Sample records for h2s methyl mercaptan

  1. Detection of Atmospheric Methyl Mercaptan Using Wavelength Modulation Spectroscopy with Multicomponent Spectral Fitting

    PubMed Central

    Du, Zhenhui; Wan, Jiaxin; Li, Jinyi; Luo, Gang; Gao, Hong; Ma, Yiwen

    2017-01-01

    Detection of methyl mercaptan (CH3SH) is essential for environmental atmosphere assessment and exhaled-breath analysis. This paper presents a sensitive CH3SH sensor based on wavelength modulation spectroscopy (WMS) with a mid-infrared distributed feedback interband cascade laser (DFB-ICL). Multicomponent spectral fitting was used not only to enhance the sensitivity of the sensor but also to determine the concentration of interferents (atmospheric water and methane). The results showed that the uncertainties in the measurement of CH3SH, H2O, and CH4 were less than 1.2%, 1.7% and 2.0%, respectively, with an integration time of 10 s. The CH3SH detection limit was as low as 7.1 ppb with an integration time of 295 s. Overall, the reported sensor, boasting the merits of high sensitivity, can be used for atmospheric methyl mercaptan detection, as well as multiple components detection of methyl mercaptan, water, and methane, simultaneously. PMID:28212311

  2. Removal of H{sub 2}S, methyl macapton dimethyl sulfide and dimethyl disulfide with biofiltration

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Singleton, B.; Milligan, D.

    1996-12-31

    A pilot study describes the biofiltration process control that was necessary to remove H{sub 2}S, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide, when mixed in an airstream. A pilot test at a waste water treatment facility was operated over a six month period. During that time H{sub 2}S was removed with very high efficiency at concentrations that reached to 400 ppm{sub v}; H{sub 2}S loading reached as high as 20 gms/m{sup 3}/hr. Methyl mercaptan and the organic sulfides were not removed sufficiently to deodorize the air-stream until a second stage biofilter was added. An odor analysis indicated that the odormore » detection level was approximately 250,000 odor units at the inlet and 1100 odor units at the outlet. The sulfur distribution in the media indicated that elemental sulfur and sulfate is deposited as a byproduct of the H{sub 2}S oxidation. Data from a fall scale biofilter treating H{sub 2}S from a pumping station is also presented. This data shows very efficient removal of H{sub 2}S, no organic reduced sulfur compounds were found in this air-stream.« less

  3. REACTIONS OF MERCAPTANS. I. FORMATION OF 2-METHYL-2-THIAZOLINE-4- CARBOXYLIC ACID FROM N-ACETYLCYSTEINE. II. A SPECTROPHOTOMETRIC METHOD FOR STUDY OF THE REACTION OF RADIATION-PROTECTIVE MERCAPTANS WITH ARYL DISULFIDES

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smith, H.A. Jr.

    1962-08-01

    I. Methyl 2-methyl-2-thiazoline-4-carboxylate was synthesized and converted to the corresponding acid. The behavior of the carboxythiazoline in various concentrations of mineral acids was studied spectrophotometrically. The cyclization of N-acetylcysteine to form a thiazoline-ring compound in concentrated mineral acids was also studied by this means. N-Acetylcysteine in concentrated mineral acid solutions yielded 2-methyl-2-thiazoline-4-carboxylic acid, which also was obtained by controlied hydrolysis of the corresponding methyl ester. Hydrolysis of methyl 2-methyl2-thiazoline-4-carboxylate, pK 3.05, in 0.1M sodium hydroxide yielded the corresponding carboxythiazoline in solution, pK 2.20 and 4.95. The carboxythiazoline was hydrolyzed very slowly in 7M hydrochloric acid, but the velocity of reactionmore » increased with decreasing acid concentration to a maximum at about pH 1.7; the products were N- and Sacetylcysteine, as well as cysteine and acetic acid. At acid concentrations below 0.2M, the last two products were formed slowly, and a pseudo-equilibrium could be established between thiazolinium ion, N-, and S-acetylcysteine. Equilibrium constants were determined. II. 4,4'-Dithiobis (benzenesulfonic acid) (I) and 4,4'-dithiobis(1-naphthalenesulfonic acid) (II) were synthesized from sulfanilic and naphthionic acids, respectively. The absorption spectra of I and II and of the corresponding mercaptans were determined. The thiol-disuifide interchange reactions were studied by spectrophotometric means for the reactions of cysteine with I and with II, and the equilibrium constants were determined. The systems had spectra very similar to those of the respective mixed disuifides with cysteine, and it was not possible to determine the concentrations from absorbancy measurements. On the other hand, the mercaptide ions had spectra different from the other species, with maxima at 285 and 348 m mu , respectively, and the concentrations of the corresponding mercaptans could

  4. Discrimination of the oral microbiota associated with high hydrogen sulfide and methyl mercaptan production

    PubMed Central

    Takeshita, Toru; Suzuki, Nao; Nakano, Yoshio; Yasui, Masaki; Yoneda, Masahiro; Shimazaki, Yoshihiro; Hirofuji, Takao; Yamashita, Yoshihisa

    2012-01-01

    Both hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) are frequently detected in large amounts in malodorous mouth air. We investigated the bacterial composition of saliva of 30 subjects with severe oral malodor exhibiting extreme CH3SH/H2S ratios (high H2S but low CH3SH concentrations, n = 14; high CH3SH but low H2S concentrations, n = 16) and 13 subjects without malodor, using barcoded pyrosequencing analysis of the 16S rRNA gene. Phylogenetic community analysis with the UniFrac distance metric revealed a distinct bacterial community structure in each malodor group. The H2S group showed higher proportions of the genera Neisseria, Fusobacterium, Porphyromonas and SR1 than the other two groups, whereas the CH3SH group had higher proportions of the genera Prevotella, Veillonella, Atopobium, Megasphaera, and Selenomonas. Our results suggested that distinct bacterial populations in the oral microbiota are involved in production of high levels of H2S and CH3SH in the oral cavity. PMID:22355729

  5. Discrimination of the oral microbiota associated with high hydrogen sulfide and methyl mercaptan production.

    PubMed

    Takeshita, Toru; Suzuki, Nao; Nakano, Yoshio; Yasui, Masaki; Yoneda, Masahiro; Shimazaki, Yoshihiro; Hirofuji, Takao; Yamashita, Yoshihisa

    2012-01-01

    Both hydrogen sulfide (H2S) and methyl mercaptan (CH(3)SH) are frequently detected in large amounts in malodorous mouth air. We investigated the bacterial composition of saliva of 30 subjects with severe oral malodor exhibiting extreme CH(3)SH/H(2)S ratios (high H(2)S but low CH(3)SH concentrations, n 5 14; high CH(3)SH but low H2S concentrations, n 5 16) and 13 subjects without malodor, using barcoded pyrosequencing analysis of the 16S rRNA gene. Phylogenetic community analysis with the UniFrac distance metric revealed a distinct bacterial community structure in each malodor group. The H2S group showed higher proportions of the genera Neisseria, Fusobacterium, Porphyromonas and SR1 than the other two groups, whereas the CH(3)SH group had higher proportions of the genera Prevotella, Veillonella,Atopobium, Megasphaera, and Selenomonas. Our results suggested that distinct bacterial populations in the oral microbiota are involved in production of high levels of H2S and CH3SH in the oral cavity.

  6. Effect of oxygen, methyl mercaptan, and methyl chloride on friction behavior of copper-iron contacts

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1978-01-01

    Sliding friction experiments were conducted with an iron rider on a copper disk and a copper rider on an iron disk. The sputter cleaned iron and copper disk surfaces were saturated with oxygen, methyl mercaptan, and methyl chloride at atmospheric pressure. Auger emission spectroscopy was used to monitor the surfaces. Lower friction was obtained in all experiments with the copper rider sliding on the iron disk than when the couple was reversed. For both iron and copper disks, methyl mercaptan gave the best surface coverage and was most effective in reducing friction. For both iron and copper disks, methyl chloride was the least effective in reducing friction. With sliding, copper transferred to iron and iron to copper.

  7. Inhibitory effect of betel quid on the volatility of methyl mercaptan.

    PubMed

    Wang, C K; Chen, S L; Wu, M G

    2001-04-01

    Betel quid, a popular natural masticatory in Taiwan, is mainly composed of fresh areca fruit, Piper betle (leaf or inflorescence), and slaked lime paste. People say that halitosis disappears during betel quid chewing. In this study, the removal of mouth odor during betel quid chewing was discussed by using a model system which measured its inhibition on the volatility of methyl mercaptan. Results showed that crude extracts of betel quid (the mixture of areca fruit, Piper betle, and slaked lime paste) and extracts of the mixture of areca fruit and slaked lime paste exhibited marked effects on the volatility of methyl mercaptan, and the inhibition function increased when increasing amounts of slaked lime paste were added. The same condition (increased inhibition) was also found by replacing the slaked lime paste with alkaline salts (calcium hydroxide, potassium hydroxide, or sodium hydroxide). Areca fruit, the major ingredient of betel quid, contained abundant phenolics. However, the crude phenolic extract of areca fruit did not show any inhibitory activity on the volatility of methyl mercaptan. Great inhibitory activity occurred only when the crude phenolic extract of areca fruit was treated with alkali. Further studies by using gel filtration determined that the effect probably came from the oxidative polymerization of phenolics of areca fruit after alkaline treatment.

  8. Porphyromonas gingivalis hydrogen sulfide enhances methyl mercaptan-induced pathogenicity in mouse abscess formation.

    PubMed

    Nakamura, Suguru; Shioya, Koki; Hiraoka, B Yukihiro; Suzuki, Nao; Hoshino, Tomonori; Fujiwara, Taku; Yoshinari, Nobuo; Ansai, Toshihiro; Yoshida, Akihiro

    2018-04-01

    Porphyromonas gingivalis produces hydrogen sulfide (H2S) from l-cysteine. However, the role of H2S produced by P. gingivalis in periodontal inflammation is unclear. In this study, we identified the enzyme that catalyses H2S production from l-cysteine and analysed the role of H2S using a mouse abscess model. The enzyme identified was identical to methionine γ-lyase (PG0343), which produces methyl mercaptan (CH3SH) from l-methionine. Therefore, we analysed H2S and CH3SH production by P. gingivalis W83 and a PG0343-deletion mutant (ΔPG0343) with/without l-cysteine and/or l-methionine. The results indicated that CH3SH is produced constitutively irrespective of the presence of l-methionine, while H2S was greatly increased by both P. gingivalis W83 and ΔPG0343 in the presence of l-cysteine. In contrast, CH3SH production by ΔPG0343 was absent irrespective of the presence of l-methionine, and H2S production was eliminated in the absence of l-cysteine. Thus, CH3SH and H2S production involves different substrates, l-methionine or l-cysteine, respectively. Based on these characteristics, we analysed the roles of CH3SH and H2S in abscess formation in mice by P. gingivalis W83 and ΔPG0343. Abscess formation by P. gingivalis W83, but not ΔPG0343, differed significantly in the presence and absence of l-cysteine. In addition, the presence of l-methionine did not affect the size of abscesses generated by P. gingivalis W83 and ΔPG0343. Therefore, we conclude that H2S produced by P. gingivalis does not induce inflammation; however, H2S enhances inflammation caused by CH3SH. Thus, these results suggest the H2S produced by P. gingivalis plays a supportive role in inflammation caused by methionine γ-lyase.

  9. High-resolution Fourier transform synchrotron spectroscopy of the C-S stretching band of methyl mercaptan, CH332SH

    NASA Astrophysics Data System (ADS)

    Lees, R. M.; Xu, Li-Hong; Billinghurst, B. E.

    2016-01-01

    The C-S stretching fundamental band of 12CH332SH, the principal isotopologue of methyl mercaptan, has been investigated by Fourier transform infrared spectroscopy on the Far-Infrared beamline at the Canadian Light Source synchrotron. The band is centered around 710 cm-1 and shows well-resolved a-type parallel structure. Most of the A and E spectral sub-bands have been assigned up to K = 12 for the vt = 0 torsional state and K = 9 for the vt = 1 state, along with a smaller variety of sub-bands for vt = 2. C-S stretching energy term values have been determined employing known ground-state energies, and have been fitted to series expansions in powers of J(J + 1) to determine the substate origins. The origins have in turn been fitted to a Fourier model to characterize the oscillatory torsional energy structure of the C-S stretching state. The amplitude of oscillation of the vt = 0 torsional curves is significantly larger for the C-S stretch state compared to the ground state. A strategy devised to relate this amplitude to an effective torsional barrier height indicates a decrease of about 7% in the effective V3 for the C-S stretch. The vibrational frequency determined for the stretching fundamental from the Fourier fit is 710.3 cm-1. The C-S stretching manifold is crossed by excited vt = 4 torsional levels of the ground state, and strong torsion-vibrational resonant coupling is observed via perturbations in the spectrum together with forbidden sub-bands induced by mixing and intensity borrowing.

  10. Terahertz and far-infrared synchrotron spectroscopy and global modeling of methyl mercaptan, CH332SH

    NASA Astrophysics Data System (ADS)

    Xu, Li-Hong; Lees, R. M.; Crabbe, G. T.; Myshrall, J. A.; Müller, H. S. P.; Endres, C. P.; Baum, O.; Lewen, F.; Schlemmer, S.; Menten, K. M.; Billinghurst, B. E.

    2012-09-01

    In this work, terahertz and Fourier transform far-infrared (FTFIR) synchrotron spectra of methyl mercaptan, CH3SH, have been investigated in order to provide new laboratory information for enhanced observations of this species in interstellar molecular clouds and star-forming regions. Like its methanol cousin, methyl mercaptan has particularly rich spectra associated with its large-amplitude internal rotation that extend throughout the THz and FIR regions. We have recorded new spectra for CH3SH from 1.1-1.5 and 1.790-1.808 THz at the University of Cologne as well as high-resolution FTFIR synchrotron spectra from 50-550 cm-1 at 0.001 cm-1 resolution on the far-IR beam-line at the Canadian Light Source. Assignments are reported for rotational quantum numbers up to J ≈ 40 and K ≈ 15, and torsional states up to vt = 2 for the THz measurements and vt = 3 for the FTFIR observations. The THz and FTFIR measurements together with literature results have been combined in a global analysis of a dataset comprising a total of 1725 microwave and THz frequencies together with ˜18000 FTFIR transitions, ranging up to vt = 2 and Jmax = 30 for MW/THz and 40 for FTFIR. The global fit employs 78 torsion-rotation parameters and has achieved a weighted standard deviation of ˜1.1. A prediction list (vt ≤ 2, J ≤ 45 and K ≤ 20) has been generated from the model giving essentially complete coverage of observable CH332SH transitions within the bandwidths of major new astronomical facilities such as HIFI (Heterodyne Instrument for the Far Infrared) on the Herschel Space Observatory, ALMA (Atacama Large Millimeter Array), SOFIA (Stratospheric Observatory For Infrared Astronomy) and APEX (Atacama Pathfinder Experiment) to close to spectroscopic accuracy.

  11. Effects of aeration and leachate recirculation on methyl mercaptan emissions from landfill.

    PubMed

    Zhang, Siyuan; Long, Yuyang; Fang, Yuan; Du, Yao; Liu, Weijia; Shen, Dongsheng

    2017-10-01

    The issue of odorous volatile organic sulfur compound methyl mercaptan (MM) released from landfill sites cannot be ignored for its extremely low odor threshold and high toxicity. In this study, we focused on the formation and emission of MM in four lab-scaled simulated landfill reactors running in different operation modes, namely, R1 and R2, without leachate recirculation, running under anaerobic and semi-aerobic atmosphere, R3 and R4, with leachate recirculation, running under anaerobic and semi-aerobic atmosphere, respectively. From the perspective of odor abatement, the semi-aerobic operation mode can efficiently lower the emitted MM concentration by 87.4-94.9%, relative to the semi-aerobic operation mode. Furthermore, under semi-aerobic conditions, leachate recirculation substantially shortened the period of MM influence by 12.7%, thus reducing the risk of affecting the surrounding atmospheric environment. The formation of MM was dependent on the characteristics such as the volatile fatty acid concentration and chemical oxygen demand in the leachate and sulfide concentration of the refuse. Overall, MM release can be effectively controlled with semi-aerobic operation mode and leachate recirculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Optical bio-sniffer for methyl mercaptan in halitosis.

    PubMed

    Mitsubayashi, Kohji; Minamide, Takeshi; Otsuka, Kimio; Kudo, Hiroyuki; Saito, Hirokazu

    2006-07-28

    An optical bio-sniffer for methyl mercaptan (MM) one of major odorous chemicals in halitosis (bad breath) was constructed by immobilizing monoamine oxidase type A (MAO-A) onto a tip of a fiber optic oxygen sensor (od: 1.59 mm) with an oxygen sensitive ruthenium organic complex (excitation: 470 nm, fluorescent: 600 nm). A flow cell for circulating buffer solution was applied to rinse and clean the tip of the device like nasal mucosa. In order to amplify the bio-sniffer output, a substrate regeneration cycle caused by coupling MAO-A with l-ascorbic acid (AsA) as reducing reaction with reagent system was applied to the sensor system. After evaluating the sensor characteristics using a gas flow measurement system with a gas generator, the optical bio-sniffer was applied to expired gases from healthy male volunteers for halitosis analysis as a physiological application. The optical bio-sniffer was applied to detect the oxygen consumption induced by MAO-A enzymatic reaction (and AsA chemical reduction) with gaseous MM application. The bio-sniffer was calibrated against MM vapor from 8.7 to 11500 ppb with correlation coefficient of 0.977, including a MM threshold (200 ppb) of pathologic halitosis and the human sense of smell level 3.5 (10.0 ppb), with good gas-selectivity based on the MAO-A substrate specificity. As the result of the physiological application, the optical bio-sniffer could successfully monitor the MM level change in breath samples during daytime, which is consistent with the previously reported results.

  13. The method for on-site determination of trace concentrations of methyl mercaptan and dimethyl sulfide in air using a mobile mass spectrometer with atmospheric pressure chemical ionization, combined with a fast enrichment/separation system.

    PubMed

    Kudryavtsev, Andrey S; Makas, Alexey L; Troshkov, Mikhail L; Grachev, Mikhail А; Pod'yachev, Sergey P

    2014-06-01

    A method for fast simultaneous on-site determination of methyl mercaptan and dimethyl sulfide in air was developed. The target compounds were actively collected on silica gel, followed by direct flash thermal desorption, fast separation on a short chromatographic column and detection by means of mass spectrometer with atmospheric pressure chemical ionization. During the sampling of ambient air, water vapor was removed with a Nafion selective membrane. A compact mass spectrometer prototype, which was designed earlier at Trofimuk Institute of Petroleum Geology and Geophysics, was used. The minimization of gas load of the atmospheric pressure ion source allowed reducing the power requirements and size of the vacuum system and increasing its ruggedness. The measurement cycle is about 3 min. Detection limits in a 0.6 L sample are 1 ppb for methyl mercaptan and 0.2 ppb for dimethyl sulfide. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Sulfur Hydrogen Bonding in Isolated Monohydrates: Furfuryl Mercaptan versus Furfuryl Alcohol.

    PubMed

    Juanes, Marcos; Lesarri, Alberto; Pinacho, Ruth; Charro, Elena; Rubio, José E; Enríquez, Lourdes; Jaraíz, Martín

    2018-05-02

    The hydrogen bonds involving sulfur in the furfuryl mercaptan monohydrate are compared with the interactions originating from the hydroxyl group in furfuryl alcohol. The dimers with water were created in a supersonic jet expansion and characterized using microwave spectroscopy and supporting molecular orbital calculations. In furfuryl alcohol-water, a single isomer is observed, in which the water molecule forms an insertion complex with two simultaneous hydrogen bonds to the alcohol (O-H⋅⋅⋅O w ) and the ring oxygen (O w -H⋅⋅⋅O r ). When the alcohol is replaced by a thiol group in furfuryl mercaptan-water, two isomers are observed, with the thiol group preferentially behaving as proton donor to water. The first isomer is topologically equivalent to the alcohol analog but the stronger hydrogen bond is now established by water and the ring oxygen, assisted by a thiol S-H⋅⋅⋅O w hydrogen bond. In the second isomer the sulfur group accepts a proton from water, forming a O w -H⋅⋅⋅S hydrogen bond. Binding energies for the mercaptan-water dimer are predicted around 12 kJ mol -1 weaker than in the alcohol hydrate (B3LYP-D3(BJ)). The non-covalent interactions in the furfuryl dimers are dominantly electrostatic according to a SAPT(0) energy decomposition, but with increasing dispersion components in the mercaptan dimers, which are larger for the isomer with the weaker O w -H⋅⋅⋅S interaction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Synthesis Of [2h, 13c] And [2h3, 13c]Methyl Aryl Sulfides

    DOEpatents

    Martinez, Rodolfo A.; Alvarez, Marc A.; Silks, III, Louis A.; Unkefer, Clifford J.

    2004-03-30

    The present invention is directed to labeled compounds, [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfides wherein the .sup.13 C methyl group attached to the sulfur of the sulfide includes exactly one, two or three deuterium atoms and the aryl group is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are each independently, hydrogen, a C.sub.1 -C.sub.4 lower alkyl, a halogen, an amino group from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each a C.sub.1 -C.sub.4 lower alkyl, a phenyl, or an alkoxy group. The present invention is also directed to processes of preparing [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2,.sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfides wherein the .sup.13 C methyl group attached to the sulfur of the sulfide includes exactly one, two or three deuterium atoms. The present invention is also directed to the labeled compounds of [.sup.2 H.sub.1, .sup.13 C]methyl iodide and [.sup.2 H.sub.2, .sup.13 C]methyl iodide.

  16. Degradation of ethyl mercaptan and its major intermediate diethyl disulfide by Pseudomonas sp. strain WL2.

    PubMed

    Wang, Xiangqian; Wu, Chao; Liu, Nan; Li, Sujing; Li, Wei; Chen, Jianmeng; Chen, Dongzhi

    2015-04-01

    A Pseudomonas sp. strain WL2 that is able to efficiently metabolize ethyl mercaptan (EM) into diethyl disulfide (DEDS) through enzymatic oxidation was isolated from the activated sludge of a pharmaceutical wastewater plant. One hundred percent removal of 113.5 mg L(-1) EM and 110.3 mg L(-1) DEDS were obtained within 14 and 32 h, respectively. A putative EM degradation pathway that involved the catabolism via DEDS was proposed, which indicated DEDS were further mineralized into carbon dioxide (CO2), bacterial cells, and sulfate (SO4 (2-)) through the transformation of element sulfur and ethyl aldehyde. Degradation kinetics for EM and DEDS with different initial concentrations by strain WL2 were evaluated using Haldane-Andrews model with maximum specific degradation rates of 3.13 and 1.33 g g(-1) h(-1), respectively, and maximum degradation rate constants of 0.522 and 0.175 h(-1) using pseudo-first-order kinetic model were obtained. Results obtained that aerobic degradation of EM by strain WL2 was more efficient than those from previous studies. Substrate range studies of strain WL2 demonstrated its ability to degrade several mercaptans, disulfides, aldehydes, and methanol. All the results obtained highlight the potential of strain WL2 for the use in the biodegradation of volatile organic sulfur compounds (VOSCs).

  17. Investigating the effects of alkali metal Na addition on catalytic activity of HZSM-5 for methyl mercaptan elimination

    NASA Astrophysics Data System (ADS)

    Yu, Jie; He, Dedong; Chen, Dingkai; Liu, Jiangping; Lu, Jichang; Liu, Feng; Liu, Pan; Zhao, Yutong; Xu, Zhizhi; Luo, Yongming

    2017-10-01

    Na-modified HZSM-5 catalysts with different Na loading amounts were prepared by incipient-wetness impregnation method and their catalytic activities for methyl mercaptan catalytic elimination were analyzed. XRD, N2 adsorption-desorption, NH3-TPD, CO2-TPD and FT-IR measurements were carried out to investigate the effects of modification of alkali metal Na on the physicochemical properties of the HZSM-5 zeolite catalyst. Research results illustrated that the introduction of alkali metal Na can improve catalytic activity for CH3SH catalytic elimination. CH3SH can be almost completely converted over 3%-Na/HZSM-5 at 450 °C compared to pure HZSM-5 at 600 °C based on our experimental results and the results from previous research. The improved catalytic activity could be attributed to the regulated acid-base properties of the HZSM-5 catalysts by doping with alkali metal Na. High alkali concentration treatment, however, may destroy the framework structure of the catalyst sample, thus causing the poor stability performance of the obtained catalyst.

  18. Pure Rotational Spectroscopy of Vinyl Mercaptan

    NASA Astrophysics Data System (ADS)

    Martin-Drumel, Marie-Aline; Zingsheim, Oliver; Thorwirth, Sven; Müller, Holger S. P.; Lewen, Frank; Schlemmer, Stephan

    2014-06-01

    Vinyl mercaptan (ethenethiol, CH_2=CHSH) exists in the gas phase in two distinct rotameric forms, syn (planar) and anti (quasi-planar in the ground vibrational state). The microwave spectra of these two isomers were investigated previously, however not exceeding frequencies of about 65 GHz. In the present investigation, the pure rotational spectra of both species have been investigated at millimeter wavelengths. Vinyl mercaptan was produced in a radiofrequency discharge through a constant flow of ethanedithiol at low pressure. Both syn and anti rotamers were observed and new extensive sets of molecular parameters were obtained. Owing to its close structural relationship to vinyl alcohol and the astronomical abundance of complex sulfur-bearing molecules, vinyl mercaptan is a plausible candidate for future radio astronomical searches. M. Tanimoto et al. J. Mol. Spectrosc. 78, 95--105 & 106--119 (1979)

  19. Apparatus and method for production of methanethiol

    DOEpatents

    Agarwal, Pradeep K.; Linjewile, Temi M.; Hull, Ashley S.; Chen, Zumao

    2006-02-07

    A method for the production of methyl mercaptan is provided. The method comprises providing raw feed gases consisting of methane and hydrogen sulfide, introducing the raw feed gases into a non-thermal pulsed plasma corona reactor, and reacting the raw feed gases within the non-thermal pulsed plasma corona reactor with the reaction CH4+H2S.fwdarw.CH3SH+H2. An apparatus for the production of methyl mercaptan using a non-thermal pulsed plasma corona reactor is also provided.

  20. Synthesis Of [2h, 13c]M [2h2m 13c], And [2h3,, 13c] Methyl Aryl Sulfones And Sulfoxides

    DOEpatents

    Martinez, Rodolfo A.; Alvarez, Marc A.; Silks, III, Louis A.; Unkefer, Clifford J.; Schmidt, Jurgen G.

    2004-07-20

    The present invention is directed to labeled compounds, [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfones and [.sup.2 H.sub.1, .sup.13 C], [.sup.2 H.sub.2, .sup.13 C] and [.sup.2 H.sub.3, .sup.13 C]methyl aryl sulfoxides, wherein the .sup.13 C methyl group attached to the sulfur of the sulfone or sulfoxide includes exactly one, two or three deuterium atoms and the aryl group is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently, hydrogen, a C.sub.1 -C.sub.4 lower alkyl, a halogen, an amino group from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each a C.sub.1 -C.sub.4 lower alkyl, a phenyl, or an alkoxy group. The present invention is also directed to processes of preparing methyl aryl sulfones and methyl aryl sulfoxides.

  1. IGF2 DNA methylation is a modulator of newborn’s fetal growth and development

    PubMed Central

    St-Pierre, Julie; Hivert, Marie-France; Perron, Patrice; Poirier, Paul; Guay, Simon-Pierre; Brisson, Diane; Bouchard, Luigi

    2012-01-01

    The insulin-like growth factor 2 (IGF2) gene, located within a cluster of imprinted genes on chromosome 11p15, encodes a fetal and placental growth factor affecting birth weight. DNA methylation variability at the IGF2 gene locus has been previously reported but its consequences on fetal growth and development are still mostly unknown in normal pediatric population. We collected one hundred placenta biopsies from 50 women with corresponding maternal and cord blood samples and measured anthropometric indices, blood pressure and metabolic phenotypes using standardized procedures. IGF2/H19 DNA methylation and IGF2 circulating levels were assessed using sodium bisulfite pyrosequencing and ELISA, respectively. Placental IGF2 (DMR0 and DMR2) DNA methylation levels were correlated with newborn’s fetal growth indices, such as weight, and with maternal IGF2 circulating concentration at the third trimester of pregnancy, whereas H19 (DMR) DNA methylation levels were correlated with IGF2 levels in cord blood. The maternal genotype of a known IGF2/H19 polymorphism (rs2107425) was associated with birth weight. Taken together, we showed that IGF2/H19 epigenotype and genotypes independently account for 31% of the newborn’s weight variance. No association was observed with maternal diabetic status, glucose concentrations or prenatal maternal body mass index. This is the first study showing that DNA methylation at the IGF2/H19 genes locus may act as a modulator of IGF2 newborn’s fetal growth and development within normal range. IGF2/H19 DNA methylation could represent a cornerstone in linking birth weight and fetal metabolic programming of late onset obesity. PMID:22907587

  2. DNA methylation modulates H19 and IGF2 expression in porcine female eye

    PubMed Central

    Wang, Dongxu; Wang, Guodong; Yang, Hao; Liu, Haibo; Li, Cuie; Li, Xiaolan; Lin, Chao; Song, Yuning; Li, Zhanjun; Liu, Dianfeng

    2017-01-01

    Abstract The sexually dimorphic expression of H19/IGF2 is evolutionarily conserved. To investigate whether the expression of H19/IGF2 in the female porcine eye is sex-dependent, gene expression and methylation status were evaluated using quantitative real-time PCR (qPCR) and bisulfite sequencing PCR (BSP). We hypothesized that H19/IGF2 might exhibit a different DNA methylation status in the female eye. In order to evaluate our hypothesis, parthenogenetic (PA) cells were used for analysis by qPCR and BSP. Our results showed that H19 and IGF2 were over-expressed in the female eye compared with the male eye (3-fold and 2-fold, respectively). We observed a normal monoallelic methylation pattern for H19 differentially methylated regions (DMRs). Compared with H19 DMRs, IGF2 DMRs showed a different methylation pattern in the eye. Taken together, these results suggest that elevated expression of H19/IGF2 is caused by a specific chromatin structure that is regulated by the DNA methylation status of IGF2 DMRs in the female eye. PMID:28266684

  3. Extraction of heavy metals by mercaptans attached to silica gel by a corkscrew mechanism.

    PubMed

    Bowe, Craig A; Benson, Robert F; Martin, Dean F

    2002-09-01

    Saturated, straight chain mercaptans were attached to silica gel and used as coordinating agents for removal of cadmium(II), copper(II), lead(II), and nickel(II) ions from standard solutions. It is believed that the mercaptans become wedged in the silica pores, but are available for reaction. Four thiols were used, viz., 1-hexanethiol, 1-dodecanethiol, 1-hexadecanethiol, and 1-octadecanethiol. Standard solutions of metals (1.57 mM) were stirred with the supported mercaptans for two hours, and at 25 degrees C, and the sample supernatants were analyzed using atomic absorption spectrometry. At pH = 8, the percent removal was 99 (Cd), 91.5 (Cu), 80.8 (Pb), and 97 (Ni). It was possible to acidify the metal-containing solids, and regenerate the supported chelating agents.

  4. Glutamine methylation in histone H2A is an RNA-polymerase-I-dedicated modification

    NASA Astrophysics Data System (ADS)

    Tessarz, Peter; Santos-Rosa, Helena; Robson, Sam C.; Sylvestersen, Kathrine B.; Nelson, Christopher J.; Nielsen, Michael L.; Kouzarides, Tony

    2014-01-01

    Nucleosomes are decorated with numerous post-translational modifications capable of influencing many DNA processes. Here we describe a new class of histone modification, methylation of glutamine, occurring on yeast histone H2A at position 105 (Q105) and human H2A at Q104. We identify Nop1 as the methyltransferase in yeast and demonstrate that fibrillarin is the orthologue enzyme in human cells. Glutamine methylation of H2A is restricted to the nucleolus. Global analysis in yeast, using an H2AQ105me-specific antibody, shows that this modification is exclusively enriched over the 35S ribosomal DNA transcriptional unit. We show that the Q105 residue is part of the binding site for the histone chaperone FACT (facilitator of chromatin transcription) complex. Methylation of Q105 or its substitution to alanine disrupts binding to FACT in vitro. A yeast strain mutated at Q105 shows reduced histone incorporation and increased transcription at the ribosomal DNA locus. These features are phenocopied by mutations in FACT complex components. Together these data identify glutamine methylation of H2A as the first histone epigenetic mark dedicated to a specific RNA polymerase and define its function as a regulator of FACT interaction with nucleosomes.

  5. New Synthesis, Structure and Analgesic Properties of Methyl 1-R-4-Methyl-2,2-Dioxo-1H-2λ⁶,1-Benzothiazine-3-Carboxylates.

    PubMed

    Azotla-Cruz, Liliana; Lijanova, Irina V; Ukrainets, Igor V; Likhanova, Natalya V; Olivares-Xometl, Octavio; Bereznyakova, Natalya L

    2017-01-12

    According to the principles of the methodology of bioisosteric replacements a series of methyl 1-R-4-methyl-2,2-dioxo-1 H -2λ⁶,1-benzothiazine-3-carboxylates has been obtained as potential analgesics. In addition, a fundamentally new strategy for the synthesis of compounds of this chemical class involving the introduction of N -alkyl substituent at the final stage in 2,1-benzothiazine nucleus already formed has been proposed. Using nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and X-ray diffraction analysis it has been proven that in the DMSO/K₂CO₃ system the reaction of methyl 4-methyl-2,2-dioxo-1 H -2λ⁶,1-benzothiazine-3-carboxylate and alkyl halides leads to formation of N -substituted derivatives with good yields regardless of the structure of the alkylating agent. The peculiarities of NMR (¹Н and 13 С) spectra of the compounds synthesized, their mass spectrometric behavior and the spatial structure are discussed. In N -benzyl derivative the ability to form a monosolvate with methanol has been found. According to the results of the pharmacological testing conducted on the model of the thermal tail-flick it has been determined that replacement of 4-ОН-group in methyl 1-R-4-hydroxy-2,2-dioxo-1 H -2λ⁶,1-benzothiazine-3-carboxylates for the methyl group is actually bioisosteric since all methyl 1-R-4-methyl-2,2-dioxo-1 H -2λ⁶,1-benzothiazine-3-carboxylates synthesized demonstrated a statistically significant analgesic effect. The majority of the substances can inhibit the thermal pain response much more effective than piroxicam in the same dose. Under the same conditions as an analgesic the N- methyl-substituted analog exceeds not only piroxicam, but more active meloxicam as well. Therefore, it deserves in-depth biological studies on other experimental models.

  6. Community health assessment following mercaptan spill: Eight Mile, Mobile County, Alabama, September 2012.

    PubMed

    Behbod, Behrooz; Parker, Erin M; Jones, Erin A; Bayleyegn, Tesfaye; Guarisco, John; Morrison, Melissa; McIntyre, Mary G; Knight, Monica; Eichold, Bert; Yip, Fuyuen

    2014-01-01

    In 2008, a lightning strike caused a leak of tert-butyl mercaptan from its storage tank at the Gulf South Natural Gas Pumping Station in Prichard, Alabama. On July 27, 2012, the Alabama Department of Public Health requested Centers for Disease Control and Prevention epidemiologic assistance investigating possible health effects resulting from airborne exposure to mercaptan from a contaminated groundwater spring, identified in January 2012. To assess the self-reported health effects in the community, to determine the scope of the reported medical services received, and to develop recommendations for prevention and response to future incidents. In September 2012, we performed a representative random sampling design survey of households, comparing reported exposures and health effects among residents living in 2 circular zones located within 1 and 2 miles from the contaminated source. Eight Mile community, Prichard, Alabama. We selected 204 adult residents of each household (≥ 18 years) to speak for all household members. Self-reported mercaptan odor exposure, physical and mental health outcomes, and medical-seeking practices, comparing residents in the 1- and 2-mile zones. In the past 6 months, 97.9% of respondents in the 1-mile zone and 77.6% in the 2-mile zone reported mercaptan odors. Odor severity was greater in the 1-mile zone, in which significantly more subjects reported exposures aggravating their physical and mental health including shortness of breath, eye irritations, and agitated behavior. Overall, 36.5% sought medical care for odor-related symptoms. Long-term odorous mercaptan exposures were reportedly associated with physical and psychological health complaints. Communication messages should include strategies to minimize exposures and advise those with cardiorespiratory conditions to have medications readily available. Health care practitioners should be provided information on mercaptan health effects and approaches to prevent exacerbating existing

  7. Chromatin signaling to kinetochores: Trans-regulation of Dam1 methylation by histone H2B ubiquitination

    PubMed Central

    Latham, John A.; Chosed, Renée J.; Wang, Shanzhi; Dent, Sharon Y.R.

    2011-01-01

    Summary Histone H3K4 trimethylation by the Set1/MLL family of proteins provides a hallmark for transcriptional activity from yeast to humans. In S. cerevisiae, H3K4 methylation is mediated by the Set1-containing COMPASS complex and is regulated in trans by prior ubiquitination of histone H2BK123. All of the events that regulate H2BK123ub and H3K4me are thought to occur at gene promoters. Here we report that this pathway is indispensable for methylation of the only other known substrate of Set1, K233 in Dam1, at kinetochores. Deletion of RAD6, BRE1, or Paf1 complex members abolishes Dam1 methylation, as does mutation of H2BK123. Our results demonstrate that Set1-mediated methylation is regulated by a general pathway regardless of substrate that is composed of transcriptional regulatory factors functioning independently of transcription. Moreover, our data identify a node of regulatory cross-talk in trans between a histone modification and modification on a non-histone protein, demonstrating that changing chromatin states can signal functional changes in other essential cellular proteins and machineries. PMID:21884933

  8. Practical Methylation Procedure for (1H)-1,2,4-Triazole (Postprint)

    DTIC Science & Technology

    2007-09-01

    Francis Group, LLC. 14. ABSTRACT Conversion of (1H)-1,2,4-triazole to its sodium salt with methanolic sodium methoxide is followed by reaction ...From - To) 04-06-2007 Journal Article 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Practical Methylation Procedure for (1H)-1,2,4-Triazole (Postprint...continuous extraction (chloroform/water) with a final short-path distillation under a controlled vacuum to obtain spectroscopically pure 1- methyl -1,2,4

  9. The histone H3 variant H3.3 regulates gene body DNA methylation in Arabidopsis thaliana.

    PubMed

    Wollmann, Heike; Stroud, Hume; Yelagandula, Ramesh; Tarutani, Yoshiaki; Jiang, Danhua; Jing, Li; Jamge, Bhagyshree; Takeuchi, Hidenori; Holec, Sarah; Nie, Xin; Kakutani, Tetsuji; Jacobsen, Steven E; Berger, Frédéric

    2017-05-18

    Gene bodies of vertebrates and flowering plants are occupied by the histone variant H3.3 and DNA methylation. The origin and significance of these profiles remain largely unknown. DNA methylation and H3.3 enrichment profiles over gene bodies are correlated and both have a similar dependence on gene transcription levels. This suggests a mechanistic link between H3.3 and gene body methylation. We engineered an H3.3 knockdown in Arabidopsis thaliana and observed transcription reduction that predominantly affects genes responsive to environmental cues. When H3.3 levels are reduced, gene bodies show a loss of DNA methylation correlated with transcription levels. To study the origin of changes in DNA methylation profiles when H3.3 levels are reduced, we examined genome-wide distributions of several histone H3 marks, H2A.Z, and linker histone H1. We report that in the absence of H3.3, H1 distribution increases in gene bodies in a transcription-dependent manner. We propose that H3.3 prevents recruitment of H1, inhibiting H1's promotion of chromatin folding that restricts access to DNA methyltransferases responsible for gene body methylation. Thus, gene body methylation is likely shaped by H3.3 dynamics in conjunction with transcriptional activity.

  10. Fourier transformation microwave spectroscopy of the methyl glycolate-H2O complex

    NASA Astrophysics Data System (ADS)

    Fujitake, Masaharu; Tanaka, Toshihiro; Ohashi, Nobukimi

    2018-01-01

    The rotational spectrum of one conformer of the methyl glycolate-H2O complex has been measured by means of the pulsed jet Fourier transform microwave spectrometer. The observed a- and b-type transitions exhibit doublet splittings due to the internal rotation of the methyl group. On the other hand, most of the c-type transitions exhibit quartet splittings arising from the methyl internal rotation and the inversion motion between two equivalent conformations. The spectrum was analyzed using parameterized expressions of the Hamiltonian matrix elements derived by applying the tunneling matrix formalism. Based on the results obtained from ab initio calculation, the observed complex of methyl glycolate-H2O was assigned to the most stable conformer of the insertion complex, in which a non-planer seven membered-ring structure is formed by the intermolecular hydrogen bonds between methyl glycolate and H2O subunits. The inversion motion observed in the c-type transitions is therefore a kind of ring-inversion motion between two equivalent conformations. Conformational flexibility, which corresponds to the ring-inversion between two equivalent conformations and to the isomerization between two possible conformers of the insertion complex, was investigated with the help of the ab initio calculation.

  11. Antioxidant and Antimicrobial Activity of 5-methyl-2-(5-methyl-1,3-diphenyl-1H-pyrazole-4-carbonyl)-2,4-dihydro-pyrazol-3-one

    PubMed Central

    Umesha, K. B.; Rai, K. M. L.; Harish Nayaka, M. A.

    2009-01-01

    Cycloaddition of nitrile imines 4 generated in situ by the catalytic dehydrogenation of diphenyl hydrazones 3 using Chloramine-T (CAT) as oxidant in glacial acetic acid with enolic form of ethyl acetoacetate 5 afforded Ethyl 3-aryl-5-methyl-1-phenyl-1H-pyrazol-4-carboxylate 6 in 80% yield. The said pyrazoles 6 refluxed with 80% hydrazine hydrate using absolute alcohol as solvent for about 2–3 hours to produce the respective 5-methyl-1,3-diphenyl-1H-pyrazole-4-carboxylic acid hydrazide 7. The alcoholic solution of pyrazole acid hydrazides on heating with ethyl acetoacetate 5 to give the 5-methyl-2-(5-methyl-1,3-diphenyl-1H-pyrazole-4-carbonyl)-2,4-dihydro-pyrazol-3-one 8. The synthesized compounds were found to exhibit good antimicrobial and antioxidant activity as evaluated by 1,1-diphenyl-2-picryl Hydrazyl (DPPH) radical scavenging, reducing power and DNA protection assays. PMID:23675159

  12. DNA methylation of the IGF2/H19 imprinting control region and adiposity distribution in young adults

    PubMed Central

    2012-01-01

    Background The insulin-like growth factor 2 (IGF2) and H19 imprinted genes control growth and body composition. Adverse in-utero environments have been associated with obesity-related diseases and linked with altered DNA methylation at the IGF2/H19 locus. Postnatally, methylation at the IGF2/H19 imprinting control region (ICR) has been linked with cerebellum weight. We aimed to investigate whether decreased IGF2/H19 ICR methylation is associated with decreased birth and childhood anthropometry and increased contemporaneous adiposity. DNA methylation in peripheral blood (n = 315) at 17 years old was measured at 12 cytosine-phosphate-guanine sites (CpGs), analysed as Sequenom MassARRAY EpiTYPER units within the IGF2/H19 ICR. Birth size, childhood head circumference (HC) at six time-points and anthropometry at age 17 years were measured. DNA methylation was investigated for its association with anthropometry using linear regression. Results The principal component of IGF2/H19 ICR DNA methylation (representing mean methylation across all CpG units) positively correlated with skin fold thickness (at four CpG units) (P-values between 0.04 to 0.001) and subcutaneous adiposity (P = 0.023) at age 17, but not with weight, height, BMI, waist circumference or visceral adiposity. IGF2/H19 methylation did not associate with birth weight, length or HC, but CpG unit 13 to 14 methylation was negatively associated with HC between 1 and 10 years. β-coefficients of four out of five remaining CpG units also estimated lower methylation with increasing childhood HC. Conclusions As greater IGF2/H19 methylation was associated with greater subcutaneous fat measures, but not overall, visceral or central adiposity, we hypothesize that obesogenic pressures in youth result in excess fat being preferentially stored in peripheral fat depots via the IGF2/H19 domain. Secondly, as IGF2/H19 methylation was not associated with birth size but negatively with early childhood HC, we hypothesize that the

  13. Biotreatment of refinery spent-sulfidic caustic using an enrichment culture immobilized in a novel support matrix.

    PubMed

    Conner, J A; Beitle, R R; Duncan, K; Kolhatkar, R; Sublette, K L

    2000-01-01

    Sodium hydroxide solutions are used in petroleum refining to remove hydrogen sulfide (H2S) and mercaptans from various hydrocarbon streams. The resulting sulfide-laden waste stream is called spent-sulfidic caustic. An aerobic enrichment culture was previously developed using a gas mixture of H2S and methyl-mercaptan (MeSH) as the sole energy source. This culture has now been immobilized in a novel support matrix, DuPont BIO-SEP beads, and is used to bio-treat a refinery spent-sulfidic caustic containing both inorganic sulfide and mercaptans in a continuous flow, fluidized-bed column bioreactor. Complete oxidation of both inorganic and organic sulfur to sulfate was observed with no breakthrough of H2S and < 2 ppmv of MeSH produced in the bioreactor outlet gas. Excessive buildup of sulfate (> 12 g/L) in the bioreactor medium resulted in an upset condition evidenced by excessive MeSH breakthrough. Therefore, bioreactor performance was limited by the steady-state sulfate concentration. Further improvement in volumetric productivity of a bioreactor system based on this enrichment culture will be dependent on maintenance of sulfate concentrations below inhibitory levels.

  14. Theoretical spectroscopic characterization at low temperatures of detectable sulfur-organic compounds: Ethyl mercaptan and dimethyl sulfide

    NASA Astrophysics Data System (ADS)

    Senent, M. L.; Puzzarini, C.; Domínguez-Gómez, R.; Carvajal, M.; Hochlaf, M.

    2014-03-01

    Highly correlated ab initio methods are used for the spectroscopic characterization of ethyl mercaptan (CH3CH232SH, ETSH) and dimethyl sulfide (CH332SCH3, DMS), considering them on the vibrational ground and excited torsional states. Since both molecules show non-rigid properties, torsional energy barriers and splittings are provided. Equilibrium geometries and the corresponding rotational constants are calculated by means of a composite scheme based on CCSD(T) calculations that accounts for the extrapolation to the complete basis set limit and core-correlation effects. The ground and excited states rotational constants are then determined using vibrational corrections obtained from CCSD/cc-pVTZ force-field calculations, which are also employed to determine anharmonic frequencies for all vibrational modes. CCSD(T) and CCSD force fields are employed to predict quartic and sextic centrifugal-distortion constants, respectively. Equilibrium rotational constants are also calculated using CCSD(T)-F12. The full-dimensional anharmonic analysis does not predict displacements of the lowest torsional excited states due to Fermi resonances with the remaining vibrational modes. Thus, very accurate torsional transitions are calculated by solving variationally two-dimensional Hamiltonians depending on the CH3 and SH torsional coordinates of ethyl mercaptan or on the two methyl groups torsions of dimethyl-sulfide. For this purpose, vibrationally corrected potential energy surfaces are computed at the CCSD(T)/aug-cc-pVTZ level of theory. For ethyl mercaptan, calculations show large differences between the gauche (g) and trans (t) conformer spectral features. Interactions between rotating groups are responsible for the displacements of the g-bands with respect to the t-bands that cannot therefore be described with one-dimensional models. For DMS, the CCSD(T) potential energy surface has been semi-empirically adjusted to reproduce experimental data. New assignments are suggested for

  15. Syntheses, structures and characterization of isomorphous CoII and NiII coordination polymers based on 2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole and benzene-1,4-dicarboxylate.

    PubMed

    Huang, Qiu Ying; Zhao, Yang; Meng, Xiang Ru

    2017-08-01

    Careful choice of the organic ligands is one of the most important parameters in the rational design and synthesis of coordination polymers. Aromatic polycarboxylates have been widely used in the preparation of metal-organic polymers since they can utilize various coordination modes to form diverse structures and can act as hydrogen-bond acceptors and donors in the assembly of supramolecular structures. Nitrogen-heterocyclic organic compounds have also been used extensively as ligands for the construction of polymers with interesting structures. In the polymers catena-poly[[[diaquabis{2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole-κN 3 }cobalt(II)]-μ 2 -benzene-1,4-dicarboxylato-κ 2 O 1 :O 4 ] dihydrate], {[Co(C 8 H 4 O 4 )(C 12 H 11 N 4 ) 2 (H 2 O) 22H 2 O} n , (I), and catena-poly[[[diaquabis{2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole-κN 3 }nickel(II)]-μ 2 -benzene-1,4-dicarboxylato-κ 2 O 1 :O 4 ] dihydrate], {[Ni(C 8 H 4 O 4 )(C 12 H 11 N 4 ) 2 (H 2 O) 22H 2 O} n , (II), the Co II or Ni II ion lies on an inversion centre and exhibits a slightly distorted octahedral coordination geometry, coordinated by two N atoms from two imidazole rings and four O atoms from two monodentate carboxylate groups and two water molecules. The dicarboxylate ligands bridge metal ions forming a polymeric chain. The 2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole ligands coordinate to the Co II or Ni II centres in monodentate modes through an imidazole N atom and are pendant on opposite sides of the main chain. The two structures are isomorphous. In the crystal, the one-dimensional chains are further connected through O-H...O, O-H...N and N-H...O hydrogen bonds, leading to a three-dimensional supramolecular architecture. In addition, the IR spectroscopic properties, PXRD patterns, thermogravimetric behaviours and fluorescence properties of both polymers have been investigated.

  16. Crystal structure of [(2R,3R,4S)-3,4-bis(acet-yloxy)-5-iodo-3,4-di-hydro-2H-pyran-2-yl]methyl acetate.

    PubMed

    Zukerman-Schpector, Julio; Caracelli, Ignez; Stefani, Hélio A; Shamim, Anwar; Tiekink, Edward R T

    2015-01-01

    In the title compound, C12H15IO7, the 3,4-di-hydro-2H-pyran ring is in a distorted half-boat conformation with the atom bearing the acet-yloxy group adjacent to the C atom bearing the methyl-acetate group lying 0.633 (6) Å above the plane of the remaining ring atoms (r.m.s. deviation = 0.0907 Å). In the crystal, mol-ecules are linked into a supra-molecular chain along the a axis through two C-H⋯O inter-actions to the same acceptor carbonyl O atom; these chains pack with no specific inter-molecular inter-actions between them.

  17. EPR study of gamma irradiated N-methyl taurine (C3H9NO3S) and sodium hydrogen sulphate monohydrate (NaHSO3·H2O) single crystals.

    PubMed

    Yıldırım, Ilkay; Karabulut, Bünyamin

    2011-03-01

    EPR study of gamma irradiated C(3)H(9)NO(3)S and NaHSO(3).H(2)O single crystals have been carried out at room temperature. There is one site for the radicals in C(3)H(9)NO(3)S and two magnetically distinct sites for the radicals in NaHSO(3). The observed lines in the EPR spectra have been attributed to the species of SO(3)(-) and RH radicals for N-methyl taurine, and to the SO(3)(-) and OH radicals for sodium hydrogen sulfate monohydrate single crystals. The principal values of the g for SO(3)(-), the hyperfine values of RH and OH proton splitting have been calculated and discussed. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. A practical and improved synthesis of (3S,5S)-3-[(tert-butyloxycarbonyl)methyl]- 5-[(methanesulfonyloxy)methyl]-2- pyrrolidinone.

    PubMed

    Yee, Nathan K; Dong, Yong; Kapadia, Suresh R; Song, Jinhua J

    2002-11-29

    A practical and improved synthesis of (3S,5S)-3-[(tert-butyloxycarbonyl)methyl]-5-[(methanesulfonyloxy)methyl]-2-pyrrolidinone (1) is described. The key transformations involve a highly efficient reaction sequence consisting of ethoxycarbonylation, alkylation, hydrolysis, and decarboxylation to produce compound 10. The process described herein is practical, robust, and cost-effective, and it has been successfully implemented in a pilot plant to produce a multikilogram quantity of mesylate 1.

  19. Omeprazole, a specific inhibitor of gastric (H/sup +/-K/sup +/)-ATPase, is a H/sup +/-activated oxidizing agent of sulfhydryl groups

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Im, W.B.; Sih, J.C.; Blakeman, D.P.

    1985-04-25

    Omeprazole (5-methoxy-2-(((4-methoxy-3,5- dimethylpyridinyl)methyl)sulfinyl)-1H-benzimidazole) appeared to inhibit gastric (H/sup +/-K/sup +/)-ATPase by oxidizing its essential sulfhydryl groups, since the gastric ATPase inactivated by the drug in vivo or in vitro recovered its K+-dependent ATP hydrolyzing activity upon incubation with mercaptoethanol. Biological reducing agents like cysteine or glutathione, however, were unable to reverse the inhibitory effect of omeprazole. Moreover, acidic environments enhanced the potency of omeprazole. The chemical reactivity of omeprazole with mercaptans is also consistent with the biological action of omeprazole. The N-sulfenylated compound reacted at neutral pH with another stoichiometric amount of ethyl mercaptan to produce omeprazole sulfide quantitatively. Themore » gastric polypeptides of 100 kilodaltons representing (H/sup +/-K/sup +/)-ATPase in the rat gastric mucosa or isolated hog gastric membranes were covalently labeled with (/sup 14/C)omeprazole. The radioactive label bound to the ATPase, however, could not be displaced by mercaptoethanol under the identical conditions where the ATPase activity was fully restored. These observations suggest that the essential sulfhydryl groups which reacted with omeprazole did not form a stable covalent bond with the drug, but rather that they further reacted with adjacent sulfhydryl groups to form disulfides which could be reduced by mercaptoethanol.« less

  20. Exhaustive methylation analysis revealed uneven profiles of methylation at IGF2/ICR1/H19 11p15 loci in Russell Silver syndrome.

    PubMed

    Azzi, Salah; Steunou, Virginie; Tost, Jörg; Rossignol, Sylvie; Thibaud, Nathalie; Das Neves, Cristina; Le Jule, Marilyne; Habib, Walid Abi; Blaise, Annick; Koudou, Yves; Busato, Florence; Le Bouc, Yves; Netchine, Irène

    2015-01-01

    The structural organisation of the human IGF2/ICR1/H19 11p15 domain is very complex, and the mechanisms underlying its regulation are poorly understood. The Imprinted Center Region 1 (ICR1) contains seven binding sites for the zinc-finger protein CTCF (CBS: CTCF Binding Sites); three additional differentially methylated regions (DMR) are located at the H19 promoter (H19DMR) and two in the IGF2 gene (DMR0 and DMR2), respectively. Loss of imprinting at the IGF2/ICR1/H19 domain results in two growth disorders with opposite phenotypes: Beckwith-Wiedemann syndrome and Russell Silver syndrome (RSS). Despite the IGF2/ICR1/H19 locus being widely studied, the extent of hypomethylation across the domain remains not yet addressed in patients with RSS. We assessed a detailed investigation of the methylation status of the 11p15 ICR1 CBS1-7, IGF2DMR0 and H19DMR (H19 promoter) in a population of controls (n=50) and RSS carrying (n=104) or not (n=65) carrying a hypomethylation at the 11p15 ICR1 region. The methylation indexes (MI) were balanced at all regions in the control population and patients with RSS without any as yet identified molecular anomaly. Interestingly, patients with RSS with ICR1 hypomethylation showed uneven profiles of methylation among the CBSs and DMRs. Furthermore, normal MIs at CBS1 and CBS7 were identified in 9% of patients. The hypomethylation does not spread equally throughout the IGF2/ICR1/H19 locus, and some loci could have normal MI, which may lead to underdiagnosis of patients with RSS with ICR1 hypomethylation. The uneven pattern of methylation suggests that some CBSs may play different roles in the tridimensional chromosomal looping regulation of this locus. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. Design, synthesis and anticonvulsant activity of some new 6,8-halo-substituted-2h-[1,2,4]triazino[5,6-b]indole-3(5h)-one/-thione and 6,8-halo-substituted 5-methyl-2h-[1,2,4]triazino[5,6-b]indol-3(5h)-one/-thione

    PubMed Central

    Kumar, Rajeev; Singh, Tejendra; Singh, Hariram; Jain, Sandeep; Roy, R. K.

    2014-01-01

    A new series of 6,8-halo-substituted-2H-[1,2,4]triazino[5,6-b]indole-3(5H)-one/-thione and 6,8-halo-substituted 5-methyl-2H-[1,2,4]triazino[5,6-b]indol-3(5H)-one/-thione (5a-5l) were designed and synthesized keeping in view of the structural requirement of pharmacophore. The above compounds were characterized by thin layer chromatography and spectral analysis. Anticonvulsant activity of the synthesized compounds was evaluated by the maximal electroshock (MES) test. Neurotoxicity and CNS depressant effects were evaluated by the rotarod motor impairment and Porsolt’s force swim tests, respectively. A computational study was carried out, for calculation of pharmacophore pattern, prediction of pharmacokinetic properties and toxicity properties. The above study revealed that the compounds 8-chloro-2H-[1,2,4]triazino[5,6-b]indol-3(5H)-one (5e), 6,8-dibromo-2H-[1,2,4]triazino[5,6-b]indol-3(5H)-one (5i) and 6,8-dibromo-5-methyl-2H-[1,2,4]triazino[5,6-b]indol-3(5H)-one (5k) possess excellent anticonvulsant activity in the series with little CNS depressant effect and no neurotoxicity as compared to standard drugs phenytoin and carbamazepine. PMID:26417257

  2. Trimethylation of histone H3 lysine 4 impairs methylation of histone H3 lysine 9

    PubMed Central

    LeRoy, Gary; Bua, Dennis J; Garcia, Benjamin A; Gozani, Or; Richard, Stéphane

    2010-01-01

    Chromatin is broadly compartmentalized in two defined states: euchromatin and heterochromatin. Generally, euchromatin is trimethylated on histone H3 lysine 4 (H3K4me3) while heterochromatin contains the H3K9me3 mark. The H3K9me3 modification is added by lysine methyltransferases (KMTs) such as SETDB1. Herein, we show that SETDB1 interacts with its substrate H3, but only in the absence of the euchromatic mark H3K4me3. In addition, we show that SETDB1 fails to methylate substrates containing the H3K4me3 mark. Likewise, the functionally related H3K9 KMTs G9A, GLP and SUV39H1 also fail to bind and to methylate H3K4me3 substrates. Accordingly, we provide in vivo evidence that H3K9me2-enriched histones are devoid of H3K4me2/3 and that histones depleted of H3K4me2/3 have elevated H3K9me2/3. The correlation between the loss of interaction of these KMTs with H3K4me3 and concomitant methylation impairment leads to the postulate that at least these four KMTs require stable interaction with their respective substrates for optimal activity. Thus, novel substrates could be discovered via the identification of KMT interacting proteins. Indeed, we find that SETDB1 binds to and methylates a novel substrate, the inhibitor of growth protein ING2, while SUV39H1 binds to and methylates the heterochromatin protein HP1α. Thus, our observations suggest a mechanism of post-translational regulation of lysine methylation and propose a potential mechanism for the segregation of the biologically opposing marks, H3K4me3 and H3K9me3. Furthermore, the correlation between H3-KMTs interaction and substrate methylation highlights that the identification of novel KMT substrates may be facilitated by the identification of interaction partners. PMID:21124070

  3. Association of in vitro fertilization with global and IGF2/H19 methylation variation in newborn twins.

    PubMed

    Loke, Y J; Galati, J C; Saffery, R; Craig, J M

    2015-04-01

    In vitro fertilization (IVF) and its subset intracytoplasmic sperm injection (ICSI), are widely used medical treatments for conception. There has been controversy over whether IVF is associated with adverse short- and long-term health outcomes of offspring. As with other prenatal factors, epigenetic change is thought to be a molecular mediator of any in utero programming effects. Most studies focused on DNA methylation at gene-specific and genomic level, with only a few on associations between DNA methylation and IVF. Using buccal epithelium from 208 twin pairs from the Peri/Postnatal Epigenetic Twin Study (PETS), we investigated associations between IVF and DNA methylation on a global level, using the proxies of Alu and LINE-1 interspersed repeats in addition to two locus-specific regulatory regions within IGF2/H19, controlling for 13 potentially confounding factors. Using multiple correction testing, we found strong evidence that IVF-conceived twins have lower DNA methylation in Alu, and weak evidence of lower methylation in one of the two IGF2/H19 regulatory regions and LINE-1, compared with naturally conceived twins. Weak evidence of a relationship between ICSI and DNA methylation within IGF2/H19 regulatory region was found, suggesting that one or more of the processes associated with IVF/ICSI may contribute to these methylation differences. Lower within- and between-pair DNA methylation variation was also found in IVF-conceived twins for LINE-1, Alu and one IGF2/H19 regulatory region. Although larger sample sizes are needed, our results provide additional insight to the possible influence of IVF and ICSI on DNA methylation. To our knowledge, this is the largest study to date investigating the association of IVF and DNA methylation.

  4. Clr4 specificity and catalytic activity beyond H3K9 methylation.

    PubMed

    Kusevic, Denis; Kudithipudi, Srikanth; Iglesias, Nahid; Moazed, Danesh; Jeltsch, Albert

    2017-04-01

    In fission yeast, the catalytic activity of the protein lysine methyltransferase (PKMT) Clr4, the sole homolog of the mammalian SUV39H1 and SUV39H2 enzymes, majorly contributes to the formation of heterochromatin. The enzyme introduces histone 3 lysine 9 (H3K9) di- and tri-methylation, a central heterochromatic histone modification, and later it was also found to methylate the Mlo3 protein, which has a role in heterochromatin formation as well. Herein, we have investigated the substrate specificity of Clr4 using custom made mutational scanning peptide arrays. Our data show, that Clr4 recognizes an RK core motif, showing high preference for R8. In addition, it exhibits specific contacts at the S10, T11, G12 and G13 positions of the H3 peptide recognizing an R-K-SKRT-TCS-G sequence. Based on the specificity profile and in vitro methyltransferase assay targeted searches, 11 putative methylation sites in S. pombe proteins were identified from reported Clr4 interacting proteins including Mlo3. Peptide methylation was observed on Mlo3 and 7 novel target sites with strongest methylation signals on Spbc28F2.11 (HMG box-containing protein) at lysine 292 and Hrp3 (Chromodomain ATP-dep DNA helicase) at lysine 89. These data suggest that Clr4 has additional methylation substrates and it will be important to study the biological function of these novel methylation events. Furthermore, the specificity profile of Clr4 has been used to develop a quantitative method to compare and cluster specificity profiles of PKMTs. It shows that the specificity profile of Clr4 is most similar to that of the SUV39H2 enzyme, one of its human homologs. This approach will be helpful in the comparison of the recognition profiles of other families of PKMTs as well. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  5. 4-Methyl-N-(1-methyl-1H-indazol-5-yl)benzene-sulfonamide.

    PubMed

    Chicha, Hakima; Oulemda, Bassou; Rakib, El Mostapha; Saadi, Mohamed; El Ammari, Lahcen

    2013-01-01

    In the title compound, C15H15N3O2S, the fused ring system is close to planar, the largest deviation from the mean plane being 0.030 (2) Å, and makes a dihedral angle of 48.84 (9)° with the benzene ring belonging to the methyl-benzene-sulfonamide moiety. In the crystal, mol-ecules are -connected through N-H⋯N hydrogen bonds and weak C-H⋯O contacts, forming a two-dimensional network parallel to (001).

  6. Photochemical Generation of H_{2}NCNX, H_{2}NNCX, H_{2}NC(NX) (x = O, s) in Low-Temperature Matrices

    NASA Astrophysics Data System (ADS)

    Voros, Tamas; Lajgut, Gyozo Gyorgy; Magyarfalvi, Gabor; Tarczay, Gyorgy

    2017-06-01

    The [NH_{2}, C, N, O] and the [NH_{2}, C, N, S] systems were investigated by quantum-chemical computations and matrix-isolation spectroscopic methods. The equilibrium structures of the isomers and their relative energies were determined by CCSD(T) method. This was followed by the computation of the harmonic and anharmonic vibrational wavenumbers, infrared intensities, relative Raman activities and UV excitation energies. These computed data were used to assist the identification of products obtained by UV laser photolysis of 3,4-diaminofurazan, 3,4-diaminothiadiazole and 1,2,4-thiadiazole-3,5-diamine in low-temperature Ar and Kr matrices. Experimentally, first the precursors were studied by matrix-isolation IR and UV spectroscopic methods. Based on these UV spectra, different wavelengths were selected for photolysis. The irradiations, carried out by a tunable UV laser-light source, resulted in the decomposition of the precursors, and in the appearance of new bands in the IR spectra. Some of these bands were assigned to cyanamide (H_{2}NCN) and its isomer, the carbodiimide molecule (HNCNH), generated from H_{2}NCN. By the analysis of the relative absorbance vs. photolysis time curves, the other bands were grouped to three different species both for the O- and the S-containing systems. In the case of the O-containing isomers, these bands were assigned to the H_{2}NNCO:H_{2}NCN, and H_{2}NCNO:H_{2}NCN complexes, and to the ring-structure H_{2}NC(NO) isomer. In a similar way, the complexes of H_{2}NNCS and H_{2}NCNS with the H_{2}NCN, and H_{2}NC(NS) were also identified. 1,2,4-thiadiazole-3,5-diamine was also investigated in similar way like the above mentioned precursors. The results of this study also support the identification of the new S-containing isomers. Except for H_{2}NNCO and H_{2}NCNS, these molecules were not identified previously. It is expected that at least some of these species, like the methyl isocyanate (CH_{3}CNO) isomer, are present and could be

  7. 40 CFR 721.4468 - 1H-Imidazole, 2-ethyl-4,5-dihydro-4-methyl-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1H-Imidazole, 2-ethyl-4,5-dihydro-4... Specific Chemical Substances § 721.4468 1H-Imidazole, 2-ethyl-4,5-dihydro-4-methyl-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1H-imidazole...

  8. Synthesis of [.sup.13C] and [.sup.2H] substituted methacrylic acid, [.sup.13C] and [.sup.2H] substituted methyl methacrylate and/or related compounds

    DOEpatents

    Alvarez, Marc A [Santa Fe, NM; Martinez, Rodolfo A [Santa Fe, NM; Unkefer, Clifford J [Los Alamos, NM

    2008-01-22

    The present invention is directed to labeled compounds of the formulae ##STR00001## wherein Q is selected from the group consisting of --S--, --S(.dbd.O)--, and --S(.dbd.O).sub.2--, Z is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl, a halogen, and an amino group selected from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each independently selected from the group consisting of a C.sub.1-C.sub.4 lower alkyl, an aryl, and an alkoxy group, and X is selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl group, and a fully-deuterated C.sub.1-C.sub.4 lower alkyl group. The present invention is also directed to a process of preparing labeled compounds, e.g., process of preparing [.sup.13C]methacrylic acid by reacting a (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13CH.sub.2)-- aryl sulfone precursor with .sup.13CHI to form a (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13C(.sup.13CH.sub.3).sub.2)-- aryl sulfone intermediate, and, reacting the (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13C(.sup.13CH.sub.3).sub.2)-- aryl sulfone intermediate with sodium hydroxide, followed by acid to form [.sup.13C]methacrylic acid. The present invention is further directed to a process of preparing [.sup.2H.sub.8]methyl methacrylate by reacting a (HOOC--C(C.sup.2H.sub.3).sub.2-- aryl sulfinyl intermediate with CD.sub.3I to form a (.sup.2H.sub.3COOC--C(C.sup.2H.sub.3).sub.2)-- aryl sulfinyl intermediate, and heating the(.sup.2H.sub.3COOC--C(C.sup.2H.sub.3).sub.2)-- aryl sulfinyl intermediate at temperatures and for time sufficient to form [.sup.2H.sub.8]methyl methacrylate.

  9. Analysis of a microbial community oxidizing inorganic sulfide and mercaptans.

    PubMed

    Duncan, K E; Sublette, K L; Rider, P A; Stepp, A; Beitle, R R; Conner, J A; Kolhatkar, R

    2001-01-01

    Successful treatment of refinery spent-sulfidic caustic (which results from the addition of sodium hydroxide solutions to petroleum refinery waste streams) was achieved in a bioreactor containing an enrichment culture immobilized in organic polymer beads with embedded powdered activated carbon (Bio-Sep). The aerobic enrichment culture had previously been selected using a gas mixture of hydrogen sulfide and methyl mercaptan (MeSH) as the sole carbon and energy sources. The starting cultures for the enrichment consisted of several different Thiobacilli spp. (T. thioparus, T. denitrificans, T. thiooxidans, and T. neopolitanus), as well as activated sludge from a refinery aerobic wastewater treatment system and sludge from an industrial anaerobic digester. Microscopic examination (light and SEM) of the beads and of microbial growth on the walls of the bioreactor revealed a great diversity of microorganisms. Further characterization was undertaken starting with culturable aerobic heterotrophic microorganisms (sequencing of PCR-amplified DNA coding for 16S rRNA, Gram staining) and by PCR amplification of DNA coding for 16S rRNA extracted directly from the cell mass, followed by the separation of the PCR products by DGGE (denaturing gradient gel electrophoresis). Eight prominent bands from the DGGE gel were sequenced and found to be closest to sequences of uncultured Cytophagales (3 bands), Gram-positive cocci (Micrococcineae), alpha proteobacteria (3 bands), and an unidentified beta proteobacterium. Culturable microbes included several genera of fungi as well as various Gram-positive and Gram-negative heterotrophic bacteria not seen in techniques using direct DNA extraction.

  10. Characterization of a distonic isomer C6H5C+(OH)OCH2 of methyl benzoate radical cation by associative ion-molecule reactions

    NASA Astrophysics Data System (ADS)

    Dechamps, Noémie; Flammang, Robert; Gerbaux, Pascal; Nam, Pham-Cam; Nguyen, Minh Tho

    2006-03-01

    The C6H5C+(OH)OCH2 radical cation, formally a distonic isomer of ionized methyl benzoate, has been prepared by dissociative ionization of neopentyl benzoate, as earlier suggested by Audier et al. [H.E. Audier, A. Milliet, G. Sozzi, S. Hammerum, Org. Mass. Spectrom. 25 (1990) 44]. Its distonic character has now been firmly established by its high reactivity towards neutral methyl isocyanide (ionized methylene transfer) producing N-methyl ketenimine ions. Other mass spectrometric experiments and ab initio quantum chemical calculations also concur with each other pointing toward the existence of a stable distonic radical cation.

  11. The effects of maternal anxiety during pregnancy on IGF2/H19 methylation in cord blood

    PubMed Central

    Mansell, T; Novakovic, B; Meyer, B; Rzehak, P; Vuillermin, P; Ponsonby, A-L; Collier, F; Burgner, D; Saffery, R; Ryan, J; Vuillermin, Peter; Ponsonby, Anne-Louise; Carlin, John B; Allen, Katie J; Tang, Mimi L; Saffery, Richard; Ranganathan, Sarath; Burgner, David; Dwyer, Terry; Jachno, Kim; Sly, Peter

    2016-01-01

    Compelling evidence suggests that maternal mental health in pregnancy can influence fetal development. The imprinted genes, insulin-like growth factor 2 (IGF2) and H19, are involved in fetal growth and each is regulated by DNA methylation. This study aimed to determine the association between maternal mental well-being during pregnancy and differentially methylated regions (DMRs) of IGF2 (DMR0) and the IGF2/H19 imprinting control region (ICR) in newborn offspring. Maternal depression, anxiety and perceived stress were assessed at 28 weeks of pregnancy in the Barwon Infant Study (n=576). DNA methylation was measured in purified cord blood mononuclear cells using the Sequenom MassArray Platform. Maternal anxiety was associated with a decrease in average ICR methylation (Δ=−2.23% 95% CI=−3.68 to −0.77%), and across all six of the individual CpG units in anxious compared with non-anxious groups. Birth weight and sex modified the association between prenatal anxiety and infant methylation. When stratified into lower (⩽3530 g) and higher (>3530 g) birth weight groups using the median birth weight, there was a stronger association between anxiety and ICR methylation in the lower birth weight group (Δ=−3.89% 95% CI=−6.06 to −1.72%), with no association in the higher birth weight group. When stratified by infant sex, there was a stronger association in female infants (Δ=−3.70% 95% CI=−5.90 to −1.51%) and no association in males. All the linear regression models were adjusted for maternal age, smoking and folate intake. These findings show that maternal anxiety in pregnancy is associated with decreased IGF2/H19 ICR DNA methylation in progeny at birth, particularly in female, low birth weight neonates. ICR methylation may help link poor maternal mental health and adverse birth outcomes, but further investigation is needed. PMID:27023171

  12. Reduced Histone H3 Lysine 9 Methylation Contributes to the Pathogenesis of Latent Autoimmune Diabetes in Adults via Regulation of SUV39H2 and KDM4C.

    PubMed

    Liu, Xi-Yu; Li, Hong

    2017-01-01

    Aims . Latent autoimmune diabetes in adults (LADA) is an autoimmune disease of which the mechanism is not clear. Emerging evidence suggests that histone methylation contributes to autoimmunity. Methods . Blood CD4 + T lymphocytes from 26 LADA patients and 26 healthy controls were isolated to detect histone H3 lysine 4 and H3 lysine 9 methylation status. Results . Reduced global H3 lysine 9 methylation was observed in LADA patients' CD4 + T lymphocytes, compared to healthy controls ( P < 0.05). H3 lysine 4 methylation was not statistically different. The reduced H3 lysine 9 methylation was associated with GADA titer but not correlated with glycosylated hemoglobin (HbA1c). When the LADA patient group was divided into those with complication and those without, relatively reduced global H3 lysine 9 methylation was observed in LADA patients with complication ( P < 0.05). The expression of histone methyltransferase SUV39H2 for H3 lysine 9 methylation was downregulated in LADA patients, and the expression of histone demethylase KDM4C which made H3 lysine 9 demethylation was upregulated. Conclusion . The reduction of histone H3 lysine 9 methylation which may due to the downregulation of methyltransferase SUV39H2 and the upregulation of demethylase KDM4C was found in CD4 + T lymphocytes of LADA patients.

  13. ZrO2/MoS2 heterojunction photocatalysts for efficient photocatalytic degradation of methyl orange

    NASA Astrophysics Data System (ADS)

    Prabhakar Vattikuti, Surya Veerendra; Byon, Chan; Reddy, Chandragiri Venkata

    2016-10-01

    We report a simple solution-chemistry approach for the synthesis of ZrO2/MoS2 hybrid photocatalysts, which contain MoS2 as a cocatalyst. The material is usually obtained by a wet chemical method using ZrO(NO3)2 or (NH4)6Mo7O24·4H2O and C8H6S as precursors. The structural features of obtained materials were characterized by X-ray diffraction (XRD), highresolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), thermal analysis (TG-DTA), N2 adsorption-desorption, and photoluminescence (PL). The influence on the photocatalytic activity of the MoS2 cocatalyst concentration with ZrO2 nanoparticles was studied. The MZr-2 hybrid sample had the highest photocatalytic activity for the degradation of methyl orange (MO), which was 8.45 times higher than that of pristine ZrO2 ascribed to high specific surface area and absorbance efficiency. Recycling experiments revealed that the reusability of the MZr-2 hybrid was due to the low photocorrosive effect and good catalytic stability. PL spectra confirmed the electronic interaction between ZrO2 and MoS2. The photoinduced electrons could be easily transferred from CB of ZrO2 to the MoS2 cocatalyst, which facilitate effective charge separation and enhanced the photocatalytic degradation in the UV region. A photocatalytic mechanism is proposed. It is believed that the ZrO2/MoS2 hybrid structure has promise as a photocatalyst with low cost and high efficiency for photoreactions.

  14. Citrullination/Methylation Crosstalk on Histone H3 Regulates ER-Target Gene Transcription.

    PubMed

    Clancy, Kathleen W; Russell, Anna-Maria; Subramanian, Venkataraman; Nguyen, Hannah; Qian, Yuewei; Campbell, Robert M; Thompson, Paul R

    2017-06-16

    Posttranslational modifications of histone tails are a key contributor to epigenetic regulation. Histone H3 Arg26 and Lys27 are both modified by multiple enzymes, and their modifications have profound effects on gene expression. Citrullination of H3R26 by PAD2 and methylation of H3K27 by PRC2 have opposing downstream impacts on gene regulation; H3R26 citrullination activates gene expression, and H3K27 methylation represses gene expression. Both of these modifications are drivers of a variety of cancers, and their writer enzymes, PAD2 and EZH2, are the targets of drug therapies. After biochemical and cell-based analysis of these modifications, a negative crosstalk interaction is observed. Methylation of H3K27 slows citrullination of H3R26 30-fold, whereas citrullination of H3R26 slows methylation 30,000-fold. Examination of the mechanism of this crosstalk interaction uncovered a change in structure of the histone tail upon citrullination which prevents methylation by the PRC2 complex. This mechanism of crosstalk is reiterated in cell lines using knockdowns and inhibitors of both enzymes. Based our data, we propose a model in which, after H3 Cit26 formation, H3K27 demethylases are recruited to the chromatin to activate transcription. In total, our studies support the existence of crosstalk between citrullination of H3R26 and methylation of H3K27.

  15. 4-Methyl-N-(1-methyl-1H-indazol-5-yl)benzene­sulfonamide

    PubMed Central

    Chicha, Hakima; Oulemda, Bassou; Rakib, El Mostapha; Saadi, Mohamed; El Ammari, Lahcen

    2013-01-01

    In the title compound, C15H15N3O2S, the fused ring system is close to planar, the largest deviation from the mean plane being 0.030 (2) Å, and makes a dihedral angle of 48.84 (9)° with the benzene ring belonging to the methyl­benzene­sulfonamide moiety. In the crystal, mol­ecules are ­connected through N—H⋯N hydrogen bonds and weak C—H⋯O contacts, forming a two-dimensional network parallel to (001). PMID:24427093

  16. Fabrication of TiO2/MoS2@zeolite photocatalyst and its photocatalytic activity for degradation of methyl orange under visible light

    NASA Astrophysics Data System (ADS)

    Zhang, Weiping; Xiao, Xinyan; Zheng, Lili; Wan, Caixia

    2015-12-01

    TiO2/MoS2@zeolite composite photocatalysts with visible-light activity were fabricated via a simple ultrasonic-hydrothermal synthesis method, using TiCl4 as Ti source, MoS2 as a direct sensitizer, glycerol water solution with certain dispersion agent as hydrolytic agent, and zeolite as carrier. The structure, morphology, composition, optical properties, and specific surface area of the as-prepared photocatalysts were characterized by using XRD, FTIR, SEM-EDS, TEM, XPS, UV-vis, PL and BET analyzer, respectively. And the photocatalytic degradation of methyl orange (MO) in aqueous suspension has been employed to evaluate the photocatalytic activity and degradation kinetics of as-prepared photocatalysts with xenon lamp as irradiation source. The results indicate that: (1) TiO2/MoS2@zeolite composite photocatalysts exhibit enhanced photocatalytic activities for methyl orange (MO) degradation compared to Degussa P25; (2) photocatalytic degradation of MO obeys Langmuir-Hinshelwood kinetic model (pseudo-first order reaction), and its degradation rate constant (kapp) (2.304 h-1) is higher than that of Degussa P25 (0.768 h-1); (3) the heterostructure consisted of zeolite, MoS2 and TiO2 nanostructure could provide synergistic effect for degradation of MO due to the efficient electron transfer process and better absorption property of TiO2/MoS2@zeolite composite photocatalyst.

  17. The 2:1 salt-type adduct formed between 6-amino-3-methyl-5-nitrosopyrimidine-2,4(1H,3H)-dione and piperidine: sheets containing 20 independent hydrogen bonds.

    PubMed

    Orozco, Fabián; Insuasty, Braulio; Cobo, Justo; Glidewell, Christopher

    2009-05-01

    The title compound, piperidinium 6-amino-3-methyl-5-nitroso-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-1-ide 6-amino-3-methyl-5-nitrosopyrimidine-2,4(1H,3H)-dione, C(5)H(12)N(+).C(5)H(5)N(4)O(3)(-).C(5)H(6)N(4)O(3), (I), crystallizes with Z' = 2 in the space group P1. There is an intramolecular N-H...O hydrogen bond in each pyrimidine unit and within the selected asymmetric unit the six independent components are linked by 11 hydrogen bonds, seven of the N-H...O type and four of the N-H...N type. These six-component aggregates are linked into sheets by five further hydrogen bonds, three of the N-H...O type and one each of the N-H...N and C-H...O types.

  18. Analysis of cardiovascular responses to the H2S donors Na2S and NaHS in the rat

    PubMed Central

    Yoo, Daniel; Jupiter, Ryan C.; Pankey, Edward A.; Reddy, Vishwaradh G.; Edward, Justin A.; Swan, Kevin W.; Peak, Taylor C.; Mostany, Ricardo

    2015-01-01

    Hydrogen sulfide (H2S) is an endogenous gaseous molecule formed from L-cysteine in vascular tissue. In the present study, cardiovascular responses to the H2S donors Na2S and NaHS were investigated in the anesthetized rat. The intravenous injections of Na2S and NaHS 0.03–0.5 mg/kg produced dose-related decreases in systemic arterial pressure and heart rate, and at higher doses decreases in cardiac output, pulmonary arterial pressure, and systemic vascular resistance. H2S infusion studies show that decreases in systemic arterial pressure, heart rate, cardiac output, and systemic vascular resistance are well-maintained, and responses to Na2S are reversible. Decreases in heart rate were not blocked by atropine, suggesting that the bradycardia was independent of parasympathetic activation and was mediated by an effect on the sinus node. The decreases in systemic arterial pressure were not attenuated by hexamethonium, glybenclamide, Nw-nitro-l-arginine methyl ester hydrochloride, sodium meclofenamate, ODQ, miconazole, 5-hydroxydecanoate, or tetraethylammonium, suggesting that ATP-sensitive potassium channels, nitric oxide, arachidonic acid metabolites, cyclic GMP, p450 epoxygenase metabolites, or large conductance calcium-activated potassium channels are not involved in mediating hypotensive responses to the H2S donors in the rat and that responses are not centrally mediated. The present data indicate that decreases in systemic arterial pressure in response to the H2S donors can be mediated by decreases in vascular resistance and cardiac output and that the donors have an effect on the sinus node independent of the parasympathetic system. The present data indicate that the mechanism of the peripherally mediated hypotensive response to the H2S donors is uncertain in the intact rat. PMID:26071540

  19. Association between H3K4 methylation and cancer prognosis: A meta-analysis.

    PubMed

    Li, Simin; Shen, Luyan; Chen, Ke-Neng

    2018-05-08

    Histone H3 lysine 4 methylation (H3K4 methylation), including mono-methylation (H3K4me1), di-methylation (H3K4me2), or tri-methylation (H3K4me3), is one of the epigenetic modifications to histone proteins, which are related to the transcriptional activation of genes. H3K4 methylation has both tumor inhibiting and promoting effects, and the prognostic value of H3K4 methylation in cancer remains controversial. Therefore, we performed a systematic review and meta-analysis to examine the association between H3K4 methylation and cancer prognosis. A comprehensive search of PubMed, Web of Science, ScienceDirect, Embase, and Ovid databases was conducted to identify studies investigating the association between H3K4 methylation and prognosis of patients with malignant tumors. The data and characteristics of each study were extracted, and the hazard ratio (HR) at a 95% confidence interval (CI) was calculated to estimate the effect. A total of 1474 patients in 10 studies were enrolled in this meta-analysis. The pooled HR of 1.52 (95% CI 1.02-2.26) indicated that patients with a lower level of H3K4me2 expression were expected to have shorter overall survival, while the pooled HR of 0.45 (95% CI 0.27-0.74) indicated that patients with a lower level of H3K4me3 expression were expected to have longer overall survival. This meta-analysis indicates that increased H3K4me3 expression and decreased H3K4me2 expression might be predictive factors of poor prognosis in cancer. Further large cohort studies are needed to confirm these findings. © 2018 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

  20. 40 CFR 721.10356 - Zinc, bis[3-(acetyl-.kappa.O)-6-methyl-2H-pyran-2,4(3H)-dionato-.kappa.O4]diaqua-.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Zinc, bis[3-(acetyl-.kappa.O)-6-methyl-2H-pyran-2,4(3H)-dionato-.kappa.O4]diaqua-. 721.10356 Section 721.10356 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific...

