Crystal structure of (±-1-({[4-(allyloxyphenyl]sulfanyl}methyl-2-(diphenylthiophosphorylferrocene

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Audric Michelot

2015-08-01

Full Text Available The title compound, [Fe(C5H5(C27H24OPS2], is built up from a ferrocene moiety substituted in the 1- and 2-positions by {[4-(allyloxyphenyl]sulfanyl}methyl and diphenylthiophosphoryl groups, respectively. The two S atoms lie on opposite sides of the cyclopentadienyl ring plane to which they are attached. In the crystal, C—H...S hydrogen bonds link the molecules into a ribbon running parallel to the (-110 plane. C—H...π interactions link the ribbons to form a three-dimensional network.

Kinetics of the reactions H+C2H4->C2H5, H+C2H5->2CH3 and CH3+C2H5->products studies by pulse radiolysis combined with infrared diode laser spectroscopy

DEFF Research Database (Denmark)

Sillesen, A.; Ratajczak, E.; Pagsberg, P.

1993-01-01

Formation of methyl radicals via the consecutive reactions H+C2H4+M-->C2H5+M (1) and H+C2H5-->CH3+CH3 (2a) was initiated by pulse radiolysis of 10-100 mbar H-2 in the presence of ethylene. The kinetics of CH3 Were studied by monitoring the transient infrared absorption at the Q(3, 3) line of the ...

Hydroxylation of methylated DNA by TET1 in chondrocyte differentiation of C3H10T1/2 cells

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Ryo Ito

2016-03-01

Full Text Available DNA methylation is closely involved in the regulation of cellular differentiation, including chondrogenic differentiation of mesenchymal stem cells. Recent studies showed that Ten–eleven translocation (TET family proteins converted 5-methylcytosine (5mC to 5-hydroxymethylcytosine, 5-formylcytosine and 5carboxylcytosine by oxidation. These reactions constitute potential mechanisms for active demethylation of methylated DNA. However, the relationship between the DNA methylation patterns and the effects of TET family proteins in chondrocyte differentiation is still unclear. In this study, we showed that DNA hydroxylation of 5mC was increased during chondrocytic differentiation of C3H10T1/2 cells and that the expression of Tet1 was particularly enhanced. Moreover, knockdown experiments revealed that the downregulation of Tet1 expression caused decreases in chondrogenesis markers such as type 2 and type 10 collagens. Furthermore, we found that TET proteins had a site preference for hydroxylation of 5mC on the Insulin-like growth factor 1 (Igf1 promoter in chondrocytes. Taken together, we showed that the expression of Tet1 was specifically facilitated in chondrocyte differentiation and Tet1 can regulate chondrocyte marker gene expression presumably through its hydroxylation activity for DNA.

The synthesis of [[sup 2]H],[[sup 3]H], and [[sup 14]C]-labeled 8[beta]-[(methylthio)methyl]-6-propylergoline mesylate (pergolide mesylate), a potent, long-acting dopamine agonist

Energy Technology Data Exchange (ETDEWEB)

Wheeler, W.J.; Kau, D.L.K.; Bach, N.J. (Lilly (Eli) and Co., Indianapolis, IN (United States). Lilly Research Labs.)

1990-03-01

The [[sup 3]H]- and two[[sup 14]C]-isopomers of 8[beta]-[(methylthio)methyl]-6-propylergoline mesylate (pergolide mesylate) have been synthesized. The [[sup 3]H]-derivative was synthesized by the palladium catalyzed tritiation of the corresponding 6-allyl derivative. Reaction of 8[beta]-[(methylthio)methyl]-ergoline with 1-[[sup 14]C]-1-propyl bromide yielded pergolide labeled in the 6-propyl group. Alternatively, reaction of 8[beta]-mesyloxy-6-propylergoline with [[sup 14]C]-sodium cyanide, followed by base hydrolysis, yielded 8 [beta]-carboxy-6-propylergoline-[[sup 14]C], which was subsequently converted to pergolide mesylate radiolabeled in the 17-position via a four step sequence. (Author).

2-Methyl-1H-benzimidazol-3-ium hydrogen phthalate

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YuanQi Yu

2011-10-01

Full Text Available The asymmetric unit of the title compound, C8H9N2+·C8H5O4−, contains two independent ion pairs. In each 2-methyl-1H-benzimidazolium ion, an intramolecular O—H...O bond forms an S(7 graph-set motif. In the crystal, the components are linked by N—H...O hydrogen bonds, forming chains along [210]. Further stabilization is provided by weak C—H...O hydrogen bonds.

m-plane GaN layers grown by rf-plasma assisted molecular beam epitaxy with varying Ga/N flux ratios on m-plane 4H-SiC substrates

International Nuclear Information System (INIS)

Armitage, R.; Horita, M.; Suda, J.; Kimoto, T.

2007-01-01

A series of m-plane GaN layers with the Ga beam-equivalent pressure (BEP) as the only varied parameter was grown by rf-plasma assisted molecular beam epitaxy on m-plane 4H-SiC substrates using AlN buffer layers. The smoothest growth surfaces and most complete film coalescence were found for the highest Ga BEP corresponding to the Ga droplet accumulation regime. However, better structural quality as assessed by x-ray rocking curves was observed for growth at a lower Ga BEP value below the droplet limit. The variation of rocking curve widths for planes inclined with respect to the epilayer c axis followed a different trend with Ga BEP than those of reflections parallel to the c axis. The GaN layers were found to exhibit a large residual compressive strain along the a axis

4-Methyl-N-(1-methyl-1H-indazol-5-ylbenzenesulfonamide

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Hakima Chicha

2013-09-01

Full Text Available 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.

2-(7-Methyl-1H-indol-3-ylacetonitrile

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Yu-Hua Ge

2012-01-01

Full Text Available In the title compound, C11H10N2, the carbonitrile group is twisted away from the indole plane [Ccy—Cme—Car—Car = 66.6 (2°; cy = cyanide, me = methylene and ar = aromatic]. In the crystal, N—H...N hydrogen bonds link the molecules into C(7 chains propagating in the [001] direction.

C-Methylated Flavonoids from Cleistocalyx operculatus and Their Inhibitory Effects on Novel Influenza A (H1N1) Neuraminidase

DEFF Research Database (Denmark)

Dao, Trong-Tuan; Tung, Bui-Thanh; Nguyen, Phi-Hung

2010-01-01

As part of an ongoing study focused on the discovery of anti-influenza agents from plants, four new (1-4) and 10 known (5-14) C-methylated flavonoids were isolated from a methanol extract of Cleistocalyx operculatus buds using an influenza H1N1 neuraminidase inhibition assay. Compounds 4, 7, 8...... mutant) expressed in 293T cells with IC50 values of 8.15 ± 1.05 and 3.31 ± 1.34 μM, respectively. Compounds 4, 7, 8, and 14 behaved as noncompetitive inhibitors in the kinetic studies. These results indicate that C-methylated flavonoids from C. operculatus have the potential to be developed...

Methylation changes of H19 gene in sperms of X-irradiated mouse and maintenance in offspring

International Nuclear Information System (INIS)

Zhu Bin; Huang Xinghua; Chen Jindong; Lu Yachao; Chen Ying; Zhao Jingyong

2006-01-01

The nature of imprinting is just differential methylation of imprinted genes. Unlike the non-imprinted genes, the methylation pattern of imprinted genes established during the period of gametogenesis remains unchangeable after fertilization and during embryo development. It implies that gametogenesis is the key stage for methylation pattern of imprinted genes. The imprinting interfered by exogenous factors during this stage could be inherited to offspring and cause genetic effect. Now many studies have proved that ionizing irradiation could disturb DNA methylation. Here we choose BALB/c mice as a research model and X-ray as interfering source to further clarify it. We discovered that the whole-body irradiation of X-ray to male BALB/c mice could influence the methylation pattern of H 19 gene in sperms, which resulted in some cytosines of partial CpG islands in the imprinting control region could not transform to methylated cytosines. Furthermore, by copulating the interfered male mice with normal female, we analyzed the promoter methylation pattern of H 19 in offspring fetal liver and compared the same to the pattern of male parent in sperms. We found that the majority of methylation changes in offspring liver were related to the ones in their parent sperms. Our data proved that the changes of the H 19 gene methylation pattern interfered by X-ray irradiation could be transmitted and maintained in First-generation offspring

Synthesis of [methyl-14C]crotonobetaine from DL-[methyl-14C]carnitine

International Nuclear Information System (INIS)

Loester, H.; Seim, H.

1996-01-01

The causes of carnitine deficiency syndromes are not completely understood, but decomposition of L-carnitine in vivo is likely to be involved. Carnitine is metabolized to γ-butyrobetaine, and crotonobetaine is probably an intermediate in this pathway. To validate experimentally the precursor-product relationship between the three physiologically occuring γ-betaines - L-carnitine, crotonobetaine, γ-butyrobetaine - labelling with stable or radioactive isotopes became necessary. Methyl-labelled carnitine isomers (L(-)-, D(+)- or DL-) or γ-butyrobetaine can be easily synthesized by methylation of 4-amino-3-hydroxybutyric acid isomers or 4-aminobutyric acid, respectively. Because of problems with the 4-aminocrotonic acid, we synthesized labelled crotonbetaine from labelled carnitine. Thus, DL-[methyl- 14 C]carnitine was dehydrated by reaction with concentrated sulfuric acid. After removal of the latter the products were separated and purified by ion exchange chromatography on DOWEX 50 WX8 (200 - 400 mesh) and gradient elution with hydrochloric acid. In addition to the labelled main product [methyl- 14 C]crotonobetaine (yield about 50 %), [methyl- 14 C]glycine betaine and [methyl- 14 C]acetonyl-trimethylammonium (ATMA) were formed. The end products were identified by combined thin layer chromatography/autoradiography and quantified by liquid scintillation counting. (Author)

Crystal structure of methyl (Z-2-[(Z-3-methyl-2-({(E-1-[(R*-4-methylcyclohex-3-en-1-yl]ethylidene}hydrazinylidene-4-oxothiazolidin-5-ylidene]acetate

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Mourad Fawzi

2017-11-01

Full Text Available The new title 4-thiazolidinone derivative, C16H21N3O3S, was obtained from the cyclization reaction of 4-methyl-3-thiosemicarbazone and dimethyl acetylenedicarboxylate (DMAD. The cyclohexylidene ring has an envelope conformation with the stereogenic centre C atom as the flap. Its mean plane makes a dihedral angle of 56.23 (9° with the thiazolidine ring mean plane. In the crystal, molecules are linked by C—H...O hydrogen bonds forming chains propagating in the [001] direction. Within the chains there are offset π–π interactions between the thiazolidine rings of inversion-related molecules [centroid–centroid distance = 3.703 (1 Å]. The chains are linked by further C—H...O hydrogen bonds, forming slabs parallel to the ac plane.

1-Methyl-5-nitro-3-phenyl-1H-indazole

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Mohammed Naas

2016-06-01

Full Text Available The title compound, C14H11N3O2, crystallizes with two molecules in the asymmetric unit. The indazole ring system and the nitro group are nearly coplanar, with the largest deviations from the mean plane being 0.070 (4 Å in one molecule and 0.022 (3 Å in the second. The dihedral angle between the mean plane through the phenyl ring and the mean plane of the indazole ring system is of 23.24 (18° in the first molecule and 26.87 (18° in the second. In the crystal, molecules are linked by two C—H...O hydrogen bonds, forming linear zigzag tapes running along the c-axis direction, and by π–π stacking of molecules along the b axis, generating a three-dimensional structure.

Histone H4 Lysine 20 methylation

DEFF Research Database (Denmark)

Jørgensen, Stine; Schotta, Gunnar; Sørensen, Claus Storgaard

2013-01-01

of histones have emerged as key regulators of genomic integrity. Intense research during the past few years has revealed histone H4 lysine 20 methylation (H4K20me) as critically important for the biological processes that ensure genome integrity, such as DNA damage repair, DNA replication and chromatin...... compaction. The distinct H4K20 methylation states are mediated by SET8/PR-Set7 that catalyses monomethylation of H4K20, whereas SUV4-20H1 and SUV4-20H2 enzymes mediate further H4K20 methylation to H4K20me2 and H4K20me3. Disruption of these H4K20-specific histone methyltransferases leads to genomic...

Implication for using heme methyl hyperfine shifts as indicators of heme seating as related to stereoselectivity in the catabolism of heme by heme oxygenase: in-plane heme versus axial his rotation.

Science.gov (United States)

Ogura, Hiroshi; Evans, John P; de Montellano, Paul R Ortiz; La Mar, Gerd N

2008-01-08

The triple mutant of the solubilized, 265-residue construct of human heme oxygenase, K18E/E29K/R183E-hHO, has been shown to redirect the exclusive alpha-regioselectivity of wild-type hHO to primarily beta,delta-selectivity in the cleavage of heme (Wang, J., Evans, J. P., Ogura, H., La Mar, G. N., and Ortiz de Montellano, P. R. (2006) Biochemistry 45, 61-73). The 1H NMR hyperfine shift pattern for the substrate and axial His CbetaH's and the substrate-protein contacts of the cyanide-inhibited protohemin and 2,4-dimethyldeuterohemin complexes of the triple mutant have been analyzed in detail and compared to data for the WT complex. It is shown that protein contacts for the major solution isomers for both substrates in the mutant dictate approximately 90 degrees in-plane clockwise rotation relative to that in the WT. The conventional interpretation of the pattern of substrate methyl hyperfine shifts, however, indicates substrate rotations of only approximately 50 degrees . This paradox is resolved by demonstrating that the axial His25 imidazole ring also rotates counterclockwise with respect to the protein matrix in the mutant relative to that in the WT. The axial His25 CbetaH hyperfine shifts are shown to serve as independent probes of the imidazole plane orientation relative to the protein matrix. The analysis indicates that the pattern of heme methyl hyperfine shifts cannot be used alone to determine the in-plane orientation of the substrate as it relates to the stereospecificity of heme cleavage, without explicit consideration of the orientation of the axial His imidazole plane relative to the protein matrix.

Accurate Determination of Leucine and Valine Side-chain Conformations using U-[{sup 15}N/{sup 13}C/{sup 2}H]/[{sup 1}H-(methine/methyl)-Leu/Val] Isotope Labeling, NOE Pattern Recognition, and Methine C{gamma}-H{gamma}/C{beta}-H{beta} Residual Dipolar Couplings

Energy Technology Data Exchange (ETDEWEB)

Tang, Chun; Iwahara, Junji; Clore, G. Marius [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Laboratory of Chemical Physics (United States)], E-mail: mariusc@intra.niddk.nih.gov

2005-10-15

An isotope labeling scheme is described in which specific protonation of methine and methyl protons of leucine and valine is obtained on a {sup 15}N/{sup 13}C labeled background with uniform deuteration of all other non-exchangeable protons. The presence of a protonated methine group has little effect on the favorable relaxation properties of the methyl protons of Leu and Val. This labeling scheme permits the rotameric state of leucine side-chains to be readily determined by simple inspection of the pattern of H{gamma}(i)-H{sub N}(i) and H{gamma}(i)-H{sub N}(i+1) NOEs in a 3D {sup 15}N-separated NOE spectrum free of complications arising from spectral overlap and spin-diffusion. In addition, one-bond residual dipolar couplings for the methine {sup 13}C-{sup 1}H bond vectors of Leu and Val can be accurately determined from an intensity J-modulated constant-time HCCH-COSY experiment and used to accurately orient the side-chains of Leu and Val. Incorporation of these data into structure refinement improves the accuracy with which the conformations of Leu and Val side-chains can be established. This is important to ensure optimal packing both within the protein core and at intermolecular interfaces. The impact of the method on protein structure determination is illustrated by application to enzyme IIA{sup Chitobiose}, a 34 kDa homotrimeric phosphotransferase protein.

Synthesis of new trihalo methylated and non-symmetrical substituted 2-(1H-pyrazolyl)-5-(1H-pyrazolylcarbonyl)pyridines

International Nuclear Information System (INIS)

Bonacorso, Helio G.; Paim, Gisele R.; Guerra, Carolina Z.; Sehnem, Ronan C.; Cechinel, Cleber A.; Porte, Liliane M. F.; Martins, Marcos A. P.; Zanatta, Nilo

2009-01-01

This paper describes the synthesis of a new series of 2-[3-alkyl(aryl/heteroaryl)-5-trifluoro(chloro)methyl-5-hydroxy-4,5-dihydro -1H-pyrazol-1-yl]-5- [3-alkyl(aryl/heteroaryl)-5-trifluoro(chloro)methyl-5-hydroxy= -4,5-dihydro-1H-pyrazol-1-yl-1-carbonyl] pyridines by the cyclocondensation reaction of 4-alkoxy-4-alkyl(aryl/heteroaryl)-1,1,1- trifluoro(chloro) -3-alken- 2-ones [CX 3 C(O)CH=CR 1 OR, where R = Me, Et; R 1 = H, Me, Ph, 4-MeOPh, 4-NO 2 Ph, 4,4'-Biphenyl, 1-Naphthyl, Fur-2-yl, Thien-2-yl and X = F, Cl] with 6-hydrazinonicotinic hydrazide hydrate. Yields of 62 to 97% were obtained when the reactions were performed in ethanol as solvent at 78 deg C for 4 hours. In a subsequent step, the dehydration reactions of 2-(5-hydroxy-1H-pyrazol-1-yl)-5-(5-hydroxy-1H?pyrazol-1-yl-1-carbonyl) pyridines were carried out in pyridine/benzene in the presence of thionyl chloride and led to the isolation of a series of 2- [3-alkyl(aryl/heteroaryl)-5-trifluoro(chloro)methyl-1H-pyrazol-1-yl]-5- [3-alkyl(aryl/heteroaryl)-5 -trifluoro(chloro)methyl-1H-pyrazol-1-yl-1-carbonyl]pyridi= nes, in 64 to 86% yields. (author)

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

Science.gov (United States)

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

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

Science.gov (United States)

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.

Syntheses of DNA adducts of two heterocyclic amines, 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C) and 2-amino-9H-pyrido[2,3-b]indole (A alpha C) and identification of DNA adducts in organs from rats dosed with MeA alpha C

DEFF Research Database (Denmark)

Frederiksen, Hanne; Frandsen, Henrik Lauritz; Pfau, W.

2004-01-01

2-Amino-3-methyl-9H-pyrido[2,3-b]indole (MeAalphaC) and 2-amino-3-methyl-9H-pyrido[2,3-b]indole (AalphaC) are mutagenic and carcinogenic heterocyclic amines formed during ordinary cooking. MeAalphaC and AalphaC are activated to mutagenic metabolites by cytochrome P450-mediated N-oxidation...... by reaction of the parent amines with acetylated guanine N3-oxide. N-2-OH-MeAalphaC and N-2-OH-AalphaC reacted with calf thymus DNA after addition of acetic anhydride. P-32-postlabelling analysis of modified DNA showed one major adduct co-migrating with N-2-(3',5'-diphospho-2'-deoxyguanosin-8-yl...

Identification of metabolites in urine and feces from rats dosed with the heterocyclic amine, 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C)

DEFF Research Database (Denmark)

Frederiksen, H; Frandsen, H

2004-01-01

2-Amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C) is a proximate mutagenic and carcinogenic heterocyclic amine formed during ordinary cooking. In model systems, MeA alpha C can be formed by pyrolyses of either tryptophan or proteins of animal or vegetable origin. In the present study, the in ......2-Amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C) is a proximate mutagenic and carcinogenic heterocyclic amine formed during ordinary cooking. In model systems, MeA alpha C can be formed by pyrolyses of either tryptophan or proteins of animal or vegetable origin. In the present study...

Synthesis of [methyl-{sup 14}C]crotonobetaine from DL-[methyl-{sup 14}C]carnitine

Energy Technology Data Exchange (ETDEWEB)

Loester, H.; Seim, H. [Leipzig Univ. (Germany). Inst. of Clinical Chemistry and Pathobiochemistry

1996-02-01

The causes of carnitine deficiency syndromes are not completely understood, but decomposition of L-carnitine in vivo is likely to be involved. Carnitine is metabolized to {gamma}-butyrobetaine, and crotonobetaine is probably an intermediate in this pathway. To validate experimentally the precursor-product relationship between the three physiologically occuring {gamma}-betaines - L-carnitine, crotonobetaine, {gamma}-butyrobetaine - labelling with stable or radioactive isotopes became necessary. Methyl-labelled carnitine isomers (L(-)-, D(+)- or DL-) or {gamma}-butyrobetaine can be easily synthesized by methylation of 4-amino-3-hydroxybutyric acid isomers or 4-aminobutyric acid, respectively. Because of problems with the 4-aminocrotonic acid, we synthesized labelled crotonbetaine from labelled carnitine. Thus, DL-[methyl-{sup 14}C]carnitine was dehydrated by reaction with concentrated sulfuric acid. After removal of the latter the products were separated and purified by ion exchange chromatography on DOWEX 50 WX8 (200 - 400 mesh) and gradient elution with hydrochloric acid. In addition to the labelled main product [methyl-{sup 14}C]crotonobetaine (yield about 50 %), [methyl-{sup 14}C]glycine betaine and [methyl-{sup 14}C]acetonyl-trimethylammonium (ATMA) were formed. The end products were identified by combined thin layer chromatography/autoradiography and quantified by liquid scintillation counting. (Author).

Synthesis of DL-adrenaline (methyl C{sup 14}) (1961); Synthese de la DL-adrenaline (methyle {sup 14}C) (1961)

Energy Technology Data Exchange (ETDEWEB)

Pichat, L; Audinot, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The sodium derivative of 5-3-4 dibenzyl oxyphenyl 2-oxazolidinone reacted with methyl iodide {sup 14}C, in stoichiometric quantity, gives rise to the corresponding N-methyl {sup 14}C derivative. The oxazolidinone ring is opened by concentrated hydrochloric acid and the benzyl groups removed by catalytic hydrogenolysis. Adrenaline methyl {sup 14}C is then purified on Dowex 50 X-12 exchange resin. Overall-yield is 45 per cent based upon methyl iodide {sup 14}C. (author) [French] Le derive sode de la (dibenzyloxy-3-4-phenyl)-5 oxazolidinone-2 traite par l'iodure de methyle {sup 14}C, en proportion stoechiometrique, fournit le derive N-methyle {sup 14}C correspondant. Apres ouverture du cycle oxazolidinone par HCL concentre et debenzylation par hydrogenation catalytique, on purifie l'adrenaline (methyle {sup 14}C) par chromatographie sur resine echangeuse Dowex 50 X-12. Le rendement est de 45 pour cent par rapport a l'iodure de methyle {sup 14}C. (auteurs)

Synthesis of DL-adrenaline (methyl C{sup 14}) (1961); Synthese de la DL-adrenaline (methyle {sup 14}C) (1961)

Energy Technology Data Exchange (ETDEWEB)

Pichat, L.; Audinot, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The sodium derivative of 5-3-4 dibenzyl oxyphenyl 2-oxazolidinone reacted with methyl iodide {sup 14}C, in stoichiometric quantity, gives rise to the corresponding N-methyl {sup 14}C derivative. The oxazolidinone ring is opened by concentrated hydrochloric acid and the benzyl groups removed by catalytic hydrogenolysis. Adrenaline methyl {sup 14}C is then purified on Dowex 50 X-12 exchange resin. Overall-yield is 45 per cent based upon methyl iodide {sup 14}C. (author) [French] Le derive sode de la (dibenzyloxy-3-4-phenyl)-5 oxazolidinone-2 traite par l'iodure de methyle {sup 14}C, en proportion stoechiometrique, fournit le derive N-methyle {sup 14}C correspondant. Apres ouverture du cycle oxazolidinone par HCL concentre et debenzylation par hydrogenation catalytique, on purifie l'adrenaline (methyle {sup 14}C) par chromatographie sur resine echangeuse Dowex 50 X-12. Le rendement est de 45 pour cent par rapport a l'iodure de methyle {sup 14}C. (auteurs)

Ferrocene Compounds. XXVI. C- and O-Ferrocenylalkylation of Methyl Salicylate

OpenAIRE

Kovač, Veronika; Rapić, Vladimir; Alagić, Jasmina; Barišić, Lidija

1999-01-01

Reaction of equimolar amounts of methyl salicylate, sodium and N,N,N-trimethylferrocylammonium iodide (1a) in ethanol gave 55% of ethyl 1-ferrocenylethyl ether (4). By refluxing a solution of 9 mmol sodium and 3 mmol of FcCHRNMe3I (1a, R = H; 1b, R = Me; 1c, R = Ph) in a large excess of methyl salicylate for 2-3 hours, the corresponding methyl 5-ferrocylsalicylates (5) (10-23%) and methyl-3-ferrocylsalicylates (6) (12-20%) were obtained. During conversion of salt 1b, besides of 5b and 6b, 20%...

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

OpenAIRE

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 l...

Selective backbone labelling of ILV methyl labelled proteins

International Nuclear Information System (INIS)

Sibille, Nathalie; Hanoulle, Xavier; Bonachera, Fanny; Verdegem, Dries; Landrieu, Isabelle; Wieruszeski, Jean-Michel; Lippens, Guy

2009-01-01

Adding the 13 C labelled 2-keto-isovalerate and 2-oxobutanoate precursors to a minimal medium composed of 12 C labelled glucose instead of the commonly used ( 2 D, 13 C) glucose leads not only to the 13 C labelling of (I, L, V) methyls but also to the selective 13 C labelling of the backbone C α and CO carbons of the Ile and Val residues. As a result, the backbone ( 1 H, 15 N) correlations of the Ile and Val residues and their next neighbours in the (i + 1) position can be selectively identified in HN(CA) and HN(CO) planes. The availability of a selective HSQC spectrum corresponding to the sole amide resonances of the Ile and Val residues allows connecting them to their corresponding methyls by the intra-residue NOE effect, and should therefore be applicable to larger systems

Crystal structures of eight mono-methyl alkanes (C26–C32 via single-crystal and powder diffraction and DFT-D optimization

Directory of Open Access Journals (Sweden)

Lee Brooks

2015-09-01

Full Text Available The crystal structures of eight mono-methyl alkanes have been determined from single-crystal or high-resolution powder X-ray diffraction using synchrotron radiation. Mono-methyl alkanes can be found on the cuticles of insects and are believed to act as recognition pheromones in some social species, e.g. ants, wasps etc. The molecules were synthesized as pure S enantiomers and are (S-9-methylpentacosane, C26H54; (S-9-methylheptacosane and (S-11-methylheptacosane, C28H58; (S-7-methylnonacosane, (S-9-methylnonacosane, (S-11-methylnonacosane and (S-13-methylnonacosane, C30H62; and (S-9-methylhentriacontane, C32H66. All crystallize in space group P21. Depending on the position of the methyl group on the carbon chain, two packing schemes are observed, in which the molecules pack together hexagonally as linear rods with terminal and side methyl groups clustering to form distinct motifs. Carbon-chain torsion angles deviate by less than 10° from the fully extended conformation, but with one packing form showing greater curvature than the other near the position of the methyl side group. The crystal structures are optimized by dispersion-corrected DFT calculations, because of the difficulties in refining accurate structural parameters from powder diffraction data from relatively poorly crystalline materials.

Pseudosymmetric fac-di-aqua-trichlorido[(di-methyl-phosphor-yl)methanaminium-κO]manganese(II).

Science.gov (United States)

Reiss, Guido J

2013-05-01

In the title compound, [Mn(C3H11NOP)Cl3(H2O)2], the Mn(II) metal center has a distorted o-cta-hedral geometry, coordinated by the three chloride ligands showing a facial arrangement. Two water mol-ecules and the O-coordinated dpmaH cation [dpmaH = (di-methyl-phosphor-yl)methanaminium] complete the coordination sphere. Each complex mol-ecule is connected to its neighbours by O-H⋯Cl and N-H⋯Cl hydrogen bonds. Two of the chloride ligands and the two water ligands form a hydrogen-bonded polymeric sheet in the ab plane. Furthermore, these planes are connected to adjacent planes by hydrogen bonds from the aminium function of cationic dpmaH ligand. A pseudo-mirror plane perpendicular to the b axis in the chiral space group P21 is observed together with inversion twinning [ratio = 0.864 (5):0.136 (5)].

Cleavage of sp3 C-O bonds via oxidative addition of C-H bonds.

Science.gov (United States)

Choi, Jongwook; Choliy, Yuriy; Zhang, Xiawei; Emge, Thomas J; Krogh-Jespersen, Karsten; Goldman, Alan S

2009-11-04

(PCP)Ir (PCP = kappa(3)-C(6)H(3)-2,6-[CH(2)P(t-Bu)(2)](2)) is found to undergo oxidative addition of the methyl-oxygen bond of electron-poor methyl aryl ethers, including methoxy-3,5-bis(trifluoromethyl)benzene and methoxypentafluorobenzene, to give the corresponding aryloxide complexes (PCP)Ir(CH(3))(OAr). Although the net reaction is insertion of the Ir center into the C-O bond, density functional theory (DFT) calculations and a significant kinetic isotope effect [k(CH(3))(OAr)/k(CD(3))(OAr) = 4.3(3)] strongly argue against a simple insertion mechanism and in favor of a pathway involving C-H addition and alpha-migration of the OAr group to give a methylene complex followed by hydride-to-methylene migration to give the observed product. Ethoxy aryl ethers, including ethoxybenzene, also undergo C-O bond cleavage by (PCP)Ir, but the net reaction in this case is 1,2-elimination of ArO-H to give (PCP)Ir(H)(OAr) and ethylene. DFT calculations point to a low-barrier pathway for this reaction that proceeds through C-H addition of the ethoxy methyl group followed by beta-aryl oxide elimination and loss of ethylene. Thus, both of these distinct C-O cleavage reactions proceed via initial addition of a C(sp(3))-H bond, despite the fact that such bonds are typically considered inert and are much stronger than C-O bonds.

2-{[2-Methyl-3-(2-methylphenyl-4-oxo-3,4-dihydroquinazolin-8-yl]oxy}acetonitrile

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Adel S. El-Azab

2012-07-01

Full Text Available In the title compound, C18H15N3O2, the fused ring system is almost planar [the dihedral angle between the six-membered rings is 1.81 (6°]. The 2-tolyl ring is approximately orthogonal to this plane [dihedral angle = 83.03 (7°] as is the acetonitrile group [C—O—C—C torsion angle = 79.24 (14°] which is also syn to the methyl substituent of the tolyl group. In the crystal, supramolecular layers are formed in the bc plane mediated by C—H...O, C—H...N and C—H...π interactions. The tolyl group is disordered over two positions in a 0.852 (3:0.148 (3 ratio.

Substituent effects on the photolysis of methyl 2-carboxylate substituted aliphatic 2 H-azirines

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Gómez-Zavaglia, Andrea; Kaczor, Agnieszka; Cardoso, Ana L.; Pinho e Melo, Teresa M. V. D.; Fausto, Rui

2007-05-01

In this study, the UV induced photochemical reactions of two 2 H-azirines - methyl 2-chloro-3-methyl-2 H-azirine-2-carboxylate (MCMAC) and methyl 3-methyl-2 H-azirine-2-carboxylate (MMAC) - isolated in argon matrices are compared. For both compounds, irradiation with λ > 235 nm led to observation of two primary photoprocesses: (a) C sbnd C bond cleavage, with production of nitrile ylides (P1-type products), and (b) C sbnd N bond cleavage, with production of methylated ketene imines (P2-type products). However, subsequent photoprocesses were found to be different in the two cases. In MCMAC, both primary photoproducts were shown to undergo further reactions: P1-type products decarboxylate, giving [(1-chloroethylidene)imino]ethanide, which bears a C dbnd N +dbnd C - group (P3-type product); P2-type products decarbonylate, yielding a substituted ylidene methanamine (P4-type product). In MMAC, only P2-type primary photoproducts appeared to react, undergoing decarbonylation or decarboxylation (both reactions leading to P4-type products), whereas P1-type products were found to be non-reactive. The non-observation of any secondary photoproduct resulting from photolysis of P1-MMAC revealed the higher photostability of this species when compared with the corresponding photoproduct obtained from MCMAC. The C sbnd N photochemical cleavage is an unusual process in aliphatic 2 H-azirines. In the studied compounds, its preference over the commonly observed C sbnd C azirine-ring bond photocleavage is attributed to the presence of electron withdrawing substituents (methylcarboxy group in both azirines and also the chlorine atom in MCMAC), which accelerates intersystem crossing towards the triplet state from where the cleavage of the C sbnd N bond takes place. The lack of the chlorine atom in MMAC may be partially compensated by the significantly higher stabilization of the P2-type photoproduct derived from this molecule ( ca. -52 kJ mol -1) relatively to the reactant, when

Crystal structure of 2-methyl-1H-imidazol-3-ium hydrogen oxalate dihydrate

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Mouhamadou Birame Diop

2016-08-01

Full Text Available Single crystals of the title molecular salt, C4H7N2+·HC2O4−·2H2O, were isolated from the reaction of 2-methyl-1H-imidazole and oxalic acid in a 1:1 molar ratio in water. In the crystal, the cations and anions are positioned alternately along an infinite [010] ribbon and linked together through bifurcated N—H...(O,O hydrogen bonds. The water molecules of crystallization link the chains into (10-1 bilayers, with the methyl groups of the cations organized in an isotactic manner.

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

Science.gov (United States)

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.

Crystal structure of 1-ethylpyrazolo[3,4-d]pyrimidine-4(5H-thione

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Mohammed El Fal

2014-09-01

Full Text Available In the title compound, C7H8N4S, the methyl C atom is displaced by 1.232 (7 Å from the mean plane of the pyrazolo[3,4-d]pyrimidine ring system (r.m.s. deviation = 0.007 Å. The N—N—C—Cm (m = methyl torsion angle is −60.3 (6°. In the crystal, molecules are linked by N—H...S hydrogen bonds, generating [010] chains, which are reinforced by C—H...N interactions. The chains are cross-linked by weak C—H...S hydrogen bonds, generating (001 sheets.

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.

Science.gov (United States)

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.

(E-3-Methyl-6-(3-oxo-3-(thiophen-2-yl-1-propenyl-2(3H-benzothiazolone

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Yordanka Ivanova

2016-04-01

Full Text Available The title compound, (E-3-methyl-6-(3-oxo-3-(thiophen-2-yl-1-propenyl-2(3H-benzothiazolone, was synthesized by Claisen-Schmidt condensation of 3-methyl-2(3H-benzothiazolone-6-carbaldehyde with 2-acetylthiophene in 94% yield. The structure of the target compound was confirmed using 1H-NMR, 13C-NMR, IR, MS, and elemental analysis.

