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Sample records for decahydronaphthalene

  1. Discovery and identification of a series of alkyl decalin isomers in petroleum geological samples.

    PubMed

    Wang, Huitong; Zhang, Shuichang; Weng, Na; Zhang, Bin; Zhu, Guangyou; Liu, Lingyan

    2015-07-01

    The comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOFMS) has been used to characterize a crude oil and a source rock extract sample. During the process, a series of pairwise components between monocyclic alkanes and mono-aromatics have been discovered. After tentative assignments of decahydronaphthalene isomers, a series of alkyl decalin isomers have been synthesized and used for identification and validation of these petroleum compounds. From both the MS and chromatography information, these pairwise compounds were identified as 2-alkyl-decahydronaphthalenes and 1-alkyl-decahydronaphthalenes. The polarity of 1-alkyl-decahydronaphthalenes was stronger. Their long chain alkyl substituent groups may be due to bacterial transformation or different oil cracking events. This systematic profiling of alkyl-decahydronaphthalene isomers provides further understanding and recognition of these potential petroleum biomarkers. PMID:25945366

  2. Enhanced coal liquefaction by low-severity catalytic reactions: Technical progress report for the period December 1986 to February 1987. [3,5 dimethyl phenol, diphenyl ketone, p-hydroxybenzaldehyde, tetrahydro-1-naphthol, bibenzyl, biphenyl, pyrene, benzyl ether, phenyl ether, phenyl-ethyl-ether, decahydronaphthalene

    SciTech Connect

    Davis, A.; Derbyshire, F.J.; Schobert, H.H.

    1987-03-01

    The objective of this investigation is to examine the potential and limitations of temperature-staged catalytic liquefaction. Experiments have been planned to examine the chemical reactions which occur during the low- and high-severity stages, the effects of coal rank and process conditions, the function of catalyst and influence of solvent donor capability. Initial experiments have been conducted using a lignite, subbituminous B, hvC and hvA bituminous coals. Experimental conditions were varied by using separate single low and high severity stages and a two-stage liquefaction sequence. Although no catalyst or solvent were used in these experiments, the atmosphere was systematically changed, using either hydrogen or nitrogen. From the low-severity single-stage reations (275/sup 0/C) it appears that the atmosphere has negligible effects on the product distributions. Reaction variables had a greater influence in the single-stage high severity (425/sup 0/C) runs and a temperature sequence, the highest conversions being obtained in the latter. As expected, the presence of nitrogen in either the high-severity single- or two-stage reactions significantly lowered the percentage conversions when compared to the presence of H/sub 2/ atmosphere in otherwise similar runs. Eleven model compounds, representing structures which could exist in coal, were hydrogenated either in the presence or absence of a molybdenum sulfide catalyst. Reaction products were analyzed by gas chromatography and characterized by the number of fragments that differ in boiling point relative to unreacted material. It was found that, under the reaction conditions employed, the catalyst can be effective in hydrogenating condensed aromatics, cleaving certain bridging linkages, and stabilizing other bond types. 24 refs., 7 figs., 7 tabs.

  3. Volumetric properties of cyclic hydrocarbons in tetrachloromethane at 25{degrees}C

    SciTech Connect

    Matteoli, E.; Lepori, L.; Spanedda, A.

    1994-05-01

    By means of a vibrating-tube densimeter, the densities at 25{degrees}C have been determined for binary mixtures of tetrachloromethane with a liquid (cyclodecane, cis-decahydronaphthalene, trans-decahydronaphthalene, bicyclohexyl, pentane) or a solid hydrocarbon (cyclododecane, cyclopentadecane, norbornane, adamantane, octahydro-4,7-methano-1H-indene). Excess molar volumes have been obtained in the whole mole fraction range for mixtures containing a liquid hydrocarbon. For solid cycloalkanes, apparent molar volumes have been evaluated in the whole range of miscibility. The partial molar volumes at infinite dilution {bar V} have been calculated for all examined cycloalkanes and compared with those of n-alkanes. The dependence of {bar V} upon the size and shape of the ring or cage structure of the solute is discussed. The capability of the Flory theory to reproduce V{sup E} for these mixtures is also tested.

  4. Novel approaches to the production of higher alcohols from synthesis gas. Quarterly technical progress report No. 20, July 1, 1995--September 30, 1995

    SciTech Connect

    Roberts, G.W.

