²H kinetic isotope effects and pH dependence of catalysis as mechanistic probes of rat monoamine oxidase A: comparisons with the human enzyme.

Science.gov (United States)

Wang, Jin; Edmondson, Dale E

2011-09-06

Monoamine oxidase A (MAO A) is a mitochondrial outer membrane-bound flavoenzyme important in the regulation of serotonin and dopamine levels. Because the rat is extensively used as an animal model in drug studies, it is important to understand how rat MAO A behaves in comparison with the more extensively studied human enzyme. For many reversible inhibitors, rat MAO A exhibits K(i) values similar to those of human MAO A. The pH profile of k(cat) for rat MAO A shows a pK(a) of 8.2 ± 0.1 for the benzylamine ES complex and pK(a) values of 7.5 ± 0.1 and 7.6 ± 0.1 for the ES complexes with p-CF(3)-(1)H- and p-CF(3)-(2)H-benzylamine, respectively. In contrast to the human enzyme, the rat enzyme exhibits a single pK(a) value (8.3 ± 0.1) with k(cat)/K(m) for benzylamine versus pH and pK(a) values of 7.8 ± 0.1 and 8.1 ± 0.2 for the ascending limbs, respectively, of k(cat)/K(m) versus pH profiles for p-CF(3)-(1)H- and p-CF(3)-(2)H-benzylamine and 9.3 ± 0.1 and 9.1 ± 0.2 for the descending limbs, respectively. The oxidation of para-substituted benzylamine substrate analogues by rat MAO A has large deuterium kinetic isotope effects on k(cat) and on k(cat)/K(m). These effects are pH-independent and range from 7 to 14, demonstrating a rate-limiting α-C-H bond cleavage step in catalysis. Quantitative structure-activity correlations of log k(cat) with the electronic substituent parameter (σ) at pH 7.5 and 9.0 show a dominant contribution with positive ρ values (1.2-1.3) and a pH-independent negative contribution from the steric term. Quantitative structure-activity relationship analysis of the binding affinities of the para-substituted benzylamine analogues for rat MAO A shows an increased van der Waals volume (V(w)) increases the affinity of the deprotonated amine for the enzyme. These results demonstrate that rat MAO A exhibits functional properties similar but not identical with those of the human enzyme and provide additional support for C-H bond cleavage via a polar

Electronegativity of aromatic amines as a basis for the development of ground state inhibitors of lysyl oxidase

International Nuclear Information System (INIS)

Williamson, P.R.; Kagan, H.M.

1987-01-01

Benzylamine derivatives containing para substituents of differing electronegativity as well as isomers of aminomethylpyridine have been assessed for their substrate and inhibitor potentials toward lysyl oxidase. Substituted benzylamines with increasingly electronegative para substituents had the lowest KI values and thus were the most effective inhibitors of the oxidation of elastin by lysyl oxidase. The kcat values for these compounds as substrates of lysyl oxidase were also reduced with increasingly electronegative para substituents. Both the Dkcat and D(kcat/Km) kinetic isotope effects decreased with increasingly electronegative p-substituents in [alpha, alpha'- 2 H]benzylamines. In contrast, there was no Dkcat solvent isotope effect with [ 2 H] H 2 O while the D(kcat/Km) solvent isotope effect tended to increase with increasingly electronegative p-substituents. These results are consistent with the stabilization of an enzyme-generated substrate carbanion and the retardation of substrate oxidation by electronegative substituents. Such ground state stabilization can result in compounds with increased potential for the inhibition of the oxidation of protein substrates of lysyl oxidase

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

cobaloxime by aliphatic amine ligands · M Bhoopal N Ravi Kumar Reddy S Satyanarayana .... pp 129-134 Physical and Theoretical. Kinetics and mechanism of the oxidation of substituted benzylamines by cetyltrimethylammonium permanganate.

Dietary Phenolic Compounds Interfere with the Fate of Hydrogen Peroxide in Human Adipose Tissue but Do Not Directly Inhibit Primary Amine Oxidase Activity

Directory of Open Access Journals (Sweden)

Christian Carpéné

2016-01-01

Full Text Available Resveratrol has been reported to inhibit monoamine oxidases (MAO. Many substrates or inhibitors of neuronal MAO interact also with other amine oxidases (AO in peripheral organs, such as semicarbazide-sensitive AO (SSAO, known as primary amine oxidase, absent in neurones, but abundant in adipocytes. We asked whether phenolic compounds (resveratrol, pterostilbene, quercetin, and caffeic acid behave as MAO and SSAO inhibitors. AO activity was determined in human adipose tissue. Computational docking and glucose uptake assays were performed in 3D models of human AO proteins and in adipocytes, respectively. Phenolic compounds fully inhibited the fluorescent detection of H2O2 generated during MAO and SSAO activation by tyramine and benzylamine. They also quenched H2O2-induced fluorescence in absence of biological material and were unable to abolish the oxidation of radiolabelled tyramine and benzylamine. Thus, phenolic compounds hampered H2O2 detection but did not block AO activity. Only resveratrol and quercetin partially impaired MAO-dependent [14C]-tyramine oxidation and behaved as MAO inhibitors. Phenolic compounds counteracted the H2O2-dependent benzylamine-stimulated glucose transport. This indicates that various phenolic compounds block downstream effects of H2O2 produced by biogenic or exogenous amine oxidation without directly inhibiting AO. Phenolic compounds remain of interest regarding their capacity to limit oxidative stress rather than inhibiting AO.

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

dependent anion channel and volume-regulated anion channel in frog aorta .... Proteomic analysis of cell lines to identify the irinotecan resistance proteins ... benzylamine, could be evaluated further for developing a drug to control M. tuberculosis.

Smooth isoindolinone formation from isopropyl carbamates via Bischler-Napieralski-type cyclization.

Science.gov (United States)

Adachi, Satoshi; Onozuka, Masao; Yoshida, Yuko; Ide, Mitsuaki; Saikawa, Yoko; Nakata, Masaya

2014-01-17

Isopropyl carbamates derived from benzylamines provide isoindolinones by treatment with phosphorus pentoxide at room temperature. Utility of this Bischler-Napieralski-type cyclization and a new mechanism involving a carbamoyl cation for rationalization of this smooth conversion are discussed.

Synthesis of N-protected Galactosamine Building Blocks from D-Tagatose via the Heyns Rearrangement

DEFF Research Database (Denmark)

Wrodnigg, Tanja M.; Lundt, Inge; Stütz, Arnold E.

2006-01-01

N-Acetyl-D-galactosamine (11), a very important naturally occurring building block of oligosaccharides, is easily accessible via the Heyns rearrangement of D-tagatose (3) with benzylamine. The short and efficient synthesis of various differently N-protected D-galactosamine derivatives is reported....

Comparing Amide-Forming Reactions Using Green Chemistry Metrics in an Undergraduate Organic Laboratory

Science.gov (United States)

Fennie, Michael W.; Roth, Jessica M.

2016-01-01

In this laboratory experiment, upper-division undergraduate chemistry and biochemistry majors investigate amide-bond-forming reactions from a green chemistry perspective. Using hydrocinnamic acid and benzylamine as reactants, students perform three types of amide-forming reactions: an acid chloride derivative route; a coupling reagent promoted…

The Synthesis of "N"-Benzyl-2-Azanorbornene via Aqueous Hetero Diels-Alder Reaction: An Undergraduate Project in Organic Synthesis and Structural Analysis

Science.gov (United States)

Sauvage, Xavier; Delaude, Lionel

2008-01-01

The synthesis of "N"-benzyl-2-azanorbornene via aqueous hetero Diels-Alder reaction of cyclopentadiene and benzyliminium chloride formed in situ from benzylamine hydrochloride and formaldehyde is described. Characterization of the product was achieved by IR and NMR spectroscopies. The spectral data acquired are thoroughly discussed. Numerous…

Adsorption of polar aromatic hydrocarbons on synthetic calcite

DEFF Research Database (Denmark)

Madsen, Lene; Grahl-Madsen, Laila; Grøn, Christian

1996-01-01

The wettability of hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. A model system of synthetic call cite, cyclohexane and the three probe molecules: benzoic acid, benzyl alcohol and benzylamine, have been...

Chemical Property Change in a Metal-Organic Framework by Fluoro Functionality

International Nuclear Information System (INIS)

Ko, Nakeun; Hong, Jisu; You, Laekyeong; Park, Hye Jeong; Yang, Jin Kuk; Kim, Jaheon

2015-01-01

A fluorine-functionalized HKUST-1 (HKUST-1-F) has been synthesized by a solvo thermal reaction between copper nitrate and a potassium salt of 2-fluoro-1,3,5-benzenetricarboxylic acid (K[H 2 BTC-F]). HKUST-1-F shows nearly the same crystal structure as that of UHM-31, a known fluorinated HKUST-1. Because of its reduced surface area, HKUST-1-F takes up smaller amounts of gases (N 2 , H 2 , CO 2 ) than UHM-31 at 1 bar. After a water vapor adsorption measurement at 298 K, HKUST-1-F turned into an unknown structure, based on powder X-ray diffraction analyses. HKUST-1-F could be further functionalized with benzylamine in a post synthetic modification; the nucleophilic replacement of the F atom in BTC-F with benzylamine in methylene chloride at room temperature took place in a conversion yield of -38% based on 1H NMR analyses

Chemical Property Change in a Metal-Organic Framework by Fluoro Functionality

Energy Technology Data Exchange (ETDEWEB)

Ko, Nakeun; Hong, Jisu; You, Laekyeong; Park, Hye Jeong; Yang, Jin Kuk; Kim, Jaheon [Soongsil University, Seoul (Korea, Republic of)

2015-01-15

A fluorine-functionalized HKUST-1 (HKUST-1-F) has been synthesized by a solvo thermal reaction between copper nitrate and a potassium salt of 2-fluoro-1,3,5-benzenetricarboxylic acid (K[H{sub 2}BTC-F]). HKUST-1-F shows nearly the same crystal structure as that of UHM-31, a known fluorinated HKUST-1. Because of its reduced surface area, HKUST-1-F takes up smaller amounts of gases (N{sub 2}, H{sub 2}, CO{sub 2}) than UHM-31 at 1 bar. After a water vapor adsorption measurement at 298 K, HKUST-1-F turned into an unknown structure, based on powder X-ray diffraction analyses. HKUST-1-F could be further functionalized with benzylamine in a post synthetic modification; the nucleophilic replacement of the F atom in BTC-F with benzylamine in methylene chloride at room temperature took place in a conversion yield of -38% based on 1H NMR analyses.

Sodium benzyl(monoethanol)ammonium bis(gluconatoborate). Bis(glyukonatoborat) natriya-benzil(monoehtanol)ammoniya

Energy Technology Data Exchange (ETDEWEB)

Tel' zhenskaya, P N; Shvarts, E M; Vitola, I M [AN Latvijskoj SSR, Riga (USSR). Inst. Neorganicheskoj Khimii

1990-01-01

Boron compounds with gluconic acid and monoethanol- and benzylamines are synthesized and investigated by physicochemical methods (IR-spectroscopy, thermal decomposition, conductometry, Fischer titration). Tetracoordinated boron has two free hydroxyl groups, dimer of boron-gluconate anion is held by hydrogen bonds, sodium ions and ammonium protonated salts are cations.

Sodium benzyl(monoethanol)ammonium bis(gluconatoborate)

International Nuclear Information System (INIS)

Tel'zhenskaya, P.N.; Shvarts, E.M.; Vitola, I.M.

1990-01-01

Boron compounds with gluconic acid and monoethanol- and benzylamines are synthesized and investigated by physicochemical methods (IR-spectroscopy, thermal decomposition, conductometry, Fischer titration). Tetracoordinated boron has two free hydroxyl groups, dimer of boron-gluconate anion is held by hydrogen bonds, sodium ions and ammonium protonated salts are cations

Bioactive maca (Lepidium meyenii) alkamides are a result of traditional Andean postharvest drying practices.

Science.gov (United States)

Esparza, Eliana; Hadzich, Antonella; Kofer, Waltraud; Mithöfer, Axel; Cosio, Eric G

2015-08-01

Maca, Lepidium meyenii Walpers (Brassicaceae), is an annual herbaceous plant native to the high plateaus of the Peruvian central Andes. Its underground storage hypocotyls have been a traditional medicinal agent and dietary staple since pre-Columbian times. Reported properties include energizing and fertility-enhancing effects. Published reports have focused on the benzylalkamides (macamides) present in dry hypocotyls as one of the main bioactive components. Macamides are secondary amides formed by benzylamine and a fatty acid moiety, with varying hydrocarbon chain lengths and degree of unsaturation. Although it has been assumed that they are usually present in fresh undamaged tissues, analyses show them to be essentially absent from them. However, hypocotyls dried by traditional Andean postharvest practices or industrial oven drying contain up to 800μgg(-1) dry wt (2.3μmolg(-1) dry wt) of macamides. In this study, the generation of macamides and their putative precursors were studied during nine-week traditional drying trials at 4200m altitude and in ovens under laboratory conditions. Freeze-thaw cycles in the open field during drying result in tissue maceration and release of free fatty acids from storage and membrane lipids up to levels of 1200μgg(-1) dry wt (4.3μmolg(-1) dry wt). Endogenous metabolism of the isothiocyanates generated from glucosinolate hydrolysis during drying results in maximal benzylamine values of 4300μgg(-1) dry wt (40.2μmolg(-1) dry wt). Pearson correlation coefficients of the accumulation profiles of benzylamine and free fatty acid to that of macamides showed good values of 0.898 and 0.934, respectively, suggesting that both provide sufficient substrate for amide synthesis during the drying process. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Carbon nanotube-supported Au-Pd alloy with cooperative effect of metal nanoparticles and organic ketone/quinone groups as a highly efficient catalyst for aerobic oxidation of amines.

Science.gov (United States)

Deng, Weiping; Chen, Jiashu; Kang, Jincan; Zhang, Qinghong; Wang, Ye

2016-05-21

Functionalised carbon nanotube (CNT)-supported Au-Pd alloy nanoparticles were highly efficient catalysts for the aerobic oxidation of amines. We achieved the highest turnover frequencies (>1000 h(-1)) for the oxidative homocoupling of benzylamine and the oxidative dehydrogenation of dibenzylamine. We discovered a cooperative effect between Au-Pd nanoparticles and ketone/quinone groups on CNTs.

Kinetics and mechanism of the oxidation of substituted ...

Indian Academy of Sciences (India)

Unknown

Oxidation of meta- and para-substituted benzylamines by cetyltrimethyl- ... method.12 As per this method, the aldimine is hydrolysed to the aldehyde and then ... reactions were studied at constant temperature (± 0⋅1 K) and were followed by .... electronic interaction between the substituent and the reaction centre, (σ+–σ0) is ...

An improved synthesis of 4-[18F]-ADAM, a potent serotonin transporter imaging agent

International Nuclear Information System (INIS)

Huang, Y.-Y.; Huang, W.-S.; Chu, T.-C.; Shiue, C.-Y.

2009-01-01

An improved synthesis of N,N-dimethyl-2-(2-amino-4-[ 18 F]fluorophenylthio)benzylamine (4-[ 18 F]-ADAM, 2) as a potent serotonin transporter (SERT) imaging agent is described. Molecular orbital (MO) calculation predicts that N,N-dimethyl-2- (2-nitro-4-trimethylammoniumtrifluoromethanesulfonylphenylthio)benzamide (8) is probably a better precursor than N,N-dimethyl-2-(2,4-dinitrophenylthio)benzylamine (1) for preparing 2. Radioligand 2 was synthesized by the reaction of either precursor 1 or precursor 8 with K[ 18 F]/K 2.2.2 at 120 deg. C followed by reduction with BH 3 at 80 deg. C. The radiochemical yield (EOB) of 2 synthesized from precursor 1 and 8 was 5.7±2.4% (n=6) and 14.8±4.0% (n=5), respectively, in a synthesis time of 120 min from EOB. The specific activity of 2 was 3 Ci/μmol or 111 GBq/μmol (EOB). Thus, this new synthetic method has significantly improved the radiochemical yield of 4-[ 18 F]-ADAM and makes this radioligand more accessible to PET Centers without a cyclotron.

Separation of polyethylene glycols and amino-terminated polyethylene glycols by high-performance liquid chromatography under near critical conditions.

Science.gov (United States)

Wei, Y-Z; Zhuo, R-X; Jiang, X-L

2016-05-20

The separation and characterization of polyethylene glycols (PEGs) and amino-substituted derivatives on common silica-based reversed-phase packing columns using isocratic elution is described. This separation is achieved by liquid chromatography under the near critical conditions (LCCC), based on the number of amino functional end groups without obvious effect of molar mass for PEGs. The mobile phase is acetonitrile in water with an optimal ammonium acetate buffer. The separation mechanism of PEG and amino-substituted PEG under the near LCCC on silica-based packing columns is confirmed to be ion-exchange interaction. Under the LCCC of PEG backbone, with fine tune of buffer concentration, the retention factor ratios for benzylamine and phenol in buffered mobile phases, α(benzylamine/phenol)-values, were used to assess the ion-exchange capacity on silica-based reversed-phase packing columns. To the best of our knowledge, this is the first report on separation of amino-functional PEGs independent of the molar mass by isocratic elution using common C18 or phenyl reversed-phase packing columns. Copyright © 2016 Elsevier B.V. All rights reserved.

Kinetic investigation of the catalytic mechanism for bovine liver mitochondrial monoamine oxidase

International Nuclear Information System (INIS)

Walker, M.C.

1988-01-01

The kinetic behavior of the oxidative deamination reaction catalyzed by bovine liver mitochondrial monoamine oxidase was investigated with a series of ring-substituted benzylamines. Oxidation rates were fastest with the meta isomers. Dalziel coefficients were consistent with a mechanism involving a ternary complex for all substrates tested. Alterations in the Michaelis constant for oxygen were similar in magnitude to those for the rate of catalysis. Deuterium and tritium isotope effects were determined to obtain more detailed information on the mechanism of catalysis. Large deuterium isotope effects expressed on k cat were obtained for all substrates. Determination of the tritium isotope effect for benzylamine allowed the calculation of an intrinsic isotope effect of 6.5 and a secondary isotope effect of 1.17. Steady-state experiments were supplemented with pre-steady-state kinetic techniques. Rates of flavin reduction were faster than that of turnover. The deuterium isotope effect obtained for the rate of flavin reduction was 7-15 for the various substrates. The observed isotope effect was found to be an appropriate estimate for the intrinsic isotope effect

15-00467_SI.doc

Indian Academy of Sciences (India)

Following the general procedure, benzylalcohol (1 mmol) was used as the alcohol species and 4-methyl benzylamine (1.2 mmol) as the amine species. The title compound was recovered as a white solid (79-88%), after column chromatography eluting with 6:4, hexane: ethyl acetate. TON: 88/79/84. 1H NMR (300.13 MHz, ...