Bis(2-methyl-4-nitroanilinium tetrachloridomercurate(II

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Andreas Lemmerer

2008-12-01

Full Text Available The title compound, (C7H9N2O22[HgCl4], self-assembles into cationic organic bilayers containing the 2-methyl-4-nitroanilinium cations, sandwiched between anionic inorganic layers built up by the distorted tetrahedral [HgCl4]2− groups. The organic sheets are interlinked through weak C—H...O hydrogen bonds, while they interact with the anionic part via strong charge-assisted N+—H...Cl—Hg hydrogen bonds. The [HgCl4]2− anions are bisected by a mirror plane passing through the metal and two of the chloride ions.

Dopamine transporter binding in rat striatum: a comparison of [O-methyl-{sup 11}C]{beta}-CFT and [N-methyl-{sup 11}C]{beta}-CFT

Energy Technology Data Exchange (ETDEWEB)

Yoder, Karmen K.; Hutchins, Gary D.; Mock, Bruce H.; Fei, Xiangshu; Winkle, Wendy L. [Department of Radiology, Indiana University School of Medicine, L3-208, Indianapolis, IN 46202 (United States); Gitter, Bruce D.; Territo, Paul R. [Lilly Center for Anatomical and Molecular Imaging, Integrative Biology Division, Lilly Research Laboratories, Greenfield, IN 46140 (United States); Zheng Qihuang [Department of Radiology, Indiana University School of Medicine, L3-208, Indianapolis, IN 46202 (United States)], E-mail: qzheng@iupui.edu

2009-01-15

Introduction: Positron emission tomography scanning with radiolabeled phenyltropane cocaine analogs is important for quantifying the in vivo density of monoamine transporters, including the dopamine transporter (DAT). [{sup 11}C]{beta}-CFT is useful for studying DAT as a marker of dopaminergic innervation in animal models of psychiatric and neurological disorders. [{sup 11}C]{beta}-CFT is commonly labeled at the N-methyl position. However, labeling of [{sup 11}C]{beta}-CFT at the O-methyl position is a simpler procedure and results in a shorter synthesis time [desirable in small-animal studies, where specific activity (SA) is crucial]. In this study, we sought to validate that the O-methylated form of [{sup 11}C]{beta}-CFT provides equivalent quantitative results to that of the more commonly reported N-methyl form. Methods: Four female Sprague-Dawley rats were scanned twice on the IndyPET II small-animal scanner, once with [N-methyl-{sup 11}C]{beta}-CFT and once with [O-methyl-{sup 11}C]{beta}-CFT. DAT binding potentials (BP{identical_to}B'{sub avail}/K{sub d}) were estimated for right and left striata with a nonlinear least-squares algorithm, using a reference region (cerebellum) as the input function. Results: [N-Methyl-{sup 11}C]{beta}-CFT and [O-methyl-{sup 11}C]{beta}-CFT were synthesized with 40-50% radiochemical yields (HPLC purification). Radiochemical purity was >99%. SA at end of bombardment was 258{+-}30 GBq/{mu}mol. Average BP values for right and left striata with [N-methyl-{sup 11}C]{beta}-CFT were 1.16{+-}0.08 and 1.23{+-}0.14, respectively. BP values for [O-methyl-{sup 11}C]{beta}-CFT were 1.18{+-}0.08 (right) and 1.22{+-}0.16 (left). Paired t tests demonstrated that labeling position did not affect striatal DAT BP. Conclusions: These results suggest that [O-methyl-{sup 11}C]{beta}-CFT is quantitatively equivalent to [N-methyl-{sup 11}C]{beta}-CFT in the rat striatum.

DNA methylation modulates H19 and IGF2 expression in porcine female eye

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Dongxu Wang

2017-03-01

Full Text Available 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.

DNA methylation modulates H19 and IGF2 expression in porcine female eye

Science.gov (United States)

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

1-13C; methyl-2H3 methionine kinetics in humans: Methionine conservation and cystine sparing

International Nuclear Information System (INIS)

Storch, K.J.; Wagner, D.A.; Burke, J.F.; Young, V.R.

1990-01-01

Methionine (Met) conservation in healthy young adult men (4/diet group) was explored by supplying one of the following three L-amino acid based diets: (1) adequate Met but no cystine; (2) neither Met nor cystine; or (3) no Met but cystine supplementation. After 5 days, subjects received a continuous intravenous infusion of L-[1-13C; methyl-2H3]Met for 5 h while the diet was given as small isocaloric isonitrogenous meals. Estimates were made of rates of Met incorporation into protein synthesis (S) and release from body proteins (B), transmethylation (TM), remethylation of homocysteine (RM), and transsulfuration (TS). For the adequate Met diet, the rates were S = 24 +/- 2, B = 18 +/- 1, TM = 12.4 +/- 1.7, RM = 4.7 +/- 1.1, and TS = 7.6 +/- 0.6 (SE) mumol.kg-1.h-1. The sulfur amino acid-devoid diet significantly (P less than 0.05) reduced S, TM, RM, and TS. Supplementation of this diet with cystine reduced Met oxidation (P = 0.05). Therefore, two loci are quantitatively important regulatory points in Met conservation in vivo: (1) the distribution of Met between the pathways of protein anabolism and TM (Met locus) and (2) the distribution of homocysteine between RM and TS (homocysteine locus)

Methionine kinetics in adult men: effects of dietary betaine on L-[2H3-methyl-1-13C]methionine

International Nuclear Information System (INIS)

Storch, K.J.; Wagner, D.A.; Young, V.R.

1991-01-01

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 from 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

4-Methyl-2-oxo-2H-chromen-7-yl 4-methoxybenzenesulfonate

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Suman Sinha

2011-12-01

Full Text Available In the title compound, C17H14O6S, the 2H-chromene ring is essentially planar, with a maximum deviation of 0.016 (1 Å. The dihedral angle between the 2H-chromene and the benzene rings is 54.61 (5°. The C atom of the methoxy group is close to coplanar with its attached ring [deviation = 0.082 (2 Å]. In the crystal, molecules are connected via C—H...O hydrogen bonds, forming sheets lying parallel to the bc plane. Weak C—H...π interactions are also observed.

Synthesis of N-methyl and N-11C-methyl spiperone by phase transfer catalysis in anhydrous solvent

International Nuclear Information System (INIS)

Omokawa, Hiroyoshi; Tanaka, Akira; Iio, Mayumi; Nishihara, Yoshiaki; Inoue, Osamu; Yamazaki, Toshio.

1985-01-01

Spiperone, a butyrophenone neuroleptic drug, has been used in binding studies of dopamine receptors. Langstrom et al. developed N- 11 C-methyl spiperone, and, in cooperate with Wagner et al., made it possible to visualize the distribution of dopamine receptors in the human brain in vivo. In this paper, we independently developed another synthetic method of N- 11 C-methyl spiperone using the phase transfer catalyst in an anhydrous solvent. Separation of the product is feasible only by passing the reactant solution through a Millipore filter and injecting it onto high pressure liquid chromatography (HPLC). The time required for the synthesis and purification of N- 11 C-methyl spiperone from 11 C-methyl iodide and spiperone was 20 min. Radiochemical yield exceeded 35 % against 11 C-methyl iodide without correcting decay of the radioactivity. (author)

In silico identification of BIM-1 (2-methyl-1H-indol-3-yl) as a potential ...

African Journals Online (AJOL)

In silico identification of BIM-1 (2-methyl-1H-indol-3-yl) as a potential therapeutic agent against elevated protein kinase C beta associated diseases. U Saeed, N Nawaz, Y Waheed, N Chaudry, HT Bhatti, S Urooj, H Waheed, M Ashraf, UHK Naizi ...

DNA methylation regulates expression of VEGF-C, and S-adenosylmethionine is effective for VEGF-C methylation and for inhibiting cancer growth

Energy Technology Data Exchange (ETDEWEB)

Da, M.X. [Department of Surgical Oncology, Gansu Provincial Hospital, Lanzhou (China); Zhang, Y.B. [Department of Surgery, Ningxia Medical University, Yinchuan (China); Yao, J.B. [Department of Surgical Oncology, Gansu Provincial Hospital, Lanzhou (China); Duan, Y.X. [Department of Surgery, Ningxia Medical University, Yinchuan (China)

2014-09-30

DNA hypomethylation may activate oncogene transcription, thus promoting carcinogenesis and tumor development. S-adenosylmethionine (SAM) is a methyl donor in numerous methylation reactions and acts as an inhibitor of intracellular demethylase activity, which results in hypermethylation of DNA. The main objectives of this study were to determine whether DNA hypomethylation correlated with vascular endothelial growth factor-C (VEGF-C) expression, and the effect of SAM on VEGF-C methylation and gastric cancer growth inhibition. VEGF-C expression was assayed by Western blotting and RT-qPCR in gastric cancer cells, and by immunohistochemistry in tumor xenografts. VEGF-C methylation was assayed by bisulfite DNA sequencing. The effect of SAM on cell apoptosis was assayed by flow cytometry analyses and its effect on cancer growth was assessed in nude mice. The VEGF-C promoters of MGC-803, BGC-823, and SGC-7901 gastric cancer cells, which normally express VEGF-C, were nearly unmethylated. After SAM treatment, the VEGF-C promoters in these cells were highly methylated and VEGF-C expression was downregulated. SAM also significantly inhibited tumor growth in vitro and in vivo. DNA methylation regulates expression of VEGF-C. SAM can effectively induce VEGF-C methylation, reduce the expression of VEGF-C, and inhibit tumor growth. SAM has potential as a drug therapy to silence oncogenes and block the progression of gastric cancer.

Quantum Mechanics on the h-deformed Quantum Plane

OpenAIRE

Cho, Sunggoo

1998-01-01

We find the covariant deformed Heisenberg algebra and the Laplace-Beltrami operator on the extended $h$-deformed quantum plane and solve the Schr\\"odinger equations explicitly for some physical systems on the quantum plane. In the commutative limit the behaviour of a quantum particle on the quantum plane becomes that of the quantum particle on the Poincar\\'e half-plane, a surface of constant negative Gaussian curvature. We show the bound state energy spectra for particles under specific poten...

4-[(5-Hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-ylphenylmethyl]-5-methyl-2-phenyl-1H-pyrazol-3(2H-one ethanol hemisolvate

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Hoong-Kun Fun

2009-01-01

Full Text Available The asymmetric unit of the title compound, C27H24N4O2·0.5C2H6O, comprises two crystallographically independent molecules (A and B with slightly different conformations, and one ethanol molecule of crystallization. Intramolecular C—H...O and O—H...O hydrogen bonds generate six- and eight-membered rings, producing S(6 and S(8 ring motifs, respectively. In molecule A, one of the benzene rings is disordered over two positions, with site-occupancy factors of 0.542 (11 and 0.458 (11. The dihedral angles between the central benzene ring and the two outer benzene rings are 73.88 (9 and 82.6 (2/88.9 (2° in molecule A, and 80.81 (8 and 79.38 (8° in molecule B. In the crystal structure, molecules form infinite one-dimensional chains in the (101 plane. The crystal structure is stabilized by intermolecular O—H...N, N—H...N, N—H...O and C—H...O hydrogen bonds, weak C—H...π and π–π [centroid–centroid = 3.5496 (1 Å] interactions.

EPR study of gamma irradiated N-methyl taurine (C 3H 9NO 3S) and sodium hydrogen sulphate monohydrate (NaHSO 3·H 2O) single crystals

Science.gov (United States)

Yıldırım, İlkay; Karabulut, Bünyamin

2011-03-01

EPR study of gamma irradiated C 3H 9NO 3S and NaHSO 3.H 2O single crystals have been carried out at room temperature. There is one site for the radicals in C 3H 9NO 3S 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 SO3- and RH radicals for N-methyl taurine, and to the SO3- and OH radicals for sodium hydrogen sulfate monohydrate single crystals. The principal values of the g for SO3-, the hyperfine values of RH and OH proton splitting have been calculated and discussed.

Synthesis of (R,S)-[2,3-13C2]-1-(1'-methyl-2'-pyrrolidinyl)propan-2-one; {(R,S)-[2',3'-13C2]hygrinePound right bracePound

International Nuclear Information System (INIS)

Abraham, T.W.; Leete, Edward

1996-01-01

2-Ethoxy-1-methyl-5-pyrrolidinone (1) was reacted with ethyl [3,4- 13 C 2 ]-acetoacetate (2) in the presence of TiCl 4 to give ethyl [3,4- 13 C 2 ]-2-(1'-methyl-5'-oxo-2'-pyrrolidinyl)-3-oxobutanoate (3) in 85% yield. Decarboethoxylation of ethyl [3,4- 13 C 2 ]-2-(1'-methyl-5'-oxo-2'-pyrrolidinyl)-3-oxobutan-oate (3) was accomplished using NaCl and H 2 O in DMSO to give (R,S)-[2,3- 13 C 2 ]-1-(1'-methyl-5'-oxo-2'-pyrrolidinyl)propan-2-o ne (4) in 91% yield. Protection of the ketone as a ketal (ethylene glycol, H + ), followed by reduction of the amide to the amine using LiAlH 4 and subsequent deprotection of the ketal gave (R,S)-[2,3- 13 C 2 ]-1-(1'-methyl-2'-pyrrolidinyl)propan-2-one ((R,s)-[2', 3'- 13 C 2 ]Hygrine) (8) in 78% yield. (61% overall yield from ethyl [3,4- 13 C 2 ]acetoacetate). (Author)

Selective labelling of apolipoproteins A-I and C-I at methionine residues by (TH) methyl exchange

Energy Technology Data Exchange (ETDEWEB)

Hancock, W.S.; Harding, D.R.K.; Barling, P.M.; Sparrow, J.T.

1985-01-01

Apolipoproteins C-I and A-I were radioactively labelled with tritium by (TH)-methyl exchange. The methionine residues were first methylated with (TH)-methyl iodide at pH4 and the reaction products were purified by gel filtration and cation exchange chromatography. The products were then demethylated with 2-mercaptoethanol (6 M) at pH 8.6 to regenerate the apolipoproteins in an unmodified but tritiated form. The specific radioactivity for apolipoprotein C-I and A-I was 3.5 x 10W and 1.5 x 10X dpm/pmol respectively. The properties of (TH)-apolipoprotein C-I were examined by reversed phase HPLC and by incorporation into very low density lipoproteins (VLDL).

Regioselectivity in the Thermal Rearrangement of Unsymmetrical 4-Methyl-4H-1,2,4-triazoles to 1-Methyl-1H-1,2,4-triazoles

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Per H.J. Carlsen

2001-11-01

Full Text Available The rearrangement of 4-methyl-3,5-diaryl-4H-1,2,4-triazoles to the corresponding 1-methyl-3,5-diaryl-1H-1,2,4-triazoles showed regioselectivity comparable to that observed for the alkylation of 3,5-diaryl-1H-1,2,4-triazoles. This lends support to a proposed mechanism for the rearrangement that involves consecutive nucleophilic displacements steps.

Nature of the C2-methylation effect on the properties of imidazolium ionic liquids.

Science.gov (United States)

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.

Synthesis and characteristics in tumor-bearing mice of N-[11C]methyl-1-deoxynojirimycin and N-[11C]methyl-1-deoxymannojirimycin

International Nuclear Information System (INIS)

Ishiwata, Kiichi; Sasaki, Toru; Ishii, Shin-ichi; Senda, Michio; Seki, Hiroyuki; Kitasato Univ.; Nozaki, Tadashi

1993-01-01

N-[ 11 C]Methyl-1-deoxynojirimycin ([ 11 C]MDNM) and N-[ 11 C]methyl-1-deoxymannojirimycin ([ 11 C]MDMM) were prepared by 11 C-methylation of 1-deoxynojirimycin (DNM) and 1-deoxymannojirimycin (DMM), which are specific inhibitors of glucosidase and mannosidase, respectively. In mice bearing Ehrich ascitic tumor, the highest uptake of the [ 11 C]MDNM was observed in the kidney, followed by the liver and small intestine, while the tumour uptake was moderate. By MDNM loading, saturable uptake was observed in these tissues. In homogenates of the kidney and tumor tissues, a considerable amount of radioactivity was detected in a high-molecular weight fraction. These results demonstrate that the [ 11 C]MDNM has a potential for imaging the glucosidase activity by positron emission tomography. On the other hand, [ 11 C]MDMM showed lower uptake than [ 11 C]MDNM in the kidney, liver and small intestine and no effect of carrier DMM, suggesting that the [ 11 C]MDMM would not reflect mannosidase activity. (Author)

5-(4-Fluorophenyl-2,2,6-trimethyl-4H-1,3-dioxin-4-one

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Julio Zukerman-Schpector

2009-07-01

Full Text Available The 1,3-dioxine ring in the title compound, C13H13FO3, is in a half-boat conformation with the methyl-bonded C atom 0.612 (2 Å out of the plane defined by the remaining five atoms.

Synthesis of [methyl-[sup 14]C]-N-methylputrescine

Energy Technology Data Exchange (ETDEWEB)

Secor, H.V.; Izac, R.R.; Hassam, S.B.; Frisch, A.F. (Philip Morris Research Center, Richmond, VA (United States))

1994-05-01

[Methyl-[sup 14]C]-N-methylputrescine was prepared from [[sup 14]C]methylamine hydrochloride in five steps. Reaction of benzaldehyde and [[sup 14]C]methylamine (10 mCi) followed by catalytic hydrogenation yielded [methyl-[sup 14]C]-N-methylbenzylamine. The key step in this process is the alkylation of [methyl-[sup 14]C]-N-methylbenzylamine in aqueous medium with 4-bromobutyronitrile. The radiochemical purity of the final product after two successive catalytic hydrogenations was in excess of 97%. The radiochemical yields in two successive runs were 26 and 38%, based on starting [[sup 14]C]methylamine, with specific activities of 22 and 23 mCi/mmol, respectively. This sequence provides a convenient and efficient regioselective radiosynthesis of [methyl-[sup 14]C]-N-methylputrescine. (author).

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

Science.gov (United States)

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.

Influence of basal-plane dislocation structures on expansion of single Shockley-type stacking faults in forward-current degradation of 4H-SiC p-i-n diodes

Science.gov (United States)

Hayashi, Shohei; Yamashita, Tamotsu; Senzaki, Junji; Miyazato, Masaki; Ryo, Mina; Miyajima, Masaaki; Kato, Tomohisa; Yonezawa, Yoshiyuki; Kojima, Kazutoshi; Okumura, Hajime

2018-04-01

The origin of expanded single Shockley-type stacking faults in forward-current degradation of 4H-SiC p-i-n diodes was investigated by the stress-current test. At a stress-current density lower than 25 A cm-2, triangular stacking faults were formed from basal-plane dislocations in the epitaxial layer. At a stress-current density higher than 350 A cm-2, both triangular and long-zone-shaped stacking faults were formed from basal-plane dislocations that converted into threading edge dislocations near the interface between the epitaxial layer and the substrate. In addition, the conversion depth of basal-plane dislocations that expanded into the stacking fault was inside the substrate deeper than the interface. These results indicate that the conversion depth of basal-plane dislocations strongly affects the threshold stress-current density at which the expansion of stacking faults occurs.

Identification of metabolites in urine and feces from rats dosed with the heterocyclic amine, 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C)

DEFF Research Database (Denmark)

Frederiksen, H.; Frandsen, Henrik Lauritz

2004-01-01

2-Amino-3-methyl-9H-pyrido[2,3-b]indole (MeAalphaC) is a proximate mutagenic and carcinogenic heterocyclic amine formed during ordinary cooking. In model systems, MeAalphaC can be formed by pyrolyses of either tryptophan or proteins of animal or vegetable origin. In the present study, the in vivo...

Zeolite H-USY for the production of lactic acid and methyl lactate from C-3-sugars

DEFF Research Database (Denmark)

West, R.M.; Holm, Martin Spangsberg; Shunmugavel, Saravanamurugan

2010-01-01

and dihydroxyacetone directly to methyl lactate and lactic acid catalyzed by inexpensive commercially available zeolites is presented. One particular zeolite, H-USY (Si/Al = 6) is shown to be quite active with near quantitative yields for this isomerization. Deactivation of the H-USY-zeolite was studied by correlating...

Anaerobic C1 metabolism of the O-methyl-14C-labeled substituent of vanillate

International Nuclear Information System (INIS)

Frazer, A.C.; Young, L.Y.

1986-01-01

The O-methyl substituents of aromatic compounds constitute a C 1 growth substrate for a number of taxonomically diverse anaerobic acetogens. In this study, strain TH-001, an O-demethylating obligate anaerobe, was chosen to represent this physiological group, and the carbon flow when cells were grown on O-methyl substituents as a C 1 substrate was determined by 14 C radiotracer techniques. O-[methyl- 14 C]vanillate (4-hydroxy-3-methoxy-benzoate) was used as the labeled C 1 substrate. The data showed that for every O-methyl carbon converted to [ 14 C]acetate, two were oxidized to 14 CO 2 . Quantitation of the carbon recovered in the two products, acetate and CO 2 , indicated that acetate was formed in part by the fixation of unlabeled CO 2 . The specific activity of 14 C in acetate was 70% of that in the O-methyl substrate, suggesting that only one carbon of acetate was derived from the O-methyl group. Thus, it is postulated that the carboxyl carbon of the product acetate is derived from CO 2 and the methyl carbon is derived from the O-methyl substituent of vanillate

Fibrillarin methylates H2A in RNA polymerase I trans-active promoters in Brassica oleracea

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lloyd eLoza-Muller

2015-11-01

Full Text Available Fibrillarin is a well conserved methyltransferase involved in several if not all of the more than 100 methylations sites in rRNA which are essential for proper ribosome function. It is mainly localized in the nucleoli and Cajal bodies inside the cell nucleus where it exerts most of its functions. In plants, fibrillarin binds directly the guide RNA together with Nop56, Nop58 and 15.5ka proteins to form a snoRNP complex that selects the sites to be methylated in pre-processing of ribosomal RNA. Recently, the yeast counterpart NOP1 was found to methylate histone H2A in the nucleolar regions. Here we show that plant fibrillarin can also methylate histone H2A. In Brassica floral meristem cells the methylated histone H2A is mainly localized in the nucleolus but unlike yeast or human cells it also localize in the periphery of the nucleus. In specialized transport cells the pattern is altered and it exhibits a more diffuse staining in the nucleus for methylated histone H2A as well as for fibrillarin. Here we also show that plant fibrillarin is capable of interacting with H2A and carry out its methylation in the rDNA promoter.

Implantation temperature and thermal annealing behavior in H{sub 2}{sup +}-implanted 6H-SiC

Energy Technology Data Exchange (ETDEWEB)

Li, B.S., E-mail: b.s.li@impcas.ac.cn; Wang, Z.G.; Jin, J.F.

2013-12-01

The effects of hydrogen implantation temperature and annealing temperature in 6H-SiC are studied by the combination of Rutherford backscattering in channeling geometry (RBS/C), high-resolution X-ray diffraction (HRXRD) and scanning electron microscopy (SEM). 6H-SiC wafers were implanted with 100 keV H{sub 2}{sup +} ions to a fluence of 2.5 × 10{sup 16} H{sub 2}{sup +} cm{sup −2} at room temperature (RT), 573 K and 773 K. Post-implantation, the samples were annealing under argon gas flow at different temperatures from 973 K to 1373 K for isochronal annealing (15 min). The relative Si disorder at the damage peak for the sample implanted at RT decreases gradually with increasing annealing temperature. However, the reverse annealing effect is found for the samples implanted at 573 K and 773 K. As-implantation, the intensity of in-plane compressive stress is the maximum as the sample was implanted at RT, and is the minimum as the sample was implanted at 573 K. The intensity of in-plane compressive stress for the sample implanted at RT decreases gradually with increasing annealing temperature, while the intensities of in-plane compressive stress for the sample implanted at 573 K and 773 K show oscillatory changes with increasing annealing temperature. After annealing at 1373 K, blisters and craters occur on the sample surface and their average sizes increase with increasing implantation temperature.

Pseudosymmetric fac-di­aqua­trichlorido[(di­methyl­phosphor­yl)methanaminium-κO]manganese(II)

Science.gov (United States)

Reiss, Guido J.

2013-01-01

In the title compound, [Mn(C3H11NOP)Cl3(H2O)2], the MnII metal center has a distorted o­cta­hedral geometry, coordinated by the three chloride ligands showing a facial arrangement. Two water mol­ecules and the O-coordinated dpmaH cation [dpmaH = (di­methyl­phosphor­yl)methanaminium] complete the coordination sphere. Each complex mol­ecule is connected to its neighbours by O—H⋯Cl and N—H⋯Cl hydrogen bonds. Two of the chloride ligands and the two water ligands form a hydrogen-bonded polymeric sheet in the ab plane. Furthermore, these planes are connected to adjacent planes by hydrogen bonds from the aminium function of cationic dpmaH ligand. A pseudo-mirror plane perpendicular to the b axis in the chiral space group P21 is observed together with inversion twinning [ratio = 0.864 (5):0.136 (5)]. PMID:23723764

1-(2-Ethoxy-2-methyl-2H-chromen-3-ylethanone

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Afsaneh Zonouzi

2009-04-01

Full Text Available The Csp3 atom of the chromenyl fused-ring system in the title compound, C14H16O3, deviates by 0.407 (2 Å from the plane of the other atoms (r.m.s. deviation = 0.041 Å. The ethoxy substituent occupies a pseudo-axial position.

Bioactivation of the heterocyclic aromatic amine 2-amino-3-methyl-9H-pyrido [2,3-b]indole (MeA alpha C) in recombinant test systems expressing human xenobiotic-metabolizing enzymes

DEFF Research Database (Denmark)

Glatt, H.; Pabel, U.; Meinl, W.

2004-01-01

2-Amino-3-methyl-9H-pyrido[2,3-b]indole (MeAalphaC) and some metabolites were investigated for mutagenicity in mammalian cell lines and bacterial strains engineered for the expression of human enzymes. MeAalphaC induced gene mutations (studied at the hprt locus) in Chinese hamster V79-derived cel...

The autoradiolytic and the γ-induced demethylation of solid thymine-(methyl-14C)

International Nuclear Information System (INIS)

Merwitz, O.

1980-01-01

The autoradiolytic and the γ-induced demethylation of solid thymine were measured qualitatively and quantitatively for the first time with specially purified thymine-(methyl- 14 C). Analogous experiments with thymine-(methyl- 3 H) and radio-gaschromatographic analysis provided proof for the formation of molecular hydrogen and methane. Ethane was not detected. The results are discussed in connection with e.s.r.-spectroscopic studies. (author)

cyclo-Tetrakis(μ-3-acetyl-4-methyl-1H-pyrazole-5-carboxylato-κ4N2,O3:N1,O5tetrakis[aquacopper(II] tetradecahydrate

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Sergey Malinkin

2011-09-01

Full Text Available The title compound, [Cu4(C7H6N2O34(H2O4]·14H2O, a tetranuclear [2 × 2] grid-type complex with S4 symmetry, contains four CuII atoms which are bridged by four pyrazolecarboxylate ligand anions and are additionally bonded to a water molecule. Each CuII atom is coordinated by two O atoms of the carboxylate and acetyl groups, two pyrazole N atoms of doubly deprotonated 3-acetyl-4-methyl-1H-pyrazole-5-carboxylic acid and one O atom of a water molecule. The geometry at each CuII atom is distorted square-pyramidal, with the two N and two O atoms in the equatorial plane and O atoms in the axial positions. O—H...O hydrogen-bonding interactions additionally stabilize the structure. One of the uncoordinated water molecules shows half-occupancy.

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

Science.gov (United States)

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.

Alterations of global histone H4K20 methylation during prostate carcinogenesis

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Behbahani Turang E

2012-03-01

Full Text Available Abstract Background Global histone modifications have been implicated in the progression of various tumour entities. Our study was designed to assess global methylation levels of histone 4 lysine 20 (H4K20me1-3 at different stages of prostate cancer (PCA carcinogenesis. Methods Global H4K20 methylation levels were evaluated using a tissue microarray in patients with clinically localized PCA (n = 113, non-malignant prostate disease (n = 27, metastatic hormone-naive PCA (mPCA, n = 30 and castration-resistant PCA (CRPC, n = 34. Immunohistochemistry was performed to assess global levels of H4K20 methylation levels. Results Similar proportions of the normal, PCA, and mPCA prostate tissues showed strong H4K20me3 staining. CRPC tissue analysis showed the weakest immunostaining levels of H4K20me1 and H4K20me2, compared to other prostate tissues. H4K20me2 methylation levels indicated significant differences in examined tissues except for normal prostate versus PCA tissue. H4K20me1 differentiates CRPC from other prostate tissues. H4K20me1 was significantly correlated with lymph node metastases, and H4K20me2 showed a significant correlation with the Gleason score. However, H4K20 methylation levels failed to predict PSA recurrence after radical prostatectomy. Conclusions H4K20 methylation levels constitute valuable markers for the dynamic process of prostate cancer carcinogenesis.

Preparation of H3-labelled methyl ethers of saturated fatty acids by heterogeneous catalytic isotope exchange in solution with gaseous tritium

International Nuclear Information System (INIS)

Shevchenko, V.P.; Myasoedov, N.F.

1980-01-01

A simple method of preparing 3 H-labelled methyl ethers of saturated fatty acids in the dioxane solution using the method of isotopic heterogenous catalytic exchange with gaseous tritium, is suggested. 3 H-labelled natural fatty acids (C 12 -C 18 ) are prepared by alkaline hydrolysis [ru

Mobility-Aware Modeling and Analysis of Dense Cellular Networks With $C$ -Plane/ $U$ -Plane Split Architecture

KAUST Repository

Ibrahim, Hazem

2016-09-19

The unrelenting increase in the population of mobile users and their traffic demands drive cellular network operators to densify their network infrastructure. Network densification shrinks the footprint of base stations (BSs) and reduces the number of users associated with each BS, leading to an improved spatial frequency reuse and spectral efficiency, and thus, higher network capacity. However, the densification gain comes at the expense of higher handover rates and network control overhead. Hence, user’s mobility can diminish or even nullifies the foreseen densification gain. In this context, splitting the control plane ( C -plane) and user plane ( U -plane) is proposed as a potential solution to harvest densification gain with reduced cost in terms of handover rate and network control overhead. In this paper, we use stochastic geometry to develop a tractable mobility-aware model for a two-tier downlink cellular network with ultra-dense small cells and C -plane/ U -plane split architecture. The developed model is then used to quantify the effect of mobility on the foreseen densification gain with and without C -plane/ U -plane split. To this end, we shed light on the handover problem in dense cellular environments, show scenarios where the network fails to support certain mobility profiles, and obtain network design insights.

1H and 13C NMR studies of palladium(2) and platinium(2) complexes with S-Methyl-L-Cysteine

International Nuclear Information System (INIS)

Allain, A.; Jezowska-Trzebiatowska, B.; Kozlowski, H.

1979-01-01

Our recent 1 H NMR studies on Pd(2)-S-Methyl-L-Cysteine(SMC) complexes have shown that the use of a conformational analysis to establish the complexed species existing in solution may provide clearer results than considering the proton chemical shift only. However, the use of the vicinal coupling constant of ABC spectrum of αCH-βCH 2 proton unit to estimate the rotational isomer fractions, may contain some ambiguity, especially on the proton assignment of the methylene group. For this reason 13 C NMR method has been applied to study these systems. (author)

Distinct crystallinity and orientations of hydroxyapatite thin films deposited on C- and A-plane sapphire substrates

Science.gov (United States)

Akazawa, Housei; Ueno, Yuko

2014-10-01

We report how the crystallinity and orientation of hydroxyapatite (HAp) films deposited on sapphire substrates depend on the crystallographic planes. Both solid-phase crystallization of amorphous HAp films and crystallization during sputter deposition at elevated temperatures were examined. The low-temperature epitaxial phase on C-plane sapphire substrates has c-axis orientated HAp crystals regardless of the crystallization route, whereas the preferred orientation switches to the (310) direction at higher temperatures. Only the symmetric stretching mode (ν1) of PO43- units appears in the Raman scattering spectra, confirming well-ordered crystalline domains. In contrast, HAp crystals grown on A-plane sapphire substrates are always oriented toward random orientations. Exhibiting all vibrational modes (ν1, ν3, and ν4) of PO43- units in the Raman scattering spectra reflects random orientation, violating the Raman selection rule. If we assume that Raman intensities of PO43- units represent the crystallinity of HAp films, crystallization terminating the surface with the C-plane is hindered by the presence of excess H2O and OH species in the film, whereas crystallization at random orientations on the A-plane sapphire is rather promoted by these species. Such contrasting behaviors between C-plane and A-plane substrates will reflect surface-plane dependent creation of crystalline seeds and eventually determine the orientation of resulting HAp films.

Synthesis of 24-methyl sterols sterospecifically labelled with 2H in the isopropyl methyl groups. 13C NMR spectral assignment of C-26 and C-27 resonances

International Nuclear Information System (INIS)

Colombo, D.; Ronchetti, F.; Toma, L.

1990-01-01

Through analysis of the 13 C NMR spectra of (25S)-[27- 2 H]campesterol (1) and (25R)-[26- 2 H]dihydrobrassicasterol (2), the C-26 and C-27 resonances have been unambiguously assigned; the biosynthetic applications are discussed. (author)

(Salicylato[tris(1-methyl-1H-benzimidazol-2-ylmethylamine]copper(II perchlorate dimethylformamide disolvate

Directory of Open Access Journals (Sweden)

Huilu Wu

2008-01-01

Full Text Available In the title complex, [Cu(C7H5O3(C27H27N7]ClO4·2C3H7NO, the CuII ion is five-coordinated by four N atoms from the tris(1-methyl-1H-benzimidazol-2-ylmethylamine ligand and an O atom of the monodentate salicylate ligand. The N4O donor set defines a coordination geometry intermediate between square-pyramidal and trigonal–bipyramidal. The crystal structure is stabilized by O—H...O interactions. The atoms of the aromatic ring of the salicylate ligand are disordered over two sites of equal occupancy. In addition, one of the dimethylformamide solvent molecules is partially disordered over two positions, of approximately equal occupancy.

Synthesis of Poly(N-vinyl-2-pyrrolidone-co-methyl methacrylate by Maghnite-H+ a Non-toxic Catalyst

Directory of Open Access Journals (Sweden)

Mohamed Benadda

2014-10-01

Full Text Available In the present work poly (N-vinyl-2-pyrrolidone-co-methyl methacrylate copolymers were prepared successfully and cleanly by a one step process via cationic copolymerization of N-vinyl-2-pyrrolidone (NVP with methyl methacrylate (MMA, in heterogeneous phase using “Maghnite-H+” (Mag-H+ as catalyst in bulk, Maghnite is a montmorillonite sheet silicate clay exchanged with protons to produce Maghnite-H+. Temperature is varied between 20 and 80 °C. The effects of reaction temperature, amount of Mag-H+ on the yield and the intrinsic viscosity (η were investigated. A typical reaction product of poly (NVP-co- MMA was analyzed by infra red spectroscopy (FTIR and 1H-NMR, 13C-NMR spectroscopy as well as by viscosimetry. © 2014 BCREC UNDIP. All rights reservedReceived: 24th November 2013; Revised: 30th June 2014; Accepted: 8th July 2014How to Cite: Benadda, M., Ferrahi, M.I., Belbachir, M. (2014. Synthesis of Poly(N-vinyl-2-pyrrolidone-co-methyl methacrylate by Maghnite-H+ a Non-toxic Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (3: 201-206. (doi: 10.9767/bcrec.9.3.5743.201-206Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.3.5743.201-206

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

Science.gov (United States)

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.