    1996-09-05

    Standard thermal stability tests were carried out on four liquids: decahydroquinoline (DHQ); 1, 3-Di-4 piperidylpropane (134PPDP), Naphthenic Base 37 and tetrahydronaphthalene (tetralin). Tetralin was more stable than decahydronaphthalene (Decalin{reg_sign}), and THQ was slightly less stable. Both tetralin and THQ should be evaluated further as slurry liquids in the presence of catalyst and syngas. Naphthenic Base 37 and 134PPDP do not have satisfactory thermal stability. Vapor pressure osmometry (VPO) was shown to be an unreliable technique for measuring the average molecular weight of slurry liquids. Gas chromatography/mass spectroscopy (GUMS) is a more accurate technique for pure compounds.

  5. Reactions of coal model compounds in tetralin using microwave energy: Effects of catalysts

    SciTech Connect

    Eray, E.; Yagmur, E.; Simsek, E.H.; Alibeyli, R.; Togrul, T.

    2006-10-01

    Reaction mechanisms of model compounds of coal in tetralin by microwave energy were investigated. Diphenylmethane (DFM), phenyl-methyl ether (anisole), and phenyl-methyl ketone (acetophenon) were chosen as model compounds. Experiments were carried out for 10 minutes of microwave energy and different catalysts were used (pyratol, zeolite, BaCl{sub 2}, AlNiMo) to find out the distribution of reaction products of the model compounds. GC and GC/MS are used to analyze the reaction products. The main reaction products from DFM and tetralin under microwave radiation with catalysts were ethyl benzene, naphthalene, 2-methyl naphthalene, 3,4-dihydronaphthaleneone, 1-1'-ethyldene 1-benzene, and 1-methyl 4-phenyl methyl benzene. The main reaction products from anisole and tetralin under microwave radiation were ethyl benzene, phenol, methyl phenol, decahydronaphthalene, and tetrahydronaphthalenol. The main reaction products from acetophenon and tetralin under microwave radiation with catalysts were ethyl benzene, methoxy benzene, decahydronaphthalene, naphthalene, tetrahydronaphthalenol, 3,4-dihydronaphthalenone and 2-butene-1-one-1,3 diphenyl. The estimated mechanism of the model compounds with tetralin is compared with the results taken from GC/MS analysis. It is obtained that the results suggested theoretically were similar with the GC/MS results.

  6. Effect of surfactant excess on the stability of low-polarity ferrofluids probed by small-angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Petrenko, V. I.; Avdeev, M. V.; Bulavin, L. A.; Almasy, L.; Grigoryeva, N. A.; Aksenov, V. L.

    2016-01-01

    The structures of ferrofluids (FFs) based on nonpolar solvent decahydronaphthalene, stabilized by saturated monocarboxylic acids with hydrocarbon chains of different lengths, C16 (palmitic acid) and ?12 (lauric acid), with an excess of acid molecules, have been studied by small-angle neutron scattering. It is found that the addition of acid to an initially stable system with optimal composition leads to more significant structural changes (related to aggregation) than those observed previously for this class of FFs. A comparison of the influence of monocarboxylic acids on the stability of nonpolar FFs suggests that the enhancement of aggregation is much more pronounced in the case of palmitic acid excess. This fact confirms the conclusion of previous studies, according to which an increase in the hydrocarbon chain length in a saturated acid reduces the efficiency of the corresponding FF stabilization.

  7. Determination of the viscosity of various hydrocarbons and mixtures of hydrocarbons versus temperature and pressure

    NASA Astrophysics Data System (ADS)

    Et-Tahir, A.; Boned, C.; Lagourette, B.; Xans, P.

    1995-11-01

    The dynamic viscosity η and density ρ of 10 pure substances and three binary systems were measured as a function of temperature T (298.15, 313.15, 333.15, 353.15, and 363.15 K.) and pressure P (⩽100 MPa). The pure substances were toluene, p-xylene, m-xylene, o-xylene, methylcyclohexane, methylnaphthalene, decahydronaphthalene, phenyldodecane, heptamethylnonane, and tetramethylpentadecane (pristane). The three binaries were toluene + tetramethylpentadecane, toluene + methylnaphthalene, and toluene + heptamethylnonane, for molar fractions x of toluene ranging between 0 and 1. The three binaries are highly “contrasted” systems, i.e., systems in which the viscosities of the pure components are very different for each P, T pair. In all, 547 experimental determinations were carried out (279 experimental data for viscosity of the pure substances and 268 data concerning the mixtures: x⊋0 and 1).