An improved synthesis of 4-[{sup 18}F]-ADAM, a potent serotonin transporter imaging agent

Energy Technology Data Exchange (ETDEWEB)

Huang, Y.-Y. [PET Center, Department of Nuclear Medicine, Tri-Service General Hospital 325 Section 2, Cheng-Kung Road, Neihu 114, Taipei, Taiwan (China); Department of Biomedical Engineering and Environmental Sciences, National Thising Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Huang, W.-S. [PET Center, Department of Nuclear Medicine, Tri-Service General Hospital 325 Section 2, Cheng-Kung Road, Neihu 114, Taipei, Taiwan (China); Chu, T.-C. [Department of Biomedical Engineering and Environmental Sciences, National Thising Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Shiue, C.-Y. [PET Center, Department of Nuclear Medicine, Tri-Service General Hospital 325 Section 2, Cheng-Kung Road, Neihu 114, Taipei, Taiwan (China)], E-mail: shiue@ndmctsgh.edu.tw

2009-06-15

An improved synthesis of N,N-dimethyl-2-(2-amino-4-[{sup 18}F]fluorophenylthio)benzylamine (4-[{sup 18}F]-ADAM, 2) as a potent serotonin transporter (SERT) imaging agent is described. Molecular orbital (MO) calculation predicts that N,N-dimethyl-2- (2-nitro-4-trimethylammoniumtrifluoromethanesulfonylphenylthio)benzamide (8) is probably a better precursor than N,N-dimethyl-2-(2,4-dinitrophenylthio)benzylamine (1) for preparing 2. Radioligand 2 was synthesized by the reaction of either precursor 1 or precursor 8 with K[{sup 18}F]/K{sub 2.2.2} at 120 deg. C followed by reduction with BH{sub 3} at 80 deg. C. The radiochemical yield (EOB) of 2 synthesized from precursor 1 and 8 was 5.7{+-}2.4% (n=6) and 14.8{+-}4.0% (n=5), respectively, in a synthesis time of 120 min from EOB. The specific activity of 2 was 3 Ci/{mu}mol or 111 GBq/{mu}mol (EOB). Thus, this new synthetic method has significantly improved the radiochemical yield of 4-[{sup 18}F]-ADAM and makes this radioligand more accessible to PET Centers without a cyclotron.

Enhanced reactivities toward amines by introducing an imine arm to the pincer ligand: Direct coupling of two amines to form an imine without oxidant

KAUST Repository

He, Lipeng

2012-07-23

Dehydrogenative homocoupling of primary alcohols to form esters and coupling of amines to form imines was accomplished using a class of novel pincer ruthenium complexes. The reactivities of the ruthenium pincer complexes for the direct coupling of amines to form imines were enhanced by introducing an imine arm to the pincer ligand. Selective oxidation of benzylamines to imines was achieved using aniline derivatives as the substrate and solvent. © 2012 American Chemical Society.

Enhanced reactivities toward amines by introducing an imine arm to the pincer ligand: Direct coupling of two amines to form an imine without oxidant

KAUST Repository

He, Lipeng; Chen, Tao; Gong, Dirong; Lai, Zhiping; Huang, Kuo-Wei

2012-01-01

Dehydrogenative homocoupling of primary alcohols to form esters and coupling of amines to form imines was accomplished using a class of novel pincer ruthenium complexes. The reactivities of the ruthenium pincer complexes for the direct coupling of amines to form imines were enhanced by introducing an imine arm to the pincer ligand. Selective oxidation of benzylamines to imines was achieved using aniline derivatives as the substrate and solvent. © 2012 American Chemical Society.

1-[18F]fluoro-2-propanol p-toluenesulfonate: a synthon for the preparation of N-([18F]fluoroisopropyl)amines

International Nuclear Information System (INIS)

Groot, T.J. de; Elsinga, P.H.; Visser, G.M.; Vaalburg, W.

1992-01-01

The new radiochemical synthon 1-[ 18 F]fluoro-2-propanol p-toluenesulfonate is prepared with a radiochemical yield of 45% [corrected for decay to beginning of synthesis, synthesis time 40 min]. This compound is used to prepare the [ 18 F]fluoroisopropyl-alkylated derivatives of benzylamine and norephedrine with a yield of 7 and 2% respectively, (synthesis time 90 min). This alkylation reaction a good perspective for the preparation of [ 18 F]fluoro-labelled analogues of β 1 -adrenergic receptor binding ligands for PET. (Author)

o-Naphthoquinone-Catalyzed Aerobic Oxidation of Amines to (Ket)imines: A Modular Catalyst Approach.

Science.gov (United States)

Goriya, Yogesh; Kim, Hun Young; Oh, Kyungsoo

2016-10-07

A modular aerobic oxidation of amines to imines has been achieved using an ortho-naphthoquinone (o-NQ) catalyst. The cooperative catalyst system of o-NQ and Cu(OAc) 2 enabled the formation of homocoupled imines from benzylamines, while the presence of TFA helped the formation of cross-coupled imines in excellent yields. The current mild aerobic oxidation protocol could also be applied to the oxidation of secondary amines to imines or ketimines with the help of cocatalyst, Ag 2 CO 3 , with excellent yields.

A rapid detection method for policy-sensitive amines real-time supervision.

Science.gov (United States)

Zhang, Haixu; Shu, Jinian; Yang, Bo; Zhang, Peng; Ma, Pengkun

2018-02-01

Many organic amines that comprise a benzene ring are policy-sensitive because of their toxicity and links to social harm. However, to date, detection of such compounds mainly relies on offline methods. This study proposes an online pptv (parts per trillion by volume) level of detection method for amines, using the recently-built vacuum ultraviolet photoionization mass spectrometer (VUV-PIMS) combined with a new doping technique. Thus, the dichloromethane doping-assisted photoionization mass spectra of aniline, benzylamine, phenethylamine, amphetamine, and their structural isomers were recorded. The dominant characteristic mass peaks for all amines are those afforded by protonated amines and the amino radical-loss. The signal intensities of the amines were enhanced by 60-130 times compared to those recorded without doping assistance. Under 10s detection time, the sensitivities of aniline and benzylamine in the gas phase were determined as 4.0 and 2.7 countspptv -1 , with limits of detection (LODs) of 36 and 22 pptv, respectively. Notably, the detection efficiency of this method can be tenfold better in future applications since the ion transmission efficiency of the mass spectrometer was intentionally reduced to ~ 10% in this study. Therefore, dichloromethane doping-assisted photoionization mass spectrometry has proven to be a highly promising on-line approach to amine detection in environmental and judicial supervision and shows great potential for application in the biological field. Copyright © 2017 Elsevier B.V. All rights reserved.

A new efficient and stereospecific conversion of aminodeoxyalditols into aminoalkyl-substituted tetrahydrofurans

DEFF Research Database (Denmark)

Norrild, Jens Chr.; Pedersen, Christian; Defaye, Jacques

1996-01-01

Reaction of a series of aminodeoxy-pentitols and -hexitols in anhydrous hydrogen fluoride with formic acid as catalyst gave the corresponding 2,5- and 3,6-anhydro-anlinodeoxyalditols; namely, 1-amino-2,5-anhydro-1-deoxy-D-arabinitol, -D-xylitol, and -D-ribitol; 1-amino-3,6-anhydro-1-deoxy......-trimethylammonio-D-gulitol chloride. D-arabino-Hexosulose phenylosotriazole gave the corresponding 3,6-anhydro-D-avabino-hexosulose phenylosotriazole. Syntheses of the 1-amino-1-deoxyalditols were performed by reductive amination with benzylamine-sodium borohydride followed by catalytic hydrogenation over Pd-C. (C...

A straightforward and efficient method for the synthesis of diversely substituted {beta}-aminoketones and {gamma}-aminoalcohols from 3-(N,N-dimethylamino)propiophenones as starting materials

Energy Technology Data Exchange (ETDEWEB)

Abonia, Rodrigo; Arteaga, Danny; Castillo, Juan; Insuasty, Braulio; Quiroga, Jairo; Ortiz, Alejandro, E-mail: rodrigo.abonia@correounivalle.edu.co [Universidad del Valle, Cali (Colombia). Department of Chemistry. Research Group of Heterocyclic Compounds

2013-09-15

Libraries of novel {beta}-aminoketones and {gamma}-aminoalcohols showing a wide structural diversity were easily obtained from a simple approach, using 3-(N,N-dimethylamino)propiophenone derivatives as key starting material. The procedure involved initially an N-alkylation of secondary benzylamines with propiophenone salts yielding the desired {beta}-aminoketones. Chemical or catalytic reduction of their carbonyl groups provided the final {gamma}-aminoalcohols in good yields. This protocol proved to be convenient as an alternative route for the synthesis of the local anesthetic Falicain Registered-Sign and for the topic antifungal drug Naftifine Registered-Sign . (author)

1-[[sup 18]F]fluoro-2-propanol p-toluenesulfonate: a synthon for the preparation of N-([[sup 18]F]fluoroisopropyl)amines

Energy Technology Data Exchange (ETDEWEB)

Groot, T.J. de; Elsinga, P.H.; Visser, G.M.; Vaalburg, W. (Groningen Univ. (Netherlands). PET Center and GCCS)

1992-11-01

The new radiochemical synthon 1-[[sup 18]F]fluoro-2-propanol p-toluenesulfonate is prepared with a radiochemical yield of 45% [corrected for decay to beginning of synthesis, synthesis time 40 min]. This compound is used to prepare the [[sup 18]F]fluoroisopropyl-alkylated derivatives of benzylamine and norephedrine with a yield of 7 and 2% respectively, (synthesis time 90 min). This alkylation reaction a good perspective for the preparation of [[sup 18]F]fluoro-labelled analogues of [beta][sub 1]-adrenergic receptor binding ligands for PET. (Author).

Co-polymer Films for Sensors

Science.gov (United States)

Ryan, Margaret A. (Inventor); Jewell, April D. (Inventor); Taylor, Charles (Inventor); Yen, Shiao-Pin S. (Inventor); Kisor, Adam (Inventor); Manatt, Kenneth S. (Inventor); Blanco, Mario (Inventor); Goddard, William A. (Inventor); Homer, Margie L. (Inventor); Shevade, Abhijit V. (Inventor)

2012-01-01

Embodiments include a sensor comprising a co-polymer, the co-polymer comprising a first monomer and a second monomer. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is polystyrene and the second monomer is poly-2-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium benzylamine chloride. Other embodiments are described and claimed.

Cauliflower-like CuI nanostructures: Green synthesis and applications as catalyst and adsorbent

Energy Technology Data Exchange (ETDEWEB)

Jiang Yi [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang, Henan 453007 (China); Gao Shuyan, E-mail: shuyangao@htu.cn [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang, Henan 453007 (China); Li Zhengdao; Jia Xiaoxia; Chen Yanli [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang, Henan 453007 (China)

2011-08-15

Highlights: > In this study we report a green, environment-friendly, efficient, and direct one-step process for the preparation of CuI cauliflower. > The as-formed CuI cauliflower shows excellent catalytic activity for coupling reaction between benzylamine and iodobenzene. > The cauliflower-like CuI nanostructures have been successfully demonstrated as adsorbent for Cd (II) with high removal capacity. > To the best of our knowledge, it is the first report that nanostructured CuI acts as catalyst for coupling reaction and adsorbent for heavy metal ion. > It is also a good example for the organic combination of green chemistry and functional materials. - Abstract: Cauliflower-like CuI nanostructures is realized by an ampicillin-assisted clean, nontoxic, environmentally friendly synthesis strategy at room temperature. The morphology, composition, and phase structure of as-prepared powders were characterized by field emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results show that ampicillin plays dual roles, reducing and morphology-directing agents, in the formation of the products. A possible growth mechanism of the cauliflower-like CuI nanostructures is tentatively proposed. The preliminary investigations show that the cauliflower-like CuI structure not only exhibits high catalytic activity with respect to coupling reaction between benzylamine and iodobenzene but also possesses high removal capacity for Cd (II), which may be ascribed to the high specific surface area of the special configuration. To the best of our knowledge, it is the first report that cauliflower-like CuI nanoparticles act as catalyst for coupling reaction and adsorbent for heavy metal ion.

Acrolein generation stimulates hypercontraction in isolated human blood vessels

International Nuclear Information System (INIS)

Conklin, D.J.; Bhatnagar, A.; Cowley, H.R.; Johnson, G.H.; Wiechmann, R.J.; Sayre, L.M.; Trent, M.B.; Boor, P.J.

2006-01-01

Increased risk of vasospasm, a spontaneous hyperconstriction, is associated with atherosclerosis, cigarette smoking, and hypertension-all conditions involving oxidative stress, lipid peroxidation, and inflammation. To test the role of the lipid peroxidation- and inflammation-derived aldehyde, acrolein, in human vasospasm, we developed an ex vivo model using human coronary artery bypass graft (CABG) blood vessels and a demonstrated acrolein precursor, allylamine. Allylamine induces hypercontraction in isolated rat coronary artery in a semicarbazide-sensitive amine oxidase activity (SSAO) dependent manner. Isolated human CABG blood vessels (internal mammary artery, radial artery, saphenous vein) were used to determine: (1) vessel responses and sensitivity to acrolein, allylamine, and H 2 O 2 exposure (1 μM-1 mM), (2) SSAO dependence of allylamine-induced effects using SSAO inhibitors (semicarbazide, 1 mM; MDL 72274-E, active isomer; MDL 72274-Z, inactive isomer; 100 μM), (3) the vasoactive effects of two other SSAO amine substrates, benzylamine and methylamine, and (4) the contribution of extracellular Ca 2+ to hypercontraction. Acrolein or allylamine but not H 2 O 2 , benzylamine, or methylamine stimulated spontaneous and pharmacologically intractable hypercontraction in CABG blood vessels that was similar to clinical vasospasm. Allylamine-induced hypercontraction and blood vessel SSAO activity were abolished by pretreatment with semicarbazide or MDL 72274-E but not by MDL 72274-Z. Allylamine-induced hypercontraction also was significantly attenuated in Ca 2+ -free buffer. In isolated aorta of spontaneously hypertensive rat, allylamine-induced an SSAO-dependent contraction and enhanced norepinephrine sensitivity but not in Sprague-Dawley rat aorta. We conclude that acrolein generation in the blood vessel wall increases human susceptibility to vasospasm, an event that is enhanced in hypertension

Cauliflower-like CuI nanostructures: Green synthesis and applications as catalyst and adsorbent

International Nuclear Information System (INIS)

Jiang Yi; Gao Shuyan; Li Zhengdao; Jia Xiaoxia; Chen Yanli

2011-01-01

Highlights: → In this study we report a green, environment-friendly, efficient, and direct one-step process for the preparation of CuI cauliflower. → The as-formed CuI cauliflower shows excellent catalytic activity for coupling reaction between benzylamine and iodobenzene. → The cauliflower-like CuI nanostructures have been successfully demonstrated as adsorbent for Cd (II) with high removal capacity. → To the best of our knowledge, it is the first report that nanostructured CuI acts as catalyst for coupling reaction and adsorbent for heavy metal ion. → It is also a good example for the organic combination of green chemistry and functional materials. - Abstract: Cauliflower-like CuI nanostructures is realized by an ampicillin-assisted clean, nontoxic, environmentally friendly synthesis strategy at room temperature. The morphology, composition, and phase structure of as-prepared powders were characterized by field emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results show that ampicillin plays dual roles, reducing and morphology-directing agents, in the formation of the products. A possible growth mechanism of the cauliflower-like CuI nanostructures is tentatively proposed. The preliminary investigations show that the cauliflower-like CuI structure not only exhibits high catalytic activity with respect to coupling reaction between benzylamine and iodobenzene but also possesses high removal capacity for Cd (II), which may be ascribed to the high specific surface area of the special configuration. To the best of our knowledge, it is the first report that cauliflower-like CuI nanoparticles act as catalyst for coupling reaction and adsorbent for heavy metal ion.

Synthesis of Renewable meta-Xylylenediamine from Biomass-Derived Furfural.

Science.gov (United States)

Scodeller, Ivan; Mansouri, Samir; Morvan, Didier; Muller, Eric; de Oliveira Vigier, Karine; Wischert, Raphael; Jérôme, François

2018-04-30

We report the synthesis of biomass-derived functionalized aromatic chemicals from furfural, a building block nowadays available in large scale from low-cost biomass. The scientific strategy relies on a Diels-Alder/aromatization sequence. By controlling the rate of each step, it was possible to produce exclusively the meta aromatic isomer. In particular, through this route, we describe the synthesis of renewably sourced meta-xylylenediamine (MXD). Transposition of this work to other furfural-derived chemicals is also discussed and reveals that functionalized biomass-derived aromatics (benzaldehyde, benzylamine, etc.) can be potentially produced, according to this route. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of phenanthridines via palladium-catalyzed picolinamide-directed sequential C–H functionalization

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Ryan Pearson

2013-05-01

Full Text Available We report a new synthesis of phenanthridines based on palladium-catalyzed picolinamide-directed sequential C–H functionalization reactions starting from readily available benzylamine and aryl iodide precursors. Under the catalysis of Pd(OAc2, the ortho-C–H bond of benzylpicolinamides is first arylated with an aryl iodide. The resulting biaryl compound is then subjected to palladium-catalyzed picolinamide-directed intramolecular dehydrogenative C–H amination with PhI(OAc2 oxidant to form the corresponding cyclized dihydrophenanthridines. The benzylic position of these dihydrophenanthridines could be further oxidized with Cu(OAc2, removing the picolinamide group and providing phenathridine products. The cyclization and oxidation could be carried out in a single step and afford phenathridines in moderate to good yields.

Neurotransmitter mechanisms of the action of the antihistamine dimebon on the brain

International Nuclear Information System (INIS)

Shadurskaya, S.K.; Khomenko, A.I.; Pereverzev, V.A.; Balakeevskii, A.I.

1986-01-01

To discover the possible mechanism of the stimulating effect of dimebon on the CNS, the action of the drug was studied on catecholamine concentrations and turnover and activity of forms of monoamine oxidase (MAO), differing in the substrate metabolized, in brain structures involved in the regulation of the emotional state and in the regulation of motor activity in rats. 3 H-serotonin creatinine-sulfate, 3 H-dopamine hydrochloride, and 14 C- benzylamine hydrochloride were used as substrates. The results show that dimebon can inhibit MAO activity in the basal ganglia and other brain structures both in vitro and in vivo, and can cause changes in DA and NA metabolism and in functional activity of catecholaminergic neuronal structures of the brain

Conformational analysis, spectroscopic, structure-activity relations and quantum chemical simulation studies of 4-(trifluoromethyl)benzylamine

Science.gov (United States)

Arjunan, V.; Devi, L.; Mohan, S.

2018-05-01

The FT-IR and FT-Raman spectra of 4-trifluoromethylbenzylamine (TFMBA) have been recorded in the range 4000-450 and 4000-100 cm-1 respectively. The conformational analysis of the compound has been carried out to attain stable geometry of the compound. The complete vibrational assignment and analysis of the fundamental modes of the compound are carried out using the experimental FTIR and FT-Raman data and quantum chemical studies. The experimental vibrational frequencies are compared with the wavenumbers obtained theoretically from the B3LYP gradient calculations employing the standard high level 6-311++G** and cc-pVTZ basis sets for the optimised geometry of the compound. The structural parameters, thermodynamic properties and vibrational frequencies of the normal modes obtained from the B3LYP methods are in good agreement with the experimental data. The 1H (400 MHz; CDCl3) and 13C (100 MHz; CDCl3) nuclear magnetic resonance (NMR) spectra were also recorded. The electronic properties, highest occupied molecular orbital and lowest unoccupied molecular orbital energies are measured by DFT approach. The charges of the atoms by natural bond orbital (NBO) analysis are determined by B3LYP/cc-pVTZ method. The structure-chemical reactivity relations of the compound are determined through chemical potential, global hardness, global softness, electronegativity, electrophilicity and local reactivity descriptors by conceptual DFT methods.

Meta-iodobenzylguanidine synthesis and labelling with iodine-131

International Nuclear Information System (INIS)

Miranda, J.; Herrera, J.; Robles, A.; Caballero, J.; Portilla, A.; Ticona, L.

