WorldWideScience

Sample records for alkyl amides derivatives

  1. Influence of alkali and alkaline earth ions on the -alkylation of the lower rim phenolic-OH groups of -tert-butyl-calix[4]arene to result in amide-pendants: Template action of K+ and the structure of K+ bound tetra-amide derivative crystallized with a -tert-butylcalix[4]arene anion

    Indian Academy of Sciences (India)

    Amjad Ali; Chebrolu P Rao; Philippe Guionneau

    2008-03-01

    Role of alkali and alkaline earth ions on the formation of calix[4]arene-amide derivatives through -alkylation of the lower rim phenolic-OH groups in general and template action of K+ in particular have been explored. Na+ and K+ ions among alkali, and Ca2+ and Sr2+ ions among alkaline earth have shown tetra-amide derivatives bound to metal ion species. Among all these, potassium salts act as template and yields a K+ bound tetra-amide derivative where the charge is counter balanced by a calix[4] arene-monoanion and the product is crystallographically characterized. Change in the amide precursor used in these -alkylation reactions has no effect on the type of the amide derivative formed. Also demonstrated is a direct one-step reaction for the preparation of 1,3-di-amide derivative in high yield and low reaction period using CsHCO3.

  2. Synthesis of Imidates: TFA-Mediated Regioselective Amide Alkylation Using Meerwein's Reagent.

    Science.gov (United States)

    Popov, Kirill; Somfai, Peter

    2016-04-15

    Regioselective O-alkylation of an amide to form the corresponding imidate is a common synthetic problem, often resulting in varying amounts of N-alkylation. Screening existing methods for converting amides to imidates gave inconsistent or irreproducible results, sometimes affording N-alkylamide as the major product. A simple and reliable protocol for amide O-alkylation with complete regioselectivity has been designed, and its scope and efficiency demonstrated on a number of substrates. PMID:27019206

  3. Cytotoxic effects of methionine alkyl esters and amides in normal and neoplastic cell lines.

    Science.gov (United States)

    Clement, M A; Chapman, J M; Roberts, J

    1989-06-01

    Homologous series of L-methionine alkyl ester hydrochlorides and tosylates were synthesized and evaluated for in vitro growth inhibitory activity in Meth A sarcoma. Cytotoxicity, as determined by [3H]thymidine incorporation, was found to be directly proportional to alkyl chain length and surface tension lowering activity. L-Methionine decyl and dodecyl ester hydrochlorides possessed optimum cytotoxic activity (IC50 = 29, 28 microM) which was not reversible by the addition of L-methionine. Surface tension of a 50 microM solution of the decyl and dodecyl ester hydrochlorides were 35.4 and 32.7 dyn/cm, respectively. The corresponding decyl and dodecyl ester tosylates and amide hydrochlorides were less active. The N-t-butoxycarbonyl analogues were essentially inactive, demonstrating the necessity of an unsubstituted and/or potentially cationic amino group. Methionine dependence characteristics and cytotoxicity were also determined for three human (IMR-90, LX-1, MCF7) and four additional murine (L1210, L5178Y, 3T3, SV-T2) cell lines. The human cell lines Meth A, LX-1, and SV-T2 were found to be methionine independent. The LX-1 tumor cell line and the SV-T2 transformed line exhibited two to four times more sensitivity to the cytotoxic and cytolytic properties of the decyl and dodecyl ester hydrochlorides than their normal counterparts. The dodecyl amide hydrochloride derivative demonstrated enhanced cytotoxic activity in vivo relative to the corresponding ester, possibly due to decreased metabolic hydrolysis.

  4. 40 CFR 721.6183 - Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow alkyl amines...

    Science.gov (United States)

    2010-07-01

    ... - maleic anhydride polymer and hydrogenated tallow alkyl amines, sodium salts, compds. with ethanolamine... Substances § 721.6183 Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow... subject to reporting. (1) The chemical substance identified as amides, from ammonium hydroxide -...

  5. The Synthesis of 6-Alkyl-5-Fluorouracil Derivatives

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    6-alkyl-5-fluorouracil derivatives (5a~5f) were synthesized by facile alkylation of lithiation of 5-fluorouracil derivatives with mthyl iodide (MeI) or alkyl trifluoromethanesulfonate (ROTf) in yield of 42~58%. We found that the methylated product was ethyl-substituted derivatives, not methyl-substituted derivatives.

  6. SYNTHESIS AND BIOLOGICAL ACTIVITY OF AMIDE DERIVATIVES OF GINKGOLIDE A

    Institute of Scientific and Technical Information of China (English)

    LI-HONG HU; ZHONG-LIANG CHEN; YU-YUAN XIE

    2001-01-01

    Amide derivatives of ginkgolide A were prepared and evaluated for their in vitro ability to inhibit the PAF-induced aggregation of rabbit platelets. They showed less activities than their parent compound ginkgolide A.

  7. New Umami Amides: Structure-Taste Relationship Studies of Cinnamic Acid Derived Amides and the Natural Occurrence of an Intense Umami Amide in Zanthoxylum piperitum.

    Science.gov (United States)

    Frerot, Eric; Neirynck, Nathalie; Cayeux, Isabelle; Yuan, Yoyo Hui-Juan; Yuan, Yong-Ming

    2015-08-19

    A series of aromatic amides were synthesized from various acids and amines selected from naturally occurring structural frameworks. These synthetic amides were evaluated for umami taste in comparison with monosodium glutamate. The effect of the substitution pattern of both the acid and the amine parts on umami taste was investigated. The only intensely umami-tasting amides were those made from 3,4-dimethoxycinnamic acid. The amine part was more tolerant to structural changes. Amides bearing an alkyl- or alkoxy-substituted phenylethylamine residue displayed a clean umami taste as 20 ppm solutions in water. Ultraperformance liquid chromatography coupled with a high quadrupole-Orbitrap mass spectrometer (UPLC/MS) was subsequently used to show the natural occurrence of these amides. (E)-3-(3,4-Dimethoxyphenyl)-N-(4-methoxyphenethyl)acrylamide was shown to occur in the roots and stems of Zanthoxylum piperitum, a plant of the family Rutaceae growing in Korea, Japan, and China. PMID:26230212

  8. Alkyl substitution effect: A high mobility bistetracene derivatives

    Science.gov (United States)

    Liu, Xiaoyan; Liu, Yujuan; Zheng, Yujun

    2016-03-01

    Tetracenes and their derivatives are widely used in organic semiconductors for the advantages of small reorganization energies and large electronic couplings. The influences of long alkyl chain on charge transfer mobility of two bistetracene derivatives are investigated theoretically. The results show that the introduction of long alkyl chains would lead to a more compact packing, and increase electronic coupling, but reduce intermolecular distance. However, the introduction of long alkyl chains has little influence on reorganization energy. This provides a new understanding of the introduction of long alkyl chain on designing new high efficiency organic semiconductors.

  9. Quantifying the Sigma and Pi interactions between U(V) f orbitals and halide, alkyl, alkoxide, amide and ketimide ligands

    Energy Technology Data Exchange (ETDEWEB)

    University of California, Berkeley; Lukens, Wayne W.; Edelstein, Norman M.; Magnani, Nicola; Hayton, Trevor W.; Fortier, Skye; Seaman, Lani A.

    2013-06-20

    f Orbital bonding in actinide and lanthanide complexes is critical to their behavior in a variety of areas from separations to magnetic properties. Octahedral f1 hexahalide complexes have been extensively used to study f orbital bonding due to their simple electronic structure and extensive spectroscopic characterization. The recent expansion of this family to include alkyl, alkoxide, amide, and ketimide ligands presents the opportunity to extend this study to a wider variety of ligands. To better understand f orbital bonding in these complexes, the existing molecular orbital (MO) model was refined to include the effect of covalency on spin orbit coupling in addition to its effect on orbital angular momentum (orbital reduction). The new MO model as well as the existing MO model and the crystal field (CF) model were applied to the octahedral f1 complexes to determine the covalency and strengths of the ? and ? bonds formed by the f orbitals. When covalency is significant, MO models more precisely determined the strengths of the bonds derived from the f orbitals; however, when covalency was small, the CF model was better than either MO model. The covalency determined using the new MO model is in better agreement with both experiment and theory than that predicted by the existing MO model. The results emphasize the role played by the orbital energy in determining the strength and covalency of bonds formed by the f orbitals.

  10. Coumarin amide derivatives as fluorescence chemosensors for cyanide anions

    International Nuclear Information System (INIS)

    Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group have been synthesized. Their photophysical properties and recognition properties for cyanide anions have been examined. The results indicate that the compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change, at the same time, obvious color and fluorescence change can be observed by naked eye. The in situ hydrogen nuclear magnetic resonance spectra and photophysical properties change confirm that Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin. - Highlights: • Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group were synthesized. • The compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change. • Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin

  11. Coumarin amide derivatives as fluorescence chemosensors for cyanide anions

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qianqian [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China); Liu, Zhiqiang [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong (China); Cao, Duxia, E-mail: duxiacao@ujn.edu.cn [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China); Guan, Ruifang, E-mail: mse_guanrf@ujn.edu.cn [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China); Wang, Kangnan; Shan, Yanyan; Xu, Yongxiao; Ma, Lin [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China)

    2015-07-01

    Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group have been synthesized. Their photophysical properties and recognition properties for cyanide anions have been examined. The results indicate that the compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change, at the same time, obvious color and fluorescence change can be observed by naked eye. The in situ hydrogen nuclear magnetic resonance spectra and photophysical properties change confirm that Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin. - Highlights: • Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group were synthesized. • The compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change. • Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin.

  12. A comparative study of the complexation of uranium(VI) withoxydiacetic acid and its amide derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Linfeng; Tian, Guoxin

    2005-05-01

    There has been significant interest in recent years in the studies of alkyl-substituted amides as extractants for actinide separation because the products of radiolytic and hydrolytic degradation of amides are less detrimental to separation processes than those of organophosphorus compounds traditionally used in actinide separations. Stripping of actinides from the amide-containing organic solvents is relatively easy. In addition, the amide ligands are completely incinerable so that the amount of secondary wastes generated in nuclear waste treatment could be significantly reduced. One group of alkyl-substituted oxa-diamides have been shown to be promising in the separation of actinides from nuclear wastes. For example, tetraoctyl-3-oxa-glutaramide and tetraisobutyl-oxa-glutaramide form actinide complexes that can be effectively extracted from nitric acid solutions. To understand the thermodynamic principles governing the complexation of actinides with oxa-diamides, we have studied the complexation of U(VI) with dimethyl-3-oxa-glutaramic acid (DMOGA) and tetramethyl-3-oxa-glutaramide (TMOGA) in aqueous solutions, in comparison with oxydiacetic acid (ODA) (Figure 1). Previous studies have indicated that the complexation of U(VI) with ODA is strong and entropy-driven. Comparing the results for DMOGA and TMOGA with those for ODA could provide insight into the energetics of amide complexation with U(VI) and the relationship between the thermodynamic properties and the ligand structure.

  13. SYNTHESIS, CHARACTERIZATION OF CHIRAL POLY(ESTER AMIDE)S DERIVED FROM L-ISOLEUCINE

    Institute of Scientific and Technical Information of China (English)

    Xing-He Fan; Jing-Lun Zhou; Xiao-Fang Chen; Xin-Hua Wan; Qi-Feng Zhou

    2004-01-01

    A series of new optically active aromatic poly(ester amide)s containing a chiral group in the side chain prepared from the p-toluenesulfonic acid salt of o,o'-bis(leucyl)-hexanediol (TS-+LHD+TS-) and p-phthaloyl chloride and styrene-2,5-dicarbonyl chloride styrene have been synthesized by interfacial polymerization. The structure of the monomer is elucidated by FT-IR and elemental analysis. The thermal properties of the polymers were studied by DSC and TGA. The chiroptical properties of the above polymer have also been studied by circular dichroism (CD) spectroscopy. Results indicated that these polymers form helical structures.

  14. Zirconyl chloride promoted highly efficient solid phase synthesis of amide derivatives

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An efficient solid phase route for the synthesis of amide derivatives by the reaction of carboxylic acids with urea in the presence of catalytic amount of zirconyl chloride under microwave irradiation conditions was described. In this way, a range of interesting amide derivatives was obtained in good to excellent yields. The catalyst was recycled with fresh reactants and it gave almost similar results without significant loss of activity up to the third run.

  15. Pharmaceuticals and Surfactants from Alga-Derived Feedstock: Amidation of Fatty Acids and Their Derivatives with Amino Alcohols.

    Science.gov (United States)

    Tkacheva, Anastasia; Dosmagambetova, Inkar; Chapellier, Yann; Mäki-Arvela, Päivi; Hachemi, Imane; Savela, Risto; Leino, Reko; Viegas, Carolina; Kumar, Narendra; Eränen, Kari; Hemming, Jarl; Smeds, Annika; Murzin, Dmitry Yu

    2015-08-24

    Amidation of renewable feedstocks, such as fatty acids, esters, and Chlorella alga based biodiesel, was demonstrated with zeolites and mesoporous materials as catalysts and ethanolamine, alaninol, and leucinol. The last two can be derived from amino acids present in alga. The main products were fatty alkanol amides and the corresponding ester amines, as confirmed by NMR and IR spectroscopy. Thermal amidation of technical-grade oleic acid and stearic acid at 180 °C with ethanolamine were non-negligible; both gave 61% conversion. In the amidation of stearic acid with ethanolamine, the conversion over H-Beta-150 was 80% after 3 h, whereas only 63% conversion was achieved for oleic acid; this shows that a microporous catalyst is not suitable for this acid and exhibits a wrinkled conformation. The highest selectivity to stearoyl ethanolamide of 92% was achieved with mildly acidic H-MCM-41 at 70% conversion in 3 h at 180 °C. Highly acidic catalysts favored the formation of the ester amine, whereas the amide was obtained with a catalyst that exhibited an optimum acidity. The conversion levels achieved with different fatty acids in the range C12-C18 were similar; this shows that the fatty acid length does not affect the amidation rate. The amidation of methyl palmitate and biodiesel gave low conversions over an acidic catalyst, which suggested that the reaction mechanism in the amidation of esters was different. PMID:26197759

  16. Synthesis and antiangiogenic activity of N-alkylated levamisole derivatives.

    Directory of Open Access Journals (Sweden)

    Anders N Hansen

    Full Text Available Inhibition of angiogenesis is a promising addition to current cancer treatment strategies. Neutralization of vascular endothelial growth factor by monoclonal antibodies is clinically effective but may cause side effects due to thrombosis. Low molecular weight angiogenesis inhibitors are currently less effective than antibody treatment and are also associated with serious side effects. The discovery of new chemotypes with efficient antiangiogenic activity is therefore of pertinent interest. (S-levamisole hydrochloride, an anthelminthic drug approved for human use and with a known clinical profile, was recently shown to be an inhibitor of angiogenesis in vitro and exhibited tumor growth inhibition in mice. Here we describe the synthesis and in vitro evaluation of a series of N-alkylated analogues of levamisole with the aim of characterizing structure-activity relationships with regard to inhibition of angiogenesis. N-methyllevamisole and p-bromolevamisole proved more effective than the parent compound, (S-levamisole hydrochloride, with respect to inhibition of angiogenesis and induction of undifferentiated cluster morphology in human umbilical vein endothelial cells grown in co-culture with normal human dermal fibroblasts. Interestingly, the cluster morphology caused by N-methyllevamisole was different than the clusters observed for levamisole, and a third "cord-like" morphology resembling that of the known drug suramin was observed for an aniline-containing derivative. New chemotypes exhibiting antiangiogenic effects in vitro are thus described, and further investigation of their underlying mechanism of action is warranted.

  17. Novel amide derivatives as inhibitors of histone deacetylase: design, synthesis and SAR

    DEFF Research Database (Denmark)

    Andrianov, V.; Gailite, V.; Lola, D.;

    2009-01-01

    Enzymatic inhibition of histone deacetylase (HDAC) activity is emerging as an innovative and effective approach for the treatment of cancer. A series of novel amide derivatives have been synthesized and evaluated for their ability to inhibit human HDACs. Multiple compounds were identified as pote...

  18. Preparation and spectrometric identification of amide derivatives with antimalaric

    International Nuclear Information System (INIS)

    The structures of polymeric compounds using spectrometric analysis of infrared, ultraviolet and protonic magnetic resonance and 13C nuclear magnetic resonance are studied. Some structural models are used such as antimalaric-sulfones and pyrimidinic derivatives, and non-polymeric derivatives of active compounds. A comparative analysis on structures less complexes is shown. (M.J.C.). Spectrums 186 p

  19. Alpha-amidated peptides derived from pro-opiomelanocortin in human pituitary tumours

    DEFF Research Database (Denmark)

    Fenger, M; Johnsen, A H

    1988-01-01

    Human pituitary tumours, obtained at surgery for Cushing's disease and Nelson's syndrome, were extracted and the content and molecular forms of pro-opiomelanocortin (POMC)-derived peptides determined by radioimmunoassay, gel chromatography, reversed-phase high-performance liquid chromatography....... In conclusion, all the molecular forms of the amidated peptides detected in tumours from patients with Cushing's disease and Nelson's syndrome were similar to the molecular forms found in the normal human pituitary. The main difference between the tumours and the normal pituitary was the greater amount...... (HPLC) and sequence analysis. In the tumours from patients with Cushing's disease the mean concentrations of amidated peptides relative to the total amount of POMC were as follows: alpha-MSH, 1.7%; amidated gamma-MSH (gamma 1-MSH), 8.5% and the peptide linking gamma-MSH and ACTH in the precursor (hinge...

  20. Lanthanide(III) complexation with an amide derived pyridinophane.

    Science.gov (United States)

    Castro, Goretti; Bastida, Rufina; Macías, Alejandro; Pérez-Lourido, Paulo; Platas-Iglesias, Carlos; Valencia, Laura

    2015-02-16

    Herein we report a detailed investigation of the solid state and solution structures of lanthanide(III) complexes with the 18-membered pyridinophane ligand containing acetamide pendant arms TPPTAM (TPPTAM = 2,2',2″-(3,7,11-triaza-1,5,9(2,6)-tripyridinacyclododecaphane-3,7,11-triyl)triacetamide). The ligand crystallizes in the form of a clathrated hydrate, where the clathrated water molecule establishes hydrogen-bonding interactions with the amide NH groups and two N atoms of the macrocycle. The X-ray structures of 13 different Ln(3+) complexes obtained as the nitrate salts (Ln(3+) = La(3+)-Yb(3+), except Pm(3+)) have been determined. Additionally, the X-ray structure of the La(3+) complex obtained as the triflate salt was also obtained. In all cases the ligand provides 9-fold coordination to the Ln(3+) ion, ten coordination being completed by an oxygen atom of a coordinated water molecule or a nitrate or triflate anion. The bond distances of the metal coordination environment show a quadratic change along the lanthanide series, as expected for isostructural series of Ln(3+) complexes. Luminescence lifetime measurements obtained from solutions of the Eu(3+) and Tb(3+) complexes in H2O and D2O point to the presence of a water molecule coordinated to the metal ion in aqueous solutions. The analysis of the Ln(3+)-induced paramagnetic shifts indicates that the complexes are ten-coordinated throughout the lanthanide series from Ce(3+) to Yb(3+), and that the solution structure is very similar to the structures observed in the solid state. The complexes of the light Ln(3+) ions are fluxional due to a fast Δ(λλλλλλ) ↔ Λ(δδδδδδ) interconversion that involves the inversion of the macrocyclic ligand and the rotation of the acetamide pendant arms. The complexes of the small Ln(3+) ions are considerably more rigid, the activation free energy determined from VT (1)H NMR for the Lu(3+) complex being ΔG(⧧)298 = 72.4 ± 5.1 kJ mol(-1).

  1. Synthesis and Biological Investigation of some Novel Sulfonamide and Amide Derivatives Containing Coumarin Moieties

    OpenAIRE

    Saeedi, Mina; Goli, Fereshteh; Mahdavi, Mohammad; Dehghan, Gholamreza; Faramarzi, Mohammad Ali; Foroumadi, Alireza; Shafiee, Abbas

    2014-01-01

    New sulfonamide and amide derivatives containing coumarin moieties; oxo-2H-chromen-sulfamoylphenylacetamides and oxo-2H-chromen-arylacetamides were synthesized starting from diverse 2-chloroacetamide derivatives and a wide range of coumarins. The structures of compounds were elucidated by IR and NMR spectra and also analytical elemental analysis. In the next step, the above mentioned compounds were screened for their antimicrobial and antioxidant activities. Their antimicrobial activity was a...

  2. Anti-proliferative activity of Monensin and its tertiary amide derivatives.

    Science.gov (United States)

    Huczyński, Adam; Klejborowska, Greta; Antoszczak, Michał; Maj, Ewa; Wietrzyk, Joanna

    2015-10-15

    New tertiary amide derivatives of polyether ionophore Monensin A (MON) were synthesised and their anti-proliferative activity against cancer cell lines was studied. Very high activity (IC50=0.09 μM) and selectivity (SI=232) of MON against human biphenotypic myelomonocytic leukemia cell line (MV4-11) was demonstrated. The MON derivatives obtained exhibit interesting anti-proliferative activity, high selectivity index and also are able to break the drug-resistance of cancer cell line.

  3. Solvent-Driven Conformational Exchange for Amide-Linked Bichromophoric BODIPY Derivatives.

    Science.gov (United States)

    Thakare, Shrikant; Stachelek, Patrycja; Mula, Soumyaditya; More, Ankush B; Chattopadhyay, Subrata; Ray, Alok K; Sekar, Nagaiyan; Ziessel, Raymond; Harriman, Anthony

    2016-09-26

    The fluorescence lifetime and quantum yield are seen to depend in an unexpected manner on the nature of the solvent for a pair of tripartite molecules composed of two identical boron dipyrromethene (BODIPY) residues attached to a 1,10-phenanthroline core. A key feature of these molecular architectures concerns the presence of an amide linkage that connects the BODIPY dye to the heterocyclic platform. The secondary amide derivative is more sensitive to environmental change than is the corresponding tertiary amide. In general, increasing solvent polarity, as measured by the static dielectric constant, above a critical threshold tends to reduce fluorescence but certain hydrogen bond accepting solvents exhibit anomolous behaviour. Fluorescence quenching is believed to arise from light-induced charge transfer between the two BODIPY dyes, but thermodynamic arguments alone do not explain the experimental findings. Molecular modelling is used to argue that the conformation changes in strongly polar media in such a way as to facilitate improved rates of light-induced charge transfer. These solvent-induced changes, however, differ remarkably for the two types of amide. PMID:27529596

  4. A new feruloyl amide derivative from the fruits of Tribulus terrestris.

    Science.gov (United States)

    Zhang, Xiaopo; Wei, Na; Huang, Jian; Tan, Yinfeng; Jin, Dejun

    2012-01-01

    A new feruloyl amide derivative, named tribulusamide C, was isolated from the fruits of Tribulus terrestris. Its structure was determined on the basis of spectroscopic analysis including IR, 1-D-, 2-D-NMR and HR-ESI-MS. The structure of tribulusamide C was characterised by a unit of pyrrolidine-2,5-dione, which distinguished it from other lignanamides previously isolated from the fruits of T. terrestris. PMID:22149942

  5. Direct amidation of amino acid derivatives catalyzed by arylboronic acids : applications in dipeptide synthesis.

    OpenAIRE

    Liu, S.; Yang, Y.; Liu, X.; Ferdousi, F. K.; Batsanov, A.S.; Whiting, A

    2013-01-01

    The direct amidation of amino acid derivatives catalyzed by arylboronic acids has been examined. The reaction was generally slow relative to simple amine-carboxylic acid combinations though proceeded at 65–68 °C generally avoiding racemization. 3,4,5-Trifluorophenylboronic and o-nitrophenylboronic acids were found to be the best catalysts, though for slower dipeptide formations, high catalyst loadings were required and an interesting synergistic catalytic effect between two arylboronic acids ...

  6. Alkyl, hydride, and related bis(trimethylsilyl)-amide derivatines of the 4f- and 5f-block metals

    International Nuclear Information System (INIS)

    Physical properties (magnetic susceptibility, NMR, crystal structure, etc.) are reviewed for trivalent lanthanide/actinide derivatives, divalent lanthanide derivatives, and tetravalent actinide derivatives

  7. Effect of successive alkylation of N,N-dialkyl amides on the complexation behavior of uranium and thorium: solvent extraction, small angle neutron scattering, and computational studies.

    Science.gov (United States)

    Verma, Parveen Kumar; Pathak, Priyanath N; Kumari, Neelam; Sadhu, Biswajit; Sundararajan, Mahesh; Aswal, Vinod Kumar; Mohapatra, Prasanta Kumar

    2014-12-11

    The effect of successive alkylation of the Cα atom adjacent to the carbonyl group in N,N-dialkyl amides (i.e., di(2-ethylhexyl)acetamide (D2EHAA), di(2-ethylhexyl)propionamide (D2EHPRA), di(2-ethylhexyl)isobutyramide (D2EHIBA), and di(2-ethylhexyl)pivalamide (D2EHPVA)) on the extraction behavior of hexavalent uranium (U(VI)) and tetravalent thorium (Th(IV)) ions has been investigated. These studies show that the extraction of Th(IV) is significantly suppressed compared to that of U(VI) with increased branching at the Cα atom adjacent to the carbonyl group. Small angle neutron scattering (SANS) studies showed an increased aggregation tendency in the presence of nitric acid and metal ions. D2EHAA showed more aggregation compared to its branched homologues, which explains its capacity for higher extraction of metal ions. These experimental observations were further supported by density function theory calculations, which provided structural evidence of differential binding affinities of these extractants for uranyl cations. The complexation process is primarily controlled by steric and electronic effects. Quantum chemical calculations showed that local hardness and polarizability can be extremely useful inputs for designing novel extractants relevant to a nuclear fuel cycle.

  8. Effect of successive alkylation of N,N-dialkyl amides on the complexation behavior of uranium and thorium: solvent extraction, small angle neutron scattering, and computational studies.

    Science.gov (United States)

    Verma, Parveen Kumar; Pathak, Priyanath N; Kumari, Neelam; Sadhu, Biswajit; Sundararajan, Mahesh; Aswal, Vinod Kumar; Mohapatra, Prasanta Kumar

    2014-12-11

    The effect of successive alkylation of the Cα atom adjacent to the carbonyl group in N,N-dialkyl amides (i.e., di(2-ethylhexyl)acetamide (D2EHAA), di(2-ethylhexyl)propionamide (D2EHPRA), di(2-ethylhexyl)isobutyramide (D2EHIBA), and di(2-ethylhexyl)pivalamide (D2EHPVA)) on the extraction behavior of hexavalent uranium (U(VI)) and tetravalent thorium (Th(IV)) ions has been investigated. These studies show that the extraction of Th(IV) is significantly suppressed compared to that of U(VI) with increased branching at the Cα atom adjacent to the carbonyl group. Small angle neutron scattering (SANS) studies showed an increased aggregation tendency in the presence of nitric acid and metal ions. D2EHAA showed more aggregation compared to its branched homologues, which explains its capacity for higher extraction of metal ions. These experimental observations were further supported by density function theory calculations, which provided structural evidence of differential binding affinities of these extractants for uranyl cations. The complexation process is primarily controlled by steric and electronic effects. Quantum chemical calculations showed that local hardness and polarizability can be extremely useful inputs for designing novel extractants relevant to a nuclear fuel cycle. PMID:25422857

  9. Synthesis and biological evaluation of some new amide moiety bearing quinoxaline derivatives as antimicrobial agents.

    Science.gov (United States)

    Abu Mohsen, U; Yurttaş, L; Acar, U; Özkay, Y; Kaplacikli, Z A; Karaca Gencer, H; Cantürk, Z

    2015-05-01

    In this study, we aimed to synthesize some new quinoxaline derivatives bearing amide moiety and to evaluate their antimicrobial activity. A set of 16 novel compounds of N-[2,3-bis(4-methoxy/methylphenyl)quinoxalin-6-yl]-substituted benzamide derivatives were synthesized by reacting 2,3-bis(4-methoxyphenyl)-6-aminoquinoxaline or 2,3-bis(4-methylphenyl)-6-aminoquinoxaline with benzoyl chloride derivatives in tetrahydrofuran and investigated for their antimicrobial activity. The structures of the obtained final compounds were confirmed by spectral data (IR, (1)H-NMR, (13)C-NMR and MS). The antimicrobial activity of the compounds were determined by using the microbroth dilution method. Antimicrobial activity results revealed that synthesized compounds exhibited remarkable activity against Candida krusei (ATCC 6258) and Candida parapsilosis (ATCC 22019).

  10. Synthesis and Biological Investigation of some Novel Sulfonamide and Amide Derivatives Containing Coumarin Moieties.

    Science.gov (United States)

    Saeedi, Mina; Goli, Fereshteh; Mahdavi, Mohammad; Dehghan, Gholamreza; Faramarzi, Mohammad Ali; Foroumadi, Alireza; Shafiee, Abbas

    2014-01-01

    New sulfonamide and amide derivatives containing coumarin moieties; oxo-2H-chromen-sulfamoylphenylacetamides and oxo-2H-chromen-arylacetamides were synthesized starting from diverse 2-chloroacetamide derivatives and a wide range of coumarins. The structures of compounds were elucidated by IR and NMR spectra and also analytical elemental analysis. In the next step, the above mentioned compounds were screened for their antimicrobial and antioxidant activities. Their antimicrobial activity was assigned using the conventional agar dilution method and the antioxidant activity was assessed using two methods, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method and ferric reducing antioxidant power (FRAP) assay. Although the compounds showed no remarkable antimicrobial activities, most of them exhibited good antioxidant activities. Compounds 5b showed the most potent DPPH activity, whereas 8c was the most efficient compound in FRAP assay. PMID:25276188

  11. Synthesis and Antiangiogenic Activity of N-Alkylated Levamisole Derivatives

    DEFF Research Database (Denmark)

    Hansen, Anders N.; Bendiksen, Christine D.; Sylvest, Lene;

    2012-01-01

    -culture with normal human dermal fibroblasts. Interestingly, the cluster morphology caused by N-methyllevamisole was different than the clusters observed for levamisole, and a third "cord-like" morphology resembling that of the known drug suramin was observed for an aniline-containing derivative. New chemotypes...... exhibiting antiangiogenic effects in vitro are thus described, and further investigation of their underlying mechanism of action is warranted....

  12. Syntheses and metal ions recognition of dendritic calix[n]arenes(n=6,8)amide derivative

    Institute of Scientific and Technical Information of China (English)

    WANG Yunyan; CAI Yahua; YAN Chaoguo

    2007-01-01

    Dendritic p-t'butylcalix[n]arene amide derivatives with terminal amino groups of the first and second generations were synthesized by using divergent methods from ammonolysis of ethyl calixarylacetate with 1,6-diaminohexane and Michael addition of methyl acrylate.Their structures were confirmed by IR,1H NMR.The recognition properties of these amide derivatives for several kinds of metal ions were studied with UV-Vis spectroscopy.The results showed a great affinity for soft Ag+ and UO22+ ions and formed 1:2 or 1:3 stoichiometric complexes.

  13. Synthesis and pharmacology of N-alkylated derivatives of the excitotoxin ibotenic acid

    DEFF Research Database (Denmark)

    Madsen, U; Dumpis, M A; Bräuner-Osborne, Hans;

    1998-01-01

    Three amino-alkylated derivatives of the naturally occurring excitatory amino acid (EAA) receptor agonist ibotenic acid (Ibo) have been synthesized and tested pharmacologically. N-Methyl-Ibo (1a) and N-ethyl-Ibo (1b) were shown to be agonists at NMDA receptors (EC50 = 140 and 320 microM, respecti......Three amino-alkylated derivatives of the naturally occurring excitatory amino acid (EAA) receptor agonist ibotenic acid (Ibo) have been synthesized and tested pharmacologically. N-Methyl-Ibo (1a) and N-ethyl-Ibo (1b) were shown to be agonists at NMDA receptors (EC50 = 140 and 320 micro......-c and the potent NMDA agonist 2-amino-2-(3-hydroxy-5-methyl-4-isoxazolyl)acetic acid (AMAA) in order to elucidate the observed structure-activity data....

  14. N-Alkylation by Hydrogen Autotransfer Reactions.

    Science.gov (United States)

    Ma, Xiantao; Su, Chenliang; Xu, Qing

    2016-06-01

    Owing to the importance of amine/amide derivatives in all fields of chemistry, and also the green and environmentally benign features of using alcohols as alkylating reagents, the relatively high atom economic dehydrative N-alkylation reactions of amines/amides with alcohols through hydrogen autotransfer processes have received much attention and have developed rapidly in recent decades. Various efficient homogeneous and heterogeneous transition metal catalysts, nano materials, electrochemical methods, biomimetic methods, asymmetric N-alkylation reactions, aerobic oxidative methods, and even certain transition metal-free, catalyst-free, or autocatalyzed methods, have also been developed in recent years. With a brief introduction to the background and developments in this area of research, this chapter focuses mainly on recent progress and technical and conceptual advances contributing to the development of this research in the last decade. In addition to mainstream research on homogeneous and heterogeneous transition metal-catalyzed reactions, possible mechanistic routes for hydrogen transfer and alcohol activation, which are key processes in N-alkylation reactions but seldom discussed in the past, the recent reports on computational mechanistic studies of the N-alkylation reactions, and the newly emerged N-alkylation methods based on novel alcohol activation protocols such as air-promoted reactions and transition metal-free methods, are also reviewed in this chapter. Problems and bottlenecks that remained to be solved in the field, and promising new research that deserves greater future attention and effort, are also reviewed and discussed. PMID:27573267

  15. Formation of carboxy- and amide-terminated alkyl monolayers on silicon(111) investigated by ATR-FTIR, XPS, and X-ray scattering: Construction of photoswitchable surfaces

    DEFF Research Database (Denmark)

    Rück-Braun, Karola; Petersen, Michael Åxman; Michalik, Fabian;

    2013-01-01

    -FTIR and XPS studies of the fulgimide samples revealed closely covered amide-terminated SAMs. Reversible photoswitching of the headgroup was read out by applying XPS, ATR-FTIR, and difference absorption spectra in the mid-IR. In XPS, we observed a reversible breathing of the amide/imide C1s and N1s signals...

  16. Thermodynamic Interactions between Polystyrene and Long-Chain Poly(n-Alkyl Acrylates) Derived from Plant Oils.

    Science.gov (United States)

    Wang, Shu; Robertson, Megan L

    2015-06-10

    Vegetable oils and their fatty acids are promising sources for the derivation of polymers. Long-chain poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) are readily derived from fatty acids through conversion of the carboxylic acid end-group to an acrylate or methacrylate group. The resulting polymers contain long alkyl side-chains with around 10-22 carbon atoms. Regardless of the monomer source, the presence of alkyl side-chains in poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) provides a convenient mechanism for tuning their physical properties. The development of structured multicomponent materials, including block copolymers and blends, containing poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) requires knowledge of the thermodynamic interactions governing their self-assembly, typically described by the Flory-Huggins interaction parameter χ. We have investigated the χ parameter between polystyrene and long-chain poly(n-alkyl acrylate) homopolymers and copolymers: specifically we have included poly(stearyl acrylate), poly(lauryl acrylate), and their random copolymers. Lauryl and stearyl acrylate were chosen as model alkyl acrylates derived from vegetable oils and have alkyl side-chain lengths of 12 and 18 carbon atoms, respectively. Polystyrene is included in this study as a model petroleum-sourced polymer, which has wide applicability in commercially relevant multicomponent polymeric materials. Two independent methods were employed to measure the χ parameter: cloud point measurements on binary blends and characterization of the order-disorder transition of triblock copolymers, which were in relatively good agreement with one another. The χ parameter was found to be independent of the alkyl side-chain length (n) for large values of n (i.e., n > 10). This behavior is in stark contrast to the n-dependence of the χ parameter predicted from solubility parameter theory. Our study complements prior work investigating the interactions between

  17. Thermodynamic Interactions between Polystyrene and Long-Chain Poly(n-Alkyl Acrylates) Derived from Plant Oils.

    Science.gov (United States)

    Wang, Shu; Robertson, Megan L

    2015-06-10

    Vegetable oils and their fatty acids are promising sources for the derivation of polymers. Long-chain poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) are readily derived from fatty acids through conversion of the carboxylic acid end-group to an acrylate or methacrylate group. The resulting polymers contain long alkyl side-chains with around 10-22 carbon atoms. Regardless of the monomer source, the presence of alkyl side-chains in poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) provides a convenient mechanism for tuning their physical properties. The development of structured multicomponent materials, including block copolymers and blends, containing poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) requires knowledge of the thermodynamic interactions governing their self-assembly, typically described by the Flory-Huggins interaction parameter χ. We have investigated the χ parameter between polystyrene and long-chain poly(n-alkyl acrylate) homopolymers and copolymers: specifically we have included poly(stearyl acrylate), poly(lauryl acrylate), and their random copolymers. Lauryl and stearyl acrylate were chosen as model alkyl acrylates derived from vegetable oils and have alkyl side-chain lengths of 12 and 18 carbon atoms, respectively. Polystyrene is included in this study as a model petroleum-sourced polymer, which has wide applicability in commercially relevant multicomponent polymeric materials. Two independent methods were employed to measure the χ parameter: cloud point measurements on binary blends and characterization of the order-disorder transition of triblock copolymers, which were in relatively good agreement with one another. The χ parameter was found to be independent of the alkyl side-chain length (n) for large values of n (i.e., n > 10). This behavior is in stark contrast to the n-dependence of the χ parameter predicted from solubility parameter theory. Our study complements prior work investigating the interactions between

  18. Microcalorimetric Study on the Inhibition of Escherichia coil by Some Novel Pyridine Amide Schiff Base Derivatives

    Institute of Scientific and Technical Information of China (English)

    LI Chao-Hong; ZHANG Li-Xia; CAI Li-Hua; LIU Yi; HU Pei-Zhi

    2008-01-01

    The antibacterial effect of a series of novel pyridine amide Schiff base compounds on Escherichia coli was investigated by a microcalorimetric method at 37℃.The metabolic power-time curves of the bacteria treated by the compounds were obtained,and the thermokinetic parameters were analyzed,from which the antibacterial activities of these compounds were evaluated.The results show that two compounds F and G have good activity on aerobic multiplying metabolism of E.coli,with the value of IC50 106 and 113 mg/L respectively,but have no effective action on the fermentation metabolism of E.coli.The action of the compounds on the non-multiplying metabolism was investigated by taking the heat output of E.coli in the stationary phase as the guideline of the activity.The experimental results revealed that the hydrophilicity of these Schiff bases had a great influence on their antibacterial activity,which results from the bacterial cell wall structure.The antibacterial structure-activity relationship of these Schiff base derivatives was also briefly discussed.The antibacterial activity of the compounds against E.coli was as follows:compound F>G>C>D>E>B>A.

  19. [Synthesis and anti-proliferative activity of fluoroquinolone (rhodanine unsaturated ketone) amide derivatives].

    Science.gov (United States)

    Gao, Liu-zhou; Xie, Yu-suo; Yan, Qiang; Wu, Shu-min; Ni, Li-li; Zhao, Hui; Huang, Wen-long; Hu, Guo-qiang

    2015-08-01

    To discover novel antitumor rhodanine unsaturated ketones, a series of fluoroquinolone (rhodanine α, β-unsaturated ketone) amine derivatives (5a-5r) were designed and synthesized with fluoroquinolone amide scaffold as a carrier. The structures of eighteen title compounds were characterized by elemental analysis, 1H NMR and MS. The in vitro anti-proliferative activity against Hep-3B, Capan-1 and HL60 cells was evaluated by MTT assay. The results showed that the title compounds not only had more significant anti-proliferative activity against three tested cancer cell lines than that of the parent ciprofloxacin 1, but also exhibited the highest activity against Capan-1 cells. The SAR revealed that some compounds carrying aromatic heterocyclic rings or phenyl attached to an electron-withdrawing carboxyl or sulfonamide substituent were comparable to or better than comparison doxorubicin against Capan-1 cells. As such, it suggests that fluoroquinolone (rhodanine α, β-unsaturated ketone) amines are promising leads for the development of novel antitumor fluoroquinolones or rhodanine analogues. PMID:26669001

  20. Versatile Biodegradable Poly(ester amides Derived from α-Amino Acids for Vascular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Pooneh Karimi

    2010-03-01

    Full Text Available Biodegradable poly(ester amide (PEA biomaterials derived from α-amino acids, diols, and diacids are promising materials for biomedical applications such as tissue engineering and drug delivery because of their optimized properties and susceptibility for either hydrolytic or enzymatic degradation. The objective of this work was to synthesize and characterize biodegradable PEAs based on the α-amino acids L-phenylalanine and L-methionine. Four different PEAs were prepared using 1,4-butanediol, 1,6-hexanediol, and sebacic acid by interfacial polymerization. High molecular weight PEAs with narrow polydispersity indices and excellent film-forming properties were obtained. The incubation of these PEAs in PBS and chymotrypsin indicated that the polymers are biodegradable. Human coronary artery smooth muscle cells were cultured on PEA films for 48 h and the results showed a well-spread morphology. Porous 3D scaffolds fabricated from these PEAs were found to have excellent porosities indicating the utility of these polymers for vascular tissue engineering.

  1. SYNTHESIS OF BIOLOGICALLY ACTIVE 2-CHLORO-N-ALKYL/ARYL ACETAMIDE DERIVATIVES

    OpenAIRE

    S.A.Katke; S.V.Amrutkar; R.J.Bhor; M.V.Khairnar

    2011-01-01

    Medicinal chemistry plays an important role in development of drug for cure; maintain and improved health of human being. It is also equally important to design chemical entities for prevent the growth of micro-organism, which come in contact with human being in day-to-day life. We have synthesized 2-chloro-N-alkyl/aryl Acetamide derivatives with an aim as new bioactive agent, which can be used as anti microbial agents such as herbicides, antifungal, disinfectant. The present study involves t...

  2. N-Alkyl Carbazole Derivatives as New Tools for Alzheimer’s Disease: Preliminary Studies

    Directory of Open Access Journals (Sweden)

    Carmela Saturnino

    2014-07-01

    Full Text Available Alzheimer’s disease (AD is a progressive and age-related neurodegenerative disorder affecting brain cells and is the most common form of “dementia”, because of the cognitive detriment which takes place. Neuronal disruption represents its major feature, due to the cytosolic accumulation of amyloid β-peptide (Aβ which leads to senile plaques formation and intracellular neurofibrillary tangles. Many studies have focused on the design and therapeutic use of new molecules able to inhibit Aβ aggregation. In this context, we evaluated the ability of two recently synthesized series of N-alkyl carbazole derivatives to increase the Aβ soluble forms, through molecular docking simulations and in vitro experiments. Our data evidenced that two carbazole derivatives, the most active, adopt distinct binding modes involving key residues for Aβ fibrillization. They exhibit a good interfering activity on Aβ aggregation in mouse (N2a cells, stably expressing wild-type human amyloid precursor protein (APP 695. These preliminary results are promising and we are confident that the N-alkyl carbazole derivatives may encourage next future studies needed for enlarging the knowledge about the AD disease approach.

  3. Structures of Plutonium(IV) and Uranium(VI) with N,N-Dialkyl Amides from Crystallography, X-ray Absorption Spectra, and Theoretical Calculations.

    Science.gov (United States)

    Acher, Eléonor; Hacene Cherkaski, Yanis; Dumas, Thomas; Tamain, Christelle; Guillaumont, Dominique; Boubals, Nathalie; Javierre, Guilhem; Hennig, Christoph; Solari, Pier Lorenzo; Charbonnel, Marie-Christine

    2016-06-01

    The structures of plutonium(IV) and uranium(VI) ions with a series of N,N-dialkyl amides ligands with linear and branched alkyl chains were elucidated from single-crystal X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), and theoretical calculations. In the field of nuclear fuel reprocessing, N,N-dialkyl amides are alternative organic ligands to achieve the separation of uranium(VI) and plutonium(IV) from highly concentrated nitric acid solution. EXAFS analysis combined with XRD shows that the coordination structure of U(VI) is identical in the solution and in the solid state and is independent of the alkyl chain: two amide ligands and four bidentate nitrate ions coordinate the uranyl ion. With linear alkyl chain amides, Pu(IV) also adopt identical structures in the solid state and in solution with two amides and four bidentate nitrate ions. With branched alkyl chain amides, the coordination structure of Pu(IV) was more difficult to establish unambiguously from EXAFS. Density functional theory (DFT) calculations were consequently performed on a series of structures with different coordination modes. Structural parameters and Debye-Waller factors derived from the DFT calculations were used to compute EXAFS spectra without using fitting parameters. By using this methodology, it was possible to show that the branched alkyl chain amides form partly outer-sphere complexes with protonated ligands hydrogen bonded to nitrate ions. PMID:27171842

  4. New optically active poly(amide-imide)s derived from N,N'-(4,4-diphthaloyl)-bis-L-leucine and hydantoin derivatives: Synthesis and properties

    Institute of Scientific and Technical Information of China (English)

    Khalil Faghihi

    2009-01-01

    Six new optically active poly(amide-imide)s (5a-f) were synthesized through the direct polycondensation reaction of N,N'-(4,4'-diphthaloyl)-bis-L-leucine (3) with six hydantoin derivatives (4a-f). Triphenyl phosphlte (TPP)/pyridine in the presence of calcium chloride (CaCl_2) and N-methyl-2-pyrrolidone (NMP) were successfully applied for direct polycondensation. The polycondensation reactions produce a series of new poly(amide-imide)s (Sa-f) in high yields, and inherent viscosity between 0.42 and 0.55 dL/g. The resulting poly(amide-imide)s (Sa-f) were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA and DTG), solubility test and FT-IR spectroscopy.

  5. Pharmacological Classification and Activity Evaluation of Furan and Thiophene Amide Derivatives Applying Semi-Empirical ab initio Molecular Modeling Methods

    OpenAIRE

    Leszek Bober; Tomasz Baczek; Piotr Kawczak

    2012-01-01

    Pharmacological and physicochemical classification of the furan and thiophene amide derivatives by multiple regression analysis and partial least square (PLS) based on semi-empirical ab initio molecular modeling studies and high-performance liquid chromatography (HPLC) retention data is proposed. Structural parameters obtained from the PCM (Polarizable Continuum Model) method and the literature values of biological activity (antiproliferative for the A431 cells) expressed...

  6. Nanostructures and Self-Assembly of Organogels via Benzimidazole/Benzothiazole Imide Derivatives with Different Alkyl Substituent Chains

    Directory of Open Access Journals (Sweden)

    Xihai Shen

    2013-01-01

    Full Text Available New benzimidazole/benzothiazole imide derivatives with different alkyl substituent chains were designed and synthesized. Their gelation behaviors in 22 solvents were tested as novel low-molecular-mass organic gelators. The test showed that the alkyl substituent chains and headgroups of benzimidazole/benzothiazole residues in gelators played a crucial role in the gelation behavior of all compounds in various organic solvents. More alkyl chains in molecular skeletons in present gelators are favorable for the gelation of organic solvents. SEM and AFM observations revealed that the gelator molecules self-assemble into different aggregates from wrinkle, lamella and belt to dot with change of solvents. Spectral studies indicated that there existed different H-bond formation between imide groups and hydrophobic force of alkyl substituent chains in molecular skeletons. The present work may give some insights into design and character of new organogelators and soft materials with special molecular structures.

  7. One-pot synthesis and antifungal activity against plant pathogens of quinazolinone derivatives containing an amide moiety.

    Science.gov (United States)

    Zhang, Jin; Liu, Jia; Ma, Yangmin; Ren, Decheng; Cheng, Pei; Zhao, Jiawen; Zhang, Fan; Yao, Yuan

    2016-05-01

    An efficient one-pot, three-component synthesis of quinazolinone derivatives containing 3-acrylamino motif was carried out using CeO2 nanoparticles as catalyst. Thirty-nine synthesized compounds were obtained with satisfied yield and elucidated by spectroscopic analysis. Four phytopathogenic fungi were chosen to test the antifungal activities by minimum inhibitory concentration (MIC) method. Compounds 4ag, 4bb, 4bc showed broad antifungal activities against at least three fungi, and dramatic effects of substituents on the activities were observed. Docking studies were established to explore the potential antifungal mechanism of quinazolinone derivatives as the chitinase inhibitors, and also verified the importance of the amide moiety. PMID:27040656

  8. Protein structure validation and refinement using amide proton chemical shifts derived from quantum mechanics

    DEFF Research Database (Denmark)

    Christensen, Anders Steen; Linnet, Troels Emtekær; Borg, Mikael;

    2013-01-01

    We present the ProCS method for the rapid and accurate prediction of protein backbone amide proton chemical shifts - sensitive probes of the geometry of key hydrogen bonds that determine protein structure. ProCS is parameterized against quantum mechanical (QM) calculations and reproduces high level...

  9. Amide, urea and thiourea-containing triphenylene derivatives: influence of H-bonding on mesomorphic properties

    NARCIS (Netherlands)

    Paraschiv, I.; Tomkinson, A.; Giesbers, M.; Sudhölter, E.J.R.; Zuilhof, H.; Marcelis, A.T.M.

    2007-01-01

    The synthesis and thermotropic properties are reported for a series of hexaalkoxytriphenylenes that contain an amide, urea or thiourea group in one of their alkoxy tails. The intermolecular hydrogen bonding abilities of these molecules have a disturbing influence on the formation and stability of th

  10. Inhibition of fatty acid amide hydrolase and cyclooxygenase by the N-(3-methylpyridin-2-yl)amide derivatives of flurbiprofen and naproxen.

    Science.gov (United States)

    Cipriano, Mariateresa; Björklund, Emmelie; Wilson, Alan A; Congiu, Cenzo; Onnis, Valentina; Fowler, Christopher J

    2013-11-15

    Inhibitors of the metabolism of the endogenous cannabinoid ligand anandamide by fatty acid amide hydrolase (FAAH) reduce the gastric damage produced by non-steroidal anti-inflammatory agents and synergise with them in experimental pain models. This motivates the design of compounds with joint FAAH/cyclooxygenase (COX) inhibitory activity. Here we present data on the N-(3-methylpyridin-2-yl)amide derivatives of flurbiprofen and naproxen (Flu-AM1 and Nap-AM1, respectively) with respect to their properties towards these two enzymes. Flu-AM1 and Nap-AM1 inhibited FAAH-catalysed hydrolysis of [(3)H]anandamide by rat brain homogenates with IC50 values of 0.44 and 0.74 µM. The corresponding values for flurbiprofen and naproxen were 29 and >100 µM, respectively. The inhibition by Flu-AM1 was reversible, mixed-type, with K(i)slope and K(i)intercept values of 0.21 and 1.4 µM, respectively. Flurbiprofen and Flu-AM1 both inhibited COX in the same manner with the order of potencies COX-2 vs. 2-arachidonoylglycerol>COX-1 vs. arachidonic acid>COX-2 vs. arachidonic acid with flurbiprofen being approximately 2-3 fold more potent than Flu-AM1 in the assays. Nap-AM1 was a less potent inhibitor of COX. Flu-AM1 at low micromolar concentrations inhibited the FAAH-driven uptake of [(3)H]anandamide into RBL2H3 basophilic leukaemia cells in vitro, but did not penetrate the brain in vivo sufficiently to block the binding of [(18)F]DOPP to brain FAAH. It is concluded that Flu-AM1 is a dual-action inhibitor of FAAH and COX that may be useful in exploring the optimal balance of effects on these two enzyme systems in producing peripheral alleviation of pain and inflammation in experimental models.

  11. Corrosion inhibition efficiency of linear alkyl benzene derivatives for carbon steel pipelines in 1M HCl

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2011-06-01

    Full Text Available Linear alkyl benzene sulfonic acid (L and three of its ester derivatives (L1, L2, L3 were prepared, followed by quaternization of these esters (L1Q, L2Q, L3Q. The corrosion inhibition effect on carbon steel in 1 M HCl was studied using weight loss and potentiodynamic polarization measurements. The adsorption of the inhibitors on carbon steel surface obeyed the Langmuir’s adsorption isotherm. The associated activation energy of corrosion and other thermodynamic parameters such as enthalpy (ΔH∗, entropy (ΔS∗ of activation, adsorption–desorption equilibrium constant (Kads, standard free energy of adsorption (ΔGoads, heat (ΔHoads, and entropy of adsorption (ΔSoads were calculated to elaborate the corrosion inhibition mechanism.

  12. Synthesis of Poly(aryl amide imide)s Derived from o-diphenyltrimellitic Anhydride

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The synthesis and characterization of a series of novel poly(aryl amide imide)s based on o-diphenyltrimellitic anhydride are described.The poly(aryl amide-imide)s having inherent viscosities of 0.39-1.43dL/g in N-methyl-2-pyrrolidinone at 30℃,were prepared by polymerization with aromatic diamines in N,N-dimethylacetamide and subsequent chemical imidization.All the polymers were amorphous,readily soluble in aprotic polar solvents such as DMAC,NMP,DMF,DMSO,and m-cresol,and could be cast to form flexible and tough films.The glass trsanition temperatures were in the range of 284-336℃,and the temperatures for 5% weight loss in nitrogen were above 468℃.

  13. Protein structure validation and refinement using amide proton chemical shifts derived from quantum mechanics.

    Directory of Open Access Journals (Sweden)

    Anders S Christensen

    Full Text Available We present the ProCS method for the rapid and accurate prediction of protein backbone amide proton chemical shifts--sensitive probes of the geometry of key hydrogen bonds that determine protein structure. ProCS is parameterized against quantum mechanical (QM calculations and reproduces high level QM results obtained for a small protein with an RMSD of 0.25 ppm (r = 0.94. ProCS is interfaced with the PHAISTOS protein simulation program and is used to infer statistical protein ensembles that reflect experimentally measured amide proton chemical shift values. Such chemical shift-based structural refinements, starting from high-resolution X-ray structures of Protein G, ubiquitin, and SMN Tudor Domain, result in average chemical shifts, hydrogen bond geometries, and trans-hydrogen bond ((h3J(NC' spin-spin coupling constants that are in excellent agreement with experiment. We show that the structural sensitivity of the QM-based amide proton chemical shift predictions is needed to obtain this agreement. The ProCS method thus offers a powerful new tool for refining the structures of hydrogen bonding networks to high accuracy with many potential applications such as protein flexibility in ligand binding.

  14. Protein structure validation and refinement using amide proton chemical shifts derived from quantum mechanics

    CERN Document Server

    Christensen, Anders S; Borg, Mikael; Boomsma, Wouter; Lindorff-Larsen, Kresten; Hamelryck, Thomas; Jensen, Jan H

    2013-01-01

    We present the ProCS method for the rapid and accurate prediction of protein backbone amide proton chemical shifts - sensitive probes of the geometry of key hydrogen bonds that determine protein structure. ProCS is parameterized against quantum mechanical (QM) calculations and reproduces high level QM results obtained for a small protein with an RMSD of 0.25 ppm (r = 0.94). ProCS is interfaced with the PHAISTOS protein simulation program and is used to infer statistical protein ensembles that reflect experimentally measured amide proton chemical shift values. Such chemical shift-based structural refinements, starting from high-resolution X-ray structures of Protein G, ubiquitin, and SMN Tudor Domain, result in average chemical shifts, hydrogen bond geometries, and trans-hydrogen bond (h3JNC') spin-spin coupling constants that are in excellent agreement with experiment. We show that the structural sensitivity of the QM-based amide proton chemical shift predictions is needed to refine protein structures to this...

  15. Formation of 6-thioguanine and 6-mercaptopurine from their 9-alkyl derivatives in mice.

    Science.gov (United States)

    Nelson, J A; Vidale, E

    1986-01-01

    Several 9-alkyl, 6-thiopurines have been reported to have more favorable therapeutic indexes than do the parent drugs, 6-mercaptopurine (MP) and 6-thioguanine (TG). Some of these compounds were reported to be active against cells in culture resistant to 6-thiopurines, and it has been assumed that their mechanisms of action may differ from those of TG and MP. 9-(n-Butyl)-6-thioguanine was essentially inactive toward Chinese hamster ovary cells in vitro when compared with TG (50% effective dose, 250 and 1 microM, respectively). However, lethal doses of 9-(n-butyl)-6-thioguanine and TG in mice were similar when these agents were given i.p. daily for 9 consecutive days (50% lethal dose, 13 and 9 mg/kg/day). Similar organ toxicities were observed upon histopathological examination of dying animals. The cumulative, daily urinary excretion of TG was virtually identical in mice given 20- and 10-mg/kg/day of doses of 9-(n-butyl)-6-thioguanine or TG, respectively, for 9 days. The TG formed was identified by ultraviolet light (340 nm) detection following separation on a reverse phase high performance liquid chromatography system and by fluorescent detection of the permanganate oxidation product separated on a strong anion-exchange system. Dealkylation of 9-(n-butyl)-6-mercaptopurine and 9-ethyl-6-mercaptopurine also occurred in AKR mice. At near equitoxic doses, the daily cumulative urinary excretion of MP from 9-(n-butyl)-6-mercaptopurine and 9-ethyl-6-mercaptopurine was about 20-30% of that observed in mice receiving MP. The MP was confirmed in each case by enzymatic peak-shift of MP to 6-thiouric acid and ultraviolet light detection using the high performance liquid chromatography systems referred to above. The results suggest that these 9-alkyl derivatives serve as prodrugs for TG and MP, a finding that explains a number of their pharmacological and toxicological properties.

  16. Palladium-Catalyzed 6-Endo Selective Alkyl-Heck Reactions: Access to 5-Phenyl-1,2,3,6-tetrahydropyridine Derivatives.

    Science.gov (United States)

    Dong, Xu; Han, Ying; Yan, Fachao; Liu, Qing; Wang, Ping; Chen, Kexun; Li, Yueyun; Zhao, Zengdian; Dong, Yunhui; Liu, Hui

    2016-08-01

    A new type of palladium-catalyzed 6-endo-selective alkyl-Heck reaction of unactivated alkyl iodides has been described. This strategy provides efficient access to a variety of 5-phenyl-1,2,3,6-tetrahydropyridine derivatives, which are important structural motifs for bioactive molecules. This process displays a broad substrate scope with excellent 6-endo selectivity. Mechanistic investigations reveal that this alkyl-Heck reaction performs via a hybrid palladium-radical process. PMID:27409716

  17. RAPID SYNTHESIS OF NOVEL OPTICALLY ACTIVE POLY(AMIDE-IMIDE)S DERIVED FROM N,N'-(PYROMELLITOYL)-BIS-L-ALANINE DIACID CHLORIDE AND HYDANTOIN DERIVATIVES UNDER MICROWAVE IRRADIATION

    Institute of Scientific and Technical Information of China (English)

    Khalil Faghihi; Azizollah Mirsamie

    2005-01-01

    Eight novel poly(amide-imide)s were synthesized under microwave irradiation by using a domestic microwave oven from the polycondensation reactions of N,N'-(pyromellitoyl)-bis-L-alanine diacid chloride (1) with eight different derivatives of hydantoin compounds (2a-h) in the presence of a small amount of a polar organic medium such as o-cresol.The polycondensation proceeded rapidly, compared with the conventional solution polycondensation and was completed within 8-10 min, producing a series of new poly(amide-imide)s (3a-h) with inherent viscosities about 0.35-0.68 dL/g in high yields. The obtained PAIs (3a-h) were fully characterized by means of FT-IR spectroscopy, elemental analyses, inherent viscosity (ηinh), solubility and specific rotation measurements. All of the resulting polymers show optical rotation and are optically active. Thermal properties of the poly(amide-imide)s were investigated by using thermal gravimetric analysis(TGA).

  18. Synthesis, characterization and properties of novel amide derivatives based open-chain crown ether and their Tb (III) complexes

    International Nuclear Information System (INIS)

    Six amide-based open-chain crown ether and their solid complexes with terbium nitrates were synthesized. The target complexes were characterized by elemental analysis, mass spectra, EDTA titrimetric analysis, thermal analysis, molar conductivity, infrared spectra and UV–vis spectra. Luminescence properties of the ligands and the corresponding complexes in solid were studied. The results showed that the introduction of electron-donating group to the ligand enhanced the luminescence intensity of the corresponding complex, but electron-withdrawing group conversely. Meanwhile, among all complexes, the luminescence quantum yield of the complex Tb(NO3)3Y1 was highest up to 0.76. Electrochemical properties were also investigated, and the results showed that the introduction of electron-donating group to the ligand enhanced the highest occupied molecular orbit (HOMO) and the lowest unoccupied molecular orbit (LUMO) energy level, but electron-withdrawing group conversely. And these target complexes may possibly be useful for studying in organic light-emitting devices field. - Highlights: • Novel amide derivatives based open-chain crown ether and their Tb (III) complexes were prepared and characterized. • The target complexes presented high thermodynamic stability. • Influence of the substituent on luminescence intensity and electrochemical property were discussed

  19. Synthesis, characterization and properties of novel amide derivatives based open-chain crown ether and their Tb (III) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanhong; He, Wei [School of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Yang, Zehui [School of Chemical Engineering, Ningbo University of Technology, Ningbo 315016 (China); Chen, Yanwen [Hunan Labour Protection Institute of Nonferrous Metals, Changsha 410014 (China); Wang, Xinwei [School of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Guo, Dongcai, E-mail: dcguo2001@hnu.edu.cn [School of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

    2015-04-15

    Six amide-based open-chain crown ether and their solid complexes with terbium nitrates were synthesized. The target complexes were characterized by elemental analysis, mass spectra, EDTA titrimetric analysis, thermal analysis, molar conductivity, infrared spectra and UV–vis spectra. Luminescence properties of the ligands and the corresponding complexes in solid were studied. The results showed that the introduction of electron-donating group to the ligand enhanced the luminescence intensity of the corresponding complex, but electron-withdrawing group conversely. Meanwhile, among all complexes, the luminescence quantum yield of the complex Tb(NO{sub 3}){sub 3}Y{sup 1} was highest up to 0.76. Electrochemical properties were also investigated, and the results showed that the introduction of electron-donating group to the ligand enhanced the highest occupied molecular orbit (HOMO) and the lowest unoccupied molecular orbit (LUMO) energy level, but electron-withdrawing group conversely. And these target complexes may possibly be useful for studying in organic light-emitting devices field. - Highlights: • Novel amide derivatives based open-chain crown ether and their Tb (III) complexes were prepared and characterized. • The target complexes presented high thermodynamic stability. • Influence of the substituent on luminescence intensity and electrochemical property were discussed.

  20. Synthesis, Properties and Applications of Biodegradable Polymers Derived from Diols and Dicarboxylic Acids: From Polyesters to Poly(ester amides

    Directory of Open Access Journals (Sweden)

    Angélica Díaz

    2014-04-01

    Full Text Available Poly(alkylene dicarboxylates constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amides derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

  1. Synthesis of triated N1`-alkyl derivatives of the delta opioid receptor ligand naltrindole

    Energy Technology Data Exchange (ETDEWEB)

    Lever, J.R.; Johnson, S.M. [Johns Hopkins Univ. School of Hygiene and Public Health, Environmental Health Sciences Dept., Baltimore, MD (United States)

    1997-02-01

    Tritiated N1`-methyl and N1`-ethyl analogues of naltrindole (NTI) have been synthesized for evaluation as radioligands for studies of delta opioid receptors. The two N1`-alkyl-5`,7`-dibromoNTI precursors for radiolabeling were prepared by base-promoted alkylation of 2,4-dibromophenylhydrazine with either iodomethane or iodoethane followed by condensation with naltrexone using the Fischer indole synthesis. Catalytic debromotritiation followed by HPLC purification afforded [{sup 3}H]MeNTI (17.3 Ci/mmol) and [{sup 3}H]EtNTI (22.5 Ci/mmol) with high chemical and radiochemical purities ({>=} 99.8%). (author).