Role for DNA methylation in the regulation of miR-200c and miR-141 expression in normal and cancer cells

Energy Technology Data Exchange (ETDEWEB)

Vrba, Lukas; Jensen, Taylor J.; Garbe, James C.; Heimark, Ronald L.; Cress, Anne E.; Dickinson, Sally; Stampfer, Martha R.; Futscher, Bernard W.

2009-12-23

BACKGROUND: The microRNA-200 family participates in the maintenance of an epithelial phenotype and loss of its expression can result in epithelial to mesenchymal transition (EMT). Furthermore, the loss of expression of miR-200 family members is linked to an aggressive cancer phenotype. Regulation of the miR-200 family expression in normal and cancer cells is not fully understood. METHODOLOGY/ PRINCIPAL FINDINGS: Epigenetic mechanisms participate in the control of miR-200c and miR-141 expression in both normal and cancer cells. A CpG island near the predicted mir-200c/mir-141 transcription start site shows a striking correlation between miR-200c and miR-141 expression and DNA methylation in both normal and cancer cells, as determined by MassARRAY technology. The CpG island is unmethylated in human miR-200/miR-141 expressing epithelial cells and in miR-200c/miR-141 positive tumor cells. The CpG island is heavily methylated in human miR-200c/miR-141 negative fibroblasts and miR-200c/miR-141 negative tumor cells. Mouse cells show a similar inverse correlation between DNA methylation and miR-200c expression. Enrichment of permissive histone modifications, H3 acetylation and H3K4 trimethylation, is seen in normal miR-200c/miR-141-positive epithelial cells, as determined by chromatin immunoprecipitation coupled to real-time PCR. In contrast, repressive H3K9 dimethylation marks are present in normal miR-200c/miR-141-negative fibroblasts and miR-200c/miR-141 negative cancer cells and the permissive histone modifications are absent. The epigenetic modifier drug, 5-aza-2'-deoxycytidine, reactivates miR-200c/miR-141 expression showing that epigenetic mechanisms play a functional role in their transcriptional control. CONCLUSIONS/ SIGNIFICANCE: We report that DNA methylation plays a role in the normal cell type-specific expression of miR-200c and miR-141 and this role appears evolutionarily conserved, since similar results were obtained in mouse. Aberrant DNA methylation

Solvent-free synthesis of C10 and C11 branched alkanes from furfural and methyl isobutyl ketone.

Science.gov (United States)

Yang, Jinfan; Li, Ning; Li, Guangyi; Wang, Wentao; Wang, Aiqin; Wang, Xiaodong; Cong, Yu; Zhang, Tao

2013-07-01

Our best results jet: C10 and C11 branched alkanes, with low freezing points, are synthesized through the aldol condensation of furfural and methyl isobutyl ketone from lignocellulose, which is then followed by hydrodeoxygenation. These jet-fuel-range alkanes are obtained in high overall yields (≈90%) under solvent-free conditions. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Stereoselective synthesis of the Halaven C14-C26 fragment from D-quinic acid: crystallization-induced diastereoselective transformation of an α-methyl nitrile.

Science.gov (United States)

Belanger, Francis; Chase, Charles E; Endo, Atsushi; Fang, Francis G; Li, Jing; Mathieu, Steven R; Wilcoxen, Annie Z; Zhang, Huiming

2015-04-20

Crystallization-induced diastereoselective transformation (CIDT) of an α-methyl nitrile completes an entirely non-chromatographic synthesis of the halichondrin B C14-C26 stereochemical array. The requisite α-methyl nitrile substrate is derived from D-quinic acid through a series of substrate-controlled stereoselective reactions via a number of crystalline intermediates that benefit from a rigid polycyclic template. Therefore, all four stereogenic centers in the Halaven C14-C26 fragment were derived from the single chiral source D-quinic acid. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cytosine methylation at CpCpG sites triggers accumulation of non-CpG methylation in gene bodies

OpenAIRE

Zabet, NR; Catoni, Marco; Prischi, F; Paszkowski, Jerzy Waclaw

2017-01-01

Methylation of cytosine is an epigenetic mark involved in the regulation of transcription, usually associated with transcriptional repression. In mammals, methylated cytosines are found predominantly in CpGs but in plants non-CpG methylation (in the CpHpG or CpHpH contexts, where H is A, C or T) is also present and is associated with the transcriptional silencing of transposable elements. In addition, CpG methylation is found in coding regions of active genes. In the absence of the demethylas...

6-Bromo-2-(4-chlorophenyl-3-methyl-3H-imidazo[4,5-b]pyridine

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Selma Bourichi

2016-05-01

Full Text Available In the title compound, C13H9BrClN3, the imidazopyridine fused-ring system is almost planar, with r.m.s. deviation of 0.006 (19 Å, and makes a dihedral angle of 29.32 (8° with the mean plane of the 4-chlorophenyl group. In the crystal, C—H...N hydrogen bonds link the molecules into chains propagating in the [100] direction. Weak intermolecular π–π interactions between the five- and six-membered rings of the 3H-imidazo[4,5-b]pyridine moieties of neighbouring molecules [centroid–centroid distance = 3.8648 (12 Å] further consolidate the packing into layers parallel to the ab plane.

Direct methylation procedure for converting fatty amides to fatty acid methyl esters in feed and digesta samples.

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Jenkins, T C; Thies, E J; Mosley, E E

2001-05-01

Two direct methylation procedures often used for the analysis of total fatty acids in biological samples were evaluated for their application to samples containing fatty amides. Methylation of 5 mg of oleamide (cis-9-octadecenamide) in a one-step (methanolic HCl for 2 h at 70 degrees C) or a two-step (sodium methoxide for 10 min at 50 degrees C followed by methanolic HCl for 10 min at 80 degrees C) procedure gave 59 and 16% conversions of oleamide to oleic acid, respectively. Oleic acid recovery from oleamide was increased to 100% when the incubation in methanolic HCl was lengthened to 16 h and increased to 103% when the incubation in methoxide was modified to 24 h at 100 degrees C. However, conversion of oleamide to oleic acid in an animal feed sample was incomplete for the modified (24 h) two-step procedure but complete for the modified (16 h) one-step procedure. Unsaturated fatty amides in feed and digesta samples can be converted to fatty acid methyl esters by incubation in methanolic HCl if the time of exposure to the acid catalyst is extended from 2 to 16 h.

(E-3-Methyl-6-(3-oxo-3-(3,4,5-trimethoxyphenylprop-1-en-1-yl-2(3H-benzothiazolone

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Yordanka Ivanova

2016-09-01

Full Text Available The title compound, (E-3-methyl-6-(3-oxo-3-(3,4,5-trimethoxyphenylprop-1-en-1-yl-2(3H-benzothiazolone, was synthesized by both an acid- and base-catalyzed aldol condensation of 3-methyl-6-acetyl-2(3H-benzothiazolone and 3,4,5-trimethoxyacetophenone. The structure of the target compound was confirmed using 1H-NMR, 13C-NMR, IR, MS, and elemental analysis.

Iridium complexes containing mesoionic C donors: selective C(sp3)-H versus C(sp2)-H bond activation, reactivity towards acids and bases, and catalytic oxidation of silanes and water.

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Petronilho, Ana; Woods, James A; Mueller-Bunz, Helge; Bernhard, Stefan; Albrecht, Martin

2014-11-24

Metalation of a C2-methylated pyridylimidazolium salt with [IrCp*Cl2]2 affords either an ylidic complex, resulting from C(sp(3))-H bond activation of the C2-bound CH3 group if the metalation is performed in the presence of a base, such as AgO2 or Na2CO3, or a mesoionic complex via cyclometalation and thermally induced heterocyclic C(sp(2))-H bond activation, if the reaction is performed in the absence of a base. Similar cyclometalation and complex formation via C(sp(2))-H bond activation is observed when the heterocyclic ligand precursor consists of the analogous pyridyltriazolium salt, that is, when the metal bonding at the C2 position is blocked by a nitrogen rather than a methyl substituent. Despite the strongly mesoionic character of both the imidazolylidene and the triazolylidene, the former reacts rapidly with D(+) and undergoes isotope exchange at the heterocyclic C5 position, whereas the triazolylidene ligand is stable and only undergoes H/D exchange under basic conditions, where the imidazolylidene is essentially unreactive. The high stability of the Ir-C bond in aqueous solution over a broad pH range was exploited in catalytic water oxidation and silane oxidation. The catalytic hydrosilylation of ketones proceeds with turnover frequencies as high as 6,000 h(-1) with both the imidazolylidene and the triazolylidene system, whereas water oxidation is enhanced by the stronger donor properties of the imidazol-4-ylidene ligands and is more than three times faster than with the triazolylidene analogue. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crystal and molecular structure studies of (Z)-N-methyl-C-4-substituted phenyl nitrones by XRD, DFT, FTIR and NMR methods

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Lasri, Jamal; Eltayeb, Naser Eltaher; Haukka, Matti; Alghamdi, Yousef

2017-01-01

(Z)-N-methyl-C-4-substituted phenyl nitrones -O+N(Me)=C(H)R (Z-2a R = 4-ClC6H4, Z-2b R = 4-NO2C6H4, Z-2c R = 4-CH3OC6H4) were synthesized and characterized by elemental analyses, FTIR, 1H, 13C and DEPT-135 NMR spectroscopy and also by single crystal X-ray diffraction (in the case of Z-2a and Z-2b). The geometries of the nitrone molecules Z-2a, Z-2b and Z-2c and their E-isomers; (E)-N-methyl-C-4-chlorophenyl nitrone E-2a, (E)-N-methyl-C-4-nitrophenyl nitrone E-2b and (E)-N-methyl-C-4-methoxyphenyl nitrone E-2c were optimized using density functional theory (DFT) at the B3LYP/6-311++G(d,p) level of theory. The theoretical vibrational frequencies obtained by DFT calculations are in good agreement with the experimental values. The electronics structures were described in terms of the distribution of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). Gauge independent atomic orbital (GIAO) method was used to calculate the NMR spectra, the correlation between the calculated and experimental chemical shifts is mostly in the range of 0.94-0.97 for 1H, whereas, the correlation for 13C is 0.99. Thermodynamics study showed that the Z-isomer is favoured than E-isomer with energy barrier of 7.1, 7.2 and 7.1 kcal/mol for Z-2a, Z-2b and Z-2c, respectively. The abundance of the most stable species Z-isomers is equal to 99.99% for all three compounds at 298 K in gas phase.

Crystal structure of N′-diphenylmethylidene-5-methyl-1H-pyrazole-3-carbohydrazide

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Khalid Karrouchi

2015-11-01

Full Text Available In the title compound, C18H16N4O, the planes of the phenyl rings are approximately perpendicular to each other [dihedral angle = 78.07 (8°] and form dihedral angles of 56.43 (8 and 24.59 (8° with the pyrazole ring. In the crystal, molecules are linked by N—H...O hydrogen bonds to form one-dimensional chains parallel to the [010] direction.

H19DMR methylation analysis in patients with Beckwith-Wiedemann syndrome and isolated hemihyperplasia

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Marcus Vinícius de Matos Gomes

2005-01-01

Full Text Available Beckwith-Wiedemann syndrome (BWS is a congenital overgrowth disorder of complex and heterogeneous etiology involving alterations in genomic imprinting. The cause of isolated hemihyperplasia (IHH is unknown but might be due to partial or incomplete expression of BWS because both these conditions share predisposition for the same types of neoplasias. We investigated the methylation pattern of the putative imprinting control region H19DMR using peripheral blood from 12 patients, six with clinical features of BWS and six with IHH. All the patients had normal karyotypes and paternal uniparental disomy (UPD was excluded in 10 informative cases. The normal H19DMR methylation pattern was found in eight informative patients, indicating that H19DMR methylation was not related to their condition. We suggest that the absence of neoplasias in the BWS and IHH patients studied might be related to the absence of UPD and to the presence of normal H19DMR methylation.

Tissue-specific and cation/anion-specific DNA methylation variations occurred in C. virgata in response to salinity stress.

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Xiang Gao

Full Text Available Salinity is a widespread environmental problem limiting productivity and growth of plants. Halophytes which can adapt and resist certain salt stress have various mechanisms to defend the higher salinity and alkalinity, and epigenetic mechanisms especially DNA methylation may play important roles in plant adaptability and plasticity. In this study, we aimed to investigate the different influences of various single salts (NaCl, Na2SO4, NaHCO3, Na2CO3 and their mixed salts on halophyte Chloris. virgata from the DNA methylation prospective, and discover the underlying relationships between specific DNA methylation variations and specific cations/anions through the methylation-sensitive amplification polymorphism analysis. The results showed that the effects on DNA methylation variations of single salts were ranked as follows: Na2CO3> NaHCO3> Na2SO4> NaCl, and their mixed salts exerted tissue-specific effects on C. virgata seedlings. Eight types of DNA methylation variations were detected and defined in C. virgata according to the specific cations/anions existed in stressful solutions; in addition, mix-specific and higher pH-specific bands were the main type in leaves and roots independently. These findings suggested that mixed salts were not the simple combination of single salts. Furthermore, not only single salts but also mixed salts showed tissue-specific and cations/anions-specific DNA methylation variations.

Tissue-specific and cation/anion-specific DNA methylation variations occurred in C. virgata in response to salinity stress.

Science.gov (United States)

Gao, Xiang; Cao, Donghui; Liu, Jie; Wang, Xiaoping; Geng, Shujuan; Liu, Bao; Shi, Decheng

2013-01-01

Salinity is a widespread environmental problem limiting productivity and growth of plants. Halophytes which can adapt and resist certain salt stress have various mechanisms to defend the higher salinity and alkalinity, and epigenetic mechanisms especially DNA methylation may play important roles in plant adaptability and plasticity. In this study, we aimed to investigate the different influences of various single salts (NaCl, Na2SO4, NaHCO3, Na2CO3) and their mixed salts on halophyte Chloris. virgata from the DNA methylation prospective, and discover the underlying relationships between specific DNA methylation variations and specific cations/anions through the methylation-sensitive amplification polymorphism analysis. The results showed that the effects on DNA methylation variations of single salts were ranked as follows: Na2CO3> NaHCO3> Na2SO4> NaCl, and their mixed salts exerted tissue-specific effects on C. virgata seedlings. Eight types of DNA methylation variations were detected and defined in C. virgata according to the specific cations/anions existed in stressful solutions; in addition, mix-specific and higher pH-specific bands were the main type in leaves and roots independently. These findings suggested that mixed salts were not the simple combination of single salts. Furthermore, not only single salts but also mixed salts showed tissue-specific and cations/anions-specific DNA methylation variations.

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

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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.

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

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Huang Rae-Chi

2012-11-01

Full Text Available Abstract 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

Synthesis of (R,S)-[2,3-{sup 13}C{sub 2}]-1-(1`-methyl-2`-pyrrolidinyl)propan-2-one; {l_brace}(R,S)-[2`,3`-{sup 13}C{sub 2}]hygrinePound right bracePound

Energy Technology Data Exchange (ETDEWEB)

Abraham, T.W.; Leete, Edward [Minnesota Univ., Minneapolis, MN (United States). Dept. of Chemistry

1996-05-01

2-Ethoxy-1-methyl-5-pyrrolidinone (1) was reacted with ethyl [3,4-{sup 13}C{sub 2}]-acetoacetate (2) in the presence of TiCl{sub 4} to give ethyl [3,4-{sup 13}C{sub 2}]-2-(1`-methyl-5`-oxo-2`-pyrrolidinyl)-3-oxobutanoate (3) in 85% yield. Decarboethoxylation of ethyl [3,4-{sup 13}C{sub 2}]-2-(1`-methyl-5`-oxo-2`-pyrrolidinyl)-3-oxobutan-oate (3) was accomplished using NaCl and H{sub 2}O in DMSO to give (R,S)-[2,3-{sup 13}C{sub 2}]-1-(1`-methyl-5`-oxo-2`-pyrrolidinyl)propan-2-o ne (4) in 91% yield. Protection of the ketone as a ketal (ethylene glycol, H{sup +}), followed by reduction of the amide to the amine using LiAlH{sub 4} and subsequent deprotection of the ketal gave (R,S)-[2,3-{sup 13}C{sub 2}]-1-(1`-methyl-2`-pyrrolidinyl)propan-2-one ((R,s)-[2`, 3`-{sup 13}C{sub 2}]Hygrine) (8) in 78% yield. (61% overall yield from ethyl [3,4-{sup 13}C{sub 2}]acetoacetate). (Author).

Crystal structure of 2-methylamino-4-(6-methyl-4-oxo-4H-chromen-3-yl-3-nitropyrano[3,2-c]chromen-5(4H-one with an unknown solvate

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Rajamani Raja

2015-09-01

Full Text Available In the title compound, C23H16N2O7, the mean planes of the two chromene units (r.m.s. deviations = 0.031 and 0.064 Å are almost normal to one another with a dihedral angle of 85.59 (6°. The central six-membered pyran ring has a distorted envelope conformation, with the methine C atom at the flap. There is an intramolecular N—H...O hydrogen bond, which generates an S(6 ring motif. In the crystal, molecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers with an R22(12 ring motif. The dimers are linked by pairs of C—H...O hydrogen bonds, enclosing R22(6 ring motifs, forming zigzag chains along [001]. The chains are linked by a second pair of C—H...O hydrogen bonds, forming slabs parallel to (110. Within the slabs there are C—H...π interactions present. A region of disordered electron density was treated with the SQUEEZE procedure in PLATON [Spek (2015. Acta Cryst. C71, 9–18] following unsuccessful attempts to model it as plausible solvent molecule(s. The given chemical formula and other crystal data do not take into account the unknown solvent molecule(s.

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.

Science.gov (United States)

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.

Crystal structures and luminescence properties of two Cd(II) complexes based on 2-(1H-imidazol-1methyl)-6-methyl-1H-benzimidazole

International Nuclear Information System (INIS)

Zhang, Yuhong; Meng, Xiangru; Wen, Yu; Li, Peng; Ma, Lin; Zhang, Qiuju

2015-01-01

Two new complexes, {[Cd(immb)I 2 ].DMF} n (1) and {[Cd 3 (immb)(btc) 2 ]. H 2 O} n (2) (immb = 2-(1H-imidazol- 1-methyl)-6-methyl-1H-benzimidazole, btc = 1,2,3-benzenetricarboxylate, DMF = dimethyl formamide), have been synthesized and characterized. Single crystal X-ray diffraction shows that 1 exhibits a chain structure constructed by immb ligands bridging Cd(II) ions. In 2, Cd(II) ions are linked by immb ligands with bridging mode and btc3- anions with the μ 2 -η 2 :η 1 bonding pattern leading to a 2D structure. Luminescent properties have been investigated in the solid state at room temperature.

Rietveld refinement of the structures of 1.0 C-S-H and 1.5 C-S-H

KAUST Repository

Battocchio, Francesco

2012-11-01

Low-Q region Rietveld analyses were performed on C-S-H synchrotron XRD patterns, using the software MAUD. Two different crystal structures of tobermorite 11 Å were used as a starting model: monoclinic ordered Merlino tobermorite, and orthorhombic disordered Hamid tobermorite. Structural modifications were required to adapt the structures to the chemical composition and the different interlayer spacing of the C-S-H samples. Refinement of atomic positions was done by using special constraints called fragments that maintain interatomic distances and orientations within atomic polyhedra. Anisotropic crystallite size refinement showed that C-S-H has a nanocrystalline disordered structure with a preferred direction of elongation of the nanocrystallites in the plane of the Ca interlayer. The quality of the fit showed that the monoclinic structure gives a more adequate representation of C-S-H, whereas the disordered orthorhombic structure can be considered a more realistic model if the lack of long-range order of the silica chain along the c-direction is assumed. © 2012 Elsevier Ltd. All rights reserved.

Vitamin C induces specific demethylation of H3K9me2 in mouse embryonic stem cells via Kdm3a/b.

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Ebata, Kevin T; Mesh, Kathryn; Liu, Shichong; Bilenky, Misha; Fekete, Alexander; Acker, Michael G; Hirst, Martin; Garcia, Benjamin A; Ramalho-Santos, Miguel

2017-01-01

Histone methylation patterns regulate gene expression and are highly dynamic during development. The erasure of histone methylation is carried out by histone demethylase enzymes. We had previously shown that vitamin C enhances the activity of Tet enzymes in embryonic stem (ES) cells, leading to DNA demethylation and activation of germline genes. We report here that vitamin C induces a remarkably specific demethylation of histone H3 lysine 9 dimethylation (H3K9me2) in naïve ES cells. Vitamin C treatment reduces global levels of H3K9me2, but not other histone methylation marks analyzed, as measured by western blot, immunofluorescence and mass spectrometry. Vitamin C leads to widespread loss of H3K9me2 at large chromosomal domains as well as gene promoters and repeat elements. Vitamin C-induced loss of H3K9me2 occurs rapidly within 24 h and is reversible. Importantly, we found that the histone demethylases Kdm3a and Kdm3b are required for vitamin C-induced demethylation of H3K9me2. Moreover, we show that vitamin C-induced Kdm3a/b-mediated H3K9me2 demethylation and Tet-mediated DNA demethylation are independent processes at specific loci. Lastly, we document Kdm3a/b are partially required for the upregulation of germline genes by vitamin C. These results reveal a specific role for vitamin C in histone demethylation in ES cells and document that DNA methylation and H3K9me2 cooperate to silence germline genes in pluripotent cells.

Methyl 2-Benzamido-2-(1H-benzimidazol-1-ylmethoxyacetate

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Alami Anouar

2012-09-01

Full Text Available The heterocyclic carboxylic α-aminoester methyl 2-benzamido-2-(1H-benzimidazol-1-ylmethoxyacetate is obtained by O-alkylation of methyl α-azido glycinate N-benzoylated with 1H-benzimidazol-1-ylmethanol.

6-Hydroxy-5-[(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl(4-nitrophenylmethyl]-1,3-dimethylpyrimidine-2,4(1H,3H-dione

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N. Sureshbabu

2013-11-01

Full Text Available In the title compound, C21H23N3O7, the pyrimidinedione ring adopts a screw-boat conformation, whereas the cyclohexenone ring adopts an envelope conformation, with the C atom bearing the methyl groups as the flap atom. The dihedral angle between the mean planes of the pyrimidinedione and cyclohexenone rings is 58.78 (2°. The pyrimidinedione and cyclohexenone rings form dihedral angles of 59.94 (3 and 54.73 (2°, respectively, with the 4-nitrophenyl ring. Relatively strong intramolecular O—H...O hydrogen bonds are observed. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a chain along the c-axis direction.

(E)-3-Hydr?oxy-13-methyl-16-[4-(methyl?sulfan?yl)benzyl?idene]-7,8,9,11,12,13,15,16-octa?hydro-6H-cyclo?penta?[a]phen?an????thren-17(14H)-one

OpenAIRE

Gunasekaran, B.; Murugan, R.; Narayanan, S. Sriman; Manivannan, V.

2008-01-01

In the title compound, C26H28O2S, the dihedral angles between the mean plane of the five membered ring and the 4-(methylsulfanyl)benzylidine ring in the two crystallographically independent molecules are 34.05 (10) and 40.53 (15)°. The packing is stabilized by intermolecular O—H...O and C—H...O interactions.

Long-range current flow and percolation in Rabbits-type conductors and the relative importance of out-of-plane and in-plane mis orientations in determining J {sub c}

Energy Technology Data Exchange (ETDEWEB)

Goyal, A. [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831-6116 (United States)]. E-mail: goyala@ornl.gov; Rutter, N. [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831-6116 (United States); University of Cambridge, Pembroke St., Cambridge CB2 3QZ (United Kingdom); Cantoni, C. [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831-6116 (United States); Lee, D.F. [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831-6116 (United States)

2005-10-01

Calculations of long-range current flow using an advanced percolation model show that with the presently observed texture in RABiTS substrates, the dependence of J {sub c} on length as a function of width is greatly reduced. Furthermore, this dependence becomes almost negligible in applied fields. These results suggest that sub-division of a wide conductor into narrow filaments should be possible without loss in J {sub c}. The relative importance of the out-of-plane texture in affecting intergranular J {sub c} was also explored by fabricating RABiTS substrates with different out-of-plane textures but approximately the same in-plane texture. This was accomplished by using TiN as a seed layer for which significant sharpening of the out-of-plane texture is observed. Similar J {sub c} was found for samples with differing out-of-plane texture but almost the same in-plane texture. Finally, separation of the total misorientation in GB networks into in-plane and out-of-plane misorientations using manipulations in Rodrigues space shows that J {sub c} correlates best with in-plane texture.

N-[11C]methyl-3,4-methylenedioxyamphetamine (Ecstasy) and 2-methyl-N-[11C]methyl-4,5-methylenedioxyamphetamine. Synthesis and biodistribution studies

International Nuclear Information System (INIS)

Patt, M.; Machulla, H.J.; Guendisch, D.; Kovar, K.A.; Wuellner, U.; Blocher, A.

1999-01-01

In order to evaluate the neurobiological mechanism causing the psychogenic effects of methylenedioxy-derivatives of amphetamine, the carbon-11 labeled analogues of 3,4-methylenedioxymethamphetamine (MDMA), 2 and 2,N-dimethyl-4,5-methylenedioxyamphetamine (MADAM-6) 4 were prepared for application in in-vivo PET studies by methylation of 3,4-methylenedioxyamphetamine (MDA) 1 and 2-methyl-4,5-methylenedioxyamphetamine 3 with [ 11 C]CH 3 I. The radiochemical yield was determined in dependence on time, temperature and amount of precursor. The best conditions for a fast labeling reaction with carbon-11 on a preparative scale were found to be a reaction time of 10 min using 1 mg of the corresponding dimethyl-precursors 1 or 3, thus obtaining radiochemical yields of 60% (based on produced [ 11 C]CH 3 I). Biodistribution studies were performed in rats, a high brain to blood ratio of 7.5 was observed for [ 11 C]MDMA in contrast to a ratio of 3.7 for [ 11 C]MADAM-6. (author)

Mild synthesis of [N-methyl-11C]-isovaleroyl-(L)-carnitine. The usefulness of a tritium approach

International Nuclear Information System (INIS)

Angelini, G.; Carnevaletti, F.; Margonelli, A.; Corsi, G.; Ragni, P.; Fazio, F.; Todde, S.; Tinti, O.

1999-01-01

The title carnitine derivative was labelled both with [ 11 C]methyl iodide and [ 3 H]methyl iodide. The former was synthesized in order to improve the knowledge of the acyl carnitines fate in humans. The latter was synthesized, at approximately the same concentration level as that of the former, in order to optimize its radiosynthesis, taking advantage from the long half-life of the tritium

Collective flows of protons and $\\pi^-$ mesons in $^{2}$H + C, Ta and He plus C, Ta collisions at 3.4 GeV/nucleon

CERN Document Server

Chkhaidze, L; Djobava, T; Kladnitskaya, E; Kharkhelauri, L; Uzhinsky, V

2011-01-01

Collective flows of protons and negative pions have been studied in (2)H + C, Ta and He + C, Ta collisions at an energy of 3.4 GeV/nucleon. The data have been obtained by the 2-m Propane Bubble Chamber (PBC-500) at JINR. It is found that the directed flow of protons and pi(-) mesons characterized by d /d(y) increases with increase of the mass numbers of colliding nucleus pairs; the elliptic proton flow points out of the reaction plane and also strengthens as the system mass increases; the negative pion directed flow is in the same reaction plane as the proton flow for the lighter (2H + C, He + C) systems and in the opposite direction for the heavier ((2)H + Ta, He + Ta) systems. In (2)H + C, He + C, C + C, C + Ne, (2)H + Ta, He + Ta, C + Cu, and C + Ta collisions, the linear dependence of directed and elliptic flow parameters from mass numbers of projectile and target nuclei, (A(P).A(T))(1/2), is similar for protons while for pi(-) mesons the dependence of directed flow parameters is stronger. The ultrarelati...

(E-4-Hydroxy-6-methyl-3-[1-(2-phenylhydrazinylideneethyl]-2H-pyran-2-one

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Samra Rahmouni

2016-05-01

Full Text Available The title compound, C14H14N2O3, crystallized with three crystallographically independent molecules (A, B and C in the asymmetric unit. The three molecules each have an E conformation about the C=N bond but differ in the orientation of the phenyl and pyran rings. The dihedral angles between the phenyl and pyran ring planes are 14.30 (1, 28.38 (1 and 25.58 (1° in molecules A, B and C, respectively. There is an intramolecular O—H...N hydrogen bond in each molecule with an S(6 ring motif. In the crystal, molecules are linked by N—H...O and C—H...O hydrogen bonds, forming layers parallel to (001, enclosing R22(8 and R33(21 ring motifs. The layers are linked via C—H...π interactions, forming bilayers, which are joined by a further C—H...π interaction, forming a three-dimensional structure.

Hole transport in c-plane InGaN-based green laser diodes

Energy Technology Data Exchange (ETDEWEB)

Cheng, Yang; Liu, Jianping, E-mail: jpliu2010@sinano.ac.cn; Tian, Aiqin; Zhang, Feng; Feng, Meixin; Hu, Weiwei; Zhang, Shuming; Ikeda, Masao; Li, Deyao; Zhang, Liqun; Yang, Hui [Key Lab of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123 (China); School of Nano Technology and Nano Bionics, University of Science and Technology of China, Suzhou 215123 (China)

2016-08-29

Hole transport in c-plane InGaN-based green laser diodes (LDs) has been investigated by both simulations and experiments. It is found that holes can overflow from the green double quantum wells (DQWs) at high current density, which reduces carrier injection efficiency of c-plane InGaN-based green LDs. A heavily silicon-doped layer right below the green DQWs can effectively suppress hole overflow from the green DQWs.

High levels of glucose induce "metabolic memory" in cardiomyocyte via epigenetic histone H3 lysine 9 methylation.

Science.gov (United States)

Yu, Xi-Yong; Geng, Yong-Jian; Liang, Jia-Liang; Zhang, Saidan; Lei, He-Ping; Zhong, Shi-Long; Lin, Qiu-Xiong; Shan, Zhi-Xin; Lin, Shu-Guang; Li, Yangxin

2012-09-01

Diabetic patients continue to develop inflammation and cardiovascular complication even after achieving glycemic control, suggesting a "metabolic memory". Metabolic memory is a major challenge in the treatment of diabetic complication, and the mechanisms underlying metabolic memory are not clear. Recent studies suggest a link between chromatin histone methylation and metabolic memory. In this study, we tested whether histone 3 lysine-9 tri-methylation (H3K9me3), a key epigenetic chromatin marker, was involved in high glucose (HG)-induced inflammation and metabolic memory. Incubating cardiomyocyte cells in HG resulted in increased levels of inflammatory cytokine IL-6 mRNA when compared with myocytes incubated in normal culture media, whereas mannitol (osmotic control) has no effect. Chromatin immunoprecipitation (ChIP) assays showed that H3K9me3 levels were significantly decreased at the promoters of IL-6. Immunoblotting demonstrated that protein levels of the H3K9me3 methyltransferase, Suv39h1, were also reduced after HG treatment. HG-induced apoptosis, mitochondrial dysfunction and cytochrome-c release were reversible. However, the effects of HG on the expression of IL-6 and the levels of H3K9me3 were irreversible after the removal of HG from the culture. These results suggest that HG-induced sustained inflammatory phenotype and epigenetic histone modification, rather than HG-induced mitochondrial dysfunction and apoptosis, are main mechanisms responsible for metabolic memory. In conclusion, our data demonstrate that HG increases expression of inflammatory cytokine and decreases the levels of histone-3 methylation at the cytokine promoter, and suggest that modulating histone 3 methylation and inflammatory cytokine expression may be a useful strategy to prevent metabolic memory and cardiomyopathy in diabetic patients.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Thermal Decomposition of Potential Ester Biofuels. Part I: Methyl Acetate and Methyl Butanoate

Energy Technology Data Exchange (ETDEWEB)

Porterfield, Jessica P.; Bross, David H.; Ruscic, Branko; Thorpe, James H.; Nguyen, Thanh Lam; Baraban, Joshua H.; Stanton, John F.; Daily, John W.; Ellison, G. Barney

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 (CH₃COOCH₃) and methyl butanoate (CH₃CH₂CH₂COOCH₃) 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 of 300 – 1600 K were explored. Decomposition of CH₃COOCH₃ commences at 1000 K and the initial products are (CH₂=C=O and CH₃OH). As the micro-reactor is heated to 1300 K, a mixture of (CH₂=C=O and CH₃OH, CH₃, CH₂=O, H, CO, CO₂) appears. The thermal cracking of CH₃CH₂CH₂COOCH₃ begins at 800 K with the formation of (CH₃CH₂CH=C=O, CH₃OH). By 1300 K, the pyrolysis of methyl butanoate yields a complex mixture of (CH₃CH₂CH=C=O, CH₃OH, CH₃, CH₂=O, CO, CO₂, CH₃CH=CH₂, CH₂CHCH₂, CH₂=C=CH₂, HCCCH₂, CH₂=C=C=O, CH₂=CH₂, HCΞCH, CH₂=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 CH₂-COOCH₃. The lowest energy fragmentation will be a 4-center elimination of methanol to form the ketene, RCH=C=O. At higher temperatures, concerted

1,1′,2,2′,3,3′,4,4′-Octa­methyl­ferro­cenium 2,5-dibromo-4-hy­droxy-3,6-dioxocyclo­hexa-1,4-dien-1-olate

Science.gov (United States)

Mochida, Tomoyuki

2011-01-01

In the title salt, octa­methyl­ferrocenium bromanilate, [Fe(C9H13)2](C6HBr2O4), the Fe atom and the bromanilate anion lie on a mirror plane. The octa­methyl­ferrocenium cation adopts an eclipsed conformation. An intra­molecular O—H⋯O hydrogen bond is present in the bromanilate anion. In the crystal, the cations and anions are stacked alternately, forming a one-dimensional columnar structure along [010]. PMID:22090810

Instability of in-plane vortices in two-dimensional easy-plane ferromagnets

International Nuclear Information System (INIS)

Wysin, G.M.