1997-01-01

Meta-iodo-benzylguanidine (MIBG) synthesis is carried out through m-iodo benzylamine condensation and subsequent formation of the hemisulfate salt. The synthesized product is characterized and identified by IR spectroscopy and m.p. determination. Acute toxicity tests conducted in mice demonstrated that the synthesized product is not toxic. MIBG hemisulfate labelling methods with I-131 is carried out by nucleophilic isotopic exchange; the reaction is catalyzed with cooper sulfate in the presence of ammonium sulfate at temperatures ranging between 140 and 150 o C . Biological distribution tests in wistar rats present an average value of 1,54% of injected dose/organ gram in suprarenal glands. These values show promise for the application of this radiopharmaceutical in radiodiagnosis of suprarenal tumors and procurement of adrenal medulla, myocardium and salivary gland images

Amine oxidase from lentil seedlings: energetic domains and effect of temperature on activity.

Science.gov (United States)

Moosavi-Nejad, S Z; Rezaei-Tavirani, M; Padiglia, A; Floris, G; Moosavi-Movahedi, A A

2001-07-01

Copper/TPQ amine oxidases from mammalian and plant sources have shown many differences in substrate specificity and molecular properties. In this work the activity of lentil seedling amine oxidase was followed at various temperatures in 100 mM potassium phosphate buffer, pH 7, using benzylamine as substrate. The discontinuous Arrhenius plot of lentil amine oxidase showed two distinct phases with a jump between them. Thermal denaturation of the enzyme, using differential scanning calorimetry under the same experimental conditions, showed a transition at the same temperature ranges in the absence of substrate, indicating the occurrence of conformational changes, with an enthalpy change of about 175.9 kJ/mole. The temperature-induced changes of the activity of lentil amine oxidase are compared with those of bovine serum amine oxidase (taken from the literature).

A comparison of cationic polymerization and esterification for end-point detection in the catalytic thermometric titration of organic bases.

Science.gov (United States)

J Greenhow, E; Viñas, P

1984-08-01

A systematic comparison has been made of two indicator systems for the non-aqueous catalytic thermometric titration of strong and weak organic bases. The indicator reagents, alpha-methylstyrene and mixtures of acetic anhydride and hydroxy compounds, are shown to give results (for 14 representative bases) which do not diner significantly in coefficient of variation or titration error. Calibration graphs for all the samples, in the range 0.01-0.1 meq, are linear, with correlation coefficients of 0.995 or better. Aniline, benzylamine, n-butylamine, morpholine, pyrrole, l-dopa, alpha-methyl-l-dopa, dl-alpha-alanine, dl-leucine and l-cysteine cannot be determined when acetic anhydride is present in the sample solution, but some primary and second amines can. This is explained in terms of rates of acetylation of the amino groups.

Synthesis and formulation studies of griseofulvin analogues with improved solubility and metabolic stability

DEFF Research Database (Denmark)

Petersen, Asger Bjørn; Andersen, Nikolaj Sten; Konotop, Gleb

2017-01-01

Griseofulvin (1) is an important antifungal agent that has recently received attention due to its antiproliferative activity in mammalian cancer cells. Comprehensive SAR studies have led to the identification of 2'-benzyloxy griseofulvin 2, a more potent analogue with low micromolar anticancer...... potency in vitro. Analogue 2 was also shown to retard tumor growth through inhibition of centrosomal clustering in murine xenograft models of colon cancer and multiple myeloma. However, similar to griseofulvin, compound 2 exhibited poor metabolic stability and aqueous solubility. In order to improve...... studies. The 2'-benzylamine analogue 10 proved to be the most promising compound with low μM in vitro anticancer potency, a 200-fold increase in PBS solubility over compound 2, and with improved metabolic stability. Furthermore, this analogue proved compatible with formulations suitable for both oral...

[Substrate-inhibitory analysis of monoamine oxidase from hepatopancreas of the octopus Bathypolypus arcticus].

Science.gov (United States)

Basova, I N; Iagodina, O V

2012-01-01

Study of the substrate-inhibitory specificity of mitochondrial monoamine oxidase (MAO) of hepatopancreas of the octopus Bathypolypus arcticus revealed distinctive peculiarities of catalytic properties of this enzyme. The studied enzyme, on one hand, like the classic MAO of homoiothermal animals, is able to deaminate tyramine, serotonin, benzylamine, tryptamine, beta-phenylethylamine, while, on the other hand, deaminates histamine and does not deaminate putrescine--classic substrates of diamine oxidase (DAO). Results of the substrate-inhibitory analysis with use of chlorgiline and deprenyl are indirect proofs of the existence in the octopus hepatopancreas of one molecular MAO form. Semicarbazide and pyronine G turned out to be weak irreversible inhibitors, four derivatives of acridine--irreversible inhibitors of the intermediate effectiveness with respect to the octopus hepatopancreas MAO; specificity of action of inhibitors at deamination of different substrates was equal.

Synthesis and Characterization of Some New Thermal Stable Polymers - Polymerization of N-[4-N´ -(Benzylamino-carbonylphenyl]maleimide

Directory of Open Access Journals (Sweden)

B. L. Hiran

2007-01-01

Full Text Available This article describes the synthesis and characterization of homopolymer (H-BCPM of N-[4-N'-(benzylamino-carbonyl phenyl] maleimide (N-BACPMI and copolymer (C-BCPM of N-BACPMI with n-butyl acrylate (BA. The new monomer was synthesized from p-aminobenzoic acid, maleic anhydride and benzylamine. The homopolymerization of N-BACPMI is initiated by free radical using AIBN in THF solvent at 65°C. Radical copolymerization of N-BACPMI with BA, initiated by AIBN, was performed in THF solvent using equimolar amount. Effect of the different free radical initiator AIBN, BPO and solvents p-Dioxane, THF, DMF and DMSO was studied. Homopolymer and Copolymer were characterized by intrinsic viscosity, solubility test, FT-IR, 1H-NMR spectral analysis and elemental analysis. Thermal behaviour was studied by Thermo gravimetric analysis.

Synthesis of naturally occurring iminosugars from D-fructose by the use of a zinc-mediated fragmentation reaction

DEFF Research Database (Denmark)

Lauritsen, Anne; Madsen, Robert

2006-01-01

A short synthesis of 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) and a formal synthesis of australine are described. In both cases, D-fructose is employed as the starting material and converted into a protected methyl 6-deoxy-6-iodo-furanoside. Zinc-mediated fragmentation produces an unsaturated...... ketone which serves as a key building block for both syntheses. Ozonolysis, reductive amination with benzylamine and deprotection affordfs 1,4-dideoxy-1,4-imino-D-arabinitol in only 7 steps and 11% overall yield from D-fructose. Alternatively, reductive amination with homoallylamine, ring......-closing metathesis and protecting group manipulations give rise to an intermediate which can be converted into australine in 3 steps. The intermediate is prepared by two different strategies both of which use a total of 9 steps. The first strategy utilizes benzyl ethers for protection of fructose while the second...

Catalytic Synthesis of Nitriles in Continuous Flow

DEFF Research Database (Denmark)

Nordvang, Emily Catherine

The objective of this thesis is to report the development of a new, alternative process for the flexible production of nitrile compounds in continuous flow. Nitriles are an important class of compounds that find applications as solvents, chemical intermediates and pharmaceutical compounds......, alternative path to acetonitrile from ethanol via the oxidative dehydrogenation of ethylamine. The catalytic activity and product ratios of the batch and continuous flow reactions are compared and the effect of reaction conditions on the reaction is investigated. The effects of ammonia in the reaction...... dehydrogenation of ethylamine and post-reaction purging.Chapter 4 outlines the application of RuO2/Al2O3 catalysts to the oxidative dehydrogenation of benzylamine in air, utilizing a new reaction setup. Again, batch and continuous flow reactions are compared and the effects of reaction conditions, ammonia...

Role of Amines in Thermal-Runaway-Mitigating Lithium-Ion Battery.

Science.gov (United States)

Shi, Yang; Noelle, Daniel J; Wang, Meng; Le, Anh V; Yoon, Hyojung; Zhang, Minghao; Meng, Ying Shirley; Qiao, Yu

2016-11-16

Benzylamine (BA), dibenzylamine (DBA), and trihexylamine (THA) are investigated as thermal-runaway retardants (TRR) for lithium-ion batteries (LIBs). In a LIB, TRR is packaged separately and released when internal shorting happens, so as to suppress exothermic reactions and slow down temperature increase. THA is identified as the most efficient TRR. Upon nail penetration, 4 wt % THA can reduce the peak temperature by nearly 50%. The working mechanisms of the three amines are different: THA is highly wettable to the separator and immiscible with the electrolyte, and therefore, it blocks lithium-ion (Li + ) transport. BA and DBA decrease the ionic conductivity of electrolyte and increase the charge transfer resistance. All three amines react with charged electrodes; the reactions of DBA and THA do not have much influence on the overall heat generation, while the reaction of BA cannot be ignored.

Predicting Organic Cation Sorption Coefficients: Accounting for Competition from Sorbed Inorganic Cations Using a Simple Probe Molecule.

Science.gov (United States)

Jolin, William C; Goyetche, Reaha; Carter, Katherine; Medina, John; Vasudevan, Dharni; MacKay, Allison A

2017-06-06

With the increasing number of emerging contaminants that are cationic at environmentally relevant pH values, there is a need for robust predictive models of organic cation sorption coefficients (K d ). Current predictive models fail to account for the differences in the identity, abundance, and affinity of surface-associated inorganic exchange ions naturally present at negatively charged receptor sites on environmental solids. To better understand how organic cation sorption is influenced by surface-associated inorganic exchange ions, sorption coefficients of 10 organic cations (including eight pharmaceuticals and two simple probe organic amines) were determined for six homoionic forms of the aluminosilicate mineral, montmorillonite. Organic cation sorption coefficients exhibited consistent trends for all compounds across the various homoionic clays with sorption coefficients (K d ) decreasing as follows: K d Na + > K d NH 4 + ≥ K d K + > K d Ca 2+ ≥ K d Mg 2+ > K d Al 3+ . This trend for competition between organic cations and exchangeable inorganic cations is consistent with the inorganic cation selectivity sequence, determined for exchange between inorganic ions. Such consistent trends in competition between organic and inorganic cations suggested that a simple probe cation, such as phenyltrimethylammonium or benzylamine, could capture soil-to-soil variations in native inorganic cation identity and abundance for the prediction of organic cation sorption to soils and soil minerals. Indeed, sorption of two pharmaceutical compounds to 30 soils was better described by phenyltrimethylammonium sorption than by measures of benzylamine sorption, effective cation exchange capacity alone, or a model from the literature (Droge, S., and Goss, K. Environ. Sci. Technol. 2013, 47, 14224). A hybrid approach integrating structural scaling factors derived from this literature model of organic cation sorption, along with phenyltrimethylammonium K d values, allowed for

Spectral investigations and DFT studies of 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione (caffeine) interaction and recognition by single amino acid derived self-assembled nanostructures

Science.gov (United States)

Govindhan, R.; Karthikeyan, B.

2018-03-01

Recognition of xanthine alkaloid caffeine with 3,5-bis(trifluoromethyl)benzylamine derived peptide nanotubes (BTTPNTs) through chemical interaction have been achieved through the host-guest like interaction. DFT simulation is carried out for caffeine interacted with BTTPNTs system and also experimentally characterized by ultraviolet-visible (UV-vis) absorbance, confocal Raman spectra (CRS) with microscopic imaging (CRM), FT-Raman, surface enhanced Raman scattering (SERS), UV-diffuse reflectance spectra (UV-DRS), high resolution transmission electron microscopy (HR-TEM) and cyclic voltammetry (CV) studies. The results are used to examine the morphologies, size of the nanostructure and study of its interaction with the caffeine molecule. The results show that BTTPNTs is having potential for sensing the caffeine molecules through the binding occurred from the NH2 of tyrosine moiety of the BTTPNTs. This intermolecular association through face-to-face stacking of BTTPNTs is explained by detailed DFT calculations.

Nano Cu interaction with single amino acid tyrosine derived self-assemblies; study through XRD, AFM, confocal Raman microscopy, SERS and DFT methods

Science.gov (United States)

Govindhan, Raman; Karthikeyan, Balakrishnan

2017-12-01

3,5-Bis(trifluoromethyl)benzylamine derivatives of single amino acid tyrosine produced self-assembled nanotubes (BTTNTs) as simple Phe-Phe. It has been observed that tyrosine derivative gives exclusively micro and nano tubes irrespective of the concentration of the precursor monomer. However, the introduced xenobiotic trifluoromethyl group (TFM) present in key backbone positionsof the self assembly gives the specific therapeutic function has been highlighted. Herein this work study of such self assembled nanotubes were studied through experimental and theoretical methods. The interaction of nanocopper cluster with the nanotubes (Cu@BTTNTs) were extensively studied by various methods like XRD, AFM, confocal Raman microscopy, SERS and theoretical methods like Mulliken's atomic charge analysis. SERS reveals that the interactions of Cu cluster with NH2, OH, NH and phenyl ring π-electrons system of BTTNTs. DFT studies gave the total dipole moment values of Cu@BTTNTs and explained the nature of interaction.

Synthesis and in vitro cytotoxicity of novel C-12 substituted-14-deoxy-andrographolide derivatives as potent anti-cancer agents.

Science.gov (United States)

Kandanur, Sai Giridhar Sarma; Golakoti, Nageswara Rao; Nanduri, Srinivas

2015-12-15

Andrographolide, the major labdane diterpenoid from Andrographis paniculata has been reported to be cytotoxic against various cancer cells in vitro. Our research efforts led to the discovery of novel 12-phenyl thio and 12-aryl amino-14-deoxy-andrographolide derivatives (III q and III r) with potent cytotoxic activity, 12-benzyl amino-14-deoxy-andrographolide analogues showing broad range of cytotoxic activity against most of the cell lines and 12-alkyl amino-14-deoxy-andrographolide derivatives being selective to few cell lines (PC-3 and HOP-92), when the selected analogues were evaluated against 60 human cancer cell line panel at National Cancer Institute (N.C.I.), USA. The SAR (structure activity relationship) studies demonstrated potent activity for the compounds containing the following functionalities at C-12: substituted aryl amino/phenyl thio>benzylamine>alkyl amine. The significant cytotoxic activity observed for compounds III q and III r suggest that these could serve as templates for further optimization. Copyright © 2015 Elsevier Ltd. All rights reserved.

Atropisomeric property of 1-(2,6-difluorobenzyl)-3-[(2R)-amino-2-phenethyl]-5-(2-fluoro-3-methoxyphenyl)-6-methyluracil.

Science.gov (United States)

Tucci, Fabio C; Hu, Tao; Mesleh, Michael F; Bokser, Allan; Allsopp, Eric; Gross, Timothy D; Guo, Zhiqiang; Zhu, Yun-Fei; Struthers, R Scott; Ling, Nicholas; Chen, Chen

2005-11-01

1-(2,6-Difluorobenzyl)-3-[(2R)-amino-2-phenethyl]-5-(2-fluoro-3-methoxyphenyl)-6-methyluracil (6), a potent and orally active antagonist of the human gonadotropin-releasing hormone receptor, exists as a pair of atropisomers in solution, which was detected by NMR spectroscopy, and separable by HPLC. In addition to a (R)-configured benzylamine, there is a second stereogenic element due to the presence of a chiral axis between the substituted 5-phenyl group and the uracil core. The rate constant of the interconversion (k = 5.07 x 10(-5) s(-1)) of these two atropisomers was determined by proton NMR analysis of a diastereoisomer-enriched sample in aqueous solution at 25 degrees C, and the corresponding Gibbs free energy DeltaG(#) of rotation barrier (97.4 kJ mol(-1)) was calculated using the Eyring equation. The diastereoisomer half-life at physiological temperature (37 degrees C) in aqueous media was estimated to be about 46 min. Copyright 2005 Wiley-Liss, Inc.

Substituted N-Benzylpyrazine-2-carboxamides: Synthesis and Biological Evaluation

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Katarína Kráľová

2012-11-01

Full Text Available A series of twelve amides was synthesized via aminolysis of substituted pyrazinecarboxylic acid chlorides with substituted benzylamines. Compounds were characterized with analytical data and assayed in vitro for their antimycobacterial, antifungal, antibacterial and photosynthesis-inhibiting activity. 5-tert-Butyl-6-chloro-N-(4-methoxybenzylpyrazine-2-carboxamide (12 has shown the highest antimycobacterial activity against Mycobacterium tuberculosis (MIC = 6.25 µg/mL, as well as against other mycobacterial strains. The highest antifungal activity against Trichophyton mentagrophytes, the most susceptible fungal strain tested, was found for 5-chloro-N-(3-trifluoromethylbenzyl-pyrazine-2-carboxamide (2, MIC = 15.62 µmol/L. None of the studied compounds exhibited any activity against the tested bacterial strains. Except for 5-tert-butyl-6-chloro-N-benzylpyrazine-2-carboxamide (9, IC50 = 7.4 µmol/L and 5-tert-butyl-6-chloro-N-(4-chlorobenzylpyrazine-2-carboxamide (11, IC50 = 13.4 µmol/L, only moderate or weak photosynthesis-inhibiting activity in spinach chloroplasts (Spinacia oleracea L. was detected.

Proton conductance at elevated temperature:Formulation and investigation of poly(4-styrenesulfonic acid / 4-aminobenzylamine / phosphoric acid membranes

Directory of Open Access Journals (Sweden)

Jalal eJalili

2014-07-01

Full Text Available 4-aminobenzylamine and phosphoric acid were blended in various proportions with poly (4-styrenesulfonic acid to form a new group of membranes exhibiting proton conductance under water-free conditions. The 4-aminobenzylamine molecule, possessing an aniline-like and benzylamine-like functional group, can interact both with the phosphoric acid and the poly(4-styrenesulfonic acid via nucleophilic interaction, thereby allowing proton jumping in the structure. Physico-chemical and thermal characteristics of the prepared solid membranes were investigated by IR spectroscopy and thermo-gravimetric analysis, respectively. Electrochemical impedance spectroscopy was employed to investigate their proton-conductance properties. Transparent composite membranes were prepared. However, the membranes are opaque for relatively high content of phosphoric acid. These membranes are thermally stable up to 300°C. The proton conductivity increases with temperature and also with content of phosphoric acid. Values as high as 1.8×10–3 S cm–1 were measured at 190°C in fully anhydrous condition.

Gas-liquid chromatographic determination of aniline metabolites of substituted urea and carbamate herbicides in aqueous solution.

Science.gov (United States)

Hargesheimer, E E; Coutts, R T; Pasutto, F M

1981-07-01

A simple gas-liquid chromatographic (GLC) method has been developed which provides sensitivity and specificity for the analysis of complex mixtures of the commonly occurring herbicide metabolites aniline, 3-chloroaniline, 4-chloroaniline, 4-bromoaniline, and 3-chloro-4-methylaniline. All of these anilines react with acetic anhydride directly in basified aqueous solution. Further reaction of the acetylated anilines with trifluoroacetic anhydride gave diacyl derivatives which were readily resolved by gas chromatography. The structures of the N-acetylated and N-trifluoroacetylated derivatives of benzylamine (internal standard) and the anilines were confirmed by GLC-mass spectrometry. In distilled water the minimum detectable concentrations of aniline and the substituted anilines, using electron capture GLC, are 0.1 nmole/100 mL and 0.05 nmole/100 mL, respectively. The detection limit for the anilines is 1 nmole/100 mL distilled water, using GLC with flame ionization detection. The technique was applied to the determination of anilines added to urine samples obtained from the general population.

Mechanism of Prototropy. V. Arrhenius parameters of the tautomerization of Benzylidene Benzylamine and its α-α-alkyl derivatives

International Nuclear Information System (INIS)

Perez Ossorio, R.; Gomez Herrera, F.; Utrilla, R. M.; Hidalgo, A.; Gamboa, J. M.

1961-01-01

The reactions were conducted in ethyl alcohol-dioxan, in the presence of EtONa, as catalyst. Rates were followed by a radioactive tracer method when R=H and by spectroscopic method when R= alkyl as described in previous papers. The results suggest that polar effects alone cannot account for the relative Arrhenius parameters obtained. (Author) 3 refs

Sorption of structurally different ionized pharmaceutical and illicit drugs to a mixed-mode coated microsampler.

