sediment and water-sediment microcosms, fenoxaprop-ethyl degraded very fast with half-lives less than 1 day and it was found the herbicidally inactive S-enantiomer degraded faster. Fenoxaprop was the main primary degradation product which was quickly formed and the further degradation was relatively slow with half-lives of 6.4–12.4 days, and the S-enantiomer degraded faster too. EHPP, HPPA and CDHB could be found and S-EHPP and S-HPPA were degraded preferentially. The effects of microorganism and water content were investigated and it was found that the enantioselectivity was attributed to microorganisms. In sediment, the main degradation pathway of fenoxaprop-ethyl was hydrolysis and the degradation rate of fenoxaprop-ethyl increased with water content. The degradation products and enantioselectivity should be considered for the impact of fenoxaprop-ethyl on the aquatic system. PMID:27225540

  15. Environmental Fate of Chiral Herbicide Fenoxaprop-ethyl in Water-Sediment Microcosms.

    PubMed

    Jing, Xu; Yao, Guojun; Liu, Donghui; Liu, Mingke; Wang, Peng; Zhou, Zhiqiang

    2016-01-01

    The environmental fate of the herbicide fenoxaprop-ethyl (FE) in water, sediment and water-sediment microcosm was studied and degradation products fenoxaprop (FA), ethyl-2-(4-hydroxyphenoxy)propanoate (EHPP), 2-(4-hydroxyphenoxy)propanoic acid (HPPA) and 6-chloro-2,3-dihydrobenzoxazol-2-one (CDHB) were monitored. FE, FA, EHPP and HPPA were chiral and the environmental behavior was investigated on an enantiomeric level. In water, sediment and water-sediment microcosms, fenoxaprop-ethyl degraded very fast with half-lives less than 1 day and it was found the herbicidally inactive S-enantiomer degraded faster. Fenoxaprop was the main primary degradation product which was quickly formed and the further degradation was relatively slow with half-lives of 6.4-12.4 days, and the S-enantiomer degraded faster too. EHPP, HPPA and CDHB could be found and S-EHPP and S-HPPA were degraded preferentially. The effects of microorganism and water content were investigated and it was found that the enantioselectivity was attributed to microorganisms. In sediment, the main degradation pathway of fenoxaprop-ethyl was hydrolysis and the degradation rate of fenoxaprop-ethyl increased with water content. The degradation products and enantioselectivity should be considered for the impact of fenoxaprop-ethyl on the aquatic system. PMID:27225540

  16. Oxidase-peroxidase enzymes of Datura innoxia. Oxidation of formylphenylacetic acid ethyl ester.

    PubMed Central

    Kalyanaraman, V S; Mahadevan, S; Kumar, S A

    1975-01-01

    An enzyme system from Datura innoxia roots oxidizing formylphenylacetic acid ethyl ester was purified 38-fold by conventional methods such as (NH4)2SO4 fractionation, negative adsorption on alumina Cy gel and chromatography on DEAE-cellulose. The purified enzyme was shown to catalyse the stoicheiometric oxidation of formylphenylacetic acid ethyl ester to benzoylformic acid ethyl ester and formic acid, utilizing molecular O2. Substrate analogues such as phenylacetaldehyde and phenylpyruvate were oxidized at a very low rate, and formylphenylacetonitrile was an inhilating agents, cyanide, thiol compounds and ascorbic acid. This enzyme was identical with an oxidase-peroxidase isoenzyme. Another oxidase-peroxidase isoenzyme which separated on DEAE-chromatography also showed formylphenylacetic acid ethyl ester oxidase activity, albeit to a lesser extent. The properties of the two isoenzymes of the oxidase were compared and shown to differ in their oxidation and peroxidation properties. The oxidation of formylphenylacetic acid ethyl ester was also catalysed by horseradish peroxidase. The Datura isoenzymes exhibited typical haemoprotein spectra. The oxidation of formylphenylacetic acid ethyl ester was different from other peroxidase-catalysed reactions in not being activated by either Mn2+ or monophenols. The oxidation was inhibited by several mono- and poly-phenols and by catalase. A reaction mechanism for the oxidation is proposed. PMID:997

  17. Inactivation of Bacillus atrophaeus by OH radicals

    NASA Astrophysics Data System (ADS)

    Ono, Ryo; Yonetamari, Kenta; Tokumitsu, Yusuke; Yonemori, Seiya; Yasuda, Hachiro; Mizuno, Akira

    2016-08-01

    The inactivation of Bacillus atrophaeus by OH radicals is measured. This study aims to evaluate the bactericidal effects of OH radicals produced by atmospheric-pressure nonthermal plasma widely used for plasma medicine; however, in this study, OH radicals are produced by vacuum ultraviolet (VUV) photolysis of water vapor instead of plasma to allow the production of OH radicals with almost no other reactive species. A 172 nm VUV light from a Xe2 excimer lamp irradiates a He–H2O mixture flowing in a quartz tube to photodissociate H2O to produce OH, H, O, HO2, H2O2, and O3. The produced reactive oxygen species (ROS) flow out of the quartz tube nozzle to the bacteria on an agar plate and cause inactivation. The inactivation by OH radicals among the six ROS is observed by properly setting the experimental conditions with the help of simulations calculating the ROS densities. A 30 s treatment with approximately 0.1 ppm OH radicals causes visible inactivation.

  18. Hydroxyl radical oxidation of feruloylated arabinoxylan.

    PubMed

    Bagdi, Attila; Tömösközi, Sándor; Nyström, Laura

    2016-11-01

    Feruloylated arabinoxylan (AX) has a unique capacity to form covalent gels in the presence of certain oxidizing agents. The present study demonstrates that hydroxyl radical oxidation does not provoke ferulic acid dimerization and thus oxidative gelation. We studied the hydroxyl radical mediated oxidation of an alkali-extracted AX preparation (purity: 92g/100g dry matter) that showed gel-forming capability upon peroxidase/hydrogen peroxide treatment. Hydroxyl radicals were produced with ascorbate-driven Fenton reaction and the radical formation was monitored with electron paramagnetic resonance, using a POBN/EtOH spin trapping system. Oxidation was carried out at different catalytic concentrations of iron (50 and 100μM) and at different temperatures (20°C, 50°C, and 80°C). It was demonstrated that hydroxyl radical oxidation does not provoke gel formation, but viscosity decrease in AX solution, which suggests polymer degradation. Furthermore, it was demonstrated that hydroxyl radical formation in AX solution can be initiated merely by increasing temperature. PMID:27516272

  19. Inactivation of Bacillus atrophaeus by OH radicals

    NASA Astrophysics Data System (ADS)

    Ono, Ryo; Yonetamari, Kenta; Tokumitsu, Yusuke; Yonemori, Seiya; Yasuda, Hachiro; Mizuno, Akira

    2016-08-01

    The inactivation of Bacillus atrophaeus by OH radicals is measured. This study aims to evaluate the bactericidal effects of OH radicals produced by atmospheric-pressure nonthermal plasma widely used for plasma medicine; however, in this study, OH radicals are produced by vacuum ultraviolet (VUV) photolysis of water vapor instead of plasma to allow the production of OH radicals with almost no other reactive species. A 172 nm VUV light from a Xe2 excimer lamp irradiates a He-H2O mixture flowing in a quartz tube to photodissociate H2O to produce OH, H, O, HO2, H2O2, and O3. The produced reactive oxygen species (ROS) flow out of the quartz tube nozzle to the bacteria on an agar plate and cause inactivation. The inactivation by OH radicals among the six ROS is observed by properly setting the experimental conditions with the help of simulations calculating the ROS densities. A 30 s treatment with approximately 0.1 ppm OH radicals causes visible inactivation.

  20. Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies

    NASA Astrophysics Data System (ADS)

    Yang, Gang; Zhu, Chang; Zou, Xianli; Zhou, Lijun

    2016-07-01

    Ab initio and density functional calculations are conducted to investigate the radicalization processes and radical catalysis of biomass sugars. Structural alterations due to radicalization generally focus on the radicalized sites, and radicalization affects H-bonds in D-fructofuranose more than in D-glucopyranose, potentially with outcome of new H-bonds. Performances of different functionals and basis sets are evaluated for all radicalization processes, and enthalpy changes and Gibbs free energies for these processes are presented with high accuracy, which can be referenced for subsequent experimental and theoretical studies. It shows that radicalization can be utilized for direct transformation of biomass sugars, and for each sugar, C rather than O sites are always preferred for radicalization, thus suggesting the possibility to activate C-H bonds of biomass sugars. Radical catalysis is further combined with Brønsted acids, and it clearly states that functionalization fundamentally regulates the catalytic effects of biomass sugars. In presence of explicit water molecules, functionalization significantly affects the activation barriers and reaction energies of protonation rather than dehydration steps. Tertiary butyl and phenyl groups with large steric hindrances or hydroxyl and amino groups resulting in high stabilities for protonation products drive the protonation steps to occur facilely at ambient conditions.

  1. Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies

    PubMed Central

    Yang, Gang; Zhu, Chang; Zou, Xianli; Zhou, Lijun

    2016-01-01

    Ab initio and density functional calculations are conducted to investigate the radicalization processes and radical catalysis of biomass sugars. Structural alterations due to radicalization generally focus on the radicalized sites, and radicalization affects H-bonds in D-fructofuranose more than in D-glucopyranose, potentially with outcome of new H-bonds. Performances of different functionals and basis sets are evaluated for all radicalization processes, and enthalpy changes and Gibbs free energies for these processes are presented with high accuracy, which can be referenced for subsequent experimental and theoretical studies. It shows that radicalization can be utilized for direct transformation of biomass sugars, and for each sugar, C rather than O sites are always preferred for radicalization, thus suggesting the possibility to activate C-H bonds of biomass sugars. Radical catalysis is further combined with Brønsted acids, and it clearly states that functionalization fundamentally regulates the catalytic effects of biomass sugars. In presence of explicit water molecules, functionalization significantly affects the activation barriers and reaction energies of protonation rather than dehydration steps. Tertiary butyl and phenyl groups with large steric hindrances or hydroxyl and amino groups resulting in high stabilities for protonation products drive the protonation steps to occur facilely at ambient conditions. PMID:27405843

  2. Radicalization and Radical Catalysis of Biomass Sugars: Insights from First-principles Studies.

    PubMed

    Yang, Gang; Zhu, Chang; Zou, Xianli; Zhou, Lijun

    2016-01-01

    Ab initio and density functional calculations are conducted to investigate the radicalization processes and radical catalysis of biomass sugars. Structural alterations due to radicalization generally focus on the radicalized sites, and radicalization affects H-bonds in D-fructofuranose more than in D-glucopyranose, potentially with outcome of new H-bonds. Performances of different functionals and basis sets are evaluated for all radicalization processes, and enthalpy changes and Gibbs free energies for these processes are presented with high accuracy, which can be referenced for subsequent experimental and theoretical studies. It shows that radicalization can be utilized for direct transformation of biomass sugars, and for each sugar, C rather than O sites are always preferred for radicalization, thus suggesting the possibility to activate C-H bonds of biomass sugars. Radical catalysis is further combined with Brønsted acids, and it clearly states that functionalization fundamentally regulates the catalytic effects of biomass sugars. In presence of explicit water molecules, functionalization significantly affects the activation barriers and reaction energies of protonation rather than dehydration steps. Tertiary butyl and phenyl groups with large steric hindrances or hydroxyl and amino groups resulting in high stabilities for protonation products drive the protonation steps to occur facilely at ambient conditions. PMID:27405843

  3. Calculational and Experimental Investigations of the Pressure Effects on Radical - Radical Cross Combinations Reactions: C2H5 + C2H3

    NASA Technical Reports Server (NTRS)

    Fahr, Askar; Halpern, Joshua B.; Tardy, Dwight C.