  8. Catalytic conversions of chlorodecalin

    SciTech Connect

    Takhistov, U.V.; Kovyazin, V.E.

    1985-10-01

    This paper studies catalytic conversions of chlorinated decahydronaphthalene (chlorodecalin), since the introduction of chlorine into the hydrocarbon molecule would facilitate formation of the original carbonium ion required for conversion to adamantane. Analysis of the fractions obtained showed that two main products are formed: the tricyclic hydrocarbon C/sub 10/H/sub 16/ and the bicyclic hydrocarbon C/sub 10/H/sub 16/. Therefore, the C/sub 10/H/sub 17/ cation formed by removal of chlorine from chlorodecalin, C/sub 10/H/sub 17/CI, undergoes changes in two directions: addition of hydride ions from other chlorodecalin molecules to form Decalin, and loss of a proton to give a tricyclic system of the adamantane weries and its isomer. Introduction of a substituent (chlorine) into the Decalin molecule made it possible to conduct the process at low temperatures.

  9. PROMOTED ZINC CHROMITE CATALYSTS FOR HIGHER ALCOHOL SYNTHESIS

    SciTech Connect

    Ms. Xiaolei Sun; Professor George W. Roberts

    2000-08-29

    During this reporting period, a ''zinc chromite'' catalyst promoted with 6 wt.% cesium (Cs) was evaluated at the following conditions: Temperature--375 C; Total Pressure--6.8 MPa (1000 psig); Gas Hourly Space Velocity (GHSV) - 5000 standard liters/kg(cat)-hr, and; H{sub 2}/CO feed ratio--1.0 mole/mole. Decahydronaphthalene (DHN) was used as the slurry liquid. The experiment lasted for eight days of continuous operation. Although the experimental data once again did not exhibit the desired degree of consistency, the data did show that methanol was the primary reaction product. The slurry liquid did not decompose or alkylate to a measurable extent during the continuous 8-day experiment. There was a relatively significant loss of catalyst surface area during the experiment. Gas chromatography/mass spectrometry (GC/MS) analysis of various fractions of ''spent'' THQ was carried out. The fractions were prepared by silica gel liquid chromatography (LC). Chemical formuli and probable structures for each major compound were obtained. However, a higher degree of purification will be necessary to allow nuclear magnetic resonance (NMR) analysis to be used for definitive compound identification. A new Maxpro gas booster (DLE 15-75) was purchased because the existing Haskel gas booster once again developed a severe leak of carbon monoxide and hydrogen, and was judged to be unworthy of repair.

  10. Superparamagnetic-oil-filled nanocapsules of a ternary graft copolymer.

    PubMed

    Miao, Lei; Liu, Feng; Lin, Shudong; Hu, Jiwen; Liu, Guojun; Yang, Yang; Tu, Yuanyuan; Hou, Chengmin; Li, Fei; Hu, Meilong; Luo, Hongsheng

    2014-04-15

    Stearic and oleic acid-coated Fe3O4 nanoparticles were dispersed in decahydronaphthalene (DN). This oil phase was dispersed in water using ternary graft copolymer poly(glycidyl methacrylate)-graft-[polystyrene-ran-(methoxy polyethylene glycol)-ran-poly(2-cinnamoyloxyethyl methacrylate)] or PGMA-g-(PS-r-MPEG-r-PCEMA) to yield capsules. The walls of these capsules were composed of PCEMA chains that were soluble in neither water nor DN, and the DN-soluble PS chains stretched into the droplet phase and the water-soluble MPEG chains extended into the aqueous phase. Structurally stable capsules were prepared by photolyzing the capsules with UV light to cross-link the PCEMA layer. Both the magnetite particles and the magnetite-containing capsules were superparamagnetic. The sizes of the capsules increased as they were loaded with more magnetite nanoparticles, reaching a maximal loading of ~0.5 mg of ligated magnetite nanoparticles per mg of copolymer. But the radii of the capsules were always <100 nm. Thus, a novel nanomaterial--superparamagnetic-oil-filled polymer nanocapsules--was prepared. The more heavily loaded capsules were readily captured by a magnet and could be redispersed via shaking. Although the cross-linked capsules survived this capturing and redispersing treatment many times, the un-cross-linked capsules ruptured after four cycles. These results suggest the potential to tailor-make capsules with tunable wall stability for magnetically controlled release applications. PMID:24684287

  11. Far infrared (terahertz) spectroscopy of a series of polycyclic aromatic hydrocarbons and application to structure interpretation of asphaltenes and related compounds.