Science.gov (United States)

Peltenburg, Hester; Timmer, Niels; Bosman, Ingrid J; Hermens, Joop L M; Droge, Steven T J

2016-05-20

The mixed-mode (C18/strong cation exchange-SCX) solid-phase microextraction (SPME) fiber has recently been shown to have increased sensitivity for ionic compounds compared to more conventional sampler coatings such as polyacrylate and polydimethylsiloxane (PDMS). However, data for structurally diverse compounds to this (prototype) sampler coating are too limited to define its structural limitations. We determined C18/SCX fiber partitioning coefficients of nineteen cationic structures without hydrogen bonding capacity besides the charged group, stretching over a wide hydrophobicity range (including amphetamine, amitriptyline, promazine, chlorpromazine, triflupromazine, difenzoquat), and eight basic pharmaceutical and illicit drugs (pKa>8.86) with additional hydrogen bonding moieties (MDMA, atenolol, alprenolol, metoprolol, morphine, nicotine, tramadol, verapamil). In addition, sorption data for three neutral benzodiazepines (diazepam, temazepam, and oxazepam) and the anionic NSAID diclofenac were collected to determine the efficiency to sample non-basic drugs. All tested compounds showed nonlinear isotherms above 1mmol/L coating, and linear isotherms below 1mmol/L. The affinity for C18/SCX-SPME for tested organic cations without Hbond capacities increased with longer alkyl chains, ranging from logarithmic fiber-water distribution coefficients (log Dfw) of 1.8 (benzylamine) to 5.8 (triflupromazine). Amines smaller than benzylamine may thus have limited detection levels, while cationic surfactants with alkyl chain lengths >12 carbon atoms may sorb too strong to the C18/SCX sampler which hampers calibration of the fiber-water relationship in the linear range. The log Dfw for these simple cation structures closely correlates with the octanol-water partition coefficient of the neutral form (Kow,N), and decreases with increased branching and presence of multiple aromatic rings. Oxygen moieties in organic cations decreased the affinity for C18/SCX-SPME. Log Dfw values of

Bis[N,N-bis(1-allyl-1H-benzimidazol-2-ylmethyl-κN3benzylamine-κN]cadmium dipicrate

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Jing-Kun Yuan

2011-06-01

Full Text Available The crystal structure of the title compound, [Cd(C29H29N52](C6H2N3O72, consists of CdII complex cations and picrate anions. In the complex cation, the CdII ion is chelated by two bis(1-allylbenzimidazol-2-ylmethylbenzylamine (babb ligands in a distorted octahedral geometry. Extensive C—H...O hydrogen bonding occurs between cations and anions in the crystal structure.

Adamantane-bearing benzylamines and benzylamides: novel building blocks for supramolecular systems with finely tuned binding properties towards β-cyclodextrin

Czech Academy of Sciences Publication Activity Database

Rouchal, M.; Matelová, A.; de Carvalho, F. P.; Bernat, R.; Grbić, D.; Kuřitka, I.; Babinský, M.; Marek, R.; Čmelík, Richard; Vícha, R.

2013-01-01

Roč. 25, č. 6 (2013), s. 349-361 ISSN 1061-0278 Institutional support: RVO:68081715 Keywords : host-guest system * cyclodextrins * adamantane Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.132, year: 2013

Photoionization mass spectrometry of ω -phenylalkylamines: Role of radical cation-π interaction

Science.gov (United States)

Corinti, Davide; Catone, Daniele; Turchini, Stefano; Rondino, Flaminia; Crestoni, Maria Elisa; Fornarini, Simonetta

2018-04-01

Linear ω-phenylalkylamines of increasing alkyl chain length have been investigated employing synchrotron radiation in the photon energy range from 7 to 15 eV. These molecules have received considerable interest because they bear the skeleton of biologically relevant compounds including neurotransmitters and because of the possible interaction between the amino moiety and the phenyl ring. Recently, the contribution of this interaction has been assayed in both neutral and protonated species, pointing to a role of the polymethylene chain length. In this work, the ionization energy (IE) values of benzylamine (BA), 2-phenylethylamine (2-PEA), 3-phenylpropylamine (3-PPA), and 4-phenylbutylamine (4-PBA) were investigated in order to ascertain the impact of the different alkyl chain lengths and to verify an amino radical cation-π interaction. The IEs obtained experimentally, 8.54, 8.37, 8.29, and 8.31 eV for BA, 2-PEA, 3-PPA and 4-PBA, respectively, show a decreasing trend that is discussed employing calculations at the CBS-QB3 level. Moreover, the appearance energy values for major fragments produced by the photofragmentation process are reported.

Synthesis of 4-([{sup 18}F]fluoromethyl)-2-chlorophenylisothiocyanate: a novel bifunctional {sup 18}F-labelling agent

Energy Technology Data Exchange (ETDEWEB)

Wuest, F.; Mueller, M.; Bergmann, R. [Inst. fuer Bioanorganische und Radiopharmazeutische Chemie, FZ-Rossendorf e.V., Dresden (Germany)

2004-07-01

The one-step radiosynthesis of 4-([{sup 18}F]fluoromethyl)-2-chlorophenylisothiocyanate {sup 18}F-7 as a novel bifunctional {sup 18}F-labelling agent is described. Optimised reaction conditions in a remotely controlled synthesis module gave isothiocyanate {sup 18}F-7 in radiochemical yields of 45% (decay-corrected) within 40 min and high radiochemical purity of > 95% after solid-phase-extraction. Coupling of compound {sup 18}F-7 with the primary amine benzylamine as a model reaction afforded the corresponding ((4-[{sup 18}F]fluoromethyl)-2-chloro-phenyl)-benzyl thiourea {sup 18}F-8 in a high radiochemical yield of > 90%. Stability studies of thiourea {sup 18}F-8 in terms of radiodefluorination showed appreciable buffer stability at pH 7.4, whereas significant radiodefluorination was observed when {sup 18}F-8 was incubated in buffers at pH 3.6 and pH 9.4. Preliminary dynamic PET studies with thiourea {sup 18}F-8 in male Wistar rats showed high bone accumulation, indicative of high in vivo radiodefluorination. (orig.)

Column Chromatography To Obtain Organic Cation Sorption Isotherms.

Science.gov (United States)

Jolin, William C; Sullivan, James; Vasudevan, Dharni; MacKay, Allison A

2016-08-02

Column chromatography was evaluated as a method to obtain organic cation sorption isotherms for environmental solids while using the peak skewness to identify the linear range of the sorption isotherm. Custom packed HPLC columns and standard batch sorption techniques were used to intercompare sorption isotherms and solid-water sorption coefficients (Kd) for four organic cations (benzylamine, 2,4-dichlorobenzylamine, phenyltrimethylammonium, oxytetracycline) with two aluminosilicate clay minerals and one soil. A comparison of Freundlich isotherm parameters revealed isotherm linearity or nonlinearity was not significantly different between column chromatography and traditional batch experiments. Importantly, skewness (a metric of eluting peak symmetry) analysis of eluting peaks can establish isotherm linearity, thereby enabling a less labor intensive means to generate the extensive data sets of linear Kd values required for the development of predictive sorption models. Our findings clearly show that column chromatography can reproduce sorption measures from conventional batch experiments with the benefit of lower labor-intensity, faster analysis times, and allow for consistent sorption measures across laboratories with distinct chromatography instrumentation.

Lewis basicity, adhesion thermodynamic work and coordinating ability on aminated silicon surfaces

International Nuclear Information System (INIS)

Sánchez, M. Alejandra; Paniagua, Sergio A.; Borge, Ignacio; Viales, Christian; Montero, Mavis L.

2014-01-01

Highlights: • Silicon(1 0 0) surfaces with diamines followed by anchoring of copper complexes over the diamine layer, an approach that could be used for advanced functionalization of semiconducting surfaces. • Lewis basicity (using Fowkes–van Oss–Chaudhury–Good surface tension model) and adhesion thermodynamic work (using chemical force microscopy) were determined. • Higher basicity and thermodynamic work correlate with selective copper acetate monolayer grow. The cyclic voltammetry studies confirm the confined copper redox activity. - Abstract: Silicon(1 0 0) surfaces have been modified with three different amines (aniline, benzylamine and dodecylamine) and diamines (4-aminopyridine, 4-aminomethylpyridine, 1,12-dodecyldiamine). The surface energy was measured by contact angle technique. For Si-diamine surfaces, Lewis basicity (using Fowkes–van Oss–Chaudhury–Good surface tension model) and adhesion thermodynamic work (using chemical force microscopy) were determined. We related these data, the amine/diamine nature and their geometry on the surface (via DFT calculations) with the consequent ability to coordinate copper(II) acetate. Finally, copper(II) acetate monolayers behavior was studied by cyclic voltammetry

Synthesis and reactions of 4-(p-methoxybenzyl-6-[5,6,7,8-tetrahydro-2-naphthyl]-pyridazin-3(2H-one

Directory of Open Access Journals (Sweden)

NAGWA M.S. EL-DIN HARB

1999-11-01

Full Text Available The condensation of 4-(p-methoxybenzyl-6-[5,6,7,8-tetrahydro-2-naphthyl]-pyridazin-3(2H-one (3, prepared by the reaction of 6-[5,6,7,8-tetrahydro-2-naphthyl]-4,5-dihydropyridazin-3(2H-one (1 and anisaldehyde, with dimethyl sulphate, formaldehyde and acrylonitrile, and also the formation of the Mannich base, proceeded smoothly at the 2-position to give compounds 4,5,6,7, respectively. 4-p-Methoxybenzyl-3-chloro-6-[5,6,7,8-tetrahydro-2-naphthyl]-pyridazine (9 was prepared in law yield by the action of phosphorus oxychloride on 3. The reaction of 9 with benzylamine, aniline and piperidine gave 10a,b,c, respectively. 4-p-Methoxybenzyl-6-[5,6,7,8-tetrahydro-2-napthyl]pyridazine-3(2H-thione (12 was prepared either by the action of thiourea on 9, or by the reaction of 3 with phosphorus pentasulphide. The reaction of these thiones with acrylonitrile, morpholine and piperidine to give 13 and 14 a,b, respectively, were also investigated.

MnFe2 O4 Nanocrystals Wrapped in a Porous Organic Polymer: A Designed Architecture for Water-Splitting Photocatalysis.

Science.gov (United States)

Dhanalaxmi, Karnekanti; Yadav, Rajkumar; Kundu, Sudipta K; Reddy, Benjaram Mahipal; Amoli, Vipin; Sinha, Anil Kumar; Mondal, John

2016-10-24

A novel MnFe 2 O 4 -porous organic polymer (POP) nanocomposite was synthesized by a facile hydrothermal method and using the highly cross-linked N-rich benzene-benzylamine POP. The nanocomposite presented highly efficient photocatalytic performance in the hydrogen evolution reaction (HER) from pure water without addition of any sacrificial agent under one AM 1.5 G sunlight illumination. A photocatalytic activity of 6.12 mmol h -1  g -1 was achieved in the absence of any noble metal cocatalyst, which is the highest H 2 production rate reported for nonprecious metal catalysts. The photocatalytic performance of MnFe 2 O 4 -POP could be attributed to the intrinsic synergistic effects of manganese ferrite (MnFe 2 O 4 ) nanoclusters interacting with the nitrogen dopant POP with a unique mesoporous nanoarchitecture and spatially confined growth of MnFe 2 O 4 in the interconnected POP network, leading to high visible-light absorption with fast electron transport. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, reactions and biological activity of 3-arylidene-5-(4-methylphenyl-2(3H-furanones

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ASIF HUSAIN

2009-02-01

Full Text Available 3-Arylidene-5-(4-methylphenyl-2(3H-furanones 2a–m were prepared from 3-(4-methyl-benzoylpropanoic acid 1 and several aromatic aldehydes. Some of the selected furanones were reacted with ammonia gas and benzylamine to give corresponding 3-arylidene-1,3-dihydro-5-(4-methylphenyl-2H-pyrrol-2-ones 3a–h and 3-arylidene-1-benzyl-1,3-dihydro-5-(4-methylphenyl-2H-pyrrol-2-ones 4a–f, respectively, which were characterized on the basis of IR, 1H-NMR, mass spectral data and elemental analysis results. These compounds were tested for their anti-inflammatory and antibacterial activities. The compounds, which showed significant anti-inflammatory activity, were further screened for their analgesic and ulcerogenic activities. Three new compounds (2e, 2h and 4d, out of twenty-seven showed very good anti-inflammatory activity in the carrageenan induced rat paw edema test, with significant analgesic activity in the acetic acid induced writhing test together with negligible ulcerogenic action. The antibacterial activity is expressed as the corresponding MIC values.

Sea urchin-like mesoporous carbon material grown with carbon nanotubes as a cathode catalyst support for fuel cells

Energy Technology Data Exchange (ETDEWEB)

Kuo, Ping-Lin; Hsu, Chun-Han; Li, Wan-Ting; Jhan, Jing-Yi; Chen, Wei-Fu [Department of Chemical Engineering, National Cheng Kung University, Tainan 70101 (China)

2010-12-15

A sea urchin-like carbon (UC) material with high surface area (416 m{sup 2} g{sup -1}), adequate electrical conductivity (59.6 S cm{sup -1}) and good chemical stability was prepared by growing carbon nanotubes onto mesoporous carbon hollow spheres. A uniform dispersion of Pt nanoparticles was then anchored on the UC, where the Pt nanoparticles were prepared using benzylamine as the stabilizer. For this Pt loaded carbon, cyclic voltammogram measurements showed an exceptionally high electrochemically active surface area (EAS) (114.8 m{sup 2} g{sup -1}) compared to the commonly used commercial E-TEK catalyst (65.2 m{sup 2} g{sup -1}). The durability test demonstrates that the carbon used as a support exhibited minor loss in EAS of Pt. Compared to the E-TEK (20 wt%) cathode catalyst, this Pt loaded UC catalyst has greatly enhanced catalytic activity toward the oxygen reduction reaction, less cathode flooding and considerably improved performance, resulting in an enhancement of ca. 37% in power density compared with that of E-TEK. Based on the results obtained, the UC is an excellent support for Pt nanoparticles used as cathode catalysts in proton exchange membrane fuel cells. (author)

Oral Administration of Semicarbazide Limits Weight Gain together with Inhibition of Fat Deposition and of Primary Amine Oxidase Activity in Adipose Tissue

Directory of Open Access Journals (Sweden)

Josep Mercader

2011-01-01

Full Text Available An enzyme hitherto named semicarbazide-sensitive amine oxidase (SSAO, involved in the oxidation of primary amines, is abundantly expressed in adipocytes. Although SSAO physiological functions remain unclear, several molecules inhibiting its activity have been described to limit fat accumulation in preadipocyte cultures or to reduce body weight gain in obese rodents. Here, we studied whether oral administration of semicarbazide, a prototypical SSAO inhibitor, limits fat deposition in mice. Prolonged treatment with semicarbazide at 0.125% in drinking water limited food and water consumption, hampered weight gain, and deeply impaired fat deposition. The adiposomatic index was reduced by 31%, while body mass was reduced by 15%. Such treatment completely inhibited SSAO, but did not alter MAO activity in white adipose tissue. Consequently, the insulin-like action of the SSAO substrate benzylamine on glucose transport was abolished in adipocytes from semicarbazide-drinking mice, while their insulin sensitivity was not altered. Although semicarbazide is currently considered as a food contaminant with deleterious effects, the SSAO inhibition it induces appears as a novel concept to modulate adipose tissue development, which is promising for antiobesity drug discovery.

O-Hydroxyl- or o-amino benzylamine-tacrine hybrids: multifunctional biometals chelators, antioxidants, and inhibitors of cholinesterase activity and amyloid-β aggregation.

Science.gov (United States)

Mao, Fei; Huang, Ling; Luo, Zonghua; Liu, Anqiu; Lu, Chuanjun; Xie, Zhiyong; Li, Xingshu

2012-10-01

In an effort to identify novel multifunctional drug candidates for the treatment of Alzheimer's disease (AD), a series of hybrid molecules were synthesised by reacting N-(aminoalkyl)tacrine with salicylic aldehyde or derivatives of 2-aminobenzaldehyde. These compounds were then evaluated as multifunctional anti-Alzheimer's disease agents. All of the hybrids are potential biometal chelators, and in addition, most of them were better antioxidants and inhibitors of cholinesterases and amyloid-β (Aβ) aggregation than the lead compound tacrine. Compound 7c has the potential to be a candidate for AD therapy: it is a much better inhibitor of acetylcholinesterase (AChE) than tacrine (IC(50): 0.55 nM vs 109 nM), has good biometal chelation ability, is able to inhibit Aβ aggregation and has moderate antioxidant activity (1.22 Trolox equivalents). Copyright © 2012 Elsevier Ltd. All rights reserved.

A sensitive method using SPME pre-concentration for the quantification of aromatic amines in indoor air.

Science.gov (United States)

Lucaire, Vincent; Schwartz, Jean-Jacques; Delhomme, Olivier; Ocampo-Torres, Ruben; Millet, Maurice

2018-03-01

Monitoring the levels of aliphatic and aromatic amines (AA) in indoor air is important to protect human health because of exposure to these compounds through diet and inhalation. A sampling and analytical method using XAD-2 cartridges and gas chromatography coupled to mass spectrometry used for assessing 25 AA in different smoking and non-smoking indoor environment was developed. After sampling and delivering 1 m 3 of air (6-8 h sampling), an adsorbent was ultrasonically extracted with acetonitrile, concentrated to 1 mL and diluted in 25 mL of water (pH = 9; 5% NaCl), and then extracted for 40 min at 80 °C using a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber and injected in a GC/MS system. With this method, 22 of the 25 AA can be analyzed with detection limits up to five times lower than that of classic liquid injection. Benzylamine, 3-aminophenol, and 4-aminophenol were not detected with the solid-phase micro-extraction (SPME) method. It can be assumed that aminophenols required a derivatization step for their analysis by GC as these molecules were not detected regardless of the injection mode used. Graphical abstract Analysis of aromatic amines in indoor air by SPME-GC/MS.

[{sup 11}C]SMe-ADAM, an imaging agent for the brain serotonin transporter: synthesis, pharmacological characterization and microPET studies in rats

Energy Technology Data Exchange (ETDEWEB)

Zessin, Joerg [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany)]. E-mail: j.zessin@fz-rossendorf.de; Deuther-Conrad, Winnie [Institut fuer Interdisziplinaere Isotopenforschung, 04318 Leipzig (Germany); Kretzschmar, Marion [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Wuest, Frank [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Pawelke, Beate [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Brust, Peter [Institut fuer Interdisziplinaere Isotopenforschung, 04318 Leipzig (Germany); Steinbach, Joerg [Institut fuer Interdisziplinaere Isotopenforschung, 04318 Leipzig (Germany); Bergmann, Ralf [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany)

2006-01-15

N,N-Dimethyl-2-(2-amino-4-methylthiophenylthio)benzylamine (S Me-Adam, 1) is a highly potent and selective inhibitor of the serotonin transporter (SPERT). This compound was labeled with carbon-11 by methylation of the S-desmethyl precursor 10 with [{sup 11}C]methyl iodide to obtain the potential positron emission tomography (PET) radioligand [{sup 11}C]S Me-Adam. The radiochemical yield was 27{+-}5%, and the specific radioactivity was 26-40 GBq/{mu}mol at the end of synthesis. Ex vivo and in vivo biodistribution experiments in rats demonstrated a rapid accumulation of the radiotracer in brain regions known to be rich in SPERT, such as the thalamus/hypothalamus region (3.59{+-}0.41%ID/g at 5 min after injection). The specific uptake reached a thalamus to cerebellum ratio of 6.74{+-}0.95 at 60 min postinjection. The [{sup 11}C]SMe-ADAM uptake in the thalamus was significantly decreased by pretreatment with fluoxetine to 38{+-}11% of the control value. Furthermore, no metabolites of [{sup 11}C]SMe-ADAM could be detected in the SERT-rich regions of the rat brain. It is concluded that [{sup 11}C]SMe-ADAM may be a suitable PET ligand for SERT imaging in the living brain.