    2007-01-01

    Pressure-dependent product yields have been experimentally determined for the cross-radical reaction C2H5 + C2H3. These results have been extended by calculations. It is shown that the chemically activated combination adduct, 1-C4H8*, is either stabilized by bimolecular collisions or subject to a variety of unimolecular reactions including cyclizations and decompositions. Therefore the "apparent" combination/disproportionation ratio exhibits a complex pressure dependence. The experimental studies were performed at 298 K and at selected pressures between about 4 Torr (0.5 kPa) and 760 Torr (101 kPa). Ethyl and vinyl radicals were simultaneously produced by 193 nm excimer laser photolysis of C2H5COC2H3 or photolysis of C2H3Br and C2H5COC2H5. Gas chromatograph/mass spectrometry/flame ionization detection (GC/MS/FID) were used to identify and quantify the final reaction products. The major combination reactions at pressures between 500 (66.5 kPa) and 760 Torr are (1c) C2H5 + C2H3 yields 1-butene, (2c) C2H5 + C2H5 yields n-butane, and (3c) C2H3 + C2H3 yields 1,3-butadiene. The major products of the disproportionation reactions are ethane, ethylene, and acetylene. At moderate and lower pressures, secondary products, including propene, propane, isobutene, 2-butene (cis and trans), 1-pentene, 1,4-pentadiene, and 1,5-hexadiene are also observed. Two isomers of C4H6, cyclobutene and/or 1,2-butadiene, were also among the likely products. The pressure-dependent yield of the cross-combination product, 1-butene, was compared to the yield of n-butane, the combination product of reaction (2c), which was found to be independent of pressure over the range of this study. The [ 1-C4H8]/[C4H10] ratio was reduced from approx.1.2 at 760 Torr (101 kPa) to approx.0.5 at 100 Torr (13.3 kPa) and approx.0.1 at pressures lower than about 5 Torr (approx.0.7 kPa). Electronic structure and RRKM calculations were used to simulate both unimolecular and bimolecular processes. The relative importance

  4. Ethyl acetate-n-butanol gradient solvent system for high-speed countercurrent chromatography to screen bioactive substances in okra.

    PubMed

    Ying, Hao; Jiang, Heyuan; Liu, Huan; Chen, Fangjuan; Du, Qizhen

    2014-09-12

    High-speed countercurrent chromatographic separation (HSCCC) possesses the property of zero-loss of sample, which is very useful for the screening of bioactive components. In the present study, the ethyl acetate-n-butanol gradient HSCCC solvent system composed of n-hexane-ethyl acetate-n-butanol-water was investigated for the screening of bioactive substances. To screen the antiproliferative compounds in okra extract, we used the stationary phase ethyl acetate-n-butanol-water (1:1:10) as the stationary phase, and eluted the antiproliferative components by 6-steps of gradient using mobile phases n-hexane-ethyl acetate (1:2), n-hexane-ethyl acetate (1:4), n-hexane-ethyl acetate (0:4), n-butanol-ethyl acetate (1:4) n-butanol-ethyl acetate (1:2), n-butanol-ethyl acetate (2:2), and n-butanol-ethyl acetate (2:1). The fractions collected from HSCCC separation with the gradient solvent system were assayed for antiproliferative activity against cancer cells. Bioactive components were identified: a major anti-cancer compound, 4'-hydroxy phenethyl trans-ferulate, with middle activity, and a minor anti-cancer compound, carolignan, with strong activity. The result shows that the gradient solvent system is potential for the screening of bioactive compounds from natural products.

  5. Ethyl acetate-n-butanol gradient solvent system for high-speed countercurrent chromatography to screen bioactive substances in okra.

    PubMed

    Ying, Hao; Jiang, Heyuan; Liu, Huan; Chen, Fangjuan; Du, Qizhen

    2014-09-12

    High-speed countercurrent chromatographic separation (HSCCC) possesses the property of zero-loss of sample, which is very useful for the screening of bioactive components. In the present study, the ethyl acetate-n-butanol gradient HSCCC solvent system composed of n-hexane-ethyl acetate-n-butanol-water was investigated for the screening of bioactive substances. To screen the antiproliferative compounds in okra extract, we used the stationary phase ethyl acetate-n-butanol-water (1:1:10) as the stationary phase, and eluted the antiproliferative components by 6-steps of gradient using mobile phases n-hexane-ethyl acetate (1:2), n-hexane-ethyl acetate (1:4), n-hexane-ethyl acetate (0:4), n-butanol-ethyl acetate (1:4) n-butanol-ethyl acetate (1:2), n-butanol-ethyl acetate (2:2), and n-butanol-ethyl acetate (2:1). The fractions collected from HSCCC separation with the gradient solvent system were assayed for antiproliferative activity against cancer cells. Bioactive components were identified: a major anti-cancer compound, 4'-hydroxy phenethyl trans-ferulate, with middle activity, and a minor anti-cancer compound, carolignan, with strong activity. The result shows that the gradient solvent system is potential for the screening of bioactive compounds from natural products. PMID:25069743

  6. Practicing Radical Pedagogy: Balancing Ideals with Institutional Constraints.

    ERIC Educational Resources Information Center

    Sweet, Stephen

    1998-01-01

    Describes radical pedagogy and observes that an overview of "Teaching Sociology" suggests that few teachers fully practice it. Argues that while professors are free to teach radical theory, radical pedagogy is hindered by institutional constraints. Concludes that radical teachers may benefit from remaining more within the confines imposed by their…

  7. In Vitro Antimicrobial Bioassays, DPPH Radical Scavenging Activity, and FTIR Spectroscopy Analysis of Heliotropium bacciferum

    PubMed Central

    2016-01-01

    The present study deals with the antimicrobial, antioxidant, and functional group analysis of Heliotropium bacciferum extracts. Disc diffusion susceptibility method was followed for antimicrobial assessment. Noteworthy antimicrobial activities were recorded by various plant extracts against antibiotic resistant microorganisms. Plant flower extracts antioxidant activity was investigated against 2, 2-diphenyl-1-picryl hydrazyl radical by ultraviolet spectrophotometer (517 nm). Plant extracts displayed noteworthy radical scavenging activities at all concentrations (25–225 μg/mL). Notable activities were recorded by crude, chloroform and ethyl acetate extracts up to 88.27% at 225 μg/mL concentration. Compounds functional groups were examined by Fourier transform infrared spectroscopic studies. Alkanes, alkenes, alkyl halides, amines, carboxylic acids, amides, esters, alcohols, phenols, nitrocompounds, and aromatic compounds were identified by FTIR analysis. Thin layer chromatography bioautography was carried out for all plant extracts. Different bands were separated by various solvent systems. The results of the current study justify the use of Heliotropium bacciferum in traditional remedial herbal medicines.

  8. In Vitro Antimicrobial Bioassays, DPPH Radical Scavenging Activity, and FTIR Spectroscopy Analysis of Heliotropium bacciferum

    PubMed Central

    2016-01-01

    The present study deals with the antimicrobial, antioxidant, and functional group analysis of Heliotropium bacciferum extracts. Disc diffusion susceptibility method was followed for antimicrobial assessment. Noteworthy antimicrobial activities were recorded by various plant extracts against antibiotic resistant microorganisms. Plant flower extracts antioxidant activity was investigated against 2, 2-diphenyl-1-picryl hydrazyl radical by ultraviolet spectrophotometer (517 nm). Plant extracts displayed noteworthy radical scavenging activities at all concentrations (25–225 μg/mL). Notable activities were recorded by crude, chloroform and ethyl acetate extracts up to 88.27% at 225 μg/mL concentration. Compounds functional groups were examined by Fourier transform infrared spectroscopic studies. Alkanes, alkenes, alkyl halides, amines, carboxylic acids, amides, esters, alcohols, phenols, nitrocompounds, and aromatic compounds were identified by FTIR analysis. Thin layer chromatography bioautography was carried out for all plant extracts. Different bands were separated by various solvent systems. The results of the current study justify the use of Heliotropium bacciferum in traditional remedial herbal medicines. PMID:27597961

  9. Evaluation of Antioxidant, Free Radical Scavenging, and Antimicrobial Activity of Quercus incana Roxb.

    PubMed Central

    Sarwar, Rizwana; Farooq, Umar; Khan, Ajmal; Naz, Sadia; Khan, Sara; Khan, Afsar; Rauf, Abdur; Bahadar, Haji; Uddin, Reaz

    2015-01-01

    Considering the indigenous utilization of Quercus incana Roxb., the present study deals with the investigation of antioxidant, free radical scavenging activity, total phenolic content, and antimicrobial activity of Q. incana Roxb. In vitro antioxidant activity of the plant fractions were determined by 1,1-diphenyl-2-picrylhydrazyl and nitric oxide scavenging method. Total phenolic contents were determined by gallic acid equivalent and antimicrobial activities were determined by agar well diffusion method. It was observed that Q. incana Roxb. showed significant antibacterial activity against Gram-positive and Gram-negative bacteria. n-Butanol fraction showed maximum activity against Micrococcus leuteus with 19 mm zone of inhibition. n-Butanol fraction of Q. incana Roxb. showed immense antifungal activity against Aspergillus niger (32 mm ± 0.55) and A. flavus (28 mm ± 0.45). Similarly n-butanol fraction showed relatively good antioxidant activity with IC50 value of 55.4 ± 0.21 μg/mL. The NO scavenging activity of ethyl acetate fraction (IC50 = 23.21 ± 0.31 μg/mL) was fairly good compared to other fractions. The current study of Q. incana Roxb. suggests the presences of synergetic action of some biological active compounds that may be present in the leaves of medicinal plant. Further studies are needed to better characterize the important active constituents responsible for the antimicrobial, antioxidant and free radical scavenging activity. PMID:26635607

  10. Rate constant calculations of H-atom abstraction reactions from ethers by HȮ2 radicals.

    PubMed

    Mendes, Jorge; Zhou, Chong-Wen; Curran, Henry J

    2014-02-27

    In this work, we detail hydrogen atom abstraction reactions from six ethers by the hydroperoxyl radical, including dimethyl ether, ethyl methyl ether, propyl methyl ether, isopropyl methyl ether, butyl methyl ether, and isobutyl methyl ether, in order to test the effect of the functional group on the rate constant calculations. The Møller-Plesset (MP2) method with the 6-311G(d,p) basis set has been employed in the geometry optimizations and frequency calculations of all of the species involved in the above reaction systems. The connections between each transition state and the corresponding local minima have been determined by intrinsic reaction coordinate calculations. Energies are reported at the CCSD(T)/cc-pVTZ level of theory and include the zero-point energy corrections. As a benchmark in the electronic energy calculations, the CCSD(T)/CBS extrapolation was used for the reactions of dimethyl ether + HȮ2 radicals. A systematic calculation of the high-pressure limit rate constants has been performed using conventional transition-state theory, including asymmetric Eckart tunneling corrections, in the temperature range of 500-2000 K. The one dimensional hindrance potentials obtained at MP2/6-311G(d,p) for the reactants and transition states have been used to describe the low frequency torsional modes. Herein, we report the calculated individual, average, and total rate constants. A branching ratio analysis for every reaction site has also been performed. PMID:24483837

  11. In Vitro Antimicrobial Bioassays, DPPH Radical Scavenging Activity, and FTIR Spectroscopy Analysis of Heliotropium bacciferum.