  2. Design and synthesis of 4-arylpiperidinyl amide and N-arylpiperdin-3-yl-cyclopropane carboxamide derivatives as novel melatonin receptor ligands.

    Science.gov (United States)

    Li, Guiying; Zhou, Hao; Jiang, Yu; Keim, Holger; Topiol, Sidney W; Poda, Suresh B; Ren, Yong; Chandrasena, Gamini; Doller, Darío

    2011-02-15

    Two series of 4-arylpiperidinyl amide and N-arylpiperdin-3-yl-cyclopropane carboxamide derivatives exhibiting diverse functionality at rat MT(1) and MT(2) receptors are reported. Compounds 11f and 18b (MT(1)/MT(2) agonist) have human microsomal intrinsic clearance comparable to ramelteon.

  3. NMR study of 1,4-dihydropyridine derivatives endowed with long alkyl and functionalized chains

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, Margarita; Salfran, Esperanza; Rodriguez, Hortensia; Coro, Julieta, E-mail: msuarez@fq.uh.c [Universidad de La Habana (Cuba). Facultad de Quimica. Lab. de Sintesis Organica; Molero, Dolores; Saez, Elena [Universidad Complutense, Madrid (Spain). CAI-RMN; Martinez-Alvarez, Roberto; Martin, Nazario [Universidad Complutense, Madrid (Spain). Facultad de Quimica. Dept. de Quimica Organica I

    2011-07-01

    The {sup 1}H , {sup 13}C and {sup 15}N NMR spectroscopic data for 1,4-dihydropyridine endowed with long alkyl and functionalized chain on C-3 and C-5, have been fully assigned by combination of one- and two dimensional experiments (DEPT, HMBC, HMQC, COSY, nOe). (author)

  4. Synthesis and evaluation of 1-alkyl-4-phenyl-[1,2,3]-triazole derivatives as antimycobacterial agent

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, Hugo; Conte, Gilmar; Bryk, Fernando [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Quimica]. E-mail: hugo@qmc.ufsc.br; Lourenco, Maria Cristina S. [Fundacao Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Instituto de Pesquisa Evandro Chagas; Costa, Marilia S.; Ferreira, Vitor F. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Quimica]. E-mail: cegvito@vm.uff.br

    2007-07-01

    Fourteen small molar mass 1-alkyl-4-phenyl-[1,2,3]-triazole derivatives were prepared using a straightforward and efficient method for the regioselective synthesis of [1,2,3]-triazoles and the compounds were screened for antimycobacterial activity against multiple-drug-resistant strains of Mycobacterium tuberculosis H37Rv. The synthetic methodology consisted of a Cu(I)-catalyzed 1,3-dipolar cycloaddition of aryl azides to terminal arylacetylenes (click-reaction). Six [1,2,3]-triazoles were found to be more active against M. tuberculosis than the positive control ethambutol. (author)

  5. Synthesis and in vivo distribution in rat brain of 11C-labelled N-alkylated ADTN derivatives

    International Nuclear Information System (INIS)

    A method for the rapid production and purification of 11C-labelled N-alkylated derivatives of the dopamine agonist 2-amino-6,7-dihydroxytetralin (ADTN) is described. The label is introduced by N-methylation with no-carrier-added 11CH3I of the corresponding secondary amines via their lithium salts. Following systemic injection in rats a uniform distribution of radioactivity in the brain was found for both the labelled 2-(N-methyl-N-n-propylamino)- and 2-(N,N-dimethylamino)-6,7-dihydroxytetralin. (author)

  6. Interaction of alkyl radicals with derivatives of 3,5-di-tret-butylpyrocatechol during radiolysis of their solutions

    International Nuclear Information System (INIS)

    Effect of 3.5-di-tret-butylpyrocatechol and its analogues on radical hexane transformations in deaerated solutions under impact of gamma-radiation is studied. It is shown that e.5-di-tret-butylpyrocatechol is by two-three times more effective by than its derivatives inhibits the formation of hexyle recombination products. It is shown by UV-, IR- and chromato-mass-spectrometry methods that adduct of alkyl radicals and 3.5-di-tret-butylpyrocatechenol has the structure of monoalkyl ether

  7. Organocatalyzed One-Step Synthesis of Functionalized N-Alkyl-Pyridinium Salts from Biomass Derived 5-Hydroxymethylfurfural.

    Science.gov (United States)

    Sowmiah, Subbiah; Veiros, Luís F; Esperança, José M S S; Rebelo, Luís P N; Afonso, Carlos A M

    2015-11-01

    An efficient and scalable method has been developed for the synthesis of N-alkylpyridinium salts from biomass derived 5-hydroxymethylfurfural and alkyl amines using a catalytic amount of formic acid. This protocol is also extended to various diamines providing the exclusive formation of mono-N-alkylpyridinium salts. In addition, the mechanism for the formation of pyridinium salts was studied by DFT and using H2(18)O isotope labeled experiments showing no incorporation of (18)O in the product. PMID:26493742

  8. L-Valine derived chiral N-sulfinamides as effective organocatalysts for the asymmetric hydrosilylation of N-alkyl and N-aryl protected ketimines.

    Science.gov (United States)

    Wang, Chao; Wu, Xinjun; Zhou, Li; Sun, Jian

    2015-01-14

    L-Valine derived N-sulfinamides have been developed as efficient enantioselective Lewis basic organocatalysts for the asymmetric reduction of N-aryl and N-alkyl ketimines with trichlorosilane. Catalyst 3c afforded up to 99% yield and 96% ee in the reduction of N-alkyl ketimines and up to 98% yield and 98% ee in the reduction of N-aryl ketimines.

  9. In vivo detection of central dopaminergic processes: studies with 1-C-11-dopa and C-11-labelled N-alkylated ADTN derivatives

    International Nuclear Information System (INIS)

    N-alkyl derivatives of 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydro-naphthalene were labelled with 11C by methylation with methyl iodide. They are dopamine agonists and have been found to bind, with high affinity, to dopamine receptors, in vitro and in vivo, after intracerebral administration. These compounds can pass the blood-brain barrier while the non-alkyl compound (ADTN) cannot. (U.K.)

  10. Synthesis, characterization and antimicrobial activities of amide derivatives of febuxostat intermediate

    Directory of Open Access Journals (Sweden)

    Sreedhar Badvel

    2015-06-01

    Full Text Available A series of new carboxamide derivatives of 3-(4-(5-(ethoxycarbonyl-4-methylthiazol-2-ylphenoxypropionic acid were synthesized by Schotten-Baumann reaction. The newly synthesized compounds were characterized by IR, NMR and mass spectral analysis. The target molecules were evaluated for their efficacy as antimicrobial agents in vitro by disc diffusion method. Compounds 4c, 4f, 4g and 4i showed high inhibitory activity.

  11. Characteristic Conformation of Mosher’s Amide Elucidated Using the Cambridge Structural Database

    Directory of Open Access Journals (Sweden)

    Akio Ichikawa

    2015-07-01

    Full Text Available Conformations of the crystalline 3,3,3-trifluoro-2-methoxy-2-phenylpropanamide derivatives (MTPA amides deposited in the Cambridge Structural Database (CSD were examined statistically as Racid-enantiomers. The majority of dihedral angles (48/58, ca. 83% of the amide carbonyl groups and the trifluoromethyl groups ranged from –30° to 0° with an average angle θ1 of −13°. The other conformational properties were also clarified: (1 one of the fluorine atoms was antiperiplanar (ap to the amide carbonyl group, forming a staggered conformation; (2 the MTPA amides prepared from primary amines showed a Z form in amide moieties; (3 in the case of the MTPA amide prepared from a primary amine possessing secondary alkyl groups (i.e., Mosher-type MTPA amide, the dihedral angles between the methine groups and the carbonyl groups were syn and indicative of a moderate conformational flexibility; (4 the phenyl plane was inclined from the O–Cchiral bond of the methoxy moiety with an average dihedral angle θ2 of +21°; (5 the methyl group of the methoxy moiety was ap to the ipso-carbon atom of the phenyl group.

  12. Characteristic conformation of Mosher's amide elucidated using the cambridge structural database.

    Science.gov (United States)

    Ichikawa, Akio; Ono, Hiroshi; Mikata, Yuji

    2015-07-16

    Conformations of the crystalline 3,3,3-trifluoro-2-methoxy-2-phenylpropanamide derivatives (MTPA amides) deposited in the Cambridge Structural Database (CSD) were examined statistically as Racid-enantiomers. The majority of dihedral angles (48/58, ca. 83%) of the amide carbonyl groups and the trifluoromethyl groups ranged from -30° to 0° with an average angle θ1 of -13°. The other conformational properties were also clarified: (1) one of the fluorine atoms was antiperiplanar (ap) to the amide carbonyl group, forming a staggered conformation; (2) the MTPA amides prepared from primary amines showed a Z form in amide moieties; (3) in the case of the MTPA amide prepared from a primary amine possessing secondary alkyl groups (i.e., Mosher-type MTPA amide), the dihedral angles between the methine groups and the carbonyl groups were syn and indicative of a moderate conformational flexibility; (4) the phenyl plane was inclined from the O-Cchiral bond of the methoxy moiety with an average dihedral angle θ2 of +21°; (5) the methyl group of the methoxy moiety was ap to the ipso-carbon atom of the phenyl group.

  13. Differentiation of skeletal osteogenic progenitor cells to osteoblasts with 3,4-diarylbenzopyran based amide derivatives: Novel osteogenic agents.

    Science.gov (United States)

    Gupta, Atul; Ahmad, Imran; Kureel, Jyoti; John, Aijaz A; Sultan, Eram; Chanda, Debabrata; Agarwal, Naresh Kumar; Alauddin; Wahajuddin; Prabhaker, S; Verma, Amita; Singh, Divya

    2016-10-01

    A series of 3,4-diarylbenzopyran based amide derivatives was synthesized and evaluated for osteogenic activity in in vitro and in vivo models of osteoporosis. Compounds 17a, 21b-c and 22a-b showed significant osteogenic activity in osteoblast differentiation assay. Among the synthesized compounds, 22b was identified as lead molecule which showed significant osteogenic activity at 1 pM concentration in osteoblast differentiation assay and at 1 mg kg(-1) body weight dose in estrogen deficient balb/c mice model. In vitro bone mineralization and expression of osteogenic marker genes viz BMP-2, RUNX-2, OCN, and collagen type 1 further confirmed the osteogenic potential of 22b. Gene expression study for estrogen receptor α and β (ER-α and ER-β) in mouse calvarial osteoblasts (MCOs) unveiled that possibly 22b exerted osteogenic efficacy via activation of Estrogen receptor-β preferentially. In vivo pharmacokinetic, estrogenicity and acute toxicity studies of 22b showed that it had good bioavailability and was devoid of uterine estrogenicity at 1 mg kg(-1) and inherent toxicity up to 1000 mg kg(-1) body weight dose respectively. PMID:27236065

  14. Metabolism and toxicological evaluation of the aromatic amide herbicide propanil and its derivatives

    International Nuclear Information System (INIS)

    Since propanil is structurally similar to other carcinogenic arylamides, the potential chronic toxicity of propanil and its derivatives were examined in short-term assays for genotoxicity. Propanil, 3,4-dichloroaniline, and their N-oxidized derivatives were inactive in the Salmonella typhimurium reversion, Chinese hamster ovary/hypoxanthine guanine phosphoribosyl transferase (CHO/HGPRT), and rat hepatocyte/DNA repair assays. The metabolism of propanil and 3,4-dichloroaniline was subsequently examined in liver microsomes from males Sprague-Dawley rats to identify metabolites that may be involved in the acute toxicity of propanil. The major pathway of propanil metabolism was acylamidase-catalyzed hydrolysis to 3,4-dichloroaniline. Oxidized metabolites were isolated by high performance liquid chromatography, and identified as 2'-hydroxy-propanil and 6-hydroxy-propanil by comparison of their mass and nuclear magnetic resonance spectra to synthetic standards. Experiments were performed to determine if propanil exposure could be monitored by the analysis of hemoglobin binding. Administration of [ring-U-14C]propanil to rats increased methemoglobin formation in a dose-dependent manner. Concomitant with methemoglobin formation, dose-dependent covalent binding of radiolabeled propanil to hemoglobin was detected. HPLC analysis indicated that the hemoglobin adducts were sulfinic acid esters, and these data suggest that human exposure to propanil may be monitored by the analysis of propanil metabolites bound to hemoglobin

  15. Relationship between chromatographic resolution and amide structure of chiral 2-hydroxy acids as O-(-)-menthoxycarbonylated diastereomeric derivatives for enantiomeric separation on achiral gas chromatography.

    Science.gov (United States)

    Cha, Eunju; Kim, Sohee; Lee, Kang Mi; Kim, Ho Jun; Kim, Ki Hun; Kwon, Oh-Seung; Park, Ki Duk; Lee, Jaeick

    2016-02-15

    The relationship between chromatographic resolution and amide structure of chiral 2-hydroxy acids as O-(-)-menthoxycarbonylated diastereomeric derivatives on achiral gas chromatography was investigated to elucidate the best diastereomeric conformation for enantiomeric separation of chiral 2-hydroxy acids. Thirteen chiral 2-hydroxy acids were converted into nine different diastereomeric O-(-)-menthoxycarbonylated amide derivatives using the primary, secondary and cyclic amines to achieve complete enantiomeric separation through an achiral column. Each enantiomeric pair of 2-hydroxy acids as O-(-)-menthoxycarbonylated tert-butylamide derivatives was resolved on both the DB-5 and DB-17 columns with resolution factors ranging from 1.7 to 4.8 and 1.7 to 3.4, respectively. The results revealed that the structure of the amide moiety is shown to significantly affect chromatographic resolution. In addition, O-(-)-menthoxycarbonylated tert-butylamide derivatives were shown to be the best diastereomeric conformations for enantiomeric separation of 2-hydroxy acids. When comparing with our previous O-trifluoroacetylated(-)-menthyl ester derivatization method, the present results suggested that size differences between groups attached to the chiral center and conformational rigidity can have stronger effects on resolution than the distance between chiral centers. The elution of R- and S-stereoisomers was affected by the class of amine; i.e., primary, secondary, or cyclic, regardless of the substituents on the amine group, the structure of the 2-hydroxy acid, and the polarity of the column. PMID:26800225

  16. Sodium butyrate and its synthetic amide derivative modulate nociceptive behaviors in mice.

    Science.gov (United States)

    Russo, Roberto; De Caro, Carmen; Avagliano, Carmen; Cristiano, Claudia; La Rana, Giovanna; Mattace Raso, Giuseppina; Berni Canani, Roberto; Meli, Rosaria; Calignano, Antonio

    2016-01-01

    In the present study we investigated the role of sodium butyrate (butyrate), and its more palatable derivative, the N-(1-carbamoyl-2-phenyl-ethyl) butyramide (FBA), in animal models of acute and chronic pain. We found that oral administrations of butyrate (10-200mg/Kg) or equimolecular FBA (21.2-424mg/Kg) reduced visceral pain in a dose- and time-dependent manner. Both drugs were also effective in the formalin test, showing an antinociceptive effect. This analgesic effect was blocked by glibenclamide, suggesting the involvement of ATP-dependent K(+) channels. Moreover, following repeated administration butyrate (100-200mg/Kg) and FBA (212-424mg/Kg) retained their analgesic properties in a model of neuropathic pain, reducing mechanical and thermal hyperalgesia in the chronic constriction injury (CCI) model. The involvement of peroxisome proliferator-activated receptor (PPAR) -α and -γ for the analgesic effect of butyrate was also investigated by using PPAR-α null mice or the PPAR-γ antagonist GW9662. Western blot analysis, confirmed the role of peroxisome receptors in butyrate effects, evidencing the increase of PPAR-α and -γ expression, associated to the reduction of inflammatory markers (COX-2, iNOS, TNF-α and cFOS). In conclusion, we describe the role of butyrate-based drugs in pain, identifying different and converging non-genomic and genomic mechanisms of action, which cooperate in nociception maintenance.

  17. The amphiphilic alkyl ester derivatives of l-ascorbic acid induce reorganization of phospholipid vesicles.

    Science.gov (United States)

    Giudice, Francesca; Ambroggio, Ernesto E; Mottola, Milagro; Fanani, Maria Laura

    2016-09-01

    l-ascorbic acid alkyl esters (ASCn) are lipophilic forms of vitamin C, which maintain some of its antioxidant power. Those properties make this drug family attractive to be used in pharmacological preparations protecting other redox-sensible drugs or designed to reduce possible toxic oxidative processes. In this work, we tested the ability of l-ascorbic acid alkyl esters (ASCn) to modulate the structure, permeability, and rheological properties of phospholipid bilayers. The ASCn studied here (ASC16, ASC14, and ASC12) alter the structural integrity as well as the rheological properties of phospholipid membranes without showing any evident detergent activity. ASC14 appeared as the most efficient drug in destabilize the membrane structure of nano- and micro-size phospholipid liposomes inducing vesicle content leakage and shape elongation on giant unilamellar vesicles. It also was the most potent enhancer of membrane microviscosity and surface water structuring. Only ASC16 induced the formation of drug-enriched condensed domains after its incorporation into the lipid bilayer, while ASC12 appeared as the less membrane-disturbing compound, likely because of its poor, and more superficial, partition into the membrane. We also found that incorporation of ASCn into the lipid bilayers enhanced the reduction of membrane components, compared with soluble vitamin C. Our study shows that ASCn compounds, which vary in the length of the acyl chain, show different effects on phospholipid vesicles used as biomembrane models. Those variances may account for subtly differences in the effectiveness on their pharmacological applications. PMID:27342371

  18. Design and Synthesis of Bis-amide and Hydrazide-containing Derivatives of Malonic Acid as Potential HIV-1 Integrase Inhibitors

    Directory of Open Access Journals (Sweden)

    Nouri Neamati

    2008-10-01

    Full Text Available HIV-1 integrase (IN is an attractive and validated target for the development of novel therapeutics against AIDS. In the search for new IN inhibitors, we designed and synthesized three series of bis-amide and hydrazide-containing derivatives of malonic acid. We performed a docking study to investigate the potential interactions of the title compounds with essential amino acids on the IN active site.

  19. Efficient SN2 fluorination of primary and secondary alkyl bromides by copper(I) fluoride complexes

    KAUST Repository

    Liu, Yanpin

    2013-11-11

    Copper(I) fluoride complexes ligated by phenanthroline derivatives have been synthesized and structurally characterized by X-ray crystallography. These complexes adopt as either ionic or neutral forms in the solid state, depending on the steric bulkiness of the substituent groups on the phenanthroline ligands. These complexes react with primary and secondary alkyl bromides to produce the corresponding alkyl fluorides in modest to good yields. This new method is compatible with a variety of important functional groups such as ether, thioether, amide, nitrile, methoxyl, hydroxyl, ketone, ester, and heterocycle moieties. © 2013 American Chemical Society.

  20. Ring-alkyl connecting group effect on mesogenic properties of p-carborane derivatives and their hydrocarbon analogues

    Directory of Open Access Journals (Sweden)

    Aleksandra Jankowiak

    2009-12-01

    Full Text Available The effect of the phenyl–alkyl connecting group on mesogenic properties of several series of isostructural compounds containing p-carborane (A and B, bicyclo[2.2.2]octane (C, and benzene (D was investigated using thermal and optical methods. Results demonstrated that mesophase stability in the series containing A–D follows the order (AlkCH2CH2– < (AlkOOC– < (AlkCH2O– < (AlkCOO–. Surprisingly, the connecting groups (AlkCH2CH2– and (AlkOOC– destabilize the mesophase significantly stronger for carboranes (A and B than for carbocyclic derivatives (C and D. Analysis indicates that this effect may have quadrupolar and conformational origin.

  1. Synthesis, Central Nervous System Activity and Structure-Activity Relationships of Novel 1-(1-Alkyl-4-aryl-4,5-dihydro-1H-imidazo-3-substituted Urea Derivatives

    Directory of Open Access Journals (Sweden)

    Elżbieta Szacoń

    2015-02-01

    Full Text Available A series of 10 novel urea derivatives has been synthesized and evaluated for their central nervous system activity. Compounds 3a–3h were prepared in the reaction between the respective 1-alkyl-4-aryl-4,5-dihydro-1H-imidazol-2-amines 1a and 1b and appropriate benzyl-, phenethyl-isocyanate or ethyl 4-isocyanatobenzoate and ethyl isocyanatoacetate 2 in dichloromethane. Derivatives 4c and 4g resulted from the conversion of 3c and 3g into the respective amides due to action of an aqueous ammonia solution. The results obtained in this study, based on literature data suggest a possible involvement of serotonin system and/or the opioid system in the effects of tested compounds, and especially in the effect of compound 3h. The best activity of compound 3h may be primarily attributed to its favourable ADMET properties, i.e., higher lipophilicity (related to lower polar surface area and greater molecular surface, volume and mass than for other compounds and good blood-brain permeation. This compound has also the greatest polarizability and ovality. The HOMO and LUMO energies do not seem to be directly related to activity.

  2. Synthesis and antibacterial activity of sulfonamide derivatives at C-8 alkyl chain of anacardic acid mixture isolated from a natural product cashew nut shell liquid (CNSL)

    Indian Academy of Sciences (India)

    N Subhakara Reddy; A Srinivas Rao; M Adharvana Chari; V Ravi Kumar; V Jyothy; V Himabindu

    2012-05-01

    Synthesis and antibacterial activity of some novel biologically active sulfonamide derivatives at C-8 alkyl chain of anacardic acid (7a-7l), prepared from commercially available anacardic acid mixture (1a-d). These compounds were tested for Gram positive and Gram negative bacterial cultures; most of the compounds showed higher antibacterial activity compared with standard drug ampicillin.

  3. Synthesis and structural studies of amino amide salts derived from 2-(aminomethyl)benzimidazole and α-amino acids

    Science.gov (United States)

    Avila-Montiel, Concepción; Tapia-Benavides, Antonio R.; Falcón-León, Martha; Ariza-Castolo, Armando; Tlahuext, Hugo; Tlahuextl, Margarita

    2015-11-01

    2-{[(Ammoniumacetyl)amino]methyl}-1H-benzimidazol-3-ium dichloride 4, 2-{[(2-ammoniumpropanoyl)amino]methyl}-1H-benzimidazol-3-ium dichloride 5, and 2-{[(2-ammonium-3-phenylpropanoyl)amino]methyl}-1H-benzimidazol-3-ium dichloride 6 amino amides were synthesized via condensation of 2AMBZ dihydrochloride with the corresponding amino acid. Compounds 7-12 were obtained by replacing chloride ions (in salts 4-6) with nitrate or tetrachlorozincate ions. The results of X-ray diffraction crystallographic studies indicated that the geometries, charges and sizes of the anions are essential for the formation of the strong hydrogen bond interactions of compounds 4, 5, 9-12. Moreover, in most cases, the presence of water and solvent molecules stabilizes the supramolecular structures of these compounds. Nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy indicated that the presence of chloride or tetrachlorozincate anions increases the acidity of the benzimidazolic and amide groups more significantly than the presence of nitrate anions. However, Quantum Theory of Atoms in Molecules (QTAIM) computations of the crystal structures demonstrate that amino amides interact more strongly with NO3- than with Cl- and ZnCl42- anions; this difference explains the spectroscopic results.

  4. Alkylation of 2'-deoxynucleosides and DNA by quinone methides derived from 2,6-di-tert-butyl-4-methylphenol.

    Science.gov (United States)

    Lewis, M A; Yoerg, D G; Bolton, J L; Thompson, J A

    1996-12-01

    4-Alkylphenols, such as the antioxidant 2, 6-di-tert-butyl-4-methylphenol (BHT), exhibit toxicities that appear to be mediated by their oxidative metabolism to electrophilic quinone methides. Reactions of these Michael acceptors with simple nucleophiles and proteins have been reported, but little information is available on quinone methide binding to the competing nucleophilic sites in DNA. In the present investigation, 2'-deoxynucleoside adducts generated in vitro with two BHT-derived quinone methides, 2,6-di-tert-butyl-4-methylenecyclohexa-2,5-dienone and 6-tert-butyl-2- (2'-hydroxy-1',1'-dimethylethyl)-4-methylenecyclohexa-2,5-dieno ne (BHTOH-QM) were isolated and identified. Both quinone methides produced adducts at the 1- and N2-positions of deoxyguanosine (dG) and the N6-position of deoxyadenosine (dA). In addition, a labile adduct formed at the 7-position of dG, which degraded to the corresponding 7-alkylguanine derivative. Additional work was conducted with BHTOH-QM, the more reactive of the two quinone methides. This species also formed stable adducts at the N4-position of deoxycytosine (dC) and the 3-position of thymidine and formed a labile adduct at the 3-position of dC that underwent hydrolytic cleavage to regenerate dC. In mixtures of deoxynucleosides treated with [14C]BHTOH-QM, alkylation occurred primarily at the N2- and 7-positions of dG and the N6-position of dA and occurred secondarily at the 1-position of dG. Treatment of calf thymus DNA with this quinone methide yielded N6-dA and N2-dG adducts with the former predominating. The unstable 7-dG adduct was detected by analysis of the 7-alkylguanine product from depurination. These results demonstrate that quinone methides are most likely to damage DNA through alkylation of the exocyclic amino groups of purine residues and possibly also by attack at the 7-position of dG followed by depurination. PMID:8951242

  5. Pharmacological Classification and Activity Evaluation of Furan and Thiophene Amide Derivatives Applying Semi-Empirical ab initio Molecular Modeling Methods

    Directory of Open Access Journals (Sweden)

    Leszek Bober

    2012-05-01

    Full Text Available Pharmacological and physicochemical classification of the furan and thiophene amide derivatives by multiple regression analysis and partial least square (PLS based on semi-empirical ab initio molecular modeling studies and high-performance liquid chromatography (HPLC retention data is proposed. Structural parameters obtained from the PCM (Polarizable Continuum Model method and the literature values of biological activity (antiproliferative for the A431 cells expressed as LD50 of the examined furan and thiophene derivatives was used to search for relationships. It was tested how variable molecular modeling conditions considered together, with or without HPLC retention data, allow evaluation of the structural recognition of furan and thiophene derivatives with respect to their pharmacological properties.

  6. Supramolecular assembly and nanostructures of a series of luminol derivatives with aromatic/alkyl substituted groups in Langmuir-Blodgett films.

    Science.gov (United States)

    Jiao, Tifeng; Xing, Yuanyuan; Zhang, Qingrui; Zhang, Li; Liu, Minghua; Zhou, Jingxin; Gao, Faming

    2014-06-01

    A series of functional luminol derivatives with aromatic and alkyl substituted groups has been designed and synthesized from the reaction of the corresponding chloride precursors with luminol. These compounds can be spread on water surface to form stable Langmuir films at the air-water interface. It has been found that UV and IR spectra confirmed the characteristic aromatic segment, imide group, and aromatic/alkyl substituted groups. In addition, for the interfacial assembly process of compounds with alkyl substituted groups, there are obvious spectral changes for the alkyl chains. AFM results indicated that various different aggregated domains may be fabricated in the transferred LB films. For all cases, the substituted groups in molecular structures have an important effect in regulating the aggregation mode and spectral changes in organized molecular films. The present results showed that the modified luminol derivatives may have potential application in functional material fields such as ECL sensor, which may give some insight to study the relationship between the molecular structures and supramolecular aggregation of amphiphiles in organized molecular films.

  7. Electrochemical Study of a New Fatty Amide Derivative Inhibitor for Carbon Steel%脂肪酰胺类缓蚀剂对碳钢缓蚀作用的电化学研究

    Institute of Scientific and Technical Information of China (English)

    陶蕾; 陈军; 王超; 秦立娟

    2012-01-01

    A new "green" corrosion inhibitor named N-alkyl-N-fatty acylamino fatty acid salt (TS-417) was synthesized and characterized. The corrosion inhibition performance of TS-417 on low carbon steel in simulated circulation cooling water conditions was studied by polarization curves, electrochemical impedance spectroscopy (EIS). The results show that the new fatty amide derivative inhibitor TS-417 was a good corrosion inhibitor for low carbon steel, which behaved as a type of anodic inhibitor. The inhibition efficiency increases with the TS-417 concentration increased, which can attain 90 % at 100 mg/L.%开发了一种新型环境友好型N-烷基-N-脂肪酰基氨基脂肪酸盐(TS-417)无磷缓蚀剂。采用极化曲线和电化学阻抗谱方法研究了TS一417对低碳钢在模拟中碱中硬循环冷却水中的缓蚀作用。结果表明:TS-417缓蚀剂对碳钢具有良好的缓蚀作用,属于阳极抑制型缓蚀剂;其缓蚀效率随着缓蚀剂浓度的增大而增大,当添加浓度为100mg/L时,缓蚀剂效率即可达到90%。

  8. Cyclodextrin-mediated enantioseparation of phenylalanine amide derivatives and amino alcohols by capillary electrophoresis-role of complexation constants and complex mobilities.

    Science.gov (United States)

    Aranyi, Anita; Péter, Antal; Ilisz, István; Fülöp, Ferenc; Scriba, Gerhard K E

    2014-10-01

    The separation of the enantiomers of phenylalanine amide and N-methyl derivatives as well as some amino alcohols was studied by CE in acidic BGEs using CDs as chiral selectors. The native CDs displayed only low chiral recognition ability at a concentration of 15 mg/mL in 20 mM sodium phosphate buffer, pH 2.5. In contrast, the analyte enantiomers were separated in the presence of randomly sulfated CDs under reversed polarity of the applied voltage. Sulfated β-CD proved to be the most universal selector resulting in the enantioseparation of all analytes. Opposite enantiomer migration order depending on the size of the CD cavity was observed for phenylalanine amide and 2-amino-2-phenylethanol. The R-enantiomers migrated first in the presence of sulfated α-CD and γ-CD while the S-enantiomers were detected first in the presence of sulfated β-CD. The enantioseparations could be rationalized based on analyte complexation by the respective CDs except for 2-amino-2-phenylethanol and sulfated β-CD where essentially equal complexation constants were derived for the enantiomers. In this case, the migration behavior could be attributed to the mobilities of the enantiomer-CD complexes adding another example to the CE-specific phenomenon of enantioseparations based primarily on complex mobilities.

  9. Synthesis and Anticancer Activity of Some New S-Glycosyl and S-Alkyl 1,2,4-Triazinone Derivatives

    Directory of Open Access Journals (Sweden)

    Hosam A. Saad

    2011-07-01

    Full Text Available A series of S-glycosyl and S-alkyl derivatives of 4-amino-3-mercapto-6-(2-(2-thienylvinyl-1,2,4-triazin-5(4H-one (1 were synthesized using different halo compounds such as preacetylated sugar bromide, 4-bromobutylacetate, 2-acetoxyethoxy-methyl bromide, 3-chloropropanol, 1,3-dichloro-2-propanol, epichlorohydrin, allyl bromide, propargyl bromide, phthalic and succinic acids in POCl3. The structures of the synthesized compounds have been deduced from their elemental analysis and spectral (IR, 1H-NMR, and 13C-NMR data. Some of the synthesized compounds were screened as anticancer agents. Significant anticancer activities were observed in vitro for some members of the series, and compounds 4-Amino-3-(3-hydroxypropylthio-6-(2-(2-thienylvinyl-1,2,4-triazin-5(4H-one (12 and 3-(4-Oxo-3-(2-(2-thienylvinyl-4H-[1,3,4]thiadiazolo-[2,3-c][1,2,4]tr-iazin-7-ylpropanoic acid (18 are active cytotoxic agents against different cancer cell lines.

  10. PPA-SiO2 Catalyzed Multi-component Synthesis of N-[α-(β-Hydroxy-α-naphthyl)(benzyl)]O-Alkyl Carbamate Derivatives

    Institute of Scientific and Technical Information of China (English)

    SHATERIAN,Hamid Reza; HOSSEINIAN,Asghar; GHASHANG,Majid

    2009-01-01

    Silica-supported polyphosphoric acid (PPA-SiO2) was found to be an efficient catalyst for the multi-component condensation reaction of benzaldehydes,2-naphthol,and methyl/benzyl carbamate to afford the corresponding N-[α-(β-hydroxy-α-naphthyl)(benzyl)]O-alkyl carbamate derivatives in good to excellent yields.This new approach consistently has the advantage of short reaction time,high conversions,clean reaction profiles,and simple experimental and work-up procedures.

  11. Synthesis of methyl (E)-2',4''-thiazachalcones and their N-alkyl derivatives, photochemistry with theoretical calculations and antimicrobial activities

    OpenAIRE

    USTA, Asu; Yaşar, Ahmet; YAYLI, Nuran

    2009-01-01

    A series of 9 new (E)-thiazachalcones (1-3), and their N-alkyl substituted derivatives (4-6), and stereoselective dimerization products (7-9) were synthesized, then tested for antimicrobial activity against all test microorganisms except Pseudomonas aeruginosa. The new compounds (1-6) without dimerization products (7-9) showed good antimicrobial property against Staphylococcus aureus, Listeria monocitogenes, and Enterococcus faecalis. The possible dimerization products of compounds (...

  12. Amide bond direction modulates G-quadruplex recognition and telomerase inhibition by 2,6 and 2,7 bis-substituted anthracenedione derivatives.

    Science.gov (United States)

    Zagotto, Giuseppe; Sissi, Claudia; Moro, Stefano; Dal Ben, Diego; Parkinson, Gary N; Fox, Keith R; Neidle, Stephen; Palumbo, Manlio

    2008-01-01

    G-quadruplex structures of DNA represent a potentially useful target for anticancer drugs. Stabilisation of this arrangement at the ends of chromosomes may inhibit the action of telomerase, an enzyme involved in immortalization of cancer cells. Appropriately substituted amido anthracenediones are effective G-quadruplex stabilizers, but no information is available as yet on the possible modulation of G-quadruplex recognition and telomerase inhibition produced by the direction of the amide bond. To understand the basis of amido anthracenedione selectivity, we have synthesized a number of derivatives bearing the -CO-NH- or -NH-CO- group linked to the planar anthraquinone (AQ) moiety at 2,6 and 2,7 positions. The various isomers were tested in terms of telomerase inhibition, determined by the TRAP assay, G-quadruplex stabilisation measured by the increase in melting temperature of the appropriately folded oligonucleotide using FRET, and conformational and G4 binding properties examined by molecular modelling techniques. In all cases, enzymatic inhibition and G-quadruplex stabilization were directly related, which strongly supports the proposed molecular mechanism of telomerase interference. Interestingly, the AQ-NH-CO- arrangement performs invariantly better than the AQ-CO-NH- arrangement, showing a clear preference among isomeric derivatives. Theoretical calculations suggest that the former amide arrangement is co-planar with the aromatic system, whereas the latter is tilted by about 30 degrees when considering the most stable conformation. A more extended planar surface would allow more efficient stacking interactions with the quadruplex structure, hence more effective telomerase inhibition. PMID:17936629

  13. Mass spectrometry of analytical derivatives. 1. Cyanide cations in the spectra of N-alkyl-N-perfluoroacyl-α-amino acids and their methyl esters

    Science.gov (United States)

    Todua, Nino G.; Tretyakov, Kirill V.; Mikaia, Anzor I.

    2016-01-01

    The central mission for the development of the National Institute of Standards and Technology/National Institutes of Health/Environmental Protection Agency Mass Spectral Library is the acquisition of reference gas chromatography–mass spectrometry data for important compounds and their chemical modification products. The addition of reliable reference data of various derivatives of amino acids to The Library, and the study of their behavior under electron ionization conditions may be useful for their identification, structure elucidation, and a better understanding of the data obtained when the same derivatives are subjected to other ionization methods. N-Alkyl-N-perfluoroacyl derivatives of amino acids readily produce previously unreported alkylnitrilium cations of composition [HC≡N-alkyl]+. Homologous [HC≡N-aryl]+ cations are typical for corresponding N-aryl analogs. The formation of other ions characteristic for these derivatives involves oxygen rearrangement giving rise to ions [CnF2n+1–C≡N+–CnH2n+1] and [CnF2n+1–C≡N+-aryl]. The introduction of an N-benzyl substituent in a molecule favors a process producing benzylidene iminium cations. l-Threonine and l-cysteine derivatives exhibit more fragmentation pathways not typical for other α-amino acids; additionally, the Nω-amino group in l-lysine directs the dissociation process and provides structural information on the substitution at the amino functions in the molecule. PMID:26307698

  14. Copolymerization of ε-caprolactone and morpholine-2,5-dione derivatives

    NARCIS (Netherlands)

    Veld, in 't Peter J.A.; Wei-Ping, Ye; Klap, Richard; Dijkstra, Pieter J.; Feijen, Jan

    1992-01-01

    Novel biodegradable poly(ester-amide)s were prepared by ring-opening copolymerization of -caprolactone and 3- and/or 6-alkyl-substituted morpholine-2,5-dione derivatives. The copolymerizations were carried out in the bulk using stannous octoate as an initiator. Molecular weights of the copolymers ra

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

    International Nuclear Information System (INIS)

    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

  16. Synthesis of novel chiral phosphine-triazine ligand derived from α-phenylethylamine for Pd-catalyzed asymmetric allylic alkylation

    Institute of Scientific and Technical Information of China (English)

    Jia Di Huang; Xiang Ping Hu; Zhuo Zheng

    2008-01-01

    A novel chiral phosphine-triazine ligand was synthesized from chiral model reaction of Pd-catalyzed allylic alkylation of rac-l,3-diphenylprop-2-en-l-yl pivalate with dimethyl malonate, good enantioselectivity (90% e.e.) was obtained by using this ligand.

  17. Design, synthesis and biological evaluation of 1,4-dihydrothieno [3′,2′:5,6]thiopyrano [4,3-c]pyrazole-3-carboxylic amide derivatives as potential estrogen receptor antagonists

    Institute of Scientific and Technical Information of China (English)

    Rui Sun; Jing Song; Si Jie Liu; Hui Zhao; Chun Li Yan; Ai Jun Zhang; Diwa Koirala; Da Wei Li; Chun Hu

    2011-01-01

    The estrogen receptor is a target for therapeutic agents for hormone replacement in menopausal women, osteoporosis, reproductive cancers such as breast cancer, uterine cancer and prostate cancer. 1,4-Dihydrothieno [3',2':5,6]thiopyrano [4,3-c]pyrazole-3-carboxylic amide derivatives were designed, synthesized and biological evaluated as potential estrogen receptor antagonists.

  18. Synthesis and Characterization of DOTA-(amide)4 Derivatives: Equilibrium and Kinetic Behavior of Their Lanthanide(III) Complexes

    OpenAIRE

    Pasha, Azhar; Tircsó, Gyula; Benyó, Enikő Tircsóné; Brücher, Ernő; Sherry, A. Dean

    2007-01-01

    Lanthanide complexes of tetraamide derivatives of DOTA are of interest today because of their application as chemical exchange saturation transfer (CEST) agents for magnetic resonance imaging (MRI). The protonation constants of some simple tetraamide derivatives of DOTA and the stability constants of the complexes formed with some endogenous metal ions, namely Mg2+, Ca2+, Cu2+, Zn2+, and lanthanide(III) ions, have been studied. These complexes were found to be considerably less stable than th...

  19. On complex compounds of molybdenum(5) with nicotinic amide, isonicotinic acid hydrazide and some of its derivatives

    International Nuclear Information System (INIS)

    Oxychloride complexes of molybdenum (5) with polyfunctional ligands (L), namely with nicotinamide (NA), isonicotinic acid hydrazide (INH) and its derivatives (ftivazide, saluzide and larusan) have been synthesized and investigated. In ethanol all the ligands independently of their molar ratio form with MoCl5 a non-electrolite compound MoOCl3xL2. Infrared spectra of the complexes suggest that in Mo(5) complexeS with NA and INH the central atom is bound through the pyridine nitrogen, whereas in the complexes with INH derivatives it is bound throught the carbonyl group oxygen

  20. Synthesis and In Vitro Antiproliferative Activity of Novel Phenyl Ring-Substituted 5-Alkyl-12(H-quino[3,4-b][1,4]benzothiazine Derivatives

    Directory of Open Access Journals (Sweden)

    Andrzej Zięba

    2016-11-01

    Full Text Available A novel series of tetracyclic quinobenzothiazine derivatives was synthetized. Compounds containing a substituent (hydroxyl, methyl, phenyl, piperidyl, or piperazinyl in positions 9 and 11 were obtained by cyclization of suitable 4-aminoquinolinium-3-thiolates. Quinobenzothiazine 10-O-substituted derivatives were obtained by alkylating the hydroxyl group in position 10 of the parent (quinobenzothiazine system. Antiproliferative activity of the synthesized compounds was studied using cultured neoplastic cells (MDA-MB-231, SNB-19, and C-32 cell lines. Four selected compounds were investigated in more detail for cytotoxicity and antiproliferative effect. Transcriptional activity of genes regulating cell cycle (TP53, apoptosis (BAX, BCL-2, as well as proliferation (H3 were assessed. Finally, the ability of the selected compounds to bind DNA was checked in the presence of ethidium bromide.

  1. Synthesis and Characterization of Poly(ether amide)s Containing Bisphthalazinone and Ether Linkages

    Institute of Scientific and Technical Information of China (English)

    Cheng LIU; Shou Hai ZHANG; Ming Jing WANG; Qi Zhen LIANG; Xi Gao JIAN

    2005-01-01

    A novel aromatic diacid, 4, 4'-bis[2-(4-carboxyphenyl)phthalazin-1-one-4-yl]-bisphenyl ether Ⅲ, containing bisphthalazinone and ether linkages was prepared from nucleophilic substitution of p-chlorobenzonitrile with the bisphenol-like monomer Ⅰ, followed by alkaline hydrolysis of the intermediate dinitrile Ⅱ. A series of poly(ether amide)s containing bisphthalazinone and ether linkages derived from diacid Ⅲ and aromatic diamines were synthesized by one-step solution condensation polymerization using triphenyl phosphite and pyridine as condensing agents. Moreover, the properties of poly(ether amide)s including thermal stability,solubility and crystallinity were also studied.

  2. Alkyl-Substituted δ-Lactones Derived from Dihydrojasmone and Their Stereoselective Fungi-Mediated Conversion: Production of New Antifeedant Agents.

    Science.gov (United States)

    Gliszczyńska, Anna; Semba, Damian; Szczepanik, Maryla; Dancewicz, Katarzyna; Gabryś, Beata

    2016-01-01

    A chemoenzymatic method was applied to obtain optically pure alkyl-substituted δ-lactones. First, chemical Baeyer-Villiger oxidation of dihydrojasmone (1) was carried out, affording two new alkyl-substituted δ-lactones: 3,4-dihydro-5-methyl-6-pentyl-2H-pyran-2-one (2) and 5-methyl-6-pentyl-1,13-dioxabicyclo[4.1.0]heptan-2-one (3). In the next step, fungal strains were investigated as biocatalysts to enantioselective conversion of δ-lactones (2) and (3). The fungal cultures: Fusarium culmorum AM10, Fusarium equiseti AM15 and Beauveria bassiana AM278 catalyzed the stereoselective hydration of the double bond of lactone (2) (ee = 20%-99%) while Didymosphaeria igniaria KCh6670 proved to be the best biocatalyst for the reduction of carbonyl group in the epoxylactone (3) (ee = 99%). In both cases, chiral oxyderivatives were obtained in low to high yields (7%-91%). The synthetic lactones (2), (3) and its derivatives (4), (5) were tested for their antifeedant activity towards larvae and adults of lesser mealworm (Alphitobius diaperinus Panzer) and peach potato aphid (Myzus persicae [Sulzer]) and some of them were active towards studied insects. PMID:27649116

  3. Alkylating enzymes.

    Science.gov (United States)

    Wessjohann, Ludger A; Keim, Jeanette; Weigel, Benjamin; Dippe, Martin

    2013-04-01

    Chemospecific and regiospecific modifications of natural products by methyl, prenyl, or C-glycosyl moieties are a challenging and cumbersome task in organic synthesis. Because of the availability of an increasing number of stable and selective transferases and cofactor regeneration processes, enzyme-assisted strategies turn out to be promising alternatives to classical synthesis. Two categories of alkylating enzymes become increasingly relevant for applications: firstly prenyltransferases and terpene synthases (including terpene cyclases), which are used in the production of terpenoids such as artemisinin, or meroterpenoids like alkylated phenolics and indoles, and secondly methyltransferases, which modify flavonoids and alkaloids to yield products with a specific methylation pattern such as 7-O-methylaromadendrin and scopolamine.

  4. Activity of Antifungal Organobismuth(III Compounds Derived from Alkyl Aryl Ketones against S. cerevisiae: Comparison with a Heterocyclic Bismuth Scaffold Consisting of a Diphenyl Sulfone

    Directory of Open Access Journals (Sweden)

    Toshihiro Murafuji

    2014-07-01

    Full Text Available A series of hypervalent organobismuth(III compounds derived from alkyl aryl ketones [XBi(5-R'C6H3-2-COR(Ar] was synthesized to investigate the effect of the compounds’ structural features on their antifungal activity against the yeast Saccharomyces cerevisiae. In contrast to bismuth heterocycles [XBi(5-RC6H3-2-SO2C6H4-1'-] derived from diphenyl sulfones, a systematic quantitative structure-activity relationship study was possible. The activity depended on the Ar group and increased for heavier X atoms, whereas lengthening the alkyl chain (R or introducing a substituent (R' reduced the activity. IBi(C6H4-2-COCH3(4-FC6H4 was the most active. Its activity was superior to that of the related acyclic analogues ClBi[C6H4-2-CH2N(CH32](Ar and ClBi(C6H4-2-SO2 tert-Bu(Ar and also comparable to that of heterocyclic ClBi(C6H4-2-SO2C6H4-1'-, which was the most active compound in our previous studies. Density function theory calculations suggested that hypervalent bismuthanes undergo nucleophilic addition with a biomolecule at the bismuth atom to give an intermediate ate complex. For higher antifungal activity, adjusting the lipophilicity-hydrophilicity balance, modeling the three-dimensional molecular structure around the bismuth atom, and stabilizing the ate complex appear to be more important than tuning the Lewis acidity at the bismuth atom.

  5. Cytotoxicity of copper(II)-complexes with some S-alkyl derivatives of thiosalicylic acid. Crystal structure of the binuclear copper(II)-complex with S-ethyl derivative of thiosalicylic acid

    Science.gov (United States)

    Nikolić, Miloš V.; Mijajlović, Marina Ž.; Jevtić, Verica V.; Ratković, Zoran R.; Novaković, Slađana B.; Bogdanović, Goran A.; Milovanović, Jelena; Arsenijević, Aleksandar; Stojanović, Bojana; Trifunović, Srećko R.; Radić, Gordana P.

    2016-07-01

    The spectroscopically predicted structure of the obtained copper(II)-complex with S-ethyl derivative of thiosalicylic acid was confirmed by X-ray structural study and compared to previously reported crystal structure of the Cu complex with S-methyl derivative. Single crystals suitable for X-ray measurements were obtained by slow crystallization from a water solution. Cytotoxic effects of S-alkyl (R = benzyl (L1), methyl (L2), ethyl (L3), propyl (L4) and butyl (L5)) derivatives of thiosalicylic acid and the corresponding binuclear copper(II)-complexes on murine colon carcinoma cell lines, CT26 and CT26.CL25 and human colon carcinoma cell line HCT-116 were reported here. The analysis of cancer cell viability showed that all the tested complexes had low cytotoxic effect on murine colon carcinoma cell lines, but several times higher cytotoxicity on normal human colon carcinoma cells.

  6. Development of the first well-defined tungsten oxo alkyl derivatives supported on silica by SOMC: towards a model of WO3/SiO2 olefin metathesis catalyst

    KAUST Repository

    Mazoyer, Etienne

    2010-01-01

    A well-defined, silica-supported tungsten oxo alkyl species prepared by the surface organometallic chemistry approach displays high and sustained activity in propene metathesis. Remarkably, its catalytic performances outpace those of the parent imido derivative, underlining the importance of the oxo ligand in the design of robust catalysts. © 2010 The Royal Society of Chemistry.

  7. Optimization of alkylating agent prodrugs derived from phenol and aniline mustards: a new clinical candidate prodrug (ZD2767) for antibody-directed enzyme prodrug therapy (ADEPT).

    Science.gov (United States)

    Springer, C J; Dowell, R; Burke, P J; Hadley, E; Davis, D H; Blakey, D C; Melton, R G; Niculescu-Duvaz, I

    1995-12-22

    Sixteen novel potential prodrugs derived from phenol or aniline mustards and their 16 corresponding drugs with ring substitution and/or different alkylating functionalities were designed. The [[[4-]bis(2-bromoethyl)-(1a), [[[4-[bis(2-iodoethyl)-(1b), and [[[4-[(2-chloroethyl)-[2-(mesyloxy)ethyl]amino]phenyl]oxy] carbonyl]-L-glutamic acids (1c), their [[[2- and 3-substituted-4-[bis(2-chloroethyl)amino]phenyl]oxy]carbonyl]-L- glutamic acids (1e-1), and the [[3-substituted-4-[bis(2-chloroethyl)amino]phenyl]carbamoyl]-L- glutamic acids (1o-r) were synthesized. They are bifunctional alkylating agents in which the activating effect of the phenolic hydroxyl or amino function is masked through an oxycarbonyl or a carbamoyl bond to a glutamic acid. These prodrugs were designed to be activated to their corresponding phenol and aniline nitrogen mustard drugs at a tumor site by prior administration of a monoclonal antibody conjugated to the bacterial enzyme carboxypeptidase G2 (CPG2) in antibody-directed enzyme prodrug therapy (ADEPT). The synthesis of the analogous novel parent drugs (2a-r) is also described. The viability of a colorectal cell line (LoVo) was monitored with the potential prodrugs and the parent drugs. The differential in the cytotoxicity between the potential prodrugs and their corresponding active drugs ranged between 12 and > 195 fold. Compounds 1b-d,f,o exhibited substantial prodrug activity, since a cytotoxicity differential of > 100 was achieved compared to 2b-d,f,o respectively. The ability of the potential prodrugs to act as substrates for CPG2 was determined (kinetic parameters KM and kcat), and the chemical stability was measured for all the compounds. The unsubstituted phenols with different alkylating functionalities (1a-c) proved to have the highest ratio of the substrates kcat:KM. From these studies [[[4-[bis(2-iodoethyl)amino]phenyl]oxy]carbonyl]-L-glutamic acid (1b) emerges as a new ADEPT clinical trial candidate due to its physicochemical and

  8. Silver-catalyzed coupling reactions of alkyl halides with indenyllithiums

    OpenAIRE

    Someya, Hidenori; Yorimitsu, Hideki; Oshima, Koichiro

    2010-01-01

    Coupling reactions of tertiary and secondary alkyl halides with indenyllithiums proceeded effectively in the presence of a catalytic amount of silver bromide to provide tertiary- and secondary-alkyl-substituted indene derivatives in good yields.

  9. Efficient sonochemical synthesis of alkyl 4-aryl-6-chloro-5-formyl-2-methyl-1,4-dihydropyridine-3-carboxylate derivatives.

    Science.gov (United States)

    Ruiz, Enrique; Rodríguez, Hortensia; Coro, Julieta; Niebla, Vladimir; Rodríguez, Alfredo; Martínez-Alvarez, Roberto; de Armas, Hector Novoa; Suárez, Margarita; Martín, Nazario

    2012-03-01

    A facile, efficient and environment-friendly protocol for the synthesis of 6-chloro-5-formyl-1,4-dihydropyridine derivatives has been developed by the convenient ultrasound-mediated reaction of 2(1H)pyridone derivatives with the Vilsmeier-Haack reagent. This method provides several advantages over current reaction methodologies including a simpler work-up procedure, shorter reaction times and higher yields.

  10. Heteroleptic Fe(II) complexes of 2,2'-biimidazole and its alkylated derivatives: spin-crossover and photomagnetic behavior.

    Science.gov (United States)

    Phan, Hoa V; Chakraborty, Pradip; Chen, Meimei; Calm, Yitzi M; Kovnir, Kirill; Keniley, Lawrence K; Hoyt, Jordan M; Knowles, Elisabeth S; Besnard, Céline; Meisel, Mark W; Hauser, Andreas; Achim, Catalina; Shatruk, Michael

    2012-12-01

    Three iron(II) complexes, [Fe(TPMA)(BIM)](ClO(4))(2)⋅0.5H(2)O (1), [Fe(TPMA)(XBIM)](ClO(4))(2) (2), and [Fe(TPMA)(XBBIM)](ClO(4))(2)⋅0.75CH(3)OH (3), were prepared by reactions of Fe(II) perchlorate and the corresponding ligands (TPMA=tris(2-pyridylmethyl)amine, BIM=2,2'-biimidazole, XBIM=1,1'-(α,α'-o-xylyl)-2,2'-biimidazole, XBBIM=1,1'-(α,α'-o-xylyl)-2,2'-bibenzimidazole). The compounds were investigated by a combination of X-ray crystallography, magnetic and photomagnetic measurements, and Mössbauer and optical absorption spectroscopy. Complex 1 exhibits a gradual spin crossover (SCO) with T(1/2) =190 K, whereas 2 exhibits an abrupt SCO with approximately 7 K thermal hysteresis (T(1/2) =196 K on cooling and 203 K on heating). Complex 3 is in the high-spin state in the 2-300 K range. The difference in the magnetic behavior was traced to differences between the inter- and intramolecular interactions in 1 and 2. The crystal packing of 2 features a hierarchy of intermolecular interactions that result in increased cooperativity and abruptness of the spin transition. In 3, steric repulsion between H atoms of one of the pyridyl substituents of TPMA and one of the benzene rings of XBBIM results in a strong distortion of the Fe(II) coordination environment, which stabilizes the high-spin state of the complex. Both 1 and 2 exhibit a photoinduced low-spin to high-spin transition (LIESST effect) at 5 K. The difference in the character of intermolecular interactions of 1 and 2 also manifests in the kinetics of the decay of the photoinduced high-spin state. For 1, the decay rate constant follows the single-exponential law, whereas for 2 it is a stretched exponential, reflecting the hierarchical nature of intermolecular contacts. The structural parameters of the photoinduced high-spin state at 50 K are similar to those determined for the high-spin state at 295 K. This study shows that N-alkylation of BIM has a negligible effect on the ligand field strength. Therefore

  11. Rhodium-catalyzed aerobic N-alkylation of sulfonamides with alcohols

    Institute of Scientific and Technical Information of China (English)

    Sun Lin Feng; Chuan Zhi Liu; Qiang Li; Xiao Chun Yu; Qing Xu

    2011-01-01

    By using the famous Wilkinson's catalyst, N-alkylation of sulfonamides can be easily realized under mild aerobic conditions by using alcohols as the alkylating reagent, giving monoalkylated sulfonamides in high yields and selectivities with water produced as the only byproduct. This advantageous aerobic method is potentially general in substrate scope that it can also be applied to other amides, amines and alcohols.

  12. A New Derivative of Valproic Acid Amide Possesses a Broad-spectrum Antiseizure Profile and Unique Activity Against Status Epilepticus and Organophosphate Neuronal Damage

    Science.gov (United States)

    White, H. Steve; Alex, Anitha B.; Pollock, Amanda; Hen, Naama; Shekh-Ahmad, Tawfeeq; Wilcox, Karen S.; McDonough, John H.; Stables, James P.; Kaufmann, Dan; Yagen, Boris; Bialer, Meir

    2011-01-01

    Summary Purpose sec-Butyl-propylacetamide (SPD) is a one-carbon homologue of valnoctamide (VCD), a CNS-active amide derivative of valproic acid (VPA) currently in phase II clinical trials. The current study evaluated the anticonvulsant activity of SPD in a battery of rodent seizure and epilepsy models and assessed its efficacy in rat and guinea pig models of status epilepticus (SE) and neuroprotection in an organotypic hippocampal slice model of excitotoxic cell death. Methods SPD’s anticonvulsant activity was evaluated in several rodent seizure and epilepsy models including: maximal electroshock (MES), 6Hz psychomotor, subcutaneous (s.c.) metrazol-, s.c., picrotoxin, s.c. bicuculline, audiogenic and corneal and hippocampal kindled seizures following intraperitoneal administration. Results obtained with SPD are discussed in relationship to those obtained with VPA and VCD. SPD was also evaluated for its ability to block benzodiazepine-resistant SE induced by pilocarpine (rats) and soman (rats and guinea pigs) following intraperitoneal administration. SPD was tested for its ability to block excitotoxic cell death induced by the glutamate agonists N-methyl-D-Aspartate (NMDA) and kainic acid (KA) using organotypic hippocampal slices and SE-induced hippocampal cell death using FluoroJade B staining. The cognitive function of SPD-treated rats that were protected against pilocarpine-induced convulsive SE was examined 10-14 days post SE using the Morris water maze (MWM). The relationship between the pharmacokinetic profile of SPD and its efficacy against soman-induced SE was evaluated in two parallel studies following SPD (60 mg/kg, i.p.) administration in the soman SE rat model. Key Findings SPD was highly effective and displayed a wide protective index (PI=TD50/ED50) in the standardized seizure and epilepsy models employed. SPD’s wide PI values demonstrate that it is effective at doses well below those that produce behavioral impairment. Unlike VCD, SPD also

  13. Design, synthesis and antiproliferative activity of novel 5-nitropyrimidine-2,4-diamine derivatives bearing alkyl acetate moiety.

    Science.gov (United States)

    Zhao, Pei-Liang; Li, Yan-Hong; Yang, Hai-Kui; Chen, Peng; Zhang, Bei; Sun, Qi; Li, Qiu; You, Wen-Wei

    2016-08-01

    In order to discover new anticancer drug leads, a series of novel alkylamino pyrimidine derivatives were designed and synthesized based on our previous work via a ring-opening strategy. Biological evaluation with four human cancer cell lines (MDA-MB-231, A549, HepG2, and MCF-7) showed that most of these compounds possessed moderate to potent antiproliferative activities. The most promising compound 7w displayed a three-fold improvement compared with commercial anticancer drug fluorouracil in inhibiting HepG2 cell proliferation with IC50 value of 10.37 μM. Moreover, flow-activated cell sorting analysis suggested that compound 7w mainly arrested HepG2 cells in G2/M stage. Hence, it could serve as a promising lead for the design of novel anticancer small-molecule drugs. PMID:27128180

  14. Synthesis of 4H-chromene derivatives by reaction between alkyl isocyanides and dialkyl acetylenedicarboxylate in the presence of 6-hydroxyquinoline

    Institute of Scientific and Technical Information of China (English)

    Bita Mohtat; Hoorieh Djahaniani; Issa Yavari; Masomeh G. Dehbalaei; Saba A. Jam

    2011-01-01

    The reactive intermediate generated by the addition of alkyl isocyanides to dialkyl acetylenedicarboxylate was trapped by 6-quinolinol to produce highlyfunctionalized 4H-chromenes in fairly good yields.

  15. Supramolecular chirality in organo-, hydro-, and metallogels derived from bis-amides of L-(+)-tartaric acid: formation of highly aligned 1D silica fibers and evidence of 5-c net SnS topology in a metallogel network.

    Science.gov (United States)

    Das, Uttam Kumar; Dastidar, Parthasarathi

    2012-10-01

    A series of bis-amides derived from L-(+)-tartaric acid was synthesized as potential low-molecular-weight gelators. Out of 14 bis-amides synthesized, 13 displayed organo-, hydro-, and ambidextrous gelation behavior. The gels were characterized by methods including circular dichroism, differential scanning calorimetry, optical and electron microscopy, and rheology. One of the gels derived from di-3-pyridyltartaramide (D-3-PyTA) displayed intriguing nanotubular morphology of the gel network, which was exploited as a template to generate highly aligned 1D silica fibers. The gelator D-3-PyTA was also exploited to generate metallogels by treatment with various Cu(II) /Zn(II) salts under suitable conditions. A structure-property correlation on the basis of single-crystal and powder X-ray diffraction data was attempted to gain insight into the structures of the gel networks in both organo- and metallogels. Such study led to the determination of the gel-network structure of the Cu(II) coordination-polymer-based metallogel, which displayed a 2D sheet architecture made of a chloride-bridged double helix that resembled a 5-c net SnS topology.

  16. Mild and Highly Efficient Method for Synthesis of14-Aryl(alkyl)-14H-dibenzo[a,j]xanthenes and1,8-Dioxooctahydroxanthene Derivatives Using Pentafluorophenyl Ammonium Triflate as a Novel Organocatalyst%Mild and Highly Efficient Method for Synthesis of 14-Aryl(alkyl)-14H-dibenzo[a,j]xanthenes and 1,8-Dioxooctahydroxanthene Derivatives Using Pentafluorophenyl Ammonium Triflate as a Novel Organocatalyst

    Institute of Scientific and Technical Information of China (English)

    Samad KHAKSAR; Nosratollah BEHZADI

    2012-01-01

    A simple and facile synthesis of 14-aryl and alkyl-14H-dibenzo[a,j]xanthenes and 1,8-dioxooctahydroxanthene derivatives has been successfully developed by treatment ofβ-naphthol or dimedone with aldehydes under mild conditions in the presence of a pentafluorophenyl ammonium triflate (PFPAT) organocatalyst.These catalytic condensation reactions represent green chemical processes and the PFPAT organocatalyst is air-stable,cost-effective,easy to handle,and easily removed from the reaction mixtures.

  17. Polycyclic aromatic hydrocarbons (PAHs) and their derivatives (alkyl-PAHs, oxygenated-PAHs, nitrated-PAHs and azaarenes) in urban road dusts from Xi'an, Central China.

    Science.gov (United States)

    Wei, Chong; Bandowe, Benjamin A Musa; Han, Yongming; Cao, Junji; Zhan, Changlin; Wilcke, Wolfgang

    2015-09-01

    Urban road dusts are carriers of polycyclic aromatic compounds (PACs) and are therefore considered to be a major source of contamination of other environmental compartments and a source of exposure to PACs for urban populations. We determined the occurrence, composition pattern and sources of several PACs (29 alkyl- and parent-PAHs, 15 oxygenated-PAHs (OPAHs), 4 azaarenes (AZAs), and 11 nitrated-PAHs (NPAHs)) in twenty urban road dusts and six suburban surface soils (0-5cm) from Xi'an, central China. The average concentrations of ∑29PAHs, ∑4AZAs, ∑15OPAHs, and ∑11NPAHs were 15767, 673, 4754, and 885 n gg(-1) in road dusts and 2067, 784, 854, and 118 ng g(-1) in surface soils, respectively. The concentrations of most individual PACs were higher in street dusts than suburban soils, particularly for PACs with molecular weight>192 g mol(-1). The enrichment factors of individual PACs were significantly positively correlated with log KOA and log KOW, indicating an increasing deposition and co-sorption of the PACs in urban dusts with decreasing volatility and increasing hydrophobicity. Significant correlations between the concentrations of individual and sum of PACs, carbon fractions (soot and char), and source-characteristic PACs (combustion-derived PAHs and retene, etc.), indicated that PAHs, OPAHs and AZAs were mostly directly emitted from combustion activities and had similar post-emission fates, but NPAHs were possibly more intensely photolyzed after deposition as well as being emitted from vehicle exhaust sources. The incremental lifetime cancer risk (ILCR) resulting from exposure to urban dust bound-PACs was higher than 10(-6), indicating a non-negligible cancer risk to residents of Xi'an.