  1. 40 CFR 721.10356 - Zinc, bis[3-(acetyl-.kappa.O)-6-methyl-2H-pyran-2,4(3H)-dionato-.kappa.O4]diaqua-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Zinc, bis[3-(acetyl-.kappa.O)-6-methyl-2H-pyran-2,4(3H)-dionato-.kappa.O4]diaqua-. 721.10356 Section 721.10356 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific...

  2. 40 CFR 721.10356 - Zinc, bis[3-(acetyl-.kappa.O)-6-methyl-2H-pyran-2,4(3H)-dionato-.kappa.O4]diaqua-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Zinc, bis[3-(acetyl-.kappa.O)-6-methyl-2H-pyran-2,4(3H)-dionato-.kappa.O4]diaqua-. 721.10356 Section 721.10356 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific...

  3. Synthesis of zinc sulfide nanoparticles during zinc oxidization by H2S and H2S/H2O supercritical fluids

    NASA Astrophysics Data System (ADS)

    Vostrikov, A. A.; Fedyaeva, O. N.; Sokol, M. Ya.; Shatrova, A. V.

    2014-12-01

    Formation of zinc sulfide nanoparticles was detected during interaction of bulk samples with hydrogen sulfide at supercritical parameters. Synthesis proceeds with liberation of H2 by the reaction nZn + nH2S = (ZnS) n + nH2. It has been found by the X-ray diffraction method, scanning electron microscopy, and mass spectrometry that the addition of water stimulates coupled reactions of nanoparticle synthesis nZn + nH2O = (ZnO) n + nH2 and (ZnO) n + nH2S = (ZnS) n + nH2O and brings about an increase in the synthesis rate and morphological changes of (ZnS) n nanoparticles.

  4. CaMV-35S promoter sequence-specific DNA methylation in lettuce.

    PubMed

    Okumura, Azusa; Shimada, Asahi; Yamasaki, Satoshi; Horino, Takuya; Iwata, Yuji; Koizumi, Nozomu; Nishihara, Masahiro; Mishiba, Kei-ichiro

    2016-01-01

    We found 35S promoter sequence-specific DNA methylation in lettuce. Additionally, transgenic lettuce plants having a modified 35S promoter lost methylation, suggesting the modified sequence is subjected to the methylation machinery. We previously reported that cauliflower mosaic virus 35S promoter-specific DNA methylation in transgenic gentian (Gentiana triflora × G. scabra) plants occurs irrespective of the copy number and the genomic location of T-DNA, and causes strong gene silencing. To confirm whether 35S-specific methylation can occur in other plant species, transgenic lettuce (Lactuca sativa L.) plants with a single copy of the 35S promoter-driven sGFP gene were produced and analyzed. Among 10 lines of transgenic plants, 3, 4, and 3 lines showed strong, weak, and no expression of sGFP mRNA, respectively. Bisulfite genomic sequencing of the 35S promoter region showed hypermethylation at CpG and CpWpG (where W is A or T) sites in 9 of 10 lines. Gentian-type de novo methylation pattern, consisting of methylated cytosines at CpHpH (where H is A, C, or T) sites, was also observed in the transgenic lettuce lines, suggesting that lettuce and gentian share similar methylation machinery. Four of five transgenic lettuce lines having a single copy of a modified 35S promoter, which was modified in the proposed core target of de novo methylation in gentian, exhibited 35S hypomethylation, indicating that the modified sequence may be the target of the 35S-specific methylation machinery.

  5. Synthesis of bilayer MoS{sub 2} nanosheets by a facile hydrothermal method and their methyl orange adsorption capacity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ye, Lijuan; Xu, Haiyan; Zhang, Dingke

    2014-07-01

    Highlights: • Hexagonal phase of MoS{sub 2} nanosheets was synthesized by a facile hydrothermal method. • FE-SEM and TEM images show the sheets-like morphology of MoS{sub 2}. • Bilayer MoS{sub 2} can be grown under the optimized mole ratio of 2:1 of S:Mo at 180 °C for 50 h. • The MoS{sub 2} nanosheets possess high methyl orange adsorption capacity due to the large surface area. - Abstract: Molybdenum disulfide (MoS{sub 2}) nanosheets have received significant attention recently due to the potential applications for exciting physics and technology. Here we show that MoS{sub 2} nanosheets can be prepared by amore » facile hydrothermal method. The study of the properties of the MoS{sub 2} nanosheets prepared at different conditions suggests that the mole ratio of precursors and hydrothermal time significantly influences the purity, crystalline quality and thermal stability of MoS{sub 2}. X-ray diffraction, Raman spectra and transmission electron microscopy results indicate that bilayer MoS{sub 2} can be grown under an optimized mole ratio of 2:1 of S:Mo at 180 °C for 50 h. Moreover, such ultrathin nanosheets exhibit a prominent photoluminescence and possess high methyl orange adsorption capacity due to the large surface area, which can be potentially used in photodevice and photochemical catalyst.« less

  6. Cocrystals of 6-methyl-2-thiouracil: presence of the acceptor-donor-acceptor/donor-acceptor-donor synthon.

    PubMed

    Hützler, Wilhelm Maximilian; Egert, Ernst

    2015-03-01

    The results of seven cocrystallization experiments of the antithyroid drug 6-methyl-2-thiouracil (MTU), C(5)H(6)N(2)OS, with 2,4-diaminopyrimidine, 2,4,6-triaminopyrimidine and 6-amino-3H-isocytosine (viz. 2,6-diamino-3H-pyrimidin-4-one) are reported. MTU features an ADA (A = acceptor and D = donor) hydrogen-bonding site, while the three coformers show complementary DAD hydrogen-bonding sites and therefore should be capable of forming an ADA/DAD N-H...O/N-H...N/N-H...S synthon with MTU. The experiments yielded one cocrystal and six cocrystal solvates, namely 6-methyl-2-thiouracil-2,4-diaminopyrimidine-1-methylpyrrolidin-2-one (1/1/2), C(5)H(6)N(2)OS·C(4)H(6)N(4)·2C(5)H(9)NO, (I), 6-methyl-2-thiouracil-2,4-diaminopyrimidine (1/1), C(5)H(6)N(2)OS·C(4)H(6)N(4), (II), 6-methyl-2-thiouracil-2,4-diaminopyrimidine-N,N-dimethylacetamide (2/1/2), 2C(5)H(6)N(2)OS·C(4)H(6)N(4)·2C(4)H(9)NO, (III), 6-methyl-2-thiouracil-2,4-diaminopyrimidine-N,N-dimethylformamide (2/1/2), C(5)H(6)N(2)OS·0.5C(4)H(6)N(4)·C(3)H(7)NO, (IV), 2,4,6-triaminopyrimidinium 6-methyl-2-thiouracilate-6-methyl-2-thiouracil-N,N-dimethylformamide (1/1/2), C(4)H(8)N(5)(+)·C(5)H(5)N(2)OS(-)·C(5)H(6)N(2)OS·2C(3)H(7)NO, (V), 6-methyl-2-thiouracil-6-amino-3H-isocytosine-N,N-dimethylformamide (1/1/1), C(5)H(6)N(2)OS·C(4)H(6)N(4)O·C(3)H(7)NO, (VI), and 6-methyl-2-thiouracil-6-amino-3H-isocytosine-dimethyl sulfoxide (1/1/1), C(5)H(6)N(2)OS·C(4)H(6)N(4)O·C(2)H(6)OS, (VII). Whereas in cocrystal (I) an R(2)(2)(8) interaction similar to the Watson-Crick adenine/uracil base pair is formed and a two-dimensional hydrogen-bonding network is observed, the cocrystals (II)-(VII) contain the triply hydrogen-bonded ADA/DAD N-H...O/N-H...N/N-H...S synthon and show a one-dimensional hydrogen-bonding network. Although 2,4-diaminopyrimidine possesses only one DAD hydrogen-bonding site, it is, due to orientational disorder, triply connected to two MTU molecules in (III) and (IV).

  7. Promoter methylation of AREG, HOXA11, hMLH1, NDRG2, NPTX2 and Tes genes in glioblastoma.

    PubMed

    Skiriutė, Daina; Vaitkienė, Paulina; Ašmonienė, Virginija; Steponaitis, Giedrius; Deltuva, Vytenis Pranas; Tamašauskas, Arimantas

    2013-07-01

    Epigenetic alterations alone or in combination with genetic mechanisms play a key role in brain tumorigenesis. Glioblastoma is one of the most common, lethal and poor clinical outcome primary brain tumors with extraordinarily miscellaneous epigenetic alterations profile. The aim of this study was to investigate new potential prognostic epigenetic markers such as AREG, HOXA11, hMLH1, NDRG2, NTPX2 and Tes genes promoter methylation, frequency and value for patients outcome. We examined the promoter methylation status using methylation-specific polymerase chain reaction in 100 glioblastoma tissue samples. The value for clinical outcome was calculated using Kaplan-Meier estimation with log-rank test. DNA promoter methylation was frequent event appearing more than 45 % for gene. AREG and HOXA11 methylation status was significantly associated with patient age. HOXA11 showed the tendency to be associated with patient outcome in glioblastomas. AREG gene promoter methylation showed significant correlation with poor patient outcome. AREG methylation remained significantly associated with patient survival in a Cox multivariate model including MGMT promoter methylation status. This study of new epigenetic targets has shown considerably high level of analyzed genes promoter methylation variability in glioblastoma tissue. AREG gene might be valuable marker for glioblastoma patient survival prognosis, however further analysis is needed to clarify the independence and appropriateness of the marker.

  8. Development and field testing of a highly sensitive mercaptans instrument.

    DOT National Transportation Integrated Search

    2012-10-01

    Mercaptans are sulfur compounds that are used to odorize natural gas so that leaks are : apparent. They are introduced into the gas stream at various locations in the natural gas : distribution system. As per DoTs regulation 49 CFR 192.625, that a...

  9. ATRX tolerates activity-dependent histone H3 methyl/phos switching to maintain repetitive element silencing in neurons

    PubMed Central

    Noh, Kyung-Min; Zhao, Dan; Xiang, Bin; Wenderski, Wendy; Lewis, Peter W.; Shen, Li; Li, Haitao; Allis, C. David

    2015-01-01

    ATRX (the alpha thalassemia/mental retardation syndrome X-linked protein) is a member of the switch2/sucrose nonfermentable2 (SWI2/SNF2) family of chromatin-remodeling proteins and primarily functions at heterochromatic loci via its recognition of “repressive” histone modifications [e.g., histone H3 lysine 9 tri-methylation (H3K9me3)]. Despite significant roles for ATRX during normal neural development, as well as its relationship to human disease, ATRX function in the central nervous system is not well understood. Here, we describe ATRX’s ability to recognize an activity-dependent combinatorial histone modification, histone H3 lysine 9 tri-methylation/serine 10 phosphorylation (H3K9me3S10ph), in postmitotic neurons. In neurons, this “methyl/phos” switch occurs exclusively after periods of stimulation and is highly enriched at heterochromatic repeats associated with centromeres. Using a multifaceted approach, we reveal that H3K9me3S10ph-bound Atrx represses noncoding transcription of centromeric minor satellite sequences during instances of heightened activity. Our results indicate an essential interaction between ATRX and a previously uncharacterized histone modification in the central nervous system and suggest a potential role for abnormal repetitive element transcription in pathological states manifested by ATRX dysfunction. PMID:25538301

  10. Protection of Grain Products from Sitophilus oryzae (L.) Contamination by Anti-Insect Pest Repellent Sachet Containing Allyl Mercaptan Microcapsule.

    PubMed

    Chang, Yoonjee; Lee, Soo-Hyun; Na, Ja Hyun; Chang, Pahn-Shick; Han, Jaejoon

    2017-11-01

    The purpose of this study was to develop an anti-insect pest repellent sachet to prevent Sitophilus oryzae (L.) (Coleoptera: Curculionidae) contamination in grain packaging. The anti-insect pest activities of essential oils (EOs) from garlic (Allium Sativum), ginger (Zingiber Officinalis), black pepper (Piper nigrum), onion (Allium cepa), and fennel (Foeniculum vulgare) as well as major compounds (allyl disulfide, AD; allyl mercaptan, AM) isolated from of garlic and onion (AD and AM) were measured against S. oryzae. The results revealed that garlic EO, onion EO, AD, and AM showed strong fumigant insecticidal activities. Among these, AM showed the highest acetylcholinesterase (AChE) inhibition rate, indicating that the fumigation insecticidal efficacy of AM is related with its AChE inhibition ability. Subsequently, the microcapsules were produced with a high efficiency (80.02%) by using AM as a core material and rice flour as a wall material. Finally, sachet composed of rice flour microcapsule containing 2% AM (RAM) was produced. Repellent assay was performed to measure anti-insect pest ability of the RAM sachet, showed remarkable repelling effect within 48 h both in the presence or absence of attractant. In a release profile of RAM sachet, it was expected to last over 20 mo during the distribution period of brown rice. Moreover, RAM sachet showed no undesirable changes to the sensory properties of the rice both before and after cooking. Taken together, these results suggest that the newly developed RAM sachet could be used as a packaging material to protect grain products from S. oryzae contamination. The rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), causes damages to stored products and its contamination in grain products has become a major problem in cereal market. To preserve brown rice, an anti-insect pest repellent sachet containing 2% allyl mercaptan was newly developed and it showed remarkable repellent abilities against S. oryzae. It

  11. Biodegradation tests of mercaptocarboxylic acids, their esters, related divalent sulfur compounds and mercaptans.

    PubMed

    Rücker, Christoph; Mahmoud, Waleed M M; Schwartz, Dirk; Kümmerer, Klaus

    2018-04-17

    Mercaptocarboxylic acids and their esters, a class of difunctional compounds bearing both a mercapto and a carboxylic acid or ester functional group, are industrial chemicals of potential environmental concern. Biodegradation of such compounds was systematically investigated here, both by literature search and by experiments (Closed Bottle Test OECD 301D and Manometric Respirometry Test OECD 301F). These compounds were found either readily biodegradable or at least biodegradable to a significant extent. Some related compounds of divalent sulfur were tested for comparison (mercaptans, sulfides, disulfides). For the two relevant monofunctional compound classes, carboxylic acids/esters and mercaptans, literature data were compiled, and by comparison with structurally similar compounds without these functional groups, the influence of COOH/COOR' and SH groups on biodegradability was evaluated. Thereby, an existing rule of thumb for biodegradation of carboxylic acids/esters was supported by experimental data, and a rule of thumb could be formulated for mercaptans. Concurrent to biodegradation, abiotic processes were observed in the experiments, rapid oxidative formation of disulfides (dimerisation of monomercaptans and cyclisation of dimercaptans) and hydrolysis of esters. Some problems that compromise the reproducibility of biodegradation test results were discussed.

  12. H2S protects against methionine-induced oxidative stress in brain endothelial cells.

    PubMed

    Tyagi, Neetu; Moshal, Karni S; Sen, Utpal; Vacek, Thomas P; Kumar, Munish; Hughes, William M; Kundu, Soumi; Tyagi, Suresh C

    2009-01-01

    Homocysteine (Hcy) causes cerebrovascular dysfunction by inducing oxidative stress. However, to date, there are no strategies to prevent Hcy-induced oxidative damage. Hcy is an H2S precursor formed from methionine (Met) metabolism. We aimed to investigate whether H2S ameliorated Met-induced oxidative stress in mouse brain endothelial cells (bEnd3). The bEnd3 cells were exposed to Met treatment in the presence or absence of NaHS (donor of H2S). Met-induced cell toxicity increased the levels of free radicals in a concentration-dependent manner. Met increased NADPH-oxidase-4 (NOX-4) expression and mitigated thioredxion-1(Trx-1) expression. Pretreatment of bEnd3 with NaHS (0.05 mM) attenuated the production of free radicals in the presence of Met and protected the cells from oxidative damage. Furthermore, NaHS enhanced inhibitory effects of apocynin, N-acetyl-l-cysteine (NAC), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), Nomega-nitro-l-arginine methyl ester (L-NAME) on ROS production and redox enzymes levels induced by Met. In conclusion, the administration of H2S protected the cells from oxidative stress induced by hyperhomocysteinemia (HHcy), which suggested that NaHS/H2S may have therapeutic potential against Met-induced oxidative stress.

  13. Histone H4K20 tri-methylation at late-firing origins ensures timely heterochromatin replication.

    PubMed

    Brustel, Julien; Kirstein, Nina; Izard, Fanny; Grimaud, Charlotte; Prorok, Paulina; Cayrou, Christelle; Schotta, Gunnar; Abdelsamie, Alhassan F; Déjardin, Jérôme; Méchali, Marcel; Baldacci, Giuseppe; Sardet, Claude; Cadoret, Jean-Charles; Schepers, Aloys; Julien, Eric

    2017-09-15

    Among other targets, the protein lysine methyltransferase PR-Set7 induces histone H4 lysine 20 monomethylation (H4K20me1), which is the substrate for further methylation by the Suv4-20h methyltransferase. Although these enzymes have been implicated in control of replication origins, the specific contribution of H4K20 methylation to DNA replication remains unclear. Here, we show that H4K20 mutation in mammalian cells, unlike in Drosophila , partially impairs S-phase progression and protects from DNA re-replication induced by stabilization of PR-Set7. Using Epstein-Barr virus-derived episomes, we further demonstrate that conversion of H4K20me1 to higher H4K20me2/3 states by Suv4-20h is not sufficient to define an efficient origin per se , but rather serves as an enhancer for MCM2-7 helicase loading and replication activation at defined origins. Consistent with this, we find that Suv4-20h-mediated H4K20 tri-methylation (H4K20me3) is required to sustain the licensing and activity of a subset of ORCA/LRWD1-associated origins, which ensure proper replication timing of late-replicating heterochromatin domains. Altogether, these results reveal Suv4-20h-mediated H4K20 tri-methylation as a critical determinant in the selection of active replication initiation sites in heterochromatin regions of mammalian genomes. © 2017 The Authors.

  14. Identification and Mapping of Mechanically Exfoliated 1H-MoS2 Flakes for Field-Effect Transistors

    DTIC Science & Technology

    2014-08-01

    structures directly onto 1H- and 2H-MoS2. A methyl methacrylate (MMA) and polymethyl methacrylate ( PMMA ) bilayer resist process will be used for all...the fiscal year. 9 5. References 1. Novoselov KS, Geim AK, Morozov SV, Jiang D, Zhang Y, Dubonos SV, Grigorieva IV, Firsov AA . Electric...photoluminescence PMMA polymethyl methacrylate TMDs transition metal dichalcogenides 12 1 DEFENSE TECH INFO CTR (PDF) ATTN DTIC OCA (PDF) 2

  15. Design and synthesis of highly potent benzodiazepine gamma-secretase inhibitors: preparation of (2S,3R)-3-(3,4-difluorophenyl)-2-(4-fluorophenyl)-4- hydroxy-N-((3S)-1-methyl-2-oxo-5- phenyl-2,3-dihydro-1H-benzo[e][1,4]-diazepin-3-yl)butyramide by use of an asymmetric Ireland-Claisen rearrangement.

    PubMed

    Churcher, Ian; Williams, Susie; Kerrad, Sonia; Harrison, Timothy; Castro, José L; Shearman, Mark S; Lewis, Huw D; Clarke, Earl E; Wrigley, Jonathan D J; Beher, Dirk; Tang, Yui S; Liu, Wensheng

    2003-06-05

    Novel benzodiazepine-containing gamma-secretase inhibitors for potential use in Alzheimer's disease have been designed that incorporate a substituted hydrocinnamide C-3 side chain. A syn combination of alpha-alkyl or aryl and beta-hydroxy or hydroxymethyl substituents was shown to give highly potent compounds. In particular, (2S,3R)-3-(3,4-difluorophenyl)-2-(4-fluorophenyl)-4-hydroxy-N-((3S)-2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)butyramide (34) demonstrated excellent in vitro potency (IC(50) = 0.06 nM). 34 could also be selectively methylated to give [(3)H]-28, which is of use in radioligand binding assays.

  16. 3-Ethyl-2-methyl-5-methyl­ene-6,7-di­hydroindol-4(5H)-one

    PubMed Central

    Sonar, Vijayakumar N.; Parkin, Sean; Crooks, Peter A.

    2008-01-01

    The title compound, C12H15NO, a degradation product of molindone hydro­chloride, was prepared by the reaction of molindone with methyl iodide and subsequent reaction of the resulting quaternary ammonium salt with 2N aqueous sodium hydroxide. The newly formed double bond is exocyclic in nature and the carbonyl group is conjugated with the π-electrons of the pyrrole ring. The six-membered ring is in the half-chair conformation. The H atom attached to the N atom is involved in an inter­molecular hydrogen bond with the O atom of a screw-related mol­ecule, thus forming a continuous chain. PMID:21200723

  17. Arabidopsis RNA Polymerases IV and V Are Required To Establish H3K9 Methylation, but Not Cytosine Methylation, on Geminivirus Chromatin

    PubMed Central

    Jackel, Jamie N.; Storer, Jessica M.; Coursey, Tami

    2016-01-01

    ABSTRACT In plants, RNA-directed DNA methylation (RdDM) employs small RNAs to target enzymes that methylate cytosine residues. Cytosine methylation and dimethylation of histone 3 lysine 9 (H3K9me2) are often linked. Together they condition an epigenetic defense that results in chromatin compaction and transcriptional silencing of transposons and viral chromatin. Canonical RdDM (Pol IV-RdDM), involving RNA polymerases IV and V (Pol IV and Pol V), was believed to be necessary to establish cytosine methylation, which in turn could recruit H3K9 methyltransferases. However, recent studies have revealed that a pathway involving Pol II and RNA-dependent RNA polymerase 6 (RDR6) (RDR6-RdDM) is likely responsible for establishing cytosine methylation at naive loci, while Pol IV-RdDM acts to reinforce and maintain it. We used the geminivirus Beet curly top virus (BCTV) as a model to examine the roles of Pol IV and Pol V in establishing repressive viral chromatin methylation. As geminivirus chromatin is formed de novo in infected cells, these viruses are unique models for processes involved in the establishment of epigenetic marks. We confirm that Pol IV and Pol V are not needed to establish viral DNA methylation but are essential for its amplification. Remarkably, however, both Pol IV and Pol V are required for deposition of H3K9me2 on viral chromatin. Our findings suggest that cytosine methylation alone is not sufficient to trigger de novo deposition of H3K9me2 and further that Pol IV-RdDM is responsible for recruiting H3K9 methyltransferases to viral chromatin. IMPORTANCE In plants, RNA-directed DNA methylation (RdDM) uses small RNAs to target cytosine methylation, which is often linked to H3K9me2. These epigenetic marks silence transposable elements and DNA virus genomes, but how they are established is not well understood. Canonical RdDM, involving Pol IV and Pol V, was thought to establish cytosine methylation that in turn could recruit H3K9 methyltransferases, but

  18. Arabidopsis RNA Polymerases IV and V Are Required To Establish H3K9 Methylation, but Not Cytosine Methylation, on Geminivirus Chromatin.

    PubMed

    Jackel, Jamie N; Storer, Jessica M; Coursey, Tami; Bisaro, David M

    2016-08-15

    In plants, RNA-directed DNA methylation (RdDM) employs small RNAs to target enzymes that methylate cytosine residues. Cytosine methylation and dimethylation of histone 3 lysine 9 (H3K9me2) are often linked. Together they condition an epigenetic defense that results in chromatin compaction and transcriptional silencing of transposons and viral chromatin. Canonical RdDM (Pol IV-RdDM), involving RNA polymerases IV and V (Pol IV and Pol V), was believed to be necessary to establish cytosine methylation, which in turn could recruit H3K9 methyltransferases. However, recent studies have revealed that a pathway involving Pol II and RNA-dependent RNA polymerase 6 (RDR6) (RDR6-RdDM) is likely responsible for establishing cytosine methylation at naive loci, while Pol IV-RdDM acts to reinforce and maintain it. We used the geminivirus Beet curly top virus (BCTV) as a model to examine the roles of Pol IV and Pol V in establishing repressive viral chromatin methylation. As geminivirus chromatin is formed de novo in infected cells, these viruses are unique models for processes involved in the establishment of epigenetic marks. We confirm that Pol IV and Pol V are not needed to establish viral DNA methylation but are essential for its amplification. Remarkably, however, both Pol IV and Pol V are required for deposition of H3K9me2 on viral chromatin. Our findings suggest that cytosine methylation alone is not sufficient to trigger de novo deposition of H3K9me2 and further that Pol IV-RdDM is responsible for recruiting H3K9 methyltransferases to viral chromatin. In plants, RNA-directed DNA methylation (RdDM) uses small RNAs to target cytosine methylation, which is often linked to H3K9me2. These epigenetic marks silence transposable elements and DNA virus genomes, but how they are established is not well understood. Canonical RdDM, involving Pol IV and Pol V, was thought to establish cytosine methylation that in turn could recruit H3K9 methyltransferases, but recent studies compel a

  19. ATRX tolerates activity-dependent histone H3 methyl/phos switching to maintain repetitive element silencing in neurons.

    PubMed

    Noh, Kyung-Min; Maze, Ian; Zhao, Dan; Xiang, Bin; Wenderski, Wendy; Lewis, Peter W; Shen, Li; Li, Haitao; Allis, C David

    2015-06-02

    ATRX (the alpha thalassemia/mental retardation syndrome X-linked protein) is a member of the switch2/sucrose nonfermentable2 (SWI2/SNF2) family of chromatin-remodeling proteins and primarily functions at heterochromatic loci via its recognition of "repressive" histone modifications [e.g., histone H3 lysine 9 tri-methylation (H3K9me3)]. Despite significant roles for ATRX during normal neural development, as well as its relationship to human disease, ATRX function in the central nervous system is not well understood. Here, we describe ATRX's ability to recognize an activity-dependent combinatorial histone modification, histone H3 lysine 9 tri-methylation/serine 10 phosphorylation (H3K9me3S10ph), in postmitotic neurons. In neurons, this "methyl/phos" switch occurs exclusively after periods of stimulation and is highly enriched at heterochromatic repeats associated with centromeres. Using a multifaceted approach, we reveal that H3K9me3S10ph-bound Atrx represses noncoding transcription of centromeric minor satellite sequences during instances of heightened activity. Our results indicate an essential interaction between ATRX and a previously uncharacterized histone modification in the central nervous system and suggest a potential role for abnormal repetitive element transcription in pathological states manifested by ATRX dysfunction.

  20. Enantioseparation of the carboxamide-type synthetic cannabinoids N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-(5-fluoropentyl)-1H-indazole-3-carboxamide and methyl [1-(5-fluoropentyl)-1H-indazole-3-carbonyl]-valinate in illicit herbal products.

    PubMed

    Doi, Takahiro; Asada, Akiko; Takeda, Akihiro; Tagami, Takaomi; Katagi, Munehiro; Kamata, Hiroe; Sawabe, Yoshiyuki

    2016-11-18

    Synthetic cannabinoids, recently used as alternatives to Cannabis sativa, are among the most frequently abused drugs. Identified in 2014, the synthetic cannabinoids N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-(5-fluoropentyl)-1H-indazole-3-carboxamide (5F-AB-PINACA) and methyl [1-(5-fluoropentyl)-1H-indazole-3-carbonyl]-valinate (5F-AMB) are carboxamides composed of 1-(5-fluoropentyl)-1H-indazole-3-carboxylic acid and valine amide/methyl ester. Because of their composition, these molecules have pairs of enantiomers derived from the chiral center of their amino acid structures. Previous studies on the identification of 5F-AB-PINACA and 5F-AMB did not consider the existence of enantiomers, and there have been no reports on the enantiopurities of synthetic cannabinoids. We synthesized both enantiomers of these compounds and then separated the enantiomers by liquid chromatography-high-resolution mass spectrometry using a column with a chiral stationary phase consisted with amylose tris (3-chloro-4-methylphenylcarbamate). Under the optimized conditions, the enantiomer resolutions were 2.2 and 2.3 for 5F-AB-PINACA and 5F-AMB, respectively. Analysis of 10 herbal samples containing 5F-AB-PINACA and one herbal sample containing 5F-AMB showed that they all contained the (S)-enantiomer, but the (R)-enantiomer was only detected in two samples and at a ratio of less than 20%. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Synthesis and molecular crystal of 3-Chloro-2-(1-chloro-1-methyl-ethyl)-2,3-dihydro-1H-naphtho[2,1-b]oxepin-4-one

    NASA Astrophysics Data System (ADS)

    Tittal, Ram Kumar

    2018-03-01

    CuCl/TMEDA-promoted halogen atom transfer radical cyclization (HATRC) of dichloroacetic acid 1-(3-methyl-but-2-enyl)-naphthalen-2-yl ester in refluxing DCE gave chlorine containing 7-member lactone 3-Chloro-2-(1-chloro-1-methyl-ethyl)-2,3-dihydro-1H-naphtho[2,1-b]oxepin-4-one via 7-exo trig radical cyclization reaction. The structure of the Lactone was confirmed by X-ray diffraction data.

  2. H2S Protects Against Methionine–Induced Oxidative Stress in Brain Endothelial Cells

    PubMed Central

    Tyagi, Neetu; Moshal, Karni S.; Sen, Utpal; Vacek, Thomas P.; Kumar, Munish; Hughes, William M.; Kundu, Soumi

    2009-01-01

    Abstract Homocysteine (Hcy) causes cerebrovascular dysfunction by inducing oxidative stress. However, to date, there are no strategies to prevent Hcy-induced oxidative damage. Hcy is an H2S precursor formed from methionine (Met) metabolism. We aimed to investigate whether H2S ameliorated Met-induced oxidative stress in mouse brain endothelial cells (bEnd3). The bEnd3 cells were exposed to Met treatment in the presence or absence of NaHS (donor of H2S). Met-induced cell toxicity increased the levels of free radicals in a concentration-dependent manner. Met increased NADPH-oxidase-4 (NOX-4) expression and mitigated thioredxion-1(Trx-1) expression. Pretreatment of bEnd3 with NaHS (0.05 mM) attenuated the production of free radicals in the presence of Met and protected the cells from oxidative damage. Furthermore, NaHS enhanced inhibitory effects of apocynin, N-acetyl-l-cysteine (NAC), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), Nω-nitro-l-arginine methyl ester (L-NAME) on ROS production and redox enzymes levels induced by Met. In conclusion, the administration of H2S protected the cells from oxidative stress induced by hyperhomocysteinemia (HHcy), which suggested that NaHS/H2S may have therapeutic potential against Met-induced oxidative stress. Antioxid. Redox Signal. 11, 25–33. PMID:18837652

  3. Fertility of male rats treated with 15(S)-15-methyl prostaglandin F2 alpha methyl ester-containing silastic implants.

    PubMed

    Kimball, F A; Frielink, R D; Porteus, S E

    1978-01-01

    Male Spraque-Dawley rats receiving implants of silicone rubber discs containing 1% or 2% 15(S)-15-methyl prostaglandin F2 alpha methyl ester (15-Me-PGF 2 alpha) or no prostaglandin were tested in successive breeding trials for potency and fertility. One week after implantation, discs containing 1% 15-Me-PGF2 alpha reduced potency and fertility, which returned 2 weeks after implantation. Animals receiving implants of the 2% discs were apparently impotent the 1st week following implantation; potency returned before full fertility returned 11 weeks after implantation.

  4. Volatile sulphur compound levels and related factors in patients with chronic renal failure.

    PubMed

    Gulsahi, Ayse; Evirgen, Sehrazat; Öztaş, Bengi; Genç, Yasemin; Çetinel, Yasemin

    2014-08-01

    To analyse specific volatile sulphur compound(VSC) levels in a group of chronic renal failure (CRF) patients and determine the relationship between these VSC levels and organoleptic measurements, blood urea nitrogen (BUN) levels, dental and periodontal conditions, salivary flow rate, and tongue coating scores. One examiner performed organoleptic and VSC measurements on fifty patients with CRF before and after haemodialysis (HD) and controls. DMFT and CPITN indexes, tongue coating scores, salivary flow rates were measured. Comparisons were performed using the Mann-Whitney U, Wilcoxon signed-ranks, and chi-square tests. Spearman correlation coefficient was used to analyse correlations. Before HD, the mean dimethyl sulphide level was 1.04 ± 1.20 in the CRF patients and 0.51 ± 0.65 in controls, with a significant difference. The mean hydrogen sulphide, methyl mercaptan and dimethyl sulphide levels in CRF patients were 1.47 ± 3.04, 1.03 ± 1.85, and 1.04 ± 1.20, respectively, before HD; and 0.53 ± 1.65, 0.48 ± 1.27, and 0.56 ± 0.85, respectively, after HD; with the differences being significant. Methyl mercaptan levels increased with an increase in HD duration. Tongue coating and organoleptic measurements were significantly correlated with methyl mercaptan. Dimethyl sulphide is the main VSC in extraoral blood-borne halitosis; but methyl mercaptan may also contribute to this type of halitosis. A decreased salivary flow rate and an increased pH of the biofilm matrix may be a significant parameter for VSC levels in CRF patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Syntheses, crystal structures and luminescent properties of two salts with 2-((1H-imidazol-1-yl)methyl)-1H-benzimidazole

    NASA Astrophysics Data System (ADS)

    Wang, Yong-Tao; Lü, Lin-Rui; Tang, Gui-Mei

    2018-03-01

    Two new benzimidazole salts, namely, [H2IBI]2+ 2X (X = NO3- (1), ClO4- (2) [IBI = 2-((1H-imidazol-1-yl)methyl)-1H-benzimidazole], were grown through reacting IBI and two different inorganic acids by slow evaporation method, respectively. Compounds 1 and 2 have been characterized by single-crystal X-ray diffraction, IR, UV-Vis, and thermogravimetric analyses (TGA). In both compounds, a set of hydrogen bonds (C/Nsbnd H⋯O) can be clearly observed, through which a three-dimensional framework will be generated. The luminescent spectra show the emission peaks in compounds 1 and 2 are found at 375 and 371 nm, respectively. By comparison with the free IBI, the emission maxima of compounds 1 and 2 are obviously red-shifted about 67 and 63 nm, respectively.

  6. Experimental and theoretical studies of the molecular structure of 7-Methyl-3-[(3-methyl-3-mesityl-cyclobutyl]-5-phenyl-5H-thiazolo[3,2-α]pyrimidine-6-carboxylic acid ethyl ester

    NASA Astrophysics Data System (ADS)

    Acar, Betül; Yilmaz, Ibrahim; Çalışkan, Nezihe; Cukurovali, Alaaddin

    2017-07-01

    In this work, the title molecule, 7-Methyl-3-[(3-methyl-3-mesityl-cyclobutyl]-5-phenyl-5H-thiazolo[3,2-α]pyrimidine-6-carboxylic acid ethyl ester (C30H34N2O2S1), was synthesized and characterized by FT-IR spectroscopy and single crystal X-ray diffraction. The compound crystallizes in the triclinic space group P21/c. with Z = 4, a = 14.1988(6), b = 19.0893(5), c = 10.1325(4) Å, V = 2674.56(17) A3. The optimized structure parameters of the studied molecule was determined theoretically using HF/6-31G(d) and B3LYP/6-31G(d) methods for ground state, and compared with previously reported experimental findings. The calculated harmonic vibrational frequencies are scaled and they are compared with experimental frequencies obtained by FT-IR spectra. The electronic properties, such as HOMO and LUMO energies, and molecular electrostatic potential (MEP) are also performed.

  7. Generation of Five Human Lactoferrin Transgenic Cloned Goats Using Fibroblast Cells and Their Methylation Status of Putative Differential Methylation Regions of IGF2R and H19 Imprinted Genes

    PubMed Central

    Sun, Yanyan; Zhang, Yanli; Wang, Ziyu; Song, Yang; Wang, Feng

    2013-01-01

    Background Somatic cell nuclear transfer (SCNT) is a promising technique to produce transgenic cloned mammalian, including transgenic goats which may produce Human Lactoferrin (hLF). However, success percentage of SCNT is low, because of gestational and neonatal failure of transgenic embryos. According to the studies on cattle and mice, DNA methylation of some imprinted genes, which plays a vital role in the reprogramming of embryo in NT maybe an underlying mechanism. Methodology/Principal Findings Fibroblast cells were derived from the ear of a two-month-old goat. The vector expressing hLF was constructed and transfected into fibroblasts. G418 selection, EGFP expression, PCR, and cell cycle distribution were applied sequentially to select transgenic cells clones. After NT and embryo transfer, five transgenic cloned goats were obtained from 240 cloned transgenic embryos. These transgenic goats were identified by 8 microsatellites genotyping and southern blot. Of the five transgenic goats, 3 were lived after birth, while 2 were dead during gestation. We compared differential methylation regions (DMR) pattern of two paternally imprinted genes (H19 and IGF2R) of the ear tissues from the lived transgenic goats, dead transgenic goats, and control goats from natural reproduction. Hyper-methylation pattern appeared in cloned aborted goats, while methylation status was relatively normal in cloned lived goats compared with normal goats. Conclusions/Significance In this study, we generated five hLF transgenic cloned goats by SCNT. This is the first time the DNA methylation of lived and dead transgenic cloned goats was compared. The results demonstrated that the methylation status of DMRs of H19 and IGF2R were different in lived and dead transgenic goats and therefore this may be potentially used to assess the reprogramming status of transgenic cloned goats. Understanding the pattern of gene imprinting may be useful to improve cloning techniques in future. PMID:24204972

  8. Microwave assisted synthesis and structure-activity relationship of 4-hydroxy-N'-[1-phenylethylidene]-2H/2-methyl-1,2-benzothiazine-3-carbohydrazide 1,1-dioxides as anti-microbial agents.

    PubMed

    Ahmad, Naveed; Zia-ur-Rehman, Muhammad; Siddiqui, Hamid Latif; Ullah, Muhammad Fasih; Parvez, Masood

    2011-06-01

    A series of 4-hydroxy-N'-[1-phenylethylidene]-2H/2-methyl, 1,2-benzothiazine-3-carbohydrazide 1,1-dioxides was synthesized from commercially available sodium saccharin. Base catalyzed ring expansion of methyl (1,1-dioxido-3-oxo-1,2-benzisothiazol-2(3H)-yl)acetate followed by ultrasound mediated hydrazinolysis and subsequent reaction with 1-phenylethanones under the influence of microwaves yielded the title compounds. Besides, microwave assisted synthesis of 1,4-dihydropyrazolo[4,3-c][1,2]benzothiazin-3-ol 5,5-dioxide and 4-methyl-1,4-dihydropyrazolo[4,3-c][1,2]benzothiazin-3-ol 5,5-dioxide is also discussed. Most of the synthesized compounds were found to possess moderate to significant anti-microbial (anti-bacterial and anti-fungal) activities. It is found that compounds with greater lipophilicity (N-methyl analogues) possessed higher anti-bacterial activities. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  9. Synthesis, spectral and structural characterization of isobutyl 4-(2-chlorophenyl)-5-cyano-6-(((dimethylamino)methylene)amino)-2-methyl-4H-pyran-3-carboxylate

    NASA Astrophysics Data System (ADS)

    Udhaya Kumar, C.; Velayutham Pillai, M.; Gokula Krishnan, K.; Ramalingan, C.

    2017-09-01

    A fascinating selectivity in the direction of the formation of the formamidine was observed upon the reaction of isobutyl 6-amino-4-(2-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate with N,N-dimethyl formamide. A development in selectivity is explored and a probable mechanism for the reaction is also proposed. The formamidine has been analyzed by FT-IR, FT-Raman, LC-MS and NMR (1D and 2D (1H-1H COSY, 1H-13C COSY and HMBC)) spectra. The experimental findings are compared with the theoretical data calculated by using DFT-B3LYP with 6-311++G(d,p) basis set. A good agreement has been observed between experimental and theoretical data. Single crystal X-ray structural analysis of isobutyl 4-(2-chlorophenyl)-5-cyano-6-(((dimethylamino)methylene)amino)-2-methyl-4H-pyran-3-carboxylate (PDMF), evidences the conformation of pyran ring as "flattened-boat".

  10. Fumonisin FB1 treatment acts synergistically with methyl donor deficiency during rat pregnancy to produce alterations of H3- and H4-histone methylation patterns in fetuses.

    PubMed

    Pellanda, Hélène; Forges, Thierry; Bressenot, Aude; Chango, Abalo; Bronowicki, Jean-Pierre; Guéant, Jean-Louis; Namour, Fares

    2012-06-01

    Prenatal folate and methyl donor malnutrition lead to epigenetic alterations that could enhance susceptibility to disease. Methyl-deficient diet (MDD) and fumonisin FB1 are risk factors for neural tube defects and cancers. Evidence indicates that FB1 impairs folate metabolism. Folate receptors and four heterochromatin markers were investigated in rat fetuses liver derived from dams exposed to MDD and/or FB1 administered at a dose twice higher than the provisional maximum tolerable daily intake (PMTDI = 2 μg/kg/day). Even though folate receptors transcription seemed up-regulated by methyl depletion regardless of FB1 treatment, combined MDD/FB1 exposure might reverse this up-regulation since folate receptors transcripts were lower in the MDD/FB1 versus MDD group. Methyl depletion decreased H4K20me3. Combined MDD/FB1 decreased H4K20me3 even more and increased H3K9me3. The elevated H3K9me3 can be viewed as a defense mechanism inciting the cell to resist heterochromatin disorganization. H3R2me2 and H4K16Ac varied according to this mechanism even though statistical significance was not consistent. Considering that humans are exposed to FB1 levels above the PMTDI, this study is relevant because it suggests that low doses of FB1 interact with MDD thus contributing to disrupt the epigenetic landscape. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Infrared Spectra of Polycyclic Aromatic Hydrocarbons: Methyl Substitution and Loss of H

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W.; Langhoff, Stephen R.; Arnold, James O. (Technical Monitor)

    1998-01-01

    The B3LYP approach, in conjunction with the 4-31G basis set, is used to compute the harmonic frequencies of 1- and 2-methylnaphthalene, 1-, 2-, and 9-methylanthracene, and their cations. The IR spectra of the methyl substituted species are very similar to the parent spectra, except for the addition of the methyl C-H stretch at lower frequency than the aromatic C-H stretch. The loss of a single hydrogen from naphthalene, anthracene, and their cations is shown to have a very small effect on the IR spectra. Loss of a methyl hydrogen from 1- or 2-methylnaphthalene, or their cations, is shown to shift the side group C-H frequencies from below aromatic hydrogen stretching frequencies to above them. The loss of IT from 2-methylenenaphthalene shows only a small shift in the side group C-H stretching frequency.

  12. 21 CFR 73.3122 - 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one. 73.3122 Section 73.3122 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical...

  13. 21 CFR 73.3122 - 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one. 73.3122 Section 73.3122 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical...

  14. 21 CFR 73.3122 - 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one. 73.3122 Section 73.3122 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical...

  15. 21 CFR 73.3122 - 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one. 73.3122 Section 73.3122 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical...

  16. 21 CFR 73.3122 - 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false 4-[(2,4-dimethylphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one. 73.3122 Section 73.3122 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Medical...

  17. In vivo estradiol-dependent dephosphorylation of the repressor MDBP-2-H1 correlates with the loss of in vitro preferential binding to methylated DNA.

    PubMed Central

    Bruhat, A; Jost, J P

    1995-01-01

    We have previously shown that estradiol treatment of roosters resulted in a rapid loss of binding activity of the repressor MDBP-2-H1 (a member of the histone H1 family) to methylated DNA that was not due to a decrease in MDBP-2-H1 concentration. Here we demonstrate that MDBP-2-H1 from rooster liver nuclear extracts is a phosphoprotein. Phosphoamino acid analysis reveals that the phosphorylation occurs exclusively on serine residues. Two-dimensional gel electrophoresis and tryptic phosphopeptide analysis show that MDBP-2-H1 is phosphorylated at several sites. Treatment of roosters with estradiol triggers a dephosphorylation of at least two sites in the protein. Phosphatase treatment of purified rooster MDBP-2-H1 combined with gel mobility shift assay indicates that phosphorylation of MDBP-2-H1 is essential for the binding to methylated DNA and that the dephosphorylation can occur on the protein bound to methylated DNA causing its release from DNA. Thus, these results suggest that in vivo modification of the phosphorylation status of MDBP-2-H1 caused by estradiol treatment may be a key step for the down regulation of its binding to methylated DNA. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:7731964

  18. Crystal structure of N′-[(E)-(1S,3R)-(3-isopropyl-1-methyl-2-oxo­cyclo­pent­yl)methyl­idene]-4-methyl­benzene­sulfono­hydrazide

    PubMed Central

    Tymann, David; Dragon, Dina Christina; Golz, Christopher; Preut, Hans; Strohmann, Carsten; Hiersemann, Martin

    2015-01-01

    The title compound, C17H24N2O3S, was synthesized in order to determine the relative configuration of the corresponding β-keto aldehyde. In the U-shaped mol­ecule, the five-membered ring approximates an envelope, with the methyl­ene C atom adjacent to the quaternary C atom being the flap, and the methyl and isopropyl substituents lying to the same side of the ring. The dihedral angles between the four nearly coplanar atoms of the five-membered ring and the flap and the aromatic ring are 35.74 (15) and 55.72 (9)°, respectively. The bond angles around the S atom are in the range from 103.26 (12) to 120.65 (14)°. In the crystal, mol­ecules are linked via N—H⋯O hydrogen bonds, forming a chain along the a axis. PMID:26870519

  19. Self-Driven Photoelectrochemical Splitting of H2S for S and H2 Recovery and Simultaneous Electricity Generation.

    PubMed

    Luo, Tao; Bai, Jing; Li, Jinhua; Zeng, Qingyi; Ji, Youzhi; Qiao, Li; Li, Xiaoyan; Zhou, Baoxue

    2017-11-07

    A novel, facile self-driven photoelectrocatalytic (PEC) system was established for highly selective and efficient recovery of H 2 S and simultaneous electricity production. The key ideas were the self-bias function between a WO 3 photoanode and a Si/PVC photocathode due to their mismatched Fermi levels and the special cyclic redox reaction mechanism of I - /I 3 - . Under solar light, the system facilitated the separation of holes in the photoanode and electrons in the photocathode, which then generated electricity. Cyclic redox reactions were produced in the photoanode region as follows: I - was transformed into I 3 - by photoholes or hydroxyl radicals, H 2 S was oxidized to S by I 3 - , and I 3 - was then reduced to I - . Meanwhile, H + was efficiently converted to H 2 in the photocathode region. In the system, H 2 S was uniquely oxidized to sulfur but not to polysulfide (S x n- ) because of the mild oxidation capacity of I 3 - . High recovery rates for S and H 2 were obtained up to ∼1.04 mg h -1 cm -1 and ∼0.75 mL h -1 cm -1 , respectively, suggesting that H 2 S was completely converted into H 2 and S. In addition, the output power density of the system reached ∼0.11 mW cm -2 . The proposed PEC-H 2 S system provides a self-sustaining, energy-saving method for simultaneous H 2 S treatment and energy recovery.

  20. Crystal structures of bis-[(9S,13S,14S)-3-meth-oxy-17-methyl-morphinanium] tetra-chlorido-cobaltate and tetra-chlorido-cuprate.

    PubMed

    Gauchat, Eric; Nazarenko, Alexander Y

    2017-01-01

    (9 S ,13 S ,14 S )-3-Meth-oxy-17-methyl-morphinan (dextromethorphan) forms two isostructural salts with ( a ) tetra-chlorido-cobaltate, namely bis-[(9 S ,13 S ,14 S )-3-meth-oxy-17-methyl-morphinanium] tetra-chlorido-cobaltate, (C 18 H 26 NO) 2 [CoCl 4 ], and ( b ) tetra-chlorido-cuprate, namely bis-[(9 S ,13 S ,14 S )-3-meth-oxy-17-methyl-morphinanium] tetra-chlorido-cuprate, (C 18 H 26 NO) 2 [CuCl 4 ]. The distorted tetra-hedral anions are located on twofold rotational axes. The dextromethorphan cation can be described as being composed of two ring systems, a tetra-hydro-naphthalene system A + B and a deca-hydro-isoquinolinium subunit C + D , that are nearly perpendicular to one another: the angle between mean planes of the A + B and C + D moieties is 78.8 (1)° for ( a ) and 79.0 (1)° for ( b ). Two symmetry-related cations of protonated dextromethorphan are connected to the tetra-chlorido-cobaltate (or tetra-chlorido-cuprate) anions via strong N-H⋯Cl hydrogen bonds, forming neutral ion associates. These associates are packed in the (001) plane with no strong attractive bonding between them. Both compounds are attractive crystalline forms for unambiguous identification of the dextromethorphan and, presumably, of its optical isomer, levomethorphan.

  1. Design, synthesis, and characterization of (1-(4-aryl)- 1H-1,2,3-triazol-4-yl)methyl, substituted phenyl-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates against Mycobacterium tuberculosis

    PubMed Central

    Venugopala, Katharigatta N; Dharma Rao, G B; Bhandary, Subhrajyoti; Pillay, Melendhran; Chopra, Deepak; Aldhubiab, Bandar E; Attimarad, Mahesh; Alwassil, Osama Ibrahim; Harsha, Sree; Mlisana, Koleka

    2016-01-01

    The novel (1-(4-aryl)-1H-1,2,3-triazol-4-yl)methyl, substituted phenyl-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives were synthesized by the click reaction of the dihydropyrimidinones, bearing a terminal alkynyl group, with various substituted aryl azides at room temperature using a catalytic amount of Cu(OAc)2 and sodium ascorbate in a 1:2 ratio of acetone and water as a solvent. The newly synthesized compounds were characterized by a number of spectroscopic techniques, such as infrared, liquid chromatography-mass spectrometry, 1H, and 13C nuclear magnetic resonance along with single crystal X-ray diffraction. The current procedure for the synthesis of 1,2,3-triazole hybrids with dihydropyrimidinones is appropriate for the synthesis of a library of analogs 7a-l and the method accessible here is operationally simple and has excellent yields. The title compounds 7a-l were evaluated for their in vitro antitubercular activity against H37RV and multidrug-resistant strains of Mycobacterium tuberculosis by resazurin microplate assay plate method and it was found that compound 7d was promising against H37RV and multidrug-resistant strains of M. tuberculosis at 10 and 15 μg/mL, respectively. PMID:27601885

  2. Design, synthesis, and characterization of (1-(4-aryl)- 1H-1,2,3-triazol-4-yl)methyl, substituted phenyl-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates against Mycobacterium tuberculosis.

    PubMed

    Venugopala, Katharigatta N; Dharma Rao, G B; Bhandary, Subhrajyoti; Pillay, Melendhran; Chopra, Deepak; Aldhubiab, Bandar E; Attimarad, Mahesh; Alwassil, Osama Ibrahim; Harsha, Sree; Mlisana, Koleka

    2016-01-01

    The novel (1-(4-aryl)-1H-1,2,3-triazol-4-yl)methyl, substituted phenyl-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives were synthesized by the click reaction of the dihydropyrimidinones, bearing a terminal alkynyl group, with various substituted aryl azides at room temperature using a catalytic amount of Cu(OAc)2 and sodium ascorbate in a 1:2 ratio of acetone and water as a solvent. The newly synthesized compounds were characterized by a number of spectroscopic techniques, such as infrared, liquid chromatography-mass spectrometry, (1)H, and (13)C nuclear magnetic resonance along with single crystal X-ray diffraction. The current procedure for the synthesis of 1,2,3-triazole hybrids with dihydropyrimidinones is appropriate for the synthesis of a library of analogs 7a-l and the method accessible here is operationally simple and has excellent yields. The title compounds 7a-l were evaluated for their in vitro antitubercular activity against H37RV and multidrug-resistant strains of Mycobacterium tuberculosis by resazurin microplate assay plate method and it was found that compound 7d was promising against H37RV and multidrug-resistant strains of M. tuberculosis at 10 and 15 μg/mL, respectively.

  3. Methyl 4-eth-oxy-2-methyl-2H-1,2-benzothia-zine-3-carboxyl-ate 1,1-dioxide.

    PubMed

    Zia-Ur-Rehman, Muhammad; Choudary, Jamil Anwar; Elsegood, Mark R J; Akbar, Noshin; Latif Siddiqui, Hamid

    2008-07-16

    In the crystal structure of the title compound, C(13)H(15)NO(5)S, the mol-ecules exhibit weak S=O⋯H-C and C=O⋯H-C inter-molecular inter-actions and arrange themselves into centrosymmetric dimers by means of π-π inter-actions (ring centroids are separated by 3.619 Å, while the closest C⋯C contacts are 3.514 Å). 1,2-Benzothia-zines of this kind have a range of biological activities and are used as medicines in the treatment of inflammation and rheumatoid arthritis.

  4. Discovery of 2-((1H-benzo[d]imidazol-1-yl)methyl)-4H-pyrido[1,2-a]pyrimidin-4-ones as novel PKM2 activators.

    PubMed

    Guo, Chuangxing; Linton, Angelica; Jalaie, Mehran; Kephart, Susan; Ornelas, Martha; Pairish, Mason; Greasley, Samantha; Richardson, Paul; Maegley, Karen; Hickey, Michael; Li, John; Wu, Xin; Ji, Xiaodong; Xie, Zhi

    2013-06-01

    The M2 isoform of pyruvate kinase is an emerging target for antitumor therapy. In this letter, we describe the discovery of 2-((1H-benzo[d]imidazol-1-yl)methyl)-4H-pyrido[1,2-a]pyrimidin-4-ones as potent and selective PKM2 activators which were found to have a novel binding mode. The original lead identified from high throughput screening was optimized into an efficient series via computer-aided structure-based drug design. Both a representative compound from this series and an activator described in the literature were used as molecular tools to probe the biological effects of PKM2 activation on cancer cells. Our results suggested that PKM2 activation alone is not sufficient to alter cancer cell metabolism. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Crystal structure of 1-methyl-3-([2,2-dimethyl-4,6-dioxo-1,3-dioxane-5-ylidene]methyl)urea

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Habibi, A., E-mail: habibi@khu.ac.ir; Ghorbani, H. S.; Bruno, G.

    2013-12-15

    The crystal structure of 1-Methyl-3-([2,2-dimethyl-4,6-dioxo-1,3-dioxane-5-ylidene]methyl)urea (C{sub 9}H{sub 12}N{sub 2}O{sub 5}) has been determined by single crystal X-ray diffraction analysis. The crystals are monoclinic, a = 5.3179(2), b = 18.6394(6), c =10.8124(3) Å, β = 100.015(2)°, Z = 4, sp. gr. P2{sub 1}/c, R = 0.0381 for 2537 reflections with I > 2σ(I). Except for C(CH{sub 3}){sub 2} group, the molecule is planar. The structure is stabilized by inter- and intramolecular N-H...O hydrogen bonds and weak C-H...O interactions.

  6. Nucleoside-O-Methyl-(H)-Phosphinates: Novel Monomers for the Synthesis of Methylphosphonate Oligonucleotides Using H-Phosphonate Chemistry.

    PubMed

    Kostov, Ondřej; Páv, Ondřej; Rosenberg, Ivan

    2017-09-18

    This unit comprises the straightforward synthesis of protected 2'-deoxyribonucleoside-O-methyl-(H)-phosphinates in both 3'- and 5'-series. These compounds represent a new class of monomers compatible with the solid-phase synthesis of oligonucleotides using H-phosphonate chemistry and are suitable for the preparation of both 3'- and 5'-O-methylphosphonate oligonucleotides. The synthesis of 4-toluenesulfonyloxymethyl-(H)-phosphinic acid as a new reagent for the preparation of O-methyl-(H)-phosphinic acid derivatives is described. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  7. Nitric oxide reactivity of [2Fe-2S] clusters leading to H2S generation.

    PubMed

    Tran, Camly T; Williard, Paul G; Kim, Eunsuk

    2014-08-27

    The crosstalk between two biologically important signaling molecules, nitric oxide (NO) and hydrogen sulfide (H2S), proceeds via elusive mechanism(s). Herein we report the formation of H2S by the action of NO on synthetic [2Fe-2S] clusters when the reaction environment is capable of providing a formal H(•) (e(-)/H(+)). Nitrosylation of (NEt4)2[Fe2S2(SPh)4] (1) in the presence of PhSH or (t)Bu3PhOH results in the formation of (NEt4)[Fe(NO)2(SPh)2] (2) and H2S with the concomitant generation of PhSSPh or (t)Bu3PhO(•). The amount of H2S generated is dependent on the electronic environment of the [2Fe-2S] cluster as well as the type of H(•) donor. Employment of clusters with electron-donating groups or H(•) donors from thiols leads to a larger amount of H2S evolution. The 1/NO reaction in the presence of PhSH exhibits biphasic decay kinetics with no deuterium kinetic isotope effect upon PhSD substitution. However, the rates of decay increase significantly with the use of 4-MeO-PhSH or 4-Me-PhSH in place of PhSH. These results provide the first chemical evidence to suggest that [Fe-S] clusters are likely to be a site for the crosstalk between NO and H2S in biology.

  8. 40 CFR 180.426 - 2-[4,5-Dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinoline carboxylic acid...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinoline carboxylic acid; tolerance for residues. 180.426 Section 180...-Dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinoline carboxylic acid; tolerance for...)-5-oxo-1H-imidazol-2-yl]-3-quinoline carboxylic acid, in or on the raw agricultural commodity soybean...

  9. Synthesis and antiviral bioactivities of 2-aryl- or 2-methyl-3-(substituted- benzalamino)-4(3H)-quinazolinone derivatives.

    PubMed

    Gao, Xingwen; Cai, Xuejian; Yan, Kai; Song, Baoan; Gao, Lili; Chen, Zhuo

    2007-12-27

    A simple and general method has been developed for the synthesis of various4(3H)-quinazolinone derivatives by the treatment of the appropriate 3-amino-2-aryl-4(3H)-quinazolinone with a substituted benzaldehyde in ethanol. The structures of the compoundswere characterized by elemental analysis, IR, (1)H-NMR and (13)C-NMR spectra. The title 2-aryl- or 2-methyl-3-(substituted-benzalamino)-4(3H)-quinazolinone compounds III-1~III-31 were found to possess moderate to good antiviral activity. Semi-quantitative PCR andReal Time PCR assays were used to ascertain the target of action of compound III-31against TMV. The studies suggest that III-31 possesses antiviral activity due to inductionof up-regulation of PR-1a and PR-5, thereby inhibiting virus proliferation and movementby enhancement of the activity of some defensive enzyme.

  10. Tautomeric equilibria in solutions of 1-methyl-2-phenacylbenzimidazoles

    NASA Astrophysics Data System (ADS)

    Skotnicka, Agnieszka; Czeleń, Przemysław; Gawinecki, Ryszard

    2017-04-01

    Until now the susceptibility of 1-methyl-2-phenacylbenzimidazoles to the proton transfer has not been carefully examined. There only have been selective trials to recognize tautomeric equilibrium of substituted compounds. Unfortunately, conclusions of these studies are often conflicting. Therefore, the aim of this work was to analyze the influence of the factors affecting the tautomeric processes of substituted 1-methyl-2-phenacylbenzimidazoles in solutions of chloroform by spectroscopic technique of 1H and 13C NMR. Complex equilibria may only take place when molecules of tautomeric species contain multiple basic and/or acidic centres. Analysis of NMR spectra show unequivocally that 1-methyl-2-phenacylbenzimidazoles (ketimine tautomeric form) are in equilibrium with (Z)-2-(1-methyl-1H-benzo[d]imidazol-2yl)-1-phenylethenols (enolimine).

  11. (Z)-3-Methyl-4-[1-(4-methyl­anilino)propyl­idene]-1-phenyl-1H-pyrazol-5(4H)-one

    PubMed Central

    Sharma, Naresh; Vyas, Komal M.; Jadeja, R. N.; Kant, Rajni; Gupta, Vivek K.

    2013-01-01

    In the title mol­ecule, C20H21N3O, the central pyrazole ring forms dihedral angles of 4.75 (9) and 49.11 (9)°, respectively, with the phenyl and methyl-substituted benzene rings. The dihedral angle between the phenyl and benzene rings is 51.76 (8)°. The amino group and carbonyl O atom are involved in an intra­molecular N—H⋯O hydrogen bond. In the crystal, π–π inter­actions are observed between benzene rings [centroid–centroid seperation = 3.892 (2) Å] and pyrazole rings [centroid–centroid seperation = 3.626 (2) Å], forming chains along [111]. The H atoms of the methyl group on the p-tolyl substituent were refined as disordered over two sets of sites in a 0.60 (4):0.40 (4) ratio. PMID:24109353

  12. Template-free fabrication of hierarchical macro/mesoporpous SnS2/TiO2 composite with enhanced photocatalytic degradation of Methyl Orange (MO)

    NASA Astrophysics Data System (ADS)

    Dai, Gaopeng; Qin, Haiquan; Zhou, Huan; Wang, Wanqiang; Luo, Tianxiong

    2018-02-01

    Ordered macro/mesoporous SnS2/TiO2 composite was successfully prepared via a template-free aqueous technique using tetrabutyl titanate as the titanium precursor and SnCl4•5H2O as the tin precursor. The photocatalytic activity of SnS2/TiO2 composite was tested by the degradation of Methyl Orange (MO) aqueous solution under irradiation of the simulated sunlight. It was found that SnS2/TiO2 composite displayed an enhanced photocatalytic activity with a 0.055 min-1 apparent rate constant (degradation efficiency of 90.9% within 50 min). The ordered macro/mesoporous structure and SnS2/TiO2 heterostructure were considered to play synergistic effects in its enhanced photocatalytic performance, because the ordered porous structure can improve mass transfer and light capture, and heterostructure between SnS2 and TiO2 can reduce the recombination rate of photogenerated electrons and holes.

  13. Synthesis of methyl (13(2)R/S)-alkyl-pyropheophorbide a and a non-epimerized chlorophyll a mimic.

    PubMed

    Ogasawara, Shin; Tamiaki, Hitoshi

    2015-10-15

    The (13(2)R/S)-methoxycarbonyl group of methyl pheophorbides a/a' (chlorophyll a/a' derivatives) was converted to methyl, ethyl, propyl, and isopropyl groups through the C13(2)-alkylation under basic conditions followed by pyrolysis in 2,4,6-collidine with lithium iodide. All the resulting products, methyl 13(2)-alkyl-pyropheophorbides a, predominantly gave the (13(2)R)-stereoisomers with about one tenth of the (13(2)S)-epimers. Their stereochemistry was determined by 1D/2D NMR and their optical properties were characterized by visible absorption and circular dichroism spectroscopy. Methyl (13(2)R)-propyl-pyropheophorbide a was converted to (13(2)R)-propyl-pyrochlorophyll a by ester exchanging and magnesium chelating reactions. The synthetic chlorophyll a analogue showed non-epimerization at the 13(2)-position in pyridine-d5 at 40°C, while naturally occurring chlorophyll a was easily epimerized under the same conditions to give its epimeric mixture. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. 40 CFR 721.8485 - 2-Propenoic acid, 2-methyl-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.8485 2-Propenoic acid, 2-methyl-, (octahydro-4,7-methano-1H- indene-5-diyl)bis(methylene) ester. (a) Chemical substance and...

  15. Toxicological evaluation of two novel bitter modifying flavour compounds: 3-(1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazol-4-yl)-1-(3-hydroxybenzyl)imidazolidine-2,4-dione and 3-(1-((3,5-dimethylisoxazol-4-yl)methyl)-1H-pyrazol-4-yl)-1-(3-hydroxybenzyl)-5,5-dimethylimidazolidine-2,4-dione.

    PubMed

    Karanewsky, Donald S; Arthur, Amy J; Liu, Hanghui; Chi, Bert; Ida, Lily; Markison, Stacy

    2016-01-01

    A toxicological evaluation of two novel bitter modifying flavour compounds, 3-(1-((3,5-dimethylisoxazol-4-yl)methyl)-1 H -pyrazol-4-yl)-1-(3-hydroxybenzyl)imidazolidine-2,4-dione (S6821, CAS 1119831-25-2) and 3-(1-((3,5-dimethylisoxazol-4-yl)methyl)-1 H -pyrazol-4-yl)-1-(3-hydroxybenzyl)-5,5-dimethylimidazolidine-2,4-dione (S7958, CAS 1217341-48-4), were completed for the purpose of assessing their safety for use in food and beverage applications. S6821 undergoes oxidative metabolism in vitro , and in rat pharmacokinetic studies both S6821 and S7958 are rapidly converted to the corresponding O-sulfate and O-glucuronide conjugates. S6821 was not found to be mutagenic or clastogenic in vitro , and did not induce micronuclei in bone marrow polychromatic erythrocytes in vivo . S7958, a close structural analog of S6821, was also found to be non-mutagenic in vitro . In short term and subchronic oral toxicity studies in rats, the no-observed-adverse-effect-level (NOAEL) for both S7958 and S6821 was 100 mg/kg bw/day (highest dose tested) when administered as a food ad-mix for either 28 or 90 consecutive days, respectively. Furthermore, S6821 demonstrated a lack of maternal toxicity, as well as adverse effects on fetal morphology at the highest dose tested, providing a NOAEL of 1000 mg/kg bw/day for both maternal toxicity and embryo/fetal development when administered orally during gestation to pregnant rats.

  16. Tungsten phosphanylarylthiolato complexes [W{PhP(2-SC6H4)2-kappa3S,S',P} 2] and [W{P(2-SC6H4)3-kappa4S,S',S",P}2]: synthesis, structures and redox chemistry.

    PubMed

    Hildebrand, Alexandra; Lönnecke, Peter; Silaghi-Dumitrescu, Luminita; Hey-Hawkins, Evamarie

    2008-09-14

    PhP(2-SHC6H4)2 (PS2H2) reacts with WCl6 with reduction of tungsten to give the air-sensitive tungsten(IV) complex [W{PhP(2-SC6H4)2-kappa(3)S,S',P}2] (1). 1 is oxidised in air to [WO{PhPO(2-SC6H4)2-kappa(3)S,S',O}{PhP(2-SC6H4)2-kappa(3)S,S',P}] (2). The attempted synthesis of 2 by reaction of 1 with iodosobenzene as oxidising agent was unsuccessful. [W{P(2-SC6H4)3-kappa(4)S,S',S",P}2] (3) was formed in the reaction of P(2-SHC6H4)3 (PS3H3) with WCl6. The W(VI) complex 3 contains two PS3(3-) ligands, each coordinated in a tetradentate fashion resulting in a tungsten coordination number of eight. The reaction of 3 with AgBF4 yields the dinuclear tungsten complex [W2{P(2-SC6H4)3-kappa(4)S,S',S",P}3]BF4 (4). Complexes 1-4 were characterised by spectral methods and X-ray structure determination.

  17. DNA precursor pool: a significant target for N-methyl-N-nitrosourea in C3H/10T1/2 clone 8 cells.

    PubMed Central

    Topal, M D; Baker, M S

    1982-01-01

    Synchronized C3H/10T1/2 clone 8 cells were treated in vitro with a nontoxic dose of N-methyl-N-nitrosourea during their S phase. Chromatographic isolation of the deoxyribonucleotide DNA precursor pool and measurement of the precursor content per cell showed that a nucleic acid residue in the precursor pool is 190-13,000 times more susceptible to methylation than a residue in the DNA duplex, depending on the site of methylation. This conclusion comes from measurements indicating that, for example, the N-1 position of adenine in dATP is 6.3 times more methylated than the same position in the DNA, even though the adenine content of the pool is only a fraction (0.0005) of the adenine content of the DNA helix. The comparative susceptibility between pool and DNA was found to vary with the site of methylation in the order the N-1 position of adenine greater than phosphate greater than the N-3 position of adenine greater than the O6 position of guanine greater than the N-7 position of guanine. The significance of these results for chemical mutagenesis and carcinogenesis is discussed. PMID:6954535

  18. Bis(tetra­phenyl­phospho­nium) tris­[N-(methyl­sulfon­yl)dithio­carbimato(2−)-κ2 S,S′]stannate(IV)

    PubMed Central

    Barolli, João P.; Oliveira, Marcelo R. L.; Corrêa, Rodrigo S.; Ellena, Javier

    2009-01-01

    In the title complex, (C24H20P)2[Sn(C2H3NO2S3)3], the SnIV atom is coordinated by three N-(methyl­sulfon­yl)dithio­carbimate bidentate ligands through the anionic S atoms in a slightly distorted octa­hedral coordination geometry. There is one half-mol­ecule in the asymmetric unit; the complex is located on a crystallographic twofold rotation axis passing through the cation and bis­ecting one of the (non-symmetric) ligands, which appears thus disordered over two sites of equal occupancy. In the crystal structure, weak inter­molecular C—H⋯O and C—H⋯S inter­actions contribute to the packing stabilization. PMID:21577695

  19. Experimental, DFT and molecular docking studies on 2-(2-mercaptophenylimino)-4-methyl-2H-chromen-7-ol

    NASA Astrophysics Data System (ADS)

    Singh, Ashok Kumar; Singh, Ravindra Kumar

    2016-10-01

    A new coumarin derivative 2-(2-mercaptophenylimino)-4-methyl-2H-chromen-7-ol (COMSB) was synthesized and characterized with the help of 1H,13C NMR, FT-IR, FT-Raman and mass spectrometry. All quantum calculations were performed at DFT level of theory using B3LYP functional and 6-31G (d,p) as basis set. The UV-Vis spectrum studied by TD-DFT theory, with a hybrid exchange-correlation functional using Coulomb-attenuating method (CAM-B3LYP) in solvent phase gives similar pattern of bands, at energies and is consistent with that of experimental findings. The detailed analysis of vibrational (IR and Raman) spectra and their assignments has been done by computing Potential Energy Distribution (PED) using Gar2ped. Intra-molecular interactions were analyzed by 'Atoms in molecule' (AIM) approach. Computed first static hyperpolarizability (β0 = 8.583 × 10-30 esu) indicates non-linear optical (NLO) response of the molecule. Molecular docking studies show that the title molecule may act as potential acetylcholine esterase (AChE) inhibitor.

  20. Structure-activity relationship of 5-chloro-2-methyl-3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole analogues as 5-HT(6) receptor agonists.

    PubMed

    Mattsson, Cecilia; Svensson, Peder; Boettcher, Henning; Sonesson, Clas

    2013-05-01

    To further investigate the structure-activity relationship (SAR) of the 5-hydroxytryptamine type 6 (5-HT6) receptor agonist 5-chloro-2-methyl-3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole (EMD386088, 6), a series of 2-methyl-3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indoles were synthesized, and in vitro affinity to, and functional activity at 5-HT6 receptors was tested. We focused on substituents made at the indole N(1)-, 2- and 5-positions and these were found to not only influence the affinity at 5-HT6 receptors but also the intrinsic activity leading to antagonists, partial agonists and full agonists. In order for a compound to demonstrate potent 5-HT6 receptor agonist properties, the indole N(1) should be unsubstituted, an alkyl group such as 2-methyl is needed and finally halogen substituents in the indole 5-position (fluoro, chloro or, bromo) were essential requirements. However, the introduction of a benzenesulfonyl group at N(1)-position switched the full agonist 6 to be a 5-HT6 receptor antagonist (30). A few compounds within the 2-methyl-3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indoles were also screened for off-targets and generally they displayed low affinity for other 5-HT subtypes and serotonin transporter protein (SERT). Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  1. 2-(2-Methyl-4-chlorophenoxy)propionic acid (MCPP)

    Integrated Risk Information System (IRIS)

    2 - ( 2 - Methyl - 4 - chlorophenoxy ) propionic acid ( MCPP ) ; CASRN 93 - 65 - 2 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 ( H

  2. Synthesis and characterization of bis-(2-cyano-1-methyl-3-{2- {{(5-methylimidazol-4-yl)methyl}thio}ethyl)guanidine copper(II) sulfate tetrahydrate

    NASA Astrophysics Data System (ADS)

    Rahardjo, Sentot B.; Endah Saraswati, Teguh; Pramono, Edy; Fitriana, Nur

    2016-02-01

    Complex of copper(II) with 2-cyano-1-methyl-3-{2-{{(5-methylimidazol-4- yl)methyl}thio}ethyl)guanidin(xepamet) had been synthesized in 1 : 4 mole ratio of metal to the ligand in methanol. The complex was characterized by metal analysis, thermal gravimetry/differential thermal analyzer (TG/DTA), molar conductivity meter, (Fourier transform infrared spectroscopy) FT-IR, UV-Vis spectroscopy, and magnetic susceptibility balance. The molar conductivity measurement shows that the complex was 2: 1 for electrolyte and SO42- which was acting as a counter ion. The thermal analysis by Thermogravimetric (TG) indicates that the complex contained four molecules of H2O. The Infrared spectral data indicates that functional groups of (C=N) imidazole and (C-S) are coordinated to the center ion Cu2+. Magnetic moment measurement shows that the complex is paramagnetic with peff = 1.78 ± 0.01 BM. Electronic spectra of the complex show a broad band at 608 nm (16447.23 cm-1) are due to Eg→T2g transition. Based on those of characteristics, The complex formula was estimated as [Cu(xepamet)2]SO4.4H2O. The structure of [Cu(xepamet)2]SO4.4H2O complex is probably square planar.

  3. Thiol surface functionalization via continuous phase plasma polymerization of allyl mercaptan, with subsequent maleimide-linked conjugation of collagen.

    PubMed

    Stynes, Gil D; Gengenbach, Thomas R; Kiroff, George K; Morrison, Wayne A; Kirkland, Mark A

    2017-07-01

    Thiol groups can undergo a large variety of chemical reactions and are used in solution phase to conjugate many bioactive molecules. Previous research on solid substrates with continuous phase glow discharge polymerization of thiol-containing monomers may have been compromised by oxidation. Thiol surface functionalization via glow discharge polymerization has been reported as requiring pulsing. Herein, continuous phase glow discharge polymerization of allyl mercaptan (2-propene-1-thiol) was used to generate significant densities of thiol groups on a mixed macrodiol polyurethane and tantalum. Three general classes of chemistry are used to conjugate proteins to thiol groups, with maleimide linkers being used most commonly. Here the pH specificity of maleimide reactions was used effectively to conjugate surface-bound thiol groups to amine groups in collagen. XPS demonstrated surface-bound thiol groups without evidence of oxidation, along with the subsequent presence of maleimide and collagen. Glow discharge reactor parameters were optimized by testing the resistance of bound collagen to degradation by 8 M urea. The nature of the chemical bonding of collagen to surface thiol groups was effectively assessed by colorimetric assay (ELISA) of residual collagen after incubation in 8 M urea over 8 days and after incubation with keratinocytes over 15 days. The facile creation of useable solid-supported thiol groups via continuous phase glow discharge polymerization of allyl mercaptan opens a route for attaching a vast array of bioactive molecules. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1940-1948, 2017. © 2017 Wiley Periodicals, Inc.

  4. Certain and progressive methylation of histone H4 at lysine 20 during the cell cycle.

    PubMed

    Pesavento, James J; Yang, Hongbo; Kelleher, Neil L; Mizzen, Craig A

    2008-01-01

    Methylation of histone H4 at lysine 20 (K20) has been implicated in transcriptional activation, gene silencing, heterochromatin formation, mitosis, and DNA repair. However, little is known about how this modification is regulated or how it contributes to these diverse processes. Metabolic labeling and top-down mass spectrometry reveal that newly synthesized H4 is progressively methylated at K20 during the G(2), M, and G(1) phases of the cell cycle in a process that is largely inescapable and irreversible. Approximately 98% of new H4 becomes dimethylated within two to three cell cycles, and K20 methylation turnover in vivo is undetectable. New H4 is methylated regardless of prior acetylation, and acetylation occurs predominantly on K20-dimethylated H4, refuting the hypothesis that K20 methylation antagonizes H4 acetylation and represses transcription epigenetically. Despite suggestions that it is required for normal mitosis and cell cycle progression, K20 methylation proceeds normally during colchicine treatment. Moreover, delays in PR-Set7 synthesis and K20 methylation which accompany altered cell cycle progression during sodium butyrate treatment appear to be secondary to histone hyperacetylation or other effects of butyrate since depletion of PR-Set7 did not affect cell cycle progression. Together, our data provide an unbiased perspective of the regulation and function of K20 methylation.

  5. Destruction of C2H4O2 isomers in ice-phase by X-rays: Implication on the abundance of acetic acid and methyl formate in the interstellar medium

    NASA Astrophysics Data System (ADS)

    Rachid, Marina G.; Faquine, Karla; Pilling, S.

    2017-12-01

    The C2H4O2 isomers methyl formate (HCOOCH3), acetic acid (CH3COOH) and glycoaldehyde (HOCH2CHO) have been detected in molecular clouds in the interstellar medium, as well as, hot cores, hot corinos and around protostellar objects. However, their abundances are very different, being methyl formate more abundant than the other two isomers. This fact may be related to the different destruction by ionizing radiation of these molecules. The goal of this work is experimentally study the photodissociation processes of methyl formate and acetic acid ices when exposed to broadband soft X-ray from 6 up to 2000 eV. The experiments were performed coupled to the SGM beamline in the Brazilian Synchrotron Light Source (LNLS/CNPEM) at Campinas, Brazil. The simulated astrophysical ices (12 K) were monitored throughout the experiment using infrared vibrational spectroscopy (FTIR). The analysis of processed ices allowed the determination of the effective destruction cross sections of the parent molecules as well as the effective formation cross section of daughter molecular species such as CO, CO2, H2O, CH4 and H2CO (only for methyl formate) and the hydrocarbons C2H6 and C5H10 (only for acetic acid). The half-lives of molecules at ices toward young stellar objects (YSOs) and inside molecular clouds (e.g. Sgr B2 and W51) due to the presence of incoming soft X-rays were estimated. We determined the effective formation rate and the branching ratios for assigned daughter species after the establishment of a chemical equilibrium. The main product from photodissociation of both methyl formate and acetic acid is CO, that can be formed by recombination of ions, formed during the photodissociation, in the ice surface. The relative abundance between methyl formate and acetic acid (NCH3COOH/NHCOOCH3) in different astronomical scenarios and their column density evolution in the presence of X-rays were calculated. Our results suggest that such radiation field can be one of the factors that

  6. P110β Inhibition Reduces Histone H3K4 Di-Methylation in Prostate Cancer.

    PubMed

    Pang, Jun; Yang, Yue-Wu; Huang, Yiling; Yang, Jun; Zhang, Hao; Chen, Ruibao; Dong, Liang; Huang, Yan; Wang, Dongying; Liu, Jihong; Li, Benyi

    2017-02-01

    Epigenetic alteration plays a major role in the development and progression of human cancers, including prostate cancer. Histones are the key factors in modulating gene accessibility to transcription factors and post-translational modification of the histone N-terminal tail including methylation is associated with either transcriptional activation (H3K4me2) or repression (H3K9me3). Furthermore, phosphoinositide 3-kinase (PI3 K) signaling and the androgen receptor (AR) are the key determinants in prostate cancer development and progression. We recently showed that prostate-targeted nano-micelles loaded with PI3 K/p110beta specific inhibitor TGX221 blocked prostate cancer growth in vitro and in vivo. Our objective of this study was to determine the role of PI3 K signaling in histone methylation in prostate cancer, with emphasis on histone H3K4 methylation. PI3 K non-specific inhibitor LY294002 and p110beta-specific inhibitor TGX221 were used to block PI3 K/p110beta signaling. The global levels of H3K4 and H3K9 methylation in prostate cancer cells and tissue specimens were evaluated by Western blot assay and immunohistochemical staining. A synthetic androgen R1881 was used to stimulate AR activity in prostate cancer cells. A castration-resistant prostate cancer (CRPC) specific human tissue microarray (TMA) was used to assess the global levels of H3K4me2 methylation by immunostaining approach. Our data revealed that H3K4me2 levels were significantly elevated after androgen stimulation. With RNA silencing and pharmacology approaches, we further defined that inhibition of PI3 K/p110beta activity through gene-specific knocking down and small chemical inhibitor TGX221 abolished androgen-stimulated H3K4me2 methylation. Consistently, prostate cancer-targeted delivery of TGX221 in vivo dramatically reduced the global levels of H3K4me2 as assessed by immunohistochemical staining on tissue section of mouse xenografts from CRPC cell lines 22RV1 and C4-2. Finally

  7. Selective Electrocatalytic Degradation of Odorous Mercaptans Derived from S-Au Bond Recongnition on a Dendritic Gold/Boron-Doped Diamond Composite Electrode.

    PubMed

    Chai, Shouning; Wang, Yujing; Zhang, Ya-Nan; Liu, Meichuan; Wang, Yanbin; Zhao, Guohua

    2017-07-18

    To improve selectivity of electrocatalytic degradation of toxic, odorous mercaptans, the fractal-structured dendritic Au/BDD (boron-doped diamond) anode with molecular recognition is fabricated through a facile replacement method. SEM and TEM characterizations show that the gold dendrites are single crystals and have high population of the Au (111) facet. The distinctive structure endows the electrode with advantages of low resistivity, high active surface area, and prominent electrocatalytic activity. To evaluate selectivity, the dendritic Au/BDD is applied in degrading two groups of synthetic wastewater containing thiophenol/2-mercaptobenzimidazole (targets) and phenol/2-hydroxybenzimidazole (interferences), respectively. Results show that targets removals reach 91%/94%, while interferences removals are only 58%/48% in a short time. The corresponding degradation kinetic constants of targets are 3.25 times and 4.1 times that of interferences in the same group, demonstrating modification of dendritic gold on BDD could effectively enhance electrocatalytic target-selectivity. XPS and EXAFS further reveal that the selective electrocatalytic degradation derives from preferential recognition and fast adsorption to thiophenol depending on strong Au-S bond. The efficient, selective degradation is attributed to the synergetic effects between accumulative behavior and outstanding electrochemical performances. This work provides a new strategy for selective electrochemical degradation of contaminants for actual wastewater treatment.

  8. A neural network potential energy surface for the NaH2 system and dynamics studies on the H(2S) + NaH(X1Σ+) → Na(2S) + H2(X1Σg+) reaction.

    PubMed

    Wang, Shufen; Yuan, Jiuchuang; Li, Huixing; Chen, Maodu

    2017-08-02

    In order to study the dynamics of the reaction H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), a new potential energy surface (PES) for the ground state of the NaH 2 system is constructed based on 35 730 ab initio energy points. Using basis sets of quadruple zeta quality, multireference configuration interaction calculations with Davidson correction were carried out to obtain the ab initio energy points. The neural network method is used to fit the PES, and the root mean square error is very small (0.00639 eV). The bond lengths, dissociation energies, zero-point energies and spectroscopic constants of H 2 (X 1 Σ g + ) and NaH(X 1 Σ + ) obtained on the new NaH 2 PES are in good agreement with the experiment data. On the new PES, the reactant coordinate-based time-dependent wave packet method is applied to study the reaction dynamics of H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), and the reaction probabilities, integral cross-sections (ICSs) and differential cross-sections (DCSs) are obtained. There is no threshold in the reaction due to the absence of an energy barrier on the minimum energy path. When the collision energy increases, the ICSs decrease from a high value at low collision energy. The DCS results show that the angular distribution of the product molecules tends to the forward direction. Compared with the LiH 2 system, the NaH 2 system has a larger mass and the PES has a larger well at the H-NaH configuration, which leads to a higher ICS value in the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction. Because the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction releases more energy, the product molecules can be excited to a higher vibrational state.