[11C]SMe-ADAM, an imaging agent for the brain serotonin transporter: synthesis, pharmacological characterization and microPET studies in rats

International Nuclear Information System (INIS)

Zessin, Joerg; Deuther-Conrad, Winnie; Kretzschmar, Marion; Wuest, Frank; Pawelke, Beate; Brust, Peter; Steinbach, Joerg; Bergmann, Ralf

2006-01-01

N,N-Dimethyl-2-(2-amino-4-methylthiophenylthio)benzylamine (S Me-Adam, 1) is a highly potent and selective inhibitor of the serotonin transporter (SPERT). This compound was labeled with carbon-11 by methylation of the S-desmethyl precursor 10 with [ 11 C]methyl iodide to obtain the potential positron emission tomography (PET) radioligand [ 11 C]S Me-Adam. The radiochemical yield was 27±5%, and the specific radioactivity was 26-40 GBq/μmol at the end of synthesis. Ex vivo and in vivo biodistribution experiments in rats demonstrated a rapid accumulation of the radiotracer in brain regions known to be rich in SPERT, such as the thalamus/hypothalamus region (3.59±0.41%ID/g at 5 min after injection). The specific uptake reached a thalamus to cerebellum ratio of 6.74±0.95 at 60 min postinjection. The [ 11 C]SMe-ADAM uptake in the thalamus was significantly decreased by pretreatment with fluoxetine to 38±11% of the control value. Furthermore, no metabolites of [ 11 C]SMe-ADAM could be detected in the SERT-rich regions of the rat brain. It is concluded that [ 11 C]SMe-ADAM may be a suitable PET ligand for SERT imaging in the living brain

N-Substituted 5-Amino-6-methylpyrazine-2,3-dicarbonitriles: Microwave-Assisted Synthesis and Biological Properties

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Ondrej Jandourek

2014-01-01

Full Text Available In this work a series of 15 N-benzylamine substituted 5-amino-6-methyl-pyrazine-2,3-dicarbonitriles was prepared by the aminodehalogenation reactions using microwave assisted synthesis with experimentally set and proven conditions. This approach for the aminodehalogenation reaction was chosen due to its higher yields and shorter reaction times. The products of this reaction were characterized by IR, NMR and other analytical data. The compounds were evaluated for their antibacterial, antifungal and herbicidal activity. Compounds 3 (R = 3,4-Cl, 9 (R = 2-Cl and 11 (R = 4-CF3 showed good antimycobacterial activity against Mycobacterium tuberculosis (MIC = 6.25 µg/mL. It was found that the lipophilicity is important for antimycobacterial activity and the best substitution on the benzyl moiety of the compounds is a halogen or trifluoromethyl group according to Craig’s plot. The activities against bacteria or fungi were insignificant. The presented compounds also inhibited photosynthetic electron transport in spinach chloroplasts and the IC50 values of the active compounds varied in the range from 16.4 to 487.0 µmol/L. The most active substances were 2 (R = 3-CF3, 3 (R = 3,4-Cl and 11 (R = 4-CF3. A linear dependence between lipophilicity and herbicidal activity was observed.

Synthesis and characterization of sulfolane-based amino alcohols: A combined experimental and computational study

Science.gov (United States)

Palchykov, Vitalii A.; Zarovnaya, Iryna S.; Tretiakov, Serhii V.; Reshetnyak, Alyona V.; Omelchenko, Iryna V.; Shishkin, Oleg V.; Okovytyy, Sergiy I.

2018-04-01

Aminolysis of 3,4-epoxysulfolane in aqueous media leads to a very complex mixture of products with unresolved stereochemistry. Herein, we report a detailed theoretical and experimental mechanistic investigation of this reaction along with extensive spectroscopic characterization of the resulting amino alcohols, using 1D and 2D NMR techniques (1H, 13C, NOE, NOESY, COSY, HSQC, HMBC) as well as XRD analysis. In addition to simple amines such as ammonia and benzylamine, our study also employed the more sterically hindered endo-bicyclo[2.2.1]hept-5-en-2-ylmethanamine. The mechanism of the aminolysis of 3,4-epoxysulfolane by aqueous ammonia was studied in more detail using quantum chemical calculations at the M06-2X/6-31++G** level of theory. The computational results led us to conclude that the most probable way of initial epoxide transformation is base-catalyzed rearrangement to a corresponding allylic alcohol. Subsequent formation of vicinal amino alcohols and diols proceeds via addition of ammonia or hydroxy-anions to activated double Cdbnd C bond with some preference of a cis-attack. Detailed analytical data obtained in the course of our work will be useful for the stereochemical identification of new sulfolane derivatives.

[11C]SMe-ADAM, an imaging agent for the brain serotonin transporter: synthesis, pharmacological characterization and microPET studies in rats.

Science.gov (United States)

Zessin, Jörg; Deuther-Conrad, Winnie; Kretzschmar, Marion; Wüst, Frank; Pawelke, Beate; Brust, Peter; Steinbach, Jörg; Bergmann, Ralf

2006-01-01

N,N-Dimethyl-2-(2-amino-4-methylthiophenylthio)benzylamine (SMe-ADAM, 1) is a highly potent and selective inhibitor of the serotonin transporter (SERT). This compound was labeled with carbon-11 by methylation of the S-desmethyl precursor 10 with [(11)C]methyl iodide to obtain the potential positron emission tomography (PET) radioligand [(11)C]SMe-ADAM. The radiochemical yield was 27 +/- 5%, and the specific radioactivity was 26-40 GBq/micromol at the end of synthesis. Ex vivo and in vivo biodistribution experiments in rats demonstrated a rapid accumulation of the radiotracer in brain regions known to be rich in SERT, such as the thalamus/hypothalamus region (3.59 +/- 0.41%ID/g at 5 min after injection). The specific uptake reached a thalamus to cerebellum ratio of 6.74 +/- 0.95 at 60 min postinjection. The [(11)C]SMe-ADAM uptake in the thalamus was significantly decreased by pretreatment with fluoxetine to 38 +/- 11% of the control value. Furthermore, no metabolites of [(11)C]SMe-ADAM could be detected in the SERT-rich regions of the rat brain. It is concluded that [(11)C]SMe-ADAM may be a suitable PET ligand for SERT imaging in the living brain.

Amperometric biosensor for total monoamines using a glassy carbon paste electrode modified with human monoamine oxidase B and manganese dioxide particles

International Nuclear Information System (INIS)

Aigner, Maximilian; Telsnig, Dietlind; Teubl, Christian; Ortner, Astrid; Kalcher, Kurt; Macheroux, Peter; Wallner, Silvia; Edmondson, Dale

2015-01-01

We have prepared a biosensor for the determination of the total monoamine content in complex matrices by immobilizing a human monoamine oxidase B (hMAO B) on a glassy carbon paste electrode and adding manganese dioxide microparticles as the mediator. The enzyme hMAO B (expressed in Pichia pastoris and immobilized by using a dialysis membrane) catalyzes the oxidative deamination of monoamines, and this results in the formation of the corresponding aldehyde, ammonia and hydrogen peroxide. The latter was detected at pH 7.5 at a working voltage of 400 mV (vs. Ag/AgCl) by differential pulse voltammetry and amperometrically by applying flow injection analysis. Analytical parameters were established by using phenylethylamine (PEA) as a standard substrate. Peak height and concentration of PEA are linearly related in the 0.5 to 150 μg mL −1 concentration range, and the limits of detection and of quantification are 0.15 and 0.5 μg mL −1 of PEA, respectively. Substrate specificity was investigated with different monoamines including PEA, serotonin, benzylamine, dopamine, tyramine, and norepinephrine. The applicability of the biosensor was successfully tested in a commercial fish sauce that served as a complex matrix. The total monoamine content was calculated as PEA-equivalents. (author)

High throughput Screening to Identify Natural Human Monoamine Oxidase B Inhibitors

Science.gov (United States)

Mazzio, E; Deiab, S; Park, K; Soliman, KFA

2012-01-01

Age-related increase in monoamine oxidase B (MAO-B) may contribute to CNS neurodegenerative diseases. Moreover, MAO-B inhibitors are used in the treatment of idiopathic Parkinson disease as preliminary monotherapy or adjunct therapy with L-dopa. To date, meager natural sources of MAO-B inhibitors have been identified, and the relative strength, potency and rank of many plants relative to standard drugs such as Selegiline (L-deprenyl, Eldepryl) are not known. In this work, we developed and utilized a high throughput enzyme microarray format to screen and evaluate 905 natural product extracts (0.025–.7 mg/ml) to inhibit human MAO-B derived from BTI-TN-5B1-4 cells infected with recombinant baculovirus. The protein sequence of purified enzyme was confirmed using 1D gel electrophoresis-matrix assisted laser desorption ionization-time-of-flight-tandem mass spectroscopy, and enzyme activity was confirmed by [1] substrate conversion (3-mM benzylamine) to H202 and [2] benzaldehyde. Of the 905 natural extracts tested, the lowest IC50s [Comfrey, Bringraj, Skullcap, Kava-kava, Wild Indigo, Gentian and Green Tea. In conclusion, the data reflect relative potency information by rank of commonly used herbs and plants that contain human MAO-B inhibitory properties in their natural form. PMID:22887993

Optical storage in azobenzene-containing epoxy polymers processed as Langmuir Blodgett films

International Nuclear Information System (INIS)

Fernández, Raquel; Mondragon, Iñaki; Sanfelice, Rafaela C.; Pavinatto, Felippe J.; Oliveira, Osvaldo N.; Oyanguren, Patricia; Galante, María J.

2013-01-01

In this study, azocopolymers containing different main-chain segments have been synthesized with diglycidyl ether of bisphenol A (DGEBA, DER 332, n = 0.03) and the azochromophore Disperse Orange 3 (DO3) cured with two monoamines, viz. benzylamine (BA) and m-toluidine (MT). The photoinduced birefringence was investigated in films produced with these azopolymers using the spin coating (SC) and Langmuir Blodgett (LB) techniques. In the LB films, birefringence increased with the content of azochromophore and the film thickness, as expected. The nanostructured nature of the LB films led to an enhanced birefringence and faster dynamics in the writing process, compared to the SC films. In summary, the combination of azocopolymers and the LB method may allow materials with tuned properties for various optical applications, including in biological systems were photoisomerization may be used to trigger actions such as drug delivery. Highlights: ► Langmuir Blodgett (LB) films of epoxy-based azopolymers were obtained and analyzed. ► Optical properties of LB and spin coated (SC) films were compared. ► Azo content, structure, laser power and number of layers were main factors studied. ► LB films had larger free volume for the azobenzenes isomerization than SC. ► LB films led to higher birefringence and faster dynamics compared to SC

Optical storage in azobenzene-containing epoxy polymers processed as Langmuir Blodgett films

Energy Technology Data Exchange (ETDEWEB)

Fernández, Raquel; Mondragon, Iñaki [‘Materials - Technologies’ Group, Department of Chemical and Environmental Engineering, Polytechnic School, Universidad País Vasco/Euskal Herriko Unibertsitatea, Pza Europa 1, 20018 Donostia-San Sebastián (Spain); Sanfelice, Rafaela C.; Pavinatto, Felippe J.; Oliveira, Osvaldo N. [Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador São Carlense, 400, Centro, CEP 13560-970, São Carlos (Brazil); Oyanguren, Patricia [Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), J. B. Justo 4302, 7600 Mar del Plata (Argentina); Galante, María J., E-mail: galant@fi.mdp.edu.ar [Institute of Materials Science and Technology (INTEMA), University of Mar del Plata and National Research Council (CONICET), J. B. Justo 4302, 7600 Mar del Plata (Argentina)

2013-04-01

In this study, azocopolymers containing different main-chain segments have been synthesized with diglycidyl ether of bisphenol A (DGEBA, DER 332, n = 0.03) and the azochromophore Disperse Orange 3 (DO3) cured with two monoamines, viz. benzylamine (BA) and m-toluidine (MT). The photoinduced birefringence was investigated in films produced with these azopolymers using the spin coating (SC) and Langmuir Blodgett (LB) techniques. In the LB films, birefringence increased with the content of azochromophore and the film thickness, as expected. The nanostructured nature of the LB films led to an enhanced birefringence and faster dynamics in the writing process, compared to the SC films. In summary, the combination of azocopolymers and the LB method may allow materials with tuned properties for various optical applications, including in biological systems were photoisomerization may be used to trigger actions such as drug delivery. Highlights: ► Langmuir Blodgett (LB) films of epoxy-based azopolymers were obtained and analyzed. ► Optical properties of LB and spin coated (SC) films were compared. ► Azo content, structure, laser power and number of layers were main factors studied. ► LB films had larger free volume for the azobenzenes isomerization than SC. ► LB films led to higher birefringence and faster dynamics compared to SC.

Justification of the solvent choice for the industrial amizon substance production

Directory of Open Access Journals (Sweden)

V. A. Georgiyants

2014-08-01

Full Text Available INTRODUCTION In recent years, the rapid development gets implementing principles of quality management in the pharmaceutical industry. It should be noted that instead of the mechanical control of the quality associated with the chemical characteristics of pharmaceutical substances and drugs innovative ways to ensure the quality associated primarily with the understanding of the processes occurring during the manufacturing process come. Objective: To study solvent selection for the industrial production of methiodide benzyl amide isonicotinic acid substance considering the conception “Quality by design”. MATERIALS AND METHODS Solution of 0.1 moles of isonicotinic acid in 0.12 moles of benzylamine was heated at 160-185°C during 4-5 hours while distilling off water and excess benzylamine. The resulting melt - cooled isonicotinic acid benzylamide was dissolved in acetone and filtered. It was used in further synthesis without further purification. 0.1 moles of isonicotinic acid benzylamide was dissolved in0.6 litersof a suitable solvent and 0.12 mole of methyl iodide was added to the solution at room temperature. The mixture was heated at 40-50 ° C for 3-4 hours, the reaction mixture was cooled, filtered the product was dried. After calculating the aim product was recrystallized from an appropriate solvent. Isonicotinic acid benzylamide iodomethylate quantitative content was determined by acid-base titration in non-aqueous medium (fixing the endpoint - potentiometrically. The impurity content benzylamide isonicotinic acid – by HPLC. RESULTS AND DISCUSSION When solvent have been chosen we took into account previously developed scheme of laboratory synthesis. We guided primarily data about security and efficiency. The least toxic solvents conventionally used in pharmaceutical production , included 2- propanol and ethanol (limit of residual amounts of these solvents, allowable HFC substances was 0.5 % and 1 %, respectively. Therefore, these

Correlation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxicity with blood-brain barrier monoamine oxidase activity

International Nuclear Information System (INIS)

Kalaria, R.N.; Mitchell, M.J.; Harik, S.I.

1987-01-01

Systemic administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes parkinsonism in humans and subhuman primates, but not in rats and many other laboratory animals; mice are intermediate in their susceptibility. Since MPTP causes selective dopaminergic neurotoxicity when infused directly into rat substantia nigra, the authors hypothesized that systemic MPTP may be metabolized by monoamine oxidase and/or other enzymes in rat brain capillaries and possibly other peripheral organs and thus prevented from reaching its neuronal sites of toxicity. They tested this hypothesis by assessing monoamine oxidase in isolated cerebral microvessels of humans, rats, and mice by measuring the specific binding of [ 3 H]pargyline, an irreversible monoamine oxidase inhibitor, and by estimating the rates of MPTP and benzylamine oxidation. [ 3 H]Pargyline binding to rat cerebral microvessels was about 10-fold higher than to human or mouse microvessels. Also, MPTP oxidation by rat brain microvessels was about 30-fold greater than by human microvessels; mouse microvessels yielded intermediate values. These results may explain, at least in part, the marked species differences in susceptibility to systemic MPTP. They also suggest the potential importance of enzyme barriers at the blood-brain interface that can metabolize toxins not excluded by structural barriers, and may provide biological bases for developing therapeutic strategies for the prevention of MPTP-induced neurotoxicity and other neurotoxic conditions including, possibly, Parkinson's disease

Biocatalytic Behaviour of Immobilized Rhizopus oryzae Lipase in the 1,3-Selective Ethanolysis of Sunflower Oil to Obtain a Biofuel Similar to Biodiesel

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Carlos Luna

2014-08-01

Full Text Available A new biofuel similar to biodiesel was obtained in the 1,3-selective transesterification reaction of sunflower oil with ethanol using as biocatalyst a Rhizopus oryzae lipase (ROL immobilized on Sepiolite, an inorganic support. The studied lipase was a low cost powdered enzyme preparation, Biolipase-R, from Biocon-Spain, a multipurpose additive used in food industry. In this respect, it is developed a study to optimize the immobilization procedure of these lipases on Sepiolite. Covalent immobilization was achieved by the development of an inorganic-organic hybrid linker formed by a functionalized hydrocarbon chain with a pendant benzaldehyde, bonded to the AlPO4 support surface. Thus, the covalent immobilization of lipases on amorphous AlPO4/sepiolite (20/80 wt % support was evaluated by using two different linkers (p-hydroxybenzaldehyde and benzylamine-terephthalic aldehyde, respectively. Besides, the catalytic behavior of lipases after physical adsorption on the demineralized sepiolite  was also evaluated. Obtained results indicated that covalent immobilization with the p-hydroxybenzaldehyde linker gave the best biocatalytic behavior. Thus, this covalently immobilized lipase showed a remarkable stability as well as an excellent capacity of reutilization (more than five successive reuses without a significant loss of its initial catalytic activity. This could allow a more efficient fabrication of biodiesel minimizing the glycerol waste production.

A versatile synthesis of cyclic dipeptides using the stepwise construction of the piperazine-2,5-dione ring from simple precursors: synthetic sequence and the structure of a representative product, (3RS)-4-(2-allyl-3,5-dimethylphenyl)-1-benzyl-3-phenylpiperazine-2,5-dione.

Science.gov (United States)

Acosta Quintero, Lina M; Palma, Alirio; Cobo, Justo; Glidewell, Christopher

2018-02-01

A versatile synthesis of multiply substituted cyclic dipeptides has been designed, based on the stepwise construction of the piperazine-2,5-dione ring using molecular fragments from four different precursor molecules. Starting from substituted 2-allylanilines, reaction with methyl 2-bromo-2-phenylacetate yields the corresponding methyl 2-(2-allylanilino)-2-phenylacetates, which react with haloacetyl chlorides to give methyl 2-[N-(2-allylphenyl)-2-haloacetamido]-2-phenylacetates, which then undergo ring closure with benzylamine to yield the corresponding cyclic dipeptides of type 4-(2-allylphenyl)-1-benzyl-3-phenylpiperazine-2,5-dione. (3RS)-4-(2-Allyl-3,5-dimethylphenyl)-1-benzyl-3-phenylpiperazine-2,5-dione, C 28 H 28 N 2 O 2 , (IIId), crystallizes with Z' = 2 in the space group P2 1 /c; the allyl groups in the two independent molecules adopt different conformations and, in one of them, the allyl group is disordered over two sets of atomic sites having occupancies of 0.534 (4) and 0.466 (4). In both molecules, the piperazine-2,5-dione ring adopts a boat conformation, with the 3-phenyl ring in a quasi-axial site. The molecules of (IIId) are linked into a three-dimensional framework structure by a combination of three C-H...O hydrogen bonds and three C-H...π(arene) hydrogen bonds. Comparisons are made with some related structures.