    PubMed

    Cataldo, Franco; Angelini, Giancarlo; García-Hernández, D Aníbal; Manchado, Arturo

    2013-07-01

    A series of 33 different polycyclic aromatic hydrocarbons (PAHs) were studied by far infrared spectroscopy (terahertz spectroscopy) in the spectral range comprised between 600 and 50 cm(-1). In addition to common PAHs like naphthalene, anthracene, phenanthrene, fluoranthene, picene, pyrene, benzo[α]pyrene, and perylene, also quite unusual PAHs were studied like tetracene, pentacene, acenaphtene, acenaphtylene, triphenylene, and decacyclene. A series of alkylated naphthalenes and anthracenes were studied as well as methypyrene. Partially or totally hydrogenated PAHs were also object of the present investigation, ranging from tetrahydronaphthalene (tetralin) to decahydronaphthalene (decalin), 9,10-dihydroanthracene, 9,10-dihydrophenanthrene, hexahydropyrene, and dodecahydrotriphenylene. Finally, the large and quite rare PAHs coronene, quaterrylene, hexabenzocoronene, and dicoronylene were studied by far infrared spectroscopy. The resulting reference spectra were used in the interpretation of the chemical structure of asphaltenes (as extracted from a heavy petroleum fraction and from bitumen), the chemical structures of other petroleum fractions known as DAE (distillate aromatic extract) and RAE (residual aromatic extract), and a possible interpretation of components of the chemical structure of anthracite coal. Asphaltenes, heavy petroleum fractions, and coal were proposed as model compounds for the interpretation of the emission spectra of certain proto-planetary nebulae (PPNe) with a good matching in the mid infrared between the band pattern of the PPNe emission spectra and the spectra of these oil fractions or coal. Although this study was finalized in an astrochemical context, it may find application also in the petroleum and coal chemistry. PMID:23603577

  12. Determination of unconverted HDPE in coal/plastics co-liquefaction stream samples

    SciTech Connect

    Robbins, G.A.; Winschel, R.A.; Burke, F.P.

    1996-12-31

    In several coal/plastics liquefaction runs performed by Hydrocarbon Technologies, Inc. (HTI), a substantial amount of incompletely converted high-density polyethylene (HDPE) was present in ash-free recycle resid streams when either the ROSE-SR unit was used in Run POC-2, or the pressure filter unit was used in Runs CMSL-8 and CMSL-9. This indicates that the HDPE is less reactive than coal at the liquefaction conditions used. In these ash-free streams, there is no solid organic or inorganic material arising from the coal, and the incompletely converted HDPE can be recovered by extraction and filtration with tetrahydrofuran (THF) at room temperature. The HDPE (or HDPE-like material, which could also consist of heavy waxes) is THF insoluble. However, in ashy streams, there are both inorganic ({open_quotes}ash{close_quotes}) and organic (unconverted coal) components present from liquefaction of the coal, that interfere with an easy and clean separation of the HDPE from the coal/plastics liquefaction stream sample. Therefore, CONSOL developed an analytical procedure for HDPE in the ashy stream samples based on extraction of HDPE from the sample using hot (150{degrees}C) decalin (decahydronaphthalene), in which the HDPE is soluble. The decalin extraction is both preceded and succeeded by extractions and washes with THF at room temperature, to remove the coal-derived components from the sample.

  13. The origin of light cycloalkanes in petroleum

    SciTech Connect

    Mango, F.D. )

    1990-01-01

    It has been suggested that the light cycloalkanes in petroleum are generated through the thermal decomposition of heavier polycyclic natural products, such as the steranes and triterpanes. However, no support could be found for the assumption that the polycycloalkanes should decompose to light cycloalkanes at typical subsurface temperatures. For example, at 150{degree}C, decahydronaphthalene-the bicyclodecyl unit fundamental to the steranes and triterpanes-has a half-life of approximately 30 billion years. At this same temperature, cyclohexane has a half-life of approximately 60 billion years. The surprising thermal stability of the cycloalkane ring can be traced to a prohibitively high activation energy for ring opening due to the steric strain associated with the {beta}-elimination step. Cholestane undergoes thermal decomposition almost exclusively by loss of the alkyl side chain. Under thermal conditions sufficiently severe to break the carbon-carbon bonds of normal alkanes (weeks, 330{degree}C), cholestane gives only insignificant amounts of light cycloalkanes. It is most doubtful, therefore, that the C{sub 5} to C{sub 9} cycloalkanes could be thermally produced from natural products like the steranes and triterpanes. An alternative hypothesis is offered in which the light cycloalkanes in petroleum are formed in a steady-state catalytic process.