  18. Self-assembly and antimicrobial activity of long-chain amide-functionalized ionic liquids in aqueous solution.

    Science.gov (United States)

    Garcia, M Teresa; Ribosa, Isabel; Perez, Lourdes; Manresa, Angeles; Comelles, Francesc

    2014-11-01

    Surface active amide-functionalized ionic liquids (ILs) consisting of a long alkyl chain (C6C14) connected to a polar head group (methylimidazolium or pyridinium cation) via an amide functional group were synthesized and their thermal stability, micellar properties and antimicrobial activity in aqueous solution investigated. The incorporation of an amide group increased the thermal stability of the functionalized ionic liquids compared to simple alkyl chain substituted ionic liquids. The surface activity and aggregation behaviour in aqueous solution of amide-functionalized ionic liquids were examined by tensiometry, conductivity and spectrofluorimetry. Amide-functionalized ILs displayed surface activity and their critical micelle concentration (cmc) in aqueous media decreased with the elongation of the alkyl side chain as occurs for typical surfactants. Compared to non-functionalized ILs bearing the same alkyl chain, ionic liquids with an amide moiety possess higher surface activity (pC20) and lower cmc values. The introduction of an amide group in the hydrophobic chain close to the polar head enhances adsorption at the air/water interface and micellization which could be attributed to the H-bonding in the headgroup region. The antimicrobial activity was evaluated against a panel of representative Gram-negative and Gram-positive bacteria and fungi. Amide-functionalized ILs with more than eight carbon atoms in the side chain showed broad antimicrobial activity. Antibacterial activities were found to increase with the alkyl chain length being the C12 homologous the most effective antimicrobial agents. The introduction of an amide group enhanced significantly the antifungal activity as compared to non-functionalized ILs.

  19. Efficient Amide Based Halogenide Anion Receptors

    Institute of Scientific and Technical Information of China (English)

    Hong Xing WU; Feng Hua LI; Hai LIN; Shou Rong ZHU; Hua Kuan LIN

    2005-01-01

    In this paper, we present the synthesis and anion recognition properties of the amide based phenanthroline derivatives 1, 2 and 3. In all cases 1:1 receptor: anion complexes were observed. The receptors were found to be selective for fluoride and chloride respectively over other putative anionic guest species.

  20. Effect of donor strength of extended alkyl auxiliary groups on optoelectronic and charge transport properties of novel naphtha[2,1-b:6,5-b']difuran derivatives: simple yet effective strategy.

    Science.gov (United States)

    Chaudhry, Aijaz Rasool; Ahmed, R; Irfan, Ahmad; Shaari, A; Isa, Ahmad Radzi Mat; Muhammad, Shabbir; Al-Sehemi, Abdullah G

    2015-08-01

    The present study spotlights the designing of new derivatives of 2,7-bis (4-octylphenyl) naphtho [2,1-b:6,5-b'] difuran (C8-DPNDF) by substituting the alkyl groups (methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl groups) at para position. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods are employed to optimize the molecular structures in ground and first excited states, respectively. Several electro-optical properties including hole/electron reorganization energies (λh/λe), electron affinities (EAs), ionization potentials (IPs), molecular electrostatic potentials (MEP), and frontier molecular orbitals (FMOs) have been evaluated. Furthermore their transfer integrals and intrinsic mobilities values have also been calculated. From this study, it is found that hole mobility of octyl containing derivative is raised to 4.69 cm(2) V(-1) s(-1). Moreover with attaching octyl group, hole transfer integral values have also been enhanced in newly designed derivatives. The balanced hole and electron reorganization energies, and improved transfer integrals lead to enhanced mobility in derivatives with octyl group, highlighting them as an efficient hole transfer material. Unlike the other electro-optical properties, the intrinsic hole mobility has increased because of transfer integral values of octyl containing derivative C8-DPNDF due to the dense and close crystal packing of C8-DPNDF. However, photostability of furan-based materials has not changed by increasing length of extended alkyl chain. Thus our present investigation highlights the importance of alkyl auxiliary groups that are often neglected/replaced with simple methyl group to save computation costs. Graphical Abstract The hole and electron reorganization energies of naphtho[2,1-b:6,5-b']difuran derivatives. PMID:26177706

  1. Proton And Carbon-13 Nuclear Magnetic Resonance Of Some 4-Amino-3-Alkyl (Aryl)-5-Thio-1,2,4-Triazolines And Their Derivatives

    OpenAIRE

    El Toukhy, Ahmed [احمد الطوخي; Al-Kubaisi, Abdulla H.; Kenawy, Ibrahim

    1991-01-01

    The proton and carbon-13 NMR spectra of some 4-amino-3-alkyl(aryl)-5-thio-1,2,4-triazolines, some 3-alkyl-5-thio- 1,2,4-triazolines and some 4-amino-3-aryl-5-thio-l,2,4-triazoles were measured in DMSO-d6 as solvent. The chemical shift for each proton and carbon in these compounds were assigned. The 'H, chemical shift of N-H protons of the thioamide group and the "C chemical shift of C(3) in the triazolines were found to be sensitive to the substituent R (alkyi or aryl) at C(3), and correlated...

  2. The formation of [M-H]+ ions in N-alkyl-substituted thieno[3,4-c]-pyrrole-4,6-dione derivatives during atmospheric pressure photoionization mass spectrometry

    KAUST Repository

    Sioud, Salim

    2014-10-09

    RESULTS [M-H]+ ions were observed under APPI conditions. The type of dopant and the length of the alkyl chain affected the formation of these ions. MS/MS fragmentation of [M-H]+ and [M + H]+ ions exhibited completely different patterns. Theoretical calculations revealed that the loss of hydrogen molecules from the [M + H]+ ions is the most favourable condition under which to form [M-H]+ ions.CONCLUSIONS [M-H]+ ions were detected in all the TPD derivatives studied here under the special experimental conditions during APPI, using a halogenated benzene dopant, and TPD containing substituted N-alkyl side chains with a minimum of four carbon atoms. Density functional theory calculations showed that for [M-H]+ ions to be formed under these conditions, the loss of hydrogen molecules from the [M + H]+ ions is proposed to be necessary.RATIONALE The formation of ions during atmospheric pressure photoionization (APPI) mass spectrometry in the positive mode usually provides radical cations and/or protonated species. Intriguingly, during the analysis of some N-alkyl-substituted thieno[3,4-c]pyrrole-4,6-dione (TPD) derivatives synthesized in our laboratory, unusual [M-H]+ ion peaks were observed. In this work we investigate the formation of [M-H]+ ions observed under APPI conditions.METHODS Multiple experimental parameters, including the type of ionization source, the composition of the solvent, the type of dopant, the infusion flow rate, and the length of the alkyl side chain were investigated to determine their effects on the formation of [M-H]+ ions. In addition, a comparison study of the gas-phase tandem mass spectrometric (MS/MS) fragmentation of [M + H]+ vs [M-H]+ ions and computational approaches were used.

  3. Mesoporous Niobium Oxide Spheres as an Effective Catalyst for the Transamidation of Primary Amides with Amines

    KAUST Repository

    Ghosh, Subhash Chandra

    2014-02-06

    Mesoporous niobium oxide spheres (MNOS), conveniently prepared by a novel antisolvent precipitation approach, have been shown to be an effective catalyst for the transamidation of primary amides with amines. This novel transamidation can be efficiently carried out under solvent-free conditions and is applicable to a wide range of primary amides and amines to provide N-alkyl amides in good to excellent yields. The catalyst is highly stable and reusable. The application of this transamidation reaction has been demonstrated in the synthesis of antidepressant drug moclobemide and other druglike compounds. © 2014 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim.

  4. Selective anion sensing by a tris-amide CTV derivative: 1H NMR titration, self-assembled monolayers, and impedance spectroscopy.

    Science.gov (United States)

    Zhang, Sheng; Echegoyen, Luis

    2005-02-16

    A hydrogen-bond forming tris(amide) receptor based on cyclotriveratrylene (CTV) was prepared. Self-assembled monolayers (SAMs) of the receptor were formed on gold surfaces. Desorption experiments show a surface coverage of 2.26 x 10(-10) mol/cm(2). (1)H NMR and UV measurements confirm that the receptor exhibits the highest affinity for acetate ions among the anions studied. Electrochemical impedance was used to investigate anion sensing by the SAMs and proved to be an efficient and convenient technique for detecting anions in aqueous solutions. Upon binding acetate anions, the monolayer-modified gold electrodes show a drastic increase of the R(ct) values when Fe(CN)(6)(3-/4-) is used as the redox probe. When the probe was changed to a positively charged one, Ru(NH3)(6)(3+/2+), the R(ct) values decreased monotonically as the acetate concentration was increased, thus confirming the accumulation of negative surface charge upon anion binding. H(2)PO(4-) shows some interference when sensing AcO-. Other monovalent anions such as Cl-, Br-, NO3(-) and HSO4(-) do not bind to the CTV receptor either in solution or on the surfaces. PMID:15701037

  5. Diarmed (adamantyl/alkyl) surfactants from nitrilotriacetic acid.

    Science.gov (United States)

    Trillo, Juan V; Vázquez Tato, José; Jover, Aida; de Frutos, Santiago; Soto, Victor H; Galantini, Luciano; Meijide, Francisco

    2014-11-01

    The compounds presented here constitute a clear example of molecular biomimetics as their design is inspired on the structure and properties of natural phospholipids. Thus novel double-armed surfactants have been obtained in which nitrilotriacetic acid plays the role of glycerol in phospholipids. The hydrophobic arms are linked to the head group through amide bonds (which is also the case of sphingomyelin): (R1NHCOCH2)(R2NHCOCH2)NCH2CO2H (R1 being CH3(CH2)11, CH3(CH2)17, CH3(CH2)7CHCH(CH2)8, and adamantyl, and R2=adamantyl). The dependence of the surface tension with concentration shows the typical profile of surfactants since a breaking point, which corresponds to the critical aggregation concentration (cac), is observed in all cases. The cac of these diarmed derivatives are about 1-3 orders of magnitude lower than those of classical monoalkyl derivatives used as reference compounds. In contrast to conventional surfactants, reversed trends in cac values and molecular areas at the solution-air interface have been observed. This anomalous behavior is tied to the structure of the surfactants and suggests that long and flexible alkyl chains should self-coil previous to the aggregation or adsorption phenomena. Above cac all compounds form large aggregates, globular in shape, which tend to associate forming giant aggregates. PMID:25465758

  6. Backbone amide linker strategy

    DEFF Research Database (Denmark)

    Shelton, Anne Pernille Tofteng; Jensen, Knud Jørgen

    2013-01-01

    In the backbone amide linker (BAL) strategy, the peptide is anchored not at the C-terminus but through a backbone amide, which leaves the C-terminal available for various modifications. This is thus a very general strategy for the introduction of C-terminal modifications. The BAL strategy...... to assemble the final peptide. One useful application of this strategy is in the synthesis of C-terminal peptide aldehydes. The C-terminal aldehyde is masked as an acetal during synthesis and then conveniently demasked in the final cleavage step to generate the free aldehyde. Another application...... amino acid residue by reductive amination. This can be used as a general approach for the introduction of other C-terminal modifications as well as functionalities, such as fluorophors. The second step is an acylation of a secondary amine, followed by standard Fmoc-based solid-phase synthesis...

  7. Retinobenzoic acids. 4. Conformation of aromatic amides with retinoidal activity. Importance of trans-amide structure for the activity.

    Science.gov (United States)

    Kagechika, H; Himi, T; Kawachi, E; Shudo, K

    1989-10-01

    N-Methylation of two retinoidal amide compounds, 4-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carbamoyl]benz oic acid (3, Am80) and 4-[[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2- naphthalenyl)carbonyl]amino]benzoic acid (5, Am580), resulted in the disappearance of their potent differentiation-inducing activity on human promyelocytic leukemia cell line HL-60. Studies with 1H NMR and UV spectroscopy indicated that large conformational differences exist between the active secondary amides and the inactive N-methyl amides. From a comparison of the spectroscopic results of these amides with those of stilbene derivatives, the conformations of the active amides are expected to resemble that of (E)-stilbene, whereas the inactive amides resemble the Z isomer: 3 (Am80) and 5 (Am580) have a trans-amide bond and their whole structures are elongated, while the N-methylated compounds [4 (Am90) and 6 (Am590)] have a cis-amide bond, resulting in the folding of the two benzene rings. These structures in the crystals were related to those in solution by 13C NMR spectroscopic comparison between the two phases (solid and solution).

  8. Crystallochemical study of amides derived from 6{alpha}, 7{beta}-diidroxivoacapan-17{beta}-oic acid by X-ray diffraction; Estudo cristaloquimico de amidas derivadas do acido 6{alpha}, 7{beta}-di- hidroxivouacapan-17 {beta}-oico por difracao de raios-X

    Energy Technology Data Exchange (ETDEWEB)

    Branco, Marcello Cardoso; Prado Gambardella, Maria Teresa do [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica. Dept. de Quimica e Fisica Molecular

    1995-12-31

    Abstract. The 6{alpha}, 7{beta}-diidroxivoacapan-17{beta}-oic acid (DVA) is a Furane-diterpene isolated from Peterodon genus. It has anti inflammatory and analgesic properties. The purpose of this work is the characterization of amides derived from DVA, in order to understand the relationship between Chemical Structure and Biological Activity of Vouacapanes. The structures of DVA derivatives will be solved by single-crystal X-ray diffraction. (author) 15 refs., 2 figs.

  9. Preparation of a new chiral stationary phase for HPLC based on the (R)- 1-phenyl-2-(4-methylphenyl)ethylamine amide derivative of (S)-valine and 2-chloro-3,5-dinitrobenzoic acid: enantioseparation of amino acid derivatives and pyrethroid insecticides.

    Science.gov (United States)

    Tan, Xulin; Hou, Shicong; Jiang, Jingli; Wang, Min

    2007-08-01

    A novel chiral stationary phase (CSP) for HPLC was prepared by bonding (R)-1-phenyl-2-(4-methylphenyl)ethylamine amide derivative of (S)-valine to aminopropyl silica gel through a 2-amino-3,5-dinitro-1-carboxamido-benzene unit. The CSP was used for the separation of some amino acid derivatives and pyrethroid insecticides by chiral HPLC. Satisfactory baseline separation required optimization of the variables of mobile phase composition. Use of dichloromethane as modifier in the mobile phase gave baseline separations of amino acid derivatives. The two enantiomers of fenpropathrin and four stereoisomers of fenvalerate were baseline separated using hexane-dichloromethane-ethanol as mobile phase. The results show that the enantioselectivity of the new CSP is better than Pirkle type 1-A column for these compounds. Only partial separations were observed for the stereoisomers of cypermethrin and cyfluthrin, which gave even and eight peaks, respectively.

  10. Cleavage of an amide bond by a ribozyme

    Science.gov (United States)

    Dai, X.; De Mesmaeker, A.; Joyce, G. F.; Miller, S. L. (Principal Investigator)

    1995-01-01

    A variant form of a group I ribozyme, optimized by in vitro evolution for its ability to catalyze magnesium-dependent phosphoester transfer reactions involving DNA substrates, also catalyzes the cleavage of an unactivated alkyl amide when that linkage is presented in the context of an oligodeoxynucleotide analog. Substrates containing an amide bond that joins either two DNA oligos, or a DNA oligo and a short peptide, are cleaved in a magnesium-dependent fashion to generate the expected products. The first-order rate constant, kcat, is 0.1 x 10(-5) min-1 to 1 x 10(-5) min-1 for the DNA-flanked substrates, which corresponds to a rate acceleration of more than 10(3) as compared with the uncatalyzed reaction.

  11. Alkylator-Induced and Patient-Derived Xenograft Mouse Models of Therapy-Related Myeloid Neoplasms Model Clinical Disease and Suggest the Presence of Multiple Cell Subpopulations with Leukemia Stem Cell Activity.

    Science.gov (United States)

    Jonas, Brian A; Johnson, Carl; Gratzinger, Dita; Majeti, Ravindra

    2016-01-01

    Acute myeloid leukemia (AML) is a heterogeneous group of aggressive bone marrow cancers arising from transformed hematopoietic stem and progenitor cells (HSPC). Therapy-related AML and MDS (t-AML/MDS) comprise a subset of AML cases occurring after exposure to alkylating chemotherapy and/or radiation and are associated with a very poor prognosis. Less is known about the pathogenesis and disease-initiating/leukemia stem cell (LSC) subpopulations of t-AML/MDS compared to their de novo counterparts. Here, we report the development of mouse models of t-AML/MDS. First, we modeled alkylator-induced t-AML/MDS by exposing wild type adult mice to N-ethyl-N-nitrosurea (ENU), resulting in several models of AML and MDS that have clinical and pathologic characteristics consistent with human t-AML/MDS including cytopenia, myelodysplasia, and shortened overall survival. These models were limited by their inability to transplant clinically aggressive disease. Second, we established three patient-derived xenograft models of human t-AML. These models led to rapidly fatal disease in recipient immunodeficient xenografted mice. LSC activity was identified in multiple HSPC subpopulations suggesting there is no canonical LSC immunophenotype in human t-AML. Overall, we report several new t-AML/MDS mouse models that could potentially be used to further define disease pathogenesis and test novel therapeutics. PMID:27428079

  12. Alkylator-Induced and Patient-Derived Xenograft Mouse Models of Therapy-Related Myeloid Neoplasms Model Clinical Disease and Suggest the Presence of Multiple Cell Subpopulations with Leukemia Stem Cell Activity

    Science.gov (United States)

    Johnson, Carl; Gratzinger, Dita; Majeti, Ravindra

    2016-01-01

    Acute myeloid leukemia (AML) is a heterogeneous group of aggressive bone marrow cancers arising from transformed hematopoietic stem and progenitor cells (HSPC). Therapy-related AML and MDS (t-AML/MDS) comprise a subset of AML cases occurring after exposure to alkylating chemotherapy and/or radiation and are associated with a very poor prognosis. Less is known about the pathogenesis and disease-initiating/leukemia stem cell (LSC) subpopulations of t-AML/MDS compared to their de novo counterparts. Here, we report the development of mouse models of t-AML/MDS. First, we modeled alkylator-induced t-AML/MDS by exposing wild type adult mice to N-ethyl-N-nitrosurea (ENU), resulting in several models of AML and MDS that have clinical and pathologic characteristics consistent with human t-AML/MDS including cytopenia, myelodysplasia, and shortened overall survival. These models were limited by their inability to transplant clinically aggressive disease. Second, we established three patient-derived xenograft models of human t-AML. These models led to rapidly fatal disease in recipient immunodeficient xenografted mice. LSC activity was identified in multiple HSPC subpopulations suggesting there is no canonical LSC immunophenotype in human t-AML. Overall, we report several new t-AML/MDS mouse models that could potentially be used to further define disease pathogenesis and test novel therapeutics. PMID:27428079

  13. Cleavage kinetics and anchor linked intermediates in solid phase peptide amide synthesis.

    Science.gov (United States)

    Dürr, H; Beck-Sickinger, A G; Schnorrenberg, G; Rapp, W; Jung, G

    1991-08-01

    Kinetics and cleavage conditions of peptide amide synthesis were studied using the anchor molecules 5-(4'-aminomethyl-3',5'-dimethoxyphenoxy)valeric acid (4-ADPV-OH) and 5-(2'-aminomethyl-3'-5'-dimethoxyphenoxy) valeric acid (2-ADPV-OH). Unexpectedly the anchor amide alanyl-4-ADPV-NH2 was isolated and characterized as an intermediate during the cleavage with trifluoroacetic acid (TFA) of alanyl-4-ADPV-alanyl-aminomethyl-polystyrene to yield the alanine amide. As a matter of fact the NH--CH alpha bond of the alanyl spacer has to be cleaved to form this intermediate. Using TFA-dichloromethane (1:9) alanyl-4-ADPV-NH2 was obtained as a cleavage product in 50% yield within 60 min, whereas the isomeric alanyl-2-ADPV-NH2 was formed more slowly under these mild conditions. At high TFA concentration no difference between the 2- and 4-ADPV anchor was observed in the rate of formation of the free alanine amide. The presence of tryptophan amide in the cleavage mixture resulted in an anchor alkylated tryptophan amide, which remains stable in acidic solution but disappears rapidly in the presence of the resin. A low TFA/high TFA cleavage procedure is recommended for peptide amid synthesis applying the ADPV anchor.

  14. Spectroscopic and structural characterization of the charge-transfer interaction of N,N'-bis-alkyl derivatives of 1,4,6,8-naphthalenediimide with chloranilic and picric acids

    Science.gov (United States)

    Refat, Moamen S.; Ahmed, Hamdy A.; Grabchev, Ivo; El-Zayat, Lamia A.

    2008-09-01

    Charge-transfer (CT) complexes formed from the reactions of two N,N'-bis-alkyl derivatives of 1,4,6,8-naphthalenediimide such as N, N'-bis[2-hydroxyethyl)]-1,4,6,8-naphthalenediimide (BHENDI) and N, N'-bis-[2- N, N-dimethylaminoethyl)]-1,4,6,8-naphthalenediimide (BDMAENDI) with chloranilic acid (CLA) and piciric acid (PA) as π-acceptors, have been studied spectrophotometrically in methanol and chloroform, respectively at 25 °C. The photometric titration curves for the reactions indicated that the data obtained refer to 1:1 charge-transfer complexes of [(BHENDI)(CLA)], [(BDMAENDI)(CLA)], [(BHENDI)(PA)] and [(BDMAENDI)(PA)] were formed. Benesi-Hildebrand and its modification methods were applied to the determination of association constant ( K), molar extinction coefficient ( ɛ). The solid CT complexes have been synthesized and characterization by different spectral methods.

  15. Selective and reactive hydration of nitriles to amides in water using silver nanoparticles stabilized by organic ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Koji [Hokkaido University, Division of Materials Science and Engineering, Faculty of Engineering (Japan); Kawakami, Hayato [Miyoshi Oil & Fat Co., Ltd. (Japan); Narushima, Takashi; Yonezawa, Tetsu, E-mail: tetsu@eng.hokudai.ac.jp [Hokkaido University, Division of Materials Science and Engineering, Faculty of Engineering (Japan)

    2015-02-15

    Water-dispersible silver nanoparticles stabilized by silver–carbon covalent bonds were prepared. They exhibited high catalytic activities for the selective hydration of nitriles to amides in water. The activation of a nitrile group by the functional groups of the substrates and the hydrophobic layer on the nanoparticles influenced the catalyzed reaction were confirmed. Alkyl nitriles could also be selectively hydrated.

  16. Nanostructured poly(benzimidazole membranes by N-alkylation

    Directory of Open Access Journals (Sweden)

    J. Weber

    2014-01-01

    Full Text Available Modification of poly(benzimidazole (PBI by N-alkylation leads to polymers capable of undergoing microphase separation. Polymers with different amounts of C18 alkyl chains have been prepared. The polymers were analyzed by spectroscopy, thermal analysis, electron microscopy and X-ray scattering. The impact of the amount of alkyl chains on the observed microphase separation was analyzed. Membranes prepared from the polymers do show microphase separation, as evidenced by scattering experiments. While no clear morphology could be derived for the domains in the native state, evidence for the formation of lamellar morphologies upon doping with phosphoric acid is provided. Finally, the proton conductivity of alkyl-modified PBI is compared with that of pure PBI, showing that the introduction of alkyl side chains does not result in significant conductivity changes.

  17. Synthesis of Glycosyl Amides Using Selenocarboxylates as Traceless Reagents for Amide Bond Formation.

    Science.gov (United States)

    Silva, Luana; Affeldt, Ricardo F; Lüdtke, Diogo S

    2016-07-01

    Carbohydrate-derived amides were successfully prepared in good yields from a broad range of substrates, including furanosyl and pyranosyl derivatives. The methodology successfully relied on the in situ generation of lithium selenocarboxylates from Se/LiEt3BH and acyl chlorides or carboxylic acids and their reaction with sugar azides. A key aspect of the present protocol is that we start from elemental selenium; isolation and handling of all reactive and sensitive selenium-containing intermediates is avoided, therefore providing the selenocarboxylate the status of a traceless reagent. PMID:27275515

  18. Supported Gold Nanoparticles for Efficient α-Oxygenation of Secondary and Tertiary Amines into Amides.

    Science.gov (United States)

    Jin, Xiongjie; Kataoka, Kengo; Yatabe, Takafumi; Yamaguchi, Kazuya; Mizuno, Noritaka

    2016-06-13

    Although the α-oxygenation of amines is a highly attractive method for the synthesis of amides, efficient catalysts suited to a wide range of secondary and tertiary alkyl amines using O2 as the terminal oxidant have no precedent. This report describes a novel, green α-oxygenation of a wide range of linear and cyclic secondary and tertiary amines mediated by gold nanoparticles supported on alumina (Au/Al2 O3 ). The observed catalysis was truly heterogeneous, and the catalyst could be reused. The present α-oxygenation utilizes O2 as the terminal oxidant and water as the oxygen atom source of amides. The method generates water as the only theoretical by-product, which highlights the environmentally benign nature of the present reaction. Additionally, the present α-oxygenation provides a convenient method for the synthesis of (18) O-labeled amides using H2 (18) O as the oxygen source. PMID:27151621

  19. Design, synthesis, and fungicidal activities of imino diacid analogs of valine amide fungicides.

    Science.gov (United States)

    Sun, Man; Yang, Hui-Hui; Tian, Lei; Li, Jian-Qiang; Zhao, Wei-Guang

    2015-12-15

    The novel imino diacid analogs of valine amides were synthesized via several steps, including the protection, amidation, deprotection, and amino alkylation of valine, with the resulting structures confirmed by (1)H and (13)C NMR and HRMS. Bioassays showed that some of these compounds exhibited good fungicidal activity. Notably, isopropyl 2-((1-((1-(3-fluorophenyl)ethyl)amino)-3-methyl-1-oxobutan-2-yl)amino)propanoate 5i displayed significant levels of control, at 50%, against Erysiphe graminis at 3.9μM as well as a level of potency very similar to the reference azoxystrobin, which gave 60% activity at this concentration. The present work demonstrates that imino diacid analogs of valine amides could be potentially useful key compounds for the development of novel fungicides against wheat powdery mildew.

  20. Synthesis of {alpha}- and {beta}-lapachone derivatives from hetero diels-alder trapping of alkyl and aryl o-quinone methides

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fernando de C. da; Ferreira, Sabrina B.; Ferreira, Vitor F. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Quimica. Dept. de Quimica Organica], e-mail: cegvito@vm.uff.br; Kaiser, Carlos R.; Pinto, Angelo C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica

    2009-07-01

    Methylene and aryl o-quinone methides (o-QMs) generated by Knoevenagel condensation of 2-hydroxy-1,4-naphthoquinone with formaldehyde and arylaldehydes, undergo facile hetero Diels-Alder reaction with some substituted styrenes (as dienophiles) in aqueous ethanol media providing derivatives of {alpha}- and {beta}-lapachone (author)

  1. Selective Pro-Apoptotic Activity of Novel 3,3′-(Aryl/Alkyl-Methylene)Bis(2-Hydroxynaphthalene-1,4-Dione) Derivatives on Human Cancer Cells via the Induction Reactive Oxygen Species

    Science.gov (United States)

    Sinha, Krishnendu; Brahmachari, Goutam; Sil, Parames C.

    2016-01-01

    Selective induction of apoptosis in cancer cells barring the normal cells is considered as an effective strategy to combat cancer. In the present study, a series of twenty-two (22) synthetic 3,3'-(aryl/alkyl-methylene)bis(2-hydroxynaphthalene-1,4-dione) bis-lawsone derivatives were assayed for their pro-apoptotic activity in six different cell lines (five cancerous and one normal) using MTT assay. Out of these 22 test compounds, 1j was found to be the most effective in inducing apoptosis in human glioma cells (CCF-4) among the different cell lines used in the study. The activity of this compound, 1j, was then compared to a popular anticancer drug, cisplatin, having limited usage because of its nephrotoxic nature. In this study, 1j derivative showed much less toxicity to the normal kidney cells compared to cisplatin, thus indicating the superiority of 1j as a possible anticancer agent. This compound was observed to induce apoptosis in the glioma cells by inducing the caspase dependent apoptotic pathways via ROS and downregulating the PI3K/AKT/mTOR pathway. Estimation of different oxidative stress markers also confirms the induction of oxidative stress in 1j exposed cancer cells. The toxicity of 1j compound toward cancer cells was confirmed further by different flow cytometrical analyses to estimate the mitochondrial membrane potential and cell cycle. The sensitivity of malignant cells to apoptosis, provoked by this synthetic derivative in vitro, deserves further studies in suitable in vivo models. These studies not only identified a novel anticancer drug candidate but also help to understand the metabolism of ROS and its application in cancer treatment. PMID:27380262

  2. Iodine-Catalyzed Decarboxylative Amidation of β,γ-Unsaturated Carboxylic Acids with Chloramine Salts Leading to Allylic Amides.

    Science.gov (United States)

    Kiyokawa, Kensuke; Kojima, Takumi; Hishikawa, Yusuke; Minakata, Satoshi

    2015-10-26

    The iodine-catalyzed decarboxylative amidation of β,γ-unsaturated carboxylic acids with chloramine salts is described. This method enables the regioselective synthesis of allylic amides from various types of β,γ-unsaturated carboxylic acids containing substituents at the α- and β-positions. In the reaction, N-iodo-N-chloroamides, generated by the reaction of a chloramine salt with I2 , function as a key active species. The reaction provides an attractive alternative to existing methods for the synthesis of useful secondary allylic amine derivatives. PMID:26493878

  3. Syntheses of Macrocyclic Amides from L-Amino Acid Esters by RCM

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A series of succinate-derived macrocyclic amides( 1 ) was synthesized via ring-closing metathesis (RCM) as the key step. The substrate included 12 to 15 members. The metathesis precursors were obtained from the amide coupling of tert-butyl 3-carboxyhex-5-enoate(2) with numerous side-chain alkenylated amino acid esters of general type(3)derived from L-lysine and L-ornithine.

  4. Method of making alkyl esters

    Science.gov (United States)

    Elliott, Brian

    2010-09-14

    Methods of making alkyl esters are described herein. The methods are capable of using raw, unprocessed, low-cost feedstocks and waste grease. Generally, the method involves converting a glyceride source to a fatty acid composition and esterifying the fatty acid composition to make alkyl esters. In an embodiment, a method of making alkyl esters comprises providing a glyceride source. The method further comprises converting the glyceride source to a fatty acid composition comprising free fatty acids and less than about 1% glyceride by mass. Moreover, the method comprises esterifying the fatty acid composition in the presence of a solid acid catalyst at a temperature ranging firm about 70.degree. C. to about 120.degree. C. to produce alkyl esters, such that at least 85% of the free fatty acids are converted to alkyl esters. The method also incorporates the use of packed bed reactors for glyceride conversion and/or fatty acid esterification to make alkyl esters.

  5. Cu(I)-Catalyzed Enantioselective Friedel-Crafts Alkylation of Indoles with 2-Aryl-N-sulfonylaziridines as Alkylating Agents.

    Science.gov (United States)

    Ge, Chen; Liu, Ren-Rong; Gao, Jian-Rong; Jia, Yi-Xia

    2016-07-01

    A highly enantioselective Friedel-Crafts alkylation of indoles with N-sulfonylaziridines as alkylating agents has been developed by utilizing the complex of Cu(CH3CN)4BF4/(S)-Segphos as a catalyst. A range of optically active tryptamine derivatives are obtained in good to excellent yields and enantioselectivities (up to >99% ee) via a kinetic resolution process. PMID:27309541

  6. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl...

  7. Surprisingly Mild Enolate-Counterion-Free Pd(0)-Catalyzed Intramolecular Allylic Alkylations

    DEFF Research Database (Denmark)

    Madec, David; Prestat, Guillaume; Martini, Elisabetta;

    2005-01-01

    Palladium-catalyzed intramolecular allylic alkylations of unsaturated EWG-activated amides can take place under phase-transfer conditions or in the presence of a crown ether. These new reaction conditions are milder and higher yielding than those previously reported. A rationalization for such an...... for such an unexpected result is put forth and validated by DFT-B3LYP calculations. The results suggest cyclization via a counterion-free (E)-enolate TS....

  8. Synthesis of Hydroxytyrosyl Alkyl Ethers from Olive Oil Waste Waters

    Directory of Open Access Journals (Sweden)

    Juan Fernández-Bolaños

    2009-05-01

    Full Text Available The preparation of a new type of derivatives of the naturally occurring antioxidant hydroxytyrosol is reported. Hydroxytyrosyl alkyl ethers were obtained in high yield by a three-step procedure starting from hydroxytyrosol isolated from olive oil waste waters. Preliminary results obtained by the Rancimat method have shown that these derivatives retain the high protective capacity of free hydroxytyrosol.

  9. A Versatile Approach for the Asymmetric Synthesis of 3-Alkyl-isoindolin-1-ones

    Institute of Scientific and Technical Information of China (English)

    CHEN,Ming-De(陈明德); HE,Ming-Zhu(贺明珠); HUANG,Li-Qiang(黄利强); RUAN, Yuan-Ping( 阮源萍 ); HUANG, Pei-Qiang (黄培强)

    2002-01-01

    A flexxible approach to(R)-3-alkyl-isoindolin-1-ones and (R)-3-aryl-isoindolin-1-ones via a diastereoselective-alkylation is described. Present method is versatile in scope, allowing the easy introduction of various C-3 substituents by Grignard addition to phthalimide derived from (R)-phenylglycinol.3-Alkyl-3-hydroxy-isoindolin-1-ones can also be obtained in the first step of the present method.

  10. Synthesis and characterization of alternating poly(amide urethane)s

    OpenAIRE

    Sharma, Bhaskar

    2004-01-01

    This thesis deals with the preparation of alternating poly(amide urethane)s which might be of interest for the manufacture of powder coatings. The synthesis of poly(amide urethane)s was performed in environmentally friendly way without using isocyanates or phosgene. The starting materials for the synthesis were e-caprolactam, e-caprolactone, amino alcohols, diamines and carbonic acid derivatives, i.e. diphenyl carbonate and ethylene carbonate as substitutes for phosgene. A new synthesis was d...

  11. Thermally induced alkylation of diamond.

    Science.gov (United States)

    Hoeb, Marco; Auernhammer, Marianne; Schoell, Sebastian J; Brandt, Martin S; Garrido, Jose A; Stutzmann, Martin; Sharp, Ian D

    2010-12-21

    We present an approach for the thermally activated formation of alkene-derived self-assembled monolayers on oxygen-terminated single and polycrystalline diamond surfaces. Chemical modification of the oxygen and hydrogen plasma-treated samples was achieved by heating in 1-octadecene. The resulting layers were characterized using X-ray photoelectron spectroscopy, thermal desorption spectroscopy, atomic force microscopy, Fourier transform infrared spectroscopy, and water contact angle measurements. This investigation reveals that alkenes selectively attach to the oxygen-terminated sites via covalent C-O-C bonds. The hydrophilic oxygen-terminated diamond is rendered strongly hydrophobic following this reaction. The nature of the process limits the organic layer growth to a single monolayer, and FTIR measurements reveal that such monolayers are dense and well ordered. In contrast, hydrogen-terminated diamond sites remain unaffected by this process. This method is thus complementary to the UV-initiated reaction of alkenes with diamond, which exhibits the opposite reactivity contrast. Thermal alkylation increases the range of available diamond functionalization strategies and provides a means of straightforwardly forming single organic layers in order to engineer the surface properties of diamond. PMID:21090790

  12. Synthesis of 2-substituted tryptophans via a C3- to C2-alkyl migration

    Directory of Open Access Journals (Sweden)

    Michele Mari

    2014-08-01

    Full Text Available The reaction of 3-substituted indoles with dehydroalanine (Dha derivatives under Lewis acid-mediated conditions has been investigated. The formation of 2-substituted tryptophans is proposed to occur through a selective alkylative dearomatization–cyclization followed by C3- to C2-alkyl migration and rearomatization.

  13. γ‐ and δ-Lactams through Palladium-Catalyzed Intramolecular Allylic Alkylation: Enantioselective Synthesis, NMR Investigation, and DFT Rationalization

    DEFF Research Database (Denmark)

    Bantreil, Xavier; Prestat, Guillaume; Moreno, Aitor;

    2011-01-01

    The Pd-catalyzed intramolecular allylic alkylation of unsaturated amides to give gamma- and delta-lactams has been studied in the presence of chiral ligands. Ligand (R)-3,5-tBu-MeOBIPHEP (MeOBIPHEP=6,6'-dimethoxybiphenyl-2,2-diyl)bis(diphenylphosphine)) afforded the best results and allowed the c...

  14. Columnar mesophase from non-symmetrical tapered hydrazide derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Bai Binglian, E-mail: baibinglian@jlu.edu.cn [Key Laboratory for Automobile Materials (JLU), Ministry of Education, Institute of Materials Science and Engineering, Jilin University, Changchun 130012 (China); College of Physics, Jilin University, Changchun 130012 (China); Zhao Chengxiao; Wang Haitao; Ran Xia [Key Laboratory for Automobile Materials (JLU), Ministry of Education, Institute of Materials Science and Engineering, Jilin University, Changchun 130012 (China); Wang Dan [College of Physics, Jilin University, Changchun 130012 (China); Li Min, E-mail: minli@mail.jlu.edu.cn [Key Laboratory for Automobile Materials (JLU), Ministry of Education, Institute of Materials Science and Engineering, Jilin University, Changchun 130012 (China)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer We aimed at developing new liquid-crystalline hydrazide derivatives. Black-Right-Pointing-Pointer The columnar mesophases are observed in these hydrazide derivatives. Black-Right-Pointing-Pointer Experimental results revealed that the amide protons of the central hydrazide group participated in intermolecular double hydrogen bonds based on C=O and -NH in mesophase. Black-Right-Pointing-Pointer The intermolecular hydrogen-bonding interaction among dihydrazine units is the main driving force to form the mesophase. - Abstract: A new series of liquid-crystalline tapered hydrazide derivatives with an amino head group, e.g. N-(3,4,5-trialkoxylbenzoyl)-N Prime -(4 Prime -aminobenzoyl) hydrazine (Dn, where n is the number of carbon atoms in the alkyl chains, n = 6, 8, 16), were designed and synthesized. Results of {sup 1}H NMR diluting experiment and FTIR spectroscopy revealed that the amide protons of the central hydrazide group in Dn participated in intermolecular double hydrogen bonds based on C=O and -NH in liquid crystalline phase. Investigations on the liquid crystalline properties showed that the D6 exhibited non-mesophase, D8 exhibited monotropic hexagonal columnar mesophase, while D16 exhibited enantiotropic oblique columnar mesophase with increasing the length of the terminal chains.

  15. Isolation of a Cyclic (Alkyl(aminogermylene

    Directory of Open Access Journals (Sweden)

    Liliang Wang

    2016-07-01

    Full Text Available A 1,4-addition of a dichlorogermylene dioxane complex with α,β-unsaturated imine 1 gave a dichlorogermane derivative 2 bearing a GeC3N five-membered ring skeleton. By reducing 2 with KC8, cyclic (alkyl(aminogermylene 3 was synthesized and fully characterized. Germylene 3 readily reacted with TEMPO, N2O and S8, producing the 1:2 adduct 4, the oxo-bridged dimer 5 and the sulfido-bridged dimer 6, respectively.

  16. The use of chiral lithium amides in the desymmetrisation of N-trialkylsilyl dimethyl sulfoximines

    Directory of Open Access Journals (Sweden)

    McGrath Matthew J

    2007-10-01

    Full Text Available Abstract Background Chiral base desymmetrisation of dimethyl sulfoximines could provide a general route to chiral, enantioenriched dialkyl sulfoximines with potential for use in asymmetric catalysis. Results Asymmetric deprotonation of N-trialkylsilyl dimethyl sulfoximines with either enantiomer of lithium N,N-bis(1-phenylethylamide in the presence of lithium chloride affords enantioenriched sulfoximines on electrophilic trapping. Ketones, ketimines, trialkylsilyl chlorides and activated alkyl halides may be used as electrophiles in the reaction. Furthermore, a modified Horner-Emmons methodology was investigated. Conclusion Simple chiral lithium amides afford products with enantiomeric excesses of up to 70%, illustrating that chiral base desymmetrisation of dimethyl sulfoximines is possible.

  17. Catalytic synthesis of amides via aldoximes rearrangement.

    Science.gov (United States)

    Crochet, Pascale; Cadierno, Victorio

    2015-02-14

    Amide bond formation reactions are among the most important transformations in organic chemistry because of the widespread occurrence of amides in pharmaceuticals, natural products and biologically active compounds. The Beckmann rearrangement is a well-known method to generate secondary amides from ketoximes. However, under the acidic conditions commonly employed, aldoximes RHC=NOH rarely rearrange into the corresponding primary amides RC(=O)NH2. In recent years, it was demonstrated that this atom-economical transformation can be carried out efficiently and selectively with the help of metal catalysts. Several homogeneous and heterogenous systems have been described. In addition, protocols offering the option to generate the aldoximes in situ from the corresponding aldehydes and hydroxylamine, or even from alcohols, have also been developed, as well as a series of tandem processes allowing the access to N-substituted amide products. In this Feature article a comprehensive overview of the advances achieved in this particular research area is presented.

  18. Alkyl and aryl neoalkanamides: highly effective insect repellents.

    Science.gov (United States)

    Steltenkamp, R J; Hamilton, R L; Cooper, R A; Schal, C

    1992-03-01

    Alkyl and aryl neoalkanamides with a total carbon number between 11 and 14, or within a molecular weight range between 185 and 227, were highly effective repellents of male German cockroaches, Blattella germanica (L.). Comparison with known repellents showed that members of this unique family of secondary amides are among the most effective and long-lasting repellents of cockroaches examined to date. In assays with females and nymphs of the German cockroach, male American cockroaches, Periplaneta americana (L.), and carpenter ant workers, Camponotus pennsylvanicus (De Geer) methyl neodecanamide, propyl neodecanamide, and methyl neotridecanamide were found highly repellent. Because of their broad spectrum of activity, longevity, and safety, these compounds, along with several other members of this family, have important applications as repellents of nuisance pests and of arthropods of public health importance. PMID:1495022

  19. Metal extraction by amides of carboxylic acids

    International Nuclear Information System (INIS)

    Extraction ability of various amides was studied. Data on extraction of rare earths, vanadium, molybdenum, rhenium, uranium, niobium, tantalum by N,N-dibutyl-amides of acetic, nonanic acids and fatly synthetic acids of C7-C9 fractions are presented. Effect of salting-out agents, inorganic acid concentrations on extraction process was studied. Potential ability of using amides of carboxylic acids for extractional concentration of rare earths as well as for recovery and separation of iron, rhenium, vanadium, molybdenum, uranium, niobium, and tantalum was shown

  20. Synthesis, Anticancer and Antibacterial Activity of Salinomycin N-Benzyl Amides

    Directory of Open Access Journals (Sweden)

    Michał Antoszczak

    2014-11-01

    Full Text Available A series of 12 novel monosubstituted N-benzyl amides of salinomycin (SAL was synthesized for the first time and characterized by NMR and FT-IR spectroscopic methods. Molecular structures of three salinomycin derivatives in the solid state were determined using single crystal X-ray method. All compounds obtained were screened for their antiproliferative activity against various human cancer cell lines as well as against the most problematic bacteria strains such as methicillin-resistant Staphylococcus aureus (MRSA and Staphylococcus epidermidis (MRSE, and Mycobacterium tuberculosis. Novel salinomycin derivatives exhibited potent anticancer activity against drug-resistant cell lines. Additionally, two N-benzyl amides of salinomycin revealed interesting antibacterial activity. The most active were N-benzyl amides of SAL substituted at -ortho position and the least anticancer active derivatives were those substituted at the -para position.

  1. Novel endogenous N-acyl amides activate TRPV1-4 receptors, BV-2 microglia, and are regulated in brain in an acute model of inflammation

    Directory of Open Access Journals (Sweden)

    Siham eRaboune

    2014-08-01

    Full Text Available A family of endogenous lipids, structurally analogous to the endogenous cannabinoid, N-arachidonoyl ethanolamine (Anandamide, and called N-acyl amides have emerged as a family of biologically active compounds at TRP receptors. N-acyl amides are constructed from an acyl group and an amine via an amide bond. This same structure can be modified by changing either the fatty acid or the amide to form potentially hundreds of lipids. More than 70 N-acyl amides have been identified in nature. We have ongoing studies aimed at isolating and characterizing additional members of the family of N-acyl amides in both central and peripheral tissues in mammalian systems. Here, using a unique in-house library of over 70 N-acyl amides we tested the following three hypotheses: 1 Additional N-acyl amides will have activity at TRPV1-4, 2 Acute peripheral injury will drive changes in CNS levels of N-acyl amides, and 3 N-acyl amides will regulate calcium in CNS-derived microglia. Through these studies, we have identified 20 novel N-acyl amides that collectively activate (stimulating or inhibiting TRPV1-4. Using lipid extraction and HPLC coupled to tandem mass spectrometry we showed that levels of at least 10 of these N-acyl amides that activate TRPVs are regulated in brain after intraplantar carrageenan injection. We then screened the BV2 microglial cell line for activity with this N-acyl amide library and found overlap with TRPV receptor activity as well as additional activators of calcium mobilization from these lipids. Together these data provide new insight into the family of N-acyl amides and their roles as signaling molecules at ion channels, in microglia, and in the brain in the context of inflammation.

  2. Synthesis and Performance of a Biomimetic Indicator for Alkylating Agents.

    Science.gov (United States)

    Provencher, Philip A; Love, Jennifer A

    2015-10-01

    4-(4-Nitrobenzyl)pyridine (NBP) is a colorimetric indicator compound for many types of carcinogenic alkylating agents. Because of the similar reactivity of NBP and guanine in DNA, NBP serves as a DNA model. NBP assays are used in the toxicological screening of pharmaceutical compounds, detection of chemical warfare agents, environmental hygiene technology, preliminary toxicology tests, mutagenicity of medicinal compounds, and other chemical analyses. Nevertheless, the use of NBP as a DNA model suffers from the compound's low water solubility, its lack of reactive oxygen sites, and dissimilar steric encumbrance compared to DNA. We report herein the design and synthesis of NBP derivatives that address some of these issues. These derivatives have been tested in solution and found to be superior in the colorimetric assay of the alkylating anticancer drug cyclophosphamide. The derivatives have also been integrated into a polymeric silica material which changes color upon the exposure to dangerous alkylating agents, such as iodomethane vapor, without the need for an exogenous base. This material modernizes the NBP assay from a time-consuming laboratory analysis to a real-time solid state sensor, which requires neither solvent nor additional reagents and can detect both gas- and solution-phase alkylating agents.

  3. A biological source of oceanic alkyl nitrates

    Science.gov (United States)

    Dahl, E. E.; Lewis, C. B.; Velasco, F. L.; Escobar, C.; Kellogg, D.; Velcamp, M.

    2013-12-01

    Alkyl nitrates are an important component of reactive nitrogen in the troposphere. The oceans are a source of alkyl nitrates to the atmosphere, however the source of alkyl nitrates in the oceans is unknown. It has been demonstrated that the reaction of alkyl peroxy radicals (ROO) with nitric oxide (NO) produces alkyl nitrates in the aqueous phase. We hypothesize that alkyl nitrates may be formed by organisms through the same reaction and therefore biological production could be a source of alkyl nitrates to the troposphere. This work focuses on the production of alkyl nitrates by the diatoms Chaetoceros muelleri and Thalassiosira weisfloggi. Using chemostats, we measure alkyl nitrates formed under nitrate limited conditions. We also use triggers and inhibitors of nitric oxide formation to determine if alkyl nitrate formation is affected by changes in NO production. To date, the rates of production of alkyl nitrates in our cultures, lead us to estimate a production rate on the order of femtomolar/day for C1-C3 alkyl nitrates by diatom species in the equatorial Pacific Ocean. This suggests that diatoms may contribute to the overall ocean source of alkyl nitrates; however, it is possible that other types of phytoplankton, such as cyanobacteria, that are more abundant in the open ocean, may contribute to a greater extent.

  4. Recent developments in amide synthesis: direct amidation of carboxylic acids and transamidation reactions

    OpenAIRE

    Lanigan, R. M.; Sheppard, T. D.

    2013-01-01

    The synthesis of amides is of huge importance in a wide variety of industrial and academic fields and is of particular significance in the synthesis of pharmaceuticals. Many of the well established methods for amide synthesis involve reagents that are difficult to handle and lead to the generation of large quantities of waste products. As a consequence, there has been a considerable amount of interest in the development of new approaches to amide synthesis. Over the past few years a wide rang...

  5. CHROMIUM(II) AMIDES - SYNTHESIS AND STRUCTURES

    NARCIS (Netherlands)

    EDEMA, JJH; GAMBAROTTA, S; MEETSMA, A; SPEK, AL; SMEETS, WJJ; CHIANG, MY

    1993-01-01

    A novel class of mono- and di-meric chromium(II) amides has been prepared and characterized. Reaction of [CrCl2(thf)2] (thf = tetrahydrofuran) with 2 equivalents of M(NR2) (R = C6H11, Pr(i), Ph, or phenothiazinyl; M = Li or Na) allowed the formation of the homoleptic amides [{Cr(mu-NR2)(NR2)}2] (R =

  6. Quantitative structure–activity relationships for chronic toxicity of alkyl-chrysenes and alkyl-benz[a]anthracenes to Japanese medaka embryos (Oryzias latipes)

    International Nuclear Information System (INIS)

    Highlights: • Medaka embryos were exposed to alkyl chrysenes and benzo[a]anthracenes (BAA). • Concentrations were kept constant by partition controlled delivery. • Chrysene was not toxic within solubility limits, in contrast to BAA. • Alkylation increased the toxicity of chrysene and BAA. • Toxicity was related to hydrophobicity and to specific modes of action. - Abstract: Alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) are a class of compounds found at significant concentrations in crude oils, and likely the main constituents responsible for the chronic toxicity of oil to fish. Alkyl substituents at different locations on the aromatic rings change the size and shape of PAH molecules, which results in different interactions with tissue receptors and different severities of toxicity. The present study is the first to report the toxicity of several alkylated derivatives of chrysene and benz[a]anthracene to the embryos of Japanese medaka (Oryzias latipes) using the partition controlled delivery (PCD) method of exposure. The PCD method maintained the desired exposure concentrations by equilibrium partitioning of hydrophobic test compounds from polydimethylsiloxane (PDMS) films. Test concentrations declined by only 13% over a period of 17 days. Based on the prevalence of signs of blue sac disease (BSD), as expressed by median effective concentrations (EC50s), benz[a]anthracene (B[a]A) was more toxic than chrysene. Alkylation generally increased toxicity, except at position 2 of B[a]A. Alkyl-PAHs substituted in the middle region had a lower EC50 than those substituted at the distal region. Except for B[a]A and 7-methylbenz[a]anthracene (7-MB), estimated EC50 values were higher than their solubility limits, which resulted in limited toxicity within the range of test concentrations. The regression between log EC50s and log Kow values provided a rough estimation of structure–activity relationships for alkyl-PAHs, but Kow alone did not provide a complete

  7. Chemical Modifications of Hyaluronan using DMTMM-Activated Amidation

    OpenAIRE

    Rydergren, Sara

    2013-01-01

    An alternative approach to chemically modifying hyaluronan (HA) has been investigated. The triazine derivative 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium (DMTMM) has been used to activate carboxylic groups on HA, which react further to form stable amide bonds with primary and secondary amines. The reaction can either be used to couple monoamines to HA or to produce hydrogels by using diamines that form crosslinks between the HA chains. The reaction between HA and DMTMM has been...

  8. Introduction of Peripheral Carboxylates to Decrease the Charge on Tm(3+) DOTAM-Alkyl Complexes: Implications for Detection Sensitivity and in Vivo Toxicity of PARACEST MRI Contrast Agents.

    Science.gov (United States)

    Suchý, Mojmír; Milne, Mark; Elmehriki, Adam A H; McVicar, Nevin; Li, Alex X; Bartha, Robert; Hudson, Robert H E

    2015-08-27

    A series of structurally modified Tm(3+) DOTAM-alkyl complexes as potential PARACEST MRI contrast agents has been synthesized with the aim to decrease the overall positive charge associated with these molecules and increase their biocompatibility. Two types of structural modification have been performed, an introduction of terminal carboxylate arms to the alkyl side chains and a conjugation of one of the alkyl side chains with aspartic acid. Detailed evaluation of the magnetic resonance imaging chemical exchange contrast associated with the structurally modified contrast agents has been performed. In contrast to the acutely toxic Tm(3+) DOTAM-alkyl complexes, the structurally modified compounds were found to be tolerated well during in vivo MRI studies in mice; however, only the aspartic acid modified chelates produced an amide proton-based PARACEST signal.

  9. Sequential backbone assignment based on dipolar amide-to-amide correlation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, ShengQi; Grohe, Kristof; Rovó, Petra; Vasa, Suresh Kumar; Giller, Karin; Becker, Stefan; Linser, Rasmus, E-mail: rali@nmr.mpibpc.mpg.de [Max Planck Institute for Biophysical Chemistry, Department for NMR-Based Structural Biology (Germany)

    2015-07-15

    Proton detection in solid-state NMR has seen a tremendous increase in popularity in the last years. New experimental techniques allow to exploit protons as an additional source of information on structure, dynamics, and protein interactions with their surroundings. In addition, sensitivity is mostly improved and ambiguity in assignment experiments reduced. We show here that, in the solid state, sequential amide-to-amide correlations turn out to be an excellent, complementary way to exploit amide shifts for unambiguous backbone assignment. For a general assessment, we compare amide-to-amide experiments with the more common {sup 13}C-shift-based methods. Exploiting efficient CP magnetization transfers rather than less efficient INEPT periods, our results suggest that the approach is very feasible for solid-state NMR.

  10. Computation of the amide I band of polypeptides and proteins using a partial Hessian approach.

    Science.gov (United States)

    Besley, Nicholas A; Metcalf, Katie A

    2007-01-21

    A partial Hessian approximation for the computation of the amide I band of polypeptides and proteins is introduced. This approximation exploits the nature of the amide I band, which is largely localized on the carbonyl groups of the backbone amide residues. For a set of model peptides, harmonic frequencies computed from the Hessian comprising only derivatives of the energy with respect to the displacement of the carbon, oxygen, and nitrogen atoms of the backbone amide groups introduce mean absolute errors of 15 and 10 cm(-1) from the full Hessian values at the Hartree-Fock/STO-3G and density functional theory EDF16-31G(*) levels of theory, respectively. Limiting the partial Hessian to include only derivatives with respect to the displacement of the backbone carbon and oxygen atoms yields corresponding errors of 24 and 22 cm(-1). Both approximations reproduce the full Hessian band profiles well with only a small shift to lower wave number. Computationally, the partial Hessian approximation is used in the solution of the coupled perturbed Hartree-Fock/Kohn-Sham equations and the evaluation of the second derivatives of the electron repulsion integrals. The resulting computational savings are substantial and grow with the size of the polypeptide. At the HF/STO-3G level, the partial Hessian calculation for a polypeptide comprising five tryptophan residues takes approximately 10%-15% of the time for the full Hessian calculation. Using the partial Hessian method, the amide I bands of the constituent secondary structure elements of the protein agitoxin 2 (PDB code 1AGT) are calculated, and the amide I band of the full protein estimated. PMID:17249900

  11. High-Throughput Screening of the Asymmetric Decarboxylative Alkylation Reaction of Enolate-Stabilized Enol Carbonates

    KAUST Repository

    Stoltz, Brian

    2010-06-14

    The use of high-throughput screening allowed for the optimization of reaction conditions for the palladium-catalyzed asymmetric decarboxylative alkylation reaction of enolate-stabilized enol carbonates. Changing to a non-polar reaction solvent and to an electron-deficient PHOX derivative as ligand from our standard reaction conditions improved the enantioselectivity for the alkylation of a ketal-protected,1,3-diketone-derived enol carbonate from 28% ee to 84% ee. Similar improvements in enantioselectivity were seen for a β-keto-ester derived- and an α-phenyl cyclohexanone-derived enol carbonate.

  12. Tuning the thermoresponsive properties of Hyperbranched Poly(ester amide)s based on diisopropanolamine and cyclic dicarboxylic anhydrides

    OpenAIRE

    Kelland, Malcolm

    2011-01-01

    A range of water-soluble hyperbranched poly(ester amide)s has been synthesized with a view to studying their thermoresponsive behavior in water. Poly(ester amide)s with lower critical solution temperature (LCST) values around physiological temperatures are of interest for biological and medical applications, whereas poly(ester amide)s with high LCST values may be useful as kinetic hydrate inhibitors for high salinity produced fluids in the oil and gas industry. The LCST of these p...

  13. Isolation of a Cyclic (Alkyl)(amino)germylene.

    Science.gov (United States)

    Wang, Liliang; Lim, Yi Shan; Li, Yongxin; Ganguly, Rakesh; Kinjo, Rei

    2016-07-29

    A 1,4-addition of a dichlorogermylene dioxane complex with α,β-unsaturated imine 1 gave a dichlorogermane derivative 2 bearing a GeC₃N five-membered ring skeleton. By reducing 2 with KC₈, cyclic (alkyl)(amino)germylene 3 was synthesized and fully characterized. Germylene 3 readily reacted with TEMPO, N₂O and S₈, producing the 1:2 adduct 4, the oxo-bridged dimer 5 and the sulfido-bridged dimer 6, respectively.

  14. Gas-Phase Amidation of Carboxylic Acids with Woodward's Reagent K Ions

    Science.gov (United States)

    Peng, Zhou; Pilo, Alice L.; Luongo, Carl A.; McLuckey, Scott A.

    2015-06-01

    Gas-phase amidation of carboxylic acids in multiply-charged peptides is demonstrated via ion/ion reactions with Woodward's reagent K (wrk) in both positive and negative mode. Woodward's reagent K, N-ethyl-3-phenylisoxazolium-3'-sulfonate, is a commonly used reagent that activates carboxylates to form amide bonds with amines in solution. Here, we demonstrate that the analogous gas-phase chemistry occurs upon reaction of the wrk ions and doubly protonated (or doubly deprotonated) peptide ions containing the carboxylic acid functionality. The reaction involves the formation of the enol ester intermediate in the electrostatic complex. Upon collisional activation, the ethyl amine on the reagent is transferred to the activated carbonyl carbon on the peptide, resulting in the formation of an ethyl amide (addition of 27 Da to the peptide) with loss of a neutral ketene derivative. Further collision-induced dissociation (CID) of the products and comparison with solution-phase amidation product confirms the structure of the ethyl amide.

  15. Electrostatic frequency shifts in amide I vibrational spectra: Direct parameterization against experiment

    Science.gov (United States)

    Reppert, Mike; Tokmakoff, Andrei

    2013-04-01

    The interpretation of protein amide I infrared spectra has been greatly assisted by the observation that the vibrational frequency of a peptide unit reports on its local electrostatic environment. However, the interpretation of spectra remains largely qualitative due to a lack of direct quantitative connections between computational models and experimental data. Here, we present an empirical parameterization of an electrostatic amide I frequency map derived from the infrared absorption spectra of 28 dipeptides. The observed frequency shifts are analyzed in terms of the local electrostatic potential, field, and field gradient, evaluated at sites near the amide bond in molecular dynamics simulations. We find that the frequency shifts observed in experiment correlate very well with the electric field in the direction of the C=O bond evaluated at the position of the amide oxygen atom. A linear best-fit mapping between observed frequencies and electric field yield sample standard deviations of 2.8 and 3.7 cm-1 for the CHARMM27 and OPLS-AA force fields, respectively, and maximum deviations (within our data set) of 9 cm-1. These results are discussed in the broader context of amide I vibrational models and the effort to produce quantitative agreement between simulated and experimental absorption spectra.

  16. Preparation and Characterization of a Homoleptic Vanadium(III) Amide Complex and Its Transformation into Terminal Chalcogenide Derivatives [(3,5-Me(2)Ph)AdN](3)V=E (E = S, Se; Ad = Adamantyl).

    Science.gov (United States)

    Ruppa, Kamalesh B. P.; Desmangles, Nathalie; Gambarotta, Sandro; Yap, Glenn; Rheingold, Arnold L.

    1997-03-12

    Reaction of VCl(3)(THF)(3) with (3,5-Me(2)Ph)AdNLi.Et(2)O (Ad = adamantyl) yields the homoleptic vanadium complex [(3,5-Me(2)Ph)AdN](3)V (1), which reacts with chalcogens E (E = S, Se) to yield diamagnetic terminal chalcogenide derivatives [(3,5-Me(2)Ph)AdN](3)V=E [E = S (3a), Se (3b)] Crystal data for 1 and 3a are as follows. 1: C(54)H(72)N(3)V, fw 814.09, triclinic P&onemacr;, a = 10.441(1) Å, b = 11.648(4) Å, c = 19.321(2) Å, alpha = 83.69(2) degrees, beta = 83.89(1) degrees, gamma = 82.42(2) degrees, Z = 2. 3a: C(54)H(72)N(3)VS.(1)/(2)Et(2)O, fw 883.25, monoclinic C2/c, a = 43.400(9) Å, b = 11.744(3) Å, c = 20.705(4) Å, beta = 113.05(1) degrees, Z = 8.

  17. Variation of protein backbone amide resonance by electrostatic field

    OpenAIRE

    Sharley, John N.

    2015-01-01

    Amide resonance is found to be sensitive to electrostatic field with component parallel or antiparallel the amide C-N bond. This effect is linear and without threshold in the biologically plausible electrostatic field range -0.005 to 0.005 au. Variation of amide resonance varies Resonance-Assisted Hydrogen Bonding such as occurs in the hydrogen bonded chains of backbone amides of protein secondary structures such as beta sheet and alpha helix, varying the stability of the secondary structure....

  18. The Scarlet Letter of Alkylation: A Mini Review of Selective Alkylating Agents

    OpenAIRE

    Oronsky, Bryan T.; Reid, Tony; Knox, Susan J.; Scicinski, Jan J.

    2012-01-01

    If there were a stigma scale for chemotherapy, alkylating agents would be ranked at the top of the list. The chemical term alkylation is associated with nonselective toxicity, an association that dates back to the use of nitrogen mustards during World War I as chemical warfare agents. That this stigma persists and extends to compounds that, through selectivity, attempt to “tame” the indiscriminate destructive potential of alkylation is the subject of this review. Selective alkylation, as it i...

  19. Metabolism of amino acid amides in Pseudomonas putida ATCC 12633

    NARCIS (Netherlands)

    Hermes, H.F.M.; Croes, L.M.; Peeters, W.P.H.; Peters, P.J.H.; Dijkhuizen, L.

    1993-01-01

    The metabolism of the natural amino acid L-valine, the unnatural amino acids D-valine, and D-, L-phenylglycine (D-, L-PG), and the unnatural amino acid amides D-, L-phenylglycine amide (D, L-PG-NH2) and L-valine amide (L-Val-NH2) was studied in Pseudomonas putida ATCC 12633. The organism possessed c

  20. Production of alkyl aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Bonacci, J.C.; Billings, R.P.

    1975-01-30

    An improved method is claimed for producing aromatic hydrocarbons from a hydrocarbon charge containing aromatic hydrocarbons including benzene and C/sub 8/ alkyl aromatics and aliphatic hydrocarbons which charge is rich in such aromatic hydrocarbons and lean in aliphatic hydrocarbons boiling above about 220/sup 0/F by reason of conversion under severe conditions which comprises subjecting said charge to distillation conditions of temperature and pressure such that at least a portion of the benzene content of said fraction is separated as vapor from an alkyl aromatic fraction containing aliphatic hydrocarbons and the major portion of C/sub 8/ aromatics in said charge, reacting said alkyl aromatic fraction in the presence of hydrogen in contact with a catalyst containing type ZSM-5 zeolite, zeolite ZSM-12, zeolite ZSM-21 or zeolite beta in combination with a hydrogenation/dehydrogenation component at conversion conditions to convert aliphatic hydrocarbons to lower boiling material of five carbon atoms and lighter separable from aromatics by distillation including a temperature of about 500/sup 0/ to 1000/sup 0/F, a pressure of about 100 to about 600 pounds, a hydrogen to hydrocarbon mol ratio of 0.2 to 8 and weight hourly space velocity of 0.5 to 15, concurrently contacting a mixture of hydrogen and toluene with a disproportionation catalyst under reaction conditions to disproportionate said toluene, combining the effluents of said contacting steps, separating hydrogen from the combined effluents of said contacting steps, separating hydrogen from the combined effluents, recycling at least a portion of said separated hydrogen to said contacting steps, distilling the hydrocarbon residue from said separation step to recover therefrom at least toluene and mixed xylenes, and recycling at least a portion of said recovered toluene as feed to the disproportionation step aforesaid.