Signaling molecule methylglyoxal ameliorates cadmium injury in wheat (Triticum aestivum L) by a coordinated induction of glutathione pool and glyoxalase system.

Science.gov (United States)

Li, Zhong-Guang; Nie, Qian; Yang, Cong-Li; Wang, Yue; Zhou, Zhi-Hao

2018-03-01

Methylglyoxal (MG) now is found to be an emerging signaling molecule. It can relieve the toxicity of cadmium (Cd), however its alleviating mechanism still remains unknown. In this study, compared with the Cd-stressed seedlings without MG treatment, MG treatment could stimulate the activities of glutathione reductase (GR) and gamma-glutamylcysteine synthetase (γ-ECS) in Cd-stressed wheat seedlings, which in turn induced an increase of reduced glutathione (GSH). Adversely, the activated enzymes related to GSH biosynthesis and increased GSH were weakened by N-acetyl-L-cysteine (NAC, MG scavenger), 2,4-dihydroxy-benzylamine (DHBA) and 1,3-bischloroethyl-nitrosourea (BCNU, both are specific inhibitors of GR), buthionine sulfoximine (BSO, a specific inhibitors of GSH biosynthesis), and N-ethylmaleimide (NEM, GSH scavenger), respectively. In addition, MG increased the activities of glyoxalase I (Gly I) and glyoxalase II (Gly II) in Cd-treated seedlings, followed by declining an increase in endogenous MG as comparision to Cd-stressed seedlings alone. On the contrary, the increased glyoxalase activity and decreased endogenous MG level were reversed by NAC and specific inhibitors of Gly I (isoascorbate, IAS; squaric acid, SA). Furthermore, MG alleviated an increase in hydrogen peroxide (H 2 O 2 ) and malondialdehyde (MDA) in Cd-treated wheat seedlings. These results indicated that MG could alleviate Cd toxicity and improve the growth of Cd-stressed wheat seedlings by a coordinated induction of glutathione pool and glyoxalase system. Copyright © 2017 Elsevier Inc. All rights reserved.

Isotopic and stereochemical probes of the mechanism of bovine plasma amine oxidase

International Nuclear Information System (INIS)

Farnum, M.F.

1986-01-01

Isotopic and stereochemical probes have been employed to investigate the mechanisms of bovine plasma amine oxidase (BPAO). The pH dependence of isotope effects on steady-state parameters for benzylamine oxidation indicate that the C-H bond breaking step is fully rate-limiting on k/sub cat//K/sub m/ over the experimental pH range. The rate of enzyme reoxidation appears to be partially rate-limiting on k/sub cat/ as values of /sup D/k/sub cat/ are reduced relative to /sup D/k/sub cat//K/sub m/ from pH 5.5 - 10.0. Two microscopic ionizations on k/sub cat//K/sub m/, pK 1 = 8.0 +/- 0.10 and pK/sub s/ = 9.0 +/- 0.16, are ascribed to an active site residue which must be unprotonated for catalysis, and to substrate binding in the unionized form to the enzyme, respectively. EF 1 undergoes a pK/sub a/ perturbation from 8.0 to 5.6 in the E x S complex as a result of charge from the protonated imine nitrogen of the enzyme substrate Schiff's base. A pK/sub a/ of 5.5 +/- 0.1 is observed in the pH profile for exchange of tritium from C-2 during oxidation of [2- 3 H]-dopamine. These data support the conclusion that EB 1 catalyzes both imine exchange at C-2 of phenethylamine substrates as well as substrate oxidation at C-1

A study of monoamine oxidase activity in fetal membranes.

Science.gov (United States)

Sekizawa, A; Ishikawa, H; Morimoto, T; Hirose, K; Suzuki, A; Saito, H; Yanaihara, T; Arai, Y; Oguchi, K

1996-05-01

To study the role of decidual monoamine oxidase (MAO)-A and -B activities before delivery, the relationship between MAO activity in fetal membranes and catecholamine (CA) concentration in amniotic fluid (AF) was determined. Fetal membranes and AF were obtained at the time of elective Cesarean section (CS group, n = 11) and Cesarean section due to fetal distress without labor pains (FD group, n = 5). MAO-A and -B activities were radiometrically measured using 14C-5-hydroxytriptamine for MAO-A substrate and 14C-benzylamine for MAO-B substrate. CA concentrations in AF were measured by high performance liquid chromatograph with an electro-chemical detector. Both MAO-A and -B activities in decidua obtained from CS were significantly lower than those obtained from FD. Both norepinephrine (NE) and epinephrine (EP) concentrations were significantly lower in the CS group than the FD group. A significant positive correlation between decidual MAO-A activity and NE concentration in AF was observed. No significant correlation was observed between MAO-B activity and the concentration of NE in AF. There was no correlation between EP concentrations and MAO activities. These results suggest that CA concentration in AF may be related to the activity of MAO in fetal membranes, determined by certain physiological processes during pregnancy. It has been suggested that metabolism of monoamines in fetal membranes also plays an important role in reducing monoamine influx into maternal myometrium from the AF.

Adsorption of hydrocarbons in chalk reservoirs

Energy Technology Data Exchange (ETDEWEB)

Madsen, L.

1996-12-31

The present work is a study on the wettability of hydrocarbon bearing chalk reservoirs. Wettability is a major factor that influences flow, location and distribution of oil and water in the reservoir. The wettability of the hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. Organic compounds such as carboxylic acids are found in formation waters from various hydrocarbon reservoirs and in crude oils. In the present investigation the wetting behaviour of chalk is studied by the adsorption of the carboxylic acids onto synthetic calcite, kaolinite, quartz, {alpha}-alumina, and chalk dispersed in an aqueous phase and an organic phase. In the aqueous phase the results clearly demonstrate the differences between the adsorption behaviour of benzoic acid and hexanoic acid onto the surfaces of oxide minerals and carbonates. With NaCl concentration of 0.1 M and with pH {approx_equal} 6 the maximum adsorption of benzoic acid decreases in the order: quartz, {alpha}-alumina, kaolinite. For synthetic calcite and chalk no detectable adsorption was obtaind. In the organic phase the order is reversed. The maximum adsorption of benzoic acid onto the different surfaces decreases in the order: synthetic calcite, chalk, kaolinite and quartz. Also a marked difference in adsorption behaviour between probes with different functional groups onto synthetic calcite from organic phase is observed. The maximum adsorption decreases in the order: benzoic acid, benzyl alcohol and benzylamine. (au) 54 refs.

Impact of the counterion on the solubility and physicochemical properties of salts of carboxylic acid drugs.

Science.gov (United States)

David, S E; Timmins, P; Conway, B R

2012-01-01

Salt formation is a widely used approach to improve the physicochemical and solid state properties of an active pharmaceutical ingredient. In order to better understand the relationships between the active drug, the selected counterion and the resultant salt form, crystalline salts were formed using four different carboxylic acid drugs and a closely related series of amine counterions. Thirty-six related crystalline salts were prepared, characterized and the relationship between solubility and dissolution behaviour and other properties of the salt and the counterion studied. Salts of four model acid drugs, gemfibrozil, flurbiprofen, ibuprofen and etodolac were prepared using the counterions butylamine, hexylamine, octylamine, benzylamine, cyclohexylamine, tert-butylamine, 2-amino-2-methylpropan-1-ol, 2-amino-2-methylpropan-1,3-diol and tris(hydroxymethyl)aminomethane. Salt formation was confirmed, the salts were characterized and their corresponding solubilities determined and rationalized with respect to the counterions' properties. The properties of the salt highly dependent on the nature of the counterion and, although there is considerable variation, some general conclusion can be drawn. For the alkyl amines series, increasing chain length leads to a reduction in solubility across all the acidic drugs studied and a reduction in melting point, thus contradicting simplistic relationships between solubility and melting point. Small, compact counterions consistently produce crystalline salts with high melting point accompanied with a modest improvement in solubility and the nature of hydrogen bonding between the ions has a major impact on the solubility.

Plasma amine oxidase activities in Norrie disease patients with an X-chromosomal deletion affecting monoamine oxidase.

Science.gov (United States)

Murphy, D L; Sims, K B; Karoum, F; Garrick, N A; de la Chapelle, A; Sankila, E M; Norio, R; Breakefield, X O

1991-01-01

Two individuals with an X-chromosomal deletion were recently found to lack the genes encoding monoamine oxidase type A (MAO-A) and MAO-B. This abnormality was associated with almost total (90%) reductions in the oxidatively deaminated urinary metabolites of the MAO-A substrate, norepinephrine, and with marked (100-fold) increases in an MAO-B substrate, phenylethylamine, confirming systemic functional consequences of the genetic enzyme deficiency. However, urinary concentrations of the deaminated metabolites of dopamine and serotonin (5-HT) were essentially normal. To investigate other deaminating systems besides MAO-A and MAO-B that might produce these metabolites of dopamine and 5-HT, we examined plasma amine oxidase (AO) activity in these two patients and two additional patients with the same X-chromosomal deletion. Normal plasma AO activity was found in all four Norrie disease-deletion patients, in four patients with classic Norrie disease without a chromosomal deletion, and in family members of patients from both groups. Marked plasma amine metabolite abnormalities and essentially absent platelet MAO-B activity were found in all four Norrie disease-deletion patients, but in none of the other subjects in the two comparison groups. These results indicate that plasma AO is encoded by gene(s) independent of those for MAO-A and MAO-B, and raise the possibility that plasma AO, and perhaps the closely related tissue AO, benzylamine oxidase, as well as other atypical AOs or MAOs encoded independently from MAO-A and MAO-B may contribute to the oxidative deamination of dopamine and 5-HT in humans.

Stability and Reactivity of Cyclometallated Naphthylamine Complexes in Pd-C Bond Insertion Reactions with Coordinated Alkynylphosphanes

KAUST Repository

Chen, Shuli

2013-09-17

Phenylbis(phenylethynyl)phosphane PhP(C≡CPh)2 coordinates regiospecifically to the α-methyl-chiral ortho-platinated and -palladated naphthylamine units at the positions trans to the nitrogen donors. The P→Pt coordination bond is kinetically inert, whereas the P→Pd bond is labile. Upon heating of these phosphane complexes at 70 °C, one of the C≡C bonds in the coordinated PhP(C≡CPh)2 was activated towards an intermolecular Pd-C bond insertion reaction with an external ortho-palladated naphthylamine ring. No intramolecular insertion reaction occurred. In contrast to its palladium analogue, the ortho-platinated ring is not reactive towards coordinated PhP(C≡CPh)2, although it can promote the Pd-C bond insertion reaction. However, despite the high kinetic stability of the P→Pt coordination, the organoplatinum unit is a noticeably weaker activator than its organopalladium counterpart. The chirality of the reacting ortho-metallated naphthylamine ligand exhibited high stereochemical influence on the formation of the new stereogenic phosphorus center during the course of these C-C bond-formation reactions. The coordination chemistry and the absolute stereochemistry of the dimetallic products were determined by single-crystal X-ray crystallographic analysis. The asymmetric monoinsertion of PhP(C≡CPh)2 coordinated to a cyclometallated N,N-dimethyl naphthyl/benzylamine template into the Pd-C bonds of N,N-dimethylnaphthylamine palladacycles has been demonstrated for the synthesis of a variety of new P-stereogenic homo- or heterodimetallic complexes. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metavanadate causes cellular accumulation of copper and decreased lysyl oxidase activity

International Nuclear Information System (INIS)

Cui, Changtai T.; Uriu-Adams, Janet Y.; Tchaparian, Eskouhie H.; Keen, Carl L.; Rucker, Robert B.

2004-01-01

Selected indices of copper metabolism in weanling rats and fibroblast cultures were progressively altered in response to increased levels of sodium metavanadate. In diets, vanadium was added in amounts ranging from 0 to 80 μg V/g of diet, that is, 0-1.6 μmol V/g of diet. In fibroblast cultures, vanadium ranged from 0 to 400 nmol V/ml. The inhibition of P-ATPase-7A activity by metavanadate, important to copper egress from cells, was a primary focus. In skin, and tendon, the copper concentration was increased in response to increased dietary levels of metavanadate, whereas lysyl oxidase activity, a secreted cuproprotein, was reduced. The reduction in lysyl oxidase activity was also accompanied by reduced redox cycling potential of isolated fractions of lysyl oxidase, presumably due to reduced lysyltyrosyl quinone (LTQ) formation at the active site of lysyl oxidase. In contrast, liver copper concentrations and plasma ceruloplasmin activity were not affected by metavanadate exposure. However, semicarbazide-sensitive benzylamine oxidase (SCBO) activity, which was taken as an indirect measure of vascular adhesive protein-1 (VAP-1), was increased. In cultured fibroblasts, cellular copper was also increased and lysyl oxidase decreased in response to metavanadate. Moreover, the steady-state levels of atp7a and lysyl oxidase mRNAs were not affected by addition of metavanadate to culture medium up to 200 nmol/ml. Taken together, these data suggest that pathways involving copper egress and lysyl oxidase activation are particularly sensitive to metavanadate exposure through processes that are predominately posttranslational

Two-dimensional inorganic–organic hybrid semiconductors composed of double-layered ZnS and monoamines with aromatic and heterocyclic aliphatic rings: Syntheses, structures, and properties

International Nuclear Information System (INIS)

Wang, Sujing; Li, Jing

2015-01-01

As an addition to the II–VI based inorganic–organic hybrid semiconductor family, five new two-dimensional (2D) double-layered structures have been synthesized employing monoamines with different aromatic or heterocyclic aliphatic rings. Zn 2 S 2 (bza) (1), Zn 2 S 2 (mbza) (2), Zn 2 S 2 (fbza) (3), Zn 2 S 2 (pca) (4), and Zn 2 S 2 (thfa) (5) (bza=benzylamine, mbza=4-methoxybenzylamine, fbza=4-flurobenzylamine, pca=3-picolylamine, and thfa=tetrahydrofurfurylamine) are prepared by solvothermal reactions and characterized by different analytical methods, including powder X-ray diffraction, optical diffuse reflection, thermogravimetric analysis and photoluminescence spectroscopy. The powder X-ray diffraction patterns show that all five compounds adopt 2D double-layered structures. Optical diffuse reflectance spectra of these compounds suggest that they have notably lower band gaps than those of the similar compounds composed of aliphatic alkyl amines. Their photoluminescence properties and thermal stability are also analyzed. - Graphical abstract: Five new members of two-dimensional double-layered 2D-Zn 2 S 2 (L) (L=Ligand) structures employing monoamines with different aromatic or heterocyclic aliphatic rings have been designed, synthesized, and characterized. - Highlights: • A new sub-family of II-VI based hybrid semiconductors are designed, synthesized, and structurally characterized using amines with aromatic or aliphatic cyclic rings. • These compounds have notably lower band gaps than those made of aliphatic alkyl amines, greatly broadening the range of band gaps of this material family. • They emit strongly with systematically tunable emission intensity and energy

Incongruent reduction of serotonin transporter associated with suicide attempts in patients with major depressive disorder: a positron emission tomography study with 4-[18F]-ADAM.

Science.gov (United States)

Yeh, Yi-Wei; Ho, Pei-Shen; Chen, Chun-Yen; Kuo, Shin-Chang; Liang, Chih-Sung; Ma, Kuo-Hsing; Shiue, Chyng-Yann; Huang, Wen-Sheng; Cheng, Cheng-Yi; Wang, Tzu-Yun; Lu, Ru-Band; Huang, San-Yuan

2014-10-31

Much evidence supports the role of the serotonin transporter (SERT) in the pathophysiology and pharmacotherapy of major depressive disorder (MDD) and suicidal behaviors. In this study, we recruited 17 antidepressant-naïve patients with MDD and 17 age- and gender-matched healthy controls. SERT availability was measured in vivo with N,N-dimethyl-2-(2-amino-4-[(18)F]fluorophenylthio)benzylamine (4-[(18)F]-ADAM) positron emission tomography (PET) imaging. The 21-item Hamilton Depression Rating Scale (HDRS) and Beck Scale for Suicide Ideation were used to assess the severity of depression and the intent of suicide ideation prior to PET imaging. All subjects with MDD were in a current state of depression with HDRS scores ≧18. Subjects who attempted suicide within two weeks of the study onset were recruited in the depressed suicidal group (n = 8). Subjects with MDD who denied any prior suicide attempt were recruited into the depressed non-suicidal group (n = 9). A significant reduction of SERT availability in the midbrain, thalamus, and striatum was noted in the MDD group relative to the control group (Bonferroni-adjusted p-value depressed suicidal group compared to the control group (Bonferroni-adjusted p-value depressed non-suicidal and control groups, the depressed suicidal group showed an increased prefrontal cortex (PFC)/midbrain SERT binding ratio (Bonferroni-adjusted p-value depressed suicide attempters and non-attempters in patients with MDD and may be involved in the pathophysiology of suicide behaviors. © The Author 2015. Published by Oxford University Press on behalf of CINP.

The serotonin transporter in rhesus monkey brain: comparison of DASB and citalopram binding sites

International Nuclear Information System (INIS)

Zeng Zhizhen; Chen, T.-B.; Miller, Patricia J.; Dean, Dennis; Tang, Y.S.; Sur, Cyrille; Williams, David L.

2006-01-01

We have characterized the interaction of the serotonin transporter ligand [ 3 H]-N,N-dimethyl-2-(2-amino-4-cyanophenylthio)-benzylamine (DASB) with rhesus monkey brain in vitro using tissue homogenate binding and autoradiographic mapping. [ 3 H]-DASB, a tritiated version of the widely used [ 11 C] positron emission tomography tracer, was found to selectively bind to a single population of sites with high affinity (K d =0.20±0.04 nM). The serotonin transporter density (B max ) obtained for rhesus frontal cortex was found to be 66±8 fmol/mg protein using [ 3 H]-DASB, similar to the B max value obtained using the reference radioligand [ 3 H]-citalopram, a well-characterized and highly selective serotonin reuptake inhibitor (83±22 fmol/mg protein). Specific binding sites of both [ 3 H]-DASB and [ 3 H]-citalopram were similarly and nonuniformly distributed throughout the rhesus central nervous system, in a pattern consistent with serotonin transporter localization reported for human brain. Regional serotonin transporter densities, estimated from optical densities of the autoradiographic images, were well correlated between the two radioligands. Finally, DASB and fluoxetine showed dose-dependent full inhibition of [ 3 H]-citalopram binding in a competition autoradiographic study, with K i values in close agreement with those obtained from rhesus brain homogenates. This side-by-side comparison of [ 3 H]-DASB and [ 3 H]-citalopram binding sites in rhesus tissue homogenates and in adjacent rhesus brain slices provides additional support for the use of [ 11 C]-DASB to assess the availability and distribution of serotonin transporters in nonhuman primates

Evaluation of brain SERT occupancy by resveratrol against MDMA-induced neurobiological and behavioral changes in rats: A 4-[¹⁸F]-ADAM/small-animal PET study.