  14. Sonochemical effect on size reduction of CaCO3 nanoparticles derived from waste eggshells.

    PubMed

    Hassan, Tarig A; Rangari, Vijay K; Rana, Rohit K; Jeelani, Shaik

    2013-09-01

    A novel combination of mechanochemical and sonochemical techniques was developed to produce high-surface-area, bio-based calcium carbonate (CaCO3) nanoparticles from eggshells. Size reduction of eggshell achieved via mechanochemical and followed by sonochemical method. First, eggshells were cleaned and ground, then ball milled in wet condition using polypropylene glycol for ten hours to produce fine particles. The ball milled eggshell particles were then irradiated with a high intensity ultrasonic horn (Ti-horn, 20 kHz, and 100 W/cm(2)) in the presence of N,N-dimethylformamide (DMF); decahydronaphthalene (Decalin); or tetrahydrofuran (THF). The ultrasonic irradiation times varied from 1 to 5 h. Transmission electron microscopic (TEM) studies showed that the resultant particle shapes and sizes were different from each solvent. The sonochemical effect of DMF is more pronounced and the particles were irregular platelets of ~10 nm. The BET surface area (43.687 m(2)/g) of these nanoparticles is much higher than that of other nanoparticles derived from eggshells. PMID:23473569

  15. Far infrared (terahertz) spectroscopy of a series of polycyclic aromatic hydrocarbons and application to structure interpretation of asphaltenes and related compounds

    NASA Astrophysics Data System (ADS)

    Cataldo, Franco; Angelini, Giancarlo; García-Hernández, D. A.; Manchado, Arturo

    2013-07-01

    A series of 33 different polycyclic aromatic hydrocarbons (PAHs) were studied by far infrared spectroscopy (terahertz spectroscopy) in the spectral range comprised between 600 and 50 cm-1. In addition to common PAHs like naphthalene, anthracene, phenanthrene, fluoranthene, picene, pyrene, benzo[α]pyrene, and perylene, also quite unusual PAHs were studied like tetracene, pentacene, acenaphtene, acenaphtylene, triphenylene, and decacyclene. A series of alkylated naphthalenes and anthracenes were studied as well as methypyrene. Partially or totally hydrogenated PAHs were also object of the present investigation, ranging from tetrahydronaphthalene (tetralin) to decahydronaphthalene (decalin), 9,10-dihydroanthracene, 9,10-dihydrophenanthrene, hexahydropyrene, and dodecahydrotriphenylene. Finally, the large and quite rare PAHs coronene, quaterrylene, hexabenzocoronene, and dicoronylene were studied by far infrared spectroscopy. The resulting reference spectra were used in the interpretation of the chemical structure of asphaltenes (as extracted from a heavy petroleum fraction and from bitumen), the chemical structures of other petroleum fractions known as DAE (distillate aromatic extract) and RAE (residual aromatic extract), and a possible interpretation of components of the chemical structure of anthracite coal. Asphaltenes, heavy petroleum fractions, and coal were proposed as model compounds for the interpretation of the emission spectra of certain proto-planetary nebulae (PPNe) with a good matching in the mid infrared between the band pattern of the PPNe emission spectra and the spectra of these oil fractions or coal. Although this study was finalized in an astrochemical context, it may find application also in the petroleum and coal chemistry.

  16. Synthesis and Comprehensive Structural and Chiroptical Characterization of Enones Derived from (-)-α-Santonin by Experiment and Theory.