    PubMed

    Ahmad, Sohail; AbdEl-Salam, Naser M; Ullah, Riaz

    2016-01-01

    The present study deals with the antimicrobial, antioxidant, and functional group analysis of Heliotropium bacciferum extracts. Disc diffusion susceptibility method was followed for antimicrobial assessment. Noteworthy antimicrobial activities were recorded by various plant extracts against antibiotic resistant microorganisms. Plant flower extracts antioxidant activity was investigated against 2, 2-diphenyl-1-picryl hydrazyl radical by ultraviolet spectrophotometer (517 nm). Plant extracts displayed noteworthy radical scavenging activities at all concentrations (25-225 μg/mL). Notable activities were recorded by crude, chloroform and ethyl acetate extracts up to 88.27% at 225 μg/mL concentration. Compounds functional groups were examined by Fourier transform infrared spectroscopic studies. Alkanes, alkenes, alkyl halides, amines, carboxylic acids, amides, esters, alcohols, phenols, nitrocompounds, and aromatic compounds were identified by FTIR analysis. Thin layer chromatography bioautography was carried out for all plant extracts. Different bands were separated by various solvent systems. The results of the current study justify the use of Heliotropium bacciferum in traditional remedial herbal medicines. PMID:27597961

  12. Assessing the neurotoxic potential of methyl ethyl ketoxime in rats.

    PubMed

    Schulze, G E; Derelanko, M J

    1993-11-01

    The potential of methyl ethyl ketoxime (MEKO) to produce neurotoxicity following acute and subchronic exposure was studied in rats. A Functional Observational Battery, assessment of motor activity, and neuropathology evaluations were conducted in the context of acute and subchronic toxicity studies. Three independent studies are reported: a pilot time-effect study designed to determine the time course and time to peak effect following a single high dose of MEKO, a single-dose neurotoxicity study, and a subchronic (13-week) repeated-dose neurotoxicity study in rats. An acrylamide-positive control group was included in the acute and subchronic studies for comparison with MEKO. Following an acute oral exposure of MEKO at a dose level of 900 mg/kg, locomotor activity was decreased compared to control with maximum decreases occurring between 30 and 60 min following oral administration. In the acute study, transient treatment-related changes in ease of cage removal, ease of handling, and in posture and gait were observed 1 hr after dosing with 900 mg/kg MEKO, as were significant depressions in motor activity. Following a single 300 mg/kg dose, transient MEKO-related changes in gait and aerial righting reflex were noted 1 hr after dosing. All effects were reversible within 24 hr of dosing. The single 100 mg/kg dose of MEKO was without observable effects. No acrylamide-related behavioral effects were noted following a single 50 mg/kg dose. In the subchronic study, transient treatment-related changes in ease of cage removal, ease of handling, and in posture, gait, and aerial righting were observed at the 400 mg/kg/day dose level when assessments were conducted immediately after dose administration. No consistent behavioral effects were observed prior to daily dose administration even after 13 weeks of exposure, indicating a lack of cumulative behavioral effect. No consistent behavioral changes were noted at doses of 125 mg/kg/day and below. Significant dose

  13. Artifact suppression in electron paramagnetic resonance imaging of 14N- and 15N-labeled nitroxyl radicals with asymmetric absorption spectra

    NASA Astrophysics Data System (ADS)

    Takahashi, Wataru; Miyake, Yusuke; Hirata, Hiroshi

    2014-10-01

    This article describes an improved method for suppressing image artifacts in the visualization of 14N- and 15N-labeled nitroxyl radicals in a single image scan using electron paramagnetic resonance (EPR). The purpose of this work was to solve the problem of asymmetric EPR absorption spectra in spectral processing. A hybrid function of Gaussian and Lorentzian lineshapes was used to perform spectral line-fitting to successfully separate the two kinds of nitroxyl radicals. This approach can process the asymmetric EPR absorption spectra of the nitroxyl radicals being measured, and can suppress image artifacts due to spectral asymmetry. With this improved visualization method and a 750-MHz continuous-wave EPR imager, a temporal change in the distributions of a two-phase paraffin oil and water/glycerin solution system was visualized using lipophilic and hydrophilic nitroxyl radicals, i.e., 2-(14-carboxytetradecyl)-2-ethyl-4,4-dimethyl-3-oxazolidinyloxy (16-DOXYL stearic acid) and 4-hydroxyl-2,2,6,6-tetramethylpiperidine-d17-1-15N-1-oxyl (TEMPOL-d17-15N). The results of the two-phase separation experiment verified that reasonable artifact suppression could be achieved by the present method that deals with asymmetric absorption spectra in the EPR imaging of 14N- and 15N-labeled nitroxyl radicals.

  14. Study of the Reaction Cl + Ethyl Formate at 700-950 Torr and 297 to 435 K: Product Distribution and the Kinetics of the Reaction C2H5OC(═O) → CO2 + C2H5.

    PubMed

    Kaiser, E W

    2016-05-26

    The kinetics and mechanism of the reaction of atomic chlorine with ethyl formate [Cl + CH3CH2O(C═O)H, reaction 1] have been examined. These experiments were performed at pressures of 760-950 Torr and temperatures from 297 to 435 K. Reactants and products were quantified by gas chromatography-flame ionization detector (GC/FID) analysis. The initial mixture contained ethyl formate, Cl2, and N2. Cl atoms were generated by UV photolysis of this initial mixture at 360 nm, which dissociates Cl2. The rate constant of reaction 1 was measured at 297 K relative to that of the reaction Cl + C2H5Cl (reaction 2), yielding the rate constant ratio k1/k2 = 1.09 ± 0.05. The final products formed from reaction 1 are ethyl chloroformate, 1-chloroethyl formate, and 2-chloroethyl formate. These products result from the reactions with Cl2 of the three free radicals formed by H atom abstraction from ethylformate in reaction 1. Based on the molar yields of these three chlorinated products, the yields of the three radicals formed from reaction 1 at 297 K are (25 ± 3) mole percent of CH3CH2O(C═O); (67 ± 5) mole percent of CH3CHO(C═O)H; and (8 ± 2) mole percent of CH2CH2O(C═O)H. A second phase of this experiment measured the rate constant of the decarboxylation of the ethoxy carbonyl radical [CH3CH2O(C═O) → CO2 + C2H5, reaction 4] relative to the rate constant of its reaction with Cl2 [CH3CH2O(C═O) + Cl2 → CH3CH2O(C═O)Cl + Cl, reaction 3a]. Over the temperature range 297 to 404 K at 1 atm total pressure, this ratio can be expressed by k4/k3a = 10(23.56±0.22) e(-(12700±375)/RT) molecules cm(-3). Estimating the value of k3a (which has not been measured) based on similar reactions, the expression k4 = 5.8 × 10(12) e(-(12700)/RT) s(-1) is obtained. The estimated error of this rate constant is ± a factor of 2 over the experimental temperature range. This rate expression is compared with recent ab initio calculations of the decarboxylation of the analogous methoxy

  15. Study of the Reaction Cl + Ethyl Formate at 700-950 Torr and 297 to 435 K: Product Distribution and the Kinetics of the Reaction C2H5OC(═O) → CO2 + C2H5.

    PubMed

    Kaiser, E W

    2016-05-26

    The kinetics and mechanism of the reaction of atomic chlorine with ethyl formate [Cl + CH3CH2O(C═O)H, reaction 1] have been examined. These experiments were performed at pressures of 760-950 Torr and temperatures from 297 to 435 K. Reactants and products were quantified by gas chromatography-flame ionization detector (GC/FID) analysis. The initial mixture contained ethyl formate, Cl2, and N2. Cl atoms were generated by UV photolysis of this initial mixture at 360 nm, which dissociates Cl2. The rate constant of reaction 1 was measured at 297 K relative to that of the reaction Cl + C2H5Cl (reaction 2), yielding the rate constant ratio k1/k2 = 1.09 ± 0.05. The final products formed from reaction 1 are ethyl chloroformate, 1-chloroethyl formate, and 2-chloroethyl formate. These products result from the reactions with Cl2 of the three free radicals formed by H atom abstraction from ethylformate in reaction 1. Based on the molar yields of these three chlorinated products, the yields of the three radicals formed from reaction 1 at 297 K are (25 ± 3) mole percent of CH3CH2O(C═O); (67 ± 5) mole percent of CH3CHO(C═O)H; and (8 ± 2) mole percent of CH2CH2O(C═O)H. A second phase of this experiment measured the rate constant of the decarboxylation of the ethoxy carbonyl radical [CH3CH2O(C═O) → CO2 + C2H5, reaction 4] relative to the rate constant of its reaction with Cl2 [CH3CH2O(C═O) + Cl2 → CH3CH2O(C═O)Cl + Cl, reaction 3a]. Over the temperature range 297 to 404 K at 1 atm total pressure, this ratio can be expressed by k4/k3a = 10(23.56±0.22) e(-(12700±375)/RT) molecules cm(-3). Estimating the value of k3a (which has not been measured) based on similar reactions, the expression k4 = 5.8 × 10(12) e(-(12700)/RT) s(-1) is obtained. The estimated error of this rate constant is ± a factor of 2 over the experimental temperature range. This rate expression is compared with recent ab initio calculations of the decarboxylation of the analogous methoxy

  16. Choice of Bond Dissociation Enthalpies on which to Base the Stabilization Energies of Simple Radicals: DH(R-H)is Preferred because DH(R-Me) is Perturbed by Changes in Chain Branching

    SciTech Connect

    Poutsma, Marvin L

    2008-01-01

    The relative stabilization energies of radicals, SE(R ), along the simple series methyl/ethyl/i-propyl/t-butyl are known to vary in spread and even direction dependent on which dissociation enthalpies, DH(R-X), they are based on. Using a highly electronegative X is recognized as unwise, but it is not clear whether a choice of X = Me or X = R might not be preferred over the almost universal use of R = H. The enthalpies of isomerization of C4 radical pairs that vary only in the substitution pattern at the radical center but not in carbon skeleton illustrate that R = H is indeed the better choice. Comparisons in the context of recent predictive models for alkane and radical stability indicate that, while relative DH(R-H) values highlight the desired difference in substitution pattern at the radical center, relative DH(R-Me) values are perturbed by differences in skeletal branching or protobranching which are well-known to affect thermochemistry. As a result, SE(R ) values derived from relative DH(R-Me) values are consistently too small. The same pattern is illustrated for prim, sec, and tert allylic and benzylic radicals (larger SE(R )) and for the parent vinyl, phenyl, and ethynyl radicals (negative SE(R )).