  9. DNA Replication Origin Function Is Promoted by H3K4 Di-methylation in Saccharomyces cerevisiae

    PubMed Central

    Rizzardi, Lindsay F.; Dorn, Elizabeth S.; Strahl, Brian D.; Cook, Jeanette Gowen

    2012-01-01

    DNA replication is a highly regulated process that is initiated from replication origins, but the elements of chromatin structure that contribute to origin activity have not been fully elucidated. To identify histone post-translational modifications important for DNA replication, we initiated a genetic screen to identify interactions between genes encoding chromatin-modifying enzymes and those encoding proteins required for origin function in the budding yeast Saccharomyces cerevisiae. We found that enzymes required for histone H3K4 methylation, both the histone methyltransferase Set1 and the E3 ubiquitin ligase Bre1, are required for robust growth of several hypomorphic replication mutants, including cdc6-1. Consistent with a role for these enzymes in DNA replication, we found that both Set1 and Bre1 are required for efficient minichromosome maintenance. These phenotypes are recapitulated in yeast strains bearing mutations in the histone substrates (H3K4 and H2BK123). Set1 functions as part of the COMPASS complex to mono-, di-, and tri-methylate H3K4. By analyzing strains lacking specific COMPASS complex members or containing H2B mutations that differentially affect H3K4 methylation states, we determined that these replication defects were due to loss of H3K4 di-methylation. Furthermore, histone H3K4 di-methylation is enriched at chromosomal origins. These data suggest that H3K4 di-methylation is necessary and sufficient for normal origin function. We propose that histone H3K4 di-methylation functions in concert with other histone post-translational modifications to support robust genome duplication. PMID:22851644

  10. DNA replication origin function is promoted by H3K4 di-methylation in Saccharomyces cerevisiae.

    PubMed

    Rizzardi, Lindsay F; Dorn, Elizabeth S; Strahl, Brian D; Cook, Jeanette Gowen

    2012-10-01

    DNA replication is a highly regulated process that is initiated from replication origins, but the elements of chromatin structure that contribute to origin activity have not been fully elucidated. To identify histone post-translational modifications important for DNA replication, we initiated a genetic screen to identify interactions between genes encoding chromatin-modifying enzymes and those encoding proteins required for origin function in the budding yeast Saccharomyces cerevisiae. We found that enzymes required for histone H3K4 methylation, both the histone methyltransferase Set1 and the E3 ubiquitin ligase Bre1, are required for robust growth of several hypomorphic replication mutants, including cdc6-1. Consistent with a role for these enzymes in DNA replication, we found that both Set1 and Bre1 are required for efficient minichromosome maintenance. These phenotypes are recapitulated in yeast strains bearing mutations in the histone substrates (H3K4 and H2BK123). Set1 functions as part of the COMPASS complex to mono-, di-, and tri-methylate H3K4. By analyzing strains lacking specific COMPASS complex members or containing H2B mutations that differentially affect H3K4 methylation states, we determined that these replication defects were due to loss of H3K4 di-methylation. Furthermore, histone H3K4 di-methylation is enriched at chromosomal origins. These data suggest that H3K4 di-methylation is necessary and sufficient for normal origin function. We propose that histone H3K4 di-methylation functions in concert with other histone post-translational modifications to support robust genome duplication.

  11. Small Molecule Reversible Inhibitors of Bruton’s Tyrosine Kinase (BTK): Structure–Activity Relationships Leading to the Identification of 7-(2-Hydroxypropan-2-yl)-4-[2-methyl-3-(4-oxo-3,4-dihydroquinazolin-3-yl)phenyl]-9 H -carbazole-1-carboxamide (BMS-935177)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    De Lucca, George V.; Shi, Qing; Liu, Qingjie

    Bruton’s tyrosine kinase (BTK) belongs to the TEC family of nonreceptor tyrosine kinases and plays a critical role in multiple cell types responsible for numerous autoimmune diseases. This article will detail the structure–activity relationships (SARs) leading to a novel second generation series of potent and selective reversible carbazole inhibitors of BTK. With an excellent pharmacokinetic profile as well as demonstrated in vivo activity and an acceptable safety profile, 7-(2-hydroxypropan-2-yl)-4-[2-methyl-3-(4-oxo-3,4-dihydroquinazolin-3-yl)phenyl]-9H-carbazole-1-carboxamide 6 (BMS-935177) was selected to advance into clinical development.

  12. A one-dimensional zinc(II) coordination polymer with a three-dimensional supramolecular architecture incorporating 1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole and adipate.

    PubMed

    Liu, Chun Li; Huang, Qiu Ying; Meng, Xiang Ru

    2016-12-01

    The synthesis of coordination polymers or metal-organic frameworks (MOFs) has attracted considerable interest owing to the interesting structures and potential applications of these compounds. It is still a challenge to predict the exact structures and compositions of the final products. A new one-dimensional coordination polymer, catena-poly[[[bis{1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole-κN 3 }zinc(II)]-μ-hexane-1,6-dicarboxylato-κ 4 O 1 ,O 1' :O 6 ,O 6' ] monohydrate], {[Zn(C 6 H 8 O 4 )(C 9 H 8 N 6 ) 2H 2 O} n , has been synthesized by the reaction of Zn(Ac) 2 (Ac is acetate) with 1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole (bimt) and adipic acid (H 2 adi) at room temperature. In the polymer, each Zn II ion exhibits an irregular octahedral ZnN 2 O 4 coordination geometry and is coordinated by two N atoms from two symmetry-related bimt ligands and four O atoms from two symmetry-related dianionic adipate ligands. Zn II ions are connected by adipate ligands into a one-dimensional chain which runs parallel to the c axis. The bimt ligands coordinate to the Zn II ions in a monodentate mode on both sides of the main chain. In the crystal, the one-dimensional chains are further connected through N-H...O hydrogen bonds, leading to a three-dimensional supramolecular architecture. In addition, the title polymer exhibits fluorescence, with emissions at 334 and 350 nm in the solid state at room temperature.

  13. Histone H3 K79 methylation states play distinct roles in UV-induced sister chromatid exchange and cell cycle checkpoint arrest in Saccharomyces cerevisiae

    PubMed Central

    Rossodivita, Alyssa A.; Boudoures, Anna L.; Mecoli, Jonathan P.; Steenkiste, Elizabeth M.; Karl, Andrea L.; Vines, Eudora M.; Cole, Arron M.; Ansbro, Megan R.; Thompson, Jeffrey S.

    2014-01-01

    Histone post-translational modifications have been shown to contribute to DNA damage repair. Prior studies have suggested that specific H3K79 methylation states play distinct roles in the response to UV-induced DNA damage. To evaluate these observations, we examined the effect of altered H3K79 methylation patterns on UV-induced G1/S checkpoint response and sister chromatid exchange (SCE). We found that the di- and trimethylated states both contribute to activation of the G1/S checkpoint to varying degrees, depending on the synchronization method, although methylation is not required for checkpoint in response to high levels of UV damage. In contrast, UV-induced SCE is largely a product of the trimethylated state, which influences the usage of gene conversion versus popout mechanisms. Regulation of H3K79 methylation by H2BK123 ubiquitylation is important for both checkpoint function and SCE. H3K79 methylation is not required for the repair of double-stranded breaks caused by transient HO endonuclease expression, but does play a modest role in survival from continuous exposure. The overall results provide evidence for the participation of H3K79 methylation in UV-induced recombination repair and checkpoint activation, and further indicate that the di- and trimethylation states play distinct roles in these DNA damage response pathways. PMID:24748660

  14. Histone H3K9 Demethylase JMJD2B Activates Adipogenesis by Regulating H3K9 Methylation on PPARγ and C/EBPα during Adipogenesis

    PubMed Central

    Jang, Min-Kyung; Kim, Ji-Hyun; Jung, Myeong Ho

    2017-01-01

    Previous studies have shown that tri- or di-methylation of histone H3 at lysine 9 (H3K9me3/me2) on the promoter of the peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα) contribute to the repression of PPARγ and C/EBPα and inhibition of adipogenesis in 3T3-L1 preadipocytes. The balance of histone methylation is regulated by histone methyltransferases and demethylases. However, it is poorly understood which demethylases are responsible for removing H3K9me3/me2 on the promoter of PPARγ and C/EBPα. JMJD2B is a H3K9me3/me2 demethylase that was previously shown to activate adipogenesis by promoting mitotic clonal expansion. Nevertheless, it remains unclear whether JMJD2B plays a role in the regulation of adipogenesis by removing H3K9me3/me2 on the promoter of PPARγ and C/EBPα and subsequently activating PPARγ and C/EBPα expression. Here, we showed that JMJD2B decreased H3K9me3/me2 on the promoter of PPARγ and C/EBPα, which in turn stimulated the expression of PPARγ and C/EBPα. JMJD2B knockdown using siRNA in 3T3-L1 preadipocytes repressed the expression of PPARγ and C/EBPα, resulting in inhibition of adipogenesis. This was accompanied by increased enrichment of H3K9me3/me2 on the promoter of PPARγ and C/EBPα. In contrast, overexpression of JMJD2B increased the expression of PPARγ and C/EBPα, which was accompanied by decreased enrichment of H3K9me3/me2 on the promoter and activated adipogenesis. Together, these results indicate that JMJD2B regulates PPARγ and C/EBPα during adipogenesis. PMID:28060835

  15. Methylation of S100A8 is a promising diagnosis and prognostic marker in hepatocellular carcinoma.

    PubMed

    Liu, Kun; Zhang, Yuening; Zhang, Chengdong; Zhang, Qinle; Li, Jiatong; Xiao, Feifan; Li, Yingfang; Zhang, Ruoheng; Dou, Dongwei; Liang, Jiezhen; Qin, Jian; Lin, Zhidi; Zhao, Dong; Jiang, Min; Liang, Zhenxin; Su, Jie; Gupta, Vanaparthy Pranay; He, Min; Yang, Xiaoli

    2016-08-30

    The abnormality of DNA methylation is one of the major epigenetic alterations in the human hepatocellular carcinoma (HCC). We have assessed the global genomic DNA methylation profiles in human HCC patients by using the Infinium Human Methylation27 BeadChip. A CpG loci of S100A8 was found to be significantly hypomethylated in HCC.Pooled meta-analysis of five validation public datasets demonstrated its methylation level was significantly lower for HCC compared to paired adjacent normal tissues. Quantitative pyrosequencing analysis also showed that the S100A8 methylation level was decreased in cancer tissues (31.90%±13.31%) than that in the paired adjacent normal tissues (65.33%±3.64%, p<0.01). The area under the ROC curve (AUC) value was 0.950 (p<0.01). Kaplan-Meier survival curves revealed that hypomethylation of S100A8 was associated with shortened overall survival (OS) and progression-free survival (PFS) (log rank p<0.05). Multivariate Cox proportional hazards model also indicated significantly shorter OS (HR, 1.709; 95 % CI, 1.127-2.591) and PFS (HR, 1.767; 95 % CI, 1.168-2.974) were observed in the low-methylation-level group compared to the high-methylation-level group. Furthermore, S100A8 overexpression in Huh7 and MHCC-97H hepatoma cell lines led to increased cell proliferation, migration, invasion, and tumor growth. These findings suggested S100A8 methylation to be served as potential diagnosis and prognosis marker for HCC. S100A8 also may play as a tumor promoter in HCC.

  16. Methylation of S100A8 is a promising diagnosis and prognostic marker in hepatocellular carcinoma

    PubMed Central

    Xiao, Feifan; Li, Yingfang; Zhang, Ruoheng; Dou, Dongwei; Liang, Jiezhen; Qin, Jian; Lin, Zhidi; Zhao, Dong; Jiang, Min; Liang, Zhenxin; Su, Jie; Gupta, Vanaparthy Pranay; He, Min; Yang, Xiaoli

    2016-01-01

    The abnormality of DNA methylation is one of the major epigenetic alterations in the human hepatocellular carcinoma (HCC). We have assessed the global genomic DNA methylation profiles in human HCC patients by using the Infinium Human Methylation27 BeadChip. A CpG loci of S100A8 was found to be significantly hypomethylated in HCC. Pooled meta-analysis of five validation public datasets demonstrated its methylation level was significantly lower for HCC compared to paired adjacent normal tissues. Quantitative pyrosequencing analysis also showed that the S100A8 methylation level was decreased in cancer tissues (31.90%±13.31%) than that in the paired adjacent normal tissues (65.33%±3.64%, p<0.01). The area under the ROC curve (AUC) value was 0.950 (p<0.01). Kaplan-Meier survival curves revealed that hypomethylation of S100A8 was associated with shortened overall survival (OS) and progression-free survival (PFS) (log rank p<0.05). Multivariate Cox proportional hazards model also indicated significantly shorter OS (HR, 1.709; 95 % CI, 1.127–2.591) and PFS (HR, 1.767; 95 % CI, 1.168–2.974) were observed in the low-methylation-level group compared to the high-methylation-level group. Furthermore, S100A8 overexpression in Huh7 and MHCC-97H hepatoma cell lines led to increased cell proliferation, migration, invasion, and tumor growth. These findings suggested S100A8 methylation to be served as potential diagnosis and prognosis marker for HCC. S100A8 also may play as a tumor promoter in HCC. PMID:27462864

  17. Synthesis, radiolabeling, and preliminary biological evaluation of [3H]-1-[(S)-N,O-bis-(isoquinolinesulfonyl)-N-methyl-tyrosyl]-4-(o-tolyl)-piperazine, a potent antagonist radioligand for the P2X7 receptor.

    PubMed

    Romagnoli, Romeo; Baraldi, Pier Giovanni; Pavani, Maria Giovanna; Tabrizi, Mojgan Aghazadeh; Moorman, Allan R; Di Virgilio, Francesco; Cattabriga, Elena; Pancaldi, Cecilia; Gessi, Stefania; Borea, Pier Andrea

    2004-11-15

    The design, synthesis, and preliminary biological evaluation of the first potent radioligand antagonist for the P2X(7) receptor, named [(3)H]-1-[(S)-N,O-bis-(isoquinolinesulfonyl)-N-methyl-tyrosyl]-4-(o-tolyl)-piperazine (compound 13), are reported. This compound bound to human P2X(7) receptors expressed in HEK transfected cells with K(D) and B(max) value of 3.46+/-0.1 nM and 727+/-73 fmol/mg of protein, respectively. The high affinity and facile labeling makes it a promising radioligand for a further characterization of P2X(7) receptor subtype.

  18. Oxygen and sulfur interactions with a clean iron surface and the effect of rubbing contact on these interactions

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1973-01-01

    The interaction of sulfur and oxygen with an iron surface was studied with Auger spectroscopy analysis both statically and during sliding-friction experiments in a vacuum environment. Oxygen, hydrogen sulfide, methyl mercaptan, and sulfur dioxide were adsorbed to an iron surface. Results indicate that sulfide films formed on clean iron surfaces are completely displaced by oxygen. Hydrocarbons containing sulfur, such as methyl mercaptan, adsorb dissociatively. Less sulfur is adsorbed during sliding with hydrogen sulfide and methyl mercaptan than in the absence of sliding. With both oxygen and sulfur dioxide, sliding did not affect the amount of material adsorbed to iron.

  19. The South Karelia Air Pollution Study. The effects of malodorous sulfur compounds from pulp mills on respiratory and other symptoms

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jaakkola, J.J.; Vilkka, V.; Marttila, O.

    1990-12-01

    The paper mills in South Karelia, the southeast part of Finland, are responsible for releasing a substantial amount of malodorous sulfur compounds such as hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and methyl sulfides ((CH3)2S and (CH3)2S2), into ambient air. In the most polluted residential area the annual mean concentrations of hydrogen sulfide and methyl mercaptan are estimated to be 8 and 2 to 5 micrograms/m3 and the highest daily average concentration 100 and 50 micrograms/m3. The annual mean and highest daily concentrations of sulfur dioxide (SO2) are very low. We studied the effects of malodorous sulfur compounds on eye, nasalmore » and respiratory symptoms, and headache in adults. A cross-sectional self-administered questionnaire was distributed in February 1987 and responded to by 488 adults living in a severely (n = 198), a moderately (n = 204), and a nonpolluted community (n = 86). This included questions about occurrence of the symptoms of interest during the previous 4 wk and 12 months and individual, behavioral, and other environmental determinants of the symptoms. The response rate was 83%. The odds ratios (OR) for symptoms experienced often or constantly in severely versus nonpolluted and moderately versus nonpolluted communities were estimated in logistic regression analysis controlling potential confounders. The odds ratios for eye (moderate exposure OR 11.70, Cl95% 2.33 to 58.65; severe exposure OR 11.78, Cl95% 2.35 to 59.09) and nasal symptoms (OR 2.01, Cl95% 0.97 to 4.15; OR 2.19, Cl95% 1.06 to 4.55) and cough (OR 1.89, Cl95% 0.61 to 5.86; OR 3.06, Cl95% 1.02 to 9.29) during the previous 12 months were increased, with a dose-response pattern.« less

  20. Electrochromic device using mercaptans and organothiolate compounds

    DOEpatents

    Lampert, Carl M.; Ma, Yan-ping; Doeff, Marca M.; Visco, Steven

    1995-01-01

    An electrochromic cell is disclosed which comprises an electrochromic layer and a composite ion counter electrode for transporting ions. The counter electrode further comprises a polymer electrolyte material and an organosulfur material in which, in its discharged state, the organosulfur material is further comprised of a mercaptan or an organothiolate. In one preferred embodiment, both the electrochromic electrode and the counter electrode are transparent either to visible light or to the entire electromagnetic spectrum in both charged and discharged states. An electrochromic device is disclosed which comprises one or more electrochromic electrodes encased in glass or plastic plates on the inner surface of each of which is formed a transparent electrically conductive film. Electrical contacts, which are in electrical contact with the conductive films, facilitate external electrical connection.

  1. Electrochromic device using mercaptans and organothiolate compounds

    DOEpatents

    Lampert, C.M.; Ma, Y.P.; Doeff, M.M.; Visco, S.

    1995-08-15

    An electrochromic cell is disclosed which comprises an electrochromic layer and a composite ion counter electrode for transporting ions. The counter electrode further comprises a polymer electrolyte material and an organosulfur material in which, in its discharged state, the organosulfur material is further comprised of a mercaptan or an organothiolate. In one preferred embodiment, both the electrochromic electrode and the counter electrode are transparent either to visible light or to the entire electromagnetic spectrum in both charged and discharged states. An electrochromic device is disclosed which comprises one or more electrochromic electrodes encased in glass or plastic plates on the inner surface of each of which is formed a transparent electrically conductive film. Electrical contacts, which are in electrical contact with the conductive films, facilitate external electrical connection. 5 figs.

  2. Structure-activity relationship of daptomycin analogues with substitution at (2S, 3R) 3-methyl glutamic acid position.

    PubMed

    Lin, Du'an; Lam, Hiu Yung; Han, Wenbo; Cotroneo, Nicole; Pandya, Bhaumik A; Li, Xuechen

    2017-02-01

    Daptomycin is a highly effective lipopeptide antibiotic against Gram-positive pathogens. The presence of (2S, 3R) 3-methyl glutamic acid (mGlu) in daptomycin has been found to be important to the antibacterial activity. However the role of (2S, 3R) mGlu is yet to be revealed. Herein, we reported the syntheses of three daptomycin analogues with (2S, 3R) mGlu substituted by (2S, 3R) methyl glutamine (mGln), dimethyl glutamic acid and (2S, 3R) ethyl glutamic acid (eGlu), respectively, and their antibacterial activities. The detailed synthesis of dimethyl glutamic acid was also reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Vibrational spectroscopic (FT-IR, FT-Raman) and quantum mechanical study of 4-(2-chlorophenyl)-2-ethyl-9-methyl-6H-thieno[3,2-f] [1,2,4]triazolo[4,3-a][1,4] diazepine

    NASA Astrophysics Data System (ADS)

    Kuruvilla, Tintu K.; Prasana, Johanan Christian; Muthu, S.; George, Jacob

    2018-04-01

    The spectroscopic properties of 4-(2-chlorophenyl)-2-ethyl-9-methyl-6H-thieno [3,2-f] [1,2,4] triazolo [4,3-a] [1,4] diazepine were investigated in the present study using FT-IR and FT-Raman techniques. The results obtained were compared with quantum mechanical methods, as it serves as an important tool in interpreting and predicting vibrational spectra. The optimized molecular geometry, the vibrational wavenumbers, the infrared intensities and Raman scattering were calculated using density functional theory B3LYP method with 6-311++g (d,p) basis set. All the experimental results were in line with the theoretical data. The molecular electrostatic potential (MEP) and HOMO LUMO energies of the title compound were accounted. The results indicated that the title compound has a lower softness value (0.27) and high electrophilicity index (4.98) hence describing its biological activity. Further, natural bond orbital was also analyzed as part of the work. Fukui functions were calculated in order to explain the chemical selectivity or the reactivity site in 4-(2-chlorophenyl)-2-ethyl-9-methyl-6H-thieno [3,2-f] [1,2,4] triazolo [4,3-a] [1,4] diazepine. The thermodynamic properties of the title compound were closely examined at different temperatures. It revealed the correlations between heat capacity (C), entropy (S) and enthalpy changes (H) with temperatures. The paper further explains that the title compound can act as good antidepressant through molecular docking studies.

  4. Degradation of Kresoxim-Methyl in Water: Impact of Varying pH, Temperature, Light and Atmospheric CO2 Level.

    PubMed

    Khandelwal, Ashish; Gupta, Suman; Gajbhiye, Vijay T; Varghese, Eldho

    2016-01-01

    In the present investigation, persistence of kresoxim-methyl (a broad spectrum strobilurin fungicide) was studied in water. Results revealed that kresoxim-methyl readily form acid metabolite. Therefore, residues of kresoxim-methyl were quantified on the basis of parent molecule alone and sum total of kresoxim-methyl and its acid metabolite. In water, influence of various abiotic factors like pH, temperature, light and atmospheric carbon dioxide level on dissipation of kresoxim-methyl was studied. The half life value for kresoxim-methyl and total residue varied from 1 to 26.1 and 6.1 to 94.0 days under different conditions. Statistical analysis revealed the significant effect of abiotic factors on the dissipation of kresoxim-methyl from water.

  5. Investigations on the synthesis and pharmacological properties of 4-alkoxy-2-[2-hydroxy-3-(4-aryl-1-piperazinyl)propyl]-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones.

    PubMed

    Sladowska, Helena; Filipek, Barbara; Szkatuła, Dominika; Sabiniarz, Aleksandra; Kardasz, Małgorzata; Potoczek, Joanna; Sieklucka-Dziuba, Maria; Rajtar, Grazyna; Kleinrok, Zdzisław; Lis, Tadeusz

    2002-11-01

    Synthesis of 2-[2-hydroxy-3-(4-aryl-1-piperazinyl)propyl] derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones (8-12) is described. The chlorides used in the above synthesis can exist in two isomeric forms: chain (18-20) and cyclic (19a, 20a). The compounds 8-12 exhibited potent analgesic activity which was superior than that of acetylsalicylic acid in two different tests. Most of the investigated imides suppressed significantly spontaneous locomotor activity in mice.

  6. Dibromidobis(N,N,N′,N′-tetra­methyl­thio­urea-κS)cadmium(II)

    PubMed Central

    Nawaz, Sidra; Sadaf, Sana; Fettouhi, Mohammed; Fazal, Atif; Ahmad, Saeed

    2010-01-01

    In the title compound, [CdBr2(C5H12N2S)2], the CdII atom lies on a twofold rotation axis. It exhibits a distorted tetra­hedral coordination environment defined by two S atoms of two tetra­methyl­thio­urea (tmtu) ligands and two bromide ions. The crystal structure is consolidated by C—H⋯N and C—H⋯S hydrogen bonds. PMID:21588180

  7. Crystal structures and Hirshfeld surface analyses of bis-[N,N-bis-(2-meth-oxy-eth-yl)di-thio-carbamato-κ2S,S']di-n-butyl-tin(IV) and [N-(2-meth-oxy-eth-yl)-N-methyl-dithio-carbamato-κ2S,S']tri-phenyl-tin(IV).

    PubMed

    Mohamad, Rapidah; Awang, Normah; Kamaludin, Nurul Farahana; Jotani, Mukesh M; Tiekink, Edward R T

    2018-03-01

    The crystal and mol-ecular structures of the two title organotin di-thio-carbamate compounds, [Sn(C 4 H 9 ) 2 (C 7 H 14 NO 2 S 2 ) 2 ], (I), and [Sn(C 6 H 5 ) 3 (C 5 H 10 NOS 2 )], (II), are described. Both structures feature asymmetrically bound di-thio-carbamate ligands leading to a skew-trapezoidal bipyramidal geometry for the metal atom in (I) and a distorted tetra-hedral geometry in (II). The complete mol-ecule of (I) is generated by a crystallographic twofold axis (Sn site symmetry 2). In the crystal of (I), mol-ecules self-assemble into a supra-molecular array parallel to (10-1) via methyl-ene-C-H⋯O(meth-oxy) inter-actions. In the crystal of (II), supra-molecular dimers are formed via pairs of weak phenyl-C-H⋯π(phen-yl) contacts. In each of (I) and (II), the specified assemblies connect into a three-dimensional architecture without directional inter-actions between them. Hirshfeld surface analyses confirm the importance of H⋯H contacts in the mol-ecular packing of each of (I) and (II), and in the case of (I), highlight the importance of short meth-oxy-H⋯H(but-yl) contacts between layers.

  8. Genome-wide methylation analysis identifies a core set of hypermethylated genes in CIMP-H colorectal cancer.

    PubMed

    McInnes, Tyler; Zou, Donghui; Rao, Dasari S; Munro, Francesca M; Phillips, Vicky L; McCall, John L; Black, Michael A; Reeve, Anthony E; Guilford, Parry J

    2017-03-28

    Aberrant DNA methylation profiles are a characteristic of all known cancer types, epitomized by the CpG island methylator phenotype (CIMP) in colorectal cancer (CRC). Hypermethylation has been observed at CpG islands throughout the genome, but it is unclear which factors determine whether an individual island becomes methylated in cancer. DNA methylation in CRC was analysed using the Illumina HumanMethylation450K array. Differentially methylated loci were identified using Significance Analysis of Microarrays (SAM) and the Wilcoxon Signed Rank (WSR) test. Unsupervised hierarchical clustering was used to identify methylation subtypes in CRC. In this study we characterized the DNA methylation profiles of 94 CRC tissues and their matched normal counterparts. Consistent with previous studies, unsupervized hierarchical clustering of genome-wide methylation data identified three subtypes within the tumour samples, designated CIMP-H, CIMP-L and CIMP-N, that showed high, low and very low methylation levels, respectively. Differential methylation between normal and tumour samples was analysed at the individual CpG level, and at the gene level. The distribution of hypermethylation in CIMP-N tumours showed high inter-tumour variability and appeared to be highly stochastic in nature, whereas CIMP-H tumours exhibited consistent hypermethylation at a subset of genes, in addition to a highly variable background of hypermethylated genes. EYA4, TFPI2 and TLX1 were hypermethylated in more than 90% of all tumours examined. One-hundred thirty-two genes were hypermethylated in 100% of CIMP-H tumours studied and these were highly enriched for functions relating to skeletal system development (Bonferroni adjusted p value =2.88E-15), segment specification (adjusted p value =9.62E-11), embryonic development (adjusted p value =1.52E-04), mesoderm development (adjusted p value =1.14E-20), and ectoderm development (adjusted p value =7.94E-16). Our genome-wide characterization of DNA

  9. Extensive investigation of the IGF2/H19 imprinting control region reveals novel OCT4/SOX2 binding site defects associated with specific methylation patterns in Beckwith-Wiedemann syndrome.

    PubMed

    Abi Habib, Walid; Azzi, Salah; Brioude, Frédéric; Steunou, Virginie; Thibaud, Nathalie; Das Neves, Cristina; Le Jule, Marilyne; Chantot-Bastaraud, Sandra; Keren, Boris; Lyonnet, Stanislas; Michot, Caroline; Rossi, Massimiliano; Pasquier, Laurent; Gicquel, Christine; Rossignol, Sylvie; Le Bouc, Yves; Netchine, Irène

    2014-11-01

    Isolated gain of methylation (GOM) at the IGF2/H19 imprinting control region 1 (ICR1) accounts for about 10% of patients with BWS. A subset of these patients have genetic defects within ICR1, but the frequency of these defects has not yet been established in a large cohort of BWS patients with isolated ICR1 GOM. Here, we carried out a genetic analysis in a large cohort of 57 BWS patients with isolated ICR1 GOM and analyzed the methylation status of the entire domain. We found a new point mutation in two unrelated families and a 21 bp deletion in another unrelated child, both of which were maternally inherited and affected the OCT4/SOX2 binding site in the A2 repeat of ICR1. Based on data from this and previous studies, we estimate that cis genetic defects account for about 20% of BWS patients with isolated ICR1 GOM. Methylation analysis at eight loci of the IGF2/H19 domain revealed that sites surrounding OCT4/SOX2 binding site mutations were fully methylated and methylation indexes declined as a function of distance from these sites. This was not the case in BWS patients without genetic defects identified. Thus, GOM does not spread uniformly across the IGF2/H19 domain, suggesting that OCT4/SOX2 protects against methylation at local sites. These findings add new insights to the mechanism of the regulation of the ICR1 domain. Our data show that mutations and deletions within ICR1 are relatively common. Systematic identification is therefore necessary to establish appropriate genetic counseling for BWS patients with isolated ICR1 GOM. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Working with "H2S": facts and apparent artifacts.

    PubMed

    Wedmann, Rudolf; Bertlein, Sarah; Macinkovic, Igor; Böltz, Sebastian; Miljkovic, Jan Lj; Muñoz, Luis E; Herrmann, Martin; Filipovic, Milos R

    2014-09-15

    Hydrogen sulfide (H2S) is an important signaling molecule with physiological endpoints similar to those of nitric oxide (NO). Growing interest in its physiological roles and pharmacological potential has led to large sets of contradictory data. The principle cause of these discrepancies can be the common neglect of some of the basic H2S chemistry. This study investigates how the experimental outcome when working with H2S depends on its source and dose and the methodology employed. We show that commercially available NaHS should be avoided and that traces of metal ions should be removed because these can reduce intramolecular disulfides and change protein structure. Furthermore, high H2S concentrations may lead to a complete inhibition of cell respiration, mitochondrial membrane potential depolarization and superoxide generation, which should be considered when discussing the biological effects observed upon treatment with high concentrations of H2S. In addition, we provide chemical evidence that H2S can directly react with superoxide. H2S is also capable of reducing cytochrome c(3+) with the concomitant formation of superoxide. H2S does not directly react with nitrite but with NO electrodes that detect H2S. In addition, H2S interferes with the Griess reaction and should therefore be removed from the solution by Cd(2+) or Zn(2+) precipitation prior to nitrite quantification. 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) is reduced by H2S, and its use should be avoided in combination with H2S. All these constraints must be taken into account when working with H2S to ensure valid data. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Synthesis, biological evaluation, and automated docking of constrained analogues of the opioid peptide H-Dmt-D-Ala-Phe-Gly-NH₂ using the 4- or 5-methyl substituted 4-amino-1,2,4,5-tetrahydro-2-benzazepin-3-one scaffold.

    PubMed

    De Wachter, Rien; de Graaf, Chris; Keresztes, Atilla; Vandormael, Bart; Ballet, Steven; Tóth, Géza; Rognan, Didier; Tourwé, Dirk

    2011-10-13

    The Phe(3) residue of the N-terminal tetrapeptide of dermorphin (H-Dmt-d-Ala-Phe-Gly-NH(2)) was conformationally constrained using 4- or 5-methyl-substituted 4-amino-1,2,4,5-tetrahydro-2-benzazepin-3-one (Aba) stereoisomeric scaffolds. Several of the synthesized peptides were determined to be high affinity agonists for the μ opioid receptor (OPRM) with selectivity over the δ opioid receptor (OPRD). Interesting effects of the Aba configuration on ligand binding affinity were observed. H-Dmt-d-Ala-erythro-(4S,5S)-5-Me-Aba-Gly-NH(2)9 and H-Dmt-threo-(4R,5S)-5-Me-Aba-Gly-NH(2)12 exhibited subnanomolar affinity for OPRM, while they possess an opposite absolute configuration at position 4 of the Aba ring. However, in the 4-methyl substituted analogues, H-Dmt-d-Ala-(4R)-Me-Aba-Gly-NH(2)14 was significantly more potent than the (4S)-derivative 13. These unexpected results were rationalized using the binding poses predicted by molecular docking simulations. Interestingly, H-Dmt-d-Ala-(4R)-Me-Aba-Gly-NH(2)14 is proposed to bind in a different mode compared with the other analogues. Moreover, in contrast to Ac-4-Me-Aba-NH-Me, which adopts a β-turn in solution and in the crystal structure, the binding mode of this analogue suggests an alternative receptor-bound conformation.

  12. Histone H3K36 methylation regulates pre-mRNA splicing in Saccharomyces cerevisiae

    PubMed Central

    Sorenson, Matthew R.; Jha, Deepak K.; Ucles, Stefanie A.; Flood, Danielle M.; Strahl, Brian D.; Stevens, Scott W.; Kress, Tracy L.

    2016-01-01

    ABSTRACT Co-transcriptional splicing takes place in the context of a highly dynamic chromatin architecture, yet the role of chromatin restructuring in coordinating transcription with RNA splicing has not been fully resolved. To further define the contribution of histone modifications to pre-mRNA splicing in Saccharomyces cerevisiae, we probed a library of histone point mutants using a reporter to monitor pre-mRNA splicing. We found that mutation of H3 lysine 36 (H3K36) – a residue methylated by Set2 during transcription elongation – exhibited phenotypes similar to those of pre-mRNA splicing mutants. We identified genetic interactions between genes encoding RNA splicing factors and genes encoding the H3K36 methyltransferase Set2 and the demethylase Jhd1 as well as point mutations of H3K36 that block methylation. Consistent with the genetic interactions, deletion of SET2, mutations modifying the catalytic activity of Set2 or H3K36 point mutations significantly altered expression of our reporter and reduced splicing of endogenous introns. These effects were dependent on the association of Set2 with RNA polymerase II and H3K36 dimethylation. Additionally, we found that deletion of SET2 reduces the association of the U2 and U5 snRNPs with chromatin. Thus, our study provides the first evidence that H3K36 methylation plays a role in co-transcriptional RNA splicing in yeast. PMID:26821844

  13. Variations in DNA methylation, acetylated histone H4, and methylated histone H3 during Pinus radiata needle maturation in relation to the loss of in vitro organogenic capability.

    PubMed

    Valledor, Luis; Meijón, Mónica; Hasbún, Rodrigo; Jesús Cañal, Maria; Rodríguez, Roberto

    2010-03-15

    Needle differentiation is a very complex process associated with the formation of a mature photosynthetic organ. From meristem differentiation to leaf maturation, gene control must play an important role switching required genes on and off to define tissue functions, with the epigenetic code being one of the main regulation mechanisms. In this work, we examined the connections between the variation in the levels of some epigenetic players (DNA methylation, acetylated histone H4 and histone H3 methylation at Lys 4 and Lys 9) at work during needle maturation. Our results indicate that needle maturation, which is associated with a decrease in organogenic capability, is related to an increase in heterochromatin-related epigenetic markers (high DNA methylation and low acetylated histone H4 levels, and the presence of histone H3 methylated at lys 9). Immunohistochemical analyses also showed that the DNA methylation of palisade parenchyma cell layers during the transition from immature to mature scions is associated with the loss of the capacity to induce adventitious organs. Copyright 2009 Elsevier GmbH. All rights reserved.

  14. Low-temperature methyl group dynamics of hexamethylbenzene in crystalline and glassy matrices as studied by 2H NMR

    NASA Astrophysics Data System (ADS)

    Börner, K.; Diezemann, G.; Rössler, E.; Vieth, H. M.

    1991-07-01

    2H NMR spectra of hexamethylbenzene (HMB) in protonated crystalline and amorphous matrices at low temperatures are presented. All spectra reveal lineshape changes which can be attributed to methyl group tunnelling. Compared to neat HMB, a drastic increase of the tunnelling frequency is found for all systems. This indicates that the hindering potential originates predominantly from intermolecular forces. We studied the temperature dependence of these spectra and the spin-lattice relaxation in order to exclude a distribution of motional correlation times describing a thermally activated process. In addition, we find a distortion of the methyl tetrahedron.

  15. Addition reaction of methyl cinnamate with 2-amino-4- nitrophenol

    NASA Astrophysics Data System (ADS)

    Suryanti, Venty; Rakhman Wibowo, Fajar; Pranoto; Robingatun Isnaeni, Siti; Ratna Kumala Sari, Meiyanti; Handayani, Sekar

    2016-02-01

    A novel compound which have one N-H fragment and nitrophenyl group has been designed and synthesized from cinnamaldehyde. The reaction was conducted in 3 step reactions to give the final product. Firstly, cinnamaldehyde was converted into cinnamic acid, which was then esterified with methyl alcohol to obtained methyl cinnamate. The last step was the addition reaction between methyl cinnamate and 2-amino-4-nitrophenol to give a cinnamaldehyde derivative, namely methyl-3-(2-hidroksi-5-nitrophenyl amino)-3- phenylpropanoate.

  16. Synthesis, Spatial Structure and Analgesic Activity of Sodium 3-Benzylaminocarbonyl-1-methyl-2,2-dioxo-1H-2λ6,1-benzothiazin-4-olate Solvates

    PubMed Central

    Ukrainets, Igor V.; Petrushova, Lidiya A.; Shishkina, Svitlana V.; Grinevich, Lina A.; Sim, Galina

    2016-01-01

    In order to obtain and then test pharmocologically any possible conformers of the new feasible analgesic N-benzyl-4-hydroxy-1-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamide, its 4-O-sodium salt was synthesized using two methods. X-ray diffraction study made possible to determine that, depending on the chosen synthesis conditions, the above-mentioned compound forms either monosolvate with methanol or monohydrate, where organic anion exists in the form of three different conformers. Pharmacological testing of the two known pseudo-enantiomeric forms of the original N-benzylamide and of the two solvates of its sodium salt was performed simultaneously under the same conditions and in equimolar doses. Comparison of the results obtained while studying the peculiarities of the synthesized compounds spatial structure and biological properties revealed an important structure-action relationship. In particular, it was shown that the intensity of analgesic effect of different conformational isomers of N-benzyl-4-hydroxy-1-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamide may change considerably: while low active conformers are comparable with piroxicam, highly active conformers are more than twice as effective as meloxicam. PMID:27775559

  17. Both H4K20 mono-methylation and H3K56 acetylation mark transcription-dependent histone turnover in fission yeast

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Hanna; Kwon, Chang Seob; Choi, Yoonjung, E-mail: jjungii@kaist.ac.kr

    Nucleosome dynamics facilitated by histone turnover is required for transcription as well as DNA replication and repair. Histone turnover is often associated with various histone modifications such as H3K56 acetylation (H3K56Ac), H3K36 methylation (H3K36me), and H4K20 methylation (H4K20me). In order to correlate histone modifications and transcription-dependent histone turnover, we performed genome wide analyses for euchromatic regions in G2/M-arrested fission yeast. The results show that transcription-dependent histone turnover at 5′ promoter and 3′ termination regions is directly correlated with the occurrence of H3K56Ac and H4K20 mono-methylation (H4K20me1) in actively transcribed genes. Furthermore, the increase of H3K56Ac and H4K20me1 and antisense RNAmore » production was observed in the absence of the histone H3K36 methyltransferase Set2 and histone deacetylase complex (HDAC) that are involved in the suppression of histone turnover within the coding regions. These results together indicate that H4K20me1 as well as H3K56Ac are bona fide marks for transcription-dependent histone turnover in fission yeast.« less

  18. Synthesis and pharmacological properties of new derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones.

    PubMed

    Sladowska, Helena; Sabiniarz, Aleksandra; Sapa, Jacek; Filipek, Barbara

    2009-01-01

    Synthesis of 2-(2-hydroxy-3-amino)propyl derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones (24-35) is described. The chlorides used in the above synthesis exist mainly in the cyclic forms (18, 20-23). Only chloride with benzhydryl substituent at the nitrogen atom of piperazine has the chain structure (19). Among the studied imides the most active analgesics in the "writhing" syndrome test proved to be compounds 30 and 31 (with LD50 > 2000 mg/kg) containing 4-benzylpiperidino group. Furthermore, all imides suppressed significantly spontaneous locomotor activity of mice.

  19. 3-Chloro-4-methyl­quinolin-2(1H)-one

    PubMed Central

    Kassem, Mohamed G.; Ghabbour, Hazem A.; Abdel-Aziz, Hatem A.; Fun, Hoong-Kun; Ooi, Chin Wei

    2012-01-01

    The title compound, C10H8ClNO, is almost planar (r.m.s. deviation for the 13 non-H atoms = 0.023 Å). In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R 2 2(8) rings. Weak aromatic π–π stacking inter­actions [centroid–centroid distance = 3.7622 (12) Å] also occur. PMID:22589913

  20. IGF2 DNA methylation is a modulator of newborn's fetal growth and development.

    PubMed

    St-Pierre, Julie; Hivert, Marie-France; Perron, Patrice; Poirier, Paul; Guay, Simon-Pierre; Brisson, Diane; Bouchard, Luigi

    2012-10-01

    The insulin-like growth factor 2 (IGF2) gene, located within a cluster of imprinted genes on chromosome 11p15, encodes a fetal and placental growth factor affecting birth weight. DNA methylation variability at the IGF2 gene locus has been previously reported but its consequences on fetal growth and development are still mostly unknown in normal pediatric population. We collected one hundred placenta biopsies from 50 women with corresponding maternal and cord blood samples and measured anthropometric indices, blood pressure and metabolic phenotypes using standardized procedures. IGF2/H19 DNA methylation and IGF2 circulating levels were assessed using sodium bisulfite pyrosequencing and ELISA, respectively. Placental IGF2 (DMR0 and DMR2) DNA methylation levels were correlated with newborn's fetal growth indices, such as weight, and with maternal IGF2 circulating concentration at the third trimester of pregnancy, whereas H19 (DMR) DNA methylation levels were correlated with IGF2 levels in cord blood. The maternal genotype of a known IGF2/H19 polymorphism (rs2107425) was associated with birth weight. Taken together, we showed that IGF2/H19 epigenotype and genotypes independently account for 31% of the newborn's weight variance. No association was observed with maternal diabetic status, glucose concentrations or prenatal maternal body mass index. This is the first study showing that DNA methylation at the IGF2/H19 genes locus may act as a modulator of IGF2 newborn's fetal growth and development within normal range. IGF2/H19 DNA methylation could represent a cornerstone in linking birth weight and fetal metabolic programming of late onset obesity.

  1. A High-Yield Synthesis of Chalcopyrite CuIn S 2 Nanoparticles with Exceptional Size Control

    DOE PAGES

    Sun, Chivin; Gardner, Joseph S.; Shurdha, Endrit; ...

    2009-01-01

    We repormore » t high-yield and efficient size-controlled syntheses of Chalcopyrite CuIn S 2 nanoparticles by decomposing molecular single source precursors (SSPs) via microwave irradiation in the presence of 1,2-ethanedithiol at reaction temperatures as low as 100 ° C and times as short as 30 minutes. The nanoparticles sizes were 1.8 nm to 10.8 nm as reaction temperatures were varied from 100 ° C to 200 ° C with the bandgaps from 2.71 eV to 1.28 eV with good size control and high yields (64%–95%). The resulting nanoparticles were analyzed by XRD, UV-Vis, ICP-OES, XPS, SEM, EDS, and HRTEM. Titration studies by 1 H NMR using SSP 1 with 1,2-ethanedithiol and benzyl mercaptan were conducted to elucidate the formation of Chalcopyrite CuIn S 2 nanoparticles.« less

  2. Folate Polyglutamylation Is Involved in Chromatin Silencing by Maintaining Global DNA Methylation and Histone H3K9 Dimethylation in Arabidopsis[C][W

    PubMed Central

    Zhou, Hao-Ran; Zhang, Fang-Fang; Ma, Ze-Yang; Huang, Huan-Wei; Jiang, Ling; Cai, Tao; Zhu, Jian-Kang; Zhang, Chuyi; He, Xin-Jian

    2013-01-01

    DNA methylation and repressive histone Histone3 Lysine9 (H3K9) dimethylation correlate with chromatin silencing in plants and mammals. To identify factors required for DNA methylation and H3K9 dimethylation, we screened for suppressors of the repressor of silencing1 (ros1) mutation, which causes silencing of the expression of the RD29A (RESPONSE TO DESSICATION 29A) promoter-driven luciferase transgene (RD29A-LUC) and the 35S promoter-driven NPTII (NEOMYCIN PHOSPHOTRANSFERASE II) transgene (35S-NPTII). We identified the folylpolyglutamate synthetase FPGS1 and the known factor DECREASED DNA METHYLATION1 (DDM1). The fpgs1 and ddm1 mutations release the silencing of both RD29A-LUC and 35S-NPTII. Genome-wide analysis indicated that the fpgs1 mutation reduces DNA methylation and releases chromatin silencing at a genome-wide scale. The effect of fpgs1 on chromatin silencing is correlated with reduced levels of DNA methylation and H3K9 dimethylation. Supplementation of fpgs1 mutants with 5-formyltetrahydrofolate, a stable form of folate, rescues the defects in DNA methylation, histone H3K9 dimethylation, and chromatin silencing. The competitive inhibitor of methyltransferases, S-adenosylhomocysteine, is markedly upregulated in fpgs1, by which fpgs1 reduces S-adenosylmethionine accessibility to methyltransferases and accordingly affects DNA and histone methylation. These results suggest that FPGS1-mediated folate polyglutamylation is required for DNA methylation and H3K9 dimethylation through its function in one-carbon metabolism. Our study makes an important contribution to understanding the complex interplay among metabolism, development, and epigenetic regulation. PMID:23881414

  3. Lap shear strength and healing capability of self-healing adhesive containing epoxy/mercaptan microcapsules

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ghazali, Habibah; Ye, Lin; Zhang, Ming-Qiu

    The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for developing self-healing epoxy adhesive. The influence of different content of microcapsules on the shear strength and healing capability of epoxy adhesive were investigated using single-lap-joints with average thickness of adhesive layer of about 180 µm. This self-healing adhesive was used in bonding of 5000 series aluminum alloys adherents after mechanical and alkaline cleaning surface treatment. The adhesion strength was measured and presented as function of microcapsules loading. The results indicated that the virgin lapmore » shear strength was increased by about 26% with addition of 3 wt% of self-healing microcapsules. 12% to 28% recovery of the shear strength is achieved after self-healing depending on the microcapsules content. Scanning electron microscopy was used to study fracture surface of the joints. The self-healing adhesives exhibit recovery of both cohesion and adhesion properties with room temperature healing.« less

  4. N.m.r. studies of the conformation of analogues of methyl beta-lactoside in methyl sulfoxide-d6.

    PubMed

    Rivera-Sagredo, A; Jiménez-Barbero, J; Martín-Lomas, M

    1991-12-16

    The 1H- and 13C-n.m.r. spectra of solutions of methyl beta-lactoside (1), all of its monodeoxy derivatives (2, 3, 6-10), the 3-O-methyl derivative (4), and methyl 4-O-beta-D-galactopyranosyl-D-xylopyranoside (5) in methyl sulfoxide-d6 have been analysed. The n.O.e.'s and specific desheildings indicate similar distributions of low-energy conformers, comparable to those in aqueous solution. The major conformer has torsion angles phi H and psi H of 49 degrees and 5 degrees, respectively, with contributions of conformers with phi/psi 24 degrees/-59 degrees, 22 degrees/32 degrees, and 6 degrees/44 degrees.

  5. AOI [3] High-Temperature Nano-Derived Micro-H 2 and - H 2S Sensors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sabolsky, Edward M.

    2014-08-01

    The emissions from coal-fired power plants remain a significant concern for air quality. This environmental challenge must be overcome by controlling the emission of sulfur dioxide (SO 2) and hydrogen sulfide (H 2S) throughout the entire coal combustion process. One of the processes which could specifically benefit from robust, low cost, and high temperature compatible gas sensors is the coal gasification process which converts coal and/or biomass into syngas. Hydrogen (H 2), carbon monoxide (CO) and sulfur compounds make up 33%, 43% and 2% of syngas, respectively. Therefore, development of a high temperature (>500°C) chemical sensor for in-situ monitoring ofmore » H 2, H 2S and SO2 2 levels during coal gasification is strongly desired. The selective detection of SO 2/H 2S in the presence of H 2, is a formidable task for a sensor designer. In order to ensure effective operation of these chemical sensors, the sensor system must inexpensively function within harsh temperature and chemical environment. Currently available sensing approaches, which are based on gas chromatography, electrochemistry, and IR-spectroscopy, do not satisfy the required cost and performance targets. This work focused on the development microsensors that can be applied to this application. In order to develop the high- temperature compatible microsensor, this work addressed various issues related to sensor stability, selectivity, and miniaturization. In the research project entitled “High-Temperature Nano-Derived Micro-H 2 and -H 2S Sensors”, the team worked to develop micro-scale, chemical sensors and sensor arrays composed of nano-derived, metal-oxide composite materials to detect gases like H 2, SO 2, and H 2S within high-temperature environments (>500°C). The research was completed in collaboration with NexTech Materials, Ltd. (Lewis Center, Ohio). NexTech assisted in the testing of the sensors in syngas with contaminate levels of H 2S. The idea of including nanomaterials as the

  6. Stereospecific enzymatic transformation of alpha-ketoglutarate to (2S,3R)-3-methyl glutamate during acidic lipopeptide biosynthesis.

    PubMed

    Mahlert, Christoph; Kopp, Florian; Thirlway, Jenny; Micklefield, Jason; Marahiel, Mohamed A

    2007-10-03

    The acidic lipopeptides, including the calcium-dependent antibiotics (CDA), daptomycin, and A54145, are important macrocyclic peptide natural products produced by Streptomyces species. All three compounds contain a 3-methyl glutamate (3-MeGlu) as the penultimate C-terminal residue, which is important for bioactivity. Here, biochemical in vitro reconstitution of the 3-MeGlu biosynthetic pathway is presented, using exclusively enzymes from the CDA producer Streptomyces coelicolor. It is shown that the predicted 3-MeGlu methyltransferase GlmT and its homologues DptI from the daptomycin producer Streptomyces roseosporus and LptI from the A54145 producer Streptomyces fradiae do not methylate free glutamic acid, PCP-bound glutamate, or Glu-containing CDA in vitro. Instead, GlmT, DptI, and LptI are S-adenosyl methionine (SAM)-dependent alpha-ketoglutarate methyltransferases that catalyze the stereospecific methylation of alpha-ketoglutarate (alphaKG) leading to (3R)-3-methyl-2-oxoglutarate. Subsequent enzyme screening identified the branched chain amino acid transaminase IlvE (SCO5523) as an efficient catalyst for the transformation of (3R)-3-methyl-2-oxoglutarate into (2S,3R)-3-MeGlu. Comparison of reversed-phase HPLC retention time of dabsylated 3-MeGlu generated by the coupled enzymatic reaction with dabsylated synthetic standards confirmed complete stereocontrol during enzymatic catalysis. This stereospecific two-step conversion of alphaKG to (2S,3R)-3-MeGlu completes our understanding of the biosynthesis and incorporation of beta-methylated amino acids into the nonribosomal lipopeptides. Finally, understanding this pathway may provide new possibilities for the production of modified peptides in engineered microbes.

  7. Investigation of H2S separation from H2S/CH4 mixtures using functionalized and non-functionalized vertically aligned carbon nanotube membranes

    NASA Astrophysics Data System (ADS)

    Gilani, Neda; Towfighi, Jafar; Rashidi, Alimorad; Mohammadi, Toraj; Omidkhah, Mohammad Reza; Sadeghian, Ahmad

    2013-04-01

    Separation of H2S from binary mixtures of H2S/CH4 using vertically aligned carbon nanotube membranes fabricated in anodic aluminum oxide (AAO) template was studied experimentally. Carbon nanotubes (CNTs) were grown in five AAO templates with different pore diameters using chemical vapor deposition, and CNT/AAO membranes with tubular carbon nanotube structure and open caps were selected for separation of H2S. For this, two tubular CNT/AAO membranes were fabricated with the CNT inner diameters of 23 and 8 nm. It was found that permeability and selectivity of the membrane with inner diameter of 23 nm for CNT were independent of upstream feed pressure and H2S feed concentration unlike that of CNT having an inner diameter of 8 nm. Selectivity of these membranes for separation of H2S was obtained in the ranges of 1.36-1.58 and 2.11-2.86, for CNTs with internal diameters of 23 and 8 nm, respectively. In order to enhance the separation of H2S from H2S/CH4 mixtures, dodecylamine was used to functionalize the CNT/AAO membrane with higher selectivity. The results showed that for amido-functionalized membrane, both upstream feed pressure and H2S partial pressure in the feed significantly increased H2S permeability, and selectivity for H2S being in the range of 3.0-5.57 respectively.

  8. N-(1-Allyl-1H-indazol-5-yl)-4-methyl-benzene-sulfonamide.

    PubMed

    Chicha, Hakima; Rakib, El Mostapha; Abderrafia, Hafid; Saadi, Mohamed; El Ammari, Lahcen

    2013-11-30

    The asymmetric unit of the title compound, C17H17N3O2S, contains two independent mol-ecules linked by an N-H⋯O hydrogen bond. The mol-ecules show different conformations. In the first mol-ecule, the fused five- and six-membered ring system is almost perpendicular to the plane through the atoms forming the allyl group, as indicated by the dihedral angle of 85.1 (4)°. The dihedral angle with the methyl-benzene-sulfonamide group is 78.8 (1)°. On the other hand, in the second mol-ecule, the dihedral angles between the indazole plane and the allyl and methyl-benzene-sulfonamide groups are 80.3 (3) and 41.5 (1)°, respectively. In the crystal, mol-ecules are further linked by N-H⋯N and C-H⋯O hydrogen bonds, forming a three-dimensional network.

  9. The DNA methylation profile of liver tumors in C3H mice and identification of differentially methylated regions involved in the regulation of tumorigenic genes.

    PubMed

    Matsushita, Junya; Okamura, Kazuyuki; Nakabayashi, Kazuhiko; Suzuki, Takehiro; Horibe, Yu; Kawai, Tomoko; Sakurai, Toshihiro; Yamashita, Satoshi; Higami, Yoshikazu; Ichihara, Gaku; Hata, Kenichiro; Nohara, Keiko

    2018-03-22

    C3H mice have been frequently used in cancer studies as animal models of spontaneous liver tumors and chemically induced hepatocellular carcinoma (HCC). Epigenetic modifications, including DNA methylation, are among pivotal control mechanisms of gene expression leading to carcinogenesis. Although information on somatic mutations in liver tumors of C3H mice is available, epigenetic aspects are yet to be clarified. We performed next generation sequencing-based analysis of DNA methylation and microarray analysis of gene expression to explore genes regulated by DNA methylation in spontaneous liver tumors of C3H mice. Overlaying these data, we selected cancer-related genes whose expressions are inversely correlated with DNA methylation levels in the associated differentially methylated regions (DMRs) located around transcription start sites (TSSs) (promoter DMRs). We further assessed mutuality of the selected genes for expression and DNA methylation in human HCC using the Cancer Genome Atlas (TCGA) database. We obtained data on genome-wide DNA methylation profiles in the normal and tumor livers of C3H mice. We identified promoter DMRs of genes which are reported to be related to cancer and whose expressions are inversely correlated with the DNA methylation, including Mst1r, Slpi and Extl1. The association between DNA methylation and gene expression was confirmed using a DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-aza-dC) in Hepa1c1c7 cells and Hepa1-6 cells. Overexpression of Mst1r in Hepa1c1c7 cells illuminated a novel downstream pathway via IL-33 upregulation. Database search indicated that gene expressions of Mst1r and Slpi are upregulated and the TSS upstream regions are hypomethylated also in human HCC. These results suggest that DMRs, including those of Mst1r and Slpi, are involved in liver tumorigenesis in C3H mice, and also possibly in human HCC. Our study clarified genome wide DNA methylation landscape of C3H mice. The data provide useful information

  10. Molecular structure studies of (1S,2S)-2-benzyl-2,3-dihydro-2-(1H-inden-2-yl)-1H-inden-1-ol

    PubMed Central

    Zhang, Tao; Paluch, Krzysztof; Scalabrino, Gaia; Frankish, Neil; Healy, Anne-Marie; Sheridan, Helen

    2015-01-01

    The single enantiomer (1S,2S)-2-benzyl-2,3-dihydro-2-(1H-inden-2-yl)-1H-inden-1-ol (2), has recently been synthesized and isolated from its corresponding diastereoisomer (1). The molecular and crystal structures of this novel compound have been fully analyzed. The relative and absolute configurations have been determined by using a combination of analytical tools including X-ray crystallography, X-ray Powder Diffraction (XRPD) analysis and Nuclear Magnetic Resonance (NMR) spectroscopy. PMID:25750458

  11. Hemi-methylated DNA regulates DNA methylation inheritance through allosteric activation of H3 ubiquitylation by UHRF1.

    PubMed

    Harrison, Joseph S; Cornett, Evan M; Goldfarb, Dennis; DaRosa, Paul A; Li, Zimeng M; Yan, Feng; Dickson, Bradley M; Guo, Angela H; Cantu, Daniel V; Kaustov, Lilia; Brown, Peter J; Arrowsmith, Cheryl H; Erie, Dorothy A; Major, Michael B; Klevit, Rachel E; Krajewski, Krzysztof; Kuhlman, Brian; Strahl, Brian D; Rothbart, Scott B

    2016-09-06

    The epigenetic inheritance of DNA methylation requires UHRF1, a histone- and DNA-binding RING E3 ubiquitin ligase that recruits DNMT1 to sites of newly replicated DNA through ubiquitylation of histone H3. UHRF1 binds DNA with selectivity towards hemi-methylated CpGs (HeDNA); however, the contribution of HeDNA sensing to UHRF1 function remains elusive. Here, we reveal that the interaction of UHRF1 with HeDNA is required for DNA methylation but is dispensable for chromatin interaction, which is governed by reciprocal positive cooperativity between the UHRF1 histone- and DNA-binding domains. HeDNA recognition activates UHRF1 ubiquitylation towards multiple lysines on the H3 tail adjacent to the UHRF1 histone-binding site. Collectively, our studies are the first demonstrations of a DNA-protein interaction and an epigenetic modification directly regulating E3 ubiquitin ligase activity. They also define an orchestrated epigenetic control mechanism involving modifications both to histones and DNA that facilitate UHRF1 chromatin targeting, H3 ubiquitylation, and DNA methylation inheritance.

  12. Deodorizing Substance in Black Cumin (Nigella sativa L.) Seed Oil.

    PubMed

    Nakasugi, Toru; Murakawa, Takushi; Shibuya, Koji; Morimoto, Masanori

    2017-08-01

    A deodorizing substance in black cumin (Nigella sativa L.), a spice for curry and vegetable foods in Southwest Asia, was examined. The essential oil prepared from the seeds of this plant exhibited strong deodorizing activity against methyl mercaptan, which is a main factor in oral malodor. After purification with silica gel column chromatography, the active substance in black cumin seed oil was identified as thymoquinone. This monoterpenic quinone functions as the main deodorizing substance in this oil against methyl mercaptan. Metabolite analysis suggested that the deodorizing activity may be generated by the addition of a reactive quinone molecule to methyl mercaptan. In the present study, the menthane-type quinone and phenol derivatives exhibited deodorizing activities via this mechanism.

  13. Crystal structure of 1-ferrocenyl-2-(4-methyl-benzo-yl)spiro-[11H-pyrrolidizine-3,11'-indeno[1,2-b]quinoxaline].

    PubMed

    Chandralekha, Kuppan; Gavaskar, Deivasigamani; Sureshbabu, Adukamparai Rajukrishnan; Lakshmi, Srinivasakannan

    2014-09-01

    In the title compound, [Fe(C5H5)(C34H28N3O)], the four-fused-rings system of the 11H-indeno-[1,2-b]quinoxaline unit is approximately planar [maximum deviation = 0.167 (4) Å] and forms a dihedral angle of 37.25 (6)° with the plane of the benzene ring of the methyl-benzoyl group. Both pyrrolidine rings adopt a twist conformation. An intra-molecular C-H⋯O hydrogen bond is observed. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds and weak C-H⋯π inter-actions, forming double chains extending parallel to the c axis.

  14. Synthesis, DFT calculations, electronic structure, electronic absorption spectra, natural bond orbital (NBO) and nonlinear optical (NLO) analysis of the novel 5-methyl-8H-benzo[h]chromeno[2,3-b][1,6] naphthyridine-6(5H),8-dione (MBCND)

    NASA Astrophysics Data System (ADS)

    Halim, Shimaa Abdel; Ibrahim, Magdy A.

    2017-02-01

    New derivative of heteroannulated chromone identified as 5-methyl-8H-benzo[h]chromeno[2,3-b][1,6]naphthyridine-6(5H),8-dione (5, MBCND) was easily and efficiently synthesized from DBU catalyzed condensation reaction of 2-aminochromone-3-carboxaldehyde (1) with 4-hydroxy-1-methylquinolin-2(1H)-one (2). The same product 5 was isolated from condensation reaction of aldeyde 1 with 3-(4-hydroxy-1-methyl-2-oxo-1,2-dihydroquinolin-3-yl)-3-oxopropanoic acid (3) or ethyl 4-(4-hydroxy-1-methyl-2-oxo-1,2-dihydroquinolin-3-yl)-2,4-dioxobutanoate (4). Structure of compound (5, MBCND) was deduced based on their elemental analyses and spectral data (IR, 1H NMR and mass spectra). Density Functional Theory (DFT) calculations at the B3LYP/6-311G (d,p) level of theory have been carried out to investigate the equilibrium geometry of the novel compound (5, MBCND). Moreover, total energy, energy of HOMO and LUMO and Mullikan atomic charges were calculated. In addition, the dipole moment, theoretical study of the electronic structure, nonlinear optical properties (NLO), and natural bonding orbital (NBO) analysis and orientation have been performed and discussed. Also the electronic absorption spectra were measured in polar (methanol) as well as non polar (dioxane) solvents and the assignment of the observed bands has been discussed by TD-DFT calculations. The correspondences between calculated and experimental transitions energies are satisfactory.

  15. 40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

    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-methyl-, 1,1â²-[2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10122 2-Propenoic acid, 2-methyl-, 1,1... new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, 1...

  16. 40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

    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-methyl-, 1,1â²-[2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10122 2-Propenoic acid, 2-methyl-, 1,1... new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, 1...

  17. 40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

    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-methyl-, 1,1â²-[2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10122 2-Propenoic acid, 2-methyl-, 1,1... new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, 1...

  18. A simple hydrogen-bonded chain in (3Z)-3-{1-[(5-phenyl-1H-pyrazol-3-yl)amino]ethylidene}-4,5-dihydrofuran-2(3H)-one, and a hydrogen-bonded ribbon of centrosymmetric rings in the self-assembled adduct (3Z)-3-{1-[(5-methyl-1H-pyrazol-3-yl)amino]ethylidene}-4,5-dihydrofuran-2(3H)-one-6-(2-hydroxyethyl)-2,5-dimethylpyrazolo[1,5-a]pyrimidin-7(4H)-one (1/1).

    PubMed

    Quiroga, Jairo; Portilla, Jaime; Cobo, Justo; Glidewell, Christopher

    2010-01-01

    (3Z)-3-{1-[(5-Phenyl-1H-pyrazol-3-yl)amino]ethylidene}-4,5-dihydrofuran-2(3H)-one, C(15)H(15)N(3)O(2), (I), and the stoichiometric adduct (3Z)-3-{1-[(5-methyl-1H-pyrazol-3-yl)amino]ethylidene}-4,5-dihydrofuran-2(3H)-one-6-(2-hydroxyethyl)-2,5-dimethylpyrazolo[1,5-a]pyrimidin-7(4H)-one (1/1), C(10)H(13)N(3)O(2).C(10)H(13)N(3)O(2), (II), in which the two components have the same composition but different constitutions, are formed in the reactions of 2-acetyl-4-butyrolactone with 5-amino-3-phenyl-1H-pyrazole and 5-amino-3-methyl-1H-pyrazole, respectively. In each compound, the furanone component contains an intramolecular N-H...O hydrogen bond. The molecules of (I) are linked into a chain by a single intermolecular N-H...O hydrogen bond, while in (II), a combination of one O-H...N hydrogen bond, within the selected asymmetric unit, and two N-H...O hydrogen bonds link the molecular components into a ribbon containing alternating centrosymmetric R(4)(4)(20) and R(6)(6)(22) rings.

  19. MLL5, a trithorax homolog, indirectly regulates H3K4 methylation, represses cyclin A2 expression, and promotes myogenic differentiation

    PubMed Central

    Sebastian, Soji; Sreenivas, Prethish; Sambasivan, Ramkumar; Cheedipudi, Sirisha; Kandalla, Prashanth; Pavlath, Grace K.; Dhawan, Jyotsna

    2009-01-01

    Most cells in adult tissues are nondividing. In skeletal muscle, differentiated myofibers have exited the cell cycle permanently, whereas satellite stem cells withdraw transiently, returning to active proliferation to repair damaged myofibers. We have examined the epigenetic mechanisms operating in conditional quiescence by analyzing the function of a predicted chromatin regulator mixed lineage leukemia 5 (MLL5) in a culture model of reversible arrest. MLL5 is induced in quiescent myoblasts and regulates both the cell cycle and differentiation via a hierarchy of chromatin and transcriptional regulators. Knocking down MLL5 delays entry of quiescent myoblasts into S phase, but hastens S-phase completion. Cyclin A2 (CycA) mRNA is no longer restricted to S phase, but is induced throughout G0/G1, with activation of the cell cycle regulated element (CCRE) in the CycA promoter. Overexpressed MLL5 physically associates with the CCRE and impairs its activity. MLL5 also regulates CycA indirectly: Cux, an activator of CycA promoter and S phase is induced in RNAi cells, and Brm/Brg1, CCRE-binding repressors that promote differentiation are repressed. In knockdown cells, H3K4 methylation at the CCRE is reduced, reflecting quantitative global changes in methylation. MLL5 appears to lack intrinsic histone methyl transferase activity, but regulates expression of histone-modifying enzymes LSD1 and SET7/9, suggesting an indirect mechanism. Finally, expression of muscle regulators Pax7, Myf5, and myogenin is impaired in MLL5 knockdown cells, which are profoundly differentiation defective. Collectively, our results suggest that MLL5 plays an integral role in novel chromatin regulatory mechanisms that suppress inappropriate expression of S-phase-promoting genes and maintain expression of determination genes in quiescent cells. PMID:19264965

  20. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric...

  1. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric...

  2. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric...

  3. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric...

  4. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric...

  5. Startup and long-term performance of biotrickling filters packed with polyurethane foam and poplar wood chips treating a mixture of ethylmercaptan, H2S, and NH3.

    PubMed

    Hernández, J; Lafuente, J; Prado, O J; Gabriel, D

    2013-04-01

    Treatment of a mixture of NH3, H2S, and ethylmercaptan (EM) was investigated for more than 15 months in two biotrickling filters packed with poplar wood chips and polyurethane foam. Inlet loads ranging from 5 to 10 g N-NH3 m-3 hr-1, from 5 to 16 g S-H2S m-3 hr-1, and from 0 to 5 g EM m-3 hr-1 were applied. During startup, the biotrickling filter packed with polyurethane foam was re-inoculated due to reduced biomass retention as well as a stronger effect of nitrogen compounds inhibition compared with the biotrickling filter packed with poplar wood. Accurate pH control between 7 and 7.5 favored pollutants abatement. In the long run, complete NH3 removal in the gas phase was achieved in both reactors, while H2S removal efficiencies exceeded 90%. EM abatement was significantly different in both reactors. A systematically lower elimination capacity was found in the polyurethane foam bioreactor. N fractions in the liquid phase proved that high nitrification rates were reached throughout steady-state operation in both bioreactors. CO2 production showed the extent of the organic packing material degradation, which allowed estimating its service lifetime in around 2 years. In the long run, the bioreactor packed with the organic packing material had a lower stability. However, an economic analysis indicated that poplar wood chips are a competitive alternative to inorganic packing materials in biotrickling filters. We provide new insights in the use of organic packing materials in biotrickling filters for the treatment of H2S, NH3, and mercaptans and compare them with polyurethane foam, a packing commonly used in biotrickling filters. We found interesting features related with the startup of the reactors and parameterized both the performance under steady-state conditions and the influence of the gas contact time. We provide relevant conclusions in the profitability of organic packing materials under a biotrickling filter configuration, which is infrequent but proven reliable

  6. A heterozygous IDH1R132H/WT mutation induces genome-wide alterations in DNA methylation.

    PubMed

    Duncan, Christopher G; Barwick, Benjamin G; Jin, Genglin; Rago, Carlo; Kapoor-Vazirani, Priya; Powell, Doris R; Chi, Jen-Tsan; Bigner, Darell D; Vertino, Paula M; Yan, Hai

    2012-12-01

    Monoallelic point mutations of the NADP(+)-dependent isocitrate dehydrogenases IDH1 and IDH2 occur frequently in gliomas, acute myeloid leukemias, and chondromas, and display robust association with specific DNA hypermethylation signatures. Here we show that heterozygous expression of the IDH1(R132H) allele is sufficient to induce the genome-wide alterations in DNA methylation characteristic of these tumors. Using a gene-targeting approach, we knocked-in a single copy of the most frequently observed IDH1 mutation, R132H, into a human cancer cell line and profiled changes in DNA methylation at over 27,000 CpG dinucleotides relative to wild-type parental cells. We find that IDH1(R132H/WT) mutation induces widespread alterations in DNA methylation, including hypermethylation of 2010 and hypomethylation of 842 CpG loci. We demonstrate that many of these alterations are consistent with those observed in IDH1-mutant and G-CIMP+ primary gliomas and can segregate IDH wild-type and mutated tumors as well as those exhibiting the G-CIMP phenotype in unsupervised analysis of two primary glioma cohorts. Further, we show that the direction of IDH1(R132H/WT)-mediated DNA methylation change is largely dependent upon preexisting DNA methylation levels, resulting in depletion of moderately methylated loci. Additionally, whereas the levels of multiple histone H3 and H4 methylation modifications were globally increased, consistent with broad inhibition of histone demethylation, hypermethylation at H3K9 in particular accompanied locus-specific DNA hypermethylation at several genes down-regulated in IDH1(R132H/WT) knock-in cells. These data provide insight on epigenetic alterations induced by IDH1 mutations and support a causal role for IDH1(R132H/WT) mutants in driving epigenetic instability in human cancer cells.

  7. Mineralization of Basalts in the CO 2-H 2O-H 2S System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schaef, Herbert T.; McGrail, B. Peter; Owen, Antionette T.

    2013-05-10

    Basalt samples representing five different formations were immersed in water equilibrated with supercritical carbon dioxide containing 1% hydrogen sulfide (H2S) at reservoir conditions (100 bar, 90°C) for up to 3.5 years. Surface coatings in the form of pyrite and metal cation substituted carbonates were identified as reaction products associated with all five basalts. In some cases, high pressure tests contained excess H2S, which produced the most corroded basalts and largest amount of secondary products. In comparison, tests containing limited amounts of H2S appeared least reacted with significantly less concentrations of reaction products. In all cases, pyrite appeared to precede carbonation,more » and in some instances, was observed in the absence of carbonation such as in cracks, fractures, and within the porous glassy mesostasis. Armoring reactions from pyrite surface coatings observed in earlier shorter duration tests were found to be temporary with carbonate mineralization observed with all the basalts tested in these long duration experiments. Geochemical simulations conducted with the geochemical code EQ3/6 accurately predicted early pyrite precipitation followed by formation of carbonates. Reactivity with H2S was correlated with measured Fe(II)/Fe(III) ratios in the basalts with more facile pyrite formation occurring with basalts containing more Fe(III) phases. These experimental and modeling results confirm potential for long term sequestration of acid gas mixtures in continental flood basalt formations.« less

  8. The preparation and degradation performance of CdS photocatalysts to methyl orange solution.

    PubMed

    Duan, Limei; Zhao, Weiqiang; Xu, Ling; Chen, Xiaohong; Lita, A; Liu, Zongrui

    2013-03-01

    In this paper, the CdS samples were prepared using thiourea or sodium sulfide as sulfur source by hydrothermal or solvothermal synthesis method, the results of XRD, TEM and SEM showed all the samples belong to hexagonal CdS nano-material with different morphologies. Using the degradation of methyl orange solution as a model reaction, the photocatalytic performance of different CdS samples was measured, and the samples prepared using thiourea as sulfur source exhibited better photocatalytic activity than those using sodium sulfide as sulfur source. The factors on degradation effect were discussed including the pH value of degradation system and the type of light source. The degradation effect of CdS samples increased with the pH value decreased, and the degradation effect was better when the methyl orange solution was irradiated under sunlight than under 250 W mercury lamp.

  9. 2-[3-Furyl(hydroxy)methyl]-2,3-dimethylcyclohexanone.

    PubMed

    García, Esther; Mendoza, Virgilio; Guzmán, José Agustín; Maldonado Graniel, Luis Angel; Hernández-Ortega, Simón

    2002-06-01

    Contribution No. 1750 of the Instituto de Quimica, UNAM, Mexico. In the molecule of the title compound, C(13)H(18)O(3), there is a syn relationship between the two vicinal methyl groups. The six-membered ring adopts a chair conformation, with one equatorial and two axial groups, and the furyl group is almost parallel to the ketone group. Intermolecular hydrogen bonds [O[bond]H...O[double bond]C 2.814 (3) A] form chains along [100].

  10. MET-2-Dependent H3K9 Methylation Suppresses Transgenerational Small RNA Inheritance.

    PubMed

    Lev, Itamar; Seroussi, Uri; Gingold, Hila; Bril, Roberta; Anava, Sarit; Rechavi, Oded

    2017-04-24

    In C. elegans, alterations to chromatin produce transgenerational effects, such as inherited increase in lifespan and gradual loss of fertility. Inheritance of histone modifications can be induced by double-stranded RNA-derived heritable small RNAs. Here, we show that the mortal germline phenotype, which is typical of met-2 mutants, defective in H3K9 methylation, depends on HRDE-1, an argonaute that carries small RNAs across generations, and is accompanied by accumulated transgenerational misexpression of heritable small RNAs. We discovered that MET-2 inhibits small RNA inheritance, and, as a consequence, induction of RNAi in met-2 mutants leads to permanent RNAi responses that do not terminate even after more than 30 generations. We found that potentiation of heritable RNAi in met-2 animals results from global hyperactivation of the small RNA inheritance machinery. Thus, changes in histone modifications can give rise to drastic transgenerational epigenetic effects, by controlling the overall potency of small RNA inheritance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Impact of folic acid intake during pregnancy on genomic imprinting of IGF2/H19 and 1-carbon metabolism.

    PubMed

    Tserga, Aggeliki; Binder, Alexandra M; Michels, Karin B

    2017-12-01

    Folic acid is an essential component of 1-carbon metabolism, which generates methyl groups for DNA methylation. Disruption of genomic imprinting leads to biallelic expression which may affect disease susceptibility possibly reflected in high levels of S -adenosyl-homocysteine (SAH) and low levels of S -adenosyl-methionine (SAM). We investigated the association between folic acid supplementation during pregnancy and loss of imprinting (LOI) of IGF2 and H19 genes in placentas and cord blood of 90 mother-child dyads in association with the methylenetetrahydrofolate reductase ( MTHFR ) genotype. Pyrosequencing was used to evaluate deviation from monoallelic expression among 47 placentas heterozygous for H19 and 37 placentas and cord blood tissues heterozygous for IGF2 and H19 methylation levels of 48 placentas. We detected relaxation of imprinting (ROI) and LOI of H19 in placentas not associated with differences in methylation levels of the H19ICR. Placentas retained monoallelic allele-specific gene expression of IGF2 , but 32.4% of cord blood samples displayed LOI of IGF2 and 10.8% showed ROI. High SAH levels were significantly associated with low H19 methylation. An interesting positive association between SAM/SAH ratio and high H19 methylation levels was detected among infants with low B 12 levels. Our data suggest profound differences in regulation of imprinting in placenta and cord blood; a lack of correlation of the methylome, transcriptome, and proteome; and a complex regulatory feedback network between free methyl groups and genomic imprinting at birth.-Tserga, A., Binder, A. M., Michels, K. B. Impact of folic acid intake during pregnancy on genomic imprinting of IGF2/H19 and 1-carbon metabolism. © FASEB.

  12. Synthesis, characterization, antimicrobial, DNA-cleavage and antioxidant activities of 3-((5-chloro-2-phenyl-1H-indol-3-ylimino)methyl)quinoline-2(1H)-thione and its metal complexes

    NASA Astrophysics Data System (ADS)

    Vivekanand, B.; Mahendra Raj, K.; Mruthyunjayaswamy, B. H. M.

    2015-01-01

    Schiff base 3-((5-chloro-2-phenyl-1H-indol-3-ylimino)methyl)quinoline-2(1H)-thione and its Cu(II), Co(II), Ni(II), Zn(II) and Fe(III), complexes have been synthesized and characterized by elemental analysis, UV-Visible, IR, 1H NMR, 13C NMR and mass spectra, molar conductance, magnetic susceptibility, ESR and TGA data. The ligand and its metal complexes have been screened for their antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa, antifungal activity against Aspergillus niger and Aspergillus flavus in minimum inhibition concentration (MIC) by cup plate method respectively, antioxidant activity using 1,1-diphenyl-2-picryl hydrazyl (DPPH), which was compared with that of standard drugs vitamin-C and vitamin-E and DNA cleavage activity using calf-thymus DNA.

  13. Methylation variable position profiles of hMLH1 promoter CpG islands in human sporadic colorectal carcinoma.

    PubMed

    Huang, Qing; Huang, Jun-Fu; Zhang, Bo; Baum, Larry; Fu, Wei-Ling

    2012-03-01

    Aberrant hypermethylation of CpG islands (CGIs) in hMLH1 promoter regions has been well known to play an important role in the tumorigenesis of human sporadic colorectal carcinoma (SCRC). In this study, bisulfite sequencing was performed to analyze the methylation variable positions (MVPs) profiles of hMLH1 promoter CGIs in 30 clinical SCRC patients, and further analysis was carried out to evaluate the associations between the CGI methylation and the clinicopathological features in SCRC. Among the 2 CGIs in the hMLH1 promoter, that is, CGI-I and CGI-II, 20% (6/30) and 13% (4/30) of the patients had methylated CGI-I and CGI-II, respectively. Suppressed expression of hMLH1was significantly correlated with methylation of CGI-I but not CGI-II. Further analysis of the MVP profiles of CGI-I showed that most of the MVPs were hypermethylated and others were poorly methylated or unmethylated. The profiles could be classified into at least 4 groups based on the methylation status of 3 MVPs at positions 21 to 23 in CGI-I. All 6 patients with methylated CGI-I belonged to group I. This result suggests that the above 3 MVPs in CGI-I should be a targeted region to further analyze the epigenetic features of hMLH1 in human SCRC. Our results further suggest that MVP profiling is useful for identifying the aberrantly methylated CGIs associated with suppressed gene expression.

  14. (Carbonyl-1κC)bis-[2,3(η)-cyclo-penta-dien-yl][μ(3)-(S-methyl trithio-carbonato)methylidyne-1:2:3κC,S'':C:C](triphenyl-phosphine-1κP)(μ(3)-sulfido-1:2:3κS)dicobalt(II)iron(II) trifluoro-methane-sulfonate.

    PubMed

    Manning, Anthony R; McAdam, C John; Palmer, Anthony J; Simpson, Jim

    2008-04-10

    The asymmetric unit of the title compound, [FeCo(2)(C(5)H(5))(2)(C(3)H(3)S(3))S(C(18)H(15)P)(CO)]CF(3)SO(3), consists of a triangular irondicobalt cluster cation and a trifluoro-methane-sulfonate anion. In the cation, the FeCo(2) triangle is symmetrically capped on one face by an S atom and on the other by a C atom linked to a methyl trithio-carbonate residue that bridges the Fe-C bond. Each Co atom carries a cyclo-penta-dienyl ligand while the Fe atom coordinates to one carbonyl and one triphenyl-phosphine ligand. In the crystal structure, the cation is linked to the anion by a number of weak non-classical C-H⋯O and C-H⋯F hydrogen bonds and weak S⋯O (3.317 Å) and S⋯F (3.198 Å) inter-actions. The structure is further stabilized by additional inter-molecular C-H⋯O, C-H⋯F and O⋯O (2.942 Å) contacts, together with an unusual S⋯π(Cp) inter-action (S⋯centroid distance = 3.385 Å), generating an extended network.

  15. Arsenic activates the expression of 3β-HSD in mouse Leydig cells through repression of histone H3K9 methylation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Alamdar, Ambreen; Xi, Guochen

    Arsenic exposure has been associated with male reproductive dysfunction by disrupting steroidogenesis; however, the roles of epigenetic drivers, especially histone methylation in arsenic-induced steroidogenic toxicity remain not well documented. In this study, we investigated the role of histone H3 lysine 9 (H3K9) methylation in steroidogenesis disturbance in mouse Leydig cells (MLTC-1) due to arsenic exposure. Our results indicated that mRNA and protein expression levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) were both significantly up-regulated while the rest of key genes involved in steroidogenesis were down-regulated. Moreover, arsenic exposure significantly decreased the histone H3K9 di- and tri-methylation (H3K9me2/3) levels in MLTC-1 cells. Sincemore » H3K9 demethylation leads to gene activation, we further investigated whether the induction of 3β-HSD expression was ascribed to reduced H3K9 methylation. The results showed that H3K9me2/3 demethylase (JMJD2A) inhibitor, quercetin (Que) significantly attenuated the decrease of H3K9me2/3 and increase of 3β-HSD expression induced by arsenic. To further elucidate the mechanism for the activation of 3β-HSD, we determined the histone H3K9 methylation levels in Hsd3b gene promoter, which also showed significant decrease of H3K9me2/3 in the investigated region after arsenic exposure. Considering these results, we conclude that arsenic exposure induced 3β-HSD up-regulation by suppressing H3K9me2/3 status, which is suggested as a compensatory mechanism for steroidogenic disturbance in MLTC-1 cells. - Highlights: • Epigenetic mechanisms of arsenic-induced male reproductive toxicity remain unclear. • Arsenic disturbs the expression of key steroidogenic genes in MLTC-1 cells. • Histone H3K9 di- and tri-methylation was suppressed in arsenic-exposed cells. • Arsenic activates 3β-HSD expression through repression of histone H3K9 methylation.« less

  16. Crystal structure of 2-bromo-3-di­methyl­amino-N,N,N′,N′,4-penta­methyl-4-(tri­methyl­sil­yloxy)pent-2-eneamidinium bromide

    PubMed Central

    Tiritiris, Ioannis; Kress, Ralf; Kantlehner, Willi

    2015-01-01

    The reaction of the ortho­amide 1,1,1-tris­(di­methyl­amino)-4-methyl-4-(tri­methyl­sil­yloxy)pent-2-yne with bromine in benzene, yields the title salt, C15H33BrN3OSi+·Br−. The C—N bond lengths in the amidinium unit are 1.319 (6) and 1.333 (6) Å, indicating double-bond character, pointing towards charge delocalization within the NCN plane. The C—Br bond length of 1.926 (5) Å is characteristic for a C—Br single bond. Additionally, there is a bromine–bromine inter­action [3.229 (3) Å] present involving the anion and cation. In the crystal, weak C—H⋯Br inter­actions between the methyl H atoms of the cation and the bromide ions are present. PMID:26870498

  17. Transport of H2S and HS− across the human red blood cell membrane: rapid H2S diffusion and AE1-mediated Cl−/HS− exchange

    PubMed Central

    2013-01-01

    The rates of H2S and HS− transport across the human erythrocyte membrane were estimated by measuring rates of dissipation of pH gradients in media containing 250 μM H2S/HS−. Net acid efflux is caused by H2S/HS− acting analogously to CO2/HCO3− in the Jacobs-Stewart cycle. The steps are as follows: 1) H2S efflux through the lipid bilayer and/or a gas channel, 2) extracellular H2S deprotonation, 3) HS− influx in exchange for Cl−, catalyzed by the anion exchange protein AE1, and 4) intracellular HS− protonation. Net acid transport by the Cl−/HS−/H2S cycle is more efficient than by the Cl−/HCO3−/CO2 cycle because of the rapid H2S-HS− interconversion in cells and medium. The rates of acid transport were analyzed by solving the mass flow equations for the cycle to produce estimates of the HS− and H2S transport rates. The data indicate that HS− is a very good substrate for AE1; the Cl−/HS− exchange rate is about one-third as rapid as Cl−/HCO3− exchange. The H2S permeability coefficient must also be high (>10−2 cm/s, half time <0.003 s) to account for the pH equilibration data. The results imply that H2S and HS− enter erythrocytes very rapidly in the microcirculation of H2S-producing tissues, thereby acting as a sink for H2S and lowering the local extracellular concentration, and the fact that HS− is a substrate for a Cl−/HCO3− exchanger indicates that some effects of exogenous H2S/HS− may not result from a regulatory role of H2S but, rather, from net acid flux by H2S and HS− transport in a Jacobs-Stewart cycle. PMID:23864610

  18. Transport of H2S and HS(-) across the human red blood cell membrane: rapid H2S diffusion and AE1-mediated Cl(-)/HS(-) exchange.