  1. Depolymerization of coal by oxidation and alkylation; Sanka bunkai to alkyl ka ni yoru sekitan kaijugo

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, H.; Isoda, T.; Kusakabe, K.; Morooka, S. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Hayashi, J. [Hokkaido University, Sapporo (Japan). Center for Advanced Research of Energy Technology

    1996-10-28

    Change in depolymerization degree and coal structure was studied for depolymerization treatment of coal in various alcohol containing aqueous hydrogen peroxide. In experiment, the mixture of Yallourn coal, alcohol and aqueous hydrogen peroxide was agitated in nitrogen atmosphere of normal pressure at 70{degree}C for 12 hours. As the experimental result, the methanol solubility of only 5% of raw coal increased up to 35.2% by hydrogen peroxide treatment, while the yield of insoluble matters also decreased from 94% to 62%. Most of the gas produced during treatment was composed of inorganic gases such as CO and CO2, and its carbon loss was extremely decreased by adding alcohol. From the analytical result of carbon loss in hydrogen peroxide treatment, it was clarified that alkylation advances with introduction of alkyl group derived from alcohol into coal by hydrogen peroxide treatment under a coexistence of alcohol, and depolymerization reaction of coal itself is thus promoted by alcohol. 4 refs., 7 figs., 1 tab.

  2. Synthesis and Antioxidant Activity of Alkyl Nitroderivatives of Hydroxytyrosol

    Directory of Open Access Journals (Sweden)

    Elena Gallardo

    2016-05-01

    Full Text Available A series of alkyl nitrohydroxytyrosyl ether derivatives has been synthesized from free hydroxytyrosol (HT, the natural olive oil phenol, in order to increase the assortment of compounds with potential neuroprotective activity in Parkinson’s disease. In this work, the antioxidant activity of these novel compounds has been evaluated using Ferric Reducing Antioxidant Power (FRAP, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS, and Oxygen Radical Scavenging Capacity (ORAC assays compared to that of nitrohydroxytyrosol (NO2HT and free HT. New compounds showed variable antioxidant activity depending on the alkyl side chain length; compounds with short chains (2–4 carbon atoms maintained or even improved the antioxidant activity compared to NO2HT and/or HT, whereas those with longer side chains (6–8 carbon atoms showed lower activity than NO2HT but higher than HT.

  3. 40 CFR 721.9892 - Alkylated urea.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated urea. 721.9892 Section 721.9892 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9892 Alkylated urea. (a) Chemical...

  4. C-Alkylation by Hydrogen Autotransfer Reactions.

    Science.gov (United States)

    Obora, Yasushi

    2016-04-01

    The development of practical, efficient, and atom-economical methods for the formation of carbon-carbon bonds remains a topic of considerable interest in current synthetic organic chemistry. In this review, we have summarized selected topics from the recent literature with particular emphasis on C-alkylation processes involving hydrogen transfer using alcohols as alkylation reagents. This review includes selected highlights concerning recent progress towards the modification of catalytic systems for the α-alkylation of ketones, nitriles, and esters. Furthermore, we have devoted a significant portion of this review to the methylation of ketones, alcohols, and indoles using methanol. Lastly, we have also documented recent advances in β-alkylation methods involving the dimerization of alcohols (Guerbet reaction), as well as new developments in C-alkylation methods based on sp (3) C-H activation. PMID:27573136

  5. Glycyrrhetinic acid and its derivatives as inhibitors of poly(ADP-ribosepolymerases 1 and 2, apurinic/apyrimidinic endonuclease 1 and DNA polymerase β

    Directory of Open Access Journals (Sweden)

    Salakhutdinov N. F.

    2012-06-01

    Full Text Available Aim. For strengthening the efficiency of monofunctional alkylating antineoplastic drugs it is important to lower the capacity of base excision repair (BER system which corrects the majority of DNA damages caused by these reagents. The objective was to create inhibitors of the key BER enzymes (PARP1, PARP2, DNA polymerase β, and APE1 by the directed modification of glycyrrhetinic acid (GA. Methods. Amides of GA were produced from the GA acetate by formation of the corresponding acyl chloride, amidation with the appropriate amine and subsequent deacylation. Small library of 2-cyano substituted derivatives of GA methyl esters was obtained by the structural modification of GA framework and carboxylic acid group. The inhibitory capacity of the compounds was estimated by comparison of the enzyme activities in specific tests in the presence of compounds versus their absence. Results. None of tested compounds inhibits PARP1 significantly. Unmodified GA and its morpholinic derivative were shown to be weak inhibitors of PARP2. The derivatives of GA containing keto-group in 11 triterpene framework were shown to be moderate inhibitors of pol β. Compound 3, containing 12-oxo-9(11-en moiety in the ring C, was shown to be a single inhibitor of APE1 among all compounds studied. Conclusions. The class of GA derivatives, selective pol β inhibitors, was found out. The selective inhibitor of APE1 and weak selective inhibitor of PARP2 were also revealed.

  6. An Efficient Protocol for the Palladium-catalyzed Asymmetric Decarboxylative Allylic Alkylation Using Low Palladium Concentrations and a Palladium(II) Precatalyst

    OpenAIRE

    Marziale, Alexander N.; Duquette, Douglas C.; Craig, Robert A.; Kim, Kelly E.; Liniger, Marc; Numajiri, Yoshitaka; Stoltz, Brian M.

    2015-01-01

    Enantioselective catalytic allylic alkylation for the synthesis of 2-alkyl-2-allylcycloalkanones and 3,3-disubstituted pyrrolidinones, piperidinones and piperazinones has been previously reported by our laboratory. The efficient construction of chiral all-carbon quaternary centers by allylic alkylation was previously achieved with a catalyst derived in situ from zero valent palladium sources and chiral phosphinooxazoline (PHOX) ligands. We now report an improved reaction protocol with broad a...

  7. Regularly timed events amid chaos

    Science.gov (United States)

    Blakely, Jonathan N.; Cooper, Roy M.; Corron, Ned J.

    2015-11-01

    We show rigorously that the solutions of a class of chaotic oscillators are characterized by regularly timed events in which the derivative of the solution is instantaneously zero. The perfect regularity of these events is in stark contrast with the well-known unpredictability of chaos. We explore some consequences of these regularly timed events through experiments using chaotic electronic circuits. First, we show that a feedback loop can be implemented to phase lock the regularly timed events to a periodic external signal. In this arrangement the external signal regulates the timing of the chaotic signal but does not strictly lock its phase. That is, phase slips of the chaotic oscillation persist without disturbing timing of the regular events. Second, we couple the regularly timed events of one chaotic oscillator to those of another. A state of synchronization is observed where the oscillators exhibit synchronized regular events while their chaotic amplitudes and phases evolve independently. Finally, we add additional coupling to synchronize the amplitudes, as well, however in the opposite direction illustrating the independence of the amplitudes from the regularly timed events.

  8. Tertiary fatty amides as diesel fuel substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Serdari, Aikaterini; Lois, Euripides; Stournas, Stamoulis [National Technical Univ. of Athens, Dept. of Chemical Engineering, Athens (Greece)

    2000-07-01

    This paper presents experimental results regarding the impact of adding different tertiary amides of fatty acids to mineral diesel fuel; an assessment of the behaviour of these compounds as possible diesel fuel extenders is also included. Measurements of cetane number, cold flow properties (cloud point, pour point and CFPP), density, kinematic viscosity, flash point and distillation temperatures are reported, while initial experiments concerning the effects on particulate emissions are also described. Most of the examined tertiary fatty amides esters have very good performance and they can be easily prepared from fatty acids (biomass). Such compounds or their blends could be used as mineral diesel fuel or even fatty acid methylesters (FAME, biodiesel) substitutes or extenders. (Author)

  9. 76 FR 69636 - Amides, C5

    Science.gov (United States)

    2011-11-09

    ... March 29, 2011 (76 FR 17374) (FRL-8867- 4), EPA issued a notice pursuant to section 408 of FFDCA, 21 U.S... in guinea pigs showed that amides, C 5 - C 9 , N- was not a skin sensitizer (OPPTS 870.2600). Several... female rats on gestation days 6-19. All females in the 1,000 mg/kg/day group were found dead...

  10. Quantitative structure–activity relationships for chronic toxicity of alkyl-chrysenes and alkyl-benz[a]anthracenes to Japanese medaka embryos (Oryzias latipes)

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Hongkang [Department of Biology, Queen' s University, Kingston, Ontario K7L3N6 (Canada); Morandi, Garrett D. [School of Environmental Studies, Queen' s University, Kingston, Ontario K7L3N6 (Canada); Brown, R. Stephen [School of Environmental Studies, Queen' s University, Kingston, Ontario K7L3N6 (Canada); Department of Chemistry, Queen' s University, Kingston, Ontario K7L3N6 (Canada); Snieckus, Victor; Rantanen, Toni [Department of Chemistry, Queen' s University, Kingston, Ontario K7L3N6 (Canada); Jørgensen, Kåre B. [Department of Mathematics and Natural Sciences, University of Stavanger, 4036 Stavanger (Norway); Hodson, Peter V., E-mail: peter.hodson@queensu.ca [Department of Biology, Queen' s University, Kingston, Ontario K7L3N6 (Canada); School of Environmental Studies, Queen' s University, Kingston, Ontario K7L3N6 (Canada)

    2015-02-15

    Highlights: • Medaka embryos were exposed to alkyl chrysenes and benzo[a]anthracenes (BAA). • Concentrations were kept constant by partition controlled delivery. • Chrysene was not toxic within solubility limits, in contrast to BAA. • Alkylation increased the toxicity of chrysene and BAA. • Toxicity was related to hydrophobicity and to specific modes of action. - Abstract: Alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) are a class of compounds found at significant concentrations in crude oils, and likely the main constituents responsible for the chronic toxicity of oil to fish. Alkyl substituents at different locations on the aromatic rings change the size and shape of PAH molecules, which results in different interactions with tissue receptors and different severities of toxicity. The present study is the first to report the toxicity of several alkylated derivatives of chrysene and benz[a]anthracene to the embryos of Japanese medaka (Oryzias latipes) using the partition controlled delivery (PCD) method of exposure. The PCD method maintained the desired exposure concentrations by equilibrium partitioning of hydrophobic test compounds from polydimethylsiloxane (PDMS) films. Test concentrations declined by only 13% over a period of 17 days. Based on the prevalence of signs of blue sac disease (BSD), as expressed by median effective concentrations (EC50s), benz[a]anthracene (B[a]A) was more toxic than chrysene. Alkylation generally increased toxicity, except at position 2 of B[a]A. Alkyl-PAHs substituted in the middle region had a lower EC50 than those substituted at the distal region. Except for B[a]A and 7-methylbenz[a]anthracene (7-MB), estimated EC50 values were higher than their solubility limits, which resulted in limited toxicity within the range of test concentrations. The regression between log EC50s and log K{sub ow} values provided a rough estimation of structure–activity relationships for alkyl-PAHs, but K{sub ow} alone did not provide

  11. Alkyl aryl ethers in lignite solubilization

    Energy Technology Data Exchange (ETDEWEB)

    Mustral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1985-03-01

    The FT-I.R. and /sup 1/H N.M.R. spectroscopic analyses of oils or maltenes from a Spanish lignite (Utrillas, Teruel), are reported. These oils were obtained by depolymerization with alkyl aromatic ethers (anisole, 3-methyl anisole and 1,3-dimethoxybenzene) catalyzed by Lewis acids ZnCl/sub 2/, AlCl/sub 3/, SbCl/sub 3/ and BF/sub 3/ (as boron trifluoride etherate), at atmospheric pressure and temperatures <220/sup 0/C. Bands due to aromatic ethers in the I.R. and N.M.R. spectra of the oils obtained by depolymerization indicate solvent incorporation. Oils obtained by direct lignite extraction showed 25% aromatic H and some H /sub i/ (approx. = 3%) without OH groups. These appeared in some oils obtained by depolymerization with AlCl/sub 3/ and were due to secondary reactions with the aromatic extract. Oils derived from processes with good yields showed increases in aromaticity. The extent of substitution of aromatic rings in oils obtained by depolymerization was less than for oils directly extracted. All the oils studied show a low degree of condensation.

  12. Urea and amide-based inhibitors of the juvenile hormone epoxide hydrolase of the tobacco hornworm (Manduca sexta: Sphingidae).

    Science.gov (United States)

    Severson, Tonya F; Goodrow, Marvin H; Morisseau, Christophe; Dowdy, Deanna L; Hammock, Bruce D

    2002-12-01

    A new class of inhibitors of juvenile hormone epoxide hydrolase (JHEH) of Manduca sexta and further in vitro characterization of the enzyme are reported. The compounds are based on urea and amide pharmacophores that were previously demonstrated as effective inhibitors of mammalian soluble and microsomal epoxide hydrolases. The best inhibitors against JHEH activity so far within this class are N-[(Z)-9-octadecenyl]-N'-propylurea and N-hexadecyl-N'-propylurea, which inhibited hydrolysis of a surrogate substrate (t-DPPO) with an IC(50) around 90 nM. The importance of substitution number and type was investigated and results indicated that N, N'-disubstitution with asymmetric alkyl groups was favored. Potencies of pharmacophores decreased as follows: amide>urea>carbamate>carbodiimide>thiourea and thiocarbamate for N, N'-disubstituted compounds with symmetric substituents, and urea>amide>carbamate for compounds with asymmetric N, N'-substituents. JHEH hydrolyzes t-DPPO with a K(m) of 65.6 microM and a V(max) of 59 nmol min(-1) mg(-1) and has a substantially lower K(m) of 3.6 microM and higher V(max) of 322 nmol min(-1) mg(-1) for JH III. Although none of these compounds were potent inhibitors of hydrolysis of JH III by JHEH, they are the first leads toward inhibitors of JHEH that are not potentially subject to metabolism through epoxide degradation. PMID:12429126

  13. Direct Lactamization of Azido Amides via Staudinger-Type Reductive Cyclization

    Energy Technology Data Exchange (ETDEWEB)

    Heo, In Jung; Lee, Su Jeong; Cho, Chang Woo [Kyungpook National University, Daegu (Korea, Republic of)

    2012-01-15

    The direct lactamization of 1,3- and 1,4-azido amides has been achieved using triphenylphosphine and water, affording various γ- and δ-lactams in good to excellent yields. The direct lactamization of the azido amides was performed via the Staudinger-type reductive cyclization in which the amide group acts as the electrophile for lactam synthesis. This lactamization provides a mild, functional group tolerant and efficient route for the synthesis of various γ- and δ-lactams found in natural products and pharmaceuticals. Further studies will be conducted to develop new synthetic routes for the synthesis of various lactams. The lactam ring system is one of the most ubiquitous structural motifs found in natural products and pharmaceuticals. Owing to the prevalence of lactams, their synthesis has attracted considerable attention. Lactams are usually prepared by the coupling of activated carboxylic acid derivatives with amines. Alternative routes include the Beckmann rearrangement of oximes, the Schmidt reaction of cyclic ketones and hydrazoic acid, the Kinugasa reaction of nitrones and terminal acetylenes, the Diels-Alder reaction of cyclopentadiene and chlorosulfonyl isocyanate, transition metal catalyzed lactamization of amino alcohols, and iodolactamization of amides and alkenes. In particular, the intramolecular Staudinger ligation of azides and activated carboxy acids, including esters, is well known as an environmentally friendly and mild protocol for lactam synthesis.

  14. Direct Lactamization of Azido Amides via Staudinger-Type Reductive Cyclization

    International Nuclear Information System (INIS)

    The direct lactamization of 1,3- and 1,4-azido amides has been achieved using triphenylphosphine and water, affording various γ- and δ-lactams in good to excellent yields. The direct lactamization of the azido amides was performed via the Staudinger-type reductive cyclization in which the amide group acts as the electrophile for lactam synthesis. This lactamization provides a mild, functional group tolerant and efficient route for the synthesis of various γ- and δ-lactams found in natural products and pharmaceuticals. Further studies will be conducted to develop new synthetic routes for the synthesis of various lactams. The lactam ring system is one of the most ubiquitous structural motifs found in natural products and pharmaceuticals. Owing to the prevalence of lactams, their synthesis has attracted considerable attention. Lactams are usually prepared by the coupling of activated carboxylic acid derivatives with amines. Alternative routes include the Beckmann rearrangement of oximes, the Schmidt reaction of cyclic ketones and hydrazoic acid, the Kinugasa reaction of nitrones and terminal acetylenes, the Diels-Alder reaction of cyclopentadiene and chlorosulfonyl isocyanate, transition metal catalyzed lactamization of amino alcohols, and iodolactamization of amides and alkenes. In particular, the intramolecular Staudinger ligation of azides and activated carboxy acids, including esters, is well known as an environmentally friendly and mild protocol for lactam synthesis

  15. Composition of the epicuticular waxes coating the adaxial side of Phyllostachys aurea leaves: Identification of very-long-chain primary amides.

    Science.gov (United States)

    Racovita, Radu C; Jetter, Reinhard

    2016-10-01

    The present study presents comprehensive chemical analyses of cuticular wax mixtures of the bamboo Phyllostachys aurea. The epicuticular and intracuticular waxes were sampled selectively from the adaxial side of leaves on young and old plants and investigated by gas chromatography-mass spectrometry and flame ionization detection. The epi- and intracuticular layers on young and old leaves had wax loads ranging from 1.7 μg/cm(2) to 1.9 μg/cm(2). Typical very-long-chain aliphatic wax constituents were found with characteristic chain length patterns, including alkyl esters (primarily C48), alkanes (primarily C29), fatty acids (primarily C28 and C16), primary alcohols (primarily C28) and aldehydes (primarily C30). Alicyclic wax components were identified as tocopherols and triterpenoids, including substantial amounts of triterpenoid esters. Alkyl esters, alkanes, fatty acids and aldehydes were found in greater amounts in the epicuticular layer, while primary alcohols and most terpenoids accumulated more in the intracuticular wax. Alkyl esters occurred as mixtures of metamers, combining C20 alcohol with various acids into shorter ester homologs (C36C40), and a wide range of alcohols with C22 and C24 acids into longer esters (C42C52). Primary amides were identified, with a characteristic chain length profile peaking at C30. The amides were present exclusively in the epicuticular layer and thus at or near the surface, where they may affect plant-herbivore or plant-pathogen interactions. PMID:27402630

  16. Base-promoted reactions of bridged ketones and 1,3- and 1,4-haloalkyl azides: competitive alkylation vs azidation reactions of ketone enolates.

    Science.gov (United States)

    Yao, Lei; Smith, Brenton T; Aubé, Jeffrey

    2004-03-01

    The reactions of 1,3- and 1,4-haloalkyl azides with enolates of 2-norbornanone (and a ring-expanded analog) afford polycyclic 1,2,3-triazolines in good yields. The reaction occurs by the initial azidation of the ketone enolate, followed in order by triazoline formation and O-alkylation. An interesting element of this process is the preferential reaction of the alkyl azide with an enolate anion as opposed to the more familiar reaction of the alkyl halide (including Cl and I derivatives). Reactions of acyclic or monocyclic enolates generally lead to 1,2,3-triazoles but none of the alternative C-alkylation product. PMID:14987033

  17. Variation of protein backbone amide resonance by electrostatic field

    CERN Document Server

    Sharley, John N

    2015-01-01

    Amide resonance is found to be sensitive to electrostatic field with component parallel or antiparallel the amide C-N bond. This effect is linear and without threshold in the biologically plausible electrostatic field range -0.005 to 0.005 au. Variation of amide resonance varies Resonance Assisted Hydrogen Bonding such as occurs in the hydrogen bonded chains of backbone amides of protein secondary structures such as beta sheet and non-polyproline helix such as alpha helix, varying the stability of the secondary structure. The electrostatic properties including permittivity of amino acid residue sidegroups influence the electrostatic field component parallel or antiparallel the C-N bond of each amide. The significance of this factor relative to other factors in protein folding depends on the magnitude of electrostatic field component parallel or antiparallel the C-N bond of each amide, and preliminary protein-scale calculations of the magnitude of these components suggest this factor warrants investigation in ...

  18. Benzoxazole and benzothiazole amides as novel pharmacokinetic enhancers of HIV protease inhibitors.

    Science.gov (United States)

    Jonckers, Tim H M; Rouan, Marie-Claude; Haché, Geerwin; Schepens, Wim; Hallenberger, Sabine; Baumeister, Judith; Sasaki, Jennifer C

    2012-08-01

    A new class of benzoxazole and benzothiazole amide derivatives exhibiting potent CYP3A4 inhibiting properties was identified. Extensive lead optimization was aimed at improving the CYP3A4 inhibitory properties as well as overall ADME profile of these amide derivatives. This led to the identification of thiazol-5-ylmethyl (2S,3R)-4-(2-(ethyl(methyl)amino)-N-isobutylbenzo[d]oxazole-6-carboxamido)-3-hydroxy-1-phenylbutan-2-ylcarbamate (C1) as a lead candidate for this class. This compound together with structurally similar analogues demonstrated excellent 'boosting' properties when tested in dogs. These findings warrant further evaluation of their properties in an effort to identify valuable alternatives to Ritonavir as pharmacokinetic enhancers.

  19. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases; Part 1: alkyl halide alkylations.

    Science.gov (United States)

    Sorochinsky, Alexander E; Aceña, José Luis; Moriwaki, Hiroki; Sato, Tatsunori; Soloshonok, Vadim A

    2013-10-01

    Alkylations of chiral or achiral Ni(II) complexes of glycine Schiff bases constitute a landmark in the development of practical methodology for asymmetric synthesis of α-amino acids. Straightforward, easy preparation as well as high reactivity of these Ni(II) complexes render them ready available and inexpensive glycine equivalents for preparing a wide variety of α-amino acids, in particular on a relatively large scale. In the case of Ni(II) complexes containing benzylproline moiety as a chiral auxiliary, their alkylation proceeds with high thermodynamically controlled diastereoselectivity. Similar type of Ni(II) complexes derived from alanine can also be used for alkylation providing convenient access to quaternary, α,α-disubstituted α-amino acids. Achiral type of Ni(II) complexes can be prepared from picolinic acid or via recently developed modular approach using simple secondary or primary amines. These Ni(II) complexes can be easily mono/bis-alkylated under homogeneous or phase-transfer catalysis conditions. Origin of diastereo-/enantioselectivity in the alkylations reactions, aspects of practicality, generality and limitations of this methodology is critically discussed.

  20. Analytical applications of resins containing amide and polyamine functional groups

    Energy Technology Data Exchange (ETDEWEB)

    Orf, G. M.

    1977-12-01

    A dibutyl amide resin is used for the separation of uranium(VI), thorium(IV), and zirconium(IV) from each other and several other metal ions. Uranium(VI) and thorium(IV) are determined in the presence of large excesses of foreign metal ions and anions. A practical application of the amide resin is studied by determining uranium in low grade uranium ores. The amide resin is also used for the selective concentration of gold(III) from sea water.

  1. IR-spectra of amides of steroidal alkaloids with lactic acid

    OpenAIRE

    Kastelic-Suhadolc, Tatjana

    2015-01-01

    IR spectra of lactamides of 1,4-tomatidien-3-one, 4-solasoden-3-one, dihydrotomatidine and tomatine were taken and the frequency of the ▫$C=0$▫ amide band compared with that of the lactamides of piperidine and its derivatives, and with that of N-acetyltomatidine. It was found that the ▫$C=0$▫ bands of lactamides of steroidal alkaloids show an unusual but characteristic frequency at 1730-1733 cm▫$^{-1}$▫.

  2. Chiral amide from (1, 2)-(+)-norephedrine and furoic acid: An efficient catalyst for asymmetric Reformatsky reaction

    Indian Academy of Sciences (India)

    Nallamuthu Ananthi; Sivan Velmathi

    2014-01-01

    Chiral amide derived from (1, 2)-(+)-norephedrine and 2-furoic acid was found to catalyse the asymmetric Reformatsky reaction between prochiral aldehydes and α-bromo ethylacetate with diethylzinc as zinc source. The corresponding chiral -hydroxy esters were formed in 99% yield with over 80% enantiomeric excess. The presence of air was found to be essential for the effective C-C bond formation. The mechanism for the catalytic reaction was proposed.

  3. Activity of organophosphorus insecticides in bacterial tests for mutagenicity and DNA repair--direct alkylation versus metabolic activation and breakdown. II. O,O-dimethyl-O-(1,2-dibromo-2,2-dichloroethyl)-phosphate and two O-ether derivatives of trichlorfon.

    Science.gov (United States)

    Braun, R; Schöneich, J; Weissflog, L; Dedek, W

    1983-03-01

    The following organophosphates were tested for their ability to induce DNA damage in a rec-type repair test with Proteus mirabilis strains PG713 (rec- hcr-) and PG273 (wild-type) and point mutations in the his- strain TA100 of Salmonella typhimurium: O,O-dimethyl-O-(1,2-dibromo-2,2-dichloroethyl)-phosphate (NALED); trichlorfon-O-methyl ether (TCP-O-ME), O,O-dimethyl-(1-methoxy-2,2,2-trichlorethyl)-phosphonate; trichlorfon-O-methyl ether vinyl derivative (TCP-O-MEVD), O,O-dimethyl-(1-methoxy-2,2-dichlorovinyl)-phosphonate. All compounds were negative in the repair test but induced base pair substitutions in S. typhimurium. The mutagenicity of NALED is due to the direct alkylating ability of the parental molecule and to mutagenic metabolites generated by enzymatic splitting of the side chain. Glutathion-dependent enzymes in the S9-mix eliminate the mutagenic activity of NALED completely. Mutation induction by TCP-O-ME and TCP-O-MEVD is predominantly caused by the reactive O-methyl ether configuration of the side chain and is resistant to metabolic inactivation by NADPH- or glutathion-dependent enzymatic pathways in the S9-mix of mice. PMID:6337735

  4. PREPARATION OF ALKYL HALIDES VIA ORGANOTELLURIUMS

    OpenAIRE

    チカマツ, キヨフミ; オオツボ, テツオ; オグラ, フミオ; ヤマグチ, ハチロウ; Kiyofumi, CHIKAMATSU; Tetsuo, OTSUBO; Fumio, OGURA; Hachiro, YAMAGUCHI

    1982-01-01

    The conversion of phenyltelluroalkanes to haloalkanes was studied in connection with the homologation of alkyl halides. Similar reactions of 1,1-bis(phenyltelluro)alkanes provided a new synthetic method of aldehydes.

  5. Copper-catalyzed oxidative amidation of aldehydes with amine salts: synthesis of primary, secondary, and tertiary amides.

    Science.gov (United States)

    Ghosh, Subhash Chandra; Ngiam, Joyce S Y; Seayad, Abdul M; Tuan, Dang Thanh; Chai, Christina L L; Chen, Anqi

    2012-09-21

    A practical method for the amidation of aldehydes with economic ammonium chloride or amine hydrochloride salts has been developed for the synthesis of a wide variety of amides by using inexpensive copper sulfate or copper(I) oxide as a catalyst and aqueous tert-butyl hydroperoxide as an oxidant. This amidation reaction is operationally straightforward and provides primary, secondary, and tertiary amides in good to excellent yields for most cases utilizing inexpensive and readily available reagents under mild conditions. In situ formation of amine salts from free amines extends the substrate scope of the reaction. Chiral amides are also synthesized from their corresponding chiral amines without detectable racemization. The practicality of this amide formation reaction has been demonstrated in an efficient synthesis of the antiarrhythmic drug N-acetylprocainamide. PMID:22894712

  6. AMID: autonomous modeler of intragenic duplication.

    Science.gov (United States)

    Kummerfeld, Sarah K; Weiss, Anthony S; Fekete, Alan; Jermiin, Lars S

    2003-01-01

    Intragenic duplication is an evolutionary process where segments of a gene become duplicated. While there has been much research into whole-gene or domain duplication, there have been very few studies of non-tandem intragenic duplication. The identification of intragenically replicated sequences may provide insight into the evolution of proteins, helping to link sequence data with structure and function. This paper describes a tool for autonomously modelling intragenic duplication. AMID provides: identification of modularly repetitive genes; an algorithm for identifying repeated modules; and a scoring system for evaluating the modules' similarity. An evaluation of the algorithms and use cases are presented.

  7. Pd-Catalyzed Coupling of γ-C(sp(3))-H Bonds of Oxalyl Amide-Protected Amino Acids with Heteroaryl and Aryl Iodides.

    Science.gov (United States)

    Han, Jian; Zheng, Yongxiang; Wang, Chao; Zhu, Yan; Huang, Zhi-Bin; Shi, Da-Qing; Zeng, Runsheng; Zhao, Yingsheng

    2016-07-01

    Pd-catalyzed regioselective coupling of γ-C(sp(3))-H bonds of oxalyl amide-protected amino acids with heteroaryl and aryl iodides is reported. A wide variety of iodides are tolerated, giving the corresponding products in moderate to good yields. Various oxalyl amide-protected amino acids were compatible in this C-H transformation, thus representing a practical method for constructing non-natural amino acid derivatives. PMID:27286881

  8. Synthesis of 3,6-bis[H-Tyr/H-Dmt-NH(CH2)m,n]-2(1H)pyrazinone derivatives: function of alkyl chain length on opioid activity.

    Science.gov (United States)

    Shiotani, Kimitaka; Li, Tingyou; Miyazaki, Anna; Tsuda, Yuko; Bryant, Sharon D; Ambo, Akihiro; Sasaki, Yusuke; Lazarus, Lawrence H; Okada, Yoshio

    2006-11-15

    Dimeric opioid analogues linked to a pyrazinone platform, 3-[Tyr/Dmt-NH(CH2)m]-6-[Tyr/Dmt-NH(CH2)n]-2(1H)-pyrazinone (m, n=3 or 4), were synthesized. The Tyr-containing compound (m=4, n=3) exhibited mu-receptor affinity (K(i)mu; 7.58 nM) comparable to that of morphine, while the Dmt derivatives exhibited considerably higher affinity (K(i)mu; 0.021-0.051 nM) with corresponding agonism (IC50=1.79-4.93 nM). Interestingly one compound (m=4, n=3) revealed modest delta-opioid agonism; the converse analogue (m=3, n=4), however, was inactive in MVD assay.

  9. Copper-Catalyzed N-Arylation of Amides Using (S-N-Methylpyrrolidine-2-carboxylate as the Ligand

    Directory of Open Access Journals (Sweden)

    Dong-Sheng Ma

    2010-03-01

    Full Text Available (S-N-methylpyrrolidine-2-carboxylate, a derivative of natural L-proline, was found to be an efficient ligand for the copper-catalyzed Goldberg-type N-arylation of amides with aryl halides under mild conditions. A variety of N-arylamides were synthesized in good to high yields.

  10. Polymer amide as an early topology.

    Directory of Open Access Journals (Sweden)

    Julie E M McGeoch

    Full Text Available Hydrophobic polymer amide (HPA could have been one of the first normal density materials to accrete in space. We present ab initio calculations of the energetics of amino acid polymerization via gas phase collisions. The initial hydrogen-bonded di-peptide is sufficiently stable to proceed in many cases via a transition state into a di-peptide with an associated bound water molecule of condensation. The energetics of polymerization are only favorable when the water remains bound. Further polymerization leads to a hydrophobic surface that is phase-separated from, but hydrogen bonded to, a small bulk water complex. The kinetics of the collision and subsequent polymerization are discussed for the low-density conditions of a molecular cloud. This polymer in the gas phase has the properties to make a topology, viz. hydrophobicity allowing phase separation from bulk water, capability to withstand large temperature ranges, versatility of form and charge separation. Its flexible tetrahedral carbon atoms that alternate with more rigid amide groups allow it to deform and reform in hazardous conditions and its density of hydrogen bonds provides adhesion that would support accretion to it of silicon and metal elements to form a stellar dust material.

  11. Amide as an efficient ligand in the palladium-catalyzed Suzuki coupling reaction in water/ethanol under aerobic conditions

    Institute of Scientific and Technical Information of China (English)

    Hai Yang Liu; Kun Wang; Hai Yan Fu; Mao Lin Yuan; Hua Chen; Rui Xiang Li

    2011-01-01

    Amide, which is derived from proline and is inexpensive and air-stable, has been synthesized and characterized by 1H NMR,13C NMR, and MS. It was found to be an efficient ligand in the palladium-catalyzed Suzuki cross-coupling reaction. In the Pd/amide catalytic system, aryl bromides can be coupled with phenylboronic acid in ethanol/water (1:2;v/v) in excellent yields even with a low Pd loading of 0.01 mol%. Moreover, the scope of the reaction is broad, and a wide variety of functional groups are tolerant.

  12. Ionic liquids as solvent for efficient esterification of carboxylic acids with alkyl halides

    OpenAIRE

    carboxylic, Ionic liquids as solvent for efficient e

    2010-01-01

    The selective esterification of carboxylic acid derivatives with a variety of alkyl halides was carried out using ionic liquid as solvent in the presence of triethylamine. The reaction was found to proceed under relatively mild conditions with excellent conversions (up to 99%) and selectivities. The ionic liquid was recycled and reused.

  13. Pd-catalyzed cascade allylic alkylation and dearomatization reactions of indoles with vinyloxirane.

    Science.gov (United States)

    Gao, Run-Duo; Xu, Qing-Long; Dai, Li-Xin; You, Shu-Li

    2016-09-14

    We have developed Pd-catalyzed intermolecular Friedel-Crafts-type allylic alkylation and allylic dearomatization reactions of substituted indoles bearing a nucleophilic group with vinyloxirane, providing an efficient method to synthesize structurally diverse tetrahydrocarboline and spiroindolenine derivatives under mild conditions. PMID:27511802

  14. Enantioselective Friedel-Crafts Alkylation Reactions of 3-Substituted Indoles with Electron-Deficient Alkenes.

    Science.gov (United States)

    Weng, Jian-Quan; Fan, Ren-Jie; Deng, Qiao-Man; Liu, Ren-Rong; Gao, Jian-Rong; Jia, Yi-Xia

    2016-04-01

    Highly enantioselective Friedel-Crafts C2-alkylation reactions of 3-substituted indoles with α,β-unsaturated esters and nitroalkenes were developed using chiral Lewis acids as catalysts, which afforded chiral indole derivatives bearing C2-benzylic stereogenic centers in good to excellent yields (up to 99%) and enantioselectivities (up to 96% ee). PMID:26959867

  15. Synthesis and characterisation of uniform bisester tetra-amide segments

    NARCIS (Netherlands)

    Krijgsman, J.; Husken, D.; Gaymans, R.J.

    2003-01-01

    The synthesis and characterisation of a new type of high melting and fast crystallising amide units that can be used for copolymerisation have been studied. These bisester tetra-amide or TxTxT-dimethyl segments (T is a terephthalic unit and x=(CH2)n (n=2–8)) can be synthesised in a two-step reaction

  16. Oxidative activation of dihydropyridine amides to reactive acyl donors

    DEFF Research Database (Denmark)

    Funder, Erik Daa; Trads, Julie Brender; Gothelf, Kurt Vesterager

    2015-01-01

    Amides of 1,4-dihydropyridine (DHP) are activated by oxidation for acyl transfer to amines, alcohols and thiols. In the reduced form the DHP amide is stable towards reaction with amines at room temperature. However, upon oxidation with DDQ the acyl donor is activated via a proposed pyridinium...

  17. Picosecond thermometer in the amide I band of myoglobin

    DEFF Research Database (Denmark)

    Austin, R.H.; Xie, A.; Meer, L. van der;

    2005-01-01

    The amide I and II bands in myoglobin show a heterogeneous temperature dependence, with bands at 6.17 and 6.43 mu m which are more intense at low temperatures. The amide I band temperature dependence is on the long wavelength edge of the band, while the short wavelength side has almost no tempera...

  18. New serine-derived gemini surfactants as gene delivery systems.

    Science.gov (United States)

    Cardoso, Ana M; Morais, Catarina M; Cruz, A Rita; Silva, Sandra G; do Vale, M Luísa; Marques, Eduardo F; de Lima, Maria C Pedroso; Jurado, Amália S

    2015-01-01

    Gemini surfactants have been extensively used for in vitro gene delivery. Amino acid-derived gemini surfactants combine the special aggregation properties characteristic of the gemini surfactants with high biocompatibility and biodegradability. In this work, novel serine-derived gemini surfactants, differing in alkyl chain lengths and in the linker group bridging the spacer to the headgroups (amine, amide and ester), were evaluated for their ability to mediate gene delivery either per se or in combination with helper lipids. Gemini surfactant-based DNA complexes were characterized in terms of hydrodynamic diameter, surface charge, stability in aqueous buffer and ability to protect DNA. Efficient formulations, able to transfect up to 50% of the cells without causing toxicity, were found at very low surfactant/DNA charge ratios (1/1-2/1). The most efficient complexes presented sizes suitable for intravenous administration and negative surface charge, a feature known to preclude potentially adverse interactions with serum components. This work brings forward a new family of gemini surfactants with great potential as gene delivery systems. PMID:25513958

  19. Oil recovery with sulfomethylated poly (lower alkyl vinyl ether/maleic anhydride)

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1973-05-22

    Lower alkyl vinyl ether e.g., methyl vinyl ether, propyl vinyl ether, isopropyl vinyl ether, hexyl vinyl ether, is copolymerized conventionally with maleic anhydride, the resulting copolymer is treated with ammonia or ammonium hydroxide to form the partial amide-ammonium salt, and this salt is in turn treated with formaldehyde and thereafter or simultaneously with ammonium or alkali metal salt sulfite (including bisulfites, etc.) to form an at least partially sulfomethylated copolymer. Aqueous solutions of the sulfomethylated copolymer are useful in increasing the viscosity of drive fluids used in the supplemented recovery of petroleum from subterranean formations. In general, enhancing the polyionic character of mobility control agents used in supplemented recovery of petroleum provides enhanced recovery. Achieving this enhancement of polyionic character through use of sulfonate groups provides a mobility control agent with good ability to sustain viscosity in the presence of brine and lime, usually present in the connate waters of petroleum-bearing formations. (7 claims)

  20. Cytotoxic Amides from Fruits of Kawakawa, Macropiper excelsum.

    Science.gov (United States)

    Lei, Jeremy; Burgess, Elaine J; Richardson, Alistair T B; Hawkins, Bill C; Baird, Sarah K; Smallfield, Bruce M; van Klink, John W; Perry, Nigel B

    2015-08-01

    Cytotoxic amides have been isolated from the fruits of the endemic New Zealand medicinal plant kawakawa, Macropiper excelsum (Piperaceae). The main amide was piperchabamide A and this is the first report of this rare compound outside the genus Piper. Eleven other amides were purified including two new compounds with the unusual 3,4-dihydro-1(2H)-pyridinyl group. The new compounds were fully characterized by 2D NMR spectroscopy, which showed a slow exchange between two rotamers about the amide bond, and they were chemically synthesized. In view of the antitumor activity of the related piperlongumine, all of these amides plus four synthetic analogs were tested for cytotoxicity. The most active was the piperine homolog piperdardine, with an IC50 of 14 µM against HT 29 colon cancer cells. PMID:26039266

  1. Synthesis, properties and self-organization of meso-arylporphyrins with higher alkyl substituents

    Science.gov (United States)

    Bragina, N. A.; Zhdanova, K. A.; Mironov, A. F.

    2016-05-01

    The review summarizes published data on the methods for preparation of meso-arylporphyrins with higher alkyl substituents. The methods for creation of self-organized nanostructures based on these compounds and the data on their applications are presented. Approaches to the synthesis of functionalized lipophilic and amphiphilic meso-arylporphyrins are discussed. The ways and driving forces for the formation of supramolecular porphyrin arrays in solutions and on the substrate surface are considered. The prospects of using alkyl porphyrin derivatives for the design of nanomaterials are shown. The bibliography includes 204 references.

  2. Practical Ni-Catalyzed Aryl-Alkyl Cross-Coupling of Secondary Redox-Active Esters.

    Science.gov (United States)

    Cornella, Josep; Edwards, Jacob T; Qin, Tian; Kawamura, Shuhei; Wang, Jie; Pan, Chung-Mao; Gianatassio, Ryan; Schmidt, Michael; Eastgate, Martin D; Baran, Phil S

    2016-02-24

    A new transformation is presented that enables chemists to couple simple alkyl carboxylic acids with aryl zinc reagents under Ni-catalysis. The success of this reaction hinges on the unique use of redox-active esters that allow one to employ such derivatives as alkyl halides surrogates. The chemistry exhibits broad substrate scope and features a high degree of practicality. The simple procedure and extremely inexpensive nature of both the substrates and pre-catalyst (NiCl2·6H2O, ca. $9.5/mol) bode well for the immediate widespread adoption of this method. PMID:26835704

  3. Passive Membrane Permeability of Macrocycles Can Be Controlled by Exocyclic Amide Bonds.

    Science.gov (United States)

    Hickey, Jennifer L; Zaretsky, Serge; St Denis, Megan A; Kumar Chakka, Sai; Morshed, M Monzur; Scully, Conor C G; Roughton, Andrew L; Yudin, Andrei K

    2016-06-01

    We have developed a strategy for synthesizing passively permeable peptidomimetic macrocycles. The cyclization chemistry centers on using aziridine aldehydes in a multicomponent reaction with peptides and isocyanides. The linker region in the resulting product contains an exocyclic amide positioned α to the peptide backbone, an arrangement that is not found among natural amino acids. This amide provides structural rigidity within the cyclic peptidomimetic and promotes the creation of a stabilizing intramolecular hydrogen bonding network. This exocyclic control element also contributes to the increased membrane permeability exhibited by multicomponent-derived macrocycles with respect to their homodetic counterparts. The exocyclic control element is employed along with a strategic placement of N-methyl and d-amino acids to produce passively permeable peptides, which contain multiple polar residues. This strategy should be applicable in the pursuit of synthesizing therapeutically relevant macrocycles. PMID:27120576

  4. Tyrosine-selective protein alkylation using pi-allylpalladium complexes.

    Science.gov (United States)

    Tilley, S David; Francis, Matthew B

    2006-02-01

    A new protein modification reaction has been developed based on a palladium-catalyzed allylic alkylation of tyrosine residues. This technique employs electrophilic pi-allyl intermediates derived from allylic acetate and carbamate precursors and can be used to modify proteins in aqueous solution at room temperature. To facilitate the detection of modified proteins using SDS-PAGE analysis, a fluorescent allyl acetate was synthesized and coupled to chymotrypsinogen A and bacteriophage MS2. The tyrosine selectivity of the reaction was confirmed through trypsin digest analysis. The utility of the reaction was demonstrated by using taurine-derived carbamates as water solubilizing groups that are cleaved upon protein functionalization. This solubility switching technique was used to install hydrophobic farnesyl and C(17) chains on chymotrypsinogen A in water using little or no cosolvent. Following this, the C(17) alkylated proteins were found to associate with lipid vesicles. In addition to providing a new protein modification strategy targeting an under-utilized amino acid side chain, this method provides convenient access to synthetic lipoproteins. PMID:16433516

  5. Liquid-phase alkylation of Assam (Baragolai) coal

    Energy Technology Data Exchange (ETDEWEB)

    Kalra, R.L.; Choudhury, R.; Sarkar, M.K.

    1982-12-01

    Liquid paraffin which consists of a large number of alkylated aliphatics and aromatics seems to be acting as an alkyl group transfer medium to receptive complexes like coal. The alkyl group receptive spots could be created in the coal complex by treatment with molten alkalis like sodium or potassium hydroxide. By repeating extractions of fresh coal with the same volume of liquid paraffin on a laboratory scale it was found that a stage was reached when liquid paraffin became rich enough in alkyl groups to become an alkyl group donor. This suggests a method for liquid phase alkylation of coal. (3 refs.)

  6. Interactions and hybrid complex formation of anionic algal polysaccharides with a cationic glycine betaine-derived surfactant.

    Science.gov (United States)

    Covis, Rudy; Vives, Thomas; Gaillard, Cédric; Benoit, Maud; Benvegnu, Thierry

    2015-05-01

    The interaction between anionic algal polysaccharides ((κ)-, (ι)-, (λ)-carrageenans, alginate and ulvan) and a cationic glycine betaine (GB) amide surfactant possessing a C18:1 alkyl chain has been studied using isothermal titration calorimetry (ITC), zeta-potential measurements, dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), and surface tension measurements. It was observed that this cationic surfactant derived from renewable raw materials induced cooperative binding with the anionic polymers at critical aggregation concentration (CAC) and the CAC values are significantly lower than the corresponding critical micelle concentration (CMC) for the surfactant. The CMC of cationic GB surfactant was obtained at higher surfactant concentration in polysaccharide solution than in pure water. More interestingly, the presence of original polysaccharide/surfactant hybrid complexes formed above the CMC value was evidenced from (κ)-carrageenan by microscopy (TEM and AFM). Preliminary investigations of the structure of these complexes revealed the existence of surfactant nanoparticles surrounded with polysaccharide matrix, probably resulting from electrostatic attraction. In addition, ITC measurements clearly showed that the interactions of the κ-carrageenan was stronger than for other polysaccharides ((ι)-, (λ)-carrageenans, alginate and ulvan). These results may have important impact on the use of the GB amide surfactant in formulations based on algal polysaccharides for several applications such as in food, cosmetics, and detergency fields.

  7. Naturally occurring antifungal aromatic esters and amides

    International Nuclear Information System (INIS)

    During the search of antifungal natural products from terrestrial plants, a new long chained aromatic ester named grandiflorate along with spatazoate from Portulaca grandiflora and N-[2-methoxy-2-(4-methoxyphenyl) ethyl]-trans-cinnamide and aegeline from Solanum erianthum of Nigeria were isolated and tested against six fungal species. The known constituents have not been reported so far from mentioned investigated plants. Structures of the isolated compounds were elucidated with the aid of spectroscopic techniques including two dimensional NMR experiments. Among the compounds, the esters found more potent than amides against Candida albicans and Aspergillus flavus. The new compound grandiflorate gave response against all tested fungal species while aegeline was found to give lowest inhibition during this study. (author)

  8. Synthesis of a new conjugated polymer for DNA alkylation and gene regulation.

    Science.gov (United States)

    Nie, Chenyao; Zhu, Chunlei; Feng, Liheng; Lv, Fengting; Liu, Libing; Wang, Shu

    2013-06-12

    A new polyfluorene derivative containing pendent alkylating chlorambucil (PFP-Cbl) was synthesized and characterized. Under direct incubation with DNA in vitro, PFP-Cbl could undergo an efficient DNA alkylating reaction and induce DNA cross-linking. In vitro transcription and translation experiment exhibited that the PFP-Cbl significantly down-regulated the gene expression of luciferase reporter plasmid. The down-regulation of gene expression was also verified through the transfection experiment of p-EGFP plasmid, which showed decreased green fluorescent protein (GFP) in cells. Meanwhile, the self-luminous property of PFP-Cbl could make it able to trace the internalized PFP-Cbl and plasmid complexes resulted from cross-linking in cells by fluorescent microscopy. Combining the features of alkylating function, multivalent binding sites, and fluorescent characteristics, PFP-Cbl provides a new insight in the area of gene regulation and extends the new applications of conjugated polymers (CPs). PMID:23548104

  9. The 6-amino-6-methyl-1,4-diazepine group as an ancillary ligand framework for neutral and cationic scandium and yttrium alkyls

    NARCIS (Netherlands)

    Ge, Shaozhong; Bambirra, Sergio; Meetsma, Auke; Hessen, Bart

    2006-01-01

    The 6-amino-6-methyl-1,4-diazepine framework is a readily available neutral 6-electron ligand moiety, suitable to support cationic group 3 metal alkyl catalysts; it also provides convenient access to tri- and tetradentate monoanionic ligand derivatives.

  10. Photophysical studies on the interaction of amides with Bovine Serum Albumin (BSA) in aqueous solution: Fluorescence quenching and protein unfolding

    Energy Technology Data Exchange (ETDEWEB)

    Kumaran, R., E-mail: kumaranwau@rediffmail.com [Department of Chemistry, Dwaraka Doss Goverdhan Doss Vaishnav College, Arumbakkam, Chennai 600106 (India); Ramamurthy, P. [National Centre for Ultrafast Processes, University of Madras, Sekhizar Campus, Taramani, Chennai 600113 (India)

    2014-04-15

    Addition. of amides containing a H-CO(NH{sub 2}) or CH{sub 3}-CO(NH{sub 2}) framework to BSA results in a fluorescence quenching. On the contrary, fluorescence enhancement with a shift in the emission maximum towards the blue region is observed on the addition of dimethylformamide (DMF) (H-CON(CH{sub 3}){sub 2}). Fluorescence quenching accompanied initially with a shift towards the blue region and a subsequent red shift in the emission maximum of BSA is observed on the addition of formamide (H-CO(NH{sub 2})), whereas a shift in the emission maximum only towards the red region results on the addition of acetamide (CH{sub 3}-CONH{sub 2}). Steady state emission spectral studies reveal that amides that possess a free NH{sub 2} and N(CH{sub 3}){sub 2} moiety result in fluorescence quenching and enhancement of BSA respectively. The 3D contour spectral studies of BSA with formamide exhibit a shift in the emission towards the red region accompanied with fluorescence quenching, which indicates that the tryptophan residues of the BSA are exposed to a more polar environment. Circular Dichroism (CD) studies of BSA with amides resulted in a gradual decrease in the α-helical content of BSA at 208 nm, which confirms that there is a conformational change in the native structure of BSA. Time-resolved fluorescence studies illustrate that the extent of buried trytophan moieties exposed to the aqueous phase on the addition of amides follows the order DMFalkyl substituted amides. Amides act as a hydrogen-bonding donor and acceptor resulting in a hydrogen-bonding interaction with amino and carboxy moieties (amino acids) present in BSA. The fact that the –NH{sub 2} hydrogen and the carbonyl oxygen of amide form a concerted hydrogen-bonding network with the carbonyl oxygen and the amino moieties of amino acids respectively is established from fluorescence methods. -- Highlights:

  11. Application of cyclic ketones in MCR: Ugi/amide coupling based synthesis of fused tetrazolo[1,5-a][1,4]benzodiazepines

    NARCIS (Netherlands)

    Yerande, Swapnil; Newase, Kiran; Singh, Bhawani; Boltjes, André; Dömling, Alex

    2014-01-01

    Azido-Ugi reaction involving cyclic ketone, primary amine, isonitrile, and azide afforded substituted tetrazole derivatives 5. These intermediates were hydrolyzed to corresponding acid derivatives. EDAC/HOBt mediated amide bond formation of 5 gave fused tetrazolo[1,5-a][1,4]benzodiazepine 6 in high

  12. Assessing the reactivity of sodium alkyl-magnesiates towards quinoxaline: single electron transfer (SET) vs. nucleophilic alkylation processes.

    Science.gov (United States)

    Livingstone, Zoe; Hernán-Gómez, Alberto; Baillie, Sharon E; Armstrong, David R; Carrella, Luca M; Clegg, William; Harrington, Ross W; Kennedy, Alan R; Rentschler, Eva; Hevia, Eva

    2016-04-14

    By exploring the reactivity of sodium butyl-magnesiate (1) supported by the bulky chelating silyl(bisamido) ligand {Ph2Si(NAr*)2}(2-) (Ar* = 2,6-iPr2-C6H3) towards Quinoxaline (Qx), the ability of this bimetallic system to effectively promote SET processes has been disclosed. Thus 1 executes the single-electron reduction of Qx affording complex (2) whose structure in the solid state contains two quinaxolyl radical anions Qx˙ stabilised within a dimeric magnesiate framework. Combining multinuclear NMR and EPR measurements with DFT calculations, new insights into the constitution of 2 in solution and its magnetic behaviour have been gained. Further evidence on the SET reactivity of 1 was found when it was reacted with nitroxyl radical TEMPO which furnished contacted ion pair sodium magnesiate [(Ph2Si(NAr*)2)Mg(TEMPO(-))Na(THF)3] (4) where both metals are connected by an alkoxide bridge, resulting from reduction of TEMPO. The role that the different ligands present in 1 can play in these new SET reactions has also been assessed. Using an amination approach, the Bu group in 1 can be replaced by the more basic amide TMP allowing the isolation of (3) which was characterised by multinuclear NMR and X-ray crystallography. (1)H NMR monitoring of the reaction of 3 with Qx showed its conversion to 2, leaving the hydrogen atoms of the heterocycle untouched. Contrastingly, using sodium homoalkyl magnesiate [NaMg(CH2SiMe3)3] (5) led to the chemoselective C2 alkylation of this heterocycle, suggesting that the presence of the steric stabiliser {Ph2Si(NAr*)2}(2-) on the mixed-metal reagent is required in order to facilitate the Qx reduction.

  13. Outlook for the U.S. alkylation industry

    International Nuclear Information System (INIS)

    Alkylation has long been recognized in the refining industry as one of the best options to convert refinery olefins into valuable, clean, high octane blending components. In fact, refinery alkylation is a preferred source of blending stocks for reformulated gasoline. However, the hydrofluoric acid (HF) alkylation process and, to a lesser extent, the sulfuric acid (SA) process have come under increasing pressure in the US due to safety and environmental concerns. This paper examines the current outlook for the US alkylation industry including: key trends and driving forces in the industry, the impact of environmental issues on both HF and SA alkylation, US alkylation supply/demand forecast including the outlook for oxygenates, how US refines will respond to the increased demand and restricted supply for alkylates, and the outlook for new solid acid alkylation (SAC) technology

  14. Synthesis and Antiangiogenic Activity of N-Alkylated Levamisole Derivatives

    DEFF Research Database (Denmark)

    Hansen, Anders N.; Bendiksen, Christine D.; Sylvest, Lene;

    2012-01-01

    Inhibition of angiogenesis is a promising addition to current cancer treatment strategies. Neutralization of vascular endothelial growth factor by monoclonal antibodies is clinically effective but may cause side effects due to thrombosis. Low molecular weight angiogenesis inhibitors are currently...

  15. Rational design and synthesis of an orally bioavailable peptide guided by NMR amide temperature coefficients

    Science.gov (United States)

    Wang, Conan K.; Northfield, Susan E.; Colless, Barbara; Chaousis, Stephanie; Hamernig, Ingrid; Lohman, Rink-Jan; Nielsen, Daniel S.; Schroeder, Christina I.; Liras, Spiros; Price, David A.; Fairlie, David P.; Craik, David J.

    2014-01-01

    Enhancing the oral bioavailability of peptide drug leads is a major challenge in drug design. As such, methods to address this challenge are highly sought after by the pharmaceutical industry. Here, we propose a strategy to identify appropriate amides for N-methylation using temperature coefficients measured by NMR to identify exposed amides in cyclic peptides. N-methylation effectively caps these amides, modifying the overall solvation properties of the peptides and making them more membrane permeable. The approach for identifying sites for N-methylation is a rapid alternative to the elucidation of 3D structures of peptide drug leads, which has been a commonly used structure-guided approach in the past. Five leucine-rich peptide scaffolds are reported with selectively designed N-methylated derivatives. In vitro membrane permeability was assessed by parallel artificial membrane permeability assay and Caco-2 assay. The most promising N-methylated peptide was then tested in vivo. Here we report a novel peptide (15), which displayed an oral bioavailability of 33% in a rat model, thus validating the design approach. We show that this approach can also be used to explain the notable increase in oral bioavailability of a somatostatin analog. PMID:25416591

  16. Role of an amide bond for self-assembly of surfactants.

    Science.gov (United States)

    Bordes, Romain; Tropsch, Juergen; Holmberg, Krister

    2010-03-01

    Self-assembly in solution and adsorption at the air-water interface and at solid surfaces were investigated for two amino-acid-based surfactants with conductimetry, NMR, tensiometry, quartz crystal microbalance with monitoring of the dissipation (QCM-D), and surface plasmon resonance (SPR). The surfactants studied were sodium N-lauroylglycinate and sodium N-lauroylsarcosinate, differing only in a methyl group on the amide nitrogen for the sarcosinate. Thus, the glycinate but not the sarcosinate surfactant is capable of forming intermolecular hydrogen bonds via the amide group. It was found that the amide bond, N-methylated or not, gave a substantial contribution to the hydrophilicity of the amphiphile. The ability to form intermolecular hydrogen bonds led to tighter packing at the air-water interface and at a hydrophobic surface. It also increased the tendency for precipitation as an acid-soap pair on addition of acid. Adsorption of the surfactants at a gold surface was also investigated and gave unexpected results. The sarcosine-based surfactant seemed to give bilayer adsorption, while the glycine derivative adsorbed as a monolayer.

  17. 40 CFR 721.575 - Substituted alkyl halide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted alkyl halide. 721.575... Substances § 721.575 Substituted alkyl halide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted alkyl halide (PMN P-83-1222)...

  18. Amberlyst-15 catalyzed synthesis of alkyl/aryl/heterocyclic phosphonates

    Institute of Scientific and Technical Information of China (English)

    U.M. Rao Kunda; V.N. Reddy Mudumala; C.S. Reddy Gangireddy; B.R. Nemallapudi; K.N. Sandip; S.R. Cirandur

    2011-01-01

    A novel and efficient procedure for the synthesis of alkyl phosphonates through one pot condensation of alkyl halide and tri-alkyl/aryl phosphite in the presence of Amberlyst-15 as catalyst under solvent free conditions was applied. It demonstrated several advantages such as good yields of products, simple operation, convenient separation and inexpensive catalyst.

  19. IONIC LIQUID-CATALYZED ALKYLATION OF ISOBUTANE WITH 2-BUTENE

    Science.gov (United States)

    A detailed study of the alkylation of isobutane with 2-butene in ionic liquid media has been conducted using 1-alkyl-3-methylimidazolium halides?aluminum chloride encompassing various alkyl groups (butyl-, hexyl-, and octyl-) and halides (Cl, Br, and I) on its cations and anions,...

  20. Polypyrrole Doped with Alkyl Benzene Sulphonates

    DEFF Research Database (Denmark)

    Bay, Lasse; Mogensen, Naja; Skaarup, Steen;

    2002-01-01

    The properties of polypyrrole (PPy) are to a large extent determined by the condition of synthesis and especially by the counterion incorporated as dopant during synthesis. In this work, PPy doped with different alkyl benzenesulfonates are compared. The polymer films are prepared by constant curr...

  1. Assessment of the combined approach of N-alkylation and salt formation to enhance aqueous solubility of tertiary amines using bupivacaine as a model drug

    DEFF Research Database (Denmark)

    Nielsen, Anders Bach; Frydenvang, Karla Andrea; Liljefors, Tommy;

    2005-01-01

    tertiary amine (up to a factor of 3200 at pH 8). A moderate reduction in solubility with increasing length of the alkyl chain was observed for the iodide salts of the N-alkylated bupivacaine derivatives. In case of the N-methyl-bupivacaine derivative variation of the counterion had a significant impact......Quaternary prodrug types of poorly water-soluble tertiary amines have been shown to exhibit significantly enhanced solubilities as compared to the parent amine. In the present study the combined effect of N-alkylation and salt formation to enhance aqueous solubility of tertiary amines have been...... investigated using bupivacaine as a model compound. X-ray structure analyses of selected salts were included to investigate the potential existence of correlations between salt solubility and crystal packing modes. Alkyl groups were methyl, ethyl, propyl, and butyl and the derivatives were isolated...

  2. Novel Benzosuberone Derivatives:Synthesis, Characterization and Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    J. Venkateswara Rao

    2015-12-01

    Full Text Available The synthesis of novel amide derivatives of benzosuberone 7a-j from commercially available benzosuberone was successfully achieved in six steps. Some of the important reactions that are involved in the synthesis are (i insertion of methylester (ii Suzki reaction and (iii saponification followed by amide bond formation. The newly synthesis benzosuberone derivatives 7a-j were screened for antibacterial activity and the results indicated that in general, benzosuberone derivatives with R = piperazine ring showed good antibacterial activity.

  3. Alkaline earth alkyl insertion chemistry of in situ generated aminoboranes.

    Science.gov (United States)

    Bellham, Peter; Hill, Michael S; Kociok-Köhn, Gabriele; Liptrot, David J

    2013-01-21

    Reactions of equimolar quantities of secondary amine boranes, R(2)NH·BH(3), with the homoleptic group 2 alkyl compounds [M{CH(SiMe(3))(2)}(2)(THF)(2)] (M = Mg, Ca, Sr) provide the alkyl group 2 amido borane derivatives [M{CH(SiMe(3))(2)}{NR(2)BH(3)}(THF)](2). While the strontium derivatives of reactions with dimethylamine and pyrrolidine borane are stable and isolable compounds, the analogous magnesium and calcium compounds are found to be unstable at room temperature. Studies of the thermolysis of the alkylstrontium derivatives have allowed this instability to be rationalised as a result of β-hydride elimination, the facility of which varies with changing M(2+) charge density, to form the products of M-C insertion of H(2)B=NR(2). Subsequent to this process, alkylaminoboranes, [HB(NR(2)){CH(SiMe(3))(2)}], are observed to form through a further suggested β-hydride elimination reaction. This chemistry is also extended to the reaction of the primary amine borane (t)BuNH(2)·BH(3) with [Sr{CH(SiMe(3))(2)}(2)(THF)(2)]. In this case the crystal structure of a heteroleptic species, which may be considered as a tetrameric aggregate of two [Sr{CH(SiMe(3))(2)}{(NH(t)Bu)BH(3)}(2)] anions and two cationic [Sr{(NH(t)Bu)(BH(3))}(THF)(2)] components, has been determined. Kinetic studies of the reactions of [M{CH(SiMe(3))(2)}(2)(THF)(2)] (M = Mg, Ca, Sr) with dimethylamine borane have also been undertaken and describe a complex mechanism in which the barriers to formation of the various intermediate species are a consequence of M(2+) radius and resultant charge density as well as the steric demands of the coordinated amidoborane ligands. PMID:23070304

  4. Artists with Arthritis Create Beauty amid Pain

    Institute of Scientific and Technical Information of China (English)

    Alan; Mozes; 蔡峥伟

    2000-01-01

    得此来稿,我们曾犹豫再三,是否刊用此文。因为,其内容给人的第一印象颇有点离奇。Artists with Arthritis Create Beauty amid Pain,怎么可能呢?细读之下,你也许会觉得,此文虽是一家之言,但也并非荒唐。尤其是本文的收尾句,笔锋一转,抖出了妙言: ...in addition to the emotional support such stories can give RA patients,there are now new drug options that far surpass the treatment choices Renoir faced. 此句是否可译:除了此类故事能够给患风湿病者一种情感上的支持之外,现在可选的新药要比Renoir(雷诺阿,法国印象派画家。主要作品有《包厢》、《游船上的午餐》、《浴女》等。)时代强得多。

  5. Phase space investigation of the lithium amide halides

    Energy Technology Data Exchange (ETDEWEB)

    Davies, Rosalind A. [Hydrogen Storage Chemistry Group, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Hydrogen and Fuel Cell Group, School of Chemical Engineering, University of Birmingham, Edgbaston B15 2TT (United Kingdom); Hewett, David R.; Korkiakoski, Emma [Hydrogen Storage Chemistry Group, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Thompson, Stephen P. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Anderson, Paul A., E-mail: p.a.anderson@bham.ac.uk [Hydrogen Storage Chemistry Group, School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2015-10-05

    Highlights: • The lower limits of halide incorporation in lithium amide have been investigated. • The only amide iodide stoichiometry observed was Li{sub 3}(NH{sub 2}){sub 2}I. • Solid solutions were observed in both the amide chloride and amide bromide systems. • A 46% reduction in chloride content resulted in a new phase: Li{sub 7}(NH{sub 2}){sub 6}Cl. • New low-chloride phase maintained improved H{sub 2} desorption properties of Li{sub 4}(NH{sub 2}){sub 3}Cl. - Abstract: An investigation has been carried out into the lower limits of halide incorporation in lithium amide (LiNH{sub 2}). It was found that the lithium amide iodide Li{sub 3}(NH{sub 2}){sub 2}I was unable to accommodate any variation in stoichiometry. In contrast, some variation in stoichiometry was accommodated in Li{sub 7}(NH{sub 2}){sub 6}Br, as shown by a decrease in unit cell volume when the bromide content was reduced. The amide chloride Li{sub 4}(NH{sub 2}){sub 3}Cl was found to adopt either a rhombohedral or a cubic structure depending on the reaction conditions. Reduction in chloride content generally resulted in a mixture of phases, but a new rhombohedral phase with the stoichiometry Li{sub 7}(NH{sub 2}){sub 6}Cl was observed. In comparison to LiNH{sub 2}, this new low-chloride phase exhibited similar improved hydrogen desorption properties as Li{sub 4}(NH{sub 2}){sub 3}Cl but with a much reduced weight penalty through addition of chloride. Attempts to dope lithium amide with fluoride ions have so far proved unsuccessful.