  17. Laboratory Detection of the Trans-Gauche Conformer of Ethyl Formate.

    NASA Astrophysics Data System (ADS)

    Neill, Justin L.; Muckle, Matt T.; Zaleski, Daniel P.; Pate, Brooks H.; Lattanzi, V.; Spezzano, S.; McCarthy, M. C.

    2010-06-01

    Ethyl formate has two coordinates of conformational flexibility, in the ester (O=C-O-C) and ethyl (C-O-C-C) dihedral angles. Two conformers, one with a cis ester and trans ethyl orientation, the other with a cis ester and gauche ethyl orientation, have been previously detected by rotational spectroscopy. In addition, the cis-trans isomer, the lowest-energy conformer, has recently been detected in the SgrB2(N) hot core. The third conformer of ethyl formate, with a trans ester orientation and gauche ethyl orientation, is significantly higher in energy than the cis-trans conformer according to electronic structure calculations (1900 cm-1, or 1330 K), but there is a barrier of 2870 cm-1 (2000 K) for this conformer to relax into the more stable cis ester potential well, and so local thermodynamic equilibrium between these conformers is not expected in the interstellar medium. Similar behavior is found for the trans ester conformer of methyl formate, for which a tentative detection in SgrB2(N) was presented at this meeting last year, with a column density roughly 1% of that of the more stable cis isomer. Here we report the laboratory detection of trans-gauche ethyl formate using Fourier transform microwave spectroscopy; its low population at room temperature equilibrium has been enhanced by the use of a pulsed discharge nozzle. The spectrum is complicated by a low barrier (140 cm-1) to tunneling between equivalent structures. J.M. Riveros and E.B. Wilson, J. Chem. Phys. 46, 4605 (1967). A. Belloche. et al., A&A 499, 215 (2009). M.T. Muckle et al., RH15, 64th International Symposium on Molecular Spectroscopy (2009).

  18. Environmentally persistent free radicals (EPFRs)-2. Are free hydroxyl radicals generated in aqueous solutions?

    PubMed

    Khachatryan, Lavrent; Dellinger, Barry

    2011-11-01

    A chemical spin trap, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), in conjunction with electron paramagnetic resonance (EPR) spectroscopy was employed to measure the production of hydroxyl radical (·OH) in aqueous suspensions of 5% Cu(II)O/silica (3.9% Cu) particles containing environmentally persistent free radicals (EPFRs) of 2-monochlorophenol (2-MCP). The results indicate: (1) a significant differences in accumulated DMPO-OH adducts between EPFR containing particles and non-EPFR control samples, (2) a strong correlation between the concentration of DMPO-OH adducts and EPFRs per gram of particles, and (3) a slow, constant growth of DMPO-OH concentration over a period of days in solution containing 50 μg/mL EPFRs particles + DMPO (150 mM) + reagent balanced by 200 μL phosphate buffered (pH = 7.4) saline. However, failure to form secondary radicals using standard scavengers, such as ethanol, dimethylsulfoxide, sodium formate, and sodium azide, suggests free hydroxyl radicals may not have been generated in solution. This suggests surface-bound, rather than free, hydroxyl radicals were generated by a surface catalyzed-redox cycle involving both the EPFRs and Cu(II)O. Toxicological studies clearly indicate these bound free radicals promote various types of cardiovascular and pulmonary disease normally attributed to unbound free radicals; however, the exact chemical mechanism deserves further study in light of the implication of formation of bound, rather than free, hydroxyl radicals.

  19. DFT and ENDOR Study of Bixin Radical Cations and Neutral Radicals on Silica-Alumina.

    PubMed

    Tay-Agbozo, Sefadzi S; Krzyaniak, Matthew D; Bowman, Michael K; Street, Shane; Kispert, Lowell D

    2015-06-18

    Bixin, a carotenoid found in annatto (Bixa orellana), is unique among natural carotenoids by being water-soluble. We stabilized free radicals from bixin on the surface of silica-alumina (Si-Al) and characterized them by pulsed electron-nuclear double resonance (ENDOR). DFT calculations of unpaired electron spin distribution for various bixin radicals predict the EPR hyperfine couplings. Least-square fitting of experimental ENDOR spectra by spectra calculated from DFT hyperfine couplings characterized the radicals trapped on Si-Al. DFT predicts that the trans bixin radical cation is more stable than the cis bixin radical cation by 1.26 kcal/mol. This small energy difference is consistent with the 26% trans and 23% cis radical cations in the ENDOR spectrum. The remainder of the ENDOR spectrum is due to several neutral radicals formed by loss of a H(+) ion from the 9, 9', 13, or 13' methyl group, a common occurrence in all water-insoluble carotenoids previously studied. Although carboxyl groups of bixin strongly affect its solubility relative to other natural carotenoids, they do not alter properties of its free radicals based on DFT calculations and EPR measurements which remain similar to typical water-insoluble carotenoids.

  20. DFT and ENDOR Study of Bixin Radical Cations and Neutral Radicals on Silica-Alumina.

    PubMed

    Tay-Agbozo, Sefadzi S; Krzyaniak, Matthew D; Bowman, Michael K; Street, Shane; Kispert, Lowell D

    2015-06-18

    Bixin, a carotenoid found in annatto (Bixa orellana), is unique among natural carotenoids by being water-soluble. We stabilized free radicals from bixin on the surface of silica-alumina (Si-Al) and characterized them by pulsed electron-nuclear double resonance (ENDOR). DFT calculations of unpaired electron spin distribution for various bixin radicals predict the EPR hyperfine couplings. Least-square fitting of experimental ENDOR spectra by spectra calculated from DFT hyperfine couplings characterized the radicals trapped on Si-Al. DFT predicts that the trans bixin radical cation is more stable than the cis bixin radical cation by 1.26 kcal/mol. This small energy difference is consistent with the 26% trans and 23% cis radical cations in the ENDOR spectrum. The remainder of the ENDOR spectrum is due to several neutral radicals formed by loss of a H(+) ion from the 9, 9', 13, or 13' methyl group, a common occurrence in all water-insoluble carotenoids previously studied. Although carboxyl groups of bixin strongly affect its solubility relative to other natural carotenoids, they do not alter properties of its free radicals based on DFT calculations and EPR measurements which remain similar to typical water-insoluble carotenoids. PMID:25333911

  1. Tuning the Reactivity of Radical through a Triplet Diradical Cu(II) Intermediate in Radical Oxidative Cross-Coupling

    NASA Astrophysics Data System (ADS)

    Zhou, Liangliang; Yi, Hong; Zhu, Lei; Qi, Xiaotian; Jiang, Hanpeng; Liu, Chao; Feng, Yuqi; Lan, Yu; Lei, Aiwen

    2015-11-01

    Highly selective radical/radical cross-coupling is paid more attention in bond formations. However, due to their intrinsic active properties, radical species are apt to achieve homo-coupling instead of cross-coupling, which makes the selective cross-coupling as a great challenge and almost untouched. Herein a notable strategy to accomplish direct radical/radical oxidative cross-coupling has been demonstrated, that is metal tuning a transient radical to a persistent radical intermediate followed by coupling with another transient radical. Here, a transient nitrogen-centered radical is tuned to a persistent radical complex by copper catalyst, followed by coupling with a transient allylic carbon-centered radical. Firstly, nitrogen-centered radical generated from N-methoxybenzamide stabilized by copper catalyst was successfully observed by EPR. Then DFT calculations revealed that a triplet diradical Cu(II) complex formed from the chelation N-methoxybenzamide nitrogen-centered radical to Cu(II) is a persistent radical species. Moreover, conceivable nitrogen-centered radical Cu(II) complex was observed by high-resolution electrospray ionization mass spectrometry (ESI-MS). Ultimately, various allylic amides derivatives were obtained in good yields by adopting this strategy, which might inspire a novel and promising landscape in radical chemistry.

  2. Tuning the Reactivity of Radical through a Triplet Diradical Cu(II) Intermediate in Radical Oxidative Cross-Coupling

    PubMed Central

    Zhou, Liangliang; Yi, Hong; Zhu, Lei; Qi, Xiaotian; Jiang, Hanpeng; Liu, Chao; Feng, Yuqi; Lan, Yu; Lei, Aiwen

    2015-01-01

    Highly selective radical/radical cross-coupling is paid more attention in bond formations. However, due to their intrinsic active properties, radical species are apt to achieve homo-coupling instead of cross-coupling, which makes the selective cross-coupling as a great challenge and almost untouched. Herein a notable strategy to accomplish direct radical/radical oxidative cross-coupling has been demonstrated, that is metal tuning a transient radical to a persistent radical intermediate followed by coupling with another transient radical. Here, a transient nitrogen-centered radical is tuned to a persistent radical complex by copper catalyst, followed by coupling with a transient allylic carbon-centered radical. Firstly, nitrogen-centered radical generated from N-methoxybenzamide stabilized by copper catalyst was successfully observed by EPR. Then DFT calculations revealed that a triplet diradical Cu(II) complex formed from the chelation N-methoxybenzamide nitrogen-centered radical to Cu(II) is a persistent radical species. Moreover, conceivable nitrogen-centered radical Cu(II) complex was observed by high-resolution electrospray ionization mass spectrometry (ESI-MS). Ultimately, various allylic amides derivatives were obtained in good yields by adopting this strategy, which might inspire a novel and promising landscape in radical chemistry. PMID:26525888

  3. Tuning the Reactivity of Radical through a Triplet Diradical Cu(II) Intermediate in Radical Oxidative Cross-Coupling.

    PubMed

    Zhou, Liangliang; Yi, Hong; Zhu, Lei; Qi, Xiaotian; Jiang, Hanpeng; Liu, Chao; Feng, Yuqi; Lan, Yu; Lei, Aiwen

    2015-01-01

    Highly selective radical/radical cross-coupling is paid more attention in bond formations. However, due to their intrinsic active properties, radical species are apt to achieve homo-coupling instead of cross-coupling, which makes the selective cross-coupling as a great challenge and almost untouched. Herein a notable strategy to accomplish direct radical/radical oxidative cross-coupling has been demonstrated, that is metal tuning a transient radical to a persistent radical intermediate followed by coupling with another transient radical. Here, a transient nitrogen-centered radical is tuned to a persistent radical complex by copper catalyst, followed by coupling with a transient allylic carbon-centered radical. Firstly, nitrogen-centered radical generated from N-methoxybenzamide stabilized by copper catalyst was successfully observed by EPR. Then DFT calculations revealed that a triplet diradical Cu(II) complex formed from the chelation N-methoxybenzamide nitrogen-centered radical to Cu(II) is a persistent radical species. Moreover, conceivable nitrogen-centered radical Cu(II) complex was observed by high-resolution electrospray ionization mass spectrometry (ESI-MS). Ultimately, various allylic amides derivatives were obtained in good yields by adopting this strategy, which might inspire a novel and promising landscape in radical chemistry. PMID:26525888

  4. Radical-pair based avian magnetoreception

    NASA Astrophysics Data System (ADS)

    Procopio, Maria; Ritz, Thorsten

    2014-03-01

    Behavioural experiments suggest that migratory birds possess a magnetic compass sensor able to detect the direction of the geomagnetic. One hypothesis for the basis of this remarkable sensory ability is that the coherent quantum spin dynamics of photoinduced radical pair reactions transduces directional magnetic information from the geomagnetic field into changes of reaction yields, possibly involving the photoreceptor cryptochrome in the birds retina. The suggested radical-pair based avian magnetoreception has attracted attention in the field of quantum biology as an example of a biological sensor which might exploit quantum coherences for its biological function. Investigations on such a spin-based sensor have focussed on uncovering the design features for the design of a biomimetic magnetic field sensor. We study the effects of slow fluctuations in the nuclear spin environment on the directional signal. We quantitatively evaluate the robustness of signals under fluctuations on a timescale longer than the lifetime of a radical pair, utilizing two models of radical pairs. Our results suggest design principles for building a radical-pair based compass sensor that is both robust and highly directional sensitive.