    PubMed

    Jennings, Michael L

    2013-11-01

    The rates of H2S and HS(-) transport across the human erythrocyte membrane were estimated by measuring rates of dissipation of pH gradients in media containing 250 μM H2S/HS(-). Net acid efflux is caused by H2S/HS(-) acting analogously to CO2/HCO3(-) in the Jacobs-Stewart cycle. The steps are as follows: 1) H2S efflux through the lipid bilayer and/or a gas channel, 2) extracellular H2S deprotonation, 3) HS(-) influx in exchange for Cl(-), catalyzed by the anion exchange protein AE1, and 4) intracellular HS(-) protonation. Net acid transport by the Cl(-)/HS(-)/H2S cycle is more efficient than by the Cl(-)/HCO3(-)/CO2 cycle because of the rapid H2S-HS(-) interconversion in cells and medium. The rates of acid transport were analyzed by solving the mass flow equations for the cycle to produce estimates of the HS(-) and H2S transport rates. The data indicate that HS(-) is a very good substrate for AE1; the Cl(-)/HS(-) exchange rate is about one-third as rapid as Cl(-)/HCO3(-) exchange. The H2S permeability coefficient must also be high (>10(-2) cm/s, half time <0.003 s) to account for the pH equilibration data. The results imply that H2S and HS(-) enter erythrocytes very rapidly in the microcirculation of H2S-producing tissues, thereby acting as a sink for H2S and lowering the local extracellular concentration, and the fact that HS(-) is a substrate for a Cl(-)/HCO3(-) exchanger indicates that some effects of exogenous H2S/HS(-) may not result from a regulatory role of H2S but, rather, from net acid flux by H2S and HS(-) transport in a Jacobs-Stewart cycle.

  19. 21 CFR 172.515 - Synthetic flavoring substances and adjuvants.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...-hydroxyundecanoic acid γ-lactone; peach aldehyde; aldehyde C-14. Undecenal. 2-Undecanone; methyl nonyl ketone. 9.... Acetophenone; methyl phenyl ketone. Allyl anthranilate. Allyl butyrate. Allyl cinnamate. Allyl...-heptanone; benzyl dipropyl ketone. Benzyl isobutyrate. Benzyl isovalerate. Benzyl mercaptan; α-toluenethiol...

  20. Optical resolution of {pi}-thiophene complexes (C{sub 6}Me{sub 6}) Ru(2-RC{sub 4}H{sub 3}S){sup 2+} and related studies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dailey, K.K.; Rauchfuss, T.B.

    Diasteriomeric iminium thiolato complexes were prepared by the addition of S-(-)-{alpha}-methylbenzylamine to the {pi}-thiophene complexes [(C{sub 6}Me{sub 6})Ru(2-RC{sub 4}H{sub 3}S)]{sup 2+}, where R = Me(1{sup 2+}), CH{sub 2}OH (3{sup 2+}), and 2-C{sub 4}H{sub 3}S(6{sup 2+}). After chromatographic separation, the diastereomers were treated with HOTf to generate optically pure {pi}-thiophene complexes. The absolute configuration of [(C{sub 6}Me{sub 6})RuSCMeC{sub 2}H{sub 2}(CHNHCHMePh)]OTf, (-)-2(OTf), was determined by a single-crystal X-ray diffraction; the monohydrate crystallized in the acentric space group P2{sub 1}2{sub 1}2{sub 1}. Base hydrolysis of (-)-1{sup 2+} gave the formyl thiolato complex (-)-9{sub kin}, which isomerized to (+)-9{sub therm} with inversion of configurationmore » at Ru, as indicated by circular dichroism measurements. The methyl ester of the amino acid (L)-phenylalanine was shown to add to (C{sub 6}Me{sub 6})Ru(C{sub 4}H{sub 4}S){sup 2+} to give a 2:1 mixture of diastereomeric iminium thiolato complexes. 19 refs., 3 figs., 2 tabs.« less

  1. A Computational Study of Chalcogen-containing H2 X…YF and (CH3 )2 X…YF (X=O, S, Se; Y=F, Cl, H) and Pnicogen-containing H3 X'…YF and (CH3 )3 X'…YF (X'=N, P, As) Complexes.

    PubMed

    McDowell, Sean A C; Buckingham, A David

    2018-04-20

    A computational study was undertaken for the model complexes H 2 X…YF and (CH 3 ) 2 X…YF (X=O, S, Se; Y=F, Cl, H), and H 3 X'…YF and (CH 3 ) 3 X'…YF (X'=N, P, As), at the MP2/6-311++G(d,p) level of theory. For H 2 X…YF and H 3 X'…YF, noncovalent interactions dominate the binding in order of increasing YF dipole moment, except for H 3 As…F 2 , and possibly H 3 As…ClF. However, for the methyl-substituted complexes (CH 3 ) 2 X…YF and (CH 3 ) 3 X'…YF the binding is especially strong for the complexes containing F 2 , implying significant chemical bonding between the interacting molecules. The relative stability of these complexes can be rationalized by the difference in the electronegativity of the X or X' and Y atoms. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Adsorption Assisted Photocatalytic Removal of Methyl Orange by MgAl2O4-Sb2S3 Composite Material.

    PubMed

    Muneeb, Muhammad; Ismail, Bushra; Fazal, Tanzeela; Khan, Abdur Rehman; Afzia, Mehwish

    2016-01-01

    The current article is about the water treatment in which colored water contaminated by methyl orange has been used for adsorption assisted photocatalysis. Coupling of photocatalysis with the traditional water treatment processes has been in practice since last couple of years for the improvement of degradation efficiencies, for example, photocatalysis coupled with ultrafilteration, adsorption, flocculation, biological methods, photolysis, membrane distillation, etc. Among all these coupling approaches, adsorption assisted photocatalysis being a very simple and highly efficient approach is suffering from few drawbacks on the account of high cost, low stability and surface area of the adsorbent support. The present study is a contribution towards improvement in this coupling approach. A low cost, highly stable spinel magnesium aluminate (MgAl2O4) material synthesized at nanoscale is used for composite formation with antimony sulphide (Sb2S3) material having high absorption coefficient in the visible light of solar spectrum. A review of recent patents shows that the field of photoctalysis is dominated by the traditional TiO2 catalyst. The modification of TiO2 by either composite formation or by doping is the main focus. Coprecipitation method is used for the synthesis of spinel in which the desired precursors in the respective molar ratios were mixed and annealing of the resulting precipitates was carried out at 800oC for 8 h. Sb2S3 was synthesized by the hydrothermal method in which the required molar solution of precursors was mixed with urea solution and the whole mixture was maintained at 105oC for 6 hrs in a Teflon lined autoclave. The resulting suspension was then annealed at 37oC for 3 hours. The composite of Sb2S3 and MgAl2O4 has been synthesized by mixing both the materials in 1:1 and heat treated in an oven at a temperature of 200oC. Peaks in X-ray diffraction pattern correspond to both the Sb2S3 and spinel phase. All the peaks corresponding to the Sb2S3

  3. Convergent evolution of chromatin modification by structurally distinct enzymes: comparative enzymology of histone H3 Lys²⁷ methylation by human polycomb repressive complex 2 and vSET.

    PubMed

    Swalm, Brooke M; Hallenbeck, Kenneth K; Majer, Christina R; Jin, Lei; Scott, Margaret Porter; Moyer, Mikel P; Copeland, Robert A; Wigle, Tim J

    2013-07-15

    H3K27 (histone H3 Lys27) methylation is an important epigenetic modification that regulates gene transcription. In humans, EZH (enhancer of zeste homologue) 1 and EZH2 are the only enzymes capable of catalysing methylation of H3K27. There is great interest in understanding structure-function relationships for EZH2, as genetic alterations in this enzyme are thought to play a causal role in a number of human cancers. EZH2 is challenging to study because it is only active in the context of the multi-subunit PRC2 (polycomb repressive complex 2). vSET is a viral lysine methyltransferase that represents the smallest protein unit capable of catalysing H3K27 methylation. The crystal structure of this minimal catalytic protein has been solved and researchers have suggested that vSET might prove useful as an EZH2 surrogate for the development of active site-directed inhibitors. To test this proposition, we conducted comparative enzymatic analysis of human EZH2 and vSET and report that, although both enzymes share similar preferences for methylation of H3K27, they diverge in terms of their permissiveness for catalysing methylation of alternative histone lysine sites, their relative preferences for utilization of multimeric macromolecular substrates, their active site primary sequences and, most importantly, their sensitivity to inhibition by drug-like small molecules. The cumulative data led us to suggest that EZH2 and vSET have very distinct active site structures, despite the commonality of the reaction catalysed by the two enzymes. Hence, the EZH2 and vSET pair of enzymes represent an example of convergent evolution in which distinct structural solutions have developed to solve a common catalytic need.

  4. Histone Methylation and Epigenetic Silencing in Breast Cancer

    DTIC Science & Technology

    2011-02-01

    Chen, S., Bohrer, L.R., Nair-Rai, A., Pan , Y., Gan, L., Zhou, X., Bagchi, A., Simon, J.A. and Huang, H. (2010). Cyclin-dependent kinases regulate...EZH2 suppresses methylation of lysine 27 in histone H3. Science 310(5746): 306-310. Chen, S., Bohrer, L.R., Rai, A.N., Pan , Y., Gan, L., Zhou, X...recent study finds that ri-methyl-H3-K27 levels are decreased in breast, ovarian and pan - reatic cancer samples [65], which could reflect a shift in

  5. [Mifepristone inhibites the migration of endometrial cancer cells through regulating H19 methylation].

    PubMed

    Lu, Z Z; Yan, L; Zhang, H; Li, M J; Zhang, X H; Zhao, X X

    2016-06-23

    To investigate the effect and mechanism of mifepristone on the migration of human endometrial carcinoma cells. A human endometrial carcinoma cell line, Ishikawa cells, was cultured in vitro and treated with mifepristone at different concentrations. Wound healing assay was applied to detect the migration of Ishikawa cells. RT-PCR and methylation-specific PCR (MSP) were used to detect the levels of H19 mRNA and its DNA methylation. Western-blot was used to detect the expressions of HMGA2 and epithelial to mesenchymal transition (EMT) related proteins. When treated with different concentrations of mifepristone for 48 hours, the width of scratch of the the control group, the 5 mg/L and the 10 mg/L mifepristone treatment groups were (4.18±0.07)mm, (4.68±0.07)mm, and(4.99±0.07)mm, respectively (P<0.05 for all) and treated with mifepristone for 72 hours, those were(3.46±0.07)mm, (4.29±0.07)mm, and(4.78±0.04)mm, respectively (P<0.05 for all). In the Ishikawa cells, mifepristone suppressed the transcriptional level of H19 through enhancing its promoter methylation, which resulted in inhibited expressions of HMGA2 and vimentin and increased expression of E-cadherin in a time- and concentration-dependent manner. Mifepristone inhibits the migration of endometrial carcinoma cells partially through methylation-induced of transcriptional inhibition of H19, which results in the down-regulation of HMGA2 and vimentin and upregulation of E-cadherin.

  6. Relative Importance of H2 and H2S as Energy Sources for Primary Production in Geothermal Springs▿ †

    PubMed Central

    D'Imperio, Seth; Lehr, Corinne R.; Oduro, Harry; Druschel, Greg; Kühl, Michael; McDermott, Timothy R.

    2008-01-01

    Geothermal waters contain numerous potential electron donors capable of supporting chemolithotrophy-based primary production. Thermodynamic predictions of energy yields for specific electron donor and acceptor pairs in such systems are available, although direct assessments of these predictions are rare. This study assessed the relative importance of dissolved H2 and H2S as energy sources for the support of chemolithotrophic metabolism in an acidic geothermal spring in Yellowstone National Park. H2S and H2 concentration gradients were observed in the outflow channel, and vertical H2S and O2 gradients were evident within the microbial mat. H2S levels and microbial consumption rates were approximately three orders of magnitude greater than those of H2. Hydrogenobaculum-like organisms dominated the bacterial component of the microbial community, and isolates representing three distinct 16S rRNA gene phylotypes (phylotype = 100% identity) were isolated and characterized. Within a phylotype, O2 requirements varied, as did energy source utilization: some isolates could grow only with H2S, some only with H2, while others could utilize either as an energy source. These metabolic phenotypes were consistent with in situ geochemical conditions measured using aqueous chemical analysis and in-field measurements made by using gas chromatography and microelectrodes. Pure-culture experiments with an isolate that could utilize H2S and H2 and that represented the dominant phylotype (70% of the PCR clones) showed that H2S and H2 were used simultaneously, without evidence of induction or catabolite repression, and at relative rate differences comparable to those measured in ex situ field assays. Under in situ-relevant concentrations, growth of this isolate with H2S was better than that with H2. The major conclusions drawn from this study are that phylogeny may not necessarily be reliable for predicting physiology and that H2S can dominate over H2 as an energy source in terms of

  7. Crystal structure of (7-methyl-2-oxo-2H-chromen-4-yl)methyl piperidine-1-carbo­di­thio­ate

    PubMed Central

    Roopashree, K. R.; Meenakshi, T. G.; Kumar, K. Mahesh; Kotresh, O.; Devarajegowda, H. C.

    2015-01-01

    In the title compound, C17H19NO2S2, the 2H-chromene ring system is nearly planar, with a maximum deviation of 0.0383 (28) Å, and the piperidine ring adopts a chair conformation. The 2H-chromene ring makes dihedral angles of 32.89 (16) and 67.33 (8)°, respectively, with the mean planes of the piperidine ring and the carbodi­thio­ate group. In the crystal, C—H⋯O and weak C—H⋯S hydrogen bonds link the mol­ecules into chains along [001]. The crystal structure also features C—H⋯π and π–π inter­actions, with a centroid–centroid distance of 3.7097 (17) Å. PMID:26396821

  8. Microbial oxidation of mixtures of methylmercaptan and hydrogen sulfide.

    PubMed

    Subramaniyan, A; Kolhatkar, R; Sublette, K L; Beitle, R

    1998-01-01

    Refinery spent-sulfidic caustic, containing only inorganic sulfides, has previously been shown to be amenable to biotreatment with Thiobacillus denitrificans strain F with complete oxidation of sulfides to sulfate. However, many spent caustics contain mercaptans that cannot be metabolized by this strict autotroph. An aerobic enrichment culture was developed from mixed Thiobacilli and activated sludge that was capable of simultaneous oxidation of inorganic sulfide and mercaptans using hydrogen sulfide (H2S) and methylmercaptan (MeSH) gas feeds used to simulate the inorganic and organic sulfur of a spent-sulfidic caustic. The enrichment culture was also capable of biotreatment of an actual mercaptan-containing, spent-sulfidic caustic but at lower rates than predicted by operation on MeSH and H2S fed to the culture in the gas phase, indicating that the caustic contained other inhibitory components.

  9. Detection and quantification of RNA 2′-O-methylation and pseudouridylation

    PubMed Central

    Karijolich, John

    2016-01-01

    RNA-guided RNA modification is a naturally occurring process that introduces 2′-O-methylation and pseudouridylation into rRNA, spliceosomal snRNA and several other types of RNA. The Box C/D ribonucleoproteins (RNP) and Box H/ACA RNP, each containing one unique guide RNA (Box C/D RNA or Box H/ACA RNA) and a set of core proteins, are responsible for 2′-O-methylation and pseudouridylation respectively. Box C/D RNA and Box H/ACA RNA provide the modification specificity through base pairing with their RNA substrate. These post-transcriptional modifications could profoundly alter the properties and functions of substrate RNAs. Thus it is desirable to establish reliable and standardized modification methods to study biological functions of modified nucleotides in RNAs. Here, we present several sensitive and efficient methods and protocols for detecting and quantifying post-transcriptional 2′-O-methylation and pseudouridylation. PMID:26853326

  10. Functionalization of liquid-exfoliated two-dimensional 2H-MoS2.

    PubMed

    Backes, Claudia; Berner, Nina C; Chen, Xin; Lafargue, Paul; LaPlace, Pierre; Freeley, Mark; Duesberg, Georg S; Coleman, Jonathan N; McDonald, Aidan R

    2015-02-23

    Layered two-dimensional (2D) inorganic transition-metal dichalchogenides (TMDs) have attracted great interest as a result of their potential application in optoelectronics, catalysis, and medicine. However, methods to functionalize and process such 2D TMDs remain scarce. We have established a facile route towards functionalized layered MoS2 . We found that the reaction of liquid-exfoliated 2D MoS2 , with M(OAc)2 salts (M=Ni, Cu, Zn; OAc=acetate) yielded functionalized MoS2 -M(OAc)2 materials. Importantly, this method furnished the 2H-polytype of MoS2 which is a semiconductor. X-ray photoelectron spectroscopy (XPS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT-IR), and thermogravimetric analysis (TGA) provide strong evidence for the coordination of MoS2 surface sulfur atoms to the M(OAc)2 salt. Interestingly, functionalization of 2H-MoS2 allows for its dispersion/processing in more conventional laboratory solvents. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Dry efficient cleaning of poly-methyl-methacrylate residues from graphene with high-density H{sub 2} and H{sub 2}-N{sub 2} plasmas

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cunge, G., E-mail: gilles.cunge@cea.fr; Petit-Etienne, C.; Davydova, A.

    Graphene is the first engineering electronic material, which is purely two-dimensional: it consists of two exposed sp{sup 2}-hybridized carbon surfaces and has no bulk. Therefore, surface effects such as contamination by adsorbed polymer residues have a critical influence on its electrical properties and can drastically hamper its widespread use in devices fabrication. These contaminants, originating from mandatory technological processes of graphene synthesis and transfer, also impact fundamental studies of the electronic and structural properties at the atomic scale. Therefore, graphene-based technology and research requires “soft” and selective surface cleaning techniques dedicated to limit or to suppress this surface contamination. Here,more » we show that a high-density H{sub 2} and H{sub 2}-N{sub 2} plasmas can be used to selectively remove polymeric residues from monolayer graphene without any damage on the graphene surface. The efficiency of this dry-cleaning process is evidenced unambiguously by a set of spectroscopic and microscopic methods, providing unprecedented insights on the cleaning mechanisms and highlighting the role of specific poly-methyl-methacrylate residues at the graphene interface. The plasma is shown to perform much better cleaning than solvents and has the advantage to be an industrially mature technology adapted to large area substrates. The process is transferable to other kinds of two-dimensional material and heterostructures.« less

  12. The testis-specific factor CTCFL cooperates with the protein methyltransferase PRMT7 in H19 imprinting control region methylation.

    PubMed

    Jelinic, Petar; Stehle, Jean-Christophe; Shaw, Phillip

    2006-10-01

    Expression of imprinted genes is restricted to a single parental allele as a result of epigenetic regulation-DNA methylation and histone modifications. Igf2/H19 is a reciprocally imprinted locus exhibiting paternal Igf2 and maternal H19 expression. Their expression is regulated by a paternally methylated imprinting control region (ICR) located between the two genes. Although the de novo DNA methyltransferases have been shown to be necessary for the establishment of ICR methylation, the mechanism by which they are targeted to the region remains unknown. We demonstrate that CTCFL/BORIS, a paralog of CTCF, is an ICR-binding protein expressed during embryonic male germ cell development, coinciding with the timing of ICR methylation. PRMT7, a protein arginine methyltransferase with which CTCFL interacts, is also expressed during embryonic testis development. Symmetrical dimethyl arginine 3 of histone H4, a modification catalyzed by PRMT7, accumulates in germ cells during this developmental period. This modified histone is also found enriched in both H19 ICR and Gtl2 differentially methylated region (DMR) chromatin of testis by chromatin immunoprecipitation (ChIP) analysis. In vitro studies demonstrate that CTCFL stimulates the histone-methyltransferase activity of PRMT7 via interactions with both histones and PRMT7. Finally, H19 ICR methylation is demonstrated by nuclear co-injection of expression vectors encoding CTCFL, PRMT7, and the de novo DNA methyltransferases, Dnmt3a, -b and -L, in Xenopus oocytes. These results suggest that CTCFL and PRMT7 may play a role in male germline imprinted gene methylation.

  13. The Testis-Specific Factor CTCFL Cooperates with the Protein Methyltransferase PRMT7 in H19 Imprinting Control Region Methylation

    PubMed Central

    Jelinic, Petar; Stehle, Jean-Christophe; Shaw, Phillip

    2006-01-01

    Expression of imprinted genes is restricted to a single parental allele as a result of epigenetic regulation—DNA methylation and histone modifications. Igf2/H19 is a reciprocally imprinted locus exhibiting paternal Igf2 and maternal H19 expression. Their expression is regulated by a paternally methylated imprinting control region (ICR) located between the two genes. Although the de novo DNA methyltransferases have been shown to be necessary for the establishment of ICR methylation, the mechanism by which they are targeted to the region remains unknown. We demonstrate that CTCFL/BORIS, a paralog of CTCF, is an ICR-binding protein expressed during embryonic male germ cell development, coinciding with the timing of ICR methylation. PRMT7, a protein arginine methyltransferase with which CTCFL interacts, is also expressed during embryonic testis development. Symmetrical dimethyl arginine 3 of histone H4, a modification catalyzed by PRMT7, accumulates in germ cells during this developmental period. This modified histone is also found enriched in both H19 ICR and Gtl2 differentially methylated region (DMR) chromatin of testis by chromatin immunoprecipitation (ChIP) analysis. In vitro studies demonstrate that CTCFL stimulates the histone-methyltransferase activity of PRMT7 via interactions with both histones and PRMT7. Finally, H19 ICR methylation is demonstrated by nuclear co-injection of expression vectors encoding CTCFL, PRMT7, and the de novo DNA methyltransferases, Dnmt3a, -b and -L, in Xenopus oocytes. These results suggest that CTCFL and PRMT7 may play a role in male germline imprinted gene methylation. PMID:17048991

  14. H2S and polysulfide metabolism: Conventional and unconventional pathways.

    PubMed

    Olson, Kenneth R

    2018-03-01

    It is now well established that hydrogen sulfide (H 2 S) is an effector of a wide variety of physiological processes. It is also clear that many of the effects of H 2 S are mediated through reactions with cysteine sulfur on regulatory proteins and most of these are not mediated directly by H 2 S but require prior oxidation of H 2 S and the formation of per- and polysulfides (H 2 S n , n = 2-8). Attendant with understanding the regulatory functions of H 2 S and H 2 S n is an appreciation of the mechanisms that control, i.e., both increase and decrease, their production and catabolism. Although a number of standard "conventional" pathways have been described and well characterized, novel "unconventional" pathways are continuously being identified. This review summarizes our current knowledge of both the conventional and unconventional. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. The solubility of gold in H 2 O-H 2 S vapour at elevated temperature and pressure

    NASA Astrophysics Data System (ADS)

    Zezin, Denis Yu.; Migdisov, Artashes A.; Williams-Jones, Anthony E.

    2011-09-01

    This experimental study sheds light on the complexation of gold in reduced sulphur-bearing vapour, specifically, in H 2O-H 2S gas mixtures. The solubility of gold was determined in experiments at temperatures of 300, 350 and 365 °C and reached 2.2, 6.6 and 6.3 μg/kg, respectively. The density of the vapour varied from 0.02 to 0.22 g/cm 3, the mole fraction of H 2S varied from 0.03 to 0.96, and the pressure in the cell reached 263 bar. Statistically significant correlations of the amount of gold dissolved in the fluid with the fugacity of H 2O and H 2S permit the experimental data to be fitted to a solvation/hydration model. According to this model, the solubility of gold in H 2O-H 2S gas mixtures is controlled by the formation of sulphide or bisulphide species solvated by H 2S or H 2O molecules. Formation of gold sulphide species is favoured statistically over gold bisulphide species and thus the gold is interpreted to dissolve according to reactions of the form: Au(s)+(n+1)HS(g)=AuS·(HS)n(g)+H(g) Au(s)+HS(g)+mHO(g)=AuS·(HO)m(g)+H(g) Equilibrium constants for Reaction (A1) and the corresponding solvation numbers ( K A1 and n) were evaluated from the study of Zezin et al. (2007). The equilibrium constants as well as the hydration numbers for Reaction (A2) ( K A2 and m) were adjusted simultaneously by a custom-designed optimization algorithm and were tested statistically. The resulting values of log K A2 and m are -15.3 and 2.3 at 300 and 350 °C and -15.1 and 2.2 at 365 °C, respectively. Using the calculated stoichiometry and stability of Reactions (A1) and (A2), it is now possible to quantitatively evaluate the contribution of reduced sulphur species to the transport of gold in aqueous vapour at temperatures up to 365 °C. This information will find application in modelling gold ore-forming processes in vapour-bearing magmatic hydrothermal systems, notably those of epithermal environments.

  16. Protein Arginine Methyltransferase 7 Regulates Cellular Response to DNA Damage by Methylating Promoter Histones H2A and H4 of the Polymerase δ Catalytic Subunit Gene, POLD1*

    PubMed Central

    Karkhanis, Vrajesh; Wang, Li; Tae, Sookil; Hu, Yu-Jie; Imbalzano, Anthony N.; Sif, Saïd

    2012-01-01

    Covalent modification of histones by protein arginine methyltransferases (PRMTs) impacts genome organization and gene expression. In this report, we show that PRMT7 interacts with the BRG1-based hSWI/SNF chromatin remodeling complex and specifically methylates histone H2A Arg-3 (H2AR3) and histone H4 Arg-3 (H4R3). To elucidate the biological function of PRMT7, we knocked down its expression in NIH 3T3 cells and analyzed global gene expression. Our findings show that PRMT7 negatively regulates expression of genes involved in DNA repair, including ALKBH5, APEX2, POLD1, and POLD2. Chromatin immunoprecipitation (ChIP) revealed that PRMT7 and dimethylated H2AR3 and H4R3 are enriched at target DNA repair genes in parental cells, whereas PRMT7 knockdown caused a significant decrease in PRMT7 recruitment and H2AR3/H4R3 methylation. Decreased PRMT7 expression also resulted in derepression of target DNA repair genes and enhanced cell resistance to DNA-damaging agents. Furthermore, we show that BRG1 co-localizes with PRMT7 on target promoters and that expression of a catalytically inactive form of BRG1 results in derepression of PRMT7 target DNA repair genes. Remarkably, reducing expression of individual PRMT7 target DNA repair genes showed that only the catalytic subunit of DNA polymerase, POLD1, was able to resensitize PRMT7 knock-down cells to DNA-damaging agents. These results provide evidence for the important role played by PRMT7 in epigenetic regulation of DNA repair genes and cellular response to DNA damage. PMID:22761421

  17. Protein arginine methyltransferase 7 regulates cellular response to DNA damage by methylating promoter histones H2A and H4 of the polymerase δ catalytic subunit gene, POLD1.

    PubMed

    Karkhanis, Vrajesh; Wang, Li; Tae, Sookil; Hu, Yu-Jie; Imbalzano, Anthony N; Sif, Saïd

    2012-08-24

    Covalent modification of histones by protein arginine methyltransferases (PRMTs) impacts genome organization and gene expression. In this report, we show that PRMT7 interacts with the BRG1-based hSWI/SNF chromatin remodeling complex and specifically methylates histone H2A Arg-3 (H2AR3) and histone H4 Arg-3 (H4R3). To elucidate the biological function of PRMT7, we knocked down its expression in NIH 3T3 cells and analyzed global gene expression. Our findings show that PRMT7 negatively regulates expression of genes involved in DNA repair, including ALKBH5, APEX2, POLD1, and POLD2. Chromatin immunoprecipitation (ChIP) revealed that PRMT7 and dimethylated H2AR3 and H4R3 are enriched at target DNA repair genes in parental cells, whereas PRMT7 knockdown caused a significant decrease in PRMT7 recruitment and H2AR3/H4R3 methylation. Decreased PRMT7 expression also resulted in derepression of target DNA repair genes and enhanced cell resistance to DNA-damaging agents. Furthermore, we show that BRG1 co-localizes with PRMT7 on target promoters and that expression of a catalytically inactive form of BRG1 results in derepression of PRMT7 target DNA repair genes. Remarkably, reducing expression of individual PRMT7 target DNA repair genes showed that only the catalytic subunit of DNA polymerase, POLD1, was able to resensitize PRMT7 knock-down cells to DNA-damaging agents. These results provide evidence for the important role played by PRMT7 in epigenetic regulation of DNA repair genes and cellular response to DNA damage.

  18. Influence of Threonine Metabolism on S-adenosyl-methionine and Histone Methylation

    PubMed Central

    Shyh-Chang, Ng; Locasale, Jason W.; Lyssiotis, Costas A.; Zheng, Yuxiang; Teo, Ren Yi; Ratanasirintrawoot, Sutheera; Zhang, Jin; Onder, Tamer; Unternaehrer, Juli J.; Zhu, Hao; Asara, John M.; Daley, George Q.; Cantley, Lewis C.

    2013-01-01

    Threonine is the only amino acid critically required for the pluripotency of mouse embryonic stem cells (mESCs) but the detailed mechanism remains unclear. We found that threonine (Thr) and S-adenosyl-methionine (SAM) metabolism are coupled in pluripotent stem cells, resulting in regulation of histone methylation. Isotope labeling of mESCs revealed that Thr provides a substantial fraction of both the cellular glycine (Gly) and the acetyl-coenzyme A (CoA) needed for SAM synthesis. Depletion of Thr from the culture medium or threonine dehydrogenase (Tdh) from mESCs decreased accumulation of SAM and decreased tri-methylation of histone H3 lysine-4 (H3K4me3), leading to slowed growth, and increased differentiation. Thus abundance of SAM appears to influence H3K4me3, providing a possible mechanism by which modulation of a metabolic pathway might influence stem cell fate. PMID:23118012

  19. Optically active antifungal azoles. XII. Synthesis and antifungal activity of the water-soluble prodrugs of 1-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone.

    PubMed

    Ichikawa, T; Kitazaki, T; Matsushita, Y; Yamada, M; Hayashi, R; Yamaguchi, M; Kiyota, Y; Okonogi, K; Itoh, K

    2001-09-01

    1-[(1R,2R)-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone (1: TAK-456) was selected as a candidate for clinical trials, but since its water-solubility was insufficient for an injectable formulation, the quaternary triazolium salts 2 were designed as water-soluble prodrugs. Among the prodrugs prepared, 4-acetoxymethyl-1-[(2R,3R)-2-(2,4-difluorophenyl)-2-hydroxy-3-[2-oxo-3-[4-(1H-1-terazolyl)phenyl]-1-imidazolidinyl]butyl]-1H-1,2,4-triazolium chloride (2a: TAK-457) was selected as an injectable candidate for clinical trials based on the results of evaluations on solubility, stability, hemolytic effect and in vivo antifungal activities.

  20. Steric control of the asymmetric synthesis of N-substituted 2-methyl-4-piperidones

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Grishina, G.V.; Potapov, V.M.; Abdulganeeva, S.A.

    Transmission of the iodomethylate of 1,2-dimethyl-4-piperidone by (S)-sec-butylamine gives 1-(S-sec-butyl)-2S-methyl-4-piperidone in 33% optical yield while transamination by (S)-1-methyl-2-phenylethylamine gives a 1:1 diastereomeric mixture of 1-(1-methyl-2-phenylethyl)-2-methyl-4-piperidone. The decrease in the optical yield is related to the facile opening of the piperidone ring at the C-N bond with subsequent recyclization. The /sup 13/C NMR data indicate that all the diastereomers of the 4-piperidones obtained are in the chain conformation with predominantly equatorial orientation of the methyl group at C/sub (2)/. The chiral optical properties were studied and the absolution configurations of the 4-piperidones obtained were established.

  1. Endogenous mitigation of H2S inside of the landfills.

    PubMed

    Fang, Yuan; Zhong, Zhong; Shen, Dongsheng; Du, Yao; Xu, Jing; Long, Yuyang

    2016-02-01

    Vast quantities of hydrogen sulfide (H2S) emitted from landfill sites require urgent disposal. The current study focused on source control and examined the migration and conversion behavior of sulfur compounds in two lab-scale simulated landfills with different operation modes. It aimed to explore the possible strategies and mechanisms for H2S endogenous mitigation inside of landfills during decomposition. It was found that the strength of H2S emissions from the landfill sites was dependent on the municipal solid waste (MSW) degradation speed and vertical distribution of sulfide. Leachate recirculation can shorten both the H2S influence period and pollution risk to the surrounding environment. H2S endogenous mitigation may be achieved by chemical oxidation, biological oxidation, adsorption, and/or precipitation in different stages. Migration and conversion mainly affected H2S release behavior during the initial stabilization phase in the landfill. Microbial activities related to sulfur, nitrogen, and iron can further promote H2S endogenous mitigation during the high reducing phase. Thus, H2S endogenous mitigation can be effectively enhanced via control of the aforementioned processes.

  2. Synthesis, biological evaluation and docking analysis of 3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones as potential cyclooxygenase-2 (COX-2) inhibitors.

    PubMed

    Grover, Jagdeep; Kumar, Vivek; Sobhia, M Elizabeth; Jachak, Sanjay M

    2014-10-01

    As a part of our continued efforts to discover new COX inhibitors, a series of 3-methyl-1-phenylchromeno[4,3-c]pyrazol-4(1H)-ones were synthesized and evaluated for in vitro COX inhibitory potential. Within this series, seven compounds (3a-d, 3h, 3k and 3q) were identified as potential and selective COX-2 inhibitors (COX-2 IC50's in 1.79-4.35μM range; COX-2 selectivity index (SI)=6.8-16.7 range). Compound 3b emerged as most potent (COX-2 IC50=1.79μM; COX-1 IC50 >30μM) and selective COX-2 inhibitor (SI >16.7). Further, compound 3b displayed superior anti-inflammatory activity (59.86% inhibition of edema at 5h) in comparison to celecoxib (51.44% inhibition of edema at 5h) in carrageenan-induced rat paw edema assay. Structure-activity relationship studies suggested that N-phenyl ring substituted with p-CF3 substituent (3b, 3k and 3q) leads to more selective inhibition of COX-2. To corroborate obtained experimental biological data, molecular docking study was carried out which revealed that compound 3b showed stronger binding interaction with COX-2 as compared to COX-1. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Crystallization of lysozyme with ( R)-, ( S)- and ( RS)-2-methyl-2,4-pentanediol

    DOE PAGES

    Stauber, Mark; Jakoncic, Jean; Berger, Jacob; ...

    2015-03-01

    Chiral control of crystallization has ample precedent in the small-molecule world, but relatively little is known about the role of chirality in protein crystallization. In this study, lysozyme was crystallized in the presence of the chiral additive 2-methyl-2,4-pentanediol (MPD) separately using the R and S enantiomers as well as with a racemic RS mixture. Crystals grown with ( R)-MPD had the most order and produced the highest resolution protein structures. This result is consistent with the observation that in the crystals grown with ( R)-MPD and ( RS)-MPD the crystal contacts are made by ( R)-MPD, demonstrating that there ismore » preferential interaction between lysozyme and this enantiomer. These findings suggest that chiral interactions are important in protein crystallization.« less

  4. Assisted Reproductive Technology affects developmental kinetics, H19 Imprinting Control Region methylation and H19 gene expression in individual mouse embryos

    PubMed Central

    Fauque, Patricia; Jouannet, Pierre; Lesaffre, Corinne; Ripoche, Marie-Anne; Dandolo, Luisa; Vaiman, Daniel; Jammes, Hélène

    2007-01-01

    Background In the last few years, an increase in imprinting anomalies has been reported in children born from Assisted Reproductive Technology (ART). Various clinical and experimental studies also suggest alterations of embryo development after ART. Therefore, there is a need for studying early epigenetic anomalies which could result from ART manipulations, especially on single embryos. In this study, we evaluated the impact of superovulation, in vitro fertilization (IVF) and embryo culture conditions on proper genomic imprinting and blastocyst development in single mouse embryos. In this study, different experimental groups were established to obtain embryos from superovulated and non-superovulated females, either from in vivo or in vitro fertilized oocytes, themselves grown in vitro or not. The embryos were cultured either in M16 medium or in G1.2/G2.2 sequential medium. The methylation status of H19 Imprinting Control Region (ICR) and H19 promoter was assessed, as well as the gene expression level of H19, in individual blastocysts. In parallel, we have evaluated embryo cleavage kinetics and recorded morphological data. Results We show that: 1. The culture medium influences early embryo development with faster cleavage kinetics for culture in G1.2/G2.2 medium compared to M16 medium. 2. Epigenetic alterations of the H19 ICR and H19 PP are influenced by the fertilization method since methylation anomalies were observed only in the in vitro fertilized subgroup, however to different degrees according to the culture medium. 3. Superovulation clearly disrupted H19 gene expression in individual blastocysts. Moreover, when embryos were cultured in vitro after either in vivo or in vitro fertilization, the percentage of blastocysts which expressed H19 was higher in G1.2/G2.2 medium compared to M16. Conclusion Compared to previous reports utilizing pools of embryos, our study enables us to emphasize a high individual variability of blastocysts in the H19 ICR and H19

  5. Assisted Reproductive Technology affects developmental kinetics, H19 Imprinting Control Region methylation and H19 gene expression in individual mouse embryos.

    PubMed

    Fauque, Patricia; Jouannet, Pierre; Lesaffre, Corinne; Ripoche, Marie-Anne; Dandolo, Luisa; Vaiman, Daniel; Jammes, Hélène

    2007-10-18

    In the last few years, an increase in imprinting anomalies has been reported in children born from Assisted Reproductive Technology (ART). Various clinical and experimental studies also suggest alterations of embryo development after ART. Therefore, there is a need for studying early epigenetic anomalies which could result from ART manipulations, especially on single embryos. In this study, we evaluated the impact of superovulation, in vitro fertilization (IVF) and embryo culture conditions on proper genomic imprinting and blastocyst development in single mouse embryos. In this study, different experimental groups were established to obtain embryos from superovulated and non-superovulated females, either from in vivo or in vitro fertilized oocytes, themselves grown in vitro or not. The embryos were cultured either in M16 medium or in G1.2/G2.2 sequential medium. The methylation status of H19 Imprinting Control Region (ICR) and H19 promoter was assessed, as well as the gene expression level of H19, in individual blastocysts. In parallel, we have evaluated embryo cleavage kinetics and recorded morphological data. We show that: 1. The culture medium influences early embryo development with faster cleavage kinetics for culture in G1.2/G2.2 medium compared to M16 medium. 2. Epigenetic alterations of the H19 ICR and H19 PP are influenced by the fertilization method since methylation anomalies were observed only in the in vitro fertilized subgroup, however to different degrees according to the culture medium. 3. Superovulation clearly disrupted H19 gene expression in individual blastocysts. Moreover, when embryos were cultured in vitro after either in vivo or in vitro fertilization, the percentage of blastocysts which expressed H19 was higher in G1.2/G2.2 medium compared to M16. Compared to previous reports utilizing pools of embryos, our study enables us to emphasize a high individual variability of blastocysts in the H19 ICR and H19 promoter methylation and H19 gene

  6. Synthesis of Microporous Materials and Their VSC Adsorption Properties

    NASA Astrophysics Data System (ADS)

    Yokogawa, Y.; Morikawa, H.; Sakanishi, M.; Utaka, H.; Nakamura, A.; Kishida, I.

    2011-10-01

    Oral malodor is caused by volatile sulfur compounds (VSC) such as hydrogen sulfide (H2S), methyl mercaptan and dimethyl sulfide produced in mouth. VSC induces permeability of mucous membrane and oral malodor formation. Thus, the adsorbent which highly adsorbs VSC should be useful for health in mouth and may prevent teeth from decaying. The microporous material, hydrotalcite, was synthesized by a wet method, and the H2S adsorption was studied. The samples, identified by powder X-ray diffraction method, were put into glass flask filled with H2S gas. The initial concentration of H2S was 30 ppm. The change in concentrations of H2S was measured at rt, and the amount of H2S absorbed on the hydrotalcite for 24 h was 300 micro L/g. The samples were taken out from the above glass flask and put into a pyrolysis plant attached to gas chromatography-mass spectrometry to determine the amount of H2S desorbed from samples. Only 3 % of H2S was desorbed when heated at 500 °C. H2S in water was also found to adsorb into hydrotalcite, which was confirmed by the headspace gas chromatography with flame photometric detector. The hydrotalcite material should be expected to be an adsorbent material, useful for health in mouth.

  7. SETD2 and histone H3 lysine 36 methylation deficiency in advanced systemic mastocytosis.

    PubMed

    Martinelli, G; Mancini, M; De Benedittis, C; Rondoni, M; Papayannidis, C; Manfrini, M; Meggendorfer, M; Calogero, R; Guadagnuolo, V; Fontana, M C; Bavaro, L; Padella, A; Zago, E; Pagano, L; Zanotti, R; Scaffidi, L; Specchia, G; Albano, F; Merante, S; Elena, C; Savini, P; Gangemi, D; Tosi, P; Ciceri, F; Poletti, G; Riccioni, L; Morigi, F; Delledonne, M; Haferlach, T; Cavo, M; Valent, P; Soverini, S

    2018-01-01

    The molecular basis of advanced systemic mastocytosis (SM) is not fully understood and despite novel therapies the prognosis remains dismal. Exome sequencing of an index-patient with mast cell leukemia (MCL) uncovered biallelic loss-of-function mutations in the SETD2 histone methyltransferase gene. Copy-neutral loss-of-heterozygosity at 3p21.3 (where SETD2 maps) was subsequently found in SM patients and prompted us to undertake an in-depth analysis of SETD2 copy number, mutation status, transcript expression and methylation levels, as well as functional studies in the HMC-1 cell line and in a validation cohort of 57 additional cases with SM, including MCL, aggressive SM and indolent SM. Reduced or no SETD2 protein expression-and consequently, H3K36 trimethylation-was found in all cases and inversely correlated with disease aggressiveness. Proteasome inhibition rescued SETD2 expression and H3K36 trimethylation and resulted in marked accumulation of ubiquitinated SETD2 in SETD2-deficient patients but not in patients with near-normal SETD2 expression. Bortezomib and, to a lesser extent, AZD1775 alone or in combination with midostaurin induced apoptosis and reduced clonogenic growth of HMC-1 cells and of neoplastic mast cells from advanced SM patients. Our findings may have implications for prognostication of SM patients and for the development of improved treatment approaches in advanced SM.

  8. H2S-induced S-sulfhydration of pyruvate carboxylase contributes to gluconeogenesis in liver cells.

    PubMed

    Ju, YoungJun; Untereiner, Ashley; Wu, Lingyun; Yang, Guangdong

    2015-11-01

    Cystathionine gamma-lyase (CSE)-derived hydrogen sulfide (H(2)S) possesses diverse roles in the liver, affecting lipoprotein synthesis, insulin sensitivity, and mitochondrial biogenesis. H(2)S S-sulfhydration is now proposed as a major mechanism for H(2)S-mediated signaling. Pyruvate carboxylase (PC) is an important enzyme for gluconeogenesis. S-sulfhydration regulation of PC by H(2)S and its implication in gluconeogenesis in the liver have been unknown. Gene expressions were analyzed by real-time PCR and western blotting, and protein S-sulfhydration was assessed by both modified biotin switch assay and tag switch assay. Glucose production and PC activity was measured with coupled enzyme assays, respectively. Exogenously applied H(2)S stimulates PC activity and gluconeogenesis in both HepG2 cells and mouse primary liver cells. CSE overexpression enhanced but CSE knockout reduced PC activity and gluconeogenesis in liver cells, and blockage of PC activity abolished H(2)S-induced gluconeogenesis. H(2)S had no effect on the expressions of PC mRNA and protein, while H(2)S S-sulfhydrated PC in a dithiothreitol-sensitive way. PC S-sulfhydration was significantly strengthened by CSE overexpression but attenuated by CSE knockout, suggesting that H(2)S enhances glucose production through S-sulfhydrating PC. Mutation of cysteine 265 in human PC diminished H(2)S-induced PC S-sulfhydration and activity. In addition, high-fat diet feeding of mice decreased both CSE expression and PC S-sulfhydration in the liver, while glucose deprivation of HepG2 cells stimulated CSE expression. CSE/H(2)S pathway plays an important role in the regulation of glucose production through S-sulfhydrating PC in the liver. Tissue-specific regulation of CSE/H(2)S pathway might be a promising therapeutic target of diabetes and other metabolic syndromes. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Palladium(II) complexes with R(2)edda derived ligands. Part IV. O,O'-dialkyl esters of (S,S)-ethylenediamine-N,N'-di-2-(4-methyl)-pentanoic acid dihydrochloride and their palladium(II) complexes: synthesis, characterization and in vitro antitumoral activity against chronic lymphocytic leukemia (CLL) cells.

    PubMed

    Vujić, Jelena M; Cvijović, Milica; Kaluderović, Goran N; Milovanović, Marija; Zmejkovski, Bojana B; Volarević, Vladislav; Arsenijević, Nebojsa; Sabo, Tibor J; Trifunović, Srećko R

    2010-09-01

    Four novel bidentate N,N'-ligand precursors, including O,O'-dialkyl esters (alkyl = ethyl, n-propyl, n-butyl and n-pentyl), L1 x 2 HCl-L4 x 2 HCl, of (S,S)-ethylenediamine-N,N'-di-2-(4-methyl)-pentanoic acid dihydrochloride [(S,S)-H(4)eddl]Cl(2) and the corresponding palladium(II) complexes 1-4, were prepared and characterized by IR, (1)H NMR and (13)C NMR spectroscopy and elemental analysis. In vitro cytotoxicity of all compounds was determined against chronic lymphocytic leukemia cells (CLL). The compounds were found to exhibit higher antitumoral activity than cisplatin. The most active compound 2, [PdCl(2){(S,S)-nPr(2)eddl}], was found to be 13.6 times more active than cisplatin on CLL cells. 2010 Elsevier Masson SAS. All rights reserved.

  10. Synthesis and exploration of QSAR model of 2-methyl-3-[2-(2-methylprop-1-en-1-yl)-1H-benzimidazol-1-yl]pyrimido[1,2-a]benzimidazol-4(3H)-one as potential antibacterial agents.

    PubMed

    Sharma, Pratibha; Kumar, Ashok; Sharma, Manisha; Singh, Jitendra; Bandyopadhyay, Prabal; Sathe, Manisha; Kaushik, M P

    2012-04-01

    Present communication deals with the synthesis of novel 2-methyl-3-[2-(2-methylprop-1-en-1-yl)-1H-benzimidazol-1-yl]pyrimido[1,2-a]benzimidazol-4(3H)-one derivatives under phase transfer catalysis (PTC) conditions using benzyl triethyl ammonium chloride (BTEAC) as PTC. It also elicits the studies on in vitro antimicrobial evaluation of synthesized compounds against a representative genera of gram-negative and gram-positive bacteria i.e., Bacillus subtilis, Staphylococcus aureus, Pseudomonas diminuta and Escherichia coli. All the compounds have been found to manifest profound antimicrobial activity. Moreover, extensive quantitative structure-activity relationship (QSAR) studies have been performed to deduce a correlation between molecular descriptors under consideration and the elicited biological activity. A tri-parametric QSAR model has been generated upon rigorous statistical treatment.

  11. Structural sensitivity of Csbnd H vibrational band in methyl benzoate

    NASA Astrophysics Data System (ADS)

    Roy, Susmita; Maiti, Kiran Sankar

    2018-05-01

    The Csbnd H vibrational bands of methyl benzoate are studied to understand its coupling pattern with other vibrational bands of the biological molecule. This will facilitate to understand the biological structure and dynamics in spectroscopic as well as in microscopic study. Due to the congested spectroscopic pattern, near degeneracy, and strong anharmonicity of the Csbnd H stretch vibrations, assignment of the Csbnd H vibrational frequencies are often misleading. Anharmonic vibrational frequency calculation with multidimensional potential energy surface interprets the Csbnd H vibrational spectra more accurately. In this article we have presented the importance of multidimensional potential energy surface in anharmonic vibrational frequency calculation and discuss the unexpected red shift of asymmetric Csbnd H stretch vibration of methyl group. The Csbnd D stretch vibrational band which is splitted to double peaks due to the Fermi resonance is also discussed here.

  12. Rapid fluctuations in the northern Baltic Sea H2S layer

    NASA Astrophysics Data System (ADS)

    Kankaanpää, Harri T.; Virtasalo, Joonas J.

    2017-12-01

    Hydrogen sulfide (H2S) is linked to water quality deterioration in the Baltic Sea, with widespread seafloor hypoxia. We examined the vertical and temporal variability of in situ [H2S], oxygen concentration ([O2]), temperature (T) and pH at weekly, hourly and minute intervals at 13 locations in the western Gulf of Finland in 2013-2014. The main target was the 60-100 m water depth range, containing 3.2-290 μM O2 and 6.3-22.6 μM H2S. Where gas was detected by acoustic surveys, the structure of the H2S layer was more complex compared to stations devoid of gas. Local minima and maxima in pH frequently occurred near the H2S upper boundary (redox transition zone). Except for the homogeneous, tranquil zone above the seafloor at some stations, substantial rapid changes in hydrographic conditions were common. Typically, a layer of marked temporal T variability was present atop or within the topmost H2S layers. The largest temporal changes over a weekly period were - 0.44 °C/- 10.8 μM H2S/- 0.12 pH units (at seafloor level), + 0.18 °C/+7.9 μM H2S between casts (1 h) and + 0.03 °C/- 2.5 μM H2S per minute (high resolution logging). Abrupt [H2S] changes were recorded at two stations with sediments containing free gas. The T and [H2S] changes were synchronous at several layers, reflecting water movement. We conclude that rapid changes occur in hydrographic conditions in the near-bottom H2S layer in the northern Baltic Sea, especially at locations where free gas is present in the underlying sediments.

  13. 40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

    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-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2'-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2'-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

  14. Synthesis, Cytotoxic and Contraceptive Activity of 6,8,9-Trihydroxy-2-methyl-2H-naphtho[2,3-b]pyran-5,10-dione, a Pigment of Echinothrix diadema, and its Analogs.

    PubMed

    Pokhilo, Natalia D; Melman, Galina I; Kiseleva, Marina I; Denisenko, Vladimir A; Anufriev, Victor Ph

    2015-07-01

    6,8,9-Trihydroxy-2-methyl-2H-naphtho[2,3-b]pyran-5,10-dion, a pigment of the sea urchin Echinothrix diadema, and six analogs were synthesized. The cytotoxic activity and contraceptive properties of the synthesized pyranonaphthazarins have been investigated using the sperm and eggs of the sea urchin Strongylocentrotus intermedius.

  15. EHMT2 directs DNA methylation for efficient gene silencing in mouse embryos

    PubMed Central

    Auclair, Ghislain; Borgel, Julie; Sanz, Lionel A.; Vallet, Judith; Guibert, Sylvain; Dumas, Michael; Cavelier, Patricia; Girardot, Michael; Forné, Thierry; Feil, Robert; Weber, Michael

    2016-01-01

    The extent to which histone modifying enzymes contribute to DNA methylation in mammals remains unclear. Previous studies suggested a link between the lysine methyltransferase EHMT2 (also known as G9A and KMT1C) and DNA methylation in the mouse. Here, we used a model of knockout mice to explore the role of EHMT2 in DNA methylation during mouse embryogenesis. The Ehmt2 gene is expressed in epiblast cells but is dispensable for global DNA methylation in embryogenesis. In contrast, EHMT2 regulates DNA methylation at specific sequences that include CpG-rich promoters of germline-specific genes. These loci are bound by EHMT2 in embryonic cells, are marked by H3K9 dimethylation, and have strongly reduced DNA methylation in Ehmt2−/− embryos. EHMT2 also plays a role in the maintenance of germline-derived DNA methylation at one imprinted locus, the Slc38a4 gene. Finally, we show that DNA methylation is instrumental for EHMT2-mediated gene silencing in embryogenesis. Our findings identify EHMT2 as a critical factor that facilitates repressive DNA methylation at specific genomic loci during mammalian development. PMID:26576615

  16. 40 CFR 721.5540 - 1H,3H,5H-oxazolo [3,4-c] oxazole, dihydro-7a-methyl-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1H,3H,5H-oxazolo [3,4-c] oxazole... Specific Chemical Substances § 721.5540 1H,3H,5H-oxazolo [3,4-c] oxazole, dihydro-7a-methyl-. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as 1H,3H,5H...

  17. Na2S, a fast-releasing H2S donor, given as suppository lowers blood pressure in rats.

    PubMed

    Tomasova, Lenka; Drapala, Adrian; Jurkowska, Halina; Wróbel, Maria; Ufnal, Marcin

    2017-10-01

    Hydrogen sulfide (H 2 S) is involved in blood pressure control. The available slow-releasing H 2 S-donors are poorly soluble in water and their ability to release H 2 S in biologically relevant amounts under physiological conditions is questionable. Therefore, new slow-releasing donors or new experimental approaches to fast-releasing H 2 S donors are needed. Hemodynamics and ECG were recorded in male, anesthetized Wistar Kyoto rats (WKY) and in Spontaneously hypertensive rats (SHR) at baseline and after: 1) intravenous (iv) infusion of vehicle or Na 2 S; 2) administration of vehicle suppositories or Na 2 S suppositories. Intravenously administered vehicle and vehicle suppositories did not affect mean arterial blood pressure (MABP) and heart rate (HR). Na 2 S administered iv caused a significant, but transient (2-5min) decrease in MABP. Na 2 S suppositories produced a dose-dependent hypotensive response that lasted ∼45min in WKY and ∼75-80min in SHR. It was accompanied by a decrease in HR in WKY, and an increase in HR in SHR. Na 2 S suppositories did not produce a significant change in corrected QT, an indicator of cardiotoxicity. Na 2 S suppositories increased blood level of thiosulfates, products of H 2 S oxidation. Na 2 S administered in suppositories exerts a prolonged hypotensive effect in rats, with no apparent cardiotoxic effect. SHR and WKY differ in hemodynamic response to the H 2 S donor. Suppository formulation of fast-releasing H 2 S donors may be useful in research, if a reference slow-releasing H 2 S donor is not available. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  18. A new global analytical potential energy surface of NaH2+ system and dynamical calculation for H(2S) + NaH+(X2Σ+) → Na+(1S) + H2(X1Σg+) reaction

    NASA Astrophysics Data System (ADS)

    Yuan, Meiling; Li, Wentao; Yuan, Jiuchuang

    2018-05-01

    A new global potential energy surface (PES) of the NaH2+ system is constructed by fitting 27,621 ab initio energy points with the neural network method. The root mean square error of the new PES is only 4.1609 × 10-4 eV. Based on the new PES, dynamical calculations have been performed using the time-dependent quantum wave packet method. These results are then compared with the H(2S) + LiH+(X2Σ+) → Li+(1S) + H2(X1Σg+) reaction. The direct abstract mechanism is found to play an important role in the reaction because only forward scattering signals on the differential cross section results for all calculated collision energies.

  19. Hydrogen sulfide (H 2S) in urban ambient air

    NASA Astrophysics Data System (ADS)

    Kourtidis, K.; Kelesis, A.; Petrakakis, M.

    Despite indications of high hydrogen sulfide levels in some urban environments, only sparse measurements have been reported in the literature. Here we present one full year of hydrogen sulfide measurements in an urban traffic site in the city of Thessaloniki, Greece. In this 1-million-population city the H 2S concentrations were surprisingly high, with a mean annual concentration of 8 μg m -3 and wintertime mean monthly concentrations up to 20 μg m -3 (12.9 ppb). Daily mean concentrations in the winter were up to 30 μg m -3 (19.3 ppb), while hourly concentrations were up to 54 μg m -3 (34.8 ppb). During calm (wind velocity < 0.5 m s -1) conditions, mainly encountered during night-time hours, hourly values of H 2S were highly correlated with those of CO ( r2 = 0.75) and SO 2 ( r2 = 0.70), pointing to a common traffic source from catalytic converters. Annual mean concentrations are above the WHO recommendation for odor annoyance; hence, H 2S might play a role to the malodorous episodes that the city occasionally experiences. The high ambient H 2S levels might also be relevant to the implementation of preservation efforts for outdoor marble and limestone historical monuments that have been targeting SO 2 emissions as an atmospheric acidity source, since the measurements presented here suggest that about 19% of the annual sulfur (SO 2 + H 2S) emissions in Thessaloniki are in the form of H 2S.

  20. PHD Finger Recognition of Unmodified Histone H3R2 Links UHRF1 to Regulation of Euchromatic Gene Expression

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    E Rajakumara; Z Wang; H Ma

    2011-12-31

    Histone methylation occurs on both lysine and arginine residues, and its dynamic regulation plays a critical role in chromatin biology. Here we identify the UHRF1 PHD finger (PHD{sub UHRF1}), an important regulator of DNA CpG methylation, as a histone H3 unmodified arginine 2 (H3R2) recognition modality. This conclusion is based on binding studies and cocrystal structures of PHD{sub UHRF1} bound to histone H3 peptides, where the guanidinium group of unmodified R2 forms an extensive intermolecular hydrogen bond network, with methylation of H3R2, but not H3K4 or H3K9, disrupting complex formation. We have identified direct target genes of UHRF1 from microarraymore » and ChIP studies. Importantly, we show that UHRF1's ability to repress its direct target gene expression is dependent on PHD{sub UHRF1} binding to unmodified H3R2, thereby demonstrating the functional importance of this recognition event and supporting the potential for crosstalk between histone arginine methylation and UHRF1 function.« less

  1. PHD Finger Recognition of Unmodified Histone H3R2 Links UHRF1 to Regulation of Euchromatic Gene Expression

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rajakumara, Eerappa; Wang, Zhentian; Ma, Honghui

    2011-08-29

    Histone methylation occurs on both lysine and arginine residues, and its dynamic regulation plays a critical role in chromatin biology. Here we identify the UHRF1 PHD finger (PHD{sub UHRF1}), an important regulator of DNA CpG methylation, as a histone H3 unmodified arginine 2 (H3R2) recognition modality. This conclusion is based on binding studies and cocrystal structures of PHD{sub UHRF1} bound to histone H3 peptides, where the guanidinium group of unmodified R2 forms an extensive intermolecular hydrogen bond network, with methylation of H3R2, but not H3K4 or H3K9, disrupting complex formation. We have identified direct target genes of UHRF1 from microarraymore » and ChIP studies. Importantly, we show that UHRF1's ability to repress its direct target gene expression is dependent on PHD{sub UHRF1} binding to unmodified H3R2, thereby demonstrating the functional importance of this recognition event and supporting the potential for crosstalk between histone arginine methylation and UHRF1 function.« less

  2. H2S induced coma and cardiogenic shock in the rat: Effects of phenothiazinium chromophores

    PubMed Central

    SONOBE, TAKASHI; HAOUZI, PHILIPPE

    2015-01-01

    Context Hydrogen sulfide (H2S) intoxication produces an acute depression in cardiac contractility-induced circulatory failure, which has been shown to be one of the major contributors to the lethality of H2S intoxication or to the neurological sequelae in surviving animals. Methylene blue (MB), a phenothiazinium dye, can antagonize the effects of the inhibition of mitochondrial electron transport chain, a major effect of H2S toxicity. Objectives We investigated whether MB could affect the immediate outcome of H2S-induced coma in unanesthetized animals. Second, we sought to characterize the acute cardiovascular effects of MB and two of its demethylated metabolites—azure B and thionine—in anesthetized rats during lethal infusion of H2S. Materials and methods First, MB (4 mg/kg, intravenous [IV]) was administered in non-sedated rats during the phase of agonal breathing, following NaHS (20 mg/kg, IP)-induced coma. Second, in 4 groups of urethane-anesthetized rats, NaHS was infused at a rate lethal within 10 min (0.8 mg/min, IV). Whenever cardiac output (CO) reached 40% of its baseline volume, MB, azure B, thionine, or saline were injected, while sulfide infusion was maintained until cardiac arrest occurred. Results Seventy-five percent of the comatose rats that received saline (n = 8) died within 7 min, while all the 7 rats that were given MB survived (p = 0.007). In the anesthetized rats, arterial, left ventricular pressures and CO decreased during NaHS infusion, leading to a pulseless electrical activity within 530 s. MB produced a significant increase in CO and dP/dtmax for about 2 min. A similar effect was produced when MB was also injected in the pre-mortem phase of sulfide exposure, significantly increasing survival time. Azure B produced an even larger increase in blood pressure than MB, while thionine had no effect. Conclusion MB can counteract NaHS-induced acute cardiogenic shock; this effect is also produced by azure B, but not by thionine, suggesting

  3. Solubility and diffusivity of N{sub 2}O and CO{sub 2} in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, M.H.; Lee, W.C.

    1996-05-01

    Acid gases such as CO{sub 2} and H{sub 2}S are frequently removed from natural gas, synthetic natural gas, and other process gas streams by means of absorption into aqueous alkanol-amine solutions. The solubility and diffusivity of N{sub 2}O in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water) were measured at (30, 35, and 40)C and at atmospheric pressure. Five (diethanolamine + N-methyldiethanolamine + water) and four (diethanolamine + 2-amino-2-methyl-1-propanol + water) systems were studied. The total amine mass percent in all cases was 30. A solubility apparatus was used to measure the solubility of N{sub 2}Omore » in amine solutions. The diffusivity was measured by a wetted wall column absorber. The N{sub 2}O analogy was used to estimate the solubility and diffusivity of CO{sub 2} in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water).« less

  4. 40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

    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-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2â²-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2â²-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

  5. 40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

    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-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2â²-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2â²-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

  6. Enantioselective route to 5-methyl- and 5,7-dimethyl-6,7-dihydro-5H-dibenz[c,e]azepine: secondary amines with switchable axial chirality.

    PubMed

    Pira, Silvain L; Wallace, Timothy W; Graham, Jonathan P

    2009-04-02

    (-)-5-Methyl-6,7-dihydro-5H-dibenz[c,e]azepine 4, a new secondary amine featuring an axis-center stereochemical relay, was prepared enantioselectively from 2'-acetylbiphenyl-2-carboxylic acid, using (R)-2-phenylglycinol as an auxiliary for the control of both elements of chirality. The biaryl axis in 4 preferentially adopts the aS-configuration, with the methyl substituent pseudoequatorial, but conversion into the corresponding N-Boc derivative locks the axis into the aR-configuration, as predicted on the basis of molecular mechanics calculations.

  7. Stage 4S neuroblastoma tumors show a characteristic DNA methylation portrait.

    PubMed

    Decock, Anneleen; Ongenaert, Maté; De Wilde, Bram; Brichard, Bénédicte; Noguera, Rosa; Speleman, Frank; Vandesompele, Jo

    2016-09-06

    Stage 4S neuroblastoma (NB) is a special type of NB found in infants with metastases at diagnosis and is associated with an excellent outcome due to its remarkable capacity to undergo spontaneous regression. As genomics have not been able to explain this intriguing clinical presentation, we here aimed at profiling the DNA methylome of stage 4S NB to better understand this phenomenon. To this purpose, differential methylation analyses between International Neuroblastoma Staging System (INSS) stage 4S, stage 4 and stage 1/2 were performed, using methyl-CpG-binding domain (MBD) sequencing data of 14 stage 4S, 14 stage 4, and 13 stage 1/2 primary NB tumors (all MYCN non-amplified in order not to confound results). Stage 4S-specific hyper- and hypo-methylated promoters were determined and further characterized for genomic localization and function by cytogenetic band enrichment, gene set enrichment, transcription factor target enrichment and differential RNA expression analyses. We show that specific chromosomal locations are enriched for stage 4S differentially methylated promoters and that stage 4S tumors show characteristic hypermethylation of subtelomeres. Furthermore, genes involved in important oncogenic pathways, in neural crest development and differentiation, and in epigenetic processes are differentially methylated and expressed in stage 4S tumors. Based on these findings, we describe new biological mechanisms possibly contributing to the stage 4S-specific tumor biology and spontaneous regression. In conclusion, this study is the first to describe the highly characteristic stage 4S DNA methylome. These findings will open new avenues to further unravel the NB pathology in general and stage 4S disease specifically.

  8. Synthesis ofN-(2-chloro-5-methylthiophenyl)-N'-(3-methyl-thiophenyl)-N'-[3H3]methylguanidine, l brace [3H3]CNS-5161 r brace

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gibbs, Andrew R.; Morimoto, Hiromi; VanBrocklin, Henry F.

    2001-09-28

    The preparation of the title compound, [{sup 3}H{sub 3}]CNS-5161, was accomplished in three steps starting with the production of [{sup 3}H{sub 3}]iodomethane (CT{sub 3}I). The intermediate N-[{sup 3}H{sub 3}]methyl-3-(thiomethylphenyl)cyanamide was prepared in 77% yield by the addition of CT{sub 3}I to 3-(thiomethylphenyl)cyanamide, previously treated with sodium hydride. Reaction of this tritiated intermediate with 2-chloro-5-thiomethylaniline hydrochloride formed the guanidine compound [{sup 3}H{sub 3}]CNS-5161. Purification by HPLC gave the desired labeled product in an overall yield of 9% with greater than 96% radiochemical purity and a final specific activity of 66 Ci mmol{sup -1}.

  9. 3-Methyl-5-methyl­sulfanyl-1,3,4-thia­diazole-2(3H)-thione

    PubMed Central

    Suarez, Sebastian A.; Hazari, Saroj K. S.; Ganguly, Biplab; Doctorovich, Fabio; G. Roy, Tapashi; Baggio, Ricardo

    2012-01-01

    The title compound, C4H6N2S3, has two very similar mol­ecules per asymmetric unit. The nine non-H atoms in each mol­ecule are coplanar, both having comparable r.m.s. deviations of 0.002 Å. The main inter­est in the rather simple structure resides in a survey of very weak (in some cases, borderline) non-bonding inter­actions of various kinds, viz. S⋯S, C—H⋯π, π–π [centroid–centroid distance = 3.8958 (13) Å] and C—S⋯π [3.7271 (11) Å], which act as the major driving force for the arrangement of mol­ecules in the structure. The role of long, though highly directional, S⋯S contacts (d > 3.60 Å), and their relevance to the stability of the structure is discussed. PMID:23125808

  10. Etude des mécanismes d'ionisation de H{2}O par interaction He^{*}(2 ^1S, 2 ^3S)/Ne^{*}(^3P{0}, ^3P{2})+H{2}O

    NASA Astrophysics Data System (ADS)

    Le Nadan, André; Sinou, Guillaume; Tuffin, Firmin

    1993-06-01

    Experimental observations of Penning ionisation of H{2}O by the helium metastables 21S and 23S and by the neon metastables ^3P{0} and ^3P{2} are reported. The kinetic energies of the ions created during the collision process (both parent and fragment) are analysed. Certain particularities of the experimental results are explained by involving the hypothesis of transfers of vibrational energy to kinetic energy. Furthermore, the forms of the energy distributions of the fragment ions are explained by th predissociation of the ^2B{2} state of H{2}O+. Nous avons étudié l'ionisation Penning de H{2}O par des métastables 21S et 23S de l'hélium, ainsi que ^3P{0} et ^3P{2} du néon. Nous avons analysé l'énergie cinétique des ions créés au cours de la collision (parents et fragments). Afin d'interpréter certaines particularités expérimentales, l'hypothèse de transferts d'énergie de vibration en énergie cinétique est proposées. Par ailleurs, les caractéristiques des distributions en énergie des ions fragments sont expliquées par la prédissociation de l'état ^2B{2} de H{2}O+.

  11. Cyclical DNA Methylation and Histone Changes Are Induced by LPS to Activate COX-2 in Human Intestinal Epithelial Cells

    PubMed Central

    Brancaccio, Mariarita; Coretti, Lorena; Florio, Ermanno; Pezone, Antonio; Calabrò, Viola; Falco, Geppino; Keller, Simona; Lembo, Francesca; Avvedimento, Vittorio Enrico; Chiariotti, Lorenzo

    2016-01-01

    Bacterial lipopolysaccharide (LPS) induces release of inflammatory mediators both in immune and epithelial cells. We investigated whether changes of epigenetic marks, including selected histone modification and DNA methylation, may drive or accompany the activation of COX-2 gene in HT-29 human intestinal epithelial cells upon exposure to LPS. Here we describe cyclical histone acetylation (H3), methylation (H3K4, H3K9, H3K27) and DNA methylation changes occurring at COX-2 gene promoter overtime after LPS stimulation. Histone K27 methylation changes are carried out by the H3 demethylase JMJD3 and are essential for COX-2 induction by LPS. The changes of the histone code are associated with cyclical methylation signatures at the promoter and gene body of COX-2 gene. PMID:27253528

  12. [Effect of endogenous H2S on platelet L-Arg transport].

    PubMed

    Duan, Wen-zhuo; Wang, Yi-peng; Gong, Hai-min

    2010-05-01

    To observe the effect of novel air neuromodulator H2S on platelet function of L-Arg transport for discussing H2S of effect on platelet function. Saturate H2S solution as donate made rat rich platelet plasma and pre-incubation rat platelet with different density of H2S. To measure the velocity of L-Arg transport in platelet by radioactivity technique. At different concentrations of H2S (6.25, 12.5, 25, 50, 100 micromol/L), the velocity of L-Arg transport was lower than that in control. H2S reduced rapidly the Vmax and velocity of L-Arg transport in platelet (P < 0.05) and this effect had no effect to Km. H2S can affect platelet function by changing rapidly platelet L-Arg transport system function.

  13. Functional analysis of [methyl-(3)H]choline uptake in glioblastoma cells: Influence of anti-cancer and central nervous system drugs.

    PubMed

    Taguchi, Chiaki; Inazu, Masato; Saiki, Iwao; Yara, Miki; Hara, Naomi; Yamanaka, Tsuyoshi; Uchino, Hiroyuki

    2014-04-01

    Positron emission tomography (PET) and PET/computed tomography (PET-CT) studies with (11)C- or (18)F-labeled choline derivatives are used for PET imaging in glioblastoma patients. However, the nature of the choline transport system in glioblastoma is poorly understood. In this study, we performed a functional characterization of [methyl-(3)H]choline uptake and sought to identify the transporters that mediate choline uptake in the human glioblastoma cell lines A-172 and U-251MG. In addition, we examined the influence of anti-cancer drugs and central nervous system drugs on the transport of [methyl-(3)H]choline. High- and low-affinity choline transport systems were present in A-172 cells, U-251MG cells and astrocytes, and these were Na(+)-independent and pH-dependent. Cell viability in A-172 cells was not affected by choline deficiency. However, cell viability in U-251MG cells was significantly inhibited by choline deficiency. Both A-172 and U-251MG cells have two different choline transporters, choline transporter-like protein 1 (CTL1) and CTL2. In A-172 cells, CTL1 is predominantly expressed, whereas in U-251MG cells, CTL2 is predominantly expressed. Treatment with anti-cancer drugs such as cisplatin, etoposide and vincristine influenced [methyl-(3)H]choline uptake in U-251MG cells, but not A-172 cells. Central nervous system drugs such as imipramine, fluvoxamine, paroxetine, reboxetine, citalopram and donepezil did not affect cell viability or [methyl-(3)H]choline uptake. The data presented here suggest that CTL1 and CTL2 are functionally expressed in A-172 and U-251MG cells and are responsible for [methyl-(3)H]choline uptake that relies on a directed H(+) gradient as a driving force. Furthermore, while anti-cancer drugs altered [methyl-(3)H]choline uptake, central nervous system drugs did not affect [methyl-(3)H]choline uptake. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. First-principles characterization of potassium intercalation in the hexagonal 2H-MoS2

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Andersen, Amity; Kathmann, Shawn M.; Lilga, Michael A.

    2012-01-12

    Periodic density functional theory calculations were performed to study the structural and electronic properties of potassium intercalated into hexagonal MoS{sub 2} (2H-MoS{sub 2}). Metallic potassium (K) atoms are incrementally loaded in the hexagonal sites of the interstitial spaces between MoS2 sheets of the 2H-MoS{sub 2} bulk structure generating 2H-KxMoS2 (0.125 {<=} x {<=} 1.0) structures. To accommodate the potassium atoms, the interstitial spacing c parameter in the 2H-MoS{sub 2} bulk expands from 12.816 {angstrom} in 2H-MoS{sub 2} to 16.086 {angstrom} in 2H-K{sub 0.125}MoS{sub 2}. The second lowest potassium loading concentration (K{sub 0.25}MoS{sub 2}) results in the largest interstitial spacing expansionmore » (to c = 16.726 {angstrom}). Our calculations show that there is a small gradual contraction of the interstitial spacing as the potassium loading increases with c = 14.839 {angstrom} for KMoS{sub 2}. This interstitial contraction is correlated with an in-plane expansion of the MoS{sub 2} sheets, which is in good agreement with experimental X-ray diffraction (XRD) measurements. The electronic analysis shows that potassium readily donates its 4s electron to the conduction band of the 2H-K{sub x}MoS{sub 2}, and is largely ionic in character. As a result of the electron donation, the 2H-K{sub x}MoS{sub 2} system changes from a semiconductor to a more metallic system with increasing potassium intercalation. For loadings 0.25 {<=} x {<=} 0.625, triangular Mo-Mo-Mo moieties are prominent and tend to form rhombitrihexagonal motifs. Intercalation of H{sub 2}O molecules that solvate the K atoms is likely to occur in catalytic conditions. The inclusion of two H{sub 2}O molecules per K atom in the K{sub 0.25}MoS{sub 2} structure shows good agreement with XRD measurements.« less

  15. Arsenic activates the expression of 3β-HSD in mouse Leydig cells through repression of histone H3K9 methylation.

    PubMed

    Alamdar, Ambreen; Xi, Guochen; Huang, Qingyu; Tian, Meiping; Eqani, Syed Ali Musstjab Akber Shah; Shen, Heqing

    2017-07-01

    Arsenic exposure has been associated with male reproductive dysfunction by disrupting steroidogenesis; however, the roles of epigenetic drivers, especially histone methylation in arsenic-induced steroidogenic toxicity remain not well documented. In this study, we investigated the role of histone H3 lysine 9 (H3K9) methylation in steroidogenesis disturbance in mouse Leydig cells (MLTC-1) due to arsenic exposure. Our results indicated that mRNA and protein expression levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) were both significantly up-regulated while the rest of key genes involved in steroidogenesis were down-regulated. Moreover, arsenic exposure significantly decreased the histone H3K9 di- and tri-methylation (H3K9me2/3) levels in MLTC-1 cells. Since H3K9 demethylation leads to gene activation, we further investigated whether the induction of 3β-HSD expression was ascribed to reduced H3K9 methylation. The results showed that H3K9me2/3 demethylase (JMJD2A) inhibitor, quercetin (Que) significantly attenuated the decrease of H3K9me2/3 and increase of 3β-HSD expression induced by arsenic. To further elucidate the mechanism for the activation of 3β-HSD, we determined the histone H3K9 methylation levels in Hsd3b gene promoter, which also showed significant decrease of H3K9me2/3 in the investigated region after arsenic exposure. Considering these results, we conclude that arsenic exposure induced 3β-HSD up-regulation by suppressing H3K9me2/3 status, which is suggested as a compensatory mechanism for steroidogenic disturbance in MLTC-1 cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Histone H4 Methyltransferase Suv420h2 Maintains Fidelity of Osteoblast Differentiation.

    PubMed

    Khani, Farzaneh; Thaler, Roman; Paradise, Christopher R; Deyle, David R; Kruijthof-de Julio, Marianne; Galindo, Mario; Gordon, Jonathan A; Stein, Gary S; Dudakovic, Amel; van Wijnen, Andre J

    2017-05-01

    Osteogenic lineage commitment and progression is controlled by multiple signaling pathways (e.g., WNT, BMP, FGF) that converge on bone-related transcription factors. Access of osteogenic transcription factors to chromatin is controlled by epigenetic regulators that generate post-translational modifications of histones ("histone code"), as well as read, edit and/or erase these modifications. Our understanding of the biological role of epigenetic regulators in osteoblast differentiation remains limited. Therefore, we performed next-generation RNA sequencing (RNA-seq) and established which chromatin-related proteins are robustly expressed in mouse bone tissues (e.g., fracture callus, calvarial bone). These studies also revealed that cells with increased osteogenic potential have higher levels of the H4K20 methyl transferase Suv420h2 compared to other methyl transferases (e.g., Suv39h1, Suv39h2, Suv420h1, Ezh1, Ezh2). We find that all six epigenetic regulators are transiently expressed at different stages of osteoblast differentiation in culture, with maximal mRNAs levels of Suv39h1 and Suv39h2 (at day 3) preceding maximal expression of Suv420h1 and Suv420h2 (at day 7) and developmental stages that reflect, respectively, early and later collagen matrix deposition. Loss of function analysis of Suv420h2 by siRNA depletion shows loss of H4K20 methylation and decreased expression of bone biomarkers (e.g., alkaline phosphatase/Alpl) and osteogenic transcription factors (e.g., Sp7/Osterix). Furthermore, Suv420h2 is required for matrix mineralization during osteoblast differentiation. We conclude that Suv420h2 controls the H4K20 methylome of osteoblasts and is critical for normal progression of osteoblastogenesis. J. Cell. Biochem. 118: 1262-1272, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Histone H4 methyltransferase Suv420h2 maintains fidelity of osteoblast differentiation

    PubMed Central

    Farzaneh, Khani; Thaler, Roman; Paradise, Christopher R.; Deyle, David R.; Julio, Marianne Kruijthof-de; Galindo, Mario; Gordon, Jonathan A.; Stein, Gary S.; Dudakovic, Amel; van Wijnen, Andre J.

    2017-01-01

    Osteogenic lineage commitment and progression is controlled by multiple signaling pathways (e.g., WNT, BMP, FGF) that converge on bone-related transcription factors. Access of osteogenic transcription factors to chromatin is controlled by epigenetic regulators that generate post-translational modifications of histones (‘histone code’), as well as read, edit and/or erase these modifications. Our understanding of the biological role of epigenetic regulators in osteoblast differentiation remains limited. Therefore, we performed next-generation RNA sequencing (RNA-seq) and established which chromatin-related proteins are robustly expressed in mouse bone tissues (e.g., fracture callus, calvarial bone). These studies also revealed that cells with increased osteogenic potential have higher levels of the H4K20 methyl transferase Suv420h2 compared to other methyl transferases (e.g., Suv39h1, Suv39h2, Suv420h1, Ezh1, Ezh2). We find that all six epigenetic regulators are transiently expressed at different stages of osteoblast differentiation in culture, with maximal mRNAs levels of Suv39h1 and Suv39h2 (at day 3) preceding maximal expression of Suv420h1 and Suv420h2 (at day 7) and developmental stages that reflect, respectively, early and later collagen matrix deposition. Loss of function analysis of Suv420h2 by siRNA depletion shows loss of H4K20 methylation and decreased expression of bone biomarkers (e.g., alkaline phosphatase/Alpl) and osteogenic transcription factors (e.g., Sp7/Osterix). Furthermore, Suv420h2 is required for matrix mineralization during osteoblast differentiation. We conclude that Suv420h2 controls the H4K20 methylome of osteoblasts and is critical for normal progression of osteoblastogenesis. PMID:27862226

  18. Design and in vitro activities of N-alkyl-N-[(8-R-2,2-dimethyl-2H-chromen-6-yl)methyl]heteroarylsulfonamides, novel small molecule Hypoxia Inducible Factor-1 (HIF-1) pathway inhibitors and anti-cancer agents

    PubMed Central

    Mun, Jiyoung; Jabbar, Adnan Abdul; Devi, Narra Sarojini; Yin, Shaoman; Wang, Yingzhe; Tan, Chalet; Culver, Deborah; Snyder, James P.; Van Meir, Erwin G.; Goodman, Mark M.

    2013-01-01

    The Hypoxia Inducible Factor (HIF) pathway is an attractive target for cancer as it controls tumor adaptation to growth under hypoxia and mediates chemo- and radiation resistance. We previously discovered 3,4-dimethoxy-N-[(2,2-dimethyl-2H-chromen-6-yl)methyl]-N-phenylbenzenesulfonamide, as a novel small molecule HIF-1 pathway inhibitor in a high-throughput cell-based assay, but its in vivo delivery is hampered by poor aqueous solubility (0.009 μM in water; logP7.4: 3.7). Here we describe the synthesis of twelve N-alkyl-N-[(8-R-2,2-dimethyl-2H-chromen-6-yl)methyl]heteroarylsulfonamides, which were designed to possess optimal lipophilicities and aqueous solubilities by in silico calculations. Experimental logP7.4 values of 8 of the 12 new analogs ranged from 1.2 ∼ 3.1. Aqueous solubilities of 3 analogs were measured, among which the most soluble N-[(8-methoxy-2,2-dimethyl-2H-chromen-6-yl)methyl]-N-(propan-2-yl)pyridine-2-sulfonamide had an aqueous solubility of 80 μM, e.g. a solubility improvement of ∼9,000-fold. The pharmacological optimization had minimal impact on drug efficacy as the compounds retained IC50 values at or below 5 μM in our HIF-dependent reporter assay. PMID:22746274

  19. A DFT-Elucidated Comparison of the Solution-Phase and SAM Electrochemical Properties of Short-Chain Mercaptoalkylferrocenes: Synthetic and Spectroscopic Aspects, and the Structure of Fc-CH2CH2-S-S-CH2CH2-Fc.

    PubMed

    Lewtak, Jan P; Landman, Marilé; Fernández, Israel; Swarts, Jannie C

    2016-03-07

    Facile synthetic procedures to synthesize a series of difficult-to-obtain mercaptoalkylferrocenes, namely, Fc(CH2)nSH, where n = 1 (1), 2 (2), 3 (3), or 4 (4) and Fc = Fe(η(5)-C5H5)(η(5)-C5H4), are reported. Dimerization of 1-4 to the corresponding disulfides 19-22 was observed in air. Dimer 20 (Z = 2) crystallized in the triclinic space group P1̅. Dimers 20-22 could be reduced back to the original Fc(CH2)nSH derivatives with LiAlH4 in refluxing tetrahydrofuran. Density functional theory (DFT) calculations showed that the highest occupied molecular orbital of 1-4 lies exclusively on the ferrocenyl group implying that the electrochemical oxidation observed at ca. -15 < Epa < 76 mV versus FcH/FcH(+) involves exclusively an Fe(II) to Fe(III) process. Further DFT calculations showed this one-electron oxidation is followed by proton loss on the thiol group to generate a radical, Fc(CH2)nS(•), with spin density mainly located on the sulfur. Rapid exothermic dimerization leads to the observed dimers, Fc(CH2)n-S-S-(CH 2)nFc. Reduction of the ferrocenium groups on the dimer occurs at potentials that still showed the ferrocenyl group ΔE = Epa,monomer - Epc,dimer ≤ 78 mV, indicating that the redox properties of the ferrocenyl group on the mercaptans are very similar to those of the dimer. (1)H NMR measurements showed that, like ferrocenyl oxidation, the resonance position of the sulfhydryl proton, SH, and others, are dependent on -(CH2)n- chain length. Self-assembled monolayers (SAMs) on gold were generated to investigate the electrochemical behavior of 1-4 in the absence of diffusion. Under these conditions, ΔE approached 0 mV for the longer chain derivatives at slow scan rates. The surface-bound ferrocenyl group of the metal-thioether, Fc(CH2)n -S-Au, is oxidized at approximately equal potentials as the equivalent CH2Cl2-dissolved ferrocenyl species 1-4. Surface coverage by the SAMs is dependent on alkyl chain length with the largest coverage obtained for 4, while

  20. Emission of hydrogen sulfide (H2S) at a waterfall in a sewer: study of main factors affecting H2S emission and modeling approaches.

    PubMed

    Jung, Daniel; Hatrait, Laetitia; Gouello, Julien; Ponthieux, Arnaud; Parez, Vincent; Renner, Christophe

    2017-11-01

    Hydrogen sulfide (H 2 S) represents one of the main odorant gases emitted from sewer networks. A mathematical model can be a fast and low-cost tool for estimating its emission. This study investigates two approaches to modeling H 2 S gas transfer at a waterfall in a discharge manhole. The first approach is based on an adaptation of oxygen models for H 2 S emission at a waterfall and the second consists of a new model. An experimental set-up and a statistical data analysis allowed the main factors affecting H 2 S emission to be studied. A new model of the emission kinetics was developed using linear regression and taking into account H 2 S liquid concentration, waterfall height and fluid velocity at the outlet pipe of a rising main. Its prediction interval was estimated by the residual standard deviation (15.6%) up to a rate of 2.3 g H 2h -1 . Finally, data coming from four sampling campaigns on sewer networks were used to perform simulations and compare predictions of all developed models.

  1. Induction of H3K9me3 and DNA methylation by tethered heterochromatin factors in Neurospora crassa

    PubMed Central

    Selker, Eric U.