1994-01-01

An analysis of the core region of an in-plane vortex in the two-dimensional Heisenberg model with easy-plane anisotropy λ=J z /J xy leads to a clear understanding of the instability towards transformation into an out-of-plane vortex as a function of anisotropy. The anisotropy parameter λ c at which the in-plane vortex becomes unstable and develops into an out-of-plane vortex is determined with an accuracy comparable to computer simulations for square, hexagonal, and triangular lattices. For λ c , the in-plane vortex is stable but exhibits a normal mode whose frequency goes to zero as ω∝(λ c -λ) 1/2 as λ approaches λ c . For λ>λ c , the static nonzero out-of-plane spin components grow as (λ-λ c ) 1/2 . The lattice dependence of λ c is determined strongly by the number of spins in the core plaquette, is fundamentally a discreteness effect, and cannot be obtained in a continuum theory

{sup 13}C-METHYL FORMATE: OBSERVATIONS OF A SAMPLE OF HIGH-MASS STAR-FORMING REGIONS INCLUDING ORION-KL AND SPECTROSCOPIC CHARACTERIZATION

Energy Technology Data Exchange (ETDEWEB)

Favre, Cécile; Bergin, Edwin A.; Crockett, Nathan R.; Neill, Justin L. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Carvajal, Miguel [Dpto. Física Aplicada, Unidad Asociada CSIC, Facultad de Ciencias Experimentales, Universidad de Huelva, E-21071 Huelva (Spain); Field, David [Department of Physics and Astronomy, University of Aarhus, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Jørgensen, Jes K.; Bisschop, Suzanne E. [Centre for Star and Planet Formation, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Brouillet, Nathalie; Despois, Didier; Baudry, Alain [Univ. Bordeaux, LAB, UMR 5804, F-33270, Floirac (France); Kleiner, Isabelle [Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), CNRS, UMR 7583, Université de Paris-Est et Paris Diderot, 61, Av. du Général de Gaulle, F-94010 Créteil Cedex (France); Margulès, Laurent; Huet, Thérèse R.; Demaison, Jean, E-mail: cfavre@umich.edu, E-mail: miguel.carvajal@dfa.uhu.es [Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université Lille I, F-59655 Villeneuve d' Ascq Cedex (France)

2015-01-01

We have surveyed a sample of massive star-forming regions located over a range of distances from the Galactic center for methyl formate, HCOOCH{sub 3}, and its isotopologues H{sup 13}COOCH{sub 3} and HCOO{sup 13}CH{sub 3}. The observations were carried out with the APEX telescope in the frequency range 283.4-287.4 GHz. Based on the APEX observations, we report tentative detections of the {sup 13}C-methyl formate isotopologue HCOO{sup 13}CH{sub 3} toward the following four massive star-forming regions: Sgr B2(N-LMH), NGC 6334 IRS 1, W51 e2, and G19.61-0.23. In addition, we have used the 1 mm ALMA science verification observations of Orion-KL and confirm the detection of the {sup 13}C-methyl formate species in Orion-KL and image its spatial distribution. Our analysis shows that the {sup 12}C/{sup 13}C isotope ratio in methyl formate toward the Orion-KL Compact Ridge and Hot Core-SW components (68.4 ± 10.1 and 71.4 ± 7.8, respectively) are, for both the {sup 13}C-methyl formate isotopologues, commensurate with the average {sup 12}C/{sup 13}C ratio of CO derived toward Orion-KL. Likewise, regarding the other sources, our results are consistent with the {sup 12}C/{sup 13}C in CO. We also report the spectroscopic characterization, which includes a complete partition function, of the complex H{sup 13}COOCH{sub 3} and HCOO{sup 13}CH{sub 3} species. New spectroscopic data for both isotopomers H{sup 13}COOCH{sub 3} and HCOO{sup 13}CH{sub 3}, presented in this study, have made it possible to measure this fundamentally important isotope ratio in a large organic molecule for the first time.

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

Science.gov (United States)

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

Synthesis of all eight L-glycopyranosyl donors using C-H activation

DEFF Research Database (Denmark)

Frihed, Tobias; Pedersen, Christian Marcus; Bols, Mikael

2014-01-01

by an intramolecular C-H activation of the methyl group in g-position; both steps were catalyzed by iridium. The following Fleming-Tamao oxidation and acetylation gave the suitably protected L-hexoses. This is the first general method for the preparation of all eight L-hexoses as their thioglycosyl donors ready...... for glycosylation and the first example of an iridium-catalyzed C(sp3)-H activation on sulfide-containing compounds....

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

International Nuclear Information System (INIS)

Yang, Hanna; Kwon, Chang Seob; Choi, Yoonjung; Lee, Daeyoup

2016-01-01

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 RNA 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.

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

Energy Technology Data Exchange (ETDEWEB)

Yang, Hanna [Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Kwon, Chang Seob [Department of Chemistry and Biology, Korea Science Academy of KAIST, Busan, 614-822 (Korea, Republic of); Choi, Yoonjung, E-mail: jjungii@kaist.ac.kr [Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Lee, Daeyoup, E-mail: daeyoup@kaist.ac.kr [Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of)

2016-08-05

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 RNA 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.

Heterocyclic Analogues of Xanthone and Xanthione. 1H-Pyrano[2,3-c:6,5-c]dipyrazol-4(7H-ones and Thiones: Synthesis and NMR Data

Directory of Open Access Journals (Sweden)

Wolfgang Holzer

2010-09-01

Full Text Available The synthesis of the title compounds is described. Reaction of 1-substituted 2-pyrazolin-5-ones with 5-chloro-1-phenyl-1H-pyrazole-4-carbonyl chloride or 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbonyl chloride, respectively, using calcium hydroxide in refluxing 1,4-dioxane gave the corresponding 4-heteroaroylpyrazol-5-ols, which were cyclized into 1H-pyrano[2,3-c:6,5-c]dipyrazol-4(7H-ones by treatment with K2CO3/DMF. The latter were converted into the corresponding thiones upon reaction with Lawesson’s reagent. Detailed NMR spectroscopic investigations (1H, 13C, 15N of the ring systems and their precursors are presented.

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

Science.gov (United States)

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.

Mild synthesis of [N-methyl-{sup 11}C]-isovaleroyl-(L)-carnitine. The usefulness of a tritium approach

Energy Technology Data Exchange (ETDEWEB)

Angelini, G.; Carnevaletti, F.; Margonelli, A.; Corsi, G. [Istituto di Chimica Nucleare - C.N.R., C.P. 10, Rome (Italy); Ragni, P. [Istituto di Chimica Nucleare -- C.N.R., C.P. 10 -- 00016 Monterotondo Stazione, Roma, (Italy); Fazio, F.; Todde, S. [Istituto di Neuroscienze e Bioimmagini - C.N.R., H.S. Raffaele, Milan (Italy); Tinti, O. [Sigma-Tau, Industrie Farmaceutiche Riunite S.p.A., Pomezia, Rome (Italy)

1999-02-01

The title carnitine derivative was labelled both with [{sup 11}C]methyl iodide and [{sup 3}H]methyl iodide. The former was synthesized in order to improve the knowledge of the acyl carnitines fate in humans. The latter was synthesized, at approximately the same concentration level as that of the former, in order to optimize its radiosynthesis, taking advantage from the long half-life of the tritium.

21 CFR 172.872 - Methyl ethyl cellulose.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl ethyl cellulose. 172.872 Section 172.872... CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the number...

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

Science.gov (United States)

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.

Studies of pirimiphos-methyl residues in stored rice, using 14C-pirimiphos-methyl

International Nuclear Information System (INIS)

Varca, L.M.; Sanchez, T.E.; Gambalan, N.; Magallona, E.D.

1990-01-01

The distribution and persistence of pirimiphos-methyl on rice (hulled and unhulled) stored over a period of 6 months at 30 deg. C and about 11% moisture were studied using 14 C labelled insecticide. The procedures used for preparing the labelled formulation, applying the insecticide and for the handling and analysis of the grain samples were similar to those described for fenvalerate, see Varca, Sanchez and Magallona, ''Isotopic tracer aided studies of fenvalerate residues in stored products'', these Proceedings. After applying the pirimiphos-methyl, a concentration equal to 0.87 ppm was found on the hulled rice immediately after application; this concentration declined to 0.60 ppm after 6 months of storage. Over 28% of the residue was present in the seed in the methanol extractable form, and 38% was found on the surface at the end of the storage period. For the unhulled rice, most of the residue was retained in the hull with no decrease in the overall level during the storage period. (author)

C-11 production with MC-50 cyclotron and synthesis of L-[11C-methyl] methionine

International Nuclear Information System (INIS)

Kim, Sang Wook; Hur, Min Goo; Yang, Seung Dae; Ahn, Soon Hyuk; Chun, Kweon Soo

2003-01-01

L-[ 11 C-methyl] methionine was prepared via no-carrier-added(nca) fast S-alkylation of L-homocysteine with [ 11 C]CH 3 I using solid support (Al 2 O 3 /KF)at room temperature in ethanol. The radiochemical yield of methylation was 90.2%. After reaction, no radiochemical impurity was detected but traces of L-homocysteine precursor were monitored by UV detector. The purification was archived by passing successively through a C 18 and alumina sep-pak. the radiochemical purity of L-[ 11 C-methyl] methionine was over 98% after purification and total elapsed time to prepare was 10min from [ 11 C]CH 3 I delivery

Deoxygenation of methyl laurate over Ni based catalysts: Influence of supports

Science.gov (United States)

Xia, Xiaoqiang; Chen, Hui; Bi, Yadong; Hu, Jianli

2017-10-01

The use of a series of nickel based catalysts supported over HZSM-5, Al2O3, C and ZrO2 in the deoxygenation of methyl laurate shows that the deoxygenation activity and deoxygenation pathway of nickel based catalysts can be affected by properties of catalysts. In the absence of H2, β-elimination of methyl laurate is the dominant reaction and a small amount of laurate acid is converted into undecane by direct decarboxylation. At the same time, the highly acidic support HZSM-5 gave higher conversion and C11 alkane selectivity. In the presence of H2, Ni/HZSM-5 catalyst showed a significantly high deoxygenation activity, producing 71% alkanes by methyl laurate conversion at 280 °C and 4MPa H2. While as on mildly acidic (Al2O3) and neutral (C) supports, a restricted hydrodeoxygenation activity was achieved but more oxygenate products were yielded. According to the analysis of intermediate product, the deoxygenation reaction of methyl laurate follows three distinct pathways: in the absence of H2, decarboxylation: C11H23COOCH3→C11H23COOH→C11H24; in the presence of H2, decarbonylation: C11H23COOCH3→C11H23COOH→C11H23CHO→C11H24; and hydrodeoxygenation: C11H23COOCH3 →C11H23COOH→C11H23CHO→C12H25OH→C12H26

Aqua[bis(2-ethyl-5-methyl-1H-imidazol-4-yl-κN3methane]oxalatocopper(II dihydrate

Directory of Open Access Journals (Sweden)

Yang-Hui Luo

2011-02-01

Full Text Available In the title compound, [Cu(C2O4(C13H20N4(H2O]·2H2O, the CuII atom exhibits a distorted square-pyramidal geometry with the two N atoms of the imidazole ligand and the two O atoms of the oxalate ligand forming the basal plane, while the O atom of the coordinated water molecule is in an apical position. The CuII atom is shifted 0.232 (2 Å out of the basal plane toward the water molecule. The asymmetric unit is completed by two solvent water molecules. These water molecules participate in the formation of an intricate three-dimensionnal network of hydrogen bonds involving the coordinated water molecule and the NH groups.

DOT1L and H3K79 Methylation in Transcription and Genomic Stability.

Science.gov (United States)

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.

DOT1L and H3K79 Methylation in Transcription and Genomic Stability

Directory of Open Access Journals (Sweden)

Katherine Wood

2018-02-01

Full Text Available 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.

1-[3-(2-Methyl-4-phenylquinolin-3-yl-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl]-propane-1-one

Directory of Open Access Journals (Sweden)

Allaoua Kedjadja

2015-06-01

Full Text Available A novel compound, 1-[3-(2-methyl-4-phenylquinolin-3-yl-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl]-propane-1-one (3 has been synthesized by cyclocondensation of (E-1-(2-methyl-4-phenylquinolin-3-yl-3-phenylprop-2-en-1-one (2 and hydrazine hydrate in propionic acid. The structure of this compound was established by elemental analysis, IR, 1H-NMR, 13C-NMR and MS data.

The Aorta-Gonad-Mesonephros Organ Culture Recapitulates 5hmC Reorganization and Replication-Dependent and Independent Loss of DNA Methylation in the Germline.

Science.gov (United States)

Calvopina, Joseph Hargan; Cook, Helene; Vincent, John J; Nee, Kevin; Clark, Amander T

2015-07-01

Removal of cytosine methylation from the genome is critical for reprogramming and transdifferentiation and plays a central role in our understanding of the fundamental principles of embryo lineage development. One of the major models for studying cytosine demethylation is the mammalian germ line during the primordial germ cell (PGC) stage of embryo development. It is now understood that oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) is required to remove cytosine methylation in a locus-specific manner in PGCs; however, the mechanisms downstream of 5hmC are controversial and hypothesized to involve either active demethylation or replication-coupled loss. In the current study, we used the aorta-gonad-mesonephros (AGM) organ culture model to show that this model recapitulates germ line reprogramming, including 5hmC reorganization and loss of cytosine methylation from Snrpn and H19 imprinting control centers (ICCs). To directly address the hypothesis that cell proliferation is required for cytosine demethylation, we blocked PI3-kinase-dependent PGC proliferation and show that this leads to a G1 and G2/M cell cycle arrest in PGCs, together with retained levels of cytosine methylation at the Snrpn ICC, but not at the H19 ICC. Taken together, the AGM organ culture model is an important tool to evaluate mechanisms of locus-specific demethylation and the role of PI3-kinase-dependent PGC proliferation in the locus-specific removal of cytosine methylation from the genome.

Evaluation of radiation dose resulting from the ingestion of [3H]-and [14C]thymidine in the rat

International Nuclear Information System (INIS)

Takeda, H.; Iwakura, T.

1987-01-01

Average doses to rat tissues from the ingestion of 2-[ 14 C]thymidine were compared with those from methyl-[ 3 H]thymidine or 6-[ 3 H]thymidine. [ 14 C]thymidine gave the highest dose to spleen and small intestine. Doses to other tissues from [ 14 ]thymidine were almost the same or lower compared with those from [ 3 H]thymidine, irrespective of the 9 times higher β-ray energy of 14 C than that of 3 H. In the case of [ 14 C]thymidine, most of the dose was given by radioactivity incorporated into the organic tissue constituents (non-volatile radioactivity). In the case of [ 3 H]thymidine, the dose contributions by non-volatile radioactivity were very small and major contributions were rather from volatile radioactivity ( 3 HHO), formed by degradation of [ 3 H]thymidine. No significant difference in their total doses was found between the two [ 3 H]precursors, but the dose from non-volatile radioactivity alone was 2-3 times higher with methyl-[ 3 H]thymidine than with 6-[ 3 H]thymidine. Estimates of dose to cell nuclei in various tissues after ingestion of [ 3 H]thymidine were also made in order to predict more precisely possible radiation hazards. (author)

Crystal structure of 1-methyl-4-methylsulfanyl-1H-pyrazolo[3,4-d]pyrimidine

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Mohammed El Fal

2014-12-01

Full Text Available In the title compound, C7H8N4S, the non-H atoms of the pyrazolo[3,4-d]pyrimidine ring system and the methylsulfanyl group lie on a crystallographic mirror plane. In the crystal, molecules are linked via a number of π–π interactions [centroid–centroid distances vary from 3.452 (7 to 3.6062 (8 Å], forming a three-dimensional structure.

Synthesis of [5,6-13C2, 1-14C]olivetolic acid, methyl [1'-13C]olivetolate and [5,6-13C2, 1-14C]cannabigerolic acid

International Nuclear Information System (INIS)

Porwoll, J.P.; Leete, E.

1985-01-01

Potential advanced intermediates in the biosynthesis of delta 9 -tetrahydrocannabinol, the major psychoactive principle of marijuana, have been synthesized labeled with two contiguous 13 C atoms and 14 C. Methyl [5,6- 13 C 2 , 1- 14 C]olivetolate was prepared from lithium [ 13 C 2 ]acetylide and dimethyl [2- 14 C]malonate. Reaction with geranyl bromide afforded methyl [5,6- 13 C 2 , 1- 14 C]cannabigerolate, and hydrolysis of these methyl esters with lithium propyl mercaptide yielded the corresponding labeled acids. The 13 C- 13 C couplings observable in the 13 C NMR spectra of these 13 C-enriched compounds and their synthetic precursors are recorded. Methyl [1'- 14 C]olivetolate was prepared from 13 CO 2 to confirm assignments of the 13 C chemical shifts in the pentyl side chain of these compounds. (author)

c-Plane oriented Bi-oxide superconductor

International Nuclear Information System (INIS)

Kugimiya, K.; Kawashima, S.; Inoue, O.; Adachi, S.

1988-01-01

A newly found Bi-Sr-Ca-Cu-O superconductor with T c =80 K was synthesized in an almost pure phase. It is a laminar oxide with an Aurivillius phase and easily breaks into thin flakes. By slip-casting the flakes under pressure or by hot-pressing sintered bodies of isostatically formed green compacts, c-planes of the phase were highly oriented by more than 95%, mostly 98.5%. Sintered compacts generally contained materials with T c of 80 and 110 K as proved by the Meissner effect. 11 refs.; 6 figs

Crystal structure of an organic–inorganic supra­molecular salt based on a 4,4′-methyl­enebis(3,5-dimethyl-1H-pyrazol-2-ium) cation and a β-octa­molybdate anion

Science.gov (United States)

Amarante, Tatiana R.; Gonçalves, Isabel S.; Almeida Paz, Filipe A.

2016-01-01

The asymmetric unit of the title compound, bis­[4,4′-methyl­enebis(3,5-dimethyl-1H-pyrazol-2-ium)] β-octa­molybdate, (C11H18N4)2[Mo8O26] or (H4mbdpz)2[Mo8O26], is composed of an H4mbdpz2+ cation and half of the β-octa­molybdate anion which is completed by inversion symmetry. The organic mol­ecular units are engaged in a series of N—H⋯O hydrogen bonds with neighbouring anions, with N⋯O distances and N—H⋯O angles in the ranges 2.730 (2)–2.941 (2) Å and 122–166°, respectively. These inter­actions lead to the formation of a supra­molecular two-dimensional network parallel to the (010) plane. PMID:26958369

Crystal strucutre of rac-methyl (11aR*,12S*,13R*,15aS*,15bS*-11-oxo-11,11a,12,13-tetrahydro-9H,15bH-13,15a-epoxyisoindolo[1,2-c]pyrrolo[1,2-a][1,4]benzodiazepine-12-carboxylate

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Vladimir P. Zaytsev

2014-12-01

Full Text Available The title compound, C21H18N2O4, obtained as a racemate, contains a novel heterocyclic system, viz. isoindolo[1,2-c]pyrrolo[1,2-a][1,4]benzodiazepine. The central diazepane ring has a distorted boat conformation with two phenylene-fused and one methine C atom deviating by 0.931 (1, 0.887 (1 and 0.561 (1 Å, respectively, from the mean plane of the rest of the ring. The γ-lactone ring has an envelope conformation, with the C atom opposite to amide bond deviating by 0.355 (1 Å from its plane. In the crystal, molecules form centrosymmetric dimers through pairs of C—H...O hydrogen bonds.

Structure and spectroscopic properties of N,S-coordinating 2-methyl-sulfanyl-N-[(1H-pyrrol-2-yl)methyl-idene]aniline methanol monosolvate.

Science.gov (United States)

Richards, D Douglas; Ang, M Trisha C; McDonald, Robert; Bierenstiel, Matthias

2015-10-01

The reaction of pyrrole-2-carboxaldehyde and 2-(methyl-sulfan-yl)aniline in refluxing methanol gave an olive-green residue in which yellow crystals of the title compound, C12H12N2S·CH3OH, were grown from slow evaporation of methanol at 263 K. In the crystal, hydrogen-bonding inter-actions link the aniline mol-ecule and a nearby methanol solvent mol-ecule. These units are linked by a pair of weak C-H⋯Omethanol interactions, forming inversion dimers consisting of two main molecules and two solvent molecules.

Synthesis of Fischer carbene complexes of iridium by C-H bond activation of methyl and cyclic ethers: Evidence for reversible {alpha}-hydrogen migration

Energy Technology Data Exchange (ETDEWEB)

Luecke, H.F.; Arndtsen, B.A.; Burger, P.; Bergman, R.G. [Lawrence Berkeley Lab., CA (United States)]|[Univ. of California, Berkeley, CA (United States)

1996-03-13

We report here a mild and versatile route to Fischer carbene complexes of iridium via the activation of C-H bonds of methyl and cyclic ethers, along with our preliminary studies of this rare family of carbene complexes. Theoretical studies suggest that {alpha}-hydrogen migrations can be kinetically favorable if a coordinatively unsaturated species can be accessed. Thus, the lability of the triflate ligand presumably facilitates this process. Further evidence for the rapidity, as well as reversibility, of this rearrangement was obtained by NMR analysis. 20 refs.

5-(4-Methylphenylsulfonyl-1,3-dithiolo[4,5-c]pyrrole-2-thione

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Ning-Juan Zheng

2012-04-01

Full Text Available The asymmetric unit of the title compound, C12H9NO2S4, contains one half-molecule with the N, two S amd four C atoms lying on a mirror plane. The molecule exhibits a V-shaped conformation, with a dihedral angle of 87.00 (7° between the benzene and dithiolopyrrole rings. The methyl group was treated as rotationally disordered between two orientations in a 1:1 ratio. In the crystal, weak C—H...O hydrogen bonds link the molecules into chains in [010].

Negative ion emission at field electron emission from amorphous (alpha-C:H) carbon

CERN Document Server

Bernatskij, D P; Ivanov-Omskij, V I; Pavlov, V G; Zvonareva, T K

2001-01-01

The study on the electrons field emission from the plane cathode surface on the basis of the amorphous carbon film (alpha-C:H) is carried out. The methodology, making it possible to accomplish simultaneously the registration of the emission currents and visually observe the distribution of the emission centers on the plane emitter surface is developed. The analysis of the oscillograms indicated that apart from the proper electron constituent the negative ions of hydrogen (H sup - and H sub 2 sup -), carbon (C sup -) and hydrocarbon (CH sub n sup -) are observed. The ions emission is connected with the processes of formation and degradation of the local emission centers

Geometric factors in f.c.c. and b.c.c. metal-on-metal epitaxy

International Nuclear Information System (INIS)

Bruce, L.A.; Jaeger, H.

1978-01-01

Deposits of Ni, Au and Ag formed by condensing metal vapour in U.H.V. onto (001)W, held at a temperature Tsub(s) in the range 300K< Tsub(s)<1200 K, always form epitaxial layers. However, while Au and Ag form (001) epitaxial layers of f.c.c. single crystals, (001)d parallel to (001)s with, say, [110]d parallel to [010]s, Ni and Cu occur in two orthogonal domains, each characterized by an exclusive set of fault (or twin) planes. Within a fault plane, atoms are hexagonally close-packed and, within a domain, fault planes are normal to either [1-1-0]s or [1-10]s and a close-packed direction in the planes is normal to the substrate. The lateral stacking of the fault planes may range from random at low values of Tsub(s) to that of, say, (11-1-) planes in heavily faulted and/or twinned (110) epitaxed f.c.c. material, or of basal planes in (110) epitaxed h.c.p. material at high values of Tsub(s). The results are readily explained on the basis of a growth model developed for deposits of Ni and Cu on (001) Ag. (author)

Enzymatic methylation of band 3 anion transporter in intact human erythrocytes

International Nuclear Information System (INIS)

Lou, L.L.; Clarke, S.

1987-01-01

Band 3, the anion transport protein of erythrocyte membranes, is a major methyl-accepting substrate of the intracellular erythrocyte protein carboxyl methyltransferase (S-adenosyl-L-methionine: protein-D-aspartate O-methyltransferase; EC 2.1.1.77). The localization of methylation sites in intact cells by analysis of proteolytic fragments indicated that sites were present in the cytoplasmic N-terminal domain as well as the membranous C-terminal portion of the polypeptide. The amino acid residues that serve as carboxyl methylation sites of the erythrocyte anion transporter were also investigated. 3 H-Methylated band 3 was purified from intact erythrocytes incubated with L-[methyl- 3 H]methionine and from trypsinized and lysed erythrocytes incubated with S-adenosyl-L-[methyl- 3 H]methionine. After proteolytic digestion with carboxypeptidase Y, D-aspartic acid beta-[ 3 H]methyl ester was isolated in low yields (9% and 1%, respectively) from each preparation. The bulk of the radioactivity was recovered as [ 3 H]methanol, and the amino acid residue(s) originally associated with these methyl groups could not be determined. No L-aspartic acid beta-[ 3 H]methyl ester or glutamyl gamma-[ 3 H]methyl ester was detected. The formation of D-aspartic acid beta-[ 3 H]methyl esters in this protein in intact cells resulted from protein carboxyl methyltransferase activity since it was inhibited by adenosine and homocysteine thiolactone, which increases the intracellular concentration of the potent product inhibitor S-adenosylhomocysteine, and cycloleucine, which prevents the formation of the substrate S-adenosyl-L-[methyl- 3 H]methionine

Reaction products from N-methyl-N-nitrosourea and deoxyribonucleic acid containing thymidine residues. Synthesis and identification of a new methylation product, O4-methyl-thymidine

Science.gov (United States)

Lawley, P. D.; Orr, D. J.; Shah, S. A.; Farmer, P. B.; Jarman, M.

1973-01-01

1. DNA was treated with N-methyl-N-nitrosourea at pH7–8, 37°C, degraded to yield 3- and 7-methylpurines and deoxyribonucleosides and the reaction products were separated by chromatography on ion-exchange resins. The following methods for identification and determination of products were used: with unlabelled N-methyl-N-nitrosourea, u.v. absorption; use of methyl-14C-labelled N-methyl-N-nitrosourea and use of [14C]thymine-labelled DNA. 2. The synthesis of O4-methylthymidine and its identification by u.v. and mass spectroscopy are reported. 3. 3-Methylthymidine and O4-methylthymidine were found as methylation products from N-methyl-N-nitrosourea with thymidine and with DNA, in relatively small yields. Unidentified products containing thymine were found in enzymic digests of N-methyl-N-nitrosourea-treated DNA, which may be phosphotriesters. 4. The possible role of formation of methylthymines in mutagenesis by N-methyl-N-nitrosourea is discussed. PMID:4798180

5-Chloro-2-methyl-3-phenylsulfonyl-1-benzofuran

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Hong Dae Choi

2008-07-01

Full Text Available The title compound, C15H11ClO3S, was prepared by the oxidation of 5-chloro-2-methyl-3-phenylsulfanyl-1-benzofuran with 3-chloroperoxybenzoic acid. There are two symmetry-independent molecules in the asymmetric unit. The dihedral angles formed by the phenyl ring and the plane of the benzofuran system are 77.80 (8 and 78.34 (8°. The crystal structure is stabilized by aromatic π–π stacking interactions between the furan ring and the benzene rings of neighbouring benzofuran fragments from two symmetry-independent molecules; the centroid–centroid distances within the stacks are 3.689 (4, 3.702 (4, 3.825 (4 and 3.826 (4 Å. Additionally, the stacked molecules exhibit inter- and intramolecular C—H...O interactions.

Traceable atomic force microscopy of high-quality solvent-free crystals of [6,6]-phenyl-C61-butyric acid methyl ester

OpenAIRE

Lazzerini, GM; Paterno, GM; Tregnago, G; Treat, N; Stingelin, N; Yacoot, A; Cacialli, F

2016-01-01

We report high-resolution, traceable atomic force microscopymeasurements of high-quality, solvent-free single crystals of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). These were grown by drop-casting PCBM solutions onto the spectrosil substrates and by removing the residual solvent in a vacuum. A home-built atomic force microscope featuring a plane mirror differential optical interferometer, fiber-fed from a frequency-stabilized laser (emitting at 632.8???nm), was used to measure the cr...

Traceable atomic force microscopy of high-quality solvent-free crystals of [6,6]-phenyl-C-61-butyric acid methyl ester

OpenAIRE

Lazzerini, G. M.; Paterno, G. M.; Tregnago, G.; Treat, N.; Stingelin, N.; Yacoot, A.; Cacialli, F.

2016-01-01

We report high-resolution, traceable atomic force microscopymeasurements of high-quality, solvent-free single crystals of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). These were grown by drop-casting PCBM solutions onto the spectrosil substrates and by removing the residual solvent in a vacuum. A home-built atomic force microscope featuring a plane mirror differential optical interferometer, fiber-fed from a frequency-stabilized laser (emitting at 632.8 nm), was used to measure the crys...

Evidence for methyl group transfer between the methyl-accepting chemotaxis proteins in Bacillus subtilis

International Nuclear Information System (INIS)

Bedale, W.A.; Nettleton, D.O.; Sopata, C.S.; Thoelke, M.S.; Ordal, G.W.

1988-01-01

The authors present evidence for methyl (as methyl or methoxy) transfer from the methyl-accepting chemotaxis proteins H1 and possibly H3 of Bacillus subtilis to the methyl-accepting chemotaxis protein H2. This methyl transfer, which has been observed in vitro was strongly stimulated by the chemoattractant aspartate and thus may plan an important role in the sensory processing system of this organism. Although radiolabeling of H1 and H3 began at once after the addition of [ 3 H] methionine, radiolabeling of H2 showed a lag. Furthermore, the addition of excess nonradioactive methionine caused immediate exponential delabeling of H1 and H3 while labeling of H2 continued to increase. Methylation of H2 required the chemotactic methyltransferase, probably to first methylate H1 and H3. Aspartate caused increased labeling of H2 and strongly decreased labeling of H1 and H3 after the addition of nonradioactive methionine. Without the addition of nonradioactive methionine, aspartate caused demethylation of H1 and to a lesser extent H3, with an approximately equal increase of methylation of H2

Synthesis of [14α-methyl-3H]-24,25-dihydrolanosterol

International Nuclear Information System (INIS)

DeKeczer, S.; Kertesz, D.; Parnes, H.

1993-01-01

We describe the first synthesis of isomerically pure title compound (6) at high specific activity. This required the development of a convenient, regiospecific synthesis of the δ 8(9) -15-ketone and subsequent alkylation with methyl-[ 3 H 3 ]iodide. A key step in our procedure was the use of an electrochemical reduction of the intermediate [14α-methyl- 3 H]-15-oxo-dihydrolanosterol. This process was effected cleanly and in high yield to give (6), an important assay tool in the search for cholesterol lowering agents. This approach was found to be significantly superior to the Wolff-Kishner reduction of the corresponding 3-benzoate. (Author)

Radiosynthesis of 7-chloro-N, N-dimethyl-5-[11C] methyl-4-oxo-3-phenyl-3, 5-dihydro-4H pyridazino [4, 5-b]indole-1-acetamide, [11C]SSR180575, a novel radioligand for imaging the TSPO (peripheral benzodiazepine receptor) with PET

International Nuclear Information System (INIS)

Thominiaux, C.; Damont, A.L.; Kuhnast, B.; Demphel, St.; Le Helleix, St.; Chauveau, F.; Boutin, H.; Van Camp, N.; Boisgard, R.; Tavitian, B.; Dolle, F.; Boisnard, S.; Rivron, L.; Roy, S.; Allen, J.; Chauveau, F.; Boutin, H.; Van Camp, N.; Boisgard, R.; Tavitian, B.; Rooney, T.; Benavides, J.; Hantraye, Ph.

2010-01-01

SSR180575 (7-chloro-N, N, 5-trimethyl-4-oxo-3-phenyl-3, 5-dihydro-4H-pyridazino [4, 5-b]indole-1-acetamide) is the lead compound of an original pyridazino-indole series of potent and highly selective TSPO (peripheral benzodiazepine receptor) ligands. Isotopic labeling of SSR180575 with the short-lived positron-emitter carbon-11 (T1/2: 20.38 min) at its 5-methyl-pyridazino[4, 5-b]indole moiety as well as at its N, N-dimethylacetamide function by methylation of the corresponding nor-analogues was investigated. Best results in terms of radiochemical yields and purities were obtained for the preparation of [indole-N-methyl- 11 C]SSR180575, where routine production batches of 4.5-5.0 GBq of radiochemically pure (499%) i.v. injectable solutions (specific radioactivities: 50-90 GBq/μmol) could be prepared within a total synthesis time of 25 min (HPLC purification included) starting from a 55 GBq [ 11 C]CO 2 cyclotron production batch (non decay-corrected overall radiochemical yields: 8-9%). The process comprises (1) trapping at -10 C of [ 11 C]methyl triflate in DMF (300 μl) containing 0.2-0.3 mg of the indole precursor for labeling and 4 mg of K 2 CO 3 (excess); (2) heating at 120 C for 3 min; (3) dilution of the residue with 0.5 ml of the HPLC mobile phase and (4) purification using semi-preparative reversed phase HPLC (Zorbax R SB-C-18). In vivo pharmacological properties of [indole-N-methyl- 11 C]SSR180575 as a candidate for imaging neuro-inflammation with positron emission tomography are currently evaluated. (authors)

Synthesis of methyl-2 O-tolyl-3 quinazolone-4 {sup 14}C-2; Synthese de la methyl-2 O-tolyl-3 quinazolone-4 {sup 14}C-2

Energy Technology Data Exchange (ETDEWEB)

Herbert, M; Pichat, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

Description of the preparation of methyl-2 O-tolyl-3 quinazolone-4 {sup 14}C-2 (abbreviated to M.T.Q.), using N-acetyl {sup 14}C-1 anthranilic acid. The overall yield reaches 72 per cent with respect to acetyl chloride {sup 14}C-1. By applying the same method to acetyl chloride {sup 14}C-2, M.T.Q. labelled on the methyl group could be obtained. (author) [French] Description de la preparation de la methyl-2 O-tolyl-3 quinazolone-4 {sup 14}C-2 (abregee en M.T.Q.) par l'intermediaire de l'acide N-acetyl {sup 14}C-1 anthranilique. Le rendement global atteint 72 pour cent par rapport au chlorure d'acetyle {sup 14}C-1. La meme methode appliquee au chlorure d'acetyle {sup 14}C-2 permettrait d'obtenir la M.T.Q. marquee sur le groupement methyle. (auteur)

3-Methyl-1-(prop-2-en-1-ylquinoxalin-2(1H-one

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Youssef Ramli

2010-07-01

Full Text Available In the molecule of the title compound, C12H12N2O, the quinoxaline ring is planar with an r.m.s. deviation of 0.007 (15 Å. The dihedral angle between the quinoxaline and propenyl planes is 82.1 (2°. The crystal packing is stabilized by offset π–π stacking between the quinoxaline rings [centroid–centroid distance = 3.8832 (9 Å].