  5. Vibronic Spectroscopy of the Phenylcyanomethyl Radical

    NASA Astrophysics Data System (ADS)

    Mehta, Deepali N.; Kidwell, Nathanael M.; Zwier, Timothy S.

    2011-06-01

    Resonance stabilized radicals (RSRs) are thought to be key intermediates in the formation of larger molecules in planetary atmospheres. Given the nitrogen-rich atmosphere of Titan, and the prevalence of nitriles there, it is likely that nitrile and isonitrile RSRs could be especially important in pathways leading to the formation of more complex nitrogen-containing compounds and the aerosols ("tholins") that are ultimately produced. In this talk, the results of a gas phase, jet-cooled vibronic spectroscopy study of the phenylcyanomethyl radical (C_6H_5.{C}HCN), the nitrogen-containing analog of the 1-phenylpropargyl radical, will be presented. A resonant two color photon ionization spectrum over the range 21,350-22,200 Cm-1 (450.0-468.0 nm) has been recorded, and the D_0-D_1 origin band has been tentatively identified at 21,400 Cm-1. Studies identifying the ionization threshold, and characterizing the vibronic structure will also be presented. An analogous study of the phenylisocyanomethyl radical, C_6H_5.{C}HNC, is currently being pursued for comparison with that of phenylcyanomethyl radical.

  6. Electrochemistry and spectroelectrochemistry of nitroxyl free radicals

    SciTech Connect

    Fish, J.R.; Swarts, S.G.; Sevilla, M.D.; Malinski, T.

    1988-06-30

    This work reports electrochemical and spectroelectrochemical studies of the two nitroxyl radicals 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and 3-carbamoyl-2,2,5,5-tetramethyl-3-pyrrolin-1-yloxy (3-carbamoyl-PROXYL). Oxidation and reduction reactions have been observed in aqueous media over the pH range 2-12 in the potential range -0.8 to +0.8 V by differential pulse voltammetry, cyclic voltammetry, and thin-layer UV-visible spectroelectrochemistry, and the reaction products have been characterized by IR, NMR, and ESR spectrometry. At pH values less than 10, characteristic electrochemical behavior is observed to be analogous for both radicals, and the products from electron transfer compare quite favorably with those found by pulse radiolysis of aqueous solutions of nitroxyl radicals. At pH 2-9, a stable cation from a reversible oxidation and hydroxylamine following an irreversible reduction, as well as hydroxylated cation at pH higher than 9, are the same as those obtained in pulse radiolysis experiments. Spectroscopic evidence indicates that behavior following reduction at high pH differs for the two radicals. At pH 12, reduced TEMPO may undergo structural changes leading to the formation of a new radical consisting of a seven-membered ring.

  7. The Solution Conformation of Triarylmethyl Radicals

    SciTech Connect

    Bowman, Michael K.; Mailer, Colin; Halpern, H. J.

    2005-02-01

    Hyperfine coupling tensors to 1H, 2H and natural abundance 13C were measured using X-band pulsed electron nuclear double resonance (ENDOR) spectroscopy for two triarylmethyl (trityl) radicals used in electron paramagnetic resonance imaging and oximetry: methyl tris(8-carboxy-2,2,6,6-tetramethyl-benzo[1,2d:4,5-d?]bis(1,3)dithiol-4-yl) and methyl tris(8-carboxy-2,2,6,6-tetramethyl(-d3)-benzo[1,2d:4,5-d?]bis(1,3)dithiol-4-yl). Quantum chemical calculations using Density Functional Theory predict a structure that reproduces the experimentally determined hyperfine tensors. The radicals are propeller-shaped with the three aryl rings nearly mutually orthogonal. The central carbon atom carrying most of the unpaired electron spin density is completely surrounded by the sulfur atoms in the radical and is completely shielded from solvent. This structure explains features of the electron spin relaxation of these radicals and suggests ways in which the radicals can be chemically modified to improve their characteristics for imaging and oximetry.

  8. Modeling Radicalization Phenomena in Heterogeneous Populations

    PubMed Central

    2016-01-01

    The phenomenon of radicalization is investigated within a mixed population composed of core and sensitive subpopulations. The latest includes first to third generation immigrants. Respective ways of life may be partially incompatible. In case of a conflict core agents behave as inflexible about the issue. In contrast, sensitive agents can decide either to live peacefully adjusting their way of life to the core one, or to oppose it with eventually joining violent activities. The interplay dynamics between peaceful and opponent sensitive agents is driven by pairwise interactions. These interactions occur both within the sensitive population and by mixing with core agents. The update process is monitored using a Lotka-Volterra-like Ordinary Differential Equation. Given an initial tiny minority of opponents that coexist with both inflexible and peaceful agents, we investigate implications on the emergence of radicalization. Opponents try to turn peaceful agents to opponents driving radicalization. However, inflexible core agents may step in to bring back opponents to a peaceful choice thus weakening the phenomenon. The required minimum individual core involvement to actually curb radicalization is calculated. It is found to be a function of both the majority or minority status of the sensitive subpopulation with respect to the core subpopulation and the degree of activeness of opponents. The results highlight the instrumental role core agents can have to hinder radicalization within the sensitive subpopulation. Some hints are outlined to favor novel public policies towards social integration. PMID:27166677

  9. Modeling Radicalization Phenomena in Heterogeneous Populations.

    PubMed

    Galam, Serge; Javarone, Marco Alberto

    2016-01-01

    The phenomenon of radicalization is investigated within a mixed population composed of core and sensitive subpopulations. The latest includes first to third generation immigrants. Respective ways of life may be partially incompatible. In case of a conflict core agents behave as inflexible about the issue. In contrast, sensitive agents can decide either to live peacefully adjusting their way of life to the core one, or to oppose it with eventually joining violent activities. The interplay dynamics between peaceful and opponent sensitive agents is driven by pairwise interactions. These interactions occur both within the sensitive population and by mixing with core agents. The update process is monitored using a Lotka-Volterra-like Ordinary Differential Equation. Given an initial tiny minority of opponents that coexist with both inflexible and peaceful agents, we investigate implications on the emergence of radicalization. Opponents try to turn peaceful agents to opponents driving radicalization. However, inflexible core agents may step in to bring back opponents to a peaceful choice thus weakening the phenomenon. The required minimum individual core involvement to actually curb radicalization is calculated. It is found to be a function of both the majority or minority status of the sensitive subpopulation with respect to the core subpopulation and the degree of activeness of opponents. The results highlight the instrumental role core agents can have to hinder radicalization within the sensitive subpopulation. Some hints are outlined to favor novel public policies towards social integration. PMID:27166677

  10. The role of the position of the basic residue in the generation and fragmentation of peptide radical cations

    NASA Astrophysics Data System (ADS)

    Wee, Sheena; O'Hair, Richard A. J.; McFadyen, W. David

    2006-03-01

    Using simple di- and tripeptides GX, GGX, GXG, XG and XGG, the influence of the position of the basic residue, X (X = R, K and H), on the formation of peptide radical cations (M+) from [CuII(tpy)M]2+ complexes (where tpy = 2,2':6',2''-terpyridine) was probed. It was found that M+ is formed with greatest abundance when the basic residue is at the C-terminus. For arginine containing peptides, this may be due to further fragmentation of GRG+, RG+ and RGG+ at the MS2 stage. For lysine and histidine containing peptides, when the basic residue is not located at the C-terminus, competing fragmentation pathways that lead to peptide backbone cleavage are more facile than M+ formation. In order to gain some insights into the binding modes of these peptides to [CuII(tpy)]2+, the formation and fragmentation of copper(II) complexes of tripeptides protected as their carboxy methyl/ethyl esters (M-OR', R' = Me/Et) were also probed. The products of the competing fragmentation pathways of [CuII(tpy)M]2+, as well as the formation and fragmentation of [CuII(tpy)(M-OR')]2+, suggest that the unprotected peptides, M, mainly bind as zwitterions to [CuII(tpy)]2+. The fragmentation reactions of the radical cations (M+) were also studied. Radical driven side chain fragmentation reactions of M+ are dependent on both the position of the residue as well as the identity of other residues present in the peptide radical cations. GR and RG, which undergo rearrangement to form a mixed anhydride in their protonated forms, do not undergo the same rearrangement in their radical cation forms.

  11. Validation of a novel method to identify in utero ethanol exposure: simultaneous meconium extraction of fatty acid ethyl esters, ethyl glucuronide, and ethyl sulfate followed by LC-MS/MS quantification

    PubMed Central

    Himes, Sarah K.; Concheiro, Marta; Scheidweiler, Karl B.

    2015-01-01

    Presence of fatty acid ethyl esters (FAEE), ethyl glucuronide (EtG), and ethyl sulfate (EtS) in meconium, the first neonatal feces, identifies maternal alcohol consumption during pregnancy. Current meconium alcohol marker assays require separate analyses for FAEE and EtG/EtS. We describe development and validation of the first quantitative liquid chromatography tandem mass spectrometry assay for 9 FAEEs, EtG, and EtS in 100 mg meconium. For the first time, these alcohol markers are analyzed in the same meconium aliquot, enabling comparison of the efficiency of gestational ethanol exposure detection. 100 mg meconium was homogenized in methanol and centrifuged. The supernatant was divided, and applied to two different solid phase extraction columns for optimized analyte recovery. Limits of quantification for ethyl laurate, myristate, linolenate, palmitoleate, arachidonate, linoleate, palmitate, oleate, and stearate ranged from 25–50 ng/g, with calibration curves to 2,500–5,000 ng/g. EtG and EtS linear dynamic ranges were 5–1,000 and 2.5–500 ng/g, respectively. Mean bias and between-day imprecision were <15 %. Extraction efficiencies were 51.2–96.5 %. Matrix effects ranged from −84.7 to 16.0 %, but were compensated for by matched deuterated internal standards when available. All analytes were stable (within ±20 % change from baseline) in 3 authentic positive specimens, analyzed in triplicate, after 3 freeze/thaw cycles (−20 °C). Authentic EtG and EtS also were stable after 12 h at room temperature and 72 h at 4 °C; some FAEE showed instability under these conditions, although there was large inter-subject variability. This novel method accurately detects multiple alcohol meconium markers and enables comparison of markers for maternal alcohol consumption. PMID:24408304