    2017-01-01

    Functionally different chromatin domains display distinct chemical marks. Constitutive heterochromatin is commonly associated with trimethylation of lysine 9 on histone H3 (H3K9me3), hypoacetylated histones, and DNA methylation, but the contributions of and interplay among these features are not fully understood. To dissect the establishment of heterochromatin, we investigated the relationships among these features using an in vivo tethering system in Neurospora crassa. Artificial recruitment of the H3K9 methyltransferase DIM-5 (defective in methylation-5) induced H3K9me3 and DNA methylation at a normally active, euchromatic locus but did not bypass the requirement of DIM-7, previously implicated in the localization of DIM-5, indicating additional DIM-7 functionality. Tethered heterochromatin protein 1 (HP1) induced H3K9me3, DNA methylation, and gene silencing. The induced heterochromatin required histone deacetylase 1 (HDA-1), with an intact catalytic domain, but HDA-1 was not essential for de novo heterochromatin formation at native heterochromatic regions. Silencing did not require H3K9me3 or DNA methylation. However, DNA methylation contributed to establishment of H3K9me3 induced by tethered HP1. Our analyses also revealed evidence of regulatory mechanisms, dependent on HDA-1 and DIM-5, to control the localization and catalytic activity of the DNA methyltransferase DIM-2. Our study clarifies the interrelationships among canonical aspects of heterochromatin and supports a central role of HDA-1–mediated histone deacetylation in heterochromatin spreading and gene silencing. PMID:29078403

  2. Synthesis of a Nanostructured Composite: Octakis(1-propyl-1H-1,2,3-triazole-4-yl(methyl 2-chlorobenzoate))octasilsesquioxane via Click Reaction.

    PubMed

    Ghodsi, Mohammadi Ziarani; Shakiba Nahad, Monireh; Lashgari, Negar; Alireza, Badiei

    2015-01-01

    Octakis(1-propyl-1H-1,2,3-triazole-4-yl(methyl 2-chlorobenzoate))octasilsesquioxanes as functionalized silsesquioxanes were synthesized via click reaction (copper-catalyzed Huisgen 1,3-dipolar cycloaddition reaction) between azidemoiety functionalized silsesquioxane and prop-2-ynyl 2-chlorobenzoate. The latter one was synthesized via the condensation reaction of propargyl alcohol and 2-chlorobenzoyl chloride in the presence of SBA-Pr-NH(2) (Santa Barbara Amorphous type material) as a nano basic catalyst. This approach provides a simple and convenient route to efficiently functionalize a wide range of new structures on the surface of silsesquioxanes.

  3. N-(1-Allyl-1H-indazol-5-yl)-4-methyl­benzene­sulfonamide

    PubMed Central

    Chicha, Hakima; Rakib, El Mostapha; Abderrafia, Hafid; Saadi, Mohamed; El Ammari, Lahcen

    2013-01-01

    The asymmetric unit of the title compound, C17H17N3O2S, contains two independent mol­ecules linked by an N—H⋯O hydrogen bond. The mol­ecules show different conformations. In the first mol­ecule, the fused five- and six-membered ring system is almost perpendicular to the plane through the atoms forming the allyl group, as indicated by the dihedral angle of 85.1 (4)°. The dihedral angle with the methyl­benzene­sulfonamide group is 78.8 (1)°. On the other hand, in the second mol­ecule, the dihedral angles between the indazole plane and the allyl and methyl­benzene­sulfonamide groups are 80.3 (3) and 41.5 (1)°, respectively. In the crystal, mol­ecules are further linked by N—H⋯N and C—H⋯O hydrogen bonds, forming a three-dimensional network. PMID:24454264

  4. H2S, a novel therapeutic target in renal-associated diseases?

    PubMed

    Pan, Wen-Jun; Fan, Wen-Jing; Zhang, Chi; Han, Dan; Qu, Shun-Lin; Jiang, Zhi-Sheng

    2015-01-01

    For more than a century, hydrogen sulfide (H2S) has been regarded as a toxic gas. Recently, the understanding of the biological effects of H2S has been changed. This review surveys the growing recognition of H2S as an endogenous signaling molecule in mammals, with emphasis on its physiological and pathological pathways in the urinary system. This article reviews recent progress of basic and pharmacological researches related to endogenous H2S in urinary system, including the regulatory effects of H2S in the process of antioxidant, inflammation, cellular matrix remodeling and ion channels, and the role of endogenous H2S pathway in the pathogenesis of renal and urogenital disorders. Copyright © 2014. Published by Elsevier B.V.

  5. Weak hydrogen bonding and fluorous interactions in the chloride and bromide salts of 4-[(2,2,3,3-tetrafluoropropoxy)methyl]pyridinium.

    PubMed

    Lu, Norman; Wei, Rong Jyun; Lin, Kwan Yu; Alagesan, Mani; Wen, Yuh Sheng; Liu, Ling Kang

    2017-04-01

    Neutralization of 4-[(2,2,3,3-tetrafluoropropoxy)methyl]pyridine with hydrohalo acids HX (X = Cl and Br) yielded the pyridinium salts 4-[(2,2,3,3-tetrafluoropropoxy)methyl]pyridinium chloride, C 9 H 10 F 4 NO + ·Cl - , (1), and 4-[(2,2,3,3-tetrafluoropropoxy)methyl]pyridinium bromide, C 9 H 10 F 4 NO + ·Br - , (2), both carrying a fluorous side chain at the para position of the pyridinium ring. Single-crystal X-ray diffraction techniques revealed that (1) and (2) are isomorphous. The halide anions accept four hydrogen bonds from N-H, ortho-C-H and CF 2 -H groups. Two cations and two anions form a centrosymmetric dimeric building block, utilizing complimentary N-H...X...H-Csp 3 connections. These dimers are further crosslinked, utilizing another complimentary Csp 2 -H...X...H-Csp 2 connection. The pyridinium rings are π-stacked, forming columns running parallel to the a axis that make angles of ca 44-45° with the normal to the pyridinium plane. There are also supramolecular C-H...F-C interactions, namely bifurcated C-H...F and bifurcated C-F...H interactions; additionally, one type II C-F...F-C halogen bond has been observed.

  6. 40 CFR 721.1025 - Benzenamine, 4-chloro-2-methyl-; benzenamine, 4-chloro-2-methyl-, hydrochloride; and ben-zenamine...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-; benzenamine, 4-chloro-2-methyl-, hydrochloride; and ben-zenamine, 2-chloro-6-methyl-. 721.1025 Section 721... Benzenamine, 4-chloro-2-methyl-; benzenamine, 4-chloro-2-methyl-, hydrochloride; and ben-zenamine, 2-chloro-6...-, hydrochloride (CAS Number 3165-93-3); and benzenamine, 2-chloro-6-methyl- (CAS Number 87-63-8) are subject to...

  7. The excited-state decay of 1-methyl-2(1H)-pyrimidinone is an activated process.

    PubMed

    Ryseck, Gerald; Schmierer, Thomas; Haiser, Karin; Schreier, Wolfgang; Zinth, Wolfgang; Gilch, Peter

    2011-07-11

    The photophysics of 1-methyl-2(1H)-pyrimidinone (1MP) dissolved in water is investigated by steady-state and time-resolved fluorescence, UV/Vis absorption, and IR spectroscopy. In the experiments, excitation light is tuned to the lowest-energy absorption band of 1MP peaking at 302 nm. At room temperature (291 K) its fluorescence lifetime amounts to 450 ps. With increasing temperature this lifetime decreases and equals 160 ps at 338 K. Internal conversion (IC) repopulating the ground state and intersystem crossing (ISC) to a triplet state are the dominant decay channels of the excited singlet state. At room temperature both channels contribute equally to the decay, that is, the quantum yields of IC and ISC are both approximately 0.5. The temperature dependence of UV/Vis transient absorption signals shows that the activation energy of the IC process (2140 cm(-1)) is higher than that of the ISC process (640 cm(-1)). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Computational Study on the Unimolecular Decomposition of JP-8 Jet Fuel Surrogates III: Butylbenzene Isomers ( n-, s-, and t-C14H10).

    PubMed

    Belisario-Lara, Daniel; Mebel, Alexander M; Kaiser, Ralf I

    2018-04-26

    Ab initio G3(CCSD,MP2)//B3LYP/6-311G(d,p) calculations of potential energy surfaces have been carried out to unravel the mechanism of the initial stages of pyrolysis of three C 10 H 14 isomers: n-, s-, and t-butylbenzenes. The computed energy and molecular parameters have been utilized in RRKM-master equation calculations to predict temperature- and pressure-dependent rate constants and product branching ratios for the primary unimolecular decomposition of these molecules and for the secondary decomposition of their radical fragments. The results showed that the primary dissociation of n-butylbenzene produces mostly benzyl (C 7 H 7 ) + propyl (C 3 H 7 ) and 1-phenyl-2-ethyl (C 6 H 5 C 2 H 4 ) + ethyl (C 2 H 5 ), with their relative yields strongly dependent on temperature and pressure, together with a minor amount of 1-phenyl-prop-3-yl (C 9 H 11 ) + methyl (CH 3 ). Secondary decomposition reactions that are anticipated to occur on a nanosecond scale under typical combustion conditions split propyl (C 3 H 7 ) into ethylene (C 2 H 4 ) + methyl (CH 3 ), ethyl (C 2 H 5 ) into ethylene (C 2 H 4 ) + hydrogen (H), 1-phenyl-2-ethyl (C 6 H 5 C 2 H 4 ) into mostly styrene (C 8 H 8 ) + hydrogen (H) and to a lesser extent phenyl (C 6 H 5 ) + ethylene (C 2 H 4 ), and 1-phenyl-prop-3-yl (C 9 H 11 ) into predominantly benzyl (C 7 H 7 ) + ethylene (C 2 H 4 ). The primary decomposition of s-butylbenzene is predicted to produce 1-phenyl-1-ethyl (C 6 H 5 CHCH 3 ) + ethyl (C 2 H 5 ) and a minor amount of 1-phenyl-prop-1-yl (C 9 H 11 ) + methyl (CH 3 ), and then 1-phenyl-1-ethyl (C 6 H 5 CHCH 3 ) and 1-phenyl-prop-1-yl (C 9 H 11 ) rapidly dissociate to styrene (C 8 H 8 ) + hydrogen (H) and styrene (C 8 H 8 ) + methyl (CH 3 ), respectively. t-Butylbenzene decomposes nearly exclusively to 2-phenyl-prop-2-yl (C 9 H 11 ) + methyl (CH 3 ), and further, 2-phenyl-prop-2-yl (C 9 H 11 ) rapidly eliminates a hydrogen atom to form 2-phenylpropene (C 9 H 10 ). If hydrogen atoms or other reactive

  9. Thermodynamic properties of {Delta}H{sub f 298}{degree}, S{sub 298}{degree}, and C{sub p}(T) for 2-fluoro-2-methylpropane, {Delta}H{sub f 298}{degree} of fluorinated ethanes, and group additivity for fluoroalkanes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yamada, Takahiro; Bozzelli, J.W.

    1999-09-09

    G2(MP2) composite calculations are performed to obtain thermodynamic properties ({Delta}H{sub f 298}{degree}, S{sub 298}{degree} and C{sub p}(T)'s) of 2-fluoro-2-methylpropane. {Delta}H{sub f 298}{degree} is calculated from the G2(MP2) calculated enthalpy of reaction ({Delta}H{sub rxn 298}{degree}) and use of isodesmic reactions. Standard entropy (S{sub 298}{degree} in cal/(mol{center{underscore}dot}K)) and heat capacities (C{sub p}(T)'s in cal/(mol{center{underscore}dot}K)) are calculated using the rigid-rotor--harmonic-oscillator approximation with direct integration over energy levels of the intermolecular rotation potential energy curve. These thermodynamic properties are used to estimate data for the C/C3/F group. Enthalpies of formation ({Delta}H{sub f 298}{degree} in kcal/mol) for 1,2-difluoroethane ({minus}102.7), 1,1,2-trifluoroethane ({minus}156.9), 1,1,2,2- and 1,1,1,2-tetrafluoroethane (209.6more » and 213.3), and pentafluoroethane ({minus}264.1), are calculated using total energies obtained from G2(MP2) composite ab initio methods. Isodesmic reactions with existing literature values of {Delta}H{sub f 298}{degree} for ethane, 1-fluoroethane, 1,1-difjuoroethane and 1,1,1-trifluoroethane are used. Fluorine/fluorine interaction terms, F/F, 2F/F, 3F/F, 2F/2F, and 3F/2F, where ``/'' indicates interaction for alkane compounds, for {Delta}H{sub f 298}{degree} are reevaluated based on {Delta}H{sub f 298}{degree} of the above five fluoroethanes. Thermodynamic properties ({Delta}H{sub f 298}{degree}, S{sub 298}{degree} and C{sub p}(T)'s (300 {le} T/K {le} 1500)) for fluorinated carbon groups, C/C3F, C/C2/F/H, C/C2/F2, are calculated using data from ab initio methods and existing literature data. Fluorine-methyl (alkyl) group additivity corrections for gauche interactions are also evaluated.« less

  10. Evidence for the η(b)(2S) and observation of h(b)(1P)→η(b)(1S)γ and h(b)(2P)→η(b)(1S)γ.

    PubMed

    Mizuk, R; Asner, D M; Bondar, A; Pedlar, T K; Adachi, I; Aihara, H; Arinstein, K; Aulchenko, V; Aushev, T; Aziz, T; Bakich, A M; Bay, A; Belous, K; Bhardwaj, V; Bhuyan, B; Bischofberger, M; Bonvicini, G; Bozek, A; Bračko, M; Brodzicka, J; Browder, T E; Chekelian, V; Chen, A; Chen, P; Cheon, B G; Chilikin, K; Chistov, R; Cho, I-S; Cho, K; Choi, S-K; Choi, Y; Dalseno, J; Danilov, M; Doležal, Z; Drásal, Z; Drutskoy, A; Eidelman, S; Epifanov, D; Fast, J E; Gaur, V; Gabyshev, N; Garmash, A; Golob, B; Haba, J; Hara, T; Hayasaka, K; Hayashii, H; Horii, Y; Hoshi, Y; Hou, W-S; Hsiung, Y B; Hyun, H J; Iijima, T; Ishikawa, A; Itoh, R; Iwabuchi, M; Iwasaki, Y; Iwashita, T; Jaegle, I; Julius, T; Kang, J H; Kapusta, P; Kawasaki, T; Kim, H J; Kim, H O; Kim, J H; Kim, K T; Kim, M J; Kim, Y J; Kinoshita, K; Ko, B R; Koblitz, S; Kodyš, P; Korpar, S; Kouzes, R T; Križan, P; Krokovny, P; Kuhr, T; Kumita, T; Kuzmin, A; Kwon, Y-J; Lange, J S; Lee, S-H; Li, J; Libby, J; Liu, C; Liu, Y; Liu, Z Q; Liventsev, D; Louvot, R; Matvienko, D; McOnie, S; Miyabayashi, K; Miyata, H; Mohanty, G B; Mohapatra, D; Moll, A; Muramatsu, N; Mussa, R; Nakao, M; Natkaniec, Z; Ng, C; Nishida, S; Nishimura, K; Nitoh, O; Nozaki, T; Ohshima, T; Okuno, S; Olsen, S L; Onuki, Y; Pakhlov, P; Pakhlova, G; Park, C W; Park, H; Pestotnik, R; Petrič, M; Piilonen, L E; Poluektov, A; Röhrken, M; Sakai, Y; Sandilya, S; Santel, D; Sanuki, T; Sato, Y; Schneider, O; Schwanda, C; Senyo, K; Seon, O; Sevior, M E; Shapkin, M; Shen, C P; Shibata, T-A; Shiu, J-G; Shwartz, B; Sibidanov, A; Simon, F; Smerkol, P; Sohn, Y-S; Sokolov, A; Solovieva, E; Stanič, S; Starič, M; Sumihama, M; Sumiyoshi, T; Tanida, K; Tatishvili, G; Teramoto, Y; Tikhomirov, I; Trabelsi, K; Tsuboyama, T; Uchida, M; Uehara, S; Uglov, T; Unno, Y; Uno, S; Vanhoefer, P; Varner, G; Varvell, K E; Vinokurova, A; Vorobyev, V; Wang, C H; Wang, M-Z; Wang, P; Wang, X L; Watanabe, M; Watanabe, Y; Williams, K M; Won, E; Yabsley, B D; Yamaoka, J; Yamashita, Y; Yuan, C Z; Zhang, Z P; Zhilich, V

    2012-12-07

    We report the first evidence for the η(b)(2S) using the h(b)(2P)→η(b)(2S)γ transition and the first observation of the h(b)(1P)→η(b)(1S)γ and h(b)(2P)→η(b)(1S)γ transitions. The mass and width of the η(b)(1S) and η(b)(2S) are measured to be m(η(b)(1S))=(9402.4±1.5±1.8) MeV/c(2), m(η(b)(2S))=(9999.0±3.5(-1.9)(+2.8)) MeV/c(2), and Γ(η(b)(1S))=(10.8(-3.7-2.0)(+4.0+4.5)) MeV. We also update the h(b)(1P) and h(b)(2P) mass measurements. We use a 133.4 fb(-1) data sample collected at energies near the Υ(5S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.

  11. FLYING-WATER Renewables-H2-H2O TERRAFORMING: PERMANENT ETERNAL Drought(s)-Elimination FOREVER!!!

    NASA Astrophysics Data System (ADS)

    Wignall, J.; Lyons, Marv; Ertl, G.; Alefeld, Georg; Youdelis, W.; Radd, H.; Oertle, G.; Siegel, Edward

    2013-03-01

    ''H2O H2O everywhere; ne'er a drop to drink''[Coleridge(1798)] now: ''H2 H2 everywhere; STILL ne'er a drop to drink'': ONLY H2 (or methane CH4) can be FLYING-WATER(F-W) chemical-rain-in-pipelines Hindenberg-effect (H2-UP;H2O-DOWN): { ∖{}O/H2O{ ∖}} =[16]/[18] ∖sim 90{ ∖%} O already in air uphill; NO H2O pumping need! In global-warming driven H2O-starved glacial-melting world, rescue is possible ONLY by Siegel [ ∖underline {3rd Intl. Conf. Alt.-Energy }(1980)-vol.5/p.459!!!] Renewables-H2-H2O purposely flexible versatile agile customizable scaleable retrofitable integrated operating-system. Rosenfeld[Science 315,1396(3/9/2007)]-Biello [Sci.Am.(3/9 /2007)] crucial geomorphology which ONLY maximal-buoyancy H2 can exploit, to again make ''Mountains into Fountains'', ``upthrust rocks trapping the clouds to precipitate their rain/snow/H2O'': ''terraforming''(and ocean-rebasificaton!!!) ONLY VIA Siegel[APS March MTGS.:1960s-2000ss) DIFFUSIVE-MAGNETORESISTANCE (DMR) proprietary MAGNETIC-HYDROGEN-VALVE(MHV) ALL-IMPORTANT PRECLUDED RADIAL-diffusion, permitting ONLY AXIAL-H2-BALLISTIC-flow (``G.A''.''/DoE''/''Terrapower''/''Intellectual-Ventures''/ ''Gileland''/ ''Myhrvold''/''Gates'' ``ARCHIMEDES'') in ALREADY IN-ground dense BCC/ferritic-steels pipelines-network (NO new infrastructure) counters Tromp[Science 300,1740(2003)] dire warning of global-pandemics (cancers/ blindness/ famine)

  12. High light harvesting efficiency CuInS2 quantum dots/TiO2/MoS2 photocatalysts for enhanced visible light photocatalytic H2 production.

    PubMed

    Yuan, Yong-Jun; Fang, Gaoliang; Chen, Daqin; Huang, Yanwei; Yang, Ling-Xia; Cao, Da-Peng; Wang, Jingjing; Yu, Zhen-Tao; Zou, Zhi-Gang

    2018-04-24

    Expanding the photoresponse range of TiO2-based photocatalysts is of great interest for photocatalytic H2 production. Herein, noble-metal-free CuInS2 quantum dots were employed as a novel inorganic dye to expand the visible light absorption of TiO2/MoS2 for solar H2 generation. The as-prepared CuInS2/TiO2/MoS2 photocatalysts exhibit broad absorption from the ultraviolet to near-infrared region. Under visible light irradiation (λ > 420 nm), the CuInS2/TiO2/MoS2 photocatalyst with 0.6 mmol g-1 CuInS2 and 0.5 wt% MoS2 showed the highest H2 evolution rate with a value of 1034 μmol h-1 g-1. Moreover, a considerable H2 evolution rate of 141 μmol h-1 g-1 was obtained under the irradiation of the optimized CuInS2/TiO2/MoS2 photocatalyst with >500 nm light. The reaction mechanism of the CuInS2/TiO2/MoS2 photocatalyst for photocatalytic H2 evolution was investigated in detail by photoluminescence decay study, and the results showed that the photoexcited electrons of CuInS2 can be transferred efficiently through TiO2 to MoS2 and then react with the absorbed protons to generate H2. The reported sensitization strategy tremendously improves the visible light absorption capacity and the photocatalytic performance of TiO2-based photocatalysts.

  13. Methylation Analysis of the BMPR2 Gene Promoter Region in Patients With Pulmonary Arterial Hypertension.

    PubMed

    Pousada, Guillermo; Baloira, Adolfo; Valverde, Diana

    2016-06-01

    Pulmonary arterial hypertension is characterizated by obstruction of the pulmonary arteries. The gene mainly related to pathology is the bone morphogenetic protein receptor type II (BMPR2). The aim of this study was to analyze the methylation pattern of the BMPR2 promoter region in patients and controls. We used Methyl Primer Express(®) v.1.0 and MatInspector softwares to analyze this region. Genomic DNA obtained from the peripheral blood of patients and controls was modified with sodium bisulphite. Methylation was analyzed using methylation-specific PCR. DNA treated with CpG methyltransferase was used as a positive control for methylation and H1299 cell culture DNA was used as positive control for gene expression. We identified a CpG island, which may have been methylated, in the BMPR2 promoter region, in addition to NIT-2 (global-acting regulatory protein), sex-determining region Y) and heat shock factor transcription factor binding sites. We found no evidence of methylation in patients and controls. No methylated CpG sites were identified in H1299 cells expressing the BMPR2 gene. The BMPR2 promoter region is the most suitable for study because of the high number of transcription factor binding sites that could alter gene function. No evidence of methylation was detected in this region in patients and controls. Copyright © 2015 SEPAR. Published by Elsevier Espana. All rights reserved.

  14. 3-Methyl-7-(2-thienyl)pyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione: pi-stacked bilayers built from N-H...O, C-H...O and C-H...pi hydrogen bonds.

    PubMed

    Trilleras, Jorge; Quiroga, Jairo; Cobo, Justo; Glidewell, Christopher

    2009-06-01

    In the title compound, C(12)H(9)N(3)O(2)S, the thienyl substituent is disordered over two sets of sites with occupancies of 0.749 (3) and 0.251 (3). A combination of N-H...O, C-H...O and C-H...pi hydrogen bonds links the molecules into bilayers and these bilayers are themselves linked into a continuous structure by pi-pi stacking interactions.

  15. H{sub 2}S does not regulate proliferation via T-type Ca{sup 2+} channels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Elies, Jacobo; Johnson, Emily; Boyle, John P.

    T-type Ca{sup 2+} channels (Cav3.1, 3.2 and 3.3) strongly influence proliferation of various cell types, including vascular smooth muscle cells (VSMCs) and certain cancers. We have recently shown that the gasotransmitter carbon monoxide (CO) inhibits T-type Ca{sup 2+} channels and, in so doing, attenuates proliferation of VSMC. We have also shown that the T-type Ca{sup 2+} channel Cav3.2 is selectively inhibited by hydrogen sulfide (H{sub 2}S) whilst the other channel isoforms (Cav3.1 and Cav3.3) are unaffected. Here, we explored whether inhibition of Cav3.2 by H{sub 2}S could account for the anti-proliferative effects of this gasotransmitter. H{sub 2}S suppressed proliferation inmore » HEK293 cells expressing Cav3.2, as predicted by our previous observations. However, H{sub 2}S was similarly effective in suppressing proliferation in wild type (non-transfected) HEK293 cells and those expressing the H{sub 2}S insensitive channel, Cav3.1. Further studies demonstrated that T-type Ca{sup 2+} channels in the smooth muscle cell line A7r5 and in human coronary VSMCs strongly influenced proliferation. In both cell types, H{sub 2}S caused a concentration-dependent inhibition of proliferation, yet by far the dominant T-type Ca{sup 2+} channel isoform was the H{sub 2}S-insensitive channel, Cav3.1. Our data indicate that inhibition of T-type Ca{sup 2+} channel-mediated proliferation by H{sub 2}S is independent of the channels’ sensitivity to H{sub 2}S. - Highlights: • T-type Ca{sup 2+} channels regulate proliferation and are sensitive to the gasotransmitters CO and H{sub 2}S. • H{sub 2}S reduced proliferation in HEK293 cells expressing the H{sub 2}S sensitive Cav3.2 channel. • H{sub 2}S also inhibited proliferation in non-transfected cells and HEK293 cells expressing Cav3.1. • Native smooth muscle cells primarily express Cav3.1. Their proliferation was also inhibited by H{sub 2}S. • Unlike CO, H{sub 2}S does not regulate smooth muscle proliferation via T-type Ca

  16. From O2 to H2S: a landscape view of gas biology.

    PubMed

    Kashiba, Misato; Kajimura, Mayumi; Goda, Nobuhito; Suematsu, Makoto

    2002-03-01

    The majority of molecular oxygen (O2) consumed in the body is used as a substrate of cytochrome c oxidase to maintain oxidative phosphorylation for ATP synthesis. Rest of the O2 is used for oxidative biosynthesis including synthesis of vasoactive substances such as prostaglandins and secondary gaseous mediators such as nitric oxide (NO) and carbon monoxide (CO). Thus, O2 is not only used for maintenance of energy supply but also for regulating blood supply into tissues. Nitrous oxide (N2O), laughing gas for anesthesia, is generated endogenously through NO reductase in bacteria and fungi, and has recently been shown to modulate N-methyl-D-aspartic acid (NMDA) receptor function. A number of other biologically active gases could participate in regulation of cell and tissue functions. Carbon dioxide (CO2) is generated mainly through the Krebs cycle as a result of glucose oxidation and serves as a potent vasodilator, and hydrogen sulfide (H2S) synthesized through degradation of cysteine has recently been postulated to be a neuromodulator, although their receptor proteins for signaling have not been verified as a discernible molecular entity. Easy penetration allow these gases to access the inner space of receptor proteins and to execute their biological actions. These gases are generated and consumed in anaerobic bacteria through varied reactions distinct from those in mammals. This review summarizes recent information on mechanisms for gas generation and reception in biological systems.

  17. Predicting possible effects of H2S impurity on CO2 transportation and geological storage.

    PubMed

    Ji, Xiaoyan; Zhu, Chen

    2013-01-02

    For CO(2) geological storage, permitting impurities, such as H(2)S, in CO(2) streams can lead to a great potential for capital and energy savings for CO(2) capture and separation, but it also increases costs and risk management for transportation and storage. To evaluate the cost-benefits, using a recently developed model (Ji, X.; Zhu, C. Geochim. Cosmochim. Acta 2012, 91, 40-59), this study predicts phase equilibria and thermodynamic properties of the system H(2)S-CO(2)-H(2)O-NaCl under transportation and storage conditions and discusses potential effects of H(2)S on transportation and storage. The prediction shows that inclusion of H(2)S in CO(2) streams may lead to two-phase flow. For H(2)S-CO(2) mixtures, at a given temperature, the bubble and dew pressures decrease with increasing H(2)S content, while the mass density increases at low pressures and decreases at high pressures. For the CO(2)-H(2)S-H(2)O system, the total gas solubility increases while the mass density of the aqueous solution with dissolved gas decreases. For the CO(2)-H(2)S-H(2)O-NaCl system, at a given temperature, pressure and NaCl concentration, the solubility of the gas mixture in aqueous phase increases with increasing H(2)S content and then decreases, while the mass density of aqueous solution decreases and may be lower than the mass density of the solution without gas dissolution.

  18. Gas-phase hydrogen atom abstraction reactions of S- with H2, CH4, and C2H6

    NASA Astrophysics Data System (ADS)

    Angel, Laurence A.; Dogbevia, Moses K.; Rempala, Katarzyna M.; Ervin, Kent M.

    2003-11-01

    Reaction cross sections, product axial velocity distributions, and potential energy surfaces are presented for the hydrogen atom abstraction reactions S-+RH→R+HS- (R=H, CH3, C2H5) as a function of collision energy. The observed threshold energy, E0, for S-+H2H+HS- agrees with the reaction endothermicity, ΔrH0. At low collision energies, the H+HS- products exhibit symmetric, low-recoil-velocity scattering, consistent with statistical reaction behavior. The S-+CH4→CH3+HS- and S-+C2H6→C2H5+HS reactions, in contrast, show large excess threshold energies when compared to ΔrH0. The excess energies are partly explained by a potential energy barrier separating products from reactants. However, additional dynamical constraints must account for more than half of the excess threshold energy. The observed behavior seems to be general for collisional activation of anion-molecule reactions that proceed through a tight, late transition state. For RH=CH4 and C2H6, the HS- velocity distributions show anisotropic backward scattering at low collision energies indicating small impact parameters and a direct rebound reaction mechanism. At higher collision energies, there is a transition to HS- forward scattering and high velocities consistent with grazing collisions and a stripping mechanism.

  19. Synthesis, spectroscopic investigation and theoretical studies of 2-((E)-(2-(2-cyanoacetyl)hydrazono)methyl)-4-((E)-phenyldiazenyl)phenyl methyl carbonate

    NASA Astrophysics Data System (ADS)

    Arokiasamy, A.; Manikandan, G.; Thanikachalam, V.; Gokula Krishnan, K.

    2017-04-01

    Synthesis and computational optimization studies have been carried out by Hartree-Fock (HF) and Density Functional Theory (DFT-B3LYP) methods with 6-31+G(d, p) basis set for 2-((E)-(2-(2-cyanoacetyl)hydrazono)methyl)-4-((E)-phenyldiazenyl)phenyl methyl carbonate (CHPMC). The stable configuration of CHPMC was confirmed theoretically by potential energy surface scan analysis. The complete vibrational assignments were performed on the basis of total energy distribution (TED) analysis. The vibrational properties studied by IR and Raman spectroscopic data complemented by quantum chemical calculations support the formation of intramolecular hydrogen bond. Furthermore, the UV-Vis spectra are interpreted in terms of TD-DFT quantum chemical calculations. The shapes of the simulated absorption spectra are in good agreement with the experimental data. The comparison between the experimental and theoretical values of FT-IR, FT-Raman vibrational spectra, NMR (1H and 13C) and UV-Vis spectra have also been discussed.

  20. Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca

    PubMed Central

    Bruns, Hilke; Riclea, Ramona

    2011-01-01

    Summary The volatiles released by Micromonospora aurantiaca were collected by means of a closed-loop stripping apparatus (CLSA) and analysed by GC–MS. The headspace extracts contained more than 90 compounds from different classes. Fatty acid methyl esters (FAMEs) comprised the major compound class including saturated unbranched, monomethyl and dimethyl branched FAMEs in diverse structural variants: Unbranched, α-branched, γ-branched, (ω−1)-branched, (ω−2)-branched, α- and (ω−1)-branched, γ- and (ω−1)-branched, γ- and (ω−2)-branched, and γ- and (ω−3)-branched FAMEs. FAMEs of the last three types have not been described from natural sources before. The structures for all FAMEs have been suggested based on their mass spectra and on a retention index increment system and verified by the synthesis of key reference compounds. In addition, the structures of two FAMEs, methyl 4,8-dimethyldodecanoate and the ethyl-branched compound methyl 8-ethyl-4-methyldodecanoate were deduced from their mass spectra. Feeding experiments with isotopically labelled [2H10]leucine, [2H10]isoleucine, [2H8]valine, [2H5]sodium propionate, and [methyl-2H3]methionine demonstrated that the responsible fatty acid synthase (FAS) can use different branched and unbranched starter units and is able to incorporate methylmalonyl-CoA elongation units for internal methyl branches in various chain positions, while the methyl ester function is derived from S-adenosyl methionine (SAM). PMID:22238549

  1. Experimental investigation on thermochemical sulfate reduction by H2S initiation

    USGS Publications Warehouse

    Zhang, T.; Amrani, A.; Ellis, G.S.; Ma, Q.; Tang, Y.

    2008-01-01

    Hydrogen sulfide (H2S) is known to catalyze thermochemical sulfate reduction (TSR) by hydrocarbons (HC), but the reaction mechanism remains unclear. To understand the mechanism of this catalytic reaction, a series of isothermal gold-tube hydrous pyrolysis experiments were conducted at 330 ??C for 24 h under a constant confining pressure of 24.1 MPa. The reactants used were saturated HC (sulfur-free) and CaSO4 in the presence of variable H2S partial pressures at three different pH conditions. The experimental results showed that the in-situ pH of the aqueous solution (herein, in-situ pH refers to the calculated pH of aqueous solution under the experimental conditions) can significantly affect the rate of the TSR reaction. A substantial increase in the TSR reaction rate was recorded with a decrease in the in-situ pH value of the aqueous solution involved. A positive correlation between the rate of TSR and the initial partial pressure of H2S occurred under acidic conditions (at pH ???3-3.5). However, sulfate reduction at pH ???5.0 was undetectable even at high initial H2S concentrations. To investigate whether the reaction of H2S(aq) and HSO4- occurs at pH ???3, an additional series of isothermal hydrous pyrolysis experiments was conducted with CaSO4 and variable H2S partial pressures in the absence of HC at the same experimental temperature and pressure conditions. CaSO4 reduction was not measurable in the absence of paraffin even with high H2S pressure and acidic conditions. These experimental observations indicate that the formation of organosulfur intermediates from H2S reacting with hydrocarbons may play a significant role in sulfate reduction under our experimental conditions rather than the formation of elemental sulfur from H2S reacting with sulfate as has been suggested previously (Toland W. G. (1960) Oxidation of organic compounds with aqueous sulphate. J. Am. Chem. Soc. 82, 1911-1916). Quantification of labile organosulfur compounds (LSC), such as thiols

  2. Synthesis and characterization of 3-acetoxy-2-methyl-N-(phenyl)benzamide and 3-acetoxy-2-methyl-N-(4- methylphenyl)benzamide

    NASA Astrophysics Data System (ADS)

    Kırca, Başak Koşar; Çakmak, Şükriye; Kütük, Halil; Odabaşoğlu, Mustafa; Büyükgüngör, Orhan

    2018-01-01

    This study treats about two successfully synthesized secondary amide compounds 3-Acetoxy-2-methyl-N-(phenyl)benzamide, I and 3-Acetoxy-2-methyl-N-(4-methylphenyl)benzamide, II. Compounds were characterized by FTIR, 1H NMR, 13C NMR and X-ray single crystal diffraction analysis techniques. Single crystal X-ray diffraction analyses show that while I crystallized in the orthorhombic system with space group Pbca, II crystallized in the triclinic system with space group P-1 and the asymmetric unit of II consists of two crystallographically independent molecules. Lattice constants are a = 7.9713 (3) Å, b = 9.5059 (3) Å, c = 37.1762 (2) Å, Z = 8 for I and a = 7.5579 (8) Å, b = 8.8601 (8) Å, c = 23.363 (3) Å, α = 97.011 (9) °, β = 96.932 (9)°, γ = 90.051 (8)°, Z = 4 for II. Crystallographic studies also show that the supramolecular structures were stabilized by intramolecular, intermolecular hydrogen bonds and Csbnd H … π interactions for both compounds. Characteristic amide bonds were observed in IR and NMR spectra.

  3. A study on an unusual SN2 mechanism in the methylation of benzyne through nickel-complexation.

    PubMed

    Hatakeyama, Makoto; Sakamoto, Yuki; Ogata, Koji; Sumida, Yuto; Sumida, Tomoe; Hosoya, Takamitsu; Nakamura, Shinichiro

    2017-10-11

    In this study, three reaction mechanisms of a benzyne-nickel (Ni) complex ([Ni(C 6 H 4 )(dcpe)]) with iodomethane during the methylation process were investigated, namely (a) S N 2 reaction of the benzyne-Ni complex with iodomethane, (b) concerted σ-bond metathesis during the bond breaking/forming processes, and (c) oxidative addition of iodomethane to the Ni-center and the subsequent reductive elimination process. DFT calculations revealed that the reaction barrier of the S N 2 reaction is slightly lower than those of the other mechanisms. The results of orbital analyses suggest that [Ni(C 6 H 4 )(dcpe)] forms a metallacycle structure between benzyne and the Ni II (3d 8 ) center instead of the η 2 -structure with the Ni 0 (3d 10 ) center. The metallacycle structures became inappropriate as the intermediates of oxidative addition in the formation of the Ni II -Me bond, avoiding further oxidation to the high-valent Ni IV . The high free energy along σ-bond metathesis was generated from the steric hindrance, thus invoking methylation and Ni-I bond formation concertedly.

  4. 5-Bromo-N-methyl­pyrimidin-2-amine

    PubMed Central

    Yang, Qi; Xu, Ning; Zhu, Kai; Lv, Xiaoping; Han, Ping-fang

    2012-01-01

    In the title mol­ecule, C5H6BrN3, the pyrimidine ring is essentially planar, with an r.m.s. deviation of 0.007 Å. The Br and N atoms substituted to the pyrimidine ring are coplanar with the ring [displacements = 0.032 (1) and 0.009 (5) Å, respectively], while the methyl C atom lies 0.100 (15) Å from this plane with a dihedral angle between the pyrimidine ring and the methyl­amine group of 4.5 (3)°. In the crystal, C—H⋯N, C—H⋯Br and N—H⋯N hydrogen bonds link the mol­ecules into a two-dimensional network in the (011) plane. PMID:22259398

  5. Quantum and quasiclassical dynamics of the multi-channel H + H2S reaction.

    PubMed

    Qi, Ji; Lu, Dandan; Song, Hongwei; Li, Jun; Yang, Minghui

    2017-03-28

    The prototypical multi-channel reaction H + H 2 SH 2 + SH/H + H 2 S has been investigated using the full-dimensional quantum scattering and quasi-classical trajectory methods to unveil the underlying competition mechanism between different product channels and the mode specificity. This reaction favors the abstraction channel over the exchange channel. For both channels, excitations in the two stretching modes promote the reaction with nearly equal efficiency and are more efficient than the bending mode excitation. However, they are all less efficient than the translational energy. In addition, the experimentally observed non-Arrhenius temperature dependence of the thermal rate constants is reasonably reproduced by the quantum dynamics calculations, confirming that the non-Arrhenius behavior is caused by the pronounced quantum tunneling.

  6. H2S: a universal defense against antibiotics in bacteria.

    PubMed

    Shatalin, Konstantin; Shatalina, Elena; Mironov, Alexander; Nudler, Evgeny

    2011-11-18

    Many prokaryotic species generate hydrogen sulfide (H(2)S) in their natural environments. However, the biochemistry and physiological role of this gas in nonsulfur bacteria remain largely unknown. Here we demonstrate that inactivation of putative cystathionine β-synthase, cystathionine γ-lyase, or 3-mercaptopyruvate sulfurtransferase in Bacillus anthracis, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli suppresses H(2)S production, rendering these pathogens highly sensitive to a multitude of antibiotics. Exogenous H(2)S suppresses this effect. Moreover, in bacteria that normally produce H(2)S and nitric oxide, these two gases act synergistically to sustain growth. The mechanism of gas-mediated antibiotic resistance relies on mitigation of oxidative stress imposed by antibiotics.

  7. Vibrational mode frequencies of H2S and H2O adsorbed on Ge(0 0 1)-(2 × 1) surfaces

    NASA Astrophysics Data System (ADS)

    Hartnett, M.; Fahy, S.

    2015-02-01

    The equilibrium geometry and vibrational modes of H2S and H2O-terminated Ge(0 0 1)-(2 × 1) surfaces are calculated in a supercell approach using first-principles density functional theory in the local density (LDA), generalized gradient (GGA) approximations and van der Waals (vdW) interactions. Mode frequencies are found using the frozen phonon method. For the H2S-passivated surface, the calculated frequencies in LDA (GGA) are 2429 cm-1 (2490) for the Hsbnd S stretch mode, 712 cm-1 (706) for the Hsbnd S bond bending mode, 377 cm-1 (36) for the Gesbnd S stretch mode and 328 cm-1 (337) for Hsbnd S wag mode. Frequencies for the H2O passivated surface are 3590 cm-1 (3600) for the Hsbnd O stretch mode, 921 cm-1 (947) for the bending mode, 609 cm-1 (559) for the Gesbnd O stretch, 1995 cm-1 (1991) for the Gesbnd H stretch mode, 498 cm-1 (478) for the Gesbnd H bending mode and 342 cm-1 (336) for the Hsbnd O wag mode. The differences between the functionals including vdW terms and the LDA or GGA are less than the differences between LDA and GGA for the vibrational mode frequencies.

  8. Metal Oxide/Zeolite Combination Absorbs H2S

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E.; Sharma, Pramod K.

    1989-01-01

    Mixed copper and molybdenum oxides supported in pores of zeolite found to remove H2S from mixture of gases rich in hydrogen and steam, at temperatures from 256 to 538 degree C. Absorber of H2S needed to clean up gas streams from fuel processors that incorporate high-temperature steam reformers or hydrodesulfurizing units. Zeolites chosen as supporting materials because of their high porosity, rigidity, alumina content, and variety of both composition and form.

  9. Synthesis and Mesomorphic Behavior of Poly((2S, 3S)-(+)-2-Chloro-3- Methylpentyl 4’-(Omega-Vinyloxyalkyloxy)biphenyl-4-Carboxylate)s with Ethyl and Propyl Alkyl Groups

    DTIC Science & Technology

    1994-06-30

    1 . Synthesis of (2S, 3S)-(+)-2-chloro-3-methyl-pentyl 4’-(2-vinyloxyethyloxy) biphenyl-4-carboxylate (15-2...CH2)2-),7.65 (d, 3=8.3Hz, 2 ArH, m to -COO-), 8.11 (d, J=7.4Hz, 2 ArH, o to -COO-). 3-Chloroprop~yl- 1 -vinyl ether (13-3) The mixture of 3- chloropropan ...VA .% fo - " A’* *i f’. - % .oL.,ae- a * 1 nOl-6..io. Ocw. ’•.1ý’ ..a.. :l•t :...•.t ;,,31 -. 1 " 1 . 2 . 10 1 -- Of , • l 0’ i’*J.. e t *no suaqetg

  10. Effects of mix ratio, moisture content and aeration rate on sulfur odor emissions during pig manure composting.

    PubMed

    Zang, Bing; Li, Shuyan; Michel, Frederick; Li, Guoxue; Luo, Yuan; Zhang, Difang; Li, Yangyang

    2016-10-01

    Sulfur compounds in swine manure can cause odor emissions during composting if conditions are not conducive to their rapid oxidation and degradation. In this study, the effects of controllable composting process variables on sulfur odor emissions were investigated. These included pig manure to corn stalk mix ratio (0.7:1, 1.5:1 and 2.2:1dw basis), initial moisture content (60%, 65%, 70% and 75%) and aeration rate (1.0, 2.0, 3.0 and 4.0m(3)m(-3)h(-1)). The compounds measured were carbonyl sulfide, carbon disulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, diethyl sulfide, dimethyl sulfide (Me2S) and dimethyl disulfide (Me2SS). The results showed that total sulfur losses ranged from 3.9% to 18.3% after 26days of composting. Me2S and Me2SS were the primary (>59.61%) sulfur compounds released during this period. After turning, emission rates of both Me2S and Me2SS increased. Emissions of the other six sulfur compounds were low and inconsistent during composting. Within the compost, feedstock mix ratio significantly influenced the concentration of Me2SS, while aeration rate significantly affected Me2S concentration (p<0.05). Moisture content did not have a significant effect on the concentrations of either of these two compounds. Concentrations of sulfur odor compounds were the lowest at the highest aeration rate. Therefore, high aeration rates during the thermophilic phase, especially after turning, are recommended to minimize sulfur odors produced during swine manure composting. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Methyl 2-methyl-4-(oxiran-2-ylmeth-oxy)-2H-1,2-benzothia-zine-3-carboxyl-ate 1,1-dioxide.

    PubMed

    Ahmad, Matloob; Siddiqui, Hamid Latif; Zia-Ur-Rehman, Muhammad; Elsegood, Mark R J; Weaver, George W

    2010-01-09

    In the title compound, C(14)H(15)NO(6)S, the thia-zine ring adopts a distorted half-chair conformation. The structure displays several cooperative weak inter-molecular C-H⋯O hydrogen-bonding inter-actions, giving rise to a two-dimensional sheet packing motif. The CH(2) group in the meth-oxy linker to the oxirane ring, and the CH group in that ring, exhibit twofold positional disorder. The three-membered oxirane ring is twisted approximately perpendicular with respect to thia-zine ring (dihedral angle = 60/86° for the major/minor disorder components). 1,2-Benzothia-zines of this kind have a wide range of biological activities and are mainly used as medicines in the treatment of inflammation and rheumatoid arthritis.

  12. Theoretical study of the regioselectivity of the interaction of 3-methyl-4-pyrimidone and 1-methyl-2-pyrimidone with Lewis acids.

    PubMed

    Kasende, Okuma Emile; Muya, Jules Tshishimbi; Broeckaert, Lies; Maes, Guido; Geerlings, Paul

    2012-08-23

    A density functional theory (DFT) study is performed to determine the stability of the complexes formed between either the N or O site of 3-methyl-4-pyrimidone and 1-methyl-2-pyrimidone molecules and different ligands. The studied ligands are boron and alkali Lewis acids, namely, B(CH(3))(3), HB(CH(3))(2), H(2)B(CH(3)), BH(3), H(2)BF, HBF(2), BF(3), Li(+), Na(+), and K(+). The acids are divided into two groups according to their hardness. The reactivity predictions, according to the molecular electrostatic potential (MEP) map and the natural bond orbital (NBO) analysis, are in agreement with the calculated relative stabilities. Our findings reveal a strong regioselectivity with borane and its derivatives preferring the nitrogen site in both pyrimidone isomers, while a preference for oxygen is observed for the alkali acids in the 3-methyl-4-pyrimidone molecule. The complexation of 1-methyl-2-pyrimidone with these hard alkali acids does not show any discrimination between the two sites due to the presence of a continuous delocalized density region between the nitrogen and the oxygen atoms. The preference of boron Lewis acids toward the N site is due to the stronger B-N bond as compared to the B-O bond. The influence of fluorine or methyl substitution on the boron atom is discussed through natural orbital analysis (NBO) concentrating on the overlap of the boron empty p-orbital with the F lone pairs and methyl hyperconjugation, respectively. The electrophilicity of the boron acids gives a good overall picture of the interaction capabilities with the Lewis base.

  13. 40 CFR 180.437 - Methyl 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-p-toluate and methyl 6-(4-isopropyl-4...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific... for the combined residues of the herbicide methyl 2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-p...

  14. The cocrystal rac-1-[(N,4-dimethylbenzenesulfonamido)methyl]-2-(diphenylphosphoryl)ferrocene-rac-1-[(N,4-dimethylbenzenesulfonamido)methyl]-2-(diphenylphosphanyl)ferrocene (0.45/0.55).

    PubMed

    Wei, Muh Mei; Audin, Catherine; Manoury, Eric; Deydier, Eric; Daran, Jean Claude

    2014-03-01

    As part of our interest in the synthesis and catalytic applications of chiral (diphenylphosphanyl)ferrocene ligands, we designed a number of P,N-containing ligands for use in asymmetric transfer hydrogenation (ATH). During the synthetic procedure to obtain rac-1-[(N,4-dimethylbenzenesulfonamido)methyl]-2-(diphenylphosphanyl)ferrocene, the title compound, [Fe(C5H5)(C26H25NO2PS)]0.55 · [Fe(C5H5)(C26H25NO3PS)]0.45, was obtained as a by-product. It is composed of a ferrocene group disubstituted by a partially oxidized diphenylphosphanyl group, as confirmed by (31)P NMR analysis, and an (N,4-dimethylbenzenesulfonamido)methyl substituent. Owing to the partially oxidized diphenylphosphanyl group, it is best to view the crystal as being composed of a mixture of non-oxidized and oxidized phosphane, so it can be regarded as a cocrystal. It is also a racemate. To the best of our knowledge, the P=O distance [1.344 (4) Å] is the shortest observed for related (diphenylphosphoryl)ferrocene compounds. The packing is stabilized by weak C-H...O interactions, forming R2(2)(10) hydrogen-bonding motifs, which build up a chain along the c axis.

  15. Stage 4S neuroblastoma tumors show a characteristic DNA methylation portrait

    PubMed Central

    Decock, Anneleen; Ongenaert, Maté; De Wilde, Bram; Brichard, Bénédicte; Noguera, Rosa; Speleman, Frank; Vandesompele, Jo

    2016-01-01

    ABSTRACT Stage 4S neuroblastoma (NB) is a special type of NB found in infants with metastases at diagnosis and is associated with an excellent outcome due to its remarkable capacity to undergo spontaneous regression. As genomics have not been able to explain this intriguing clinical presentation, we here aimed at profiling the DNA methylome of stage 4S NB to better understand this phenomenon. To this purpose, differential methylation analyses between International Neuroblastoma Staging System (INSS) stage 4S, stage 4 and stage 1/2 were performed, using methyl-CpG-binding domain (MBD) sequencing data of 14 stage 4S, 14 stage 4, and 13 stage 1/2 primary NB tumors (all MYCN non-amplified in order not to confound results). Stage 4S-specific hyper- and hypomethylated promoters were determined and further characterized for genomic localization and function by cytogenetic band enrichment, gene set enrichment, transcription factor target enrichment and differential RNA expression analyses. We show that specific chromosomal locations are enriched for stage 4S differentially methylated promoters and that stage 4S tumors show characteristic hypermethylation of specific subtelomeric promoters. Furthermore, genes involved in important oncogenic pathways, in neural crest development and differentiation, and in epigenetic processes are differentially methylated and expressed in stage 4S tumors. Based on these findings, we describe new biological mechanisms possibly contributing to the stage 4S-specific tumor biology and spontaneous regression. In conclusion, this study is the first to describe the highly characteristic stage 4S DNA methylome. These findings will open new avenues to further unravel the NB pathology in general and stage 4S disease specifically. PMID:27599161

  16. 40 CFR 180.1065 - 2-Amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the requirement of a tolerance. 180.1065...-Amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the requirement of a tolerance. The inert ingredient, 2-amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha...

  17. 40 CFR 180.1065 - 2-Amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the requirement of a tolerance. 180.1065...-Amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the requirement of a tolerance. The inert ingredient, 2-amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha...

  18. 40 CFR 180.1065 - 2-Amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the requirement of a tolerance. 180.1065...-Amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the requirement of a tolerance. The inert ingredient, 2-amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha...

  19. 40 CFR 180.1065 - 2-Amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the requirement of a tolerance. 180.1065...-Amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the requirement of a tolerance. The inert ingredient, 2-amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha...

  20. 40 CFR 180.1065 - 2-Amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the requirement of a tolerance. 180.1065...-Amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha)pyrimidin-5-one; exemption from the requirement of a tolerance. The inert ingredient, 2-amino-4,5-dihydro-6-methyl-4-propyl-s-triazolo(1,5-alpha...

  1. Viral genome methylation as an epigenetic defense against geminiviruses.

    PubMed

    Raja, Priya; Sanville, Bradley C; Buchmann, R Cody; Bisaro, David M

    2008-09-01

    Geminiviruses encapsidate single-stranded DNA genomes that replicate in plant cell nuclei through double-stranded DNA intermediates that associate with cellular histone proteins to form minichromosomes. Like most plant viruses, geminiviruses are targeted by RNA silencing and encode suppressor proteins such as AL2 and L2 to counter this defense. These related proteins can suppress silencing by multiple mechanisms, one of which involves interacting with and inhibiting adenosine kinase (ADK), a cellular enzyme associated with the methyl cycle that generates S-adenosyl-methionine, an essential methyltransferase cofactor. Thus, we hypothesized that the viral genome is targeted by small-RNA-directed methylation. Here, we show that Arabidopsis plants with mutations in genes encoding cytosine or histone H3 lysine 9 (H3K9) methyltransferases, RNA-directed methylation pathway components, or ADK are hypersensitive to geminivirus infection. We also demonstrate that viral DNA and associated histone H3 are methylated in infected plants and that cytosine methylation levels are significantly reduced in viral DNA isolated from methylation-deficient mutants. Finally, we demonstrate that Beet curly top virus L2- mutant DNA present in tissues that have recovered from infection is hypermethylated and that host recovery requires AGO4, a component of the RNA-directed methylation pathway. We propose that plants use chromatin methylation as a defense against DNA viruses, which geminiviruses counter by inhibiting global methylation. In addition, our results establish that geminiviruses can be useful models for genome methylation in plants and suggest that there are redundant pathways leading to cytosine methylation.

  2. Xenobiotic metal-induced autoimmunity: mercury and silver differentially induce antinucleolar autoantibody production in susceptible H-2s, H-2q and H-2f mice

    PubMed Central

    Hansson, M; Abedi-Valugerdi, M

    2003-01-01

    Xenobiotic-metals such as mercury (Hg) and silver (Ag) induce an H-2 linked antinucleolar autoantibody (ANolA) production in susceptible mice. The mechanism for induction of ANolA synthesis is not well understood. However, it has been suggested that both metals interact with nucleolar proteins and reveal cryptic self-peptides to nontolerant autoreactive T cells, which in turn stimulate specific autoreactive B cells. In this study, we considered this suggestion and asked if mercury and silver display, if not identical, similar cryptic self-peptides, they would induce comparable ANolA responses in H-2 susceptible mice. We analysed the development of ANolA production in mercury- and/or silver-treated mice of H-2s, H-2q and H-2f genotypes. We found that while mercury stimulated ANolA synthesis in all strains tested, silver induced ANolA responses of lower magnitudes in only H-2s and H-2q mice, but not in H-2f mice. Resistance to silver in H-2f mice was independent of the dosage/time-period of silver-treatment and non-H-2 genes. Further studies showed that F1 hybrid crosses between silver-susceptible A.SW (H-2s) and -resistant A.CA (H-2f) mice were resistant to silver, but not mercury with regard to ANolA production. Additionally, the magnitudes of mercury-induced ANolA responses in the F1 hybrids were lower than those of their parental strains. The above differential ANolA responses to mercury and silver can be explained by various factors, including the different display of nucleolar cryptic peptides by these xenobiotics, determinant capture and coexistence of different MHC molecules. Our findings also suggest that the ability of a xenobiotic metal merely to create cryptic self-peptides may not be sufficient for the induction of an ANolA response. PMID:12605692

  3. (7-Chloro-2-oxo-2H-chromen-4-yl)methyl pyrrolidine-1-carbodi­thio­ate

    PubMed Central

    Kotresh, O.; Devarajegowda, H. C.; Shirahatti, Arunkumar; Kumar, K. Mahesh; Mahabhaleshwaraiah, N. M.

    2013-01-01

    In the title compound, C15H14ClNO2S2, the 2H-chromene ring system is essentially planar, with a maximum deviation of 0.0133 (10) Å. Three C atoms and their attached H atoms of the pyrrolidine ring are disordered [occupany ratio 0.874 (7):0.126 (7)] with both disorder components adopting a twisted conformation. The dihedral angle between the 2H-chromene ring system and the major occupancy component of the pyrrolidine ring is 89.45 (7)°. In the crystal, inversion dimers linked by pairs of C—H⋯S and C—H⋯O inter­actions generate R 2 2(24) and R 2 2(10) loops, respectively. Further C—H⋯O hydrogen bonds link the dimers into [100] chains. C—H⋯π inter­actions also occur and there is very weak π–π stacking [inter­planar spacing = 3.650 (5) Å; centroid–centroid distance = 4.095 (7) Å] between inversion-related chloro­benzene rings. PMID:24454115

  4. Intricate Effects of α-Amino and Lysine Modifications on Arginine Methylation of the N-Terminal Tail of Histone H4.

    PubMed

    Fulton, Melody D; Zhang, Jing; He, Maomao; Ho, Meng-Chiao; Zheng, Y George

    2017-07-18

    Chemical modifications of the DNA and nucleosomal histones tightly control the gene transcription program in eukaryotic cells. The "histone code" hypothesis proposes that the frequency, combination, and location of post-translational modifications (PTMs) of the core histones compose a complex network of epigenetic regulation. Currently, there are at least 23 different types and >450 histone PTMs that have been discovered, and the PTMs of lysine and arginine residues account for a crucial part of the histone code. Although significant progress has been achieved in recent years, the molecular basis for the histone code is far from being fully understood. In this study, we investigated how naturally occurring N-terminal acetylation and PTMs of histone H4 lysine-5 (H4K5) affect arginine-3 methylation catalyzed by both type I and type II PRMTs at the biochemical level. Our studies found that acylations of H4K5 resulted in decreased levels of arginine methylation by PRMT1, PRMT3, and PRMT8. In contrast, PRMT5 exhibits an increased rate of arginine methylation upon H4K5 acetylation, propionylation, and crotonylation, but not upon H4K5 methylation, butyrylation, or 2-hydroxyisobutyrylation. Methylation of H4K5 did not affect arginine methylation by PRMT1 or PRMT5. There was a small increase in the rate of arginine methylation by PRMT8. Strikingly, a marked increase in the rate of arginine methylation was observed for PRMT3. Finally, N-terminal acetylation reduced the rate of arginine methylation by PRMT3 but had little influence on PRMT1, -5, and -8 activity. These results together highlight the underlying mechanistic differences in substrate recognition among different PRMTs and pave the way for the elucidation of the complex interplay of histone modifications.

  5. Thermal Decomposition of Potential Ester Biofuels. Part I: Methyl Acetate and Methyl Butanoate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Porterfield, Jessica P.; Bross, David H.; Ruscic, Branko

    2017-06-09

    Two methyl esters have been examined as models for the pyrolysis of biofuels. Dilute samples (0.06 - 0.13%) of methyl acetate (CH 3COOCH 3) and methyl butanoate (CH 3CH 2CH 2COOCH 3) were entrained in (He, Ar) carrier gas and decomposed in a set of flash-pyrolysis micro-reactors. The pyrolysis products resulting from the methyl esters were detected and identified by vacuum ultraviolet photoionization mass spectrometry. Complementary product identification was provided by matrix infrared absorption spectroscopy. Pyrolysis pressures in the pulsed micro-reactor were roughly 20 Torr and residence times through the reactors were approximately 25 - 150 µs. Reactor temperatures ofmore » 300 – 1600 K were explored. Decomposition of CH 3COOCH 3 commences at 1000 K and the initial products are (CH 2=C=O and CH 3OH). As the micro-reactor is heated to 1300 K, a mixture of (CH 2=C=O and CH 3OH, CH 3, CH 2=O, H, CO, CO 2) appears. The thermal cracking of CH 3CH 2CH 2COOCH 3 begins at 800 K with the formation of (CH 3CH 2CH=C=O, CH 3OH). By 1300 K, the pyrolysis of methyl butanoate yields a complex mixture of (CH 3CH 2CH=C=O, CH 3OH, CH 3, CH 2=O, CO, CO 2, CH 3CH=CH 2, CH 2CHCH 2, CH 2=C=CH 2, HCCCH 2, CH 2=C=C=O, CH 2=CH 2, HCΞCH, CH 2=C=O). Based on the results from the thermal cracking of methyl acetate and methyl butanoate, we predict several important decomposition channels for the pyrolysis of fatty acid methyl esters, R CH 2-COOCH 3. The lowest energy fragmentation will be a 4-center elimination of methanol to form the ketene, RCH=C=O. At higher temperatures, concerted fragmentation to radicals will ensue to produce a mixture of species: (RCH 2 + CO 2 + CH 3) and (RCH 2 + CO + CH 2=O + H). Thermal cracking of the β C-C bond of the methyl ester will generate the radicals (R and H) as well as CH 2=C=O + CH 2=O. The thermochemistry of methyl acetate and its fragmentation products have been obtained via the Active Thermochemical Tables (ATcT) approach, resulting in

  6. Methyl 4-eth­oxy-2-methyl-2H-1,2-benzothia­zine-3-carboxyl­ate 1,1-dioxide

    PubMed Central

    Zia-ur-Rehman, Muhammad; Choudary, Jamil Anwar; Elsegood, Mark R. J.; Akbar, Noshin; Latif Siddiqui, Hamid

    2008-01-01

    In the crystal structure of the title compound, C13H15NO5S, the mol­ecules exhibit weak S=O⋯H—C and C=O⋯H—C inter­molecular inter­actions and arrange themselves into centrosymmetric dimers by means of π–π inter­actions (ring centroids are separated by 3.619 Å, while the closest C⋯C contacts are 3.514 Å). 1,2-Benzothia­zines of this kind have a range of biological activities and are used as medicines in the treatment of inflammation and rheumatoid arthritis. PMID:21203217

  7. H2S-mediated thermal and photochemical methane activation.

    PubMed

    Baltrusaitis, Jonas; de Graaf, Coen; Broer, Ria; Patterson, Eric V

    2013-12-02

    Sustainable, low-temperature methods for natural gas activation are critical in addressing current and foreseeable energy and hydrocarbon feedstock needs. Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) mixed with methane, deemed altogether as sub-quality or "sour" gas. We propose a unique method of activation to form a mixture of sulfur-containing hydrocarbon intermediates, CH3SH and CH3SCH3 , and an energy carrier such as H2. For this purpose, we investigated the H2S-mediated methane activation to form a reactive CH3SH species by means of direct photolysis of sub-quality natural gas. Photoexcitation of hydrogen sulfide in the CH4 + H2S complex resulted in a barrierless relaxation by a conical intersection to form a ground-state CH3SH + H2 complex. The resulting CH3SH could further be coupled over acidic catalysts to form higher hydrocarbons, and the resulting H2 used as a fuel. This process is very different from conventional thermal or radical-based processes and can be driven photolytically at low temperatures, with enhanced control over the conditions currently used in industrial oxidative natural gas activation. Finally, the proposed process is CO2 neutral, as opposed to the current industrial steam methane reforming (SMR). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A novel non-SET domain multi-subunit methyltransferase required for sequential nucleosomal histone H3 methylation by the mixed lineage leukemia protein-1 (MLL1) core complex.

    PubMed

    Patel, Anamika; Vought, Valarie E; Dharmarajan, Venkatasubramanian; Cosgrove, Michael S

    2011-02-04

    Gene expression within the context of eukaryotic chromatin is regulated by enzymes that catalyze histone lysine methylation. Histone lysine methyltransferases that have been identified to date possess the evolutionarily conserved SET or Dot1-like domains. We previously reported the identification of a new multi-subunit histone H3 lysine 4 methyltransferase lacking homology to the SET or Dot1 family of histone lysine methyltransferases. This enzymatic activity requires a complex that includes WRAD (WDR5, RbBP5, Ash2L, and DPY-30), a complex that is part of the MLL1 (mixed lineage leukemia protein-1) core complex but that also exists independently of MLL1 in the cell. Here, we report that the minimal complex required for WRAD enzymatic activity includes WDR5, RbBP5, and Ash2L and that DPY-30, although not required for enzymatic activity, increases the histone substrate specificity of the WRAD complex. We also show that WRAD requires zinc for catalytic activity, displays Michaelis-Menten kinetics, and is inhibited by S-adenosyl-homocysteine. In addition, we demonstrate that WRAD preferentially methylates lysine 4 of histone H3 within the context of the H3/H4 tetramer but does not methylate nucleosomal histone H3 on its own. In contrast, we find that MLL1 and WRAD are required for nucleosomal histone H3 methylation, and we provide evidence suggesting that each plays distinct structural and catalytic roles in the recognition and methylation of a nucleosome substrate. Our results indicate that WRAD is a new H3K4 methyltransferase with functions that include regulating the substrate and product specificities of the MLL1 core complex.

  9. Synthesis and spectral studies of some 4H-pyran derivatives: Crystal and molecular structure of isobutyl 6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate

    NASA Astrophysics Data System (ADS)

    Udhaya Kumar, C.; Sethukumar, A.; Arul Prakasam, B.

    2013-03-01

    A series of isobutyl 6-amino-4-aryl-5-cyano-2-methyl-4H-pyran-3-carboxylates (1-9) have been synthesized by the multicomponent reaction (MCR) between isobutyl ethylacetoacetate, aryl aldehydes and malononitrile using BF3:OEt2 as catalyst. The derived compounds have been analyzed by IR and NMR (1D and 2D) spectra. Single crystal X-ray structural analysis of 1, evidences the flattened-boat conformation of pyran ring.

  10. Catalytic activity of Cu4-cluster to adsorb H2S gas: h-BN nanosheet

    NASA Astrophysics Data System (ADS)

    Kansara, Shivam; Gupta, Sanjeev K.; Sonvane, Yogesh

    2018-05-01

    We have investigated the electronic properties, adsorptions strength and charge transfer using first principles calculations using density functional theory (DFT). The hexagonal boron nitride (h-BN) substrate shows metallic behavior, which helps to enhance the absorption process. The adsorption of three different orientations (S, D and T) of the H2S gas molecules to analyze the maximum adsorption strength from them onto a copper cluster (Cu4) based on h-BN nanosheet. The maximum adsorption energy of the H2S gas molecule is -1.50 eV for the S orientation and for D and U, it is -0.71 eV and -0.78 eV, respectively. The results show that Cu4 cluster helps to capture H2S gas from the environment and results are useful for the cleaning environment from the toxic gases.

  11. Liquid chromatographic determination of 9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one in human plasma with fluorescence detection.

    PubMed

    Cheng, H; Pittman, K A; Dandekar, K A

    1987-12-01

    A simple and sensitive assay for quantitating 9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one (1; BMY 26517) in human plasma was developed using high-performance liquid chromatography with fluorescence detection. The method involves precipitation of protein and reversed-phase chromatography. The method is linear in the range of 4.3-429 ng/mL of 1, and the limit of detection is 0.4 ng/mL. The day-to-day precision values of this method at 25.7 and 386 ng/mL are 2.1 and 2.6%, respectively. The day-to-day accuracy values at these concentrations are 99.7 and 99.8%, respectively. The recovery of 1 is 98.3%.

  12. H2S Loss through Nalophan™ Bags: Contributions of Adsorption and Diffusion

    PubMed Central

    2017-01-01

    Hydrogen-sulfide (H2S) is a molecule of small dimensions typically present in the odor emissions from different plants. The European Standard EN 13725:2003 set a maximum storage time allowed of 30 hours, during which the sampling bag has to maintain the mixture of odorants with minimal changes. This study investigates the H2S losses through Nalophan bags and it shows that nonnegligible losses of H2S can be observed. The percent H2S loss after 30 hrs with respect to the initial concentration is equal to 33%  ± 3% at a relative humidity of 20% and equal to 22%  ± 1% at a relative humidity of 60%. The average quantity of adsorbed H2S at 30 h is equal to 2.17 105 gH2S/gNalophan at a storage humidity of 20% and equal to 1.79 105 gH2S/gNalophan at a storage humidity of 60%. The diffusion coefficients of H2S through Nalophan, for these two humidity conditions tested, are comparable (i.e., 7.5 10−12 m2/sec at 20% humidity and 6.6 10−12 m2/sec at 60% humidity). PMID:28740857

  13. Synthesis and biological evaluation of 3-methyl-5-phenylthieno[2,3-d]pyrimidine-2,4(1H,3H)-dione derivatives for the treatment of diet-induced obesity.

    PubMed

    Sang, Yun; Pei, Heyin; Ma, Liang; Huang, Li; Xie, Caifeng; Chen, Jinying; Liang, Xiaolin; Ran, Yan; Wang, Guangcheng; Yang, Zhuang; Cao, Dong; He, Lin; Wu, Yuzhe; He, Linhong; Zhu, Jun; Lan, Jingbo; Chen, Lijuan

    2014-01-01

    Triglycerides are the main part of fats and half of the lipids in hepatocytes, and play an important role in metabolism as energy sources and transporters of dietary fat. In this study, 33 derivatives based on 3-methyl-5-phenylthieno[2,3-d]pyrimidine-2,4(1H,3H)-dione were synthesized and evaluated for their lipid-lowering activity. Among them, compound 1i was found to exhibit potent triglyceride-lowering potency in 3T3-L1 adipocytes which was comparable to that of the adenosine monophosphate-activated protein kinase (AMPK) agonist Acadesine (AIACR). Furthermore, oral administration of 1i at a dose of 50 mg kg(-1) d(-1) for 5 weeks could reduce the mean body weight and liver weight by 12.02% and 32.00%, respectively, and regulated serum levels of triglycerides in diet-induced obese mice. The results indicate that compound 1i is a potential small-molecule for the treatment of diet-induced obesity and related diseases.

  14. Visible light-driven photocatalytic H{sub 2}-generation activity of CuS/ZnS composite particles

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xiao, Liang; Chen, Hua; Huang, Jianhua, E-mail: jhhuang@zstu.edu.cn

    2015-04-15

    Highlights: • Preparation of CuS/ZnS composite photocatalyst by cation-exchange reaction. • Visible light photocatalytic activity for H{sub 2} evolution without cocatalyst. • The H{sub 2}-evolution rate from water splitting depends on the CuS content. • The highest rate of H{sub 2} evolution is obtained with CuS (0.5 mol%)/ZnS composite. - Abstract: CuS/ZnS composite particles with diameter of 200–400 nm were successfully prepared by a simple cation-exchange reaction using ZnS spheres as a precursor. CuS nanoparticles with a few nanometers in diameter were observed on the surface of composite particles. The synthesized CuS/ZnS composite particles showed photocatalytic property effective for H{submore » 2} evolution from an aqueous Na{sub 2}S and Na{sub 2}SO{sub 3} solution under visible light irradiation without any cocatalysts. The rate of H{sub 2} generation was found to be strongly dependent on the CuS content. The highest rate of H{sub 2} evolution reached 695.7 μmol h{sup −1} g{sup −1}, which was almost 7 times as high as that of the mechanical mixture of CuS and ZnS. The enhancement in the photocatalytic activity of CuS/ZnS composite particles is supposed to be due to the direct interfacial charge transfer of the CuS/ZnS heterojunction.« less

  15. Measuring urinary N-acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-L-cysteine (IPMA3) as a potential biomarker of isoprene exposure.

    PubMed

    Alwis, K Udeni; Bailey, T Liz; Patel, Dhrusti; Wang, Liqun; Blount, Benjamin C

    2016-10-19

    Isoprene, the 2-methyl analog of 1,3-butadiene, is identified as a possible human carcinogen by the International Agency for Research on Cancer (IARC). Isoprene is ubiquitous in the environment with numerous natural and anthropogenic sources. Tobacco smoke is the main exogenous source of isoprene exposure in indoor environments. Among smoke constituents, isoprene is thought to contribute significantly to cancer risk; however, no selective urinary biomarkers of isoprene exposure have been identified for humans. In this manuscript, we measured the minor isoprene metabolite IPMA1 (mixture of N-acetyl-S-(1-[hydroxymethyl]-2-methyl-2-propen-1-yl)-L-cysteine and N-acetyl-S-(2-hydroxy-3-methyl-3-buten-1-yl)-L-cysteine), and we identified IPMA3 (N-acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-L-cysteine) as a major isoprene metabolite and novel isoprene exposure biomarker for humans. Urinary isoprene metabolites were measured using ultra high performance liquid chromatography coupled with electrospray ionization triple quad tandem mass spectrometry (UPLC/ESI-MSMS). The detection rates of IPMA1 and IPMA3 are <20% and 82%, respectively. The selectivity and abundance of IPMA3 make it a useful urinary biomarker of isoprene exposure. The limit of detection of IPMA3 in urine was 0.5 ng mL -1 . IPMA3 was stable under different storage temperatures and following ten freeze-thaw cycles. The average recovery of urine spiked with IPMA3 at three different levels was 99%. IPMA3 was measured in urine samples received from 75 anonymous subjects; the median (25th percentile, 75th percentile) IPMA3 level in smokers was 36.2 (18.2, 56.8) ng mL -1 and non-smokers 2.31 (2.31, 4.38) ng mL -1 . Application of this method to large population studies will help to characterize isoprene exposure and assess potential health impact. Published by Elsevier B.V.

  16. Poisoning of Ni-Based anode for proton conducting SOFC by H2S, CO2, and H2O as fuel contaminants

    NASA Astrophysics Data System (ADS)

    Sun, Shichen; Awadallah, Osama; Cheng, Zhe

    2018-02-01

    It is well known that conventional solid oxide fuel cells (SOFCs) based on oxide ion conducting electrolyte (e.g., yttria-stabilized zirconia, YSZ) and nickel (Ni) - ceramic cermet anodes are susceptible to poisoning by trace amount of hydrogen sulfide (H2S) while not significantly impacted by the presence of carbon dioxide (CO2) and moisture (H2O) in the fuel stream unless under extreme operating conditions. In comparison, the impacts of H2S, CO2, and H2O on proton-conducting SOFCs remain largely unexplored. This study aims at revealing the poisoning behaviors caused by H2S, CO2, and H2O for proton-conducting SOFCs. Anode-supported proton-conducting SOFCs with BaZe0.1Ce0.7Y0.1Yb0.1O3 (BZCYYb) electrolyte and Ni-BZCYYb anode and La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) cathode as well as Ni-BZCYYb/BZCYYb/Ni-BZCYYb anode symmetrical cells were subjected to low ppm-level H2S or low percentage-level CO2 or H2O in the hydrogen fuel, and the responses in cell electrochemical behaviors were recorded. The results suggest that, contrary to conventional SOFCs that show sulfur poisoning and CO2 and H2O tolerance, such proton-conducting SOFCs with Ni-BZCYYb cermet anode seem to be poisoned by all three types of "contaminants". Beyond that, the implications of the experimental observations on understanding the fundamental mechanism of anode hydrogen electrochemical oxidation reaction in proton conducting SOFCs are also discussed.

  17. Fabrication of poly(methyl methacrylate)-MoS{sub 2}/graphene heterostructure for memory device application

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shinde, Sachin M.; Tanemura, Masaki; Kalita, Golap, E-mail: kalita.golap@nitech.ac.jp

    2014-12-07

    Combination of two dimensional graphene and semi-conducting molybdenum disulfide (MoS{sub 2}) is of great interest for various electronic device applications. Here, we demonstrate fabrication of a hybridized structure with the chemical vapor deposited graphene and MoS{sub 2} crystals to configure a memory device. Elongated hexagonal and rhombus shaped MoS{sub 2} crystals are synthesized by sulfurization of thermally evaporated molybdenum oxide (MoO{sub 3}) thin film. Scanning transmission electron microscope studies reveal atomic level structure of the synthesized high quality MoS{sub 2} crystals. In the prospect of a memory device fabrication, poly(methyl methacrylate) (PMMA) is used as an insulating dielectric material asmore » well as a supporting layer to transfer the MoS{sub 2} crystals. In the fabricated device, PMMA-MoS{sub 2} and graphene layers act as the functional and electrode materials, respectively. Distinctive bistable electrical switching and nonvolatile rewritable memory effect is observed in the fabricated PMMA-MoS{sub 2}/graphene heterostructure. The developed material system and demonstrated memory device fabrication can be significant for next generation data storage applications.« less

  18. H2S mediated thermal and photochemical methane activation

    PubMed Central

    Baltrusaitis, Jonas; de Graaf, Coen; Broer, Ria; Patterson, Eric

    2013-01-01

    Sustainable, low temperature methods of natural gas activation are critical in addressing current and foreseeable energy and hydrocarbon feedstock needs. Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) in mixture with methane, CH4, altogether deemed as sub-quality or “sour” gas. We propose a unique method for activating this “sour” gas to form a mixture of sulfur-containing hydrocarbon intermediates, CH3SH and CH3SCH3, and an energy carrier, such as H2. For this purpose, we computationally investigated H2S mediated methane activation to form a reactive CH3SH species via direct photolysis of sub-quality natural gas. Photoexcitation of hydrogen sulfide in the CH4+H2S complex results in a barrier-less relaxation via a conical intersection to form a ground state CH3SH+H2 complex. The resulting CH3SH can further be heterogeneously coupled over acidic catalysts to form higher hydrocarbons while the H2 can be used as a fuel. This process is very different from a conventional thermal or radical-based processes and can be driven photolytically at low temperatures, with enhanced controllability over the process conditions currently used in industrial oxidative natural gas activation. Finally, the proposed process is CO2 neutral, as opposed to the currently industrially used methane steam reforming (SMR). PMID:24150813

  19. Specific IgE to peanut 2S albumin Ara h 7 has a discriminative ability comparable to Ara h 2 and 6.

    PubMed

    Blankestijn, M A; Otten, H G; Suer, W; Weimann, A; Knol, E F; Knulst, A C

    2018-01-01

    Little is known on the clinical relevance of peanut 2S albumin Ara h 7. To investigate the discriminative ability of Ara h 7 in peanut allergy and assess the role of cross-reactivity between Ara h 2, 6 and Ara h 7 isoforms. Sensitization to recombinant peanut storage proteins Ara h 1, 2, 3, 6, and 7 was assessed using a line blot in sera from 40 peanut-tolerant and 40 peanut-allergic patients, based on food challenge outcome. A dose-dependent ELISA inhibition experiment was performed with recombinant Ara h 2, 6 and Ara h 7 isoforms. For Ara h 7.0201, an area under the ROC curve was found of 0.83, comparable to Ara h 2 (AUC 0.81) and Ara h 6 (AUC 0.85). Ara h 7 intensity values strongly correlated with those from Ara h 2 and 6 (r s = 0.81). Of all patients sensitized to 2S albumins Ara h 2, 6, or 7, the majority was co-sensitized to all three (n = 24, 68%), although mono-sensitization to either 2S albumin was also observed in selected patients (Ara h 2: n = 6, 17%; Ara h 6: n = 2, 6%; Ara h 7: n = 2, 6%). Binding to Ara h 7.0101 could be strongly inhibited by Ara h 7.0201, but not the other way around. Specific IgE against Ara h 7.0201 has a predictive ability for peanut allergy similar to Ara h 2 and 6 and possesses unique IgE epitopes as well as epitopes shared between the other Ara h 7 isoform and Ara h 2 and 6. While co-sensitization to all three 2S albumins is most common, mono-sensitization to either Ara h 2, 6, or 7 occurs in selected patients, leading to a risk of misdiagnosis when testing for a single 2S albumin. © 2017 John Wiley & Sons Ltd.

  20. 13C and 1H nuclear magnetic resonance of methyl-substituted acetophenones and methyl benzoates: steric hindrance and inhibited conjugation.

    PubMed

    Budesínský, Milos; Kulhánek, Jirí; Böhm, Stanislav; Cigler, Petr; Exner, Otto

    2004-10-01

    The 1H and 13C NMR spectra of 14 methyl-substituted acetophenones and 14 methyl-substituted methyl benzoates were assigned and interpreted with respect to the conformation of the C(ar)-C(O) bond. The substituent effects are proportional in the two series and can be divided into polar and steric: each has different effects on the 13C SCS of the individual atoms. In the case of C atoms C(O), C(1) and CH3(CO), the steric effects were quantitatively separated by comparing SCS in the ortho and para positions. The steric effects are proportional for the individual C atoms and also to steric effects estimated from other physical quantities. However, they do not depend simply on the angle of torsion phi of the functional group as anticipated hitherto. A better description distinguishes two classes of compounds: sterically not hindered or slightly hindered planar molecules and strongly sterically hindered, markedly non-planar. In order to confirm this reasoning without empirical correlations, the J(C,C) coupling constants were measured for three acetophenone derivatives labeled with 13C in the acetyl methyl group. The constants confirm unambiguously the conformation of 2-methylacetophenone; their zero values are in accord with the conformation of 2,6-dimethylacetophenone. The zero values in the unsubstituted acetophenone are at variance with previous erroneous report but all J(C,C) values are in accord with calculations at the B3LYP/6-311++G(2d,2p)//B3LYP/6-311+G(d,p) level. Copyright 2004 John Wiley & Sons, Ltd.

  1. Metsulfuron-methyl sorption/desorption behavior on volcanic ash-derived soils. effect of phosphate and pH.

    PubMed

    Cáceres, Lizethly; Fuentes, Roxana; Escudey, Mauricio; Fuentes, Edwar; Báez, María E

    2010-06-09

    Metsulfuron-methyl sorption/desorption behavior was studied through batch sorption experiments in three typical volcanic ash-derived soils belonging to Andisol and Ultisol orders. Their distinctive physical and chemical properties are acidic pH and variable surface charge. Organic matter content and mineral composition affected in different ways sorption of metsulfuron-methyl (K(OC) ranging from 113 to 646 mL g(-1)): organic matter and iron and aluminum oxides mainly through hydrophilic rather than hydrophobic interactions in Andisols, and Kaolinite group minerals, as major constituents of Ultisols, and iron and aluminum oxides only through hydrophilic interactions. The Freundlich model described metsulfuron-methyl behavior in all cases (R(2) > 0.992). K(f) values (3.1-14.4 microg(1-1/n) mL(1/n) g(-1)) were higher than those reported for different class of soils including some with variable charge. Hysteresis was more significant in Ultisols. A strong influence of pH and phosphate was established for both kinds of soil, intensive soil fertilization and liming being the most probable scenario for leaching of metsulfuron-methyl, particularly in Ultisols.

  2. N-(3-azidophenyl)-N-methyl-N'-([4-1H]- and [4-3H]-1-naphthyl)guanidine. A potent and selective ligand designed as a photoaffinity label for the phencyclidine site of the N-methyl-D-aspartate receptor.

    PubMed

    Gee, K R; Durant, G J; Holmes, D L; Magar, S S; Weber, E; Wong, S T; Keana, J F

    1993-01-01

    A novel radiolabeled photoaffinity ligand has been synthesized for the phencyclidine (PCP) site of the N-methyl-D-aspartate (NMDA) receptor. N-(3-Azidophenyl)-N-methyl-N'-([4-3H]-1-naphthyl)guanidine (13) was prepared with a specific activity of 25 Ci/mmol by diazotization of N-(3-aminophenyl)-N-methyl-N'-([4-3H]-1-naphthyl)guanidine (12) followed by treatment with sodium azide. Guanidine 12 was obtained by catalytic tritiation of N-(4-bromo-1-naphthyl)-N'-methyl-N'-(3-nitrophenyl)guanidine (11). The nontritiated analog 5 of 13 was prepared beginning with N-methyl-N'-1-naphthyl-N-(3-nitrophenyl)guanidine (9). The guanidines 9 and 11 were prepared in moderate yield by the aluminum chloride-catalyzed reaction of N-methyl-3-nitroaniline hydrochloride with 1-naphthylcyanamide and 4-bromo-1-naphthylcyanamide, respectively. Azide 5 showed high selectivity and affinity (IC50 = 100 nM vs [3H]MK801; 3000 nM vs [3H]ditolylguanidine) for the PCP site of the NMDA receptor in guinea pig brain homogenate. Photolabeling experiments with 13, however, failed to radiolabel a significant amount of receptor polypeptide.

  3. KSHV encoded ORF59 modulates histone arginine methylation of the viral genome to promote viral reactivation

    PubMed Central

    McDowell-Sargent, Maria; Uppal, Timsy; Purushothaman, Pravinkumar

    2017-01-01

    Kaposi’s sarcoma associated herpesvirus (KSHV) persists in a highly-ordered chromatin structure inside latently infected cells with the majority of the viral genome having repressive marks. However, upon reactivation the viral chromatin landscape changes into ‘open’ chromatin through the involvement of lysine demethylases and methyltransferases. Besides methylation of lysine residues of histone H3, arginine methylation of histone H4 plays an important role in controlling the compactness of the chromatin. Symmetric methylation of histone H4 at arginine 3 (H4R3me2s) negatively affects the methylation of histone H3 at lysine 4 (H3K4me3), an active epigenetic mark deposited on the viral chromatin during reactivation. We identified a novel binding partner to KSHV viral DNA processivity factor, ORF59-a protein arginine methyl transferase 5 (PRMT5). PRMT5 is an arginine methyltransferase that dimethylates arginine 3 (R3) of histone H4 in a symmetric manner, one hallmark of condensed chromatin. Our ChIP-seq data of symmetrically methylated H4 arginine 3 showed a significant decrease in H4R3me2s on the viral genome of reactivated cells as compared to the latent cells. Reduction in arginine methylation correlated with the binding of ORF59 on the viral chromatin and disruption of PRMT5 from its adapter protein, COPR5 (cooperator of PRMT5). Binding of PRMT5 through COPR5 is important for symmetric methylation of H4R3 and the expression of ORF59 competitively reduces the association of PRMT5 with COPR5, leading to a reduction in PRMT5 mediated arginine methylation. This ultimately resulted in a reduced level of symmetrically methylated H4R3 and increased levels of H3K4me3 marks, contributing to the formation of an open chromatin for transcription and DNA replication. Depletion of PRMT5 levels led to a decrease in symmetric methylation and increase in viral gene transcription confirming the role of PRMT5 in viral reactivation. In conclusion, ORF59 modulates histone

  4. Assessment of the best N(3-) donors in preparation of [M(N)(PNP)]-based (M=(99m)Tc-; (188)Re) target-specific radiopharmaceuticals: Comparison among succinic dihydrazide (SDH), N-methyl-S-methyl dithiocarbazate (HDTCZ) and PEGylated N-methyl-S-methyl dithiocarbazate (HO2C-PEG600-DTCZ).