  6. Phase space investigation of the lithium amide halides

    International Nuclear Information System (INIS)

    Highlights: • The lower limits of halide incorporation in lithium amide have been investigated. • The only amide iodide stoichiometry observed was Li3(NH2)2I. • Solid solutions were observed in both the amide chloride and amide bromide systems. • A 46% reduction in chloride content resulted in a new phase: Li7(NH2)6Cl. • New low-chloride phase maintained improved H2 desorption properties of Li4(NH2)3Cl. - Abstract: An investigation has been carried out into the lower limits of halide incorporation in lithium amide (LiNH2). It was found that the lithium amide iodide Li3(NH2)2I was unable to accommodate any variation in stoichiometry. In contrast, some variation in stoichiometry was accommodated in Li7(NH2)6Br, as shown by a decrease in unit cell volume when the bromide content was reduced. The amide chloride Li4(NH2)3Cl was found to adopt either a rhombohedral or a cubic structure depending on the reaction conditions. Reduction in chloride content generally resulted in a mixture of phases, but a new rhombohedral phase with the stoichiometry Li7(NH2)6Cl was observed. In comparison to LiNH2, this new low-chloride phase exhibited similar improved hydrogen desorption properties as Li4(NH2)3Cl but with a much reduced weight penalty through addition of chloride. Attempts to dope lithium amide with fluoride ions have so far proved unsuccessful

  7. Enantioselective synthesis and teratogenicity of propylisopropyl acetamide, a CNS-active chiral amide analogue of valproic acid.

    Science.gov (United States)

    Spiegelstein, O; Bialer, M; Radatz, M; Nau, H; Yagen, B

    1999-01-01

    Propylisopropyl acetamide (PID), an amide analogue of the major antiepileptic drug valproic acid (VPA), possesses favorable anticonvulsant and CNS properties. PID contains one chiral carbon atom and therefore exists in two enantiomeric forms. The purpose of this work was to synthesize the two PID enantiomers and evaluate their enantiospecific teratogenicity. Enantioselective synthesis of PID enantiomers was achieved by coupling valeroyl chloride with optically pure (4S)- and (4R)-benzyl-2-oxazolidinone chiral auxiliaries. The two oxazolidinone enolates were alkylated with isopropyl triflate, hydrolyzed, and amidated to yield (2R)- and (2S)-PID. These two PID enantiomers were obtained with excellent enantiomeric purity, exceeding 99.4%. Unlike VPA, both (2R)- and (2S)-PID failed to exert teratogenic effects in NMRI mice following a single 3 mmol/kg subcutaneous injection. From this study we can conclude that individual PID enantiomers do not demonstrate stereoselective teratogenicity in NMRI mice. Due to its better anticonvulsant activity than VPA and lack of teratogenicity, PID (in a stereospecific or racemic form) has the potential to become a new antiepileptic and CNS drug.

  8. Physicochemical and electrochemical properties of N-methyl-N-methoxymethylpyrrolidinium bis(fluorosulfonyl)amide and its lithium salt composites

    Science.gov (United States)

    Horiuchi, Shunsuke; Yoshizawa-Fujita, Masahiro; Takeoka, Yuko; Rikukawa, Masahiro

    2016-09-01

    The ionic liquid (IL) N-Methyl-N-methoxymethylpyrrolidinium bis(fluorosulfonyl)amide ([Pyr1,1O1][FSA]) was synthesized, and its physicochemical and electrochemical properties were investigated with respect to its application as an electrolyte in lithium-ion secondary batteries operating over a wide temperature range. [Pyr1,1O1][FSA]/Li salt (0.34 mol kg-1) composites were prepared by adding lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) into the IL. [Pyr1,1O1][FSA] and [Pyr1,1O1][FSA]/LiTFSA exhibited melting temperatures (Tm) below -30 °C. [Pyr1,1O1][FSA] exhibited a higher ionic conductivity value as compared with that of the corresponding IL with only alkyl substituents. The electrochemical window for both [Pyr1,1O1][FSA] and [Pyr1,1O1][FSA]/LiTFSA was 5.1 V. Stable lithium deposition and dissolution occurred on a Ni electrode at 25 °C.

  9. A process of spent nuclear fuel treatment with the interim storage of TRU by use amidic extractants

    Energy Technology Data Exchange (ETDEWEB)

    Tachimori, Shoichi; Suzuki, Shinichi; Sasaki, Yuji [Japan Atomic Energy Research Inst., Tokyo (Japan)

    2001-12-01

    A new chemical process, ARTIST process, is proposed for the treatment of spent nuclear fuel. The main concept of the ARTIST process is to recover and stock separately all actinides, uranium and a mixture of transuranics, and to dispose fission products. The process composed of two main steps, a uranium exclusive isolation and a total recovery of transuranium elements (TRU); which copes with the nuclear non-proliferation measures, and additional processes. Both actinide products are solidified by calcination and allowed to the interim storage for future utilization. These separations are achieved by use of amidic extractants in accord with the CHON principle. The technical feasibility of the ARTIST process was explained by the experimental results of both the branched-alkyl monoamides in extracting uranium and suppressing the extraction of tetravalent actinides due to the steric effect and the diglycolic amide in thorough extraction of all TRU by tridentate coordination. When these TRU are requested to put into reactors, LWR or FBR, for power generation or the Accelerator-Driven System (ADS) for transmutation, lanthanides are to be removed from TRU by utilizing a soft nitrogen donor ligand. (author)

  10. Ionic products of metal complexes with dithiocarbonic acid derivatives

    International Nuclear Information System (INIS)

    Ionic products of the complexes of certain sulfide-forming metal ions (In, Cd, Te, etc.) with alkyl derivates of dithiocarbonic acid have been defined. The possibility to use ionic products of alkyl xanthates for predicting the practicability of employing alkyl xanthates as analytic reagents in titrimetric methods of analysis, in extractional methods of separation and determination of elements, increase in the determination selectivity, is shown. 11 refs., 1 fig., 1 tab

  11. Oxidative Umpolung α‐Alkylation of Ketones

    DEFF Research Database (Denmark)

    Shneider, O. Svetlana; Pisarevsky, Evgeni; Fristrup, Peter;

    2015-01-01

    We disclose a hypervalent iodine mediated α-alkylative umpolung reaction of carbonyl compounds with dialkylzinc as the alkyl source. The reaction is applicable to all common classes of ketones including 1,3-dicarbonyl compounds and regular ketones via their lithium enolates. The α-alkylated carbo......We disclose a hypervalent iodine mediated α-alkylative umpolung reaction of carbonyl compounds with dialkylzinc as the alkyl source. The reaction is applicable to all common classes of ketones including 1,3-dicarbonyl compounds and regular ketones via their lithium enolates. The α...

  12. 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.

  13. Ultra-bright alkylated graphene quantum dots

    Science.gov (United States)

    Feng, Lan; Tang, Xing-Yan; Zhong, Yun-Xin; Liu, Yue-Wen; Song, Xue-Huan; Deng, Shun-Liu; Xie, Su-Yuan; Yan, Jia-Wei; Zheng, Lan-Sun

    2014-10-01

    Highly efficient and stable photoluminescence (PL) are urgently desired for graphene quantum dots (GQDs) to facilitate their prospective applications as optical materials. Here, we report the facile and straightforward synthesis of alkylated graphene quantum dots (AGQDs) via the solvothermal reaction of propagatively alkylated graphene sheets (PAGenes). In contrast to most GQDs reported so far, the synthesized AGQDs process pH-independent and ultra-bright PL with a relative quantum yield of up to 65%. Structural and chemical composition characterization demonstrated that the synthesized AGQDs are nearly oxygen-defect-free with alkyl groups decorated on edges and basal plane, which may contribute to their greatly improved pH tolerance and high quantum efficiency. The photocatalytic performance of AGQDs-P25 nanocomposites was evaluated by the degradation of Rhodamine B under visible light. The photocatalytic rate is ca. 5.9 times higher than that of pure P25, indicating that AGQDs could harness the visible spectrum of sunlight for energy conversion or environmental therapy.Highly efficient and stable photoluminescence (PL) are urgently desired for graphene quantum dots (GQDs) to facilitate their prospective applications as optical materials. Here, we report the facile and straightforward synthesis of alkylated graphene quantum dots (AGQDs) via the solvothermal reaction of propagatively alkylated graphene sheets (PAGenes). In contrast to most GQDs reported so far, the synthesized AGQDs process pH-independent and ultra-bright PL with a relative quantum yield of up to 65%. Structural and chemical composition characterization demonstrated that the synthesized AGQDs are nearly oxygen-defect-free with alkyl groups decorated on edges and basal plane, which may contribute to their greatly improved pH tolerance and high quantum efficiency. The photocatalytic performance of AGQDs-P25 nanocomposites was evaluated by the degradation of Rhodamine B under visible light. The

  14. Amidation reaction of eugenyl oxyacetate ethyl ester with 1,3 diaminopropane

    Science.gov (United States)

    Suryanti, V.; Wibowo, F. R.; Kusumaningsih, T.; Wibowo, A. H.; Khumaidah, S. A.; Wijayanti, L. A.

    2016-04-01

    Eugenol having various substituents on the aromatic ring (hydroxy, methoxy and allyl) are useful for starting material in synthesizing of its derivatives. Eugenol derivatives have shown wide future potential applications in many areas, especially as future drugs against many diseases. The aim of this work was to synthesize an amide of eugenol derivative. The starting material used was eugenol from clove oil and the reaction was conducted in 3 step reactions to give the final product. Firstly, eugenol was converted into eugenyl oxyacetate [2-(4-allyl-2-methoxyphenoxy) acetic acid] as a white crystal with 70.5% yield, which was then esterified with ethanol to have eugenyl oxyacetate ethyl ester [ethyl 2-(4-allyl-2-methoxyphenoxy) acetate] as brown liquid in 75.7%. The last step was the reaction between eugenyl oxyacetate ethyl ester and 1,3 diaminopropane to give 2-(4-allyl-2-methoxyphenoxy)-N-(3-aminopropyl) acetamide as a brown powder with 71.6% yield, where the amidation reaction was occurred.

  15. Deriving Derivatives

    OpenAIRE

    Soklakov, Andrei N.

    2013-01-01

    Quantitative Structuring is a rigorous framework for the design of financial products. We show how it incorporates traditional investment ideas while supporting a more accurate expression of clients' views on the market. We briefly touch upon adjacent topics regarding the safety of financial derivatives and the role of pricing models in product design.

  16. Cations bind only weakly to amides in aqueous solutions.

    Science.gov (United States)

    Okur, Halil I; Kherb, Jaibir; Cremer, Paul S

    2013-04-01

    We investigated salt interactions with butyramide as a simple mimic of cation interactions with protein backbones. The experiments were performed in aqueous metal chloride solutions using two spectroscopic techniques. In the first, which provided information about contact pair formation, the response of the amide I band to the nature and concentration of salt was monitored in bulk aqueous solutions via attenuated total reflection Fourier transform infrared spectroscopy. It was found that molar concentrations of well-hydrated metal cations (Ca(2+), Mg(2+), Li(+)) led to the rise of a peak assigned to metal cation-bound amides (1645 cm(-1)) and a decrease in the peak associated with purely water-bound amides (1620 cm(-1)). In a complementary set of experiments, the effect of cation identity and concentration was investigated at the air/butyramide/water interface via vibrational sum frequency spectroscopy. In these studies, metal ion-amide binding led to the ordering of the adjacent water layer. Such experiments were sensitive to the interfacial partitioning of cations in either a contact pair with the amide or as a solvent separated pair. In both experiments, the ordering of the interactions of the cations was: Ca(2+) > Mg(2+) > Li(+) > Na(+) ≈ K(+). This is a direct cationic Hofmeister series. Even for Ca(2+), however, the apparent equilibrium dissociation constant of the cation with the amide carbonyl oxygen was no tighter than ∼8.5 M. For Na(+) and K(+), no evidence was found for any binding. As such, the interactions of metal cations with amides are far weaker than the analogous binding of weakly hydrated anions.

  17. Dianthosaponins A-F, triterpene saponins, flavonoid glycoside, aromatic amide glucoside and γ-pyrone glucoside from Dianthus japonicus.

    Science.gov (United States)

    Nakano, Takahiro; Sugimoto, Sachiko; Matsunami, Katsuyoshi; Otsuka, Hideaki

    2011-01-01

    From aerial parts of Dianthus japonicus, six new and seven known oleanane-type triterpene saponins were isolated. The structures of the new saponins, named dianthosaponins A-F, were elucidated by means of high resolution mass spectrometry, and extensive inspection of one- and two-dimensional NMR spectroscopic data. A new C-glycosyl flavone, a glycosidic derivative of anthranilic acid amide and a maltol glucoside were also isolated.

  18. Hydrocarbon adsorption in an aqueous environment: A computational study of alkyls on Cu(111)

    Science.gov (United States)

    Montemore, Matthew M.; Andreussi, Oliviero; Medlin, J. Will

    2016-08-01

    Hydrocarbon chains are important intermediates in various aqueous-phase surface processes, such as CO2 electroreduction, aqueous Fischer-Tropsch synthesis, and aqueous phase reforming of biomass-derived molecules. Further, the interaction between water and adsorbed hydrocarbons represents a difficult case for modern computational methods. Here, we explore various methods for calculating the energetics of this interaction within the framework of density functional theory and explore trade-offs between the use of low water coverages, molecular dynamics approaches, and minima hopping for identification of low energy structures. An effective methodology for simulating low temperature processes is provided by using a unit cell in which the vacuum space is filled with water, employing the minima hopping algorithm to search for low-lying minima, and including dispersion (van der Waals) interactions. Using this methodology, we show that a high coverage of adsorbed alkyls is destabilized by the presence of water, while a low coverage of alkyls is stabilized. Solvation has a small effect on the energetics of hydrocarbon chain growth, generally decreasing its favorability at low temperatures. We studied higher temperatures by running molecular dynamics simulations starting at the minima found by the minima hopping algorithm and found that increased temperatures facilitate chain growth. The self-consistent continuum solvation method effectively describes the alkyl-water interaction and is in general agreement with the explicit solvation results in most cases, but care should be taken at high alkyl coverage.

  19. A polarizable QM/MM approach to the molecular dynamics of amide groups solvated in water

    Science.gov (United States)

    Schwörer, Magnus; Wichmann, Christoph; Tavan, Paul

    2016-03-01

    The infrared (IR) spectra of polypeptides are dominated by the so-called amide bands. Because they originate from the strongly polar and polarizable amide groups (AGs) making up the backbone, their spectral positions sensitively depend on the local electric fields. Aiming at accurate computations of these IR spectra by molecular dynamics (MD) simulations, which derive atomic forces from a hybrid quantum and molecular mechanics (QM/MM) Hamiltonian, here we consider the effects of solvation in bulk liquid water on the amide bands of the AG model compound N-methyl-acetamide (NMA). As QM approach to NMA we choose grid-based density functional theory (DFT). For the surrounding MM water, we develop, largely based on computations, a polarizable molecular mechanics (PMM) model potential called GP6P, which features six Gaussian electrostatic sources (one induced dipole, five static partial charge distributions) and, therefore, avoids spurious distortions of the DFT electron density in hybrid DFT/PMM simulations. Bulk liquid GP6P is shown to have favorable properties at the thermodynamic conditions of the parameterization and beyond. Lennard-Jones (LJ) parameters of the DFT fragment NMA are optimized by comparing radial distribution functions in the surrounding GP6P liquid with reference data obtained from a "first-principles" DFT-MD simulation. Finally, IR spectra of NMA in GP6P water are calculated from extended DFT/PMM-MD trajectories, in which the NMA is treated by three different DFT functionals (BP, BLYP, B3LYP). Method-specific frequency scaling factors are derived from DFT-MD simulations of isolated NMA. The DFT/PMM-MD simulations with GP6P and with the optimized LJ parameters then excellently predict the effects of aqueous solvation and deuteration observed in the IR spectra of NMA. As a result, the methods required to accurately compute such spectra by DFT/PMM-MD also for larger peptides in aqueous solution are now at hand.

  20. A polarizable QM/MM approach to the molecular dynamics of amide groups solvated in water.

    Science.gov (United States)

    Schwörer, Magnus; Wichmann, Christoph; Tavan, Paul

    2016-03-21

    The infrared (IR) spectra of polypeptides are dominated by the so-called amide bands. Because they originate from the strongly polar and polarizable amide groups (AGs) making up the backbone, their spectral positions sensitively depend on the local electric fields. Aiming at accurate computations of these IR spectra by molecular dynamics (MD) simulations, which derive atomic forces from a hybrid quantum and molecular mechanics (QM/MM) Hamiltonian, here we consider the effects of solvation in bulk liquid water on the amide bands of the AG model compound N-methyl-acetamide (NMA). As QM approach to NMA we choose grid-based density functional theory (DFT). For the surrounding MM water, we develop, largely based on computations, a polarizable molecular mechanics (PMM) model potential called GP6P, which features six Gaussian electrostatic sources (one induced dipole, five static partial charge distributions) and, therefore, avoids spurious distortions of the DFT electron density in hybrid DFT/PMM simulations. Bulk liquid GP6P is shown to have favorable properties at the thermodynamic conditions of the parameterization and beyond. Lennard-Jones (LJ) parameters of the DFT fragment NMA are optimized by comparing radial distribution functions in the surrounding GP6P liquid with reference data obtained from a "first-principles" DFT-MD simulation. Finally, IR spectra of NMA in GP6P water are calculated from extended DFT/PMM-MD trajectories, in which the NMA is treated by three different DFT functionals (BP, BLYP, B3LYP). Method-specific frequency scaling factors are derived from DFT-MD simulations of isolated NMA. The DFT/PMM-MD simulations with GP6P and with the optimized LJ parameters then excellently predict the effects of aqueous solvation and deuteration observed in the IR spectra of NMA. As a result, the methods required to accurately compute such spectra by DFT/PMM-MD also for larger peptides in aqueous solution are now at hand. PMID:27004884

  1. Drug Nanoparticle Formulation Using Ascorbic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Kunikazu Moribe

    2011-01-01

    Full Text Available Drug nanoparticle formulation using ascorbic acid derivatives and its therapeutic uses have recently been introduced. Hydrophilic ascorbic acid derivatives such as ascorbyl glycoside have been used not only as antioxidants but also as food and pharmaceutical excipients. In addition to drug solubilization, drug nanoparticle formation was observed using ascorbyl glycoside. Hydrophobic ascorbic acid derivatives such as ascorbyl mono- and di-n-alkyl fatty acid derivatives are used either as drugs or carrier components. Ascorbyl n-alkyl fatty acid derivatives have been formulated as antioxidants or anticancer drugs for nanoparticle formulations such as micelles, microemulsions, and liposomes. ASC-P vesicles called aspasomes are submicron-sized particles that can encapsulate hydrophilic drugs. Several transdermal and injectable formulations of ascorbyl n-alkyl fatty acid derivatives were used, including ascorbyl palmitate.

  2. Biodegradable poly(ester amide)s – A remarkable opportunity for the biomedical area: Review on the synthesis, characterization and

    OpenAIRE

    Fonseca, Ana C.; Gil, Maria H.; Simões, Pedro N.

    2014-01-01

    Poly(ester amide)s have emerged in the last years as an important family of biodegradable synthetic polymers. These polymers present both ester and amide linkages in their structure and they gather in the same entity the good degradability of polyesters with the good thermo-mechanical properties of polyamides. Particularly, poly(ester amide)s containing α-amino acids have risen as important materials in the biomedical field. The presence of the α-amino acid contributes to better cell–polymer ...

  3. Iron(III) Chloride mediated reduction of Bis(1-isoquinolylcarbonyl)amide to an Amide

    Indian Academy of Sciences (India)

    Rojalin Sahu; Papuli Chaliha; Vadivelu Manivannan

    2016-01-01

    In methanol, FeCl3 reacted readily with L1H (L1H = bis(1-isoquinolylcarbonyl)amide) and afforded a complex having the formula [Fe(L2)Cl2] (1) {L2− = -((1-isoquinolyl)(methoxy)methyl)isoquinoline-1-carboxamide ion}. This reaction involves reduction of one of the two carbonyl groups present in L1H to (methoxy)methyl group. A plausible mechanism for the conversion of L1H to L2− has been proposed. Determination of molecular structure of 1 confirmed this conversion. Fe(III) ion is surrounded by three nitrogen atoms of the ligand and two chloride ions, imparting a rare distorted trigonal bipyramidal N3Cl2 coordination environment.

  4. Enzymatic Synthesis of Palm Alkyl Ester Using Dialkyl Carbonate as an Alkyl Donors

    Directory of Open Access Journals (Sweden)

    Roila Awang

    2010-01-01

    Full Text Available Problem statement: Though efficient in terms of reaction yield and time, the chemical approach to synthesizing alkyl ester has drawback such as difficulties in the recovery of glycerol and the need for removal of salt residue. On the other hand, biocatalyst allow for synthesis of specific alkyl esters and easy recovery of glycerol. However, the solvent-free alcoholysis, does not give high conversion. The same problem was also found when ethyl or methyl acetate was used as acyl acceptors. Approach: Lipase catalyzed transesterification of oil and dialkyl carbonate was predicted to give higher conversion in solvent free reaction system. Results: Alkyl esters were synthesized enzymatically to overcome the problems associated with chemical processes. In this study, dialkyl carbonates were used as an alkyl donor for the production of alkyl ester. Nine commercial lipases were tested for their suitability for the reaction system. Among the lipase tested, Novozym 435 was chosen for optimization study because of their higher activity. In a solvent-free reaction system, the ester formation using dialkyl carbonate was 6 times higher than using ethanol and methanol. The effect of various reaction parameters such as temperature, amount of enzyme, organic solvent and structure of substrates were studied to determine optimal condition. The optimal conditions of ester formation were reaction temperature at 60°C, reaction time at 8 h, enzyme amount of 10% (w/w of oil and 0.2% wt added water. Conclusion: Solvent-free lipase catalyzed transesterification of palm kernel oil and dialkyl carbonates gave higher conversion of ester compared to the reaction using short chain alcohol as an alkyl donors.

  5. Metal complexation by tripodal N-Acyl(thio)urea and picolin(thio)amide compounds: synthesis/extraction and potentiometric studies

    NARCIS (Netherlands)

    Reinoso-Garcia, Marta M.; Dijkman, Arjan; Verboom, Willem; Reinhoudt, David N.; Malinowska, Elzbieta; Wojciechowska, Dorota; Pietrzak, Mariusz; Selucky, Pavel

    2005-01-01

    The synthesis and binding properties towards different cations of a series of tripodal ligands functionalized with N-acyl(thio)urea and picolin(thio)amide moieties are described. For the extraction of Am3+ and Eu3+ the compounds are not efficient. However, N-acylurea derivative 10 exhibit a signific

  6. Nickel-catalysed Suzuki-Miyaura coupling of amides

    Science.gov (United States)

    Weires, Nicholas A.; Baker, Emma L.; Garg, Neil K.

    2016-01-01

    The Suzuki-Miyaura coupling has become one of the most important and prevalent methods for the construction of C-C bonds. Although palladium catalysis has historically dominated the field, the use of nickel catalysis has become increasingly widespread because of its unique ability to cleave carbon-heteroatom bonds that are unreactive towards other transition metals. We report the first nickel-catalysed Suzuki-Miyaura coupling of amides, which proceeds by an uncommon cleavage of the amide C-N bond after N-tert-butoxycarbonyl activation. The methodology is mild, functional-group tolerant and can be strategically employed in sequential transition-metal-catalysed cross-coupling sequences to unite heterocyclic fragments. These studies demonstrate that amides, despite classically considered inert substrates, can be harnessed as synthons for use in reactions that form C-C bonds through cleavage of the C-N bond using non-precious metal catalysis.

  7. Ir/Sn dual-reagent catalysis towards highly selective alkylation of arenes and heteroarenes with benzyl alcohols

    Indian Academy of Sciences (India)

    Sujit Roy; Susmita Podder; Joyanta Choudhury

    2008-09-01

    A catalytic combination of [Ir(COD)Cl]2-SnCl4 efficiently promotes the reactions of arenes and heteroarenes with 1°/2°/3° benzyl alcohols as the alkylating agents to afford the corresponding diarylmethane and triarylmethane derivatives in high yields. The scope and limitation of the reaction with respect to catalyst and substrates variation has been studied in detail.

  8. Microwave assisted synthesis, spectral, magnetic and bioevolution of few Mn (II)-amide complexes

    Science.gov (United States)

    Joshi, Gaurav; Verma, K. K.; Gudesaria, D. D.; Bhojak, N.

    2016-05-01

    The importance and versatility of amide group containing ligands have promoted the selection of this class of ligands and their complexes for the study. The present work describes the synthesis, spectral and biological investigations on the complexes of amides derived from heterocyclic amines with Mn (II) ions. Four ligands derived 2-aminopyridine and their complexes with Mn (II) have been synthesized. A method for the synthesis of complexes has been developed by the use of microwave irradiation which is in agreement to Green chemistry approach. The complexes have been characterized on the basis of elemental analysis, infrared, electronic, ESR spectra and magnetic susceptibility studies. The diffuse reflectance spectrum of the complexes show bands in the region 20,000 cm-1 to 26,000 cm-1 assignable to 6A1g → 4T2g and 6A1g → 4E1g transitions. These are also typical of tetrahedral environment around the manganese. The magnetic moment (5.80 BM) of the complex indicates high spin tetrahedral environment. The microwave method of synthesis of complexes have been found easier, convenient and ecofriendly. Antimicrobial activities of compounds were also carried out against bacteria and fungi. Further minimal inhibitory concentration (MIC) was also determined for each compound.

  9. New GABA amides activating GABA A-receptors

    OpenAIRE

    Peter Raster; Andreas Späth; Svetlana Bultakova; Pau Gorostiza; Burkhard König; Piotr Bregestovski

    2013-01-01

    We have prepared a series of new and some literature-reported GABA-amides and determined their effect on the activation of GABAA-receptors expressed in CHO cells. Special attention was paid to the purification of the target compounds to remove even traces of GABA contaminations, which may arise from deprotection steps in the synthesis. GABA-amides were previously reported to be partial, full or superagonists. In our hands these compounds were not able to activate GABAA-receptor channels in wh...

  10. 3D, 2D and 1D networks via N-H…O and N-H…N hydrogen bonding by the bis-amide analogues: Effect of chain lengths and odd-even spacers

    Indian Academy of Sciences (India)

    Gargi Mukherjee; Kumar Biradha

    2014-09-01

    The synthesis, crystal structures and hydrogen bonding networks of four members of the bis(pyridinecarboxamido)alkane and bis(pyridyl)alkanediamides series (1 ≤ ≤ 8), where the amide moieties are separated by alkyl chain (-(CH2)-) having even or odd number of -(CH2)-groups are explored and correlated with the previously reported structures. The odd members (n= odd) of both the series are found to adopt three-dimensional networks in contrast to the 1D or 2D structures of the even members (n= even). This odd-even effect on the dimensionality of the networks however disappears with increase in chain length.

  11. Oxygen-Controlled Catalysis by Vitamin B12 -TiO2 : Formation of Esters and Amides from Trichlorinated Organic Compounds by Photoirradiation.

    Science.gov (United States)

    Shimakoshi, Hisashi; Hisaeda, Yoshio

    2015-12-14

    An oxygen switch in catalysis of the cobalamin derivative (B12 )-TiO2 hybrid catalyst for the dechlorination of trichlorinated organic compounds has been developed. The covalently bound B12 on the TiO2 surface transformed trichlorinated organic compounds into an ester and amide by UV light irradiation under mild conditions (in air at room temperature), while dichlorostilbenes (E and Z forms) were formed in nitrogen from benzotrichloride. A benzoyl chloride was formed as an intermediate of the ester and amide, which was detected by GC-MS. The substrate scope of the synthetic strategy is demonstrated with a range of various trichlorinated organic compounds. A photo-duet reaction utilizing the hole and conduction band electron of TiO2 in B12 -TiO2 for the amide formation was also developed.

  12. MEDV-13 for QSAR Studies on the COX-2 Inhibition by In domethacin Amides and Esters

    Institute of Scientific and Technical Information of China (English)

    LIU,Shu-Shen (刘树深); YIN,Chun-Sheng(印春生); SHI,Yun-Yu(施蕴渝); CAI,Shao-Xi(蔡绍皙); LI,Zhi-Liang(李志良)

    2001-01-01

    A molecular electronegativity distance vector based on 13 atomic types (MEDV-13), is a descriptor for predicting the biological activities of molecules based on the quantitative structure-activity relationship (QSAR). The MEDV-13 with 91 descriptors is employed to describe the structures of a series of selective cydooxygenase-2 (COX-2) inhibitors inchuding 16 indomethacin and its amide and ester derivatives (ImAE). A principal component regression (PCR) is used to derive a QSAR model relating the biological activities expressed by pIC50 values to the MEDV-13. With the number of principal components of 6, the correlation coeffcient (R) and the root mean square error (RMS) are 0.9245 and 0.1682 in modeling stage, and 0.8417 and 0.2389 in leave-one-out prediction step, respectively.

  13. Distributions of polycyclic aromatic hydrocarbons and alkylated polycyclic aromatic hydrocarbons in Osaka Bay, Japan

    International Nuclear Information System (INIS)

    Highlights: • Contamination of sediment by PAHs and alkylated PAHs was investigated in Osaka Bay. • The major sources appeared to be pyrogenic or both pyrogenic and petrogenic. • PAH concentrations were remarkably high at a site near Kobe. • PAHs in Kobe may have been derived from the fire associated with the earthquake. - Abstract: Contaminations in sediments by polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs were investigated at 44 sites in Osaka Bay, Japan. Concentrations of total PAHs and alkylated PAHs were in the range 6.40–7800 ng/g dry weights and 13.7–1700 ng/g dry weights, respectively. The PAH concentrations tended to be higher along the shoreline in the vicinities of big ports, industrialized areas, and densely populated regions such as the cities of Osaka and Kobe. The major sources appeared to be pyrogenic or both pyrogenic and petrogenic at most of the sites. PAH concentrations were remarkably high at a site near Kobe, where the concentrations of dibenzo(a,h)anthracene and benzo(g,h,i)perylene exceeded the effects-range-medium concentration and eight PAHs were above the corresponding effects-range-low concentrations. Those PAHs may have been derived from the great fire associated with the large earthquake in 1995

  14. Discovery and SAR of 6-alkyl-2,4-diaminopyrimidines as histamine H₄ receptor antagonists.

    Science.gov (United States)

    Savall, Brad M; Chavez, Frank; Tays, Kevin; Dunford, Paul J; Cowden, Jeffery M; Hack, Michael D; Wolin, Ronald L; Thurmond, Robin L; Edwards, James P

    2014-03-27

    This report discloses the discovery and SAR of a series of 6-alkyl-2-aminopyrimidine derived histamine H4 antagonists that led to the development of JNJ 39758979, which has been studied in phase II clinical trials in asthma and atopic dermatitis. Building on our SAR studies of saturated derivatives from the indole carboxamide series, typified by JNJ 7777120, and incorporating knowledge from the tricyclic pyrimidines led us to the 6-alkyl-2,4-diaminopyrimidine series. A focused medicinal chemistry effort delivered several 6-alkyl-2,4-diaminopyrimidines that behaved as antagonists at both the human and rodent H4 receptor. Further optimization led to a panel of antagonists that were profiled in animal models of inflammatory disease. On the basis of the preclinical profile and efficacy in several animal models, JNJ 39758979 was selected as a clinical candidate; however, further development was halted during phase II because of the observation of drug-induced agranulocytosis (DIAG) in two subjects. PMID:24495018

  15. Method for enhancing amidohydrolase activity of fatty acid amide hydrolase

    Energy Technology Data Exchange (ETDEWEB)

    John, George; Nagarajan, Subbiah; Chapman, Kent; Faure, Lionel; Koulen, Peter

    2016-10-25

    A method for enhancing amidohydrolase activity of Fatty Acid Amide Hydrolase (FAAH) is disclosed. The method comprising administering a phenoxyacylethanolamide that causes the enhanced activity. The enhanced activity can have numerous effects on biological organisms including, for example, enhancing the growth of certain seedlings. The subject matter disclosed herein relates to enhancers of amidohydrolase activity.

  16. Intramolecular Amide Hydrolysis in N-Methylmaleamic Acid Revisited

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The intramolecular amide hydrolysis of N-methylmaleamic acid have been revisited by use of density functional theory and inclusion of solvent effects. The results indicate that concerted reaction mechanism is favored over stepwise reaction mechanism. This is in agreement with the previous theoretical study. Sovlent effects have significant influence on the reaction barrier.

  17. A Bidenate Amide Bonded Stationary Phase for HPLC

    Institute of Scientific and Technical Information of China (English)

    Yan Shun MA; Yuan De LONG; Yong Liang DING; Tian Bao HUANG

    2003-01-01

    A novel bonded stationary phase, bidenate amide bonded stationary phase (BABSP), was prepared by reacting YWG silica gel firstly with 3-aminopropyltrimethoxysilane, then with diacid chloride. Hydrophobicity, selectivity, and especially silanophilic activity of BABSP were evaluated. The stationary phase exhibited good column efficiency and peak shape for separation of some basic solutes.

  18. Bovine intermediate pituitary alpha-amidation enzyme: preliminary characterization

    International Nuclear Information System (INIS)

    A secretory granule-associated enzymatic activity that converts mono-[125I]-D-Tyr-Val-Gly into mono-[125I]-D-Tyr-Val-NH2 has been studied. The activity is primarily soluble and shows optimal activity at pH 7 to pH 8. Amidation activity was stimulated 9-fold by addition of optimal amounts of copper (3 microM). In the presence of optimal copper, ascorbate stimulated the reaction 7-fold; none of the other reduced or oxidized cofactors tested was as effective. Taking into account the dependence of the reaction on ascorbate and molecular oxygen and the production of glyoxylate [2], it is suggested that the alpha-amidation enzyme is a monooxygenase. Lineweaver Burk plots with D-Tyr-Val-Gly as the varied substrate demonstrated Michelis-Menten type kinetics with the values of K/sub m/ and V/sub max/ increasing with the addition of ascorbate to the assay. A variety of peptides ending with a COOH-terminal Gly residue act as inhibitors of the reaction. Two synthetic peptides, gamma 2MSH and ACTH(1-14), with carboxyl termini similar to the presumed physiological substrates for the enzyme, act as competitive inhibitors with similar K1 values. It is likely that this secretory granule alpha-amidation activity is involved in the physiological biosynthetic alpha-amidation of a wide range of bioactive peptides

  19. Chiral amides via copper-catalysed enantioselective conjugate addition

    NARCIS (Netherlands)

    Schoonen, Anne K.; Fernández-Ibáñez, M. Ángeles; Fañanás-Mastral, Martín; Teichert, Johannes F.; Feringa, Bernard

    2014-01-01

    A highly enantioselective one pot procedure for the synthesis of β-substituted amides was developed starting from the corresponding α,β-unsaturated esters. This new methodology is based on the copper-catalysed enantioselective conjugate addition of Grignard reagents to α,β-unsaturated esters and sub

  20. Insecticidal, repellent and fungicidal properties of novel trifluoromethylphenyl amides

    Science.gov (United States)

    Twenty trifluoromethylphenyl amides were synthesized and evaluated as fungicides and as mosquito toxicants and repellents. Against Aedes aegypti larvae, (trifluoromethyl)phenyl)-3,5-dinitrobenzamide (1e) was the most toxic compound (24 h LC50 1940 nM), while against adults (trifluoromethyl)phenyl)-...

  1. Amide-modified poly(butylene terephthalate): polycondensation

    NARCIS (Netherlands)

    Bennekom, van A.C.M.; Gaymans, R.J.

    1996-01-01

    The synthesis of poly(ester amide) copolymers (PBTA) based on poly(butylene terephthalate) (PBT) and nylon-4,T with the diamide of butanediamine and dimethyl terephthelate (N,N′-bis(p-carbomethoxybenzoyl)butanediamine) has been carried out. Different melt and solid state condensation reactors were u

  2. REGIOSELECTIVE REACTIONS OF 3-ALKYL-1-PHENYL-2-PYRAZOLIN-5-ONES WITH ACYL HALIDES IN THE PRECENCE OF NONOSIZED MAGNESIUM HYDROXIDE AS A HIGHLY EFFECTIVE HETEROGENOUS BASE CATALYST Regioselektive Reaktionen von 3-Alkyl-1-PHENYL-2-pyrazolin-5-ONES Mit Acylhalogeniden IN DER PRECENCE DER NONOSIZED MAGNESIUM HYDROXIDE als hochwirksame heterogene BASE CATALYST

    Directory of Open Access Journals (Sweden)

    Hassan Sheibani and Bahman Massomi Nejad

    2012-07-01

    Full Text Available 4-Acyl-3-alkyl-1-phenyl-2-pyrazolin-5-one derivatives were prepared by the regioselective acylation of 3-alkyl-1-phenyl-2-pyrazolin-5-ones in the presence of base catalysts such as calcium hydroxide [Ca(OH2], magnesium hydroxide [Mg(OH2] and nanosized magnesium hydroxide. In the presence of nanosized magnesium hydroxide, excellent yields of products were obtained and reaction times were significantly reduced.

  3. Amidated joining peptide in the human pituitary, gut, adrenal gland and bronchial carcinoids. Immunocytochemical and immunochemical evidence

    DEFF Research Database (Denmark)

    Bjartell, A; Fenger, M; Ekman, R;

    1990-01-01

    The distribution of the proopiomelanocortin-derivated amidated joining peptide (JP-N) was examined in the human pituitary gland, adrenal gland, gut and in three bronchial carcinoids. Double immunostaining showed coexistence of immunoreactive JP-N and other proopiomelanocortin derivatives, e......-N, respectively, but under reduced conditions most of the immunoreactive material appeared as of low molecular weight in both extracts. In conclusion, immunoreactive JP-N is a major product from the processing of proopiomelanocortin in human extrapituitary tissues. The molecular forms of immunoreactive JP...

  4. Use of triphenyl phosphate as risk mitigant for metal amide hydrogen storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Cortes-Concepcion, Jose A.; Anton, Donald L.

    2016-04-26

    A process in a resulting product of the process in which a hydrogen storage metal amide is modified by a ball milling process using an additive of TPP. The resulting product provides for a hydrogen storage metal amide having a coating that renders the hydrogen storage metal amide resistant to air, ambient moisture, and liquid water while improving useful hydrogen storage and release kinetics.

  5. 40 CFR 721.10191 - Amides, coco, N-[3-(dibutylamino)propyl].

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, coco, N- . 721.10191 Section... Substances § 721.10191 Amides, coco, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- (PMN P-06-262; CAS No. 851544-20-2)...

  6. 40 CFR 721.10192 - Amides, coco, N-[3-(dibutylamino)propyl], acrylates.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, coco, N- , acrylates. 721... Substances § 721.10192 Amides, coco, N- , acrylates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- , acrylates (PMN...

  7. FMRF-amide-like immunoreactivity in brain and pituitary of the hagfish Eptatretus burgeri (Cyclostomata)

    DEFF Research Database (Denmark)

    Jirikowski, G; Erhart, G; Grimmelikhuijzen, C J;

    1984-01-01

    the hypothalamus to the olfactory system and caudally to the medulla oblongata. FMRF-amide-like immunoreactivity was also found in cells of the adenohypophysis. These observations suggest that the hagfish possesses a brain FMRF-amide-like transmitter system and pituitary cells containing FMRF-amide-like material...

  8. Synthetic N-Alkyl/aralkyl-4-methyl-N-(naphthalen-1-ylbenzenesulfonamides as Potent Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    *M. A. Abbasi

    2015-03-01

    Full Text Available The current research effort involved the reaction of napthalen-1-amine (1 with 4-methylbenzenesulfonyl chloride (2 under dynamic pH control at 9-10, maintained with 10% aqueous Na2CO3 to obtain 4-methyl-N-(naphthalen-1-yl benzenesulfonamide (3. The parent molecule 3 was further substituted at N-atom with alkyl/aralkyl halides (4a-f in polar aprotic solvent; N,N-dimethylformamide, and lithium hydride which acts as a base, to achieve N-alkyl/aralkyl-4-methyl-N-(naphthalen-1-ylbenzenesulfonamides (5a-f. All the synthesized compounds were structurally elucidated by IR, 1H-NMR and EIMS spectral techniques. All the derivatives were further screened for antibacterial and anti-enzymatic potential against various bacterial strains and enzymes, respectively, and were found to be potent antibacterial agents and moderate to weak enzyme inhibitors.

  9. Toward Efficient Palladium-Catalyzed Allylic C-H Alkylation

    DEFF Research Database (Denmark)

    Jensen, Thomas; Fristrup, Peter

    2009-01-01

    Recent breakthroughs have proved that direct palladium (II)-catalyzed allylic C-H alkylation can be achieved. This new procedure shows that the inherent requirement for a leaving group in the Tsuji-Trost palladium-catalyzed allylic alkylation can be lifted. These initial reports hold great promise...

  10. Degradable Polymer Composites Fabricated from Starch and Alkyl Cyanoacrylate Monomer

    Science.gov (United States)

    Degradable polymer composites are fabricated from alkyl cyanoacrylate monomer and starch without special equipment. Alkyl cyanoacrylate, which is a major component of “super glue”, is a monomer that polymerizes at room temperature in the presence of initiators. During the fabrication of polymer com...

  11. 40 CFR 721.10073 - Modified alkyl acrylamide (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified alkyl acrylamide (generic... Specific Chemical Substances § 721.10073 Modified alkyl acrylamide (generic). (a) Chemical substance and... acrylamide (PMN P-05-536) is subject to reporting under this section for the significant new uses...

  12. 40 CFR 721.2155 - Alkoxyamino-alkyl-coumarin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxyamino-alkyl-coumarin (generic... Substances § 721.2155 Alkoxyamino-alkyl-coumarin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as...

  13. Clinical applications of quinone-containing alkylating agents.

    Science.gov (United States)

    Begleiter, A

    2000-11-01

    Quinone-containing alkylating agents are a class of chemical agents that have received considerable interest as anticancer drugs. These agents contain a quinone moiety that can be reduced and an alkylating group that can form covalent bonds with a variety of cellular components. The oxidation state of the quinone element can modulate the activity of the alkylating element, and reduction of the quinone is required for activation of the alkylating activity of many of these agents. The quinone element may also contribute to the cytotoxic activity of quinone-containing alkylating agents through the formation of reactive oxygen species during redox cycling. The natural product, mitomycin C, has been the most widely used quinone-containing alkylating agent in the clinic, but other quinone-containing alkylating agents like porfiromycin, diaziquone, carbazilquinone, triaziquone and EO9 have also been used in the clinic for the treatment of cancer. In addition, many other quinone-containing alkylating agents have been tested in preclinical studies and the development of new agents is being actively pursued. This chapter describes the current and past clinical uses of these agents in the treatment of cancer and discusses new agents that are currently in clinical trials. PMID:11056078

  14. Synthesis, structure, and reactivity of tris(amidate) mono(amido) and tetrakis(amidate) complexes of group 4 transition metals.

    Science.gov (United States)

    Payne, Philippa R; Thomson, Robert K; Medeiros, Diane M; Wan, Geoff; Schafer, Laurel L

    2013-11-28

    The syntheses of a series of tris(amidate) mono(amido) titanium and zirconium complexes are reported. The binding motif of the amidate ligand has been determined to depend on the size of the metal centre for these sterically demanding N,O-chelating ligands; the larger zirconium metal centre supports three κ(2)-(N,O) bound amidate ligands while the titanium analogue has one ligand bound in a κ(1)-(O) fashion to alleviate steric strain. Reactivity studies indicate that, despite high steric crowding about the tris(amidate) mono(amido) zirconium metal centre, transamination of the reactive dimethylamido ligand can be achieved using aniline. This complex is also an active precatalyst for intramolecular alkene hydroamination, in which protonolysis of one amidate ligand in the presence of excess amine is observed as an initiation step prior to catalytic turnover. Eight-coordinate homoleptic κ(2)-amidate complexes of zirconium and hafnium have also been prepared.

  15. Active-site-directed reductive alkylation of xanthine oxidase by imidazo[4,5-g]quinazoline-4,9-diones functionalized with a leaving group.

    Science.gov (United States)

    Lee, C H; Skibo, E B

    1987-11-17

    A new class of purine antimetabolites, directed toward xanthine oxidase, was designed by employing some of the features found in the bioreductive alkylator mitomycin C. The design involved functionalizing the purine-like imidazo[4,5-g]quinazoline ring system as a quinone (4,9-dione) bearing a 2 alpha leaving group. Due to the presence of the electron-deficient quinone ring, the leaving group cannot participate in alkylation reactions. Reduction to the hydroquinone (4,9-dihydroxy) derivative, however, permits elimination of the leaving group to afford an alkylating quinone methide. In spite of the electronic differences, both quinone and hydroquinone derivatives of the imidazo[4,5-g]quinazoline system are able to enter the purine-utilizing active site of the enzyme. Thus, the hypoxanthine-like quinone derivative [2-(bromomethyl)-3-methylimidazo[4,5-g]quinazoline-4,8, 9(3H, 7H)-trione] and its hydroquinone derivative can act as reducing substrates for the enzyme, resulting in conversion to the xanthane-like 6-oxo derivatives. Hydrolysis studies described herein indicate that the hypoxanthine-like hydroquinone derivative eliminates HBr to afford an extended quinone methide species. The observed alkylation of the enzyme by this derivative may thus pertain to quinone methide generation and nucleophile trapping during enzymatic oxidation at the 6-position. Enzymatic studies indicate that the hypoxanthine-like quinone is an oxidizing suicide substrate for the enzyme. Thus, the reduced enzyme transfers electrons to this quinone, and the resulting hydroquinone inactivates the enzyme. As with mitomycin C, reduction and quinone methide formation are necessary for alkylation by the title quinone. This system is therefore an example of a purine active-site-directed reductive alkylator.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3427077

  16. β-Alkyl Elimination: Fundamental Principles and Some Applications.

    Science.gov (United States)

    O'Reilly, Matthew E; Dutta, Saikat; Veige, Adam S

    2016-07-27

    This review describes organometallic compounds and materials that are capable of mediating a rarely encountered but fundamentally important reaction: β-alkyl elimination at the metal-Cα-Cβ-R moiety, in which an alkyl group attached to the Cβ atom is transferred to the metal or to a coordinated substrate. The objectives of this review are to provide a cohesive fundamental understanding of β-alkyl-elimination reactions and to highlight its applications in olefin polymerization, alkane hydrogenolysis, depolymerization of branched polymers, ring-opening polymerization of cycloalkanes, and other useful organic reactions. To provide a coherent understanding of the β-alkyl elimination reaction, special attention is given to conditions and strategies used to facilitate β-alkyl-elimination/transfer events in metal-catalyzed olefin polymerization, which provide the well-studied examples. PMID:27366938

  17. Cinnamic acid amides from Tribulus terrestris displaying uncompetitive α-glucosidase inhibition.

    Science.gov (United States)

    Song, Yeong Hun; Kim, Dae Wook; Curtis-Long, Marcus J; Park, Chanin; Son, Minky; Kim, Jeong Yoon; Yuk, Heung Joo; Lee, Keun Woo; Park, Ki Hun

    2016-05-23

    The α-glucosidase inhibitory potential of Tribulus terrestris extracts has been reported but as yet the active ingredients are unknown. This study attempted to isolate the responsible metabolites and elucidate their inhibition mechanism of α-glucosidase. By fractionating T. terristris extracts, three cinnamic acid amide derivatives (1-3) were ascertained to be active components against α-glucosidase. The lead structure, N-trans-coumaroyltyramine 1, showed significant inhibition of α-glucosidase (IC50 = 0.42 μM). Moreover, all active compounds displayed uncompetitive inhibition mechanisms that have rarely been reported for α-glucosidase inhibitors. This kinetic behavior was fully demonstrated by showing a decrease of both Km and Vmax, and Kik/Kiv ratio ranging between 1.029 and 1.053. We progressed to study how chemical modifications to the lead structure 1 may impact inhibition. An α, β-unsaturation carbonyl group and hydroxyl group in A-ring of cinnamic acid amide emerged to be critical functionalities for α-glucosidase inhibition. The molecular modeling study revealed that the inhibitory activities are tightly related to π-π interaction as well as hydrogen bond interaction between enzyme and inhibitors. PMID:26974386

  18. Mapping the amide I absorption in single bacteria and mammalian cells with resonant infrared nanospectroscopy

    Science.gov (United States)

    Baldassarre, L.; Giliberti, V.; Rosa, A.; Ortolani, M.; Bonamore, A.; Baiocco, P.; Kjoller, K.; Calvani, P.; Nucara, A.

    2016-02-01

    Infrared (IR) nanospectroscopy performed in conjunction with atomic force microscopy (AFM) is a novel, label-free spectroscopic technique that meets the increasing request for nano-imaging tools with chemical specificity in the field of life sciences. In the novel resonant version of AFM-IR, a mid-IR wavelength-tunable quantum cascade laser illuminates the sample below an AFM tip working in contact mode, and the repetition rate of the mid-IR pulses matches the cantilever mechanical resonance frequency. The AFM-IR signal is the amplitude of the cantilever oscillations driven by the thermal expansion of the sample after absorption of mid-IR radiation. Using purposely nanofabricated polymer samples, here we demonstrate that the AFM-IR signal increases linearly with the sample thickness t for t \\gt 50 nm, as expected from the thermal expansion model of the sample volume below the AFM tip. We then show the capability of the apparatus to derive information on the protein distribution in single cells through mapping of the AFM-IR signal related to the amide-I mid-IR absorption band at 1660 cm-1. In Escherichia Coli bacteria we see how the topography changes, observed when the cell hosts a protein over-expression plasmid, are correlated with the amide I signal intensity. In human HeLa cells we obtain evidence that the protein distribution in the cytoplasm and in the nucleus is uneven, with a lateral resolution better than 100 nm.

  19. Synthesis, characterization and biological evaluation of novel α, β unsaturated amides

    Science.gov (United States)

    Esmailzadeh, K.; Housaindokht, M. R.; Moradi, A.; esmaeili, A. A.; Sharifi, Z.

    2016-05-01

    Three derivatives of α,β unsaturated amides have been successfully synthesized via Ugi-four component (U-4CR) reaction. The interactions of the amides with calf thymus deoxyribonucleic acid (ct-DNA) have been investigated in the Tris-HCl buffer (pH = 7.4) using viscometric, spectroscopic, thermal denaturation studies, and also molecular docking. By UV-Vis absorption spectroscopy studies, adding CT-DNA to the compound solution caused the hypochromism indicates that there are interactions between the compounds and DNA base pairs. In competitive fluorescence with methylene blue as an intercalator probe, adding compounds to DNA-MB solution caused an increase in emission spectra of the complex. This could be because of compound replacing, with similar binding mode of MB, between the DNA base pairs due to release of bonded MB molecules from DNA-MB complex. Thermal denaturation studies and viscometric experiments also indicated that all three investigated compounds bind to CT-DNA by non-classical intercalation mode. Additionally, molecular docking technique predicted partial intercalation binding mode for the compounds. Also, the highest binding energy was obtained for compound 5a. These results are in agreement with results obtained by empirical methods.

  20. One-step selective synthesis of branched 1-O-alkyl-glycerol/diglycerol monoethers by catalytic reductive alkylation of ketones

    Institute of Scientific and Technical Information of China (English)

    DAYOUB; Wissam; LEMAIRE; Marc

    2010-01-01

    Branched 1-O-alkyl glycerol and diglycerol monoethers were obtained in good yields and high selectivity by a straightforward catalytic reductive alkylation of glycerol with relevant ketones in the presence of 0.5 mol% of Pd/C under 10 bar of hydrogen pressure using a Brφnsted acid as the co-catalyst.

  1. UV absorption spectra, kinetics and mechanism for alkyl and alkyl peroxy radicals originating from t-butyl alcohol

    DEFF Research Database (Denmark)

    Langer, S.; Ljungström, E.; Sehested, J.;

    1994-01-01

    Alkyl and alkyl peroxy radicals from 1-butyl alcohol (TBA), HOC (CH3)2CH2. and HOC(CH3)2CH2O2. have been studied in the ps phase at 298 K. Two techniques were used: pulse radiolysis UV absorption to measure the spectra and kinetics, and long path-length Fourier transform infrared spectroscopy (FTIR...

  2. N-alkylated nitrogen-in-the-ring sugars: conformational basis of inhibition of glycosidases and HIV-1 replication.

    Science.gov (United States)

    Asano, N; Kizu, H; Oseki, K; Tomioka, E; Matsui, K; Okamoto, M; Baba, M

    1995-06-23

    The conformations of nitrogen-in-the-ring sugars and their N-alkyl derivatives were studied from 1H NMR analyses, mainly using 3J(H,H) coupling constants and quantitative NOE experiments. No significant difference was seen in the ring conformation of 1-deoxynojirimycin (1), N-methyl-1-deoxynojirimycin (2), and N-butyl-1-deoxynojirimycin (3). However, it was shown that the C6 OH group in 1 is predominantly equatorial to the piperidine ring, while that in 2 or 3 is predominantly axial, and its N-alkyl group is oriented equatorially. In the furanose analogues 1,4-dideoxy-1,4-imino-D-arabinitol (4) and its N-methyl (5) and N-butyl (6) derivatives, the five-membered ring conformation differed significantly by the presence or absence of the N-substituted group and the length of the N-alkyl chain. Compound 3 reduced its inhibitory effect on almost all glycosidases, resulting in an extremely specific inhibitor for processing alpha-glucosidase I since N-alkylation of 1 is known to enhance both the potency and specificity of this enzyme in vitro and in vivo. This preferred (C6 OH axial) conformation in 2 and 3 appears to be responsible for their strong alpha-glucosidase I activity. Compound 4 is a good inhibitor of intestinal alpha-glucohydrolases, alpha-glucosidase II, and Golgi alpha-mannosidases I and II, but its N-alkyl derivatives 5 and 6 markedly decreased inhibitory potential for all enzymes tested. In the case of 2,5-dideoxy-2,5-imino-D-mannitol (DMDP, 7), which is a potent beta-galactosidase inhibitor, its N-methyl (8) and N-butyl (9) derivatives completely lost potency toward beta-galactosidase as well. N-Alkylation of compounds 4 and 7, known well as potent yeast alpha-glucosidase inhibitors, resulted in a serious loss of inhibitory activity toward yeast alpha-glucohydrolases. Activity of these nine analogues against HIV-1 replication was determined, based on the inhibition of virus-induced cytopathogenicity in MT-4 and MOLT-4 cells. Compounds 2 and 3, which are

  3. Distribution of 1-alkyl-3-methylimidazolium ions and their ion pairs between dichloromethane and water.

    Science.gov (United States)

    Katsuta, Shoichi; Yamaguchi, Naoko; Ogawa, Ryuji; Kudo, Yoshihiro; Takeda, Yasuyuki

    2008-10-01

    The distribution behavior of the salts of a series of 1-alkyl-3-methylimidazolium cations (RMeIm(+); R = butyl, hexyl, and octyl) with tetrafluoroborate (BF(4)(-)), hexafluorophosphate (PF(6)(-)), bis(trifluoromethanesulfonyl)amide (NTf(2)(-)), and 2,4,6-trinitrophenolate (Pic(-)) anions has been investigated in a dichloromethane-water system at 25 degrees C. The distribution constants (K(D)) of the ion pairs and the transfer activity coefficients ((o)gamma(w)) of the single ions were determined. For the ion pairs with a given anion, the log K(D) value increases linearly with the number of methylene groups (N(CH2)) in the cation, which can be explained by using the regular solution theory. A similar relationship was observed between log (o)gamma(w) and N(CH2) for the free RMeIm(+) ions, and the result was discussed by decomposing the transfer activity coefficient into the Born-type electrostatic contribution and the non-electrostatic one. For the free anions and their ion pairs with a given cation, the (o)gamma(w) and K(D) values increase with increasing molar volume of the anion: i.e., BF(4)(-) ion-pair formation in water are also discussed by comparing the present results with those of tetraalkylammonium salts previously reported.

  4. Organomontmorillonites Modified with 2-Methacryloyloxy Ethyl Alkyl Dimethyl Ammonium Bromide

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-quan; WU Wen-hui

    2007-01-01

    Organomontmorillonites (organo-MMT) were synthesized by means of montmorillonites (MMT) modified with a series of 2-methacryloyloxy ethyl alkyl dimethyl ammonium bromide (MAAB) having different alkyl chain lengths as cationic surfactants through a cationic exchanging reaction, and were characterized by FTIR, TG, elemental analysis, and XRD. The microenvironment of the organic interlayer such as the orientation and arrangement of the alkyl chains of MAAB, as well as the properties of nanocomposite hydrogels, were also investigated. The amount of organic components absorbed on interlayer and the basal spacing of organo-MMT both increase with the increasing of alkyl length of MAAB. When carbon number of alkyl chain is in the region of 8 to 14, the alkyl chains between layers would adopt a disordered gauche conformation; while the carbon number is 16, an ordered all-trans conformation with a vertical orientation would be found together with the disordered gauche conformation according to the results of XRD and FTIR. Due to the difference of microenvironment of organic interlayer, the Young's moduli of the nanocomposite hydrogels increased as the alkyl chains of MAAB became longer.

  5. In vivo behavior of hydrogel beads based on amidated pectins.

    Science.gov (United States)

    Munjeri, O; Collett, J H; Fell, J T; Sharma, H L; Smith, A M

    1998-01-01

    Radio-labeled hydrogel beads, based on amidated pectin, have been produced by adding droplets of an amidated pectin solution to calcium chloride. Incorporation of model drugs into the beads and measurement of the dissolution rate showed that the properties of the beads were unaffected by the incorporation of the radiolabel. The labeled beads were used to carry out an in vivo study of their behavior in the gastrointestinal tract using human volunteers. The volunteers were given the beads after an overnight fast and images were obtained at frequent intervals during transit through the upper gastrointestinal tract and the colon. The beads exhibited rapid gastric emptying and proceeded to pass through the small intestine individually before regrouping at the ileo-caecal junction. Once in the colon, the beads again proceeded as individuals and evidence of the degradation of the beads was observed.

  6. Simulations of the temperature dependence of amide I vibration.

    Science.gov (United States)

    Kaminský, Jakub; Bouř, Petr; Kubelka, Jan

    2011-01-13

    For spectroscopic studies of peptide and protein thermal denaturation it is important to single out the contribution of the solvent to the spectral changes from those originated in the molecular structure. To obtain insights into the origin and size of the temperature solvent effects on the amide I spectra, combined molecular dynamics and density functional simulations were performed with the model N-methylacetamide molecule (NMA). The computations well reproduced frequency and intensity changes previously observed in aqueous NMA solutions. An empirical correction of vacuum frequencies in single NMA molecule based on the electrostatic potential of the water molecules provided superior results to a direct density functional average obtained for a limited number of solute-solvent clusters. The results thus confirm that the all-atom quantum and molecular mechanics approach captures the overall influence of the temperature dependent solvent properties on the amide I spectra and can improve the accuracy and reliability of molecular structural studies.

  7. A tale of switched functions: from cyclooxygenase inhibition to M-channel modulation in new diphenylamine derivatives.

    Directory of Open Access Journals (Sweden)

    Asher Peretz

    Full Text Available Cyclooxygenase (COX enzymes are molecular targets of nonsteroidal anti-inflammatory drugs (NSAIDs, the most used medication worldwide. However, the COX enzymes are not the sole molecular targets of NSAIDs. Recently, we showed that two NSAIDs, diclofenac and meclofenamate, also act as openers of Kv7.2/3 K(+ channels underlying the neuronal M-current. Here we designed new derivatives of diphenylamine carboxylate to dissociate the M-channel opener property from COX inhibition. The carboxylate moiety was derivatized into amides or esters and linked to various alkyl and ether chains. Powerful M-channel openers were generated, provided that the diphenylamine moiety and a terminal hydroxyl group are preserved. In transfected CHO cells, they activated recombinant Kv7.2/3 K(+ channels, causing a hyperpolarizing shift of current activation as measured by whole-cell patch-clamp recording. In sensory dorsal root ganglion and hippocampal neurons, the openers hyperpolarized the membrane potential and robustly depressed evoked spike discharges. They also decreased hippocampal glutamate and GABA release by reducing the frequency of spontaneous excitatory and inhibitory post-synaptic currents. In vivo, the openers exhibited anti-convulsant activity, as measured in mice by the maximal electroshock seizure model. Conversion of the carboxylate function into amide abolished COX inhibition but preserved M-channel modulation. Remarkably, the very same template let us generating potent M-channel blockers. Our results reveal a new and crucial determinant of NSAID-mediated COX inhibition. They also provide a structural framework for designing novel M-channel modulators, including openers and blockers.

  8. Hydrophilic interaction liquid chromatography-tandem mass spectrometry methylphosponic and alkyl methylphosphonic acids determination in environmental samples after pre-column derivatization with p-bromophenacyl bromide.

    Science.gov (United States)

    Baygildiev, T M; Rodin, I A; Stavrianidi, A N; Braun, A V; Lebedev, A T; Rybalchenko, I V; Shpigun, O A

    2016-04-15

    Once exposed to the environment organophosphate nerve agents readily degrade by rapid hydrolysis to the corresponding alkyl methylphosphonic acids which do not exist in nature. These alkyl methylphosphonic acids are finally slowly hydrolyzed to methylphosphonic acid. Methylphosphonic acid is the most stable hydrolysis product of organophosphate nerve agents, persisting in environment for a long time. A highly sensitive method of methylphosphonic acid and alkyl methylphosphonic acids detection in dust and ground mixed samples has been developed and validated. The fact that alkyl methylphosphonic acids unlike methylphosphonic acid did not react with p-bromophenacyl bromide under chosen conditions was discovered. This allowed simultaneous chromatographic separation and mass spectrometric detection of derivatized methylphosphonic acid and underivatized alkyl methylphosphonic acids using HILIC-MS/MS method. Very simple sample pretreatment with high recoveries for each analyte was developed. Methylphosphonic acid pre-column derivate and alkyl methylphosphonic acids were detected using tandem mass spectrometry with electrospray ionization after hydrophilic interaction liquid chromatography separation. The developed approach allows achieving ultra-low detection limits: 200 pg mL(-1) for methylphosphonic acid, 70 pg mL(-1) for ethyl methylphosphonic acid, 8 pg mL(-1) for i-propyl methylphosphonic acid, 8 pg mL(-1) for i-butyl methylphosphonic acid, 5 pg mL(-1) for pinacolyl methylphosphonic acid in the extracts of dust and ground mixed samples. This approach was successfully applied to the dust and ground mixed samples from decommissioned plant for the production of chemical weapons.