Presolvated Electron Reactions with Methyl Acetoacetate: Electron Localization, Proton-Deuteron Exchange, and H-Atom Abstraction

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Alex Petrovici

2014-09-01

Full Text Available Radiation-produced electrons initiate various reaction processes that are important to radiation damage to biomolecules. In this work, the site of attachment of the prehydrated electrons with methyl acetoacetate (MAA, CH3-CO-CH2-COOCH3 at 77 K and subsequent reactions of the anion radical (CH3-CO•−-CH2-COOCH3 in the 77 to ca. 170 K temperature range have been investigated in homogeneous H2O and D2O aqueous glasses by electron spin resonance (ESR spectroscopy. At 77 K, the prehydrated electron attaches to MAA forming the anion radical in which the electron is delocalized over the two carbonyl groups. This species readily protonates to produce the protonated electron adduct radical CH3-C(•OH-CH2-COOCH3. The ESR spectrum of CH3-C(•OH-CH2-COOCH3 in H2O shows line components due to proton hyperfine couplings of the methyl and methylene groups. Whereas, the ESR spectrum of CH3-C(•OH-CH2-COOCH3 in D2O glass shows only the line components due to proton hyperfine couplings of CH3 group. This is expected since the methylene protons in MAA are readily exchangeable in D2O. On stepwise annealing to higher temperatures (ca. 150 to 170 K, CH3-C(•OH-CH2-COOCH3 undergoes bimolecular H-atom abstraction from MAA to form the more stable radical, CH3-CO-CH•-COOCH3. Theoretical calculations using density functional theory (DFT support the radical assignments.

Presolvated electron reactions with methyl acetoacetate: electron localization, proton-deuteron exchange, and H-atom abstraction.

Science.gov (United States)

Petrovici, Alex; Adhikary, Amitava; Kumar, Anil; Sevilla, Michael D

2014-09-01

Radiation-produced electrons initiate various reaction processes that are important to radiation damage to biomolecules. In this work, the site of attachment of the prehydrated electrons with methyl acetoacetate (MAA, CH3-CO-CH2-COOCH3) at 77 K and subsequent reactions of the anion radical (CH3-CO•--CH2-COOCH3) in the 77 to ca. 170 K temperature range have been investigated in homogeneous H2O and D2O aqueous glasses by electron spin resonance (ESR) spectroscopy. At 77 K, the prehydrated electron attaches to MAA forming the anion radical in which the electron is delocalized over the two carbonyl groups. This species readily protonates to produce the protonated electron adduct radical CH3-C(•)OH-CH2-COOCH3. The ESR spectrum of CH3-C(•)OH-CH2-COOCH3 in H2O shows line components due to proton hyperfine couplings of the methyl and methylene groups. Whereas, the ESR spectrum of CH3-C(•)OH-CH2-COOCH3 in D2O glass shows only the line components due to proton hyperfine couplings of CH3 group. This is expected since the methylene protons in MAA are readily exchangeable in D2O. On stepwise annealing to higher temperatures (ca. 150 to 170 K), CH3-C(•)OH-CH2-COOCH3 undergoes bimolecular H-atom abstraction from MAA to form the more stable radical, CH3-CO-CH•-COOCH3. Theoretical calculations using density functional theory (DFT) support the radical assignments.

Reaction rate and isomer-specific product branching ratios of C2H + C4H8: 1-butene, cis-2-butene, trans-2-butene, and isobutene at 79 K.

Science.gov (United States)

Bouwman, Jordy; Fournier, Martin; Sims, Ian R; Leone, Stephen R; Wilson, Kevin R

2013-06-20

The reactions of C2H radicals with C4H8 isomers 1-butene, cis-2-butene, trans-2-butene, and isobutene are studied by laser photolysis-vacuum ultraviolet mass spectrometry in a Laval nozzle expansion at 79 K. Bimolecular-reaction rate constants are obtained by measuring the formation rate of the reaction product species as a function of the reactant density under pseudo-first-order conditions. The rate constants are (1.9 ± 0.5) × 10(-10), (1.7 ± 0.5) × 10(-10), (2.1 ± 0.7) × 10(-10), and (1.8 ± 0.9) × 10(-10) cm(3) s(-1) for the reaction of C2H with 1-butene, cis-2-butene, trans-2-butene, and isobutene, respectively. Bimolecular rate constants for 1-butene and isobutene compare well to values measured previously at 103 K using C2H chemiluminescence. Photoionization spectra of the reaction products are measured and fitted to ionization spectra of the contributing isomers. In conjunction with absolute-ionization cross sections, these fits provide isomer-resolved product branching fractions. The reaction between C2H and 1-butene yields (65 ± 10)% C4H4 in the form of vinylacetylene and (35 ± 10)% C5H6 in the form of 4-penten-1-yne. The cis-2-butene and trans-2-butene reactions yield solely 3-penten-1-yne, and no discrimination is made between cis- and trans-3-penten-1-yne. Last, the isobutene reaction yields (26 ± 15)% 3-penten-1-yne, (35 ± 15)% 2-methyl-1-buten-3-yne, and (39 ± 15)% 4-methyl-3-penten-1-yne. The branching fractions reported for the C2H and butene reactions indicate that these reactions preferentially proceed via CH3 or C2H3 elimination rather than H-atom elimination. Within the experimental uncertainties, no evidence is found for the formation of cyclic species.

(E-3-Hydroxy-13-methyl-16-[4-(methylsulfanylbenzylidene]-7,8,9,11,12,13,15,16-octahydro-6H-cyclopenta[a]phenanthren-17(14H-one

Directory of Open Access Journals (Sweden)

R. Murugan

2009-01-01

Full Text Available In the title compound, C26H28O2S, the dihedral angles between the mean plane of the five membered ring and the 4-(methylsulfanylbenzylidine ring in the two crystallographically independent molecules are 34.05 (10 and 40.53 (15°. The packing is stabilized by intermolecular O—H...O and C—H...O interactions.

Magnetic measurements and neutron diffraction study of the layered hybrid compounds Mn(C8H4O4)(H2O)2 and Mn2(OH)2(C8H4O4)

International Nuclear Information System (INIS)

Sibille, Romain; Mesbah, Adel; Mazet, Thomas; Malaman, Bernard; Capelli, Silvia; François, Michel

2012-01-01

Mn(C 8 H 4 O 4 )(H 2 O) 2 and Mn 2 (OH) 2 (C 8 H 4 O 4 ) layered organic–inorganic compounds based on manganese(II) and terephthalate molecules (C 8 H 4 O 4 2− ) have been studied by DC and AC magnetic measurements and powder neutron diffraction. The dihydrated compound behaves as a 3D antiferromagnet below 6.5 K. The temperature dependence of its χT product is typical of a 2D Heisenberg system and allows determining the in-plane exchange constant J≈−7.4 K through the carboxylate bridges. The magnetic structure confirms the in-plane nearest neighbor antiferromagnetic interactions and the 3D ordering. The hydroxide based compound also orders as a 3D antiferromagnet with a higher Néel temperature (38.5 K). Its magnetic structure is described from two antiferromagnetically coupled ferromagnetic sublattices, in relation with the two independent metallic sites. The isothermal magnetization data at 2 K are consistent with the antiferromagnetic ground-state of these compounds. However, in both cases, a slope change points to field-induced modification of the magnetic structure. - Graphical abstract: The macroscopic magnetic properties and magnetic structures of two metal-organic frameworks based on manganese (II) and terephthalate molecules are presented. Highlights: ► Magnetic study of Mn(C 8 H 4 O 4 )(H 2 O) 2 and Mn 2 (OH) 2 (C 8 H 4 O 4 ). ► Two compounds with common features (interlayer linker/distance, S=5/2 spin). ► Magnetic measurements quantitatively analyzed to deduce exchange constants. ► Magnetic structures determined from neutron powder diffraction experiments.

(3R,4R,4aS,7aR,12bS-3-Cyclopropylmethyl-4a,9-dihydroxy-3-methyl-7-oxo-2,3,4,4a,5,6,7,7a-octahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-3-ium bromide

Directory of Open Access Journals (Sweden)

Xiangfeng Chen

2012-02-01

Full Text Available The title compound, C21H26NO4+·Br−, also known as R-methylnaltrexone (MNTX bromide, is a selective peripherally acting μ-opioid receptor antagonist with a oroxymorphone skeleton, synthesized by hydroxyl protection, N-methylation, deprotection and anion exchange of naltrexone. It comprises a five-ring system A/B/C/D/E. Rings C and E adopt distorted chair conformations, whereas ring D is in half-chair conformation. The C/E ring junctions are trans fused. The dihedral angle between rings D and E is 82.3 (1°, while the dihedral angles between the planes of rings C and A, and rings D and E are respectively 81.7 (1, 75.9 (1 and 12.2 (1°. In the crystal, molecules are linked by O—H...Br hydrogen bonds.

Electrochemical iodination of C-methyl derivatives of dodecahydro-7,8-dicarba-nido-undecaborate anion

International Nuclear Information System (INIS)

Rudakov, D.A.; Shirokij, V.L.; Potkin, V.I.; Dikusar, E.A.; Bragin, V.I.; Petrovskij, P.V.; Sivaev, I.B.; Bregadze, V.I.; Kisin, A.V.

2006-01-01

Electrochemical iodination of potassium 7-methyl-7,8-dicarba-nido-undecaborate and potassium 7,8-dimethyl-7,8-dicarba-nido-undecaborate in methanol at 50 deg C was used to prepare their monoiodide derivatives (isolated as tetramethylammonium salts). Their composition and structure are confirmed by elemental analysis, 1 H, 11 B NMR and IR spectra [ru

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

Science.gov (United States)

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).

Radiosynthesis and in vivo evaluation of N-[11C]methylated imidazopyridineacetamides as PET tracers for peripheral benzodiazepine receptors

International Nuclear Information System (INIS)

Sekimata, Katsuhiko; Hatano, Kentaro; Ogawa, Mikako; Abe, Junichiro; Magata, Yasuhiro; Biggio, Giovanni; Serra, Mariangela; Laquintana, Valentino; Denora, Nunzio; Latrofa, Andrea; Trapani, Giuseppe; Liso, Gaetano; Ito, Kengo

2008-01-01

Imidazopyridineacetoamide 5-8, a series of novel and potentially selective peripheral benzodiazepine receptor (PBR) ligands with affinities comparable to those of known PBR ligands, was investigated. Radiosyntheses of [ 11 C]5, 6, 7 or 8 was accomplished by N-methylation of the corresponding desmethyl precursors with [ 11 C]methyl iodide in the presence of NaH in dimethylformamide (DMF), resulting in 25% to 77% radiochemical yield and specific activitiy of 20 to 150 MBq/nmol. Each of the labeled compounds was injected in ddY mice, and the radioactivity and weight of dissected peripheral organs and brain regions were measured. Organ distribution of [ 11 C]7 was consistent with the known PBR distribution. Moreover, [ 11 C]7 showed the best combination of brain uptake and PBR binding, leading to its high retention in the olfactory bulb and cerebellum, areas where PBR density is high in mouse brain. Coinjection of PK11195 or unlabeled 7 significantly reduced the brain uptake of [ 11 C]7. These results suggest that [ 11 C]7 could be a useful radioligand for positron emission tomography imaging of PBRs

C-plane Reconstructions from Sheaf Acquisition for Ultrasound Electrode Vibration Elastography.

Science.gov (United States)

Ingle, Atul; Varghese, Tomy

2014-09-03

This paper presents a novel algorithm for reconstructing and visualizing ablated volumes using radiofrequency ultrasound echo data acquired with the electrode vibration elastography approach. The ablation needle is vibrated using an actuator to generate shear wave pulses that are tracked in the ultrasound image plane at different locations away from the needle. This data is used for reconstructing shear wave velocity maps for each imaging plane. A C-plane reconstruction algorithm is proposed which estimates shear wave velocity values on a collection of transverse planes that are perpendicular to the imaging planes. The algorithm utilizes shear wave velocity maps from different imaging planes that share a common axis of intersection. These C-planes can be used to generate a 3D visualization of the ablated region. Experimental validation of this approach was carried out using data from a tissue mimicking phantom. The shear wave velocity estimates were within 20% of those obtained from a clinical scanner, and a contrast of over 4 dB was obtained between the stiff and soft regions of the phantom.

2C-Methyl- D- erythritol 2,4-cyclodiphosphate synthase from Stevia rebaudiana Bertoni is a functional gene.

Science.gov (United States)

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.

The H.E.S.S. Galactic plane survey

Science.gov (United States)

H. E. S. S. Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Benkhali, F. Ait; Angüner, E. O.; Arakawa, M.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Tjus, J. Becker; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bonnefoy, S.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Capasso, M.; Carrigan, S.; Caroff, S.; Carosi, A.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Colafrancesco, S.; Condon, B.; Conrad, J.; Davids, I. D.; Decock, J.; Deil, C.; Devin, J.; deWilt, P.; Dirson, L.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O.'C.; Dutson, K.; Dyks, J.; Edwards, T.; Egberts, K.; Eger, P.; Emery, G.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Gaté, F.; Giavitto, G.; Giebels, B.; Glawion, D.; Glicenstein, J. F.; Gottschall, D.; Grondin, M.-H.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holch, T. L.; Holler, M.; Horns, D.; Ivascenko, A.; Iwasaki, H.; Jacholkowska, A.; Jamrozy, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katsuragawa, M.; Katz, U.; Kerszberg, D.; Khangulyan, D.; Khélifi, B.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Marandon, V.; Malyshev, D.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morå, K.; Moulin, E.; Murach, T.; Nakashima, S.; de Naurois, M.; Ndiyavala, H.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poireau, V.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Rauth, R.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rinchiuso, L.; Romoli, C.; Rowell, G.; Rudak, B.; Rulten, C. B.; Safi-Harb, S.; Sahakian, V.; Saito, S.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schandri, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Shiningayamwe, K.; Simoni, R.; Sol, H.; Spanier, F.; Spir-Jacob, M.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Steppa, C.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsirou, M.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Zorn, J.; Żywucka, N.

2018-04-01

We present the results of the most comprehensive survey of the Galactic plane in very high-energy (VHE) γ-rays, including a public release of Galactic sky maps, a catalog of VHE sources, and the discovery of 16 new sources of VHE γ-rays. The High Energy Spectroscopic System (H.E.S.S.) Galactic plane survey (HGPS) was a decade-long observation program carried out by the H.E.S.S. I array of Cherenkov telescopes in Namibia from 2004 to 2013. The observations amount to nearly 2700 h of quality-selected data, covering the Galactic plane at longitudes from ℓ = 250° to 65° and latitudes |b|≤ 3°. In addition to the unprecedented spatial coverage, the HGPS also features a relatively high angular resolution (0.08° ≈ 5 arcmin mean point spread function 68% containment radius), sensitivity (≲1.5% Crab flux for point-like sources), and energy range (0.2-100 TeV). We constructed a catalog of VHE γ-ray sources from the HGPS data set with a systematic procedure for both source detection and characterization of morphology and spectrum. We present this likelihood-based method in detail, including the introduction of a model component to account for unresolved, large-scale emission along the Galactic plane. In total, the resulting HGPS catalog contains 78 VHE sources, of which 14 are not reanalyzed here, for example, due to their complex morphology, namely shell-like sources and the Galactic center region. Where possible, we provide a firm identification of the VHE source or plausible associations with sources in other astronomical catalogs. We also studied the characteristics of the VHE sources with source parameter distributions. 16 new sources were previously unknown or unpublished, and we individually discuss their identifications or possible associations. We firmly identified 31 sources as pulsar wind nebulae (PWNe), supernova remnants (SNRs), composite SNRs, or gamma-ray binaries. Among the 47 sources not yet identified, most of them (36) have possible

Accurate Determination of Leucine and Valine Side-chain Conformations using U-[15N/13C/2H]/[1H-(methine/methyl)-Leu/Val] Isotope Labeling, NOE Pattern Recognition, and Methine Cγ-Hγ/Cβ-Hβ Residual Dipolar Couplings

International Nuclear Information System (INIS)

Tang, Chun; Iwahara, Junji; Clore, G. Marius

2005-01-01

An isotope labeling scheme is described in which specific protonation of methine and methyl protons of leucine and valine is obtained on a 15 N/ 13 C labeled background with uniform deuteration of all other non-exchangeable protons. The presence of a protonated methine group has little effect on the favorable relaxation properties of the methyl protons of Leu and Val. This labeling scheme permits the rotameric state of leucine side-chains to be readily determined by simple inspection of the pattern of Hγ(i)-H N (i) and Hγ(i)-H N (i+1) NOEs in a 3D 15 N-separated NOE spectrum free of complications arising from spectral overlap and spin-diffusion. In addition, one-bond residual dipolar couplings for the methine 13 C- 1 H bond vectors of Leu and Val can be accurately determined from an intensity J-modulated constant-time HCCH-COSY experiment and used to accurately orient the side-chains of Leu and Val. Incorporation of these data into structure refinement improves the accuracy with which the conformations of Leu and Val side-chains can be established. This is important to ensure optimal packing both within the protein core and at intermolecular interfaces. The impact of the method on protein structure determination is illustrated by application to enzyme IIA Chitobiose , a 34 kDa homotrimeric phosphotransferase protein

X-ray characterization of CdO thin films grown on a-, c-, r- and m-plane sapphire by metalorganic vapour phase-epitaxy

Energy Technology Data Exchange (ETDEWEB)

Zuniga-Perez, J.; Martinez-Tomas, C.; Munoz-Sanjose, V. [Departamento de Fisica Aplicada y Electromagnetismo, Universitat de Valencia, C/Dr. Moliner 50, 46100 Burjassot (Spain)

2005-02-01

CdO thin films have been grown on a-plane (11 anti 20), c-plane (0001), r-plane (01 anti 12) and m-plane (10 anti 10) sapphire substrates by metalorganic vapour-phase epitaxy (MOVPE). The effects of different substrate orientations on the structural properties of the films have been analyzed by means of X-ray diffraction, including {theta}-2{theta} scans, pole figures and rocking curves. (111), (001) and (110) orientations are found on a-, r-, and m-sapphire respectively, while films deposited on c-plane exhibit an orientation in which no low-index crystal plane is parallel to the sample surface. The recorded pole figures have allowed determining the epitaxial relationships between films and substrates, as well as the presence or absence of extended defects. The rocking curves indicate that high quality thin films, in terms of tilt and twist, can be obtained on r-, c- and m-plane sapphire, while further improvement is needed over the a-orientation. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

X-ray characterization of CdO thin films grown on a-, c-, r- and m-plane sapphire by metalorganic vapour phase-epitaxy

International Nuclear Information System (INIS)

Zuniga-Perez, J.; Martinez-Tomas, C.; Munoz-Sanjose, V.

2005-01-01

CdO thin films have been grown on a-plane (11 anti 20), c-plane (0001), r-plane (01 anti 12) and m-plane (10 anti 10) sapphire substrates by metalorganic vapour-phase epitaxy (MOVPE). The effects of different substrate orientations on the structural properties of the films have been analyzed by means of X-ray diffraction, including θ-2θ scans, pole figures and rocking curves. (111), (001) and (110) orientations are found on a-, r-, and m-sapphire respectively, while films deposited on c-plane exhibit an orientation in which no low-index crystal plane is parallel to the sample surface. The recorded pole figures have allowed determining the epitaxial relationships between films and substrates, as well as the presence or absence of extended defects. The rocking curves indicate that high quality thin films, in terms of tilt and twist, can be obtained on r-, c- and m-plane sapphire, while further improvement is needed over the a-orientation. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Directed C-H Bond Oxidation of (+)-Pleuromutilin.

Science.gov (United States)

Ma, Xiaoshen; Kucera, Roman; Goethe, Olivia F; Murphy, Stephen K; Herzon, Seth B

2018-05-01

Antibiotics derived from the diterpene fungal metabolite (+)-pleuromutilin (1) are useful agents for the treatment Gram-positive infections in humans and farm animals. Pleuromutilins elicit slow rates of resistance development and minimal cross-resistance with existing antibiotics. Despite efforts aimed at producing new derivatives by semisynthesis, modification of the tricyclic core is underexplored, in part due to a limited number of functional group handles. Herein, we report methods to selectively functionalize the methyl groups of (+)-pleuromutilin (1) by hydroxyl-directed iridium-catalyzed C-H silylation, followed by Tamao-Fleming oxidation. These reactions provided access to C16, C17, and C18 monooxidized products, as well as C15/C16 and C17/C18 dioxidized products. Four new functionalized derivatives were prepared from the protected C17 oxidation product. C6 carboxylic acid, aldehyde, and normethyl derivatives were prepared from the C16 oxidation product. Many of these sequences were executed on gram scales. The efficiency and practicality of these routes provides an easy method to rapidly interrogate structure-activity relationships that were previously beyond reach. This study will inform the design of fully synthetic approaches to novel pleuromutilins and underscores the power of the hydroxyl-directed iridium-catalyzed C-H silylation reaction.

4-(4-Bromophenyl-7,7-dimethyl-2-methylamino-3-nitro-7,8-dihydro-4H-chromen-5(6H-one including an unknown solvate

Directory of Open Access Journals (Sweden)

S. Antony Inglebert

2014-05-01

Full Text Available In the title compound, C18H19BrN2O4, the chromene unit is not quite planar (r.m.s. deviation = 0.199 Å, with the methyl C atoms lying 0.027 (4 and 1.929 (4 Å from the mean plane of the chromene unit. The six-membered carbocyclic ring of the chromene moiety adopts an envelope conformation, with the dimethyl-substituted C atom as the flap. The methylamine and nitro groups are slightly twisted from the chromene moiety, with C—N—C—O and O—N—C—C torsion angles of 2.7 (4 and −0.4 (4°, respectively. The dihedral angle between the mean plane of the chromene unit and the benzene ring is 85.61 (13°. An intramolecular N—H...O hydrogen bond generates an S(6 ring motif, which stabilizes the molecular conformation. In the crystal, molecules are linked via N—H...O hydrogen bonds, forming hexagonal rings lying parallel to the ab plane. A region of disordered electron density, most probably disordered ethanol solvent molecules, occupying voids of ca 432 Å3 for an electron count of 158, was treated using the SQUEEZE routine in PLATON [Spek (2009. Acta Cryst. D65, 148–155]. Their formula mass and unit-cell characteristics were not taken into account during refinement.

Structural Insights into the Methylation of C1402 in 16S rRNA by Methyltransferase RsmI.

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Mohan Zhao

Full Text Available RsmI and RsmH are conserved S-Adenosylmethionine (AdoMet-dependent methyltransferases (MTases that are responsible for the 2'-O-methylation and N4-methylation of C1402 in bacterial 16S rRNA, respectively. Methylation of m4Cm1402 plays a role in fine-tuning the shape and functions of the P-site to increase the decoding fidelity, and was recently found to contribute to the virulence of Staphylococcus aureus in host animals. Here we report the 2.20-Å crystal structure of homodimeric RsmI from Escherichia coli in complex with the cofactor AdoMet. RsmI consists of an N-terminal putative RNA-binding domain (NTD and a C-terminal catalytic domain (CTD with a Rossmann-like fold, and belongs to the class III MTase family. AdoMet is specifically bound into a negatively charged deep pocket formed by both domains by making extensive contacts. Structure-based mutagenesis and isothermal titration calorimetry (ITC assays revealed Asp100 and Ala124 are vital for AdoMet-binding. Although the overall fold of RsmI shows remarkable similarities to the characterized MTases involved in vitamin B12 biosynthesis, it exhibits a distinct charge distribution especially around the AdoMet-binding pocket because of different substrate specificity. The docking model of RsmI-AdoMet-RNA ternary complex suggested a possible base-flipping mechanism of the substrate RNA that has been observed in several known RNA MTases. Our structural and biochemical studies provide novel insights into the catalytic mechanism of C1402 methylation in 16S rRNA.

Mineralization of 14C-Pirimiphos-Methyl in Soil Under Aerobic and Anaerobic Conditions

International Nuclear Information System (INIS)

Zayed, S.M.A.D.; Farghly, M.; El-Maghrby, S.

2006-01-01

The mineralization of 14 C-ring labelled pirimiphos-methyl in clay loam soil was determined in a three months laboratory incubation period under anaerobic and aerobic conditions. Evolution of 14 CO2 increased with time and reached 9.2% and 12 %, of the initial 14 C-concentration , within 90 days in case of anaerobic and aerobic conditions, respectively, at that time, soil contained about 61.5% of the applied dose as extractable residues under anaerobic conditions and 59% under aerobic conditions. the unextractable pesticide residues gradually increased with time and the highest binding capacity of about 11%-13% was observed after 90 days of incubation. the total 14 C-activity recovered from soil was generally between 82% and 92% of the applied radiocarbon. the nature of methanolic 14 C-residues was determined by chromatographic analysis and the results revealed the presence of pirimiphos- methyl as a main product together with its phenol. the principle of radio-respirometry has been used for evaluating the effect of different application rates of pirimiphos-methyl on soil microbial activity using U- 14 C-glucose as a substrate. At two concentrations used, pirimiphos-methyl showed an inhibition in the rate of 14 Co2 evolution over 14 days of incubation as a result of oxidation of 14 C-glucose by microorganisms especially in case of high concentration

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

Directory of Open Access Journals (Sweden)

Liliana Azotla-Cruz

2017-01-01

Full Text Available According to the principles of the methodology of bioisosteric replacements a series of methyl 1-R-4-methyl-2,2-dioxo-1H-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-1H-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 13С 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-1H-2λ6,1-benzothiazine-3-carboxylates for the methyl group is actually bioisosteric since all methyl 1-R-4-methyl-2,2-dioxo-1H-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.

Identification of a Marine Bacillus Strain C5 and Parathion-Methyl Degradation Characteristics of the Extracellular Esterase B1

Directory of Open Access Journals (Sweden)

Jianhua Hao

2014-01-01

Full Text Available A bacterial strain C5 that can produce new type of marine esterase was isolated and screened from marine sludge. According to 16S rRNA sequence analysis and physiological and biochemical experiments, the strain was identified as Bacillus subtilis. A single isozyme with a molecular weight of 86 kDa was observed by SDS-PAGE and native-PAGE. On this basis, the mechanism of esterase B1 secreted by strain C5 degrading parathion-methyl was explored, and the effects of temperature and pH on the degradation rate were investigated. From the results, p-nitrophenol was one of the degradation products of B1 degrading parathion-methyl, and the best degradation effect could be achieved at the temperature of 40°C and the neutral pH value.

(7aR-1-[(2R,5S,E-6-Hydroxy-5,6-dimethylhept-3-en-2-yl]-7a-methylhexahydro-1H-inden-4(2H-one

Directory of Open Access Journals (Sweden)

Marcos L. Rivadulla

2013-02-01

Full Text Available The chiral title compound, C19H32O2, contains a [4.3.0]-bicyclic moiety in which the shared C—C bond presents a trans configuration and a side chain in which the C=C double bond shows an E conformation. The conformations of five- and six-membered rings are envelope (with the bridgehead atom bearing the methyl substituent as the flap and chair, respectively, with a dihedral angle of 4.08 (17° between the idealized planes of the rings. In the crystal, the molecules are self-assembled via classical O—H...O hydrogen bonds, forming chains along [112]; these chains are linked by weak non-classical C—H...O hydrogen bonds, giving a two-dimensional supramolecular structure parallel to (010. The absolute configuration was established according to the configuration of the starting material.

Semi-automated preparation of a 11C-labelled antibiotic - [N-methyl-11C]erythromycin A lactobionate

International Nuclear Information System (INIS)

Pike, V.W.; Palmer, A.J.; Horlock, P.L.; Liss, R.H.

1984-01-01

A fast semi-automated method is described for labelling the antibiotic, erythromycin A (1), with the short-lived positron-emitting radionuclide, 11 C(tsub(1/2)=20.4 min), in order to permit the non-invasive study of its tissue uptake in vivo. Labelling was achieved by the fast reductive methylation of N-demethylerythromycin A (2) with [ 11 C]formaldehyde, itself prepared from cyclotron-produced [ 11 C]-carbon dioxide. Rapid chemical and radiochemical purification of the [N-methyl- 11 C]erythromycin A (3) were achieved by HPLC and verified by TLC with autoradiography. The purified material was formulated for human i.v. injection as a sterile apyrogenic solution of the lactobionate salt. The preparation takes 42 min from the end of radionuclide production and from [ 11 C]carbon dioxide produces [N-methyl- 11 C]erythromycin A lactobionate in 4-12% radiochemical yield, corrected for radioactive decay. (author)

(E)-6-Amino-1,3-dimethyl-5-[(pyridin-2-yl-methyl-idene)amino]-pyrimidine-2,4(1H,3H)-dione.

Science.gov (United States)

Booysen, Irvin; Hlela, Thulani; Ismail, Muhammed; Gerber, Thomas; Hosten, Eric; Betz, Richard

2011-09-01

In the title compound, C(12)H(13)N(5)O(2), a Schiff-base-derived chelate ligand, the non-aromatic heterocycle and its substituents essentially occupy one common plane (r.m.s. of fitted non-H atoms = 0.0503 Å). The N=C bond is E-configured. Intra-cyclic angles in the pyridine moiety cover the range 117.6 (2)-124.1 (2)°. Intra- and inter-molecular N-H⋯N and N-H⋯O hydrogen bonds are observed in the crystal structure, as are intra- and inter-molecular C-H⋯O contacts which, in total, connect the mol-ecules into a three-dimensional network. The shortest ring-centroid-to-ring-centroid distance of 3.5831 (14) Å is between the two different types of six-membered rings.

Antagonism between DNA and H3K27 methylation at the imprinted Rasgrf1 locus

DEFF Research Database (Denmark)

Lindroth, Anders M; Park, Yoon Jung; McLean, Chelsea M

2008-01-01

At the imprinted Rasgrf1 locus in mouse, a cis-acting sequence controls DNA methylation at a differentially methylated domain (DMD). While characterizing epigenetic marks over the DMD, we observed that DNA and H3K27 trimethylation are mutually exclusive, with DNA and H3K27 methylation limited...... to the paternal and maternal sequences, respectively. The mutual exclusion arises because one mark prevents placement of the other. We demonstrated this in five ways: using 5-azacytidine treatments and mutations at the endogenous locus that disrupt DNA methylation; using a transgenic model in which the maternal...

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.

Science.gov (United States)

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.

Histone H3 Lysine Methylation in Cognition and Intellectual Disability Disorders

Science.gov (United States)

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…

Effect of alcohol consumption on the liver detoxication capacity as measured by [13C]methacetin- and [methyl-13C]methionine-breath tests.

Science.gov (United States)

Wutzke, Klaus D; Forberger, Anke; Wigger, Marianne

2008-06-01

The aim of this study was to investigate the hepatic microsomal and mitochondrial functions by using the 13CO2-breath test in healthy subjects either before or after the consumption of red wine. Fourteen adults received [13C]methacetin and [methyl-13C]methionine together with a standardised dinner. Expired air samples were taken over 6 h. After a wash-out period, the subjects consumed 0.4 ml ethanol/kg/day together with dinner over a 10-day period. Thereafter, 13C-tracer administration was repeated under identical conditions. The 13CO2-enrichments were measured by isotope ratio mass spectrometry. The mean cumulative percentage 13C-dose recovery (CPDR) after administration of [13C]methacetin and [methyl-13C]methionine either without or with red wine consumption amounted to 38.2+/-6.3 vs. 36.3+/-6.7% (p=0.363) and 9.5+/-3.3 vs. 8.8+/-2.5% (p=0.47), respectively. Moderate alcohol consumption does not induce significant short-term changes of the microsomal and the mitochondrial functions of the human liver in healthy subjects.

Aquantis C-Plane Ocean Current Turbine Project

Energy Technology Data Exchange (ETDEWEB)

Fleming, Alex [Dehlsen Associates, LLC, Santa Barbara, CA (United States)

2015-09-16

The Aquantis 2.5 MW Ocean Current Generation Device technology developed by Dehlsen Associates, LLC (DA) is a derivation of wind power generating technology (a means of harnessing a slow moving fluid) adapted to the ocean environment. The Aquantis Project provides an opportunity for accelerated technological development and early commercialization, since it involves the joining of two mature disciplines: ocean engineering and wind turbine design. The Aquantis Current Plane (C-Plane) technology is an ocean current turbine designed to extract kinetic energy from a current flow. The technology is capable of achieving competitively priced, continuous, base-load, and reliable power generation from a source of renewable energy not before possible in this scale or form.

FTIR measurements of mid-IR absorption spectra of gaseous fatty acid methyl esters at T=25–500 °C

International Nuclear Information System (INIS)

Campbell, M.F.; Freeman, K.G.; Davidson, D.F.; Hanson, R.K.

2014-01-01

Gas-phase mid-infrared (IR) absorption spectra (2500–3400 cm −1 ) for eleven fatty acid methyl esters (FAMEs) have been quantitatively measured at temperatures between 25 and 500 °C using an FTIR spectrometer with a resolution of 1 cm −1 . Using these spectra, the absorption cross section at 3.39 μm, corresponding to the monochromatic output of a helium–neon laser, is reported for each of these fuels as a function of temperature. The data indicate that the 3.39 μm cross section values of saturated FAMEs vary linearly with the logarithm of the number of C-H bonds in the molecule. - Highlights: • Infrared spectra of 11 fatty acid methyl esters (C 3 –C 11 ) have been measured. • A linear relationship for predicting 3.39 μm cross section values is proposed. • A molecule’s integrated area is linearly related to its number of C-H bonds. • Mono-unsaturation decreases cross section values

Synthesis of specific labelled [methyl-14C]sarin

International Nuclear Information System (INIS)

Sin-Ren, A.C.; Riggio, G.; Hopff, W.H.; Waser, P.G.

1988-01-01

The synthesis of [methyl- 14 C]sarin ([ 14 C]methylphosphono-fluoridic acid 1-methylethyl ester) was accomplished by another approach as for nonlabelled sarin in a tele-conducted reaction vessel. The purity was estimated by IR, GC, and GC-MS and the stability in different media was examined. (author)

Phase formation and strain relaxation of Ga2O3 on c-plane and a-plane sapphire substrates as studied by synchrotron-based x-ray diffraction

Science.gov (United States)

Cheng, Zongzhe; Hanke, Michael; Vogt, Patrick; Bierwagen, Oliver; Trampert, Achim

2017-10-01

Heteroepitaxial Ga2O3 was deposited on c-plane and a-plane oriented sapphire by plasma-assisted molecular beam epitaxy and probed by ex-situ and in-situ synchrotron-based x-ray diffraction. The investigation on c-plane sapphire determined a critical thickness of around 33 Å, at which the monoclinic β-phase forms on top of the hexagonal α-phase. A 143 Å thick single phase α-Ga2O3 was observed on a-plane sapphire, much thicker than the α-Ga2O3 on c-plane sapphire. The α-Ga2O3 relaxed very fast in the first 30 Å in both out-of-plane and in-plane directions as measured by the in-situ study.