  12. Fumigation of wheat using liquid ethyl formate plus methyl isothiocyanate in 50-tonne farm bins.

    PubMed

    Ren, Yonglin; Lee, Byungho; Mahon, Daphne; Xin, Ni; Head, Matthew; Reid, Robin

    2008-04-01

    Australian Standard White wheat, Triticum aestivum L. (a marketing grade with mixed grain hardness),with a moisture content of 12.5% was fumigated with a new ethyl formate formulation (95% ethyl formate plus 5% methyl isothiocyanate) identified and developed by Commonwealth Scientific and Industrial Research Organization Entomology, Canberra, Australia. Wheat was fumigated with the formulation at a calculated application rate of 80 g/m3 in two 50-tonne sealed metal vertical silos located at Fisherman Islands, Queensland, Australia. Access was gained through the top of the silo where the application of the formulation was completed within a few minutes by pouring it onto the top of the wheat. After 2 h of recirculation, using a 0.5-kW fan, the in-bin concentrations of ethyl formate achieved equilibrium with a concentration variation < 7%. The ethyl formate concentration, in both silos 1 and 2, during the first day's exposure period remained above 10 g/m3. The concentration of ethyl formate by time product achieved was 790 and 650 g h/m3 in silos 1 and 2, respectively. In silo 1, the formulation was sufficient to kill all life stages of mixed age cultures of Sitophilus oryzae (L.), Rhyzopertha dominica (F.), and Tribolium castaneum (Herbst). In silo 2, control was 100% for R. dominica and T. castaneum and 99.4% for S. oryzae. After 5 d fumigation, the silo top-hatch was opened but no forced aeration was initiated. The in-bin concentration of ethyl formate was lower than the Australian experimental threshold limit value of 100 ppm. The ethyl formate and methyl isothiocyanate residues in the grain had declined to below the Australian experimental maximum residue limit of 0.2 and 0.1 mg/kg, respectively. The workspace and environmental levels of ethyl formate and methyl isothiocyanate were less than the detection limit of 0.1 ppm. The treatment with ethyl formate formulation had no affect on the wheat germination and seed color compared with untreated controls. PMID

  13. Free radicals, antioxidant defense systems, and schizophrenia.

    PubMed

    Wu, Jing Qin; Kosten, Thomas R; Zhang, Xiang Yang

    2013-10-01

    The etiopathogenic mechanisms of schizophrenia are to date unknown, although several hypotheses have been suggested. Accumulating evidence suggests that excessive free radical production or oxidative stress may be involved in the pathophysiology of schizophrenia as evidenced by increased production of reactive oxygen or decreased antioxidant protection in schizophrenic patients. This review aims to summarize the basic molecular mechanisms of free radical metabolism, the impaired antioxidant defense system and membrane pathology in schizophrenia, their interrelationships with the characteristic clinical symptoms and the implications for antipsychotic treatments. In schizophrenia, there is accumulating evidence of altered antioxidant enzyme activities and increased levels of lipid peroxidation, as well as altered levels of plasma antioxidants. Moreover, free radical-mediated abnormalities may contribute to specific aspects of schizophrenic symptomatology and complications of its treatment with antipsychotic drugs, as well as the development of tardive dyskinesia (TD). Finally, the potential therapeutic strategies implicated by the accumulating data on oxidative stress mechanisms for the treatment of schizophrenia are discussed.

  14. Resveratrol products resulting by free radical attack

    NASA Astrophysics Data System (ADS)

    Bader, Yvonne; Quint, R. M.; Getoff, Nikola

    2008-06-01

    Trans-resveratrol ( trans-3,4',5-trihydroxystilbene; RES), which is contained in red wine and many plants, is one of the most relevant and extensively investigated stilbenes with a broad spectrum of biological activities. Among other duties, RES has been reported to have anti-carcinogenetic activities, which could be attributed to its antioxidant properties. The degradation of RES was studied under various conditions. The products (aldehydes, carboxylic acids, etc.) generated from RES by the attack of free radicals were registered as a function of the radical concentration (absorbed radiation dose). Based on the obtained data it appears that the OH radicals are initiating the rather complicated process, which involves of the numerous consecutive reactions. A possible starting reaction mechanism is presented.

  15. Formation and stabilization of persistent free radicals

    PubMed Central

    Dellinger, Barry; Lomnicki, Slawomir; Khachatryan, Lavrent; Maskos, Zofia; Hall, Randall W.; Adounkpe, Julien; McFerrin, Cheri; Truong, Hieu

    2014-01-01

    We demonstrate that stable and relatively unreactive “environmentally persistent free radicals (PFRs)” can be readily formed in the post-flame and cool-zone regions of combustion systems and other thermal processes. These resonance-stabilized radicals, including semiquinones, phenoxyls, and cyclopentadienyls, can be formed by the thermal decomposition of molecular precursors including catechols, hydroquinones and phenols. Association with the surfaces of fine particles imparts additional stabilization to these radicals such that they can persist almost indefinitely in the environment. A mechanism of chemisorption and electron transfer from the molecular adsorbate to a redox-active transition metal or other receptor is shown through experiment, and supported by molecular orbital calculations, to result in PFR formation. Both oxygen-centered and carbon-centered PFRs are possible that can significantly affect their environmental and biological reactivity. PMID:25598747

  16. Scavenging of superoxide anion radical by chaparral.

    PubMed

    Zang, L Y; Cosma, G; Gardner, H; Starks, K; Shi, X; Vallyathan, V

    1999-06-01

    Chaparral is considered to act as an antioxidant. However, the inhibitory effects of chaparral on specific radical species are not well understood. Using electron paramagnetic resonance (EPR) spectroscopy in combination with spin trapping techniques, we have found that chaparral scavenges superoxide anion radical (O2*-) in a dose-dependent manner. 5,5-dimethyl-lpyrroline-N-oxide (DMPO) was used as a spin trapping agent and the reaction of xanthine and xanthine oxidase as a source of O2*-. The kinetic parameters, IC50 and Vmax, for chaparral scavenging of O2*- were found to be 0.899 microg/mL and 8.4 ng/mL/sec, respectively. The rate constant for chaparral scavenging O2*- was found to be 1.22 x 10(6) g(-1) s(-1). Our studies suggest that the antioxidant properties of chaparral may involve a direct scavenging effect of the primary oxygen radical, O2*-.

  17. Surface-enhanced Raman scattering for quantitative detection of ethyl carbamate in alcoholic beverages.

    PubMed

    Yang, Danting; Zhou, Haibo; Ying, Yibin; Niessner, Reinhard; Haisch, Christoph

    2013-11-01

    Ethyl carbamate, a by-product of fermentation and storage with widespread occurrence in fermented food and alcoholic beverages, is a compound potentially toxic to humans. In this work, a new approach for quantitative detection of ethyl carbamate in alcoholic beverages, based on surface-enhanced Raman scattering (SERS), is reported. Individual silver-coated gold nanoparticle colloids are used as SERS amplifiers, yielding high Raman enhancement of ethyl carbamate in three kinds of alcoholic beverages (vodka, Obstler, and white rum). The characteristic band at 1,003 cm(-1), which is the strongest and best reproducible peak in the SERS spectra, was used for quantitative evaluation of ethyl carbamate. The limit of detection, which corresponds to a signal-to-noise ratio of 3, was 9.0 × 10(-9) M (0.8 μg · L(-1)), 1.3 × 10(-7) M (11.6 μg · L(-1)), and 7.8 × 10(-8) M (6.9 μg · L(-1)), respectively. Surface-enhanced Raman spectroscopy offers great practical potential for the in situ assessment and identification of ethyl carbamate in the alcoholic beverage industry.

  18. Enzymatic production of biodiesel from microalgal oil using ethyl acetate as an acyl acceptor.

    PubMed

    Alavijeh, Razieh Shafiee; Tabandeh, Fatemeh; Tavakoli, Omid; Karkhane, Aliasghar; Shariati, Parvin

    2015-01-01

    Microalgae have become an important source of biomass for biodiesel production. In enzymatic transesterification reaction, the enzyme activity is decreased in presence of alcohols. The use of different acyl acceptors such as methyl/ethyl acetate is suggested as an alternative and effective way to overcome this problem. In this study, ethyl acetate was used for the first time in the enzymatic production of biodiesel by using microalga, Chlorella vulgaris, as a triglyceride source. Enzymatic conversion of such fatty acids to biodiesel was catalyzed by Novozym 435 as an efficient immobilized lipase which is extensively used in biodiesel production. The best conversion yield of 66.71% was obtained at the ethyl acetate to oil molar ratio of 13:1 and Novozym 435 concentration of 40%, based on the amount of oil, and a time period of 72 h at 40℃. The results showed that ethyl acetate have no adverse effect on lipase activity and the biodiesel amount was not decreased even after seven transesterification cycles, so ethyl acetate has a great potential to be substituted for short-chain alcohols in transesterification reaction. PMID:25742923

  19. Enzymatic synthesis of fatty acid ethyl esters by utilizing camellia oil soapstocks and diethyl carbonate.

    PubMed

    Wang, Yingying; Cao, Xuejun

    2011-11-01

    This study was reported on a novel process for fatty acid ethyl esters preparation by transesterification and esterification from renewable low-cost feedstock camellia oil soapstocks and friendly acyl acceptor diethyl carbonate. The main components of product were 83.9% ethyl oleate, 8.9% ethyl palmitate, 4.7% ethyl linoleate and 2.1% ethyl stearate, which could be used as eco-friendly renewable resources or additives of industrial solvent and fossil fuel. The effects of molar ratio of diethyl carbonate to soapstocks oil, lipases, organic solvent, reaction temperature and time were investigated, and process conditions were optimized. The yield was up to 98.4% in solvent-free system with molar ratio of diethyl carbonate to soapstocks oil 3:1 and 5% Novozym 435 (based on the weight of soapstocks oil) at 50 °C and 180 rpm for 24 h. Moreover, there was no obvious loss in the yield after lipases were reused for 10 batches without treatment under optimized conditions.

  20. Enzymatic production of biodiesel from microalgal oil using ethyl acetate as an acyl acceptor.

    PubMed

    Alavijeh, Razieh Shafiee; Tabandeh, Fatemeh; Tavakoli, Omid; Karkhane, Aliasghar; Shariati, Parvin

    2015-01-01

    Microalgae have become an important source of biomass for biodiesel production. In enzymatic transesterification reaction, the enzyme activity is decreased in presence of alcohols. The use of different acyl acceptors such as methyl/ethyl acetate is suggested as an alternative and effective way to overcome this problem. In this study, ethyl acetate was used for the first time in the enzymatic production of biodiesel by using microalga, Chlorella vulgaris, as a triglyceride source. Enzymatic conversion of such fatty acids to biodiesel was catalyzed by Novozym 435 as an efficient immobilized lipase which is extensively used in biodiesel production. The best conversion yield of 66.71% was obtained at the ethyl acetate to oil molar ratio of 13:1 and Novozym 435 concentration of 40%, based on the amount of oil, and a time period of 72 h at 40℃. The results showed that ethyl acetate have no adverse effect on lipase activity and the biodiesel amount was not decreased even after seven transesterification cycles, so ethyl acetate has a great potential to be substituted for short-chain alcohols in transesterification reaction.