  9. Accumulation of hydroxycinnamic acid amides in winter wheat under snow.

    Science.gov (United States)

    Jin, Shigeki; Yoshida, Midori; Nakajima, Takashi; Murai, Akio

    2003-06-01

    It was found that the content of antifungal compounds p-coumaroylagmatine [1-(trans-4'-hydroxycinnamoylamino)-4-guanidinobutane] and p-coumaroyl-3-hydroxyagmatine [1-(trans-4'-hydroxycinnamoylamino)-3-hydroxy-4-guanidinobutane] in the crown of winter wheat (Triticum aestivum L. cv Chihokukomugi) significantly increased under snow cover. This finding suggests that the accumulation of these hydroxycinnamic acid amides was caused by winter stress and related to protecting the plant against snow mold under snow cover.

  10. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Styrene

    OpenAIRE

    Hasmukh S. Patel; Panchal, Kumar K.

    2004-01-01

    Novel unsaturated poly (ester-amide) resins (UPEAs) were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA) and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Styrene (STY.) to produce a homogeneous resin syrup. The curing of these UPEAs-STY. resin blends was carried out by using benzoyl peroxide (BPO) as a catalyst and was monitored by using a differential scanning calorimeter ...

  11. Macrocycle Synthesis by Chloride-Templated Amide Bond Formation.

    Science.gov (United States)

    Martí-Centelles, Vicente; Burguete, M Isabel; Luis, Santiago V

    2016-03-01

    A new family of pseudopeptidic macrocyclic compounds has been prepared involving an anion-templated amide bond formation reaction at the macrocyclization step. Chloride anion was found to be the most efficient template in the macrocyclization process, producing improved macrocyclization yields with regard to the nontemplated reaction. The data suggest a kinetic effect of the chloride template, providing an appropriate folded conformation of the open-chain precursor and reducing the energy barrier for the formation of the macrocyclic product. PMID:26820908

  12. On DABAL-Me₃ promoted formation of amides

    OpenAIRE

    Dubois, Nathalie; Glynn, Daniel; McInally, Thomas; Rhodes, Barrie; Woodward, Simon; Irvine, Derek; Dodds, Chris

    2013-01-01

    The range and utility of DABAL-Me3 couplings of methyl esters and free carboxylic acids with primary and secondary amines under a variety of conditions (reflux, sealed tube, microwave) has been compared for a significant range of coupling partners of relevance to the preparation of amides of interest in pharmaceutical chemistry. Commercial microwave reactors promote the fastest couplings and allow the use of significantly sterically hindered amines (primary and secondary) and carboxylic acids...

  13. Toxocara canis: Larvicidal activity of fatty acid amides.

    Science.gov (United States)

    Mata-Santos, Taís; D'Oca, Caroline da Ros Montes; Mata-Santos, Hílton Antônio; Fenalti, Juliana; Pinto, Nitza; Coelho, Tatiane; Berne, Maria Elisabeth; da Silva, Pedro Eduardo Almeida; D'Oca, Marcelo Gonçalves Montes; Scaini, Carlos James

    2016-02-01

    Considering the therapeutic potential of fatty acid amides, the present study aimed to evaluate their in vitro activity against Toxocara canis larvae and their cytotoxicity for the first time. Linoleylpyrrolidilamide was the most potent, with a minimal larvicidal concentration (MLC) of 0.05 mg/mL and 27% cytotoxicity against murine peritoneal macrophages C57BL/6 mice, as assessed by the MTT assay. PMID:26783180

  14. Simple and Efficient Microwave Assisted N-Alkylation of Isatin

    Directory of Open Access Journals (Sweden)

    María Mercedes Blanco

    2008-04-01

    Full Text Available We present herein the results of microwave promoted N-alkylations of isatin (1with different alkyl, benzyl and functionalized alkyl halides. Reactions were carried outunder different conditions, always employing methodologies compatible with MW assistedchemistry. Generation of isatin anion employing diverse bases and solvents or using thepreformed isatin sodium salt was tested. The best results were achieved using K2CO3 orCs2CO3 and a few drops of N,N-dimethylformamide or N-methyl-2-pyrrolidinone. Thesereactions present noteworthy advantages over those carried out employing conventionalheating.

  15. Mild Metal-Free Hydrosilylation of Secondary Amides to Amines.

    Science.gov (United States)

    Huang, Pei-Qiang; Lang, Qi-Wei; Wang, Yan-Rong

    2016-05-20

    The combination of amide activation by Tf2O with B(C6F5)3-catalyzed hydrosilylation with TMDS constitutes a method for the one-pot reduction of secondary amides to amines under mild conditions. The method displays a broad applicability for the reduction of many types of substrates, and shows good compatibility and excellent chemoselectivity for many sensitive functional groups. Reductions of a multifunctionalized α,β-unsaturated amide obtained from another synthetic methodology, and a C-H functionalization product produced the corresponding amines in good to excellent yield. Chemoselective reduction of enantiomeric pure (ee >99%) tetrahydro-5-oxo-2-furaneamides yielded 5-(aminomethyl)dihydrofuran-2(3H)-ones in a racemization-free manner. The latter were converted in one pot to N-protected 5-hydroxypiperidin-2-ones, which are building blocks for the synthesis of many natural products. Further elaboration of an intermediate led to a concise four-step synthesis of (-)-epi-pseudoconhydrine. PMID:27100232

  16. First synthesis and anticancer activity of novel naphthoquinone amides.

    Science.gov (United States)

    Pradidphol, Narathip; Kongkathip, Ngampong; Sittikul, Pichamon; Boonyalai, Nonlawat; Kongkathip, Boonsong

    2012-03-01

    Sixteen novel naphthoquinone aromatic amides were synthesized by a new route starting from 1-hydroxy-2-naphthoic acid in nine or ten steps with good to excellent yield. Amide formation reaction was carried out by using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as an efficient condensing agent leading to carboxamides in high yield. The key step for converting naphthol to 3-hydroxynaphthoquinone was the Fremy's salt oxidation followed by hydroxylation with tert-butyl hydroperoxide and triton B. Anticancer activity of these new naphthoquinone amides were evaluated and benzamide 22 showed potent inhibition against NCI-H187 cell lines while naphthamides 23 and 43 were the most potent inhibition against KB cells. The decatenation assay revealed that compounds 24 and 43 at 20 μM can inhibit hTopoIIα activity while three other compounds, namely compounds 22, 23, and 45, exhibited hTopoIIα inhibitory activity at final concentration of 50 μM. Docking experiment revealed the same trend as the cytotoxicity and decatenation assay. Therefore, naphthamides 24 and 43 can be promising target molecules for anticancer drug development. PMID:22280818

  17. Comparative study to predict dipeptidyl peptidase IV inhibitory activity of β-amino amide scaffold

    Directory of Open Access Journals (Sweden)

    S Patil

    2015-01-01

    Full Text Available Comparative study was performed on 34 β-amino amide derivatives as dipeptidyl peptidase IV inhibitors in order to determine their structural requirement to enhance the antidiabetic activities. Hologram quantitative structure activity relationships models utilized specialized fragment fingerprints (hologram length 353 which showed good predictivity with cross-validated q 2 and conventional r 2 values of 0.971 and 0.971, respectively. Models were validated and optimized by a test set of eight compounds and gave satisfactory predictive ability. Hologram quantitative structure activity relationships maps were helpful in prediction of the structural features of the ligands to account for the activity in terms of positively and negatively contributing towards activity. The information obtained from maps could be effectively use as a guiding tool for further structure modifications and synthesis of new potent antidiabetic agents.

  18. Drug Nanoparticle Formulation Using Ascorbic Acid Derivatives

    OpenAIRE

    Kunikazu Moribe; Waree Limwikrant; Kenjirou Higashi; Keiji Yamamoto

    2011-01-01

    Drug nanoparticle formulation using ascorbic acid derivatives and its therapeutic uses have recently been introduced. Hydrophilic ascorbic acid derivatives such as ascorbyl glycoside have been used not only as antioxidants but also as food and pharmaceutical excipients. In addition to drug solubilization, drug nanoparticle formation was observed using ascorbyl glycoside. Hydrophobic ascorbic acid derivatives such as ascorbyl mono- and di-n-alkyl fatty acid derivatives are used either as drugs...

  19. Synergistic effects of three Piper amides on generalist and specialist herbivores.

    Science.gov (United States)

    Dyer, L A; Dodson, C D; Stireman, J O; Tobler, M A; Smilanich, A M; Fincher, R M; Letourneau, D K

    2003-11-01

    The tropical rainforest shrub Piper cenocladum, which is normally defended against herbivores by a mutualistic ant, contains three amides that have various defensive functions. While the ants are effective primarily against specialist herbivores, we hypothesized that these secondary compounds would be effective against a wider range of insects, thus providing a broad array of defenses against herbivores. We also tested whether a mixture of amides would be more effective against herbivores than individual amides. Diets spiked with amides were offered to five herbivores: a naïve generalist caterpillar (Spodoptera frugiperda), two caterpillar species that are monophagous on P. cenocladum (Eois spp.), leaf-cutting ants (Atta cephalotes), and an omnivorous ant (Paraponera clavata). Amides had negative effects on all insects, whether they were naïve, experienced, generalized, or specialized feeders. For Spodoptera, amide mixtures caused decreased pupal weights and survivorship and increased development times. Eois pupal weights, larval mass gain, and development times were affected by additions of individual amides, but increased parasitism and lower survivorship were caused only by the amide mixture. Amide mixtures also deterred feeding by the two ant species, and crude plant extracts were strongly deterrent to P. clavata. The mixture of all three amides had the most dramatic deterrent and toxic effects across experiments, with the effects usually surpassing expected additive responses, indicating that these compounds can act synergistically against a wide array of herbivores. PMID:14682530

  20. Electrophilic Activation of α,β-Unsaturated Amides: Catalytic Asymmetric Vinylogous Conjugate Addition of Unsaturated γ-Butyrolactones.

    Science.gov (United States)

    Zhang, Ming; Kumagai, Naoya; Shibasaki, Masakatsu

    2016-04-11

    Although catalytic asymmetric conjugate addition reactions have remarkably advanced over the last two decades, the application of less electrophilic α,β-unsaturated carboxylic acid derivatives in this useful reaction manifold remains challenging. Herein, we report that α,β-unsaturated 7-azaindoline amides act as reactive electrophiles to participate in catalytic diastereo- and enantioselective vinylogous conjugate addition of γ-butyrolactones in the presence of a cooperative catalyst comprising of a soft Lewis acid and a Brønsted base. Reactions mostly reached completion with as little as 1 mol % of catalyst loading to give the desired conjugate adducts in a highly stereoselective manner. PMID:26970428

  1. Copper-catalyzed arylation of alkyl halides with arylaluminum reagents

    Directory of Open Access Journals (Sweden)

    Bijay Shrestha

    2015-12-01

    Full Text Available We report a Cu-catalyzed coupling between triarylaluminum reagents and alkyl halides to form arylalkanes. The reaction proceeds in the presence of N,N,N’,N’-tetramethyl-o-phenylenediamine (NN-1 as a ligand in combination with CuI as a catalyst. This catalyst system enables the coupling of primary alkyl iodides and bromides with electron-neutral and electron-rich triarylaluminum reagents and affords the cross-coupled products in good to excellent yields.

  2. Iminium Salts by Meerwein Alkylation of Ehrlich’s Aldehyde

    Directory of Open Access Journals (Sweden)

    Gerhard Laus

    2013-03-01

    Full Text Available 4-(Dimethylaminobenzaldehyde is alkylated at the N atom by dialkyl sulfates, MeI, or Me3O BF4. In contrast, ethylation by Et3O BF4 occurs selectively at the O atom yielding a quinoid iminium ion. 4-(Diethylaminobenzaldehyde is alkylated only at O by either Et or Me oxonium reagent. The iminium salts are prone to hydrolysis giving the corresponding hydrotetrafluoroborates. Five crystal structures were determined.

  3. Synthesis of Novel Unsaturated Alkyl Ethers of Racemic Deoxyisopodophyllotoxin as Cytotoxic Agents

    Institute of Scientific and Technical Information of China (English)

    Ju Hong FENG; Hong Xia DING; Yi XIONG; Yuan Jiang PAN; Yong Min ZHANG; Xiao Jiang HAO; Fran(c)oise GU(E)RITTE; Joachim ST(O)CKIGT; Yu ZHAO

    2006-01-01

    A series of isopentenyl-derived unsaturated alkyl ethers 19-31 of racemic deoxyisopodophyllotoxin were designed and synthesized. For comparison, compound 32 with a benzyl group at the same position was also prepared. The cytotoxicities of the synthetic compounds have been screened for six human tumor cell lines such as KB, BEL-7404, A549, Hela, PC-3 and CNE.The results showed that two of them exhibited significant cytotoxicities with their IC50 values on selected cell lines at μmol/L scale.

  4. Alkyl-halogenide promoted ionic liquid catalysis of isobutane/butene-alkylation

    Energy Technology Data Exchange (ETDEWEB)

    Schilder, L.; Korth, W.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

    2011-07-01

    The effect of two different types of promoters on the performance of Lewis-acidic chloroaluminate ionic liquid catalysts was studied for liquid liquid biphasic isobutane/2-butene alkylation. In particular, the activity and selectivity of such catalytic systems was investigated. Experimental results obtained from a batch reactor show, that tert-butyl halides increase the reaction rate significantly and shift the C8-selectivity towards the desired high-octane trimethylpentanes (TMPs). But, secondary reactions like oligomerization and cracking are not affected by the use of these promoters. (orig.)

  5. Alkyl and phenolic glycosides from Saussurea stella.

    Science.gov (United States)

    Wang, Tian-Min; Wang, Ru-Feng; Chen, Hu-Biao; Shang, Ming-Ying; Cai, Shao-Qing

    2013-07-01

    One alkyl glycoside, saussurostelloside A (1), two phenolic glycosides, saussurostellosides B1 (2) and B2 (3), and 27 known compounds, including eleven flavonoids, seven phenolics, six lignans, one neolignan, one phenethyl glucoside and one fatty acid, were isolated from an ethanol extract of Saussurea stella (Asteraceae). Their structures were elucidated by NMR, MS, UV, and IR spectroscopic analysis. Of the known compounds, (+)-medioresinol-di-O-β-D-glucoside (7), picraquassioside C (10), and diosmetin-3'-O-β-D-glucoside (27) were isolated from the Asteraceae family for the first time, while (+)-pinoresinol-di-O-β-D-glucoside (6), di-O-methylcrenatin (11), protocatechuic acid (14), 1,5-di-O-caffeoylquinic acid (17), formononetin (28), and phenethyl glucoside (29) were isolated from the Saussurea genus for the first time. The anti-inflammatory activities of three new compounds (1-3), five lignans ((-)-arctiin (4), (+)-pinoresinol-4-O-β-D-glucoside (5), (+)-pinoresinol-di-O-β-D-glucoside (6), (+)-medioresinol-di-O-β-D-glucoside (7) and (+)-syringaresinol-4-O-β-D-glucoside (8)), one neolignan (picraquassioside C (10)), and one phenolic glycoside (di-O-methylcrenatin (11)) were evaluated by testing their inhibition of the release of β-glucuronidase from PAF-stimulated neutrophils. Only compound 5 showed moderate inhibition of the release of β-glucuronidase, with an inhibition ratio of 39.1%.

  6. Final Technical Report [Development of Catalytic Alkylation and Fluoroalkylation Methods

    Energy Technology Data Exchange (ETDEWEB)

    Vicic, David A.

    2014-05-01

    In the early stages of this DOE-funded research project, we sought to prepare and study a well-defined nickel-alkyl complex containing tridentate nitrogen donor ligands. We found that reaction of (TMEDA)NiMe2 (1) with terpyridine ligand cleanly led to the formation of (terpyridyl)NiMe (2), which we also determined to be an active alkylation catalyst. The thermal stability of 2 was unlike that seen for any of the active pybox ligands, and enabled a number of key studies on alkyl transfer reactions to be performed, providing new insights into the mechanism of nickel-mediated alkyl-alkyl cross-coupling reactions. In addition to the mechanistic studies, we showed that the terpyridyl nickel compounds can catalytically cross-couple alkyl iodides in yields up to 98% and bromides in yields up to 46 %. The yields for the bromides can be increased up to 67 % when the new palladium catalyst [(tpy’)Pd-Ph]I is used. The best route to the targeted [(tpy)NiBr] (1) was found to involve the comproportionation reaction of [(dme)NiBr{sub 2}] and [Ni(COD){sub 2}] in the presence of two equivalents of terpyridine. This reaction was driven to high yields of product formation (72 % isolated) by the precipitation of 1 from THF solvent.

  7. Synthesis of P-stereogenic diarylphosphinic amides by directed lithiation: transformation into tertiary phosphine oxides via methanolysis, aryne chemistry and complexation behaviour toward zinc(ii).

    Science.gov (United States)

    del Águila-Sánchez, Miguel A; Navarro, Yolanda; García López, Jesús; Guedes, Guilherme P; López Ortiz, Fernando

    2016-02-01

    The highly diastereoselective synthesis of P-stereogenic phosphinic amides via directed ortho lithiation (DoLi) of (SC)-P,P-diphenylphosphinic amides with t-BuLi followed by electrophilic quench reactions is described. Functionalised derivatives containing a wide variety of ortho substituents (Cl, Br, I, OH, N3, SiMe3, SnMe3, P(O)Ph2, Me, allyl, (t)BuOCO) have been prepared in high yields with diastereomeric ratios up to 98 : 2. The X-ray diffraction structure of the ortho-stannylated and ortho-iodo compounds showed that the pro-S P-phenyl ring was stereoselectively ortho-deprotonated by the organolithium base. The usefulness of the method is supported by two key transformations, the synthesis of P-stereogenic methyl phosphinates through replacement of the chiral auxiliary by a methoxy group and the first example of the insertion of benzyne into the P-N bond of a P-stereogenic phosphinic amide. A DFT study of this reaction showed that the insertion proceeds through a [2 + 2] cycloaddition and a subsequent ring-opening with retention of the P-configuration. Explorative coordination chemistry of the new P-stereogenic ligands provided access to a chiral phosphinic amide-phosphine oxide Zn(ii) complex, the crystal structure of which is reported. PMID:26370566

  8. Quantitative chemoproteomics for site-specific analysis of protein alkylation by 4-hydroxy-2-nonenal in cells.

    Science.gov (United States)

    Yang, Jing; Tallman, Keri A; Porter, Ned A; Liebler, Daniel C

    2015-03-01

    Protein alkylation by 4-hydroxy-2-nonenal (HNE), an endogenous lipid derived electrophile, contributes to stress signaling and cellular toxicity. Although previous work has identified protein targets for HNE alkylation, the sequence specificity of alkylation and dynamics in a cellular context remain largely unexplored. We developed a new quantitative chemoproteomic platform, which uses isotopically tagged, photocleavable azido-biotin reagents to selectively capture and quantify the cellular targets labeled by the alkynyl analogue of HNE (aHNE). Our analyses site-specifically identified and quantified 398 aHNE protein alkylation events (386 cysteine sites and 12 histidine sites) in intact cells. This data set expands by at least an order of magnitude the number of such modification sites previously reported. Although adducts formed by Michael addition are thought to be largely irreversible, we found that most aHNE modifications are lost rapidly in situ. Moreover, aHNE adduct turnover occurs only in intact cells and loss rates are site-selective. This quantitative chemoproteomics platform provides a versatile general approach to map bioorthogonal-chemically engineered post-translational modifications and their cellular dynamics in a site-specific and unbiased manner. PMID:25654326

  9. UV absorption spectra and kinetics for alkyl and alkyl peroxy radicals originating from di-tert-butyl ether

    DEFF Research Database (Denmark)

    Nielsen, O.J.; Sehested, J.; Langer, S.;

    1995-01-01

    Alkyl, (CH3)(3)COC(CH3)(2)CH2, and alkyl peroxy, (CH3)(3)COC(CH3)(2)CH2O2, radicals from di-tert-butyl ether (DTBE), have been studied in the gas phase at 296 K. A pulse radiolysis UV absorption technique was used to measure the spectra and kinetics. Absorption cross sections were quantified over...

  10. Carboxylate-Assisted Iridium-Catalyzed C-H Amination of Arenes with Biologically Relevant Alkyl Azides.

    Science.gov (United States)

    Zhang, Tao; Hu, Xuejiao; Wang, Zhen; Yang, Tiantian; Sun, Hao; Li, Guigen; Lu, Hongjian

    2016-02-24

    An iridium-catalyzed C-H amination of arenes with a wide substrate scope is reported. Benzamides with electron-donating and -withdrawing groups and linear, branched, and cyclic alkyl azides are all applicable. Cesium carboxylate is crucial for both reactivity and regioselectivity of the reactions. Many biologically relevant molecules, such as amino acid, peptide, steroid, sugar, and thymidine derivatives can be introduced to arenes with high yields and 100 % chiral retention. PMID:26712274

  11. Novel Synthesis of N-Substituted p-Hydroxybenzoic Amides on Soluble Polymer-Support

    Institute of Scientific and Technical Information of China (English)

    胡春玲; 陈祖兴; 杨桂春

    2003-01-01

    The synthesis of N-substituted p-hydroxybenzoic amides using a liquid phase approach is described. Poly(ethylene glycol)(PEG) and p-hydroxybenzoic acid were linked by oxalyl chloride to give compound 1, which was chlorinated by thionyl chloride, followed by amidation with NHR1R2 to yield compound 3. Hydrolysis of compound 3 gave the title amide 4.These crude library members were obtained in good yields with high purities.

  12. (E)-α,β-unsaturated amides from tertiary amines, olefins and CO via Pd/Cu-catalyzed aerobic oxidative N-dealkylation.

    Science.gov (United States)

    Shi, Renyi; Zhang, Hua; Lu, Lijun; Gan, Pei; Sha, Yuchen; Zhang, Heng; Liu, Qiang; Beller, Matthias; Lei, Aiwen

    2015-02-21

    A novel Pd/Cu-catalyzed chemoselective aerobic oxidative N-dealkylation/carbonylation reaction has been developed. Tertiary amines are utilized as a "reservoir" of "active" secondary amines in this transformation, which inhibits the formation of undesired by-products and the deactivation of the catalysts. This protocol allows for an efficient and straightforward construction of synthetically useful and bioactive (E)-α,β-unsaturated amide derivatives from easily available tertiary amines, olefins and CO. PMID:25610923

  13. Synthesis of new fatty acids amides from aminolysis of fatty acid methyl esters (FAMEs)

    International Nuclear Information System (INIS)

    Recent biochemical and pharmacological studies have led to the characterization of different fatty acid amides as a new family of biologically active lipids. Here, we describe the synthesis of new amides from C16:0, 18:0, 18:1 and 18:1, OH fatty acids (FFA) families with cyclic and acyclic amines and demonstrate for the first time that these compounds produce cytotoxic effects. Application of this method to the synthesis of fatty acid amides was performed using the esters aminolysis as a key step and various carboxylic amides were prepared in good yield from fatty acid methyl esters (FAMEs). (author)

  14. Cloning of a Novel Arylamidase Gene from Paracoccus sp. Strain FLN-7 That Hydrolyzes Amide Pesticides

    OpenAIRE

    Zhang, Jun; Yin, Jin-Gang; Hang, Bao-Jian; Cai, Shu; He, Jian; Zhou, Shun-Gui; Li, Shun-Peng

    2012-01-01

    The bacterial isolate Paracoccus sp. strain FLN-7 hydrolyzes amide pesticides such as diflubenzuron, propanil, chlorpropham, and dimethoate through amide bond cleavage. A gene, ampA, encoding a novel arylamidase that catalyzes the amide bond cleavage in the amide pesticides was cloned from the strain. ampA contains a 1,395-bp open reading frame that encodes a 465-amino-acid protein. AmpA was expressed in Escherichia coli BL21 and homogenously purified using Ni-nitrilotriacetic acid affinity c...

  15. Evaluation of the Ser-His Dipeptide, a Putative Catalyst of Amide and Ester Hydrolysis.

    Science.gov (United States)

    MacDonald, Melissa J; Lavis, Luke D; Hilvert, Donald; Gellman, Samuel H

    2016-08-01

    Efficient hydrolysis of amide bonds has long been a reaction of interest for organic chemists. The rate constants of proteases are unmatched by those of any synthetic catalyst. It has been proposed that a dipeptide containing serine and histidine is an effective catalyst of amide hydrolysis, based on an apparent ability to degrade a protein. The capacity of the Ser-His dipeptide to catalyze the hydrolysis of several discrete ester and amide substrates is investigated using previously described conditions. This dipeptide does not catalyze the hydrolysis of amide or unactivated ester groups in any of the substrates under the conditions evaluated. PMID:27400366

  16. Antifungal activity of natural and synthetic amides from Piper species

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Joaquim V.; Oliveira, Alberto de; Kato, Massuo J., E-mail: majokato@iq.usp.b [Universidade de Sao Paulo (IQ/USP), SP (Brazil). Inst. de Quimica; Raggi, Ludmila; Young, Maria C. [Instituto de Botanica, Sao Paulo, SP (Brazil). Secao de Fisiologia e Bioquimica de Plantas

    2010-07-01

    The antifungal leaves extract from Piper scutifolium was submitted to bioactivity-guided chromatographic separation against Cladosporium cladosporioides and C. sphaerospermum yielding piperine, piperlonguminine and corcovadine as the active principles which displayed a detection limit of 1 {mu}g. Structure-activity relationships were investigated with the preparation of twelve analogs having differences in the number of unsaturations, aromatic ring substituents and in the amide moiety. Analogs having a single double-bond and no substituent in the aromatic ring displayed higher activity, while N,N,-diethyl analogs displayed higher dose-dependent activity. (author)

  17. Antifungal activity of natural and synthetic amides from Piper species

    International Nuclear Information System (INIS)

    The antifungal leaves extract from Piper scutifolium was submitted to bioactivity-guided chromatographic separation against Cladosporium cladosporioides and C. sphaerospermum yielding piperine, piperlonguminine and corcovadine as the active principles which displayed a detection limit of 1 μg. Structure-activity relationships were investigated with the preparation of twelve analogs having differences in the number of unsaturations, aromatic ring substituents and in the amide moiety. Analogs having a single double-bond and no substituent in the aromatic ring displayed higher activity, while N,N,-diethyl analogs displayed higher dose-dependent activity. (author)

  18. Synthesis and structures of new helical,nanoscale ferrocenylphenyl amides

    Institute of Scientific and Technical Information of China (English)

    XU Yan; RAN Chunling; WANG Haixian; SONG Maoping

    2007-01-01

    Two novel ferrocenylphenyl-containing amides have been synthesized by reaction of ferrocenylbencarboxylchloride and 1,2-di-(o-aminophenoxy)ethane.A single crystal X-ray analysis shows that compound 3 crystallizes in the triclinic system,space group P-1,and compound 4 crystallizes in orthorhombic system,space group Pca21.There areintramolecular H-bonds in both the compounds,two H-bonds in compound 3 and one in compound 4.The dihedral angels of Cp-ring and phenyl ring range from 3.8° to 20.8°.

  19. Spectroscopic and molecular modeling investigation on the binding of a synthesized steroidal amide to protein

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hua-xin, E-mail: h.x.zhang@yeah.net; Liu, E.

    2014-09-15

    Owing to the various valuable biological activities, steroidal amides have become a hot topic in steroidal pharmaceutical chemistry. In this paper, an anti-tumor steroid derivate (DAAO) was synthesized and identified. The interaction between DAAO and human serum albumin (HSA) was studied by fluorescence spectra, circular dichroism (CD) spectra, molecular modeling and molecular probe techniques. The results suggested that DAAO had reacted with HSA through hydrogen bonds and van der Waals power. The formation of DAAO–HSA complex at ground state led to static quenching of HSA's fluorescence. The number of binding sites, binding constants, enthalpy change (ΔH{sup θ}), Gibbs free energy change (ΔG{sup θ}) and entropy change (ΔS{sup θ}) were calculated at different temperatures based on fluorescence quenching theory and classic equation. Molecular modeling investigation indicated that DAAO was more inclined to absorb on Sudlow's site I in subdomain IIA of HSA molecule on grounds of the lowest energy principle and steric hindrance effect. The binding location was further confirmed by fluorescence probe experiment using warfarin (site I probe) for displacement. Furthermore, the conformational changes of HSA in presence of DAAO were investigated by CD spectra. The results could provide new evidence explaining the relationship between the chemical structure and biological activity and may be useful for understanding the anti-cancer mechanism of steroidal drug. - Highlights: • A designed steroidal amide compound (DAAO) was synthesized by introducing amido bonds into a steroid nucleus. • DAAO binds to Sudlow's site I in HSA through hydrogen bonds and van der Waals power. • The interaction was a spontaneous and exothermic process with modest degree of reversibility. • The secondary structure of HSA and the microenvironment of TRP214 altered. • Amido bond in steroid nucleus (–NH–CO–) plays important role in stabling the structure of

  20. Chiral N-1-adamantyl-N-trans-cinnamylaniline type ligands: synthesis and application to palladium-catalyzed asymmetric allylic alkylation of indoles.

    Science.gov (United States)

    Mino, Takashi; Nishikawa, Kenji; Asano, Moeko; Shima, Yamato; Ebisawa, Toshibumi; Yoshida, Yasushi; Sakamoto, Masami

    2016-08-21

    Such chiral phosphine-internal olefin hybrid type ligands as N-1-adamantyl-N-cinnamylaniline derivatives 1 with C(aryl)-N(amine) bond axial chirality were synthesized and utilized for the palladium-catalyzed asymmetric allylic alkylation of indoles to afford the desired products in high enantioselectivities (up to 98% ee). PMID:27425209

  1. Synthesis of N1-Substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyra- zolethiocarboxamide as Novel Small Molecule Inhibitors of Cysteine Protease of T. cruzi

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A series of N1-substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyrazolethiocarboxamide were prepared from the Mannich bases of aryl ketones in good yields. Some derivatives were found to be active against the cysteine protease of T.cruzi..

  2. Ultrasound promoted N-alkylation of pyrrole using potassium superoxide as base in crown ether.

    Science.gov (United States)

    Yim, E S; Park, M K; Han, B H

    1997-04-01

    Ultrasound accelerates the N-alkylation of pyrrole by alkylating reagents using potassium superoxide as base in the presence of 18-crown-6. A much lower yield of N-alkylated pyrrole was realized in the absence of ultrasound. N-alkylating reagents employed for pyrrole are methyl iodide, ethyl bromide, benzyl bromide, as well as acrylonitrile allyl cyanide and methyl acrylate. In an extension of this work, we have found that ultrasound was not necessary for the N-alkylation of indole and alkyl amine, such as diphenyl amine and piperidine with alkyl halides using our reagents. In all cases we observed that the 18-crown-6 catalyzed N-alkylation reaction gives higher yields of N-alkylated products than that without crown ether, when potassium superoxide was used as base. These observations are probably due to the potassium-crown complex which can be released when the reaction goes to completion. PMID:11237050

  3. Biological activities of substituted trichostatic acid derivatives

    Indian Academy of Sciences (India)

    Cédric Charrier; Joëlle Roche; Jean-Pierre Gesson; Philippe Bertrand

    2009-07-01

    New substituted trichostatic acid derivatives have been synthesized and evaluated for their biological activities towards the H661 non-small lung cancer cell line. These syntheses were achieved by alkylation of propiophenones to introduce the side chain with a terminal precursor of hydroxamic acid and aminobenzamide derivatives. The first fluorinated derivatives of trichostatic acid are described, such as 6-fluoro trichostatin A, with antiproliferative activities in the micromolar range and with histone deacetylase inhibitory activity.

  4. A Study on Alkyl Polyglycosides of the Starch

    Institute of Scientific and Technical Information of China (English)

    Wang Qing-ning; Li Chun-lei; Feng Hui-xia; Kang Wen-shu

    2004-01-01

    The alkyl polyglycosides (APG) is new type the surfactants that is made by regenerationresource of the starch and the grease, since the nineties of 20th century it is energetically exploited ininternational extent. APG not only good in surface activity, but also plenty on bubble, thin greasyand stabilization, there are good decontamination, compatibility, innocuity, not incitation and uniquefunction that organism decomposition of swiftness and downrightness, and so on.APG is to get production that loses one molecule water with half condensation aldehyde hydroxyand sebum alcohol hydroxy under acid catalysis. The production not is one simplicity compound, butis one of sugar polymerization degree, so it is mixture of the alkyl single glucoside, the alkyl twoglucoside and the alkyl three glucoside.Author synthesizes the surfactants of the alkyl polyglycosides, with the oleaster and potato starchand sebum alcohol, that was chosen to use duality system activator of plant acid and p-toluene-sulfoacid for the first time. The adoption way is that the lower alkyl polyglycosides is firstly formed byreaction of lower alcohol with starch then exchanged with high alcohol to obtain APG. The study isto make certain most technics condition, determining capillary tension and the pastern sheafdeepness of critical, calculating HLB value, determining construction by 1R.To synthesize principium:Peroration :[1]Duality system activator of plant acid and p-toluene-sulfo acid is compare idea activator that was the lower alkyl polyglycosides is firstly formed by reaction of lower alcohol with glucose then exchanged with high alcohol to obtain high alkyl polyglycosides. The advantage is that it overcomes agglomeration, there is reaction entirety, high of sugar transform ratio, reaction time short.[2]Most good reaction temperature is 90~ 170℃, the dosage of activator is 0.5%~0.9%, the mated ratio: The APG of glucose basic butane ratio starch is 5:1, the APG of potato starch basic glycol

  5. Poly(ester amide)s based on (L)-lactic acid oligomers and α-amino acids: influence of the α-amino acid side chain in the poly(ester amide)s properties.

    Science.gov (United States)

    Fonseca, Ana C; Coelho, Jorge F J; Valente, Joana F A; Correia, Tiago R; Correia, Ilídio J; Gil, Maria H; Simões, Pedro N

    2013-01-01

    Novel biodegradable and low cytotoxic poly(ester amide)s (PEAs) based on α-amino acids and (L)-lactic acid (L-LA) oligomers were successfully synthesized by interfacial polymerization. The chemical structure of the new polymers was confirmed by spectroscopic analyses. Further characterization suggests that the α-amino acid plays a critical role on the final properties of the PEA. L-phenylalanine provides PEAs with higher glass transition temperature, whereas glycine enhances the crystallinity. The hydrolytic degradation in PBS (pH = 7.4) at 37 °C also depends on the α-amino acid, being faster for glycine-based PEAs. The cytotoxic profiles using fibroblast human cells indicate that the PEAs did not elicit an acute cytotoxic effect. The strategy presented in this work opens the possibility of synthesizing biodegradable PEAs with low citotoxicity by an easy and fast method. It is worth to mention also that the properties of these materials can be fine-tuned only by changing the α-amino acid.

  6. Amidated pectin based hydrogels: synthesis, characterization and cytocompatibility study.

    Science.gov (United States)

    Mishra, R K; Singhal, J P; Datt, M; Banthia, A K

    2007-01-01

    The design and development of pectin-based hydrogels were attempted through the chemical modification of pectin with diethanolamine (DA). Diethanolamine modified pectin (DAMP) was synthesized by the chemical modification of pectin with varying concentrations of DA (1:1,1:2,1:3 and 1:4) at 5 oC in methanol. The modified product was used for the preparation of the hydrogel with glutaraldehyde (GA) reagent. The prepared hydrogels were characterized by Fourier transform infrared (FTIR) spectroscopy; organic elemental analysis, and X-ray diffraction (XRD), and swelling, hemocompatibility and cytocompatibility studies of the prepared hydrogels were also done. FTIR spectroscopy indicated the presence of primary and secondary amide absorption bands. The XRD pattern of the DAMP hydrogel clearly indicated that there was a considerable increase in crystallinity as compared to parent pectin. The degree of amidation (DA) and molar and mass reaction yields (Ym and Yn) was calculated based on the results of organic elemental analysis. Drug release studies from the hydrogel membranes were also evaluated in a Franz's diffusion cell. The hydrogels demonstrated good water holding properties and were found to be compatible with B-16 melanoma cells and human blood.

  7. PREPARATION AND CHARACTERIZATION OF AMIDATED PECTIN BASED POLYMER ELECTROLYTE MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    R.K.Mishra; A.Anis; S.Mondal; M.Dutt; A.K.Banthia

    2009-01-01

    The work presents the synthesis and characterization of ami dated pectin(AP)based polymer electrolyte membranes(PEM)crosslinked with glutaraldehyde(GA).The prepared membranes are characterized by Fourier transform infrared spectroscopy(FTIR),organic elemental analysis,X-ray diffraction studies(XRD),thermogravimetric analysis (TGA)and impedance spectroscopy.Mechanical properties of the membranes are evaluated by tensile tests.The degree of amidation(DA),molar and mass reaction yields(YM and YN)are calculated based on the results of organic elemental analysis.FTIR spectroscopy indicated the presence of primary and secondary amide absorption bands.XRD pattern of membranes clearly indicates that there is a considerable increase in crystallinity as compared to parent pectin.TGA studies indicate that AP is less thermally stable than reference pectin.A maximum room temperature conductivity of 1.098×10-3 Scm-1 is obtained in the membrane,which is designated as AP-3.These properties make them good candidates for low cost biopolymer electrolyte membranes for fuel cell applications.

  8. Alkyl polycyclic aromatic hydrocarbons emissions in diesel/biodiesel exhaust

    Science.gov (United States)

    Casal, Carina S.; Arbilla, Graciela; Corrêa, Sergio M.

    2014-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are widely studied in environmental matrices, such as air, water, soil and sediment, because of their toxicity, mutagenicity and carcinogenicity. Because of these properties, the environmental agencies of developed countries have listed sixteen PAHs as priority pollutants. Few countries have limits for these compounds for ambient air, but they only limit emissions from stationary and mobile sources and occupational areas. There are several studies to specifically address the 16 priority PAHs and very little for the alkyl PAHs. These compounds are more abundant, more persistent and frequently more toxic than the non-alkylated PAHs, and the toxicity increases with the number of alkyl substitutions on the aromatic ring. In this study, a method was developed for the analysis of PAHs and alkyl PAHs by using a GC-MS and large injection volume injection coupled with program temperature vaporisation, which allows for limits of detection below 1.0 ng μL-1. Several variables were tested, such as the injection volume, injection velocity, injector initial temperature, duration of the solvent split and others. This method was evaluated in samples from particulate matter from the emissions of engines employing standard diesel, commercial diesel and biodiesel B20. Samples were collected on a dynamometer bench for a diesel engine cycle and the results ranged from 0.5 to 96.9 ng mL-1, indicating that diesel/biodiesel makes a significant contribution to the formation of PAHs and alkyl PAHs.

  9. Alkyl substituent effect on density, viscosity and chemical behavior of 1-alkyl-3-methylimidazolium chloride.

    Science.gov (United States)

    Olmo, Lourdes del; Lage-Estebanez, Isabel; López, Rafael; García de la Vega, José M

    2014-09-01

    Molecular structure of the conformers of 1-C n -3-methylimidazolium chloride (n = 1 to 4) ionic liquids has been explored and the relationships with density and viscosity have been studied using COSMO related methodologies. Effects of the number of conformers, ionic character, anion-cation relative positions and the alkyl chain length of the cation on predictions of properties have been analyzed. The quality of the predictions has been tested by comparing with experimental results. Moreover, COSMO polarization charge densities, σ-profiles and σ-potentials of the conformers have been analyzed. Predictions on the chemical behavior based on the values of these properties in the conformers have been used to elucidate the affinity for electrophilic and nucleophilic reagents of ionic liquids. PMID:25149437

  10. A combined approach of experiments and computational docking simulation to the Coprinus cinereus peroxidase-catalyzed oxidative polymerization of alkyl phenols.

    Science.gov (United States)

    Park, Jong Chul; Joo, Jeong Chan; An, Eun Suk; Song, Bong Keun; Kim, Yong Hwan; Yoo, Young Je

    2011-04-01

    The characteristics of the oxidative polymerization of alkyl phenol derivatives catalyzed by Coprinus cinereus peroxidase (CIP) were studied qualitatively and quantitatively using a combined approach of experiments and computational docking simulations. As determined by docking study of CIP and alkyl phenols, the binding interaction was found to be important for the determination of substrate specificity. The distant binding and indirect orientation of o-isopropyl phenol and o-tertiary butyl phenol to the catalytic residue (56His) could explain the inability of CIP to polymerize these substrates. Three hydrophobic residues (156Pro, 192Leu, and 230Phe) at the entrance of the binding pocket were also found to be crucial in binding and orientation of alkyl phenols. A two-parameter QSAR equation with the binding distance and the molecular volume of the substrates was proposed and the polymerization yield was accurately predicted by two-parameter QSAR equation.

  11. Two enzymes which catalyze the amidation of peptide C-terminals are synthesized by a single mRNA. Peptide C mattan amid ka hanno wo shokubaisuru futatsu no koso wa ippon no mRNA yori goseisareru

    Energy Technology Data Exchange (ETDEWEB)

    Kato, I.; Yonekura, H.; Okamoto, H. (Tohoku Univ., Sendai (Japan))

    1991-10-25

    Recent findings by the authors are reviewed on the amidation that forms amid structure essential to physiological activities in C-terminals of peptide hormones such as oxytocin,VIP,PP. It is noted that the amidation had been considered to be catalyzed by peptidylglycine{alpha} -amidating monooxyganase ( PAM ) and that the authors investigated the PAM function by expression of PAM cDNA isolated from rat pituitary and its deletion mutant into COS-7 cells, reaching to the important findings of a singl PMA mRNA encoding two enzymes, namely one at 5 {prime} side, peptidylglicine {alpha} hydroxylase which catalyses the conversion of C-termianl glycine on peptide to the hydroxylated form ( the first step of amidation ),and another at 3{prime} side, {alpha}- hydroxylglycine amidating dealkylase which catalyzes the conversion of hydroxylated glycine to the amidated form ( the second step of amidation). 19 refs., 4 figs.

  12. Electrospun Scaffolds from Low Molecular Weight Poly(ester amide)s Based on Glycolic Acid, Adipic Acid and Odd or Even Diamines

    OpenAIRE

    Sara Keiko Murase; Luís Javier del Valle; Jordi Puiggalí

    2015-01-01

    Electrospinning of regular poly(ester amide)s (PEAs) constituted by glycolic acid, adipic acid and diamines with five and six carbon atoms has been carried out. Selected PEAs were constituted by natural origin products and could be easily prepared by a polycondensation method that avoids tedious protection and deprotection steps usually required for obtaining polymers with a regular sequence. Nevertheless, the synthesis had some limitations that mainly concerned the final low/moderate molecul...

  13. Allosteric Indole Amide Inhibitors of p97: Identification of a Novel Probe of the Ubiquitin Pathway.

    Science.gov (United States)

    Alverez, Celeste; Bulfer, Stacie L; Chakrasali, Ramappa; Chimenti, Michael S; Deshaies, Raymond J; Green, Neal; Kelly, Mark; LaPorte, Matthew G; Lewis, Taber S; Liang, Mary; Moore, William J; Neitz, R Jeffrey; Peshkov, Vsevolod A; Walters, Michael A; Zhang, Feng; Arkin, Michelle R; Wipf, Peter; Huryn, Donna M

    2016-02-11

    A high-throughput screen to discover inhibitors of p97 ATPase activity identified an indole amide that bound to an allosteric site of the protein. Medicinal chemistry optimization led to improvements in potency and solubility. Indole amide 3 represents a novel uncompetitive inhibitor with excellent physical and pharmaceutical properties that can be used as a starting point for drug discovery efforts. PMID:26985295

  14. On the temperature dependence of amide I frequencies of peptides in solution.

    Science.gov (United States)

    Amunson, Krista E; Kubelka, Jan

    2007-08-23

    The temperature dependence of the amide I vibrational frequencies of peptides in solution was investigated. In D2O, the amide I' bands of both an alpha-helical oligopeptide, the random-coil poly(L-lysine), and the simplest amide, N-methyl acetamide (NMA), exhibit linear frequency shifts of approximately 0.07 cm(-1)/degrees C with increasing temperature. Similar amide I frequency shifts are also observed for NMA in both polar (acetonitrile and DMSO) and nonpolar (1,4-dioxane) organic solvents, thus ruling out hydrogen-bonding strength as the cause of these effects. The experimental NMA amide I frequencies in the organic solvents can be accurately described by a simple theory based on the Onsager reaction field with temperature-dependent solvent dielectric properties and a solute molecular cavity. DFT-level calculations (BPW91/cc-pVDZ) for NMA with an Onsager reaction field confirm the significant contribution of the molecular cavity to the predicted amide I frequencies. Comparison of the computations to experimental data shows that the frequency-dependent response of the reaction field, taken into account by the index of refraction, is crucial for describing the amide I frequencies in polar solvents. The poor predictions of the model for the NMA amide I band in D2O might be due, in part, to the unknown temperature dependence of the refractive index of D2O in the mid-IR range, which was approximated by the available values in the visible region.

  15. A General and Efficient CuBr2-Catalyzed N-Arylation of Secondary Acyclic Amides

    Institute of Scientific and Technical Information of China (English)

    王满刚; 于华; 尤心稳; 吴军; 商志才

    2012-01-01

    A general and efficient Cu(II)-catalyzed cross-coupling method is reported for the preparation of acyclic tertiary amides. Generally moderate to excellent yields and functional group tolerance were obtained with secondary acyclic amides and aryl halides as substrates in toluene.

  16. Poly(ether amide) segmented block copolymers with adipic acid based tetraamide segments

    NARCIS (Netherlands)

    Biemond, G.J.E.; Feijen, J.; Gaymans, R.J.

    2007-01-01

    Poly(tetramethylene oxide)-based poly(ether ester amide)s with monodisperse tetraamide segments were synthesized. The tetraamide segment was based on adipic acid, terephthalic acid, and hexamethylenediamine. The synthesis method of the copolymers and the influence of the tetraamide concentration, wh

  17. Hydrophilic segmented block copolymers based on poly(ethylene oxide) and monodisperse amide segments

    NARCIS (Netherlands)

    Husken, Debby; Feijen, Jan; Gaymans, Reinoud J.

    2007-01-01

    Segmented block copolymers based on poly(ethylene oxide) (PEO) flexible segments and monodisperse crystallizable bisester tetra-amide segments were made via a polycondensation reaction. The molecular weight of the PEO segments varied from 600 to 4600 g/mol and a bisester tetra-amide segment (T6T6T)

  18. Safety Assessment of Alkyl PEG Sulfosuccinates as Used in Cosmetics.

    Science.gov (United States)

    Johnson, Wilbur; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2015-09-01

    The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) reviewed the safety of alkyl polyethylene glycol (PEG) sulfosuccinates, which function in cosmetics mostly as surfactants/cleansing agents. Although these ingredients may cause ocular and skin irritation, dermal penetration is unlikely because of the substantial polarity and molecular size of these ingredients. The Panel considered the negative oral carcinogenicity and reproductive and developmental toxicity data on chemically related laureths (PEG lauryl ethers) and negative repeated dose toxicity and skin sensitization data on disodium laureth sulfosuccinate supported the safety of these alkyl PEG sulfosuccinates in cosmetic products, but. The CIR Expert Panel concluded that the alkyl PEG sulfosuccinates are safe in the present practices of use and concentration when formulated to be nonirritating.

  19. Safety Assessment of Alkyl Ethylhexanoates as Used in Cosmetics.

    Science.gov (United States)

    Fiume, Monice; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2015-01-01

    The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) assessed the safety of 16 alkyl ethylhexanoates for use in cosmetics, concluding that these ingredients are safe in cosmetic formulations in the present practices of use and concentrations when formulated to be nonirritating. The alkyl ethylhexanoates primarily function as skin-conditioning agents in cosmetics. The highest concentration of use reported for any of the alkyl ethylhexanoates is 77.3% cetyl ethylhexanoate in rinse-off formulations used near the eye, and the highest leave-on use reported is 52% cetyl ethylhexanoate in lipstick formulations. The Panel reviewed available animal and clinical data related to these ingredients, and the similarities in structure, properties, functions, and uses of ingredients from previous CIR assessments on constituent alcohols that allowed for extrapolation of the available toxicological data to assess the safety of the entire group.

  20. Alkylation of imidazole under ultrasound irradiation over alkaline carbons

    Energy Technology Data Exchange (ETDEWEB)

    Costarrosa, L. [Dpto. de Quimica Inorganica y Quimica Tecnica, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), C/Senda del Rey, 9, E-28040 Madrid (Spain); Calvino-Casilda, V. [Dpto. de Quimica Inorganica y Quimica Tecnica, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), C/Senda del Rey, 9, E-28040 Madrid (Spain); Ferrera-Escudero, S. [Dpto. de Quimica Inorganica y Quimica Tecnica, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), C/Senda del Rey, 9, E-28040 Madrid (Spain); Duran-Valle, C.J. [Dpto. de Quimica Inorganica, Facultad de Ciencias, Universidad de Extremadura, Avenida de Elvas s/n, 06071 Badajoz (Spain); Martin-Aranda, R.M. [Dpto. de Quimica Inorganica y Quimica Tecnica, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), C/Senda del Rey, 9, E-28040 Madrid (Spain)]. E-mail: rmartin@ccia.uned.es

    2006-06-30

    N-Alkyl-imidazole has been synthesized by sonochemical irradiation of imidazole and 1-bromobutane using alkaline-promoted carbons (exchanged with the binary combinations of Na, K and Cs). The catalysts were characterized by X-ray photoelectron spectroscopy, thermal analysis and N{sub 2} adsorption isotherms. Under the experimental conditions, N-alkyl-imidazoles can be prepared with a high activity and selectivity. It is observed that imidazole conversion increases in parallel with increasing the basicity of the catalyst. The influence of the alkaline promoter, the reaction temperature, and the amount of catalyst on the catalytic activity has been studied. For comparison, the alkylation of imidazole has also been performed in a batch reactor system under thermal activation.

  1. Safety Assessment of Alkyl Ethylhexanoates as Used in Cosmetics.

    Science.gov (United States)

    Fiume, Monice; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2015-01-01

    The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) assessed the safety of 16 alkyl ethylhexanoates for use in cosmetics, concluding that these ingredients are safe in cosmetic formulations in the present practices of use and concentrations when formulated to be nonirritating. The alkyl ethylhexanoates primarily function as skin-conditioning agents in cosmetics. The highest concentration of use reported for any of the alkyl ethylhexanoates is 77.3% cetyl ethylhexanoate in rinse-off formulations used near the eye, and the highest leave-on use reported is 52% cetyl ethylhexanoate in lipstick formulations. The Panel reviewed available animal and clinical data related to these ingredients, and the similarities in structure, properties, functions, and uses of ingredients from previous CIR assessments on constituent alcohols that allowed for extrapolation of the available toxicological data to assess the safety of the entire group. PMID:26684798

  2. Fast acquisition of high resolution 4-D amide-amide NOESY with diagonal suppression, sparse sampling and FFT-CLEAN.

    Science.gov (United States)

    Werner-Allen, Jon W; Coggins, Brian E; Zhou, Pei

    2010-05-01

    Amide-amide NOESY provides important distance constraints for calculating global folds of large proteins, especially integral membrane proteins with beta-barrel folds. Here, we describe a diagonal-suppressed 4-D NH-NH TROSY-NOESY-TROSY (ds-TNT) experiment for NMR studies of large proteins. The ds-TNT experiment employs a spin state selective transfer scheme that suppresses diagonal signals while providing TROSY optimization in all four dimensions. Active suppression of the strong diagonal peaks greatly reduces the dynamic range of observable signals, making this experiment particularly suitable for use with sparse sampling techniques. To demonstrate the utility of this method, we collected a high resolution 4-D ds-TNT spectrum of a 23kDa protein using randomized concentric shell sampling (RCSS), and we used FFT-CLEAN processing for further reduction of aliasing artifacts - the first application of these techniques to a NOESY experiment. A comparison of peak parameters in the high resolution 4-D dataset with those from a conventionally-sampled 3-D control spectrum shows an accurate reproduction of NOE crosspeaks in addition to a significant reduction in resonance overlap, which largely eliminates assignment ambiguity. Likewise, a comparison of 4-D peak intensities and volumes before and after application of the CLEAN procedure demonstrates that the reduction of aliasing artifacts by CLEAN does not systematically distort NMR signals.

  3. Pyrrolic Amide: A New Hydrogen Bond Building Block for Self-assembly

    Institute of Scientific and Technical Information of China (English)

    YIN Zhen-Ming; LI Jian-Feng; HE Jia-Qi; ZHU Xiao-Qing; CHENG Jin-Pei

    2003-01-01

    @@ Molecular self-assembly has emerged as a powerful technology for the synthesis of nanostructured materials. In design of various molecular assemblies, hydrogen bonding is a preferably selected intra- or inter-molecular weak interaction in recent research by virtue of the directionality and specificity. The research for novel hydrogen bond building blocks that self-assembly into well defined structures is great important not only for gaining an understanding of the concepts of self-assembly but also for the design of new molecular materials. Pyrrolic amide moiety has one hydrogen bond acceptor (C =O) and two hydrogen bond donors (pyrrole NH and amide NH). By deliberately design, pyrrolic amide compounds would be new kinds hydrogen bond building blocks. So, pyrrolic amide compounds 1 ~ 6, which bear one, two or three pyrrolic amide moieties respectively, were designed and synthesized.

  4. Synthesis of amide-functionalized cellulose esters by olefin cross-metathesis.

    Science.gov (United States)

    Meng, Xiangtao; Edgar, Kevin J

    2015-11-01

    Cellulose esters with amide functionalities were synthesized by cross-metathesis (CM) reaction of terminally olefinic esters with different acrylamides, catalyzed by Hoveyda-Grubbs 2nd generation catalyst. Chelation by amides of the catalyst ruthenium center caused low conversions using conventional solvents. The effects of both solvent and structure of acrylamide on reaction conversion were investigated. While the inherent tendency of acrylamides to chelate Ru is governed by the acrylamide N-substituents, employing acetic acid as a solvent significantly improved the conversion of certain acrylamides, from 50% to up to 99%. Homogeneous hydrogenation using p-toluenesulfonyl hydrazide successfully eliminated the α,β-unsaturation of the CM products to give stable amide-functionalized cellulose esters. The amide-functionalized product showed higher Tg than its starting terminally olefinic counterpart, which may have resulted from strong hydrogen bonding interactions of the amide functional groups.

  5. Synthesis, Structure and Catalytic Activity Comparison of Tris- and Tetracoordinated Lanthanide Amides

    Institute of Scientific and Technical Information of China (English)

    XIE,Mei-Hua(谢美华); LIU,Xin-Yuan(刘心元); WANG,Shao-Wu(王绍武); LIU,Li(刘莉); WU,Yong-Yong(吴勇勇); YANG,Gao-Sheng(杨高升); ZHOU,Shuang-Liu(周双六); SHENG,En-Hong(盛恩宏); HUANG,Zi-Xiang(黄子祥)

    2004-01-01

    Tetracoordinated lanthanide amides [(Me3Si)2N]3Ln (μ-Cl)Li(THF)3 (Ln=La (1), Pr (2)) were synthesized by the reaction of anhydrous lanthanide(Ⅲ) chlorides LnCl3 (Ln=La, Pr) with 3 equiv. of lithium bis(trimethylsilyl)amide (Me3Si)2NLi in THF, followed by recrystallization from toluene. Sublimation of 1 and 2 afforded the triscoordinate lanthanide amides [(Me3Si)2N]3Ln (Ln =La, Pr). The crystal structure of 2 was determined by X-ray diffraction analysis. The catalytic activity studies show that the tetracoordinate amides can be used as single-component MMA (methyl methacrylate) polymerization catalysts, while the triscoordinate amides showed poor activity on MMA polymerization under the same conditions.

  6. Catalyst-free synthesis of sodium amide nanoparticles encapsulated in silica gel

    Energy Technology Data Exchange (ETDEWEB)

    Ogilvie, Alexander D., E-mail: alexander.ogilvie@chem.oxon.org [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Makepeace, Joshua W., E-mail: josh.makepeace@chem.ox.ac.uk [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Hore, Katie, E-mail: katie.hore@chem.ox.ac.uk [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Ramirez-Cuesta, Anibal J., E-mail: timmy.ramirez-cuesta@stfc.ac.uk [ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX (United Kingdom); Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Apperley, David C., E-mail: d.c.apperley@dur.ac.uk [EPSRC UK National Solid-State NMR Service, Department of Chemistry, Durham University, South Road, Durham DH1 3LE (United Kingdom); Mitchels, John M., E-mail: J.M.Mitchels@bath.ac.uk [Microscopy and Analysis Suite, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Edwards, Peter P., E-mail: peter.edwards@chem.ox.ac.uk [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Sartbaeva, Asel, E-mail: a.sartbaeva@bath.ac.uk [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2013-12-12

    Highlights: • Catalyst-free formation of nanoparticulate sodium amide encased in silica gel. • In situ ammoniation using Inelastic Neutron Spectroscopy. • Reduced air- and moisture-sensitivity and no pyrophoricity. • An alternative method for nanoparticle synthesis under mild conditions. - Abstract: Crystalline sodium amide nanoparticles encapsulated in an amorphous silica framework were formed by ammoniation of a precursor material, silica gel loaded with metallic sodium, under mild conditions and without catalysis. This ammoniation was performed in situ on TOSCA beamline at ISIS, RAL, using anhydrous gaseous ammonia. The resulting material exhibits no pyrophoricity and much reduced air- and moisture-sensitivity compared to the bulk amide. The nanoparticles formed will offer a greatly increased surface area for chemical reactions where amide is currently used as an important ingredient for industrial applications. We anticipate that this method of sodium amide production will have a diversity of applications.

  7. Synthesis of amide-functionalized cellulose esters by olefin cross-metathesis.

    Science.gov (United States)

    Meng, Xiangtao; Edgar, Kevin J

    2015-11-01

    Cellulose esters with amide functionalities were synthesized by cross-metathesis (CM) reaction of terminally olefinic esters with different acrylamides, catalyzed by Hoveyda-Grubbs 2nd generation catalyst. Chelation by amides of the catalyst ruthenium center caused low conversions using conventional solvents. The effects of both solvent and structure of acrylamide on reaction conversion were investigated. While the inherent tendency of acrylamides to chelate Ru is governed by the acrylamide N-substituents, employing acetic acid as a solvent significantly improved the conversion of certain acrylamides, from 50% to up to 99%. Homogeneous hydrogenation using p-toluenesulfonyl hydrazide successfully eliminated the α,β-unsaturation of the CM products to give stable amide-functionalized cellulose esters. The amide-functionalized product showed higher Tg than its starting terminally olefinic counterpart, which may have resulted from strong hydrogen bonding interactions of the amide functional groups. PMID:26256383

  8. Zinc-thiolate complexes of the bis(pyrazolyl)(thioimidazolyl)hydroborate tripods for the modeling of thiolate alkylating enzymes.

    Science.gov (United States)

    Ji, Mian; Benkmil, Boumahdi; Vahrenkamp, Heinrich

    2005-05-16

    The new tripod ligands bis(pyrazolyl)(3-tert-butyl-2-thioimidazol-1-yl)hydroborate (L(1)) and bis(pyrazolyl)(3-isopropyl-2-thioimidazol-1-yl)hydroborate (L(2)), together with zinc nitrate or zinc chloride and the corresponding thiolates, have yielded a total of 17 zinc-thiolate complexes. These comprise aliphatic as well as aromatic thiolates and a cysteine derivative. Structure determinations have confirmed the tetrahedral ZnN(2)S(2) coordination in the complexes. Upon reaction with methyl iodide, the species L(1).Zn-SR are slowly converted to L(1).Zn-I and the free thioethers CH(3)SR. A kinetic analysis has shown these alkylations to be about 1 order of magnitude slower than those of the tris(pyrazolyl)borate complexes Tp(Ph,Me)Zn-SR. Alkylations with trimethyl phosphate were found to proceed very slowly even in DMSO at 80 degrees C. PMID:15877434

  9. Interaction and dynamics of (alkylamide + electrolyte) deep eutectics: Dependence on alkyl chain-length, temperature, and anion identity

    Energy Technology Data Exchange (ETDEWEB)

    Guchhait, Biswajit; Das, Suman; Daschakraborty, Snehasis; Biswas, Ranjit, E-mail: ranjit@bose.res.in [Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098 (India)

    2014-03-14

    Here we investigate the solute-medium interaction and solute-centered dynamics in (RCONH{sub 2} + LiX) deep eutectics (DEs) via carrying out time-resolved fluorescence measurements and all-atom molecular dynamics simulations at various temperatures. Alkylamides (RCONH{sub 2}) considered are acetamide (CH{sub 3}CONH{sub 2}), propionamide (CH{sub 3}CH{sub 2}CONH{sub 2}), and butyramide (CH{sub 3}CH{sub 2}CH{sub 2}CONH{sub 2}); the electrolytes (LiX) are lithium perchlorate (LiClO{sub 4}), lithium bromide (LiBr), and lithium nitrate (LiNO{sub 3}). Differential scanning calorimetric measurements reveal glass transition temperatures (T{sub g}) of these DEs are ∼195 K and show a very weak dependence on alkyl chain-length and electrolyte identity. Time-resolved and steady state fluorescence measurements with these DEs have been carried out at six-to-nine different temperatures that are ∼100–150 K above their individual T{sub g}s. Four different solute probes providing a good spread of fluorescence lifetimes have been employed in steady state measurements, revealing strong excitation wavelength dependence of probe fluorescence emission peak frequencies. Extent of this dependence, which shows sensitivity to anion identity, has been found to increase with increase of amide chain-length and decrease of probe lifetime. Time-resolved measurements reveal strong fractional power dependence of average rates for solute solvation and rotation with fraction power being relatively smaller (stronger viscosity decoupling) for DEs containing longer amide and larger (weaker decoupling) for DEs containing perchlorate anion. Representative all-atom molecular dynamics simulations of (CH{sub 3}CONH{sub 2} + LiX) DEs at different temperatures reveal strongly stretched exponential relaxation of wavevector dependent acetamide self dynamic structure factor with time constants dependent both on ion identity and temperature, providing justification for explaining the fluorescence results in

  10. Glutathione Depletion Induced by c-Myc Downregulation Triggers Apoptosis on Treatment with Alkylating Agents

    Directory of Open Access Journals (Sweden)

    Annamaria Biroccio

    2004-05-01

    Full Text Available Here we investigate the mechanism(s involved in the c-Myc-dependent drug response of melanoma cells. By using three M14-derived c-Myc low-expressing clones, we demonstrate that alkylating agents, cisplatin and melphalan, trigger apoptosis in the c-Myc antisense transfectants, but not in the parental line. On the contrary, topoisomerase inhibitors, adriamycin and camptothecin, induce apoptosis to the same extent regardless of c-Myc expression. Because we previously demonstrated that c-Myc downregulation decreases glutathione (GSH content, we evaluated the role of GSH in the apoptosis induced by the different drugs. In control cells treated with one of the alkylating agents or the others, GSH depletion achieved by L-buthionine-sulfoximine preincubation opens the apoptotic pathway. The apoptosis proceeded through early Bax relocalization, cytochrome c release, concomitant caspase-9 activation, whereas reactive oxygen species production and alteration of mitochondria membrane potential were late events. That GSH was determining in the c-Myc-dependent druginduced apoptosis was demonstrated by altering the intracellular GSH content of the c-Myc low-expressing cells up to the level of controls. Indeed, GSH ethyl ester-mediated increase of GSH abrogated apoptosis induced by cisplatin and melphalan by inhibition of Baxicytochrome c redistribution. The relationship among c-Myc, GSH content, the response to alkylating agent has been also evaluated in the M14 Myc overexpressing clones as well as in the melanoma JR8 c-Myc antisense transfectants. All together, these results demonstrate that GSH plays a key role in governing c-Myc-dependent drug-induced apoptosis.