Synthesis of racemic, S(+)- and R(-)-N-[methyl- 3H]3,4-methylenedioxymethamphetamine

International Nuclear Information System (INIS)

Hashimoto, Kenji; Hirai, Katsumi; Goromaru, Tsuyoshi

1990-01-01

The synthesis of 3,4-methylenedioxymethampetamine (MDMA), a serotonergic neurotoxin, labeled with tritium is described. Labeling was accomplished by N-alkylation of the free base of the corresponding desmethyl compound using [ 3 H]methyl iodide. The compound was purified by preparative HPLC. The radiochemical yield was about 60% based on [ 3 H]methyl iodide. The radiochemical purity was more than 95% from HPLC and TLC. Furthermore, S(+)- and R(-)-[ 3 H]MDMA were completely separated by analytical HPLC with chiral column. (author)

Microwave spectrum, dipole moment, and internal dynamics of the methyl fluoride-carbonyl sulfide weakly bound complex.

Science.gov (United States)

Serafin, Michal M; Peebles, Sean A

2008-02-21

Rotational spectra for the normal and four isotopically substituted species of the 1:1 complex between methyl fluoride (H3CF) and carbonyl sulfide (OCS) have been measured using Fourier-transform microwave spectroscopy in the 5-16 GHz frequency region. The observed spectra fit well to a semirigid Watson Hamiltonian, and an analysis of the rotational constants has allowed a structure to be determined for this complex. The dipole moment vectors of the H3CF and OCS monomers are aligned approximately antiparallel with a C...C separation of 3.75(3) A and with an ab plane of symmetry. The values of the Pcc planar moments were found to be considerably different from the expected rigid values for all isotopologues. An estimate of approximately 14.5(50) cm-1 for the internal rotation barrier of the CH3 group with respect to the framework of the complex has been made using the Pcc values for the H3CF-OCS and D3CF-OCS isotopic species. Two structures, very close in energy and approximately related by a 60 degrees rotation about the C3 axis of the methyl fluoride, were identified by ab initio calculations at the MP2/6-311++G(2d,2p) level and provide reasonable agreement with the experimental rotational constants and dipole moment components.

[{sup 14}C]Serotonin uptake and [O-methyl-{sup 11}C]venlafaxine kinetics in porcine brain

Energy Technology Data Exchange (ETDEWEB)

Smith, D.F. E-mail: dfsmith@inet.uni2.dk; Hansen, S.B.; Oestergaard, L.; Gee, A.D.; Danielsen, E.; Ishizu, K.; Bender, D.; Poulsen, P.H.; Gjedde, A

2001-08-01

As part of our program of developing PET tracers for neuroimaging of psychotropic compounds, venlafaxine, an antidepressant drug, was evaluated. First, we measured in vitro rates of serotonin uptake in synaptosomes prepared from selected regions of porcine brain. Then, we determined the pharmacokinetics of venlafaxine, [O-methyl-{sup 11}C]-labeled for PET. Synaptosomal studies showed that the active uptake of [{sup 14}C]5-HT differed markedly between brain regions, with highest rates in hypothalamus, raphe region, and thalamus, and lowest rates in cortex and cerebellum. PET studies showed that the unidirectional rate of uptake of [O-methyl-{sup 11}C]venlafaxine from blood to brain was highest in the hypothalamus, raphe region, thalamus and basal ganglia and lowest in the cortex and cerebellum. Under normal physiological conditions, the capillary permeability-surface area (PS) product for [O-methyl-{sup 11}C]venlafaxine could not be estimated, because of complete flow-limitation of the cerebral uptake. Nevertheless, a correlation occurred between the apparent partition volume of the radiotracer and the rate of active uptake of 5-HT in selected regions of the porcine brain. During hypercapnia, limitations of blood-brain transfer were observed, giving PS-products for water that were only ca. 50% higher than those of venlafaxine. Thus, under normal physiological conditions, the rate of uptake of venlafaxine from blood into brain is completely flow-limited.

Dimethyl 4,4′-dihydroxy-3,3′-{[(3aRS,7aRS-2,3,3a,4,5,6,7,7a-octahydro-1H-1,3-benzimidazole-1,3-diyl]bis(methylene}dibenzoate

Directory of Open Access Journals (Sweden)

Augusto Rivera

2011-11-01

Full Text Available The title compound, C25H30N2O6, has the imidazolidine ring in an envelope conformation. There are two intramolecular O—H...N hydrogen-bond interactions with graph-set motif S(6. The cyclohexane ring adopts a slightly distorted chair conformation. One methyl carboxylate substituent forms a dihedral angle of 12.00 (5° with the plane of the benzene ring, while the other methyl carboxylate group is almost coplanar, making a dihedral angle of 2.26 (9°. In the crystal, pairs of intermolecular C—H...O hydrogen bonds form racemic dimers, corresponding to an R22(18 graph-set motif. Further weak C—H...O interactions generate a chain running along the c axis.

Design Guidelines for In-Plane Mechanical Properties of SiC Fiber-Reinforced Melt-Infiltrated SiC Composites

Science.gov (United States)

Morscher, Gregory N.; Pujar, Vijay V.

2008-01-01

In-plane tensile stress-strain, tensile creep, and after-creep retained tensile properties of melt-infiltrated SiC-SiC composites reinforced with different fiber types were evaluated with an emphasis on obtaining simple or first-order microstructural design guidelines for these in-plane mechanical properties. Using the mini-matrix approach to model stress-strain behavior and the results of this study, three basic general design criteria for stress and strain limits are formulated, namely a design stress limit, a design total strain limit, and an after-creep design retained strength limit. It is shown that these criteria can be useful for designing components for high temperature applications.

Methylation of Brazilein on Secang (Caesalpinia sappan Linn) Wood Extract for Maintain Color Stability to the Changes of pH

Science.gov (United States)

Ulma, Zeni; Rahayuningsih, Edia; Dwi Wahyuningsih, Tutik

2018-01-01

The stability of natural dyes to the changes of pH is really necessary when the natural dyes are applied either on fabric or food. This research aimed to increase the stability of brazilein, a compound contained within the secang wood extract, to the changes of pH. The methylation process was done by reacting Dimethyl Carbonate (DMC) with the brazilein on the secang wood extract. DMC acts as a substance that substitute hydroxyl group on brazilein. The methylation reaction of brazilein on secang wood extract was operated on a three-necked round-bottomed flask fitted with mercury-sealed stirrer and reflux condenser under 80°C temperature and 250 rpm stirring speed. There were two variables observed in this research; the DMC amount ratio to the amount of secang wood extract and the time of the methylation process. The research showed that at the 1:10 the DMC amount ratio to the amount of wood extract and 8 hours of the methylation process give the better stability of color of the secang wood extract than the variation of the other variables.

Rate Constant and RRKM Product Study for the Reaction Between CH3 and C2H3 at T = 298K

Science.gov (United States)

Thorn, R. Peyton, Jr.; Payne, Walter A., Jr.; Chillier, Xavier D. F.; Stief, Louis J.; Nesbitt, Fred L.; Tardy, D. C.

2000-01-01

The total rate constant k1 has been determined at P = 1 Torr nominal pressure (He) and at T = 298 K for the vinyl-methyl cross-radical reaction CH3 + C2H3 yields products. The measurements were performed in a discharge flow system coupled with collision-free sampling to a mass spectrometer operated at low electron energies. Vinyl and methyl radicals were generated by the reactions of F with C2H4 and CH4, respectively. The kinetic studies were performed by monitoring the decay of C2H3 with methyl in excess, 6 rate coefficient was determined to be k1(298 K) = (1.02 +/- 0.53)x10(exp -10) cubic cm/molecule/s with the quoted uncertainty representing total errors. Numerical modeling was required to correct for secondary vinyl consumption by reactions such as C2H3 + H and C2H3 + C2H3. The present result for k1 at T = 298 K is compared to two previous studies at high pressure (100-300 Torr He) and to a very recent study at low pressure (0.9-3.7 Torr He). Comparison is also made with the rate constant for the similar reaction CH3 + C2H5 and with a value for k1 estimated by the geometric mean rule employing values for k(CH3 + CH3) and k(C2H3 + C2H3). Qualitative product studies at T = 298 K and 200 K indicated formation of C3H6, C2H2, and C2H5 as products of the combination-stabilization, disproportionation, and combination-decomposition channels, respectively, of the CH3 + C2H3 reaction. We also observed the secondary C4H8 product of the subsequent reaction of C3H5 with excess CH3; this observation provides convincing evidence for the combination-decomposition channel yielding C3H5 + H. RRKM calculations with helium as the deactivator support the present and very recent experimental observations that allylic C-H bond rupture is an important path in the combination reaction. The pressure and temperature dependencies of the branching fractions are also predicted.

Applications of 3H and 2H NMR spectroscopy in studies of β-lactam antibiotic biosynthesis

International Nuclear Information System (INIS)

Crout, D.H.G.

1986-01-01

Stereochemical studies have been invaluable in illuminating the mechanisms of enzymatic reactions. The formation of cephalosporin C from penicillin N is a biological process of fundamental importance in relation to cephalosporin C production. During this transformation, two methyl groups in penicillin N, (originally the two methyl groups of the precursor L-valine) are converted into methylene groups. One is involved in the ring expansion - sulphur migration step, the other in the formation of the acetoxymethyl side chain. By synthesizing 'chiral methyl' valine in which both methyl groups were stereospecifically labeled with deuterium and tritium, and by using 3 H and 2 H n.m.r. to analyse the valine, and the cephalosporin C produced from it biosynthetically, it has been possible in a single experiment to elucidate the stereochemical changes taking place during the transformations of both methyl groups. The results obtained support the hypothesis that both transformations involve radical intermediates. 8 refs.; 6 figs.; 4 schemes

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

International Nuclear Information System (INIS)

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

2017-01-01

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. - 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.

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

Energy Technology Data Exchange (ETDEWEB)

Alamdar, Ambreen; Xi, Guochen [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Huang, Qingyu, E-mail: qyhuang@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Centre for Epigenetics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M (Denmark); Tian, Meiping [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Eqani, Syed Ali Musstjab Akber Shah [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Public Health and Environment Division, Department of Biosciences, COMSAT Institute of Information & Technology, Islamabad (Pakistan); Shen, Heqing, E-mail: hqshen@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China)

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. - 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.

Direct approaches to nitriles via highly efficient nitrogenation strategy through C-H or C-C bond cleavage.

Science.gov (United States)

Wang, Teng; Jiao, Ning

2014-04-15

Because of the importance of nitrogen-containing compounds in chemistry and biology, organic chemists have long focused on the development of novel methodologies for their synthesis. For example, nitrogen-containing compounds show up within functional materials, as top-selling drugs, and as bioactive molecules. To synthesize these compounds in a green and sustainable way, researchers have focused on the direct functionalization of hydrocarbons via C-H or C-C bond cleavage. Although researchers have made significant progress in the direct functionalization of simple hydrocarbons, direct C-N bond formation via C-H or C-C bond cleavage remains challenging, in part because of the unstable character of some N-nucleophiles under oxidative conditions. The nitriles are versatile building blocks and precursors in organic synthesis. Recently, chemists have achieved the direct C-H cyanation with toxic cyanide salts in the presence of stoichiometric metal oxidants. In this Account, we describe recent progress made by our group in nitrile synthesis. C-H or C-C bond cleavage is a key process in our strategy, and azides or DMF serve as the nitrogen source. In these reactions, we successfully realized direct nitrile synthesis using a variety of hydrocarbon groups as nitrile precursors, including methyl, alkenyl, and alkynyl groups. We could carry out C(sp(3))-H functionalization on benzylic, allylic, and propargylic C-H bonds to produce diverse valuable synthetic nitriles. Mild oxidation of C═C double-bonds and C≡C triple-bonds also produced nitriles. The incorporation of nitrogen within the carbon skeleton typically involved the participation of azide reagents. Although some mechanistic details remain unclear, studies of these nitrogenation reactions implicate the involvement of a cation or radical intermediate, and an oxidative rearrangement of azide intermediate produced the nitrile. We also explored environmentally friendly oxidants, such as molecular oxygen, to make our

Radiosynthesis and in vivo evaluation of N-[{sup 11}C]methylated imidazopyridineacetamides as PET tracers for peripheral benzodiazepine receptors

Energy Technology Data Exchange (ETDEWEB)

Sekimata, Katsuhiko [Department of Brain Sciences and Molecular Imaging, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8522 (Japan); Hatano, Kentaro [Department of Brain Sciences and Molecular Imaging, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8522 (Japan)], E-mail: hatanok@nils.go.jp; Ogawa, Mikako [Photon Medical Research Center, Hamamatsu University School of Medicine, Shizuoka 431-3192 Japan (Japan); Abe, Junichiro [Department of Brain Sciences and Molecular Imaging, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8522 (Japan); Magata, Yasuhiro [Photon Medical Research Center, Hamamatsu University School of Medicine, Shizuoka 431-3192 Japan (Japan); Biggio, Giovanni; Serra, Mariangela [Department of Experimental Biology, University of Cagliari, Cagliari 09100 (Italy); Laquintana, Valentino; Denora, Nunzio; Latrofa, Andrea; Trapani, Giuseppe; Liso, Gaetano [Pharmaco-Chemistry Department, University of Bari, Bari 70125 (Italy); Ito, Kengo [Department of Brain Sciences and Molecular Imaging, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8522 (Japan)

2008-04-15

Imidazopyridineacetoamide 5-8, a series of novel and potentially selective peripheral benzodiazepine receptor (PBR) ligands with affinities comparable to those of known PBR ligands, was investigated. Radiosyntheses of [{sup 11}C]5, 6, 7 or 8 was accomplished by N-methylation of the corresponding desmethyl precursors with [{sup 11}C]methyl iodide in the presence of NaH in dimethylformamide (DMF), resulting in 25% to 77% radiochemical yield and specific activitiy of 20 to 150 MBq/nmol. Each of the labeled compounds was injected in ddY mice, and the radioactivity and weight of dissected peripheral organs and brain regions were measured. Organ distribution of [{sup 11}C]7 was consistent with the known PBR distribution. Moreover, [{sup 11}C]7 showed the best combination of brain uptake and PBR binding, leading to its high retention in the olfactory bulb and cerebellum, areas where PBR density is high in mouse brain. Coinjection of PK11195 or unlabeled 7 significantly reduced the brain uptake of [{sup 11}C]7. These results suggest that [{sup 11}C]7 could be a useful radioligand for positron emission tomography imaging of PBRs.

Multi-branched Cu2O nanowires for photocatalytic degradation of methyl orange

Science.gov (United States)

Yu, Chunxin; Shu, Yun; Zhou, Xiaowei; Ren, Yang; Liu, Zhu

2018-03-01

Multi-branched cuprous oxide nanowires (Cu2O NWs) were prepared by one-step hydrothermal method of a facile process. The architecture of these Cu2O NWs was examined by scanning electron microscopy, and the resulting crystal nanowire consists of the trunk growing along [100] plane and the branch growing along [110] plane. Photocatalytic degradation of methyl orange (MO) in the experiment indicates that pure Cu2O NWs prepared at 150 °C have a higher photocatalytic activity (90% MO were degraded within 20 min without the presence of H2O2) compared with the samples obtained at other temperatures. In the photoelectrochemical test, pure Cu2O NWs had outstanding photoelectric response, which corresponds to the catalytic performance. The superior photocatalytic performance can be attributed to the absence of grain boundaries between the small branches and the nanowire trunk, which is conducive to the transport of photo-generated carriers, and the reduction of Cu impurities to reduce the number of recombination centers.

11C-labelling of the analgesic Tramadol and its major metabolites by selective O- and N-methylation

International Nuclear Information System (INIS)

Gail, R.; Coenen, H.H.; Hamacher, K.; Stoecklin, G.

1992-01-01

For in vivo pharmacokinetic studies with PET, the analgesic Tramadol(1-(3-methoxyphenyl)-2-dimethylaminomethyl-cyclohexan-1-ol) and its major O- and N-desmethylated metabolites M1 and M2 were labelled with carbon-11. Starting with the corresponding desmethyl precursors, [O-methyl- 11 C]Tramadol and racemic[N-methyl- 11 C]Tramadol were prepared by methylation with n.c.a. [ 11 C]methyl iodide in DMSO with radiochemical yields of 85 and 90%, respectively. Specific n.c.a. N-methylation of bis-desmethyl-Tramadol (M5) was achieved with 90% radiochemical yield. However, a selective O-methylation of M5 was not possible even with an excess of NaOH, and only 70% of [O-methyl- 11 C]M2 was obtained. Quaternization of Tramadol or M1 was >15 times slower than O-methylation, and was only observed in the presence of added CH 3 I carrier. (author)

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

DEFF Research Database (Denmark)

Tessarz, Peter; Santos-Rosa, Helena; Robson, Sam C

2014-01-01

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...

Methyl 3,4-bis(cyclopropylmethoxybenzoate

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Xian-Chao Cheng

2011-05-01

Full Text Available The title compound, C16H20O4, was obtained unintentionally as the byproduct of an attempted synthesis of methyl 3-(cyclopropylmethoxy-4-hydroxybenzoate. In the crystal, the molecules are linked by intermolecular C—H...O interactions.

Synthesis of no-carrier-added alpha-[11C]methyl-L-tryptophan

International Nuclear Information System (INIS)

Chaly, T.; Diksic, M.

1988-01-01

Described here is a synthesis of no-carrier-added alpha-[ 11 C]methyl-L-tryptophan based on alkylation with 11 CH 3 I of an anion generated by reacting the Schiff base of L-tryptophan methyl ester with di-isopropylamine. The synthesis requires approximately 30 min after the end of 11 CO 2 collection and gives alpha-[ 11 C]methyl-L-tryptophan in a 20-25% radiochemical yield calculated at the end of the synthesis and without correction for radioactive decay. The specific activity of the final radiopharmaceutical, measured at the end of the synthesis, was around 2000 Ci/mmol. Data confirming the stereospecificity of the synthesis are also presented

Intermolecular C-H···O, Cl···Cl and π-π interactions in the 2-dichloromethyl derivative of vitamin K3.

Science.gov (United States)

Soave, Raffaella; Colombo, Pietro

2013-12-15

The title 1,4-naphthoquinone, 2-dichloromethyl-3-methyl-1,4-dihydronaphthalene-1,4-dione, C12H8Cl2O2, is a chlorinated derivative of vitamin K3, which is a synthetic compound also known as menadione. Molecules of (I) are planar and lie on a crystallographic mirror plane (Z' = 0.5) in the space group Pnma. They are connected to each other by C-H···O hydrogen bonds, forming two-dimensional layers parallel to the ac plane. In addition, Cl···Cl and π-π interactions link adjacent molecules in different layers, thus forming zigzag ribbons along the b axis, such that a three-dimensional architecture is generated.

Synthesis of N-[methyl-11C]hydromorphone by using multivariate strategies for optimization of radiochemical yields

International Nuclear Information System (INIS)

Rimland, Annika; Bergson, Goeran; Obenius, Ulf; Sjoeberg, Stefan; Langstroem, Bengt

1987-01-01

The synthesis of N-[methyl- 11 C]hydromorphone has been performed by using [ 11 C]methyl iodide and desmethyl hydromorphone in a mixture of dimethylsulphoxide and dimethylformamide as solvent. Optimization of the radiochemical yield by varying the reaction conditions was performed by using multivariate strategies. The labelled hydromorphone was obtained in 72% radiochemical yield in the alkylation reaction with [ 11 C]-methyl iodide, counted from the end of the [ 11 C]methyl iodide synthesis. N-[Methyl- 11 C]hydromorphone was obtained as a ready injectable pharmaceutical solution with a total synthesis time of 40 min and in a 10% total radiochemical yield, with a radiochemical purity > 99.5%, according to HPLC analysis. (author)

Protein methylation in pea chloroplasts

International Nuclear Information System (INIS)

Niemi, K.J.; Adler, J.; Selman, B.R.

1990-01-01

The methylation of chloroplast proteins has been investigated by incubating intact pea (Pisum sativum) chloroplasts with [ 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. One 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 [ 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 [ 3 H]methyl group

Methyl 6-methoxycarbonylmethyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate

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Lucia Veizerová

2008-09-01

Full Text Available The title compound, C15H16N2O5, belongs to the class of monastrol-type anti-cancer agents and was selected for crystal structure determination in order to determine the conformational details needed for subsequent structure–activity relationship studies. The central tetrahydropyrimidine ring has a flat-envelope conformation. The 4-phenyl group occupies a pseudo-axial position and is inclined at an angle of ca 90° to the mean plane of the heterocyclic ring. Of the two methyl ester groups, one (in the 5-position is in a coplanar and the other (in the 6-position in a perpendicular orientation with respect to the heterocyclic plane. The coplanar 5-ester group has its carbonyl bond oriented cis with respect to the pyrimidine C=C double bond. By comparison of the structural results for the present compound with those determined previously for its diethyl analogue, we have identified the molecular factors which control the dual course of the Biginelli reaction with salicylaldehyde. The crystal structure is dominated by two hydrogen bonds which link the molecules into chains of dimers.

SNP rs16906252C>T is an expression and methylation quantitative trait locus associated with an increased risk of developing MGMT-methylated colorectal cancer

Science.gov (United States)

Kuroiwa-Trzmielina, Joice; Wang, Fan; Rapkins, Robert W.; Ward, Robyn L.; Buchanan, Daniel D.; Win, Aung Ko; Clendenning, Mark; Rosty, Christophe; Southey, Melissa C.; Winship, Ingrid M.; Hopper, John L.; Jenkins, Mark A.; Olivier, Jake; Hawkins, Nicholas J.; Hitchins, Megan P.

2016-01-01

Purpose Methylation of the MGMT promoter is the major cause of O6-methylguanine methyltransferase deficiency in cancer and has been associated with the T variant of the promoter-enhancer SNP rs16906252C>T. We sought evidence for an association between the rs16906252C>T genotype and increased risk of developing a subtype of colorectal cancer (CRC) featuring MGMT methylation, mediated by genotype-dependent epigenetic silencing within normal tissues. Experimental design By applying a molecular pathological epidemiology case-control study design, associations between rs16906252C>T and risk for CRC overall, and CRC stratified by MGMT methylation status, were estimated using multinomial logistic regression in two independent retrospective series of CRC cases and controls. The test sample comprised 1054 CRC cases and 451 controls from Sydney, Australia. The validation sample comprised 612 CRC cases and 245 controls from the Australasian Colon Cancer Family Registry (ACCFR). To determine if rs16906252C>T was linked to a constitutively altered epigenetic state, quantitative allelic expression and methylation analyses were performed in normal tissues. Results An association between rs16906252C>T and increased risk of developing MGMT-methylated CRC in the Sydney sample was observed (OR 3.3; 95%CI=2.0–5.3; PT represents an expression and methylation quantitative trait locus. Conclusions We provide evidence that rs16906252C>T is associated with elevated risk for MGMT-methylated CRC, likely mediated by constitutive epigenetic repression of the T allele. PMID:27267851

One column method to prepare 11C-labelled methyl iodide

International Nuclear Information System (INIS)

Kovacs, Z.; Priboczki, E.

1999-01-01

A new method in which the [ 11 C]methyl iodide is prepared on one alumina column is presented. A high specific surface alumina column, previously impregnated with lithium aluminium hydride solution, was used for direct trapping from the target gas and reduction into radiocomplex. The complex was then reacted on this column with HI to form [ 11 C]methyl iodide. The use of one alumina column, instead of a freezing trap, reaction vessel and separate unit for iodination, simplifies the apparatus, shortens the synthesis time and is well suitable for automation. (K.A.)

1-Benzyl-3′-[(1H-indol-3-ylcarbonyl]-1′-methyl-2-oxo-4′-(pyridin-3-ylspiro[indoline-3,2′-pyrrolidine]-3′-carbonitrile

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P. Seethalakshmi

2016-11-01

Full Text Available In the title compound, C34H27N5O2, the central pyrrolidine ring adopts an envelope conformation, with the N atom as the flap. The mean planes of the two indoline ring systems are inclined to the mean plane of the central pyrrolidine ring by 86.26 (9 and 69.30 (9°, respectively. The dihedral angle between the benzene and pyridine rings is 75.09 (11°. In the crystal, molecules are linked by N—H...N and C—H...N hydrogen bonds, forming sheets parallel to the ab plane.

Crystal structures of 4-meth-oxy-N-(4-methyl-phenyl)benzene-sulfonamide and N-(4-fluoro-phenyl)-4-meth-oxy-benzene-sulfonamide.

Science.gov (United States)

Rodrigues, Vinola Z; Preema, C P; Naveen, S; Lokanath, N K; Suchetan, P A

2015-11-01

Crystal structures of two N-(ar-yl)aryl-sulfonamides, namely, 4-meth-oxy-N-(4-methyl-phen-yl)benzene-sulfonamide, C14H15NO3S, (I), and N-(4-fluoro-phen-yl)-4-meth-oxy-benzene-sulfonamide, C13H12FNO3S, (II), were determined and analyzed. In (I), the benzene-sulfonamide ring is disordered over two orientations, in a 0.516 (7):0.484 (7) ratio, which are inclined to each other at 28.0 (1)°. In (I), the major component of the sulfonyl benzene ring and the aniline ring form a dihedral angle of 63.36 (19)°, while in (II), the planes of the two benzene rings form a dihedral angle of 44.26 (13)°. In the crystal structure of (I), N-H⋯O hydrogen bonds form infinite C(4) chains extended in [010], and inter-molecular C-H⋯πar-yl inter-actions link these chains into layers parallel to the ab plane. The crystal structure of (II) features N-H⋯O hydrogen bonds forming infinite one dimensional C(4) chains along [001]. Further, a pair of C-H⋯O inter-molecular inter-actions consolidate the crystal packing of (II) into a three-dimensional supra-molecular architecture.

Crystal structure of fac-[2-(4-methyl-5-phenylpyridin-2-ylphenyl-κ2C1,N]bis[2-(pyridin-2-ylphenyl-κ2C1,N]iridium(III

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Chi-Heon Lee

2016-12-01

Full Text Available In the title compound, [Ir(C11H8N2(C18H14N], the IrIII ion adopts a distorted octahedral coordination environment defined by three C,N-chelating ligands, one stemming from a 2-(4-phenyl-5-methylpyridin-2-ylphenyl ligand and two from 2-(pyridin-2-ylphenyl ligands, arranged in a facial manner. The IrIII ion lies almost in the equatorial plane [deviation = 0.0069 (15 Å]. In the crystal, intermolecular π–π stacking interactions, as well as intermolecular C—H...π interactions, are present, leading to a three-dimensional network.

Early onset MSI-H colon cancer with MLH1 promoter methylation, is there a genetic predisposition?

International Nuclear Information System (INIS)

Roon, Eddy HJ van; Hes, Frederik J; Tops, Carli MJ; Wezel, Tom van; Boer, Judith M; Morreau, Hans; Puijenbroek, Marjo van; Middeldorp, Anneke; Eijk, Ronald van; Meijer, Emile J de; Erasmus, Dianhdra; Wouters, Kim AD; Engeland, Manon van; Oosting, Jan

2010-01-01

To investigate the etiology of MLH1 promoter methylation in mismatch repair (MMR) mutation-negative early onset MSI-H colon cancer. As this type of colon cancer is associated with high ages, young patients bearing this type of malignancy are rare and could provide additional insight into the etiology of sporadic MSI-H colon cancer. We studied a set of 46 MSI-H colon tumors cases with MLH1 promoter methylation which was enriched for patients with an age of onset below 50 years (n = 13). Tumors were tested for CIMP marker methylation and mutations linked to methylation: BRAF, KRAS, GADD45A and the MLH1 -93G>A polymorphism. When available, normal colon and leukocyte DNA was tested for GADD45A mutations and germline MLH1 methylation. SNP array analysis was performed on a subset of tumors. We identified two cases (33 and 60 years) with MLH1 germline promoter methylation. BRAF mutations were less frequent in colon cancer patients below 50 years relative to patients above 50 years (p-value: 0.044). CIMP-high was infrequent and related to BRAF mutations in patients below 50 years. In comparison with published controls the G>A polymorphism was associated with our cohort. Although similar distribution of the pathogenic A allele was observed in the patients with an age of onset above and below 50 years, the significance for the association was lost for the group under 50 years. GADD45A sequencing yielded an unclassified variant. Tumors from both age groups showed infrequent copy number changes and loss-of-heterozygosity. Somatic or germline GADD45A mutations did not explain sporadic MSI-H colon cancer. Although germline MLH1 methylation was found in two individuals, locus-specific somatic MLH1 hypermethylation explained the majority of sporadic early onset MSI-H colon cancer cases. Our data do not suggest an intrinsic tendency for CpG island hypermethylation in these early onset MSI-H tumors other than through somatic mutation of BRAF

Early onset MSI-H colon cancer with MLH1 promoter methylation, is there a genetic predisposition?

Directory of Open Access Journals (Sweden)

Hes Frederik J

2010-05-01

Full Text Available Abstract Background To investigate the etiology of MLH1 promoter methylation in mismatch repair (MMR mutation-negative early onset MSI-H colon cancer. As this type of colon cancer is associated with high ages, young patients bearing this type of malignancy are rare and could provide additional insight into the etiology of sporadic MSI-H colon cancer. Methods We studied a set of 46 MSI-H colon tumors cases with MLH1 promoter methylation which was enriched for patients with an age of onset below 50 years (n = 13. Tumors were tested for CIMP marker methylation and mutations linked to methylation: BRAF, KRAS, GADD45A and the MLH1 -93G>A polymorphism. When available, normal colon and leukocyte DNA was tested for GADD45A mutations and germline MLH1 methylation. SNP array analysis was performed on a subset of tumors. Results We identified two cases (33 and 60 years with MLH1 germline promoter methylation. BRAF mutations were less frequent in colon cancer patients below 50 years relative to patients above 50 years (p-value: 0.044. CIMP-high was infrequent and related to BRAF mutations in patients below 50 years. In comparison with published controls the G>A polymorphism was associated with our cohort. Although similar distribution of the pathogenic A allele was observed in the patients with an age of onset above and below 50 years, the significance for the association was lost for the group under 50 years. GADD45A sequencing yielded an unclassified variant. Tumors from both age groups showed infrequent copy number changes and loss-of-heterozygosity. Conclusion Somatic or germline GADD45A mutations did not explain sporadic MSI-H colon cancer. Although germline MLH1 methylation was found in two individuals, locus-specific somatic MLH1 hypermethylation explained the majority of sporadic early onset MSI-H colon cancer cases. Our data do not suggest an intrinsic tendency for CpG island hypermethylation in these early onset MSI-H tumors other than through

N-(3-Chloro-4-ethoxy-1-methyl-1H-indazol-5-yl-4-methoxybenzenesulfonamide

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Hakima Chicha

2014-06-01

Full Text Available The indazole ring system of the title compound, C17H18ClN3O4S, is almost planar (r.m.s. deviation = 0.0113 Å and forms dihedral angles of 32.22 (8 and 57.5 (3° with the benzene ring and the mean plane through the 4-ethoxy group, respectively. In the crystal, molecules are connected by pairs of N—H...O hydrogen bonds into inversion dimers, which are further linked by π–π interactions between the diazole rings [intercentroid distance = 3.4946 (11 Å], forming chains parallel to [101].

Synthesis of (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolic acid, methyl (1'-/sup 13/C)olivetolate and (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolic acid

Energy Technology Data Exchange (ETDEWEB)

Porwoll, J P; Leete, E [Minnesota Univ., Minneapolis (USA). Dept. of Chemistry

1985-03-01

Potential advanced intermediates in the biosynthesis of delta/sup 9/-tetrahydrocannabinol, the major psychoactive principle of marijuana, have been synthesized labeled with two contiguous /sup 13/C atoms and /sup 14/C. Methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolate was prepared from lithium (/sup 13/C/sub 2/)acetylide and dimethyl (2-/sup 14/C)malonate. Reaction with geranyl bromide afforded methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolate, and hydrolysis of these methyl esters with lithium propyl mercaptide yielded the corresponding labeled acids. The /sup 13/C-/sup 13/C couplings observable in the /sup 13/C NMR spectra of these /sup 13/C-enriched compounds and their synthetic precursors are recorded. Methyl (1'-/sup 14/C)olivetolate was prepared from /sup 13/CO/sub 2/ to confirm assignments of the /sup 13/C chemical shifts in the pentyl side chain of these compounds.

On the C*-algebras of foliations in the plane

CERN Document Server

Wang, Xiaolu

1987-01-01

The main result of this original research monograph is the classification of C*-algebras of ordinary foliations of the plane in terms of a class of -trees. It reveals a close connection between some most recent developments in modern analysis and low-dimensional topology. It introduces noncommutative CW-complexes (as the global fibred products of C*-algebras), among other things, which adds a new aspect to the fast-growing field of noncommutative topology and geometry. The reader is only required to know basic functional analysis. However, some knowledge of topology and dynamical systems will be helpful. The book addresses graduate students and experts in the area of analysis, dynamical systems and topology.

Bis(3-acetyl-6-methyl-2-oxo-2H-pyran-4-olatobis(dimethyl sulfoxidenickel(II

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Amel Djedouani

2009-10-01

Full Text Available In the title compound, [Ni(C8H7O42{(CH32SO}2], the NiII atom is located on a crystallographic centre of symmetry and has a distorted octahedral coordination geometry of type MO6. The bidentate dehydroacetic acid (DHA ligands occupy the equatorial plane of the complex in a trans configuration, and the dimethyl sulfoxide (DMSO ligands are weakly coordinated through their O atoms in the axial positions.

Synthesis of racemic, S(+)- and R(-)-N-[methyl- [sup 3]H]3,4-methylenedioxymethamphetamine

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, Kenji; Hirai, Katsumi; Goromaru, Tsuyoshi (Fukuyama Univ. (Japan). Faculty of Pharmacy and Pharmaceutical Sciences)

1990-04-01

The synthesis of 3,4-methylenedioxymethampetamine (MDMA), a serotonergic neurotoxin, labeled with tritium is described. Labeling was accomplished by N-alkylation of the free base of the corresponding desmethyl compound using [[sup 3]H]methyl iodide. The compound was purified by preparative HPLC. The radiochemical yield was about 60% based on [[sup 3]H]methyl iodide. The radiochemical purity was more than 95% from HPLC and TLC. Furthermore, S(+)- and R(-)-[[sup 3]H]MDMA were completely separated by analytical HPLC with chiral column. (author).