  1. Effect of vanillin and ethyl vanillin on cytochrome P450 activity in vitro and in vivo.

    PubMed

    Chen, Xiao-min; Wei, Min; Zhang, Hai-mou; Luo, Cheng-hao; Chen, Yi-kun; Chen, Yong

    2012-06-01

    Food safety is of extreme importance to human health. Vanillin and ethyl vanillin are the widely used food additives and spices in foods, beverages, cosmetics and drugs. The objective of the present work was to evaluate the impact of vanillin and ethyl vanillin on the activities of CYP2C9, CYP2E1, CYP3A4, CYP2B6 and CYP1A2 in human liver microsomes (HLM) in vitro, and impact on the activities of CYP1A2, CYP2C, CYP3A and CYP2E1 in rat liver microsomes (RLM) in vivo. The in vitro results demonstrated that vanillin and ethyl vanillin had no significant effect on the activity of five human CYP450 enzymes with concentration ranged from 8 to 128 μM. However, after rats were orally administered vanillin or ethyl vanillin once a day for seven consecutive days, CYP2E1 activity was increased and CYP1A2 activity was decreased in RLM. The in vivo results revealed that drug interaction between vanillin/ethyl vanillin and the CYP2E1/CYP1A2-metabolizing drugs might be possible, and also suggested that the application of the above additives in foods and drugs should not be unlimited so as to avoid the adverse interaction.

  2. Base-Mediated Stereospecific Synthesis of Aryloxy and Amino substituted Ethyl Acrylates

    PubMed Central

    Namjoshi, Ojas A.; Verma, Ranjit; Lorenz, Michael; Tiruveedhula, V. V. N. Phani Babu; Monte, Aaron; Bertz, Steven H.

    2011-01-01

    The stereospecific synthesis of aryloxy and amino substituted E- and Z-ethyl-3-acrylates is of interest because of their potential in the polymer industry and in medicinal chemistry. During work on a copper-catalyzed cross-coupling reaction of E- and Z-ethyl-3-iodo-acrylates with phenols and N-heterocycles, we discovered a very simple (non-metallic) method for the stereospecific synthesis of aryloxy and amino substituted acrylates. To study this long standing problem on the stereoselectivity of aryloxy and amino substituted acrylates, a series of O- and N-substituted nucleophiles was allowed to react with E- and Z-ethyl-3-iodo-acrylates. Screening of different bases indicated that DABCO (1,4-diazabicyclo[2.2.2]octane) afforded successful conversion of E- and Z- ethyl-3-iodoacrylates into aryloxy and amino substituted ethyl acrylates in a stereospecific manner. Herein are the details of this DABCO-mediated stereospecific synthesis of aryloxy and amino substituted E- or Z-acrylates. PMID:22073965

  3. Brewing industry potential for the immediate and near-term production of fuel-grade ethyl alcohol. Final report

    SciTech Connect

    Mulloney, J.A. Jr.

    1980-04-15

    The brewing industry is described as it relates to productive facilities and potential for fuel grade ethyl alcohol production. The brewing process is compared to the fuel grade ethyl alcohol process in a brewery. A description is given for retrofitting a brewery as a distilled spirits plant. The following are included: estimated capital requirements and alcohol costs, targets of opportunity, barriers and actions affecting brewery production of ethyl alcohol, suggested action programs, and recommended program activities. (MHR)

  4. Quantification of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in meconium from newborns for detection of alcohol abuse in a maternal health evaluation study.

    PubMed

    Bakdash, Abdulsallam; Burger, Pascal; Goecke, Tamme W; Fasching, Peter A; Reulbach, Udo; Bleich, Stefan; Hastedt, Martin; Rothe, Michael; Beckmann, Matthias W; Pragst, Fritz; Kornhuber, Johannes

    2010-04-01

    Fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) were determined in 602 meconium samples in a maternal health evaluation study for detection of gestational alcohol consumption. A validated headspace solid phase microextraction method in combination with GC-MS was used for FAEE and the cumulative concentration of ethyl palmitate, ethyl linoleate, ethyl oleate, and ethyl stearate with a cut-off of 500 ng/g was applied for interpretation. A new and simple method was developed and validated for quantification of EtG from 10-20 mg meconium with D(5)-EtG as internal standard consisting of 30 min. extraction with methanol/water (1:1, v/v), evaporation of methanol, filtration of the aqueous solution through a cellulose filter and injection into LC-MS-MS. The limits of detection and quantification for EtG were 10 and 30 ng/g, the recovery 86.6 to 106.4% and the standard deviation of the concentrations ranged from 13% at 37 ng/g to 5% at 46,700 ng/g (N = 6). FAEE above the cut-off were found in 43 cases (7.1%) with cumulative concentrations between 507 and 22,580 ng/g and with one outlier of about 150,000 ng/g (EtG not detected). EtG was detected in 97 cases (16.3%) and concentrations between LOD and 10,200 ng/g with another outlier of 82,000 ng/g (FAEE 10,500 ng/g). Optimal agreement between the two markers was obtained with a cut-off for EtG of 274 ng/g and 547 cases with both FAEE- and EtG-negative, 33 cases with both FAEE- and EtG-positive, nine cases with FAEE-positive and EtG-negative, and seven cases with FAEE-negative and EtG-positive. Differences in physical, chemical, and biochemical properties and in the pharmacokinetic behavior are discussed as reasons for the deviating cases. In none of the 602 cases, serious alcohol consumption was reported by the mothers and no evidence for gestational ethanol exposure was observed in the medical investigation of the newborns. It is concluded that the combined use of FAEE and EtG in meconium as markers for fetal

  5. Resonance ionization detection of combustion radicals

    SciTech Connect

    Cool, T.A.

    1993-12-01

    Fundamental research on the combustion of halogenated organic compounds with emphasis on reaction pathways leading to the formation of chlorinated aromatic compounds and the development of continuous emission monitoring methods will assist in DOE efforts in the management and disposal of hazardous chemical wastes. Selective laser ionization techniques are used in this laboratory for the measurement of concentration profiles of radical intermediates in the combustion of chlorinated hydrocarbon flames. A new ultrasensitive detection technique, made possible with the advent of tunable VUV laser sources, enables the selective near-threshold photoionization of all radical intermediates in premixed hydrocarbon and chlorinated hydrocarbon flames.

  6. Evolution of radical mastectomy for breast cancer

    PubMed Central

    Plesca, M; Bordea, C; El Houcheimi, B; Ichim, E; Blidaru, A

    2016-01-01

    Surgical treatment of breast cancer has been marked by a constant evolution since the Halsted radical mastectomy described in the late 19th century has become the current standard Madden radical mastectomy, a breast surgery that involves the ablation of tissue with the axillary lymphatic preserving both pectoral muscles. The purpose of this paper was to present the stages that have marked the evolution of this intervention and to provide an overview of the way breast cancer has been understood and treated in the last century. PMID:27453752

  7. Radical Behaviorism and Buddhism: Complementarities and Conflicts

    PubMed Central

    Diller, James W; Lattal, Kennon A

    2008-01-01

    Comparisons have been made between Buddhism and the philosophy of science in general, but there have been only a few attempts to draw comparisons directly with the philosophy of radical behaviorism. The present review therefore considers heretofore unconsidered points of comparison between Buddhism and radical behaviorism in terms of their respective goals, conceptualization of human beings, and the outcomes of following either philosophy. From these comparisons it is concluded that the commonalities discerned between these two philosophies may enhance both philosophical systems. PMID:22478509

  8. Antinephritis and radical scavenging activity of prenylflavonoids.

    PubMed

    Fukai, Toshio; Satoh, Kazue; Nomura, Taro; Sakagami, Hiroshi

    2003-12-01

    Antinephritis activity of 5 prenylflavonoids similar to glabridin (1-5), isolated from Morus alba, Artocarpus communis, Glycyrrhiza uralensis and G. inflata, was evaluated in mice with glomerular disease (Masugi-nephritis). Oral administrations of artonin E (2) or licochalcone A (4) for 10 days (30 mg kg(-1) day(-1)) reduced the amount of urinary protein excretion compared to nephritic mice. ESR spectroscopy demonstrated that morusin (1) and licorisoflavan A (5) increased the radical intensity of sodium ascorbate by about two times. Morusin, licoricidin (3), licochalcone A and licorisoflavan A showed weak scavenging activity against superoxide anion radical.

  9. Cell damage by oxygen free radicals.

    PubMed

    Bellomo, G

    1991-02-01

    The exposure of isolated and cultured cells to oxygen free radicals generated extracellularly or intracellularly during the metabolism of foreing compounds results in the development of damage that eventually lead to cell death. Multiple mechanisms are involved in these cytopathological processes, including direct attack of free radicals to macromolecules essential for cell life, as well as indirect activation of catabolic processes such as proteases, endonucleases and phospholipases. A key role in triggering these indirect events is played by Ca(2+) whose cytosolic concentration during oxidative stress raises well above the physiological limits. PMID:22358959

  10. Resonant cavity spectroscopy of radical species

    NASA Astrophysics Data System (ADS)

    Ritchie, Grant

    2015-04-01

    Photo-oxidation in the troposphere is highly complex, being initiated by short lived radical species, in the daytime dominated by the hydroxyl radical, OH, with contributions from Cl atoms, and at night by either NO3 radicals or ozone. Chemical oxidation cycles, which couple OH, HO2 and peroxy (RO2) radical species, remove primary emitted trace species which are harmful to humans or to the wider environment. However, many of the secondary products produced by atmospheric photo-oxidation are also directly harmful, for example O3, NO2, acidic and multifunctional species, many of which are of low volatility and are able to partition effectively to the condensed phase, creating secondary organic aerosol (SOA), which contributes a significant fraction of tropospheric aerosol, with associated impacts on climate and human health. The accuracy of atmospheric models to predict these impacts necessarily requires accurate knowledge of the chemical oxidative cycling. Two of the simplest intermediates are the hydroperoxy radical, HO2, and the smallest and dominant organic peroxy radical, CH3O2, formed directly by the reactions of OH with CO/O2 and CH4/O2, respectively, and indirectly following the oxidation of larger VOCs. OH, HO2 and RO2 (collectively known as ROx) are rapidly cycled, being at the centre of tropospheric oxidation, and hence are some of the best targets for models to compare with field data. The reaction of HO2 and RO2 with NO constitutes the only tropospheric in-situ source of O3. Despite their importance, neither HO2 nor CH3O2 is measured directly in the atmosphere. HO2 is only measured indirectly following its conversion to OH and CH3O2 is not measured at all. Typically only the sum of RO2 radicals is measured, making no distinction between different organic peroxy radicals. This contribution will detail recent studies using (i) optical feedback cavity enhanced absorption spectroscopy with both quantum and inter-band cascade lasers in the mid-IR, and (ii

  11. [Robot-assisted radical prostatectomy: surgical techniques].