    PubMed

    Carta, Davide; Jentschel, Christian; Thieme, Stefan; Salvarese, Nicola; Morellato, Nicolò; Refosco, Fiorenzo; Ruzza, Paolo; Bergmann, Ralf; Pietzsch, Hans-Jurgen; Bolzati, Cristina

    2014-08-01

    Succinic dihydrazide (SDH), N-methyl-S-methyl dithiocarbazate (HDTCZ) and PEGylated N-methyl-S-methyl dithiocarbazate (HO2C-PEG600-DTCZ) are nitrido nitrogen atom donors employed for the preparation of nitride [M(N)]-complexes (M=(99m)Tc and (188)Re). This study aims to compare the capability and the efficiency of these three N(3-) group donors, in the preparation of [M(N)PNP]-based target-specific compounds (M=(99m)Tc, (188)Re; PNP=aminodiphosphine). For this purpose, three different kit formulations (SDH kit; HO2C-PEG600-DTCZ kit; HDTCZ kit) were assembled and used in the preparation of [M(N)(cys~)(PNP3)](0/+) complexes (cys~=cysteine derivate ligands). For each formulation, the radiochemical yield (RCY) of the [M(N)(~cys)(PNP3)] compounds, was determined by HPLC. The deviation of the percentage of RCY, due to changes in concentration of the N(3-) donors and of the exchanging ligand, was determined. For (99m)Tc, data clearly show that HDTCZ is the most efficient donor of N(3-); however, SDH is the most suitable nitrido nitrogen atom donor for the preparation of [(99m)Tc(N)(PNP)]-based target-specific agents with high specific activity. When HO2C-PEG600-DTCZ or HDTCZ are used in N(3-) donation, high amounts of the exchanging ligand (10(-4)M) were required for the formation of the final complex in acceptable yield. The possibility to use microgram amounts of HDTCZ also in [(188)Re(N)] preparation (0.050mg) reduces its ability to compete in ligand exchange reactions, minimizing the quantity of chelators required to obtain the final complex in high yield. This finding can be exploit for increasing the radiolabeling efficiency in [(188)Re(N)]-radiopharmaceutical preparations compared to the previously reported HDTCZ-based procedure, notwithstanding a purification process could be necessary to improve the specific activity of the complexes. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Chemo-Enzymatic Synthesis of Chiral Epoxides Ethyl and Methyl (S)-3-(Oxiran-2-yl)propanoates from Renewable Levoglucosenone: An Access to Enantiopure (S)-Dairy Lactone.

    PubMed

    Peru, Aurélien A M; Flourat, Amandine L; Gunawan, Christian; Raverty, Warwick; Jevric, Martyn; Greatrex, Ben W; Allais, Florent

    2016-07-29

    Chiral epoxides-such as ethyl and methyl (S)-3-(oxiran-2-yl)propanoates ((S)-1a/1b)-are valuable precursors in many chemical syntheses. Until recently, these compounds were synthesized from glutamic acid in four steps (deamination, reduction, tosylation and epoxide formation) in low to moderate overall yield (20%-50%). Moreover, this procedure requires some harmful reagents such as sodium nitrite ((eco)toxic) and borane (carcinogen). Herein, starting from levoglucosenone (LGO), a biobased chiral compound obtained through the flash pyrolysis of acidified cellulose, we propose a safer and more sustainable chemo-enzymatic synthetic pathway involving lipase-mediated Baeyer-Villiger oxidation, palladium-catalyzed hydrogenation, tosylation and treatment with sodium ethoxide/methoxide as key steps. This route afforded ethyl and methyl (S)-3-(oxiran-2-yl)propanoates in 57% overall yield, respectively. To demonstrate the potentiality of this new synthetic pathway from LGO, the synthesis of high value-added (S)-dairy lactone was undertaken from these epoxides and provided the target in 37% overall yield from LGO.

  6. Synthesis and properties of 4-alkoxy-2-[2-hydroxy-3-(4-o,m,p-halogenoaryl-1 -piperazinyl)propyl]-6-methyl-1H-pyrrolo-[3,4-c]pyridine-1,3(2H)-diones with analgesic and sedative activities.

    PubMed

    Sladowska, Helena; Sabiniarz, Aleksandra; Szkatuła, Dominika; Filipek, Barbara; Sapa, Jacek

    2006-01-01

    Synthesis of N-substituted derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones (17-26) is described. The chlorides, containing OH group, used in the above synthesis can exist in two isomeric forms: chain (12, 14-16) and cyclic (12a, 14a-16a). All final imides studied exhibited analgesic activity in the "writhing syndrome" test which was superior than that of acetylsalicylic acid. In the "hot plate" test only two compounds (19, 20) were active as antinociceptive agents. Furthermore, all compounds tested significantly suppressed the spontaneous locomotor activity of mice.

  7. Ultrafast non-adiabatic dynamics of methyl substituted ethylenes: The π3s Rydberg state

    NASA Astrophysics Data System (ADS)

    Wu, Guorong; Boguslavskiy, Andrey E.; Schalk, Oliver; Schuurman, Michael S.; Stolow, Albert

    2011-10-01

    Excited state unimolecular reactions of some polyenes exhibit localization of their dynamics at a single ethylenic double bond. Here we present studies of the fundamental photophysical processes in the ethylene unit itself. Combined femtosecond time-resolved photoelectron spectroscopy (TRPES) and ab initio quantum chemical calculations was applied to the study of excited state dynamics in cis-butene, trans-butene, trimethylethylene, and tetramethylethylene, following initial excitation to their respective π3s Rydberg states. The wavelength dependence of the π3s Rydberg state dynamics of tetramethylethylene was investigated in more detail. The π3s Rydberg to ππ* valence state decay rate varies greatly with substituent: the 1,2-di- and tri-methyl substituted ethylenes (cis-butene, trans-butene, and trimethylethylene) show an ultrafast decay (˜20 fs), whereas the fully methylated tetramethylethylene shows a decay rate of 2 to 4 orders of magnitude slower. These observations are rationalized in terms of topographical trends in the relevant potential energy surfaces, as found from ab initio calculations: (1) the barrier between the π3s state and the ππ* state increases with increasing methylation, and (2) the π3s/ππ* minimum energy conical intersection displaces monotonically away from the π3s Franck-Condon region with increasing methylation. The use of systematic methylation in combination with TRPES and ab initio computation is emerging as an important tool in discerning the excited state dynamics of unsaturated hydrocarbons.

  8. Synthesis, structural elucidation and pharmacological properties of some 5-acetyl-3,4-dihydro-6-methyl-4-(substituted phenyl)-2(1H) -pyrimidinones.

    PubMed

    Yarim, M; Sarac, S; Ertan, M; Batu, O S; Erol, K

    1999-06-30

    In this study, the synthesis of some new 5-acetyl-3,4-dihydro-6-methyl-4-(substituted phenyl)-2(1H)-pyrimidinones has been reported. The compounds were prepared by the Biginelli reaction of acetylacetone with aromatic aldehydes and urea. The structures of the compounds were characterized by UV, IR, 1H NMR, 13C NRM, mass spectra and elementary analysis. The calcium antagonistic activity of these compounds was tested in vitro on rat ileum precontracted with 4 x 10(-3) M barium chloride.

  9. Characteristics of H2S emission from aged refuse after excavation exposure.

    PubMed

    Shen, Dong-Sheng; Du, Yao; Fang, Yuan; Hu, Li-Fang; Fang, Cheng-Ran; Long, Yu-Yang

    2015-05-01

    Hydrogen sulfide (H2S(g)) emission from landfills is a widespread problem, especially when aged refuse is excavated. H2S(g) emission from aged refuse exposed to air was investigated and the results showed that large amounts of H2S(g) can be released, especially in the first few hours after excavation, when H2S(g) concentrations in air near refuse could reach 2.00 mg m(-3). Initial exposure to air did not inhibit the emission of H2S(g), as is generally assumed, but actually promoted it. The amounts of H2S(g) emitted in the first 2 d after excavation can be very dangerous, and the risks associated with the emission of H2S(g) could decrease significantly with time. Unlike a large number of sulfide existed under anaerobic conditions, the sulfide in aged municipal solid waste can be oxidized chemically to elemental sulfur (but not sulfate) under aerobic conditions, and its conversion rate was higher than 80%. Only microorganisms can oxidize the reduced sulfur species to sulfate, and the conversion rate could reach about 50%. Using appropriate techniques to enhance these chemical and biological transformations could allow the potential health risks caused by H2S(g) after refuse excavation to be largely avoided. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. 5-(4-Chloro­phen­oxy)-1-methyl-3-tri­fluoro­methyl-1H-pyrazole-4-carbaldehyde O-[(2-chloro­pyridin-5-yl)meth­yl]oxime

    PubMed Central

    Dai, Hong; Zhu, Peng-Fei; Zhu, Yu-Jun; Fang, Jian-Xin; Shi, Yu-Jun

    2011-01-01

    In the title mol­ecule, C18H13Cl2F3N4O2, the intra­molecular distance between the centroids of the benzene and pyridine rings is 3.953 (3) Å, and the trifluoro­methyl group is rotationally disordered over two orientations in a 0.678 (19):0.322 (19) ratio. The crystal packing exhibits weak inter­molecular C—H⋯F inter­actions. PMID:22199756

  11. MGMT and MLH1 methylation in Helicobacter pylori-infected children and adults.

    PubMed

    Alvarez, Marisa C; Santos, Juliana C; Maniezzo, Nathália; Ladeira, Marcelo S; da Silva, Artur L C; Scaletsky, Isabel C A; Pedrazzoli, José; Ribeiro, Marcelo L

    2013-05-28

    To evaluate the association between Helicobacter pylori (H. pylori) infection and MLH1 and MGMT methylation and its relationship with microsatellite instability (MSI). The methylation status of the MLH1 and MGMT promoter region was analysed by methylation specific methylation-polymerase chain reaction (MSP-PCR) in gastric biopsy samples from uninfected or H. pylori-infected children (n = 50), from adults with chronic gastritis (n = 97) and from adults with gastric cancer (n = 92). MLH1 and MGMT mRNA expression were measured by real-time PCR and normalised to a constitutive gene (β actin). MSI analysis was performed by screening MSI markers at 4 loci (Bat-25, Bat-26, D17S250 and D2S123) with PCR; PCR products were analysed by single strand conformation polymorphism followed by silver staining. Statistical analyses were performed with either the χ(2) test with Yates continuity correction or Fisher's exact test, and statistical significance for expression analysis was assessed using an unpaired Student's t-test. Methylation was not detected in the promoter regions of MLH1 and MGMT in gastric biopsy samples from children, regardless of H. pylori infection status. The MGMT promoter was methylated in 51% of chronic gastritis adult patients and was associated with H. pylori infection (P < 0.05); this region was methylated in 66% of gastric cancer patients, and the difference in the percentage of methylated samples between these patients and those from H. pylori-infected chronic gastritis patients was statistically significant (P < 0.05). MLH1 methylation frequencies among H. pylori-infected and non-infected chronic gastritis adult patients were 13% and 7%, respectively. We observed methylation of the MLH1 promoter (39%) and increased MSI levels (68%) in samples from gastric cancer patients in comparison to samples from H. pylori-infected adult chronic gastritis patients (P < 0.001 and P < 0.01, respectively). The frequency of promoter methylation for both genes was

  12. Self-Assembled Mercaptan on Mesoporous Silica (SAMMS) technology of mercury removal and stabilization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feng, Xiangdong; Liu, Jun; Fryxell, G.E.

    1997-09-01

    This paper explains the technology developed to produce Self-Assembled Mercaptan on Mesoporous Silica (SAMMS) for mercury removal from aqueous wastewater and from organic wastes. The characteristics of SAMMS materials, including physical characteristics and mercury loading, and its application for mercury removal and stabilization are discussed. Binding kinetics and binding speciations are reported. Preliminary cost estimates are provided for producing SAMMS materials and for mercury removal from wastewater. The characteristics of SAMMS in mercury separation were studied at PNNL using simulated aqueous tank wastes and actual tritiated pump oil wastes from Savannah River Site; preliminary results are outlined. 47 refs., 16more » figs., 16 tabs.« less

  13. Methyl-Donor and Cofactor Nutrient Intakes in the First 2–3 Years and Global DNA Methylation at Age 4: A Prospective Cohort Study

    PubMed Central

    Taylor, Rachael M.; Smith, Roger; Collins, Clare E.; Mossman, David; Wong-Brown, Michelle W.; Chan, Eng-Cheng; Evans, Tiffany-Jane; Attia, John R.; Smith, Tenele; Butler, Trent

    2018-01-01

    Background: During the early postnatal period, the impact of nutrition on DNA methylation has not been well studied in humans. The aim was to quantify the relationship between one-carbon metabolism nutrient intake during the first three years of life and global DNA methylation levels at four years. Design: Childhood dietary intake was assessed using infant feeding questionnaires, food frequency questionnaires, 4-day weighed food records and 24-h food records. The dietary records were used to estimate the intake of methionine, folate, vitamins B2, B6 and B12 and choline. The accumulative nutrient intake specific rank from three months to three years of age was used for analysis. Global DNA methylation (%5-methyl cytosines (%5-mC)) was measured in buccal cells at four years of age, using an enzyme-linked immunosorbent assay (ELISA) commercial kit. Linear regression models were used to quantify the statistical relationships. Results: Data were collected from 73 children recruited from the Women and their Children’s Health (WATCH) study. No association was found between one-carbon metabolism nutrient intake and global DNA methylation levels (P 0.05). Global DNA methylation levels in males were significantly higher than in females (median %5-mC: 1.82 vs. 1.03, males and females respectively, (P 0.05)). Conclusion: No association was found between the intake of one-carbon metabolism nutrients during the early postnatal period and global DNA methylation levels at age four years. Higher global DNA methylation levels in males warrants further investigation. PMID:29495543

  14. 5-Chloro-5''-[4-(di-methyl-amino)-benzyl-idene]-4'-[4-(di-methyl-amino)-phen-yl]-1',1''-di-methyl-dispiro-[indoline-3,2'-pyrrolidine-3',3''-piperidine]-2,4''-dione.

    PubMed

    Farag, I S Ahmed; Girgis, Adel S; Ramadan, A A; Moustafa, A M; Tiekink, Edward R T

    2014-01-01

    The title compound, C34H38ClN5O2, has spiro links connecting the pyrrolidine ring and indole residue, as well as the piperidine and pyrrolidine rings. A half-chair conformation is found for the piperidine ring with the C atom connected to the spiro-C atom lying 0.738 (4) Å out of the plane of the remaining five atoms (r.m.s. deviation = 0.0407 Å). The methyl-ene C atom is the flap in the envelope conformation for the pyrrolidine ring. In the crystal, supra-molecular chains are sustained by alternating eight-membered {⋯HNCO}2 and 14-membered {⋯HC5O}2 synthons. Chains are connected into a three-dimensional network by (pyrrolidine-bound phenyl-meth-yl)C-H⋯π(pyrrolidine-bound phen-yl) edge-to-face inter-actions.

  15. Ultrafast non-adiabatic dynamics of methyl substituted ethylenes: the π3s Rydberg state.

    PubMed

    Wu, Guorong; Boguslavskiy, Andrey E; Schalk, Oliver; Schuurman, Michael S; Stolow, Albert

    2011-10-28

    Excited state unimolecular reactions of some polyenes exhibit localization of their dynamics at a single ethylenic double bond. Here we present studies of the fundamental photophysical processes in the ethylene unit itself. Combined femtosecond time-resolved photoelectron spectroscopy (TRPES) and ab initio quantum chemical calculations was applied to the study of excited state dynamics in cis-butene, trans-butene, trimethylethylene, and tetramethylethylene, following initial excitation to their respective π3s Rydberg states. The wavelength dependence of the π3s Rydberg state dynamics of tetramethylethylene was investigated in more detail. The π3s Rydberg to ππ(∗) valence state decay rate varies greatly with substituent: the 1,2-di- and tri-methyl substituted ethylenes (cis-butene, trans-butene, and trimethylethylene) show an ultrafast decay (∼20 fs), whereas the fully methylated tetramethylethylene shows a decay rate of 2 to 4 orders of magnitude slower. These observations are rationalized in terms of topographical trends in the relevant potential energy surfaces, as found from ab initio calculations: (1) the barrier between the π3s state and the ππ∗ state increases with increasing methylation, and (2) the π3s∕ππ∗ minimum energy conical intersection displaces monotonically away from the π3s Franck-Condon region with increasing methylation. The use of systematic methylation in combination with TRPES and ab initio computation is emerging as an important tool in discerning the excited state dynamics of unsaturated hydrocarbons.

  16. Methyl (2Z)-2-bromo­meth­yl-3-(3-chloro­phen­yl)prop-2-enoate

    PubMed Central

    Swaminathan, K.; Sethusankar, K.; Selvakumar, Raman; Bakthadoss, Manickam

    2013-01-01

    There are two independent mol­ecules (A and B) in the asymmetric unit of the title compound C11H10BrClO2, which represents the Z isomer. The methyl­acrylate moieties are essentially planar, within 0.084 (2) and 0.027 (5) Å in mol­ecules A and B, respectively. The benzene ring makes dihedral angles of 13.17 (7) and 27.89 (9)° with the methyl­acrylate moiety in mol­ecules A and B, respectively. The methyl­bromide moiety is almost orthogonal to the benzene ring, making dihedral angles of 81.46 (16)° in mol­ecule A and 79.61 (16)° in mol­ecule B. The methyl­acrylate moiety exhibits an extended trans conformation in both mol­ecules. In the crystal, pairs of C—H⋯O hydrogen bonds result in the formation of quasi-centrosymmetric R 2 2(14) AB dimers. PMID:23795037

  17. Yeast proteins Gar1p, Nop1p, Npl3p, Nsr1p, and Rps2p are natively methylated and are substrates of the arginine methyltransferase Hmt1p.

    PubMed

    Yagoub, Daniel; Hart-Smith, Gene; Moecking, Jonas; Erce, Melissa A; Wilkins, Marc R

    2015-09-01

    The Hmt1 methyltransferase is the predominant arginine methyltransferase in Saccharomyces cerevisiae. There are 18 substrate proteins described for this methyltransferase, however native sites of methylation have only been identified on two of these proteins. Here we used peptide immunoaffinity enrichment, followed by LC-ETD-MS/MS, to discover 21 native sites of arginine methylation on five putative Hmt1 substrate proteins, namely Gar1p (H/ACA ribonucleoprotein complex subunit 1), Nop1p (rRNA 2'-O-methyltransferase fibrillarin), Npl3p (nucleolar protein 3), Nsr1p (nuclear localization sequence-binding protein), and Rps2p (40S ribosomal protein S2). The sites, many of which were found to be mono- or di-methylated, were predominantly found in RGG (Arg-Gly-Gly) motifs. Heavy methyl-SILAC validated the majority of these peptides. The above proteins, and relevant sites of methylation, were subsequently validated by in vitro methylation with recombinant Hmt1. This brings the total of Hmt1 substrate proteins for which native methylation sites have been identified to five. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Novel reactions of homodinuclear Ni2 complexes [Ni(RNPyS4)]2 with Fe3(CO)12 to give heterotrinuclear NiFe2 and mononuclear Fe complexes relevant to [NiFe]- and [Fe]-hydrogenases.

    PubMed

    Song, Li-Cheng; Cao, Meng; Wang, Yong-Xiang

    2015-04-21

    The homodinuclear complexes [Ni(RNPyS4)]2 (; RNPyS4 = 2,6-bis(2-mercaptophenylthiomethyl)-4-R-pyridine; R = H, MeO, Cl, Br, i-Pr) were found to be prepared by reactions of the in situ generated Li2[Ni(1,2-S2C6H4)2] with 2,6-bis[(tosyloxy)methyl]pyridine and its substituted derivatives 2,6-bis[(tosyloxy)methyl]-4-R-pyridine. Further reactions of with Fe3(CO)12 gave both heterotrinuclear complexes NiFe2(RNPyS4)(CO)5 () and mononuclear complexes Fe(RNPyS4)(CO) (), unexpectedly. Interestingly, complexes and could be regarded as models for the active sites of [NiFe]- and [Fe]-hydrogenases, respectively. All the prepared complexes were characterized by elemental analysis, spectroscopy, and particularly for some of them, by X-ray crystallography. In addition, the electrochemical properties of and as well as the electrocatalytic H2 production catalyzed by and were investigated by CV techniques.

  19. Microarray-based DNA methylation study of Ewing’s sarcoma of the bone

    PubMed Central

    PARK, HYE-RIM; JUNG, WOON-WON; KIM, HYUN-SOOK; PARK, YONG-KOO

    2014-01-01

    Alterations in DNA methylation patterns are a hallmark of malignancy. However, the majority of epigenetic studies of Ewing’s sarcoma have focused on the analysis of only a few candidate genes. Comprehensive studies are thus lacking and are required. The aim of the present study was to identify novel methylation markers in Ewing’s sarcoma using microarray analysis. The current study reports the microarray-based DNA methylation study of 1,505 CpG sites of 807 cancer-related genes from 69 Ewing’s sarcoma samples. The Illumina GoldenGate Methylation Cancer Panel I microarray was used, and with the appropriate controls (n=14), a total of 92 hypermethylated genes were identified in the Ewing’s sarcoma samples. The majority of the hypermethylated genes were associated with cell adhesion, cell regulation, development and signal transduction. The overall methylation mean values were compared between patients who survived and those that did not. The overall methylation mean was significantly higher in the patients who did not survive (0.25±0.03) than in those who did (0.22±0.05) (P=0.0322). However, the overall methylation mean was not found to significantly correlate with age, gender or tumor location. GDF10, OSM, APC and HOXA11 were the most significant differentially-methylated genes, however, their methylation levels were not found to significantly correlate with the survival rate. The DNA methylation profile of Ewing’s sarcoma was characterized and 92 genes that were significantly hypermethylated were detected. A trend towards a more aggressive behavior was identified in the methylated group. The results of this study indicated that methylation may be significant in the development of Ewing’s sarcoma. PMID:25202378

  20. Process for the preparation of benozotriazoles and their polymers, and 2(2-hydroxy-5-isopropenylphenyl)2H-benzotriazole produced thereby

    DOEpatents

    Vogl, Otto; Nir, Zohar

    1989-03-14

    The compound 2(2-hydroxy-5-isopropenylphenyl)2H-benzotriazole (2H5P) is produced by azo coupling of o-nitrophenyl diazonium chloride with p-hydroxyacetophenone, subjecting the resulting isolated azo compound to reductive cyclization with zinc in the presence of sodium hydroxide at a temperature of about 50.degree.-70.degree. C., acidifying the resulting mixture so as to produce (2(2-hydroxy-5-acetylphenyl)2H-benzotriazole (2H5A), acetylating the isolated 2(2-hydroxy-5-acetylphenyl)2H-benzotriazole (2H5A), so as to produce 2(2-acetoxy-5-acetylphenyl)2H-benzotriazole (2A5A), methylating the isolated 2(2-acetoxy-5-acetylphenyl(2H-benzotriazole (2A5A) with a methyl Grignard reagent and dehydrating the isolated reaction product with potassium hydrogen sulfate so as to produce 2(2-hydroxy-5-isopropenylphenyl)2H-benzotriazole (2H5P). The compound is used as a polymerizable ultra violet light stabilizer.

  1. Synthesis, Antifungal Activity and Structure-Activity Relationships of Novel 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic Acid Amides.

    PubMed

    Du, Shijie; Tian, Zaimin; Yang, Dongyan; Li, Xiuyun; Li, Hong; Jia, Changqing; Che, Chuanliang; Wang, Mian; Qin, Zhaohai

    2015-05-08

    A series of novel 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid amides were synthesized and their activities were tested against seven phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to excellent activities. Among them N-(2-(5-bromo-1H-indazol-1-yl)phenyl)-3-(difluoro-methyl)-1-methyl-1H-pyrazole-4-carboxamide (9m) exhibited higher antifungal activity against the seven phytopathogenic fungi than boscalid. Topomer CoMFA was employed to develop a three-dimensional quantitative structure-activity relationship model for the compounds. In molecular docking, the carbonyl oxygen atom of 9m could form hydrogen bonds towards the hydroxyl of TYR58 and TRP173 on SDH.

  2. DOT1L and H3K79 Methylation in Transcription and Genomic Stability.

    PubMed

    Wood, Katherine; Tellier, Michael; Murphy, Shona

    2018-02-27

    The organization of eukaryotic genomes into chromatin provides challenges for the cell to accomplish basic cellular functions, such as transcription, DNA replication and repair of DNA damage. Accordingly, a range of proteins modify and/or read chromatin states to regulate access to chromosomal DNA. Yeast Dot1 and the mammalian homologue DOT1L are methyltransferases that can add up to three methyl groups to histone H3 lysine 79 (H3K79). H3K79 methylation is implicated in several processes, including transcription elongation by RNA polymerase II, the DNA damage response and cell cycle checkpoint activation. DOT1L is also an important drug target for treatment of mixed lineage leukemia (MLL)-rearranged leukemia where aberrant transcriptional activation is promoted by DOT1L mislocalisation. This review summarizes what is currently known about the role of Dot1/DOT1L and H3K79 methylation in transcription and genomic stability.

  3. Bardoxolone methyl decreases megalin and activates nrf2 in the kidney.

    PubMed

    Reisman, Scott A; Chertow, Glenn M; Hebbar, Sudarshan; Vaziri, Nosratola D; Ward, Keith W; Meyer, Colin J

    2012-10-01

    Inflammation and oxidative stress are hallmarks and mediators of the progression of CKD. Bardoxolone methyl, a potent activator of the nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant and anti-inflammatory response, increases estimated GFR and decreases BUN, serum phosphorus, and uric acid concentrations in patients with moderate to severe CKD. However, it also increases albuminuria, which is associated with inflammation and disease progression. Therefore, we investigated whether this bardoxolone methyl-induced albuminuria may result from the downregulation of megalin, a protein involved in the tubular reabsorption of albumin and lipid-bound proteins. Administration of bardoxolone methyl to cynomolgus monkeys significantly decreased the protein expression of renal tubular megalin, which inversely correlated with the urine albumin-to-creatinine ratio. Moreover, daily oral administration of bardoxolone methyl to monkeys for 1 year did not lead to any adverse effects on renal histopathologic findings but did reduce serum creatinine and BUN, as observed in patients with CKD. Finally, the bardoxolone methyl-induced decrease in megalin corresponded with pharmacologic induction of renal Nrf2 targets, including NAD(P)H:quinone oxidoreductase 1 enzyme activity and glutathione content. This result indicates that Nrf2 may have a role in megalin regulation. In conclusion, these data suggest that the increase in albuminuria that accompanies bardoxolone methyl administration may result, at least in part, from reduced expression of megalin, which seems to occur without adverse effects and with strong induction of Nrf2 targets.

  4. Synthesis of TiO2-CNT hybrid nanocatalyst and its application in direct oxidation of H2S to S

    NASA Astrophysics Data System (ADS)

    Daraee, Maryam; Baniadam, Majid; Rashidi, Alimorad; Maghrebi, Morteza

    2018-07-01

    In this study, a TiO2-CNT hybrid catalyst has been synthesized and its catalytic activity in the oxidation of H2S to S has been investigated and compared with those of TiO2 nanoparticles and pyrolyzed TiO2-CNT hybrid (P-TiO2-CNT). The optimum catalyst amount was determined using central composite design (CCD) method. Catalysts were characterized by various analytical techniques. The H2S conversion, sulfur selectivity and yield at the optimal temperature of 200 °C and O2/H2S ratio of 0.5 were 98.3, 99.5 and 97%, respectively. TiO2-CNT16% catalyst has a higher surface area than TiO2 nanoparticles and P-TiO2-CNT. In addition, the former catalyst gives a high conversion of H2S and sulfur selectivity at 200 °C and O2/H2S ratio of 0.5 compared with the latter two catalysts. The superior conversion (over 10%) of TiO2-CNT16% hybrid compared to TiO2 nanoparticles can be attributed to the synergistic effects of TiO2 and CNT, the reduced band gap of TiO2-CNT16% hybrid and high specific surface area of the catalyst.

  5. Mitochondrial biotransformation of ω-(phenoxy)alkanoic acids, 3-(phenoxy)acrylic acids, and ω-(1-methyl-1H-imidazol-2-ylthio)alkanoic acids: A prodrug strategy for targeting cytoprotective antioxidants to mitochondria

    PubMed Central

    Roser, Kurt S.; Brookes, Paul S.; Wojtovich, Andrew P.; Olson, Leif P.; Shojaie, Jalil; Parton, Richard L.; Anders, M. W.

    2010-01-01

    Mitochondrial reactive oxygen species (ROS) generation and the attendant mitochondrial dysfunction are implicated in a range of disease states. The objective of the present studies was to test the hypothesis that the mitochondrial β-oxidation pathway could be exploited to deliver and biotransform the prodrugs ω-(phenoxy)alkanoic acids, 3-(phenoxy)acrylic acids, and ω-(1-methyl-1H-imidazol-2-ylthio)alkanoic acids to the corresponding phenolic antioxidants or methimazole. 3 -and 5-(Phenoxy)alkanoic acids and methyl-substituted analogs were biotransformed to phenols; rates of biotransformation decreased markedly with methyl-group substitution on the phenoxy moiety. 2,6-Dimethylphenol formation from the analogs 3-([2,6-dimethylphenoxy]methylthio)propanoic acid and 3-(2,6-dimethylphenoxy)acrylic acid was greater than that observed with ω-(2,6-dimethylphenoxy)alkanoic acids. 3- and 5-(1-Methyl-1H-imidazol-2-ylthio)alkanoic acids were rapidly biotransformed to the antioxidant methimazole and conferred significant cytoprotection against hypoxia-reoxygenation injury in isolated cardiomyocytes. Both 3-(2,6-dimethylphenoxy)propanoic acid and 3-(2,6-dimethylphenoxy)acrylic acid also afforded cytoprotection against hypoxia-reoxygenation injury in isolated cardiomyocytes. These results demonstrate that mitochondrial β-oxidation is a potentially useful delivery system for targeting antioxidants to mitochondria. PMID:20129794

  6. Solubility and diffusivity of N{sub 2}O and CO{sub 2} in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-1-propanol + water)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, M.H.; Lai, M.D.

    1995-03-01

    Solutions of amines are frequently used in gas-treating processes to remove acid gases, such as CO{sub 2} and H{sub 2}S, from gas streams in the natural gas and synthetic ammonia industries and petroleum chemical plants. The solubility and diffusivity of N{sub 2}O in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-l-propanol + water) were measured at 30, 35, and 40 C and at atmospheric pressure. Six (monoethanolamine + N-methyldiethanolamine + water) and five (monoethanolamine + 2-amino-2-methyl-l-propanol + water) systems were studied. The total amine mass percent in all cases was 30. The solubilities were measured by a solubilitymore » apparatus similar to that of Haimour and Sandall (1984). A wetted wall column absorber was used to obtain the diffusivity of N{sub 2}O in amines. The N{sub 2}O solubilities in amine solutions have been correlated on the basis of the excess Henry constant correlation of Wang et al. (1992). The N{sub 2}O analogy was used to estimate the solubility and diffusivity of CO{sub 2} in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-l-propanol + water).« less

  7. 40 CFR 180.561 - Acibenzolar-S-methyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... acibenzolar-S-methyl, in or on the following raw agricultural commodities. Commodity Parts per million Banana..., group 8 1.0 Vegetable, leafy, group 4 0.25 1 There are no United States registrations for banana. (2...

  8. 40 CFR 180.561 - Acibenzolar-S-methyl; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... acibenzolar-S-methyl, in or on the following raw agricultural commodities. Commodity Parts per million Banana..., group 8 1.0 Vegetable, leafy, group 4 0.25 1 There are no United States registrations for banana. (2...

  9. 40 CFR 180.561 - Acibenzolar-S-methyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... acibenzolar-S-methyl, in or on the following raw agricultural commodities. Commodity Parts per million Banana..., group 8 1.0 Vegetable, leafy, group 4 0.25 1 There are no United States registrations for banana. (2...

  10. Identification and electrophysiological studies of (4 S,5 S)-5-hydroxy-4-methyl-3-heptanone and 4-methyl-3,5-heptanedione in male lucerne weevils

    NASA Astrophysics Data System (ADS)

    Unelius, C. R.; Park, K.-C.; McNeill, M.; Wee, S. L.; Bohman, B.; Suckling, D. M.

    2013-02-01

    An investigation to identify a sex or aggregation pheromone of Sitona discoideus Gyllenhål (Coleoptera: Curculionidae) is presented. Antenna flicking and attraction behaviors evoked by conspecifics of both sexes were recorded in arena bioassays, where attraction of females to males was observed. Air entrainment of both males and females was conducted in separate chambers. Gas chromatographic-mass spectrometric analysis of headspace volatiles revealed that two male-specific compounds, 4-methyl-3,5-heptanedione (major) and (4 S,5 S)-5-hydroxy-4-methyl-3-heptanone (minor), were emitted during the autumnal post-aestivatory flight period. The stereoisomers of the minor component were separated by enantioselective gas chromatography and their absolute configurations assigned by NMR (diastereomers) and the known preference of enantioselective transesterification reactions catalyzed by Candida antarctica lipase B. Electroantennogram and single sensillum recording studies indicate that 4-methyl-3,5-heptanedione as well as all individual stereoisomers of 5-hydroxy-4-methyl-3-heptanone are detected by the antennae of male and female S. discoideus. Further, single sensillum recordings suggest that both sexes of S. discoideus have specialized olfactory receptor neurons (ORNs) for detecting 4-methyl-3,5-heptanedione and different populations of stereoselective ORNs for detecting the stereoisomers of 5-hydroxy-4-methyl-3-heptanone. Some of these stereoselective ORNs appear to be sex-specific in S. discoideus.

  11. Corrosion of 310 stainless steel in H2-H2O-H2S gas mixtures: Studies at constant temperature and fixed oxygen potential

    NASA Technical Reports Server (NTRS)

    Rao, D. B.; Jacob, K. T.; Nelson, H. G.

    1981-01-01

    Corrosion of SAE 310 stainless steel in H2-H2O-H2S gas mixtures was studied at a constant temperature of 1150 K. Reactive gas mixtures were chosen to yield a constant oxygen potential of approximately 6 x 10 to the minus 13th power/cu Nm and sulfur potentials ranging from 0.19 x 10 to the minus 2nd power/cu Nm to 33 x 10 to the minus 2nd power/cu Nm. The kinetics of corrosion were determined using a thermobalance, and the scales were analyzed using metallography, scanning electron microscopy, and energy dispersive X-ray analysis. Two corrosion regimes, which were dependent on sulfur potential, were identified. At high sulfur potentials (p sub S sub 2 less than or equal to 2.7 x 10 to the minus 2nd power/cu Nm) the corrosion rates were high, the kinetics obeyed a linear rate equation, and the scales consisted mainly of sulfide phases similar to those observed from pure sulfication. At low sulfur potentials (P sub S sub 2 less than or equal to 0.19 x 10 to the minus 2nd power/cu Nm) the corrosion rates were low, the kinetics obeyed a parabolic rate equation, and scales consisted mainly of oxide phases.

  12. 2S protein Ara h 7.0201 has unique epitopes compared to other Ara h 7 isoforms and is comparable to 2S proteins Ara h 2 and 6 in basophil degranulation capacity.

    PubMed

    Hayen, S M; Ehlers, A M; den Hartog Jager, C F; Garssen, J; Knol, E F; Knulst, A C; Suer, W; Willemsen, L E M; Otten, H G

    2018-07-01

    Screening for specific IgE against 2S albumin proteins Ara h 2 and 6 has good positive predictive value in diagnosing peanut allergy. From the third 2S member Ara h 7, 3 isoforms have been identified. Their allergenicity has not been elucidated. This study investigated the allergenicity of Ara h 7 isoforms compared to Ara h 2 and 6. Sensitization of 15 DBPCFC-confirmed peanut-allergic patients to recombinant Ara h 2.0201, Ara h 6.01 and isoforms of recombinant Ara h 7 was determined by IgE immunoblotting strips. A basophil activation test (BAT) was performed in 9 patients to determine IgE-cross-linking capacities of the allergens. Sensitivity to the allergens was tested in 5 patients who were sensitized to at least 1 Ara h 7 isoform, by a concentration range in the BAT. 3D prediction models and sequence alignments were used to visualize differences between isoforms and to predict allergenic epitope regions. Sensitization to Ara h 7.0201 was most frequent (80%) and showed to be equally potent as Ara h 2.0201 and 6.01 in inducing basophil degranulation. Sensitization to Ara h 7.0201 together with Ara h 2.0201 and/or 6.01 was observed, indicating the presence of unique epitopes compared to the other 2 isoforms. Differences between the 3 Ara h 7 isoforms were observed in C-terminal cysteine residues, pepsin and trypsin cleavage sites and 3 single amino acid substitutions. The majority of peanut-allergic patients are sensitized to isoform Ara h 7.0201, which is functionally as active as Ara h 2.0201 and 6.01. Unique epitopes are most likely located in the C-terminus or an allergenic loop region which is a known allergenic epitope region for Ara h 2.0201 and 6.01. Due to its unique epitopes and allergenicity, it is an interesting candidate to improve the diagnostic accuracy for peanut allergy. © 2018 The Authors. Clinical & Experimental Allergy Published by John Wiley & Sons Ltd.

  13. Protein kinase G–regulated production of H2S governs oxygen sensing

    PubMed Central

    Yuan, Guoxiang; Vasavda, Chirag; Peng, Ying-Jie; Makarenko, Vladislav V.; Raghuraman, Gayatri; Nanduri, Jayasri; Gadalla, Moataz M.; Semenza, Gregg L.; Kumar, Ganesh K.; Snyder, Solomon H.; Prabhakar, Nanduri R.

    2015-01-01

    Reflexes initiated by the carotid body, the principal O2-sensing organ, are critical for maintaining cardio-respiratory homeostasis during hypoxia. O2 sensing by the carotid body requires carbon monoxide (CO) generation by heme oxygenase-2 (HO-2) and hydrogen sulfide (H2S) synthesis by cystathionine-γ-lyase (CSE). We report that O2 stimulated the generation of CO, but not that of H2S, and required two cysteine residues in the heme regulatory motif (Cys265 and Cys282) of HO-2. CO stimulated protein kinase G (PKG)–dependent phosphorylation of Ser377 of CSE, inhibiting the production of H2S. Hypoxia decreased the inhibition of CSE by reducing CO generation resulting in increased H2S, which stimulated carotid body neural activity. In carotid bodies from mice lacking HO-2, compensatory increased abundance of nNOS (neuronal nitric oxide synthase) mediated O2 sensing through PKG-dependent regulation of H2S by nitric oxide. These results provide a mechanism for how three gases work in concert in the carotid body to regulate breathing. PMID:25900831

  14. Molecular dynamics simulation on HP1 protein binding by histone H3 tail methylation and phosphorylation

    NASA Astrophysics Data System (ADS)

    Jiang, Yan-Ke; Zou, Jian-Wei; Wu, Yu-Qian; Zhang, Na; Yu, Qing-Sen; Jiang, Yong-Jun

    Trimethylation of histone H3 lysine 9 is important for recruiting heterochromatin protein 1 (HP1) to discrete regions of the genome, thereby regulating gene expression, chromatin packaging, and heterochromatin formation. Phosphorylation of histone H3 has been linked with mitotic chromatin condensation. During mitosis in vivo, H3 lysine 9 methylation and serine 10 phosphorylation can occur concomitantly on the same histone tail, whereas the influence of phosphorylation to trimethylation H3 tail recruiting HP1 remains controversial. In this work, molecular dynamics simulation of HP1 complexed with both trimethylated and phosphorylated H3 tail were performed and compared with the results from the previous methylated H3-HP1 trajectory. It is clear from the 10-ns dynamics simulation that two adjacent posttranslational modifications directly increase the flexibility of the H3 tail and weaken HP1 binding to chromatin. A combinatorial readout of two adjacent posttranslational modifications-a stable methylation and a dynamic phosphorylation mark-establish a regulatory mechanism of protein-protein interactions.

  15. Effects of 15(S)-15-methyl prostaglandin F2 alpha methyl ester-containing silastic discs in male rats.

    PubMed

    Kimball, F A; Frielink, R D; Porteus, S E

    1978-01-01

    Silicone rubber discs containing 15(S)-15-methyl prostaglandin F2 alpha ester (15-Me-PGF2 alpha) in the matrix were implanted in the left side of the scrotums of Sprague-Dawley rats. The effect of 1% and 2% drug concentration was examined for 10, 20, or 28 days and compared with the effects of Silastic discs containing no prostaglandin. The discs containing prostaglandin reduced mean testicular and accessory gland weights. Histologically the testes and epididymides showed decreased or absent spermatogenic elements and hypertrophy of the interstitial cell masses in comparison with other cells. Implanted prostaglandin significantly depressed serum testosterone, luteinizing hormone, and follicle-stimulating hormone (FSH) concentrations when 15-Me-PGF2 alpha plasma concentrations exceeded 2 ng/ml. Hormone concentrations returned to control values as drug concentrations declined. FSH concentrations significantly exceeded control values 10 and 20 days after implantation, when prostaglandin concentration was nondetectable. The acute suppression of all three hormones suggest that 15-Me-PGF2 alpha either may act directly on the tests to suppress testosterone production or may suppress testosterone production or may suppress gonadotropin secretion, resulting in depressed testosterone output.

  16. Broadening of spectral lines of CO2, N2O , H2CO, HCN, and H2S by pressure of gases dominant in planetary atmospheres (H2, He and CO2)

    NASA Astrophysics Data System (ADS)

    Samuels, Shanelle; Gordon, Iouli; Tan, Yan

    2018-01-01

    HITRAN1,2 is a compilation of spectroscopic parameters that a variety of computer codes use to predict and simulate the transmission and emission of light in planetary atmospheres. The goal of this project is to add to the potential of the HITRAN database towards the exploration of the planetary atmospheres by including parameters describing broadening of spectral lines by H2, CO2, and He. These spectroscopic data are very important for the study of the hydrogen and helium-rich atmospheres of gas giants as well as rocky planets with volcanic activities, including Venus and Mars, since their atmospheres are dominated by CO2. First step in this direction was accomplished by Wilzewski et al.3 where this was done for SO2, NH3, HF, HCl, OCS and C2H2. The molecules investigated in this work were CO2, N2O, H2CO, HCN and H2S. Line-broadening coefficients, line shifts and temperature-dependence exponents for transitions of these molecules perturbed by H2, CO2 and He have been assembled from available peer-reviewed experimental and theoretical sources. The data was evaluated and the database was populated with these data and their extrapolations/interpolations using semi-empirical models that were developed to this end.Acknowledgements: Financial support from NASA PDART grant NNX16AG51G and the Smithsonian Astrophysical Observatory Latino Initiative Program from the Latino Initiatives Pool, administered by the Smithsonian Latino Center is gratefully acknowledged.References: 1. HITRAN online http://hitran.org/2. Gordon, I.E., Rothman, L.S., Hill, C., Kochanov, R.V., Tan, Y., et al., 2017. The HITRAN2016 Molecular Spectroscopic Database. J. Quant. Spectrosc. Radiat. Transf. doi:10.1016/j.jqsrt.2017.06.0383. Wilzewski, J.S., Gordon, I.E., Kochanov, R. V., Hill, C., Rothman, L.S., 2016. H2, He, and CO2 line-broadening coefficients, pressure shifts and temperature-dependence exponents for the HITRAN database. Part 1: SO2, NH3, HF, HCl, OCS and C2H2. J. Quant. Spectrosc. Radiat

  17. H2S induced hypometabolism in mice is missing in sedated sheep.

    PubMed

    Haouzi, Philippe; Notet, Véronique; Chenuel, Bruno; Chalon, Bernard; Sponne, Isabelle; Ogier, Virginie; Bihain, Bernard

    2008-01-01

    On the basis of studies performed in mice that showed H(2)S inhalation decreasing dramatically the metabolic rate, H(2)S was proposed as a means of protecting vital organs from traumatic or ischemic episodes in humans. Hypoxia has in fact also long been shown to induce hypometabolism. However, this effect is observed solely in small-sized animals with high VO2 kg(-1), and not in large mammals. Thus, extrapolating the hypometabolic effect of H(2)S to large mammals is questionable and could be potentially dangerous. We measured metabolism in conscious mice (24 g) exposed to H(2)S (60 ppm) at an ambient temperature of 23-24 degrees C. H(2)S caused a rapid and large (50%) drop in gas exchange rate, which occurred independently of the change in body temperature. The metabolic response occurred within less than 3 min. In contrast, sheep, sedated with ketamine and weighing 74 kg did not exhibit any decrease in metabolic rate during a similar challenge at an ambient temperature of 22 degrees C. While a part of H(2)S induced hypometabolism in the mice is related to the reduction in activity, we speculate that the difference between sheep and mice may rely on the nature and the characteristics of the relationship between basal metabolic rate and body weight thus on the different mechanisms controlling resting metabolic rate according to body mass. Therefore, the proposed use of H(2)S administration as a way of protecting vital organs should be reconsidered in view of the lack of hypometabolic effect in a large sedated mammal and of H(2)S established toxicity.

  18. Synthesis, anti-inflammatory evaluation in vivo and docking studies of some new 5-(benzo[b]furan-2-ylmethyl)-6-methyl-pyridazin-3(2H)-one derivatives

    NASA Astrophysics Data System (ADS)

    Boukharsa, Youness; Lakhlili, Wiame; El harti, Jaouad; Meddah, Bouchra; Tiendrebeogo, Ramata Yvette; Taoufik, Jamal; El Abbes Faouzi, My; Ibrahimi, Azeddine; Ansar, M'hammed

    2018-02-01

    Seven novel 5-(benzo[b]furan-2-ylmethyl)-6-methyl-pyridazin-3(2H)-one derivatives (6a to 6g) have been synthesized by the condensation of appropriate 3-(benzofuran-2-ylmethylene)-4-oxopentanoic acid and hydrazine hydrate in ethanol. Structures of all compounds were elucidated by elemental analysis, IR, 1H NMR and 13C NMR. These compounds were tested for their anti-inflammatory activity in carrageenan-induced rat paw edema model. In silico molecular docking study has been executed to study the binding interactions of the synthesized compounds with COX-2 protein. Compounds 6a, 6b, 6e and 6g showed a good anti-inflammatory activity at 50 mg/kg compared with the indometacin at 10 mg/kg and the aspirin at 150 mg/kg and good binding affinity with COX-2.

  19. [Central muscle relaxant activities of 2-methyl-3-aminopropiophenone derivatives].

    PubMed

    Kontani, H; Mano, A; Koshiura, R; Yamazaki, M; Shimada, Y; Oshita, M; Morikawa, K; Kato, H; Ito, Y

    1987-02-01

    In this experiment, we synthetized new 2-methyl-3-aminopropiophenone (MP) derivatives, whose structure is known to have central muscle relaxant activities, and quinolizidine and indan . tetralin derivatives derived from MP by cyclization, and we investigated the central muscle relaxant activity. Among the quinolizidine derivatives, there was a very strong central depressant agent, trans (3H, 9aH)-3-(p-chloro) benzoyl-quinolizidine (HSR-740), and among the indan . tetralin derivatives, there was an excitant agents, trans (1H, 2H)-5-methoxy-3, 3-dimethyl-2-piperidinomethyl indan-1-ol (HSR-719). From the results, these derivatives were not considered to be adequate for central muscle relaxant. Among the MP derivatives, (4'-chloro-2'-methoxy-3-piperidino) propiophenone HCl (HSR-733) and (4'-ethyl-2-methyl-3-pyrrolidino) propiophenone HCl (HSR-770) strongly inhibited the cooperative movement in the rotating rod method using mice, and it exerted almost the same depressant activity on the cross extensor reflex using alpha-chloralose anesthetized rats. However, the inhibitory effects of HSR-733 on the anemic decerebrate rigidity and the rigidity induced by intracollicular decerebration in rats were weaker than those of HSR-770 and eperisone. In spinal cats, at a low dose (5 mg/kg, i.v.), HSR-733 depressed monosynaptic and dorsal root reflex potentials as compared with polysynaptic reflex potentials, and inhibitory effects of HSR-733 on these three reflex potentials were more potent than those of eperisone and HSR-770. Although HSR-770 acts on the spinal cord and supraspinal level on which eperisone has been reported to act, HSR-733 may mainly act on the spinal cord. These results indicate that the MP derivative with a 2-methyl group may be suitable as a central muscle relaxant. HSR-770, which has equipotent muscle relaxant activity to eperisone, exerted strong inhibitory effects on oxotremorine-induced tremor and weak inhibitory effects on spontaneous motor activity in the

  20. EPR study of gamma-irradiated N-methyl-L-alanine, DL-2-methyl glutamic acid hemihydrate and Di-leucine hydrochloride in solid state

    NASA Astrophysics Data System (ADS)

    Sütçü, Kerem; Osmanoğlu, Y. Emre

    2017-12-01

    In this study, it was aimed to investigate ɣ-irradiated powders of N-methyl-L-alanine (NMLA), DL-2-methyl glutamic acid hemihydrate (DL2MGAH), and Di-leucine hydrochloride (DLHCl) at room temperature by electron paramagnetic resonance spectroscopy. After the γ-irradiation the samples indicated the existence of the CH3ĊNHCH3COOH, HOOCCH3NH2CĊHCH2COOH·1/2H2O and (CH3)2ĊCH2CH NHCOOHCOCH (NH2HCl) CH2CH (CH3)2 radicals, respectively. The spectral parameters of the radicals were determined. The results were compared with the earlier studies and discussed accordingly.

  1. Synthesis and odor evaluation of five new sulfur-containing ester flavor compounds from 4-ethyloctanoic acid.

    PubMed

    Liu, Yuping; Chen, Haitao; Yin, Decai; Sun, Baoguo

    2010-07-29

    Five sulfur-containing flavor compounds were synthesized for the first time by the reaction of 4-ethyloctanoyl chloride with sulfur-containing alcohols or mercaptans. The synthesized compounds are 3-(methylthio)propyl 4-ethyloctanoate, 2-methyl-3-tetrahydro-furanthiol 4-ethyloctanoate, 4-methyl-5-thiazoleethanol 4-ethyloctanoate, 2-furan-methanethiol 4-ethyloctanoate and 2-methyl-3-furanthiol 4-ethyloctanoate. These five synthetic sulfur-containing ester flavor compounds all have meaty odor and might be used in foods if approved for this purpose in the future.

  2. KSHV encoded ORF59 modulates histone arginine methylation of the viral genome to promote viral reactivation.

    PubMed

    Strahan, Roxanne C; McDowell-Sargent, Maria; Uppal, Timsy; Purushothaman, Pravinkumar; Verma, Subhash C

    2017-07-01

    Kaposi's sarcoma associated herpesvirus (KSHV) persists in a highly-ordered chromatin structure inside latently infected cells with the majority of the viral genome having repressive marks. However, upon reactivation the viral chromatin landscape changes into 'open' chromatin through the involvement of lysine demethylases and methyltransferases. Besides methylation of lysine residues of histone H3, arginine methylation of histone H4 plays an important role in controlling the compactness of the chromatin. Symmetric methylation of histone H4 at arginine 3 (H4R3me2s) negatively affects the methylation of histone H3 at lysine 4 (H3K4me3), an active epigenetic mark deposited on the viral chromatin during reactivation. We identified a novel binding partner to KSHV viral DNA processivity factor, ORF59-a protein arginine methyl transferase 5 (PRMT5). PRMT5 is an arginine methyltransferase that dimethylates arginine 3 (R3) of histone H4 in a symmetric manner, one hallmark of condensed chromatin. Our ChIP-seq data of symmetrically methylated H4 arginine 3 showed a significant decrease in H4R3me2s on the viral genome of reactivated cells as compared to the latent cells. Reduction in arginine methylation correlated with the binding of ORF59 on the viral chromatin and disruption of PRMT5 from its adapter protein, COPR5 (cooperator of PRMT5). Binding of PRMT5 through COPR5 is important for symmetric methylation of H4R3 and the expression of ORF59 competitively reduces the association of PRMT5 with COPR5, leading to a reduction in PRMT5 mediated arginine methylation. This ultimately resulted in a reduced level of symmetrically methylated H4R3 and increased levels of H3K4me3 marks, contributing to the formation of an open chromatin for transcription and DNA replication. Depletion of PRMT5 levels led to a decrease in symmetric methylation and increase in viral gene transcription confirming the role of PRMT5 in viral reactivation. In conclusion, ORF59 modulates histone

  3. Excessive S-Adenosyl-L-Methionine-Dependent Methylation Increases Levels of Methanol, Formaldehyde and Formic Acid in Rat Brain Striatal Homogenates: Possible role in S-adenosyl-L-methionine-induced Parkinson’s disease-like disorders

    PubMed Central

    Lee, Eun-Sook; Chen, Hongtao; Hardman, Chadwick; Simm, Anthony; Charlton, Clivel

    2009-01-01

    Aims Excessive methylation may be a precipitating factor for Parkinson’s disease (PD) since S-adenosylmethionine (SAM), the endogenous methyl donor, induces PD-like changes when injected into the rat brain. The hydrolysis of the methyl ester bond of the methylated proteins produces methanol. Since methanol is oxidized into formaldehyde, and formaldehyde into formic acid in the body, we investigated the effects of SAM on the production of methanol, formaldehyde and formic acid in rat brain striatal homogenates and the toxicity of these products in PC12 cells. Main methods radio-enzymatic and colorimetric assays, cell viability, Western blot. Key findings SAM increased the formation of methanol, formaldehyde and formic acid in a concentration and time-dependent manner. Concentrations of [3H-methyl]-SAM at 0.17, 0.33, 0.67 and 1.34 nM produced 3.8, 8.0, 18.3 and 34.4 fmol/mg protein/h of [3H] methanol in rat striatal homogenates, respectively. SAM also significantly generated formaldehyde and formic acid in striatal homogenates. Formaldehyde was the most toxic metabolite to differentiated PC12 pheochromocytoma cells in cell culture studies, indicating that formaldehyde formed endogenously may contribute to neuronal damage in excessive methylation conditions. Subtoxic concentration of formaldehyde decreased the expression of tyrosine hydroxylase, the limiting factor in dopamine synthesis. Formaldehyde was more toxic to catecholaminergic PC12 cells than C6 glioma cells, indicating that neurons are more vulnerable to formaldehyde than glia cells. Significance We suggest that excessive carboxylmethylation of proteins might be involved in the SAM-induced PD-like changes and in the aging process via the toxic effects of formaldehyde. PMID:18930743

  4. Metathesis-mediated synthesis of (R)-10-methyl-2-tridecanone, the southern corn rootworm pheromone.

    PubMed

    Shikichi, Yasumasa; Mori, Kenji

    2012-01-01

    (R)-10-Methyl-2-tridecanone, the female sex pheromone of the southern corn rootworm (Diabrotica undecimpunctata howardi Barber), was synthesized in 9 steps from methyl (S)-3-hydroxy-2-methylpropanoate in a 15.7% overall yield. Olefin cross metathesis between (R)-6-methyl-1-nonene and 5-hexen-2-one employing Grubbs' first-generation catalyst was the key step of the synthesis.

  5. Deuterium incorporation experiments from (3R)- and (3S)-[3-2H]leucine into characteristic isoprenoidal lipid-core of halophilic archaea suggests the involvement of isovaleryl-CoA dehydrogenase.

    PubMed

    Yamauchi, Noriaki; Tanoue, Ryo

    2017-11-01

    The stereochemical reaction course for the two C-3 hydrogens of leucine to produce a characteristic isoprenoidal lipid in halophilic archaea was observed using incubation experiments with whole cell Halobacterium salinarum. Deuterium-labeled (3R)- and (3S)-[3- 2 H]leucine were freshly prepared as substrates from 2,3-epoxy-4-methyl-1-pentanol. Incorporation of deuterium from (3S)-[3- 2 H]leucine and loss of deuterium from (3R)-[3- 2 H]leucine in the lipid-core of H. salinarum was observed. Taken together with the results of our previous report, involving the incubation of chiral-labeled [5- 2 H]leucine, these results strongly suggested an involvement of isovaleryl-CoA dehydrogenase in leucine conversion to isoprenoid lipid in halophilic archaea. The stereochemical course of the reaction (anti-elimination) might have been the same as that previously reported for mammalian enzyme reactions. Thus, these results suggested that branched amino acids were metabolized to mevalonate in archaea in a manner similar to other organisms.

  6. A fluorescent turn-on H2S-responsive probe: design, synthesis and application.

    PubMed

    Zhang, Yufeng; Chen, Haiyan; Chen, Dan; Wu, Di; Chen, Xiaoqiang; Liu, Sheng Hua; Yin, Jun

    2015-10-14

    Hydrogen sulfide (H2S) is considered as the third signaling molecule in vivo and it plays an important role in various physiological processes and pathological processes in vivo, such as vasodilation, apoptosis, neurotransmission, ischemia/reperfusion-induced injury, insulin secretion and inflammation. Developing a highly selective and sensitive method that can detect H2S in the biological system is very important. In this work, a colorimetric and "turn-on" fluorescent probe is developed. Furthermore, this probe displays a highly selective response to H2S in aqueous solution and possesses good capability for bioimaging H2S without interference in living cells. The results suggest that a H2S-selective probe has good water-solubility, biocompatibility and cell-penetrability and can serve as an efficient tool for probing H2S in the cell level.

  7. Microwave-assisted synthesis of NiS2 nanostructures for supercapacitors and cocatalytic enhancing photocatalytic H2 production.

    PubMed

    Pang, Huan; Wei, Chengzhen; Li, Xuexue; Li, Guochang; Ma, Yahui; Li, Sujuan; Chen, Jing; Zhang, Jiangshan

    2014-01-06

    Uniform NiS2 nanocubes are successfully synthesized with a microwave-assisted method. Interestingly, NiS2 nanocubes, nanospheres and nanoparticles are obtained by controlling microwave reaction time. NiS2 nanomaterials are primarily applied to supercapacitors and cocatalytic enhancing photocatalytic H2 production. Different morphologies of NiS2 nanostructures show different electrochemical and cocatalytic enhancing H2 production activities. Benefited novel nanostructures, NiS2 nanocube electrodes show a large specific capacitance (695 F g(-1) at 1.25 A g(-1)) and excellent cycling performance (the retention 93.4% of initial specific capacitance after 3000 cycles). More importantly, NiS2 nanospheres show highly cocatalytic enhancing photocatalytic for H2 evolution, in which the photocatalytic H2 production is up to 3400 μmol during 12 hours under irradiation of visible light (λ>420 nm) with an average H2 production rate of 283 μmol h(-1).

  8. Microwave-assisted synthesis of NiS2 nanostructures for supercapacitors and cocatalytic enhancing photocatalytic H2 production

    NASA Astrophysics Data System (ADS)

    Pang, Huan; Wei, Chengzhen; Li, Xuexue; Li, Guochang; Ma, Yahui; Li, Sujuan; Chen, Jing; Zhang, Jiangshan

    2014-01-01

    Uniform NiS2 nanocubes are successfully synthesized with a microwave-assisted method. Interestingly, NiS2 nanocubes, nanospheres and nanoparticles are obtained by controlling microwave reaction time. NiS2 nanomaterials are primarily applied to supercapacitors and cocatalytic enhancing photocatalytic H2 production. Different morphologies of NiS2 nanostructures show different electrochemical and cocatalytic enhancing H2 production activities. Benefited novel nanostructures, NiS2 nanocube electrodes show a large specific capacitance (695 F g-1 at 1.25 A g-1) and excellent cycling performance (the retention 93.4% of initial specific capacitance after 3000 cycles). More importantly, NiS2 nanospheres show highly cocatalytic enhancing photocatalytic for H2 evolution, in which the photocatalytic H2 production is up to 3400 μmol during 12 hours under irradiation of visible light (λ>420 nm) with an average H2 production rate of 283 μmol h-1.

  9. Cfr and RlmN contain a single [4Fe-4S] cluster, which directs two distinct reactivities for S-adenosylmethionine: methyl transfer by SN2 displacement and radical generation.

    PubMed

    Grove, Tyler L; Radle, Matthew I; Krebs, Carsten; Booker, Squire J

    2011-12-14

    The radical SAM (RS) proteins RlmN and Cfr catalyze methylation of carbons 2 and 8, respectively, of adenosine 2503 in 23S rRNA. Both reactions are similar in scope, entailing the synthesis of a methyl group partially derived from S-adenosylmethionine (SAM) onto electrophilic sp(2)-hybridized carbon atoms via the intermediacy of a protein S-methylcysteinyl (mCys) residue. Both proteins contain five conserved Cys residues, each required for turnover. Three cysteines lie in a canonical RS CxxxCxxC motif and coordinate a [4Fe-4S]-cluster cofactor; the remaining two are at opposite ends of the polypeptide. Here we show that each protein contains only the one "radical SAM" [4Fe-4S] cluster and the two remaining conserved cysteines do not coordinate additional iron-containing species. In addition, we show that, while wild-type RlmN bears the C355 mCys residue in its as-isolated state, RlmN that is either engineered to lack the [4Fe-4S] cluster by substitution of the coordinating cysteines or isolated from Escherichia coli cultured under iron-limiting conditions does not bear a C355 mCys residue. Reconstitution of the [4Fe-4S] cluster on wild-type apo RlmN followed by addition of SAM results in rapid production of S-adenosylhomocysteine (SAH) and the mCys residue, while treatment of apo RlmN with SAM affords no observable reaction. These results indicate that in Cfr and RlmN, SAM bound to the unique iron of the [4Fe-4S] cluster displays two reactivities. It serves to methylate C355 of RlmN (C338 of Cfr), or to generate the 5'-deoxyadenosyl 5'-radical, required for substrate-dependent methyl synthase activity. © 2011 American Chemical Society

  10. Photoabsorption and photoionization cross sections of NH3, PH3, H2S, C2H2, and C2H4 in the VUV region

    NASA Technical Reports Server (NTRS)

    Xia, T. J.; Chien, T. S.; Wu, C. Y. Robert; Judge, D. L.

    1991-01-01

    Using synchrotron radiation as a continuum light source, the photoabsorption and photoionization cross sections of NH3, PH3, H2S, C2H2, and C2H4 have been measured from their respective ionization thresholds to 1060 A. The vibrational constants associated with the nu(2) totally symmetric, out-of-plane bending vibration of the ground electronic state of PH3(+) have been obtained. The cross sections and quantum yields for producing neutral products through photoexcitation of these molecules in the given spectral regions have also been determined. In the present work, autoionization processes were found to be less important than dissociation and predissociation processes in NH3, PH3, and C2H4. Several experimental techniques have been employed in order to examine the various possible systematic errors critically.

  11. Identification of Hydrogen Disulfanes and Hydrogen Trisulfanes in H2S Bottle, in Flint, and in Dry Mineral White Wine.

    PubMed

    Starkenmann, Christian; Chappuis, Charles Jean-Francois; Niclass, Yvan; Deneulin, Pascale

    2016-11-30

    Through the accidental contamination of a gas cylinder of H 2 S, the importance of polysulfanes for flint, gun powder, and match odors was discovered. The hydrogen disulfane was prepared from disulfanediylbis[methyl(diphenyl)silane], and its odor descriptor was evaluated in the gas phase from a gas chromatograph coupled to an olfaction port. The occurrence of this compound in flint and pebbles was confirmed by analyses after derivatization with pentafluorobromobenzene. The occurrence of this sulfane was also confirmed in two dry white Swiss Chasselas wines, sorted by a large-scale sensory analysis from 80 bottles and evaluated by 62 wine professionals. The occurrence of disulfane was confirmed for the two wines described as the most mineral. Polysulfane comprises a class of compounds contributing to the flint odor and that may contribute to the wine mineral odor descriptor. Due to the high volatility and instability pure HSSH was not isolated but kept in solution and its odor profile was described by gas chromatography coupled to an olfaction port as flint, matches, and fireworks with a higher odor intensity compared to H 2 S.

  12. Diastereoselective syntheses of 3-aryl-5-(arylalkyl)-6-methyl-1-(1-phenylethyl)thioxotetrahydropyrimidin-4(1H)-ones: a stereochemical perspective from endo and exocyclic chiral centres.

    PubMed

    Kumar, Varun; Raghavaiah, Pallepogu; Mobin, Shaikh M; Nair, Vipin A

    2010-11-07

    Diastereoselective syntheses of 3-aryl-(S/R)-6-methyl-1-[(S/R)-1-phenylethyl)]-2-thioxotetrahydro pyrimidin-4(1H)-ones were achieved in good yields by the condensation of aryl isothiocyanates with ethyl 3-(1-phenylethylamino)butanoate in a one-pot reaction. Benzylation of these substrates illustrated that the orientations of the exocylic and endocylic groups determine the stereochemical outcome of the product formed.

  13. 78 FR 32157 - Methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate; Exemption from the Requirement of a Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... assessment of exposures and risks associated with methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate follows... received and the nature of the adverse effects caused by methyl 5-(dimethylamino)-2-methyl-5- oxopentanoate... treatment with methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate. A Mammalian Erythrocyte Micronucleus Test...

  14. Synthesis of methyl 2-O- and 3-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside.

    PubMed

    Rana, S S; Matta, K L

    1986-09-01

    Methyl 3,4,6-tri-O-benzyl-2-O-[6-O-(tert-butyldiphenylsilyl)-alpha-D- mannopyranosyl]-alpha-D-mannopyranoside (2) was synthesized by treatment of methyl 3,4,6-tri-O-benzyl-2-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside with tert-butylchlorodiphenylsilane in the presence of imidazole. Isopropylidenation, followed by oxidation with pyridinium chlorochromate, and stereoselective reduction with sodium borohydride, converted 2 into methyl 3,4,6-tri-O-benzyl-2-O-[6-O-(tert-butyldiphenylsilyl)-2,3-O-isopro pylidene- alpha-D-talopyranosyl]-alpha-D-mannopyranoside (5). Treatment of 5 with a molar solution of tetrabutylammonium fluoride in dry oxolane produced a diol which, on O-de-isopropylidenation followed by catalytic hydrogenolysis, afforded the disaccharide glycoside methyl 2-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside. Synthesis of methyl 3-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside was accomplished by a similar reaction-sequence. The structures of the final disaccharides, and of various other intermediates, were established by 1H- and 13C-n.m.r. spectroscopy.

  15. Trichlorido(tetra­hydro­furan){(1,2,3,3a,7a-η)-1-[2-(1-trimethyl­silyl-1H-imidazol-2-yl-κN 3)-1-methyl­prop­yl]inden­yl}zirconium(IV)

    PubMed Central

    Guan, Shengzhou; Nie, Wanli; Borzov, Maxim V.

    2011-01-01

    The title compound, [ZrCl3(C19H25N2Si)(C4H8O)], was prepared from bis­(N,N-dimethyl­amido-κN)(2-{2-[(1,2,3,3a,7a-η)-inden­yl]-2-methyl­prop­yl}-1H-imidazolido-κN 1)zirconium(IV) [(C16H16N2)Zr(NMe2)] by reaction with excess Me3SiCl in tetra­hydro­furan (THF) at elevated temperature. The crystal studied contained a minor non-merohedral twin contaminant [6.3 (4)%] which was taken into account during the refinement. The coordination polyhedron of the ZrIV atom is a distorted octa­hedron [assuming that the five-membered ring of the indenyl group (Cp) occupies one coordination site], with the Cp group and a THF O atom at the apical positions and the three Cl and ligating N atoms at the equatorial positions. The Zr, Si and the methyl­ene C atoms deviate noticeably from the imidazole ring plane [by −0.197 (5), −0.207 (5) and 0.119 (6) Å, respectively]. The THF ligand adopts an envelope conformation. PMID:21754279

  16. 4-(2-Methyl-4-chlorophenoxy) butyric acid (MCPB)

    Integrated Risk Information System (IRIS)

    Integrated Risk Information System ( IRIS ) Chemical Assessment Summary U.S . Environmental Protection Agency National Center for Environmental Assessment This IRIS Summary has been removed from the IRIS database and is available for historical reference purposes . ( July 2016 ) 4 - ( 2 - Methyl - 4

  17. Modes of physiologic H2S signaling in the brain and peripheral tissues.

    PubMed

    Paul, Bindu D; Snyder, Solomon H

    2015-02-10

    Hydrogen sulfide (H2S), once associated with rotten eggs and sewers, is now recognized as a gasotransmitter that is synthesized in vivo in a regulated fashion. This ancient gaseous molecule has been retained throughout evolution to perform various roles in different life forms. H2S modulates important signaling functions in diverse cellular processes ranging from regulation of blood pressure to redox homeostasis. One of the modes by which H2S signals is by post-translational modification of reactive cysteine residues in a process designated as sulfhydration, resulting in conversion of the -SH groups of target cysteine residues to -SSH. Using the modified biotin-switch assay and a fluorescent maleimide-based analysis, sulfhydration of several proteins has been detected in various cell types. Aberrant sulfhydration patterns occur in neurodegenerative conditions such as Parkinson's disease. The exact concentration, source of H2S, and conditions under which various stores of H2S are utilized have not been fully elucidated. Currently, available inhibitors of the biosynthetic enzymes of H2S lack sufficient specificity to shed light on detailed mechanisms of H2S action. Probes with a higher sensitivity that can reliably detect cellular and tissue H2S levels are yet to be developed. Availability of advanced probes and biosynthesis inhibitors would help in the measurement of real-time changes of endogenous H2S levels in an in vivo context. The study of the dynamics of sulfhydration and nitrosylation of critical cysteine residues of regulatory proteins involved in physiology and pathophysiology is an area of interest for the future.

  18. Heterogeneous Photochemistry of Agrochemicals at the Leaf Surface: A Case Study of Plant Activator Acibenzolar-S-methyl.

    PubMed

    Sleiman, M; de Sainte Claire, P; Richard, C

    2017-09-06

    The photoreactivity of plant activator benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH), commonly named acibenzolar-S-methyl, was studied on the surfaces of glass, paraffinic wax films, and apple leaves. Experiments were carried out in a solar simulator using pure and formulated BTH (BION). Surface photoproducts were identified using liquid chromatography coupled with electrospray ionization and high-resolution Orbitrap mass spectrometry, while volatile photoproducts were characterized using an online thermal desorption system coupled to a gas chromatography-mass spectrometry (GC-MS) system. Pure BTH degraded quickly on wax surfaces with a half-life of 5.0 ± 0.5 h, whereas photolysis of formulated BTH was 7 times slower (t 1/2 = 36 ± 14 h). On the other hand, formulated BTH was found to photolyze quickly on detached apple leaves with a half-life of 2.8 h ± 0.4 h. This drastic difference in photoreactivity was attributed to the nature and spreading of the BTH deposit, as influenced by the surfactant and surface characteristics. Abiotic stress of irradiated apple leaf was also shown to produce OH radicals which might contribute to the enhanced photodegradability. Eight surface photoproducts were identified, whereas GC-MS analyses revealed the formation of gaseous dimethyl disulfide and methanethiol. The yield of dimethyl disulfide ranged between 1.5% and 12%, and a significant fraction of dimethyl disulfide produced was found to be absorbed by the leaf. This is the first study to report on the formation of volatile chemicals and OH radicals during agrochemical photolysis on plant surfaces. The developed experimental approach can provide valuable insights into the heterogeneous photoreactivity of sprayed agrochemicals and could help improve dissipation models.

  19. Polymethylated [Fe(η6-arene)2]2+ dications: methyl-group rearrangements and application of the EINS mechanism.

    PubMed

    Štíbr, Bohumil; Bakardjiev, Mario; Hájková, Zuzana; Holub, Josef; Padělková, Zdenka; Růžička, Aleš; Kennedy, John D

    2011-06-14

    Reactions between the methylated arenes ArMe(n) [where ArMe(n) = C(6)Me(n)H((6-n)), and n = 1-6] and FeCl(2) in heptane at 90 °C in the presence of anhydrous AlCl(3) give, for the arenes with n = 1-5, extensive isomerisations and disproportionations involving the methyl groups on the arene rings, and the formation of mixtures of [Fe(ArMe(n))(2)](2+) dications that defy separation into pure species. GC-MS studies of AlCl(3)/mesitylene and AlCl(3)/durene reactions in the absence of FeCl(2) (90 °C, 2 h) allow quantitative assessments of the rearrangements, and the EINS mechanism (electrophile-induced nucleophilic substitution) is applied to rationalise the phenomena. By contrast, ArMe(n) / FeCl(2) /AlCl(3) reactions in heptane for 24-36 h at room-temperature proceed with no rearrangements, allowing the synthesis of the complete series of pure [Fe(ArMen)](2+) cations in yields of 48-71%. The pure compounds are characterised by (1)H NMR spectroscopy and electrospray-ionization mass-spectrometry (ESI-MS), and the structures of [Fe(m-xylene)(2)][PF(6)](2) and [Fe(durene)(2)][PF(6)](2) are established by single-crystal X-ray diffraction analyses.

  20. H2S adsorption on chromium, chromia, and gold/chromia surfaces: Photoemission studies

    NASA Astrophysics Data System (ADS)

    Rodriguez, J. A.; Chaturvedi, S.; Kuhn, M.; van Ek, J.; Diebold, U.; Robbert, P. S.; Geisler, H.; Ventrice, C. A., Jr.

    1997-12-01

    The reaction of H2S with chromium, chromia, and Au/chromia films grown on a Pt(111) crystal has been investigated using synchrotron-based high-resolution photoemission spectroscopy. At 300 K, H2S completely decomposes on polycrystalline chromium producing a chemisorbed layer of S that attenuates the Cr 3d valence features. No evidence was found for the formation of CrSx species. The dissociation of H2S on Cr3O4 and Cr2O3 films at room temperature produces a decrease of 0.3-0.8 eV in the work function of the surface and significant binding-energy shifts (0.2-0.6 eV) in the Cr 3p core levels and Cr 3d features in the valence region. The rate of dissociation of H2S increases following the sequence: Cr2O3H2S than the valence and conduction bands of the chromium oxides. This leads to a large dissociation probability for H2S on the metal, and a low dissociation probability for the molecule on the oxides. In the case of Cr3O4 and Cr2O3, there is a correlation between the size of the band gap in the oxide and its reactivity toward H2S. The uptake of sulfur by the oxides significantly increases when they are "promoted" with gold. The Au/Cr2O3 surfaces exhibit a unique electronic structure in the valence region and a larger ability to dissociate H2S than polycrystalline Au or pure Cr2O3. The results of ab initio SCF calculations for the adsorption of H2S on AuCr4O6 and AuCr10O15 clusters show a shift of electrons from the gold toward the oxide unit that enhances the strength of the Au(6s)↔H2S(5a1,2b1) bonding interactions and facilitates the decomposition of the molecule.

  1. ZnO-carbon nanofibers for stable, high response, and selective H2S sensors.

    PubMed

    Zhang, Jitao; Zhu, Zijian; Chen, Changmiao; Chen, Zhi; Cai, Mengqiu; Qu, Baihua; Wang, Taihong; Zhang, Ming

    2018-07-06

    Hydrogen sulfide (H 2 S), as a typical atmospheric pollutant, is neurotoxic and flammable even at a very low concentration. In this study, we design stable H 2 S sensors based on ZnO-carbon nanofibers. Nanofibers with 30.34 wt% carbon are prepared by a facial electrospinning route followed by an annealing treatment. The resulting H 2 S sensors show excellent selectivity and response compared to the pure ZnO nanofiber H 2 S sensors, particularly the response in the range of 102-50 ppm of H 2 S. Besides, they exhibited a nearly constant response of approximately 40-20 ppm of H 2 S over 60 days. The superior performance of these H 2 S sensors can be attributed to the protection of carbon, which ensures the high stability of ZnO, and oxygen vacancies that improve the response and selectivity of H 2 S. The good performance of ZnO-carbon H 2 S sensors suggests that composites with oxygen vacancies prepared by a facial electrospinning route may provide a new research strategy in the field of gas sensors, photocatalysts, and semiconductor devices.

  2. H2S adsorption and dissociation on NH-decorated graphene: A first principles study

    NASA Astrophysics Data System (ADS)

    Faye, Omar; Eduok, Ubong; Szpunar, Jerzy; Samoura, Almoustapha; Beye, Aboubaker

    2018-02-01

    The removal of H2S gas poses an emerging environmental concern because of the lack of knowledge of an efficient adsorbent. A detailed theoretical study of H2S adsorption and dissociation on NH-doped graphene (GNH) has been carried out by means of density theory calculations. Our results reveal that the adsorption of H2S molecule on GNH composite is enhanced by the presence of active site such as the NH radicals. These NH radical sites formed NHsbnd H bonds and increase the charge transfer from H2S to GNH. The dissociation of the adsorbed H2S molecule leads the chemisorption of SH radical via H-transfer to GNH, while the formation of GNH2 at a weight percent of 3.76 wt% of NH radical is an endothermic process with an energy of 0.299 eV and 0.358 eV for ortho and para-position respectively. However, at 7.25 wt% NH radical, we observed a complete dissociation of H2S molecule with an energy released of 0.711 eV for the chemisorbed S atom on GN2H4. Moreover, the H-transfer of the second H atom of H2S molecule at 3.76 wt% was energetic unfavorable. The trend of predicted results within this study reveals that NH-doped graphene (GNH) successfully adsorbed and eliminated of H2S molecule; this work unveils definitive theoretical procedures which can be tested and validated experimentally.

  3. Studies on two-gap superconductivity in 2H-NbS2

    NASA Astrophysics Data System (ADS)

    Kačmarčík, J.; Pribulová, Z.; Marcenat, C.; Klein, T.; Rodière, P.; Cario, L.; Samuely, P.

    2010-12-01

    We present the ac-calorimetry measurements of superconducting 2H-NbS2 in the temperature range down to 0.6 K and magnetic fields up to 8 T. The temperature and magnetic field dependence of the electronic specific heat consistently indicate existence of two superconducting energy gaps in the system - one of them with the coupling ratio below the BCS weak-coupling limit and the other above that value. These results support previous findings by scanning tunneling microscopy and spectroscopy measurements [I. Guillamón, H. Suderow, S. Vieira, L. Cario, et al., Phys. Rev. Lett. 101 (2008) 166407] of two pronounced features in density of states related to a two-gap superconductivity in this system.

  4. Electron collisions with methyl-substituted ethylenes: Cross section measurements and calculations for 2-methyl–2-butene and 2,3-dimethyl–2-butene

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Szmytkowski, Czesław, E-mail: czsz@mif.pg.gda.pl; Stefanowska, Sylwia; Zawadzki, Mateusz

    We report electron-scattering cross sections determined for 2-methyl–2-butene [(H{sub 3}C)HC = C(CH{sub 3}){sub 2}] and 2,3-dimethyl–2-butene [(H{sub 3}C){sub 2}C = C(CH{sub 3}){sub 2}] molecules. Absolute grand-total cross sections (TCSs) were measured for incident electron energies in the 0.5–300 eV range, using a linear electron-transmission technique. The experimental TCS energy dependences for the both targets appear to be very similar with respect to the shape. In each TCS curve, three features are discernible: the resonant-like structure located around 2.6–2.7 eV, the broad distinct enhancement peaking near 8.5 eV, and a weak hump in the vicinity of 24 eV. Theoretical integral elasticmore » (ECS) and ionization (ICS) cross sections were computed up to 3 keV by means of the additivity rule (AR) approximation and the binary-encounter-Bethe method, respectively. Their sums, (ECS+ICS), are in a reasonable agreement with the respective measured TCSs. To examine the effect of methylation of hydrogen sides in the ethylene [H{sub 2}C = CH{sub 2}] molecule on the TCS, we compared the TCS energy curves for the sequence of methylated ethylenes: propene [H{sub 2}C = CH(CH{sub 3})], 2-methylpropene [H{sub 2}C = C(CH{sub 3}){sub 2}], 2-methyl–2-butene [(H{sub 3}C)HC = C(CH{sub 3}){sub 2}], and 2,3-dimethyl–2-butene [(H{sub 3}C){sub 2}C = C(CH{sub 3}){sub 2}], measured in the same laboratory. Moreover, the isomeric effect is also discussed for the C{sub 5}H{sub 10} and C{sub 6}H{sub 12} compounds.« less

  5. 2′-O Methylation of Internal Adenosine by Flavivirus NS5 Methyltransferase

    PubMed Central

    Dong, Hongping; Chang, David C.; Hua, Maggie Ho Chia; Lim, Siew Pheng; Chionh, Yok Hian; Hia, Fabian; Lee, Yie Hou; Kukkaro, Petra; Lok, Shee-Mei; Dedon, Peter C.; Shi, Pei-Yong

    2012-01-01

    RNA modification plays an important role in modulating host-pathogen interaction. Flavivirus NS5 protein encodes N-7 and 2′-O methyltransferase activities that are required for the formation of 5′ type I cap (m7GpppAm) of viral RNA genome. Here we reported, for the first time, that flavivirus NS5 has a novel internal RNA methylation activity. Recombinant NS5 proteins of West Nile virus and Dengue virus (serotype 4; DENV-4) specifically methylates polyA, but not polyG, polyC, or polyU, indicating that the methylation occurs at adenosine residue. RNAs with internal adenosines substituted with 2′-O-methyladenosines are not active substrates for internal methylation, whereas RNAs with adenosines substituted with N6-methyladenosines can be efficiently methylated, suggesting that the internal methylation occurs at the 2′-OH position of adenosine. Mass spectroscopic analysis further demonstrated that the internal methylation product is 2′-O-methyladenosine. Importantly, genomic RNA purified from DENV virion contains 2′-O-methyladenosine. The 2′-O methylation of internal adenosine does not require specific RNA sequence since recombinant methyltransferase of DENV-4 can efficiently methylate RNAs spanning different regions of viral genome, host ribosomal RNAs, and polyA. Structure-based mutagenesis results indicate that K61-D146-K181-E217 tetrad of DENV-4 methyltransferase forms the active site of internal methylation activity; in addition, distinct residues within the methyl donor (S-adenosyl-L-methionine) pocket, GTP pocket, and RNA-binding site are critical for the internal methylation activity. Functional analysis using flavivirus replicon and genome-length RNAs showed that internal methylation attenuated viral RNA translation and replication. Polymerase assay revealed that internal 2′-O-methyladenosine reduces the efficiency of RNA elongation. Collectively, our results demonstrate that flavivirus NS5 performs 2′-O methylation of internal adenosine of

  6. Characterization of H2S removal and microbial community in landfill cover soils.

    PubMed

    Xia, Fang-Fang; Zhang, Hong-Tao; Wei, Xiao-Meng; Su, Yao; He, Ruo

    2015-12-01

    H2S is a source of odors at landfills and poses a threat to the surrounding environment and public health. In this work, compared with a usual landfill cover soil (LCS), H2S removal and biotransformation were characterized in waste biocover soil (WBS), an alternative landfill cover material. With the input of landfill gas (LFG), the gas concentrations of CH4, CO2, O2, and H2S, microbial community and activity in landfill covers changed with time. Compared with LCS, lower CH4 and H2S concentrations were detected in the WBS. The potential sulfur-oxidizing rate and sulfate-reducing rate as well as the contents of acid-volatile sulfide, SO4(2-), and total sulfur in the WBS and LCS were all increased with the input of LFG. After exposure to LFG for 35 days, the sulfur-oxidizing rate of the bottom layer of the WBS reached 82.5 μmol g dry weight (d.w.)(-1) day(-1), which was 4.3-5.4 times of that of LCS. H2S-S was mainly deposited in the soil covers, while it escaped from landfills to the atmosphere. The adsorption, absorption, and biotransformation of H2S could lead to the decrease in the pH values of landfill covers; especially, in the LCS with low pH buffer capacity, the pH value of the bottom layer dropped to below 4. Pyrosequencing of 16S ribosomal RNA (rRNA) gene showed that the known sulfur-metabolizing bacteria Ochrobactrum, Paracoccus, Comamonas, Pseudomonas, and Acinetobacter dominated in the WBS and LCS. Among them, Comamonas and Acinetobacter might play an important role in the metabolism of H2S in the WBS. These findings are helpful to understand sulfur bioconversion process in landfill covers and to develop techniques for controlling odor pollution at landfills.