Intra-operative adjustment of standard planes in C-arm CT image data.

Science.gov (United States)

Brehler, Michael; Görres, Joseph; Franke, Jochen; Barth, Karl; Vetter, Sven Y; Grützner, Paul A; Meinzer, Hans-Peter; Wolf, Ivo; Nabers, Diana

2016-03-01

With the help of an intra-operative mobile C-arm CT, medical interventions can be verified and corrected, avoiding the need for a post-operative CT and a second intervention. An exact adjustment of standard plane positions is necessary for the best possible assessment of the anatomical regions of interest but the mobility of the C-arm causes the need for a time-consuming manual adjustment. In this article, we present an automatic plane adjustment at the example of calcaneal fractures. We developed two feature detection methods (2D and pseudo-3D) based on SURF key points and also transferred the SURF approach to 3D. Combined with an atlas-based registration, our algorithm adjusts the standard planes of the calcaneal C-arm images automatically. The robustness of the algorithms is evaluated using a clinical data set. Additionally, we tested the algorithm's performance for two registration approaches, two resolutions of C-arm images and two methods for metal artifact reduction. For the feature extraction, the novel 3D-SURF approach performs best. As expected, a higher resolution ([Formula: see text] voxel) leads also to more robust feature points and is therefore slightly better than the [Formula: see text] voxel images (standard setting of device). Our comparison of two different artifact reduction methods and the complete removal of metal in the images shows that our approach is highly robust against artifacts and the number and position of metal implants. By introducing our fast algorithmic processing pipeline, we developed the first steps for a fully automatic assistance system for the assessment of C-arm CT images.

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

DEFF Research Database (Denmark)

Alamdar, Ambreen; Xi, Guochen; Huang, Qingyu

2017-01-01

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......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...

Simple automated system for simultaneous production of 11C-labeled tracers by solid supported methylation

International Nuclear Information System (INIS)

Quincoces, Gemma; Penuelas, Ivan; Valero, Marta; Serra, Patricia; Collantes, Maria; Marti-Climent, Josep; Arbizu, Javier; Jose Garcia-Velloso, Maria; Angel Richter, Jose

2006-01-01

We herein describe a simple setup for the automated simultaneous synthesis of L-[methyl- 11 C]methionine and N-[methyl- 11 C]choline by solid-supported methylation . The setup is extremely simple and easy to adapt to other automated systems and due to its versatility, the method can be utilized for the production of other radiopharmaceuticals requiring a simple [ 11 C]methylation step. Furthermore, it can be used for multiple simultaneous synthesis

The incorporation of [1-14C] acetate into the methyl ketones that occur in steam-distillates of bovine milk fat.

Science.gov (United States)

Lawrence, R C; Hawke, J C

1966-01-01

1. The (14)C-labelling of the fatty acids and the methyl ketones in steam-distillates of milk fat from a lactating cow that had been injected intravenously with [1-(14)C]acetate was determined. 2. The labelling patterns of the C(6)-C(16) fatty acids and the corresponding methyl ketones with one fewer carbon atoms were similar, particularly so for the C(5)-C(10) compounds at 9 and 22hr. after the injection of [1-(14)C]acetate. The isolation of (14)C-labelled methyl ketones in the range C(3)-C(15) is evidence that the beta-oxo acid precursors, which are glyceride-bound in the milk fat, are synthesized in the mammary gland from acetate. The absence of heptadecan-2-one in steam-distillates and the extremely low specific radioactivity of stearic acid are further evidence for this biosynthetic pathway. 3. The specific radioactivities of the C(5)-C(15) methyl ketones were higher (with the exception of C(9) methyl ketone in the second milking) than the specific activities of the corresponding fatty acids with one more carbon atom. This is consistent with the methyl ketone precursors' being formed during the biosynthesis of fatty acids rather than being products of beta-oxidation of fatty acids.

The effect of a slight mis-orientation angle of c-plane sapphire substrate on surface and crystal quality of MOCVD grown GaN thin films

Energy Technology Data Exchange (ETDEWEB)

Kim, Seong-Woo; Suzuki, Toshimasa [Nippon Institute of Technology, 4-1 Gakuendai, Miyashiro, Saitama, 345-8501 (Japan); Aida, Hideo [NAMIKI Precision Jewel Co. Ltd., 3-8-22 Shinden, Adachi-ku, Tokyo, 123-8511 (Japan)

2004-09-01

The effect of a slight mis-orientation of c-plane sapphire substrate on the surface morphology and crystal quality of GaN thin films grown by MOCVD has been investigated. The mis-orientation angle of vicinal c-plane sapphire substrate was changed within the range of 0.00(zero)-1.00(one) degree, and the experimental results were compared with those on just angle (zero degree) c-plane sapphire substrate. The surface morphology and crystal quality were found to be very sensitive to mis-orientation angle. Consequently, the mis-orientation angle was optimized to be 0.15 . (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

(E-2-Methyl-6-{[(5-methylpyridin-2-ylimino]methyl}phenol

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Md. Azharul Arafath

2017-01-01

Full Text Available In the title compound, C14H14N2O, the dihedral angle between the aromatic rings is 5.54 (9°. The conformation is reinforced by an intramolecular O—H...N hydrogen bond, which closes an S(6 ring. The pyridine N atom and methyl group lie to opposite sides of the molecule. In the crystal, the molecules are linked into a zigzag chain propagating in [0-11] by weak C—H...O hydrogen bonds.

Cobalt-Catalyzed C(sp(2))-H Borylation: Mechanistic Insights Inspire Catalyst Design.

Science.gov (United States)

Obligacion, Jennifer V; Semproni, Scott P; Pappas, Iraklis; Chirik, Paul J

2016-08-24

A comprehensive study into the mechanism of bis(phosphino)pyridine (PNP) cobalt-catalyzed C-H borylation of 2,6-lutidine using B2Pin2 (Pin = pinacolate) has been conducted. The experimentally observed rate law, deuterium kinetic isotope effects, and identification of the catalyst resting state support turnover limiting C-H activation from a fully characterized cobalt(I) boryl intermediate. Monitoring the catalytic reaction as a function of time revealed that borylation of the 4-position of the pincer in the cobalt catalyst was faster than arene borylation. Cyclic voltammetry established the electron withdrawing influence of 4-BPin, which slows the rate of C-H oxidative addition and hence overall catalytic turnover. This mechanistic insight inspired the next generation of 4-substituted PNP cobalt catalysts with electron donating and sterically blocking methyl and pyrrolidinyl substituents that exhibited increased activity for the C-H borylation of unactivated arenes. The rationally designed catalysts promote effective turnover with stoichiometric quantities of arene substrate and B2Pin2. Kinetic studies on the improved catalyst, 4-(H)2BPin, established a change in turnover limiting step from C-H oxidative addition to C-B reductive elimination. The iridium congener of the optimized cobalt catalyst, 6-(H)2BPin, was prepared and crystallographically characterized and proved inactive for C-H borylation, a result of the high kinetic barrier for reductive elimination from octahedral Ir(III) complexes.

The Variation Analysis of DNA Methylation in Wheat Carrying Gametocidal Chromosome 3C from Aegilops triuncialis.

Science.gov (United States)

Wang, Dan; Zhao, Jieyu; Bai, Yan; Ao, You; Guo, Changhong

2017-08-10

Gametocidal (Gc) chromosomes can ensure their preferential transmission by killing the gametes without themselves through causing chromosome breakage and therefore have been exploited as an effective tool for genetic breeding. However, to date very little is known about the molecular mechanism of Gc action. In this study, we used methylation-sensitive amplified polymorphism (MSAP) technique to assess the extent and pattern of cytosine methylation alterations at the whole genome level between two lines of wheat Gc addition line and their common wheat parent. The results indicated that the overall levels of cytosine methylation of two studied Gc addition lines (CS-3C and CS-3C3C, 48.68% and 48.65%, respectively) were significantly increased when compared to common wheat CS (41.31%) and no matter fully methylated or hemimethylated rates enhanced in Gc addition lines. A set of 30 isolated fragments that showed different DNA methylation or demethylation patterns between the three lines were sequenced and the results indicated that 8 fragments showed significant homology to known sequences, of which three were homologous to MITE transposon (Miniature inverted-repeat transposable elements), LTR-retrotransposon WIS-1p and retrotransposon Gypsy , respectively. Overall, our results showed that DNA methylation could play a role in the Gc action.

The Variation Analysis of DNA Methylation in Wheat Carrying Gametocidal Chromosome 3C from Aegilops triuncialis

Directory of Open Access Journals (Sweden)

Dan Wang

2017-08-01

Full Text Available Gametocidal (Gc chromosomes can ensure their preferential transmission by killing the gametes without themselves through causing chromosome breakage and therefore have been exploited as an effective tool for genetic breeding. However, to date very little is known about the molecular mechanism of Gc action. In this study, we used methylation-sensitive amplified polymorphism (MSAP technique to assess the extent and pattern of cytosine methylation alterations at the whole genome level between two lines of wheat Gc addition line and their common wheat parent. The results indicated that the overall levels of cytosine methylation of two studied Gc addition lines (CS–3C and CS–3C3C, 48.68% and 48.65%, respectively were significantly increased when compared to common wheat CS (41.31% and no matter fully methylated or hemimethylated rates enhanced in Gc addition lines. A set of 30 isolated fragments that showed different DNA methylation or demethylation patterns between the three lines were sequenced and the results indicated that 8 fragments showed significant homology to known sequences, of which three were homologous to MITE transposon (Miniature inverted–repeat transposable elements, LTR-retrotransposon WIS-1p and retrotransposon Gypsy, respectively. Overall, our results showed that DNA methylation could play a role in the Gc action.

Identification of Methyl Halide-Utilizing Genes in the Methyl Bromide-Utilizing Bacterial Strain IMB-1 Suggests a High Degree of Conservation of Methyl Halide-Specific Genes in Gram-Negative Bacteria

Science.gov (United States)

Woodall, C.A.; Warner, K.L.; Oremland, R.S.; Murrell, J.C.; McDonald, I.R.

2001-01-01

Strain IMB-1, an aerobic methylotrophic member of the alpha subgroup of the Proteobacteria, can grow with methyl bromide as a sole carbon and energy source. A single cmu gene cluster was identified in IMB-1 that contained six open reading frames: cmuC, cmuA, orf146, paaE, hutI, and partial metF. CmuA from IMB-1 has high sequence homology to the methyltransferase CmuA from Methylobacterium chloromethanicum and Hyphomicrobium chloromethanicum and contains a C-terminal corrinoid-binding motif and an N-terminal methyl-transferase motif. However, cmuB, identified in M. chloromethanicum and H. chloromethanicum, was not detected in IMB-1.

Mapping of the methylation pattern of the hMSH2 promoter in colon cancer, using bisulfite genomic sequencing

Directory of Open Access Journals (Sweden)

Zhang Hua

2006-08-01

Full Text Available Abstract The detailed methylation status of CpG sites in the promoter region of hMSH2 gene has yet not to be reported. We have mapped the complete methylation status of the hMSH2 promoter, a region that contains 75 CpG sites, using bisulfite genomic sequencing in 60 primary colorectal cancers. And the expression of hMSH2 was detected by immunohistochemistry. The hypermethylation of hMSH2 was detected in 18.33% (11/60 of tumor tissues. The protein of hMSH2 was detected in 41.67% (25/60 of tumor tissues. No hypermethylation of hMSH2 was detected in normal tissues. The protein of hMSH2 was detected in all normal tissues. Our study demonstrated that hMSH2 hypermethylation and protein expression were associated with the development of colorectal cancer.

Synthesis of (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolic acid, methyl (1'-/sup 13/C)olivetolate and (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolic acid

Energy Technology Data Exchange (ETDEWEB)

Porwoll, J.P.; Leete, E. (Minnesota Univ., Minneapolis (USA). Dept. of Chemistry)

1985-03-01

Potential advanced intermediates in the biosynthesis of delta/sup 9/-tetrahydrocannabinol, the major psychoactive principle of marijuana, have been synthesized labeled with two contiguous /sup 13/C atoms and /sup 14/C. Methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)olivetolate was prepared from lithium (/sup 13/C/sub 2/)acetylide and dimethyl (2-/sup 14/C)malonate. Reaction with geranyl bromide afforded methyl (5,6-/sup 13/C/sub 2/, 1-/sup 14/C)cannabigerolate, and hydrolysis of these methyl esters with lithium propyl mercaptide yielded the corresponding labeled acids. The /sup 13/C-/sup 13/C couplings observable in the /sup 13/C NMR spectra of these /sup 13/C-enriched compounds and their synthetic precursors are recorded. Methyl (1'-/sup 14/C)olivetolate was prepared from /sup 13/CO/sub 2/ to confirm assignments of the /sup 13/C chemical shifts in the pentyl side chain of these compounds.

Pt/Cu single-atom alloys as coke-resistant catalysts for efficient C-H activation

Science.gov (United States)

Marcinkowski, Matthew D.; Darby, Matthew T.; Liu, Jilei; Wimble, Joshua M.; Lucci, Felicia R.; Lee, Sungsik; Michaelides, Angelos; Flytzani-Stephanopoulos, Maria; Stamatakis, Michail; Sykes, E. Charles H.

2018-03-01

The recent availability of shale gas has led to a renewed interest in C-H bond activation as the first step towards the synthesis of fuels and fine chemicals. Heterogeneous catalysts based on Ni and Pt can perform this chemistry, but deactivate easily due to coke formation. Cu-based catalysts are not practical due to high C-H activation barriers, but their weaker binding to adsorbates offers resilience to coking. Using Pt/Cu single-atom alloys (SAAs), we examine C-H activation in a number of systems including methyl groups, methane and butane using a combination of simulations, surface science and catalysis studies. We find that Pt/Cu SAAs activate C-H bonds more efficiently than Cu, are stable for days under realistic operating conditions, and avoid the problem of coking typically encountered with Pt. Pt/Cu SAAs therefore offer a new approach to coke-resistant C-H activation chemistry, with the added economic benefit that the precious metal is diluted at the atomic limit.

Synthesis, NMR spectral and antimicrobial studies of some [N-methyl-3t-alkyl-2r,6c-diarylpiperidin-4-ylidine]-5‧-methylthiazolidine-4-ones

Science.gov (United States)

Prakash, S. M.; Pandiarajan, K.; Kumar, S.

2013-06-01

Four new [N-methyl-3t-alkyl-2r,6c-diaryl-4-ylidine]-5'-methylthiozolidin-4-ones 9-12 have been synthesized by the condensation of N-methyl-3t-alkyl-2r,6c-diarylpiperidin-4-one thiosemicarbazones with ethyl 2-bromopropionate. These compounds have been characterized using FT-IR, 1H NMR, 13C NMR spectral techniques. HOMOCOSY, HSQC and HMBC spectral study have been done for [N-methyl-3,3-dimethyl-2r,6c-bis(p-methoxyphenyl)piperidin-4-ylidine]-5'-methylthiazolidine-4-one (12). Two geometrical isomers are formed in this reaction. In all these compounds piperidin rings adopt chair conformation. The rotation of the aryl group at C-2 is rather slow in 10-12. Antimicrobial activities have also been studied for 9-12. These compounds are active against all the tested bacterial and fungal strains.

4-[(5R*,10bR*-2-Methyl-1,10b-dihydropyrazolo[1,5-c][1,3]benzoxazin-5-yl]benzoic acid

Directory of Open Access Journals (Sweden)

Jan Světlík

2008-03-01

Full Text Available In the title compound, C18H16N2O3, a potential inhibitor of the cyclooxygenase-2 isoenzyme, the pyrazoline ring exists in a flattened envelope conformation with one C atom deviating by 0.463 Å from the mean plane of the remaining four atoms. The puckering of the central oxazine ring is more severe, with one N atom and one C atom displaced by 0.235 (6 and 0.370 (2 Å, respectively, on opposite sides of the mean plane defined by the other four atoms; the conformation is that of a half-chair. As a result, the molecule as a whole is not planar. The carboxyl group is involved in an intermolecular O—H...N hydrogen bond, which links the molecules into centrosymmetric dimers.

(R,S-2′-Amino-6′-methyl-2,5′,5′-trioxo-6′H-spiro[indoline-3,4′-pyrano[3,2-c][2,1]benzothiazine]-3′-carbonitrile dimethylformamide monosolvate

Directory of Open Access Journals (Sweden)

Svitlana V. Shishkina

2014-07-01

Full Text Available The title solvate, C20H14N4O4S·C3H7NO, comprises a stereogenic centre but the centrosymmetric space group causes the presence of the racemate in the crystal. The spiro-joined fragments are almost orthogonal, with a dihedral angle of 86.8 (2° between the mean planes of the pyrane ring and the dihydroindolone ring system. The atoms of the indolinone bicycle are coplanar, with an r.m.s. deviation of 0.005 Å. In the crystal, pairs of N—H...O hydrogen bonds link the molecules into centrosymmetric dimers which are linked to the dimethylformamide solvent molecules by further N—H...O hydrogen bonds. N—H...N hydrogen bonds link neighbouring dimers into [010] chains.

In vitro evaluation of N-methyl amide tripeptidomimetics as substrates for the human intestinal di-/tri-peptide transporter hPEPT1

DEFF Research Database (Denmark)

Andersen, Rikke; Nielsen, Carsten Uhd; Begtrup, Mikael

2006-01-01

application of N-methyl amide bioisosteres as peptide bond replacements in tripeptides in order to decrease degradation by peptidases and yet retain affinity for and transport via hPEPT1. Seven structurally diverse N-methyl amide tripeptidomimetics were selected based on a principal component analysis...... of structural properties of 6859 N-methyl amide tripeptidomimetics. In vitro extracellular degradation of the selected tripeptidomimetics as well as affinity for and transepithelial transport via hPEPT1 were investigated in Caco-2 cells. Decreased apparent degradation was observed for all tripeptidomimetics...... to be substrates for hPEPT1 than tripeptidomimetics with charged side chains. The results of the present study indicate that the N-methyl amide peptide bond replacement approach for increasing bioavailability of tripeptidomimetic drug candidates is not generally applicable to all tripeptides. Nevertheless...

Methylation profiling in individuals with Russell-Silver syndrome.

Science.gov (United States)

Peñaherrera, Maria S; Weindler, Susanne; Van Allen, Margot I; Yong, Siu-Li; Metzger, Daniel L; McGillivray, Barbara; Boerkoel, Cornelius; Langlois, Sylvie; Robinson, Wendy P

2010-02-01

Russell-Silver syndrome (RSS) is a heterogeneous disorder associated with pre- and post-natal growth restriction and relative macrocephaly. Involvement of imprinted genes on both chromosome 7 and 11p15.5 has been reported. To further characterize the role of epimutations in RSS we evaluated the methylation status at both 11p15.5 imprinting control regions (ICRs): ICR1 associated with H19/IGF2 expression and ICR2 (KvDMR1) associated with CDKN1C expression in a series of 35 patients with RSS. We also evaluated methylation at the promoter regions of other imprinted genes involved in growth such as PLAGL1 (6q24), GCE (7q21), and PEG10 (7q21) in this series of 35 patients with RSS. Thirteen of the 35 patient samples, but none of 22 controls, showed methylation levels at ICR1 that were more than 2 SD below the mean for controls. Three RSS patients were highly methylated at the SCGE promoter, all of which were diagnosed with upd(7)mat. To identify further potential global methylation changes in RSS patients, a subset of 22 patients were evaluated at 1505 CpG sites by the Illumina GoldenGate methylation array. Among the few CpG sites displaying a significant difference between RSS patients and controls, was a CpG associated with the H19 promoter. No other sites associated with known imprinted genes were identified as abnormally methylated in RSS patients by this approach. While the association of hypomethylation of the H19/IGF2 ICR1 is clear, the continuous distribution of methylation values among the patients and controls complicates the establishment of clear cut-offs for clinical diagnosis. Copyright 2010 Wiley-Liss, Inc.

Synergistic complexes of uranyl ion with 1-phenyl-3-methyl-4-acetyl-pyrazolone-5 and some oxo-donors

International Nuclear Information System (INIS)

Nagar, M.S.; Ruikar, P.B.; Subramanian, M.S.

1987-01-01

Complexes of uranyl ion with 1-phenyl-3-methyl-4-acetyl-pyrazolone-5(PMAP) and various oxo-donors such as aliphatic sulphoxides [R 2 SO, where R = i-C 5 H 11 (DISO), n-C 6 H 13 (DHSO), n-C 7 H 15 (DSSO), n-C 8 H 17 (DOSO), n-C 9 H 19 (DNSO), n-C 10 H 21 (DDSO), n-C 11 H 23 (DUDSO) and n-C 4 H 9 (DBUSO)] tributylphosphate (TBP) and tri-n-octyl phosphine oxide (TOPO) have been synthesised and characterized. Analytical data establish that they have the stoichiometry UO 2 (PMAP) 2 X where X is the oxo-donor. The IR spectra of the sulphoxide complexes in the S - O stretching region indicate that the ligands R 2 SO are O-bonded. The methyl protons of the pyrazole ring and acetyl group in the PMAP ligand are equivalent giving rise to a single sharp peak in the PMR spectra, whereas in the synergistic complexes with the oxo-donors, two deshielded peaks of equal intensity are observed which indicate the non-equivalence of the methyl groups. The peak which is more deshielded has been ascribed to the methyl of the acetyl group. The higher deshielding of these methyl protons arises due to the transfer of electron density to the metal atom on complexation. (author)

pH-dependent fluorescence property of methyl red isomers in silver colloids

International Nuclear Information System (INIS)

Wong, Jian-How; Lee, Szetsen

2012-01-01

We report the use of silver (Ag) colloids in the spectroscopic differentiation of methyl red (MR) isomers (o-MR, m-MR, p-MR) by fluorescence techniques. Under different pH conditions, the formation of MR-Ag complex has an impact on the fluorescence band shapes and peak position shift, which are distinctive between MR isomers. The fluorescence quenching between 400 and 414 nm accompanied by simultaneous enhancement between 510 and 541 nm changes with pH are closely related to energy transfer efficiency and the interaction between the MR isomers and the Ag surface.

Free-radical coupling, cleavage, and redox reactions in 60Co γ radiolysis of aqueous methyl acetate. Effects of additives

International Nuclear Information System (INIS)

Bernath, T.; Parsons, G.H. Jr.; Cohen, S.G.

1975-01-01

Reaction of methyl acetate with e - /sub aq/ may lead to CH 3 C(O )OCH 3 (I - ), CH 3 C(OH)OCH 3 (II), and CH 3 CO (IIA), and with .OH and H. to .CH 2 CO 2 CH 3 (III), and to CH 3 CO 2 CH 2 . (IV). Methyl acetate is consumed, G = --3.5, and the loss is decreased by formate which scavenges .H and .OH, and increased by N 2 O which converts e - /sub aq/ to .OH. Hydrogen is formed, G = 1.1, and this is decreased by scavengers for H., and increased by H + which converts e - /sub aq/ to H.. In radiolysis of 0.027 M methyl acetate, 1.5 x 10 22 ev/l., radical combination products are: ethylene diacetate (CH 3 CO 2 CH 2 CH 2 OCOCH 3 ) (EDA), G = 0.48, from IV + IV; methyl β-acetoxypropionate (CH 3 CO 2 CH 2 CH 2 CO 2 CH 3 ) (MAP), G = 0.28, from IV + III; dimethyl succinate (DMS), G = 0.05, from III + III; and a mixture of methyl acetoacetate and acetonyl acetate (MAA and AA), (MAS and AA), G = 0.07. Biacetyl is not observed. β-Mercaptopropionic acid, 0.0005 M, prevents formation of coupling products, as it reduces radicals III and IV, and thiyl radical oxidizes radical II back to methyl acetate. Other sources of .OH, Fenton's reagent and H 2 O 2 -uv, lead to EDA, MAP, and DMS with a high IV/III ratio. H. preferentially attacks acyl C--H; .OH preferentially attacks alkoxyl C--H. Yields of radicals involved in formation of coupling products and acetic acid are estimated: G(II and IIA) = 1.2; G(III) = 1.4; G(IV) = 1.7. Part of the radicals, G approximately 1.6, regenerate methyl acetate by self-repair reduction of IV and III by II. Deuterium is introduced into methyl acetate during radiolysis in D 2 O. (U.S.)

The synthesis of [O-methyl-{sup 11}C]venlafaxine: a non-classical, fast-acting antidepressant

Energy Technology Data Exchange (ETDEWEB)

Gee, A.D.; Gjedde, A. [Aarhus Univ. Hospital, PET Center, Aarhus (Denmark); Smith, D.F. [Aarhus Univ. Psychiatric Hospital, Inst. for Biological Psychiatry, Risskov (Denmark)

1997-01-01

As part of our program to develop PET tracers for the 5-HT reuptake site, venlafaxine, a non-classical, fast-acting antidepressant, was selected as a candidate for labelling with {sup 11}C for in vivo evaluation. [O-methyl-{sup 11}C]venlafaxine was produced by the alkylation of O-desmethyl venlafaxine with [{sup 11}C]methyl iodide followed by HPLC purification and formulation. Radiochemically pure [O-methyl-{sup 11}C]venlafaxine was obtained in a 30 {+-} 5% decay corrected radiochemical yield and a specific activity > 50 GBq/{mu}mol(1.4 Ci/{mu}mol) at the end of synthesis. For a typical production starting with 46 GBq (1.3 Ci) [{sup 11}C]CO{sub 2}, 5.2 GBq (140 mCi) [O-methyl-{sup 11}C]venlafaxine was obtained as a sterile, formulated solution in a synthesis time of 30 min (counted from EOB). (Author).

Crystal structure of rubidium methyl-diazo-tate.

Science.gov (United States)

Grassl, Tobias; Korber, Nikolaus

2017-02-01

The title compound, Rb + ·H 3 CN 2 O - , has been crystallized in liquid ammonia as a reaction product of the reductive ammonolysis of the natural compound streptozocin. Elemental rubidium was used as reduction agent as it is soluble in liquid ammonia, forming a blue solution. Reductive bond cleavage in biogenic materials under kinetically controlled conditions offers a new approach to gain access to sustainably produced raw materials. The anion is nearly planar [dihedral angle O-N-N-C = -0.4 (2)°]. The Rb + cation has a coordination number of seven, and coordinates to five anions. One anion is bound via both its N atoms, one by both O and N, two anions are bound by only their O atoms, and the last is bound via the N atom adjacent to the methyl group. The diazo-tate anions are bridged by cations and do not exhibit any direct contacts with each other. The cations form corrugated layers that propagate in the (-101) plane.

An efficient protocol for the complete incorporation of methyl-protonated alanine in perdeuterated protein

International Nuclear Information System (INIS)

Ayala, Isabel; Sounier, Remy; Use, Nathalie; Gans, Pierre; Boisbouvier, Jerome

2009-01-01

A strategy for the introduction of ( 1 H, 13 C-methyl)-alanine into perdeuterated proteins is described. Specific protonation of alanine methyl groups to a level of 95% can be achieved by overexpressing proteins in M9/D 2 O based bacterial growth medium supplemented with 800 mg/l of 2-[ 2 H], 3-[ 13 C] l-alanine. However, though simple, this approach results in undesired, non-specific background labeling due to isotope scrambling via different amino acid metabolic pathways. Following a careful analysis of known metabolic pathways we found that co-addition of perdeuterated forms of α-ketoisovalerate-d 7 , succinate-d 4 and l-isoleucine-d 10 with labeled l-alanine, reduces undesired background labeling to <1%. When combined with recently developed methyl TROSY experiments, this methyl-specific labeling protocol permits the acquisition of excellent quality correlation spectra of alanine methyl groups in high molecular weight proteins. Our cost effective strategy offers a significant enhancement in the level of incorporation of methyl-labeled alanine in overexpressed proteins over previously reported methods

Autoradiographic disposition of [1-methyl-14C]- and [2-14C]caffeine in mice

International Nuclear Information System (INIS)

Lachance, M.P.; Marlowe, C.; Waddell, W.J.

1983-01-01

Male, C57B1/6J mice received either [1-methyl-14C]caffeine or [2-14C]caffeine via the tail vein at a dose of 0.7 or 11 mg/kg, respectively. At 0.1, 0.33, 1, 3, 9, and 24 hr after treatment, the mice were anesthetized with ether and frozen by immersion in dry ice/hexane. The mice were processed for whole-body autoradiography by the Ullberg technique; this procedure does not allow thawing or contact with solvents. All autoradiographs revealed some retention of radioactivity at early time intervals in the lacrimal glands, seminal vesicle fluid, nasal and olfactory epithelium, and retinal melanocytes. The remaining portion of the animal was densitometrically uniform except for the lower levels noted in the CNS and adipose tissues. Excretion of radioactivity by the liver and kidneys seems to be the major routes of elimination. Localization in the liver at late time intervals was confined principally to the centrilobular region. Late sites of retention, observed only after [1-methyl-14C]caffeine administration, included the pancreas, minor and major salivary glands, splenic red pulp, thymal cortex, bone marrow, and gastrointestinal epithelium. Sites of localization present in both studies included the olfactory epithelium, lacrimal glands, hair follicles, and retinal melanocytes. Further studies are needed to determine whether the localization at these various sites is due to metabolic degradation, active transport, or possibly a specific receptor interaction

Iridium Clusters Encapsulated in Carbon Nanospheres as Nanocatalysts for Methylation of (Bio)Alcohols.

Science.gov (United States)

Liu, Qiang; Xu, Guoqiang; Wang, Zhendong; Liu, Xiaoran; Wang, Xicheng; Dong, Linlin; Mu, Xindong; Liu, Huizhou

2017-12-08

C-H methylation is an attractive chemical transformation for C-C bonds construction in organic chemistry, yet efficient methylation of readily available (bio)alcohols in water using methanol as sustainable C1 feedstock is limited. Herein, iridium nanocatalysts encapsulated in yolk-shell-structured mesoporous carbon nanospheres (Ir@YSMCNs) were synthesized for this transformation. Monodispersed Ir clusters (ca. 1.0 nm) were encapsulated in situ and spatially isolated within YSMCNs by a silica-assisted sol-gel emulsion strategy. A selection of (bio)alcohols (19 examples) was selectively methylated in aqueous phase with good-to-high yields over the developed Ir@YSMCNs. The improved catalytic efficiencies in terms of activity and selectivity together with the good stability and recyclability were contributable to the ultrasmall Ir clusters with oxidation chemical state as a consequence of the confinement effect of YSMCNs with interconnected nanostructures. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metabolism of methyl-branched iodo palmitic acids in cultured hepatocytes

International Nuclear Information System (INIS)

Thomas, G.; Pepin, D.; Loriette, C.; Chambaz, J.; Bereziat, G.; Vidal, M.; Apparu, M.; Coornaert, S.

1989-01-01

The metabolic fate of methyl-branched iodo fatty acids was studied in primary culture of rat hepatocytes. We compared 16-iodo-2-R,S-methyl palmitic acid (2-Me), which can be β oxidized, with 16-iodo-3-R,S-methyl palmitic acid (3-Me) which can be β oxidized only after an initial α oxydation and with 16-iodo-2,2-dimethyl palmitic acid (2,2-Me 2 ) and 16-iodo-3,3-dimethyl palmitic acid (3,3-Me 2 ) which cannot be β oxidized at all. The normal fate of natural fatty acids was given by comparative experiments with [1- 14 C] palmitic acid. Monomethyl-branched iodo fatty acids were taken up in the same range as palmitic acid but more than dimethyl-branched iodo fatty acids. After a 15-h incubation, acido-soluble products (ASP) accounted for 75% of the radioactivity taken up as 16-iodo-2-methyl palmitic acid, 50% as other methyl-branched iodo fatty acids and only 30% as palmitic acid. Cultured hepatocytes, labelled for 3 h with the various fatty acids and reincubated for 12 h without fatty acid, secreted large amounts of free dimethyl-branched iodo fatty acids as compared to the monomethyl ones and palmitic acid. Only hepatocytes prelabelled with 16-[ 125 I]iodo-2,2-dimethyl palmitic acid exhibited an appreciable secretion of labeled triglycerides, but at a lower rate than with [1- 14 C] palmitic acid. Conversely, the 16-iodo-monomethyl palmitic acids remained chiefly in hepatocyte triglycerides. Minute amounts of 16-iodo-methyl-branched palmitic acids were found in hepatocyte or secreted phospholipids as compared with palmitic acid. (orig.)

NMR characterization of HtpG, the E. coli Hsp90, using sparse labeling with 13C-methyl alanine.

Science.gov (United States)

Pederson, Kari; Chalmers, Gordon R; Gao, Qi; Elnatan, Daniel; Ramelot, Theresa A; Ma, Li-Chung; Montelione, Gaetano T; Kennedy, Michael A; Agard, David A; Prestegard, James H

2017-07-01

A strategy for acquiring structural information from sparsely isotopically labeled large proteins is illustrated with an application to the E. coli heat-shock protein, HtpG (high temperature protein G), a 145 kDa dimer. It uses 13 C-alanine methyl labeling in a perdeuterated background to take advantage of the sensitivity and resolution of Methyl-TROSY spectra, as well as the backbone-centered structural information from 1 H- 13 C residual dipolar couplings (RDCs) of alanine methyl groups. In all, 40 of the 47 expected crosspeaks were resolved and 36 gave RDC data. Assignments of crosspeaks were partially achieved by transferring assignments from those made on individual domains using triple resonance methods. However, these were incomplete and in many cases the transfer was ambiguous. A genetic algorithm search for consistency between predictions based on domain structures and measurements for chemical shifts and RDCs allowed 60% of the 40 resolved crosspeaks to be assigned with confidence. Chemical shift changes of these crosspeaks on adding an ATP analog to the apo-protein are shown to be consistent with structural changes expected on comparing previous crystal structures for apo- and complex- structures. RDCs collected on the assigned alanine methyl peaks are used to generate a new solution model for the apo-protein structure.

Cationic Tungsten(VI) Penta-Methyl Complex: Synthesis, Characterization and its Application in Olefin Metathesis Reaction

KAUST Repository

Dey, Raju; Samantaray, Manoja; Callens, Emmanuel; Hamieh, Ali Imad Ali; Emwas, Abdul-Hamid M.; Abou-Hamad, Edy; Kavitake, Santosh Giridhar; Basset, Jean-Marie

2016-01-01

Tungsten-hexa-methyl readily reacts with B(C6F5)3 in dichloromethane and generates the corresponding well-defined cationic tungsten-penta-methyl complex which was identified precisely by 1H NMR, 13C NMR, 1H-13C NMR correlation spectroscopy. Unlike WMe6, this cationic complex has low energy barrier to form tungsten carbene intermediate, which was further supported by the fact that WMe6 alone has no activity in olefin metathesis reaction whereas the cationic complex shows catalytic activity for self-metathesis of 1-octene.