Science.gov (United States)

Shih, Jui-Hu; Ma, Kuo-Hsing; Chen, Chien-Fu F; Cheng, Cheng-Yi; Pao, Li-Heng; Weng, Shao-Ju; Huang, Yuahn-Sieh; Shiue, Chyng-Yann; Yeh, Ming-Kung; Li, I-Hsun

2016-01-01

The misuse of 3,4-methylenedioxymethamphetamine (MDMA) has drawn a growing concern worldwide for its psychophysiological impacts on humans. MDMA abusers are often accompanied by long-term serotonergic neurotoxicity, which is associated with reduced density of cerebral serotonin transporters (SERT) and depressive disorders. Resveratrol (RSV) is a natural polyphenolic phytoalexin that has been known for its antidepressant and neuroprotective effects. However, biological targets of RSV as well as its neuroprotective effects against MDMA remained largely unknown. In this study, we examined binding potency of RSV and MDMA to SERT using small-animal positron emission tomography (PET) with the SERT radioligand, N,N-dimethyl-2-(2-amino-4-[(18)F]fluorophenylthio)benzylamine (4-[(18)F]-ADAM) and investigated the protection of RSV against the acute and long-term adverse effects of MDMA. We found that RSV exhibit binding potentials to SERT in vivo in a dose-dependent manner with variation among brain regions. When the MDMA-treated rats (10mg/kg, s.c.) were co-injected with RSV (20mg/kg, i.p.) twice daily for 4 consecutive days, MDMA-induced acute elevation in plasma corticosterone was significantly reduced. Further, 4-[(18)F]-ADAM PET imaging revealed that RSV protected against the MDMA-induced decrease in SERT availability in the midbrain and the thalamus 2 weeks following the co-treatment. The PET data were comparable to the observation from the forced swim test that RSV sufficiently ameliorated the depressive-like behaviors of the MDMA-treated rats. Together, these findings suggest that RSV is a potential antidepressant and may confer protection against neurobiological and behavioral changes induced by MDMA. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

The serotonin transporter in rhesus monkey brain: comparison of DASB and citalopram binding sites

Energy Technology Data Exchange (ETDEWEB)

Zeng Zhizhen [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States)]. E-mail: zhizhen_zeng@merck.com; Chen, T.-B. [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States); Miller, Patricia J. [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States); Dean, Dennis [Labeled Compound Synthesis Group, Drug Metabolism, Merck Research Laboratories, Rahway, NJ 07065-0900 (United States); Tang, Y.S. [Labeled Compound Synthesis Group, Drug Metabolism, Merck Research Laboratories, Rahway, NJ 07065-0900 (United States); Sur, Cyrille [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States); Williams, David L. [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States)

2006-05-15

We have characterized the interaction of the serotonin transporter ligand [{sup 3}H]-N,N-dimethyl-2-(2-amino-4-cyanophenylthio)-benzylamine (DASB) with rhesus monkey brain in vitro using tissue homogenate binding and autoradiographic mapping. [{sup 3}H]-DASB, a tritiated version of the widely used [{sup 11}C] positron emission tomography tracer, was found to selectively bind to a single population of sites with high affinity (K {sub d}=0.20{+-}0.04 nM). The serotonin transporter density (B {sub max}) obtained for rhesus frontal cortex was found to be 66{+-}8 fmol/mg protein using [{sup 3}H]-DASB, similar to the B {sub max} value obtained using the reference radioligand [{sup 3}H]-citalopram, a well-characterized and highly selective serotonin reuptake inhibitor (83{+-}22 fmol/mg protein). Specific binding sites of both [{sup 3}H]-DASB and [{sup 3}H]-citalopram were similarly and nonuniformly distributed throughout the rhesus central nervous system, in a pattern consistent with serotonin transporter localization reported for human brain. Regional serotonin transporter densities, estimated from optical densities of the autoradiographic images, were well correlated between the two radioligands. Finally, DASB and fluoxetine showed dose-dependent full inhibition of [{sup 3}H]-citalopram binding in a competition autoradiographic study, with K {sub i} values in close agreement with those obtained from rhesus brain homogenates. This side-by-side comparison of [{sup 3}H]-DASB and [{sup 3}H]-citalopram binding sites in rhesus tissue homogenates and in adjacent rhesus brain slices provides additional support for the use of [{sup 11}C]-DASB to assess the availability and distribution of serotonin transporters in nonhuman primates.

Two-dimensional inorganic–organic hybrid semiconductors composed of double-layered ZnS and monoamines with aromatic and heterocyclic aliphatic rings: Syntheses, structures, and properties

Energy Technology Data Exchange (ETDEWEB)

Wang, Sujing; Li, Jing, E-mail: jingli@rutgers.edu

2015-04-15

As an addition to the II–VI based inorganic–organic hybrid semiconductor family, five new two-dimensional (2D) double-layered structures have been synthesized employing monoamines with different aromatic or heterocyclic aliphatic rings. Zn{sub 2}S{sub 2}(bza) (1), Zn{sub 2}S{sub 2}(mbza) (2), Zn{sub 2}S{sub 2}(fbza) (3), Zn{sub 2}S{sub 2}(pca) (4), and Zn{sub 2}S{sub 2}(thfa) (5) (bza=benzylamine, mbza=4-methoxybenzylamine, fbza=4-flurobenzylamine, pca=3-picolylamine, and thfa=tetrahydrofurfurylamine) are prepared by solvothermal reactions and characterized by different analytical methods, including powder X-ray diffraction, optical diffuse reflection, thermogravimetric analysis and photoluminescence spectroscopy. The powder X-ray diffraction patterns show that all five compounds adopt 2D double-layered structures. Optical diffuse reflectance spectra of these compounds suggest that they have notably lower band gaps than those of the similar compounds composed of aliphatic alkyl amines. Their photoluminescence properties and thermal stability are also analyzed. - Graphical abstract: Five new members of two-dimensional double-layered 2D-Zn{sub 2}S{sub 2}(L) (L=Ligand) structures employing monoamines with different aromatic or heterocyclic aliphatic rings have been designed, synthesized, and characterized. - Highlights: • A new sub-family of II-VI based hybrid semiconductors are designed, synthesized, and structurally characterized using amines with aromatic or aliphatic cyclic rings. • These compounds have notably lower band gaps than those made of aliphatic alkyl amines, greatly broadening the range of band gaps of this material family. • They emit strongly with systematically tunable emission intensity and energy.

The amine oxidase inhibitor phenelzine limits lipogenesis in adipocytes without inhibiting insulin action on glucose uptake.

Science.gov (United States)

Carpéné, Christian; Grès, Sandra; Rascalou, Simon

2013-06-01

The antidepressant phenelzine is a monoamine oxidase inhibitor known to inhibit various other enzymes, among them semicarbazide-sensitive amine oxidase (currently named primary amine oxidase: SSAO/PrAO), absent from neurones but abundant in adipocytes. It has been reported that phenelzine inhibits adipocyte differentiation of cultured preadipocytes. To further explore the involved mechanisms, our aim was to study in vitro the acute effects of phenelzine on de novo lipogenesis in mature fat cells. Therefore, glucose uptake and incorporation into lipid were measured in mouse adipocytes in response to phenelzine, other hydrazine-based SSAO/PrAO-inhibitors, and reference agents. None of the inhibitors was able to impair the sevenfold activation of 2-deoxyglucose uptake induced by insulin. Phenelzine did not hamper the effect of lower doses of insulin. However, insulin-stimulated glucose incorporation into lipids was dose-dependently inhibited by phenelzine and pentamidine, but not by semicarbazide or BTT2052. In contrast, all these SSAO/PrAO inhibitors abolished the transport and lipogenesis stimulation induced by benzylamine. These data indicate that phenelzine does not inhibit glucose transport, the first step of lipogenesis, but inhibits at 100 μM the intracellular triacylglycerol assembly, consistently with its long-term anti-adipogenic effect and such rapid action was not found with all the hydrazine derivatives tested. Therefore, the alterations of body weight control consecutive to the use of this antidepressant drug might be not only related to central effects on food intake/energy expenditure, but could also depend on its direct action in adipocytes. Nonetheless, phenelzine antilipogenic action is not merely dependent on SSAO/PrAO inhibition.

Synthesis and characterization of anionic rare-earth metal amides stabilized by phenoxy-amido ligands and their catalytic behavior for the polymerization of lactide.

Science.gov (United States)

Lu, Min; Yao, Yingming; Zhang, Yong; Shen, Qi

2010-10-28

A dianionic phenoxyamido ligand was the first to be used to stabilize organo-rare-earth metal amido complexes. Amine elimination reaction of Nd[N(TMS)(2)](3)(μ-Cl)Li(THF)(3) (TMS = SiMe(3)) with aminophenol [HNOH] {[HNOH] = N-p-methylphenyl(2-hydroxy-3,5-di-tert-butyl)benzylamine} in a 1 : 1 molar-ratio gave the anionic phenoxyamido neodymium amide [NO](2)Nd[N(TMS)(2)][Li(THF)](2) (2) in a low isolated yield. A further study revealed that the stoichiometric reactions of Ln[N(TMS)(2)](3)(μ-Cl)Li(THF)(3) with the lithium aminophenoxy [HNOLi(THF)](2) (1) in tetrahydrofuran (THF) gave the anionic rare-earth metal amido complexes [NO](2)Ln[N(TMS)(2)][Li(THF)](2) [Ln = Nd (2), Sm (3), Yb (4), Y (5)] in high isolated yields. All of these complexes are fully characterized. X-Ray structure determination revealed that complex 1 has a solvated dimeric structure, and complexes 2-5 are isostructural, and have solvated monomeric structures. Each of the rare-earth metal ions is coordinated by two oxygen atoms and two nitrogen atoms from two phenoxyamido ligands and one nitrogen atom from the N(TMS)(2) group to form a distorted trigonal bipyramidal geometry. Each of the lithium atoms in complexes 2-5 is coordinated with one oxygen atom and one nitrogen atom from two different phenoxyamido groups, and one oxygen atom from one THF molecule to form a trigonal planar geometry. Furthermore, the catalytic behavior of complexes 2-5 for the ring-opening polymerization of l-lactide was explored.

PET imaging of the brain serotonin transporters (SERT) with N,N-dimethyl-2-(2-amino-4-[18F]fluorophenylthio)benzylamine (4-[18F]-ADAM) in humans: a preliminary study

International Nuclear Information System (INIS)

Huang, Wen-Sheng; Huang, San-Yuan; Ho, Pei-Shen; Yeh, Chin-Bin; Ma, Kuo-Hsing; Huang, Ya-Yao; Shiue, Chyng-Yann; Liu, Ren-Syuan; Cheng, Cheng-Yi

2013-01-01

The aim of this study was to assess the feasibility of using 4-[ 18 F]-ADAM as a brain SERT imaging agent in humans. Enrolled in the study were 19 healthy Taiwanese subjects (11 men, 8 women; age 33 ± 9 years). The PET data were semiquantitatively analyzed and expressed as specific uptake ratios (SUR) and distribution volume ratios (DVR) using the software package PMOD. The SUR and DVR of 4-[ 18 F]-ADAM in the raphe nucleus (RN), midbrain (MB), thalamus (TH), striatum (STR) and prefrontal cortex (PFC) were determined using the cerebellum (CB) as the reference region. 4-[ 18 F]-ADAM bound to known SERT-rich regions in human brain. The order of the regional brain uptake was MB (RN) > TH > STR > PFC > CB. The DVR (n = 4, t* = 60 min) in the RN, TH, STR and PFC were 3.00 ± 0.50, 2.25 ± 0.45, 2.05 ± 0.31 and 1.40 ± 0.13, respectively. The optimal time for imaging brain SERT with 4-[ 18 F]-ADAM was 120-140 min after injection. At the optimal imaging time, the SURs (n = 15) in the MB, TH, STR, and PFC were 2.25 ± 0.20, 2.28 ± 0.20, 2.12 ± 0.18 and 1.47 ± 0.14, respectively. There were no significant differences in SERT availability between men and women (p 18 F]-ADAM was safe for human studies and its distribution in human brain appeared to correlate well with the known distribution of SERT in the human brain. In addition, it had high specific binding and a reasonable optimal time for imaging brain SERT in humans. Thus, 4-[ 18 F]-ADAM may be feasible for assessing the status of brain SERT in humans. (orig.)

Characterization of 4-[18F]-ADAM as an imaging agent for SERT in non-human primate brain using PET: a dynamic study

International Nuclear Information System (INIS)

Chen, Yu-An; Huang, Wen-Sheng; Lin, Yaoh-Shiang; Cheng, Cheng-Yi; Liu, Ren-Shyan; Wang, Shyh-Jen; Li, I-Hsun; Huang, San-Yuan; Shiue, Chyng-Yann; Chen, Cheng-Yu; Ma, Kuo-Hsing

2012-01-01

Introduction: Serotonin transporter (SERT) has been associated with many psychiatric diseases. This study investigated the biodistribution of a serotonin transporter imaging agent, N,N-dimethyl-2-(2-amino-4- 18 F-fluorophenylthio)benzylamine (4-[ 18 F]-ADAM), in nonhuman primate brain using positron emission tomography (PET). Methods: Six and four Macaca cyclopis monkeys were used to determine the transit time (i.e., time necessary to reach biodistribution equilibrium) and the reproducibility of 4-[ 18 F]-ADAM biodistribution in the brain, respectively. The sensitivity and specificity of 4-[ 18 F]-ADAM binding to SERT were evaluated in one monkey challenged with different doses of fluoxetine and one monkey treated with 3,4-methylendioxymethamphetamine (MDMA). Dynamic PET imaging was performed for 3 h after 4-[ 18 F]-ADAM intravenous bolus injection. The specific uptake ratios (SURs) in the midbrain (MB), thalamus (TH), striatum (ST) and frontal cortex (FC) were calculated. Results: The distribution of 4-[ 18 F]-ADAM reached equilibrium 120–150 min after injection. The mean SURs were 2.49±0.13 in MB, 1.59±0.17 in TH, 1.35±0.06 in ST and 0.34±0.03 in FC, and the minimum variability was shown 120–150 min after 4-[ 18 F]-ADAM injection. Using SURs and intraclass coefficient of correlation, the test/retest variability was under 8% and above 0.8, respectively, in SERT-rich areas. Challenge with fluoxetin (0.75–2 mg) dose-dependently inhibited the SURs in various brain regions. 4-[ 18 F]-ADAM binding was markedly reduced in the brain of an MDMA-treated monkey compared to that in brains of normal controls. Conclusion: 4-[ 18 F]-ADAM appears to be a highly selective radioligand for imaging SERT in monkey brain.

Rational Design and Synthesis of Biologically Active Disubstituted 2(3H) Furanones and Pyrrolone Derivatives as Potent and Safer Non Steroidal Anti-inflammatory Agents.

Science.gov (United States)

Khokra, S L; Khan, S A; Choudhary, D; Hasan, S M; Ahmad, A; Husain, Asif

2016-01-01

Furanone and pyrrolone heterocyclic ring system represent important and interesting classes of bioactive compounds. Medicinal chemists use these heterocycyclic moieties as scaffolds in drug design and discovery. A series of 3-arylidene-5-(naphthalene-2-yl)-furan-2(3H)-ones (2a-j) were synthesized by incorporating pharmacophore of COX-2 inhibitor rofecoxib and naphthyl ring of naproxen as potential non steroidal anti-inflammatory agents. These furanone derivatives were subsequently reacted with dry ammonia gas and benzylamine to furnish corresponding 3-arylidene-5-(naphthlen-2-yl)-1H-pyrrol-2(3H)-ones (3a-e) and 3-arylidene-1-benzyl-5- (naphthalene-2-yl)-1H-pyrrol-2(3H)-ones (4a-e), respectively. The newly prepared heterocyclics were screened for their expected in-vivo biological activities including anti-inflammatory, analgesic and ulcerogenic actions in rodents. The COX-2 inhibitory behavior of synthesized compounds was also assessed via automated docking studies. The chemical structure of the synthesized compounds was characterized by using modern spectroscopic techniques. Result of in-vivo pharmacological studies demonstrated that almost all N-Benzyl-pyrrol-2(3H)-ones (4a-e) showed better anti-inflammatory and analgesic activities in comparison with the other two series of furan-2(3H)-ones and pyrrol- 2(3H)-ones. The moldock score value of the tested compounds was found in the range of -116.66 to -170.328 and was better than the standard drug. Among all the synthesized compounds, only nine compounds (2d, 2g, 2h, 3d, 4a, 4b, 4c, 4d and 4e) exhibited potent anti-inflammatory and analgesic activities with significantly reduced gastrointestinal toxicity in various animal models in comparison to standard drug, diclofenac. Therefore, it is recommended to explore the potential of the synthesized compounds as lead candidates for the development of new therapeutic agents.

Amine binding and oxidation at the catalytic site for photosynthetic water oxidation

Science.gov (United States)

Ouellette, Anthony J. A.; Anderson, Lorraine B.; Barry, Bridgette A.

1998-01-01

Photosynthetic water oxidation occurs at the Mn-containing catalytic site of photosystem II (PSII). By the use of 14C-labeled amines and SDS-denaturing PAGE, covalent adducts derived from primary amines and the PSII subunits, CP47, D2/D1, and the Mn-stabilizing protein, can be observed. When PSII contains the 18- and 24-kDa extrinsic proteins, which restrict access to the active site, no 14C labeling is obtained. NaCl, but not Na2SO4, competes with 14C labeling in Mn-containing PSII preparations, and the concentration dependence of this competition parallels the activation of oxygen evolution. Formation of 14C-labeled adducts is observed in the presence or in the absence of a functional manganese cluster. However, no significant Cl− effect on 14C labeling is observed in the absence of the Mn cluster. Isolation and quantitation of the 14C-labeled aldehyde product, produced from [14C]benzylamine, gives yields of 1.8 ± 0.3 mol/mol PSII and 2.9 ± 0.2 mol/mol in Mn-containing and Mn-depleted PSII, respectively. The corresponding specific activities are 0.40 ± 0.07 μmol(μmol PSII-hr)−1 and 0.64 ± 0.04 μmol(μmol PSII-hr)−1. Cl− suppresses the production of [14C]benzaldehyde in Mn-containing PSII, but does not suppress the production in Mn-depleted preparations. Control experiments show that these oxidation reactions do not involve the redox-active tyrosines, D and Z. Our results suggest the presence of one or more activated carbonyl groups in protein subunits that form the active site of PSII. PMID:9482863

PET imaging of the brain serotonin transporters (SERT) with N,N-dimethyl-2-(2-amino-4-[{sup 18}F]fluorophenylthio)benzylamine (4-[{sup 18}F]-ADAM) in humans: a preliminary study

Energy Technology Data Exchange (ETDEWEB)

Huang, Wen-Sheng [PET Center, Tri-Service General Hospital, Department of Nuclear Medicine, Neihu, Taipei (China); Changhua Christian Hospital, Department of Nuclear Medicine, Changhua (China); Huang, San-Yuan; Ho, Pei-Shen; Yeh, Chin-Bin [Tri-Service General Hospital, Department of Psychiatry, Taipei (China); Ma, Kuo-Hsing [National Defense Medical Center, Department of Biology and Anatomy, Taipei (China); Huang, Ya-Yao; Shiue, Chyng-Yann [PET Center, Tri-Service General Hospital, Department of Nuclear Medicine, Neihu, Taipei (China); PET Center, National Taiwan University Hospital, Department of Nuclear Medicine, Taipei (China); Liu, Ren-Syuan [Taipei Veterans General Hospital, Department of Nuclear Medicine, Taipei (China); Cheng, Cheng-Yi [PET Center, Tri-Service General Hospital, Department of Nuclear Medicine, Neihu, Taipei (China)

2013-01-15

The aim of this study was to assess the feasibility of using 4-[{sup 18}F]-ADAM as a brain SERT imaging agent in humans. Enrolled in the study were 19 healthy Taiwanese subjects (11 men, 8 women; age 33 {+-} 9 years). The PET data were semiquantitatively analyzed and expressed as specific uptake ratios (SUR) and distribution volume ratios (DVR) using the software package PMOD. The SUR and DVR of 4-[{sup 18}F]-ADAM in the raphe nucleus (RN), midbrain (MB), thalamus (TH), striatum (STR) and prefrontal cortex (PFC) were determined using the cerebellum (CB) as the reference region. 4-[{sup 18}F]-ADAM bound to known SERT-rich regions in human brain. The order of the regional brain uptake was MB (RN) > TH > STR > PFC > CB. The DVR (n = 4, t* = 60 min) in the RN, TH, STR and PFC were 3.00 {+-} 0.50, 2.25 {+-} 0.45, 2.05 {+-} 0.31 and 1.40 {+-} 0.13, respectively. The optimal time for imaging brain SERT with 4-[{sup 18}F]-ADAM was 120-140 min after injection. At the optimal imaging time, the SURs (n = 15) in the MB, TH, STR, and PFC were 2.25 {+-} 0.20, 2.28 {+-} 0.20, 2.12 {+-} 0.18 and 1.47 {+-} 0.14, respectively. There were no significant differences in SERT availability between men and women (p < 0.05). The results of this study showed that 4-[{sup 18}F]-ADAM was safe for human studies and its distribution in human brain appeared to correlate well with the known distribution of SERT in the human brain. In addition, it had high specific binding and a reasonable optimal time for imaging brain SERT in humans. Thus, 4-[{sup 18}F]-ADAM may be feasible for assessing the status of brain SERT in humans. (orig.)

