WorldWideScience

Sample records for aliphatic acyclic diols

  1. Drude polarizable force field for aliphatic ketones and aldehydes, and their associated acyclic carbohydrates

    Science.gov (United States)

    Small, Meagan C.; Aytenfisu, Asaminew H.; Lin, Fang-Yu; He, Xibing; MacKerell, Alexander D.

    2017-04-01

    The majority of computer simulations exploring biomolecular function employ Class I additive force fields (FF), which do not treat polarization explicitly. Accordingly, much effort has been made into developing models that go beyond the additive approximation. Development and optimization of the Drude polarizable FF has yielded parameters for selected lipids, proteins, DNA and a limited number of carbohydrates. The work presented here details parametrization of aliphatic aldehydes and ketones (viz. acetaldehyde, propionaldehyde, butaryaldehyde, isobutaryaldehyde, acetone, and butanone) as well as their associated acyclic sugars ( d-allose and d-psicose). LJ parameters are optimized targeting experimental heats of vaporization and molecular volumes, while the electrostatic parameters are optimized targeting QM water interactions, dipole moments, and molecular polarizabilities. Bonded parameters are targeted to both QM and crystal survey values, with the models for ketones and aldehydes shown to be in good agreement with QM and experimental target data. The reported heats of vaporization and molecular volumes represent a compromise between the studied model compounds. Simulations of the model compounds show an increase in the magnitude and the fluctuations of the dipole moments in moving from gas phase to condensed phases, which is a phenomenon that the additive FF is intrinsically unable to reproduce. The result is a polarizable model for aliphatic ketones and aldehydes including the acyclic sugars d-allose and d-psicose, thereby extending the available biomolecules in the Drude polarizable FF.

  2. Acyclic models

    CERN Document Server

    Barr, Michael

    2002-01-01

    Acyclic models is a method heavily used to analyze and compare various homology and cohomology theories appearing in topology and algebra. This book is the first attempt to put together in a concise form this important technique and to include all the necessary background. It presents a brief introduction to category theory and homological algebra. The author then gives the background of the theory of differential modules and chain complexes over an abelian category to state the main acyclic models theorem, generalizing and systemizing the earlier material. This is then applied to various cohomology theories in algebra and topology. The volume could be used as a text for a course that combines homological algebra and algebraic topology. Required background includes a standard course in abstract algebra and some knowledge of topology. The volume contains many exercises. It is also suitable as a reference work for researchers.

  3. Molybdenum-catalyzed deoxydehydration of vicinal diols

    DEFF Research Database (Denmark)

    Dethlefsen, Johannes Rytter; Lupp, Daniel; Oh, Byung Chang

    2014-01-01

    The commercially available (NH4)6Mo7O24 and other molybdenum compounds are shown to be viable substitutes for the typically employed rhenium compounds in the catalytic deoxydehydration of aliphatic diols into the corresponding alkenes. The transformation, which represents a model system for the v...

  4. Random acyclic networks

    OpenAIRE

    Karrer, Brian; Newman, M. E. J.

    2009-01-01

    Directed acyclic graphs are a fundamental class of networks that includes citation networks, food webs, and family trees, among others. Here we define a random graph model for directed acyclic graphs and give solutions for a number of the model's properties, including connection probabilities and component sizes, as well as a fast algorithm for simulating the model on a computer. We compare the predictions of the model to a real-world network of citations between physics papers and find surpr...

  5. Molybdenum-catalyzed conversion of diols and biomass-derived polyols to alkenes using isopropyl alcohol as reductant and solvent

    DEFF Research Database (Denmark)

    Dethlefsen, Johannes Rytter; Lupp, Daniel; Gorfo, Ayele Teshome

    2015-01-01

    in isopropyl alcohol (iPrOH), which serves as both the solvent and reductant. The reaction proceeds at 240-250 °C in a pressurized autoclave, and the alkene yield from simple aliphatic diols can be as high as 77%. The major byproducts are carbonyl compounds - formed by dehydration of the diol...

  6. Catalytic asymmetric synthesis of acyclic arrays by tandem 1,4-addition-aldol reactions

    NARCIS (Netherlands)

    Howell, Gareth P.; Fletcher, Stephen P.; Geurts, Koen; ter Horst, Bjorn; Feringa, Ben L.

    2006-01-01

    Herein, we report efficient acyclic stereocontrol in tandem 1,4-addition-aldol reactions triggered by catalytic asymmetric organometallic addition. Grignard reagents add to alpha,beta-unsaturated thioesters in a 1,4-fashion and the resulting magnesium enolatesare trapped with aromatic or aliphatic

  7. Synthese De Diols Copolyesters (Synthesis of Copolyester Diols)

    Science.gov (United States)

    1979-05-01

    RESUME Des diols copolyesters ont 6t6 preper6s en pr6sence du titanate dt t6traoctylane glycol comme catalyseur 9 160 - 2300 C, A Spartir d’-caprolactone... de propergols At partir des polyesters . . . . 4 3.0 PARTIE EXPERIMENTALE .. .. ...... .......... ..................6 3.1 Preparation de diols...d16poxydes et dtce-caprolactone (c-CL) .. .. ...... ........ 6 3 .3 Preparation de diols copol~yesters At partir du diol polyesteramine N-8 et l1

  8. Elastic Compositions Based on Polyurethane/ Aliphatic Polyesters

    International Nuclear Information System (INIS)

    Motawie, A.M.; Mazroua, A.M.; Sadek, E.M.; Emam, A.S.; Ramadan, A.M.

    2004-01-01

    Aliphatic polyesters were prepared by melt condensation reaction of a dicarboxylic acid such as adipic and sebacic with different types of diol compounds in 1: 1.1 molar ratio. Ethylene glycol, di-, trio, tetra ethylene glycol and poly( ethylene glycol) with different molecular weights 1000, 4000, 6000 as well as the prepared hydroxy natural rubber were used as diol compounds. Polyurethane, with NCO/OH ratio equal 4, was synthesized from the reaction of toluene diisocyanate with poly(ethylene glycol) 1 000. The prepared polyurethane was mixed with different weight percentages of the prepared aliphatic polyesters. The film samples were tested mechanically, electrically and chemically. The results show that the weight percentage 10% of the added polyadipate or poly sebacate glycols improves flexibility, electrical volume resistivity, dielectric constant and dielectric loss of unmodified rigid polyurethane film sample as well as reduces its swelling by aromatic solvents. All the above mentioned properties improve by increasing the hydrocarbon chain length of the glycol portion in the glycol used and the number of methylene in the aliphatic dicarboxylic acid. Compositions based on hydroxy natural rubber impart better properties than those based on ethylene glycols

  9. On acyclicity of games with cycles

    DEFF Research Database (Denmark)

    Andersson, Klas Olof Daniel; Hansen, Thomas Dueholm; Gurvich, Vladimir

    2010-01-01

    We study restricted improvement cycles (ri-cycles) in finite positional n-person games with perfect information modeled by directed graphs (di-graphs) that may contain directed cycles (di-cycles). We assume that all these di-cycles form one outcome c, for example, a draw. We obtain criteria...... of restricted improvement acyclicity (ri-acyclicity) in two cases: for n D 2 and for acyclic di-graphs. We provide several examples that outline the limits of these criteria and show that, essentially, there are no other ri-acyclic cases. We also discuss connections between ri-acyclicity and some open problems...

  10. On Acyclicity of Games with Cycles

    DEFF Research Database (Denmark)

    Andersson, Daniel; Gurvich, Vladimir; Hansen, Thomas Dueholm

    2009-01-01

    We study restricted improvement cycles (ri-cycles) in finite positional n-person games with perfect information modeled by directed graphs (digraphs) that may contain cycles. We obtain criteria of restricted improvement acyclicity (ri-acyclicity) in two cases: for n = 2 and for acyclic digraphs. ...... provide several examples that outline the limits of these criteria and show that, essentially, there are no other ri-acyclic cases. We also discuss connections between ri-acyclicity and some open problems related to Nash-solvability....

  11. New diols with imidazoquinazoline ring

    Science.gov (United States)

    Szyszkowska, Agnieszka; Klasek, Antonin; Pawlędzio, Sylwia; Trzybiński, Damian; Woźniak, Krzysztof; Zarzyka, Iwona

    2018-02-01

    The objective of these studies was to synthesize and characterize new diols with an imidazoquinazoline ring. New diols were obtained in reactions of 2,6-bis-(ethoxycarbonylmethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione with excess of ethylene glycol or in reaction of 1-phenyl-2H,6H-imidazo[1,5-c]quinazoline-3,5-dione with 2-M excess of ethylene oxide. The products were isolated at high yield and characterized by instrumental methods (IR, 1H- and 13C-NMR, MS-ESI, UV, TGA). The structure of 2,6-bis(2-hydroxyethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione (BEFIQ) was also investigated by single-crystal X-ray diffraction. BEFIQ crystallizes in the monoclinic P21/n space group with two molecules in the asymmetric unit of the crystal lattice. The nature of the packing of molecules in the crystal lattice of BEFIQ was investigated by Hirshfeld surface analysis. The described methods enable the synthesis of new diols with an imidazoquinazoline ring. The new diols are quite soluble in typical organic solvents. Therefore, they can be used as raw materials for the synthesis of thermally stable polymers, and they can also have biological activity.

  12. Aliphatic long-chain C20 polyesters from olefin metathesis.

    Science.gov (United States)

    Trzaskowski, Justyna; Quinzler, Dorothee; Bährle, Christian; Mecking, Stefan

    2011-09-01

    Self-metathesis of undecenoic acid with [(PCy3)2Cl2Ru=CHPh] (2), followed by exhaustive hydrogenation yielded pure 1,20-eicosanedioic acid (5) (>99%) free of side-products from isomerization. Polycondensation with eicosane-1,20-diol (6), formed by reduction of the diol, yielded polyester 20,20 (Tm = 108 °C). By comparison, the known ADMET polymerization of undec-10-enyl undec-10-enoate (7), and subsequent exhaustive polymer-analogous hydrogenation yielded a polyester (poly-8) with irregular structure of the ester groups in the polymer chain (-O(C=O)- vs. -C(=O)O-) (Tm = 103 °C). Hydrogenation of secondary dispersions of poly-7 yielded aqueous dispersions of the long-chain aliphatic polyester poly-8. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Iterative tandem catalysis of secondary diols and diesters to chiral polyesters.

    Science.gov (United States)

    van As, Bart A C; van Buijtenen, Jeroen; Mes, Tristan; Palmans, Anja R A; Meijer, E W

    2007-01-01

    The well-known dynamic kinetic resolution of secondary alcohols and esters was extended to secondary diols and diesters to afford chiral polyesters. This process is an example of iterative tandem catalysis (ITC), a polymerization method where the concurrent action of two fundamentally different catalysts is required to achieve chain growth. In order to procure chiral polyesters of high enantiomeric excess value (ee) and good molecular weight, the catalysts employed need to be complementary and compatible during the polymerization reaction. We here show that Shvo's catalyst and Novozym 435 fulfil these requirements. The optimal polymerization conditions of 1,1'-(1,3-phenylene) diethanol (1,3-diol) and diisopropyl adipate required 2 mol% Shvo's catalyst and 12 mg Novozym 435 per mmol alcohol group in the presence of 0.5 M 2,4-dimethyl-3-pentanol as the hydrogen donor. With these conditions, chiral polyesters were obtained with peak molecular weights up to 15 kDa, an ee value up to 99% and with 1-3 % ketone end groups. Also with the structural isomer, 1,4-diol, a chiral polyester was obtained, albeit with lower molecular weight (8.3 kDa) and slightly lower ee (94%). Aliphatic secondary diols also resulted in enantio-enriched polymers but at most an ee of 46 % was obtained with molecular weights in the range of 3.3-3.7 kDa. This low ee originates from the intrinsic low enantioselectivity of Novozym 435 for this type of secondary aliphatic diols. The results presented here show that ITC can be applied to procure chiral polyesters with good molecular weight and high ee from optically inactive AA-BB type monomers.

  14. Stability and robustness analysis of acyclic timetable

    NARCIS (Netherlands)

    Goverde, R.M.P.; Yan, F.

    2015-01-01

    o satisfy the growing passenger transportation demands and improve the service quality n railway system, a more stable and robust timetable needs to be designed while considering highly utilized capacity. Acyclic timetable is extensively applied in large ailway networks. In order to acquire the

  15. Antiviral acyclic nucleoside phosphonates structure activity studies

    Czech Academy of Sciences Publication Activity Database

    Holý, Antonín

    2006-01-01

    Roč. 71, č. 2/3 (2006), s. 248-253 ISSN 0166-3542 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleotide analogues * Adefovir * Cidofovir * Tenofovir * Open-ring ANP analogues Subject RIV: CC - Organic Chemistry Impact factor: 2.878, year: 2006

  16. Studies directed toward the exploitation of vicinal diols in the synthesis of (+-nebivolol intermediates

    Directory of Open Access Journals (Sweden)

    Runjun Devi

    2017-03-01

    Full Text Available While the exploitation of the Sharpless asymmetric dihydroxylation as the source of chirality in the synthesis of acyclic molecules and saturated heterocycles has been tremendous, its synthetic utility toward chiral benzo-annulated heterocycles is relatively limited. Thus, in the search for wider applications of Sharpless asymmetric dihydroxylation-derived diols for the synthesis of benzo-annulated heterocycles, we report herein our studies in the asymmetric synthesis of (R-1-((R-6-fluorochroman-2-ylethane-1,2-diol, (R-1-((S-6-fluorochroman-2-ylethane-1,2-diol and (S-6-fluoro-2-((R-oxiran-2-ylchroman, which have been used as late-stage intermediates for the asymmetric synthesis of the antihypertensive drug (S,R,R,R-nebivolol. Noteworthy is that a large number of racemic and asymmetric syntheses of nebivolol and their intermediates have been described in the literature, however, the Sharpless asymmetric dihydroxylation has never been employed as the sole source of chirality for this purpose.

  17. Rapid synthesis of macrocycles from diol precursors

    DEFF Research Database (Denmark)

    Wingstrand, Magnus; Madsen, Charlotte Marie; Clausen, Mads Hartvig

    2009-01-01

    A method for the formation of synthetic macrocycles with different ring sizes from diols is presented. Reacting a simple diol precursor with electrophilic reagents leads to a cyclic carbonate, sulfite or phosphate in a single step in 25-60% yield. Converting the cyclization precursor to a bis-ele...

  18. Development of aliphatic biodegradable photoluminescent polymers.

    Science.gov (United States)

    Yang, Jian; Zhang, Yi; Gautam, Santosh; Liu, Li; Dey, Jagannath; Chen, Wei; Mason, Ralph P; Serrano, Carlos A; Schug, Kevin A; Tang, Liping

    2009-06-23

    None of the current biodegradable polymers can function as both implant materials and fluorescent imaging probes. The objective of this study was to develop aliphatic biodegradable photoluminescent polymers (BPLPs) and their associated cross-linked variants (CBPLPs) for biomedical applications. BPLPs are degradable oligomers synthesized from biocompatible monomers including citric acid, aliphatic diols, and various amino acids via a convenient and cost-effective polycondensation reaction. BPLPs can be further cross-linked into elastomeric cross-linked polymers, CBPLPs. We have shown representatively that BPLP-cysteine (BPLP-Cys) and BPLP-serine (BPLP-Ser) offer advantages over the traditional fluorescent organic dyes and quantum dots because of their preliminarily demonstrated cytocompatibility in vitro, minimal chronic inflammatory responses in vivo, controlled degradability and high quantum yields (up to 62.33%), tunable fluorescence emission (up to 725 nm), and photostability. The tensile strength of CBPLP-Cys film ranged from 3.25 +/- 0.13 MPa to 6.5 +/- 0.8 MPa and the initial Modulus was in a range of 3.34 +/- 0.15 MPa to 7.02 +/- 1.40 MPa. Elastic CBPLP-Cys could be elongated up to 240 +/- 36%. The compressive modulus of BPLP-Cys (0.6) (1:1:0.6 OD:CA:Cys) porous scaffold was 39.60 +/- 5.90 KPa confirming the soft nature of the scaffolds. BPLPs also possess great processability for micro/nano-fabrication. We demonstrate the feasibility of using BPLP-Ser nanoparticles ("biodegradable quantum dots") for in vitro cellular labeling and noninvasive in vivo imaging of tissue engineering scaffolds. The development of BPLPs and CBPLPs represents a new direction in developing fluorescent biomaterials and could impact tissue engineering, drug delivery, bioimaging.

  19. 3000 Horsepower super conductive field acyclic motor

    International Nuclear Information System (INIS)

    Marshall, R.

    1983-01-01

    A 3000 hp acyclic motor was assembled and tested utilizing superconducting field coils. The magnet assembly is designed as a quadrupole magnet, utilizing a multifilamentary niobium titanium superconductor. Each magnet coil is 18 inches in diameter and 10 inches long, and operates at rated current of 200 amperes, providing 5.8 tesla in the bore of the coils in the motor configuration. The average winding current density is 10,600 A/cm 2 . The acyclic motor is of a drum-type design with liquid metal current collectors, and is designed to model full-scale machinery for ship propulsion applications. Laboratory test data verified the electrical and electromagnetic design to be within three percent of the calculated values

  20. Acyclicity in edge-colored graphs

    DEFF Research Database (Denmark)

    Gutin, Gregory; Jones, Mark; Sheng, Bin

    2017-01-01

    A walk W in edge-colored graphs is called properly colored (PC) if every pair of consecutive edges in W is of different color. We introduce and study five types of PC acyclicity in edge-colored graphs such that graphs of PC acyclicity of type i is a proper superset of graphs of acyclicity of type i......+1, i=1,2,3,4. The first three types are equivalent to the absence of PC cycles, PC closed trails, and PC closed walks, respectively. While graphs of types 1, 2 and 3 can be recognized in polynomial time, the problem of recognizing graphs of type 4 is, somewhat surprisingly, NP-hard even for 2-edge-colored...... graphs (i.e., when only two colors are used). The same problem with respect to type 5 is polynomial-time solvable for all edge-colored graphs. Using the five types, we investigate the border between intractability and tractability for the problems of finding the maximum number of internally vertex...

  1. Iridium catalysed synthesis of piperazines from diols

    DEFF Research Database (Denmark)

    Nordstrøm, Lars Ulrik Rubæk; Madsen, Robert

    2007-01-01

    A green and atom-economical method has been developed for the synthesis of piperazines by cyclocondensation of diols and amines in aqueous media in the presence of a catalytic amount of [Cp*IrCl2]2....

  2. Polar reactions of acyclic conjugated bisallenes

    Directory of Open Access Journals (Sweden)

    Reiner Stamm

    2013-01-01

    Full Text Available The chemical behaviour of various alkyl-substituted, acyclic conjugated bisallenes in reactions involving polar intermediates and/or transition states has been investigated on a broad scale for the first time. The reactions studied include lithiation, reaction of the thus formed organolithium salts with various electrophiles (among others, allyl bromide, DMF and acetone, oxidation to cyclopentenones and epoxides, hydrohalogenation (HCl, HBr addition, halogenation (Br2 and I2 addition, and [2 + 2] cycloaddition with chlorosulfonyl isocyanate. The resulting adducts were fully characterized by spectroscopic and analytical methods; they constitute interesting substrates for further organic transformations.

  3. Microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock

    Energy Technology Data Exchange (ETDEWEB)

    Akinlua, A., E-mail: geochemresearch@yahoo.com [Fossil Fuels and Environmental Geochemistry Group, Department of Chemistry, Obafemi Awolowo University, Ile-Ife (Nigeria); Jochmann, M.A.; Laaks, J.; Ewert, A.; Schmidt, T.C. [Instrumental Analytical Chemistry, University Duisburg-Essen, Universitaetsstr, 5, 45141 Essen (Germany)

    2011-04-08

    The extraction of aliphatic hydrocarbons from petroleum source rock using nonionic surfactants with the assistance of microwave was investigated and the conditions for maximum yield were determined. The results showed that the extraction temperatures and kinetic rates have significant effects on extraction yields of aliphatic hydrocarbons. The optimum temperature for microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock was 105 deg. C. The optimum extraction time for the aliphatic hydrocarbons was at 50 min. Concentration of the nonionic surfactant solution and irradiation power had significant effect on the yields of aliphatic hydrocarbons. The yields of the analytes were much higher using microwave assisted nonionic surfactant extraction than with Soxhlet extraction. The recoveries of the n-alkanes and acyclic isoprenoid hydrocarbons for GC-MS analysis from the extractant nonionic surfactant solution by in-tube extraction (ITEX 2) with a TENAX TA adsorbent were found to be efficient. The results show that microwave-assisted nonionic surfactant extraction (MANSE) is a good and efficient green analytical preparatory technique for geochemical evaluation of petroleum source rock.

  4. Microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock.

    Science.gov (United States)

    Akinlua, A; Jochmann, M A; Laaks, J; Ewert, A; Schmidt, T C

    2011-04-08

    The extraction of aliphatic hydrocarbons from petroleum source rock using nonionic surfactants with the assistance of microwave was investigated and the conditions for maximum yield were determined. The results showed that the extraction temperatures and kinetic rates have significant effects on extraction yields of aliphatic hydrocarbons. The optimum temperature for microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock was 105°C. The optimum extraction time for the aliphatic hydrocarbons was at 50 min. Concentration of the nonionic surfactant solution and irradiation power had significant effect on the yields of aliphatic hydrocarbons. The yields of the analytes were much higher using microwave assisted nonionic surfactant extraction than with Soxhlet extraction. The recoveries of the n-alkanes and acyclic isoprenoid hydrocarbons for GC-MS analysis from the extractant nonionic surfactant solution by in-tube extraction (ITEX 2) with a TENAX TA adsorbent were found to be efficient. The results show that microwave-assisted nonionic surfactant extraction (MANSE) is a good and efficient green analytical preparatory technique for geochemical evaluation of petroleum source rock. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Catalytic enantioselective allyl- and crotylboration of aldehydes using chiral diol x SnCl4 complexes. optimization, substrate scope and mechanistic investigations.

    Science.gov (United States)

    Rauniyar, Vivek; Zhai, Huimin; Hall, Dennis G

    2008-07-02

    We report a novel class of C2-symmetric chiral diols derived from the hydrobenzoin skeleton. The combination of these diols with SnCl4 under Yamamoto's concept of Lewis acid assisted Brønsted acidity (LBA catalysis) leads to high levels of asymmetric induction in the allylboration of aldehydes by commercially available allylboronic acid pinacol ester 1a. The corresponding homoallylic alcohol products of synthetically useful aliphatic aldehydes are obtained in excellent yields with up to 98:2 er. This combined acid manifold is also efficient in catalyzing the diastereo- and enantioselective crotylboration of aldehydes, thus providing the propionate units in >95:5 dr and up to 98:2 er. The X-ray crystal structure of the optimal diol x SnCl4 complex, Vivol (4m) x SnCl4, unambiguously shows the Brønsted acidic character of this LBA catalyst and its highly dissymmetrical environment. Further controls have ruled out a possible boron trans-esterification mechanism with the chiral diol and point to LBA catalyst-derived activation of the pinacol allylic boronates 1. Due to slow dissociation of the diol x SnCl4 complex, a small excess of diol is required in order to suppress a competing racemic cycle catalyzed by free SnCl4.

  6. Cs2CO3-promoted polycondensation of CO2with diols and dihalides for the synthesis of miscellaneous polycarbonates

    KAUST Repository

    Chen, Zuliang

    2016-07-12

    A one-pot protocol for the direct synthesis of polycarbonates through polycondensation of diols, dihalides and CO2 in the presence of Cs2CO3 is described. The conditions were optimized by studying the polycondensation of CO2 with 1,4-phenylenedimethanol and 1,4-dibromobutane as model monomers. Then, diols and dihalides with different spacers between the reactive groups including aliphatic, aromatic and poly(ethylene glycol) were tested under optimal conditions. Miscellaneous polycarbonates exhibiting molar masses in the range of 43 000 g mol-1 (GPC) and conversion higher than 96% could be obtained. The proposed mechanism rules out the possibility of ether linkage formation during polycondensation and accounts for the creation of carbonate linkages in two different ways. The thermal properties of the synthesized polycarbonates were unveiled by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). © 2016 The Royal Society of Chemistry.

  7. Oxidation of some aliphatic and cyclic diols by cerium(4) in perchloric acid solutions

    International Nuclear Information System (INIS)

    Dehka, M; Dzegets, Yu.

    1998-01-01

    Oxidation velocities of 1,5-pentandiol and 1,8-octanediol by cerium(4) in water solutions of perchloric acid, as well as the dependence of Ce(4) quantity reduced by trans-1,2-cyclohexanol on the reduction time are studied. Stoichiometry of the process is determined, intermediate and final products of oxidation are identified. Possible reaction mechanisms are proposed [ru

  8. Plasmid Involvement in Acyclic Isoprenoid Metabolism by Pseudomonas putida

    OpenAIRE

    Vandenbergh, Peter A.; Wright, Ann M.

    1983-01-01

    An organism identified as Pseudomonas putida was found to utilize citronellol or geraniol as the sole carbon and energy source. The ability to degrade these acyclic isoprenols was associated with pSRQ50, a 50-megadalton transmissible plasmid.

  9. Polyurethane elastomers made from linear polybutadiene diols

    Czech Academy of Sciences Publication Activity Database

    Špírková, Milena

    2002-01-01

    Roč. 85, č. 1 (2002), s. 84-91 ISSN 0021-8995 R&D Projects: GA AV ČR KSK2050602 Institutional research plan: CEZ:AV0Z4050913 Keywords : polyurethanes * polybutadiene diol * isocyanurate groups Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.927, year: 2002

  10. Propagating distributions up directed acyclic graphs.

    Science.gov (United States)

    Baum, E B; Smith, W D

    1999-01-01

    In a previous article, we considered game trees as graphical models. Adopting an evaluation function that returned a probability distribution over values likely to be taken at a given position, we described how to build a model of uncertainty and use it for utility-directed growth of the search tree and for deciding on a move after search was completed. In some games, such as chess and Othello, the same position can occur more than once, collapsing the game tree to a directed acyclic graph (DAG). This induces correlations among the distributions at sibling nodes. This article discusses some issues that arise in extending our algorithms to a DAG. We give a simply described algorithm for correctly propagating distributions up a game DAG, taking account of dependencies induced by the DAG structure. This algorithm is exponential time in the worst case. We prove that it is #P complete to propagate distributions up a game DAG correctly. We suggest how our exact propagation algorithm can yield a fast but inexact heuristic.

  11. Synthesis of some novel hydrazono acyclic nucleoside analogues

    Directory of Open Access Journals (Sweden)

    Mohammad N. Soltani Rad

    2010-05-01

    Full Text Available The syntheses of novel hydrazono acyclic nucleosides similar to miconazole scaffolds are described. In this series of acyclic nucleosides, pyrimidine as well as purine and other azole derivatives replaced the imidazole function in miconazole and the ether group was replaced with a hydrazone moiety using phenylhydrazine. To interpret the dominant formation of (E-hydrazone derivatives rather than (Z-isomers, PM3 semiempirical quantum mechanic calculations were carried out which indicated that the (E-isomers had the lower heats of formation.

  12. A novel 13 residue acyclic peptide from the marine snail, Conus monile, targets potassium channels.

    Science.gov (United States)

    Sudarslal, Sadasivannair; Singaravadivelan, Govindaswamy; Ramasamy, Palanisamy; Ananda, Kuppanna; Sarma, Siddhartha P; Sikdar, Sujit K; Krishnan, K S; Balaram, Padmanabhan

    2004-05-07

    A novel 13-residue peptide Mo1659 has been isolated from the venom of a vermivorous cone snail, Conus monile. HPLC fractions of the venom extract yielded an intense UV absorbing fraction with a mass of 1659Da. De novo sequencing using both matrix assisted laser desorption and ionization and electrospray MS/MS methods together with analysis of proteolytic fragments successfully yielded the amino acid sequence, FHGGSWYRFPWGY-NH(2). This was further confirmed by comparison with the chemically synthesized peptide and by conventional Edman sequencing. Mo1659 has an unusual sequence with a preponderance of aromatic residues and the absence of apolar, aliphatic residues like Ala, Val, Leu, and Ile. Mo1659 has no disulfide bridges distinguishing it from the conotoxins and bears no sequence similarity with any of the acyclic peptides isolated thus far from the venom of cone snails. Electrophysiological studies on the effect of Mo1659 on measured currents in dorsal root ganglion neurons suggest that the peptide targets non-inactivating voltage-dependent potassium channels.

  13. Antiviral acyclic nucleoside phosphonates: New structures and prodrugs

    Czech Academy of Sciences Publication Activity Database

    Krečmerová, Marcela; Tichý, Tomáš; Pomeisl, Karel; Andrei, G.; Balzarini, J.; Snoeck, R.

    2016-01-01

    Roč. 1, č. 2 (2016), s. 37 [PharmaMed-2016. International Conference on Medicinal and Pharmaceutical Chemistry . 05.12.2016-07.12.2016, Dubai] R&D Projects: GA ČR(CZ) GA14-00522S Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * prodrugs * antivirals * 5-azacytosine Subject RIV: CC - Organic Chemistry

  14. Polynomial kernels for deletion to classes of acyclic digraphs

    NARCIS (Netherlands)

    Mnich, Matthias; van Leeuwen, E.J.

    2017-01-01

    We consider the problem to find a set X of vertices (or arcs) with |X| ≤ k in a given digraph G such that D = G − X is an acyclic digraph. In its generality, this is Directed Feedback Vertex Set (or Directed Feedback Arc Set); the existence of a polynomial kernel for these problems is a notorious

  15. New acyclic diterpenic acids from yacon (Smallanthus sonchifolius) leaves.

    Science.gov (United States)

    Mercado, María I; Coll Aráoz, María V; Grau, Alfredo; Catalán, César A N

    2010-11-01

    Two new acyclic diterpenoids, smaditerpenic acid E (1a) and F (2a), along with nineteen melampolide-type sesquiterpene lactones, six of them not previously reported in yacon, were isolated from the methylene chloride leaf rinse extract. Their structures were elucidated from 1D and 2D NMR experiments and gas chromatography coupled to mass spectrometry.

  16. Synthesis and complexation characteristics of phenanthroline and bipyridine diols

    NARCIS (Netherlands)

    Koning, B.; Boer, J.W. de; Meetsma, A.; Kellogg, R.M.