    PubMed

    Kojima, Yoshiyuki; Sato, Yuichi; Ogawa, Soichiro; Haga, Nobuhiro; Yanagida, Tomohiko

    2016-01-01

    Robot-assisted radical prostatectomy (RARP) for the patients with localized prostate cancer is increasingly being adopted around the world. The da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA, USA) provides the advantages of simplification and precision of exposure and suturing because of allowing movements of the robotic arm in real time with increased degree of freedom and magnified 3-dimensional view. Therefore, RARP has been expected to provide superior therapeutic benefit to patients in terms of surgical outcome to open or laparoscopic radical prostatectomy. In this review, we provide our technical aspects and tips and tricks of RARP to improve surgical outcome and postoperative quality of life. PMID:26793888

  12. Determination of fatty acid ethyl esters in hair by GC-MS and application in a population of cocaine users.

    PubMed

    Politi, Lucia; Mari, Francesco; Furlanetto, Sandra; Del Bravo, Ester; Bertol, Elisabetta

    2011-04-01

    A gas chromatography-mass spectrometry method for the determination of ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate in hair samples was developed, validated and applied to real samples. Ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate are fatty acid ethyl esters (FAEE) which are known to be direct biotransformation products of ethanol. Their presence in the body fluids and tissue is therefore indicative of alcohol intake and, in particular, FAEE concentration in hair higher than 0.5 ng/mg is indicative of excessive chronic alcohol consumption. The method was applied to 80 hair samples formerly found positive for cocaine and FAEE analytical results were compared with the presence of cocaethylene, a cocaine metabolite formed only when alcohol and cocaine are used together. According to our data the two biomarkers (FAEE and cocaethylene in hair) are tools of great value in the assessment of the diagnosis of use of cocaine and ethanol. In fact, discrepancies were noted and might be related to various factors including differences in consumption habits and thus permitting to distinguish the use of both substances non-concurrently or concurrently. Also, the determination of both markers may, in some cases, discriminate the use of moderate or heavy alcohol amounts when associated with cocaine. Finally, in a population of non-cocaine-users our results support FAEE as valuable means in the assessment of excessive alcohol chronic use. PMID:21159458

  13. Oxidative decarboxylation of mandelic acid derivative by recombinant Escherichia coli: a novel method of ethyl vanillin synthesis.

    PubMed

    Pan, Xiao-Xia; Li, Jing-Jing; Wang, Mei-Gui; He, Wen-Sen; Jia, Cheng-Sheng; Zhang, Xiao-Ming; Feng, Biao; Li, Da-Li; Zeng, Zeng

    2013-06-01

    The benzoylformate decarboxylase gene (mdlC) from Pseudomonas putida was expressed in Escherichia coli BL21(DE3). The recombinant strain together with E. coli/pET30a-mdlB converted (S)-3-ethoxy-4-hydroxymandelic acid (S-EMA) into ethyl vanillin without ethyl vanillin degradation. 4 g ethyl vanillin/l was obtained from 10 g EMA/l within 12 h at 30 °C. This is the first report on the biotransformation of (S)-EMA to ethyl vanillin.

  14. Development of thermosensitive poly(n-isopropylacrylamide-co-((2-dimethylamino) ethyl methacrylate))-based nanoparticles for controlled drug release

    NASA Astrophysics Data System (ADS)

    Peng, Cheng-Liang; Tsai, Han-Min; Yang, Shu-Jyuan; Luo, Tsai-Yueh; Lin, Chia-Fu; Lin, Wuu-Jyh; Shieh, Ming-Jium

    2011-07-01

    Thermosensitive nanoparticles based on poly(N-isopropylacrylamide-co-((2-dimethylamino)ethylmethacrylate)) (poly(NIPA-co-DMAEMA)) copolymers were successfully fabricated by free radical polymerization. The lower critical solution temperature (LCST) of the synthesized nanoparticles was 41 °C and a temperature above which would cause the nanoparticles to undergo a volume phase transition from 140 to 100 nm, which could result in the expulsion of encapsulated drugs. Therefore, we used the poly(NIPA-co-DMAEMA) nanoparticles as a carrier for the controlled release of a hydrophobic anticancer agent, 7-ethyl-10-hydroxy-camptothecin (SN-38). The encapsulation efficiency and loading content of SN-38-loaded nanoparticles at an SN-38/poly(NIPA-co-DMAEMA) ratio of 1/10 (D/P = 1/10) were about 80% and 6.293%, respectively. Moreover, the release profile of SN-38-loaded nanoparticles revealed that the release rate at 42 °C (above LCST) was higher than that at 37 °C (below LCST), which demonstrated that the release of SN-38 could be controlled by increasing the temperature. The cytotoxicity of the SN-38-loaded poly(NIPA-co-DMAEMA) nanoparticles was investigated in human colon cancer cells (HT-29) to compare with the treatment of an anticancer drug, Irinotecan® (CPT-11). The antitumor efficacy evaluated in a C26 murine colon tumor model showed that the SN-38-loaded nanoparticles in combination with hyperthermia therapy efficiently suppressed tumor growth. The results indicate that these thermo-responsive nanoparticles are potential carriers for controlled drug delivery.

  15. Direct Conversion of Cellulose into Ethyl Lactate in Supercritical Ethanol-Water Solutions.

    PubMed

    Yang, Lisha; Yang, Xiaokun; Tian, Elli; Lin, Hongfei

    2016-01-01

    Biomass-derived ethyl lactate is a green solvent with a growing market as the replacement for petroleum-derived toxic organic solvents. Here we report, for the first time, the production of ethyl lactate directly from cellulose with the mesoporous Zr-SBA-15 silicate catalyst in a supercritical mixture of ethanol and water. The relatively strong Lewis and weak Brønsted acid sites on the catalyst, as well as the surface hydrophobicity, were beneficial to the reaction and led to synergy during consecutive reactions, such as depolymerization, retro-aldol condensation, and esterification. Under the optimum reaction conditions, ∼33 % yield of ethyl lactate was produced from cellulose with the Zr-SBA-15 catalyst at 260 °C in supercritical 95:5 (w/w) ethanol/water.

  16. Capillary gas chromatographic determination of cyclohexanone and 2-ethyl-1-hexanol leached from solution administration sets.

    PubMed

    Danielson, J W

    1991-01-01

    A capillary gas chromatographic method is described for the determination of cyclohexanone and 2-ethyl-1-hexanol leached from solution administration sets. A preliminary study was made of compounds leached from solution administration sets by 5% sodium bicarbonate solution (pH 8.1), 0.9% sodium chloride solution (pH 6.8), and water. Water was selected as the leaching solvent because similar quantities of the compounds were leached into water and into both types of parenteral solutions. The correlation coefficients were 0.99977 for cyclohexanone and 0.99974 for 2-ethyl-1-hexanol, and recoveries were good (93-94%). Five administration sets from each of 2 manufacturers were analyzed by this method. The amounts of cyclohexanone that were leached from the individual sets varied considerably; however, similar quantities were leached from sets of both manufacturers. 2-Ethyl-1-hexanol was also found in extracts from each of the sets analyzed.

  17. Papain-Catalyzed Chemoenzymatic Synthesis of Telechelic Polypeptides Using Bis(Leucine Ethyl Ester) Initiator.

    PubMed

    Tsuchiya, Kousuke; Numata, Keiji

    2016-07-01

    In order to construct unique polypeptide architectures, a novel telechelic-type initiator with two leucine ethyl ester units is designed for chemoenzymatic polymerization. Glycine or alanine ethyl ester is chemoenzymatically polymerized using papain in the presence of the initiator, and the propagation occurs at each leucine ethyl ester unit to produce the telechelic polypeptide. The formation of the telechelic polypeptides is confirmed by (1) H NMR and MALDI-TOF mass spectroscopies. It is revealed by AFM observation that long nanofibrils are formed from the telechelic polyalanine, whereas a conventional linear polyalanine with a similar degree of polymerization shows granule-like structures. The telechelic polyglycine and polyalanine show the crystalline structures of Polyglycine II and antiparallel β-sheet, respectively. It is demonstrated that this method to synthesize telechelic-type polypeptides potentially opens up a pathway to construct novel hierarchical structures by self-assembly. PMID:26947148

  18. Ethyl Pyruvate: An Anti-Microbial Agent that Selectively Targets Pathobionts and Biofilms

    PubMed Central

    Debebe, Tewodros; Krüger, Monika; Huse, Klaus; Kacza, Johannes; Mühlberg, Katja; König, Brigitte; Birkenmeier, Gerd

    2016-01-01

    The microbiota has a strong influence on health and disease in humans. A causative shift favoring pathobionts is strongly linked to diseases. Therefore, anti-microbial agents selectively targeting potential pathogens as well as their biofilms are urgently demanded. Here we demonstrate the impact of ethyl pyruvate, so far known as ROS scavenger and anti-inflammatory agent, on planktonic microbes and biofilms. Ethyl pyruvate combats preferably the growth of pathobionts belonging to bacteria and fungi independent of the genera and prevailing drug resistance. Surprisingly, this anti-microbial agent preserves symbionts like Lactobacillus species. Moreover, ethyl pyruvate prevents the formation of biofilms and promotes matured biofilms dissolution. This potentially new anti-microbial and anti-biofilm agent could have a tremendous positive impact on human, veterinary medicine and technical industry as well. PMID:27658257

  19. Organosolv pretreatment of Sitka spruce wood: conversion of hemicelluloses to ethyl glycosides.

    PubMed

    Bouxin, Florent P; David Jackson, S; Jarvis, Michael C

    2014-01-01

    A range of Organosolv pretreatments, using ethanol:water mixtures with dilute sulphuric acid, were applied to Sitka spruce sawdust with the aim of generating useful co-products as well as improving saccharification yield. The most efficient of the pretreatment conditions, resulting in subsequent saccharification yields of up to 86%, converted a large part of the hemicellulose sugars to their ethyl glycosides as identified by GC/MS. These conditions also reduced conversion of pentoses to furfural, the ethyl glycosides being more stable to dehydration than the parent pentoses. Through comparison with the behaviour of model compounds under the same reaction conditions it was shown that the anomeric composition of the products was consistent with a predominant transglycosylation reaction mechanism, rather than hydrolysis followed by glycosylation. The ethyl glycosides have potential as intermediates in the sustainable production of high-value chemicals. PMID:24269088

  20. Silver-catalyzed C-C bond formation between methane and ethyl diazoacetate in supercritical CO₂.

    PubMed

    Caballero, Ana; Despagnet-Ayoub, Emmanuelle; Díaz-Requejo, M Mar; Díaz-Rodríguez, Alba; González-Núñez, María Elena; Mello, Rossella; Muñoz, Bianca K; Ojo, Wilfried-Solo; Asensio, Gregorio; Etienne, Michel; Pérez, Pedro J

    2011-05-13

    Even in the context of hydrocarbons' general resistance to selective functionalization, methane's volatility and strong bonds pose a particular challenge. We report here that silver complexes bearing perfluorinated indazolylborate ligands catalyze the reaction of methane (CH(4)) with ethyl diazoacetate (N(2)CHCO(2)Et) to yield ethyl propionate (CH(3)CH(2)CO(2)Et). The use of supercritical carbon dioxide (scCO(2)) as the solvent is key to the reaction's success. Although the catalyst is only sparingly soluble in CH(4)/CO(2) mixtures, optimized conditions presently result in a 19% yield of ethyl propionate (based on starting quantity of the diazoester) at 40°C over 14 hours.