  11. Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111

    Directory of Open Access Journals (Sweden)

    Christian Godet

    2015-02-01

    Full Text Available Dynamic properties of n-alkyl monolayers covalently bonded to Si(111 were studied by broadband admittance spectroscopy as a function of the temperature and the applied voltage using rectifying Hg/C12H25/n-type Si junctions. Partial substitution of methyl end groups by polar (carboxylic acid moieties was used to enhance the chain end relaxation response. Two thermally activated dissipation mechanisms (B1 and B2, with fB1 fB2 are evidenced for all reverse bias values. The strong decrease of both relaxation frequencies with increasing reverse dc bias reveals increasing motional constraints, attributed to electrostatic pressure applied to the densely-packed nanometer-thick monolayer. Spectral decomposition of the frequency response shows a power-law dependence of their activation energies on |VDC|. A large reverse bias reversibly increases the B2 response attributed to the distribution of gauche defects, in contrast with the constant strength of the acid dipole loss (B1. A trans–gauche isomerization energy of 50 meV is derived from the temperature dependence of the B2 dipolar strength. For both dissipation mechanisms, the observed linear correlation between activation energy and logarithm of pre-exponential factor is consistent with a multi-excitation entropy model, in which the molecular reorientation path is strongly coupled with a large number of low energy excitations (here the n-alkyl bending vibrational mode collected from the thermal bath. This collective dynamic behavior of alkyl chains tethered to Si is also confirmed by the asymmetric relaxation peak shape related to many-body interactions in complex systems.

  12. Glycyrrhetinic acid and its derivatives as inhibitors of poly(ADP-ribose)polymerases 1 and 2, apurinic/apyrimidinic endonuclease 1 and DNA polymerase β

    OpenAIRE

    Salakhutdinov N. F.; Schreiber V.; Khodyreva S. N.; Ilina E. S.; Kutuzov M. M.; Sukhanova M. V.; Salomatina O. V.; Zakharenko A. L.; Lavrik O. I.

    2012-01-01

    Aim. For strengthening the efficiency of monofunctional alkylating antineoplastic drugs it is important to lower the capacity of base excision repair (BER) system which corrects the majority of DNA damages caused by these reagents. The objective was to create inhibitors of the key BER enzymes (PARP1, PARP2, DNA polymerase β, and APE1) by the directed modification of glycyrrhetinic acid (GA). Methods. Amides of GA were produced from the GA acetate by formation of the corresponding acyl chlorid...

  13. Amidated joining peptide in the human pituitary, gut, adrenal gland and bronchial carcinoids. Immunocytochemical and immunochemical evidence

    DEFF Research Database (Denmark)

    Bjartell, A; Fenger, M; Ekman, R;

    1990-01-01

    The distribution of the proopiomelanocortin-derivated amidated joining peptide (JP-N) was examined in the human pituitary gland, adrenal gland, gut and in three bronchial carcinoids. Double immunostaining showed coexistence of immunoreactive JP-N and other proopiomelanocortin derivatives, e......-N was costored with somatostatin in endocrine cells. Using radioimmunoassay, JP-N was found in higher concentrations than ACTH and alpha-MSH in the gut but not in the adrenal gland. Gel chromatography of gastric antrum and adrenal gland extracts showed three and two dominating components of immunoreactive JP......-N, respectively, but under reduced conditions most of the immunoreactive material appeared as of low molecular weight in both extracts. In conclusion, immunoreactive JP-N is a major product from the processing of proopiomelanocortin in human extrapituitary tissues. The molecular forms of immunoreactive JP...

  14. Molecular pharmacology of hepsulfam, NSC 3296801: identification of alkylated nucleosides, alkylation site, and site of DNA cross-linking.

    Science.gov (United States)

    Streeper, R T; Cotter, R J; Colvin, M E; Hilton, J; Colvin, O M

    1995-04-01

    We have determined that hepsulfam, in common with its structural homologue busulfan, alkylates both free guanosine and GMP in DNA at the 7 nitrogen. Mass spectral analysis of the products of the reaction of hepsulfam with guanosine has identified the mono- and bis-alkylated guanosine adducts. UV spectrophotometry and mass spectrometry were used to confirm that alkylation occurred at the 7 nitrogen by following the formation of the formamidopyrimidyl form of the hepsulfam-guanosine adduct at high pH. We have also isolated and identified 1-guanyl,7-hydroxyheptane, 1-guanyl,7-sulfamylheptane, and 1,7-bis(guanyl)heptane from in vitro reaction mixtures of hepsulfam and calf thymus DNA. We have isolated bis-(7-formamidopyrimidyldeoxyguanosinyl)-heptane from an enzymatic digest of DNA treated with hepsulfam. Finally, we have found that hepsulfam forms interstrand cross-links at 5'-GXC-3' sites in model oligonucleotides. PMID:7882358

  15. Design, Synthesis, and Structure–Activity Relationship, Molecular Modeling, and NMR Studies of a Series of Phenyl Alkyl Ketones as Highly Potent and Selective Phosphodiesterase-4 Inhibitors

    Science.gov (United States)

    Zheng, Shilong; Kaur, Gurpreet; Wang, Huanchen; Li, Minyong; Macnaughtan, Megan; Yang, Xiaochuan; Reid, Suazette; Prestegard, James; Wang, Binghe; Ke, Hengming

    2010-01-01

    Phosphodiesterase 4 catalyzes the hydrolysis of cyclic AMP and is a target for the development of anti-inflammatory agents. We have designed and synthesized a series of phenyl alkyl ketones as PDE4 inhibitors. Among them, 13 compounds were identified as having submicromolar IC50 values. The most potent compounds have IC50 values of in the mid- to low-nanomolar range. Compound 5v also showed preference for PDE4 with selectivity of >2000-fold over PDE7, PDE9, PDE2, and PDE5. Docking of 5v, 5zf, and 5za into the binding pocket of the PDE4 catalytic domain revealed a similar binding profile to PDE4 with rolipram except that the fluorine atoms of the difluoromethyl groups of 5v, 5za, and 5zf are within a reasonable range for hydrogen bond formation with the amide hydrogen of Thr 333 and the long alkyl chain bears additional van der Waals interactions with His 160, Asp 318, and Tyr 159. PMID:19049349

  16. In(OTf)3-Catalyzed Synthesis of Functionalized 1,5-Benzodiazepines from o-Phenylenediamine and Alkyl Propiolates under Solvent-Free Reaction Conditions%In(OTf)3-Catalyzed Synthesis of Functionalized 1,5-Benzodiazepines from o-Phenylenediamine and Alkyl Propiolates under Solvent-Free Reaction Conditions

    Institute of Scientific and Technical Information of China (English)

    吴海生; 杨进; 王磊

    2011-01-01

    A simple, environmental-friendly, and practical method for the synthesis of benzodiazepine derivatives through a reaction of substituted o-phenylenediamines with alkyl propiolates has been developed. The reactions generated the 1,5-benzodiazepines in good to excellent yields in the presence of catalytic amount of In(OTf)3 under sol- vent-free reaction conditions.

  17. The Synthesis of Some Novel N-[a-(Isoflavone-7-O-)Acetyl ] Amino Acid Derivatives

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A series of novel N-[(α)-(isoflavone-7-O-)acetyl] amino acid methyl esters were prepared from the efficient and regioselective alkylation of isoflavones with chloroacetyl amino acid derivatives under mild condition.

  18. Catalysis of a Flavoenzyme-Mediated Amide Hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Tathagata; Zhang, Yang; Abdelwahed, Sameh; Ealick, Steven E.; Begley, Tadhg P. (Cornell); (TAM)

    2010-09-13

    A new pyrimidine catabolic pathway (the Rut pathway) was recently discovered in Escherichia coli K12. In this pathway, uracil is converted to 3-hydroxypropionate, ammonia, and carbon dioxide. The seven-gene Rut operon is required for this conversion. Here we demonstrate that the flavoenzyme RutA catalyzes the initial uracil ring-opening reaction to give 3-ureidoacrylate. This reaction, while formally a hydrolysis reaction, proceeds by an oxidative mechanism initiated by the addition of a flavin hydroperoxide to the C4 carbonyl. While peroxide-catalyzed amide hydrolysis has chemical precedent, we are not aware of a prior example of analogous chemistry catalyzed by flavin hydroperoxides. This study further illustrates the extraordinary catalytic versatility of the flavin cofactor.

  19. Small Antimicrobial Agents Based on Acylated Reduced Amide Scaffold.

    Science.gov (United States)

    Teng, Peng; Huo, Da; Nimmagadda, Alekhya; Wu, Jianfeng; She, Fengyu; Su, Ma; Lin, Xiaoyang; Yan, Jiyu; Cao, Annie; Xi, Chuanwu; Hu, Yong; Cai, Jianfeng

    2016-09-01

    Prevalence of drug-resistant bacteria has emerged to be one of the greatest threats in the 21st century. Herein, we report the development of a series of small molecular antibacterial agents that are based on the acylated reduced amide scaffold. These molecules display good potency against a panel of multidrug-resistant Gram-positive and Gram-negative bacterial strains. Meanwhile, they also effectively inhibit the biofilm formation. Mechanistic studies suggest that these compounds kill bacteria by compromising bacterial membranes, a mechanism analogous to that of host-defense peptides (HDPs). The mechanism is further supported by the fact that the lead compounds do not induce resistance in MRSA bacteria even after 14 passages. Lastly, we also demonstrate that these molecules have therapeutic potential by preventing inflammation caused by MRSA induced pneumonia in a rat model. This class of compounds could lead to an appealing class of antibiotic agents combating drug-resistant bacterial strains. PMID:27526720

  20. Synthesis and pharmacological evaluation of antiinflammatory mutual amide prodrugs

    Directory of Open Access Journals (Sweden)

    D T Makhija

    2013-01-01

    Full Text Available Nonsteroidal antiinflammatory drugs have been widely used for the management of inflammation, pain and nociception. Gastric intolerance caused by most of the nonsteroidal antiinflammatory drugs used today restricts their use. Several approaches have been proposed to modify the parent nonsteroidal antiinflammatory drugs molecule in order to reduce their gastric toxicity. Oral prodrug approach is one of such approaches. In the present work three nonsteroidal antiinflammatory drugs viz. ibuprofen, diclofenac, and flurbiprofen were conjugated with sulfonamides like sulphamethoxazole and sulphanilamide via amide bond using dicyclohexylcarbodiimide coupling reaction. The synthesized prodrugs were screened for their analgesic and antiinflammatory activity using Eddy′s hot plate, acetic acid-induced writhing and carrageenan-induced rat paw edema method, respectively. These prodrugs were also evaluated for their ulcerogenic potential. All synthesized prodrugs were found to be less ulcerogenic than their parent nonsteroidal antiinflammatory drugs and showed better activity profile in terms of analgesic and antiinflammatory activity as compared to their respective parent drugs.

  1. Effect of Antimicrobial Peptide-Amide: Indolicidin on Biological Membranes

    Directory of Open Access Journals (Sweden)

    Attila Gergely Végh

    2011-01-01

    Full Text Available Indolicidin, a cationic antimicrobial tridecapeptide amide, is rich in proline and tryptophan residues. Its biological activity is intensively studied, but the details how indolicidin interacts with membranes are not fully understood yet. We report here an in situ atomic force microscopic study describing the effect of indolicidin on an artificial supported planar bilayer membrane of dipalmitoyl phosphatidylcholine (DPPC and on purple membrane of Halobacterium salinarum. Concentration dependent interaction of the peptide and membranes was found in case of DPPC resulting the destruction of the membrane. Purple membrane was much more resistant against indolicidin, probably due to its high protein content. Indolicidin preferred the border of membrane disks, where the lipids are more accessible. These data suggest that the atomic force microscope is a powerful tool in the study of indolicidin-membrane interaction.

  2. Polymer amide in the Allende and Murchison meteorites

    Science.gov (United States)

    McGeoch, Julie E. M.; McGeoch, Malcolm W.

    2015-11-01

    It has been proposed that exothermic gas phase polymerization of amino acids can occur in the conditions of a warm dense molecular cloud to form hydrophobic polymer amide (HPA) (McGeoch and McGeoch 2014). In a search for evidence of this presolar chemistry Allende and Murchison meteorites and a volcano control were diamond burr-etched and Folch extracted for potential HPA yielding 85 unique peaks in the meteorite samples via matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI TOF/MS). The amino acids after acid hydrolysis in Allende were below the level of detection but many of the Allende peaks via the more sensitive MALDI/TOF analysis could be fitted to a polymer combination of glycine, alanine, and alpha-hydroxyglycine with high statistical significance. A similar significant fit using these three amino acids could not be applied to the Murchison data indicating more complex polymer chemistry.

  3. Associative polymers and physical gels derived from natural biopolymers; Polymeres associes et gels physiques derives de biopolymeres naturels

    Energy Technology Data Exchange (ETDEWEB)

    Muller, G.; Huguet, J.; Merle, L.; Grisel, M.; Picton, L.; Bataille, I.; Charpentier, D.; Glinel, K. [CNRS, Polymeres, Biopolymeres et Membranes, Universite de Rouen, 76 - Mont-Saint-Aignan (France)

    1997-04-01

    Polymers are largely used in oil-field operations where the control of rheology of aqueous phases ids of primary importance. Polymers systems showing high viscosity present many advantages as candidates for drilling muds. Associating polymers, i.e. polymers the hydrophilic main chains of which have been properly modified by introducing hydrophobic groups and weak physical ges are good examples of such systems. The different systems chosen to be studied are derived from natural biopolymers. They are: Alkyl derivatives issued from neutral (HEC) and ionic (CMC) cellulosic ether derivatives; alkyl and fluoro alkyl derivatives from neutral (Pull) and ionic (CMP) bacterial polysaccharide pullulane; weak physical gels resulting from complex formation between borate ions and the neutral fungal polysaccharide schizophyllan. The different results are given in tables and figures. (N.C.)

  4. Conformational analysis of amide extractants by NMR in organic phase

    International Nuclear Information System (INIS)

    This study deals with nuclear fuel reprocessing. We have essentially used NMR spectroscopy. We want to understand which kind of conformational parameters control selectivity and efficiency of amide extractant. The symmetric monoamides used are DOBA (C3H7 CON (CH2 CH(C2H5) C4H9)2), DOiBA ((CH3)2 CCHON (CH2CH(C2H5)C4H9)2) and DOTA ((CH3)3 CCH2CON(CH2CH(C2H5)C4H9)2). Each gives two quasi equivalent conformers (cis and trans) in organic phases. The selected malonamide DMDBTDMA ((C4H9 (CH3)NCO)2 CHC14H29) has four conformers because of its twice disymmetric amide functions. Weak interactions between monoamides which yield to dimer formation. The malonamide also gives dimers but forms aggregates too. Nitric acid extraction is due to the competitive formation of six species L, L2, L2(HNO3), L(HNO3), L(HNO3)2, L(HNO3)3 (L: monoamide). Complexation between lanthanides (III) and monoamides yields to the stoichiometries L3Ln(NO3)3 and L2Ln(NO3)3. Their ratio depend of steric hindrance on the carbonyl and the metal ionic radius. The same thing is observed of Pu4+ and Th4+ extraction in non acidic media. L2An(NO3)4 is the main stoichiometric except for the Th4+ - DOBA system where the species (DOBA)3 Th(NO3)4 appear. Exchange rates between the ligand and the complex are pointed out. The monoamide conformations obtained with lanthanide and plutonium nitrate can explain the difference in extracting power of this molecule between An4+ and Ln3+. (author). 162 refs., 87 figs., 44 tabs., 7 annexes

  5. Chemical derivatization for electrospray ionization mass spectrometry. 1. Alkyl halides, alcohols, phenols, thiols, and amines

    Energy Technology Data Exchange (ETDEWEB)

    Quirke, J.M.E.; Adams, C.L.; Van Berkel, G.J. (Oak Ridge National Lab., TN (United States))

    1994-04-15

    Derivatization strategies and specific derivatization reactions for conversion of simple alkyl halides, alcohols, phenols, thiols, and amines to ionic or solution-ionizable derivatives, that is [open quotes]electrospray active[close quotes] (ES-active) forms of the analyte, are presented. Use of these reactions allows detection of analytes among those listed that are not normally amenable to analysis by electrospray ionization mass spectrometry (ES-MS). In addition, these reactions provide for analysis specificity and flexibility through functional group specific derivatization and through the formation of derivatives that can be detected in positive ion or in negative ion mode. For a few of the functional groups, amphoteric derivatives are formed that can be analyzed in either positive or negative ion modes. General synthetic strategies for transformation of members of these five compound classes to ES-active species are presented along with illustrative examples of suitable derivatives. Selected derivatives were prepared using model compounds and the ES mass spectra obtained for these derivatives are discussed. The analytical utility of derivatization for ES-MS analysis is illustrated in three experiments: (1) specific detection of the major secondary alcohol in oil of peppermint, (2) selective detection of phenols within a synthetic mixture of phenols, and (3) identification of the medicinal amines within a commercially available cold medication as primary, secondary or tertiary. 65 refs., 3 figs., 3 tabs.

  6. Synthesis and QSAR Study of Some HDL Cholesterol Increasing Quinazolinone Derivatives

    Directory of Open Access Journals (Sweden)

    M. B. Deshmukh

    2004-01-01

    Full Text Available We describe here an easy and efficient method to obtain S-alkylated derivatives of thio-quinazolinone using different alkylating agents via a solvent-free microwave-assisted method. The alkylated thio quinazolinones were further sequentially condensed with hydrazine hydrate and different aromatic aldehydes to get the hydrazones, which were studied for QSAR. The synthesized compounds were subjected to a prediction of biological activities. A software application (PASS was used for this purpose. The relationship between structure and different biological activities was studied and the different derivatives were recommended for the screening of some specific activities like anti-tuberculosic, anti-mycobacterial and HDL cholesterol increasing activities.

  7. 40 CFR 721.10143 - Amines, bis (C11-14-branched and linear alkyl).

    Science.gov (United States)

    2010-07-01

    ... linear alkyl). 721.10143 Section 721.10143 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10143 Amines, bis (C11-14-branched and linear alkyl). (a) Chemical..., bis (C11-14-branched and linear alkyl) (PMN P-06-733; CAS No. 900169-60-0) is subject to...

  8. Tetra-n-butylammonium Hydroxide: an Efficient Catalyst for N-Alkylation of Pyrimidines and Purines

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    An efficient procedure for N-alkylation of pyrimidines and purines in the presence of tetra-n-butylammonium hydroxide(TBAH) is described. The method is very practical and the alkylation can occur at room temperature and the yields of the N-alkyl pyrimidines and purines were found to be excellent.

  9. 40 CFR 721.5380 - Mixed alkyl phenolic novolak resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Mixed alkyl phenolic novolak resin... Specific Chemical Substances § 721.5380 Mixed alkyl phenolic novolak resin (generic). (a) Chemical... as mixed alkyl phenolic novolak resin (PMN P-98-718) is subject to reporting under this section...

  10. A simple synthesis of kaurenoic esters and other derivatives and evaluation of their antifungal activity

    International Nuclear Information System (INIS)

    Representative esters derived from kaurenoic acid were prepared in order to evaluate their antifungal properties. Alkyl and substituted benzyl esters were obtained in good yield under mild conditions by esterification of kaurenoic acid with the corresponding alkyl halide in KOH-acetone. All synthesized compounds were tested for antifungal properties against pathogenic yeasts, hialohyphomycetes and dermatophytes. Kaurenoic acid and derivatives containing a free carboxyl group were moderately active against dermatophytes. (author)

  11. On the Boiling Points of the Alkyl Halides.

    Science.gov (United States)

    Correia, John

    1988-01-01

    Discusses the variety of explanations in organic chemistry textbooks of a physical property of organic compounds. Focuses on those concepts explaining attractive forces between molecules. Concludes that induction interactions play a major role in alkyl halides and other polar organic molecules and should be given wider exposure in chemistry texts.…

  12. Alkyl Radicals as Hydrogen Bond Acceptors: Computational Evidence

    DEFF Research Database (Denmark)

    Hammerum, Steen

    2009-01-01

    , and gives rise to pronounced shifts of IR stretching frequencies and to increased absorption intensities. The hydrogen bond acceptor properties of alkyl radicals equal those of many conventional acceptors, e.g., the bond length changes and IR red-shifts suggest that tert-butyl radicals are slightly better...

  13. Students' Understanding of Alkyl Halide Reactions in Undergraduate Organic Chemistry

    Science.gov (United States)

    Cruz-Ramirez de Arellano, Daniel

    2013-01-01

    Organic chemistry is an essential subject for many undergraduate students completing degrees in science, engineering, and pre-professional programs. However, students often struggle with the concepts and skills required to successfully solve organic chemistry exercises. Since alkyl halides are traditionally the first functional group that is…

  14. Ruthenium-Catalyzed Alkylation of Oxindole with Alcohols

    DEFF Research Database (Denmark)

    Jensen, Thomas; Madsen, Robert

    2009-01-01

    An atom-economical and solvent-free catalytic procedure for the mono-3-alkylation of oxindole with alcohols is described. The reaction is mediated by the in situ generated catalyst from RuCl3 center dot xH(2)O and PPh3 in the presence of sodium hydroxide, The reactions proceed in good to excellent...

  15. Ionic liquid containing hydroxamate and N-alkyl sulfamate ions

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan

    2016-03-15

    Embodiments of the invention are related to ionic liquids and more specifically to ionic liquids used in electrochemical metal-air cells in which the ionic liquid includes a cation and an anion selected from hydroxamate and/or N-alkyl sulfamate anions.

  16. Effect of alkyl substitutions on self-assembly

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The self-assemblies of 4-hexadecyloxybenzoic acid and 3,4,5-trihexadecyloxybenzoic acid have been studied by using scanning tunneling microscopy (STM). The well-ordered assemblies with different arrangement have been investigated. The structural change is attributed to the different number of substituted alkyl chains on periphery.

  17. Ground-State Distortion in N-Acyl-tert-butyl-carbamates (Boc) and N-Acyl-tosylamides (Ts): Twisted Amides of Relevance to Amide N-C Cross-Coupling.

    Science.gov (United States)

    Szostak, Roman; Shi, Shicheng; Meng, Guangrong; Lalancette, Roger; Szostak, Michal

    2016-09-01

    Amide N-C(O) bonds are generally unreactive in cross-coupling reactions employing low-valent transition metals due to nN → π*C═O resonance. Herein we demonstrate that N-acyl-tert-butyl-carbamates (Boc) and N-acyl-tosylamides (Ts), two classes of acyclic amides that have recently enabled the development of elusive amide bond N-C cross-coupling reactions with organometallic reagents, are intrinsically twisted around the N-C(O) axis. The data have important implications for the design of new amide cross-coupling reactions with the N-C(O) amide bond cleavage as a key step. PMID:27480938

  18. Overexpressed human metallothionein IIA gene protects Chinese hamster ovary cells from killing by alkylating agents

    Energy Technology Data Exchange (ETDEWEB)

    Kaina, B.; Lohrer, H.; Karin, M.; Herrlich, P. (Kernforschungszentrum Karlsruhe, Karlsruhe (Germany, F.R.))

    1990-04-01

    Experiments were designed to detect survival advantages that cells gain by overexpressing metallothionein (MT). Chinese hamster ovary K1-2 cells and an x-ray-sensitive derivative were transfected with a bovine papillomavirus (BPV)-linked construct carrying the human metallothionein IIA (hMT-IIA) gene. Transfectants survived 40-fold higher levels of cadmium chloride, harbored at least 30 copies of hMT-IIA, and contained 25- to 166-fold more MT than the parent cells. Even under conditions of reduced glutathione synthesis, the transfectants were not more resistant to the lethal effects of ionizing radiation and bleomycin than the parent cells. Thus free radicals generated by these agents cannot be scavenged efficiently by MT in vivo. The hMT-IIA transfectants, however, but not control transfectants harboring a BPV-MT promoter-neo construct, tolerated significantly higher doses of the alkylating agents N-methyl-N-nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine. Resistance and MT overexpression occurred irrespective of selection and cultivation in cadmium and zinc. There was no increase in resistance to methyl methanesulfonate and N-hydroxyethyl-N-chloroethylnitrosourea. MT did not affect the degree of overall DNA methylation after N-methyl-N-nitrosourea treatment nor the level of O6-methylguanine-DNA methyltransferase. The results suggest that MT participates as a cofactor or regulatory element in repair or tolerance of toxic alkylation lesions.

  19. Cysteine amide adduct formation from carboxylic acid drugs via UGT-mediated bioactivation in human liver microsomes.

    Science.gov (United States)

    Harada, H; Toyoda, Y; Endo, T; Kobayashi, M

    2015-10-01

    Although chemical trapping has been widely used to evaluate cytochrome P450-mediated drug bioactivation, thus far, only a few in vitro-trapping studies have been performed on UDP-glucuronosyltransferase (UGT)-mediated drug bioactivation. In this study, we used cysteine (Cys) as trapping agent to gain new insights into the UGT-mediated bioactivation involving acyl glucuronides of carboxylic acid drugs. Diclofenac, ketoprofen and ibuprofen were incubated in human liver microsomes with UDPGA and Cys, followed by analysis using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS). The N-acyl-Cys amide adduct of diclofenac was characterized by mass analysis and was detectable even in photodiode array analysis. Our data indicated that the formation of such adducts reflects the reactivity of the corresponding acyl glucuronides. In addition, it was suggested that the adduct formation requires an N-terminal Cys moiety with both a free amine and a free thiol group, from the results using various cysteine derivatives. We propose that the S-acyl-Cys thioester adduct can form via transacylation of an acyl glucuronide and can then form to an N-acyl-Cys amide adduct through intramolecular S- to N-acyl rearrangement. This series of the reactions has important implications as a possible bioactivation mechanism for covalent binding of carboxylic acid drugs to macromolecules. PMID:26601426

  20. Preparation and surface active properties of oxypropylated diol monoesters of fatty acids with an amide oxime terminal group

    Directory of Open Access Journals (Sweden)

    Eissa, A. M.F.

    1994-10-01

    Full Text Available Locally produced non-edible oil, namely, rice bran oil (R.B.O. was utilized as starting materials for preparing new nonionic surfactant. Oxypropylated diol monoesters of linoleic and rice bran oil fatty acids were prepared. Also amide oxime derivatives were obtained. Surface active properties of these compounds were measured. Under neutral condition amide eximes served as nonionic surfactants and their properties were similar to other oxypropylated monoesters.

    Se ha utilizado un aceite no comestible de producción local, denominado, aceite de salvado de arroz (R.B.O. como materia prima para la preparación de nuevos tensioactivos no iónicos. Se prepararon diol monoésteres oxipropilados de ácido linoleico y ácidos grasos de aceite de salvado de arroz. También se obtuvieron los derivados de amido oxima. Se midieron las propiedades de tensión superficial de estos compuestos. Bajo condiciones neutras las amido eximas sirvieron como tensioactivos no iónicos y sus propiedades fueron similares a los de otros monoésteres oxipropilados.

  1. Synthesis of novel naphthoquinone aliphatic amides and esters and their anticancer evaluation.

    Science.gov (United States)

    Kongkathip, Boonsong; Akkarasamiyo, Sunisa; Hasitapan, Komkrit; Sittikul, Pichamon; Boonyalai, Nonlawat; Kongkathip, Ngampong

    2013-02-01

    Fourteen new naphthoquinone aliphatic amides and seventeen naphthoquinone aliphatic esters were synthesized in nine to ten steps from 1-hydroxy-2-naphthoic acid with 9-25% overall yield for the amides, and 16-21% overall yield for the esters. The key step of the amide synthesis is a coupling reaction between amine and various aliphatic acids using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling agent while for the ester synthesis, DCC/DMAP or CDI was used as the coupling reagent between aliphatic acids and naphthoquinone alcohol. Both naphthoquinone amides and esters were evaluated for their anticancer activity against KB cells. It was found that naphthoquinone aliphatic amides showed stronger anticancer activity than those of the esters when the chains are longer than 7-carbon atoms. The optimum chain of amides is expected to be 16-carbon atoms. In addition, naphthoquinone aliphatic esters with α-methyl on the ester moiety possessed much stronger anticancer activity than the straight chains. Decatenation assay revealed that naphthoquinone amide with 16-carbon atoms chain at 15 μM and 20 μM can completely inhibit hTopoIIα activity while at 10 μM the enzyme activity was moderately inhibited. Molecular docking result also showed the same trend as the cytotoxicity and decatenation assay. PMID:23313636

  2. Recent developments in the electronic spectroscopy of amides and alpha-helical polypeptides.

    Science.gov (United States)

    Woody, Robert W; Koslowski, Axel

    2002-12-10

    Recent experimental and theoretical advances in understanding the electronic excited states of simple amides are reviewed. Polarized reflection spectroscopy of single crystals of N-acetylglycine shows that the direction of the first pipi* (NV(1)) transition dipole moment of a secondary amide differs by approximately 15 degrees from that of a primary amide. Ab initio calculations on simple amides support this conclusion. Ab initio studies of di- and tri-amides demonstrate that several inter-amide charge-transfer (CT) transitions occur in the 150-175-nm region, between the NV(1) and NV(2) transitions. When the correct dipole transition moment direction for peptides is used in calculations of the circular dichroism of the alpha-helix, the results are much improved over those from earlier calculations that used the direction for primary amides. Studies that consider the mixing of the NV(1) transition with CT transitions are reviewed. These indicate that such mixing is likely to have a significant effect on the absorption and CD spectra of the alpha-helix and other types of peptide conformation. Nevertheless, the independent systems model gives a reasonable first approximation to the absorption and CD spectra of the alpha-helix. PMID:12488025

  3. Generation of a structurally diverse library through alkylation and ring closure reactions using 3-dimethylamino-1-(thiophen-2-yl)propan-1-one hydrochloride.

    Science.gov (United States)

    Roman, Gheorghe

    2013-01-01

    3-Dimethylamino-1-(thiophen-2-yl)propan-1-one hydrochloride (2), a ketonic Mannich base derived from 2-acetylthiophene, was used as a starting material in different types of alkylation and ring closure reactions with a view to generate a structurally diverse library of compounds. Compound 2 reacts with S-alkylated dithiocarbamic acid salts and aryl mercaptans to produce dithiocarbamates and thioethers, respectively. The dimethylamino moiety in compound 2 was exchanged with various aliphatic secondary and aromatic primary and secondary amines, whereas monocyclic NH-azoles such as pyrazole, imidazole, 1,2,4-triazole, and tetrazole were N-alkylated by compound 2. Ketones, pyrrole and indoles have been the substrates subjected to C-alkylation reactions by compound 2. Ring closure reactions of compound 2 with a suitable bifunctional nucleophile yielded pyrazolines, pyridines, 2,3-dihydro-1,5-1H-benzodiazepines, 2,3-dihydro-1,5-1H-benzothiazepine, pyrimido[1,2-a]benzimidazole and 4-hydroxypiperidine derivatives. PMID:23841334

  4. Synthesis and Biological evaluation of some of N-alkylidine/ Arylidene-5-Alkyl/Aryl - 1, 3, 4-Thiadiazol- 2 -Amines

    Directory of Open Access Journals (Sweden)

    Agarwal Alka

    2013-03-01

    Full Text Available A series N-Alkylidine/Arylidene-5- Alkyl/Aryl-1, 3, 4- Thiadiazol-2-Amines have been synthesized via multistep reaction sequence. The 5-alkyl/aryl-1, 3, 4-thiadiazol-2- amine derivatives were prepared by the reaction of different aliphatic/ aromatic carboxylic acids with thiosemicarbazide in presence of catalytic amount of concentrated sulfuric acid. These derivatives were treated with different aldehydes and ketones to afford the titled compounds. Structures of synthesized compounds were assigned on the basis analytical and spectral data. All the synthesized compounds were subjected to preliminary in-vitro antibacterial activity against Gram-positive bacterial strains Bacillus Subtillis and Gram-negative bacterial strains Klebsiella Pneumoniae, Escheria coli and Pseudomonas aeruginasa. The antifungal activity of the synthesized derivatives was evaluated against Candida albicans and Aspergillus fumigates. The synthesized compounds were found to possess comparable antimicrobial activity to the standard drug.

  5. New di:nucleotide analogues - with phosphoro:di:thioate or phosphoro:thio:amidate linkages

    DEFF Research Database (Denmark)

    1997-01-01

    -bonded (sic) to the P atom; R5 = opt. heteroatom-substd. alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, alkenyl, cycloalkenyl, aralkenyl, alkynyl, aralkynyl or cycloalkynyl; R6 and R7 = opt. heteroatom-substd. alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, alkenyl, cycloalkenyl, aralkenyl, alkynyl...

  6. Acceleration of Amide Bond Rotation by Encapsulation in the Hydrophobic Interior of a Water-Soluble Supramolecular Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Pluth, Michael D.; Bergman, Robert G.; Raymond, Kenneth N.

    2008-04-08

    The hydrophobic interior cavity of a self-assembled supramolecular assembly exploits the hydrophobic effect for the encapsulation of tertiary amides. Variable temperature 1H NMR experiments reveal that the free energy barrier for rotation around the C-N amide bond is lowered by up to 3.6 kcal/mol upon encapsulation. The hydrophobic cavity of the assembly is able to stabilize the less polar transition state of the amide rotation process. Carbon-13 labeling studies showed that the {sup 13}C NMR carbonyl resonance increases with temperature for the encapsulated amides which suggests that the assembly is able to favor a twisted for of the amide.

  7. Synthesis of phenanthrene derivatives through the net [5+5]-cycloaddition of prenylated carbene complexes with 2-alkynylbenzaldehyde derivatives

    OpenAIRE

    Menon, Suneetha; Sinha-Mahapatra, Dilip; Herndon, James W.

    2007-01-01

    The reaction of prenylated carbene complexes and 2-alkynylbenzoyl derivatives has been investigated. Phenanthrene derivatives are produced if iodine is added prior to product isolation. Under these conditions alkyl migration reactions occur to form the observed products. The product yields are considerably higher using bis(prenylated) species owing to an increase in the effective molarity of dienophilic entities.

  8. Chelate effects in sulfate binding by amide/urea-based ligands.

    Science.gov (United States)

    Jia, Chuandong; Wang, Qi-Qiang; Begum, Rowshan Ara; Day, Victor W; Bowman-James, Kristin

    2015-07-01

    The influence of chelate and mini-chelate effects on sulfate binding was explored for six amide-, amide/amine-, urea-, and urea/amine-based ligands. Two of the urea-based hosts were selective for SO4(2-) in water-mixed DMSO-d6 systems. Results indicated that the mini-chelate effect provided by a single urea group with two NH binding sites appears to provide enhanced binding over two amide groups. Furthermore, additional urea binding sites incorporated into the host framework appeared to overcome to some extent competing hydration effects with increasing water content.

  9. Amide proton transfer of carnosine in aqueous solution studied in vitro by WEX and CEST experiments.

    OpenAIRE

    Bodet, O.; Goerke, S; Behl, N.; Roeloffs, V.; Zaiss, M.; Bachert, P.

    2015-01-01

    Amide protons of peptide bonds induce an important chemical exchange saturation transfer (CEST) contrast in vivo. As a simple in vitro model for a peptide amide proton CEST effect, we suggest herein the dipeptide carnosine. We show that the metabolite carnosine creates a CEST effect and we study the properties of the exchange of the amide proton (-NH) of the carnosine peptide bond (NHCPB) in model solutions for a pH range from 6 to 8.3 and a temperature range from T = 5 degrees C to 43 degree...

  10. Stereoselective Arene-Forming Aldol Condensation: Synthesis of Axially Chiral Aromatic Amides.

    Science.gov (United States)

    Fäseke, Vincent C; Sparr, Christof

    2016-06-13

    The increasing awareness of the importance of amide atropisomers prompts the development of novel strategies for their selective preparation. Described herein is a method for the enantioselective synthesis of atropisomeric aromatic amides by an amine-catalyzed arene-forming aldol condensation. The high reactivity of the glyoxylic amide substrates enables a remarkably efficient construction of a new aromatic ring, which proceeds within minutes at ambient temperature to afford products with excellent stereoselectivity. The high rotational barriers of the reduced products highlight the utility of this stable, spatially organized chiral scaffold. PMID:27166995

  11. Bifunctional Brønsted Base Catalyzes Direct Asymmetric Aldol Reaction of α-Keto Amides.

    Science.gov (United States)

    Echave, Haizea; López, Rosa; Palomo, Claudio

    2016-03-01

    The first enantioselective direct cross-aldol reaction of α-keto amides with aldehydes, mediated by a bifunctional ureidopeptide-based Brønsted base catalyst, is described. The appropriate combination of a tertiary amine base and an aminal, and urea hydrogen-bond donor groups in the catalyst structure promoted the exclusive generation of the α-keto amide enolate which reacted with either non-enolizable or enolizable aldehydes to produce highly enantioenriched polyoxygenated aldol adducts without side-products resulting from dehydration, α-keto amide self-condensation, aldehyde enolization, and isotetronic acid formation. PMID:26835655

  12. Unusual metal coordination chemistry from an amino-amide derivative of 4-nitrophenol, a surprising ligand

    DEFF Research Database (Denmark)

    McGinley, John; McKee, Vickie; Toftlund, Hans;

    2009-01-01

    The simple ligand N-(2-aminoethyl)-2-hydroxy-5-nitrobenzamide () exhibits several coordination modes depending on the reaction conditions, acting as a zwitterion on its own or being ionic in the presence of acid and depending on the concentration of metal present in a reaction, it can coordinate...... to the metal in either a 1:1 or a 1:2 metal:ligand mode. Furthermore, the role of solvent plays an important role in these complexation reactions with both four and six coordinate copper complexes being obtained using water as solvent but only six coordinate copper complexes obtained using acetonitrile...

  13. Carbon, hydrogen, and nitrogen isotope fractionation associated with oxidative transformation of substituted aromatic N-alkyl amines.

    Science.gov (United States)

    Skarpeli-Liati, Marita; Pati, Sarah G; Bolotin, Jakov; Eustis, Soren N; Hofstetter, Thomas B

    2012-07-01

    We investigated the mechanisms and isotope effects associated with the N-dealkylation and N-atom oxidation of substituted N-methyl- and N,N-dimethylanilines to identify isotope fractionation trends for the assessment of oxidations of aromatic N-alkyl moieties by compound-specific isotope analysis (CSIA). In laboratory batch model systems, we determined the C, H, and N isotope enrichment factors for the oxidation by MnO(2) and horseradish peroxidase (HRP), derived apparent (13)C-, (2)H-, and (15)N-kinetic isotope effects (AKIEs), and characterized reaction products. The N-atom oxidation pathway leading to radical coupling products typically exhibited inverse (15)N-AKIEs (up to 0.991) and only minor (13)C- and (2)H-AKIEs. Oxidative N-dealkylation, in contrast, was subject to large normal (13)C- and (2)H-AKIEs (up to 1.019 and 3.1, respectively) and small (15)N-AKIEs. Subtle changes of the compound's electronic properties due to different types of aromatic and/or N-alkyl substituents resulted in changes of reaction mechanisms, rate-limiting step(s), and thus isotope fractionation trends. The complex sequence of electron and proton transfers during the oxidative transformation of substituted aromatic N-alkyl amines suggests highly compound- and mechanism-dependent isotope effects precluding extrapolations to other organic micropollutants reacting along the same degradation pathways. PMID:22681573

  14. Selective Gas-Phase Oxidation and Localization of Alkylated Cysteine Residues in Polypeptide Ions via Ion/Ion Chemistry.

    Science.gov (United States)

    Pilo, Alice L; Zhao, Feifei; McLuckey, Scott A

    2016-09-01

    The thiol group in cysteine residues is susceptible to several post-translational modifications (PTMs), including prenylation, nitrosylation, palmitoylation, and the formation of disulfide bonds. Additionally, cysteine residues involved in disulfide bonds are commonly reduced and alkylated prior to mass spectrometric analysis. Several of these cysteine modifications, specifically S-alkyl modifications, are susceptible to gas-phase oxidation via selective ion/ion reactions with periodate anions. Multiply protonated peptides containing modified cysteine residues undergo complex formation upon ion/ion reaction with periodate anions. Activation of the ion/ion complexes results in oxygen transfer from the reagent to the modified sulfur residue to create a sulfoxide functionality. Further activation of the sulfoxide derivative yields abundant losses of the modification with the oxidized sulfur as a sulfenic acid (namely, XSOH) to generate a dehydroalanine residue. This loss immediately indicates the presence of an S-alkyl cysteine residue, and the mass of the loss can be used to easily deduce the type of modification. An additional step of activation can be used to localize the modification to a specific residue within the peptide. Selective cleavage to create c- and z-ions N-terminal to the dehydroalanine residue is often noted. As these types of ions are not typically observed upon collision-induced dissociation (CID), they can be used to immediately indicate where in the peptide the PTM was originally located.

  15. Selective Gas-Phase Oxidation and Localization of Alkylated Cysteine Residues in Polypeptide Ions via Ion/Ion Chemistry.

    Science.gov (United States)

    Pilo, Alice L; Zhao, Feifei; McLuckey, Scott A

    2016-09-01

    The thiol group in cysteine residues is susceptible to several post-translational modifications (PTMs), including prenylation, nitrosylation, palmitoylation, and the formation of disulfide bonds. Additionally, cysteine residues involved in disulfide bonds are commonly reduced and alkylated prior to mass spectrometric analysis. Several of these cysteine modifications, specifically S-alkyl modifications, are susceptible to gas-phase oxidation via selective ion/ion reactions with periodate anions. Multiply protonated peptides containing modified cysteine residues undergo complex formation upon ion/ion reaction with periodate anions. Activation of the ion/ion complexes results in oxygen transfer from the reagent to the modified sulfur residue to create a sulfoxide functionality. Further activation of the sulfoxide derivative yields abundant losses of the modification with the oxidized sulfur as a sulfenic acid (namely, XSOH) to generate a dehydroalanine residue. This loss immediately indicates the presence of an S-alkyl cysteine residue, and the mass of the loss can be used to easily deduce the type of modification. An additional step of activation can be used to localize the modification to a specific residue within the peptide. Selective cleavage to create c- and z-ions N-terminal to the dehydroalanine residue is often noted. As these types of ions are not typically observed upon collision-induced dissociation (CID), they can be used to immediately indicate where in the peptide the PTM was originally located. PMID:27476698

  16. Direct Catalytic Asymmetric Mannich-Type Reaction of α- and β-Fluorinated Amides.

    Science.gov (United States)

    Brewitz, Lennart; Arteaga, Fernando Arteaga; Yin, Liang; Alagiri, Kaliyamoorthy; Kumagai, Naoya; Shibasaki, Masakatsu

    2015-12-23

    The last two decades have witnessed the emergence of direct enolization protocols providing atom-economical and operationally simple methods to use enolates for stereoselective C-C bond-forming reactions, eliminating the inherent drawback of the preformation of enolates using stoichiometric amounts of reagents. In its infancy, direct enolization relied heavily on the intrinsic acidity of the latent enolates, and the reaction scope was limited to readily enolizable ketones and aldehydes. Recent advances in this field enabled the exploitation of carboxylic acid derivatives for direct enolization, offering expeditious access to synthetically versatile chiral building blocks. Despite the growing demand for enantioenriched fluorine-containing small molecules, α- and β-fluorinated carbonyl compounds have been neglected in direct enolization chemistry because of the competing and dominating defluorination pathway. Herein we present a comprehensive study on direct and highly stereoselective Mannich-type reactions of α- and β-fluorine-functionalized 7-azaindoline amides that rely on a soft Lewis acid/hard Brønsted base cooperative catalytic system to guarantee an efficient enolization while suppressing undesired defluorination. This protocol contributes to provide a series of fluorinated analogs of enantioenriched β-amino acids for medicinal chemistry. PMID:26652911

  17. Synthesis and Gene Silencing Properties of siRNAs Containing Terminal Amide Linkages

    Directory of Open Access Journals (Sweden)

    Maria Gaglione

    2014-01-01

    Full Text Available The active components of the RNAi are 21 nucleotides long dsRNAs containing a 2 nucleotide overhang at the 3′ end, carrying 5′-phosphate and 3′-hydroxyl groups (siRNAs. Structural analysis revealed that the siRNA is functionally bound at both ends to RISC. Terminal modifications are considered with interest as the introduction of chemical moieties interferes with the 3′ overhang recognition by the PAZ domain and the 5′-phosphate recognition by the MID and PIWI domains of RISC. Herein, we report the synthesis of modified siRNAs containing terminal amide linkages by introducing hydroxyethylglycine PNA (hegPNA moieties at 5′, and at 3′ positions and on both terminals. Results of gene silencing studies highlight that some of these modifications are compatible with the RNAi machinery and markedly increase the resistance to serum-derived nucleases even after 24 h of incubation. Molecular docking simulations were attained to give at atomistic level a clearer picture of the effect of the most performing modifications on the interactions with the human Argonaute 2 PAZ, MID, and PIWI domains. This study adds another piece to the puzzle of the heterogeneous chemical modifications that can be attained to enhance the silencing efficiency of siRNAs.

  18. Effect of the Unsaturation of the Hydrocarbon Chain of Fatty-Amides on the CO2 Corrosion of Carbon Steel Using EIS and Real-Time Corrosion Measurement

    Directory of Open Access Journals (Sweden)

    J. Porcayo-Calderon

    2015-01-01

    Full Text Available Fatty-amide derivatives were evaluated to study the effect of the double bonds into the hydrocarbon chain (C18 on the corrosion behavior of carbon steel. Electrochemical impedance spectroscopy (EIS and real-time corrosion measurements were used to evaluate the inhibition mechanism of the fatty-amides on carbon steel in CO2-saturated (3% NaCl + 10% diesel emulsion at 50°C. EIS results demonstrated that the unsaturation present into the hydrocarbon chain contributes to the efficiency of fatty-amides, because they can be adsorbed on the metal surface by a flat-adsorption process reducing the presence of active sites and blocking the corrosion process and preventing the diffusion of corrosive species, such as H2O, H+, Cl−, and HCO3-. Real-time corrosion measurements also indicated that the effectiveness of the inhibitors is dependent on the unsaturation into the hydrocarbon chain, being also a good technique to determine the stability of the adsorption process of the inhibitors.

  19. Inhibitory Activities of Alkyl Syringates and Related Compounds on Aflatoxin Production.

    Science.gov (United States)

    Furukawa, Tomohiro; Iimura, Kurin; Kimura, Taichi; Yamamoto, Toshiyoshi; Sakuda, Shohei

    2016-01-01

    Inhibitors of aflatoxin production of aflatoxigenic fungi are useful for preventing aflatoxin contamination in crops. As methyl syringate weakly inhibits aflatoxin production, aflatoxin production inhibitory activities of additional alkyl syringates with alkyl chains from ethyl to octyl were examined. Inhibitory activity toward aflatoxin production of Aspergillus flavus became stronger as the length of the alkyl chains on the esters became longer. Pentyl, hexyl, heptyl, and octyl syringates showed strong activity at 0.05 mM. Heptyl and octyl parabens, and octyl gallate also inhibited aflatoxin production as strongly as octyl syringate. Alkyl parabens and alkyl gallates inhibit the complex II activity of the mitochondrial respiration chain; thus, whether alkyl syringates inhibit complex II activity was examined. Inhibitory activities of alkyl syringates toward complex II also became stronger as the length of the alkyl chains increased. The complex II inhibitory activity of octyl syringate was comparable to that of octyl paraben and octyl gallate. These results suggest that alkyl syringates, alkyl parabens, and alkyl gallates, including commonly used food additives, are useful for aflatoxin control. PMID:27338472

  20. Inhibitory Activities of Alkyl Syringates and Related Compounds on Aflatoxin Production

    Science.gov (United States)

    Furukawa, Tomohiro; Iimura, Kurin; Kimura, Taichi; Yamamoto, Toshiyoshi; Sakuda, Shohei

    2016-01-01

    Inhibitors of aflatoxin production of aflatoxigenic fungi are useful for preventing aflatoxin contamination in crops. As methyl syringate weakly inhibits aflatoxin production, aflatoxin production inhibitory activities of additional alkyl syringates with alkyl chains from ethyl to octyl were examined. Inhibitory activity toward aflatoxin production of Aspergillus flavus became stronger as the length of the alkyl chains on the esters became longer. Pentyl, hexyl, heptyl, and octyl syringates showed strong activity at 0.05 mM. Heptyl and octyl parabens, and octyl gallate also inhibited aflatoxin production as strongly as octyl syringate. Alkyl parabens and alkyl gallates inhibit the complex II activity of the mitochondrial respiration chain; thus, whether alkyl syringates inhibit complex II activity was examined. Inhibitory activities of alkyl syringates toward complex II also became stronger as the length of the alkyl chains increased. The complex II inhibitory activity of octyl syringate was comparable to that of octyl paraben and octyl gallate. These results suggest that alkyl syringates, alkyl parabens, and alkyl gallates, including commonly used food additives, are useful for aflatoxin control. PMID:27338472

  1. Inhibitory Activities of Alkyl Syringates and Related Compounds on Aflatoxin Production

    Directory of Open Access Journals (Sweden)

    Tomohiro Furukawa

    2016-06-01

    Full Text Available Inhibitors of aflatoxin production of aflatoxigenic fungi are useful for preventing aflatoxin contamination in crops. As methyl syringate weakly inhibits aflatoxin production, aflatoxin production inhibitory activities of additional alkyl syringates with alkyl chains from ethyl to octyl were examined. Inhibitory activity toward aflatoxin production of Aspergillus flavus became stronger as the length of the alkyl chains on the esters became longer. Pentyl, hexyl, heptyl, and octyl syringates showed strong activity at 0.05 mM. Heptyl and octyl parabens, and octyl gallate also inhibited aflatoxin production as strongly as octyl syringate. Alkyl parabens and alkyl gallates inhibit the complex II activity of the mitochondrial respiration chain; thus, whether alkyl syringates inhibit complex II activity was examined. Inhibitory activities of alkyl syringates toward complex II also became stronger as the length of the alkyl chains increased. The complex II inhibitory activity of octyl syringate was comparable to that of octyl paraben and octyl gallate. These results suggest that alkyl syringates, alkyl parabens, and alkyl gallates, including commonly used food additives, are useful for aflatoxin control.

  2. Synthesis and Structure of a New Lithium Amide Ligand Precursor: A Tridentate Nitrogen-Based Donor Set of the Formula N(SiMe(2)CH(2)NMe(2))(2). Synthesis and Structure of the Group 4 Amides MCl(3)[N(SiMe(2)CH(2)NMe(2))(2)] (M = Ti, Zr, Hf).

    Science.gov (United States)

    Fryzuk, Michael D.; Hoffman, Vera; Kickham, James E.; Rettig, Steven J.; Gambarotta, Sandro

    1997-07-30

    The new lithium amide LiN(SiMe(2)CH(2)NMe(2))(2) was prepared by reaction of NH(3) with the corresponding silylamine Me(2)NSiMe(2)CH(2)NMe(2) followed by addition of butyllithium. This lithium derivative exists as a dimer in the solid state wherein the two lithium ions are bridged by the two amido units with the amine arms of each unit bonded to opposite lithium centers in an overall pseudo D(2) structure; however, in solution, a fluxional process serves to interconvert the enantiomeric forms of the dimer unit. The coordination chemistry of the lithium amide dimer has been investigated; reaction with a series of group 4 starting halides, MCl(4), leads to the corresponding complexes MCl(3)[N(SiMe(2)CH(2)NMe(2))(2)], where M = Ti, Zr, and Hf. The structures of these starting trihalides in solution and in the solid state are presented. PMID:11670025

  3. Data of 1H/13C NMR spectra and degree of substitution for chitosan alkyl urea

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2016-06-01

    Full Text Available The data shown in this article are related to the subject of an article in Carbohydrate Polymers, entitled “Synthesis and characterization of chitosan alkyl urea” [1]. 1H NMR and 13C NMR spectra of chitosan n-octyl urea, chitosan n-dodecyl urea and chitosan cyclohexyl urea are displayed. The chemical shifts of proton and carbon of glucose skeleton in these chitosan derivatives are designated in detail. Besides, 1H NMR spectra of chitosan cyclopropyl urea, chitosan tert-butyl urea, chitosan phenyl urea and chitosan N,N-diethyl urea and the estimation of the degree of substitution are also presented. The corresponding explanations can be found in the above-mentioned article.

  4. Synthesis, Crystal Structure and Biological Activites of Rotenone O-Alkyl Oximes

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-dong; WANG Chao; HU Ai-xi; YE Jiao; ZHANG Cui-yang

    2012-01-01

    A series of rotenone O-alkyl oxime derivatives was designed and synthesized.Their structures were confirmed by elemental analyses,Fourier transform infrared(FTIR) and 1H NMR spectral studies,and the typical crystal structure of rotenone O-ethyl oxime(3b) was determined by X-ray diffraction.The preliminary biological activities of the new compounds were evaluated.The results of bioassays indicate that the title compounds exhibit moderate insecticidal and bactericidal activities.Among the synthesized compounds,compound 3q exhibited 90.0% mortality against M.separata at 1000 μg/mL.Compounds 3b and 3g exhibited both 90.0% inhibition rate against R.solani at 500 μg/mL,respectively.

  5. Reactions of hydroxymesitylboranes with metal alkyls: an approach to new sterically hindered (metaloxy)mesitylboranes.

    Science.gov (United States)

    Anulewicz-Ostrowska, Romana; Luliński, Sergiusz; Pindelska, Edyta; Serwatowski, Janusz

    2002-05-01

    Reactions of mesitylboronic acid with alkyl derivatives of aluminum R(3)Al (R = Me, Et, Bu(i)), gallium (Me(3)Ga), and zinc (Et(2)Zn) were investigated. The treatment of mesitylboronic acid, MesB(OH)(2), with trimethylgallium afforded the discrete dimer [mu-(MesB(OH)O)GaMe(2)](2) (1), which is the simple example of a O-metalated boronic acid with no hydrogen bonding in the crystal lattice. In addition, the reaction of dimesitylborinic acid, Mes(2)BOH, with diethylzinc produced the low-valent zinc compound [(mu-Mes(2)BO)ZnEt](2) (2), which was also characterized by X-ray diffraction. PMID:11978121

  6. Synthesis, characterization and pharmacological evaluation of amide prodrugs of Flurbiprofen

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Ashutosh; Veerasamy, Ravichandran; Jain, Prateek Kumar; Dixit, Vinod Kumar; Agrawal, Ram Kishor [Dr. H. S. Gour Vishwavidyalaya, Sagar (India). Dept. of Pharmaceutical Sciences. Pharmaceutical Chemistry Research Lab.]. E-mail: dragrawal2001@yahoo.co.in

    2008-07-01

    Flurbiprofen (FB) suffers from the general side effects of NSAIDs, owing to presence of free carboxylic acid group. The study was aimed to retard the adverse effects of gastrointestinal origin. Ten prodrugs of FB were synthesized by amidation with ethyl esters of amino acids, namely, glycine, L-phenylalanine, L-tryptophan, L-valine, L-isoleucine, L-alanine, L-leucine, L-glutamic acid, L-aspartic acid and {beta} alanine. Purified synthesized prodrugs were characterized by m.p., TLC, solubility, partition coefficients, elemental analyses, UV, FTIR, NMR and MS. Synthesized prodrugs were subjected for bioavailability studies, analgesic, anti-inflammatory activities and ulcerogenic index. Marked reduction of ulcerogenic index and comparable analgesic, antiinflammatory activities were obtained in all cases as compared to FB. Among synthesized prodrugs AR-9, AR-10 and AR-2 showing excellent pharmacological response and encouraging hydrolysis rate both in (Simulated Intestinal Fluid) SIF and in 80% human plasma. Prodrugs with increased aliphatic side chain length or introduction of aromatic substituent resulted in enhanced partition coefficient but diminished dissolution and hydrolysis rate. Such prodrugs can be considered for sustained release purpose. (author)

  7. Synthesis, characterization and pharmacological evaluation of amide prodrugs of Flurbiprofen

    International Nuclear Information System (INIS)

    Flurbiprofen (FB) suffers from the general side effects of NSAIDs, owing to presence of free carboxylic acid group. The study was aimed to retard the adverse effects of gastrointestinal origin. Ten prodrugs of FB were synthesized by amidation with ethyl esters of amino acids, namely, glycine, L-phenylalanine, L-tryptophan, L-valine, L-isoleucine, L-alanine, L-leucine, L-glutamic acid, L-aspartic acid and β alanine. Purified synthesized prodrugs were characterized by m.p., TLC, solubility, partition coefficients, elemental analyses, UV, FTIR, NMR and MS. Synthesized prodrugs were subjected for bioavailability studies, analgesic, anti-inflammatory activities and ulcerogenic index. Marked reduction of ulcerogenic index and comparable analgesic, antiinflammatory activities were obtained in all cases as compared to FB. Among synthesized prodrugs AR-9, AR-10 and AR-2 showing excellent pharmacological response and encouraging hydrolysis rate both in (Simulated Intestinal Fluid) SIF and in 80% human plasma. Prodrugs with increased aliphatic side chain length or introduction of aromatic substituent resulted in enhanced partition coefficient but diminished dissolution and hydrolysis rate. Such prodrugs can be considered for sustained release purpose. (author)

  8. Substituted Amides of Pyrazine-2-carboxylic acids: Synthesis and Biological Activity

    OpenAIRE

    Katarina Kralova; Jiri Kunes; Miroslav Miletin; Martin Dolezal

    2002-01-01

    Condensation of 6-chloro-, 5-tert-butyl- or 6-chloro-5-tert-butylpyrazine-2-carboxylic acid chloride with ring substituted anilines yielded a series of amides, which were tested for their in vitro antimycobacterial, antifungal and photosynthesis-inhibiting activities. The highest antituberculotic activity (72% inhibition) against Mycobacterium tuberculosis and the highest lipophilicity (log P = 6.85) were shown by the 3,5-bistrifluoromethylphenyl amide of 5-tert-butyl-6-chloropyrazine-2-carbo...

  9. Oxygen activation and intramolecular C-H bond activation by an amidate-bridged diiron(II) complex.

    Science.gov (United States)

    Jones, Matthew B; Hardcastle, Kenneth I; Hagen, Karl S; MacBeth, Cora E

    2011-07-18

    A diiron(II) complex containing two μ-1,3-(κN:κO)-amidate linkages has been synthesized using the 2,2',2''-tris(isobutyrylamido)triphenylamine (H(3)L(iPr)) ligand. The resulting diiron complex, 1, reacts with dioxygen (or iodosylbenzene) to effect intramolecular C-H bond activation at the methine position of the ligand isopropyl group. The ligand-activated product, 2, has been isolated and characterized by a variety of methods including X-ray crystallography. Electrospray ionization mass spectroscopy of 2 prepared from(18)O(2) was used to confirm that the oxygen atom incorporated into the ligand framework is derived from molecular oxygen.

  10. Safety Assessment of Alkyl Esters as Used in Cosmetics.

    Science.gov (United States)

    Fiume, Monice M; Heldreth, Bart A; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2015-09-01

    The Cosmetic Ingredient Review Expert Panel (Panel) assessed the safety of 237 alkyl esters for use in cosmetics. The alkyl esters included in this assessment have a variety of reported functions in cosmetics, with skin-conditioning agent being the most common function. The Panel reviewed available animal and clinical data in making its determination of safety on these ingredients, and where there were data gaps, similarity in structure, properties, functions, and uses of these ingredients allowed for extrapolation of the available toxicological data to assess the safety of the entire group. The Panel concluded that these ingredients are safe in cosmetic formulations in the present practices of use and concentration when formulated to be nonirritating.

  11. Molecular simulation of alkyl monolayers on the Si(111)surface

    Institute of Scientific and Technical Information of China (English)

    YUAN; Shiling; (苑世领); CAI; Zhengting; (蔡政亭); XIAO; Li; (肖莉); XU; Guiying; (徐桂英); LIU; Yongjun; (刘永军)

    2003-01-01

    The structure of twelve-carbon monolayers on the H-terminated Si(111) surface is investigated by molecular simulation method. The best substitution percent on Si(111) surface obtained via molecular mechanics calculation is equal to 50%, and the (8×8) simulated cell can be used to depict the structure of alkyl monolayer on Si surface. After two-dimensional cell containing alkyl chains and four-layer Si(111) crystal at the substitution 50% is constructed, the densely packed and well-ordered monolayer on Si(111) surface can be shown through energy minimization in the suitable-size simulation cell. These simulation results are in good agreement with the experiments. These conclusions show that molecular simulation can provide otherwise inaccessible mesoscopic information at the molecular level, and can be considered as an adjunct to experiments.

  12. Synthesis and Antiviral Activity of Hydrogenated Ferulic Acid Derivatives

    OpenAIRE

    Can Cui; Zhi-Peng Wang; Xiu-jiang Du; Li-Zhong Wang; Shu-Jing Yu; Xing-Hai Liu; Zheng-Ming Li; Wei-Guang Zhao

    2013-01-01

    A series of hydrogenated ferulic acid amide derivatives 4 were synthesized. The molecular structures of the synthesized compounds were analyzed by H1 NMR and HRMS. The biological activity study showed that some of them displayed excellent protection activity and curative activity against TMV at 500 μg/mL.

  13. Smart synthesis of high performance thermosets based on ortho-(amide-co-imide functional benzoxazines

    Directory of Open Access Journals (Sweden)

    Hatsuo eIshida

    2015-02-01

    Full Text Available High performance thermosets via amide-imide functional benzoxazine resins as precursors have been synthesized. The structures of synthesized monomers have been confirmed by 1H NMR and FT-IR. Among these two benzoxazine monomers, the ortho-amide-imide functional benzoxazine resin shows powerful features both in the synthesis of benzoxazine monomers and the properties of the corresponding thermosets. For the cross-linked poly(amide-co-imide based on ortho-amide-imide functional benzoxazine, a smart route is adopted to develop a more thermally stable cross-linked poly(benzoxazole-co-imide. Besides, the poly(benzoxazole-co-imide can also undergo a further thermal treatment to form polybenzoxazole. Furthermore, a main-chain type ortho-functional polybenzoxazine with amide-co-imide and benzoxazine groups as repeating units has also been prepared. Both the ortho-amide-imide functional benzoxazine and main-chain type polybenzoxazine resins show the possibility to form high performance thermosets with low cost and easy processability .

  14. Neurobehavioral teratogenicity of perfluorinated alkyls in an avian model

    OpenAIRE

    Pinkas, Adi; Slotkin, Theodore A.; Brick-Turin, Yael; Van der Zee, Eddy A.; Yanai, Joseph

    2010-01-01

    Perfluorinated alkyls are widely-used agents that accumulate in ecosystems and organisms because of their slow rate of degradation. There is increasing concern that these agents may be developmental neurotoxicants and the present study was designed to develop an avian model for the neurobehavioral teratogenicity of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Fertilized chicken eggs were injected with 5 or 10 mg/kg of either compound on incubation day 0. On the day of h...

  15. Synthesis and Characterization of Responsive Poly(Alkyl Methacrylate) Topologies

    OpenAIRE

    Kilian, Lars

    2004-01-01

    Dimethacrylate monomers containing two cleavable tert-butyl ester groups were synthesized and utilized in the synthesis of star-shaped polymers. Star polymer coupling was achieved by reacting the living poly(alkyl methacrylate) using 2,5-dimethyl-2,5-hexanediol dimethacrylate (DHDMA) or dicumyl dimethacrylate (DCDMA). These starshaped polymers were cleaved under hydrolytic conditions, leading to significant reductions in molecular weights. The cleavable star-shaped polymers also underwent unc...

  16. Highly Enantioselective Formation of α-Allyl-α-Arylcyclopentanones via Pd-Catalysed Decarboxylative Asymmetric Allylic Alkylation.