  7. H3K27 methylation and H3S28 phosphorylation-dependent transcriptional regulation by INHAT subunit SET/TAF-Iβ.

    PubMed

    Kim, Ji-Young; Kim, Kee-Beom; Son, Hye-Ju; Chae, Yun-Cheol; Oh, Si-Taek; Kim, Dong-Wook; Pak, Jhang Ho; Seo, Sang-Beom

    2012-09-21

    Significant progress has been made in understanding the relationship between histone modifications and 'reader' molecules and their effects on transcriptional regulation. A previously identified INHAT complex subunit, SET/TAF-Iβ, binds to histones and inhibits histone acetylation. To investigate the binding specificities of SET/TAF-Iβ to various histone modifications, we employed modified histone tail peptide array analyses. SET/TAF-Iβ strongly recognized PRC2-mediated H3K27me1/2/3; however, the bindings were completely disrupted by H3S28 phosphorylation. We have demonstrated that SET/TAF-Iβ is sequentially recruited to the target gene promoter ATF3 after the PRC2 complex via H3K27me recognition and may offer additive effects in the repression of the target gene. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  8. Effect of light on 2H/1H fractionation in lipids from continuous cultures of the diatom Thalassiosira pseudonana

    NASA Astrophysics Data System (ADS)

    Sachs, Julian P.; Maloney, Ashley E.; Gregersen, Joshua

    2017-07-01

    Continuous cultures of the marine diatom Thalassiosira pseudonana were grown at irradiances between 6 and 47 μmol m-2 s-1 in order to evaluate the effect of light on hydrogen isotope fractionation in lipids. δ2H values increased with irradiance in phytol by 1.1‰ (μmol m-2 s-1)-1 and by 0.3‰ (μmol m-2 s-1)-1 in the C14:0 fatty acid, but decreased by 0.8‰ (μmol m-2 s-1)-1 in the sterol 24-methyl-cholesta-5,24(28)-dien-3β-ol (C28Δ5,24(28)). The anticorrelation between δ2H values in C28Δ5,24(28) and irradiance is attributed to enhanced sterol precursor synthesis via the plastidic methylerythritol phosphate (MEP) pathway at high irradiance, relative to the cytosolic mevalonic acid (MVA) pathway, and the supposition that MEP precursors are 2H-depleted compared to MVA precursors because they incorporate a greater proportion of hydrogen from photosynthetically produced NADPH. Increasing δ2H values of phytol and C14:0 with irradiance is attributed to a greater proportion of pyruvate, the last common precursor to both lipids, being sourced from glycolysis in the mitochondria and cytosol, where enhanced incorporation of metabolic NADPH and further hydrogen exchange with cell water can enrich pyruvate with 2H relative to pyruvate from the chloroplast. Irrespective of the biosynthetic mechanisms responsible for the 2H/1H fractionation response to light, the high sensitivity of lipid δ2H values in T. pseudonana continuous cultures would result in -30‰ to +40‰ variations in δ2H over a 40 μmol m-2 s-1 range in sub-saturating irradiance if expressed in the environment, depending on the lipid.

  9. H2S Injection and Sequestration into Basalt - The SulFix Project

    NASA Astrophysics Data System (ADS)

    Gudbrandsson, S.; Moola, P.; Stefansson, A.

    2014-12-01

    Atmospheric H2S emissions are among major environmental concern associated with geothermal energy utilization. It is therefore of great importance for the geothermal power sector to reduce H2S emissions. Known solutions for H2S neutralization are both expensive and include production of elemental sulfur and sulfuric acid that needs to be disposed of. Icelandic energy companies that utilize geothermal power for electricity production have decided to try to find an environmentally friendly and economically feasible solution to reduce the H2S emission, in a joint venture called SulFix. The aim of SulFix project is to explore the possibilities of injecting H2S dissolved in water into basaltic formations in close proximity to the power plants for permanent fixation as sulfides. The formation of sulfides is a natural process in geothermal systems. Due to basalt being rich in iron and dissolving readily at acidic conditions, it is feasible to re-inject the H2S dissolved in water, into basaltic formations to form pyrite. To estimate the mineralization rates of H2S, in the basaltic formation, flow through experiments in columns were conducted at various H2S concentrations, temperatures (100 - 240°C) and both fresh and altered basaltic glass. The results indicate that pyrite rapidly forms during injection into fresh basalt but the precipiation in altered basalt is slower. Three different alteration stages, as a function of distance from inlet, can be observed in the column with fresh basaltic glass; (1) dissolution features along with precipitation, (2) precipitation increases, both sulfides and other secondary minerals and (3) the basalt looks to be unaltered and little if any precipitation is observed. The sulfur has precipitated in the first half of the column and thereafter the solution is possibly close to be supersaturated with respect to the rock. These results indicate that the H2S sequestration into basalt is possible under geothermal conditions. The rate limiting

  10. Crystal structures of three 3-chloro-3-methyl-2,6-di­aryl­piperidin-4-ones

    PubMed Central

    Arulraj, R.; Sivakumar, S.; Kaur, Manpreet; Jasinski, Jerry P.

    2017-01-01

    The syntheses and crystal structure of 3-chloro-3-methyl-r-2,c-6-di­phenyl­piperidin-4-one, C18H18ClNO, (I), 3-chloro-3-methyl-r-2,c-6-di-p-tolyl­piperidin-4-one, C20H22ClNO, (II), and 3-chloro-3-methyl-r-2,c-6-bis­(4-chloro­phen­yl)piperidin-4-one, C18H16Cl3NO, (III), are described. In each structure, the piperidine ring adopts a chair conformation and dihedral angles between the mean planes of the phenyl rings are 58.4 (2), 73.5 (5) and 78.6 (2)° in (I), (II) and (III), respectively. In the crystals, mol­ecules are linked into C(6) chains by weak N—H⋯O hydrogen bonds and C—H⋯π inter­actions are also observed. PMID:28217321

  11. 3,3-Dimethyl-1-[5-(1H-1,2,4-triazol-1-yl­meth­yl)-1,3,4-thia­diazol-2-ylsulfan­yl]butan-2-one

    PubMed Central

    Wei, Qing-Li; He, Fu-Jin; Li, Fang; Bi, Sai

    2008-01-01

    In the mol­ecule of the title compound, C11H15N5OS2, the thia­diazole and triazole rings are not coplanar, the dihedral angle formed by their mean planes being 59.9 (2)°. The exocyclic S atom, and the methyl­ene, carbonyl, tert-butyl and one methyl carbon form an approximately planar zigzag chain, which makes a dihedral angle of 74.6 (1)° with the thia­diazole ring. PMID:21201440

  12. Novel Energetic Compounds Based on 3-Methyl-1,2,5-Oxadiazole 2-Oxide

    NASA Astrophysics Data System (ADS)

    Xu, Zhen; Yang, Hongwei; Cheng, Guangbin

    2018-01-01

    Two derivatives of 3-methyl-1,2,5-oxadiazole 2-oxide, (E) 4-methyl-1,2,5-oxadiazole-3-carboxaldehyde 5-oxide (2,4,6-trinitrophenyl)hydrazone (1) and 2,2,2-trinitroethyl 4-methyl-1,2,5-oxadiazole-3-carboxylate 5-oxide (2), were designed, synthesized, and fully characterized. The structures of the new compounds were confirmed by single-crystal X-ray analysis. Physicochemical and energetic properties including density, thermal stability, and sensitivity were investigated, and energetic properties (e.g., detonation velocities and detonation pressures) were calculated using EXPLO5 code. The results indicated that compound 1 exhibits positive heat of formation of 448.0 kJ mol-1 and acceptable sensitivities (IS: 20 J, FS: 280 N). In addition, compound 2 possesses low melting point (99.92°C), moderate decomposition temperature (183.67°C), good detonation performances (D: 8430 m s-1; P: 31.5 GPa), and lower sensitivities (IS: 18 J; FS: 220 N), which suggest 2 has the potential to be melt-cast explosive.

  13. Role of Elemental Sulfur in Forming Latent Precursors of H2S in Wine.

    PubMed

    Jastrzembski, Jillian A; Allison, Rachel B; Friedberg, Elle; Sacks, Gavin L

    2017-12-06

    The level of hydrogen sulfide (H 2 S) can increase during abiotic storage of wines, and potential latent sources of H 2 S are still under investigation. We demonstrate that elemental sulfur (S 0 ) residues on grapes not only can produce H 2 S during fermentation but also can form precursors capable of generating additional H 2 S after bottle storage for 3 months. H 2 S could be released from S 0 -derived precursors by addition of a reducing agent (TCEP), but not by addition of strong brine to induce release of H 2 S from metal sulfide complexes. The size of the TCEP-releasable pool varied among yeast strains. Using the TCEP assay, multiple polar S 0 -derived precursors were detected following normal-phase preparative chromatography. Using reversed-phase liquid chromatography and high-resolution mass spectrometry, we detected an increase in the levels of diglutathione trisulfane (GSSSG) and glutathione disulfide (GSSG) in S 0 -fermented red wine and an increase in the levels of glutathione S-sulfonate (GSSO 3 - ) and tetrathionate (S 4 O 6 2- ) in S 0 -fermented white wine as compared to controls. GSSSG, but not S 4 O 6 2- , was shown to evolve H 2 S in the presence of TCEP. Pathways for the formation of GSSSG, GSSG, GSSO 3 - , and S 4 O 6 2- from S 0 are proposed.

  14. Electronic properties of in-plane phase engineered 1T'/2H/1T' MoS2

    NASA Astrophysics Data System (ADS)

    Thakur, Rajesh; Sharma, Munish; Ahluwalia, P. K.; Sharma, Raman

    2018-04-01

    We present the first principles studies of semi-infinite phase engineered MoS2 along zigzag direction. The semiconducting (2H) and semi-metallic (1T') phases are known to be stable in thin-film MoS2. We described the electronic and structural properties of the infinite array of 1T'/2H/1T'. It has been found that 1T'phase induced semi-metallic character in 2H phase beyond interface but, only Mo atoms in 2H phase domain contribute to the semi-metallic nature and S atoms towards semiconducting state. 1T'/2H/1T' system can act as a typical n-p-n structure. Also high holes concentration at the interface of Mo layer provides further positive potential barriers.

  15. Dynamics of DNA methylation and Histone H4 acetylation during floral bud differentiation in azalea

    PubMed Central

    2010-01-01

    Background The ability to control the timing of flowering is a key strategy for planning production in ornamental species such as azalea, however it requires a thorough understanding of floral transition. Floral transition is achieved through a complex genetic network and regulated by multiple environmental and endogenous cues. Dynamic changes between chromatin states facilitating or inhibiting DNA transcription regulate the expression of floral induction pathways in response to environmental and developmental signals. DNA methylation and histone modifications are involved in controlling the functional state of chromatin and gene expression. Results The results of this work indicate that epigenetic mechanisms such as DNA methylation and histone H4 acetylation have opposite and particular dynamics during the transition from vegetative to reproductive development in the apical shoots of azalea. Global levels of DNA methylation and histone H4 acetylation as well as immunodetection of 5-mdC and acetylated H4, in addition to a morphological study have permitted the delimitation of four basic phases in the development of the azalea bud and allowed the identification of a stage of epigenetic reprogramming which showed a sharp decrease of whole DNA methylation similar to that is defined in other developmental processes in plants and in mammals. Conclusion The epigenetic control and reorganization of chromatin seem to be decisive for coordinating floral development in azalea. DNA methylation and H4 deacetylation act simultaneously and co-ordinately, restructuring the chromatin and regulating the gene expression during soot apical meristem development and floral differentiation. PMID:20067625

  16. Pharmacokinetics of S-3-(4-acetylamino-phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamide in rats, a non-steroidal selective androgen receptor modulator

    PubMed Central

    KEARBEY, J. D.; WU, D.; GAO, W.; MILLER, D. D.; DALTON, J. T.

    2007-01-01

    1. S-3-(4-acetylamino-phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamide (also known as S-4) is a non-steroidal selective androgen receptor modulator demonstrating tissue-selective androgenic and anabolic effects. The purpose of the present study was to examine the systemic pharmacokinetics, elimination and oral bioavailability of S-4 in rats. 2. Thirty-five male Sprague–Dawley rats weighing approximately 250 g were randomly assigned to one of seven treatment groups. Intravenous doses of 0.5, 1, 10, and 30 mg kg−1 were given via a jugular catheter. Oral doses of 1, 10 and 30 mg kg−1 were administered via gavage. Plasma concentrations were determined using a validated high-performance liquid chromatography or by a high-performance liquid chromatography/mass spectrometry method. 3. Clearances ranged between 1.0 and 2.1 ml min−1 kg−1 and varied with dose. The volume of distribution was approximately 0.448 l kg−1 in all treatment groups. Oral bioavailability was also dose dependent, with the lower doses showing complete oral bioavailability. The half-life of S-4 over the dose range tested was between 2.6 and 5.3 h. 4. It was demonstrated that S-4 is rapidly absorbed, slowly cleared, and has a moderate volume of distribution in rats. The pharmacokinetics and oral bioavailability of S-4 indicate that it is an excellent candidate for clinical development. PMID:15204699

  17. Microwave-assisted synthesis of NiS2 nanostructures for supercapacitors and cocatalytic enhancing photocatalytic H2 production

    PubMed Central

    Pang, Huan; Wei, Chengzhen; Li, Xuexue; Li, Guochang; Ma, Yahui; Li, Sujuan; Chen, Jing; Zhang, Jiangshan

    2014-01-01

    Uniform NiS2 nanocubes are successfully synthesized with a microwave-assisted method. Interestingly, NiS2 nanocubes, nanospheres and nanoparticles are obtained by controlling microwave reaction time. NiS2 nanomaterials are primarily applied to supercapacitors and cocatalytic enhancing photocatalytic H2 production. Different morphologies of NiS2 nanostructures show different electrochemical and cocatalytic enhancing H2 production activities. Benefited novel nanostructures, NiS2 nanocube electrodes show a large specific capacitance (695 F g−1 at 1.25 A g−1) and excellent cycling performance (the retention 93.4% of initial specific capacitance after 3000 cycles). More importantly, NiS2 nanospheres show highly cocatalytic enhancing photocatalytic for H2 evolution, in which the photocatalytic H2 production is up to 3400 μmol during 12 hours under irradiation of visible light (λ>420 nm) with an average H2 production rate of 283 μmol h−1. PMID:24389929

  18. Two's company, three's a crowd: can H2S be the third endogenous gaseous transmitter?

    PubMed

    Wang, Rui

    2002-11-01

    Bearing the public image of a deadly "gas of rotten eggs," hydrogen sulfide (H2S) can be generated in many types of mammalian cells. Functionally, H2S has been implicated in the induction of hippocampal long-term potentiation, brain development, and blood pressure regulation. By acting specifically on KATP channels, H2S can hyperpolarize cell membranes, relax smooth muscle cells, or decrease neuronal excitability. The endogenous metabolism and physiological functions of H2S position this gas well in the novel family of endogenous gaseous transmitters, termed "gasotransmitters." It is hypothesized that H2S is the third endogenous signaling gasotransmitter, besides nitric oxide and carbon monoxide. This positioning of H2S will open an exciting field-H2S physiology-encompassing realization of the interaction of H2S and other gasotransmitters, sulfurating modification of proteins, and the functional role of H2S in multiple systems. It may shed light on the pathogenesis of many diseases related to the abnormal metabolism of H2S.

  19. (2-{[2-(1H-Benzimidazol-2-yl-κN 3)phen­yl]imino­methyl-κN}-5-methyl­phenolato-κO)chloridozinc(II)

    PubMed Central

    Eltayeb, Naser Eltaher; Teoh, Siang Guan; Chantrapromma, Suchada; Fun, Hoong-Kun

    2011-01-01

    In the title mononuclear complex, [Zn(C21H16N3O)Cl], the ZnII ion is coordinated in a distorted tetra­hedral geometry by two benzimidazole N atoms and one phenolate O atom from the tridentate Schiff base ligand and a chloride ligand. The benzimidazole ring system forms dihedral angles of 26.68 (9) and 56.16 (9)° with the adjacent benzene ring and the methyl­phenolate group benzene ring, respectively. In the crystal, mol­ecules are linked by N—H⋯Cl hydrogen bonds into chains along [100]. Furthermore, weak C—H⋯O and C—H⋯π inter­actions, in addition to π–π inter­actions with centroid–centroid distances in the range 3.5826 (13)–3.9681 (13) Å, are also observed. PMID:22065469

  20. The 2.2 A resolution structure of the O(H) blood-group-specific lectin I from Ulex europaeus.

    PubMed

    Audette, G F; Vandonselaar, M; Delbaere, L T

    2000-12-01

    The tertiary and quaternary structure of the lectin I from Ulex europaeus (UE-I) has been determined to 2.2 A resolution. UE-I is a dimeric metalloglycoprotein that binds the H-type 2 human blood group determinant [alpha-L-Fucalpha(1-->2)-beta-D-Galbeta(1-->4)-beta-D-Glc NAcalpha-]. Nine changes from the published amino acid sequence were necessary to account for the electron density. The quaternary structural organization of UE-I is that of the most commonly occurring legume lectin dimer. The tertiary structure of the monomeric subunits is similar to that in the conventional lectin subunit; however, some structural differences are noted. These differences include a four-stranded anti-parallel "S" sheet in UE-I versus the five-stranded S sheet in other lectin monomers. The Ala residue of the Ala-Asp cis-peptide bond present in the carbohydrate-binding site of the conventional lectin monomer is replaced with a Thr in the UE-I structure. Also, a novel disulfide bridge linking Cys115 and Cys150 is present. There are two metallic ions, one calcium and the other manganese, per subunit. N-linked oligosaccharides are at residues 23 and 111 of each subunit. One molecule of R-2-methyl-2, 4-pentanediol (R-MPD) is present in a shallow depression on the surface of each subunit. In order to examine the binding of the H-type 2 blood group determinant by UE-I, its beta-methyl glycoside (H-type 2-OMe) was docked into the binding site of R-MPD. The epitope previously identified for H-type 2-OMe by chemical mapping proved, with only minor adjustment of amino acid residues, to be complementary to the shallow cavity occupied by R-MPD in the structure. Several key interactions have been proposed between the H-type 2-OMe and UE-I. Copyright 2000 Academic Press.

  1. Preparation of fatty acid methyl esters for gas-liquid chromatography[S

    PubMed Central

    Ichihara, Ken'ichi; Fukubayashi, Yumeto

    2010-01-01

    A convenient method using commercial aqueous concentrated HCl (conc. HCl; 35%, w/w) as an acid catalyst was developed for preparation of fatty acid methyl esters (FAMEs) from sterol esters, triacylglycerols, phospholipids, and FFAs for gas-liquid chromatography (GC). An 8% (w/v) solution of HCl in methanol/water (85:15, v/v) was prepared by diluting 9.7 ml of conc. HCl with 41.5 ml of methanol. Toluene (0.2 ml), methanol (1.5 ml), and the 8% HCl solution (0.3 ml) were added sequentially to the lipid sample. The final HCl concentration was 1.2% (w/v). This solution (2 ml) was incubated at 45°C overnight or heated at 100°C for 1–1.5 h. The amount of FFA formed in the presence of water derived from conc. HCl was estimated to be <1.4%. The yields of FAMEs were >96% for the above lipid classes and were the same as or better than those obtained by saponification/methylation or by acid-catalyzed methanolysis/methylation using commercial anhydrous HCl/methanol. The method developed here could be successfully applied to fatty acid analysis of various lipid samples, including fish oils, vegetable oils, and blood lipids by GC. PMID:19759389

  2. TET2 functions as a resistance factor against DNA methylation acquisition during Epstein-Barr virus infection.

    PubMed

    Namba-Fukuyo, Hiroe; Funata, Sayaka; Matsusaka, Keisuke; Fukuyo, Masaki; Rahmutulla, Bahityar; Mano, Yasunobu; Fukayama, Masashi; Aburatani, Hiroyuki; Kaneda, Atsushi

    2016-12-06

    Extensive DNA methylation is observed in gastric cancer with Epstein-Barr virus (EBV) infection, and EBV infection is the cause to induce this extensive hypermethylaton phenotype in gastric epithelial cells. However, some 5' regions of genes do not undergo de novo methylation, despite the induction of methylation in surrounding regions, suggesting the existence of a resistance factor against DNA methylation acquisition. We conducted an RNA-seq analysis of gastric epithelial cells with and without EBV infection and found that TET family genes, especially TET2, were repressed by EBV infection at both mRNA and protein levels. TET2 was found to be downregulated by EBV transcripts, e.g. BARF0 and LMP2A, and also by seven human miRNAs targeting TET2, e.g., miR-93 and miR-29a, which were upregulated by EBV infection, and transfection of which into gastric cells repressed TET2. Hydroxymethylation target genes by TET2 were detected by hydroxymethylated DNA immunoprecipitation sequencing (hMeDIP-seq) with and without TET2 overexpression, and overlapped significantly with methylation target genes in EBV-infected cells. When TET2 was knocked down by shRNA, EBV infection induced de novo methylation more severely, including even higher methylation in methylation-acquired promoters or de novo methylation acquisition in methylation-protected promoters, leading to gene repression. TET2 knockdown alone without EBV infection did not induce de novo DNA methylation. These data suggested that TET2 functions as a resistance factor against DNA methylation in gastric epithelial cells and repression of TET2 contributes to DNA methylation acquisition during EBV infection.

  3. [Methylation Status of the SOCS3 Gene Promoter in H2228 Cells and 
EML4-ALK-positive Lung Cancer Tissues].

    PubMed

    Liu, Chunlai; Li, Yongwen; Dong, Yunlong; Zhang, Hongbing; Li, Ying; Liu, Hongyu; Chen, Jun

    2016-09-20

    The EML4-ALK fusion gene is a newly discovered driver gene of non-small cell lung cancer and exhibits special clinical and pathological features. The JAK-STAT signaling pathway, an important downstream signaling pathway of EML4-ALK, is aberrantly sustained and activated in EML4-ALK-positive lung cancer cells fusion gene, but the underlying reason remains unknown. The suppressor of cytokine signaling (SOCS) is a negative regulatory factor that mainly inhibits the proliferation, differentiation, and induction of apoptotic cells by inhibiting the JAK-STAT signaling pathway. The aberrant methylation of the SOCS gene leads to inactivation of tumors and abnormal activation of the JAK2-STAT signaling pathway. The aim of this study is to investigate the methylation status of the SOCS3 promoter in EML4-ALK-positive H2228 cells and lung cancer tissues. The methylation status of the SOCS3 promoter in EML4-ALK-positive H2228 lung cancer cells and lung cancer tissues was detected by methylation-specific PCR (MSP) analysis and verified by DNA sequencing. The expression levels of SOCS3 in H2228 cells were detected by Western blot and Real-time PCR analyses after treatment with the DNA methyltransferase inhibitor 5'-Aza-dC. MSP and DNA sequencing assay results indicated the presence of SOCS3 promoter methylation in H2228 cells as well as in three cases of seven EML4-ALK-positive lung cancer tissues. The expression level of SOCS3 significantly increased in H2228 cells after 5'-Aza-dC treatment. The aerrant methylation of the SOCS3 promoter region in EML4-ALK (+) H2228 cells and lung cancer tissues may be significantly involved in the pathogenesis of EML4-ALK-positive lung cancer.

  4. A complete 1H and 13C NMR data assignment for the diterpene methyl (-)-zanzibarate by 2D spectroscopy and NOE experiments.

    PubMed

    Imamura, P M; Miranda, P C M L; Giacomini, R A

    2004-06-01

    The 1H and 13C NMR spectra of methyl (-)-zanzibarate (1), an ent-labdanic diterpene isolated from the epicarp of Hymenaea courbaril var. altissima (Leguminosaea, Cesalpinoideae, Detariae), was fully assigned by COSY experiments, 13C/1H shift correlation diagrams and NOE experiments. Copyright 2004 John Wiley & Sons, Ltd.

  5. Synthetic, Infrared, 1H and 13C NMR Spectral Studies on N-(2-/3-Substituted Phenyl)-4-Substituted Benzenesulphonamides, 4-X'C6H4SO2NH(2-/3-XC6H4), where X' = H, CH3, C2H5, F, Cl or Br, and X = CH3 or Cl

    NASA Astrophysics Data System (ADS)

    Gowda, B. Thimme; Shetty, Mahesha; Jayalakshmi, K. L.

    2005-02-01

    Twenty three N-(2-/3-substituted phenyl)-4-substituted benzenesulphonamides of the general formula, 4-X'C6H4SO2NH(2-/3-XC6H4), where X' = H, CH3, C2H5, F, Cl or Br and X = CH3 or Cl have been prepared and characterized, and their infrared spectra in the solid state, 1H and 13C NMR spectra in solution were studied. The N-H stretching vibrations, νN-H, absorb in the range 3285 - 3199 cm-1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1376 - 1309 cm-1 and 1177 - 1148 cm-1, respectively. The S-N and C-N stretching vibrations absorb in the ranges 945 - 893 cm-1 and 1304 - 1168 cm-1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts of are assigned to protons and carbons of the two benzene rings. Incremental shifts of the ring protons and carbons due to -SO2NH(2-/3-XC6H4) groups in C6H5SO2NH(2-/3-XC6H4), and 4- X'C6H4SO2- and 4-X'C6H4SO2NH- groups in 4-X'C6H4SO2NH(C6H5) are computed and employed to calculate the chemical shifts of the ring protons and carbons in the substituted compounds, 4-X'C6H4SO2NH(2-/3-XC6H4). The computed values agree well with the observed chemical shifts.

  6. The Jovian atmospheric window at 2.7 microns: A search for H2S

    NASA Technical Reports Server (NTRS)

    Larson, H. P.; Davis, D. S.; Hofmann, R.; Bjoraker, G. L.

    1984-01-01

    The atmospheric transmission window at 2.7 microns in Jupiter's atmosphere was observed at a spectral resolution of 0.1/cm from the Kuiiper Airborne Observatory. From an analysis of the CH4 abundance (80 m-am) and the H2O abundance ( 0.0125 cm-am) it was determined that the penetration depth of solar flux at 2.7 microns is near the base of the NH3 cloud layer. The upper limit to H2O at 2.7 microns and other results suggest that photolytic reactions in Jupiter's lower troposphere may not be as significant as was previously thought. A search for H2S in Jupiter's atmosphere yielded an upper limit of 0.1 cm-am. The corresponding limit to the element abundance ratio S/H was approx. 1.7x10(-8), about 10(-3) times the solar value. Upon modeling the abundance and distribution of H2S in Jupiter's atmosphere it was concluded that, contrary to expectations, sulfur-bearing chromophores are not present in significant amounts in Jupiter's visible clouds. Rather, it appears that most of Jupiter's sulfur is locked up as NH4SH in a lower cloud layer. Alternatively, the global abundance of sulfur in Jupiter may be significantly depleted.

  7. Methyl 2-methyl-4-(oxiran-2-ylmeth­oxy)-2H-1,2-benzothia­zine-3-carboxyl­ate 1,1-dioxide

    PubMed Central

    Ahmad, Matloob; Siddiqui, Hamid Latif; Zia-ur-Rehman, Muhammad; Elsegood, Mark R. J.; Weaver, George W.

    2010-01-01

    In the title compound, C14H15NO6S, the thia­zine ring adopts a distorted half-chair conformation. The structure displays several cooperative weak inter­molecular C—H⋯O hydrogen-bonding inter­actions, giving rise to a two-dimensional sheet packing motif. The CH2 group in the meth­oxy linker to the oxirane ring, and the CH group in that ring, exhibit twofold positional disorder. The three-membered oxirane ring is twisted approximately perpendicular with respect to thia­zine ring (dihedral angle = 60/86° for the major/minor disorder components). 1,2-Benzothia­zines of this kind have a wide range of biological activities and are mainly used as medicines in the treatment of inflammation and rheumatoid arthritis. PMID:21579762

  8. Crystal structure of (E)-N′-{[(1R,3R)-3-isopropyl-1-methyl-2-oxo­cyclo­pent­yl]methyl­idene}-4-methyl­benzene­sulfono­hydrazide

    PubMed Central

    Tymann, David; Dragon, Dina Christina; Golz, Christopher; Preut, Hans; Strohmann, Carsten; Hiersemann, Martin

    2015-01-01

    The title compound, C17H24N2O3S, was synthesized in order to determine the relative configuration of the corresponding β-keto aldehyde. In the U-shaped mol­ecule, the five-membered ring approximates an envelope with the methyl­ene atom adjacent to the quaternary C atom being the flap. The dihedral angles between the four nearly coplanar atoms of the five-membered ring and the flap and the aromatic ring are 38.8 (4) and 22.9 (2)°, respectively. The bond angles around the S atom are in the range 104.11 (16)–119.95 (16)°. In the crystal, mol­ecules are linked via N—H⋯O by hydrogen bonds, forming a chain along the a-axis direction. PMID:25878892

  9. SOA Formation from the Atmospheric Oxidation of 2-Methyl-3-Buten-2-ol and Its Implications for PM2.5

    EPA Science Inventory

    The formation of secondary organic aerosol (SOA) generated by irradiating 2-methyl-3-buten-2-01 (MBO) in the presence and/or absence of NOx H2O2, and/or SO2 was examined. Experiments were conducted. in smog chambers operated either in dyna....

  10. Crystal structures of two 6-(2-hy-droxy-benzo-yl)-5H-thia-zolo[3,2-a]pyrimidin-5-ones.

    PubMed

    Gomes, Ligia R; Low, John Nicolson; Cagide, Fernando; Borges, Fernanda

    2015-07-01

    The title compounds, 6-(2-hy-droxy-benz-yl)-5H-thia-zolo[3,2-a]pyrimidin-5-one, C13H8N2O3S, (1), and 6-(2-hy-droxy-benz-yl)-3-methyl-5H-thia-zolo[3,2-a]pyrimidin-5-one, C14H10N2O3S, (2), were synthesized when a chromone-3-carb-oxy-lic acid, activated with (benzotriazol-1-yl-oxy)tripyrrolidinyl-phospho-nium hexa-fluorido-phosphate (PyBOP), was reacted with a primary heteromamine. Instead of the expected amidation, the unusual title thia-zolo-pyrimidine-5-one derivatives were obtained serendipitously and a mechanism of formation is proposed. Both compounds present an intra-molecular O-H⋯O hydrogen bond, which generates an S(6) ring. The dihedral angles between the heterocyclic moiety and the 2-hydroxybenzoyl ring are 55.22 (5) and 46.83 (6)° for (1) and (2), respectively. In the crystals, the mol-ecules are linked by weak C-H⋯O hydrogen bonds and π-π stacking inter-actions.

  11. Nature of the C2-methylation effect on the properties of imidazolium ionic liquids.

    PubMed

    Rodrigues, Ana S M C; Lima, Carlos F R A C; Coutinho, João A P; Santos, Luís M N B F

    2017-02-15

    Methylation at the C2 position of 1,3-disubstituted imidazolium-based ionic liquids (ILs) is one of the structural features that has gained attention due to its drastic impact on thermophysical and transport properties. Several hypotheses have been proposed to explain this effect but there is still much discrepancy. Aiming for the rationalization of the effects of these structural features on the properties of imidazolium ILs, we present a thermodynamic and computational study of two methylated ILs at the C2 position of imidazolium, [ 1 C 4 2 C 1 3 C 1 im][NTf 2 ] and [ 1 C 3 2 C 1 3 C 1 im][NTf 2 ]. The phase behaviour (glass transition and vaporization equilibrium) and computational studies of the anion rotation around the cation and ion pair interaction energies for both ILs were explored. The results have shown that C2-methylation has no impact on the enthalpy of vaporization. However, it decreases the entropy of vaporization, which is a consequence of the change in the ion pair dynamics that affects both the liquid and gas phases. In addition, the more hindered dynamics of the ion pair are also reflected in the increase in the glass transition temperature, T g . The entropic contribution of anion-around-cation rotation in the imidazolium [NTf 2 ] ILs was quantified experimentally by the comparative analysis of the entropy of vaporization, and computationally by the calculation of the entropies of hindered internal rotation. The global results exclude the existence of significant H-bonding in the C2-protonated (non-methylated) ILs and explain the C2-methylation effect in terms of reduced entropy of the ion pair in the liquid and gas phases. In light of these results, the C2-methylation effect is intrinsically entropic and originates from the more hindered anion-around-cation rotation as a consequence of the substitution of the -H with a bulkier -CH 3 group.

  12. Spectral Analysis of 3-(Adamantan-1-yl)-4-Ethyl-1-[(4-Phenylpiperazin-1-yl) Methyl]-1 H-1,2,4-Triazole-5(4 H)-Thione

    NASA Astrophysics Data System (ADS)

    Mindarava, Y. L.; Shundalau, M. B.; Al-Wahaibi, L. H.; El-Emam, A. A.; Matsukovich, A. S.; Gaponenko, S. V.

    2018-05-01

    Vibrational IR (3200-650 cm-1) and Raman spectra (3200-150 cm-1) of adamantane-containing 3-(adamantan-1-yl)-4-ethyl-1-[(4-phenylpiperazin-1-yl)methyl]-1H-1,2,4-triazole-5(4H)-thione, which is promising for drug design, were examined. The UV/Vis spectrum (450-200 nm) of the compound in EtOH was measured. Full geometry optimization using density functional theory (DFT) in the B3LYP/cc-pVDZ approximation allowed the equilibrium configuration of the molecule to be determined and IR and Raman spectra to be calculated. Based on these, the experimental vibrational IR and Raman spectra were interpreted and the biological activity indices were predicted. The UV/Vis spectrum of the title compound was simulated at the time-dependent DFT/CAM-B3LYP/cc-pVDZ level with and without solvent effects and at the ab initio multi-reference perturbation theory XMCQDPT2 level. The UV/Vis spectrum that was simulated using the multi-reference XMCQDPT2 approximation agreed very successfully with the experimental data, in contrast to the single-reference DFT method. This was probably a consequence of intramolecular charge transfer.

  13. Spectral Analysis of 3-(Adamantan-1-yl)-4-Ethyl-1-[(4-Phenylpiperazin-1-yl) Methyl]-1H-1,2,4-Triazole-5(4H)-Thione

    NASA Astrophysics Data System (ADS)

    Mindarava, Y. L.; Shundalau, M. B.; Al-Wahaibi, L. H.; El-Emam, A. A.; Matsukovich, A. S.; Gaponenko, S. V.

    2018-05-01

    Vibrational IR (3200-650 cm-1) and Raman spectra (3200-150 cm-1) of adamantane-containing 3-(adamantan-1-yl)-4-ethyl-1-[(4-phenylpiperazin-1-yl)methyl]-1H-1,2,4-triazole-5(4H)-thione, which is promising for drug design, were examined. The UV/Vis spectrum (450-200 nm) of the compound in EtOH was measured. Full geometry optimization using density functional theory (DFT) in the B3LYP/cc-pVDZ approximation allowed the equilibrium configuration of the molecule to be determined and IR and Raman spectra to be calculated. Based on these, the experimental vibrational IR and Raman spectra were interpreted and the biological activity indices were predicted. The UV/Vis spectrum of the title compound was simulated at the time-dependent DFT/CAM-B3LYP/cc-pVDZ level with and without solvent effects and at the ab initio multi-reference perturbation theory XMCQDPT2 level. The UV/Vis spectrum that was simulated using the multi-reference XMCQDPT2 approximation agreed very successfully with the experimental data, in contrast to the single-reference DFT method. This was probably a consequence of intramolecular charge transfer.

  14. Nanoliposomes for encapsulation and delivery of the potential antitumoral methyl 6-methoxy-3-(4-methoxyphenyl)-1 H-indole-2-carboxylate

    NASA Astrophysics Data System (ADS)

    Abreu, Ana S.; Castanheira, Elisabete Ms; Queiroz, Maria-João Rp; Ferreira, Paula Mt; Vale-Silva, Luís A.; Pinto, Eugénia

    2011-08-01

    A potential antitumoral fluorescent indole derivative, methyl 6-methoxy-3-(4-methoxyphenyl)-1 H-indole-2-carboxylate, was evaluated for the in vitro cell growth inhibition on three human tumor cell lines, MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), and NCI-H460 (non-small cell lung cancer), after a continuous exposure of 48 h, exhibiting very low GI50 values for all the cell lines tested (0.25 to 0.33 μM). This compound was encapsulated in different nanosized liposome formulations, containing egg lecithin (Egg-PC), dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylglycerol (DPPG), DSPC, cholesterol, dihexadecyl phosphate, and DSPE-PEG. Dynamic light scattering measurements showed that nanoliposomes with the encapsulated compound are generally monodisperse and with hydrodynamic diameters lower than 120 nm, good stability and zeta potential values lower than -18 mV. Dialysis experiments allowed to monitor compound diffusion through the lipid membrane, from DPPC/DPPG donor liposomes to NBD-labelled lipid/DPPC/DPPG acceptor liposomes.

  15. Protein methylation in pea chloroplasts. [Pisum sativum

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Niemi, K.J.; Adler, J.; Selman, B.R.

    1990-07-01

    The methylation of chloroplast proteins has been investigated by incubating intact pea (Pisum sativum) chloroplasts with ({sup 3}H-methyl)-S-adenosylmethionine. Incubation in the light increases the amount of methylation in both the thylakoid and stromal fractions. Numerous thylakoid proteins serve as substrates for the methyltransfer reactions. Three of these thylakoid proteins are methylated to a significantly greater extent in the light than in the dark. The primary stromal polypeptide methylated is the large subunit of ribulose bisphosphate carboxylase/oxygenase. One other stromal polypeptide is also methylated much more in the light than in the dark. Two distinct types of protein methylation occur. Onemore » methylinkage is stable to basic conditions whereas a second type is base labile. The base-stable linkage is indicative of N-methylation of amino acid residues while base-lability is suggestive of carboxymethylation of amino acid residues. Labeling in the light increases the percentage of methylation that is base labile in the thylakoid fraction while no difference is observed in the amount of base-labile methylations in light-labeled and dark-labeled stromal proteins. Also suggestive of carboxymethylation is the detection of volatile ({sup 3}H)methyl radioactivity which increases during the labeling period and is greater in chloroplasts labeled in the light as opposed to being labeled in the dark; this implies in vivo turnover of the ({sup 3}H)methyl group.« less

  16. Emissions of sulfur gases from wetlands

    NASA Technical Reports Server (NTRS)

    Hines, Mark E.

    1992-01-01

    Data on the emissions of sulfur gases from marine and freshwater wetlands are summarized with respect to wetland vegetation type and possible formation mechanisms. The current data base is largest for salt marshes inhabited by Spartina alterniflora. Both dimethyl sulfide (DMS) and hydrogen sulfide (H2S) dominate emissions from salt marshes, with lesser quantities of methyl mercaptan (MeSH), carbonyl sulfide (COS), carbon disulfide (CS2) and dimethyl disulfide (DMDS) being emitted. High emission rates of DMS are associated with vegetation that produces the DMS precursor dimethylsulfonionpropionate (DMSP). Although large quantities of H2S are produced in marshes, only a small percentage escapes to the atmosphere. High latitude marshes emit less sulfur gases than temperate ones, but DMS still dominates. Mangrove-inhabited wetlands also emit less sulfur than temperate S. alterniflora marshes. Few data are available on sulfur gas emissions from freshwater wetlands. In most instances, sulfur emissions from temperate freshwater sites are low. However, some temperate and subtropical freshwater sites are similar in magnitude to those from marine wetlands which do not contain vegetation that produces DMSP. Emissions are low in Alaskan tundra but may be considerably higher in some bogs and fens.

  17. Synthesis, crystal structure, DFT studies, acid dissociation constant, and antimicrobial activity of methyl 2-(4-chlorophenyl)-7a-((4-chlorophenyl)carbamothioyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate

    NASA Astrophysics Data System (ADS)

    Nural, Yahya; Gemili, Muge; Seferoglu, Nurgul; Sahin, Ertan; Ulger, Mahmut; Sari, Hayati

    2018-05-01

    A novel bicyclic thiohydantoin fused to pyrrolidine compound, methyl 2-(4-chlorophenyl)-7a-((4-chlorophenyl)carbamothioyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate, was synthesized by the cyclization reaction of dimethyl 5,5-diphenylpyrrolidine-2,4-dicarboxylate and 4-chlorophenyl isothiocyanate in the presence of 4-(dimethylamino)pyridine to form methyl 2-(4-chlorophenyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate with concomitant addition reaction of the 4-chlorophenyl isothiocyanate in 79% yield. The structural characterization was performed by NMR, FT-IR, MS and HRMS techniques, and the stereochemistry of the compound was determined by single crystal X-ray diffraction study. In addition, the molecular structure and 1H and 13C NMR chemical shifts of the compound were obtained with the density functional theory and Hartree-Fock calculations. Acid dissociation constants of the compound were determined using potentiometric titration method in 25% (v/v) dimethyl sulfoxide-water hydroorganic solvent at 25 ± 0.1 °C, at an ionic background of 0.1 mol/L of NaCl using the HYPERQUAD computer program. Four acid dissociation constants were obtained for the compound, and we suggest that these acid dissociation constants are related to the NH, for two groups of enthiols and enol groups. Antimicrobial activity study was performed against S. aureus, B. subtilis, A. hydrophila, E. coli and A. baumannii as bacterial standard strains, and against M. tuberculosis H37Rv as mycobacterial strain. The compound exhibited antibacterial activity in the range of 31.25-62.5 μg/mL, and antimycobacterial activity with a MIC value of 40 μg/mL against the indicated strains.

  18. Enhanced Synthesis of Alkyl Amino Acids in Miller's 1958 H2S Experiment

    NASA Technical Reports Server (NTRS)

    Parker, Eric T.; Cleaves, H. James; Callahan, Michael P.; Dworkin, James P.; Glavin, Daniel P.; Lazcano, Antonio; Bada, Jeffrey L.

    2011-01-01

    Stanley Miller's 1958 H2S-containing experiment, which included a simulated prebiotic atmosphere of methane (CH4), ammonia (NH3), carbon dioxide (CO2), and hydrogen sulfide (H2S) produced several alkyl amino acids, including the alpha-, beta-, and gamma-isomers of aminobutyric acid (ABA) in greater relative yields than had previously been reported from his spark discharge experiments. In the presence of H2S, aspariic and glutamic acids could yield alkyl amino acids via the formation of thioimide intermediates. Radical chemistry initiated by passing H2S through a spark discharge could have also enhanced alkyl amino acid synthesis by generating alkyl radicals that can help form the aldehyde and ketone precursors to these amino acids. We propose mechanisms that may have influenced the synthesis of certain amino acids in localized environments rich in H2S and lightning discharges, similar to conditions near volcanic systems on the early Earth, thus contributing to the prebiotic chemical inventory of the primordial Earth.

  19. Physical Localization and DNA Methylation of 45S rRNA Gene Loci in Jatropha curcas L.

    PubMed Central

    Gong, Zhiyun; Xue, Chao; Zhang, Mingliang; Guo, Rui; Zhou, Yong; Shi, Guoxin

    2013-01-01

    In eukaryotes, 45S rRNA genes are arranged in tandem arrays of repeat units, and not all copies are transcribed during mitosis. DNA methylation is considered to be an epigenetic marker for rDNA activation. Here, we established a clear and accurate karyogram for Jatropha curcas L. The chromosomal formula was found to be 2n = 2x = 22 = 12m+10sm. We found that the 45S rDNA loci were located at the termini of chromosomes 7 and 9 in J. curcas. The distribution of 45S rDNA has no significant difference in J. curcas from different sources. Based on the hybridization signal patterns, there were two forms of rDNA - dispersed and condensed. The dispersed type of signals appeared during interphase and prophase, while the condensed types appeared during different stages of mitosis. DNA methylation analysis showed that when 45S rDNA stronger signals were dispersed and connected to the nucleolus, DNA methylation levels were lower at interphase and prophase. However, when the 45S rDNA loci were condensed, especially during metaphase, they showed different forms of DNA methylation. PMID:24386362

  20. Polymorphism of a new Mannich base - [-4-methyl-2-((4-(4-nitrophenyl)piperazin-1-yl)methyl)phenol

    NASA Astrophysics Data System (ADS)

    Ayeni, Ayowole O.; Watkins, Gareth M.; Hosten, Eric C.

    2018-05-01

    Two polymorphs (forms I and II) of a new Mannich base 4-methyl-2-((4-(4-nitrophenyl)piperazin-1-yl)methyl)phenol have been isolated and characterized by single crystal and powder (experimental and theoretical) X-ray diffraction, thermal analysis (differential scanning calorimetry), Fourier transform infrared spectroscopy. 1H and 13C nuclear magnetic resonance spectroscopy was employed in characterising the new Mannich base. Single crystal X-ray diffraction revealed that the two polymorphs contain different conformers of the Mannich base whose hydrogen bonding schemes and packing arrangements in their respective crystals are different. Thermal analysis led to the conclusion that the two polymorphs are enantiotropically related, with a transition temperature of 138.5 °C.

  1. Dual-Reactable Fluorescent Probes for Highly Selective and Sensitive Detection of Biological H2 S.

    PubMed

    Wei, Chao; Wang, Runyu; Zhang, Changyu; Xu, Guoce; Li, Yanyan; Zhang, Qiang-Zhe; Li, Lu-Yuan; Yi, Long; Xi, Zhen

    2016-05-06

    Hydrogen sulfide (H2 S) is an important endogenous signaling molecule with a variety of biological functions. Development of fluorescent probes for highly selective and sensitive detection of H2 S is necessary. We show here that dual-reactable fluorescent H2 S probes could react with higher selectivity than single-reactable probes. One of the dual-reactable probes gives more than 4000-fold turn-on response when reacting with H2 S, the largest response among fluorescent H2 S probes reported thus far. In addition, the probe could be used for high-throughput enzymatic assays and for the detection of Cys-induced H2 S in cells and in zebrafish. These dual-reactable probes hold potential for highly selective and sensitive detection of H2 S in biological systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. FLYING-WATER Renewables-H2-H2O TERRAFORMING: PERMANENT Drought(s)-Elimination FOREVER!!!

    NASA Astrophysics Data System (ADS)

    Ertl, G.; Alefeld, G.; Youdelis, W.; Radd, H.; Oertle, G.; Siegel, Edward

    2011-03-01

    "H2O H2O everywhere; ne'er a drop to drink"[Coleridge(1798)]; now: "H2 H2 everywhere; STILL ne'er a drop to drink": ONLY H2 (or methane CH4) can be FLYING-WATER(F-W) chemical-rain-in-pipelines Hindenberg-effect (H2-UP;H2O-DOWN): {O/H2O}=[16]/[18] 90 % ; O already in air uphill; NO H2O pumping need! In global-warming driven H2O-starved glacial-melting world, rescue is possible ONLY by Siegel [{3rd Intl. Conf. Alt.-Energy }(1980)-vol.5/p.459!!!] Renewables-H2-H2O purposely flexible versatile agile customizable scaleable retrofitable integrated operating-system. Rosenfeld[Science 315,1396(3/9/2007)]-Biello [Sci.Am.(3/9/2007)] crucial geomorph-ology which ONLY maximal-buoyancy H2 can exploit, to again make "Mountains into Fountains", ``upthrust rocks trapping the clouds to precipitate their rain/snow/H2O'': "terraforming"(and ocean-rebasificaton!!!) Siegel proprietary magnetic-hydrogen-valve (MHV) permits H2 flow in already in-ground dense BCC/ferritic-steels pipelines-network (NO new infrastructure) counters Tromp[Science 300,1740(2003)] dire warning of global-pandemics (cancers/ blindness/famine) Hydrogen-economy CATASTROPHIC H2 ozone-layer destruction sobering cavat to dangerous H2-automotion-economy panacea hype!!!

  3. Electroactive Au@Ag nanoparticles driven electrochemical sensor for endogenous H2S detection.

    PubMed

    Zhao, Yuan; Yang, Yaxin; Cui, Linyan; Zheng, Fangjie; Song, Qijun

    2018-05-26

    In this work, a novel and facile electrochemical sensor is reported for the highly selective and sensitive detection of dissolved hydrogen sulfide (H 2 S), attributing to the redox reaction between Au@Ag core-shell nanoparticles (Au@Ag NPs) and H 2 S. Electroactive Au@Ag NPs not only possess excellent conductivity, but exhibit great electrochemical reactivity at 0.26 V due to the electrochemical oxidation from Ag° to Ag + . In the presence of H 2 S, the Ag shell of Au@Ag NPs can be oxidized to Ag 2 S, resulting in the decrease of differential pulse voltammetry (DPV) peak at 0.26 V. The electrochemical sensor exhibits a wide linear response range from 0.1 nM to 500 nM. The limit of detection (LOD) for H 2 S is as low as 0.04 nM. The developed sensor shows significant prospects in the study of pathological processes related to the mechanism of H 2 S production. Copyright © 2018. Published by Elsevier B.V.

  4. Aberrant TET1 Methylation Closely Associated with CpG Island Methylator Phenotype in Colorectal Cancer.

    PubMed

    Ichimura, Norihisa; Shinjo, Keiko; An, Byonggu; Shimizu, Yasuhiro; Yamao, Kenji; Ohka, Fumiharu; Katsushima, Keisuke; Hatanaka, Akira; Tojo, Masayuki; Yamamoto, Eiichiro; Suzuki, Hiromu; Ueda, Minoru; Kondo, Yutaka

    2015-08-01

    Inactivation of methylcytosine dioxygenase, ten-eleven translocation (TET) is known to be associated with aberrant DNA methylation in cancers. Tumors with a CpG island methylator phenotype (CIMP), a distinct subgroup with extensive DNA methylation, show characteristic features in the case of colorectal cancer. The relationship between TET inactivation and CIMP in colorectal cancers is not well understood. The expression level of TET family genes was compared between CIMP-positive (CIMP-P) and CIMP-negative (CIMP-N) colorectal cancers. Furthermore, DNA methylation profiling, including assessment of the TET1 gene, was assessed in colorectal cancers, as well as colon polyps. The TET1 was silenced by DNA methylation in a subset of colorectal cancers as well as cell lines, expression of which was reactivated by demethylating agent. TET1 methylation was more frequent in CIMP-P (23/55, 42%) than CIMP-N (2/113, 2%, P < 0.0001) colorectal cancers. This trend was also observed in colon polyps (CIMP-P, 16/40, 40%; CIMP-N, 2/24, 8%; P = 0.002), suggesting that TET1 methylation is an early event in CIMP tumorigenesis. TET1 methylation was significantly associated with BRAF mutation but not with hMLH1 methylation in the CIMP-P colorectal cancers. Colorectal cancers with TET1 methylation have a significantly greater number of DNA methylated genes and less pathological metastasis compared to those without TET1 methylation (P = 0.007 and 0.045, respectively). Our data suggest that TET1 methylation may contribute to the establishment of a unique pathway in respect to CIMP-mediated tumorigenesis, which may be incidental to hMLH1 methylation. In addition, our findings provide evidence that TET1 methylation may be a good biomarker for the prediction of metastasis in colorectal cancer. ©2015 American Association for Cancer Research.

  5. DNA methylation of the BRD2 promoter is associated with juvenile myoclonic epilepsy in Caucasians.

    PubMed

    Pathak, Shilpa; Miller, James; Morris, Emily C; Stewart, William C L; Greenberg, David A

    2018-05-01

    Juvenile myoclonic epilepsy (JME) is a common adolescent-onset genetic generalized epilepsy (GGE) syndrome. Multiple linkage and association studies have found that BRD2 influences the expression of JME. The BRD2-JME connection is further corroborated by our murine model; Brd2 haploinsufficiency produces characteristics that typify the clinical hallmarks of JME. Neither we, nor several large-scale studies of JME, found JME-related BRD2 coding mutations. Therefore, we investigated noncoding BRD2 regions, seeking the origin of BRD2's JME influence. BRD2's promoter harbors a JME-associated single nucleotide polymorphism (rs3918149) and a CpG (C-phosphate-G dinucleotides) island (CpG76), making it a potential "hotspot" for JME-associated epigenetic variants. Methylating promoter CpG sites causes gene silencing, often resulting in reduced gene expression. We tested for differences in DNA methylation at CpG76 in 3 different subgroups: (1) JME patients versus their unaffected family members, (2) JME versus patients with other forms of GGE, and (3) Caucasian versus non-Caucasian JME patients. We used DNA pyrosequencing to analyze the methylation status of 10 BRD2 promoter CpG sites in lymphoblastoid cells from JME patients of Caucasian and non-Caucasian origin, unaffected family members, and also non-JME GGE patients. We also measured global methylation levels and DNA methyl transferase 1 (DNMT1) transcript expression in JME families by standard methods. CpG76 is highly methylated in JME patients compared to unaffected family members. In families with non-JME GGE, we found no relationship between promoter methylation and epilepsy. In non-Caucasian JME families, promoter methylation was mostly not associated with epilepsy. This makes the BRD2 promoter a JME-specific, ethnicity-specific, differentially methylated region. Global methylation was constant across groups. BRD2 promoter methylation in JME, and the lack of methylation in unaffected relatives, in non-JME GGE

  6. Crystal structure, spectroscopic studies and quantum mechanical calculations of 2-[((3-iodo-4-methyl)phenylimino)methyl]-5-nitrothiophene.

    PubMed

    Özdemir Tarı, Gonca; Gümüş, Sümeyye; Ağar, Erbil

    2015-04-15

    The title compound, 2-[((3-iodo-4-methyl)phenylimino)methyl]-5-nitrothiophene, C12H9O2N2I1S1, was synthesized and characterized by IR, UV-Vis and single-crystal X-ray diffraction technique. The molecular structure was optimized at the B3LYP, B3PW91 and PBEPBE levels of the density functional method (DFT) with the 6-311G+(d,p) basis set. Using the TD-DFT method, the electronic absorption spectra of the title compound was computed in both the gas phase and ethanol solvent. The harmonic vibrational frequencies of the title compound were calculated using the same methods with the 6-311G+(d,p) basis set. The calculated results were compared with the experimental determination results of the compound. The energetic behavior such as the total energy, atomic charges, dipole moment of the title compound in solvent media were examined using the B3LYP, B3PW91 and PBEPBE methods with the 6-311G+(d,p) basis set by applying the Onsager and the polarizable continuum model (PCM). The molecular orbitals (FMOs) analysis, the molecular electrostatic potential map (MEP) and the nonlinear optical properties (NLO) for the title compound were obtained with the same levels of theory. And then thermodynamic properties for the title compound were obtained using the same methods with the 6-311G(d,p) basis set. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Reactivity and dynamics of H2S, NO, and O2 interacting with hemoglobins from Lucina pectinata.

    PubMed

    Ramos-Alvarez, Cacimar; Yoo, Byung-Kuk; Pietri, Ruth; Lamarre, Isabelle; Martin, Jean-Louis; Lopez-Garriga, Juan; Negrerie, Michel

    2013-10-08

    Hemoglobin HbI from the clam Lucina pectinata is involved in H2S transport, whereas homologous heme protein HbII/III is involved in O2 metabolism. Despite similar tertiary structures, HbI and HbII/III exhibit very different reactivity toward heme ligands H2S, O2, and NO. To investigate this reactivity at the heme level, we measured the dynamics of ligand interaction by time-resolved absorption spectroscopy in the picosecond to nanosecond time range. We demonstrated that H2S can be photodissociated from both ferric and ferrous HbI. H2S geminately rebinds to ferric and ferrous out-of-plane iron with time constants (τgem) of 12 and 165 ps, respectively, with very different proportions of photodissociated H2S exiting the protein (24% in ferric and 80% in ferrous HbI). The Gln(E7)His mutation considerably changes H2S dynamics in ferric HbI, indicating the role of Gln(E7) in controling H2S reactivity. In ferric HbI, the rate of diffusion of H2S from the solvent into the heme pocket (kentry) is 0.30 μM(-1) s(-1). For the HbII/III-O2 complex, we observed mainly a six-coordinate vibrationally excited heme-O2 complex with O2 still bound to the iron. This explains the low yield of O2 photodissociation and low koff from HbII/III, compared with those of HbI and Mb. Both isoforms behave very differently with regard to NO and O2 dynamics. Whereas the amplitude of geminate rebinding of O2 to HbI (38.5%) is similar to that of myoglobin (34.5%) in spite of different distal heme sites, it appears to be much larger for HbII/III (77%). The distal Tyr(B10) side chain present in HbII/III increases the energy barrier for ligand escape and participates in the stabilization of bound O2 and NO.

  8. Electro-Chemical Behavior of Low Carbon Steel Under H2S Influence

    NASA Astrophysics Data System (ADS)

    Zaharia, M. G.; Stanciu, S.; Cimpoesu, R.; Nejneru, C.; Savin, C.; Manole, V.; Cimpoeșu, N.

    2017-06-01

    Abstract A commercial low carbon steel material (P265GH) with application at industrial scale for natural gas delivery and transportation systems was analyzed in H2S atmosphere. The article proposed a new experimental cell in order to establish the behavior of the material in sulfur contaminated environment. In most of the industrial processes for gas purification the corrosion rate is speed up by the presence of S (sulfur) especially as ions or species like H2S. The H2S (hydrogen sulfide) is, beside a very toxic compound, a very active element in the acceleration of metallic materials deterioration especially in complex solicitations like pressure and temperature in the same time. For experiments we used a three electrodes cell with Na2SO4 + Na2S solution at pH 3 at room temperature (∼ 25 °C) to realize EIS (electrochemical impedance spectroscopy) and potentio-dynamic polarization experiments. Scanning electron microscopy and X-ray dispersive energy spectroscopy were used to characterize the metallic material surface exposed to experimental environment.

  9. Modes of Interaction of KMT2 Histone H3 Lysine 4 Methyltransferase/COMPASS Complexes with Chromatin

    PubMed Central

    Bochyńska, Agnieszka; Lüscher-Firzlaff, Juliane

    2018-01-01

    Regulation of gene expression is achieved by sequence-specific transcriptional regulators, which convey the information that is contained in the sequence of DNA into RNA polymerase activity. This is achieved by the recruitment of transcriptional co-factors. One of the consequences of co-factor recruitment is the control of specific properties of nucleosomes, the basic units of chromatin, and their protein components, the core histones. The main principles are to regulate the position and the characteristics of nucleosomes. The latter includes modulating the composition of core histones and their variants that are integrated into nucleosomes, and the post-translational modification of these histones referred to as histone marks. One of these marks is the methylation of lysine 4 of the core histone H3 (H3K4). While mono-methylation of H3K4 (H3K4me1) is located preferentially at active enhancers, tri-methylation (H3K4me3) is a mark found at open and potentially active promoters. Thus, H3K4 methylation is typically associated with gene transcription. The class 2 lysine methyltransferases (KMTs) are the main enzymes that methylate H3K4. KMT2 enzymes function in complexes that contain a necessary core complex composed of WDR5, RBBP5, ASH2L, and DPY30, the so-called WRAD complex. Here we discuss recent findings that try to elucidate the important question of how KMT2 complexes are recruited to specific sites on chromatin. This is embedded into short overviews of the biological functions of KMT2 complexes and the consequences of H3K4 methylation. PMID:29498679

  10. Paradoxical Role of DNA Methylation in Activation of FoxA2 Gene Expression during Endoderm Development*

    PubMed Central

    Bahar Halpern, Keren; Vana, Tal; Walker, Michael D.

    2014-01-01

    The transcription factor FoxA2 is a master regulator of endoderm development and pancreatic beta cell gene expression. To elucidate the mechanisms underlying the activation of the FoxA2 gene during differentiation, we have compared the epigenetic status of undifferentiated human embryonic stem cells (hESCs), hESC-derived early endoderm stage cells (CXCR4+ cells), and pancreatic islet cells. Unexpectedly, a CpG island in the promoter region of the FoxA2 gene displayed paradoxically high levels of DNA methylation in expressing tissues (CXCR4+, islets) and low levels in nonexpressing tissues. This CpG island region was found to repress reporter gene expression and bind the Polycomb group protein SUZ12 and the DNA methyltransferase (DNMT)3b preferentially in undifferentiated hESCs as compared with CXCR4+ or islets cells. Consistent with this, activation of FoxA2 gene expression, but not CXCR4 or SOX17, was strongly inhibited by 5-aza-2′-deoxycytidine and by knockdown of DNMT3b. We hypothesize that in nonexpressing tissues, the lack of DNA methylation allows the binding of DNA methyltransferases and repressing proteins, such as Polycomb group proteins; upon differentiation, DNMT activation leads to CpG island methylation, causing loss of repressor protein binding. These results suggest a novel and unexpected role for DNA methylation in the activation of FoxA2 gene expression during differentiation. PMID:25016019

  11. Isolation and characterization of fatty acid methyl ester (FAME)-producing Streptomyces sp. S161 from sheep (Ovis aries) faeces.

    PubMed

    Lu, Y; Wang, J; Deng, Z; Wu, H; Deng, Q; Tan, H; Cao, L

    2013-09-01

    An actinomycete producing oil-like mixtures was isolated and characterized. The strain was isolated from sheep faeces and identified as Streptomyces sp. S161 based on 16S rRNA gene sequence analysis. The strain showed cellulase and xylanase activities. The (1) H nuclear magnetic resonance (NMR) spectra of the mixtures showed that the mixtures were composed of fatty acid methyl esters (52·5), triglycerides (13·7) and monoglycerides (9·1) (mol.%). Based on the gas chromatography-mass spectrometry (GC-MS) analysis, the fatty acid methyl esters were mainly composed of C14-C16 long-chain fatty acids. The results indicated that Streptomyces sp. S161 could produce fatty acid methyl esters (FAME) directly from starch. To our knowledge, this is the first isolated strain that can produce biodiesel (FAME) directly from starch. © 2013 The Society for Applied Microbiology.

  12. Pharmacokinetics and pharmacodynamics of LGD-3303 [9-chloro-2-ethyl-1-methyl-3-(2,2,2-trifluoroethyl)-3H-pyrrolo-[3,2-f]quinolin-7(6H)-one], an orally available nonsteroidal-selective androgen receptor modulator.

    PubMed

    Vajda, Eric G; López, Francisco J; Rix, Peter; Hill, Robert; Chen, Yanling; Lee, Kyoung-Jin; O'Brien, Z; Chang, William Y; Meglasson, Martin D; Lee, Yong-Hee

    2009-02-01

    Selective androgen receptor modulators (SARMs) are a new class of molecules in development to treat a variety of diseases. SARMs maintain the beneficial effects of androgens, including increased muscle mass and bone density, while having reduced activity on unwanted side effects. The mechanisms responsible for the tissue-selective activity of SARMs are not fully understood, and the pharmacokinetic (PK)/pharmacodynamic (PD) relationships are poorly described. Tissue-specific compound distribution potentially could be a mechanism responsible for apparent tissue selectivity. We examined the PK/PD relationship of a novel SARM, LGD-3303 [9-chloro-2-ethyl-1-methyl-3-(2,2,2-trifluoroethyl)-3H-pyrrolo[3,2-f]quinolin-7(6H)-one], in a castrated rat model of androgen deficiency. LGD-3303 has potent activity on levator ani muscle but is a partial agonist on the preputial gland and ventral prostate. LGD-3303 never stimulated ventral prostate above intact levels despite increasing plasma concentrations of compound. Tissue-selective activity was maintained when LGD-3303 was dosed orally or by continuous infusion, two routes of administration with markedly different time versus exposure profiles. Despite the greater muscle activity relative to prostate activity, local tissue concentrations of LGD-3303 were higher in the prostate than in the levator ani muscle. LGD-3303 has SARM properties that are independent of its pharmacokinetic profile, suggesting that the principle mechanism for tissue-selective activity is the result of altered molecular interactions at the level of the androgen receptor.

  13. Two molecular wheels 12-MC-6 complexes: Synthesis, structure and magnetic property of [Co(μ{sub 2}-SEt){sub 2}]{sub 6} and [Fe(μ{sub 2}-SEt){sub 2}]{sub 6}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Jing; Jian, Fangfang, E-mail: ffj2003@163169.net; Huang, Baoxin

    2013-08-15

    The syntheses and structures of two ethyl mercaptan molecular wheels complexes, [M(μ{sub 2}-SCH{sub 2}CH{sub 3}){sub 2}]{sub 6} (M=Fe, Co), have been reported. Each metal atom is surrounded by four S atoms of the μ{sub 2}-SCH{sub 2}CH{sub 3} ligands in a distorted square plane fashion. The edge-sharing S{sub 4} square planes connect with each other to form a ring. Six metal atoms are located at the vertices of an almost hexagon, with M···M separations in the range of 2.903(1)∼2.936(2) Å for Fe and 2.889(2)∼2.962(2) Å for Co. The diameter of the ring, defined as the average distance between two opposing metalmore » atoms, is 5.850(1) Å for Fe and 5.780(1) Å for Co, respectively. The magnetic property behaves of cobalt(II) cluster complex is studied. Highlights: • Two new ethyl mercaptan cyclic hexanuclear complexes were reported. • The crystal structures shown center formation of M{sub 6}S{sub 12} molecular wheels. • The Co{sub 6} ring cluster complex represents as weak ferromagnet.« less

  14. Changes in the DNA methylation profile of the rat H19 gene upstream region during development and transgenic hepatocarcinogenesis and its role in the imprinted transcriptional regulation of the H19 gene.

    PubMed

    Manoharan, Herbert; Babcock, Karlee; Pitot, Henry C

    2004-09-01

    Monoallelic expression of the imprinted H19 and insulin-like growth factor-2 (Igf2) genes depends on the hypomethylation of the maternal allele and hypermethylation of the paternal allele of the H19 upstream region. Previous studies from our laboratory on liver carcinogenesis in the F1 hybrid of Fischer 344 (F344) and Sprague-Dawley Alb SV40 T Ag transgenic rat (SD) strains revealed the biallelic expression of H19 in hepatomas. We undertook a comparative study of the DNA methylation status of the upstream region of H19 in fetal, adult, and neoplastic liver. Bisulfite DNA sequencing analysis of a 3.745-kb DNA segment extending from 2950 to 6695 bp of the H19 upstream region revealed marked variations in the methylation patterns in fetal, adult, and neoplastic liver. In the fetal liver, equal proportions of hyper- and hypomethylated strands revealed the differentially methylated status of the parental alleles, but in neoplastic liver a pronounced change in the pattern of methylation was observed with a distinct change to hypomethylation in the short segments between 2984 and 3301 bp, 6033-6123 bp, and 6518-6548 bp. These results indicated that methylation of all cytosines in this region may contribute to the imprinting status of the rat H19 gene. This phenomenon of differential methylation-related epigenetic alteration in the key cis-regulatory domains of the H19 promoter influences switching to biallelic expression in hepatocellular carcinogenesis. Similar to mouse and human, we showed that the zinc-finger CCTCC binding factor (CTCF) binds to the unmethylated CTCF binding site in the upstream region to influence monoallelic imprinted expression in fetal liver. CTCF does not appear to be rate limiting in fetal, normal, and neoplastic liver. 3' to the CTCF binding sites, another DNA region exhibits methylation of CpG's in both DNA strands in adult liver, retention of the imprint in fetal liver, and complete demethylation in neoplastic liver. In this region is also a

  15. Superconducting order from disorder in 2H-TaSe 2-xS x

    DOE PAGES

    Li, Lijun; Deng, Xiaoyu; Wang, Zhen; ...

    2017-02-24

    Here, we report on the emergence of robust superconducting order in single crystal alloys of TaSe 2$ -$x S x (0 ≤ × ≤2). The critical temperature of the alloy is surprisingly higher than that of the two end compounds TaSe2 and TaS2. The evolution of superconducting critical temperature T c(x) correlates with the full width at half maximum of the Bragg peaks and with the linear term of the high-temperature resistivity. The conductivity of the crystals near the middle of the alloy series is higher or similar than that of either one of the end members 2H-TaSe 2 and/ormore » 2H-TaS 2. It is known that in these materials superconductivity is in close competition with charge density wave order. We interpret our experimental findings in a picture where disorder tilts this balance in favor of superconductivity by destroying the charge density wave order.« less

  16. Experimental Electronic Spectroscopy of Two PAHs: Naphthalene and 2-METHYL Naphthalene

    NASA Astrophysics Data System (ADS)

    Friha, H.; Feraud, G.; Pino, T.; Brechignac, Ph.; Parneix, P.; Dhaoudi, Z.; Jaidane, N.; Galila, H.; Troy, T.; Schmidt, T.

    2011-06-01

    The presence of polycyclic aromatic hydrocarbons (PAHs) in the interstellar medium (ISM) was suggested in the mid-80's. Since then, their important role in the physico-chemical evolution of the ISM has been confirmed. Interstellar PAHs have been in particular proposed as possible carriers of some Diffuse Interstellar Bands (DIBs). These absorption bands are seen in the spectra of reddened stars from the visible to the near infrared and constitute a major astrophysical issue. Our purpose is to obtain electronic spectra of gas phase PAHs which will be used to probe their participation to the interstellar extinction curve from the visible (DIBs) to the UV (bump). For this goal PAHs cations represent an excellent set of target species. A new way of forming PAH+-Ar_n clusters cations has been implemented in the experimental set-up 'ICARE' at ISMO (Orsay) giving us the capability to measure the electronic spectra of cold PAH cations in the gas phase through the "Ar tagging" trick. Two molecules have been investigated in this way: naphthalene (C_1_0H_8) and 2- methyl naphthalene (C_1_1H_1_0). Clusters of naphthalene and (or 2-methyl-naphthalene) with Ar atoms are first formed in a supersonic jet, before being hit by a 281 nm laser beam which photo-ionizes the clusters which are then injected in a molecular beam through a skimmer. A tunable laser beam crossing downstream photo-dissociates the cations. The bare PAH fragments are detected using a Time-Of-Flight spectrometer while scanning the visible laser wavelength from 470 to 690 nm.

  17. [Analysis of volatile sulfur compounds production of oral cavity in preschool children and influencing factors].

    PubMed

    Zhang, Qun; Liu, Xue-nan; Chang, Qing; Ao, Shuang; Zheng, Shu-guo; Xu, Tao

    2015-12-18

    To investigate the prevalence of volatile sulfur compounds(VSC) in oral cavity of preschool children, and to analyze related factors, thus to provide scientific basis for the prediction and treatment of halitosis. The VSC content (hydrogen sulfide, methyl mercaptan, dimethyl sulfide) of 170 preschool children (4 to 6 years old) was detected by a portable gas chromatograph OralChromaTM. The status of the oral health was evaluated. The living habits and other aspects were obtained through questionnaires from the children's parents. A soft package for social statistics version 13.0 (SPSS 13.0) was used in which univariate analysis and multivariate analysis were utilized to analyze the related factors of halitosis in children. In the study, 34.4% of the total subjects had excessive VSC. Hydrogen sulfide (H₂S) [(1.59 ± 2.41) ng/10 mL] and total VSC concentration [(2.14 ± 4.42) ng/10 mL] in the girls were significantly higher (P<0.05) than those in the boys. The tongue coating score had a significant positive correlation with H2S [tongue coating area (1.68 ± 2.48) ng/10 mL,tongue coating thickness (2.18 ± 2.69) ng/10 mL] and total VSC concentration [tongue coating area, (2.26 ± 4.31) ng/10 mL,tongue coating thickness (2.41 ± 3.02) ng/10 mL , P<0.01]. The site number of DI-S2 had a significant positive correlation with methyl mercaptan (CH3SH) and dimethyl sulfide [(CH3)2S] concentration (P<0.01). The concentration of H₂S [(1.19 ± 1.62) ng/10 mL] in children, whose mother had a higher degree of education, was statistically lower (P<0.01). The children who took dessert or sweat drinks more frequently had lower H2S [(1.04 ± 1.55) ng/10 mL, P<0.05] concentration, while CH3SH and (CH3₂)S concentration [(0.29 ± 1.92) ng/10 mL, (0.37 ± 2.06) ng/10 mL, P<0.05) were higher in the children with mouth-breath habit. A high prevalence of halitosis was noted in preschool children. Gender, tongue coating index, debris index-simplified, status of the mother

  18. Synthetic and Spectroscopic Studies on N-(i,j-Disubstituted Phenyl)-4- Substituted Benzenesulphonamides, 4-X'C6H4SO2NH(i,j-X2C6H3), where X' = H, CH3, C2H5, F, Cl or Br; i, j = 2, 3; 2, 4; 2, 5; 2, 6 or 3, 4; and X = CH3 or Cl

    NASA Astrophysics Data System (ADS)

    Shetty, Mahesha; Gowda, B. Thimme

    2005-02-01

    Fifty four N-(i,j-disubstituted phenyl)-4-substituted benzenesulphonamides of the general formula 4-X'C6H4SO2NH(i,j-X2C6H3), where X' = H, CH3, C2H5, F, Cl or Br; i,j = 2,3; 2,4; 2,5; 2,6 or 3, 4; and X = CH3 or Cl, are prepared and characterized and their infrared, 1H and 13C NMR spectra in solution are studied. The N-H stretching vibrations νN-H absorb in the range 3305 - 3205 cm-1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1377 - 1307 cm-1 and 1184 - 1128 cm-1, respectively. The N-(i,j-disubstituted phenyl)-4-substituted benzenesulphonamides show C-S, S-N and C-N stretching vibrations in the ranges 844 - 800 cm-1, 945 - 891 cm-1 and 1309 - 1170 cm-1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts of 2.jpg" /> are assigned to protons and carbon atoms of the two benzene rings. Incremental shifts of the ring protons and carbon atoms due to -SO2NH(i,j-X2C6H3) groups in C6H5SO2NH(i,j-X2C6H3) and 4-X'C6H4SO2NH- groups in 4-X'C6H4SO2NH(C6H*) are computed and employed to calculate the chemical shifts of the ring protons and carbon atoms in the substituted compounds 4-X'C6H4SO2NH(i,j-X2C6H3). The different methods of calculation lead to almost the same values in most cases and agree well with the observed chemical shifts, indicating the validity of the principle of additivity of the substituent effects with chemical shifts in these compounds.

  19. Antibacterial properties of 3 H-spiro[1-benzofuran-2,1'-cyclohexane] derivatives from Heliotropium filifolium.

    PubMed

    Urzúa, Alejandro; Echeverría, Javier; Rezende, Marcos C; Wilkens, Marcela

    2008-10-01

    A re-examination of cuticular components of Heliotropium filifolium allowed the isolation of four new compounds: 3'-hydroxy-2',2',6'-trimethyl-3H-spiro[1-benzo-furan-2,1'-cyclohexane]-5-carboxylic acid(2), methyl 3'-acetyloxy-2',2',6'-trimethyl-3H-spiro[1-benzofuran-2,1'-cyclohexane]-5-carboxylate (3), methyl 3'-isopentanoyloxy-2',2',6'-trimethyl-3H-spiro[1-benzofuran-2,1'-cyclohexane]-5-carboxylate (4) and methyl 3'-benzoyloxy-2',2',6'-trimethyl-3H-spiro[1-benzofuran-2,1'-cyclohexane]-5-carboxylate (5).Compounds 2-5 were identified by their spectroscopic analogies with filifolinol (1), and their structures confirmed by chemical correlation with 1. The antimicrobial properties of the compounds were tested against Gram positive and Gram negative bacteria. Some of them proved to be active against Gram positive, but inactive against Gram negative bacteria. In searching for structure-activity relationships from the obtained MIC values, lipophilicity was shown to be an important variable.

  20. 2C-Methyl- D- erythritol 2,4-cyclodiphosphate synthase from Stevia rebaudiana Bertoni is a functional gene.

    PubMed

    Kumar, Hitesh; Singh, Kashmir; Kumar, Sanjay

    2012-12-01

    Stevia [Stevia rebaudiana (Bertoni)] is a perennial herb which accumulates sweet diterpenoid steviol glycosides (SGs) in its leaf tissue. SGs are synthesized by 2C-methyl-D-erythritol 4-phosphate (MEP) pathway. Of the various enzymes of the MEP pathway, 2C-methyl-D-erythritol 2,4-cyclodiphosphate synthase (MDS) (encoded by MDS) catalyzes the cyclization of 4-(cytidine 5' diphospho)-2C-methyl-D-erythritol 2-phosphate into 2C-methyl-D-erythritol 2,4-cyclodiphosphate. Complementation of the MDS knockout mutant strain of Escherichia coli, EB370 with putative MDS of stevia (SrMDS) rescued the lethal mutant, suggesting SrMDS to be a functional gene. Experiments conducted in plant growth chamber and in the field suggested SrMDS to be a light regulated gene. Indole 3-acetic acid (IAA; 50, 100 μM) down-regulated the expression of SrMDS at 4 h of the treatment, whereas, abscisic acid did not modulate its expression. A high expression of SrMDS was observed during the light hours of the day as compared to the dark hours. The present work established functionality of SrMDS and showed the role of light and IAA in regulating expression of SrMDS.

  1. Endothelium-derived hyperpolarizing factor and protein kinase G Iα activation: H2O2 versus S-nitrosothiols.

    PubMed

    Bautista-Niño, Paula K; van der Stel, Marien; Batenburg, Wendy W; de Vries, René; Roks, Anton J M; Danser, A H Jan

    2018-05-15

    Protein kinase G (PKG) Iα mediates the cyclic guanosine monophosphate-mediated vasodilatory effects induced by NO. Endothelium-derived hyperpolarizing factors (EDHFs), like H 2 O 2 can activate PKGIα in a cyclic guanosine monophosphate-independent manner, but whether this is true for all EDHFs (e.g., S-nitrosothiols) is unknown. Here, we investigated the contribution of PKGIα to bradykinin-, H 2 O 2 -, L-S-nitrosocysteine-, and light-induced relaxation in porcine coronary arteries, making use of the fact that thioredoxin reductase inhibition with auranofin or 1-chloro-2,4-dinitrobenzene potentiates PKGIα. Thioredoxin reductase inhibition potentiated bradykinin and H 2 O 2 , but not L-S-nitrosocysteine or light. The relaxations by the latter 2 and bradykinin, but not those by H 2 O 2 , were prevented by the soluble guanylyl cyclase (sGC) inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one. Yet, after S-nitrosothiol depletion with ethacrynic acid, thioredoxin reductase inhibition also potentiated light-induced relaxation, and this was prevented by the Na + -K + ATPase inhibitor ouabain. This indicates that photorelaxation depends on sGC activation by S-nitrosothiols, while only after S-nitrosothiol depletion oxidized PKGIα comes into play, and acts via Na + -K + ATPase. In conclusion, both bradykinin- and light-induced relaxation of porcine coronary arteries depend, at least partially, on oxidized PKGIα, and this does not involve sGC. H 2 O 2 also acts via oxidized PKGIα in an sGC-independent manner. Yet, S-nitrosothiol-induced relaxation is PKGIα-independent. Clearly, PKG activation does not contribute universally to all EDHF responses, and targeting PKGIα may only mimick EDHF under certain conditions. It is therefore unlikely that PKGIα activators will be universal vasodilators. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Hot gas, regenerative, supported H.sub.2 S sorbents

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E. (Inventor); Sharma, Pramod K. (Inventor)

    1993-01-01

    Efficient, regenerable sorbents for removal of H.sub.2 S from moderately high temperature (usually 200.degree. C.-550.degree.C.) gas streams comprise a porous, high surface area aluminosilicate support, suitably a zeolite, and most preferably a sodium deficient zeolite containing 1 to 20 weight percent of binary metal oxides. The binary oxides are a mixture of a Group VB or VIB metal oxide with a Group IB, IIB or VIII metal oxide such as V-Zn-O, V-Cu-O, Cu-Mo-O, Zn-Mo-O or Fe-Mo-O contained in the support. The sorbent effectively removes H.sub.2 S from the host gas stream in high efficiency and can be repetitively regenerated at least 10 times without loss of activity.

  3. Cometabolic degradation of ethyl mercaptan by phenol-utilizing Ralstonia eutropha in suspended growth and gas-recycling trickle-bed reactor.

    PubMed

    Sedighi, Mahsa; Zamir, Seyed Morteza; Vahabzadeh, Farzaneh

    2016-01-01

    The degradability of ethyl mercaptan (EM), by phenol-utilizing cells of Ralstonia eutropha, in both suspended and immobilized culture systems, was investigated in the present study. Free-cells experiments conducted at EM concentrations ranging from 1.25 to 14.42 mg/l, showed almost complete removal of EM at concentrations below 10.08 mg/l, which is much higher than the maximum biodegradable EM concentration obtained in experiments that did not utilize phenol as the primary substrate, i.e. 2.5 mg/l. The first-order kinetic rate constant (kSKS) for EM biodegradation by the phenol-utilizing cells (1.7 l/g biomass/h) was about 10 times higher than by cells without phenol utilization. Immobilized-cells experiments performed in a gas recycling trickle-bed reactor packed with kissiris particles at EM concentrations ranging from 1.6 to 36.9 mg/l, showed complete removal at all tested concentrations in a much shorter time, compared with free cells. The first-order kinetic rate constant (rmaxKs) for EM utilization was 0.04 l/h for the immobilized system compared to 0.06 for the suspended-growth culture, due to external mass transfer diffusion. Diffusion limitation was decreased by increasing the recycling-liquid flow rate from 25 to 65 ml/min. The removed EM was almost completely mineralized according to TOC and sulfate measurements. Shut down and starvation experiments revealed that the reactor could effectively handle the starving conditions and was reliable for full-scale application. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. The structural properties of 5-methyl-2-phenyl-2H-1,2,3-triazole-4- carboxylic acid and chromogenic mechanism on its rhodamine B derivatives to Hg2+ ions

    NASA Astrophysics Data System (ADS)

    Li, Jianling; Ding, Guohua; Niu, Yanyan; Wu, Luyong; Feng, Huajie; He, Wenying

    2018-07-01

    5-Methyl-2-phenyl-2H-1,2,3-triazole-4-carboxylic acid (MPTC), a newly synthesized compound, was explored to study the structural properties and theoretical spectra by using GaussView5.0 program package and the time dependent density functional theory (TD DFT). The calculated quantum chemical values suggested that it is easy for MPTC to lose electron with weak electron accepting ability. And the results of experimental measurements on fluorescence and absorption spectra were consistent with that of the calculated spectra in great degree. In addition, MPTC was successfully used and synthesized a novel rhodamine B derivative RMPTC containing 1,2,3-triazole unit. It is found that there is special chromogenic response of RMPTC to Hg2+ ions in N, N-dimethylformamide (DMF)-H2O (v/v = 1/1, Tris-HCl, pH 7.4) with the triazole appended colorless chemosensor turned to pink and enabled naked-eye detection. The fluorescence signal for RMPTC-Hg2+ system was not affected by other coexisting metal ions. The 1:2 stoichiometric structure of RMPTC and Hg2+ is confirmed using a Job's plot estimation and TD DFT calculations. The corresponding "off-on" fluorescence mechanism of RMPTC binding to Hg2+ which were ascribed to Hg2+ inducing the ring-opened rhodamine B moiety were proposed. This study was an advancement for the application of 1,2,3-triazole compound in photophysical chemistry field and provides guidance for exploring simple and high-selectivity Hg2+ probes in aqueous solutions under physiological conditions.

  5. Histone H3K4 methylation-dependent and -independent functions of Set1A/COMPASS in embryonic stem cell self-renewal and differentiation.

    PubMed

    Sze, Christie C; Cao, Kaixiang; Collings, Clayton K; Marshall, Stacy A; Rendleman, Emily J; Ozark, Patrick A; Chen, Fei Xavier; Morgan, Marc A; Wang, Lu; Shilatifard, Ali

    2017-09-01

    Of the six members of the COMPASS (complex of proteins associated with Set1) family of histone H3 Lys4 (H3K4) methyltransferases identified in mammals, Set1A has been shown to be essential for early embryonic development and the maintenance of embryonic stem cell (ESC) self-renewal. Like its familial relatives, Set1A possesses a catalytic SET domain responsible for histone H3K4 methylation. Whether H3K4 methylation by Set1A/COMPASS is required for ESC maintenance and during differentiation has not yet been addressed. Here, we generated ESCs harboring the deletion of the SET domain of Set1A (Set1A ΔSET ); surprisingly, the Set1A SET domain is dispensable for ESC proliferation and self-renewal. The removal of the Set1A SET domain does not diminish bulk H3K4 methylation in ESCs; instead, only a subset of genomic loci exhibited reduction in H3K4me3 in Set1A ΔSET cells, suggesting a role for Set1A independent of its catalytic domain in ESC self-renewal. However, Set1A ΔSET ESCs are unable to undergo normal differentiation, indicating the importance of Set1A-dependent H3K4 methylation during differentiation. Our data also indicate that during differentiation, Set1A but not Mll2 functions as the H3K4 methylase on bivalent genes and is required for their expression, supporting a model for transcriptional switch between Mll2 and Set1A during the self-renewing-to-differentiation transition. Together, our study implicates a critical role for Set1A catalytic methyltransferase activity in regulating ESC differentiation but not self-renewal and suggests the existence of context-specific H3K4 methylation that regulates transcriptional outputs during ESC pluripotency. © 2017 Sze et al.; Published by Cold Spring Harbor Laboratory Press.