    PubMed

    Masnyk, Marek; Butkiewicz, Aleksandra; Górecki, Marcin; Luboradzki, Roman; Bannwarth, Christoph; Grimme, Stefan; Frelek, Jadwiga

    2016-06-01

    The aim of the present work is to explain the causes of the observed deviations from sector and helicity rules to determine the absolute configuration of optically active α,β-unsaturated ketones by means of electronic circular dichroism (ECD). To this end, a series of model compounds with a common decahydronaphthalene skeleton representing both cisoid and transoid enones were synthesized. In the framework of this work, detailed dichroic studies supported by single crystal X-ray analysis were performed where possible. To assist the achievement of the desired objectives the conformational flexibility of the selected cis-enones through the dependence of solvent and temperature on the ECD spectra were examined. All experimental studies were supplemented by detailed DFT calculations. A notable result of the study is assessing the applicability of the enone sector and helicity rules in dichroic studies and potential restrictions. To this end, a number of factors that could determine the signs of the individual Cotton effects has been considered. Among these nonminimum structure effects, i.e., twisting of the enone chromophore and nonplanarity of the enone double bond can be mentioned. PMID:27115057

  17. Solubilities of tetracosane in hydrocarbon solvents

    SciTech Connect

    Brecevic, L.; Garside, J. . Dept. of Chemical Engineering)

    1993-10-01

    The solubilities of tetracosane (n-C[sub 24]H[sub 50]) in heptane (n-C[sub 7]H[sub 16]), dodecane (n-C[sub 12]H[sub 26]), a mixture of isomers of decahydronaphthalene (C[sub 10]H[sub 18]), and m and p-xylene (C[sub 8]H[sub 10]) have been determined over the temperature range 279.3--305.8 K. These solvents were chosen as being representative of the types of molecules present in fuel oils. The results are well described by the equation ln x[sub 2] = [minus]([Delta]H[sup d]/RT) + ([Delta]S[sup d]/R) for which the parameters [Delta]H[sup d] and [Delta]S[sup d] are given. The liquid-phase activity coefficients for the solid at 293.2 K have been derived from the measured solubilities and compared with values calculated from the Scatchard-Hildebrand equation and the UNIFAC group contribution method. Relatively good agreement is obtained using the Scatchard-Hildebrand equation, especially in the case of normal hydrocarbon solvents.

  18. Singlet molecular oxygen ( sup 1. Delta. sub g O sub 2 ) formation upon irradiation of an oxygen ( sup 3. Sigma. sub g sup minus O sub 2 )-organic molecule charge-transfer absorption band

    SciTech Connect

    Scurlock, R.D.; Ogilby, P.R. )

    1989-07-13

    Singlet molecular oxygen ({sup 1}{Delta}{sub g}O{sub 2}) phosphorescence ({sup 3}{Sigma}{sub g}{sup {minus}}O{sub 2} {l arrow} {sup 1}{Delta}{sub g}O{sub 2}: 1270 nm) has been observed in a time-resolved experiment subsequent to pulsed UV laser irradiation of the oxygen ({sup 3}{Sigma}{sub g}{sup {minus}}O{sub 2})-organic molecule charge-transfer bands of liquid aromatic hydrocarbons (mesitylene, p-xylene, o-xylene, toluene, benzene), ethers (tetrahydrofuran, 1,4-dioxane, glyme, diglyme, triglyme), alcohols (methanol, propanol), and aliphatic hydrocarbons (cyclohexane, cyclooctane, decahydronaphthalene). Although {sup 1}{Delta}{sub g}O{sub 2} could originate from a variety of different processes in these oxygenated solvent systems, we have used the results of several independent experiments to indicate that an oxygen-solvent charge-transfer (CT) state is the {sup 1}{Delta}{sub g}O{sub 2} precursor. Other transient species have also been observed in time-resolved absorption experiments subsequent to pulsed UV irradiation of the oxygen-solvent CT bands. Some of these molecular transients, or species derived from these intermediates, may be responsible for an observed increase in the rate of {sup 1}{Delta}{sub g}O{sub 2} decay under certain conditions.

  19. Novel approaches to the production of higher alcohols from synthesis gas. Quarterly technical progress report No. 18, January 1, 1995-- March 31, 1995

    SciTech Connect

    1996-07-05

    A set of stirrer speed experiments using the Cu/ZnO methanol synthesis catalyst showed that introducing the gas feed into the reactor through an extended dip tube eliminated the dependency of catalyst performance on stirrer speed. The methanol productivity data from the reactor gas feed configuration tests conducted in December, 1994 and January, 1995, were correlated with stirrer speed. The influence on mass transfer on catalyst performance was clearly illustrated for each gas feed location. The ``high pressure, high temperature` zinc chromite methanol synthesis catalyst showed surprising activity at temperatures as low as 300{degree}C during the first successful stirred autoclave run with this catalyst. No C{sub 2{sup {plus}}} alcohols were detected, but significant levels of C{sub 2}-C{sub 4} olefins and dimethyl ether (DME) were produced. The presence of olefins suggests that higher alcohols might have formed and subsequently dehydrated. The slurry liquid, decahydronaphthalene, showed no evidence of decomposition during 15 days of continuous operation. 2 figs., 1 tab.

  20. A Great Barrier Reef Sinularia sp. Yields Two New Cytotoxic Diterpenes

    PubMed Central

    Wright, Anthony D.; Nielson, Jonathan L.; Tapiolas, Dianne M.; Liptrot, Catherine H.; Motti, Cherie A.

    2012-01-01

    The methanol extract of a Sinularia sp., collected from Bowden Reef, Queensland, Australia, yielded ten natural products. These included the new nitrogenous diterpene (4R*,5R*,9S*,10R*,11Z)-4-methoxy-9-((dimethylamino)-methyl)-12,15-epoxy-11(13)-en-decahydronaphthalen-16-ol (1), and the new lobane, (1R*,2R*,4S*,15E)-loba-8,10,13(14),15(16)-tetraen-17,18-diol-17-acetate (2). Also isolated were two known cembranes, sarcophytol-B and (1E,3E,7E)-11,12-epoxycembratrien-15-ol, and six known lobanes, loba-8,10,13(15)-triene-16,17,18-triol, 14,18-epoxyloba-8,10,13(15)-trien-17-ol, lobatrientriol, lobatrienolide, 14,17-epoxyloba-8,10,13(15)-trien-18-ol-18-acetate and (17R)-loba-8,10,13(15)-trien-17,18-diol. Structures of the new compounds were elucidated through interpretation of spectra obtained after extensive NMR and MS investigations and comparison with literature values. The tumour cell growth inhibition potential of 1 and 2 along with loba-8,10,13(15)-triene-16,17,18-triol, 14,17-epoxyloba-8,10,13(15)-trien-18-ol-18-acetate, lobatrienolide, (1E,3E,7E)-11,12-epoxycembratrien-15-ol and sarcophytol-B were assessed against three human tumour cell lines (SF-268, MCF-7 and H460). The lobanes and cembranes tested demonstrated 50% growth inhibition in the range 6.8–18.5 µM, with no selectivity, whilst 1 was less active (GI50 70–175 µM). PMID:23015765

  1. Nanocalorimetry of vapor-deposited organic glasses: tris-naphthylbenzene, decalin and ortho-terphenyl

    NASA Astrophysics Data System (ADS)

    Whitaker, Katherine R.

    Physical vapor deposition can be used to prepare glasses with extraordinary properties. By optimizing the substrate temperature and deposition rate, glasses with low enthalpy, high density and high kinetic stability, as compared to the ordinary liquid-cooled glass, can be produced. The heat capacity of 'stable glasses' has been measured with conventional calorimetry, but such techniques are limited to bulk samples; the properties of more technologically relevant thin films cannot be measured. In this thesis, nanocalorimetry was utilized to measure the heat capacity of thin films of four organic glassformers: alpha,alpha,beta-tris-naphthylbenzene (alphaalphabeta-TNB),cis- and trans-decahydronaphthalene (cis- and trans -decalin) and o-terphenyl. A number of new and important results came out of the AC nanocalorimetry experiments on these molecules. alphaalphabeta-TNB thin films showed thickness dependent transformation times for films up to one micron in thickness, consistent with the work on indomethacin. This result suggested that highly suppressed bulk transformation rates are a general feature associated with the kinetics of stable glass transformation. One way glassformers can be characterized is by their fragility, or their temperature dependent behavior as Tg is approached. Decalin, the molecular glassformer with the highest reported fragility, was shown to be capable of forming stable glasses when vapor-deposited. This result implies that surface mobility, which is deemed the controlling mechanism for stable glass formation, is also present in high fragility systems. Experiments on a variety of cis/trans-decalin mixture compositions showed that vapor deposition can also be used to make stable glasses of mixtures. The ability of an array of compositions to form stable glasses is a strong argument against nanocrystals being responsible for the extraordinary properties of stable glasses. Finally, in situ experiments on o-terphenyl were able to span the range of

  2. Higginsianins A and B, Two Diterpenoid α-Pyrones Produced by Colletotrichum higginsianum, with in Vitro Cytostatic Activity.

    PubMed

    Cimmino, Alessio; Mathieu, Veronique; Masi, Marco; Baroncelli, Riccardo; Boari, Angela; Pescitelli, Gennaro; Ferderin, Marlène; Lisy, Romana; Evidente, Marco; Tuzi, Angela; Zonno, Maria Chiara; Kornienko, Alexander; Kiss, Robert; Evidente, Antonio

    2016-01-22

    Two new diterpenoid α-pyrones, named higginsianins A (1) and B (2), were isolated from the mycelium of the fungus Colletotrichum higginsianum grown in liquid culture. They were characterized as 3-[5a,9b-dimethyl-7-methylene-2-(2-methylpropenyl)dodecahydronaphtho[2,1-b]furan-6-ylmethyl]-4-hydroxy-5,6-dimethylpyran-2-one and 4-hydroxy-3-[6-hydroxy-5,8a-dimethyl-2-methylene-5-(4-methylpent-3-enyl)decahydronaphthalen-1-ylmethyl]-5,6-dimethylpyran-2-one, respectively, by using NMR, HRESIMS, and chemical methods. The structure and relative configuration of higginsianin A (1) were confirmed by X-ray diffractometric analysis, while its absolute configuration was assigned by electronic circular dichroism (ECD) experiments and calculations using a solid-state ECD/TDDFT method. The relative and absolute configuration of higginsianin B (2), which did not afford crystals suitable for X-ray analysis, were determined by NMR analysis and by ECD in comparison with higginsianin A. 1 and 2 were the C-8 epimers of subglutinol A and diterpenoid BR-050, respectively. The evaluation of 1 and 2 for antiproliferative activity against a panel of six cancer cell lines revealed that the IC50 values, obtained with cells reported to be sensitive to pro-apoptotic stimuli, are by more than 1 order of magnitude lower than their apoptosis-resistant counterparts (1 vs >80 μM). Finally, three hemisynthetic derivatives of 1 were prepared and evaluated for antiproliferative activity. Two of these possessed IC50 values and differential sensitivity profiles similar to those of 1. PMID:26697898

  3. Elucidation of the molecular mechanism and the efficacy in vivo of a novel 1,4-benzoquinone that inhibits 5-lipoxygenase

    PubMed Central

    Schaible, A M; Filosa, R; Temml, V; Krauth, V; Matteis, M; Peduto, A; Bruno, F; Luderer, S; Roviezzo, F; Di Mola, A; Rosa, M; D'Agostino, B; Weinigel, C; Barz, D; Koeberle, A; Pergola, C; Schuster, D; Werz, O

    2014-01-01

    Background and Purpose 1,4-Benzoquinones are well-known inhibitors of 5-lipoxygenase (5-LOX, the key enzyme in leukotriene biosynthesis), but the molecular mechanisms of 5-LOX inhibition are not completely understood. Here we investigated the molecular mode of action and the pharmacological profile of the novel 1,4-benzoquinone derivative 3-((decahydronaphthalen-6-yl)methyl)-2,5-dihydroxycyclohexa-2,5-diene-1,4-dione (RF-Id) in vitro and its effectiveness in vivo. Experimental Approach Mechanistic investigations in cell-free assays using 5-LOX and other enzymes associated with eicosanoid biosynthesis were conducted, along with cell-based studies in human leukocytes and whole blood. Molecular docking of RF-Id into the 5-LOX structure was performed to illustrate molecular interference with 5-LOX. The effectiveness of RF-Id in vivo was also evaluated in two murine models of inflammation. Key Results RF-Id consistently suppressed 5-LOX product synthesis in human leukocytes and human whole blood. RF-Id also blocked COX-2 activity but did not significantly inhibit COX-1, microsomal PGE2 synthase-1, cytosolic PLA2 or 12- and 15-LOX. Although RF-Id lacked radical scavenging activity, reducing conditions facilitated its inhibitory effect on 5-LOX whereas cell stress impaired its efficacy. The reduced hydroquinone form of RF-Id (RED-RF-Id) was a more potent inhibitor of 5-LOX as it had more bidirectional hydrogen bonds within the 5-LOX substrate binding site. Finally, RF-Id had marked anti-inflammatory effects in mice in vivo. Conclusions and Implications RF-Id represents a novel anti-inflammatory 1,4-benzoquinone that potently suppresses LT biosynthesis by direct inhibition of 5-LOX with effectiveness in vivo. Mechanistically, RF-Id inhibits 5-LOX in a non-redox manner by forming discrete molecular interactions within the active site of 5-LOX. PMID:24467325