    Science.gov (United States)

    Akula, Ramulu; Doran, Robert; Guiry, Patrick J

    2016-07-11

    A highly enantioselective Pd-catalysed decarboxylative asymmetric allylic alkylation of cyclopentanone derived α-aryl-β-keto esters employing the (R,R)-ANDEN-phenyl Trost ligand has been developed. The product (S)-α-allyl-α-arylcyclopentanones were obtained in excellent yields and enantioselectivities (up to >99.9 % ee). This represents one of the most highly enantioselective formations of an all-carbon quaternary stereogenic center reported to date. This reaction was demonstrated on a 4.0 mmol scale without any deterioration of enantioselectivity and was exploited as the key enantioselective transformation in an asymmetric formal synthesis of the natural product (+)-tanikolide. PMID:27191198

  17. One-pot synthesis of S-alkyl dithiocarbamates via the reaction of N-tosylhydrazones, carbon disulfide and amines.

    Science.gov (United States)

    Sha, Qiang; Wei, Yun-Yang

    2013-09-14

    A new, convenient and efficient transition metal-free synthesis of S-alkyl dithiocarbamates through one-pot reaction of N-tosylhydrazones, carbon disulfide and amines is reported. Tosylhydrazones derived from various aromatic and aliphatic ketones or aldehydes were tested and gave dithiocarbamates in good to excellent yields. The tosylhydrazones can be generated in situ without isolation, which provides a simpler one-pot method to synthesize dithiocarbamates via the reaction of carbonyl compounds, carbon disulfide and amines in the presence of 4-methylbenzenesulfonohydrazide. PMID:23863979

  18. Chemotherapy-induced pulmonary hypertension: role of alkylating agents.

    Science.gov (United States)

    Ranchoux, Benoît; Günther, Sven; Quarck, Rozenn; Chaumais, Marie-Camille; Dorfmüller, Peter; Antigny, Fabrice; Dumas, Sébastien J; Raymond, Nicolas; Lau, Edmund; Savale, Laurent; Jaïs, Xavier; Sitbon, Olivier; Simonneau, Gérald; Stenmark, Kurt; Cohen-Kaminsky, Sylvia; Humbert, Marc; Montani, David; Perros, Frédéric

    2015-02-01

    Pulmonary veno-occlusive disease (PVOD) is an uncommon form of pulmonary hypertension (PH) characterized by progressive obstruction of small pulmonary veins and a dismal prognosis. Limited case series have reported a possible association between different chemotherapeutic agents and PVOD. We evaluated the relationship between chemotherapeutic agents and PVOD. Cases of chemotherapy-induced PVOD from the French PH network and literature were reviewed. Consequences of chemotherapy exposure on the pulmonary vasculature and hemodynamics were investigated in three different animal models (mouse, rat, and rabbit). Thirty-seven cases of chemotherapy-associated PVOD were identified in the French PH network and systematic literature analysis. Exposure to alkylating agents was observed in 83.8% of cases, mostly represented by cyclophosphamide (43.2%). In three different animal models, cyclophosphamide was able to induce PH on the basis of hemodynamic, morphological, and biological parameters. In these models, histopathological assessment confirmed significant pulmonary venous involvement highly suggestive of PVOD. Together, clinical data and animal models demonstrated a plausible cause-effect relationship between alkylating agents and PVOD. Clinicians should be aware of this uncommon, but severe, pulmonary vascular complication of alkylating agents. PMID:25497573

  19. Alkylation of Benzene with Propylene Catalyzed by Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    Sun Xuewen; Zhao Suoqi

    2006-01-01

    The alkylation of benzene with propylene catalyzed by ionic liquids to obtain cumene was investigated. Propylene conversion and cumene selectivity under mild reaction conditions were improved greatly after the ionic liquid was modified with HCl. Under the conditions of 20 oC, 0.1MPa, 5 min of reaction time, and a molar ratio of benzene to propylene of 10:1, propylene conversion increased from 83.6% to 100%, and cumene selectivity increased from 90.86% to 98.47%. In addition, it was found that the reaction could be carried out in two different stages so as to obtain a better result. At the first stage, the key reaction was alkylation and a higher propylene conversion was obtained at a lower temperature;At the second stage, the key reaction was transalkylation and a higher temperature was used to improve cumene selectivity. The reaction temperature, pressure and the amount of catalyst used in this work were lower than those used in traditional alkylation processes.

  20. Wettability of pristine and alkyl-functionalized graphane

    Science.gov (United States)

    Vanzo, Davide; Bratko, Dusan; Luzar, Alenka

    2012-07-01

    Graphane is a hydrogenated form of graphene with high bandgap and planar structure insensitive to a broad range of chemical substitutions. We describe an atomistic simulation approach to predict wetting properties of this new material. We determine the contact angle to be 73°. The lower hydrophobicity compared to graphene is explained by the increased planar density of carbon atoms while we demonstrate that the presence of partial charges on carbon and hydrogen atoms plays only a minor role. We further examine the effects of graphane functionalization by alkyl groups of increasing chain lengths. The gradual increase in contact angle with chain length offers a precise control of surface wettability. A saturated contact angle of 114° is reached in butylated form. We find the saturation of contact angle with respect to the length of the functional groups to coincide with the loss of water's ability to penetrate the n-alkyl molecular brush and interact with carbon atoms of the underlying lattice. Since no experimental data have yet become available, our modeling results provide the first estimate of the wettability of graphane. The results also show how its alkyl functionalization provides the basis for a variety of chemical modifications to tune hydrophilicity while preserving the planar geometry of the substrate.

  1. Anti-cancer agents based on N-acyl-2, 3-dihydro-1H-pyrrolo[2,3-b] quinoline derivatives and a method of making

    Science.gov (United States)

    Gakh, Andrei; Krasavin, Mikhail; Karapetian, Ruben; Rufanov, Konstantin A; Konstantinov, Igor; Godovykh, Elena; Soldatkina, Olga; Sosnov, Andrey V

    2013-04-16

    The present disclosure relates to novel compounds that can be used as anti-cancer agents in the prostate cancer therapy. In particular, the invention relates to N-acyl derivatives of 2,3-dihydro-1H-pyrrolo[2,3-b]quinolines having the structural Formula (I), ##STR00001## stereoisomers, tautomers, racemics, prodrugs, metabolites thereof, or pharmaceutically acceptable salt and/or solvate thereof. The meaning of R1 is independently selected from H; C1-C6 Alkyl, cyclo-Alkyl or iso-Alkyl substituents; R2 is selected from C1-C6 Alkyl, cyclo-Alkyl or iso-Alkyl; substituted or non-substituted, fused or non-fused to substituted or non-substituted aromatic ring, aryl or heteroaryl groups. The invention also relates to methods for preparing said compounds, and to pharmaceutical compositions comprising said compounds.

  2. Field cryofocussing hydride generation applied to the simultaneous multi-elemental determination of alkyl-metal(loid) species in natural waters using ICP-MS detection.

    Science.gov (United States)

    Tseng, C M; Amouroux, D; Brindle, I D; Donard, O F

    2000-12-01

    Two hydride generation manifold systems, utilizing flow injection and cryotrapping techniques for alkyl-metal(loid) speciation analysis in natural waters, are described in this paper. They provide shipboard capacity for simultaneous derivatization of analytes with NaBH4 and cryotrapping of the generated products in a field packed column at -196 degrees C. The first system is a large-volume hydride generator, using a reagent-injection flow technique as a flow batch type, that has been fully optimized and applied to the simultaneous detection of alkylated species in estuarine waters. The technique permits the analysis of a large volume sample (0.5-11) at a sampling rate of 3 h-1. The second is an online continuous flow hydride generator. A sampling rate of 3-12 h-1 can be achieved with samples of 0.1-0.51. In addition, shipboard operation eliminates major problems related to sample pretreatment, transport and storage. Ultra-trace multi-element determination is finally performed in the laboratory by cryogenic GC hyphenated with ICP-MS. Routine detection limits of 0.5-10 pg (as metal) for 0.51 water samples were achieved for the selected alkyl-metal(loid) species of arsenic, germanium, mercury and tin. Concentrations of various species, obtained from water samples taken from the Rhine estuary, are also presented. These species include alkylated arsenic compounds, other than methyl derivatives, that have been tentatively identified and are reported here for the first time.

  3. Catalytic dehalogenation of N-acetyl-L-4-chloro- and N-acetyl-L-4-iodophenylalanine amide in the presence of deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Oehlke, J.; Bienert, M.; Niedrich, H.; Zoepfl, H.-J.; Franke, P.

    1986-09-01

    As a model for the tritium labeling of peptides, the catalytic dehalogenation of N-Acetyl-L-4-chloro- and N-Acetyl-L-4-iodo-phenylalanine amide was investigated in the presence of deuterium, using different reaction conditions. A catalyst-mediated transfer of the solvent-hydrogen to the substrate was found to be the most probable reason for the exchange of halogen by hydrogen instead of deuterium. This unwanted transfer was most intensive in the presence of water. An incorporation of additional deuterium besides the 4-position of phenylalanine takes place simultaneously with the dehalogenation especially of the chloro derivative.

  4. Diacetoxyiodobenzene assisted C-O bond formation via sequential acylation and deacylation process: synthesis of benzoxazole amides and their mechanistic study by DFT.

    Science.gov (United States)

    Nahakpam, Lokendrajit; Chipem, Francis A S; Chingakham, Brajakishor S; Laitonjam, Warjeet S

    2016-08-10

    An efficient method for the transformation of N-substituted-N'-benzoylthioureas to substituted N-benzoxazol-2-yl-amides using diacetoxyiodobenzene (DIB) is described in this work. The transformation follows the C-O bond formation leading to the benzoxazole derivative, due to oxidative dehydrogenation by DIB, instead of the expected C-S bond formation of the benzothiazole moiety. The C-O bond formation leading to benzoxazole is due to consecutive acylation and deacylation in conjunction with the reduction of two moles of DIB. A plausible mechanism was proposed for the reaction and density functional calculations were also performed to study the reaction mechanism.

  5. [Synthetic transformations of higher terpenoids. XXX. Synthesis and cytotoxic activity of betulonic acid amides with a piperidine or pyrrolidine nitroxide moiety].

    Science.gov (United States)

    Antimonova, A N; Petrenko, N I; Shults, E E; Polienko, Iu F; Shakirov, M M; Irtegova, I G; Pokrovskiĭ, M A; Sherman, K M; Grigor'ev, I A; Pokrovskiĭ, A G; Tolstikov, G A

    2013-01-01

    The reaction of betulonic acid chloride with 4-amino-2,2,6,6-tetramethylpeperidine-1-oxyl, 3-amino-2,2,5,5-tetramethylpyrrolidine-1-oxyl and 3-aminomethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl gave corresponding triterpenoid amides. It was found that new derivatives exhibit cytotoxic activity against tumor cells CEM-13, U-937, MT-4. CCID50 value for most activity compound--N-[3-oxolup-20(29)-en-30-yl]-(2,2,6,6-tetramethylpiperidine-4-yl)-1-oxyl--was 5.7-33.1 microM.

  6. H-BONDING SELF-ASSEMBLED TEMPLATE-CONTROLLED SYNTHESIS OF A NOVEL SOLUBLE AND REACTIVE AMIDE-BRIDGED LADDERLIKE POLYHYDROSILOXANE

    Institute of Scientific and Technical Information of China (English)

    Guan-qun Zhong; Qing-hua Duan; Kui-lin Deng; Ai-qin Zhang; Ping Xie; Hai-liang Zhang; Rong-ben Zhang

    2006-01-01

    A novel soluble and reactive amide-bridged ladderlike polyhydrosiloxane (ALPHS) was first synthesized by an amido H-bonding self-assembled template. ALPHS with molecular weight M-n = 18300 has very highly ordered ladderlike structure, which was confirmed by a sharp resonance absorption peak of [-Si(H)O2/2 ] moiety with the half peak width A1/2 < 0.5 in 29Si-NMR spectrum. Presence of the reactive Si-H groups gives ALPHS an opportunity to further derive a variety of functional polymers by versatile Si-H reactions such as hydrosilylation, condensation, and so on.

  7. Expression of O6-Methylguanine-DNA Methyltransferase Examined by Alkyl-Transfer Assays, Methylation-Specific PCR and Western Blots in Tumors and Matched Normal Tissue

    OpenAIRE

    Ishiguro, Kimiko; Shyam, Krishnamurthy; Penketh, Philip G.; Baumann, Raymond P.; Sartorelli, Alan C.; Rutherford, Thomas J.; Ratner, Elena S.

    2013-01-01

    The tumor selectivity of alkylating agents that produce guanine O6-chloroethyl (laromustine and carmustine) and O6-methyl (temozolomide) lesions, depends upon O6-methylguanine-DNA methyltransferase (MGMT) activity being lower in tumor than in host tissue. Despite the established role of MGMT as a tumor resistance factor, consensus on how to assess MGMT expression in clinical samples is unsettled. The aim of this study is to examine the relationship between the values derived from distinctive ...

  8. N-acetylcysteine amide, a promising antidote for acetaminophen toxicity.

    Science.gov (United States)

    Khayyat, Ahdab; Tobwala, Shakila; Hart, Marcia; Ercal, Nuran

    2016-01-22

    Acetaminophen (N-acetyl-p-aminophenol, APAP) is one of the most widely used over the counter antipyretic and analgesic medications. It is safe at therapeutic doses, but its overdose can result in severe hepatotoxicity, a leading cause of drug-induced acute liver failure in the USA. Depletion of glutathione (GSH) is one of the initiating steps in APAP-induced hepatotoxicity; therefore, one strategy for restricting organ damage is to restore GSH levels by using GSH prodrugs. N-acetylcysteine (NAC), a GSH precursor, is the only currently approved antidote for an acetaminophen overdose. Unfortunately, fairly high doses and longer treatment times are required due to its poor bioavailability. In addition, oral and I.V. administration of NAC in a hospital setting are laborious and costly. Therefore, we studied the protective effects of N-acetylcysteine amide (NACA), a novel antioxidant with higher bioavailability, and compared it with NAC in APAP-induced hepatotoxicity in C57BL/6 mice. Our results showed that NACA is better than NAC at a low dose (106mg/kg) in preventing oxidative stress and protecting against APAP-induced damage. NACA significantly increased GSH levels and the GSH/GSSG ratio in the liver to 66.5% and 60.5% of the control, respectively; and it reduced the level of ALT by 30%. However, at the dose used, NAC was not effective in combating the oxidative stress induced by APAP. Thus, NACA appears to be better than NAC in reducing the oxidative stress induced by APAP. It would be of great value in the health care field to develop drugs like NACA as more effective and safer options for the prevention and therapeutic intervention in APAP-induced toxicity.

  9. 桥键烷基酚及其衍生物用于合成橡胶防老剂的研究进展%Research progress in antioxIDant of brIDged alkyl phenols category and its derivates used for synthetic rubber

    Institute of Scientific and Technical Information of China (English)

    杜飞; 郭付远

    2009-01-01

    The shortcoming such as easily migration, volatile and low antiaging efficiency of 2,6-di-tert-butyl-4-methylphenol(BHT) as synthetic rubber antioxIDant was analyzed, the mechanism of antiaging of BHT and brIDged alkylene phenols were explained, and the advantage, synthetic methods of brIDged alkylene bisphenols were introduced with 20 references. It was pointed out that brIDged alkylene phenols and its derivates replacing BHT would be the direction of antioxIDant for synthetic rubber.%分析了2,6-二叔丁基-4-甲基苯酚(BHT)作为合成橡胶防老剂存在易迁移、易挥发、抗老化效率低等问题,阐述了BHT与桥键烷基酚类防老剂的作用机理,介绍了桥键烷基酚类防老剂的优势、合成方法,指出用桥键烷基酚及其衍生物取代BHT是合成橡胶防老剂发展的方向.

  10. Peptide backbone cleavage by α-amidation is enhanced at methionine residues.

    Science.gov (United States)

    Hellwig, Michael; Löbmann, Katja; Orywol, Tom

    2015-01-01

    Cleavage reactions at backbone loci are one of the consequences of oxidation of proteins and peptides. During α-amidation, the Cα -N bond in the backbone is cleaved under formation of an N-terminal peptide amide and a C-terminal keto acyl peptide. On the basis of earlier works, a facilitation of α-amidation by the thioether group of adjacent methionine side chains was proposed. This reaction was characterized by using benzoyl methionine and benzoyl alanyl methionine as peptide models. The decomposition of benzoylated amino acids (benzoyl-methionine, benzoyl-alanine, and benzoyl-methionine sulfoxide) to benzamide in the presence of different carbohydrate compounds (reducing sugars, Amadori products, and reductones) was studied during incubation for up to 48 h at 80 °C in acetate-buffered solution (pH 6.0). Small amounts of benzamide (0.3-1.5 mol%) were formed in the presence of all sugars and from all benzoylated species. However, benzamide formation was strongly enhanced, when benzoyl methionine was incubated in the presence of reductones and Amadori compounds (3.5-4.2 mol%). The reaction was found to be intramolecular, because α-amidation of a similar 4-methylbenzoylated amino acid was not enhanced in the presence of benzoyl-methionine and carbohydrate compounds. In the peptide benzoyl-alanyl-methionine, α-amidation at the methionine residue is preferred over α-amidation at the benzoyl peptide bond. We propose here a mechanism for the enhancement of α-amidation at methionine residues.

  11. Safety Assessment of Alkyl PEG/PPG Ethers as Used in Cosmetics.

    Science.gov (United States)

    Fiume, Monice M; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2016-07-01

    The Cosmetic Ingredient Review (CIR) Expert Panel assessed the safety of 131 alkyl polyethylene glycol (PEG)/polypropylene glycol ethers as used in cosmetics, concluding that these ingredients are safe in the present practices of use and concentration described in this safety assessment when formulated to be nonirritating. Most of the alkyl PEG/PPG ethers included in this review are reported to function in cosmetics as surfactants, skin-conditioning agents, and/or emulsifying agents. The alkyl PEG/PPG ethers share very similar physiochemical properties as the alkyl PEG ethers, which were reviewed previously by the CIR Expert Panel and found safe when formulated to be nonirritating. The alkyl PEG ethers differ by the inclusion of PPG repeat units, which are used to fine-tune the surfactant properties of this group. The Panel relied heavily on data on analogous ingredients, extracted from the alkyl PEG ethers and PPG reports, when making its determination of safety. PMID:27383199

  12. Distance-Dependent Attractive and Repulsive Interactions of Bulky Alkyl Groups.

    Science.gov (United States)

    Hwang, Jungwun; Li, Ping; Smith, Mark D; Shimizu, Ken D

    2016-07-01

    The stabilizing and destabilizing effects of alkyl groups on an aromatic stacking interaction were experimentally measured in solution. The size (Me, Et, iPr, and tBu) and position (meta and para) of the alkyl groups were varied in a molecular balance model system designed to measure the strength of an intramolecular aromatic interaction. Opposite stability trends were observed for alkyl substituents at different positions on the aromatic rings. At the closer meta-position, smaller groups were stabilizing and larger groups were destabilizing. Conversely, at the farther para-position, the larger alkyl groups were systematically more stabilizing with the bulky tBu group forming the strongest stabilizing interaction. X-ray crystal structures showed that the stabilizing interactions of the small meta-alkyl and large para-alkyl groups were due to their similar distances and van der Waals contact areas with the edge of opposing aromatic ring. PMID:27159670

  13. Stimulation of the Fibrillar Collagen and Heat Shock Proteins by Nicotinamide or Its Derivatives in Non-Irradiated or UVA Radiated Fibroblasts, and Direct Anti-Oxidant Activity of Nicotinamide Derivatives

    OpenAIRE

    Neena Philips; Jovinna Chalensouk-Khaosaat; Salvador Gonzalez

    2015-01-01

    In skin aging, from intrinsic factors or exposure to ultraviolet (UV) radiation, there is loss of structural fibrillar collagen and regulatory heat shock proteins. Phenolic compounds, with hydroxyl groups attached to an aromatic ring, have antioxidative and anti-inflammatory properties. Nicotinamide is an amide derivative of niacin or vitamin B3, with an amide linked to an aromatic ring, with UV absorptive, antioxidant, anti-inflammatory and anti-cell death/apoptosis properties. The goal of...

  14. Synthesis and Biological Evaluation of Resveratrol Derivatives as Melanogenesis Inhibitors

    OpenAIRE

    Qing Liu; CheongTaek Kim; Yang Hee Jo; Seon Beom Kim; Bang Yeon Hwang; Mi Kyeong Lee

    2015-01-01

    Resveratrol (1), a naturally occurring stilbene compound, has been suggested as a potential whitening agent with strong inhibitory activity on melanin synthesis. However, the use of resveratrol in cosmetics has been limited due to its chemical instability and poor bioavailability. Therefore, resveratrol derivatives were prepared to improve bioavailability and anti-melanogenesis activity. Nine resveratrol derivatives including five alkyl ether derivatives with C2H5, C4H9, C5H11, C6H13, and C8H...

  15. Generation of a novel monoclonal antibody that recognizes the alpha (α)-amidated isoform of a valine residue

    OpenAIRE

    Antón Palma, Benito; Leff Gelman, Philippe; Medecigo Ríos, Mayra; Calva Nieves, Juan Carlos; Acevedo Ortuño, Rodolfo; Matus Ortega, Maura Epifanía; Hernández Calderón, Jorge Alberto; Hernández Miramontes, Ricardo; Flores Zamora, Anabel; Salazar Juárez, Alberto

    2015-01-01

    Background Alpha (α)-amidation of peptides is a mechanism required for the conversion of prohormones into functional peptide sequences that display biological activities, receptor recognition and signal transduction on target cells. Alpha (α)-amidation occurs in almost all species and amino acids identified in nature. C-terminal valine amide neuropeptides constitute the smallest group of functional peptide compounds identified in neurosecretory structures in vertebrate and invertebrate specie...

  16. Expression of peptidyl-glycine alpha-amidating mono-oxygenase (PAM) enzymes in morphological abnormalities adjacent to pulmonary tumors.

    OpenAIRE

    Martinez, A.; Treston, A M; Saldise, L. (Laura); Montuenga, L.M. (Luis M.); Linnoila, R I

    1996-01-01

    Carboxyl-terminal amidated peptide hormones are known to be autocrine growth factors for lung tumors and tumor cell lines. Expression of the enzymes necessary for the biosynthesis of active amidated peptide hormones is therefore necessary for autocrine growth stimulation in lung tumors and possibly in the early proliferative stages of lung carcinogenesis. The peptidyl amidating enzymes have previously been identified in cell lines of all histological types of lung cancer and in lung tumors by...

  17. Synthesis of Biaryls through Nickel-Catalyzed Suzuki-Miyaura Coupling of Amides by Carbon-Nitrogen Bond Cleavage.

    Science.gov (United States)

    Shi, Shicheng; Meng, Guangrong; Szostak, Michal

    2016-06-01

    The first Ni-catalyzed Suzuki-Miyaura coupling of amides for the synthesis of widely occurring biaryl compounds through N-C amide bond activation is reported. The reaction tolerates a wide range of electron-withdrawing, electron-neutral, and electron-donating substituents on both coupling partners. The reaction constitutes the first example of the Ni-catalyzed generation of aryl electrophiles from bench-stable amides with potential applications for a broad range of organometallic reactions. PMID:27101428

  18. Conserving agrobiodiversity amid global change, migration, and nontraditional livelihood networks: the dynamic uses of cultural landscape knowledge

    Directory of Open Access Journals (Sweden)

    Karl S. Zimmerer

    2014-06-01

    Full Text Available I examined agrobiodiversity in smallholder cultural landscapes with the goal of offering new insights into management and policy options for the resilience-based in situ conservation and social-ecological sustainability of local, food-producing crop types, i.e., landraces. I built a general, integrative approach to focus on both land use and livelihood functions of crop landraces in the context of nontraditional, migration-related livelihoods amid global change. The research involved a multimethod, case-study design focused on a cultural landscape of maize, i.e., corn, growing in the Andes of central Bolivia, which is a global hot spot for this crop’s agrobiodiversity. Central questions included the following: (1 What are major agroecological functions and food-related services of the agrobiodiversity of Andean maize landraces, and how are they related to cultural landscapes and associated knowledge systems? (2 What are new migration-related livelihood groups, and how are their dynamic livelihoods propelled through global change, in particular international and national migration, linked to the use and cultural landscapes of agrobiodiversity? (3 What are management and policy options derived from the previous questions? Combined social-ecological services as both cultivation and food resources are found to function in relation to the cultural landscape. Results demonstrated major variations of maturation-based, phenologic traits and food-use properties that are cornerstones of the landrace-level agrobiodiversity of Andean maize. Knowledge of these parameters is widespread. Linkage of these production and consumption functions yields a major insight into dynamics of Andean maize agrobiodiversity. Concurrently, this smallholder cultural landscape has become increasingly dependent on new rural conditions, especially increased livelihood diversification and migration amid growing peri-urban influences. Viability of landrace-level maize

  19. Coke precursor as an intermediate during the alkylation of isobutane/butene over a solid superacid

    Institute of Scientific and Technical Information of China (English)

    XIE; Wenhua; FU; Qiang

    2004-01-01

    Alkylation of isobutane/butene was conducted on a Brφnsted-Lewis conjugated solid superacid. It is found that some hydrocarbons accumulated on the catalyst surface. These hydrocarbons, as called coke precursor, played an intermediate role at the initial stage of the alkylation before they lead the catalyst to lose its activity. The presence of the intermediate is beneficial to the alkylation between isobutane and butene, while increase the TMP content and TMP/DMH ratio in the products.

  20. Effects of alkyl chain lengths of gallates upon enzymatic wool functionalisation

    OpenAIRE

    Gaffar Hossain, Kh. M.; Díaz González, María; Dagá Monmany, José María; Tzanov, Tzanko

    2010-01-01

    The covalent grafting of alkyl gallates on wool through a laccase catalysed reaction in 80/20 (v/v, %)aqueous–ethanol mixture provided in a one-step process a multifunctional textile material with antioxidant, antibacterial and water repellent properties. Gallic acid and its alkyl esters ethyl, propyl, octyl and dodecyl gallate have been enzymatically grafted on wool fibres in order to study the effect of alkyl chain length on wool functional modification. The capacity of laccase to oxidis...

  1. Highly enantio- and diastereoselective allylic alkylation of Morita-Baylis-Hillman carbonates with allyl ketones

    KAUST Repository

    Tong, Guanghu

    2013-05-17

    The asymmetric allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates with allyl ketones has been developed. The α-regioselective alkylation adducts, containing a hexa-1,5-diene framework with important synthetic value, were achieved in up to 83% yield, >99% ee, and 50:1 dr by using a commercially available Cinchona alkaloid as the catalyst. From the allylic alkylation adduct, a cyclohexene bearing two adjacent chiral centers was readily prepared. © 2013 American Chemical Society.

  2. Tandem catalysis for the production of alkyl lactates from ketohexoses at moderate temperatures.

    Science.gov (United States)

    Orazov, Marat; Davis, Mark E

    2015-09-22

    Retro-aldol reactions have been implicated as the limiting steps in catalytic routes to convert biomass-derived hexoses and pentoses into valuable C2, C3, and C4 products such as glycolic acid, lactic acid, 2-hydroxy-3-butenoic acid, 2,4-dihydroxybutanoic acid, and alkyl esters thereof. Due to a lack of efficient retro-aldol catalysts, most previous investigations of catalytic pathways involving these reactions were conducted at high temperatures (≥160 °C). Here, we report moderate-temperature (around 100 °C) retro-aldol reactions of various hexoses in aqueous and alcoholic media with catalysts traditionally known for their capacity to catalyze 1,2-intramolecular carbon shift (1,2-CS) reactions of aldoses, i.e., various molybdenum oxide and molybdate species, nickel(II) diamine complexes, alkali-exchanged stannosilicate molecular sieves, and amorphous TiO2-SiO2 coprecipitates. Solid Lewis acid cocatalysts that are known to catalyze 1,2-intramolecular hydride shift (1,2-HS) reactions that enable the formation of α-hydroxy carboxylic acids from tetroses, trioses, and glycolaldehyde, but cannot readily catalyze retro-aldol reactions of hexoses and pentoses at these moderate temperatures, are shown to be compatible with the aforementioned retro-aldol catalysts. The combination of a distinct retro-aldol catalyst with a 1,2-HS catalyst enables lactic acid and alkyl lactate formation from ketohexoses at moderate temperatures (around 100 °C), with yields comparable to best-reported chemocatalytic examples at high temperature conditions (≥160 °C). The use of moderate temperatures enables numerous desirable features such as lower pressure and significantly less catalyst deactivation. PMID:26372958

  3. New Route to 3-Alkylthiazolo[3,2-a]benzimidazole Derivatives

    Directory of Open Access Journals (Sweden)

    Nicolas Vanthuyne

    2005-02-01

    Full Text Available 3-Alkyl-thiazolo[3,2-a]benzimidazole derivatives are obtained in high yieldsvia the corresponding 4-alkyl-N-3-(2-aminophenyl-thiazoline-2-thiones which are easilyprepared from 1,2-diaminobenzene, CS2 and halogenoketones. This new route comparesadvantageously with the classical mercaptobenzimidazole routes in term of simplicity,isolated yields and availability of the starting materials.

  4. Synthesis of new biologically active triazolo, tetrazolo and coumarinoyl derivatives of isocoumarins

    OpenAIRE

    Poonam Koppula; Nalini Purohit

    2013-01-01

    With the aim of developing potential antimicrobial agents, a series of triazolo / tetrazolo isoquinolines incorporating both nitrogen and oxygen as part of the hetero aromatic ring were prepared from 4-alkyl-3-aroyl isocoumarins via a number of intermediate steps. Some novel coumarinoyl derivatives of isocoumarins were also synthesized starting from 4-alkyl-3-aroyl isocoumarin and characterized by FTIR, 1H NMR, Mass Spectroscopy and elemental analysis. All the title compounds 7a,b, 8a,b, 10a-...

  5. Sterically-controlled intermolecular Friedel-Crafts acylation with twisted amides via selective N-C cleavage under mild conditions.

    Science.gov (United States)

    Liu, Yongmei; Meng, Guangrong; Liu, Ruzhang; Szostak, Michal

    2016-05-21

    Highly chemoselective Friedel-Crafts acylation with twisted amides under mild conditions is reported for the first time. The reaction shows high functional group tolerance, obviating the need for preformed sensitive organometallic reagents and expensive transition metal catalysts. The high reactivity of amides is switched on by ground-state steric distortion to disrupt the amide bond nN→πCO* resonance as a critical design feature. Conceptually, this new acid-promoted mechanism of twisted amides provides direct access to bench-stable acylating reagents under mild, metal-free conditions. PMID:27139813

  6. Methods of producing alkylated hydrocarbons from an in situ heat treatment process liquid

    Science.gov (United States)

    Roes, Augustinus Wilhelmus Maria; Mo, Weijian; Muylle, Michel Serge Marie; Mandema, Remco Hugo; Nair, Vijay

    2009-09-01

    A method for producing alkylated hydrocarbons is disclosed. Formation fluid is produced from a subsurface in situ heat treatment process. The formation fluid is separated to produce a liquid stream and a first gas stream. The first gas stream includes olefins. The liquid stream is fractionated to produce at least a second gas stream including hydrocarbons having a carbon number of at least 3. The first gas stream and the second gas stream are introduced into an alkylation unit to produce alkylated hydrocarbons. At least a portion of the olefins in the first gas stream enhance alkylation.

  7. Catalytic Selenium-Promoted Intermolecular Friedel-Crafts Alkylation with Simple Alkenes.

    Science.gov (United States)

    Tang, E; Zhao, Yinjiao; Li, Wen; Wang, Weilin; Zhang, Meng; Dai, Xin

    2016-03-01

    A method for conducting selenium-promoted intermolecular Friedel-Crafts (F-C) alkylation reactions has been developed with simple alkenes using trimethylsilyl trifluoromethanesulfonate as a catalyst and N-phenylselenophthalimide as an efficient selenium source. Electron-rich arenes smoothly underwent F-C alkylation with a variety of alkenes to afford alkylated products in good yield and with high regioselectivity and diastereoselectivity. The regioselectivity and stereoselectivity of arenes and alkenes as well as a preliminary mechanism of the F-C alkylation reaction are discussed. PMID:26882088

  8. Effects of alkyl chain length and substituent pattern of fullerene bis-adducts on film structures and photovoltaic properties of bulk heterojunction solar cells.

    Science.gov (United States)

    Tao, Ran; Umeyama, Tomokazu; Kurotobi, Kei; Imahori, Hiroshi

    2014-10-01

    A series of alkoxycarbonyl-substituted dihydronaphthyl-based [60]fullerene bis-adduct derivatives (denoted as C2BA, C4BA, and C6BA with the alkyl chain of ethyl, n-butyl, and n-hexyl, respectively) have been synthesized to investigate the effects of alkyl chain length and substituent pattern of fullerene bis-adducts on the film structures and photovoltaic properties of bulk heterojunction polymer solar cells. The shorter alkyl chain length caused lower solubility of the fullerene bis-adducts (C6BA > C4BA > C2BA), thereby resulting in the increased separation difficulty of respective bis-adduct isomers. The device performance based on poly(3-hexylthiophene) (P3HT) and the fullerene bis-adduct regioisomer mixtures was enhanced by shortening the alkyl chain length. When using the regioisomerically separated fullerene bis-adducts, the devices based on trans-2 and a mixture of trans-4 and e of C4BA exhibited the highest power conversion efficiencies of ca. 2.4%, which are considerably higher than those of the C6BA counterparts (ca. 1.4%) and the C4BA regioisomer mixture (1.10%). The film morphologies as well as electron mobilities of the P3HT:bis-adduct blend films were found to affect the photovoltaic properties considerably. These results reveal that the alkyl chain length and substituent pattern of fullerene bis-adducts significantly influence the photovoltaic properties as well as the film structures of bulk heterojunction solar cells.

  9. Overexpression of fatty acid amide hydrolase induces early flowering in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Neal D. Teaster

    2012-02-01

    Full Text Available N-Acylethanolamines (NAEs are bioactive lipids derived from the hydrolysis of the membrane phospholipid N-acylphosphatidylethanolamine (NAPE. In animal systems this reaction is part of the endocannabinoid signaling pathway, which regulates a variety of physiological processes. The signaling function of NAE is terminated by fatty acid amide hydrolase (FAAH, which hydrolyzes NAE to ethanolamine and free fatty acid. Our previous work in Arabidopsis thaliana showed that overexpression of AtFAAH (At5g64440 lowered endogenous levels of NAEs in seeds, consistent with its role in NAE signal termination. Reduced NAE levels were accompanied by an accelerated growth phenotype, increased sensitivity to abscisic acid (ABA, enhanced susceptibility to bacterial pathogens, and early flowering. Here we investigated the nature of the early flowering phenotype of AtFAAH overexpression. AtFAAH overexpressors flowered several days earlier than wild type and AtFAAH knockouts under both non-inductive short day (SD and inductive long day (LD conditions. Microarray analysis revealed that the FLOWERING LOCUS T (FT gene, which plays a major role in regulating flowering time, and one target MADS box transcription factor, SEPATALLA3 (SEP3, were elevated in AtFAAH overexpressors. Furthermore, AtFAAH overexpressors, with the early flowering phenotype had lower endogenous NAE levels in leaves compared to wild type prior to flowering. Exogenous application of NAE 12:0, which was reduced by up to 30% in AtFAAH overexpressors, delayed the onset of flowering in wild type plants. We conclude that the early flowering phenotype of AtFAAH overexpressors is, in part, explained by elevated FT gene expression resulting from the enhanced NAE hydrolase activity of AtFAAH, suggesting that NAE metabolism may participate in floral signaling pathways.

  10. Arg-Phe-amide-related peptides influence gonadotropin-releasing hormone neurons

    Institute of Scientific and Technical Information of China (English)

    Haluk Kelestimur; Emine Kacar; Aysegul Uzun; Mete Ozcan; Selim Kutlu

    2013-01-01

    The hypothalamic Arg-Phe-amide-related peptides, gonadotropin-inhibitory hormone and orthologous mammalian peptides of Arg-Phe-amide, may be important regulators of the hypothalamus-pituitary-gonadal reproductive axis. These peptides may modulate the effects of kisspeptins because they are presently recognized as the most potent activators of the hypothalamus-pituitary-gonadal axis. However, their effects on gonadotropin-releasing hormone neurons have not been investigated. In the current study, the GT1–7 cell line-expressing gonadotropin-releasing hormone was used as a model to explore the effects of Arg-Phe- amide-related peptides on kisspeptin activation. Intracellular calcium concentration was quantified using the calcium-sensitive dye, fura-2 acetoxymethyl ester. Gonadotropin-releasing hormone released into the medium was detected via enzyme-linked immunosorbent assay. Results showed that 100 nmol/L kisspeptin-10 significantly increased gonadotropin-releasing hormone levels (at 120 minutes of exposure) and intracellular calcium concentrations. Co-treatment of kisspeptin with 1 μmol/L gonadotropin-inhibitory hormone or 1 μmol/L Arg-Phe-amide-related peptide-1 significantly attenuated levels of kisspeptin-induced gonadotropin-releasing hormone but did not affect kisspeptin-induced elevations of intracellular calcium concentration. Overall, the results suggest that gonadotropin-inhibitory hormone and Arg-Phe-amide-related peptide-1 may have inhibitory effects on kisspeptin-activated gonadotropin-releasing hormone neurons independent of the calcium signaling pathway.

  11. The design, synthesis of amide KARI inhibitors and their biological activities

    Institute of Scientific and Technical Information of China (English)

    Baolei WANG; Yi MA; Yonghong LI; Suhua WANG; Zhengming LI

    2009-01-01

    Ketol-acid reductoisomerase(KARI) is a promising target for the design of herbicides yet there are only few reports on the molecular design of KARI inhibitors. In this paper, based on the reported 0.165 nm high resolution crystal structure of the spinach KARI complex, 279 molecules with low binding energy toward KARI were obtained from an MDL/ACD 3D database search using the program DOCK 4.0. According to the structural information of 279 molecules provided, some amide compounds have been designed and synthesized. The bioassay results show that most of these amides had inhibitory activity to rice KARI at a test concentration of 200 μg/mL. Among which eight amides, compounds 1 and 6 show 57.4% and 48.1% inhibitory activity to KARI. The herbicidal activities of these amides were further investigated on di-cotyledonous rape (Brassica campestris) and mono-cotyledonous bar-nyardgrass (Echinochloa crusgalli). Compounds 1 and 6 were more favorable than others and showed 52.0% and 72.6% inhibitory activity on rape root at 100 μg/mL concentration, respectively. These amides could be further optimized for finding more potent candidates.

  12. Saturation properties of 1-alkyl-3-methylimidazolium based ionic liquids.

    Science.gov (United States)

    Rane, Kaustubh S; Errington, Jeffrey R

    2014-07-24

    We study the liquid-vapor saturation properties of room temperature ionic liquids (RTILs) belonging to the homologous series 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Cnmim][NTf2]) using Monte Carlo simulation. We examine the effect of temperature and cation alkyl chain length n on the saturated densities, vapor pressures, and enthalpies of vaporization. These properties are explicitly calculated for temperatures spanning from 280 to 1000 K for RTILs with n = 2, 4, 6, 8, 10, and 12. We also explore how the identity of the anion influences saturation properties. Specifically, we compare results for [C(4)mim][NTf2] with those for 1-butyl-3-methylimidazolium tetrafluoroborate ([C(4)mim][BF4]) and 1-butyl-3-methylimidazolium hexafluorophosphate ([C(4)mim][PF6]). Simulations are completed with a recently developed realistic united-atom force field. A combination of direct grand canonical and isothermal-isobaric temperature expanded ensemble simulations are used to construct phase diagrams. Our results are compared with experimental data and Gibbs ensemble simulation data. Overall, we find good agreement between our results and those measured experimentally. We find that the vapor pressures and enthalpies of vaporization show a strong dependence on the size of the alkyl chain at low temperatures, whereas no particular trend is observed at high temperatures. Finally, we also discuss the effect of temperature on liquid phase nanodomains observed in RTILs with large hydrophobic groups. We do not observe a drastic change in liquid phase structure upon variation of the temperature, which suggests there is not a sharp phase transition between a nanostructured and homogeneous liquid, as has been suggested in earlier studies. PMID:24986360

  13. Alkyl polyglycoside-sorbitan ester formulations for improved oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.; Iglauer, S.; Shuler, P.; Tang, Y. [Power Environmental Energy Research Institute (PEERI), Covina, CA (United States); Goddard, W.A. III [California Inst. of Technology, Pasadena, CA (US). Div. of Chemistry and Chemical Engineering, Materials and Process Simulation Center (MSC)

    2010-09-15

    We measured interfacial tensions (IFT) of aqueous alkyl polyglucoside (APG) systems formulated with sorbitan ester-type cosurfactants against n-octane. The study focused on low to ultra-low IFT systems which are relevant for enhanced oil recovery (EOR). In addition, we measured equilibrium adsorption concentrations of these surfactants and cosurfactants onto kaolinite clay, commonly found in oil reservoirs. We present one surfactant EOR laboratory flood experiment with one selected APG-sorbitan ester formulation with which we recovered 94% of initial oil in place (IOIP). (orig.)

  14. Monolayer structures of alkyl aldehydes: Odd-membered homologues

    OpenAIRE

    Phillips, T. K.; Clarke, Stuart M.; Castro Arroyo, Miguel Ángel; Millán, Carmen; Medina, Santiago

    2011-01-01

    Crystalline monolayers of three aldehydes with an odd number of carbon atoms in the alkyl chain (C 7, C 9 and C 11) at low coverages are observed by a combination of X-ray and neutron diffraction. Analysis of the diffraction data is discussed and possible monolayer crystal structures are proposed; although unique structures could not be ascertained for all molecules. We conclude that the structures are flat on the surface, with the molecules lying in the plane of the layer. The C 11 homologue...

  15. Monolayer structures of alkyl aldehydes: Odd-membered homologues

    International Nuclear Information System (INIS)

    Crystalline monolayers of three aldehydes with an odd number of carbon atoms in the alkyl chain (C7, C9 and C11) at low coverages are observed by a combination of X-ray and neutron diffraction. Analysis of the diffraction data is discussed and possible monolayer crystal structures are proposed; although unique structures could not be ascertained for all molecules. We conclude that the structures are flat on the surface, with the molecules lying in the plane of the layer. The C11 homologue is determined to have a plane group of either p2, pgb or pgg, and for the C7 homologue the p2 plane group is preferred.

  16. Alkylating HIV-1 Nef - a potential way of HIV intervention

    Directory of Open Access Journals (Sweden)

    Cai Catherine

    2010-07-01

    Full Text Available Abstract Background Nef is a 27 KDa HIV-1 accessory protein. It downregulates CD4 from infected cell surface, a mechanism critical for efficient viral replication and pathogenicity. Agents that antagonize the Nef-mediated CD4 downregulation may offer a new class of drug to combat HIV infection and disease. TPCK (N-α-p-tosyl-L-phenylalanine chloromethyl ketone and TLCK (N-α-p-tosyl-L-lysine chloromethyl ketone are alkylation reagents that chemically modify the side chain of His or Cys residues in a protein. In search of chemicals that inhibit Nef function, we discovered that TPCK and TLCK alkylated HIV Nef. Methods Nef modification by TPCK was demonstrated on reducing SDS-PAGE. The specific cysteine residues modified were determined by site-directed mutagenesis and mass spectrometry (MS. The effect of TPCK modification on Nef-CD4 interaction was studied using fluorescence titration of a synthetic CD4 tail peptide with recombinant Nef-His protein. The conformational change of Nef-His protein upon TPCK-modification was monitored using CD spectrometry Results Incubation of Nef-transfected T cells, or recombinant Nef-His protein, with TPCK resulted in mobility shift of Nef on SDS-PAGE. Mutagenesis analysis indicated that the modification occurred at Cys55 and Cys206 in Nef. Mass spectrometry demonstrated that the modification was a covalent attachment (alkylation of TPCK at Cys55 and Cys206. Cys55 is next to the CD4 binding motif (A56W57L58 in Nef required for Nef-mediated CD4 downregulation and for AIDS development. This implies that the addition of a bulky TPCK molecule to Nef at Cys55 would impair Nef function and reduce HIV pathogenicity. As expected, Cys55 modification reduced the strength of the interaction between Nef-His and CD4 tail peptide by 50%. Conclusions Our data suggest that this Cys55-specific alkylation mechanism may be exploited to develop a new class of anti HIV drugs.

  17. Differential alkylation-based redox proteomics - Lessons learnt

    DEFF Research Database (Denmark)

    Wojdyla, Katarzyna; Rogowska-Wrzesinska, Adelina

    2015-01-01

    is a critical evaluation of differential alkylation-based strategies for the analysis of S-nitrosylation and S-sulfenylation. The aim is to assess the current status and to provide insights for future directions in the dynamically evolving field of redox proteomics. To achieve that we collected 35 original......, including the amount of starting material required for analysis. The results of this meta-analysis are the core of this review, complemented by issues related to biological models and sample preparation in redox proteomics, including conditions for free thiol blocking and labelling of target cysteine...

  18. Suzuki-Miyaura Cross-Coupling Reactions of Unactivated Alkyl Halides Catalyzed by a Nickel Pincer Complex

    OpenAIRE

    Di Franco, Thomas; Boutin, Nicolas; Hu, Xile

    2013-01-01

    A nickel(II) pincer complex, [((N2N)-N-Me)Ni-Cl], was used to catalyze alkyl-alkyl and alkyl-aryl Suzuki-Miyaura coupling reactions of unactivated alkyl halides. The coupling of 9-alkyl-9-borabicyclo[3.3.1]nonane and 9-phenyl-9-borabicyclo[3.3.1]nonane reagents with alkyl halides was achieved in modest to good yields. The reactions tolerated a variety of useful functional groups including ester, ether, furan, thioether, acetal, and Boc groups.

  19. Synthesis of New Racemic α,α-Diaminocarboxylic Ester Derivatives

    Directory of Open Access Journals (Sweden)

    Mabrouk El Houssine

    2010-11-01

    Full Text Available New racemic methyl or ethyl α-aminoglycinate derivatives were synthesized by N-alkylation of amines (aniline, 4-methylaniline, 2-methylaniline, 2,4-dimethoxyaniline, 2-nitroaniline, 4-chloro-2-fluoroaniline, 2-naphthylamine, benzylamine, N,N-dibenzylamine, and cyclohexylamine with methyl or ethyl α-azidoglycinate.

  20. Synthesis of New Racemic α,α-Diaminocarboxylic Ester Derivatives

    OpenAIRE

    Mabrouk El Houssine; Elachqar Abdelrhani; Alami Anouar; El Hallaoui Abdelilah

    2010-01-01

    New racemic methyl or ethyl α-aminoglycinate derivatives were synthesized by N-alkylation of amines (aniline, 4-methylaniline, 2-methylaniline, 2,4-dimethoxyaniline, 2-nitroaniline, 4-chloro-2-fluoroaniline, 2-naphthylamine, benzylamine, N,N-dibenzylamine, and cyclohexylamine) with methyl or ethyl α-azidoglycinate.

  1. 1H NMR Spectra of Some Amidrazone Derivatives

    OpenAIRE

    BAHÇECİ, Şule; YÜKSEK, Haydar

    1999-01-01

    Fifteen amidrazone derivatives (six being new compounds) were synthesized and their proton magnetic resonance spectra were recorded in trifluoroacetic acid (TFA). The protonation shifts, related to alkyl groups and observed on comparison of the spectra run in a neutral solvent and TFA, were attributed to an amidinium-type resonance of the resulting cations in the acidic medium.

  2. Cyclodextrin ketones as oxidation catalysts: investigation of bridged derivatives

    DEFF Research Database (Denmark)

    Fenger, Thomas Hauch; Marinescu, Lavinia; Bols, Mikael

    2009-01-01

    A series of alpha-cyclodextrin derivatives containing a 3, 4 or 5 membered ether-linked bridge between the 6A and 6D oxygen atoms, with and without a ketone, were prepared. The synthesis used perbenzylated alpha-cyclodextrin A,D-diol as a starting material upon which O-alkylation and further...

  3. Choline Chloride Catalyzed Amidation of Fatty Acid Ester to Monoethanolamide: A Green Approach.

    Science.gov (United States)

    Patil, Pramod; Pratap, Amit

    2016-01-01

    Choline chloride catalyzed efficient method for amidation of fatty acid methyl ester to monoethanolamide respectively. This is a solvent free, ecofriendly, 100% chemo selective and economically viable path for alkanolamide synthesis. The Kinetics of amidation of methyl ester were studied and found to be first order with respect to the concentration of ethanolamine. The activation energy (Ea) for the amidation of lauric acid methyl ester catalyzed by choline chloride was found to be 50.20 KJ mol(-1). The 98% conversion of lauric acid monoethanolamide was obtained at 110°C in 1 h with 6% weight of catalyst and 1:1.5 molar ratio of methyl ester to ethanolamine under nitrogen atmosphere. PMID:26666271

  4. Synthesis and Characterization of Novel Polyurethanes Based on Vegetable Oils Amide and Ester Polyols

    Directory of Open Access Journals (Sweden)

    Vladimir YAKUSHIN

    2014-09-01

    Full Text Available Amide and ester type polyols were synthesized from rapeseed, sunflower and castor oils, and two types of ethanolamine (diethanolamine and triethanolamine at different molar ratio. Poly(urethane amides and polyester urethanes based on the synthesized polyols were prepared. The effect of the chemical structure of the obtained polyurethanes on density, glass transition temperature, thermal stability and mechanical properties was investigated. The influence of the content of OH groups in the synthesized polyols on the specified characteristics was estimated. It has been found that poly(urethane amides have better mechanical characteristics, but their thermal stability is lower than that of polyester urethanes. The chemical structure of the synthesized polyols and polyurethanes is qualitatively confirmed by IR-spectroscopy data. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4532

  5. Lipase-catalyzed synthesis of fatty acid amide (erucamide) using fatty acid and urea.

    Science.gov (United States)

    Awasthi, Neeraj Praphulla; Singh, R P

    2007-01-01

    Ammonolysis of fatty acids to the corresponding fatty acid amides is efficiently catalysed by Candida antartica lipase (Novozym 435). In the present paper lipase-catalysed synthesis of erucamide by ammonolysis of erucic acid and urea in organic solvent medium was studied and optimal conditions for fatty amides synthesis were established. In this process erucic acid gave 88.74 % pure erucamide after 48 hour and 250 rpm at 60 degrees C with 1:4 molar ratio of erucic acid and urea, the organic solvent media is 50 ml tert-butyl alcohol (2-methyl-2-propanol). This process for synthesis is economical as we used urea in place of ammonia or other amidation reactant at atmospheric pressure. The amount of catalyst used is 3 %.

  6. Novel derivatives of benzo[b]thieno[2,3-c]quinolones: synthesis, photochemical synthesis, and antitumor evaluation.

    Science.gov (United States)

    Dogan Koruznjak, Jasna; Grdisa, Mira; Slade, Neda; Zamola, Branimir; Pavelić, Kresimir; Karminski-Zamola, Grace

    2003-10-01

    Novel derivatives of benzo[b]thieno[2,3-c]quinolones 3a-j were synthesized in a multistep synthesis starting from substituted benzo[b]thiophene-2-carbonyl chlorides, to their corresponding benzo[b]thiophene-2-carboxamides, which were photochemically dehydrohalogenated to their corresponding substituted benzo[b]thieno[2,3-c]quinolones. Compound 4 was prepared from 3i by alkylation with 3-dimethylaminopropyl chloride in the presence of NaH. Compounds 7a,b were prepared from 3g in the multistep synthesis from compounds 5 and 6. Compounds 3b, 3c-f, 3h, 7a, and 7b were found to exert cytostatic activity against malignant cell lines: pancreatic carcinoma (MiaPaCa2), breast carcinoma (MCF7), cervical carcinoma (HeLa), laryngeal carcinoma (Hep2), colon carcinoma (CaCo-2), melanoma (HBL), human fibroblast cell lines (WI-38). The compounds that bear a 3-dimethylaminopropyl substituent on the quinolone nitrogen (3b, 3c-f, 3h) showed higher antitumor activity than compounds bearing the same substituent on the amidic nitrogen (7a and 7b). The compound 3h, which has a 3-dimethylaminopropyl substituent on the quinolone nitrogen and a methoxycarbonyl substituent at position 9, had marked antitumor activity. Because of strong cytotoxic effect of compound 4 on melanoma cells (HBL, ME 67.3, and ME 67.1), a potential mechanism of action was examined. Analysis of DNA and Annexin-V-FLUOS staining indicated that compound 4 causes cell death by apoptosis.

  7. Synthesis and characterization of alternating poly(amide urea)s and poly(amide urethane urethane)s from ε-caprolactam, diamines, and diphenyl carbonate or ethylene carbonate

    NARCIS (Netherlands)

    Ubaghs, Luc; Sharma, Bhaskar; Keul, Helmut; Höcker, Hartwig; Loontjens, Ton; Benthem, Rolf van

    2003-01-01

    Alternating poly(amide urea)s from ε-caprolactam, diamines H2N-(CH2)x-NH2 (x = 2 - 4), and diphenyl carbonate were prepared in two steps. The microstructure of the poly(amide urea)s, as determined by means of 1H NMR spectroscopy, reveals a strictly alternating sequence of the building blocks. The mo

  8. WITTIG REACTION APPROACH FOR THE SYNTHESIS OF 7-METHOXY-2-[4- ALKYL/ARYL]-L-BENZOFURAN-5-CARBOXALDEHYDE Wittig-Reaktion Ansatz für die Synthese von 7-Methoxy-2-[4 - ALKYL / ARYL]-L-BENZOFURAN-5-CARBOXALDEHYDE

    Directory of Open Access Journals (Sweden)

    Bapu R Thorata, Dyneshwar Shelke, Ramdas Atram and Ramesh Yamgar

    2013-07-01

    Full Text Available Vanillin undergoes sequence of reaction forming phosphonium salt through dimethyaminomethyl derivative (Mannich reaction. The synthesis of phosphonium salt can be achieved by sequence of three steps which was condense with series of aliphatic/aromatic acid chlorides by refluxing in toluene in presence of triethylamine (Wittig reaction as key step resulting 7-methoxy-2-alkyl/aryl-l-benzofuran-5-carboxaldehyde. The crude product was purified by using column chromatography and characterized by FTIR, NMR and Mass spectroscopy.

  9. Differential alkylation-based redox proteomics--Lessons learnt.

    Science.gov (United States)

    Wojdyla, Katarzyna; Rogowska-Wrzesinska, Adelina

    2015-12-01

    Cysteine is one of the most reactive amino acids. This is due to the electronegativity of sulphur atom in the side chain of thiolate group. It results in cysteine being present in several distinct redox forms inside the cell. Amongst these, reversible oxidations, S-nitrosylation and S-sulfenylation are crucial mediators of intracellular redox signalling, with known associations to health and disease. Study of their functionalities has intensified thanks to the development of various analytical strategies, with particular contribution from differential alkylation-based proteomics methods. Presented here is a critical evaluation of differential alkylation-based strategies for the analysis of S-nitrosylation and S-sulfenylation. The aim is to assess the current status and to provide insights for future directions in the dynamically evolving field of redox proteomics. To achieve that we collected 35 original research articles published since 2010 and analysed them considering the following parameters, (i) resolution of modification site, (ii) quantitative information, including correction of modification levels by protein abundance changes and determination of modification site occupancy, (iii) throughput, including the amount of starting material required for analysis. The results of this meta-analysis are the core of this review, complemented by issues related to biological models and sample preparation in redox proteomics, including conditions for free thiol blocking and labelling of target cysteine oxoforms. PMID:26282677

  10. Copper Complexes of Anionic Nitrogen Ligands in the Amidation and Imidation of Aryl Halides

    OpenAIRE

    Tye, Jesse W.; Weng, Zhiqiang; Johns, Adam M.; Incarvito, Christopher D.; Hartwig, John F.

    2008-01-01

    Copper(I) imidate and amidate complexes of chelating N,N-donor ligands, which are proposed intermediates in copper-catalyzed amidations of aryl halides, have been synthesized and characterized by X-ray diffraction and detailed solution-phase methods. In some cases, the complexes adopt neutral, three-coordinate trigonal planar structures in the solid state, but in other cases they adopt an ionic form consisting of an L2Cu+ cation and a CuX2− anion. A tetraalkylammonium salt of the CuX2− anion ...

  11. Evaluation of an amide-based stationary phase for supercritical fluid chromatography.

    Science.gov (United States)

    Borges-Muñoz, Amaris C; Colón, Luis A

    2016-09-01

    J. Sep. Sci. 2016, 39, 3469-3476 A stationary phase containing an amide group embedded in a hydrophobic backbone (i.e., C18-amide) attached to silica particles was characterized by means of the linear solvation energy relationship model, which relates the chromatographic retention factor to specific solute interactions. The evaluationwas conducted under supercritical fluid chromatographic conditions using a mobile phase composition of carbon dioxide and methanol as co-solvent. The stationary phase showed to provide an alternate separation selectivity that is attractive to separate drug-like polar compounds in a relatively fast analysis time. PMID:27598573

  12. Occurrence, biological activities and {sup 13}C NMR data of amides from Piper (Piperaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Jeferson C. do; Paula, Vanderlucia F. de [Universidade Estadual do Sudoeste da Bahia, Jequie, BA (Brazil). Dept. de Quimica e Exatas; David, Jorge M. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; David, Juceni P., E-mail: jmdavid@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Fac. de Farmacia

    2012-07-01

    This manuscript describes an update review with up to 285 references concerning the occurrence of amides from a variety of species of the genus Piper (Piperaceae). Besides addressing occurrence, this review also describes the biological activities attributed to extracts and pure compounds, a compiled {sup 13}C NMR data set, the main correlations between structural and NMR spectroscopic data of these compounds, and employment of hyphened techniques such as LC-MS, GC-MS and NMR for analysis of amides from biological samples and crude Piper extracts. (author)

  13. Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

    Directory of Open Access Journals (Sweden)

    Katherine M. Byrd

    2015-04-01

    Full Text Available The conjugate addition reaction has been a useful tool in the formation of carbon–carbon bonds. The utility of this reaction has been demonstrated in the synthesis of many natural products, materials, and pharmacological agents. In the last three decades, there has been a significant increase in the development of asymmetric variants of this reaction. Unfortunately, conjugate addition reactions using α,β-unsaturated amides and lactams remain underdeveloped due to their inherently low reactivity. This review highlights the work that has been done on both diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams.

  14. Amide functionalized MWNT/SPEEK composite membrane for better electrochemical performance

    Science.gov (United States)

    Gahlot, Swati; Sharma, Prem P.; Kulshrestha, Vaibhav

    2016-05-01

    Nanocomposite membranes based on multiwalled carbon nanotube /SPEEK (sulfonated poly ether ether ketone) have been synthesized via simple solution casting. Prior to use CNT have been purified and grafted with carboxylic acid groups onto its walls by means of sulfuric and nitric acid. Afterwards, amidation of carboxylated CNTs (c-CNT) has been done. Amidated CNT (a-CNT) is then incorporated in SPEEK polymer matrix to synthesize nanocomposite membranes. Physicochemical, structural, thermal and mechanical characterizations are done through the respective techniques. Electric and ionic conductivities have also been evaluated. Composites membranes show the enhanced electrochemical performance with higher electric conductivity.

  15. Design, Synthesis, Fluorescence Properties and Antibacterial Activities of New 8-Chloro-3-Alkyl-3H-Pyrazolo[4,3-a]acridine-11-Carbonitriles

    Energy Technology Data Exchange (ETDEWEB)

    Rahmani, Zeynab; Pordel, Mehdi; Davoodnia, Abolghasem [Islamic Azad Univ., Mashhad (Iran, Islamic Republic of)

    2014-02-15

    The treatment of alkylated nitro derivatives of indazole with 2-(4-chlorophenyl)acetonitrile under basic conditions gave the new 8-chloro-3-alkyl-3H-pyrazolo[4,3-a]acridine-11-carbonitriles via the nucleophilic substitution of hydrogen which proceeds at room temperature with concomitant cyclisation in fairly good yields. The structures of all newly synthesized compounds were confirmed by IR, {sup 1}H NMR, {sup 13}C NMR and mass spectral data. Fluorescence experimental results of all newly synthesized compounds revealed remarkable photoluminescence properties and strong green fluorescence properties. Also, the new compounds exhibited potent antibacterial activity and their antibacterial activity (MIC) against Gram positive (Staphylococcuse aureus methicillin resistant S. aureus and Bacillus subtilis) and negative bacterial (Pseudomonas aeruginosa and Escherichia coli) species were determined.

  16. New perylene derivative dyes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zafer, Ceylan; Turkmen, Gulsah; Demic, Serafettin; Icli, Siddik [Solar Energy Institute, Ege University, TR-35040 Izmir (Turkey); Kus, Mahmut [Solar Energy Institute, Ege University, TR-35040 Izmir (Turkey); Department of Chemistry, Faculty of Art and Science, Mugla University, TR-48000 Mugla (Turkey); Dincalp, Haluk [Department of Chemistry, Faculty of Art and Science, Celal Bayar University, TR-45030 Manisa (Turkey); Kuban, Baha; Teoman, Yildirim [Tuerkiye Sise ve Cam Fabrikalari A.S. (SiSECAM), TR-80620 Istanbul (Turkey)

    2007-03-06

    We have studied the influence of the spacer alkyl chain length of perylenemonoimide (PMI) dyes on the device performance in dye-sensitized solar cells (DSSCs). We observed that the dyes with longer and brunched alkyl chains exhibit higher efficiencies in DSSCs. In line with these statements we now report the highest efficiency obtained under standard conditions for a perylene imide derivative with PMI-DA1 that performs 300 mV open circuit voltage, 9.79 mA/cm{sup 2} short-circuit current and 1.61% overall conversion efficiency. (author)

  17. Alkylation damage in DNA and RNA--repair mechanisms and medical significance

    DEFF Research Database (Denmark)

    Drabløs, Finn; Feyzi, Emadoldin; Aas, Per Arne;

    2004-01-01

    Alkylation lesions in DNA and RNA result from endogenous compounds, environmental agents and alkylating drugs. Simple methylating agents, e.g. methylnitrosourea, tobacco-specific nitrosamines and drugs like temozolomide or streptozotocin, form adducts at N- and O-atoms in DNA bases. These lesions...

  18. Sources and proxy potential of long chain alkyl diols in lacustrine environments.

    NARCIS (Netherlands)

    Rampen, Sebastiaan W.; Datema, Mariska; Rodrigo-Gámiz, M.; Schouten, Stefan; Reichart, Gert-Jan; Sinninghe Damste, Jaap S.

    2014-01-01

    Long chain 1,13- and 1,15-alkyl diols form the base of a number of recently proposed proxies used for climate reconstruction. However, the sources of these lipids and environmental controls on their distribution are still poorly constrained. We have analyzed the long chain alkyl diol (LCD) compositi

  19. Sources and proxy potential of long chain alkyl diols in lacustrine environments

    NARCIS (Netherlands)

    Rampen, S.; Datema, M.; Rodrigo-Gámiz, M.; Schouten, S.; Reichart, G.-J.; Sinninghe Damsté, J.S.

    2014-01-01

    Long chain 1,13- and 1,15-alkyl diols form the base of a number of recently proposed proxies used for climate reconstruction. However, the sources of these lipids and environmental controls on their distribution are still poorly constrained. We have analyzed the long chain alkyl diol (LCD) compositi

  20. Synthesis and antifungal activity of natural product-based 6-alkyl-2 3 4 5-tetrahydropyridines

    Science.gov (United States)

    Seven 6-alkyl-2,3,4,5-tetrahydropyridines (5a–5g) that mimic the natural products piperideines that were recently identified in the fire ant venom have been synthesized. Compounds 5c–5g with the C-6 alkyl chain lengths from C14 to C18 showed varying degrees of antifungal activities, with 5e (6-hexa...