  6. Exogenous H2S facilitating ubiquitin aggregates clearance via autophagy attenuates type 2 diabetes-induced cardiomyopathy

    PubMed Central

    Wu, Jichao; Tian, Zhiliang; Sun, Yu; Lu, Cuicui; Liu, Ning; Gao, Zhaopeng; Zhang, Linxue; Dong, Shiyun; Yang, Fan; Zhong, Xin; Xu, Changqing; Lu, Fanghao; Zhang, Weihua

    2017-01-01

    Diabetic cardiomyopathy (DCM) is a serious complication of diabetes. Hydrogen sulphide (H2S), a newly found gaseous signalling molecule, has an important role in many regulatory functions. The purpose of this study is to investigate the effects of exogenous H2S on autophagy and its possible mechanism in DCM induced by type II diabetes (T2DCM). In this study, we found that sodium hydrosulphide (NaHS) attenuated the augment in left ventricular (LV) mass and increased LV volume, decreased reactive oxygen species (ROS) production and ameliorated H2S production in the hearts of db/db mice. NaHS facilitated autophagosome content degradation, reduced the expression of P62 (a known substrate of autophagy) and increased the expression of microtubule-associated protein 1 light chain 3 II. It also increased the expression of autophagy-related protein 7 (ATG7) and Beclin1 in db/db mouse hearts. NaHS increased the expression of Kelch-like ECH-associated protein 1 (Keap-1) and reduced the ubiquitylation level in the hearts of db/db mice. 1,4-Dithiothreitol, an inhibitor of disulphide bonds, increased the ubiquitylation level of Keap-1, suppressed the expression of Keap-1 and abolished the effects of NaHS on ubiquitin aggregate clearance and ROS production in H9C2 cells treated with high glucose and palmitate. Overall, we concluded that exogenous H2S promoted ubiquitin aggregate clearance via autophagy, which might exert its antioxidative effect in db/db mouse myocardia. Moreover, exogenous H2S increased Keap-1 expression by suppressing its ubiquitylation, which might have an important role in ubiquitin aggregate clearance via autophagy. Our findings provide new insight into the mechanisms responsible for the antioxidative effects of H2S in the context of T2DCM. PMID:28796243

  7. Pharmacokinetics and N-acetylation metabolism of S-methyl-l-cysteine and trans-S-1-propenyl-l-cysteine in rats and dogs.

    PubMed

    Amano, Hirotaka; Kazamori, Daichi; Itoh, Kenji

    2016-11-01

    1. Pharmacokinetics and N-acetylation metabolism of S-methyl-L-cysteine (SMC) and trans-S-1-propenyl-L-cysteine (S1PC) were examined in rats and dogs. SMC and S1PC (2-5 mg/kg) were well absorbed in both species with high bioavailability (88-100%). 2. SMC and S1PC were excreted only to a small extent in the urine of rats and dogs. The small renal clearance values (<0.03 l/h/kg) indicated the extensive renal reabsorption of SMC and S1PC, which potentially contributed to their long elimination half-lives (>5 h) in dogs. 3. S1PC, but not SMC, underwent N-acetylation extensively in vivo, which can be explained by the relative activities of N-acetylation of S1PC/SMC and deacetylation of their N-acetylated forms, N-acetyl-S1PC/N-acetyl-SMC, in the liver and kidney in vitro. The activities for S1PC N-acetylation were similar to or higher than those for N-acetyl-S1PC deacetylation in liver S9 fractions of rat and dog, whereas liver and kidney S9 fractions of rat and dog had little activity for SMC N-acetylation or considerably higher activities for N-acetyl-SMC deacetylation. 4. Our study demonstrated that the pharmacokinetics of SMC and S1PC in rats and dogs was characterized by high bioavailability and extensive renal reabsorption; however, the extent of undergoing the N-acetylation metabolism was extremely different between SMC and S1PC.

  8. Cu2S-Cu-TiO2 mesoporous carbon composites for the degradation of high concentration of methyl orange under visible light

    NASA Astrophysics Data System (ADS)

    Zhang, Liang; Zhao, Yuan; Zhong, Lvling; Wang, Yang; Chai, Shouning; Yang, Tao; Han, Xuanli

    2017-11-01

    A Schiff base compound was used to prepare a Cu2S-Cu-TiO2 mesoporous carbon composite photocatalyst (Cu2S-Cu-TiO2/MC) by a simple precipitation-carbonization method with a carbonization temperature of 750 °C. X-ray diffraction and x-ray photoelectron spectroscopy studies show that Cu2S, Cu, and TiO2 exist in Cu2S-Cu-TiO2/MC in the form of nanometer-sized particles. Scanning electron microscope and transmission electron microscope images show that the composites form a spherical carbon structure inlaid with Cu2S and Cu and coated TiO2. The Brunauer-Emmett-Teller test shows that the material has a large specific surface area (76.14 m2/g) and mesoporous structure. UV-vis diffuse reflection spectroscopy and photoluminescence spectroscopy indicate that the recombination of photo-generated electrons and holes in the samples were inhibited. The composites show good degradation performance in a high concentration (300 mg/L) of methyl orange (MO) solution under visible light. The composites exhibit great potential in the treatment of dyes for wastewater treatment.

  9. Bardoxolone Methyl Decreases Megalin and Activates Nrf2 in the Kidney

    PubMed Central

    Chertow, Glenn M.; Hebbar, Sudarshan; Vaziri, Nosratola D.; Ward, Keith W.; Meyer, Colin J.

    2012-01-01

    Inflammation and oxidative stress are hallmarks and mediators of the progression of CKD. Bardoxolone methyl, a potent activator of the nuclear factor erythroid 2–related factor 2 (Nrf2)–mediated antioxidant and anti-inflammatory response, increases estimated GFR and decreases BUN, serum phosphorus, and uric acid concentrations in patients with moderate to severe CKD. However, it also increases albuminuria, which is associated with inflammation and disease progression. Therefore, we investigated whether this bardoxolone methyl–induced albuminuria may result from the downregulation of megalin, a protein involved in the tubular reabsorption of albumin and lipid-bound proteins. Administration of bardoxolone methyl to cynomolgus monkeys significantly decreased the protein expression of renal tubular megalin, which inversely correlated with the urine albumin-to-creatinine ratio. Moreover, daily oral administration of bardoxolone methyl to monkeys for 1 year did not lead to any adverse effects on renal histopathologic findings but did reduce serum creatinine and BUN, as observed in patients with CKD. Finally, the bardoxolone methyl–induced decrease in megalin corresponded with pharmacologic induction of renal Nrf2 targets, including NAD(P)H:quinone oxidoreductase 1 enzyme activity and glutathione content. This result indicates that Nrf2 may have a role in megalin regulation. In conclusion, these data suggest that the increase in albuminuria that accompanies bardoxolone methyl administration may result, at least in part, from reduced expression of megalin, which seems to occur without adverse effects and with strong induction of Nrf2 targets. PMID:22859857

  10. Histone H3 Lysine Methylation in Cognition and Intellectual Disability Disorders

    ERIC Educational Resources Information Center

    Parkel, Sven; Lopez-Atalaya, Jose P.; Barco, Angel

    2013-01-01

    Recent research indicates that epigenetic mechanisms and, in particular, the post-translational modification (PTM) of histones may contribute to memory encoding and storage. Among the dozens of possible histone PTMs, the methylation/demethylation of lysines in the N-terminal tail of histone H3 exhibits particularly strong links with cognitive…

  11. Are clinicopathological features of colorectal cancers with methylation in half of CpG island methylator phenotype panel markers different from those of CpG island methylator phenotype-high colorectal cancers?

    PubMed

    Bae, Jeong Mo; Rhee, Ye-Young; Kim, Kyung Ju; Wen, Xianyu; Song, Young Seok; Cho, Nam-Yun; Kim, Jung Ho; Kang, Gyeong Hoon

    2016-01-01

    CpG island methylator phenotype (CIMP)-high (CIMP-H) colorectal cancer (CRC) is defined when a tumor shows methylation at greater than or equal to 60% of CIMP panel markers. Although CRCs with methylation at 50% of panel markers are classified as CIMP-low/CIMP-0 tumors, little is known regarding the clinicopathological and molecular features of CRCs with methylation at 4/8 panel markers (4/8 methylated markers) and whether they are akin to CIMP-H or CIMP-low/CIMP-0 CRCs in terms of their clinicopathological or molecular features. A total of 1164 cases of surgically resected CRC were analyzed for their methylation status in 8 CIMP panel markers, and the frequencies of various clinicopathological and molecular features were compared between CRCs with 0/8, 1/8 to 3/8, 4/8, and 5/8 to 8/8 methylated markers. CRCs with 4/8 methylated markers were closer to CRCs with 5/8 to 8/8 methylated markers in terms of sex distribution, mucin production, serration, nodal metastasis, CK7 expression, CK20 loss, and CDX2 loss frequencies and overall survival rate. CRCs with methylation at 4/8 markers were closer to CRCs with 1/8 to 3/8 methylated markers in terms of less frequent right colon location and poor differentiation. CRCs with 4/8 methylated markers showed the shortest overall survival time compared with CRCs with 0/8, 1/8 to 3/8, 4/8, or 5/8 to 8/8 methylated markers. In terms of clinicopathological and molecular features, CRCs with 4/8 methylated markers appeared to be closer to CIMP-H than to CIMP-low/CIMP-0 and would thus be better classified as CIMP-H if the CRCs require classification into either CIMP-H or CIMP-low/CIMP-0. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. H. pylori modifies methylation of global genomic DNA and the gastrin gene promoter in gastric mucosal cells and gastric cancer cells.

    PubMed

    Xie, Yuan; Zhou, Jian Jiang; Zhao, Yan; Zhang, Ting; Mei, Liu Zheng

    2017-07-01

    The aim of this study was to evaluate the correlation between H. pylori infection and global DNA methylation, as well as the methylation levels of the gastrin promoters. We constructed a eukaryotic expression vector, pcDNA3.1::cagA, and transfected it into GES-1 gastric mucosal cells and SGC-7901 gastric cancer cells. Both cell lines were infected with the H. pylori/CagA + strain NCTC11637. Then, we detected global DNA methylation by capture and detection antibodies, followed by colorimetric quantification. The methylation levels of the gastrin promoter were evaluated by base-specific cleavage and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. In H. pylori/CagA + -infected GES-1 and SGC-7901 cells, the methylation levels of genomic DNA decreased by 49.4% and 18.8%, and in GES-1 and SGC-7901 cells transfected with pcDNA3.1::cagA, the methylation levels of genomic DNA decreased by 17.05% and 25.6%, respectively. Among 24 methylation sites detected in the gastrin promoter region, the methylation levels of 9 CpG sites were significantly decreased in H. pylori/CagA+-infected and pcDNA3.1:: cagA-transfected cells in comparison to corresponding control cells. These results indicate that H. pylori/CagA + decreases the methylation of the genome and the gastrin promoter at some CpG sites in gastric mucosal and gastric cancer cells. Copyright © 2017. Published by Elsevier Ltd.

  13. Reactivity of 3-hydroxy-3-methyl-2-butanone: Photolysis and OH reaction kinetics

    NASA Astrophysics Data System (ADS)

    Bouzidi, H.; Laversin, H.; Tomas, A.; Coddeville, P.; Fittschen, C.; El Dib, G.; Roth, E.; Chakir, A.

    2014-12-01

    Hydroxycarbonyl compounds are important secondary reaction products in the oxidation of Volatile Organic Compounds (VOCs) in the atmosphere. The atmospheric fate of these oxygenated VOCs is however poorly understood, especially the relevance of the photolytic pathway. In this work, a combined investigation of the photolysis and temperature-dependent OH radical reaction of 3-hydroxy-3-methyl-2-butanone (3H3M2B) is presented. A photolysis lifetime of about 4-5 days was estimated with a global quantum yield of 0.10. The OH reaction rate coefficient follows the Arrhenius trend (298-356 K) and could be modelled through the following expression: k3H3M2B(T) = (5.12 ± 0.07) × 10-12 exp(-563 ± 119/T) in cm3 molecule-1 s-1. A 3H3M2B atmospheric lifetime of 15 days towards the OH radical was evaluated. Our results showed that the photolysis pathway is the major degradation channel for 3H3M2B. Photolysis products were identified and quantified in the present work with a carbon balance of around 80% enabling a reaction mechanism to be proposed. The present work underlines the need for further studies on the atmospheric chemistry of oxygenated VOCs.

  14. Advanced oxidation technology for H2S odor gas using non-thermal plasma

    NASA Astrophysics Data System (ADS)

    Tao, ZHU; Ruonan, WANG; Wenjing, BIAN; Yang, CHEN; Weidong, JING

    2018-05-01

    Non-thermal plasma technology is a new type of odor treatment processing. We deal with H2S from waste gas emission using non-thermal plasma generated by dielectric barrier discharge. On the basis of two criteria, removal efficiency and absolute removal amount, we deeply investigate the changes in electrical parameters and process parameters, and the reaction process of the influence of ozone on H2S gas removal. The experimental results show that H2S removal efficiency is proportional to the voltage, frequency, power, residence time and energy efficiency, while it is inversely proportional to the initial concentration of H2S gas, and ozone concentration. This study lays the foundations of non-thermal plasma technology for further commercial application.

  15. Energetics and kinetics of the prebiotic synthesis of simple organic acids and amino acids with the FeS-H2S/FeS2 redox couple as reductant

    NASA Technical Reports Server (NTRS)

    Schoonen, M. A.; Xu, Y.; Bebie, J.

    1999-01-01

    The thermodynamics of the FeS-H2S/FeS2 redox couple and a select number of reactions critical to the synthesis of simple carboxylic acids and amino acids have been evaluated as a function of temperature. This thermodynamic evaluation shows that the reducing power of the FeS-H2S/FeS2 redox couple decreases drastically with temperature. By contrast the equilibria describing the reduction of CO2 and the formation of simple carboxylic acids and amino acids require an increasingly higher reducing power with temperature. Given these two opposite trends, the thermodynamic driving force for CO2 reduction and amino acid formation with the FeS-H2S/FeS2 redox couple as reductant diminishes with increasing temperature. An evaluation of the mechanism of CO2 reduction by the FeS-H2S/FeS2 couple suggests that the electron transfer from pyrrhotite to CO2 is hindered by a high activation energy, even though the overall reaction is thermodynamically favorable. By comparison the electron transfer from pyrrhotite to either CS2, CO, or HCOOH are far more facile. This theoretical analysis explains the results of experimental work by Keefe et al. (1995), Heinen and Lauwers (1996) and Huber and Wachtershauser (1997). The implication is that a reaction sequence involving the reduction of CO2 with the FeS-H2S/FeS2 couple as reductant is unlikely to initiate a proposed prebiotic carbon fixation cycle (Wachtershauser, 1988b; 1990b, 1990a, 1992, 1993).

  16. RlmCD-mediated U747 methylation promotes efficient G748 methylation by methyltransferase RlmAII in 23S rRNA in Streptococcus pneumoniae; interplay between two rRNA methylations responsible for telithromycin susceptibility.

    PubMed

    Shoji, Tatsuma; Takaya, Akiko; Sato, Yoshiharu; Kimura, Satoshi; Suzuki, Tsutomu; Yamamoto, Tomoko

    2015-10-15

    Adenine at position 752 in a loop of helix 35 from positions 745 to 752 in domain II of 23S rRNA is involved in binding to the ribosome of telithromycin (TEL), a member of ketolides. Methylation of guanine at position 748 by the intrinsic methyltransferase RlmA(II) enhances binding of telithromycin (TEL) to A752 in Streptococcus pneumoniae. We have found that another intrinsic methylation of the adjacent uridine at position 747 enhances G748 methylation by RlmA(II), rendering TEL susceptibility. U747 and another nucleotide, U1939, were methylated by the dual-specific methyltransferase RlmCD encoded by SP_1029 in S. pneumoniae. Inactivation of RlmCD reduced N1-methylated level of G748 by RlmA(II) in vivo, leading to TEL resistance when the nucleotide A2058, located in domain V of 23S rRNA, was dimethylated by the dimethyltransferase Erm(B). In vitro methylation of rRNA showed that RlmA(II) activity was significantly enhanced by RlmCD-mediated pre-methylation of 23S rRNA. These results suggest that RlmCD-mediated U747 methylation promotes efficient G748 methylation by RlmA(II), thereby facilitating TEL binding to the ribosome. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. FLYING-WATER Renewables-H2-H2O TERRAFORMING: PERMANENT Drought(s)-Elimination FOREVER!!!

    NASA Astrophysics Data System (ADS)

    Lyons, M.; Siegel, E.

    2010-03-01

    ``Water water everywhere; ne'er a drop to drink''[Coleridg(1798)]; now:``Hydrogen hydrogen everywhere;STILL ne'er a drop to drink'': ONLY H2 can be ``FLYING-WATER''/``chemical-rain-in-pipelines''/ ``Hindenberg-effect (H2-UP;H2O-DOWN): atomic-weights ratio: O/H2O=[16]/[18]˜90%; O already in air uphill; NO H2O pumping need! In water-starved glacial-melting world, rescue ONLY by Siegel[3rd Intl.Conf.Alt.Energy,Hemisphere/Springer(1980)- vol.5/ p.459]Renewables-H2-H2O purposely flexible versatile agile customizable scaleable retrofitable integrated operating- system. Rosenfeld[Sci.315,1396(3/9/2007)]-Biello[Sci.Am.(3/9/ 2007)]crucial geomorphology which ONLY maximal-buoyancy light- est-element H2 can exploit, to again make ``Mountains into Fount- ains": Siegel ``terra-forming''(and ocean-rebasificaton!!!) long pre-``Holdren''-``Ciccerine" ``geo-enginering'', only via Siegel proprietary magnetic-hydrogen-valve permits H2 flow in already in-ground dense BCC/ferritic-steels pipelines-network (NO new infrastructure) counters Tromp[Sci.300,1740(03)]global-pandemics (cancers/blindness/famine)dire-warning about H2-(ALONE)economy CATASTROPHIC H2 ozone-layer destruction sobering cavat to dangerous H2-automotion-economy panacea hype!

  18. Probing microsecond time scale dynamics in proteins by methyl (1)H Carr-Purcell-Meiboom-Gill relaxation dispersion NMR measurements. Application to activation of the signaling protein NtrC(r).

    PubMed

    Otten, Renee; Villali, Janice; Kern, Dorothee; Mulder, Frans A A

    2010-12-01

    To study microsecond processes by relaxation dispersion NMR spectroscopy, low power deposition and short pulses are crucial and encourage the development of experiments that employ (1)H Carr-Purcell-Meiboom-Gill (CPMG) pulse trains. Herein, a method is described for the comprehensive study of microsecond to millisecond time scale dynamics of methyl groups in proteins, exploiting their high abundance and favorable relaxation properties. In our approach, protein samples are produced using [(1)H, (13)C]-d-glucose in ∼100% D(2)O, which yields CHD(2) methyl groups for alanine, valine, threonine, isoleucine, leucine, and methionine residues with high abundance, in an otherwise largely deuterated background. Methyl groups in such samples can be sequence-specifically assigned to near completion, using (13)C TOCSY NMR spectroscopy, as was recently demonstrated (Otten, R.; et al. J. Am. Chem. Soc. 2010, 132, 2952-2960). In this Article, NMR pulse schemes are presented to measure (1)H CPMG relaxation dispersion profiles for CHD(2) methyl groups, in a vein similar to that of backbone relaxation experiments. Because of the high deuteration level of methyl-bearing side chains, artifacts arising from proton scalar coupling during the CPMG pulse train are negligible, with the exception of Ile-δ1 and Thr-γ2 methyl groups, and a pulse scheme is described to remove the artifacts for those residues. Strong (13)C scalar coupling effects, observed for several leucine residues, are removed by alternative biochemical and NMR approaches. The methodology is applied to the transcriptional activator NtrC(r), for which an inactive/active state transition was previously measured and the motions in the microsecond time range were estimated through a combination of backbone (15)N CPMG dispersion NMR spectroscopy and a collection of experiments to determine the exchange-free component to the transverse relaxation rate. Exchange contributions to the (1)H line width were detected for 21 methyl

  19. Bardoxolone Methyl Improves Kidney Function in Patients with Chronic Kidney Disease Stage 4 and Type 2 Diabetes: Post-Hoc Analyses from Bardoxolone Methyl Evaluation in Patients with Chronic Kidney Disease and Type 2 Diabetes Study.

    PubMed

    Chin, Melanie P; Bakris, George L; Block, Geoffrey A; Chertow, Glenn M; Goldsberry, Angie; Inker, Lesley A; Heerspink, Hiddo J L; O'Grady, Megan; Pergola, Pablo E; Wanner, Christoph; Warnock, David G; Meyer, Colin J

    2018-01-01

    Increases in measured inulin clearance, measured creatinine clearance, and estimated glomerular filtration rate (eGFR) have been observed with bardoxolone methyl in 7 studies enrolling approximately 2,600 patients with type 2 diabetes (T2D) and chronic kidney disease (CKD). The largest of these studies was Bardoxolone Methyl Evaluation in Patients with Chronic Kidney Disease and Type 2 Diabetes (BEACON), a multinational, randomized, double-blind, placebo-controlled phase 3 trial which enrolled patients with T2D and CKD stage 4. The BEACON trial was terminated after preliminary analyses showed that patients randomized to bardoxolone methyl experienced significantly higher rates of heart failure events. We performed post-hoc analyses to characterize changes in kidney function induced by bardoxolone methyl. Patients in -BEACON (n = 2,185) were randomized 1: 1 to receive once-daily bardoxolone methyl (20 mg) or placebo. We compared the effects of bardoxolone methyl and placebo on a post-hoc composite renal endpoint consisting of ≥30% decline from baseline in eGFR, eGFR <15 mL/min/1.73 m2, and end-stage renal disease (ESRD) events (provision of dialysis or kidney transplantation). Consistent with prior studies, patients randomized to bardoxolone methyl experienced mean increases in eGFR that were sustained through study week 48. Moreover, increases in eGFR from baseline were sustained 4 weeks after cessation of treatment. Patients randomized to bardoxolone methyl were significantly less likely to experience the composite renal endpoint (hazards ratio 0.48 [95% CI 0.36-0.64]; p < 0.0001). Bardoxolone methyl preserves kidney function and may delay the onset of ESRD in patients with T2D and stage 4 CKD. © 2018 The Author(s) Published by S. Karger AG, Basel.

  20. Amino acid modified Ni catalyst exhibits reversible H2 oxidation/production over a broad pH range at elevated temperatures

    DOE PAGES

    Dutta, Arnab; DuBois, Daniel L.; Roberts, John A.; ...

    2014-11-18

    Hydrogenases interconvert H2 and protons at high rates and with high energy efficiencies, providing inspiration for the development of molecular catalysts. Studies designed to determine how the protein scaffold can influence a catalytically active site has led to the synthesis of amino acid derivatives, [Ni(PCy2NAmino acid2)2]2+ (CyAA), of [Ni(PR2NR'2)2]2+ complexes. It is shown that these CyAA derivatives can catalyze fully reversible H2 production/oxidation, a feature reminiscent of enzymes. The reversibility is achieved in acidic aqueous solutions, 0.25% H2/Ar, and elevated temperatures (tested up to 348 K) for the glycine (CyGly), arginine (CyArg), and arginine methyl ester (CyArgOMe) derivatives. As expectedmore » for a reversible process, the activity is dependent upon H2 and proton concentration. CyArg is significantly faster in both directions than the other two derivatives (~300 s-1 H2 production and 20 s-1 H2 oxidation; pH=1, 348 K). The significantly slower rates for CyArgOMe (35 s-1 production and 7 s-1 oxidation) compared to CyArg suggests an important role for the COOH group during catalysis. That CyArg is faster than CyGly (3 s-1 production and 4 s-1 oxidation under the same conditions) suggests that the additional structural features imparted by the guanidinium groups facilitate fast and reversible H2 addition/release. These observations demonstrate that appended, outer coordination sphere amino acids work in synergy with the active site and can play an equally important role for synthetic molecular electrocatalysts as the protein scaffold does for redox active enzymes. This work was funded by the Office of Science Early Career Research Program through the US DOE, BES (AD, WJS), and the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US DOE, BES (DLD, JASR). PNNL is operated by Battelle for the US DOE.« less

  1. Arsenic methylation by an arsenite S-adenosylmethionine methyltransferase from Spirulina platensis.

    PubMed

    Guo, Yuqing; Xue, Ximei; Yan, Yu; Zhu, Yongguan; Yang, Guidi; Ye, Jun

    2016-11-01

    Arsenic-contaminated water is a serious hazard for human health. Plankton plays a critical role in the fate and toxicity of arsenic in water by accumulation and biotransformation. Spirulina platensis (S. platensis), a typical plankton, is often used as a supplement or feed for pharmacy and aquiculture, and may introduce arsenic into the food chain, resulting in a risk to human health. However, there are few studies about how S. platensis biotransforms arsenic. In this study, we investigated arsenic biotransformation by S. platensis. When exposed to arsenite (As(III)), S. platensis accumulated arsenic up to 4.1mg/kg dry weight. After exposure to As(III), arsenate (As(V)) was the predominant species making up 64% to 86% of the total arsenic. Monomethylarsenate (MMA(V)) and dimethylarsenate (DMA(V)) were also detected. An arsenite S-adenosylmethionine methyltransferase from S. platensis (SpArsM) was identified and characterized. SpArsM showed low identity with other reported ArsM enzymes. The Escherichia coli AW3110 bearing SparsM gene resulted in As(III) methylation and conferring resistance to As(III). The in vitro assay showed that SpArsM exhibited As(III) methylation activity. DMA(V) and a small amount of MMA(V) were detected in the reaction system within 0.5hr. A truncated SpArsM derivative lacking the last 34 residues still had the ability to methylate As(III). The three single mutants of SpArsM (C59S, C186S, and C238S) abolished the capability of As(III) methylation, suggesting the three cysteine residues are involved in catalysis. We propose that SpArsM is responsible for As methylation and detoxification of As(III) and may contribute to As biogeochemistry. Copyright © 2016. Published by Elsevier B.V.

  2. Grafting of 2 (2-hydroxy-5-vinylphenyl) 2H-benzotriazole onto polymers with aliphatic groups. Synthesis and polymerization of 2 (2-hydroxy-5-isopropenylphenyl) 2H-benzotriazole and a new synthesis of 2 (2-hydroxy-5-vinylphenyl) 2H-benzotriazole

    NASA Technical Reports Server (NTRS)

    Pradellok, W.; Nir, Z.; Vogl, O.

    1981-01-01

    Successful grafting of 2(2-hydroxy-5-vinylphenyl)2H-benzotriazole onto saturated aliphatic C-H groups of polymers has been accomplished. When the grafting reaction was carried out in chlorobenzene at 150 C = 160 C with di-tertiarybutylperoxide as the grafting initiator, grafts as high as 20 percent - 30 percent at a grafting efficiency of 50 percent and 80 percent have readily been obtained. The grafting reaction was carried out in tubes sealed under high vacuum since trace amounts of oxygen cause complete inhibition of the grafting reaction by the phenolic monomer. On a variety of different polymers including atactic polypropylene, ethylene/vinyl acetate copolymer, poly(methyl methacrylate), poly(butyl acrylate), and polycarbonate were used.

  3. Synthesis of methyl 2-O-alpha-D-mannopyranosyl-alpha-D-talopyranoside and methyl 2-O-alpha-D-talopyranosyl-alpha-D-talopyranoside.

    PubMed

    Jain, R K; Dubey, R; Abbas, S A; Matta, K L

    1987-03-15

    Treatment of methyl 3-O-benzyl-2-O-(2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl)-alpha-D- mannopyranoside (1) with tert-butyldiphenylsilyl chloride in N,N-dimethylformamide afforded methyl 3-O-benzyl-6-O-tert-butyldiphenylsilyl-2-O-(2,3,4,6-tetra-O-acetyl -alpha-D- mannopyranosyl)-alpha-D-mannopyranoside (2). Oxidation of 2 with pyridinium chlorochromate, followed by reduction of the carbonyl group, and subsequent O-deacetylation afforded methyl 3-O-benzyl-6-O-tert-butyldiphenylsilyl-2-O-alpha-D-mannopyranosyl- alpha-D- talopyranoside (5). Cleavage of the tert-butyldiphenylsilyl group of 5 with tetrabutylammonium fluoride in oxolane, followed by hydrogenolysis, gave methyl 2-O-alpha-D-mannopyranosyl-alpha-D-talopyranoside (7). O-Deacetylation of 1 gave methyl 3-O-benzyl-2-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside (8). Treatment of 8 with tert-butyldiphenylsilyl chloride afforded a 6,6'-disilyl derivative, which was converted into a 2',3'-O-isopropylidene derivative, and then further oxidized with pyridinium chlorochromate. The resulting diketone was reduced and removal of the protecting groups gave methyl 2-O-alpha-D-talopyranosyl-alpha-D-talopyranoside (15). The structures of both 7 and 15 were established by 13C-n.m.r. spectroscopy.

  4. Crystal structure of bis-[μ-(4-meth-oxy-phen-yl)methane-thiol-ato-κ(2) S:S]bis-[chlorido-(η(6)-1-isopropyl-4-methyl-benzene)-ruthenium(II)] chloro-form disolvate.

    PubMed

    Stíbal, David; Süss-Fink, Georg; Therrien, Bruno

    2015-10-01

    The mol-ecular structure of the title complex, [Ru2(C8H9OS)2Cl2(C10H14)22CHCl3 or (p-MeC6H4Pr (i) )2Ru2(SCH2-p-C6H5-OCH3)2Cl2·2CHCl3, shows inversion symmetry. The two symmetry-related Ru(II) atoms are bridged by two 4-meth-oxy-α-toluene-thiol-ato [(4-meth-oxy-phen-yl)methane-thiol-ato] units. One chlorido ligand and the p-cymene ligand complete the typical piano-stool coordination environment of the Ru(II) atom. In the crystal, the CH moiety of the chloro-form mol-ecule inter-acts with the chlorido ligand of the dinuclear complex, while one Cl atom of the solvent inter-acts more weakly with the methyl group of the bridging 4-meth-oxy-α-toluene-thiol-ato unit. This assembly leads to the formation of supra-molecular chains extending parallel to [021].

  5. RlmCD-mediated U747 methylation promotes efficient G748 methylation by methyltransferase RlmAII in 23S rRNA in Streptococcus pneumoniae; interplay between two rRNA methylations responsible for telithromycin susceptibility

    PubMed Central

    Shoji, Tatsuma; Takaya, Akiko; Sato, Yoshiharu; Kimura, Satoshi; Suzuki, Tsutomu; Yamamoto, Tomoko

    2015-01-01

    Adenine at position 752 in a loop of helix 35 from positions 745 to 752 in domain II of 23S rRNA is involved in binding to the ribosome of telithromycin (TEL), a member of ketolides. Methylation of guanine at position 748 by the intrinsic methyltransferase RlmAII enhances binding of telithromycin (TEL) to A752 in Streptococcus pneumoniae. We have found that another intrinsic methylation of the adjacent uridine at position 747 enhances G748 methylation by RlmAII, rendering TEL susceptibility. U747 and another nucleotide, U1939, were methylated by the dual-specific methyltransferase RlmCD encoded by SP_1029 in S. pneumoniae. Inactivation of RlmCD reduced N1-methylated level of G748 by RlmAII in vivo, leading to TEL resistance when the nucleotide A2058, located in domain V of 23S rRNA, was dimethylated by the dimethyltransferase Erm(B). In vitro methylation of rRNA showed that RlmAII activity was significantly enhanced by RlmCD-mediated pre-methylation of 23S rRNA. These results suggest that RlmCD-mediated U747 methylation promotes efficient G748 methylation by RlmAII, thereby facilitating TEL binding to the ribosome. PMID:26365244

  6. Biotransformation and pharmacokinetics of the nitrate trans-2-amino-2-methyl-N-(4-nitroxycyclohexyl)-propionamide in dogs.

    PubMed

    Pressmar, F; Neidlein, R; Strein, K

    1992-11-01

    The biotransformation and the pharmacokinetic behavior of the organic nitrate trans-2-Amino-2-methyl-N-(4-nitroxycyclohexyl)-propionamide (BM 12.1179, CAS 129795-96-6) were examined in dogs. BM 12.1179 was predominantly eliminated by urinary excretion, and the unchanged molecule prevailed in urine as well as in plasma. By means of various mass spectroscopic methods, the chemical structures of the metabolites were elucidated. As metabolites trans-2-amino-2-methyl-N-(4-hydroxycyclohexyl)-propionamide and trans-2-amino-2-methyl-N-(4-oxocyclohexyl)-propionamide were formed. Urine levels of the main metabolite were determined by high-pressure liquid chromatography; plasma and urine levels of BM 12.1179 were determined by capillary gas chromatography. The absolute bioavailability of BM 12.1179 was 80-100%. The plasma protein binding was about 34% which is high in comparison to other organic nitrates. BM 12.1179 represents a long-acting organic nitrate in that it shows a slow reductive denitration, and a long elimination half-life of about 10 h.

  7. Characteristics of layered tin disulfide deposited by atomic layer deposition with H2S annealing

    NASA Astrophysics Data System (ADS)

    Lee, Seungjin; Shin, Seokyoon; Ham, Giyul; Lee, Juhyun; Choi, Hyeongsu; Park, Hyunwoo; Jeon, Hyeongtag

    2017-04-01

    Tin disulfide (SnS2) has attracted much attention as a two-dimensional (2D) material. A high-quality, low-temperature process for producing 2D materials is required for future electronic devices. Here, we investigate tin disulfide (SnS2) layers deposited via atomic layer deposition (ALD) using tetrakis(dimethylamino)tin (TDMASn) as a Sn precursor and H2S gas as a sulfur source at low temperature (150° C). The crystallinity of SnS2 was improved by H2S gas annealing. We carried out H2S gas annealing at various conditions (250° C, 300° C, 350° C, and using a three-step method). Angle-resolved X-ray photoelectron spectroscopy (ARXPS) results revealed the valence state corresponding to Sn4+ and S2- in the SnS2 annealed with H2S gas. The SnS2 annealed with H2S gas had a hexagonal structure, as measured via X-ray diffraction (XRD) and the clearly out-of-plane (A1g) mode in Raman spectroscopy. The crystallinity of SnS2 was improved after H2S annealing and was confirmed using the XRD full-width at half-maximum (FWHM). In addition, high-resolution transmission electron microscopy (HR-TEM) images indicated a clear layered structure.

  8. Preparation of polyaniline/PbS core-shell nano/microcomposite and its application for photocatalytic H2 electrogeneration from H2O.

    PubMed

    Rabia, Mohamed; Mohamed, H S H; Shaban, Mohamed; Taha, S

    2018-01-18

    Lead sulfide (PbS) and polyaniline (PANI) nano/microparticles were prepared. Then, PANI/PbS core-shell nano/microcomposites (I, II, and III) were prepared by oxidative polymerization of different aniline concentrations (0.01, 0.03, and 0.05 M), respectively, in the presence of 0.05 M PbS. FT-IR, XRD, SEM, HR-TEM, and UV-Vis analyses were carried out to characterize the samples. From the FT-IR data, there are redshifts in PbS and PANI nano/microparticles bands in comparison with PANI/PbS nano/microcomposites. The average crystallite sizes of PANI/PbS core-shell nano/microcomposites (I, II, and III) from XRD analyses were 46.5, 55, and 42.16 nm, respectively. From the optical analyses, nano/microcomposite (II) has the optimum optical properties with two band gaps values of 1.41 and 2.79 eV. Then, the nano/microcomposite (II) membrane electrode supported on ITO glass was prepared and applied on the photoelectrochemical (PEC) H 2 generation from H 2 O. The characteristics current-voltage and current-time behaviors were measured at different wavelengths from 390 to 636 nm. Also, the incident photon-to-current conversion efficiency (IPCE) under monochromatic illumination condition was calculated. The optimum values for IPCE were 36.5 and 35.2% at 390 and 405 nm, respectively. Finally, a simple mechanism for PEC H 2 generation from H 2 O using the nano/microcomposite (II) membrane electrode was mentioned.

  9. Methionine kinetics in adult men: effects of dietary betaine on L-(2H3-methyl-1-13C)methionine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Storch, K.J.; Wagner, D.A.; Young, V.R.

    1991-08-01

    The effects of a daily 3-g supplement of betaine on kinetic aspects of L-(2H3-methyl-1-13C)methionine (MET) metabolism in healthy young adult men were explored. Four groups of four subjects each were given a control diet, based on an L-amino acid mixture supplying 29.5 and 21.9 mg.kg-1.d-1 of L-methionine and L-cystine for 4 d before the tracer study, conducted on day 5 during the fed state. Two groups received the control diet and two groups received the betaine supplement. Tracer was given intravenously (iv) or orally. The transmethylation rate of MET (TM), homocysteine remethylation (RM), and oxidation of methionine were estimated frommore » plasma methionine labeling and 13C enrichment of expired air. RM tended to increase (P = 0.14) but the TM and methionine oxidation were significantly (P less than 0.05) higher after betaine supplementation when estimated with the oral tracer. No differences were detected with the intravenous tracer. Methionine concentration in plasma obtained from blood taken from subjects in the fed state was higher (P less than 0.01) with betaine supplementation. These results suggest that excess methyl-group intake may increase the dietary requirement for methionine.« less

  10. Emissions of sulfur gases from marine and freshwater wetlands of the Florida Everglades: Rates and extrapolation using remote sensing

    NASA Technical Reports Server (NTRS)

    Hines, Mark E.; Pelletier, Ramona E.; Crill, Patrick M.

    1992-01-01

    Rates of emissions of the biogenic sulfur (S) gases carbonyl sulfide (COS), methyl mercaptan (MSH), dimethyl sulfide (DMS), and carbon disulfide (CS2) were measured in a variety of marine and freshwater wetland habitats in the Florida Everglades during a short duration period in October using dynamic chambers, cryotrapping techniques, and gas chromatography. The most rapid emissions of greater than 500 nmol/m(sup -2)h(sup -1) occurred in red mangrove-dominated sites that were adjacent to open seawater and contained numerous crab burrows. Poorly drained red mangrove sites exhibited lower fluxes of approximately 60 nmol/m(sup -2)h(sup -1) which were similar to fluxes from the black mangrove areas which dominated the marine-influenced wetland sites in the Everglades. DMS was the dominant organo-S gas emitted especially in the freshwater areas. Spectral data from a scene from the Landsat thematic mapper were used to map habitats in the Everglades. Six vegetation categories were delineated using geographical information system software and S gas emission were extrapolated for the entire Everglades National Park. The black mangrove-dominated areas accounted for the largest portion of S gas emissions to the area. The large area extent of the saw grass communities (42 percent) accounted for approximately 24 percent of the total S emissions.

  11. Reactions of guanine with methyl chloride and methyl bromide: O6-methylation versus charge transfer complex formation

    NASA Astrophysics Data System (ADS)

    Shukla, P. K.; Mishra, P. C.; Suhai, S.

    Density functional theory (DFT) at the B3LYP/6-31+G* and B3LYP/AUG-cc-pVDZ levels was employed to study O6-methylation of guanine due to its reactions with methyl chloride and methyl bromide and to obtain explanation as to why the methyl halides cause genotoxicity and possess mutagenic and carcinogenic properties. Geometries of the various isolated species involved in the reactions, reactant complexes (RCs), and product complexes (PCs) were optimized in gas phase. Transition states connecting the reactant complexes with the product complexes were also optimized in gas phase at the same levels of theory. The reactant complexes, product complexes, and transition states were solvated in aqueous media using the polarizable continuum model (PCM) of the self-consistent reaction field theory. Zero-point energy (ZPE) correction to total energy and the corresponding thermal energy correction to enthalpy were made in each case. The reactant complexes of the keto form of guanine with methyl chloride and methyl bromide in water are appreciably more stable than the corresponding complexes involving the enol form of guanine. The nature of binding in the product complexes was found to be of the charge transfer type (O6mG+ · X-, X dbond Cl, Br). Binding of HCl, HBr, and H2O molecules to the PCs obtained with the keto form of guanine did not alter the positions of the halide anions in the PCs, and the charge transfer character of the PCs was also not modified due to this binding. Further, the complexes obtained due to the binding of HCl, HBr, and H2O molecules to the PCs had greater stability than the isolated PCs. The reaction barriers involved in the formation of PCs were found to be quite high (?50 kcal/mol). Mechanisms of genotoxicity, mutagenesis and carcinogenesis caused by the methyl halides appear to involve charge transfer-type complex formation. Thus the mechanisms of these processes involving the methyl halides appear to be quite different from those that involve the

  12. Degron Protease Blockade Sensor to Image Epigenetic Histone Protein Methylation in Cells and Living Animals

    PubMed Central

    2015-01-01

    Lysine methylation of histone H3 and H4 has been identified as a promising therapeutic target in treating various cellular diseases. The availability of an in vivo assay that enables rapid screening and preclinical evaluation of drugs that potentially target this cellular process will significantly expedite the pace of drug development. This study is the first to report the development of a real-time molecular imaging biosensor (a fusion protein, [FLuc2]-[Suv39h1]-[(G4S)3]-[H3-K9]-[cODC]) that can detect and monitor the methylation status of a specific histone lysine methylation mark (H3-K9) in live animals. The sensitivity of this sensor was assessed in various cell lines, in response to down-regulation of methyltransferase EHMT2 by specific siRNA, and in nude mice with lysine replacement mutants. In vivo imaging in response to a combination of methyltransferase inhibitors BIX01294 and Chaetocin in mice reveals the potential of this sensor for preclinical drug evaluation. This biosensor thus has demonstrated its utility in the detection of H3-K9 methylations in vivo and potential value in preclinical drug development. PMID:25489787

  13. Surface Defect Passivation and Reaction of c-Si in H2S.

    PubMed

    Liu, Hsiang-Yu; Das, Ujjwal K; Birkmire, Robert W

    2017-12-26

    A unique passivation process of Si surface dangling bonds through reaction with hydrogen sulfide (H 2 S) is demonstrated in this paper. A high-level passivation quality with an effective minority carrier lifetime (τ eff ) of >2000 μs corresponding to a surface recombination velocity of <3 cm/s is achieved at a temperature range of 550-650 °C. X-ray photoelectron spectroscopy (XPS) confirmed the bonding states of Si and S and provides insights into the reaction pathway of Si with H 2 S and other impurity elements both during and after the reaction. Quantitative analysis of XPS spectra showed that the τ eff increases with an increase in the surface S content up to ∼3.5% and stabilizes thereafter, indicative of surface passivation by monolayer coverage of S on the Si surface. However, S passivation of the Si surface is highly unstable because of thermodynamically favorable reaction with atmospheric H 2 O and O 2 . This instability can be eliminated by capping the S-passivated Si surface with a protective thin film such as low-temperature-deposited amorphous silicon nitride.

  14. Identifying DNA methylation in a nanochannel

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoyin; Yasui, Takao; Yanagida, Takeshi; Kaji, Noritada; Rahong, Sakon; Kanai, Masaki; Nagashima, Kazuki; Kawai, Tomoji; Baba, Yoshinobu

    2016-01-01

    DNA methylation is a stable epigenetic modification, which is well known to be involved in gene expression regulation. In general, however, analyzing DNA methylation requires rather time consuming processes (24-96 h) via DNA replication and protein modification. Here we demonstrate a methodology to analyze DNA methylation at a single DNA molecule level without any protein modifications by measuring the contracted length and relaxation time of DNA within a nanochannel. Our methodology is based on the fact that methylation makes DNA molecules stiffer, resulting in a longer contracted length and a longer relaxation time (a slower contraction rate). The present methodology offers a promising way to identify DNA methylation without any protein modification at a single DNA molecule level within 2 h.

  15. H2S in Shallow Groundwater: Hydrogeochemical Processes, Degassing Experiments and Health Impacts

    NASA Astrophysics Data System (ADS)

    Broers, H. P.; Weert, J. D.; Bouma, R.

    2016-12-01

    Hydrogen sulfide is known to be a hazardous gas even at rather low concentrations and may pose a serious health risk. Occurrences of H2S in groundwater and degassing into the atmosphere are known for volcanic or tectonic active regions, coal mining or gypsum dissolution regions. We studied the occurrence and origin of H2S in shallow groundwater and its degassing into air after pumping in a setting of shallow unconsolidated deposits in the south of the Netherlands, where the sulfate source is antropogenic. We measured H2S concentrations in water using a field photo spectrometer and the degassing into air with a Jerome 631. We analyzed for macro-ions and determined the apparent 3H/3He age to assess the origin of the sulfide in the groundwater. H2S was formed in-situ within organic-rich and carbonate free sediments and peat layers of a fluvio-glacial sediment series in groundwater that infiltrated approximately 15 years ago. Sulfate is omnipresent in Dutch shallow groundwater due to historical atmospheric inputs of SOx, sulfur inputs from intensive livestock farming and subsurface production of sulfate from pyrite oxidation following nitrate leaching from agricultural fields (Zhang et al. 2009 GCA, 2012 AppGeochem). The co-existence of H2S and sulfate in our groundwater appears to be determined by the low pH of the water (4.8-5.5) which limits the precipitation of mackinawite or amorphous FeS. Mapping the combination of observations wells with pH < 5.5, sulfate > 75 mg/L and Fe > 10 mg/l delineated large areas where H2S appeared to be present in concentration between 0.1 and 1.0 mg/L S2- in water. Degassing of groundwater with 0.7 mg S2-/L into a contained volume of air yielded concentrations > 50 ppmv within 15 minutes. Using the degassing rates observed in the experiments and assuming equilibrium degassing, we calibrated a simple model which describes the inflow of water, the degassing and the export of gas in relation to wind velocity. We used the model to evaluate

  16. Electrochemical H2O2 biosensor composed of myoglobin on MoS2 nanoparticle-graphene oxide hybrid structure.

    PubMed

    Yoon, Jinho; Lee, Taek; Bapurao G, Bharate; Jo, Jinhee; Oh, Byung-Keun; Choi, Jeong-Woo

    2017-07-15

    In this research, the electrochemical biosensor composed of myoglobin (Mb) on molybdenum disulfide nanoparticles (MoS 2 NP) encapsulated with graphene oxide (GO) was fabricated for the detection of hydrogen peroxide (H 2 O 2 ). Hybrid structure composed of MoS 2 NP and GO (GO@MoS 2 ) was fabricated for the first time to enhance the electrochemical signal of the biosensor. As a sensing material, Mb was introduced to fabricate the biosensor for H 2 O 2 detection. Formation and immobilization of GO@MoS 2 was confirmed by transmission electron microscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, and scanning tunneling microscopy. Immobilization of Mb, and electrochemical property of biosensor were investigated by cyclic voltammetry and amperometric i-t measurements. Fabricated biosensor showed the electrochemical signal enhanced redox current as -1.86μA at an oxidation potential and 1.95μA at a reduction potential that were enhanced relative to those of electrode prepared without GO@MoS 2 . Also, this biosensor showed the reproducibility of electrochemical signal, and retained the property until 9 days from fabrication. Upon addition of H 2 O 2 , the biosensor showed enhanced amperometric response current with selectivity relative to that of the biosensor prepared without GO@MoS 2 . This novel hybrid material-based biosensor can suggest a milestone in the development of a highly sensitive detecting platform for biosensor fabrication with highly sensitive detection of target molecules other than H 2 O 2 . Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Performance study of biofilter developed to treat H2S from wastewater odour

    PubMed Central

    Omri, Ilhem; Aouidi, Fethia; Bouallagui, Hassib; Godon, Jean-Jacques; Hamdi, Moktar

    2013-01-01

    Biofiltration is an efficient biotechnological process used for waste gas abatement in various industrial processes. It offers low operating and capital costs and produces minimal secondary waste streams. The objective of this study was to evaluate the performance of a pilot scale biofilter in terms of pollutants’ removal efficiencies and the bacterial dynamics under different inlet concentrations of H2S. The treatment of odourous pollutants by biofiltration was investigated at a municipal wastewater treatment plant (WWTP) (Charguia, Tunis, Tunisia). Sampling and analyses were conducted for 150 days. Inlet H2S concentration recorded was between 200 and 1300 mg H2S.m−3. Removal efficiencies reached 99% for the majority of the running time at an empty bed retention time (EBRT) of 60 s. Heterotrophic bacteria were found to be the dominant microorganisms in the biofilter. The bacteria were identified as the members of the genus Bacillus, Pseudomonas and xanthomonadacea bacterium. The polymerase chain reaction-single stranded conformation polymorphism (PCR-SSCP) method showed that bacterial community profiles changed with the H2S inlet concentration. Our results indicated that the biofilter system, containing peat as the packing material, was proved able to remove H2S from the WWTP odourous pollutants. PMID:23961233

  18. Variability of O2, H2S, and pH in intertidal sediments measured on a highly resolved spatial and temporal scale

    NASA Astrophysics Data System (ADS)

    Walpersdorf, E.; Werner, U.; Bird, P.; de Beer, D.

    2003-04-01

    We investigated the variability of O_2, pH, and H_2S in intertidal sediments to assess the time- and spatial scales of changes in environmental conditions and their effects on bacterial activities. Measurements were performed over the tidal cycle and at different seasons by the use of microsensors attached to an autonomous in-situ measuring device. This study was carried out at a sand- and a mixed flat in the backbarrier area of Spiekeroog (Germany) within the frame of the DFG research group "Biogeochemistry of the Wadden Sea". Results showed that O_2 variability was not pronounced in the coastal mixed flat, where only extreme weather conditions could increase O_2 penetration. In contrast, strong dynamics in O_2 availability, pH and maximum penetration depths of several cm were found at the sandflat. In these highly permeable sediments, we directly observed tidal pumping: at high tide O_2-rich water was forced into the plate and at low tide anoxic porewater drained off the sediment. From the lower part of the plate where organic rich clayey layers were embedded in the sediment anoxic water containing H_2S leaked out during low tide. Thus advective processes, driven by the tidal pump, waves and currents, control O_2 penetration and depth distribution of H_2S and pH. The effects of the resulting porewater exchange on mineralization rates and microbial activities will be discussed.

  19. Crystal structures of isomeric 3,5-di-chloro-N-(2,3-di-methyl-phen-yl)benzene-sulfonamide, 3,5-di-chloro-N-(2,6-di-methyl-phen-yl)benzene-sulfonamide and 3,5-di-chloro-N-(3,5-di-methyl-phen-yl)benzene-sulfonamide.

    PubMed

    Shakuntala, K; Naveen, S; Lokanath, N K; Suchetan, P A

    2017-05-01

    The crystal structures of three isomeric compounds of formula C 14 H 13 Cl 2 NO 2 S, namely 3,5-di-chloro- N -(2,3-di-methyl-phen-yl)-benzene-sulfonamide (I), 3,5-di-chloro- N -(2,6-di-methyl-phen-yl)benzene-sulfonamide (II) and 3,5-di-chloro- N -(3,5-di-methyl-phen-yl)benzene-sulfonamide (III) are described. The mol-ecules of all the three compounds are U-shaped with the two aromatic rings inclined at 41.3 (6)° in (I), 42.1 (2)° in (II) and 54.4 (3)° in (III). The mol-ecular conformation of (II) is stabilized by intra-molecular C-H⋯O hydrogen bonds and C-H⋯π inter-actions. The crystal structure of (I) features N-H⋯O hydrogen-bonded R 2 2 (8) loops inter-connected via C (7) chains of C-H⋯O inter-actions, forming a three-dimensional architecture. The structure also features π-π inter-actions [ Cg ⋯ Cg = 3.6970 (14) Å]. In (II), N-H⋯O hydrogen-bonded R 2 2 (8) loops are inter-connected via π-π inter-actions [inter-centroid distance = 3.606 (3) Å] to form a one-dimensional architecture running parallel to the a axis. In (III), adjacent C (4) chains of N-H⋯O hydrogen-bonded mol-ecules running parallel to [010] are connected via C-H⋯π inter-actions, forming sheets parallel to the ab plane. Neighbouring sheets are linked via offset π-π inter-actions [inter-centroid distance = 3.8303 (16) Å] to form a three-dimensional architecture.

  20. Methyl 3-[3',4'-(methylenedioxy)phenyl]-2-methyl glycidate: an ecstasy precursor seized in Sydney, Australia.

    PubMed

    Collins, Michael; Heagney, Aaron; Cordaro, Frank; Odgers, David; Tarrant, Gregory; Stewart, Samantha

    2007-07-01

    Five 44 gallon drums labeled as glycidyl methacrylate were seized by the Australian Customs Service and the Australian Federal Police at Port Botany, Sydney, Australia, in December 2004. Each drum contained a white, semisolid substance that was initially suspected to be 3,4-methylenedioxymethylamphetamine (MDMA). Gas chromatography-mass spectroscopy (GC/MS) analysis demonstrated that the material was neither glycidyl methacrylate nor MDMA. Because intelligence sources employed by federal agents indicated that this material was in some way connected to MDMA production, suspicion fell on the various MDMA precursor chemicals. Using a number of techniques including proton nuclear magnetic resonance spectroscopy ((1)H NMR), carbon nuclear magnetic resonance spectroscopy ((13)C NMR), GC/MS, infrared spectroscopy, and total synthesis, the unknown substance was eventually identified as methyl 3-[3',4'(methylenedioxy)phenyl]-2-methyl glycidate. The substance was also subjected to a published hydrolysis and decarboxylation procedure and gave a high yield of the MDMA precursor chemical, 3,4-methylenedioxyphenyl-2-propanone, thereby establishing this material as a "precursor to a precursor."

  1. Behaviour of volcanogenic S-bearing compounds (H2S and SO2) in air at Vulcano Island (Aeolian Archipelago, southern Italy)

    NASA Astrophysics Data System (ADS)

    Caponi, Chiara; Tassi, Franco; Ricci, Andrea; Capecchiacci, Francesco; Venturi, Stefania; Cabassi, Jacopo; Vaselli, Orlando

    2017-04-01

    The main sources of SO2 and H2S in air consist of both natural fluid emissions related to active/quiescent volcanoes and hydrothermal systems, and anthropogenic activities (e.g. gas and oil refineries, steel industries, urban traffic). These gas compounds have a strong impact on air quality, since they are strong toxic and climate forcing agents. Notwithstanding, the behaviour of these S-compounds in air once they are released from the contaminant source(s) is poorly known, due to the scarce available data from thermodynamics and direct measurements. Hydrogen sulfide is considered to be relatively reactive in the atmosphere, being easily oxidized to SO2 by photochemical reactions, even though the efficiency of the H2S to SO2 conversion is significantly lowered under dark, dry and relatively cold conditions, leading to a residence time of H2S in air up to 42 days in winter. In this work, H2S and SO2 measurements in air carried out at the Levante beach (Vulcano Island, Aeolian Archipelago), where a number of hydrothermal fluid discharges consisting of fumaroles and submarine emissions occur, are presented and discussed. These volcanic fluids, characterized by an H2S-rich chemical composition, are released in a close proximity to the touristic village of Vulcano Porto. The measurements were carried out using a Thermo Scientific™ Model 450i Analyzer coupled with a Davis® Vantage Vue weather station (air humidity and temperature, wind direction and speed) in 34 fixed spots and along 8 pathways, selected according to: (i) distance from the contaminant source, (ii) wind direction and (iii) accessibility by car (where the instrument was installed). The main aim was to provide empirical insights on the behavior of these air pollutants in relation to the physical and chemical processes controlling their spatial distribution. The measured data were elaborated using a statistical approach to construct spatial distribution maps and conceptual models able to forecast the

  2. Fluid inclusion volatile analysis by gas chromatography with photoionization micro-thermal conductivity detectors: Applications to magmatic MoS 2 and other H 2O-CO 2 and H 2O-CH 4 fluids

    NASA Astrophysics Data System (ADS)

    Bray, C. J.; Spooner, E. T. C.

    1992-01-01

    Eighteen fluid inclusion volatile peaks have been detected and identified from 1-2 g samples (quartz) by gas chromatography using heated (~105°C) on-line crushing, helium carrier gas, a single porous polymer column (HayeSep R; 10' × 1/8″: 100/120#; Ni alloy tubing), two temperature programme conditions for separate sample aliquots, micro-thermal conductivity (TCD) and photoionization detectors (PID; 11.7 eV lamp), and off-line digital peak processing. In order of retention time these volatile peaks are: N 2, Ar, CO, CH 4, CO 2, C 2H 4, C 2H 6, C 2H 2, COS, C 3H 6, C 3H 8, C 3H 4 (propyne), H 2O (22.7 min at 80°C), SO 2, ± iso- C4H10 ± C4H8 (1-butene) ± CH3SH, C 4H 8 (iso-butylene), (?) C 4H 6 (1,3 butadiene) and ± n- C4H10 ± C4H8 (trans-2-butene) (80 and -70°C temperature programme conditions combined). H 2O is analysed directly. O 2 can be analysed cryogenically between N 2 and Ar, but has not been detected in natural samples to date in this study. H 2S, SO 2, NH 3, HCl, HCN, and H 2 ca nnot be analysed at present. Blanks determined by crushing heat-treated Brazilian quartz (800-900°C/4 h) are zero for 80°C temperature programme conditions, except for a large, unidentified peak at ~64 min, but contain H 2O, CO 2, and some low molecular weight hydrocarbons at -70°C temperature conditions due to cryogenic accumulation from the carrier gas and subsequent elution. TCD detection limits are ~30 ppm molar in inclusions; PID detection limits are ~ 1 ppm molar in inclusions and lower for unsaturated hydrocarbons (e.g., ~0.2 ppm for C 2H 4; ~ 1 ppb for C 2H 2; ~0.3 ppb for C 3H 6). Precisions (1σ) are ~ ±1-2% and ~ ± 13% for H 2O in terms of total moles detected; the latter value is equivalent to ±0.6 mol% at the 95 mol% H 2O level. Major fluid inclusion volatile species have been successfully analysed on a ~50 mg fluid inclusion section chip (~7 mm × ~10 mm × ~100 μm). Initial inclusion volatile analyses of fluids of interpreted magmatic origin from

  3. Degradation of organic dyes by a new heterogeneous Fenton reagent - Fe2GeS4 nanoparticle.

    PubMed

    Shi, Xiaoguo; Tian, Ang; You, Junhua; Yang, He; Wang, Yuzheng; Xue, Xiangxin

    2018-07-05

    The heterogeneous Fenton system has become the hotspot in the decontamination field due to its effective degradation performance with a wide pH range. Based on the unstable chemical properties of pyrite, in this article, Fe 2 GeS 4 nanoparticles with better thermodynamic stability were prepared by vacuum sintering and high energy ball milling and its potential as Fenton reagent was investigated for the first time. Three determinants of the heterogeneous Fenton system including the iron source, hydrogen peroxide, pH and the degradation mechanism were investigated. The catalyst dosage of 0.3 g/L, initial H 2 O 2 concentration in the Fenton system of 50 m mol/L and pH of 7 were chosen as the best operational conditions. An almost complete degradation was achieved within 5 min for methylene blue and rhodamine b while 10 min for methyl orange. The total organic carbon removal efficiencies of Fe 2 GeS 4 heterogeneous Fenton system for methylene blue, methyl orange and rhodamine b in 10 min were 56.3%, 66.2% and 74.2%, respectively. It's found that the degradation ability could be attributed to a heterogeneous catalysis occurring at the Fe 2 GeS 4 surface together with a homogeneous catalysis in the aqueous phase by the dissolved iron ions. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. (Carbonyl-1κC)bis­[2,3(η5)-cyclo­penta­dien­yl][μ3-(S-methyl trithio­carbonato)methylidyne-1:2:3κ4 C,S′′:C:C](triphenyl­phosphine-1κP)(μ3-sulfido-1:2:3κ3 S)dicobalt(II)iron(II) trifluoro­methane­sulfonate

    PubMed Central

    Manning, Anthony R.; McAdam, C. John; Palmer, Anthony J.; Simpson, Jim

    2008-01-01

    The asymmetric unit of the title compound, [FeCo2(C5H5)2(C3H3S3)S(C18H15P)(CO)]CF3SO3, consists of a triangular irondicobalt cluster cation and a trifluoro­methane­sulfonate anion. In the cation, the FeCo2 triangle is symmetrically capped on one face by an S atom and on the other by a C atom linked to a methyl trithio­carbonate residue that bridges the Fe—C bond. Each Co atom carries a cyclo­penta­dienyl ligand while the Fe atom coordinates to one carbonyl and one triphenyl­phosphine ligand. In the crystal structure, the cation is linked to the anion by a number of weak non-classical C—H⋯O and C—H⋯F hydrogen bonds and weak S⋯O (3.317 Å) and S⋯F (3.198 Å) inter­actions. The structure is further stabilized by additional inter­molecular C—H⋯O, C—H⋯F and O⋯O (2.942 Å) contacts, together with an unusual S⋯π(Cp) inter­action (S⋯centroid distance = 3.385 Å), generating an extended network. PMID:21202187

  5. Molecular basis for the role of oncogenic histone mutations in modulating H3K36 methylation

    DOE PAGES

    Zhang, Yinglu; Shan, Chun -Min; Wang, Jiyong; ...

    2017-03-03

    Histone H3 lysine 36 methylation (H3K36me) is critical for epigenetic regulation and mutations at or near H3K36 are associated with distinct types of cancers. H3K36M dominantly inhibits H3K36me on wild-type histones, whereas H3G34R/V selectively affects H3K36me on the same histone tail. Here we report the crystal structures of SETD2 SET domain in complex with an H3K36M peptide and SAM or SAH. There are large conformational changes in the substrate binding regions of the SET domain, and the K36M residue interacts with the catalytic pocket of SETD2. H3G34 is surrounded by a very narrow tunnel, which excludes larger amino acid sidemore » chains. H3P38 is in the trans configuration, and the cis configuration is incompatible with SETD2 binding. Lastly, mutations of H3G34 or H3P38 alleviate the inhibitory effects of H3K36M on H3K36me, demonstrating that the stable interaction of H3K36M with SETD2 is critical for its inhibitory effects.« less

  6. Intra- and intermolecular H-bond mediated tautomerization and dimerization of 3-methyl-1,2-cyclopentanedione: Infrared spectroscopy in argon matrix and CCl 4 solution

    NASA Astrophysics Data System (ADS)

    Samanta, Amit K.; Pandey, Prasenjit; Bandyopadhyay, Biman; Mukhopadhyay, Anamika; Chakraborty, Tapas

    2011-05-01

    Mid-infrared spectra of 3-methyl-1,2-cyclopentanedione (3-MeCPD) have been recorded by isolating the molecule in a cold argon matrix (8 K) and also in CCl 4 solution at room temperature. The spectral features reveal that in both media, the molecule exists exclusively in an enol tautomeric form, which is stabilized by an intramolecular O sbnd H⋯O hydrogen bond. NBO analysis shows that the preferred conformer is further stabilized because of hyperconjugation interaction between the methyl and vinyl group of the enol tautomer. In CCl 4 solution, the molecule undergoes extensive self association and generates a doubly hydrogen bonded centrosymmetric dimer. The dimerization constant ( K d) is estimated to have a value of ˜9 L mol -1 at room temperature (25 °C) and the thermodynamic parameters, Δ H°, Δ S° and Δ G°, of dimerization are estimated by measuring K d at several temperatures within the range 22-60 °C. The same dimer is also produced when the matrix is annealed at a higher temperature. In addition, a non-centrosymmetric singly hydrogen bonded dimer is also identified in the argon matrix. A comparison between the spectral features of the two dimers indicates that the dimerization effect on doubly H-bonded case is influenced by cooperative interaction between the two H-bonds.

  7. X-ray diffraction, vibrational and quantum chemical investigations of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid

    NASA Astrophysics Data System (ADS)

    Arjunan, V.; Marchewka, Mariusz K.; Pietraszko, A.; Kalaivani, M.

    2012-11-01

    The structural investigations of the molecular complex of 2-methyl-4-nitroaniline with trichloroacetic acid, namely 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid (C11H10Cl6N2O6) have been performed by means of single crystal and powder X-ray diffraction method. The complex was formed with accompanying proton transfer from trichloroacetic acid molecule to 2-methyl-4-nitroaniline. The studied crystal is built up of singly protonated 2-methyl-4-nitroanilinium cations, trichloroacetate anions and neutral trichloroacetic acid molecules. The crystals are monoclinic, space group P21/c, with a = 14.947 Å, b = 6.432 Å, c = 19.609 Å and Z = 4. The vibrational assignments and analysis of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid have also been performed by FTIR, FT-Raman and far-infrared spectral studies. More support on the experimental findings were added from the quantum chemical studies performed with DFT (B3LYP) method using 6-31G**, cc-pVDZ, 6-31G and 6-31++G basis sets. The structural parameters, energies, thermodynamic parameters and the NBO charges of 2M4NATCA were also determined by the DFT methods.

  8. Probing lysine mono-methylation in histone H3 tail peptides with an abiotic receptor coupled to a non-plasmonic resonator.

    PubMed

    Bontempi, N; Biavardi, E; Bordiga, D; Candiani, G; Alessandri, I; Bergese, P; Dalcanale, E

    2017-06-29

    Binder and effector molecules that allow studying and manipulating epigenetic processes are of biological relevance and pose severe technical challenges. We report the first example of a synthetic receptor able to recognize mono-methylated lysines in a histone H3 tail peptide, which has relevant functions in epigenetic regulation. Recognition is robust and specific regardless of the position and the number of mono-methylated lysines along the polypeptide chain. The peptide is first captured in solution by a tetraphosphonate cavitand (Tiiii) that selectively binds its Lys-NMe + moieties. Separation from solution and detection of the peptide-Tiiii complexes is then enabled in one single step by an all dielectric SiO 2 -TiO 2 core-shell resonator (T-rex), which captures the complex and operates fully reproducible signal transduction by non-plasmonic surface enhanced Raman scattering (SERS) without degrading the complex. The realized abiotic probe is able to distinguish multiple mono-methylated peptides from the single mono-methylated ones.

  9. In vivo synthesis of phosphatidylcholine in rat brain via the phospholipid methylation pathway

    NASA Technical Reports Server (NTRS)

    Lakher, Michael; Wurtman, Richard J.

    1987-01-01

    The in vivo synthesis of brain phosphatidylcholine (PC) by the methylation of phosphatidylethanolamine (PE) was examined. (H-3)methyl)methionine was infused i.c.v., by indwelling cannula, and brain samples were taken 0.5-18 h thereafter and assayed for (H-3)PC, as well as for its biosynthetic intermediates (H-3)phosphatidyl monomethylethanolamine ((H-3)PMME) and (H-3)phosphatidyl dimethylethanolamine ((H-3)PDME), and for (H-3)lysophosphatidylcholine ((H-3)LPC) and S-(H-3)adenosylmethionine ((H-3)SAM). Most of the (H-3)PC (79-94 percent) was present ipsilateral to the infusion site; indicating that the radioactivity in the (H-3)PC was primarily of intracerebral origin, and not taken up from the blood. Moreover, only very low levels of (H-3)PC were attained in brains of animals receiving (H-3)methionine i.p. and these levels were symmetrically distributed. (H-3)PMME and (H-3)PDME turned over with apparent half-lives of 2.2 h and 2.4 h. In contrast, the accumulation of brain (H-3)PC was biphasic, suggesting the existence of two pools, the more labile of which turned over rapidly (t(sub 1/2) = 5 h) and was formed for as long as (H-3)PMME and (H-3)PDME are present in the brain, and another, which was distinguishable only at 18 h after the (H-3)methionine infusion. (The latter pool may have been synthesized from (H-3)choline that was released via the hydrolysis of some of the brain (H-3)PC previously formed by the methylation of PE.) Subcellular fractionation of brain tissue obtained after in vivo labelling with (H-3)methionine revealed that mitochondrial PC had the highest specific radioactivity (dpm per micromol total lipid phosphorus), and myelin the least. These observations affirm that rat brain does synthesize PC in vivo by methylating PE, and the technique provides an experimental system which may be useful for examining the physiological regulation of this process.

  10. Constant serum levels of secreted asialoglycoprotein receptor sH2a and decrease with cirrhosis

    PubMed Central

    Benyair, Ron; Kondratyev, Maria; Veselkin, Elena; Tolchinsky, Sandra; Shenkman, Marina; Lurie, Yoav; Lederkremer, Gerardo Z

    2011-01-01

    AIM: To investigate the existence and levels of sH2a, a soluble secreted form of the asialoglycoprotein receptor in human serum. METHODS: Production of recombinant sH2a and development of a monoclonal antibody and an enzyme-linked immunosorbent assay (ELISA). This assay was used to determine the presence and concentration of sH2a in human sera of individuals of both sexes and a wide range of ages. RESULTS: The recombinant protein was produced successfully and a specific ELISA assay was developed. The levels of sH2a in sera from 62 healthy individuals varied minimally (147 ± 19 ng/mL). In contrast, 5 hepatitis C patients with cirrhosis showed much decreased sH2a levels (50 ± 9 ng/mL). CONCLUSION: Constant sH2a levels suggest constitutive secretion from hepatocytes in healthy individuals. This constant level and the decrease with cirrhosis suggest a diagnostic potential. PMID:22219600

  11. Mechanism and Stereochemistry of Polyketide Chain Elongation and Methyl Group Epimerization in Polyether Biosynthesis.

    PubMed

    Xie, Xinqiang; Garg, Ashish; Khosla, Chaitan; Cane, David E

    2017-03-01

    The polyketide synthases responsible for the biosynthesis of the polyether antibiotics nanchangmycin (1) and salinomycin (4) harbor a number of redox-inactive ketoreductase (KR 0 ) domains that are implicated in the generation of C2-epimerized (2S)-2-methyl-3-ketoacyl-ACP intermediates. Evidence that the natural substrate for the polyether KR 0 domains is, as predicted, a (2R)-2-methyl-3-ketoacyl-ACP intermediate, came from a newly developed coupled ketosynthase (KS)-ketoreductase (KR) assay that established that the decarboxylative condensation of methylmalonyl-CoA with S-propionyl-N-acetylcysteamine catalyzed by the Nan[KS1][AT1] didomain from module 1 of the nanchangmycin synthase generates exclusively the corresponding (2R)-2-methyl-3-ketopentanoyl-ACP (7a) product. In tandem equilibrium isotope exchange experiments, incubation of [2- 2 H]-(2R,3S)-2-methyl-3-hydroxypentanoyl-ACP (6a) with redox-active, epimerase-inactive EryKR6 from module 6 of the 6-deoxyerythronolide B synthase and catalytic quantities of NADP + in the presence of redox-inactive, recombinant NanKR1 0 or NanKR5 0 , from modules 1 and 5 of the nanchangmycin synthase, or recombinant SalKR7 0 from module 7 of the salinomycin synthase, resulted in first-order, time-dependent washout of deuterium from 6a. Control experiments confirmed that this washout was due to KR 0 -catalyzed isotope exchange of the reversibly generated, transiently formed oxidation product [2- 2 H]-(2R)-2-methyl-3-ketopentanoyl-ACP (7a), consistent with the proposed epimerase activity of each of the KR 0 domains. Although they belong to the superfamily of short chain dehydrogenase-reductases, the epimerase-active KR 0 domains from polyether synthases lack one or both residues of the conserved Tyr-Ser dyad that has previously been implicated in KR-catalyzed epimerizations.

  12. Mechanism and Stereochemistry of Polyketide Chain Elongation and Methyl Group Epimerization in Polyether Biosynthesis

    PubMed Central

    Xie, Xinqiang; Garg, Ashish; Khosla, Chaitan; Cane, David E.

    2017-01-01

    The polyketide synthases responsible for the biosynthesis of the polyether antibiotics nanchangmycin (1) and salinomycin (4) harbor a number of redox-inactive ketoreductase (KR0) domains that are implicated in the generation of C2-epimerized (2S)-2-methyl-3-ketoacyl-ACP intermediates. Evidence that the natural substrate for the polyether KR0 domains is, as predicted, a (2R)-2-methyl-3-ketoacyl-ACP intermediate, came from a newly developed coupled ketosynthase (KS)-ketoreductase (KR) assay that established that the decarboxylative condensation of methylmalonyl-CoA with S-propionyl-N-acetylcysteamine catalyzed by the Nan[KS1][AT1] didomain from module 1 of the nanchangmycin synthase generates exclusively the corresponding (2R)-2-methyl-3-ketopentanoyl-ACP (7a) product. In tandem equilibrium isotope exchange experiments, incubation of [2-2H]-(2R,3S)-2-methyl-3-hydroxypentanoyl-ACP (6a) with redox-active, epimerase-inactive EryKR6 from module 6 of the 6-deoxyerythronolide B synthase and catalytic quantities of NADP+ in the presence of redox-inactive, recombinant NanKR10 or NanKR50, from modules 1 and 5 of the nanchangmycin synthase, or recombinant SalKR70 from module 7 of the salinomycin synthase, resulted in first-order, time-dependent washout of deuterium from 6a. Control experiments confirmed that this washout was due to KR0-catalyzed isotope exchange of the reversibly-generated, transiently-formed oxidation product [2-2H]-(2R)-2-methyl-3-ketopentanoyl-ACP (7a), consistent with the proposed epimerase activity of each of the KR0 domains. Although they belong to the superfamily of short chain dehydrogenase-reductases, the epimerase-active KR0 domains from polyether synthases lack one or both residues of the conserved Tyr-Ser dyad that has previously been implicated in KR-catalyzed epimerizations. PMID:28157306

  13. Tunneling chemical reactions D +H2→DH+H and D +DH→D2+H in solid D2-H2 and HD -H2 mixtures: An electron-spin-resonance study

    NASA Astrophysics Data System (ADS)

    Kumada, Takayuki

    2006-03-01

    Tunneling chemical reactions D +H2→DH+H and D +DH→D2+H in solid HD -H2 and D2-H2 mixtures were studied in the temperature range between 4 and 8K. These reactions were initiated by UV photolysis of DI molecules doped in these solids for 30s and followed by measuring the time course of electron-spin-resonance (ESR) intensities of D and H atoms. ESR intensity of D atoms produced by the photolysis decreases but that of H atoms increases with time. Time course of the D and H intensities has the fast and slow processes. The fast process, which finishes within ˜300s after the photolysis, is assigned to the reaction of D atom with one of its nearest-neighboring H2 molecules, D(H2)n(HD)12-n→H(H2)n-1(HD)13-n or D(H2)n(D2)12-n→H(HD )(H2)n-1(D2)12-n for 12⩾n⩾1. Rate constant for the D +H2 reaction between neighboring D atom-H2 molecule pair is determined to be (7.5±0.7)×10-3s-1 in solid HD -H2 and (1.3±0.3)×10-2s-1 in D2-H2 at 4.1K, which is very close to that calculated based on the theory of chemical reaction in gas phase by Hancock et al. [J. Chem. Phys. 91, 3492 (1989)] and Takayanagi and Sato [J. Chem. Phys. 92, 2862 (1990)]. This rate constant was found to be independent of temperature up to 7K within experimental error of ±30%. The slow process is assigned to the reaction of D atom produced in a cage fully surrounded by HD or D2 molecules, D(HD)12 or D(D2)12. This D atom undergoes the D +DH reaction with one of its nearest-neighboring HD molecules in solid HD -H2 or diffuses to the neighbor of H2 molecules to allow the D +H2 reaction in solid HD -H2 and D2-H2. The former is the main channel in solid HD -H2 below 6K where D atoms diffuse very slowly, whereas the latter dominates over the former above 6K. Rate for the reactions in the slow process is independent of temperature below 6K but increases with the increase in temperature above 6K. We found that the increase is due to the increase in hopping rate of D atoms to the neighbor of H2 molecules. Rate

  14. Upstream H/sub 2/S removal from geothermal steam. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1981-11-01

    The purpose of this project was to evaluate a new heat exchanger process as a method for removing hydrogen sulfide (H/sub 2/S) gas from geothermal steam upstream of a power plant turbine. The process utilizes a heat exchanger to condense geothermal steam so that noncondensable gases (including H/sub 2/S) can be removed in the form of a concentrated vent stream. Ultimate disposal of the removed H/sub 2/S gas may then be accomplished by use of other processes such as the commercially available Stretford process. The clean condensate is reevaporated on the other side of the heat exchanger using the heatmore » removed from the condensing geothermal steam. The necessary heat transfer is induced by maintaining a slight pressure difference, and consequently a slight temperature difference, between the two sides of the heat exchanger. Evaluation of this condensing and reboiling process was performed primarily through the testing of a small-scale 14 m/sup 2/ (150 ft/sup 2/) vertical tube evaporator heat exchanger at The Geysers Power Plant in northern California. The field test results demonstrated H/sub 2/S removal rates consistently better than 90 percent, with an average removal rate of 94 percent. In addition, the removal rate for all noncondensable gases is about 98 percent. Heat transfer rates were high enough to indicate acceptable economics for application of the process on a commercial scale. The report also includes an evaluation of the cost and performance of various configurations of the system, and presents design and cost estimates for a 2.5 MWe and a 55 MWe unit.« less

  15. 1-(4-Chloro-2-fluoro-phen-yl)-4-difluoro-methyl-3-methyl-1H-1,2,4-triazol-5(4H)-one.

    PubMed

    Ren, Dong-Mei; Wang, Yong-Yi

    2012-04-01

    In the crystal structure of the title compound, C(10)H(7)ClF(3)N(3)O, pairs of mol-ecules are connected into dimers via pairs of C-H⋯O hydrogen bonds. The dihedral angle between the benzene ring and attached triazolone ring is 53.2 (1)°.

  16. Fate of H2S during the cultivation of Chlorella sp. deployed for biogas upgrading.

    PubMed

    González-Sánchez, Armando; Posten, Clemens

    2017-04-15

    The H 2 S may play a key role in the sulfur cycle among the biogas production by the anaerobic digestion of wastes and the biogas upgrading by a microalgae based technology. The biogas is upgraded by contacting with slightly alkaline aqueous microalgae culture, then CO 2 and H 2 S are absorbed. The dissolved H 2 S could limit or inhibit the microalgae growth. This paper evaluated the role of dissolved H 2 S and other sulfured byproducts under prevailing biogas upgrading conditions using a microalgal technology. At initial stages of batch cultivation the growth of Chlorella sp. was presumably inhibited by dissolved H 2 S. After 2 days, the sulfides were oxidized mainly by oxic chemical reactions to sulfate, which was later rapidly assimilated by Chlorella sp., allowing high growing rates. The fate of H 2 S during the microalgae cultivation at pH > 8.5 was assessed by a mathematical model where the pentasulfide, thiosulfate and sulfite were firstly produced and converted finally to sulfate for posterior assimilation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Biofiltration of high concentration of H2S in waste air under extreme acidic conditions.

    PubMed

    Ben Jaber, Mouna; Couvert, Annabelle; Amrane, Abdeltif; Rouxel, Franck; Le Cloirec, Pierre; Dumont, Eric

    2016-01-25

    Removal of high concentrations of hydrogen sulfide using a biofilter packed with expanded schist under extreme acidic conditions was performed. The impact of various parameters such as H2S concentration, pH changes and sulfate accumulation on the performances of the process was evaluated. Elimination efficiency decreased when the pH was lower than 1 and the sulfate accumulation was more than 12 mg S-SO4(2-)/g dry media, due to a continuous overloading by high H2S concentrations. The influence of these parameters on the degradation of H2S was clearly underlined, showing the need for their control, performed through an increase of watering flow rate. A maximum elimination capacity (ECmax) of 24.7 g m(-3) h(-1) was recorded. As a result, expanded schist represents an interesting packing material to remove high H2S concentration up to 360 ppmv with low pressure drops. In addition, experimental data were fitted using both Michaelis-Menten and Haldane models, showing that the Haldane model described more accurately experimental data since the inhibitory effect of H2S was taken into account. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Synergetic photocatalytic effect between 1 T@2H-MoS2 and plasmon resonance induced by Ag quantum dots

    NASA Astrophysics Data System (ADS)

    Liu, Haiyang; Wu, Rong; Tian, Lie; Kong, Yangyang; Sun, Yanfei

    2018-07-01

    Semiconductor phase transitions and plasma noble metal quantum dots (QDs) for visible-light-driven photocatalysts have attracted significant research interest. In this study, novel microwave hydrothermal and photo-reduction methods are proposed to synthesise a visible-light-driven plasma photocatalytic 1T@2H-MoS2/Ag composite. Photoelectrochemical results show that the introduction of the 1T phase and Ag significantly enhances the light response range and charge separation. The 1T phase can act as a co-catalyst to provide a high electron concentration. Ag QDs can effectively improve the light absorption and catalytic effect. The synergistic effect between the 1T@2H-MoS2 microspheres and localised surface plasmon resonance of the Ag QDs can effectively enhance the photocatalytic activity of 1T@2H-MoS2/Ag. The developed 1T@2H-MoS2/Ag composite is superior, not only with respect to a visible-light photocatalytic degradation of conventional dyes, but also in the photocatalytic reduction of Cr(VI). Compared with 2H-MoS2, the catalytic efficiency of 1T@2H-MoS2/Ag for Cr(VI) and MB is increased by 81% and 41%, respectively. This study demonstrates that the introduction of 1T-MoS2 and Ag QDs can significantly enhance the catalytic properties of 2H-MoS2. The microwave and photo-reduction technologies can be employed as green, safe, simple, and rapid methods for the synthesis of noble metal plasma composites.

  19. Synergetic photocatalytic effect between 1 T@2H-MoS2 and plasmon resonance induced by Ag quantum dots.

    PubMed

    Liu, Haiyang; Wu, Rong; Tian, Lie; Kong, Yangyang; Sun, Yanfei

    2018-07-13

    Semiconductor phase transitions and plasma noble metal quantum dots (QDs) for visible-light-driven photocatalysts have attracted significant research interest. In this study, novel microwave hydrothermal and photo-reduction methods are proposed to synthesise a visible-light-driven plasma photocatalytic 1T@2H-MoS 2 /Ag composite. Photoelectrochemical results show that the introduction of the 1T phase and Ag significantly enhances the light response range and charge separation. The 1T phase can act as a co-catalyst to provide a high electron concentration. Ag QDs can effectively improve the light absorption and catalytic effect. The synergistic effect between the 1T@2H-MoS 2 microspheres and localised surface plasmon resonance of the Ag QDs can effectively enhance the photocatalytic activity of 1T@2H-MoS 2 /Ag. The developed 1T@2H-MoS 2 /Ag composite is superior, not only with respect to a visible-light photocatalytic degradation of conventional dyes, but also in the photocatalytic reduction of Cr(VI). Compared with 2H-MoS 2 , the catalytic efficiency of 1T@2H-MoS 2 /Ag for Cr(VI) and MB is increased by 81% and 41%, respectively. This study demonstrates that the introduction of 1T-MoS 2 and Ag QDs can significantly enhance the catalytic properties of 2H-MoS 2 . The microwave and photo-reduction technologies can be employed as green, safe, simple, and rapid methods for the synthesis of noble metal plasma composites.

  20. Structures, molecular orbitals and UV-vis spectra investigations on methyl 1-benzyl-1H-1,2,3-triazole-4-carboxylate: a computational study.

    PubMed

    Wang, Tsang-Hsiu; Chu, Hsing-Yu; Wang, I-Teng

    2014-10-15

    The methyl 1-benzyl-1H-1,2,3-triazole-4-carboxylate (C11H11N3O2) has been studied by theoretically methods. The structure of this compound is optimized by density functional theory (DFT), the second-order Møller-Plesset perturbation theory (MP2) and G3 theory (G3(MP2)) levels. Our calculation results are in very good agreement with experimental values. Compared to a perfect pentagonal structure, the geometrical structures of C11H11N3O2 show a little distortion of 1,2,3-triazole ring due to the highly electronegativity of substitution groups. In addition, dipole moment and frontier molecular orbitals (FMOs) of the C11H11N3O2 are calculated as well. Because of solvent effect, the HOMO-LUMO energy gap in methanol is predicted to be smaller than in gas phase by 0.367eV. The simulated UV-vis spectra are investigated by time-dependent density functional theory (TD-DFT), and two obviously absorption features have been predicted. These two absorption features are located between 170nm and 210nm, which is in ultraviolet C range. Moreover, the UV absorption features in methanol are predicted to be more intense than in gas phase; besides, the red shift is predicted in methanol as well. Copyright © 2014 Elsevier B.V. All rights reserved.