SEP-225289 serotonin and dopamine transporter occupancy: a PET study.

Science.gov (United States)

DeLorenzo, Christine; Lichenstein, Sarah; Schaefer, Karen; Dunn, Judith; Marshall, Randall; Organisak, Lisa; Kharidia, Jahnavi; Robertson, Brigitte; Mann, J John; Parsey, Ramin V

2011-07-01

SEP-225289 is a novel compound that, based on in vitro potencies for transporter function, potentially inhibits reuptake at dopamine, norepinephrine, and serotonin transporters. An open-label PET study was conducted during the development of SEP-225289 to investigate its dopamine and serotonin transporter occupancy. Different single doses of SEP-225289 were administered to healthy volunteers in 3 cohorts: 8 mg (n = 7), 12 mg (n = 5), and 16 mg (n = 7). PET was performed before and approximately 24 h after oral administration of SEP-225289, to assess occupancy at trough levels. Dopamine and serotonin transporter occupancies were estimated from PET using (11)C-N-(3-iodoprop-2E-enyl)-2β-carbomethoxy-3β-(4-methylphenyl)nortropane ((11)C-PE2I) and (11)C-N,N-dimethyl-2-(2-amino-4-cyanophenylthio)benzylamine ((11)C-DASB), respectively. Plasma concentration of SEP-225289 was assessed before ligand injection, and subjects were monitored for adverse events. Average dopamine and serotonin transporter occupancies increased with increasing doses of SEP-225289. Mean dopamine and serotonin transporter occupancies were 33% ± 11% and 2% ± 13%, respectively, for 8 mg; 44% ± 4% and 9% ± 10%, respectively, for 12 mg; and 49% ± 7% and 14% ± 15%, respectively, for 16 mg. On the basis of the relationship between occupancy and plasma concentration, dopamine transporter IC(50) (the plasma concentration of drug at 50% occupancy) was determined (4.5 ng/mL) and maximum dopamine transporter occupancy was extrapolated (85%); however, low serotonin transporter occupancy prevented similar serotonin transporter calculations. No serious adverse events were reported. At the doses evaluated, occupancy of the dopamine transporter was significantly higher than that of the serotonin transporter, despite similar in vitro potencies, confirming that, in addition to in vitro assays, PET occupancy studies can be instrumental to the drug development process by informing early decisions about

Antiglycation, radical scavenging, and semicarbazide-sensitive amine oxidase inhibitory activities of acetohydroxamic acid in vitro

Directory of Open Access Journals (Sweden)

Liu YH

2017-07-01

Full Text Available Yuh-Hwa Liu,1,2,* Yeh-Lin Lu,3,* Der-Zen Liu,4 Wen-Chi Hou5 1Division of Gastroenterology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; 2Department of General Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; 3Department of Pharmacy, Taipei Medical University, Taipei, Taiwan; 4Graduate Institute of Biomedical Materials and Tissue Engineering, Taipei Medical University, Taipei, Taiwan; 5Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan *These authors contributed equally to this work Abstract: Advanced glycation endproducts (AGEs can promote intracellular reactive oxygen species production, and the levels of AGEs are highly correlated with cardiovascular disease and diabetes complications. Acetohydroxamic acid (acetH is a bacterial urease inhibitor drug used to treat kidney stones and infections in the urinary tract, and hydroxyurea (HU is a drug used for antineoplasm and sickle cell diseases. Both acetH and HU are hydroxamic acid derivatives. It was found that acetH and HU at 2.5 or 5 mM showed anti-AGE formation by lowering the AGEs’ fluorescent intensities and Nε-(carboxymethyllysine formation in bovine serum albumin/galactose models, and both showed better and significant differences (P<0.05 compared to the positive control of aminoguanidine. Regarding radical scavenging activities, the half-inhibition concentrations (IC50 of acetH against α,α-diphenyl-β-picrylhydrazyl radical and hydroxyl radical were 34.86 and 104.42 µM, respectively. The IC50 of acetH against semicarbazide-sensitive amine oxidase was 10.56 µM, and acetH showed noncompetitive inhibition respective to the substrates (benzylamine. The antiglycation, antioxidant, and semicarbazide-sensitive amine oxidase inhibitory activities of acetH prove that it has the potential for treating cardiovascular disease and diabetes complications and it needs further investigation in animal models. Keywords: acetH, AGEs, Nε

Enhanced visible-light photocatalytic activity for selective oxidation of amines into imines over TiO{sub 2}(B)/anatase mixed-phase nanowires

Energy Technology Data Exchange (ETDEWEB)

Dai, Jun [Institute of Applied Chemistry, Henan Polytechnic University, Jiaozuo 454003 (China); State Key Laboratory Cultivation Base for Gas Geology and Gas Control, School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo 454003 (China); Yang, Juan, E-mail: yangjuanhpu@yahoo.com [Institute of Applied Chemistry, Henan Polytechnic University, Jiaozuo 454003 (China); Wang, Xiaohan; Zhang, Lei; Li, Yingjie [Institute of Applied Chemistry, Henan Polytechnic University, Jiaozuo 454003 (China)

2015-09-15

Graphical abstract: Visible-light photocatalytic activities for selective oxidation of amines into imines are greatly affected by the crystal structure of TiO{sub 2} catalysts and mixed-phase TiO{sub 2}(B)/anatase possess higher photoactivity because of the moderate adsorption ability and efficient charge separation. - Highlights: • Visible-light photocatalytic oxidation of amines to imines is studied over different TiO{sub 2}. • Photocatalytic activities are greatly affected by the crystal structure of TiO{sub 2} nanowires. • Mixed-phase TiO{sub 2}(B)/anatase exhibits higher catalytic activity than single-phase TiO{sub 2}. • Enhanced activity is ascribed to efficient adsorption ability and interfacial charge separation. • Photoinduced charge transfer mechanism on TiO{sub 2}(B)/anatase catalysts is also proposed. - Abstract: Wirelike catalysts of mixed-phase TiO{sub 2}(B)/anatase TiO{sub 2}, bare anatase TiO{sub 2} and TiO{sub 2}(B) are synthesized via calcining precursor hydrogen titanate obtained from hydrothermal process at different temperatures between 450 and 700 °C. Under visible light irradiation, mixed-phase TiO{sub 2}(B)/anatase TiO{sub 2} catalysts exhibit enhanced photocatalytic activity in comparison with pure TiO{sub 2}(B) and anatase TiO{sub 2} toward selective oxidation of benzylamines into imines and the highest photocatalytic activity is achieved by TW-550 sample consisting of 65% TiO{sub 2}(B) and 35% anatase. The difference in photocatalytic activities of TiO{sub 2} samples can be attributed to the different adsorption abilities resulted from their crystal structures and interfacial charge separation driven by surface-phase junctions between TiO{sub 2}(B) and anatase TiO{sub 2}. Moreover, the photoinduced charge transfer mechanism of surface complex is also proposed over mixed-phase TiO{sub 2}(B)/anatase TiO{sub 2} catalysts. Advantages of this photocatalytic system include efficient utilization of solar light, general suitability to

Enhanced visible-light photocatalytic activity for selective oxidation of amines into imines over TiO2(B)/anatase mixed-phase nanowires

International Nuclear Information System (INIS)

Dai, Jun; Yang, Juan; Wang, Xiaohan; Zhang, Lei; Li, Yingjie

2015-01-01

Graphical abstract: Visible-light photocatalytic activities for selective oxidation of amines into imines are greatly affected by the crystal structure of TiO 2 catalysts and mixed-phase TiO 2 (B)/anatase possess higher photoactivity because of the moderate adsorption ability and efficient charge separation. - Highlights: • Visible-light photocatalytic oxidation of amines to imines is studied over different TiO 2 . • Photocatalytic activities are greatly affected by the crystal structure of TiO 2 nanowires. • Mixed-phase TiO 2 (B)/anatase exhibits higher catalytic activity than single-phase TiO 2 . • Enhanced activity is ascribed to efficient adsorption ability and interfacial charge separation. • Photoinduced charge transfer mechanism on TiO 2 (B)/anatase catalysts is also proposed. - Abstract: Wirelike catalysts of mixed-phase TiO 2 (B)/anatase TiO 2 , bare anatase TiO 2 and TiO 2 (B) are synthesized via calcining precursor hydrogen titanate obtained from hydrothermal process at different temperatures between 450 and 700 °C. Under visible light irradiation, mixed-phase TiO 2 (B)/anatase TiO 2 catalysts exhibit enhanced photocatalytic activity in comparison with pure TiO 2 (B) and anatase TiO 2 toward selective oxidation of benzylamines into imines and the highest photocatalytic activity is achieved by TW-550 sample consisting of 65% TiO 2 (B) and 35% anatase. The difference in photocatalytic activities of TiO 2 samples can be attributed to the different adsorption abilities resulted from their crystal structures and interfacial charge separation driven by surface-phase junctions between TiO 2 (B) and anatase TiO 2 . Moreover, the photoinduced charge transfer mechanism of surface complex is also proposed over mixed-phase TiO 2 (B)/anatase TiO 2 catalysts. Advantages of this photocatalytic system include efficient utilization of solar light, general suitability to amines, reusability and facile separation of nanowires catalysts

Design and Synthesis of 11C-Labelled Compound Libraries for the Molecular Imaging of EGFr, VEGFr-2, AT1 and AT2 Receptors: Transition-Metal Mediated Carbonylations Using [11C]Carbon Monoxide

International Nuclear Information System (INIS)

Aaberg, Ola

2009-01-01

This work deals with radiochemistry and new approaches to develop novel PET tracers labelled with the radionuclide 11 C. Two methods for the synthesis of 11 C-labelled acrylamides have been explored. First, [1- 11 C]-acrylic acid was obtained from a palladium(0)-mediated 11 C-carboxylation of acetylene with [ 11 C]carbon monoxide; this could be converted to the corresponding acyl chloride and then combined with benzylamine to form N-benzyl[carbonyl- 11 C]acrylamide. In the second method, the palladium(0)-mediated carbonylation of vinyl halides with [ 11 C]carbon monoxide was explored. This latter method, yielded labelled acrylamides in a single step with retention of configuration at the C=C double bond, and required less amine compared to the acetylene method. The vinyl halide method was used to synthesize a library of 11 C-labelled EGFr-inhibitors in 7-61% decay corrected radiochemical yield via a combinatorial approach. The compounds were designed to target either the active or the inactive form of EGFr, following computational docking studies. The rhodium(I)-mediated carbonylative cross-coupling of an azide and an amine was shown to be a very general reaction and was used to synthesize a library of dual VEGFr-2/PDGFrβ inhibitors that were 11 C-labelled at the urea position in 38-78% dc rcy. The angiotensin II AT 1 receptor antagonist eprosartan was 11 C-labelled at one of the carboxyl groups in one step using a palladium(0)-mediated carboxylation. Autoradiography shows specific binding in rat kidney, lung and adrenal cortex, and organ distribution shows a high accumulation in the intestines, kidneys and liver. Specific binding in frozen sections of human adrenal incidentalomas warrants further investigations of this tracer. Three angiotensin II AT 2 ligands were 11 C-labelled at the amide group in a palladium(0)-mediated aminocarbonylation in 16-36% dc rcy. One of the compounds was evaluated using in vitro using autoradiography, and in vivo using organ

Design, synthesis and biological evaluation of new hybrid anticonvulsants derived from N-benzyl-2-(2,5-dioxopyrrolidin-1-yl)propanamide and 2-(2,5-dioxopyrrolidin-1-yl)butanamide derivatives.

Science.gov (United States)

Kamiński, Krzysztof; Rapacz, Anna; Łuszczki, Jarogniew J; Latacz, Gniewomir; Obniska, Jolanta; Kieć-Kononowicz, Katarzyna; Filipek, Barbara

2015-05-15

The purpose of this study was to synthesize the library of 33 new N-benzyl-2-(2,5-dioxopyrrolidin-1-yl)propanamides, 2-(3-methyl-2,5-dioxopyrrolidin-1-yl)propanamides, and 2-(2,5-dioxopyrrolidin-1-yl)butanamides as potential new hybrid anticonvulsant agents. These hybrid molecules join the chemical fragments of well-known antiepileptic drugs (AEDs) such as ethosuximide, levetiracetam, and lacosamide. The coupling reaction of the 2-(2,5-dioxopyrrolidin-1-yl)propanoic acid, 2-(3-methyl-2,5-dioxopyrrolidin-1-yl)propanoic acid, or 2-(2,5-dioxopyrrolidin-1-yl)butanoic acid with the appropriately substituted benzylamines in the presence of the coupling reagent, N,N-carbonyldiimidazole (CDI) generated the final compounds 4-36. Spectral data acquired via (1)H NMR, (13)C NMR, and LC-MS confirmed the chemical structures of the newly prepared compounds. The initial anticonvulsant screening was performed in mice intraperitoneally (ip), using the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure tests. The rotarod test determined the acute neurological toxicity (NT). The results of preliminary pharmacological screening revealed that 25 compounds showed protection in half or more of the animals tested in the MES and/or scPTZ seizure models at the fixed dose of 100mg/kg. The broad spectra of activity across the preclinical seizure models displayed compounds 4, 7, 8, 13, 15-18, 24, and 26. The quantitative pharmacological studies in mice demonstrated the highest protection for compounds 4 (ED50 MES=67.65 mg/kg, ED50scPTZ=42.83 mg/kg); 8 (ED50 MES=54.90 mg/kg, ED50scPTZ=50.29 mg/kg); and 20 (ED50scPTZ=47.39 mg/kg). These compounds were distinctly more potent and provided better safety profiles in the rotarod test compared to valproic acid or ethosuximide, which were used as model AEDs. Compound 8 underwent only a slight metabolic change by the human liver microsomes (HLMs), and also did not affect the activity of human cytochrome P450 isoform

Mechanism of Prototropy. V. Arrhenius parameters of the tautomerization of Benzylidene Benzylamine and its {alpha}-{alpha}-alkyl derivatives; Mecanismo de la prototropia V. Parametros de Arrhenius de la toutomerizacion de benciliden-bencilamina y sus {alpha}- y {alpha}-alquilderivados

Energy Technology Data Exchange (ETDEWEB)

Perez Ossorio, R; Gomez Herrera, F; Utrilla, R M; Hidalgo, A; Gamboa, J M

1961-07-01

The reactions were conducted in ethyl alcohol-dioxan, in the presence of EtONa, as catalyst. Rates were followed by a radioactive tracer method when R=H and by spectroscopic method when R= alkyl as described in previous papers. The results suggest that polar effects alone cannot account for the relative Arrhenius parameters obtained. (Author) 3 refs.

Synthesis and physical-chemical properties of functional derivatives of 3-benzyl-8-propylxanthinyl-7-acetic acid

Directory of Open Access Journals (Sweden)

E. K. Mikhal’chenko

2017-08-01

with butylamine, benzylamine, p-methylbenzylamine or p-fluorobenzylamine. It should be noted that we conducted reaction without solvent in the medium of amine and reagents were not reflux but heated at 80 оС. The structures of all obtained compounds were proved by the elemental analysis, IR- and 1H NMR-spectroscopy. Conclusions. Obtained results of our work can be used for further search of biological active compounds among functional derivatives of xanthinyl-7-alkanyl acids xanthines; organic synthesis; IR-spectroscopy; NMR-spectroscopy

Enzymatic modification of natural and synthetic polymers using lipases and proteases

Science.gov (United States)

Chakraborty, Soma

Enzymatic modification of natural/synthetic polymers [starch nanoparticles, poly (n-alkyl acrylates) and poly(vinyl formamide)] was studied. Enzymes used for catalysis were lipases and proteases. Starch nanoparticles (40nm diameter) were incorporated into AOT-coated reverse micelles. Reactions performed with the acylating agents vinyl stearate, epsilon-caprolactone and maleic anhydride in toluene in presence of Novozyme-435 at 40°C for 36h gave products with degrees of substitution of 0.8, 0.6 and 0.4 respectively. DEPT-135 NMR spectra revealed that the modification occurred regioselectively at the C-6 position of the glucose units. Infrared microspectroscopy showed that the surfactant coated starch nanoparticles diffuse into pores of Novozyme-435 beads, coming in close proximity with CALB to promote modification. The modified products retained nanoscale dimensions. Catalysis of amide bond formation between a low molar mass amine and ester side groups of poly(n-alkyl acrylates)[poly(ethyl acrylate), poly(methyl acrylate) and poly(butyl acrylate)] was also examined. The nucleophiles were mono and diamines. Among the poly(n-alkyl acrylates) and the lipases studied, poly(ethyl acrylate) was the preferred substrate and Novozyme-435 the most active lipase. Poly(ethyl acrylate) in 80% by-volume toluene was reacted with 1 equivalent per repeat unit of hexyl amine at 70°C in presence of Novozyme-435. The product contained 10.6 mol% amide groups. Attempts to increase the amidation beyond 10--11 mol% by increasing the reaction time or use of fresh enzyme were unsuccessful, showing that poly(ethylacrylate-co-10mol%hexylacrylamide) is a poor substrate for further acylation. When chiral amines ([R,S]-alpha-methyl benzylamine, [R,S]-beta-methyl phenyl amine) were used as nucleophiles, Novozyme-435 enantioselectively catalyzed amidation of poly(ethyl acrylate). Poly(vinyl formamide), P(VfAm) by acid or base-catalyzed hydrolysis leads to poly(vinylamine), P(VAm), and

Conformers, infrared spectrum, UV-induced photochemistry, and near-IR-induced generation of two rare conformers of matrix-isolated phenylglycine

Science.gov (United States)

Borba, Ana; Gómez-Zavaglia, Andrea; Fausto, Rui

2014-10-01

through two photochemical pathways that are favored for different initial conformations of the reactant: (a) decarboxylation, leading to CO2 plus benzylamine (the dominant photofragmentation channel in PG cis-COOH conformers ICa and ICc) and (b) decarbonylation, with generation of CO plus benzonitrile, H2O and H2 (prevalent in the case of the trans-COOH conformer, IITa).

Conformers, infrared spectrum, UV-induced photochemistry, and near-IR-induced generation of two rare conformers of matrix-isolated phenylglycine

International Nuclear Information System (INIS)

Borba, Ana; Fausto, Rui; Gómez-Zavaglia, Andrea

2014-01-01

undergoes facile photofragmentation through two photochemical pathways that are favored for different initial conformations of the reactant: (a) decarboxylation, leading to CO 2 plus benzylamine (the dominant photofragmentation channel in PG cis-COOH conformers ICa and ICc) and (b) decarbonylation, with generation of CO plus benzonitrile, H 2 O and H 2 (prevalent in the case of the trans-COOH conformer, IITa)