    2004-01-01

    Neocuproine (2,9-dimethyl-1,10-phenanthroline) 1 was converted to achiral and chiral tetradentate phenanthroline diols 3a-c by addition to benzophenone, adamantanone and camphor, respectively. Analogously 6,6'-dimethyl-2,2'-bipyridine 2 was converted to diol 7a on base-induced addition to

  17. New applications of the interaction between diols and boronic acids

    NARCIS (Netherlands)

    Duval, F.L.

    2015-01-01

    Florine Duval - New applications of the interaction between diols and boronic acids – Summary Chapter 1 introduces the theory and known applications of the interaction between boronic acids and diols, and explains the context of this thesis. Diagnosis of

  18. GRASr2 Evaluation of aliphatic acyclic and alicyclic terpenoid tertiary alcohols and structurally related substances used as flavoring ingredients

    NARCIS (Netherlands)

    Marnett, L.J.; Cohen, S.M.; Fukushima, S.; Gooderham, N.J.; Hecht, S.S.; Rietjens, I.; Smith, R.L.; Adams, T.B.; Bastaki, M.; Harman, C.L.; McGowen, M.M.; Taylor, S.V.

    2014-01-01

    This publication is the 1st in a series of publications by the Expert Panel of the Flavor and Extract Manufacturers Assoc. summarizing the Panel's 3rd re-evaluation of Generally Recognized as Safe (GRAS) status referred to as the GRASr2 program. In 2011, the Panel initiated a comprehensive program

  19. Aliphatic Nucleophilic Radio-fluorination

    International Nuclear Information System (INIS)

    Roeda, D.; Dolle, F.

    2010-01-01

    In this review we are looking at some aspects of nucleophilic aliphatic radio-fluorination, notably the labelled fluoride source, design aspects, the leaving group and the solvent. It should be clear that there is more to this branch of radiolabelling than one would suspect from the frequently used standard tosylate replacement with kryptofix/[ 18 F]fluoride in acetonitrile or DMSO. Competitive elimination can be a serious problem that can affect both yield and purification. De-protection of sensitive groups after radiolabelling and its possible side reactions can complicate purification. The right choice of leaving group and protecting groups may be crucial. Newer developments such as the use of tertiary alcohols or ionic liquids as solvents, long-chain poly-fluorinated sulphonate leaving groups facilitating fluorous solid phase extraction, or immobilisation of the precursor on a solid phase support may help to solve these problems, for example the longstanding problems with [ 18 F]FLT, whereas older concepts such as certain cyclic reactive entities for ring opening or even an abandoned reagent as [ 18 F]DAST should not be forgotten. (authors)

  20. Partial molar volumes of organic solutes in water. XXVIII. Three aliphatic poly(ethylene glycols) at temperatures T = 298 K–573 K and pressures up to 30 MPa

    International Nuclear Information System (INIS)

    Cibulka, Ivan

    2017-01-01

    Highlights: • Standard molar volumes of three poly(ethylene glycols) in water are presented. • Data were obtained in the range T from (298 to 573) K and p up to 30 MPa. • Data are analyzed and compared with those of similar solutes. - Abstract: Densities of dilute aqueous solutions of three poly(ethylene glycols): 3-oxapentane-1,5-diol (diethylene glycol), 3,6-dioxaoctane-1,8-diol (triethylene glycol), and 3,5,9-trioxaundecane-1,11-diol (tetraethylene glycol) measured in the temperature range from (298 to 573) K and at pressures up to 30 MPa using an automated flow vibrating-tube densimeter are reported. Standard molar volumes were evaluated from the measured data. Present data complement both the previous measurements performed at atmospheric pressure in the temperature range from (278 to 343) K and the data already available for the first member of the homologous series (ethylene glycol). A comparison with data previously measured for the homologous series of linear aliphatic polyethers (poly(ethylene glycol) dimethyl ethers, glymes), diethylene glycol monomethyl ether (3,6-dioxaheptan-1-ol), and selected alkane-α,ω-diols is presented.

  1. Detecting Elusive Intermediates in Carbohydrate Conversion: A Dynamic Ensemble of Acyclic Glucose-Catalyst Complexes

    DEFF Research Database (Denmark)

    Meier, Sebastian; Karlsson, Magnus; Jensen, Pernille Rose

    2017-01-01

    The role of acyclic carbohydrates in pathways towards value-added chemicals has remained poorly characterized due to the low population of acyclic forms, and due to their instability under reaction conditions. We conduct steady-state and pre-steady state measurements by direct reaction progress m...

  2. Towards Optimal Event Detection and Localization in Acyclic Flow Networks

    KAUST Repository

    Agumbe Suresh, Mahima

    2012-01-03

    Acyclic flow networks, present in many infrastructures of national importance (e.g., oil & gas and water distribution systems), have been attracting immense research interest. Existing solutions for detecting and locating attacks against these infrastructures, have been proven costly and imprecise, especially when dealing with large scale distribution systems. In this paper, to the best of our knowledge for the first time, we investigate how mobile sensor networks can be used for optimal event detection and localization in acyclic flow networks. Sensor nodes move along the edges of the network and detect events (i.e., attacks) and proximity to beacon nodes with known placement in the network. We formulate the problem of minimizing the cost of monitoring infrastructure (i.e., minimizing the number of sensor and beacon nodes deployed), while ensuring a degree of sensing coverage in a zone of interest and a required accuracy in locating events. We propose algorithms for solving these problems and demonstrate their effectiveness with results obtained from a high fidelity simulator.

  3. On Event Detection and Localization in Acyclic Flow Networks

    KAUST Repository

    Suresh, Mahima Agumbe

    2013-05-01

    Acyclic flow networks, present in many infrastructures of national importance (e.g., oil and gas and water distribution systems), have been attracting immense research interest. Existing solutions for detecting and locating attacks against these infrastructures have been proven costly and imprecise, particularly when dealing with large-scale distribution systems. In this article, to the best of our knowledge, for the first time, we investigate how mobile sensor networks can be used for optimal event detection and localization in acyclic flow networks. We propose the idea of using sensors that move along the edges of the network and detect events (i.e., attacks). To localize the events, sensors detect proximity to beacons, which are devices with known placement in the network. We formulate the problem of minimizing the cost of monitoring infrastructure (i.e., minimizing the number of sensors and beacons deployed) in a predetermined zone of interest, while ensuring a degree of coverage by sensors and a required accuracy in locating events using beacons. We propose algorithms for solving the aforementioned problem and demonstrate their effectiveness with results obtained from a realistic flow network simulator.

  4. The influence of montmorillonite and bentonite addition on thermal properties of polyurethanes based on aliphatic polycarbonate diols

    Czech Academy of Sciences Publication Activity Database

    Pavličević, J.; Špírková, Milena; Strachota, Adam; Meszaros Szecsenyi, K.; Lazić, N.; Budinski-Simendic, J.

    2010-01-01

    Roč. 509, 1/2 (2010), s. 73-80 ISSN 0040-6031 R&D Projects: GA ČR GAP108/10/0195 Institutional research plan: CEZ:AV0Z40500505 Keywords : segmented polyurethanes * thermal stability * elastomers Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.908, year: 2010

  5. Synthesis of Siloxyalumoxanes and Alumosiloxanes Based on Organosilicon Diols

    Directory of Open Access Journals (Sweden)

    Galina Shcherbakova

    2017-10-01

    Full Text Available We have drawn a few interesting conclusions while studying reaction products of Ph2Si(OH2 with Al(iBu3 and tetraisobutylalumoxane. In the first place, this is the production (at a Ph2Si(OH2 and Al(iBu3 equimolar ratio of an oligomer siloxyalumoxane structure with alternating four- and six-member rings. In addition, it shows isobutyl and phenyl group migration between aluminum and silicon due to the formation of an intramolecular four-member cyclic complex [Ph2(OHSiO]Al(iBu2 → [(iBuPh(OHSiO]Al(iBuPh. Ph2Si(OH2 interaction with Al(iBu3 not only starts from intramolecular complex production, but the chain is terminated for the same reason, which in the case of the Ph2Si(OH2 reaction with tetraisobutylalumoxane results in failure of to obtain high-polymer siloxyalumoxane compounds. When Al(iBu3 interacts with α- and γ-diols, no oligomer compounds are produced. In the Al(iBu3 reaction with α, γ-diols are created in monomer compounds that are likely to have a cyclic structure. Notably, when Al(iBu3 interacts with only α-diol, a double excess of Al(iBu3 allows for full replacement of hydrogen in the α-diol hydroxyl groups by aluminum alkyl residue with 1,3-bis(diisobutylalumoxymethyl-1,1,3,3-tetramethyldisiloxane production. At an equimolar ratio of initial reagents, the second isobutyl radical at Al does not interact with the second hydroxyl group of α-diol, apparently due to the steric hindrance, and 1-(diisobutylalumoxymethyl-3-(hydroxymethyl-1,1,3,3-tetramethyl-disiloxane is produced. Al(iBu3 reactions with γ-diol also result in monomer compounds, but the presence of a chain consisting of three CH2-groups between Si and the hydroxyl group facilitates interaction between the second hydroxyl group of γ-diol and the second isobutyl radical Al(iBu3. Tetraisobutylalumoxane reactions with α- and γ-diols result in oligomer compounds.

  6. DFT Study of the Molybdenum-Catalyzed Deoxydehydration of Vicinal Diols

    DEFF Research Database (Denmark)

    Lupp, Daniel; Christensen, Niels Johan; Dethlefsen, Johannes Rytter

    2015-01-01

    The mechanism of the molybdenum-catalyzed deoxydehydration (DODH) of vicinal diols has been investigated using density functional theory. The proposed catalytic cycle involves condensation of the diol with an MoVI oxo complex, oxidative cleavage of the diol resulting in an MoIV complex, and extru...

  7. Modelling discrete longitudinal data using acyclic probabilistic finite automata

    DEFF Research Database (Denmark)

    Anantharama Ankinakatte, Smitha; Edwards, David

    2015-01-01

    to minimize a penalized likelihood criterion such as AIC or BIC is described. This algorithm is compared to one implemented in Beagle, a widely used program for processing genomic data, both in terms of rate of convergence to the true model as the sample size increases, and a goodness-of-fit measure assessed...... using cross-validation. The comparisons are based on three data sets, two from molecular genetics and one from social science. The proposed algorithm performs at least as well as the algorithm in Beagle in both respects......Acyclic probabilistic finite automata (APFA) constitute a rich family of models for discrete longitudinal data. An APFA may be represented as a directed multigraph, and embodies a set of context-specific conditional independence relations that may be read off the graph. A model selection algorithm...

  8. Selective discrimination of cyclodextrin diols using cyclic sulfates

    DEFF Research Database (Denmark)

    Petrillo, Marta; Marinescu, Lavinia; Rousseau, Cyril

    2009-01-01

    A method for selective monofunctionalition of readily available cyclodextrin diols (2(A-F),3(A-F),6(B,C,E,F)-hexadeca-O-benzyl-alpha-cyclodextrin and 2(A-G),3(A-G),6(B,C,E-G)-nonadeca-O-benzyl-beta-cyclodextrin) by regioselective nucleophilic opening of their cyclic sulfates is presented. Althoug...

  9. Kinetics and mechanism of the oxidation of some diols by ...

    Indian Academy of Sciences (India)

    Michaelis–Menten type kinetics is observed with respect to diol. Addition of benzyltrimethylammonium chloride does not affect the rate. Tribromide ion is postulated to be the reactive oxidizing species. Oxidation of [1,1,2,2-2H4] ethanediol shows the absence of a kinetic isotope effect. The reaction exhibits substantial solvent.

  10. Kinetics and mechanism of the oxidation of some diols by ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 1 ... The kinetics of oxidation of five vicinal and four non-vicinal diols, and two of their monoethers by benzyltrimethylammonium tribromide (BTMAB) have been studied in ... Oxidation of [1,1,2,2-2H4] ethanediol shows the absence of a kinetic isotope effect.

  11. epoxy isocapnolactone and 8- hydroxyisocapnolactone-2'3'-diol ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    hydroxyisocapnolactone-2',3'-diol at 50% of cell population (IC50) was found to be 4.6 µg/ml (13.5 µM) and 3 µg/ml (7.8 µM) on CEM-SS cells, respectively. From DNA fragmentation, Acridine orange and Propidium iodide staining and electron.

  12. short communication aliphatic and polycyclic aromatic hydrocarbons ...

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT. The impact of sunlight on aliphatic and polycyclic aromatic hydrocarbons profiles of Agbabu natural bitumen in Nigeria was investigated. The raw flow type of the bitumen was purified and exposed to sunlight for six consecutive months. Different portions of the bitumen were withdrawn at an interval of one.

  13. Aliphatic polyester block polymers: renewable, degradable, and sustainable.

    Science.gov (United States)

    Hillmyer, Marc A; Tolman, William B

    2014-08-19

    Nearly all polymers are derived from nonrenewable fossil resources, and their disposal at their end of use presents significant environmental problems. Nonetheless, polymers are ubiquitous, key components in myriad technologies and are simply indispensible for modern society. An important overarching goal in contemporary polymer research is to develop sustainable alternatives to "petro-polymers" that have competitive performance properties and price, are derived from renewable resources, and may be easily and safely recycled or degraded. Aliphatic polyesters are particularly attractive targets that may be prepared in highly controlled fashion by ring-opening polymerization of bioderived lactones. However, property profiles of polyesters derived from single monomers (homopolymers) can limit their applications, thus demanding alternative strategies. One such strategy is to link distinct polymeric segments in an A-B-A fashion, with A and B chosen to be thermodynamically incompatible so that they can self-organize on a nanometer-length scale and adopt morphologies that endow them with tunable properties. For example, such triblock copolymers can be useful as thermoplastic elastomers, in pressure sensitive adhesive formulations, and as toughening modifiers. Inspired by the tremendous utility of petroleum-derived styrenic triblock copolymers, we aimed to develop syntheses and understand the structure-property profiles of sustainable alternatives, focusing on all renewable and all readily degradable aliphatic polyester triblocks as targets. Building upon oxidation chemistry reported more than a century ago, a constituent of the peppermint plant, (-)-menthol, was converted to the ε-caprolactone derivative menthide. Using a diol initiator and controlled catalysis, menthide was polymerized to yield a low glass transition temperature telechelic polymer (PM) that was then further functionalized using the biomass-derived monomer lactide (LA) to yield fully renewable PLA

  14. Exploring Lactobacillus reuteri DSM20016 as a biocatalyst for transformation of longer chain 1,2-diols: Limits with microcompartment.

    Science.gov (United States)

    Chen, Lu; Hatti-Kaul, Rajni

    2017-01-01

    Lactobacillus reuteri metabolises glycerol efficiently to form 3-hydroxypropionic acid (3-HP) and 1,3-propanediol (1,3PDO) by the same mechanism as that for 1,2-propanediol (1,2PDO) conversion to propionic acid and propanol via its propanediol utilization (pdu) pathway. Pdu enzymes are encoded by the pdu-operon, which also contain genes encoding the shell proteins of the microcompartment housing the metabolic pathway. In this work the selectivity and kinetics of the reactions catalysed by L. reuteri DSM20016 Pdu enzymes glycerol dehydratase (GDH), 1,3-propanediol oxidoreductase (PduQ) and coenzyme-A acylating propionaldehyde dehydrogenase (PduP), produced recombinantly, was investigated against corresponding substrates of different chain lengths. Glycerol dehydratase exhibited activity against C2-C4 polyols, with the highest activity against glycerol and 1,2-propanediol (1,2-PDO). A double mutant of the pduC gene of GDH (PduC-S302A/Q337A) was constructed that displayed lowered activity against glycerol and 1,2PDO but extended the substrate range upto C6-diol. The best substrate for both PduQ and PduP was 3-hydroxypropanal (3HPA), although PduP exhibited nearly 10-fold higher specific activity. The enzymes also showed some activity against C3-C10 aliphatic aldehydes, with PduP having higher relative activity. Subsequently, transformation of polyols using whole cells of L. reuteri containing the wild type- and mutated GDH, respectively, confirmed the reduced activity of the mutant against glycerol and 1,2PDO, but its activity against longer substrates was negligible. In contrast, recombinant Escherichia coli BL21(DE3) cells harboring the GDH variant converted diols with up to C6 carbon chain length to their respective aldehydes, suggesting that the protein shell of the microcompartment in L. reuteri posed a barrier to the passage of longer chain substrate.

  15. The mechanism of radiothermoluminescence of aliphatic ketones

    International Nuclear Information System (INIS)

    Kroh, J.; Wypych, M.

    1975-01-01

    Measurements of the bleaching spectra were performed in the wavelength range 350-800 nm using the following ketones as models: acetone, methyl butyl ketone, and dipropyl ketone. The spectra of selective bleaching obtained for all types of aliphatic ketones were similar. Based on these spectra the two kinds of chemical traps of electrons in ketones were interpreted as molecular anions and anion radicals. Recombination of charges is not the only mechanism leading to the formation of radiothermoluminescence (RTL) centres. For higher aliphatic ketones, recombination within the charge transfer complexes is likely to be an additional source of RTL emission. The contribution of this type of RTL is inversely proportional to ketone polarity. (author)

  16. Combinations of Aromatic and Aliphatic Radiolysis.

    Science.gov (United States)

    LaVerne, Jay A; Dowling-Medley, Jennifer

    2015-10-08

    The production of H(2) in the radiolysis of benzene, methylbenzene (toluene), ethylbenzene, butylbenzene, and hexylbenzene with γ-rays, 2-10 MeV protons, 5-20 MeV helium ions, and 10-30 MeV carbon ions is used as a probe of the overall radiation sensitivity and to determine the relative contributions of aromatic and aliphatic entities in mixed hydrocarbons. The addition of an aliphatic side chain with progressively from one to six carbon lengths to benzene increases the H(2) yield with γ-rays, but the yield seems to reach a plateau far below that found from a simple aliphatic such as cyclohexane. There is a large increase in H(2) with LET (linear energy transfer) for all of the substituted benzenes, which indicates that the main process for H(2) formation is a second-order process and dominated by the aromatic entity. The addition of a small amount of benzene to cyclohexane can lower the H(2) yield from the value expected from a simple mixture law. A 50:50% volume mixture of benzene-cyclohexane has essentially the same H(2) yield as cyclohexylbenzene at a wide variation in LET, suggesting that intermolecular energy transfer is as efficient as intramolecular energy transfer.

  17. Synthesis and antiviral activities of hexadecyloxypropyl prodrugs of acyclic nucleoside phosphonates containing guanine or hypoxanthine and a (S)-HPMP or PEE acyclic moiety

    Czech Academy of Sciences Publication Activity Database

    Tichý, Tomáš; Andrei, G.; Snoeck, R.; Balzarini, J.; Dračínský, Martin; Krečmerová, Marcela

    2012-01-01

    Roč. 55, Sep (2012), s. 307-314 ISSN 0223-5234 R&D Projects: GA ČR GAP207/11/0108; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : antivirals * prodrugs * acyclic nucleoside phosphonate * phosphonate ester Subject RIV: CC - Organic Chemistry Impact factor: 3.499, year: 2012

  18. Learning directed acyclic graphical structures with genetical genomics data.

    Science.gov (United States)

    Gao, Bin; Cui, Yuehua

    2015-12-15

    Large amount of research efforts have been focused on estimating gene networks based on gene expression data to understand the functional basis of a living organism. Such networks are often obtained by considering pairwise correlations between genes, thus may not reflect the true connectivity between genes. By treating gene expressions as quantitative traits while considering genetic markers, genetical genomics analysis has shown its power in enhancing the understanding of gene regulations. Previous works have shown the improved performance on estimating the undirected network graphical structure by incorporating genetic markers as covariates. Knowing that gene expressions are often due to directed regulations, it is more meaningful to estimate the directed graphical network. In this article, we introduce a covariate-adjusted Gaussian graphical model to estimate the Markov equivalence class of the directed acyclic graphs (DAGs) in a genetical genomics analysis framework. We develop a two-stage estimation procedure to first estimate the regression coefficient matrix by [Formula: see text] penalization. The estimated coefficient matrix is then used to estimate the mean values in our multi-response Gaussian model to estimate the regulatory networks of gene expressions using PC-algorithm. The estimation consistency for high dimensional sparse DAGs is established. Simulations are conducted to demonstrate our theoretical results. The method is applied to a human Alzheimer's disease dataset in which differential DAGs are identified between cases and controls. R code for implementing the method can be downloaded at http://www.stt.msu.edu/∼cui. R code for implementing the method is freely available at http://www.stt.msu.edu/∼cui/software.html. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Mathematical simulation of the kinetics of radiation induced hydroxyalkylation of aliphatic saturated alcohols

    International Nuclear Information System (INIS)

    Silaev, M.M.; Bugaenko, L.T.

    1992-01-01

    The paper reports on the development of the kinetics of radiation hydroxymethylation and hydroxypropylation chain processes relating to aliphatic saturated alcohols in the γ-radiolysis of the alcohol-unsaturated compound systems to give 1,2- and 1,4-diols respectively. These processes were simulated mathematically. The kinetic curves computed are in good agreement with the experimental dependences. The kinetic parameters of the processes, including the rate constants for the addition of α-hydroxyalkyl radicals from the saturated alcohols to the double bond of the unsaturated component, viz formaldehyde or 2-propene-1-ol in the systems, were estimated. The constants (in dm 3 /mol.s) for the saturated alcohol-formaldehyde systems incorporating ethanol as the saturated alcohol were found to be (1.5±0.3).10 4 at 413 K and (2.1±0.5).10 4 at 443K; incorporating 1-propanol- (6.0±1.3).10 3 at 413 K; for the saturated alcohol-2-propene-1-ol systems incorporating methanol, ethanol, 1- and 2-propanol-(2.5±0.3).10 4 , (6.5±0.9).10 4 , (2.7±0.4).10 4 and (1.0±0.1).10 5 , respectively, at 433 K. (author)

  20. Antimicrobial and Antibiofilm Potential of Acyclic Amines and Diamines against Multi-Drug Resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Gurmeet Kaur

    2017-09-01

    Full Text Available Multi-drug resistant Staphylococcus aureus (MDRSA remains a great challenge despite a decade of research on antimicrobial compounds against their infections. In the present study, various acyclic amines and diamines were chemically synthesized and tested for their antimicrobial as well as antibiofilm activity against MDRSA. Among all the synthesized compounds, an acyclic diamine, (2,2′-((butane-1,4-diylbis(azanediylbis(methylenediphenol designated as ADM 3, showed better antimicrobial activity (minimum inhibitory concentration at 50 μg/mL and antibiofilm activity (MBIC50 at 5 μg/mL. In addition, ADM 3 was capable of reducing the virulence factors expression (anti-virulence. Confocal laser scanning microscope analysis of the in vitro tested urinary catheters showed biofilm reduction as well as bacterial killing by ADM 3. On the whole, our data suggest that acyclic diamines, especially ADM 3 can be a potent lead for the further studies in alternative therapeutic approaches.

  1. Acyclic cucurbit[n]uril molecular containers enhance the solubility and bioactivity of poorly soluble pharmaceuticals.

    Science.gov (United States)

    Ma, Da; Hettiarachchi, Gaya; Nguyen, Duc; Zhang, Ben; Wittenberg, James B; Zavalij, Peter Y; Briken, Volker; Isaacs, Lyle

    2012-04-15

    The solubility characteristics of 40-70% of new drug candidates are so poor that they cannot be formulated on their own, so new methods for increasing drug solubility are highly prized. Here, we describe a new class of general-purpose solubilizing agents-acyclic cucurbituril-type containers-which increase the solubility of ten insoluble drugs by a factor of between 23 and 2,750 by forming container-drug complexes. The containers exhibit low in vitro toxicity in human liver, kidney and monocyte cell lines, and outbred Swiss Webster mice tolerate high doses of the container without sickness or weight loss. Paclitaxel solubilized by the acyclic cucurbituril-type containers kills cervical and ovarian cancer cells more efficiently than paclitaxel alone. The acyclic cucurbituril-type containers preferentially bind cationic and aromatic drugs, but also solubilize neutral drugs such as paclitaxel, and represent an attractive extension of cyclodextrin-based technology for drug solubilization and delivery.

  2. Validated method for the determination of propane-1,2-diol, butane-2,3-diol, and propane-1,3-diol in cheese and bacterial cultures using phenylboronic esterification and GC-MS.

    Science.gov (United States)

    Badertscher, René; Freiburghaus, Carola; Wechsler, Daniel; Irmler, Stefan

    2017-09-01

    A simple, fast, sensitive, and robust gas chromatography-mass spectrometry (GC-MS) method for the simultaneous determination of propane-1,2-diol, butane-2,3-diol, and propane-1,3-diol in cheese and bacterial cultures was developed. Target analytes were extracted and transformed into their phenylboronic esters prior to analysis. The method showed good sensitivity, without carryover between the samples. The detection limits for propane-1,2-diol, butane-2,3-diol, and propane-1,3-diol in cheese samples were 0.26, 0.02, and 0.11mgkg -1 , respectively, and for bacterial culture samples were 1.32, 0.09, and 0.54mgkg -1 , respectively. The Horwitz ratio showed good precision for all analytes (cheese for all analytes was very broad, from 0 to 1000mgkg -1 , and in bacterial cultures was from 0 to 5000mgkg -1 with R 2 >0.9991. The results confirm excellent applicability of the proposed method for the determination of the target metabolites in cheese and bacterial culture samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Acyclic monoterpenes in tree essential oils as a shrinking agent for waste-expanded polystyrene.

    Science.gov (United States)

    Shimotori, Yasutaka; Hattori, Kazuyuki; Aoyama, Masakazu; Miyakoshi, Tetsuo

    2011-01-01

    We examined the dissolution of polystyrene (PS) into acyclic monoterpenes present in tree essential oils, to develop an environmentally friendly shrinking agent for waste-expanded polystyrene (EPS). The dissolving powers of geranyl acetate, geranylacetone, and geranyl formate [221.8-241.2 g PS (100 g solvent)(-1)] compared favorably with that of (R)-limonene [181.7 g PS (100 g solvent)(-1)]. Their favorable dissolving powers for PS can be explained by their flexible linear structures, which may be more accessible to the inside of bulk PS compared with cyclic monoterpenes. These acyclic monoterpenes and PS were recovered almost quantitatively by simple steam distillation of the PS solution.

  4. Intramolecular cascade rearrangements of enynamine derived ketenimines: access to acyclic and cyclic amidines.

    Science.gov (United States)

    Chauhan, Dinesh Pratapsinh; Varma, Sreejith J; Gudem, Mahesh; Panigrahi, Nihar; Singh, Khushboo; Hazra, Anirban; Talukdar, Pinaki

    2017-06-07

    Copper-catalyzed reaction of enynamines with sulfonylazides provides acyclic and cyclic amidines. Nucleophilic addition of the tethered amino group on the in situ generated ketenimine forms a six-membered cyclic zwitterionic intermediate which facilitates migration of the tethered amino group to the C 5 -center giving the acyclic amidine. On the other hand, migration of a substituent on the amino group to C 2 - and C 4 -centers results in the formation of cyclic amidines. Computational studies were carried out to validate the mechanism which indicates that the product distribution of the process depends on the substitutions on the enynamine backbone.

  5. Distribution of coenzyme B12-dependent diol dehydratase and glycerol dehydratase in selected genera of Enterobacteriaceae and Propionibacteriaceae.

    Science.gov (United States)

    Toraya, T; Kuno, S; Fukui, S

    1980-03-01

    The presence of diol dehydratase and glycerol dehydratase was shown in several bacteria of Enterobacteriaceae grown anaerobically on 1,2-propanediol and on glycerol, respectively. Diol dehydratases of Enterobacteriaceae were immunologically similar, but distinct from that of Propionibacterium freudenreichii.

  6. 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)

  7. 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)

  8. COMPARATIVE STUDIES OF THE EFFECT OF POLYCYCLIC AROMATIC HYDROCARBON GEOMETRY ON THE HYDROLYSIS OF DIOL EPOXIDES

    Science.gov (United States)

    Comparative studies of the effect of polycyclic aromatic hydrocarbon geometry on the hydrolysis of diol epoxides The interaction of the diol epoxides (DEs) of both planar and non-planar PAHs with water have been examined using quantum mechanical and molecular dynamics. Th...

  9. Gem-diol and Ketone Crystal-to-crystal Transition Phenomena.

    Science.gov (United States)

    Bo, Zhang; Sitong, Chen; Weiming, Guo; Weijing, Zhang; Lin, Wang; Li, Yang; Jianguo, Zhang

    2017-10-18

    The generally thought unstable diol compound tetrazyl gem-diol (1, H 2 DTMdiol·2H 2 O), was firstly obtained in crystalline form by culturing the filtrate for ten days after acidification and filtration of aqueous solution of potassium salt of ketone (2, [K(HDTMone)·2H 2 O] n ). The stability of this novel gem-diol compound is found owning to the hydrogen bonds with lattice water molecules and electrophilic tetrazolyl groups. Meanwhile, the undissolved ketone (3, H 2 DTMone) was separated during the filtration in the process of gem-diol compound production. Surprisingly, the crystal-to-crystal perfect transition phenomena from gem-diol (1) to ketone (3) were firstly observed after heating up to 120  ° C as evidenced by X-ray single crystal diffraction and powder X-ray diffraction. These results found here might open new revenues for methylene oxidation and alkanediol chemistry.

  10. Isolation of a Pseudomonas aeruginosa strain from soil that can degrade polyurethane diol.

    Science.gov (United States)

    Mukherjee, Koushik; Tribedi, Prosun; Chowdhury, Arup; Ray, Tanusree; Joardar, Archi; Giri, Subhajit; Sil, Alok Kumar

    2011-04-01

    Polyurethane diol (PUR-diol), a synthetic polymer, is widely used as a modifier for water-soluble resins and emulsions in wood appliances and auto coatings. Non-biodegradability of polyurethanes (PUR) and PUR-based materials poses a threat to environment that has led scientists to isolate microbes capable of degrading PUR. However, the bio-degradation of PUR-diol has not yet been reported. In this study, we report isolation of a soil bacterium that can survive using PUR-diol as sole carbon source. PUR-diol degradation by the organism was confirmed by thin layer chromatographic analysis of the conditioned medium obtained after the growth wherein a significant reduction of PUR-diol was observed compared to non-inoculated medium. To quantify the PUR-diol degradation, a sensitive assay based on High Performance Thin Layer Chromatography has been developed that showed 32% degradation of PUR-diol by the organism in 10 days. Degradation kinetics showed the maximal depletion of PUR-diol during logarithmic growth of the organism indicating a direct relation between the growth and PUR-diol degradation. Mutagenic study and GC-MS analysis revealed that esterase activity is involved in this degradation event. The ribotyping and metabolic fingerprinting analysis showed that this organism is a strain of Pseudomonous aeruginosa (P. aeruginosa). It has also been observed that this strain is able to degrade Impranil DLN™, a variety of commercially available PUR. Therefore this study identifies a new bacterium from soil that has the potential to reduce PUR-related waste burden and adds a new facet to diverse functional activities of P. aeruginosa.

  11. Design and Synthesis of Fluorescent Acyclic Nucleoside Phosphonates as Potent Inhibitors of Bacterial Adenylate Cyclases

    Czech Academy of Sciences Publication Activity Database

    Břehová, Petra; Šmídková, Markéta; Skácel, Jan; Dračínský, Martin; Mertlíková-Kaiserová, Helena; Velasquez, M. P. S.; Watts, V. J.; Janeba, Zlatko

    2016-01-01

    Roč. 11, č. 22 (2016), s. 2534-2546 ISSN 1860-7179 R&D Projects: GA MV VG20102015046; GA MŠk LO1302 Institutional support: RVO:61388963 Keywords : adenylate cyclase toxin * acyclic nucleoside phosphonates * anthranilic acid Subject RIV: CC - Organic Chemistry Impact factor: 3.225, year: 2016

  12. Secretion of antiretroviral chemokines by human cells cultured with acyclic nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

    Zídek, Zdeněk; Kmoníčková, Eva; Holý, Antonín

    2007-01-01

    Roč. 574, - (2007), s. 77-84 ISSN 0014-2999 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z40550506 Keywords : Acyclic nucleoside phosphonate * Chemokine * Cytokine Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.376, year: 2007

  13. Acyclic nucleoside phosphonate antivirals activate gene expression of monocyte chemotactic protein 1 and 3.

    Czech Academy of Sciences Publication Activity Database

    Potměšil, Petr; Holý, Antonín; Kmoníčková, Eva; Křížková, Jana; Zídek, Zdeněk

    2007-01-01

    Roč. 14, č. 1 (2007), s. 59-66 ISSN 1021-7770 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z40550506 Keywords : Acyclic nucleoside phosponate * HIV * Monocyte chemotactic protein Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.024, year: 2007

  14. Novel and Efficient Synthesis of gem-Difluorinated Derivatives of Acyclic Nucleoside Phosphonates (ANPs)

    Czech Academy of Sciences Publication Activity Database

    Pomeisl, Karel; Beier, Petr; Pohl, Radek; Krečmerová, Marcela

    2016-01-01

    Roč. 1, č. 10 (2016), s. 2102-2106 ISSN 2365-6549 R&D Projects: GA ČR(CZ) GA14-00522S Institutional support: RVO:61388963 Keywords : difluoromethylation * difluoromethylphosphonate * acyclic nucleoside phosphonate * phosphonate ester * microwave reaction Subject RIV: CC - Organic Chemistry

  15. Melidianolic acid A and B, new antimalarial acyclic diterpenes from Aphanamixis grandifolia.

    Science.gov (United States)

    Astulla, Adil; Hirasawa, Yusuke; Rahman, Abdul; Kusumawati, Idha; Ekasari, Wiwied; Widyawaruyanti, Aty; Zaini, Noor Cholies; Morita, Hiroshi

    2011-03-01

    Two new acyclic diterpenes, melidianolic acids A (1) and B (2), have been isolated from the bark of Aphanamixis grandifolia. Their structures were elucidated on the basis of spectroscopic and chemical methods. Melidianolic acids A (1) and B (2) showed antimalarial activity against Plasmodium falciparum 3D7 with IC50 of 6.1 and 7.3 microg/mL, respectively.

  16. A new acyclic thiophene sesterterpene from the Sikao Bay sponge, Xestospongia sp.

    Science.gov (United States)

    Pedpradab, Patchara; Suwanborirux, Khanit

    2011-09-01

    Bioactivity-guided fractionation of the ethyl acetate extract of a marine sponge, Xestospongia sp., led to the isolation of a new thiophene-S-oxide acyclic sesterterpene (1). The chemical structure was extensively analyzed using NMR and mass spectral data. Compound 1 showed weak cytotoxicity against Vero cells.

  17. A novel type of acyclic nucleoside phosphonates derived from 2-(phosphonomethoxy)propanoic acid

    Czech Academy of Sciences Publication Activity Database

    Kaiser, Martin Maxmilian; Jansa, Petr; Dračínský, Martin; Janeba, Zlatko

    2012-01-01

    Roč. 68, č. 21 (2012), s. 4003-4012 ISSN 0040-4020 R&D Projects: GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * CPMEA * HPMPA * PME A * oxidation * TEMPO * microwave * antiviral Subject RIV: CC - Organic Chemistry Impact factor: 2.803, year: 2012

  18. The preparation of 3-H-labeled Acyclic Nucleoside Phosphonates and Study of their Stability

    Czech Academy of Sciences Publication Activity Database

    Elbert, Tomáš; Břehová, Petra; Holý, Antonín

    2010-01-01

    Roč. 75, č. 7 (2010), s. 757-766 ISSN 0010-0765 R&D Projects: GA MŠk 1M0508; GA AV ČR IAA400550801 Institutional research plan: CEZ:AV0Z40550506 Keywords : tritium * 3-H NMR * acyclic nucleotide analogues Subject RIV: CC - Organic Chemistry Impact factor: 0.853, year: 2010

  19. N-Branched acyclic nucleoside phosphonates as monomers for the synthesis of modified oligonucleotides

    Czech Academy of Sciences Publication Activity Database

    Hocková, Dana; Rosenbergová, Šárka; Ménová, Petra; Páv, Ondřej; Pohl, Radek; Novák, Pavel; Rosenberg, Ivan

    2015-01-01

    Roč. 13, č. 15 (2015), s. 4449-4458 ISSN 1477-0520 R&D Projects: GA ČR GAP207/11/0108; GA ČR GA13-26526S Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * oligonucleotides * solid phase synthesis Subject RIV: CC - Organic Chemistry Impact factor: 3.559, year: 2015

  20. Inhibition of hypoxanthine-guanine phosphoribosyltransferase by acyclic nucleoside phosphonates: A new class of antimalarial therapeutics

    Czech Academy of Sciences Publication Activity Database

    Keough, D. T.; Hocková, Dana; Holý, Antonín; Naesens, L.; Skinner-Adams, T. S.; de Jersey, J.; Guddat, L. W.

    2009-01-01

    Roč. 52, č. 14 (2009), s. 4391-4399 ISSN 0022-2623 R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * phosphoribosyltransferase * enzyme inhibitors * Plasmodium falciparum Subject RIV: CC - Organic Chemistry Impact factor: 4.802, year: 2009

  1. Synthesis and properties of novel types of chiral open-ring acyclic nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

    Holý, Antonín; Doláková, Petra

    2005-01-01

    Roč. 65, č. 3 (2005), A31 ISSN 0166-3542. [International Conference on Antiviral Research /8./. Barcelona, 11.04.2005-14.04.2005] Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonate * pyrimidine * antiviral activity Subject RIV: CC - Organic Chemistry Impact factor: 3.406, year: 2005

  2. Copper-catalyzed enantioselective conjugate addition of organometallic reagents to acyclic dienones

    NARCIS (Netherlands)

    Sebesta, Radovan; Pizzuti, M. Gabriella; Minnaard, Adriaan J.; Feringa, Ben L.; Šebesta, Radovan

    The enantioselective, copper/phosphoramidite-catalyzed 1,4-addition of dialkylzinc reagents to acyclic dienones is described. The products of this reaction, obtained with enantioselectivities of up to 95%, can be further functionalized by a second conjugate addition, or employed in an enolate

  3. Activities of Different Classes of Acyclic Nucleoside Phosphonates against BK Virus in Primary Human Renal Cells

    Czech Academy of Sciences Publication Activity Database

    Topalis, D.; Lebeau, I.; Krečmerová, Marcela; Andrei, G.; Snoeck, R.

    2011-01-01

    Roč. 55, č. 5 (2011), s. 1961-1967 ISSN 0066-4804 Institutional research plan: CEZ:AV0Z40550506 Keywords : polyomavirus * BK virus * nephropathy * acyclic nucleoside phosphonates * HPMP-5-azaC Subject RIV: CC - Organic Chemistry Impact factor: 4.841, year: 2011

  4. Development of Long Chain Alkyl Diol δD as a Paleohydrological Proxy

    Science.gov (United States)

    Neary, A.; Russell, J. M.; Cordero, D.

    2017-12-01

    Understanding past hydroclimate is important to better understand and prepare for future climate changes. Past hydrological change is often studied through δD of lipid biomarkers preserved in sediment. Long chain alkyl diols are lipid biomarkers that are widely distributed in lake and marine sediments. These compounds are produced by certain species of diatoms and algae (Eustigmatophytes). Diol δD is expected to record relative precipitation and evaporation, and other lake surface processes. This would be a valuable addition to the repertoire of organic compounds used for hydrologic reconstruction, such as leaf waxes which record precipitation. While long chain alkyl diols present an opportunity to expand the range of compounds available for compound specific isotope analysis, studies of diol δD are scarce. This study aims to compare diol and leaf wax δD records from Lake Tanganyika spanning approximately the past 20 kyrs in order to elucidate the controlling factors on diol δD values and evaluate the effectiveness of such a record as a paleohydrological proxy. If viable, diol δD records could be used to gain a deeper understanding of past climates. δD leaf wax records have been previously measured in Lake Tanganyika cores (Tierney et al., 2008). This study measures δD of long chain alkyl diols from the same cores in order to compare records. Our current measurements show significant deviations of the diol record from the leaf wax record at times when large magnitude changes in the leaf wax record are occurring, such as a less pronounced Younger Dryas and a more gradual decrease in δD values after Heinrich 1 than the sudden shift expressed by the leaf wax record. In addition to generating a diol δD record through time at Lake Tanganyika, we have also measured diol δD in surface sediments from several east African lakes in order to examine the potential for a proxy calibration. A positive correlation between diol and lake water δD has been observed

  5. 1-(3-Phenylisoxazol-5-ylcyclohexane-1,2-diol

    Directory of Open Access Journals (Sweden)

    Luis Astudillo

    2009-07-01

    Full Text Available In the title compound, C15H17NO3, there are two molecules in the asymmetric unit wherein the isoxazole rings make dihedral angles of 16.16 (15 and 16.79 (13° with the benzene rings, and the cyclohexane rings adopt chair conformations. In both molecules, the hydroxyl groups of the diol fragments are cis oriented, the O—C—C—O torsion angles being 60.76 (12 and −55.86 (11°. The two molecules are linked by a strong O—H...N hydrogen bond and the crystal packing is stabilized by one O—H...N and two O—H...O hydrogen bonds. An intramolecular O—H...O hydrogen bond is observed in one of the molecules.

  6. SYNTHESIS AND PROPERTIES OF 5-BROM- AND 5-CHLOROSUBSTITUTED trans-ACENAPHTHENE-1,2-DIOLS

    Directory of Open Access Journals (Sweden)

    V. V. Tarasyuk

    2017-09-01

    Full Text Available We carried out transformations that describe the preparation of an unsubstituted trans-acenaphthene-1,2-diol using 5-bromo- and 5-chloro-substituted starting materials. Thus, by the reflux of trans-1,2,5-tribromacenaphthene and 1,2-dibromo-5-chlorocenaphthene in water we obtained the corresponding 1,2-diols, which are considered to be cis-isomers by melting points and NMR 1H-spectra. So hydrolysis of trans-1,2,5-tribromo- and 1,2-dibromo-5-chloroacenaphthenes leads to very moderate yields of 1,2-diols (25-26% with undesired cis-stereoselectivity. By the reaction of 5-bromo- and 5-chlorocenaphthylenes with iodine and silver benzoate in benzene followed by hydrolysis, we obtained mixtures of cis- and trans-1,2-diols which were separated chromatographically and trans-isomers of 5-bromo- and 5-chloro-acenaphthene-1,2-diols were firstly isolated. The yield of trans-diols was low (10-15%, which led us to the search for a convenient method for preparation of trans-isomers. We found this method using the reduction reaction of 5-bromoacenaphthenequinone, replacing the explosive and non-selective reductant lithium aluminum hydride by a more selective and easy-to-handle sodium borohydride in isopropanol. Reduction of 5-bromocenaphthenequinone with sodium borohydride leads to a substantially pure trans-5-bromoacenaphthen-1,2-diol in a rather high yield (57% after re-crystallization.trans-5-Bromo- and 5-chloroacenaphthene-1,2-diols were analyzed by the complex of physical and chemical methods. It is shown that the trans-5-bromo- and 5-chloroacenaphthen-1,2-diols have essentially the same mass spectra with cis isomers, but substantially differ from them by melting points, IR and 1H NMR spectra. Melting points of trans-diols are generally lower than of cis-diols. In IR spectra cis-doils have two characteristic bands of O-H groups (due to association via intramolecular and intermolecular hydrogen bonds whereas transisomers have only one broad band (only

  7. Functionalization of a Natural Biopolymer with Aliphatic Polyamines ...

    African Journals Online (AJOL)

    Chemical modification was performed using four aliphatic polyamines: ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA). The modified bark was characterized and then investigated to determine its efficiency in removing VO2+ from aqueous solutions.

  8. Occurrence and sources of aliphatic hydrocarbons in soils within the ...

    African Journals Online (AJOL)

    The isoprenoid ratios and CPI values of the samples closer ( 20 m from the HMA plants showed mixture of both anthropogenic and biogenic sources. Keywords: Asphalt Plants; Soil; Aliphatic hydrocarbons; Pristane; Phytane.

  9. Nano-biocomposites based on synthetic aliphatic polyesters and nanoclay

    CSIR Research Space (South Africa)

    Ojijo, Vincent O

    2014-05-01

    Full Text Available This article gives an overview of the recent developments in the preparation, characterisation, properties, crystallisation behaviour, and melt rheology of clay-containing composites of biodegradable synthetic aliphatic polyesters such as poly...

  10. Bifunctional acyclic nucleoside phosphonates: 2. Symmetrical 2-{[bis(phosphono)methoxy]methyl}ethyl derivatives of purines and pyrimidines

    Czech Academy of Sciences Publication Activity Database

    Vrbková, Silvie; Dračínský, Martin; Holý, Antonín

    2007-01-01

    Roč. 72, č. 7 (2007), s. 965-983 ISSN 0010-0765 R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Grant - others:Gilead Sciences(US) HPAW-2002-10096 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * ANPs * acyclic nucleoside bisphosphonates * ANbPs * phosphonomethyl ethers Subject RIV: CC - Organic Chemistry Impact factor: 0.879, year: 2007

  11. Acyclic cucurbit[n]uril molecular containers selectively solubilize single-walled carbon nanotubes in water.

    Science.gov (United States)

    Shen, Cai; Ma, Da; Meany, Brendan; Isaacs, Lyle; Wang, YuHuang

    2012-05-02

    Making single-walled carbon nanotubes (SWNTs) soluble in water is a challenging first step to use their remarkable electronic and optical properties in a variety of applications. We report that acyclic cucurbit[n]uril molecular containers 1 and 2 selectively solubilize small-diameter and low chiral angle SWNTs. The selectivity is tunable by increasing the concentration of the molecular containers or by adjusting the ionic strength of the solution. Even at a concentration 1000 times lower than typically required for surfactants, the molecular containers render SWNTs soluble in water. Molecular mechanics simulations suggest that these C-shaped acyclic molecules complex the SWNTs such that a large portion of nanotube sidewalls are exposed to the external environment. These "naked" nanotubes fluoresce upon patching the exposed surface with sodium dodecylbenzene sulfonate. © 2012 American Chemical Society

  12. New prodrugs of two pyrimidine acyclic nucleoside phosphonates: Synthesis and antiviral activity

    Czech Academy of Sciences Publication Activity Database

    Krečmerová, Marcela; Dračínský, Martin; Snoeck, R.; Balzarini, J.; Pomeisl, Karel; Andrei, G.

    2017-01-01

    Roč. 25, č. 17 (2017), s. 4637-4648 ISSN 0968-0896 R&D Projects: GA ČR(CZ) GA14-00522S Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * open-ring * PMEO-DAPy * 5-azacytosine * PME-azaC * HPMP-5-azaC Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 2.930, year: 2016

  13. Pyrimidine acyclic nucleotide analogues with aromatic substituents in C-5 position

    Czech Academy of Sciences Publication Activity Database

    Krečmerová, Marcela; Holý, Antonín; Masojídková, Milena

    2007-01-01

    Roč. 72, č. 7 (2007), s. 927-951 ISSN 0010-0765 R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Grant - others:René Descartes Prize(XE) HPAW-2002-100096 Institutional research plan: CEZ:AV0Z40550506 Keywords : antivirals * acyclic nucleoside phosphonates * 5-phenyluracil * HPMPU * HPMPC Subject RIV: CC - Organic Chemistry Impact factor: 0.879, year: 2007

  14. Differential effects of acyclic nucleoside phosphonates on nitric oxide and cytokines in rat hepatocytes and macrophages

    Czech Academy of Sciences Publication Activity Database

    Kostecká, Petra; Holý, Antonín; Farghali, H.; Zídek, Zdeněk; Kmoníčková, Eva

    2012-01-01

    Roč. 12, č. 2 (2012), s. 342-349 ISSN 1567-5769 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * cytokines * nitric oxide Subject RIV: FR - Pharmacology ; Medidal Chemistry; CC - Organic Chemistry (UOCHB-X) Impact factor: 2.417, year: 2012

  15. Enhanced Topical and Transdermal Delivery of Antineoplastic and Antiviral Acyclic Nucleoside Phosphonate cPr-PMEDAP

    Czech Academy of Sciences Publication Activity Database

    Vávrová, K.; Kovaříková, P.; Školová, B.; Líbalová, M.; Roh, J.; Čáp, R.; Holý, Antonín; Hrabálek, A.

    2011-01-01

    Roč. 28, č. 12 (2011), s. 3105-3115 ISSN 0724-8741 R&D Projects: GA MŠk 1M0508 Grant - others:GA ČR(CZ) GAP207/11/0365 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * antiviral s * antineoplastics * permeation enhancer * topical skin application * transdermal delivery Subject RIV: CC - Organic Chemistry Impact factor: 4.093, year: 2011

  16. Characterization of E and Z isomers in macrocyclic lactones and acyclic pheromones by NMR spectra

    Energy Technology Data Exchange (ETDEWEB)

    Mahajan, J.R.; Resck, I.S. [Brasilia Univ., DF (Brazil). Dept. de Quimica; Braz Filho, R. [Universidade Estadual do Norte Fluminense (UENF), Campos, RJ (Brazil). Dept. de Produtos Quimicos Naturais; Carvalho, M.G. de [Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ (Brazil). Dept. de Quimica

    1995-12-31

    A large proportion of pheromones, isolated from a variety of insects, constitutes a big list of diversely functionalized acyclic compounds, which have been synthesized by several routes. Catalytic or chemical methods were examined for the Z to E isomerization and their efficiency checked by {sup 1} H and {sup 13} C NMR spectra. Nuclear magnetic resonance has been used to identify and characterize molecular structure of the compounds, besides chemical shifts was analysed 11 refs., 4 figs., 5 tabs.

  17. Five new triterpene bisglycosides with acyclic side chains from the rhizomes of Cimicifuga foetida L.

    Science.gov (United States)

    Lu, Lu; Chen, Jian-Chao; Song, He-Jiao; Li, Yan; Nian, Yin; Qiu, Ming-Hua

    2010-05-01

    Five new triterpene bisglycosides, foetidinosides A (1), B (2), C (3), D (4) and E (5), including three of the cycloartane type, one of its derivative, and one of the lanostane type were isolated from the rhizomes of Cimicifuga foetida. Their structures were elucidated on the basis of spectroscopic data and chemical evidence. They were the first bisglycosides with acyclic side chains which were different from the typical triterpenes with side chains epoxidized with ring D in Cimicifuga species.

  18. Thermodynamics and activity coefficients at infinite dilution for organic solutes, water and diols in the ionic liquid choline bis(trifluoromethylsulfonyl)imide

    International Nuclear Information System (INIS)

    Domańska, Urszula; Papis, Paulina; Szydłowski, Jerzy

    2014-01-01

    Graphical abstract: - Highlights: • Measurements of activity coefficients at infinite dilution using GLC. • 63 Solvents including water and 6 diols in the ionic liquid choline bis(trifluoromethylsulfonyl)imide. • High selectivity for thiophene/heptane and pyridine/heptane separation. • The excess thermodynamic functions and the (gas + liquid) partition coefficients were calculated. - Abstract: The activity coefficients at infinite dilution, γ 13 ∞ , for 63 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, ethers, ketones, esters, aldehyde, acetonitrile, pyridine and 1-nitropropane and 6 diols in the ionic liquid (IL) choline bis(trifluoromethylsulfonyl)imide, [N 1112OH ][NTf 2 ] were determined by (gas + liquid) chromatography at six temperatures in range of (318.15 to 368.15) K and at three temperatures for diols in the range of (388.15 to 418.15) K. The thermodynamic functions at infinite dilution as partial molar excess Gibbs free energy, ΔG 1 E,∞ , enthalpy ΔH 1 E,∞ , and entropy term T ref ΔS 1 E,∞ were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The density of [N 1112OH ][NTf 2 ] was measured within temperature range (313.15 to 353.15) K. The (gas + liquid) partition coefficient K L was calculated for all solutes. The values of selectivity and capacity for a few separation problems as hexane/benzene, cyclohexane/benzene, heptane/thiophene at T = 328.15 K were calculated from γ 13 ∞ and compared to literature values for similar ionic liquids, N-methyl-2-pyrrolidinone (NMP), and sulfolane. In comparison with the former measured ammonium-based ILs and the morpholinium-based ILs, the [N 1112OH ][NTf 2 ] shows average selectivity for the separation of aromatic hydrocarbons, or sulfur compound from aliphatic hydrocarbons, and very high selectivity for pyridine/heptane separation. New data show that [N 1112OH ][NTf 2 ] IL may be proposed as

  19. Solvent effects on solvated electron reaction rates in diols

    International Nuclear Information System (INIS)

    Idriss-Ali, K.M.; Freeman, G.R.

    1984-01-01

    The rate constant ksub(S) of solvated electron reaction with a solute S in an alcohol can depend strongly upon the electron solvation energy (trap depth) and on the liquid viscosity eta (diffusion coefficients). The rate constant tends to be smaller when either the solvation energy or the viscosity is larger. An appropriate indicator of solvation energy in this context is Esub(r), the energy at 0.5 Asub(max) on the low energy side of the optical absorption band. Differences in solvent viscosity are normalized by taking the ratio ksub(S)/ksub(N), where N is nitrobenzene and Ksub(N) is nearly diffusion controlled. There is an enormous difference between Ksub(S)/ksub(N) for an inefficient S such as toluene in monohydric and dihydric alcohols. At Esub(r) = 146 kJ/mol the value of k (toluene)/ksub(N) is 200 fold greater in a di-ol than in a mono-ol. This remarkable difference between reactivity in di- and mono-ols is smaller for more reactive solutes; the factor is 60 for allyl alcohol and 2 for acetone. In both di- and mono-ols differences in solute reactivity are associated with entropy of activation, not with energy of activation. The entropy of activation is related to the extent of solvent rearrangement that is needed about the reaction site to give a stable product. (author)

  20. Aliphatic alcohols in spirits inhibit phagocytosis by human monocytes.

    Science.gov (United States)

    Pál, László; Árnyas, Ervin M; Bujdosó, Orsolya; Baranyi, Gergő; Rácz, Gábor; Ádány, Róza; McKee, Martin; Szűcs, Sándor

    2015-04-01

    A large volume of alcoholic beverages containing aliphatic alcohols is consumed worldwide. Previous studies have confirmed the presence of ethanol-induced immunosuppression in heavy drinkers, thereby increasing susceptibility to infectious diseases. However, the aliphatic alcohols contained in alcoholic beverages might also impair immune cell function, thereby contributing to a further decrease in microbicidal activity. Previous research has shown that aliphatic alcohols inhibit phagocytosis by granulocytes but their effect on human monocytes has not been studied. This is important as they play a crucial role in engulfment and killing of pathogenic microorganisms and a decrease in their phagocytic activity could lead to impaired antimicrobial defence in heavy drinkers. The aim of this study was to measure monocyte phagocytosis following their treatment with those aliphatic alcohols detected in alcoholic beverages. Monocytes were separated from human peripheral blood and phagocytosis of opsonized zymosan particles by monocytes treated with ethanol and aliphatic alcohols individually and in combination was determined. It was shown that these alcohols could suppress the phagocytic activity of monocytes in a concentration-dependent manner and when combined with ethanol, they caused a further decrease in phagocytosis. Due to their additive effects, it is possible that they may inhibit phagocytosis in a clinically meaningful way in alcoholics and episodic heavy drinkers thereby contribute to their increased susceptibility to infectious diseases. However, further research is needed to address this question.

  1. The C32 alkane-1,15-diol as a tracer for riverine input in coastal seas

    OpenAIRE

    Lattaud, J.; Kim, J.-H; de Jonge, C.; Zell, C.; Sinninghe Damsté, J.S.; Schouten, S.

    2017-01-01

    Long chain alkyl diols are lipids that occur ubiquitously in marine sediments and are used as a proxy for sea surface temperature (SST), using the Long chain Diol Index (LDI), and for upwelling intensity/high nutrient conditions. The distribution of 1,13- and 1,15-diols has been documented in open marine and lacustrine sediments and suspended particulate matter, but rarely in coastal seas receiving a significant riverine, and thus continental organic matter, input. Here we studied the distrib...

  2. Matrix-assisted laser desorption/ionization mass spectrometric analysis of aliphatic biodegradable photoluminescent polymers using new ionic liquid matrices.

    Science.gov (United States)

    Serrano, Carlos A; Zhang, Yi; Yang, Jian; Schug, Kevin A

    2011-05-15

    In this study, two novel ionic liquid matrices (ILMs), N,N-diisopropylethylammonium 3-oxocoumarate and N,N-diisopropylethylammonium dihydroxymonooxoacetophenoate, were tested for the structural elucidation of recently developed aliphatic biodegradable polymers by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The polymers, formed by a condensation reaction of three components, citric acid, octane diol, and an amino acid, are fluorescent, but the exact mechanism behind their luminescent properties has not been fully elucidated. In the original studies, which introduced the polymer class (J. Yang et al., Proc. Natl. Acad. Sci. USA 2009, 106, 10086-10091), a hyper-conjugated cyclic structure was proposed as the source for the photoluminescent behavior. With the use of the two new ILMs, we present evidence that supports the presence of the proposed cyclization product. In addition, the new ILMs, when compared with a previously established ILM, N,N-diisopropylethylammonium α-cyano-3-hydroxycinnimate, provided similar signal intensities and maintained similar spectral profiles. This research also established that the new ILMs provided good spot-to-spot reproducibility and high ionization efficiency compared with corresponding crystalline matrix preparations. Many polymer features revealed through the use of the ILMs could not be observed with crystalline matrices. Ultimately, the new ILMs highlighted the composition of the synthetic polymers, as well as the loss of water that was expected for the formation of the proposed cyclic structure on the polymer backbone. Copyright © 2011 John Wiley & Sons, Ltd.

  3. A Role for the Androgen Metabolite, 5alpha androstane, 3beta, 17beta Diol (3b-DIol in the regulation of the hypothalamo-pituitary-adrenal axis.

    Directory of Open Access Journals (Sweden)

    Robert James Handa

    2011-11-01

    Full Text Available Activation of the hypothalamo-pituitary-adrenal (HPA axis is a basic reaction of animals to environmental perturbations that threaten homeostasis. These responses are ultimately regulated by neurons residing within the paraventricular nucleus of the hypothalamus (PVN. Within the PVN, corticotropin-releasing hormone (CRH, vasopressin (AVP and oxytocin (OT expressing neurons are critical as they can regulate both neuroendocrine and autonomic responses. Estradiol (E2 and testosterone (T are well known reproductive hormones, however, they have also been shown to modulate stress reactivity. In rodent models, evidence shows that under some conditions E2 enhances stress activated ACTH and corticosterone secretion. In contrast, T decreases the gain of the HPA axis. The modulatory role of testosterone was originally thought to be via 5 alpha reduction to the potent androgen, dihydrotestosterone, whereas E2 effects were thought to be mediated by both estrogen receptors alpha (ERα and beta (ERβ. However, DHT has been shown to be metabolized to the ERβ agonist, 5alpha- androstane 3beta,17beta diol (3b-Diol. The actions of 3β-Diol on the HPA axis are mediated by ERbeta which inhibits the PVN response to stressors. In gonadectomized rats, ERbeta agonists reduce CORT and ACTH responses to restraint stress, an effect that is also present in wild-type but not ERbeta knockout mice. The neurobiological mechanisms underlying the actions of ERbeta to alter HPA reactivity are not currently known. CRH, AVP and OT have all been shown to be regulated by estradiol and recent studies indicate an important role of ERbeta in these regulatory processes. Moreover, activation of the CRH and AVP promoters have been shown by 3β-Diol binding to ERbeta and this is thought to be through alternate pathways of gene regulation. Based on available data, a novel and important role for 3beta Diol in the regulation of the HPA axis is suggested.

  4. Fate of aliphatic compounds in nitric acid processing solutions

    International Nuclear Information System (INIS)

    Clark, W.E.; Howerton, W.B.

    1975-01-01

    The reaction of hyperazeotropic iodic acid-saturated nitric acid with short chain aliphatic iodides, nitrates, and acids was studied in order to determine the conditions for complete removal of organic materials from nitric acid systems. The aliphatic iodides are converted to the nitrates and the nitrates in strong HNO 3 are extensively converted into CO 2 and acids. The aliphatic acids are rather stable; acetic acid was unattacked by boiling in 20M HNO 3 and n-butyric acid was 80 percent unattacked. The dibasic acids oxalic and malonic are extensively attacked, but succinic acid is relatively stable. A wet oxidation method is successful in destroying acetic acid in 5 to 8M HNO 3 . (U.S.)

  5. Iodine - catalyzed prins cyclization of aliphatic and aromatic ketones

    Energy Technology Data Exchange (ETDEWEB)

    Kishore, K.R.; Reddy, K.; Silva Junior, Luiz F., E-mail: luizfsjr@iq.usp.br [Universidade de Sao Paulo (IQ/USP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Fundamental

    2013-09-15

    Iodine-catalyzed Prins cyclization of homoallylic alcohols and ketones was investigated. Anhydrous conditions and inert atmosphere are not required in this metal-free protocol. The reaction of 2-(3,4-dihydronaphthalene-1-yl)propan-1-ol with six aliphatic symmetric ketones gave the desired products in 67-77% yield. Cyclization was performed with four aliphatic unsymmetric ketones, leading to corresponding pyrans in 66-76% yield. Prins cyclization was also accomplished with four aromatic ketones in 37-66% yield. Finally, Prins cyclization of the monoterpene isopulegol and acetone was successfully achieved. (author)

  6. Aliphatic carboxylic acids and ketones from sapropelitic coals

    Energy Technology Data Exchange (ETDEWEB)

    Bodoev, N.V.; Rokosov, Y.V.; Koptyug, V.A. (USSR Academy of Sciences, Kemerovo (USSR). Institute of Coal)

    1990-02-01

    Normal aliphatic carboxylic acids and ketones obtained from the extraction of Taimylyr (Lensky basin, USSR) or Matagan (Irkutsky basin, USSR) sapropelitic coal with water and sodium hydroxide at elevated pressure and temperatures from 400 to 450{degree}C were investigated. The compositions of these compounds were studied by i.r. and n.m.r. spectroscopy, and combined g.c.-m.s.. The possible pathways of aliphatic carboxylic acids and ketones formation during the fossilization process are discussed. 9 refs., 6 figs., 1 tab.

  7. Iodine - catalyzed prins cyclization of aliphatic and aromatic ketones

    International Nuclear Information System (INIS)

    Kishore, K.R.; Reddy, K.; Silva Junior, Luiz F.

    2013-01-01

    Iodine-catalyzed Prins cyclization of homoallylic alcohols and ketones was investigated. Anhydrous conditions and inert atmosphere are not required in this metal-free protocol. The reaction of 2-(3,4-dihydronaphthalene-1-yl)propan-1-ol with six aliphatic symmetric ketones gave the desired products in 67-77% yield. Cyclization was performed with four aliphatic unsymmetric ketones, leading to corresponding pyrans in 66-76% yield. Prins cyclization was also accomplished with four aromatic ketones in 37-66% yield. Finally, Prins cyclization of the monoterpene isopulegol and acetone was successfully achieved. (author)

  8. Kinetic and thermodynamic studies of the formation of a polyurethane based on 1,6-hexamethylene diisocyanate and poly(carbonate-co-ester)diol

    International Nuclear Information System (INIS)

    Fernandez d'Arlas, B.; Rueda, L.; Stefani, P.M.; Caba, K. de la; Mondragon, I.; Eceiza, A.

    2007-01-01

    This paper presents the kinetic and thermodynamic characterization of a non-catalyzed reaction between poly(hexamethylene carbonate-co-caprolactone)diol (PHMC-co-PCL) and aliphatic hexamethylene diisocyanate (HDI) with a stochiometric functional concentration, using both isothermal and dynamic differential scanning calorimetry, DSC, as well as Fourier transform infrared spectroscopy, FT-IR. DSC data were fitted using a Kamal autocatalytic equation. Model-free-isoconversional methods were also applied to analyse the conversion dependence of the global activation energy. This relation was used to predict the reaction conversion versus time pattern at different temperatures and to compare it with that of the model approach. Kinetic modelling and model-free analysis successfully described the conversion versus time curves. The reaction can be divided in two different paths: the forward path and the autocatalyzed one. Results corroborated that autocatalysis is promoted by the urethane group. Activation energies for both reaction paths have been found to be higher than those presented in the literature for aromatic diisocyanate systems, which explains the lower reaction rate of the presented system

  9. A comparative study on vibrational, conformational and electronic structure of α,α'-diol-o-xylene, α,α'-diol-m-xylene and α,α'-diol-p-xylene

    Science.gov (United States)

    Arjunan, V.; Saravanan, I.; Mythili, C. V.; Kalaivani, M.; Mohan, S.

    2012-06-01

    The Fourier transform infrared (FTIR) and FT-Raman spectra of α,α'-diol-o-xylene (DOLOX), α,α'-diol-m-xylene (DOLMX) and α,α'-diol-p-xylene (DOLPX) of the configuration HOCH2-C6H4-CH2OH have been recorded in the range 4000-400 and 4000-100 cm-1, respectively. The most stable geometry of the compounds was determined by conformational analysis. The complete vibrational assignment and analysis of the fundamental modes of the most stable conformer of the compounds were carried out using the experimental FTIR and FT-Raman data and quantum chemical studies. The observed vibrational frequencies were compared with the wavenumbers derived theoretically for the optimised geometry of the compounds from the DFT-B3LYP gradient calculations employing the standard 6-31G** and high level and 6-311++G** basis sets. The structural parameters and vibrational wavenumbers obtained from the DFT method are in good agreement with the experimental data. The potential energy distributions of the fundamental modes were also calculated by Wilson's FG matrix method. The effect of -CH2OH groups on the skeletal vibrations have been discussed. The intra molecular n → σ* and π → π* interactions were discussed with NBO analysis.

  10. NMR studies of abasic sites in DNA duplexes: Deoxyadenosine stacks into the helix opposite acyclic lesions

    International Nuclear Information System (INIS)

    Kalnik, M.W.; Chang, Chienneng; Johnson, F.; Grollman, A.P.; Patel, D.J.

    1989-01-01

    Proton and phosphorus NMR studies are reported for two complementary nonanucleotide duplexes containing acyclic abasic sites. The first duplex, d(C-A-T-G-A-G-T-A-C)·d(G-T-A-C-P-C-A-T-G), contains an acyclic propanyl moiety, P, located opposite a deoxyadenosine at the center of the helix (designated AP P 9-mer duplex). The second duplex, d(C-A-T-G-A-G-T-A-C-)·d(G-T-A-C-E-C-A-T-G), contains a similarly located acyclic ethanyl moiety, E (designated AP E 9-mer duplex). The ethanyl moiety is one carbon shorter than the natural carbon-phosphodiester backbone of a single nucleotide unit of DNA. The majority of the exchangeable and nonexchangeable base and sugar protons in both the AP P 9-mer and AP E 9-mer duplexes, including those at the abasic site, have been assigned by recording and analyzing two-dimensional phase-sensitive NOESY data sets in H 2 O and D 2 O solution between -5 and 5 degree C. These spectroscopic observations establish that A5 inserts into the helix opposite the abasic site (P14 and El14) and stacks between the flanking G4·C15 and G6·C13 Watson-Crick base pairs in both the AP P 9-mer and AP E 9-mer duplexes. Proton NMR parameters for the Ap P 9-mer and AP E 9-mer duplexes are similar to those reported previously. These proton NMR experiments demonstrate that the structures at abasic sites are very similar whether the five-membered ring is open or closed or whether the phosphodiester backbone is shortened by one carbon atom. Phosphorus spectra of the AP P 9-mer and AP E 9-mer duplexes (5 degree C) indicate that the backbone conformation is similarly perturbed at three phosphodiester backbone torsion angles

  11. Applicability of the theory of thermodynamic similarity to predict the enthalpies of vaporization of aliphatic aldehydes

    Science.gov (United States)

    Esina, Z. N.; Korchuganova, M. R.

    2015-06-01

    The theory of thermodynamic similarity is used to predict the enthalpies of vaporization of aliphatic aldehydes. The predicted data allow us to calculate the phase diagrams of liquid-vapor equilibrium in a binary water-aliphatic aldehyde system.

  12. Next generation macrocyclic and acyclic cationic lipids for gene transfer: Synthesis and in vitro evaluation.

    Science.gov (United States)

    Jubeli, Emile; Maginty, Amanda B; Abdul Khalique, Nada; Raju, Liji; Abdulhai, Mohamad; Nicholson, David G; Larsen, Helge; Pungente, Michael D; Goldring, William P D

    2015-10-01

    Previously we reported the synthesis and in vitro evaluation of four novel, short-chain cationic lipid gene delivery vectors, characterized by acyclic or macrocyclic hydrophobic regions composed of, or derived from, two 7-carbon chains. Herein we describe a revised synthesis of an expanded library of related cationic lipids to include extended chain analogues, their formulation with plasmid DNA (pDNA) and in vitro delivery into Chinese hamster ovarian (CHO-K1) cells. The formulations were evaluated against each other based on structural differences in the hydrophobic domain and headgroup. Structurally the library is divided into four sets based on lipids derived from two 7- or two 11-carbon hydrophobic chains, C7 and C11 respectively, which possess either a dimethylamine or a trimethylamine derived headgroup. Each set includes four cationic lipids based on an acyclic or macrocyclic, saturated or unsaturated hydrophobic domain. All lipids were co-formulated with the commercial cationic lipid 1,2-dimyristoyl-sn-glycero-3-ethylphosphocholine (EPC) in a 1:1 molar ratio, along with one of two distinct neutral co-lipids, cholesterol or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) in an overall cationic-to-neutral lipid molar ratio of 3:2. Binding of lipid formulations with DNA, and packing morphology associated with the individual lipid-DNA complexes were characterized by gel electrophoresis and small angle X-ray diffraction (SAXD), respectively. As a general trend, lipoplex formulations based on mismatched binary cationic lipids, composed of a shorter C7 lipid and the longer lipid EPC (C14), were generally associated with higher transfection efficiency and lower cytotoxicity than their more closely matched C11/EPC binary lipid formulation counterparts. Furthermore, the cyclic lipids gave transfection levels as high as or greater than their acyclic counterparts, and formulations with cholesterol exhibited higher transfection and lower cytotoxicity than those

  13. Energy and chemicals from the selective electrooxidation of renewable diols by organometallic fuel cells.

    Science.gov (United States)

    Bellini, Marco; Bevilacqua, Manuela; Filippi, Jonathan; Lavacchi, Alessandro; Marchionni, Andrea; Miller, Hamish A; Oberhauser, Werner; Vizza, Francesco; Annen, Samuel P; Grützmacher, H

    2014-09-01

    Organometallic fuel cells catalyze the selective electrooxidation of renewable diols, simultaneously providing high power densities and chemicals of industrial importance. It is shown that the unique organometallic complex [Rh(OTf)(trop2NH)(PPh3)] employed as molecular active site in an anode of an OMFC selectively oxidizes a number of renewable diols, such as ethylene glycol , 1,2-propanediol (1,2-P), 1,3-propanediol (1,3-P), and 1,4-butanediol (1,4-B) to their corresponding mono-carboxylates. The electrochemical performance of this molecular catalyst is discussed, with the aim to achieve cogeneration of electricity and valuable chemicals in a highly selective electrooxidation from diol precursors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Gas-phase water-mediated equilibrium between methylglyoxal and its geminal diol

    Science.gov (United States)

    Axson, Jessica L.; Takahashi, Kaito; De Haan, David O.; Vaida, Veronica

    2010-01-01

    In aqueous solution, aldehydes, and to a lesser extent ketones, hydrate to form geminal diols. We investigate the hydration of methylglyoxal (MG) in the gas phase, a process not previously considered to occur in water-restricted environments. In this study, we spectroscopically identified methylglyoxal diol (MGD) and obtained the gas-phase partial pressures of MG and MGD. These results, in conjunction with the relative humidity, were used to obtain the equilibrium constant, KP, for the water-mediated hydration of MG in the gas phase. The Gibbs free energy for this process, ΔG°, obtained as a result, suggests a larger than expected gas-phase diol concentration. This may have significant implications for understanding the role of organics in atmospheric chemistry. PMID:20142510

  15. Solubility of cesium iodide crystals in aliphatic alchohols

    International Nuclear Information System (INIS)

    Kulikova, N.V.; Kulikov, B.A.

    1988-01-01

    Solubility of cesium iodide crystals in CH 3 OH, C 2 H 5 OH, C 3 H 7 OH, C 4 H 9 OH, C 5 H 11 OH, C 8 H 17 OH aliphatic alcohols at 20, 40, 60 and 80 deg C is determined by conductometric and potentiometric techniques. Equations of solubility correlation with solvent permittivity are presented

  16. Kinetics and mechanism of oxidation of aliphatic primary alcohols by ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Oxidation of nine aliphatic primary alcohols by quinolinium bromo- chromate (QBC) in dimethylsulphoxide leads to the formation of the corresponding aldehydes. The reaction is first order with respect to both QBC and the alcohol. The reaction is catalysed by hydrogen ions. The hydrogen-ion dependence has the ...

  17. Cloud condensation nuclei activity of aliphatic amine secondary aerosol

    Science.gov (United States)

    Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g. hydroxyl radical and nitrate radical). The resulting particle composition can contain both secondary organic aerosol (SOA) and inorganic salts. The fraction of organic to inorganic materials in the particulate ...

  18. Kinetics of Oxidation of Aliphatic Alcohols by Potassium Dichromate ...

    African Journals Online (AJOL)

    The kinetics of oxidation of four aliphatic alcohols in acidic aqueous and micellar media were investigated. The reaction was found to be first-order with respect to both alcohol and oxidant. Pseudo-first-order kinetics were found to be perfectly applicable with ethanol, 1-propanol and 2-propanol while deviation was observed ...

  19. Kinetics of Oxidation of Aliphatic Alcohols by Potassium Dichromate ...

    African Journals Online (AJOL)

    NICO

    2011-10-10

    Oct 10, 2011 ... The kinetics of oxidation of four aliphatic alcohols in acidic aqueous and micellar media were investigated. The reaction was ... Oxidation, dichromate, alcohol, pseudo-first-order, micellar effect. 1. Introduction. Oxidation of ... were prepared in double-distilled water and kept in the dark until needed. 2.2.

  20. In vitro evaluation of aliphatic fatty alcohol metabolites of ...

    African Journals Online (AJOL)

    Prof. Ogunji

    In vitro evaluation of aliphatic fatty alcohol metabolites of. Perseaamericana seed as potential antimalarial and antimicrobial agents. Falodun, A.1, 3*, Erharuyi, O.1, 2, Imieje V., 1, 2, Ahomafor, J.1, Akunyuli, C.1,. Jacobs, M.3, Khan, S.3, Hamann, M. T.3, Langer, P.2. 1Department of Pharmaceutical Chemistry, Faculty of ...

  1. Vapor Pressure of Selected Aliphatic Alcohols by Ebulliometry. Part 1

    Czech Academy of Sciences Publication Activity Database

    Čenský, M.; Roháč, V.; Růžička, K.; Fulem, M.; Aim, Karel

    2010-01-01

    Roč. 298, č. 2 (2010), s. 192-198 ISSN 0378-3812 R&D Projects: GA AV ČR IAA400720710 Institutional research plan: CEZ:AV0Z40720504 Keywords : vapor pressure * ebulliometry * aliphatic alcohols Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.253, year: 2010

  2. Degradation Characterization of Aliphatic POLYESTERS—IN Vitro Study

    Science.gov (United States)

    Vieira, A. C.; Vieira, J. C.; Guedes, R. M.; Marques, A. T.

    2008-08-01

    The most popular and important biodegradable polymers are aliphatic polyesters, such as polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone (PCL), polyhydoxyalkanoates (PHA's) and polyethylene oxide (PEO). However, each of these has some shortcomings which restrict its applications. Blending techniques are an extremely promising approach which can improve or tune the original properties of the polymers[1]. Aliphatic polyesters are a central class of biodegradable polymers, because hydrolytic and/or enzymatic chain cleavage of these materials leads to α-hydroxyacids, which in most cases are ultimately metabolized in human body. This is particularly useful for controlled release devices and for other biomedical applications like suture fibers and ligaments. For aliphatic polyesters, hydrolysis rates are affected by the temperature, molecular structure, and ester group density as well as by the species of enzyme used. The degree of crystallinity may be a crucial factor, since enzymes attack mainly the amorphous domains of a polymer. Four different aliphatic polyesters were characterized in terms of degradation. Sutures fibers of PGA-PCL, PGA, PLA-PCL and PDO were used in this study. Weight loss, pH, molecular weight, crystallinity and strength were measured after six stages of incubation in distilled water, physiological saline and phosphate buffer solution (PBS). Degradation rate was determined, using a first order kinetic equation for all materials in the three incubation media. A relatively wide range of mechanical properties and degradation rates were observed among the materials studied. PBS was the most aggressive environment for the majority of cases.

  3. Kinetics and mechanism of oxidation of aliphatic alcohols by ...

    Indian Academy of Sciences (India)

    Unknown

    We have been interested in the kinetic and mechanistic studies of the reactions of polyhalides and have already reported some of them 8–10. We discuss here the kinetics of oxidation of nine aliphatic alcohols by TBATB in aqueous acetic acid solution. Attempts have been made to correlate rate and structure in this reaction.

  4. Occurrence and Sources of Aliphatic Hydrocarbons in Soils within ...

    African Journals Online (AJOL)

    ADOWIE PERE

    are usually derived from the biogenic sources especially from terrestrial vascular plants. (Sakari et al. 2008; Azevedo et al., 2007). The objective of this study therefore, was to determine the occurrence and sources of aliphatic hydrocarbons in soils within the vicinity of HMA plants. MATERIALS AND METHODS. The two HMA ...

  5. In vitro evaluation of aliphatic fatty alcohol metabolites of ...

    African Journals Online (AJOL)

    From the seeds of P. americana, five known 1, 2, 4-dihydroxy derivatives aliphatic alcohols, called avocadenols were isolated and identified by spectroscopic methodsincluding 1D- and 2D NMR, and comparison with reported data in literature. Antifungal activity for 1, 2, 4-Trihydroxyheptadec-6-en-16-yne (5)(IC50< 8 μg/mL) ...

  6. 40 CFR 721.4568 - Methylpolychloro aliphatic ketone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Methylpolychloro aliphatic ketone. 721.4568 Section 721.4568 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4568 Methylpolychloro...

  7. Prediction of anticancer activity of aliphatic nitrosoureas using ...

    African Journals Online (AJOL)

    Design and development of new anticancer drugs with low toxicity is a very challenging task and computer aided methods are being increasingly used to solve this problem. In this study, we investigated the anticancer activity of aliphatic nitrosoureas using quantum chemical quantitative structure activity relation (QSAR) ...

  8. Inhibition of Tetrahymena pyriformis growth by Aliphatic Alcohols ...

    African Journals Online (AJOL)

    A Quantitative Structure- Activity Relationship (QSAR) study was undertaken to evaluate the relative toxicity of a mixed series of 21 (linear and branched-chain) alcohols and 9 normal aliphatic amines in term of the 50% inhibitory growth concentration (IGC50) of Tetrahymena pyriformis. The applied simple linear regression ...

  9. Artificial intelligence used for the interpretation of combined spectral data *1 : Part II. PEGASUS: a PROLOG program for the generation of acyclic molecular structures

    NARCIS (Netherlands)

    Kleywegt, G.J.; Luinge, H.J.; Klooster, H.A. van 't

    1987-01-01

    A computer program, PEGASUS (PROLOG-based EXSPEC Generator for Acyclic StrUctureS), has been developed which can be used to generate exhaustively and non-redundantly all possible acyclic isomers that satisfy a given molecular weight or formula PEGASUS was written in PROLOG and implemented on an

  10. Sources and proxy potential of long chain alkyl diols in lacustrine environments

    Science.gov (United States)

    Rampen, Sebastiaan W.; Datema, Mariska; Rodrigo-Gámiz, Marta; Schouten, Stefan; Reichart, Gert-Jan; Sinninghe Damsté, Jaap S.

    2014-11-01

    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) composition of cultures of ten eustigmatophyte species, with three species from different families grown at various temperatures, to identify the effect of species composition and growth temperature on the LCD distribution. The results were compared with the LCD distribution of sixty-two lake surface sediments, and with previously reported LCD distributions from marine environments. The different families within the Eustigmatophyceae show distinct LCD patterns, with the freshwater family Eustigmataceae most closely resembling LCD distributions in both marine and lake environments. Unlike the other two eustigmatophyte families analyzed (Monodopsidaceae and Goniochloridaceae), C28 and C30 1,13-alkyl diols and C30 and C32 1,15-alkyl diols are all relatively abundant in the family Eustigmataceae, while the mono-unsaturated C32 1,15-alkyl diol was below detection limit. In contrast to the marine environment, LCD distributions in lakes did not show a clear relationship with temperature. The Long chain Diol Index (LDI), a proxy previously proposed for sea surface temperature reconstruction, showed a relatively weak correlation (R2 = 0.33) with mean annual air temperature used as an approximation for annual mean surface temperature of the lakes. A much-improved correlation (R2 = 0.74, p-value model provides good estimates of temperatures for cultures of the family Eustigmataceae, suggesting that algae belonging to this family have an important role as a source for LCDs in lacustrine environments, or, alternatively, that the main sources of LCDs are similarly affected by temperature as the Eustigmataceae. The results suggest that LCDs may have the potential to be applicable as a

  11. Tandem Olefin Metathesis/Oxidative Cyclization: Synthesis of Tetrahydrofuran Diols from Simple Olefins.

    Science.gov (United States)

    Dornan, Peter K; Lee, Daniel; Grubbs, Robert H

    2016-05-25

    A tandem olefin metathesis/oxidative cyclization has been developed to synthesize 2,5-disubstituted tetrahydrofuran (THF) diols in a stereocontrolled fashion from simple olefin precursors. The ruthenium metathesis catalyst is converted into an oxidation catalyst in the second step and is thus responsible for both catalytic steps. The stereochemistry of the 1,5-diene intermediate can be controlled through the choice of catalyst and the type of metathesis conducted. This olefin stereochemistry then controls the THF diol stereochemistry through a highly stereospecific oxidative cyclization.

  12. Kinetics of phosphotungstic acid catalyzed oxidation of propan-1,3-diol and butan-1,4-diol by N-chlorosaccharin

    Directory of Open Access Journals (Sweden)

    Sanjay Kumar Singh

    2011-09-01

    Full Text Available The kinetic studies of N-chlorosaccharin (NCSA oxidation of propan-1,3-diol and butan-1,4-diol have been reported in presence of phophotungstic acid and in aqueous acetic acid medium. The reactions follow first-order in NCSA and one to zero order with respect to substrate and phosphotungstic acid. Increase in the concentration of added perchloric acid increases the rate of oxidation. A negative effect on the oxidation rate is observed for solvent whereas the ionic strength does not influence the rate of reaction. Addition of the reaction product, saccharin, exhibited retarding effect. Various activation parameters have been evaluated. The products of the reactions were identified as the corresponding aldehydes. A suitable scheme of mechanism consistent with the experimental results has been proposed.

  13. An approach based on liquid chromatography/electrospray ionization–mass spectrometry to detect diol metabolites as biomarkers of exposure to styrene and 1,3-butadiene

    Science.gov (United States)

    Shen, Shuijie; Zhang, Fan; Zeng, Su; Zheng, Jiang

    2012-01-01

    Styrene and 1,3-butadiene are important intermediates used extensively in the plastics industry. They are metabolized mainly through cytochrome P450-mediated oxidation to the corresponding epoxides, which are subsequently converted to diols by epoxide hydrolase or through spontaneous hydration. The resulting styrene glycol and 3-butene-1,2-diol have been suggested as biomarkers of exposure to styrene and 1,3-butadiene, respectively. Unfortunately, poor ionization of the diols within electrospray mass spectrometers becomes an obstacle to the detection of the two diols by liquid chromatography/electrospray ionization–mass spectrometry (LC/ESI–MS). We developed an LC/ESI–MS approach to analyze styrene glycol and 3-butene-1,2-diol by means of derivatization with 2-bromopyridine-5-boronic acid (BPBA), which not only dramatically increases the sensitivity of diol detection but also facilitates the identification of the diols. The analytical approach developed was simple, quick, and convincing without the need for complicated chemical derivatization. To evaluate the feasibility of BPBA as a derivatizing reagent of diols, we investigated the impact of diol configuration on the affinity of a selection of diols to BPBA using the established LC/ESI–MS approach. We found that both cis and trans diols can be derivatized by BPBA. In conclusion, BPBA may be used as a general derivatizing reagent for the detection of vicinal diols by LC/MS. PMID:19111668

  14. Metabolism of acyclic and cyclic N-nitrosamines in cultured human bronchi

    DEFF Research Database (Denmark)

    Harris, Curtis C.; Autrup, Herman; Stoner, Gary D.

    1977-01-01

    The metabolism of carcinogenic N-nitrosamines was studied in normal-appearing bronchial specimens obtained from 4 patients. Explants of bronchi were cultured in a chemically defined medium for 7 days. N-Nitrosamines [N-nitrosodimethylamine (DMN), N-nitrosodiethylamine (DEN), N,N'-dinitrosopiperaz......The metabolism of carcinogenic N-nitrosamines was studied in normal-appearing bronchial specimens obtained from 4 patients. Explants of bronchi were cultured in a chemically defined medium for 7 days. N-Nitrosamines [N-nitrosodimethylamine (DMN), N-nitrosodiethylamine (DEN), N...... bronchial specimens, these N-nitrosamines and/or their metabolites bound to bronchial mucosal DNA and protein. Binding levels were higher to protein than to DNA. Binding levels of DNP were as high as those with the two acyclic N-nitrosamines DMN and DEN, but binding levels of NPy and NPd were lower. Human...... bronchus was shown to metabolize and bind acyclic and cyclic N-nitrosamines found in the environment and in tobacco smoke....

  15. Novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s with functional carbonate building blocks. 1. Chemical synthesis and their structural and physical characterization.

    Science.gov (United States)

    Yang, Jing; Hao, Qinghui; Liu, Xiaoyun; Ba, Chaoyi; Cao, Amin

    2004-01-01

    This study presents chemical synthesis, structural, and physical characterization of novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s P(BS-co-CC) bearing functional carbonate building blocks. First, five kinds of six-membered cyclic carbonate monomers, namely, trimethylene carbonate (TMC), 1-methyl-1,3-trimethylene carbonate (MTMC), 2,2-dimethyl-1,3-trimethylene carbonate (DMTMC), 5-benzyloxytrimethylene carbonate (BTMC), and 5-ethyl-5-benzyloxymethyl trimethylene carbonate (EBTMC), were well prepared from ethyl chloroformate and corresponding diols at 0 degrees C in THF solution with our modified synthetic strategies. Then, a series of new P(BS-co-CC)s were synthesized at 210 degrees C through a simple combination of poly-condensation and ring-opening-polymerization (ROP) of hydroxyl capped PBS macromers and the prepared carbonate monomers, and titanium tetra-isopropoxide Ti(i-OPr)4 was used as a more suitable catalyst of 5 candidate catalysts which could concurrently catalyze poly-condensation and ROP. By means of NMR, GPC, FTIR, and thermal analytical instruments, macromolecular structures and physical properties have been characterized for these aliphatic poly(ester carbonate)s. The experimental results indicated that novel biodegradable P(BS-co-CC)s were successfully synthesized with number average molecular weight Mn ranging from 24.3 to 99.6 KDa and various CC molar contents without any detectable decarboxylation and that the more bulky side group was attached to a cyclic carbonate monomer, the lower reactivity for its copolymerization would be observed. The occurrences of 13C NMR signal splitting of succinyl carbonyl attributed to the BS building blocks could be proposed due to the randomized sequences of BS and CC building blocks. FTIR characterization indicated two distinct absorption bands at 1716 and 1733 approximately 1735 cm(-1), respectively, stemming from carbonyl stretching modes for corresponding BS and CC units. With

  16. An efficient hydrophilic interaction liquid chromatography separation of 7 phospholipid classes based on a diol column

    NARCIS (Netherlands)

    Zhu, C.; Dane, A.; Spijksma, G.; Wang, M.; Greef, J. van der; Luo, G.; Hankemeier, T.; Vreeken, R.J.

    2012-01-01

    A hydrophilic interaction liquid chromatography (HILIC) - ion trap mass spectrometry method was developed for separation of a wide range of phospholipids. A diol column which is often used with normal phase chromatography was adapted to separate different phospholipid classes in HILIC mode using a

  17. The synthesis of the 2,3-difluorobutan-1,4-diol diastereomers

    Directory of Open Access Journals (Sweden)

    Robert Szpera

    2017-12-01

    Full Text Available The diastereoselective synthesis of fluorinated building blocks that contain chiral fluorine substituents is of interest. Here we describe optimisation efforts in the synthesis of anti-2,3-difluorobutane-1,4-diol, as well as the synthesis of the corresponding syn-diastereomer. Both targets were synthesised using an epoxide opening strategy.

  18. An asymmetric route to 2, 3-epoxy-syn-1, 4-cyclohexane diol ...

    Indian Academy of Sciences (India)

    An asymmetric route to 2,3-epoxy-syn-1,4-cyclohexane diol derivatives using ring closing metathesis (RCM). Soumitra Maity Subrata Ghosh. Full Papers Volume 122 Issue 6 November 2010 pp 791-800. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/jcsc/122/06/0791-0800 ...

  19. Isolation and Characterization of Lup-20(29)-ene-3, 28- diol (Betulin ...

    African Journals Online (AJOL)

    Recrystallization was used to further purify the isolated compound. Characterization of the isolated compound was by melting point, as well as by 1H and 13C nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). Results: A triterpenoid (lup-20(29)-ene-3, 28-diol), commonly known as betulin, was ...

  20. The impact of oxic degradation on long chain alkyl diol distributions in Arabian Sea surface sediments

    NARCIS (Netherlands)

    Rodrigo-Gámiz, M.; Rampen, S.W.; Schouten, S.; Sinninghe Damsté, J.S.

    2016-01-01

    Oxygen exposure has a large impact on lipid biomarker preservation in surface sediments and may affectthe application of organic proxies used for reconstructing past environmental conditions. To determineits effect on long chain alkyl diol and keto-ol based proxies, the distributions of these lipids

  1. The impact of oxic degradation on long chain alkyl diol distributions in Arabian Sea surface sediments

    NARCIS (Netherlands)

    Rodrigo-Gámiz, M.; Rampen, Sebastiaan W.; Schouten, S.; Sinninghe Damsté, J.S.

    2016-01-01

    Oxygen exposure has a large impact on lipid biomarker preservation in surface sediments and may affect the application of organic proxies used for reconstructing past environmental conditions. To determine its effect on long chain alkyl diol and keto-ol based proxies, the distributions of these

  2. Iterative asymmetric allylic substitutions: syn- and anti-1,2-diols through catalyst control.

    Science.gov (United States)

    Park, Jin Kyoon; McQuade, D Tyler

    2012-03-12

    A copper-catalyzed asymmetric allylic boronation (AAB) gives access to syn- and anti-1,2-diols. The method facilitates an iterative strategy for the preparation of polyols, such as the fully differentiated L-ribo-tetrol and protected D-arabino-tetrol. P=protecting group. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Iridium‐Catalyzed Condensation of Amines and Vicinal Diols to Substituted Piperazines

    DEFF Research Database (Denmark)

    Lorentz-Petersen, Linda Luise Reeh; Nordstrøm, Lars Ulrik Rubæk; Madsen, Robert

    2012-01-01

    A straightforward procedure is described for the synthesis of piperazines from amines and 1,2‐diols. The heterocyclization is catalyzed by [Cp*IrCl2]2 and sodium hydrogen carbonate and can be achieved with either toluene or water as solvent. The transformation does not require any stoichiometric ...

  4. Syntheses of N3-substituted thymine acyclic nucleoside phosphonates and a comparison of their inhibitory effect towards thymidine phosphorylase

    Czech Academy of Sciences Publication Activity Database

    Pomeisl, Karel; Holý, Antonín; Votruba, Ivan; Pohl, Radek

    2008-01-01

    Roč. 18, č. 4 (2008), s. 1364-1367 ISSN 0960-894X Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * thymidine phosphorylase * fluorination * pyrimidine Subject RIV: CC - Organic Chemistry Impact factor: 2.531, year: 2008

  5. Synthesis and Evaluation of Novel Acyclic Nucleoside Phosphonates as Inhibitors of Plasmodium falciparum and Human 6-Oxopurine Phosphoribosyltransferases

    Czech Academy of Sciences Publication Activity Database

    Kaiser, Martin Maxmilian; Hocková, Dana; Wang, T. H.; Dračínský, Martin; Poštová Slavětínská, Lenka; Procházková, Eliška; Edstein, M. D.; Chavchich, M.; Keough, D. T.; Guddat, L. W.; Janeba, Zlatko

    2015-01-01

    Roč. 10, č. 10 (2015), s. 1707-1723 ISSN 1860-7179 R&D Projects: GA MV VG20102015046; GA ČR GAP207/11/0108 Institutional support: RVO:61388963 Keywords : 6-oxopurine * acyclic nucleoside phosphonates * phosphoribosyltransferases * malaria * phosphoramidates Subject RIV: CC - Organic Chemistry Impact factor: 2.980, year: 2015

  6. Swift Heavy Ion Induced Modification of Aliphatic Polymers

    OpenAIRE

    Hossain, Umme Habiba

    2015-01-01

    In this thesis, the high energy heavy ion induced modification of aliphatic polymers is studied. Two polymer groups, namely polyvinyl polymers (PVF, PVAc, PVA and PMMA) and fluoropolymers (PVDF, ETFE, PFA and FEP) were used in this work. Polyvinyl polymers were investigated since they will be used as insulating materials in the superconducting magnets of the new ion accelerators of the planned International Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz-Centre of Heavy I...

  7. Manganese-Mediated Coupling Reaction of Vinylarenes and Aliphatic Alcohols

    Science.gov (United States)

    Zhang, Wei; Wang, Nai-Xing; Bai, Cui-Bing; Wang, Yan-Jing; Lan, Xing-Wang; Xing, Yalan; Li, Yi-He; Wen, Jia-Long

    2015-10-01

    Alcohols and alkenes are the most abundant and commonly used organic building blocks in the large-scale chemical synthesis. Herein, this is the first time to report a novel and operationally simple coupling reaction of vinylarenes and aliphatic alcohols catalyzed by manganese in the presence of TBHP (tert-butyl hydroperoxide). This coupling reaction provides the oxyalkylated products of vinylarenes with good regioselectivity and accomplishes with the principles of step-economies. A possible reaction mechanism has also been proposed.

  8. Interaction of model aryl- and alkyl-boronic acids and 1,2-diols in aqueous solution.

    Science.gov (United States)

    Marinaro, William A; Prankerd, Richard; Kinnari, Kaisa; Stella, Valentino J

    2015-04-01

    The goal of this work was to quantitate ester formation between alkyl and aryl boronic acids and vicinal-diols or 1,2-diols in aqueous solution. As used here, 1,2-diols includes polyols with one or more 1,2-diol pairs. Multiple techniques were used including apparent pKa shifts of the boronic acids using UV spectrophotometry (for aryl acids) and titration (for aryl and alkyl acids). Isothermal microcalorimetry was also used, with all reactions being enthalpically favored. For all the acids and 1,2-diols and the conditions studied, evidence only supported 1:1 ester formation. All the esters formed were found to be significantly more acidic, as Lewis acids, by 3-3.5 pKa units than the corresponding nonesterified boronic acid. The equilibrium constants for ester formation increased with increasing number of 1,2-diol pairs but stereochemistry may also play a role as sorbitol with five possible 1,2-diol pairs and five isomers (taking into account the stereochemistry of the alcohol groups) was twice as efficient at ester formation compared with mannitol, also with five possible 1,2-diol pairs but only three isomers. Alkyl boronic acids formed esters to a greater extent than aryl acids. Although some quantitative differences were seen between the various techniques used, rank ordering of the structure/reactivity was consistent. Formulation implications of ester formation between boronic acids and 1,2-diols are discussed. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  9. Dimethylchrysene diol epoxides: mutagenicity in Salmonella typhimurium, tumorigenicity in newborn mice, and reactivity with deoxyadenosine in DNA.

    Science.gov (United States)

    Misra, B; Amin, S; Hecht, S S

    1992-01-01

    In contrast to 5-methylchrysene and 5,9-dimethylchrysene, 5,6-dimethylchrysene and 5,7-dimethylchrysene are weak tumor initiators on mouse skin. In order to investigate the basis for this, we have evaluated the mutagenic activities toward Salmonella typhimurium TA 100 and reactivity with DNA of (+/-)-anti-1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydro-5,6-dimethyl-ch rys ene (anti-5,6-diMeC-1,2-diol 3,4-epoxide) and anti-5,7- and anti-5,9-diMeC-1,2-diol 3,4-epoxide. The tumorigenic activities of anti-5,6- and anti-5,7-diMeC-1,2-diol 3,4-epoxides in newborn mice were also investigated. anti-5,9-diMeC-1,2-diol 3,4-epoxide was the most mutagenic of the three diol epoxides. anti-5,6-diMeC-1,2-diol 3,4-epoxide was highly tumorigenic in newborn mouse lung, with activity significantly greater than that of either anti-5-MeC- or anti-5,7-diMeC-1,2-diol 3,4-epoxide. Although the amounts of total binding of the diol epoxides to calf thymus DNA were similar, anti-5,6-diMeC-1,2-diol 3,4-epoxide bound extensively to deoxyadenosine residues. High binding to deoxyadenosine is related to the presence of a sterically hindered bay or fjord region as present in 5,6-diMeC, 7,12-dimethylbenz[a]anthracene, benzo-[g]chrysene, and benzo[c]phenanthrene. The conformations of the anti- and syn-diol epoxides of 5,6-diMeC and benzo[c]phenanthrene were similar, with both having pseudodiequatorial hydroxyl groups, in contrast to less sterically crowded diol epoxides. The high tumorigenicity of anti-5,6-diMeC-1,2-diol 3,4-epoxide in newborn mice is of interest with respect to its high deoxyadenosine binding.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Acyclic Immucillin Phosphonates. Second-Generation Inhibitors of Plasmodium falciparum Hypoxanthine- Guanine-Xanthine Phosphoribosyltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Hazelton, Keith Z. [Yeshiva Univ., New York, NY (United States); Ho, Meng-Chaio [Yeshiva Univ., New York, NY (United States); Cassera, Maria B. [Yeshiva Univ., New York, NY (United States); Clinch, Keith [Industrial Research Ltd., Lower Hutt (New Zealand); Crump, Douglas R. [Industrial Research Ltd., Lower Hutt (New Zealand); Rosario Jr., Irving [Yeshiva Univ., New York, NY (United States); Merino, Emilio F. [Yeshiva Univ., New York, NY (United States); Almo, Steve C. [Yeshiva Univ., New York, NY (United States); Tyler, Peter C. [Industrial Research Ltd., Lower Hutt (New Zealand); Schramm, Vern L. [Yeshiva Univ., New York, NY (United States)

    2012-06-22

    We found that Plasmodium falciparum is the primary cause of deaths from malaria. It is a purine auxotroph and relies on hypoxanthine salvage from the host purine pool. Purine starvation as an antimalarial target has been validated by inhibition of purine nucleoside phosphorylase. Hypoxanthine depletion kills Plasmodium falciparum in cell culture and in Aotus monkey infections. Hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRT) from P. falciparum is required for hypoxanthine salvage by forming inosine 5'-monophosphate, a branchpoint for all purine nucleotide synthesis in the parasite. We present a class of HGXPRT inhibitors, the acyclic immucillin phosphonates (AIPs), and cell permeable AIP prodrugs. The AIPs are simple, potent, selective, and biologically stable inhibitors. The AIP prodrugs block proliferation of cultured parasites by inhibiting the incorporation of hypoxanthine into the parasite nucleotide pool and validates HGXPRT as a target in malaria.

  11. Structure-Activity Relationships of Acyclic Selenopurine Nucleosides as Antiviral Agents

    Directory of Open Access Journals (Sweden)

    Pramod K. Sahu

    2017-07-01

    Full Text Available A series of acyclic selenopurine nucleosides 3a–f and 4a–g were synthesized based on the bioisosteric rationale between oxygen and selenium, and then evaluated for antiviral activity. Among the compounds tested, seleno-acyclovir (4a exhibited the most potent anti-herpes simplex virus (HSV-1 (EC50 = 1.47 µM and HSV-2 (EC50 = 6.34 µM activities without cytotoxicity up to 100 µM, while 2,6-diaminopurine derivatives 4e–g exhibited significant anti-human cytomegalovirus (HCMV activity, which is slightly more potent than the guanine derivative 4d, indicating that they might act as prodrugs of seleno-ganciclovir (4d.

  12. A new acyclic heterodinucleotide active against human immunodeficiency virus and herpes simplex virus.

    Science.gov (United States)

    Franchetti, P; Abu Sheikha, G; Cappellacci, L; Marchetti, S; Grifantini, M; Balestra, E; Perno, C; Benatti, U; Brandi, G; Rossi, L; Magnani, M

    2000-09-01

    The most common therapies against human herpes virus (HSV-1) and human immunodeficiency virus (HIV-1) infectivity are based on the administration of nucleoside analogues. Acyclovir (ACV) is the drug of choice against HSV-1 infection, while the acyclic nucleoside phosphonate analogue PMPA has shown marked anti-HIV activity in a phase I and II clinical studies. As monocyte-derived macrophages are assumed to be important as reservoirs of both HSV-1 and HIV-1 infection, new approaches able to inhibit replication of both viruses in macrophages should be welcome. ACVpPMPA, a new heterodinucleotide consisting of both an antiherpetic and an antiretroviral drug bound by a phosphate bridge, was synthesized and encapsulated into autologous erythrocytes modified to increase their phagocytosis by human macrophages. ACVpPMPA-loaded erythrocytes provided an effective in vitro protection against both HSV-1 and HIV-1 replication in human macrophages.

  13. Molecular structure and conformation of two acyclic polythioethers: Implications for the design of heavy metal chelators

    Energy Technology Data Exchange (ETDEWEB)

    Desper, J.M.; Powell, D.R.; Gellman, S.H. (Univ. of Wisconsin, Madison (USA))

    1990-05-23

    The crystal structures of the 1,9-bis(p-tolyl)-2,5,8-trithianonane (1) and 1,12-bis(p-tolyl)-2,5,8,11-tetrathiadodecane (2) are reported. Previous studies of macrocyclic polythioethers have revealed a pronounced tendency for backbone CS-CC bonds to adopt gauche torsion angles. The same tendency is observed in the homologous acyclic polythioethers 1 and 2, demonstrating that the gauche preference is not simply the result of a macrocyclic constraint. Because of this gauche preference of CS-CC torsion units and the well-established anti preference of SC-CS torsion units, polythioethers constructed from ethylene sulfide subunits are generally far from preorganized for metal ion chelation.

  14. Acid-Labile Acyclic Cucurbit[n]uril Molecular Containers for Controlled Release.

    Science.gov (United States)

    Mao, Dake; Liang, Yajun; Liu, Yamin; Zhou, Xianhao; Ma, Jiaqi; Jiang, Biao; Liu, Jia; Ma, Da

    2017-10-02

    Stimuli-responsive molecular containers are of great importance for controlled drug delivery and other biomedical applications. A new type of acid labile acyclic cucurbit[n]uril (CB[n]) molecular containers is presented that can degrade and release the encapsulated cargo at accelerated rates under mildly acidic conditions (pH 5.5-6.5). These containers retain the excellent recognition properties of CB[n]-type hosts. A cell culture study demonstrated that the cellular uptake of cargos could be fine-tuned by complexation with different containers. The release and cell uptake of cargo dye was promoted by acidic pH. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. The Acyclic Retinoid Peretinoin Inhibits Hepatitis C Virus Replication and Infectious Virus Release in Vitro

    Science.gov (United States)

    Shimakami, Tetsuro; Honda, Masao; Shirasaki, Takayoshi; Takabatake, Riuta; Liu, Fanwei; Murai, Kazuhisa; Shiomoto, Takayuki; Funaki, Masaya; Yamane, Daisuke; Murakami, Seishi; Lemon, Stanley M.; Kaneko, Shuichi

    2014-04-01

    Clinical studies suggest that the oral acyclic retinoid Peretinoin may reduce the recurrence of hepatocellular carcinoma (HCC) following surgical ablation of primary tumours. Since hepatitis C virus (HCV) infection is a major cause of HCC, we assessed whether Peretinoin and other retinoids have any effect on HCV infection. For this purpose, we measured the effects of several retinoids on the replication of genotype 1a, 1b, and 2a HCV in vitro. Peretinoin inhibited RNA replication for all genotypes and showed the strongest antiviral effect among the retinoids tested. Furthermore, it reduced infectious virus release by 80-90% without affecting virus assembly. These effects could be due to reduced signalling from lipid droplets, triglyceride abundance, and the expression of mature sterol regulatory element-binding protein 1c and fatty acid synthase. These negative effects of Peretinoin on HCV infection may be beneficial in addition to its potential for HCC chemoprevention in HCV-infected patients.

  16. A Directed Acyclic Graph-Large Margin Distribution Machine Model for Music Symbol Classification.

    Directory of Open Access Journals (Sweden)

    Cuihong Wen

    Full Text Available Optical Music Recognition (OMR has received increasing attention in recent years. In this paper, we propose a classifier based on a new method named Directed Acyclic Graph-Large margin Distribution Machine (DAG-LDM. The DAG-LDM is an improvement of the Large margin Distribution Machine (LDM, which is a binary classifier that optimizes the margin distribution by maximizing the margin mean and minimizing the margin variance simultaneously. We modify the LDM to the DAG-LDM to solve the multi-class music symbol classification problem. Tests are conducted on more than 10000 music symbol images, obtained from handwritten and printed images of music scores. The proposed method provides superior classification capability and achieves much higher classification accuracy than the state-of-the-art algorithms such as Support Vector Machines (SVMs and Neural Networks (NNs.

  17. A Directed Acyclic Graph-Large Margin Distribution Machine Model for Music Symbol Classification.

    Science.gov (United States)

    Wen, Cuihong; Zhang, Jing; Rebelo, Ana; Cheng, Fanyong

    2016-01-01

    Optical Music Recognition (OMR) has received increasing attention in recent years. In this paper, we propose a classifier based on a new method named Directed Acyclic Graph-Large margin Distribution Machine (DAG-LDM). The DAG-LDM is an improvement of the Large margin Distribution Machine (LDM), which is a binary classifier that optimizes the margin distribution by maximizing the margin mean and minimizing the margin variance simultaneously. We modify the LDM to the DAG-LDM to solve the multi-class music symbol classification problem. Tests are conducted on more than 10000 music symbol images, obtained from handwritten and printed images of music scores. The proposed method provides superior classification capability and achieves much higher classification accuracy than the state-of-the-art algorithms such as Support Vector Machines (SVMs) and Neural Networks (NNs).

  18. [Causality in objective world: Directed Acyclic Graphs-based structural parsing].

    Science.gov (United States)

    Zheng, Y J; Zhao, N Q; He, Y N

    2018-01-10

    The overall details of causality frames in the objective world remain obscure, which poses difficulty for causality research. Based on the temporality of cause and effect, the objective world is divided into three time zones and two time points, in which the causal relationships of the variables are parsed by using Directed Acyclic Graphs (DAGs). Causal DAGs of the world (or causal web) is composed of two parts. One is basic or core to the whole DAGs, formed by the combination of any one variable originating from each time unit mentioned above. Cause effect is affected by the confounding only. The other is an internal DAGs within each time unit representing a parent-child or ancestor-descendant relationship, which exhibits a structure similar to the confounding. This paper summarizes the construction of causality frames for objective world research (causal DAGs), and clarify a structural basis for the control of the confounding in effect estimate.

  19. Synergistic effects of acyclic retinoid and OSI-461 on growth inhibition and gene expression in human hepatoma cells.

    Science.gov (United States)

    Shimizu, Masahito; Suzui, Masumi; Deguchi, Atsuko; Lim, Jin T E; Xiao, Danhua; Hayes, Julia H; Papadopoulos, Kyriakos P; Weinstein, I Bernard

    2004-10-01

    Hepatoma is one of the most frequently occurring cancers worldwide. However, effective chemotherapeutic agents for this disease have not been developed. Acyclic retinoid, a novel synthetic retinoid, can reduce the incidence of postsurgical recurrence of hepatoma and improve the survival rate. OSI-461, a potent derivative of exisulind, can increase intracellular levels of cyclic GMP, which leads to activation of protein kinase G and induction of apoptosis in cancer cells. In the present study, we examined the combined effects of acyclic retinoid plus OSI-461 in the HepG2 human hepatoma cell line. We found that the combination of as little as 1.0 micromol/L acyclic retinoid and 0.01 micromol/L OSI-461 exerted synergistic inhibition of the growth of HepG2 cells. Combined treatment with low concentrations of these two agents also acted synergistically to induce apoptosis in HepG2 cells through induction of Bax and Apaf-1, reduction of Bcl-2 and Bcl-xL, and activation of caspase-3, -8, and -9. OSI-461 enhanced the G0-G1 arrest caused by acyclic retinoid, and the combination of these agents caused a synergistic decrease in the levels of expression of cyclin D1 protein and mRNA, inhibited cyclin D1 promoter activity, decreased the level of hyperphosphorylated forms of the Rb protein, induced increased cellular levels of the p21(CIP1) protein and mRNA, and stimulated p21(CIP1) promoter activity. Moreover, OSI-461 enhanced the ability of acyclic retinoid to induce increased cellular levels of retinoic acid receptor beta and to stimulate retinoic acid response element-chloramphenicol acetyltransferase activity. A hypothetical model involving concerted effects on p21(CIP1) and retinoic acid receptor beta expression is proposed to explain these synergistic effects. Our results suggest that the combination of acyclic retinoid plus OSI-461 might be an effective regimen for the chemoprevention and chemotherapy of human hepatoma and possibly other malignancies.

  20. Substrate specific hydrolysis of aromatic and aromatic-aliphatic esters in orchid tissue cultures

    Directory of Open Access Journals (Sweden)

    Agnieszka Mironowicz

    2014-01-01

    Full Text Available We found that tissue cultures of higher plants were able, similarly as microorganisms, to transform low-molecular-weight chemical compounds. In tissue cultures of orchids (Cymbidium 'Saint Pierre' and Dendrobium phalaenopsis acetates of phenols and aromatic-aliphatic alcohols were hydrolyzed, whereas methyl esters of aromatic and aromatic-aliphatic acids did not undergo this reaction. Acetates of racemic aromatic-aliphatic alcohols were hydrolyzed with distinct enantiospecificity.

  1. Bifunctional acyclic nucleoside phosphonates: synthesis of chiral 9-{3-hydroxy[1,4-bis(phosphonomethoxy)]butan-2-yl} derivatives of purines

    Czech Academy of Sciences Publication Activity Database

    Vrbková, Silvie; Dračínský, Martin; Holý, Antonín

    2007-01-01

    Roč. 18, č. 18 (2007), s. 2233-2247 ISSN 0957-4166 R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * acyclic nucleoside bisphosphonates * phosphonomethyl ethers * purines Subject RIV: CC - Organic Chemistry Impact factor: 2.634, year: 2007

  2. Decarboxylative Fluorination of Aliphatic Carboxylic Acids via Photoredox Catalysis

    Science.gov (United States)

    Ventre, Sandrine; Petronijevic, Filip R.; MacMillan, David W. C.

    2016-01-01

    The direct conversion of aliphatic carboxylic acids to the corresponding alkyl fluorides has been achieved via visible light-promoted photoredox catalysis. This operationally simple, redox-neutral fluorination method is amenable to a wide variety of carboxylic acids. Photon-induced oxidation of carboxylates leads to the formation of carboxyl radicals, which upon rapid CO2-extrusion and F• transfer from a fluorinating reagent yield the desired fluoroalkanes with high efficiency. Experimental evidence indicates that an oxidative quenching pathway is operable in this broadly applicable fluorination protocol. PMID:25881929

  3. Electron transfer reaction of butane -1,3-diol and cr(vi) in aqueous ...

    African Journals Online (AJOL)

    Kinetic and mechanistic studies of electron transfer reaction of butane-1,3-diol and Cr(VI) ion in aqueous acidic medium have been carried out in aqueous medium at 271°C, I = 1.0 mol dm-3 (NaCl), [H +] = 0.5mol dm-3 (HCl). The reaction was inhibited by added anions and showed negative salt effect. Spectroscopic ...

  4. Mesogenic polybuthadiene diols with thiol side-chain units: synthesis and thermal behaviour

    Czech Academy of Sciences Publication Activity Database

    Bubnov, Alexej; Kašpar, Miroslav; Sedláková, Zdeňka

    2010-01-01

    Roč. 83, č. 1 (2010), 16-27 ISSN 0141-1594 R&D Projects: GA AV ČR IAA100100911; GA AV ČR(CZ) GA202/09/0047; GA MŠk OC 175 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z40500505 Keywords : mesogenic polymer * phase transition * polybutadiene diol * side -chain polymer Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.006, year: 2010

  5. Tandem Olefin Metathesis/Oxidative Cyclization: Synthesis of Tetrahydrofuran Diols from Simple Olefins

    OpenAIRE

    Dornan, Peter K.; Lee, Daniel; Grubbs, Robert H.

    2016-01-01

    A tandem olefin metathesis/oxidative cyclization has been developed to synthesize 2,5-disubstituted tetrahydrofuran (THF) diols in a stereocontrolled fashion from simple olefin precursors. The ruthenium metathesis catalyst is converted into an oxidation catalyst in the second step and is thus responsible for both catalytic steps. The stereochemistry of the 1,5-diene intermediate can be controlled through the choice of catalyst and the type of metathesis conducted. This olefin stereochemistry ...

  6. One step synthesis of 6-oxo-cholestan-3β,5α-diol

    Energy Technology Data Exchange (ETDEWEB)

    Voisin, Maud; Silvente-Poirot, Sandrine; Poirot, Marc, E-mail: marc.poirot@inserm.fr

    2014-04-11

    Highlights: • Cholesterol-5,6-epoxides are metabolized into cholestane-3β,5α,6β-triol (CT) in cancer cells. • 6-Oxo-cholestan-3β,5α-diol (OCDO) is a putative metabolite of CT. • The one step syntheses of CT and OCDO from cholesterol are reported. • The one step syntheses of labelled CT and OCDO are reported. - Abstract: Cholesterol metabolism has been recently linked to cancer, highlighting the importance of the characterization of new metabolic pathways in the sterol series. One of these pathways is centered on cholesterol-5,6-epoxides (5,6-ECs). 5,6-ECs can either generate dendrogenin A, a tumor suppressor present in healthy mammalian tissues, or the carcinogenic cholestane-3β,5α,6β-triol (CT) and its putative metabolite 6-oxo-cholestan-3β,5α-diol (OCDO) in tumor cells. We are currently investigating the identification of the enzyme involved in OCDO biosynthesis, which would be highly facilitated by the use of commercially unavailable [{sup 14}C]-cholestane-3β,5α,6β-triol and [{sup 14}C]-6-oxo-cholestan-3β,5α-diol. In the present study we report the one-step synthesis of [{sup 14}C]-cholestane-3β,5α,6β-triol and [{sup 14}C]-6-oxo-cholestan-3β,5α-diol by oxidation of [{sup 14}C]-cholesterol with iodide metaperiodate (HIO{sub 4})

  7. Efficient intramolecular cyclizations of phenoxyethynyl diols into multisubstituted α,β-unsaturated lactones.

    Science.gov (United States)

    Egi, Masahiro; Ota, Yuya; Nishimura, Yuka; Shimizu, Kaori; Azechi, Kenji; Akai, Shuji

    2013-08-16

    AgOTf-catalyzed intramolecular cyclization of phenoxyethynyl diols proceeded under mild conditions to afford the multisubstituted α,β-unsaturated-γ-lactones in 55-98% yields. This method was also applicable to the synthesis of α,β-unsaturated-δ-lactones. A similar cyclization proceeded when AgOTf was replaced with a stoichiometric amount of N-bromosuccinimide to furnish the α-bromo-substituted α,β-unsaturated lactones.

  8. Binary phase diagram of monolayers of simple 1,2-diol derivatives

    DEFF Research Database (Denmark)

    Wolf, C. De; Bringezu, F.; Brezesinski, G.

    1998-01-01

    The miscibility properties of monolayers of two 1,2-diol derivatives, 1-palmitoylglycerol (1) and 1-hexadecylglycerol (2), have been studied at the air-water interface using grazing incidence X-ray diffraction (GIXD). While, at all pressures investigated, compound (I) exhibits only a NN-tilted re....... A phase diagram is presented for the mixture of (1) and (2). (C) 1998 Elsevier Science B.V. All rights reserved....

  9. Lifshitz phase: the microscopic structure of aqueous and ethanol mixtures of 1,n-diols.

    Science.gov (United States)

    Požar, Martina; Perera, Aurélien

    2017-06-14

    We study binary mixtures of ethylene glycol and 1,3-propandiol with water or ethanol using computer simulations. Despite strong hydrogen bonding tendencies between all these molecules, we find that these mixtures are surprisingly homogeneous, in contrast to the strong micro-heterogeneity found in aqueous ethanol mixtures. The aqueous diol mixtures are found to be close to ideal mixtures, with near-ideal Kirkwood-Buff integrals. Ethanol-diol mixtures show weak non-ideality. The origin of this unexpected randomness is due to the fact that the two hydrogen bonding hydroxyl groups of the 1,n-diol are bound by the neutral alkyl bond, which prevents the micro-segregation of the different types of hydroxyl groups. These findings suggest that random disorder can arise in the presence of strong interactions - in contrast to the usual picture of random disorder due to weak interactions between the components. They point to the important role of molecular topology in tuning concentration fluctuations in complex liquids. We propose and justify herein the name of Lifshitz phases to designate such types of disordered systems.

  10. Influence of Acyclic Nucleoside Phosphonate Antivirals on Gene Expression of Chemokine Receptors CCR5 and CXCR4

    Czech Academy of Sciences Publication Activity Database

    Potměšil, P.; Holý, Antonín; Zídek, Zdeněk

    2015-01-01

    Roč. 61, č. 1 (2015), s. 1-7 ISSN 0015-5500 R&D Projects: GA ČR GA305/03/1470; GA MŠk 1M0508 Institutional support: RVO:61388963 ; RVO:68378041 Keywords : acyclic nucleoside phosphonate * HIV * CCR5 * CXCR4 * cytokine * RT-PCR Subject RIV: CC - Organic Chemistry; FR - Pharmacology ; Medidal Chemistry (UEM-P) Impact factor: 0.833, year: 2015

  11. Estimation of apparent binding constant of complexes of selected acyclic nucleoside phosphonates with beta-cyclodextrin by affinity capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Šolínová, Veronika; Mikysková, Hana; Kaiser, Martin Maxmilian; Janeba, Zlatko; Holý, Antonín; Kašička, Václav

    2016-01-01

    Roč. 37, č. 2 (2016), s. 239-247 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA13-17224S; GA ČR(CZ) GA15-01948S Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * affinity capillary electrophoresis * binding constant * nucleotide analogs * beta-cyclodextrin Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.744, year: 2016

  12. Synthesis of phosphonomethoxyethyl or 1,3-bis(phosphonomethoxy)propan-2-yl lipophilic esters of acyclic nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

    Vrbková, Silvie; Dračínský, Martin; Holý, Antonín

    2007-01-01

    Roč. 63, č. 46 (2007), s. 11391-11398 ISSN 0040-4020 R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Grant - others:Descartes Prize(XE) HPAW-2002-10096 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * alkoxyalkyl phosphonates * hexadecyloxypropyl ester groups * bisphosphonates Subject RIV: CC - Organic Chemistry Impact factor: 2.869, year: 2007

  13. Acyclic nucleoside bisphosphonates: Synthesis and properties of chiral 2-amino-4,6-bis[(phosphonomethoxy)alkoxy]pyrimidines

    Czech Academy of Sciences Publication Activity Database

    Doláková, Petra; Dračínský, Martin; Masojídková, Milena; Šolínová, Veronika; Kašička, Václav; Holý, Antonín

    2009-01-01

    Roč. 44, č. 6 (2009), s. 2408-2424 ISSN 0223-5234 R&D Projects: GA MŠk 1M0508 Grant - others:NIH(US) 1UC1AIO62540-01 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * pyrimidine * bisphosphonates Subject RIV: CC - Organic Chemistry Impact factor: 3.269, year: 2009

  14. Enantiopurity analysis of new types of acyclic nucleoside phosphonates by capillary electrophoresis with cyclodextrins as chiral selectors

    Czech Academy of Sciences Publication Activity Database

    Šolínová, Veronika; Kaiser, Martin Maxmilian; Lukáč, Miloš; Janeba, Zlatko; Kašička, Václav

    2014-01-01

    Roč. 37, č. 3 (2014), s. 295-303 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * CE * chiral analysis * cyclodextrins * nucleotide analogs Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.737, year: 2014

  15. The Acyclic 2,4-Diaminopyrimidine Nucleoside Phosphonate Acts as a Purine Mimetic in HIV-1 Reverse Transcriptase DNA Polymerization

    Czech Academy of Sciences Publication Activity Database

    Herman, B. D.; Votruba, Ivan; Holý, Antonín; Sluis-Cremer, N.; Balzarini, J.

    2010-01-01

    Roč. 285, č. 16 (2010), s. 12101-12108 ISSN 0021-9258 Grant - others:NIH(US) R01 AI81571; KU Leuven(BE) GOA Kredit 05/19 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleotide analogue * purine open ring * HIV-1 RT * antiviral * antimetabolite Subject RIV: CC - Organic Chemistry Impact factor: 5.328, year: 2010

  16. Activities of several classes of acyclic nucleoside phosphonates against camelpox virus replication in different cell culture models

    Czech Academy of Sciences Publication Activity Database

    Duraffour, S.; Snoeck, R.; Krečmerová, Marcela; Van Den Oord, J.; De Vos, D.; Holý, Antonín; Crance, J. M.; Garin, D.; De Clercq, E.; Andrei, G.

    2007-01-01

    Roč. 51, č. 12 (2007), s. 4410-4419 ISSN 0066-4804 R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Grant - others:FWO(BE) G.0267.04; NIH(US) AI06540-01 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * antivirals * HPMP-5-azacytosine * camelpox virus Subject RIV: CC - Organic Chemistry Impact factor: 4.390, year: 2007

  17. Syntheses of pyrimidine acyclic nucleoside phosphonates as potent inhibitors of thymidine phosphorylase (PD-ECGF) from SD-lymphoma

    Czech Academy of Sciences Publication Activity Database

    Pomeisl, Karel; Votruba, Ivan; Holý, Antonín; Pohl, Radek

    2007-01-01

    Roč. 26, 8/9 (2007), s. 1025-1028 ISSN 1525-7770. [International Roundtable /17./. Bern, 03.09.2006-07.09.2006] R&D Projects: GA MŠk 1M0508 Grant - others:Descartes Prize(XE) HPAW-CT-2002-9001 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * thymidine phosphorylase * pyrimidines * FPMP derivatives * fluor ination Subject RIV: CC - Organic Chemistry Impact factor: 0.723, year: 2007

  18. Contact allergy to reactive diluents and related aliphatic epoxy resins.

    Science.gov (United States)

    Aalto-Korte, Kristiina; Kuuliala, Outi; Henriks-Eckerman, Maj-Len; Suuronen, Katri

    2015-06-01

    Diglycidyl ether of bisphenol A resin (DGEBA-R) is the most common sensitizer in epoxy systems, but a minority of patients also develop contact allergy to reactive diluents. To analyse the frequency and clinical relevance of allergic reactions to different epoxy reactive diluents and related aliphatic epoxy resins. Test files (January 1991 to June 2014) were screened, and the clinical records of patients with allergic reactions were analysed for occupation, concomitant allergic reactions, and exposure. A total of 67 patients reacted to at least one of the compounds. The largest numbers of allergic reactions were to phenyl glycidyl ether (PGE; n = 41), 1,4-butanediol diglycidyl ether (BDDGE; n = 34), and p-tert-butylphenyl glycidyl ether (PTBPGE; n = 19). Ten of the patients did not have contact allergy to DGEBA-R. The reactions of 5 of these were related to the use of BDDGE-containing products. We found no significant exposure to PGE or PTBPGE in patients sensitized to them, but some of the patients had used cresyl glycidyl ether-containing products. Allergic reactions to reactive diluents and related aliphatic epoxy resins usually occurred together with reactions to DGEBA-R. BDDGE was the clinically most significant compound, and was the sole cause of occupational allergic contact dermatitis in 3 patients. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Enzymatic study on AtCCD4 and AtCCD7 and their potential to form acyclic regulatory metabolites

    KAUST Repository

    Bruno, Mark

    2016-09-29

    The Arabidopsis carotenoid cleavage dioxygenase 4 (AtCCD4) is a negative regulator of the carotenoid content of seeds and has recently been suggested as a candidate for the generation of retrograde signals that are thought to derive from the cleavage of poly-cis-configured carotene desaturation intermediates. In this work, we investigated the activity of AtCCD4 in vitro and used dynamic modeling to determine its substrate preference. Our results document strict regional specificity for cleavage at the C9–C10 double bond in carotenoids and apocarotenoids, with preference for carotenoid substrates and an obstructing effect on hydroxyl functions, and demonstrate the specificity for all-trans-configured carotenes and xanthophylls. AtCCD4 cleaved substrates with at least one ionone ring and did not convert acyclic carotene desaturation intermediates, independent of their isomeric states. These results do not support a direct involvement of AtCCD4 in generating the supposed regulatory metabolites. In contrast, the strigolactone biosynthetic enzyme AtCCD7 converted 9-cis-configured acyclic carotenes, such as 9-cis-ζ-carotene, 9\\'-cis-neurosporene, and 9-cis-lycopene, yielding 9-cis-configured products and indicating that AtCCD7, rather than AtCCD4, is the candidate for forming acyclic retrograde signals.

  20. Approches synthétiques vers le mycothiazole-4,19-diol : utilisation du palladium en synthèse organique

    OpenAIRE

    Batt , Frédéric

    2009-01-01

    Mycothiazole-4,19-diol is a natural compound isolated in 2006 from a marine sponge cacospongia mycofijiensis which has never been synthesized. Its unique structure, its weak abundance and its potential biological activity make mycothiazole-4,19-diol an attractive target in organic chemistry. The challenge is the building of allylic diol-1,2 moiety. In order to make a concise and elegant synthesis of this molecule, four disconnections and many approaches have been studied. A study about the us...

  1. In vitro metabolism of benzo[a]pyrene-7,8-dihydrodiol and dibenzo[def,p]chrysene-11,12 diol in rodent and human hepatic microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jordan N.; Mehinagic, Denis; Nag, Subhasree; Crowell, Susan R.; Corley, Richard A.

    2017-03-01

    Polycyclic aromatic hydrocarbons (PAHs) are contaminants that are ubiquitously found in the environment, produced through combustion of organic matter or petrochemicals, and many of which are procarcinogens. The prototypic PAH, benzo[a]pyrene (B[a]P) and the highly carcinogenic dibenzo[def,p]chrysene (DBC) are metabolically activated by isoforms of the P450 enzyme superfamily producing benzo[a]pyrene-7,8-dihydrodiol (B[a]P diol), dibenzo[def,p]chrysene-11,12 diol (DBC diol). Each of these diols can be further metabolized by cytochrome P450 enzymes to highly reactive diol-epoxide metabolites that readily react with DNA or by phase II conjugation facilitating excretion. To complement prior in vitro metabolism studies with parent B[a]P and DBC, both phase I metabolism and phase II glucuronidation of B[a]P diol and DBC diol were measured in hepatic microsomes from female B6129SF1/J mice, male Sprague-Dawley rats, and female humans. Metabolic parameters, including intrinsic clearance and Michaelis-Menten kinetics were calculated from substrate depletion data. Mice and rats demonstrated similar B[a]P diol phase I metabolic rates. Compared to rodents, human phase I metabolism of B[a]P diol demonstrated lower overall metabolic capacity, lower intrinsic clearance at higher substrate concentrations (>0.14 µM), and higher intrinsic clearance at lower substrate concentrations (<0.07 µM). Rates of DBC diol metabolism did not saturate in mice or humans and were highest overall in mice. Higher affinity constants and lower capacities were observed for DBC diol glucuronidation compared to B[a]P diol glucuronidation; however, intrinsic clearance values for these compounds were consistent within each species. Kinetic parameters reported here will be used to extend physiologically based pharmacokinetic (PBPK) models to include the disposition of B[a]P and DBC metabolites in animal models and humans to support future human health risk assessments.

  2. Even-odd alternation of near-infrared spectra of alkane-α,ω-diols in their solid states.

    Science.gov (United States)

    Toyama, Yuta; Murakami, Kohei; Yoshimura, Norio; Takayanagi, Masao

    2018-05-15

    Even-odd alternation of the melting points of α,ω-disubstituted linear alkanes such as alkane-α,ω-diols, alkane-α,ω-dinitriles and α,ω-diaminoalkanes is well known. Melting points for compounds with an even number of carbons in their alkyl chains are systematically higher than those for compounds with an odd number of carbons. In order to clarify the origin of this alternation, near-infrared absorption spectra of linear alkane-α,ω-diols with 3 to 9 carbon atoms in their alkyl chains were measured in the liquid and solid states. The band due to the first overtone of the OH stretching mode was investigated. The temperature-dependent spectra of all alkane-α,ω-diols in their liquid states were found to be similar; no even-odd alternation was observed. In the solid state, however, spectra of alkane-α,ω-diols with even and odd numbers of carbon atoms differed greatly. Spectra of alkane-α,ω-diols with an odd number of carbon atoms in their solid states were similar to those in the liquid states, although the variation of spectra observed upon lowering the temperature of liquid seemed to continue when the liquids were frozen. In contrast, spectra of alkane-α,ω-diols with an even number of carbon atoms in their liquid and solid states were found to be quite different. New bands appeared upon freezing. The observed even-odd alternation of the spectra observed for alkane-α,ω-diols in their solid states is presumably caused by their even-odd alternation of crystal structures. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Aqueous benzene-diols react with an organic triplet excited state and hydroxyl radical to form secondary organic aerosol.

    Science.gov (United States)

    Smith, Jeremy D; Kinney, Haley; Anastasio, Cort

    2015-04-21

    Chemical processing in atmospheric aqueous phases, such as cloud and fog drops, can play a significant role in the production and evolution of secondary organic aerosol (SOA). In this work we examine aqueous SOA production via the oxidation of benzene-diols (dihydroxy-benzenes) by the triplet excited state of 3,4-dimethoxybenzaldehyde, (3)DMB*, and by hydroxyl radical, ˙OH. Reactions of the three benzene-diols (catechol (CAT), resorcinol (RES) and hydroquinone (HQ)) with (3)DMB* or ˙OH proceed rapidly, with rate constants near diffusion-controlled values. The two oxidants exhibit different behaviors with pH, with rate constants for (3)DMB* increasing as pH decreases from pH 5 to 2, while rate constants with ˙OH decrease in more acidic solutions. Mass yields of SOA were near 100% for all three benzene-diols with both oxidants. We also examined the reactivity of atmospherically relevant mixtures of phenols and benzene-diols in the presence of (3)DMB*. We find that the kinetics of phenol and benzene-diol loss, and the production of SOA mass, in mixtures are generally consistent with rate constants determined in experiments containing a single phenol or benzene-diol. Combining our aqueous kinetic and SOA mass yield data with previously published gas-phase data, we estimate a total SOA production rate from benzene-diol oxidation in a foggy area with significant wood combustion to be nearly 0.6 μg mair(-3) h(-1), with approximately half from the aqueous oxidation of resorcinol and hydroquinone, and half from the gas-phase oxidation of catechol.

  4. Oxytocin promotes bone formation during the alveolar healing process in old acyclic female rats.

    Science.gov (United States)

    Colli, Vilma Clemi; Okamoto, Roberta; Spritzer, Poli Mara; Dornelles, Rita Cássia Menegati

    2012-09-01

    OT was reported to be a direct regulator of bone mass in young rodents, and this anabolic effect on bone is a peripheral action of OT. The goal of this study was to investigate the peripheral action of oxytocin (OT) in the alveolar healing process in old female rats. Females Wistar rats (24-month-old) in permanent diestrus phase, received two ip (12h apart) injections of saline (NaCl 0.15M - control group) or OT (45μg/rat - treated group). Seven days later, the right maxillary incisor was extracted and analyses were performed up to 28 days of the alveolar healing process (35 days after saline or OT administration). Calcium and phosphorus plasma concentrations did not differ between the groups. The plasma biochemical bone formations markers, alkaline phosphatase (ALP) and osteocalcin were significantly higher in the treated group. Histomorphometric analyses confirmed bone formation as the treated group presented the highest mean value of post-extraction bone formation. Tartrate-resistant acid phosphatase (TRAP) was significantly reduced in the treated group indicating an anti-resorptive effect of OT. Immunohistochemistry reactions performed in order to identify the presence of osteocalcin and TRAP in the bone cells of the dental socket confirmed these outcomes. OT was found to promote bone formation and to inhibit bone resorption in old acyclic female rats during the alveolar healing process. Published by Elsevier Ltd.

  5. Synthesis of modified cyclic and acyclic dextrins and comparison of their complexation ability

    Directory of Open Access Journals (Sweden)

    Kata Tuza

    2014-12-01

    Full Text Available We compared the complex forming ability of α-, β- and γ-cyclodextrins (α-CD, β-CD and γ-CD with their open ring analogs. In addition to the native cyclodextrins also modified cyclodextrins and the corresponding maltooligomers, functionalized with neutral 2-hydroxypropyl moieties, were synthesized. A new synthetic route was worked out via bromination, benzylation, deacetylation and debenzylation to obtain the 2-hydroxypropyl maltooligomer counterparts. The complexation properties of non-modified and modified cyclic and acyclic dextrins were studied and compared by photon correlation spectroscopy (PCS and capillary electrophoresis (CE using model guest compounds. In some cases cyclodextrins and their open-ring analogs (acyclodextrins show similar complexation abilities, while with other guests considerably different behavior was observed depending on the molecular dimensions and chemical characteristics of the guests. This was explained by the enhanced flexibility of the non-closed rings. Even the signs of enantiorecognition were observed for the chloropheniramine/hydroxypropyl maltohexaose system. Further studies are planned to help the deeper understanding of the interactions.

  6. Peretinoin, an Acyclic Retinoid, Inhibits Hepatitis B Virus Replication by Suppressing Sphingosine Metabolic Pathway In Vitro

    Directory of Open Access Journals (Sweden)

    Kazuhisa Murai

    2018-01-01

    Full Text Available Hepatocellular carcinoma (HCC frequently develops from hepatitis C virus (HCV and hepatitis B virus (HBV infection. We previously reported that peretinoin, an acyclic retinoid, inhibits HCV replication. This study aimed to examine the influence of peretinoin on the HBV lifecycle. HBV-DNA and covalently closed circular DNA (cccDNA were evaluated by a qPCR method in HepG2.2.15 cells. Peretinoin significantly reduced the levels of intracellular HBV-DNA, nuclear cccDNA, and HBV transcript at a concentration that did not induce cytotoxicity. Conversely, other retinoids, such as 9-cis, 13-cis retinoic acid (RA, and all-trans-retinoic acid (ATRA, had no effect or rather increased HBV replication. Mechanistically, although peretinoin increased the expression of HBV-related transcription factors, as observed for other retinoids, peretinoin enhanced the binding of histone deacetylase 1 (HDAC1 to cccDNA in the nucleus and negatively regulated HBV transcription. Moreover, peretinoin significantly inhibited the expression of SPHK1, a potential inhibitor of HDAC activity, and might be involved in hepatic inflammation, fibrosis, and HCC. SPHK1 overexpression in cells cancelled the inhibition of HBV replication induced by peretinoin. This indicates that peretinoin activates HDAC1 and thereby suppresses HBV replication by inhibiting the sphingosine metabolic pathway. Therefore, peretinoin may be a novel therapeutic agent for HBV replication and chemoprevention against HCC.

  7. Bifurcatriol, a New Antiprotozoal Acyclic Diterpene from the Brown Alga Bifurcaria bifurcata

    Directory of Open Access Journals (Sweden)

    Vangelis Smyrniotopoulos

    2017-08-01

    Full Text Available Linear diterpenes that are commonly found in brown algae are of high chemotaxonomic and ecological importance. This study reports bifurcatriol (1, a new linear diterpene featuring two stereogenic centers isolated from the Irish brown alga Bifurcaria bifurcata. The gross structure of this new natural product was elucidated based on its spectroscopic data (IR, 1D and 2D-NMR, HRMS. Its absolute configuration was identified by experimental and computational vibrational circular dichroism (VCD spectroscopy, combined with the calculation of 13C-NMR chemical shielding constants. Bifurcatriol (1 was tested for in vitro antiprotozoal activity towards a small panel of parasites (Plasmodium falciparum, Trypanosoma brucei rhodesiense, T. cruzi, and Leishmania donovani and cytotoxicity against mammalian primary cells. The highest activity was exerted against the malaria parasite P. falciparum (IC50 value 0.65 μg/mL with low cytotoxicity (IC50 value 56.6 μg/mL. To our knowledge, this is the first successful application of VCD and DP4 probability analysis of the calculated 13C-NMR chemical shifts for the simultaneous assignment of the absolute configuration of multiple stereogenic centers in a long-chain acyclic natural product.

  8. Molecular Motion of the Junction Points in Model Networks Prepared by Acyclic Triene Metathesis.

    Science.gov (United States)

    da Silva, Lucas Caire; Bowers, Clifford R; Graf, Robert; Wagener, Kenneth B

    2016-03-01

    The junction dynamics in a selectively deuterated model polymer network containing junctions on every 21st chain carbon is studied by solid state (2) H echo NMR. Polymer networks are prepared via acyclic triene metathesis of deuteron-labeled symmetric trienes with deuteron probes precisely placed at the alpha carbon relative to the junction point. The effect of decreasing the cross-link density on the junction dynamics is studied by introduction of polybutadiene chains in-between junctions. The networks are characterized by swelling, gel content, and solid state (1) H MAS NMR. Line shape analysis of the (2) H quadrupolar echo spectra reveals that the degree of motion anisotropy and the distribution of motion correlation times depend on the cross-link density and structural heterogeneity of the polymer networks. A detailed model of the junction dynamics at different temperatures is proposed and explained in terms of the intermolecular cooperativity in densely-packed systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Executive Summary of Ares V: Lunar Capabilities Concept Review Through Phase A-Cycle 3

    Science.gov (United States)

    Holladay, J. B.; Baggett, K. E.; Feldman, S. M.

    2011-01-01

    This Technical Memorandum (TM) was generated as an overall Ares V summary from the Lunar Capabilities Concept Review (LCCR) through Phase A-Cycle 3 (PA-C3) with the intent that it may be coupled with separately published appendices for a more detailed, integrated narrative. The Ares V has evolved from the initial point of departure (POD) 51.00.48 LCCR configuration to the current candidate POD, PA-C3D, and the family of vehicles concept that contains vehicles PA-C3A through H. The logical progression from concept to POD vehicles is summarized in this TM and captures the trade space and performance of each. The family-of-vehicles concept was assessed during PA-C3 and offered flexibility in the path forward with the ability to add options deemed appropriate. A description of each trade space is given in addition to a summary of each Ares V element. The Ares V contributions to a Mars campaign are also highlighted with the goal of introducing Ares V capabilities within the trade space. The assessment of the Ares V vehicle as it pertains to Mars missions remained locked to the architecture presented in Mars Design Reference Authorization 5.0 using the PA-C3D vehicle configuration to assess Mars transfer vehicle options, in-space EDS capabilities, docking adaptor and propellant transfer assessments, and lunar and Mars synergistic potential.

  10. Phosphonylated Acyclic Guanosine Analogues with the 1,2,3-Triazole Linker

    Directory of Open Access Journals (Sweden)

    Iwona E. Głowacka

    2015-10-01

    Full Text Available A novel series of {4-[(2-amino-6-chloro-9H-purin-9-ylmethyl]-1H-1,2,3-triazol-1-yl}alkylphosphonates and {4-[(2-amino-6-oxo-1,6-dihydro-9H-purin-9-ylmethyl]-1H-1,2,3-triazol-1-yl}alkylphosphonates as acyclic analogues of guanosine were synthesized and assessed for antiviral activity against a broad range of DNA and RNA viruses and for their cytostatic activity toward three cancerous cell lines (HeLa, L1210 and CEM. They were devoid of antiviral activity; however, several phosphonates were found slightly cytostatic against HeLa cells at an IC50 in the 80–210 µM range. Compounds (1R,2S-17k and (1S,2S-17k showed the highest inhibitory effects (IC50 = 15–30 µM against the proliferation of murine leukemia (L1210 and human T-lymphocyte (CEM cell lines.

  11. Optimal allocation of multi-state retransmitters in acyclic transmission networks

    International Nuclear Information System (INIS)

    Levitin, Gregory

    2002-01-01

    In this paper, an algorithm for optimal allocation of multi-state elements (MEs) in acyclic transmission networks (ATNs) is suggested. The ATNs consist of a number of positions (nodes) in which MEs capable of receiving and sending a signal are allocated. Each network has a root position where the signal source is located, a number of leaf positions that can only receive a signal, and a number of intermediate positions containing MEs capable of transmitting the received signal to some other nodes. Each ME that is located in a nonleaf node can have different states determined by a set of nodes receiving the signal directly from this ME. The probability of each state is assumed to be known for each ME. The ATN reliability is defined as the probability that a signal from the root node is transmitted to each leaf node. The optimal distribution of MEs with different characteristics among ATN positions provides the greatest possible ATN reliability. The suggested algorithm is based on using a universal generating function technique for network reliability evaluation. A genetic algorithm is used as the optimization tool. Illustrative examples are presented

  12. Maximizing survivability of acyclic transmission networks with multi-state retransmitters and vulnerable nodes

    International Nuclear Information System (INIS)

    Levitin, Gregory

    2002-01-01

    In this paper, an algorithm for optimal allocation of multi-state elements (MEs) in acyclic transmission networks (ATNs) with vulnerable nodes is suggested. The ATNs consist of a number of positions (nodes) in which MEs capable of receiving and sending a signal are allocated. Each network has a root position where the signal source is located, a number of leaf positions that can only receive a signal, and a number of intermediate positions containing MEs capable of transmitting the received signal to some other nodes. Each ME that is located in a nonleaf node can have different states determined by a set of nodes receiving the signal directly from this ME. The probability of each state is assumed to be known for each ME. Each ATN node with all the MEs allocated at this node can be destroyed by external impact (common cause failure) with a given probability. The ATN survivability is defined as the probability that a signal from the root node is transmitted to each leaf node. The optimal distribution of MEs with different characteristics among ATN positions provides the greatest possible ATN survivability. It is shown that the node vulnerability index affects the optimal distribution. The suggested algorithm is based on using a universal generating function technique for network survivability evaluation. A genetic algorithm is used as the optimization tool. Illustrative examples are presented

  13. Estimates of Gibbs free energies of formation of chlorinated aliphatic compounds

    NARCIS (Netherlands)

    Dolfing, Jan; Janssen, Dick B.

    1994-01-01

    The Gibbs free energy of formation of chlorinated aliphatic compounds was estimated with Mavrovouniotis' group contribution method. The group contribution of chlorine was estimated from the scarce data available on chlorinated aliphatics in the literature, and found to vary somewhat according to the

  14. Synthesis of Functionalized Aliphatic Polyesters by the ``Click'' Copper-Catalyzed Alkyne—Azide Cycloaddition

    Science.gov (United States)

    Lecomte, Philippe; Riva, Raphael; Jerome, Christine

    The functionalization of aliphatic polyesters by the copper-mediated azide—alkyne Huisgen's cycloaddition is very efficient under mild conditions, which prevents degradation from occurring. The implementation of this reaction requires the synthesis of aliphatic polyesters bearing pendant alkynes and azides, which can be carried out either by polycondensation or by ring-opening polymerization.

  15. The influence of aliphatic side chain of anacardic acid on molecular ...

    African Journals Online (AJOL)

    Interestingly, the presence of the aliphatic side chain in AnMcr resulted in more uniform imprinted beads as compared to particle agglomerates obtained from SaMcr in the presence of propranolol template. Therefore, the aliphatic side chain of anacardic acid improves both molecular recognition of imprinted polymers as ...

  16. Solubility and thermodynamic behavior of vanillin in propane-1,2-diol+water cosolvent mixtures at different temperatures.

    Science.gov (United States)

    Shakeel, Faiyaz; Haq, Nazrul; Siddiqui, Nasir A; Alanazi, Fars K; Alsarra, Ibrahim A

    2015-12-01

    The solubilities of bioactive compound vanillin were measured in various propane-1,2-diol+water cosolvent mixtures at T=(298-318)K and p=0.1 MPa. The experimental solubility of crystalline vanillin was determined and correlated with calculated solubility. The results showed good correlation of experimental solubilities of crystalline vanillin with calculated ones. The mole fraction solubility of crystalline vanillin was recorded highest in pure propane-1,2-diol (7.06×10(-2) at 298 K) and lowest in pure water (1.25×10(-3) at 298 K) over the entire temperature range investigated. Thermodynamic behavior of vanillin in various propane-1,2-diol+water cosolvent mixtures was evaluated by Van't Hoff and Krug analysis. The results showed an endothermic, spontaneous and an entropy-driven dissolution of crystalline vanillin in all propane-1,2-diol+water cosolvent mixtures. Based on solubility data of this work, vanillin has been considered as soluble in water and freely soluble in propane-1,2-diol. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Crystal structures and fungicidal activities of anti-2,4-bis(X-phenyl)pentane-2,4-diols

    Science.gov (United States)

    Jiao, Yinchun; Cao, Chenzhong; Zhao, Xiaolin

    2012-11-01

    The 1,3-diol moiety is present in a number of natural products and has some biological activity. Four symmetric anti-2,4-bis(X-phenyl)pentane-2,4-diols (a, X = p-F; b, X = p-CF3; c, X = m-OMe; d, X = m-CF3) have been characterized by X-ray diffraction, and the results indicated that the dihedral angles between the every two benzene rings in the systems are 34.38(10)°, 39.46(13)°, 23.42(7)°(A), 30.42(7)°(B) and 44.74(9)°, respectively. All of the structures were stabilized by classical intra- and intermolecular hydrogen bonding and some other weak interactions. It was observed that the hydrogen bonding patterns were formed between each single-molecule in compounds a-d, whereas H-bonding dimers were formed in the crystal lattices of both the anti- and syn-2,4-bisphenylpentane-2,4-diols. The four symmetric diaryl 1,3-diols were evaluated alongside several other 1,3-diols as potential antifungal agents, and their in vitro antifungal activities were measured against several fungal species, including Gibberella zeae, Botrytis cinerea, Alternaria alternata and Sclerotonia sclerotiorum.

  18. 40 CFR 721.10190 - Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, polymer with aliphatic... Formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4-methyl-2-pentanone (generic... identified generically as formaldehyde, polymer with aliphatic diamine and phenol, reaction products with 4...

  19. Synthesis of tritium labeled 4-androstenedione, 4-androsten 3α and 3β diols

    International Nuclear Information System (INIS)

    Matei, Lidia; Postolache, C.; Chiper, Diana; Tuta, C.; Bubueanu, G; Tanase, C.

    2009-01-01

    Androgen dependent diseases can appear due to blocking in different stages of biosynthesis of sexual hormones (testosterone, dihydrotestosterone) or to some modification in signalizing pathways through androgen receptor. In the diagnosis of these diseases which appear both in men and women (polycystic ovaries, hirsutism) it is also important the enzymatic activity determination of some key enzymes in steroid genesis steroid 5α-reductase, 3α and 3β-hydroxy-steroid-dehydrogenase, 17β- hydroxy-steroid-dehydrogenase. In this paper, we describe the method of obtaining tritium labeled 4-androstenedione, 4-androsten 3α and 3β diols by biosynthesis and chemical synthesis with testosterone used as substrate. (authors)

  20. Rheological characterization of a liquid crystalline diol and its dependence with an applied electric field

    Czech Academy of Sciences Publication Activity Database

    Cidade, M.T.; Pereira, G.; Bubnov, Alexej; Hamplová, Věra; Kašpar, Miroslav; Casquilho, J.P.

    2012-01-01

    Roč. 39, č. 2 (2012), s. 191-197 ISSN 0267-8292 R&D Projects: GA AV ČR IAA100100911; GA AV ČR(CZ) GA202/09/0047; GA ČR(CZ) GAP204/11/0723 Grant - others:RFASI(RU) 02.740.11.5166 Institutional research plan: CEZ:AV0Z10100520 Keywords : rheological characterization, * liquid crystalline diol * mesomorphic behaviour * electrorheological effect Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.959, year: 2012 http://dx.doi.org/10.1080/02678292.2011.628702

  1. Catalytic di-dehydroxylation of diols and carbohydrates to alkenes by (pentamethylcyclopentadienyl)/trioxorhenium(VII)

    Energy Technology Data Exchange (ETDEWEB)

    Cook, G.K.; Andrews, M.A. [Brookhaven National Laboratory, Upton, NY (United States)

    1996-10-01

    Oxygenated organics, which are traditionally prepared by the oxidation of petroleum-based feedstocks, are potentially accessible by the partial deoxygenation of renewable carbohydrate feedstocks. Towards this end, we have recently accomplished the catalytic di-dehydroxylation of both diols and polyols (including protected and unprotected sugars) to alkenes utilizing Cp {sup *}ReO{sub 3} in the presence of a suitable stoichiometric reductant such as triphenylphosphine. The reaction conditions, scope, effect of co-catalysts, and mechanism, including catalyst deactivation and regeneration, will be discussed.

  2. Alteration in substrate specificity of horse liver alcohol dehydrogenase by an acyclic nicotinamide analog of NAD(+).

    Science.gov (United States)

    Malver, Olaf; Sebastian, Mina J; Oppenheimer, Norman J

    2014-11-01

    A new, acyclic NAD-analog, acycloNAD(+) has been synthesized where the nicotinamide ribosyl moiety has been replaced by the nicotinamide (2-hydroxyethoxy)methyl moiety. The chemical properties of this analog are comparable to those of β-NAD(+) with a redox potential of -324mV and a 341nm λmax for the reduced form. Both yeast alcohol dehydrogenase (YADH) and horse liver alcohol dehydrogenase (HLADH) catalyze the reduction of acycloNAD(+) by primary alcohols. With HLADH 1-butanol has the highest Vmax at 49% that of β-NAD(+). The primary deuterium kinetic isotope effect is greater than 3 indicating a significant contribution to the rate limiting step from cleavage of the carbon-hydrogen bond. The stereochemistry of the hydride transfer in the oxidation of stereospecifically deuterium labeled n-butanol is identical to that for the reaction with β-NAD(+). In contrast to the activity toward primary alcohols there is no detectable reduction of acycloNAD(+) by secondary alcohols with HLADH although these alcohols serve as competitive inhibitors. The net effect is that acycloNAD(+) has converted horse liver ADH from a broad spectrum alcohol dehydrogenase, capable of utilizing either primary or secondary alcohols, into an exclusively primary alcohol dehydrogenase. This is the first example of an NAD analog that alters the substrate specificity of a dehydrogenase and, like site-directed mutagenesis of proteins, establishes that modifications of the coenzyme distance from the active site can be used to alter enzyme function and substrate specificity. These and other results, including the activity with α-NADH, clearly demonstrate the promiscuity of the binding interactions between dehydrogenases and the riboside phosphate of the nicotinamide moiety, thus greatly expanding the possibilities for the design of analogs and inhibitors of specific dehydrogenases. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Asymmetric reduction and Meerwein-Ponndorf-Verley reaction of prochiral aromatic ketones in the presence of optically pure 1-aryl-2,2-dimethylpropane-1,3-diols

    NARCIS (Netherlands)

    Hu, Xianming; Kellogg, Richard M.

    In THF solution, NaBH4 in the presence of (S)-(-)-1-(2-chlorophenyl)-2,2-dimethylpropane-1,3-diol together with 2-chlorobenzoic acid reduced propiophenone to 1-phenylpropan-1-ol in up to 40% enantiomeric excess (ee). Only 21% ee was obtained without an added acid. (R)-(-)-butane-1,3-diol and

  4. Recurrence of hyperprolactinemia and continuation of ovarian acyclicity in captive African elephants (Loxodonta africana) treated with cabergoline.

    Science.gov (United States)

    Morfeld, Kari A; Ball, Ray L; Brown, Janine L

    2014-09-01

    Hyperprolactinemia is associated with reproductive acyclicity in zoo African elephants (Loxodonta africana) and may contribute to the non-self-sustainability of the captive population in North America. It is a common cause of infertility in women and other mammals and can be treated with the dopamine agonist cabergoline. The objectives of this study were to assess prolactin responses to cabergoline treatment in hyperprolactinemic, acyclic African elephants and to determine the subsequent impact on ovarian cyclic activity. Five elephants, diagnosed as hyperprolactinemic (>11 ng/ml prolactin) and acyclic (maintenance of baseline progestagens for at least 1 yr), were treated with 1-2 mg cabergoline orally twice weekly for 16-82 wk. Cabergoline reduced (P elephants (11.5 +/- 3.2 vs. 9.1 +/- 3.4 ng/ml; 20.3 +/- 16.7 vs. 7.9 +/- 9.8 ng/ml; 26.4 +/- 15.0 vs. 6.8 +/- 1.5 ng/ml; 42.2 +/- 22.6 vs. 18.6 +/- 8.9 ng/ml). However, none of the females resumed ovarian cyclicity based on serum progestagen analyses up to 1 yr posttreatment. In addition, within 1 to 6 wk after cessation of oral cabergoline, serum prolactin concentrations returned to concentrations that were as high as or higher than before treatment (P elephant that exhibited the highest pretreatment prolactin concentration (75.2 +/- 10.5 ng/ml) did not respond to cabergoline and maintained elevated levels throughout the study. Thus, oral cabergoline administration reduced prolactin concentrations in elephants with hyperprolactinemia, but there was no resumption of ovarian cyclicity, and a significant prolactin rebound effect was observed. It is possible that higher doses or longer treatment intervals may be required for cabergoline treatment to result in permanent suppression of prolactin secretion and to mitigate associated ovarian cycle problems.

  5. Rhodium-Catalyzed Insertion Reaction of PhP Group of Pentaphenylcyclopentaphosphine with Acyclic and Cyclic Disulfides.

    Science.gov (United States)

    Arisawa, Mieko; Sawahata, Kyosuke; Yamada, Tomoki; Sarkar, Debayan; Yamaguchi, Masahiko

    2018-02-16

    Organophosphorus compounds with a phosphorus atom attached to a phenyl group and two organothio/organoseleno groups were synthesized using the rhodium-catalyzed insertion reaction of the PhP group of pentaphenylcyclopentaphosphine (PhP) 5 with acyclic disulfides and diselenides. The method was applied to the synthesis of heterocyclic compounds containing the S-P-S group by the reaction of (PhP) 5 and cyclic disulfides such as 1,2-dithietes, 1,2-dithiocane, 1,4,5-dithiopane, and 1,2-dithiolanes.

  6. Inhibitory activities of three classes of acyclic nucleoside phosphonates against murine polyomavirus and primate simian virus 40 strains

    Czech Academy of Sciences Publication Activity Database

    Lebeau, I.; Andrei, G.; Krečmerová, Marcela; De Clercq, E.; Holý, Antonín; Snoeck, R.

    2007-01-01

    Roč. 51, č. 6 (2007), s. 2268-2273 ISSN 0066-4804 R&D Projects: GA AV ČR 1QS400550501; GA MŠk 1M0508 Grant - others:FWO(BE) G.0267.04; NIH(US) AI 062540-01; René Descartes Prize 2001(XE) HPAV-2002-100096 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * polyomavirus * 5-azacytosine Subject RIV: CC - Organic Chemistry Impact factor: 4.390, year: 2007

  7. Shape memory polymers based on uniform aliphatic urethane networks

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, T S; Bearinger, J P; Herberg, J L; Marion III, J E; Wright, W J; Evans, C L; Maitland, D J

    2007-01-19

    Aliphatic urethane polymers have been synthesized and characterized, using monomers with high molecular symmetry, in order to form amorphous networks with very uniform supermolecular structures which can be used as photo-thermally actuable shape memory polymers (SMPs). The monomers used include hexamethylene diisocyanate (HDI), trimethylhexamethylenediamine (TMHDI), N,N,N{prime},N{prime}-tetrakis(hydroxypropyl)ethylenediamine (HPED), triethanolamine (TEA), and 1,3-butanediol (BD). The new polymers were characterized by solvent extraction, NMR, XPS, UV/VIS, DSC, DMTA, and tensile testing. The resulting polymers were found to be single phase amorphous networks with very high gel fraction, excellent optical clarity, and extremely sharp single glass transitions in the range of 34 to 153 C. Thermomechanical testing of these materials confirms their excellent shape memory behavior, high recovery force, and low mechanical hysteresis (especially on multiple cycles), effectively behaving as ideal elastomers above T{sub g}. We believe these materials represent a new and potentially important class of SMPs, and should be especially useful in applications such as biomedical microdevices.

  8. Liquid-crystalline aromatic-aliphatic copolyester bioresorbable polymers.

    Science.gov (United States)

    de Oca, Horacio Montes; Wilson, Joanne E; Penrose, Andrew; Langton, David M; Dagger, Anthony C; Anderson, Melissa; Farrar, David F; Lovell, Christopher S; Ries, Michael E; Ward, Ian M; Wilson, Andrew D; Cowling, Stephen J; Saez, Isabel M; Goodby, John W

    2010-10-01

    The synthesis and characterisation of a series of liquid-crystalline aromatic-aliphatic copolyesters are presented. Differential scanning calorimetry showed these polymers have a glass transition temperature in the range 72 degrees C-116 degrees C. Polarised optical microscopy showed each polymer exhibits a nematic mesophase on heating to the molten state at temperatures below 165 degrees C. Melt processing is demonstrated by the production of injection moulded and compression moulded specimens with Young's modulus of 5.7 +/- 0.3 GPa and 2.3 +/- 0.3 GPa, respectively. Wide-angle X-ray scattering data showed molecular orientation is responsible for the increase of mechanical properties along the injection direction. Degradation studies in the temperature range 37 degrees C-80 degrees C are presented for one polymer of this series and a kinetic constant of 0.002 days(-1) is obtained at 37 degrees C assuming a first order reaction. The activation energy (83.4 kJ mol(-1)) is obtained following the Arrhenius analysis of degradation, showing degradation of this material is less temperature sensitive compared with other commercially available biodegradable polyesters. In vitro and in vivo biocompatibility data are presented and it is shown the unique combination of degradative, mechanical and biological properties of these polymers may represent in the future an alternative for medical device manufacturers. Copyright 2010 Elsevier Ltd. All rights reserved.

  9. Properties of aliphatic hyperbranched polyesters in dilute solutions

    Directory of Open Access Journals (Sweden)

    JASNA VUKOVIC

    2007-12-01

    Full Text Available The results of an investigation of the influence of the synthesis procedure, number of pseudo generations and degree of branching of hydroxy-functional aliphatic hyperbranched polyesters (AHBP on the values of limiting viscosity number, [η], hydrodynamic radius, Rη, molar mass and polydispersity index, Q, are presented in this paper. Two series of AHBP, synthesized from 2,2-bis(hydroxylmethylpropionic acid and di-trimethylolpropane using a pseudo-one-step and a one-step procedure were investigated. The obtained results show that the values of [η] and Rη for all examined samples are the highest in a 0.7 mass % solution of LiCl in N,N-dimethylacetamide (LiCl/DMAc, which indicates that this solvent is the best from the investigated ones. The values of [η] in N-methyl-2-pyrrolidinone (NMP increased up to the sixth pseudo generation, after which a slight decrease occurred as the consequence of the presence of side-reaction products, formed during the synthesis. The appearance of these side-reaction products was also confirmed from the characteristic the GPC chromatograms. For the samples of AHBP synthesized using the pseudo-one-step procedure, a good linear dependence between log [η] and log Mw was obtained up to the fifth pseudo generation, when LiCl/DMAc, NMP and DMAc were used as solvents. The values of the “shrinking” factor, g’, were calculated for all investigated AHBPs.

  10. Recent Advances in 3D Printing of Aliphatic Polyesters

    Science.gov (United States)

    Frone, Adriana Nicoleta; Brandabur, Călin

    2017-01-01

    3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed. PMID:29295559

  11. Recent Advances in 3D Printing of Aliphatic Polyesters

    Directory of Open Access Journals (Sweden)

    Ioana Chiulan

    2017-12-01

    Full Text Available 3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid (PLA and polyhydroxyalkanoates (PHA, two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed.

  12. Recent Advances in 3D Printing of Aliphatic Polyesters.

    Science.gov (United States)

    Chiulan, Ioana; Frone, Adriana Nicoleta; Brandabur, Călin; Panaitescu, Denis Mihaela

    2017-12-24

    3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed.

  13. The origin of aliphatic hydrocarbons in olive oil.

    Science.gov (United States)

    Pineda, Manuel; Rojas, María; Gálvez-Valdivieso, Gregorio; Aguilar, Miguel

    2017-11-01

    There are many substances that can interfere with olive oil quality. Some of them are well characterized, but many others have an unknown origin. Saturated hydrocarbons make an extraordinary complex family of numerous molecules, some of them present naturally in vegetable oils. When major natural saturated hydrocarbons are analyzed by standard chromatographic methods, this complex mixture of saturated hydrocarbons appears as a hump in the chromatogram and is commonly named as unresolved complex mixture (UCM), whose origin remains unknown. In this work we studied the occurrence and the origin of aliphatic saturated hydrocarbons in olive oil. Hydrocarbons were analyzed in olive oil and along the industrial process of oil extraction. We also analyzed n-alkanes and the UCM fraction of hydrocarbons in leaf, fruit and oil from different varieties and different locations, and we also analyzed the soils at these locations. We conclude that the hydrocarbons present in olive oil do not necessarily have their origin in a contamination during olive oil elaboration; they seem to have a natural origin, as a result of olive tree metabolism and/or as the result of an intake and accumulation by the olive tree directly from the environment during its entire life cycle. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Aliphatic polyesters for medical imaging and theranostic applications.

    Science.gov (United States)

    Nottelet, Benjamin; Darcos, Vincent; Coudane, Jean

    2015-11-01

    Medical imaging is a cornerstone of modern medicine. In that context the development of innovative imaging systems combining biomaterials and contrast agents (CAs)/imaging probes (IPs) for improved diagnostic and theranostic applications focuses intense research efforts. In particular, the classical aliphatic (co)polyesters poly(lactide) (PLA), poly(lactide-co-glycolide) (PLGA) and poly(ɛ-caprolactone) (PCL), attract much attention due to their long track record in the medical field. This review aims therefore at providing a state-of-the-art of polyester-based imaging systems. In a first section a rapid description of the various imaging modalities, including magnetic resonance imaging (MRI), optical imaging, computed tomography (CT), ultrasound (US) and radionuclide imaging (SPECT, PET) will be given. Then, the two main strategies used to combine the CAs/IPs and the polyesters will be discussed. In more detail we will first present the strategies relying on CAs/IPs encapsulation in nanoparticles, micelles, dendrimers or capsules. We will then present chemical modifications of polyesters backbones and/or polyester surfaces to yield macromolecular imaging agents. Finally, opportunities offered by these innovative systems will be illustrated with some recent examples in the fields of cell labeling, diagnostic or theranostic applications and medical devices. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Samarium Barbier reactions of alpha-iodomethyloxazoles and thiazoles with aliphatic aldehydes.

    Science.gov (United States)

    Williams, David R; Berliner, Martin A; Stroup, Bryan W; Nag, Partha P; Clark, Michael P

    2005-09-15

    [reaction: see text] The reductive coupling of substituted alpha-iodomethyloxazoles and thiazoles with aliphatic aldehydes under Barbier conditions provides an effective method for the direct incorporation of intact heterocyclic systems.

  16. Fully Biobased Unsaturated Aliphatic Polyesters from Renewable Resources : Enzymatic Synthesis, Characterization, and Properties

    NARCIS (Netherlands)

    Jiang, Yi; Alberda van Ekenstein, Gerhard; Woortman, Albert J. J.; Loos, Katja

    2014-01-01

    Fully biobased saturated and unsaturated aliphatic polyesters and oligoesters are successfully prepared by Candida antarctica lipase B (CALB)-catalyzed polycondensations of succinate, itaconate, and 1,4-butanediol. The effects of monomer substrates and polymerization methods on enzymatic

  17. Thermally reversible thermoset materials based on the chemical modification of alternating aliphatic polyketones

    NARCIS (Netherlands)

    Araya Hermosilla, Rodrigo Andrés

    2016-01-01

    This thesis focused on the synthesis and characterization of different kinds of reversible thermosets and thermoset nanocomposite materials by using alternating aliphatic polyketone (PK) as raw material. Fundamental knowledge was generated regarding the molecular design of new polymers via chemical

  18. Aliphatic polycarbonate-based polyurethane elastomers and nanocomposites. II. Mechanical, thermal, and gas transport properties

    Czech Academy of Sciences Publication Activity Database

    Poreba, Rafal; Špírková, Milena; Brožová, Libuše; Lazić, N.; Pavličevič, Jelena; Strachota, Adam

    2013-01-01

    Roč. 127, č. 1 (2013), s. 329-341 ISSN 0021-8995 R&D Projects: GA ČR GAP108/10/0195 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyurethane elastomer * nanocomposite * polycarbonate diol Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.640, year: 2013

  19. The effect of acyclic retinoid on the metabolomic profiles of hepatocytes and hepatocellular carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Xian-Yang Qin

    Full Text Available BACKGROUND/PURPOSE: Acyclic retinoid (ACR is a promising chemopreventive agent for hepatocellular carcinoma (HCC that selectively inhibits the growth of HCC cells (JHH7 but not normal hepatic cells (Hc. To better understand the molecular basis of the selective anti-cancer effect of ACR, we performed nuclear magnetic resonance (NMR-based and capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS-based metabolome analyses in JHH7 and Hc cells after treatment with ACR. METHODOLOGY/PRINCIPAL FINDINGS: NMR-based metabolomics revealed a distinct metabolomic profile of JHH7 cells at 18 h after ACR treatment but not at 4 h after ACR treatment. CE-TOFMS analysis identified 88 principal metabolites in JHH7 and Hc cells after 24 h of treatment with ethanol (EtOH or ACR. The abundance of 71 of these metabolites was significantly different between EtOH-treated control JHH7 and Hc cells, and 49 of these metabolites were significantly down-regulated in the ACR-treated JHH7 cells compared to the EtOH-treated JHH7 cells. Of particular interest, the increase in adenosine-5'-triphosphate (ATP, the main cellular energy source, that was observed in the EtOH-treated control JHH7 cells was almost completely suppressed in the ACR-treated JHH7 cells; treatment with ACR restored ATP to the basal levels observed in both EtOH-control and ACR-treated Hc cells (0.72-fold compared to the EtOH control-treated JHH7 cells. Moreover, real-time PCR analyses revealed that ACR significantly increased the expression of pyruvate dehydrogenase kinases 4 (PDK4, a key regulator of ATP production, in JHH7 cells but not in Hc cells (3.06-fold and 1.20-fold compared to the EtOH control, respectively. CONCLUSIONS/SIGNIFICANCE: The results of the present study suggest that ACR may suppress the enhanced energy metabolism of JHH7 cells but not Hc cells; this occurs at least in part via the cancer-selective enhancement of PDK4 expression. The cancer-selective metabolic pathways

  20. Structure and properties of porous films based on aliphatic copolyamide developed for cellular technologies

    Czech Academy of Sciences Publication Activity Database

    Dobrovol`skaya, I.P.; Popryadukhin, P.V.; Yudin, V. E.; Ivankova, E.M.; Elokhovskiy, V.Y.; Weishauptová, Zuzana; Balík, Karel

    2015-01-01

    Roč. 26, č. 1 (2015), article number 46 ISSN 0957-4530 Institutional support: RVO:67985891 Keywords : porous film * aliphatic copolyamide * structure * properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.272, year: 2015 http://www.stem-art.com/Library/Science/Structure%20and%20properties%20of%20porous%20films%20based%20on%20aliphatic%20copolyamide%20developed%20for%20cellular%20technologies.pdf

  1. Room-temperature Cu-catalyzed N-arylation of aliphatic amines in neat water.

    Science.gov (United States)

    Wang, Deping; Zheng, Yanwen; Yang, Min; Zhang, Fuxing; Mao, Fangfang; Yu, Jiangxi; Xia, Xiaohong

    2017-10-04

    A room-temperature and PTC-free copper-catalyzed N-arylation of aliphatic amines in neat water has been developed. Using a combination of CuI and 6,7-dihydroquinolin-8(5H)-one oxime as the catalyst and KOH as the base, a wide range of aliphatic amines are arylated with various aryl and heteroaryl halides to give the corresponding products in up to 95% yield.

  2. Phylogenetic Investigation of the Aliphatic, Non-hydrolyzable Biopolymer Algaenan, with a Focus on Green Algae

    OpenAIRE

    Kodner, Robin B.; Summons, Roger E.; Knoll, Andrew Herbert

    2009-01-01

    Algaenan, an aliphatic biopolymer found in various microalgae, has been implicated as the source of a sizable proportion of the aliphatic refractory organic matter in sedimentary rocks. Because of its recalcitrant nature, algaenan is thought to be preserved selectively in the formation of kerogen and microfossils. Its taxonomic distribution in organisms has not been studied in detail or in a phylogenetic context. Here, we evaluate the distribution and phylogenetic relationships of algaenan-pr...

  3. Facile synthesis of aliphatic isothiocyanates and thioureas on solid phase using peptide coupling reagents

    DEFF Research Database (Denmark)

    Boas, Ulrik; Andersen, Heidi Gertz; Christensen, Jørn B.

    2004-01-01

    Peptide coupling reagents can be used as versatile reagents for the formation of aliphatic isothiocyanates and thioureas on solid phase from the corresponding solid-phase anchored aliphatic primary amines. The formation of the thioureas is fast and highly chemoselective, and proceeds via formatio...... of the intermediate isothiocyanate. The isothiocyanate and subsequent thiourea formation take place under standard peptide coupling conditions using carbon disulfide as the 'amino acid'. The thioureas are released from the resin and isolated in moderate to high yields....

  4. Dynamic mechanical and thermal behavior of liquid-crystalline polybutadiene-diols with mesogenic groups in side chains

    Czech Academy of Sciences Publication Activity Database

    Jigounov, A.; Sedláková, Zdeňka; Spěváček, Jiří; Ilavský, Michal

    2006-01-01

    Roč. 42, č. 10 (2006), s. 2450-2457 ISSN 0014-3057 R&D Projects: GA AV ČR IAA4112401 Institutional research plan: CEZ:AV0Z40500505 Keywords : polybutadiene-diols * liquid crystalline thiol * dynamic mechanical spectroscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.113, year: 2006

  5. Dielectric and thermal behavior of liquid crystalline comb-like polybutadiene-diols with mesogenic groups in side chains

    Czech Academy of Sciences Publication Activity Database

    Jigounov, A.; Sedláková, Zdeňka; Kripotou, R.; Pissis, P.; Nedbal, J.; Baldrian, Josef; Ilavský, Michal

    2007-01-01

    Roč. 48, č. 19 (2007), s. 5721-5733 ISSN 0032-3861 R&D Projects: GA AV ČR IAA4112401 Institutional research plan: CEZ:AV0Z40500505 Keywords : liquid crystalline polybutadiene -diols * dielectric spectroscopy * mesophase transitions Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.065, year: 2007

  6. Facile and Highly Diastereoselective Synthesis of syn- and cis-1,2-Diol Derivatives from Protected alpha-Hydroxy Ketones

    Czech Academy of Sciences Publication Activity Database

    Jahn, Emanuela; Smrček, Jakub; Pohl, Radek; Císařová, I.; Jones, P. G.; Jahn, Ullrich

    2015-01-01

    Roč. 2015, č. 35 (2015), s. 7785-7798 ISSN 1434-193X Grant - others:COST(XE) CM1201 Institutional support: RVO:61388963 Keywords : synthetic methods * reduction * diastereoselectivity * diols * ketones Subject RIV: CC - Organic Chemistry Impact factor: 3.068, year: 2015

  7. Ruthenium-catalysed synthesis of 2- and 3-substituted quinolines from anilines and 1,3-diols

    DEFF Research Database (Denmark)

    Monrad, Rune Nygaard; Madsen, Robert

    2011-01-01

    A straightforward synthesis of substituted quinolines is described by cyclocondensation of anilines with 1,3-diols. The reaction proceeds in mesitylene solution with catalytic amounts of RuCl3·xH 2O, PBu3 and MgBr2·OEt2. The transformation does not require any stoichiometric additives and only...

  8. Impact of culturing conditions on the abundance and composition of long chain alkyl diols in species of the genus

    NARCIS (Netherlands)

    Balzano, S.; Villanueva, L.; de Bar, M.; Sinninghe Damsté, J.S.; Schouten, S.

    2017-01-01

    Long chain alkyl diols (LCDs) are widespread in sediments and are synthesized, among others, by microalgae of the genus Nannochloropsis. The factors regulating the synthesis of LCDs and their biological function are, however, unclear. We investigated the changes in abundance of free + ester-bound

  9. The introduction of a double bond on the steroid skeleton - the preparation of enol silyl ether derivatives from vicinal diols

    Czech Academy of Sciences Publication Activity Database

    Marek, Aleš; Klepetářová, Blanka; Elbert, Tomáš

    2011-01-01

    Roč. 76, č. 5 (2011), s. 443-456 ISSN 0010-0765 R&D Projects: GA AV ČR IAA400550801 Institutional research plan: CEZ:AV0Z40550506 Keywords : enol silyl ether * vicinal diol * steroids Subject RIV: CC - Organic Chemistry Impact factor: 1.283, year: 2011

  10. Benzo(a)pyrene diol epoxides as intermediates in nucleic acid binding in vivo and in vitro

    DEFF Research Database (Denmark)

    Weinstein, I.B.; Jeffrey, A.M.; Jennette, K.W.

    1976-01-01

    Evidence has been obtained that a specific isomer of a diol epoxide derivative of benzo(a)pyrene, (+/-)-7 beta,8alpha-dihydroxy-9alpha, 10alpha-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene, is an intermediate in the binding of benzo(a)pyrene to RNA in cultured bovine bronchial mucosa. An adduct is for...

  11. Enantioselective Synthesis of Vicinal (R,R)-Diols by Saccharomyces cerevisiae Butanediol Dehydrogenase.

    Science.gov (United States)

    Calam, Eduard; González-Roca, Eva; Fernández, M Rosario; Dequin, Sylvie; Parés, Xavier; Virgili, Albert; Biosca, Josep A

    2016-01-04

    Butanediol dehydrogenase (Bdh1p) from Saccharomyces cerevisiae belongs to the superfamily of the medium-chain dehydrogenases and reductases and converts reversibly R-acetoin and S-acetoin to (2R,3R)-2,3-butanediol and meso-2,3-butanediol, respectively. It is specific for NAD(H) as a coenzyme, and it is the main enzyme involved in the last metabolic step leading to (2R,3R)-2,3-butanediol in yeast. In this study, we have used the activity of Bdh1p in different forms-purified enzyme, yeast extracts, permeabilized yeast cells, and as a fusion protein (with yeast formate dehydrogenase, Fdh1p)-to transform several vicinal diketones to the corresponding diols. We have also developed a new variant of the delitto perfetto methodology to place BDH1 under the control of the GAL1 promoter, resulting in a yeast strain that overexpresses butanediol dehydrogenase and formate dehydrogenase activities in the presence of galactose and regenerates NADH in the presence of formate. While the use of purified Bdh1p allows the synthesis of enantiopure (2R,3R)-2,3-butanediol, (2R,3R)-2,3-pentanediol, (2R,3R)-2,3-hexanediol, and (3R,4R)-3,4-hexanediol, the use of the engineered strain (as an extract or as permeabilized cells) yields mixtures of the diols. The production of pure diol stereoisomers has also been achieved by means of a chimeric fusion protein combining Fdh1p and Bdh1p. Finally, we have determined the selectivity of Bdh1p toward the oxidation/reduction of the hydroxyl/ketone groups from (2R,3R)-2,3-pentanediol/2,3-pentanedione and (2R,3R)-2,3-hexanediol/2,3-hexanedione. In conclusion, Bdh1p is an enzyme with biotechnological interest that can be used to synthesize chiral building blocks. A scheme of the favored pathway with the corresponding intermediates is proposed for the Bdh1p reaction. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  12. BENZO[a]PYRENE DIOL EPOXIDE PERTURBATION OF CELL CYCLE KINETICS OF SYNCHRONIZED MOUSE LIVER EPITHELIAL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Pearlman, A.L.; Navsky, B.N.; Bartholomew, J.C

    1980-07-01

    A cell cycle synchronization system is described for the analysis of the perturbation of cell cycle kinetics and the cycle-phase specificity of chemicals and other agents. We used the system to study the effects of ({+-})r-7, t-8-dihydroxy-t-9, 10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BaP diol epoxide) upon the cell cycle of mouse liver epithelial cells(NMuLi). BaP diol epoxide(0.6 uM) was added to replated cultures of NMuLi cells that had been synchronized in various stages of the cell cycle by centrifugal elutriation. DNA histograms were obtained by flow cytometry as a function of time after replating. The data were analyzed by a computer modeling routine and reduced to a few graphs illustrating the 'net effects' of the BaP diol epoxide relative to controls. BaP diol epoxide slowed S-phase traversal in all samples relative to their respective control. Traversal through G{sub 2}M was also slowed by at least 50%. BaP diol epoxide had no apparent effect upon G{sub 1} traversal by cycling cells, but delayed the recruitment of quiescent G{sub 0} cells by about 2 hrs. The methods described constitute a powerful new approach for probing the cell cycle effects of a wide variety of agents. The present system appears to be extremely sensitive and capable of characterizing the action of agents on each phase of the cell cycle. The methods are automatable and would allow for the assay and possible differential characterization of mutagens and carcinogens.

  13. [BMIM][PF(6)] promotes the synthesis of halohydrin esters from diols using potassium halides.

    Science.gov (United States)

    Oromí-Farrús, Mireia; Eras, Jordi; Villorbina, Gemma; Torres, Mercè; Llopis-Mestre, Veronica; Welton, Tom; Canela, Ramon

    2008-10-01

    Haloesterification of diverse diols with various carboxylic acids was achieved using potassium halides (KX) as the only halide source in ionic liquids. The best yield was obtained in [BMIM][PF(6)] when 1,2-octanediol, palmitic acid and KBr were used. This yield was 85% and the regioisomer with the bromine in primary position was present in a 75:25 ratio. The regioisomeric ratio could be improved using either KCl or some phenylcarboxylic acids. [BMIM][PF(6)] acts as both reaction media and catalyst of the reaction. To the best of our knowledge, this type of combined reaction using an ionic liquid is unprecedented. The other solvents tested did not lead either to the same yield or to the same regioisomeric ratio.

  14. Liquid crystalline polybutadiene diols with chiral thiol side-chain units

    Czech Academy of Sciences Publication Activity Database

    Kašpar, Miroslav; Bubnov, Alexej M.; Sedláková, Zdeňka; Stojanović, M.; Havlíček, J.; Obadović, D.; Ilavský, Michal

    2008-01-01

    Roč. 44, č. 1 (2008), s. 233-243 ISSN 0014-3057 R&D Projects: GA ČR GP202/03/P011; GA ČR GA202/05/0431; GA MŠk OC 175; GA AV ČR IAA100100710; GA AV ČR IAA4112401 Grant - others:MSEP(CS) 141020; ESF-COST(XE) D35 WG13-05 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z40500505 Keywords : chiral thiols * liquid crystal * polybutadiene * diols * side-chain polymer * polarizing optical microscopy * X-ray * dielectric spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.143, year: 2008

  15. Pharmacological activities of cilantro's aliphatic aldehydes against Leishmania donovani.

    Science.gov (United States)

    Donega, Mateus A; Mello, Simone C; Moraes, Rita M; Jain, Surendra K; Tekwani, Babu L; Cantrell, Charles L

    2014-12-01

    Leishmaniasis is a chronic infectious disease caused by different Leishmania species. Global occurrences of this disease are primarily limited to tropical and subtropical regions. Treatments are available; however, patients complain of side effects. Different species of plants have been screened as a potential source of new drugs against leishmaniasis. In this study, we investigated the antileishmanial activity of cilantro (Coriandrum sativum) essential oil and its main components: (E)-2-undecenal, (E)-2-decenal, (E)-2-dodecenal, decanal, dodecanal, and tetradecanal. The essential oil of C. sativum leaves inhibits growth of Leishmani donovani promastigotes in culture with an IC50 of 26.58 ± 6.11 µg/mL. The aliphatic aldehydes (E)-2-decenal (7.85 ± 0.28 µg/mL), (E)-2-undecenal (2.81 ± 0.21 µg/mL), and (E)-2-dodecenal (4.35 ± 0.15 µg/mL), all isolated from C. sativum essential oil, are effective inhibitors of in vitro cultures of L. donovani promastigotes. Aldehydes (E)-2-decenal, (E)-2-undecenal, and (E)-2-dodecenal were also evaluated against axenic amastigotes and IC50 values were determined to be 2.47 ± 0.25 µg/mL, 1.25 ± 0.11 µg/mL, and 4.78 ± 1.12 µg/mL, respectively. (E)-2-Undecenal and (E)-2-dodecenal demonstrated IC50 values of 5.65 ± 0.19 µg/mL and 9.60 ± 0.89 µg/mL, respectively, against macrophage amastigotes. These cilantro compounds showed no cytotoxicity against THP-1 macrophages. Georg Thieme Verlag KG Stuttgart · New York.

  16. Acid-base thermochemistry of gaseous aliphatic α-aminoacids.

    Science.gov (United States)

    Bouchoux, Guy; Huang, Sihua; Inda, Bhawani Singh

    2011-01-14

    Acid-base thermochemistry of isolated aliphatic amino acids (denoted AAA): glycine, alanine, valine, leucine, isoleucine and proline has been examined theoretically by quantum chemical computations at the G3MP2B3 level. Conformational analysis on neutral, protonated and deprotonated species has been used to identify the lowest energy conformers and to estimate the population of conformers expected to be present at thermal equilibrium at 298 K. Comparison of the G3MP2B3 theoretical proton affinities, PA, and ΔH(acid) with experimental results is shown to be correct if experimental thermochemistry is re-evaluated and adapted to the most recent acidity-basicity scales. From this point of view, a set of evaluated proton affinities of 887, 902, 915, 916, 919 and 941 kJ mol(-1), and a set of evaluated ΔH(acid) of 1433, 1430, 1423, 1423, 1422 and 1426 kJ mol(-1), is proposed for glycine, alanine, valine, leucine, isoleucine and proline, respectively. Correlations with structural parameters (Taft's σ(α) polarizability parameter and molecular size) suggest that polarizability of the side chain is the major origin of the increase in PA and decrease in ΔH(acid) along the homologous series glycine, alanine, valine and leucine/isoleucine. Heats of formation of gaseous species AAA, AAAH(+) and [AAA-H](-) were computed at the G3MP2B3 level. The present study provides previously unavailable Δ(f)H°(298) for the ionized species AAAH(+) and [AAA-H](-). Comparison with Benson's estimate, and correlation with molecular size, show that several experimental Δ(f)H°(298) values of neutral or gaseous AAA might be erroneous.

  17. Antiviral activities of 2,6-diaminopurine-based acyclic nucleoside phosphonates against herpesviruses: In vitro study results with pseudorabies virus (PrV, SuHV-1)

    Czech Academy of Sciences Publication Activity Database

    Zouharová, D.; Lipenská, I.; Fojtiková, M.; Kulich, P.; Neca, J.; Slaný, M.; Kovařčík, K.; Turanek-Knotigová, P.; Hubatka, F.; Celechovská, H.; Mašek, J.; Koudelka, Š.; Procházka, L.; Eyer, L.; Plocková, J.; Bartheldyová, E.; Miller, A. D.; Růžek, Daniel; Raška, M.; Janeba, Zlatko; Turánek, J.

    2016-01-01

    Roč. 184, FEB 29 (2016), s. 84-93 ISSN 0378-1135 Institutional support: RVO:60077344 ; RVO:61388963 Keywords : Pseudorabies * Acyclic nucleoside phosphonates * DNA viruses * Cidofovir * Anti viral drugs * DNA polymerase Subject RIV: EE - Microbiology, Virology; CC - Organic Chemistry (UOCHB-X) Impact factor: 2.628, year: 2016

  18. A novel and efficient one-pot synthesis of symmetrical diamide (bis-amidate) prodrugs of acyclic nucleoside phosphonates and evaluation of their biological activities

    Czech Academy of Sciences Publication Activity Database

    Jansa, Petr; Baszczyňski, Ondřej; Dračínský, Martin; Votruba, Ivan; Zídek, Zdeněk; Bahador, G.; Stepan, G.; Cihlar, T.; Mackman, R.; Holý, Antonín; Janeba, Zlatko

    2011-01-01

    Roč. 46, č. 9 (2011), s. 3748-3754 ISSN 0223-5234 R&D Projects: GA MV VG20102015046 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50390703 Keywords : prodrugs * phosphonodiamides * bis-amidates * acyclic nucleoside phosphonates * GS-9219 Subject RIV: CC - Organic Chemistry Impact factor: 3.346, year: 2011

  19. Synthesis and biological evaluation of acyclic nucleotide analogues with a furo[2,3-d]pyrimidin-2(3H)-one base

    Czech Academy of Sciences Publication Activity Database

    Janeba, Zlatko; Holý, Antonín; Pohl, Radek; Snoeck, R.; Andrei, G.; De Clercq, E.; Balzarini, J.

    2010-01-01

    Roč. 88, č. 7 (2010), s. 628-638 ISSN 0008-4042 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * Sonogashira reaction * intramolecular cyclization Subject RIV: CC - Organic Chemistry Impact factor: 1.374, year: 2010

  20. Swift heavy ion induced modification of aliphatic polymers

    International Nuclear Information System (INIS)

    Hossain, Umme Habiba

    2015-01-01

    In this thesis, the high energy heavy ion induced modification of aliphatic polymers is studied. Two polymer groups, namely polyvinyl polymers (PVF, PVAc, PVA and PMMA) and fluoropolymers (PVDF, ETFE, PFA and FEP) were used in this work. Polyvinyl polymers were investigated since they will be used as insulating materials in the superconducting magnets of the new ion accelerators of the planned International Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz-Centre of Heavy Ion Research (GSI) in Darmstadt. In order to study ion-beam induced degradation, all polymer foils were irradiated at the GSI linear accelerator UNILAC using several projectiles (U, Au, Sm, Xe) and experimentation sites (beam lines X0 and M3) over a large fluence regime (1 x 10 10 - 5 x 10 12 ions/cm 2 ). Five independent techniques, namely infrared (FT-IR) and ultraviolet-visible (UV-Vis) spectroscopy, residual gas analysis (RGA), thermal gravimetric analysis (TGA), and mass loss analysis (ML), were used to analyze the irradiated samples. FT-IR spectroscopy revealed that ion irradiation led to the decrease of characteristic band intensities showing the general degradation of the polymers, with scission of side groups and the main backbone. As a consequence of the structural modification, new bands appeared. UV-Vis transmission analysis showed an absorption edge shift from the ultraviolet region towards the visible region indicating double bond and conjugated double bond formation. On-line massspectrometric residual gas analysis showed the release of small gaseous fragment molecules. TGA analysis gave evidence of a changed thermal stability. With ML analysis, the considerable mass loss was quantified. The results of the five complementary analytical methods show how heavy ion irradiation changes the molecular structure of the polymers. Molecular degradation mechanisms are postulated. The amount of radiation damage is found to be sensitive to the used type of ionic species. While

  1. Highly stable triple helix formation by homopyrimidine (l)-acyclic threoninol nucleic acids with single stranded DNA and RNA

    DEFF Research Database (Denmark)

    Kumar, Vipin; Kesavan, Venkitasamy; Gothelf, Kurt Vesterager

    2015-01-01

    Acyclic (l)-threoninol nucleic acid (aTNA) containing thymine, cytosine and adenine nucleobases were synthesized and shown to form surprisingly stable triplexes with complementary single stranded homopurine DNA or RNA targets. The triplex structures consist of two (l)-aTNA strands and one DNA...... or RNA, and these triplexes are significantly stronger than the corresponding DNA or RNA duplexes as shown in competition experiments. As a unique property the (l)-aTNAs exclusively form triplex structures with DNA and RNA and no duplex structures are observed by gel electrophoresis. The results were...... compared to the known enantiomer (d)-aTNA, which forms much weaker triplexes depending upon temperature and time. It was demonstrated that (l)-aTNA triplexes are able to stop primer extension on a DNA template, showing the potential of (l)-aTNA for antisense applications....

  2. Acyclic Diene Metathesis (ADMET Polymerization for Precise Synthesis of Defect-Free Conjugated Polymers with Well-Defined Chain Ends

    Directory of Open Access Journals (Sweden)

    Tahmina Haque

    2015-03-01

    Full Text Available This accounts introduces unique characteristics by adopting the acyclic diene metathesis (ADMET polymerization for synthesis of conjugated polymers, poly(arylene vinylenes, known as promising molecular electronics. The method is more suitable than the other methods in terms of atom efficiency affording defect-free, stereo-regular (exclusive trans polymers with well-defined chain ends; the resultant polymers possess better property than those prepared by the conventional methods. The chain ends (vinyl group in the resultant polymer prepared by ruthenium-carbene catalyst(s can be modified by treating with molybdenum-alkylidene complex (olefin metathesis followed by addition of various aldehyde (Wittig type cleavage, affording the end-functionalized polymers exclusively. An introduction of initiating fragment, the other conjugated segment, and one-pot synthesis of end-functionalized block copolymers, star shape polymers can be achieved by adopting this methodology.

  3. Spectral, Electrochemical, Fluorescence, Kinetic and Anti-microbial Studies of Acyclic Schiff-base Gadolinium(III) Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Vijayaraj, A.; Prabu, R.; Suresh, R.; Narayanan, V.; Sangeetha Kumari, R.; Kaviyarasan, V. [Univ. of Madras, Madras (India)

    2012-11-15

    A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around -2.15 to -1.60 V. The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity.

  4. Synthesis of a new series of phosphonylated 1,2,3-triazoles as acyclic analogs of ribavirin.

    Science.gov (United States)

    Głowacka, Iwona E; Balzarini, Jan; Wróblewski, Andrzej E

    2013-09-01

    A novel series of phosphonylated 1,2,3-triazoles as structural acyclic analogs of ribavirin, in which the 1,2,3-triazole ring was substituted at C4' with COOMe, CONH2, CONHOH, and CH2 NHBoc groups, were synthesized from diethyl azidomethyl-, 2-azidoethyl-, 3-azidopropyl-, 4-azidobutyl-, 2-azido-1-hydroxyethyl-, 3-azido-2-hydroxypropyl-, 2-azidoethoxymethyl- and 2-azidoethoxyethylphosphonate. The efficient synthesis of diethyl azidomethylphosphonate from diethyl 4-nitrobenzenesulfonylmethylphosphonate employing the in situ formed azides is described. All synthesized compounds were evaluated in vitro for their inhibitory activity against a broad variety of RNA and DNA viruses. No antiviral activity was observed at 100 µM. Only compound 13g exhibited inhibitory effects on the proliferation of HeLa cells (IC50=169±45 µM). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Process for removing halogenated aliphatic and aromatic compounds from petroleum products

    Science.gov (United States)

    Googin, J.M.; Napier, J.M.; Travaglini, M.A.

    1983-09-20

    A process is described for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 1 fig.

  6. Stereoselective synthesis of protected 1,2-diols and 1,2,3-triols by a tandem hydroboration-coupling sequence.

    Science.gov (United States)

    Kapur, Manmohan; Khartulyari, Anton; Maier, Martin E

    2006-04-13

    [reaction: see text] A new approach to complex chiral diols and polyols is described utilizing a tandem hydroboration/Suzuki cross-coupling reaction. This method utilizes the versatility of a glycolate-derived chiral template.

  7. Efficient Pd@MIL-101(Cr) hetero-catalysts for 2-butyne-1,4-diol hydrogenation exhibiting high selectivity

    KAUST Repository

    Yin, Dongdong

    2017-01-05

    Pd@MIL-101(Cr) hetero-catalysts have been successfully prepared using the metal-organic chemical vapour deposition (MOCVD) approach, by choosing [Pd(η-CH)(η-CH)] as a volatile precursor, and the hydrothermally stable metal-organic framework, MIL-101(Cr) as a support. The prepared Pd@MIL-101(Cr) hetero-catalysts characterized with various analytical techniques, exhibited highly monodispersed immobilized Pd nanoparticles in the MIL-101(Cr) cavities, while retaining the pristine crystallinity and porosity. The intact hybrid Pd@MIL-101(Cr) has been demonstrated to be an efficient catalyst for 2-butyne-1,4-diol hydrogenation with excellent activity, stability and selectivity (2-butene-1,4-diol (>94%)).

  8. Synthesis, characterization and reaction behaviour of lamellar AFm phases with aliphatic sulfonate-anions

    International Nuclear Information System (INIS)

    Poellmann, Herbert; Stefan, Stoeber; Stern, Edda

    2006-01-01

    The addition of alkanesulfonates as admixtures to cementitious materials allows the formation of new lamellar phases (AFm), which was proofed by X-ray diffraction (XRD). The course of hydration was investigated by heat flow calorimetry. The layered structures of AFm phases are composed of brucite-like main layers and interlayers containing alkanesulfonate ions and additional H 2 O molecules. These structural not necessary H 2 O molecules release gradually at definite steps with increasing temperature. With varying relative humidity the layer thickness c' of short aliphatic chained calcium aluminate alkanesulfonate hydrates changes considerably, whereas large organic molecules dominate the layer thickness of those with longer aliphatic chains. By means of the increase of layer thickness with increasing chain lengths it is possible to determine the tilt angles of the aliphatic chains in the interlayers

  9. STIMULATION BY HYDROCHLORIC ACID AND BY THE NORMAL ALIPHATIC ACIDS IN THE SUNFISH EUPOMOTIS

    Science.gov (United States)

    Allison, James B.

    1932-01-01

    1. The reaction of the sunfish, Eupomotis gibbosus, to different concentrations of hydrochloric acid and of the first six members of the N aliphatic acids has been studied. 2. The stimulating efficiency of hydrochloric acid may best be related to the concentration of hydrogen ions produced by that acid. 3. The stimulating efficiency of the N aliphatic acids may best be correlated with the non-polar nature of a portion of the molecule, but it is necessary to consider the higher potential of the polar group of formic acid to account satisfactorily for its position in the series. 4. When equally effective concentrations of the N aliphatic acids are compared, formic acid is more effective at lower concentrations than at higher. 5. Per cent variation in response appears to be independent of the chemical environment to which the animal responded. PMID:19872671

  10. Seasonal distribution of aliphatic hydrocarbons in the Vaza Barris Estuarine System, Sergipe, Brazil.

    Science.gov (United States)

    Barbosa, José Carlos S; Santos, Lukas G G V; Sant'Anna, Mércia V S; Souza, Michel R R; Damasceno, Flaviana C; Alexandre, Marcelo R

    2016-03-15

    The seasonal assessment of anthropogenic activities in the Vaza Barris estuarine river system, located in the Sergipe state, northeastern Brazil, was performed using the aliphatic hydrocarbon distribution. The aliphatic hydrocarbon and isoprenoid (Pristane and Phytane) concentrations ranged between 0.19 μg g(-1) and 8.5 μg g(-1) of dry weight. Data were analyzed using Kruskal-Wallis test, with significance level set at p n-alkanes/n-C16, Low Molecular Weight/High Molecular Weight ratio (LMW/HMW) and Terrigenous to Aquatic Ratio (TAR) suggested biogenic input of aliphatic hydrocarbons for most samples, with significant contribution of higher plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Nickel-catalysed retro-hydroamidocarbonylation of aliphatic amides to olefins

    Science.gov (United States)

    Hu, Jiefeng; Wang, Minyan; Pu, Xinghui; Shi, Zhuangzhi

    2017-05-01

    Amide and olefins are important synthetic intermediates with complementary reactivity which play a key role in the construction of natural products, pharmaceuticals and manmade materials. Converting the normally highly stable aliphatic amides into olefins directly is a challenging task. Here we show that a Ni/NHC-catalytic system has been established for decarbonylative elimination of aliphatic amides to generate various olefins via C-N and C-C bond cleavage. This study not only overcomes the acyl C-N bond activation in aliphatic amides, but also encompasses distinct chemical advances on a new type of elimination reaction called retro-hydroamidocarbonylation. This transformation shows good functional group compatibility and can serve as a powerful synthetic tool for late-stage olefination of amide groups in complex compounds.

  12. Effects of the Amount and Type of Diol Ring Openers on the Properties of Oligolactide Acrylates for UV-Curable Printing Inks

    Directory of Open Access Journals (Sweden)

    Santi Kulsiriswad

    2017-10-01

    Full Text Available This study aimed to synthesize low viscosity oligolactide acrylates for UV-curable inks from oligolactide diols. Firstly, low molecular weight oligolactide diols were prepared by ring opening reaction of L-lactide with diols. Oligolactide acrylates were then synthesized by functionalizing the oligolactide diols with acrylic acid. In this study, three diol ring openers having short and long alkyl chain length were used to investigate the effects of the amount and type of diols on the properties of the oligolactide acrylates. The obtained oligomers were characterized, and the viscosities of oligolactide acrylates were measured. Results showed that oligolactide acrylates were successfully synthesized in all cases of ring openers, as confirmed by 1H-NMR (proton nuclear magnetic resonance spectroscopy and FTIR (Fourier transform infrared spectroscopy. An increase in the alkyl chain length of the ring openers resulted in oligomers with lower viscosity and a decrease in Tg. Following that, the obtained oligolactide acrylates were employed for the formulation of UV-curable screen printing inks and their properties were investigated. Results showed that the inks formulated from oligomers with lower molecular weight exhibited better ink flow. Additionally, all ink films cured by UV radiation were very flexible with excellent adhesion, high impact resistance, and excellent water resistance.

  13. Dielectric and ferroelectric sensing based on molecular recognition in Cu(1,10-phenlothroline)2SeO4.(diol) systems

    Science.gov (United States)

    Ye, Heng-Yun; Liao, Wei-Qiang; Zhou, Qionghua; Zhang, Yi; Wang, Jinlan; You, Yu-Meng; Wang, Jin-Yun; Chen, Zhong-Ning; Li, Peng-Fei; Fu, Da-Wei; Huang, Songping D.; Xiong, Ren-Gen

    2017-02-01

    The process of molecular recognition is the assembly of two or more molecules through weak interactions. Information in the process of molecular recognition can be transmitted to us via physical signals, which may find applications in sensing and switching. The conventional signals are mainly limited to light signal. Here, we describe the recognition of diols with Cu(1,10-phenlothroline)2SeO4 and the transduction of discrete recognition events into dielectric and/or ferroelectric signals. We observe that systems of Cu(1,10-phenlothroline)2SeO4.(diol) exhibit significant dielectric and/or ferroelectric dependence on different diol molecules. The compounds including ethane-1,2-diol or propane-1,2-diol just show small temperature-dependent dielectric anomalies and no reversible polarization, while the compound including ethane-1,3-diol shows giant temperature-dependent dielectric anomalies as well as ferroelectric reversible spontaneous polarization. This finding shows that dielectricity and/or ferroelectricity has the potential to be used for signalling molecular recognition.

  14. Synthesis and evaluation of aminoborates derived from boric acid and diols for protecting wood against fungal and thermal degradation

    Science.gov (United States)

    George C. Chen

    2008-01-01

    N-methyl amino catechol borate (1), N-methyl amino-4-methyl catechol borate (2), N-methyl amino-4-t-butyl catechol borate (3), and N-methyl amino-2, 3-naphthyl borate (4) were synthesized by reflux of boric acid with a diol in solvent N,N-dimethyl formamide. The aminoborates were characterized by proton nuclear magnetic resonance spectroscopy, FTIR spectroscopy and...

  15. A novel type of banana liquid crystals based on 1-substituted naphtalene-2,7-diol cores

    Czech Academy of Sciences Publication Activity Database

    Svoboda, J.; Novotná, Vladimíra; Kozmík, V.; Glogarová, Milada; Weissflog, W.; Diele, S.; Pelzl, G.

    2003-01-01

    Roč. 13, - (2003), s. 2104-2110 ISSN 0959-9428 R&D Projects: GA ČR(CZ) GA202/02/0840 Grant - others:COST(XE) D14 WG 00015 Institutional research plan: CEZ:AV0Z1010914 Keywords : liquid crystals * banana -shaped mesogens * substituted naphthalene diols Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.659, year: 2003

  16. Iridium- and ruthenium-catalysed synthesis of 2,3-disubstituted indoles from anilines and vicinal diols

    DEFF Research Database (Denmark)

    Tursky, Matyas; Lorentz-Petersen, Linda Luise Reeh; Olsen, L. B.

    2010-01-01

    A straightforward and atom-economical method is described for the synthesis of 2,3-disubstituted indoles. Anilines and 1,2-diols are condensed under neat conditions with catalytic amounts of either [Cp*IrCl2](2)/MsOH or RuCl3 center dot xH(2)O/phosphine (phosphine = PPh3 or xantphos). The reactio...

  17. Identification and characterization of dimeric oxidation products of p-cymene-2,3-diol isolated from Thymus vulgaris L.

    Science.gov (United States)

    Rainis, Guido; Ternes, Waldemar

    2014-01-08

    The aim of this study was to investigate the oxidation products of p-cymene-2,3-diol, a major antioxidative constituent of thyme (Thymus vulgaris L.). Although a dimeric form of p-cymene-2,3-diol and some derivative substances exhibiting valuable food technological and health-promoting properties have been reported in earlier publications, no obvious correlation has been shown between these substances. A modified HPLC-ESI-MS method made it possible to prove that two dimers, 3,4,3',4'-tetrahydroxy-5,5'-diisopropyl-2,2'-dimethylbiphenyl (1) and the newly identified 3',4'-dihydroxy-5,5'-diisopropyl-2,2'-dimethylbiphenyl-3,4-dione (2), are oxidation products of p-cymene-2,3-diol. 2 was characterized by the fragmentation pattern determined by multiple mass spectrometry, (1)H NMR, (13)C NMR, H-H COSY, HSQC, and HMBC. Both biphenyls were also quantitated in freeze-dried thyme as well as in a food matrix spiked with thyme extract. Model experiments using raw and cooked minced pork meat as matrix and sodium nitrite as oxidizing and reduction agent with and without ascorbic acid as protective reagent showed the correlation between food processing and dimer generation.

  18. One pot simultaneous preparation of both enantiomer of β-amino alcohol and vicinal diol via cascade biocatalysis.

    Science.gov (United States)

    Zhao, Jian-Wei; Wu, Hua-Lei; Zhang, Jian-Dong; Gao, Wen-Chao; Fan, Xiao-Jun; Chang, Hong-Hong; Wei, Wen-Long; Xu, Jian-He

    2018-02-01

    To investigate the efficiency of a new cascade biocatalysis system for the conversion of R, S-β-amino alcohols to enantiopure vicinal diol and β-amino alcohol. An efficient cascade biocatalysis was achieved by combination of a transaminase, a carbonyl reductase and a cofactor regeneration system. An ee value of > 99% for 2-amino-2-phenylethanol and 1-phenyl-1, 2-ethanediol were simultaneously obtained with 50% conversion from R, S-2-amino-2-phenylethanol. The generality of the cascade biocatalysis was further demonstrated with the whole-cell approaches to convert 10-60 mM R, S-β-amino alcohol to (R)- and (S)-diol and (R)- and (S)-β-amino alcohol in 90-99% ee with 50-52% conversion. Preparative biotransformation was demonstrated at a 50 ml scale with mixed recombinant cells to give both (R)- and (S)-2-amino-2-phenylethanol and (R)- and (S)-1-phenyl-1, 2-ethanediol in > 99% ee and 40-42% isolated yield from racemic 2-amino-2-phenylethanol. This cascade biocatalysis system provides a new practical method for the simultaneous synthesis of optically pure vicinal diol and an β-amino alcohol.

  19. Simple Preparation of Rhodococcus erythropolis DSM 44534 as Biocatalyst to Oxidize Diols into the Optically Active Lactones.

    Science.gov (United States)

    Martinez-Rojas, Enriqueta; Olejniczak, Teresa; Neumann, Konrad; Garbe, Leif-Alexander; Boratyñski, Filip

    2016-09-01

    In the current study, we present a green toolbox to produce ecological compounds like lactone moiety. Rhodococcus erythropolis DSM 44534 cells have been used to oxidize both decane-1,4-diol () and decane-1,5-diol () into the corresponding γ- () and δ-decalactones () with yield of 80% and enantiomeric excess (ee) = 75% and ee = 90%, respectively. Among oxidation of meso diols, (-)-(1S,5R)-cis-3-oxabicyclo[4.3.0]non-7-en-2-one (5a) with 56% yield and ee = 76% as well as (-)-(2R,3S)-cis-endo-3-oxabicyclo[2.2.1]dec-7-en-2-one (6a) with 100% yield and ee = 90% were formed. It is worth mentioning that R. erythropolis DSM 44534 grew in a mineral medium containing ethanol as the sole source of energy and carbon Chirality 28:623-627, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Aggressive electrolyte poisons and multifunctional fluids comprised of diols and diamines for emergency shutdown of lithium-ion batteries

    Science.gov (United States)

    Noelle, Daniel J.; Shi, Yang; Wang, Meng; Le, Anh V.; Qiao, Yu

    2018-04-01

    Electrolyte poisons comprised of diols and diamines are investigated for the intended function of exacerbating internal resistance in lithium-ion batteries upon short circuit failure, to quickly arrest uncontrolled joule heat generation in the earliest stages. The competing dynamics of powerful short circuit currents and electrolyte poisoning interactions are evaluated via simultaneous nail penetration and poison injection of LIR2450 format LiCoO2/graphite 120 mAh coin cells. To forcibly increase electrolyte impedance, diols serve to hinder charge-carrying ion mobility by raising solution viscosity, while diamines disrupt solvent permittivity by rapidly polymerizing the ethylene carbonate solvent. Diamines demonstrate great potency, and are suitable for integration into battery cells within chemically-inert, breakable containers, rigged for release upon mechanical activation. Mixtures of 1,2-ethanediol and 1,2-ethanediamine show synergistic poisoning effects, decreasing peak temperature accrued by 70% when introduced simultaneously upon nail penetration. With the innate presence and abundance of diols and diamines in electric vehicle heat exchangers, they may be employed for multifunctional applications.

  1. Reduced Cu–Co–Al Mixed Metal Oxides for the Ring-Opening of Furfuryl Alcohol to Produce Renewable Diols

    Energy Technology Data Exchange (ETDEWEB)

    Sulmonetti, Taylor P. [School; amp, Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, United States; Hu, Bo [School; amp, Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, United States; Lee, Sungsik [Advanced; Agrawal, Pradeep K. [School; amp, Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, United States; Jones, Christopher W. [School; amp, Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, United States

    2017-08-29

    The ring-opening of furfuryl alcohol to diol products, including 1,2-pentanediol and 1,5- pentanediol, is investigated over reduced Cu-Co-Al mixed metal oxides in a liquid phase batch reactor under H2 pressure. These catalysts are synthesized through the calcination of layered double hydroxides (LDH) to yield well-dispersed, porous mixed metal oxides, which upon reduction displayed activity towards diols, mainly the valuable monomer 1,5-pentanediol. The addition of Cu facilitated the reduction of Co oxide species at lower temperatures, and under optimized conditions a yield towards 1,5-pentanediol of 44% (total diol yield of 62%) was achieved. Various characterization techniques including TPR, XPS, and XAS are employed to elucidate the structure of the catalysts, suggesting the formation of both metallic (Co and Cu) and oxide (CoO) species after reduction and passivation. Ultimately, this study demonstrates the promising characteristics that non-precious multi-metal catalysts have for the conversion of biomass derived platform molecules to plastic precursors

  2. 3-Monochloropropane-1,2-diol fatty acid esters in commercial deep-fat fried foods.

    Science.gov (United States)

    Arisseto, Adriana Pavesi; Marcolino, Priscila Francisca Corrêa; Vicente, Eduardo

    2015-01-01

    Levels of 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters were evaluated in commercial deep-fat fried foods from the Brazilian market using a GC-MS method preceded by acid-catalysed methanolysis. A limit of detection of 0.04 mg kg(-1), a limit of quantitation of 0.08 mg kg(-1), mean recoveries varying from 82% to 92%, and coefficients of variation ranging from 2.5% to 5.0% for repeatability and from 3.6% to 6.5% for within-laboratory reproducibility were obtained during in-house validation. The levels of the compounds in the evaluated samples, expressed as free 3-MCPD equivalent, ranged from not detected to 0.99 mg kg(-)(1), and the highest concentrations were observed in samples of chopped onion and garlic. A preliminary estimation of 3-MCPD intake using these occurrence data suggested low risks to human health, but a potential concern may arise in particular cases of consumers of fried food.

  3. Antioxidants Inhibit Formation of 3-Monochloropropane-1,2-diol Esters in Model Reactions.

    Science.gov (United States)

    Li, Chang; Jia, Hanbing; Shen, Mingyue; Wang, Yuting; Nie, Shaoping; Chen, Yi; Zhou, Yongqiang; Wang, Yuanxing; Xie, Mingyong

    2015-11-11

    The capacities of six antioxidants to inhibit the formation of 3-monochloropropane-1,2 diol (3-MCPD) esters were examined in this study. Inhibitory capacities of the antioxidants were investigated both in chemical models containing the precursors (tripalmitoyl glycerol, 1,2-dipalmitoyl-sn-glycerol, monopalmitoyl glycerol, and sodium chloride) of 3-MCPD esters and in oil models (rapeseed oil and sodium chloride). Six antioxidants, butylated hydroxytoluene (BHT), butylated hydroxy anisole (BHA), tert-butyl hydroquinone (TBHQ), propyl gallate (PG), L-ascorbyl palmitate (AP), and α-tocopherol (VE), were found to exhibit inhibiting capacities on 3-MCPD ester formation both in chemical models and in oil models. TBHQ provided the highest inhibitory capacity both in chemical models and in oil models; 44% of 3-MCPD ester formation was inhibited in the presence of TBHQ (66 mg/kg of oil) after heating of rapeseed oil at 230 °C for 30 min, followed by PG and AP. BHT, BHA, and VE appeared to have weaker inhibitory abilities in both models. VE exhibited the lowest inhibition rate; 22% of 3-MCPD esters were inhibited in the presence of VE (172 mg/kg of oil) after heating of rapeseed oil at 230 °C for 30 min. In addition, the inhibition rates of PG and VE decreased dramatically with an increase in temperature or heating time. The results suggested that some antioxidants, such as TBHQ, PG, and AP, could be the potential inhibitors of 3-MCPD esters in practice.

  4. Surface characteristics of polyurethane elastomers based on chitin/1,4-butane diol blends.

    Science.gov (United States)

    Zia, Khalid Mahmood; Barikani, Mehdi; Zuber, Mohammad; Bhatti, Ijaz Ahmad; Barmar, Mohammad

    2009-03-01

    Biodegradable polyurethane elastomers with tunable hydrophobicity were synthesized by step-growth polymerization techniques using poly(epsilon-caprolactone) (PCL) and 4,4'-diphenylmethane diisocyanate (MDI). The prepolymer was extended with different mass ratios of chitin and 1,4-butane diol (BDO). The effect of chitin contents in chain extenders (CE) proportion on surface properties was studied and investigated. Incorporation of chitin contents into the final PU showed decrease in surface free energy and its polar component. Simultaneously, the work of water adhesion to polymer decreases significantly by increasing the chitin contents in the synthesized polymer. Contact angle measurement, water absorption and swelling behavior of the synthesized polyurethane samples were affected by varying the chitin contents in the chemical composition of the final PU. The interactions of the final PU films with solvents on the surface were displayed clear dependent on the contents of chitin in to the final polyurethane formulation. The results of different tests demonstrated that the synthesized products are a potential candidate as non-absorbable suture as previously investigated into their in vitro biocompatibility and non-toxicity [K.M. