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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.

  2. New terpenoids from Mentha pulegium L. and their antimicrobial activity.

    PubMed

    Ibrahim, Amany K

    2013-04-01

    In addition to one previously reported compound: two new terpenoidal compounds 1α, 6βdimethyl-5β-hydroxy-4β-(prop-1-en-2-yl)-decahydronaphthalen-2-one (1) and 1-(O-β-D-glucopyranosyl)-2,7-dimethyloct-5-en-3-one (2) were isolated from the chloroformic extract of Mentha pulegium L. The structure elucidation of these compounds was based primarily on 1D and 2D-nuclear magnetic resonance analyses. Compound 1 displayed moderate anti-MRSa (IC50 8.5 µg mL(-1)).

  3. 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.

  4. The infinite possible growth ambients that support single-wall carbon nanotube forest growth.

    PubMed

    Kimura, Hiroe; Goto, Jundai; Yasuda, Satoshi; Sakurai, Shunsuke; Yumura, Motoo; Futaba, Don N; Hata, Kenji

    2013-01-01

    We report the virtually infinite possible carbon feedstocks which support the highly efficient growth of single-wall carbon nanotubes (SWCNTs) using on the water-assisted chemical vapor deposition method. Our results demonstrate that diverse varieties of carbon feedstocks, in the form of hydrocarbons, spanning saturated rings (e.g. trans-deca-hydronaphthalene), saturated chains (e.g. propane), unsaturated rings (e.g. dicyclopentadiene), and unsaturated chains (e.g. ethylene) could be used as a carbon feedstocks with SWCNT forests with heights exceeding 100 ums. Further, we found that all the resultant SWCNTs possessed similar average diameter indicating that the diameter was mainly determined by the catalyst rather than the carbon feedstock within this synthetic system. A demonstration of the generality was the synthesis of a carbon nanotube forest from a highly unorthodox combination of gases where trans-decahydronaphthalene acted as the carbon feedstock and benzaldehyde acted as the growth enhancer.

  5. Use of comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry for the characterization of biodegradation and unresolved complex mixtures in petroleum

    NASA Astrophysics Data System (ADS)

    Tran, Tin C.; Logan, Graham A.; Grosjean, Emmanuelle; Ryan, Danielle; Marriott, Philip J.

    2010-11-01

    A comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOFMS) method has been developed for separation of a series of petroleum samples using a polar/non-polar column set configuration. Groups of oils were selected to provide samples from the same oil family to assist in comparison of compositional changes during biodegradation. The groups also represented different sources and ages to allow an assessment of the application of GC × GC for the differentiation of oil source, as well as fluid history. The increased resolution and separation afforded by the GC × GC technique provides more complete compositional information on complex biodegraded oil samples than one-dimensional GC, and improves the ability to study biodegradation trends. Among the components identified, it is proposed that alkyl-decahydronaphthalenes constitute a significant contribution to the UCM.

  6. The Infinite Possible Growth Ambients that Support Single-Wall Carbon Nanotube Forest Growth

    NASA Astrophysics Data System (ADS)

    Kimura, Hiroe; Goto, Jundai; Yasuda, Satoshi; Sakurai, Shunsuke; Yumura, Motoo; Futaba, Don N.; Hata, Kenji

    2013-11-01

    We report the virtually infinite possible carbon feedstocks which support the highly efficient growth of single-wall carbon nanotubes (SWCNTs) using on the water-assisted chemical vapor deposition method. Our results demonstrate that diverse varieties of carbon feedstocks, in the form of hydrocarbons, spanning saturated rings (e.g. trans-deca-hydronaphthalene), saturated chains (e.g. propane), unsaturated rings (e.g. dicyclopentadiene), and unsaturated chains (e.g. ethylene) could be used as a carbon feedstocks with SWCNT forests with heights exceeding 100 ums. Further, we found that all the resultant SWCNTs possessed similar average diameter indicating that the diameter was mainly determined by the catalyst rather than the carbon feedstock within this synthetic system. A demonstration of the generality was the synthesis of a carbon nanotube forest from a highly unorthodox combination of gases where trans-decahydronaphthalene acted as the carbon feedstock and benzaldehyde acted as the growth enhancer.

  7. 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.

  8. Novel approaches to the production of higher alcohols from synthesis gas. Quarterly technical progress report No. 17, October 1, 1994-- December 31, 1994

    SciTech Connect

    1996-07-05

    A series of experiments in which the stirrer speed was varied during a methanol synthesis run with BASF S3-86 catalyst showed that mass transfer limitations were present at 750 psig reactor pressure and at space velocities of 5000 and 10000 sl/kg(cat.)-hr.. There was no effect of stirrer speed on reaction rate at 2500 psig reactor pressure and 16500 sl/kg(cat.)-hr. space velocity. However, this was probably due to a close approach to equilibrium rather than to the lack of a mass transfer effect. The most plausible explanation for the presence of a mass transfer influence is the position of the gas feed dip tube relative to the agitator impeller. A second set of stirrer speed experiments using the same catalyst showed that feeding into the reactor headspace produced much lower reaction rates, compared with gas feed through a dip tube. The headspace feed also showed a strong dependence on stirrer speed, consistent with the dip tube feed results. In a ``blank` run at 375{degree}C with decahydronaphthalene, about 110 mL of the initial charge of 150 mL remained in the reactor after 73 hours of operation at 375{degree}C and 850 psig of hydrogen. The rate of hydrocarbon evolution was low throughout the run. Decalin is the most stable liquid identified to date. Three stirred autoclave runs with a commercial, high-pressure methanol synthesis catalyst (zinc chromite) slurried in decahydronaphthalene ended son after the initial catalyst reduction due to failures of the liquid return pump in the overhead system. However, the catalyst appeared to be reduced and the liquid appeared to be stable. 4 figs., 1 tab.

  9. Series of solvent-induced single-crystal to single-crystal transformations with different sizes of solvent molecules.

    PubMed

    He, Yuan-Chun; Yang, Jin; Liu, Ying-Ying; Ma, Jian-Fang

    2014-07-21

    A highly stable soft porous coordination polymer (PCP), namely [Cu3(TP)4(N3)2(DMF)2]·2H2O·2DMF (1), has been synthesized via an in situ synthesis of 4-tetrazole pyridine (TP) under solvothermal conditions (DMF = N,N'-dimethylformamide). Remarkably, the solvent molecules in 1 can be respectively exchanged with cyclohexane (C6H12), cyclopentane (C5H10), decahydronaphthalene (C10H18), 1,4-dioxane (C4H8O2), and tetrahydropyrane (C5H10O) in single-crystal to single-crystal (SCSC) manners to yield [Cu3(TP)4(N3)2(DMF)2]·3C6H12 (1a), [Cu3(TP)4(N3)2(DMF)2]·2C5H10 (1b), [Cu3(TP)4(N3)2(DMF)2]·H2O·C10H18 (1c), [Cu3(TP)4(N3)2(DMF)2]·C4H8O2 (1d), [Cu3(TP)4(N3)2]·3C4H8O2 (1e), and [Cu3(TP)4(N3)2]·2H2O·C5H10O (1f). Further, the occluded cyclohexane molecules in 1a can be removed by heating to give its porous guest-free form [Cu3(TP)4(N3)2(DMF)2] (1g). Particularly, in water, 1 can lose its coordinated N3(-) anions to generate [Cu(TP)2(H2O)4]·4H2O (1h). More interestingly, the soft PCP (1) demonstrates the guest selectivity for the cycloalkane solvents, namely cyclohexane, cyclopentane, and decahydronaphthalene, in SCSC manners for the first time, attributed to the synergy effect between the size and geometry of the solvent and the shape of the framework cavity. Moreover, the desolvated samples of 1e show the highly selective gas adsorption of CO2 over N2, indicating its potential application in the separation of the CO2/N2 mixture.

  10. 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.

  11. Novel Approaches to the Production of Higher Alcohols From Synthesis Gas. Quarterly report, January 1 - March 31, 1996

    SciTech Connect

    Roberts, George W

    1997-02-13

    Effort during this quarter was devoted to three areas: 1) analyzing the data from earlier runs with "zinc chromite"catalyst and three different slurry liquids: decahydronaphthalene (Decalin®, DHN), tetrahydronaphthalene (tetralin, THN) and tetrahydroquinoline (THQ); 2) analyzing newly-obtained data from earlier thermal stability tests on DHN and THN, and 3) carrying out a thermal stability test on THQ. Both the activity and selectivity of "zinc chromite" catalyst depended on the slurry liquid that was used. The catalyst activity for methanol synthesis was in the order: THQ > DHN > THN. Despite the basic nature of THQ, it exhibited the highest dimethyl ether (DME) production rates of the three liquids. Gas chromatography/mass spectroscopy (GC/MS) analyses of samples of THN and DHN were taken at the end of standard thermal stability tests at 375°C. With both liquids, the only measurable compositional change was a minor amount of isomerization. Analysis of a sample of THN after a thermal stability test at 425°C showed a small reduction in molecular weight, and a significant amount of opening of the naphthenic ring. Preliminary data from the tehrmal stability test of THQ showed that this molecule is more stable than DHN, but less stable than THN.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Thermal stability of coal-derived jet fuels in the autoxidative and pyrolytic regimes

    SciTech Connect

    Andresen, J.M.; Strohm, J.J.; Song, C.

    1999-07-01

    Coal-based liquids have a great potential as precursors for advanced jet fuels that meet the more stringent thermal stability requirements for the future high-Mach jet aircraft. In current commercial planes, the fuel may be exposed to temperatures up to 300 C. However, as the flight speed will be increased to high Mach numbers, the fuel is expected to experience temperatures as high as 480 C (900 F) in the future, since the jet fuel also functions as the main coolant for the different electronic and mechanical parts of the aircraft. Even though the residence time at such elevated temperatures is expected to be fairly short (matter of minutes), the jet fuels presently used have shown to form solid deposits that can lead to catastrophic malfunction of the jet aircraft. The current jet fuels are petroleum-derived and consequently rich in linear alkanes, which are highly susceptible to pyrolytic cracking resulting in coking. The thermal stability of a jet fuel in the pyrolytic regime can be greatly enhanced by utilizing liquids rich in cyclo-alkanes. This is the case for hydro-treated coal-derived liquids, where the aromatic structures have been transformed over to their corresponding cyclo-alkanes. An additional problem with jet fuels is the presence of dissolved oxygen (from air), which reacts with the fuel during the autoxidative regime (150--250 C) before the fuel and its oxygenated reaction products enter the pyrolytic regime (400--500 C). Accordingly, this study compares the thermal stability of a linear alkane (tetradecane), a cyclo-alkane (decahydronaphthalene) and a coal-derived jet-fuel as they go through the autoxidative regime into the pyrolytic regime. Differences in chemical reactivity between the linear- and cyclo-alkane have been related to the stability of the coal-derived jet-fuel.

  20. 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

  1. Effects of molecular structure on oxidation reactivity of cyclic hydrocarbons: Experimental observations and conformational analysis

    SciTech Connect

    Yang, Yi; Boehman, Andre L.; Simmie, John M.

    2010-12-15

    This work concerns the pre-ignition reactivity of cyclic hydrocarbons and its dependence on cyclic structures. In the first part, global reactivity of five cyclic hydrocarbons, methylcyclopentane (MCP), cyclohexane (CH), methylcyclohexane (MCH), decahydronaphthalene (decalin), and 1,2,3,4-tetrahydronaphthalene (tetralin), whose detailed product analyses were recently reported [Y. Yang, A.L. Boehman, Proc. Combust. Inst. 32(1) (2009) 419-426; Y. Yang, A.L. Boehman, Combust. Flame 157(3) (2010) 495-505], were compared over a range of compression ratio and intake temperature in a motored engine. Molecular structure exerts a profound effect on low temperature oxidation reactivity. Decalin is the most reactive compound whose extent of oxidation increases monotonically with increasing temperature and pressure. MCH shows higher low temperature reactivity than CH, and both show distinct negative temperature coefficient behavior. MCP and tetralin exhibit little low temperature reaction before critical conditions are reached for autoignition. In the second part, conformational analysis is conducted to understand how molecular structures affect the low temperature oxidative reactivity, in particular the (1,5) H-shift of fuel peroxy radicals (ROO{yields}{sup (1,5)}QOOH), the key step in low temperature chain branching. In comparison with open-chain structures, cyclic structures significantly reduce the total number of hydrogens that can be abstracted in the (1,5) H-shift. This is because the (1,5) H-shift of a cyclohexylperoxy radical requires both the peroxy group and the to-be-abstracted hydrogen locate at an axial position on the cyclohexane ring. The total number of available hydrogens in decalin, MCH, CH, and tetralin is 14, 11, 6, and 4, respectively. Also important is the number of hydrogens available for the (1,5) isomerization of a given peroxy group, i.e., the degeneracy of the (1,5) H-shift. Degeneracy in (1,5) H-shift for decalin, MCH, CH, and tetralin is