Cationic Tungsten(VI) Penta-Methyl Complex: Synthesis, Characterization and its Application in Olefin Metathesis Reaction

KAUST Repository

Dey, Raju

2016-04-13

Tungsten-hexa-methyl readily reacts with B(C6F5)3 in dichloromethane and generates the corresponding well-defined cationic tungsten-penta-methyl complex which was identified precisely by 1H NMR, 13C NMR, 1H-13C NMR correlation spectroscopy. Unlike WMe6, this cationic complex has low energy barrier to form tungsten carbene intermediate, which was further supported by the fact that WMe6 alone has no activity in olefin metathesis reaction whereas the cationic complex shows catalytic activity for self-metathesis of 1-octene.

DNA methylation of IGF2DMR and H19 is associated with fetal and infant growth: the generation R study.

Directory of Open Access Journals (Sweden)

Marieke I Bouwland-Both

Full Text Available Changes in epigenetic programming of embryonic growth genes during pregnancy seem to affect fetal growth. Therefore, in a population-based prospective birth cohort in the Netherlands, we examined associations between fetal and infant growth and DNA methylation of IGF2DMR, H19 and MTHFR. For this study, we selected 69 case children born small-for-gestational age (SGA, birth weight <-2SDS and 471 control children. Fetal growth was assessed with serial ultrasound measurements. Information on birth outcomes was retrieved from medical records. Infant weight was assessed at three and six months. Methylation was assessed in DNA extracted from umbilical cord white blood cells. Analyses were performed using linear mixed models with DNA methylation as dependent variable. The DNA methylation levels of IGF2DMR and H19 in the control group were, median (90% range, 53.6% (44.5-61.6 and 30.0% (25.6-34.2 and in the SGA group 52.0% (43.9-60.9 and 30.5% (23.9-32.9, respectively. The MTHFR region was found to be hypomethylated with limited variability in the control and SGA group, 2.5% (1.4-4.0 and 2.4% (1.5-3.8, respectively. SGA was associated with lower IGF2DMR DNA methylation (β = -1.07, 95% CI -1.93; -0.21, P-value = 0.015, but not with H19 methylation. A weight gain in the first three months after birth was associated with lower IGF2DMR DNA methylation (β = -0.53, 95% CI -0.91; -0.16, P-value = 0.005. Genetic variants in the IGF2/H19 locus were associated with IGF2DMR DNA methylation (P-value<0.05, but not with H19 methylation. Furthermore, our results suggest a possibility of mediation of DNA methylation in the association between the genetic variants and SGA. To conclude, IGF2DMR and H19 DNA methylation is associated with fetal and infant growth.

A simple biosynthetic method for stereospecific resonance assignment of prochiral methyl groups in proteins

International Nuclear Information System (INIS)

Plevin, Michael J.; Hamelin, Olivier; Boisbouvier, Jérôme; Gans, Pierre

2011-01-01

A new method for stereospecific assignment of prochiral methyl groups in proteins is presented in which protein samples are produced using U-[ 13 C]glucose and subsaturating amounts of 2-[ 13 C]methyl-acetolactate. The resulting non-uniform labeling pattern allows proR and proS methyl groups to be easily distinguished by their different phases in a constant-time two-dimensional 1 H- 13 C correlation spectra. Protein samples are conveniently prepared using the same media composition as the main uniformly-labeled sample and contain higher levels of isotope-enrichment than fractional labeling approaches. This new strategy thus represents an economically-attractive, robust alternative for obtaining isotopically-encoded stereospecific NMR assignments of prochiral methyl groups.

Alteration in Expression and Methylation of IGF2/H19 in Placenta and Umbilical Cord Blood Are Associated with Macrosomia Exposed to Intrauterine Hyperglycemia.

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Rina Su

Full Text Available Macrosomia is one of the most common complications in gestational diabetes mellitus. Insulin-like growth factor 2 and H19 are two of the imprinted candidate genes that are involved in fetal growth and development. Change in methylation at differentially methylated region of the insulin-like growth factor 2 and H19 has been proved to be an early event related to the programming of metabolic profile, including macrosomia and small for gestational age in offspring. Here we hypothesize that alteration in methylation at differentially methylated region of the insulin-like growth factor 2 and H19 is associated with macrosomia induced by intrauterine hyperglycemia.The expression of insulin-like growth factor 2 is significant higher in gestational diabetes mellitus group (GDM group compared to normal glucose tolerance group (NGT group both in umbilical cord blood and placenta, while the expression of H19 is significant lower in GDM group in umbilical cord blood. The expression of insulin-like growth factor 2 is significant higher in normal glucose tolerance with macrosomia group (NGT-M compared to normal glucose tolerance with normal birthweight group (NGT-NBW group both in placenta and umbilical cord blood. A model with interaction term of gene expression of IGF2 and H19 found that IGF2 and the joint action of IGF2 and H19 in placenta showed significantly relationship with GDM/NGT and GDM-NBW/NGT-NBW. A borderline significant association was seen among IGF2 and H19 in cord blood and GDM-M/NGT-M. The methylation level at different CpG sites of insulin-like growth factor 2 and H19 in umbilical cord blood was also significantly different among groups. Based on the multivariable linear regression analysis, the methylation of the insulin-like growth factor 2 / H19 is closely related to birth weight and intrauterine hyperglycemia.We confirmed the existence of alteration in DNA methylation in umbilical cord blood exposed to intrauterine hyperglycemia and

Methyl 3-(Quinolin-2-ylindolizine-1-carboxylate

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Roumaissa Belguedj

2015-12-01

Full Text Available A novel compound, methyl 3-(quinolin-2-ylindolizine-1-carboxylate (2 has been synthesized by cycloaddition reaction of 1-(quinolin-2-ylmethylpyridinium ylide (1 with methyl propiolate in presence of sodium hydride in THF. The structure of this compound was established by IR, 1H-NMR, 13C-NMR and MS data

Dicty_cDB: SSL385 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available C37A2, complete sequence. 38 0.049 3 BZ347525 |BZ347525.1 hm84h07.b1 WGS-SbicolorF (JM107 adapted methyl filter...-SbicolorF (JM107 adapted methyl filtered) Sorghum bicolor genomic clone ho57b09 ..._Ba0020C03 5', genomic survey sequence. 42 0.33 2 BZ366117 |BZ366117.1 ic94g05.g1 WGS-SbicolorF (JM107 adapted methyl filter...in ordered pieces. 44 0.88 1 BZ626058 |BZ626058.1 ih42h02.b1 WGS-SbicolorF (DH5a methyl filter...07.g1 WGS-SbicolorF (DH5a methyl filtered) Sorghum bicolor genomic clone ii21a07, DNA sequence. 38 3.0 2 dna

Crystal structure of 4-(4b,8a-dihydro-9H-pyrido[3,4-b]indol-1-yl-7-methyl-2H-chromen-2-one

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S. Samundeeswari

2017-01-01

Full Text Available The title compound, C21H14N2O2, was prepared by Pictet–Spengler cyclization of tryptamine and 4-formyl coumarin. In the molecule, the dihedral angle between the mean planes of the coumarin and β-carboline ring systems is 63.8 (2°. In the crystal, molecules are linked via N—H...N hydrogen bonds, forming chains along the b-axis direction. Within the chains, there are a number of offset π–π interactions present [shortest intercentroid distance = 3.457 (2 Å].

Role of DNA methylation in miR-200c/141 cluster silencing in invasive breast cancer cells

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Wernet Peter

2010-08-01

Full Text Available Abstract Background The miR-200c/141 cluster has recently been implicated in the epithelial to mesenchymal transition (EMT process. The expression of these two miRNAs is inversely correlated with tumorigenicity and invasiveness in several human cancers. The role of these miRNAs in cancer progression is based in part on their capacity to target the EMT activators ZEB1 and ZEB2, two transcription factors, which in turn repress expression of E-cadherin. Little is known about the regulation of the mir200c/141 cluster, whose targeting has been proposed as a promising new therapy for the most aggressive tumors. Findings We show that the miR-200c/141 cluster is repressed by DNA methylation of a CpG island located in the promoter region of these miRNAs. Whereas in vitro methylation of the miR-200c/141 promoter led to shutdown of promoter activity, treatment with a demethylating agent caused transcriptional reactivation in breast cancer cells formerly lacking expression of miR-200c and miR-141. More importantly, we observed that DNA methylation of the identified miR-200c/141 promoter was tightly correlated with phenotype and the invasive capacity in a panel of 8 human breast cancer cell lines. In line with this, in vitro induction of EMT by ectopic expression of the EMT transcription factor Twist in human immortalized mammary epithelial cells (HMLE was accompanied by increased DNA methylation and concomitant repression of the miR-200c/141 locus. Conclusions The present study demonstrates that expression of the miR-200c/141 cluster is regulated by DNA methylation, suggesting epigenetic regulation of this miRNA locus in aggressive breast cancer cell lines as well as untransformed mammary epithelial cells. This epigenetic silencing mechanism might represent a novel component of the regulatory circuit for the maintenance of EMT programs in cancer and normal cells.

Role of DNA methylation in miR-200c/141 cluster silencing in invasive breast cancer cells.

Science.gov (United States)

Neves, Rui; Scheel, Christina; Weinhold, Sandra; Honisch, Ellen; Iwaniuk, Katharina M; Trompeter, Hans-Ingo; Niederacher, Dieter; Wernet, Peter; Santourlidis, Simeon; Uhrberg, Markus

2010-08-03

The miR-200c/141 cluster has recently been implicated in the epithelial to mesenchymal transition (EMT) process. The expression of these two miRNAs is inversely correlated with tumorigenicity and invasiveness in several human cancers. The role of these miRNAs in cancer progression is based in part on their capacity to target the EMT activators ZEB1 and ZEB2, two transcription factors, which in turn repress expression of E-cadherin. Little is known about the regulation of the mir200c/141 cluster, whose targeting has been proposed as a promising new therapy for the most aggressive tumors. We show that the miR-200c/141 cluster is repressed by DNA methylation of a CpG island located in the promoter region of these miRNAs. Whereas in vitro methylation of the miR-200c/141 promoter led to shutdown of promoter activity, treatment with a demethylating agent caused transcriptional reactivation in breast cancer cells formerly lacking expression of miR-200c and miR-141. More importantly, we observed that DNA methylation of the identified miR-200c/141 promoter was tightly correlated with phenotype and the invasive capacity in a panel of 8 human breast cancer cell lines. In line with this, in vitro induction of EMT by ectopic expression of the EMT transcription factor Twist in human immortalized mammary epithelial cells (HMLE) was accompanied by increased DNA methylation and concomitant repression of the miR-200c/141 locus. The present study demonstrates that expression of the miR-200c/141 cluster is regulated by DNA methylation, suggesting epigenetic regulation of this miRNA locus in aggressive breast cancer cell lines as well as untransformed mammary epithelial cells. This epigenetic silencing mechanism might represent a novel component of the regulatory circuit for the maintenance of EMT programs in cancer and normal cells.

Control of box C/D snoRNP assembly by N6-methylation of adenine.

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Huang, Lin; Ashraf, Saira; Wang, Jia; Lilley, David Mj

2017-09-01

N 6 -methyladenine is the most widespread mRNA modification. A subset of human box C/D snoRNA species have target GAC sequences that lead to formation of N 6 -methyladenine at a key trans Hoogsteen-sugar A·G base pair, of which half are methylated in vivo The GAC target is conserved only in those that are methylated. Methylation prevents binding of the 15.5-kDa protein and the induced folding of the RNA Thus, the assembly of the box C/D snoRNP could in principle be regulated by RNA methylation at its critical first stage. Crystallography reveals that N 6 -methylation of adenine prevents the formation of trans Hoogsteen-sugar A·G base pairs, explaining why the box C/D RNA cannot adopt its kinked conformation. More generally, our data indicate that sheared A·G base pairs (but not Watson-Crick base pairs) are more susceptible to disruption by N 6 mA methylation and are therefore possible regulatory sites. The human signal recognition particle RNA and many related Alu retrotransposon RNA species are also methylated at N6 of an adenine that forms a sheared base pair with guanine and mediates a key tertiary interaction. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Specific variants in the MLH1 gene region may drive DNA methylation, loss of protein expression, and MSI-H colorectal cancer.

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Miralem Mrkonjic

Full Text Available We previously identified an association between a mismatch repair gene, MLH1, promoter SNP (rs1800734 and microsatellite unstable (MSI-H colorectal cancers (CRCs in two samples. The current study expanded on this finding as we explored the genetic basis of DNA methylation in this region of chromosome 3. We hypothesized that specific polymorphisms in the MLH1 gene region predispose it to DNA methylation, resulting in the loss of MLH1 gene expression, mismatch-repair function, and consequently to genome-wide microsatellite instability.We first tested our hypothesis in one sample from Ontario (901 cases, 1,097 controls and replicated major findings in two additional samples from Newfoundland and Labrador (479 cases, 336 controls and from Seattle (591 cases, 629 controls. Logistic regression was used to test for association between SNPs in the region of MLH1 and CRC, MSI-H CRC, MLH1 gene expression in CRC, and DNA methylation in CRC. The association between rs1800734 and MSI-H CRCs, previously reported in Ontario and Newfoundland, was replicated in the Seattle sample. Two additional SNPs, in strong linkage disequilibrium with rs1800734, showed strong associations with MLH1 promoter methylation, loss of MLH1 protein, and MSI-H CRC in all three samples. The logistic regression model of MSI-H CRC that included MLH1-promoter-methylation status and MLH1 immunohistochemistry status fit most parsimoniously in all three samples combined. When rs1800734 was added to this model, its effect was not statistically significant (P-value  = 0.72 vs. 2.3×10(-4 when the SNP was examined alone.The observed association of rs1800734 with MSI-H CRC occurs through its effect on the MLH1 promoter methylation, MLH1 IHC deficiency, or both.

Release of /sup 3/H-. cap alpha. -methyl-m-tyramine from rat striatum in vitro

Energy Technology Data Exchange (ETDEWEB)

Dorris, R L [Baylor College of Dentistry, Dallas, Tex. (USA). Dept. of Pharmacology

1976-01-01

Release of /sup 3/H-d-..cap alpha..-methyl-m-tyramine (/sup 3/H-MMTA), a false dopaminergic transmitter from rat striatum was studied in vitro. After its initial uptake, /sup 3/H-MMTA was released by high K/sup +/ and by amphetamine. The release requirements were essentially the same as those known to exist for release of dopamine in vitro. These studies indicate that /sup 3/H-MMTA might serve as a useful tool with which to study dopamine release mechanisms in vitro.

Classification of extremely metal-poor stars: absent region in A(C)-[Fe/H] plane and the role of dust cooling

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Chiaki, Gen; Tominaga, Nozomu; Nozawa, Takaya

2017-11-01

Extremely metal-poor (EMP) stars are the living fossils with records of chemical enrichment history at the early epoch of galaxy formation. By the recent large observation campaigns, statistical samples of EMP stars have been obtained. This motivates us to reconsider their classification and formation conditions. From the observed lower limits of carbon and iron abundances of Acr(C) ∼ 6 and [Fe/H]cr ∼ -5 for C-enhanced EMP (CE-EMP) and C-normal EMP (CN-EMP) stars, we confirm that gas cooling by dust thermal emission is indispensable for the fragmentation of their parent clouds to form such low mass, i.e. long-lived stars, and that the dominant grain species are carbon and silicate, respectively. We constrain the grain radius r_i^cool of a species i and condensation efficiency fij of a key element j as r_C^cool / f_C,C = 10 {μ m} and r_Sil^cool / f_Sil,Mg = 0.1 {μ m} to reproduce Acr(C) and [Fe/H]cr, which give a universal condition 10[C/H] - 2.30 + 10[Fe/H] > 10-5.07 for the formation of every EMP star. Instead of the conventional boundary [C/Fe] = 0.7 between CE-EMP and CN-EMP stars, this condition suggests a physically meaningful boundary [C/Fe]b = 2.30 above and below which carbon and silicate grains are dominant coolants, respectively.

Radiosynthesis of N-¹¹C-Methyl-Taurine-Conjugated Bile Acids and Biodistribution Studies in Pigs by PET/CT.

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Schacht, Anna Christina; Sørensen, Michael; Munk, Ole Lajord; Frisch, Kim

2016-04-01

During cholestasis, accumulation of conjugated bile acids may occur in the liver and lead to hepatocellular damage. Inspired by our recent development of N-(11)C-methyl-glycocholic acid-that is, (11)C-cholylsarcosine-a tracer for PET of the endogenous glycine conjugate of cholic acid, we report here a radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids and biodistribution studies in pigs by PET/CT. A radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids was developed and used to prepare N-(11)C-methyl-taurine conjugates derived from cholic, chenodeoxycholic, deoxycholic, ursodeoxycholic, and lithocholic acid. The lipophilicity of these new tracers was determined by reversed-phase thin-layer chromatography. The effect of lipophilicity and structure on the biodistribution was investigated in pigs by PET/CT using the tracers derived from cholic acid (3α-OH, 7α-OH, 12α-OH), ursodeoxycholic acid (3α-OH, 7β-OH), and lithocholic acid (3α-OH). The radiosyntheses of the N-(11)C-methyl-taurine-conjugated bile acids proceeded with radiochemical yields of 61% (decay-corrected) or greater and radiochemical purities greater than 99%. PET/CT in pigs revealed that the tracers were rapidly taken up by the liver and secreted into bile. There was no detectable radioactivity in urine. Significant reflux of N-(11)C-methyl-taurolithocholic acid into the stomach was observed. We have successfully developed a radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids. These tracers behave in a manner similar to endogenous taurine-conjugated bile acids in vivo and are thus promising for functional PET of patients with cholestatic diseases. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Reinvestigation of the synthesis and evaluation of [N-methyl-11C]vorozole, a radiotracer targeting cytochrome P450 aromatase

International Nuclear Information System (INIS)

Kim, Sung Won; Biegon, Anat; Katsamanis, Zachary E.; Ehrlich, Carolin W.; Hooker, Jacob M.; Shea, Colleen; Muench, Lisa; Xu Youwen; King, Payton; Carter, Pauline; Alexoff, David L.; Fowler, Joanna S.

2009-01-01

Introduction: We reinvestigated the synthesis of [N-methyl- 11 C]vorozole, a radiotracer for aromatase, and discovered the presence of an N-methyl isomer which was not removed in the original purification method. Herein we report the preparation and positron emission tomography (PET) studies of pure [N-methyl- 11 C]vorozole. Methods: Norvorozole was alkylated with [ 11 C]methyl iodide as previously described and also with unlabeled methyl iodide. A high-performance liquid chromatography (HPLC) method was developed to separate the regioisomers. Nuclear magnetic resonance (NMR) spectroscopy ( 13 C and 2D-nuclear Overhauser effect spectroscopy NMR) was used to identify and assign structures to the N-methylated products. Pure [N-methyl- 11 C]vorozole and the contaminating isomer were compared by PET imaging in the baboon. Results: Methylation of norvorozole resulted in a mixture of isomers (1:1:1 ratio) based on new HPLC analysis using a pentafluorophenylpropyl bonded silica column, in which vorozole coeluted one of its isomers under the original HPLC conditions. Baseline separation of the three labeled isomers was achieved. The N-3 isomer was the contaminant of vorozole, thus correcting the original assignment of isomers. PET studies of pure [N-methyl- 11 C]vorozole with and without the contaminating N-3 isomer revealed that only [N-methyl- 11 C]vorozole binds to aromatase. [N-methyl- 11 C]Vorozole accumulated in all brain regions with highest accumulation in the aromatase-rich amygdala and preoptic area. Accumulation was blocked with vorozole and letrozole consistent with reports of some level of aromatase in many brain regions. Conclusions: The discovery of a contaminating labeled isomer and the development of a method for isolating pure [N-methyl- 11 C]vorozole combine to provide a new scientific tool for PET studies of the biology of aromatase and for drug research and development.

Structural TEM study of nonpolar a-plane gallium nitride grown on(112_0) 4H-SiC by organometallic vapor phase epitaxy

Energy Technology Data Exchange (ETDEWEB)

Zakharov, Dmitri N.; Liliental-Weber, Zuzanna; Wagner, Brian; Reitmeier,Zachary J.; Preble, Edward A.; Davis, Robert F.

2005-04-05

Conventional and high resolution electron microscopy havebeen applied for studying lattice defects in nonpolar a-plane GaN grownon a 4H-SiC substrate with an AlN buffer layer. Samples in plan-view andcross-section configurations have been investigated. Basal and prismaticstacking faults together with Frank and Shockley partial dislocationswere found to be the main defects in the GaN layers. High resolutionelectron microscopy in combination with image simulation supported Drum smodel for the prismatic stacking faults. The density of basal stackingfaults was measured to be ~;1.6_106cm-1. The densities of partialdislocations terminating I1 and I2 types of intrinsic basal stackingfaults were ~;4.0_1010cm-2 and ~;0.4_1010cm-2, respectively. The energyof the I2 stacking fault in GaN was estimated to be (40+-4) erg/cm2 basedon the separation of Shockley partial dislocations. To the best of ourknowledge, the theoretically predicted I3 basal stacking fault in GaN wasobserved experimentally for the first time.

Genome-wide DNA methylation analysis of the porcine hypothalamus-pituitary-ovary axis

DEFF Research Database (Denmark)

Yuan, Xiao Long; Zhang, Zhe; Li, Bin

2017-01-01

Previous studies have suggested that DNA methylation in both CpG and CpH (where H = C, T or A) contexts plays a critical role in biological functions of different tissues. However, the genome-wide DNA methylation patterns of porcine hypothalamus-pituitary-ovary (HPO) tissues remain virtually unex...

In-plane Schottky-barrier field-effect transistors based on 1T/2H heterojunctions of transition-metal dichalcogenides

Science.gov (United States)

Fan, Zhi-Qiang; Jiang, Xiang-Wei; Luo, Jun-Wei; Jiao, Li-Ying; Huang, Ru; Li, Shu-Shen; Wang, Lin-Wang

2017-10-01

As Moore's law approaches its end, two-dimensional (2D) materials are intensely studied for their potentials as one of the "More than Moore' (MM) devices. However, the ultimate performance limits and the optimal design parameters for such devices are still unknown. One common problem for the 2D-material-based device is the relative weak on-current. In this study, two-dimensional Schottky-barrier field-effect transistors (SBFETs) consisting of in-plane heterojunctions of 1T metallic-phase and 2H semiconducting-phase transition-metal dichalcogenides (TMDs) are studied following the recent experimental synthesis of such devices at a much larger scale. Our ab initio simulation reveals the ultimate performance limits of such devices and offers suggestions for better TMD materials. Our study shows that the Schottky-barrier heights (SBHs) of the in-plane 1T/2H contacts are smaller than the SBHs of out-of-plane contacts, and the contact coupling is also stronger in the in-plane contact. Due to the atomic thickness of the monolayer TMD, the average subthreshold swing of the in-plane TMD-SBFETs is found to be close to the limit of 60 mV/dec, and smaller than that of the out-of-plane TMD-SBFET device. Different TMDs are considered and it is found that the in-plane WT e2-SBFET provides the best performance and can satisfy the performance requirement of the sub-10-nm high-performance transistor outlined by the International Technology Roadmap for Semiconductors, and thus could be developed into a viable sub-10-nm MM device in the future.

Methyl 2-({6-[(1-methoxy-2-methyl-1-oxopropan-2-ylcarbamoyl]pyridin-2-yl}formamido-2-methylpropanoate

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Abdel-Galil E. Amr

2012-05-01

Full Text Available In the title compound, C17H23N3O6, the two methoxycarbonyl C—O—C=O planes are inclined at dihedral angles of 5.3 (4 and 83.9 (4° with respect to the central pyridine ring. An intramolecular N—H...O hydrogen bond generates an S(5 ring motif. In the crystal, molecules are linked into a chain along the c axis via C—H...O hydrogen bonds.

Synthesis of 14C- and 2H-labeled 1,3 dihydro-3, 3-dimethyl-5-(1,4,5,6,- tetrahydro-6-oxo-3-pyridazinyl)-2H-indol-2-one (LY195115), an orally effective positive inotrope

International Nuclear Information System (INIS)

Robertson, D.W.; Krushinski, J.H.; Kau, D.

1986-01-01

The synthesis of 14 C- and 2 H-labeled 1,3-dihydro-3,3-dimethyl-5-(1,4,5,6-tetrahydro-6-oxo-3-pyridazinyl)-2H-indol -2-one (LY195115), an extremely potent, orally-effective cardiotonic with inotropic and vasodilator activities is described. The 14 C-label was introduced in the antepenultimate step by reaction of a β-chloroketone precursor with Na 14 CN; acid-catalyzed hydrolysis and cyclization with hydrazine provided the tetrahydropyridazinone bearing the 14 C-label in the oxo-carbon. 1,3-Dihydro-3,3-di(methyl-d 3 ) -2H-indol-2-one was prepared by exhaustive methylation of 1-acetyl-1,3-dihydro-2H-indol-2-one with sodium hydride and iodomethane-d 3 , followed by removal of the nitrogen protecting group. This labeled material was converted in two steps to [ 2 H 6 ]-LY195115. (author)

4-Methyl-N-(2-methylbenzoylbenzenesulfonamide

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B. Thimme Gowda

2010-06-01

Full Text Available In the title compound, C15H15NO3S, the conformation of the N—H bond in the C—SO2—NH—C(O segment is anti to the C=O bond. Further, the conformation of the C=O bond is syn to the ortho-methyl group in the benzoyl ring. The dihedral angle between the sulfonyl benzene ring and the —SO2—NH—C—O segment is 87.1 (1° and that between the sulfonyl and the benzoyl benzene rings is 58.2 (1°. In the crystal structure, molecules are linked by pairs of N—H...O(S hydrogen bonds, forming inversion dimers.

A MODIFIED H-α PLANE FOR THE EXTRACTION OF SCATTERING MECHANISMS FROM DUAL CIRCULAR POLARIZATION SAR DATA

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S. Ghods

2015-12-01

Full Text Available Cloude–Pottier entropy and α-angle are two important parameters for the interpretation of fully polarimetric data. They indicate the randomness of the polarisation of the back scattered waves and the scattering mechanisms of the targets respectively. For fully polarimetric data the H-α plane is presented which using the borders of it the full polarimetric data can be classified into 8 different physical scattering mechanisms. In recent years new approaches have proposed H-α classification spaces by mapping the points which are belong to each PSMs of FP data into the space of H/α for CP data and approximate borders were extracted for the classification purpose. In this paper a novel approach for defining H/α classification plane has been presented which maximizes the producer’s accuracy. The optimum borders have been found and the results of classification using the new plane have been compared with the rival method and the superiority of the new proposed method has been revealed.

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

Science.gov (United States)

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 (Pendometrial 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.

(3R,5S,7R,8R,9S,10S,12S,13R,14S-10,13-Dimethyl-17-[5-oxo-5-(prop-2-yn-1-yloxypentan-2-yl]hexadecahydro-1H-cyclopenta[a]phenanthrene-3,7,12-triyl triacetate

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T. Kavitha

2017-03-01

Full Text Available In the title compound, C33H48O8, four terminal H atoms of cholic acid are replaced by three acetyl and one terminal alkyne group. All the acetyl residues are twisted with respect to the rings (A, B and C to which they are attached. The cyclopentane ring D adopts an envelope conformation with the methyl-substituted C atom as the flap. Rings A, B and C have chair conformations. The dihedral angle between the mean planes of rings C and D is 4.70 (11°. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a three-dimensional structure.

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

Science.gov (United States)

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

Styrylpyrylium Salts: 1H and 13C NMR High-Resolution Spectroscopy (1D and 2D

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Jean Claude W. Ouédraogo

2010-01-01

Full Text Available 1H and 13C NMR high-resolution spectroscopy (1D and 2D (1H, 1H-COSY, HSQC, HMBC for four styrylpyrylium perchlorates were carried out and signal attributions are reported. Chemical shifts observed on 13C NMR spectra for the styrylpyrylium salts were compared with net atomic charge for carbon obtained by AM1 semiempirical calculations. The position of the styryl group present low effect on chemical shifts for carbon atoms, while the presence of methyl group led to the unshielding of the substituted carbon.

The Rate Constant for the Reaction H + C2H5 at T = 295 - 150K

Science.gov (United States)

Pimentel, Andre S.; Payne, Walter A.; Nesbitt, Fred L.; Cody, Regina J.; Stief, Louis J.

2004-01-01

The reaction between the hydrogen atom and the ethyl (C2H3) radical is predicted by photochemical modeling to be the most important loss process for C2H5 radicals in the atmospheres of Jupiter and Saturn. This reaction is also one of the major sources for the methyl radicals in these atmospheres. These two simplest hydrocarbon radicals are the initial species for the synthesis of larger hydrocarbons. Previous measurements of the rate constant for the H + C2H5 reaction varied by a factor of five at room temperature, and some studies showed a dependence upon temperature while others showed no such dependence. In addition, the previous studies were at higher temperatures and generally higher pressures than that needed for use in planetary atmospheric models. The rate constant for the reaction H + C2H5 has been measured directly at T = 150, 202 and 295 K and at P = 1.0 Torr He for all temperatures and additionally at P = 0.5 and 2.0 Torr He at T = 202 K. The measurements were performed in a discharge - fast flow system. The decay of the C2H5 radical in the presence of excess hydrogen was monitored by low-energy electron impact mass spectrometry under pseudo-first order conditions. H atoms and C2H5 radicals were generated rapidly and simultaneously by the reaction of fluorine atoms with H2 and C2H6, respectively. The total rate constant was found to be temperature and pressure independent. The measured total rate constant at each temperature are: k(sub 1)(295K) = (1.02+/-0.24)x10(exp -10), k(sub 1)(202K) = (1.02+/-0.22)x10(exp -10) and k(sub 1)(150K) = (0.93+/-0.21)x10(exp -10), all in units of cu cm/molecule/s. The total rate constant derived from all the combined measurements is k(sub 1) = (l.03+/-0.17)x10(exp -10) cu cm/molecule/s. At room temperature our results are about a factor of two higher than the recommended rate constant and a factor of three lower than the most recently published study.

Avocado and olive oil methyl esters

International Nuclear Information System (INIS)

Knothe, Gerhard

2013-01-01

Biodiesel, the mono-alkyl esters of vegetable oils, animal fats or other triacylglycerol-containing materials and an alternative to conventional petroleum-based diesel fuel, has been derived from a variety of feedstocks. Numerous feedstocks have been investigated as potential biodiesel sources, including commodity oils, however, the methyl esters of avocado and olive oil would likely be suitable as biodiesel fuel. In order to expand the database and comprehensive evaluation of the properties of vegetable oil esters, in this work the fuel-related properties of avocado and olive oil methyl esters, which exhibit similar fatty acid profiles including high oleic acid content, are determined. The cetane numbers of avocado oil methyl esters and olive oil methyl esters are relatively high, determined as 59.2 and 62.5, respectively, due to their elevated content of methyl oleate. Other properties are well within the ranges specified in biodiesel standards. The cloud points of both esters are slightly above 0 °C due to their content of saturated esters, especially methyl palmitate. Overall, avocado and olive oil yield methyl esters with fuel properties comparable to methyl esters from other commodity vegetable oils. The 1 H and 13 C NMR spectra of avocado and olive oil methyl esters are reported. -- Highlights: • Methyl esters of avocado and olive oil meet biodiesel fuel standards. • Provides comparison for methyl esters of other vegetable oils with high oleic content. • Discusses and compares present results with prior literature

Origin of the Ability of α-Fe2 O3 Mesopores to Activate C-H Bonds in Methane.

Science.gov (United States)

Dong, Bing; Han, Zhen; Zhang, Yongbo; Yu, Youyi; Kong, Aiguo; Shan, Yongkui

2016-02-01

Methane is a most abundant and inexpensive hydrocarbon feedstock for the production of chemicals and fuels. However, it is extremely difficult to directly convert methane to higher hydrocarbons because the C-H bonds in methane are the most stable C-H bonds of all hydrocarbons. The activation of the C-H bonds in methane by using an efficient and mild route remains a daunting challenge. Here, we show that the inner surface structures of the pore walls in mesoporous α-Fe 2 O 3 possess excellent catalytic performance for methane activation and convert C-H bonds into the C-O bonds in an O 2 atmosphere at 140 °C. We found that such unusual structures are mainly comprised of turbostratic ribbons and K crystal faces and have higher catalytic activity than the (110) plane. These results are without precedent in the history of catalysis chemistry and will provide a new pathway for designing and preparing highly efficient catalytic materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Stress-induced gene expression and behavior are controlled by DNA methylation and methyl donor availability in the dentate gyrus

Science.gov (United States)

Saunderson, Emily A.; Spiers, Helen; Gutierrez-Mecinas, Maria; Trollope, Alexandra F.; Shaikh, Abeera; Mill, Jonathan; Reul, Johannes M. H. M.

2016-01-01

Stressful events evoke long-term changes in behavioral responses; however, the underlying mechanisms in the brain are not well understood. Previous work has shown that epigenetic changes and immediate-early gene (IEG) induction in stress-activated dentate gyrus (DG) granule neurons play a crucial role in these behavioral responses. Here, we show that an acute stressful challenge [i.e., forced swimming (FS)] results in DNA demethylation at specific CpG (5′-cytosine–phosphate–guanine-3′) sites close to the c-Fos (FBJ murine osteosarcoma viral oncogene homolog) transcriptional start site and within the gene promoter region of Egr-1 (early growth response protein 1) specifically in the DG. Administration of the (endogenous) methyl donor S-adenosyl methionine (SAM) did not affect CpG methylation and IEG gene expression at baseline. However, administration of SAM before the FS challenge resulted in an enhanced CpG methylation at the IEG loci and suppression of IEG induction specifically in the DG and an impaired behavioral immobility response 24 h later. The stressor also specifically increased the expression of the de novo DNA methyltransferase Dnmt3a [DNA (cytosine-5-)-methyltransferase 3 alpha] in this hippocampus region. Moreover, stress resulted in an increased association of Dnmt3a enzyme with the affected CpG loci within the IEG genes. No effects of SAM were observed on stress-evoked histone modifications, including H3S10p-K14ac (histone H3, phosphorylated serine 10 and acetylated lysine-14), H3K4me3 (histone H3, trimethylated lysine-4), H3K9me3 (histone H3, trimethylated lysine-9), and H3K27me3 (histone H3, trimethylated lysine-27). We conclude that the DNA methylation status of IEGs plays a crucial role in FS-induced IEG induction in DG granule neurons and associated behavioral responses. In addition, the concentration of available methyl donor, possibly in conjunction with Dnmt3a, is critical for the responsiveness of dentate neurons to environmental

Extraction and high-performance liquid chromatographic analysis of C60, C70, and [6,6]-phenyl C61-butyric acid methyl ester in synthetic and natural waters.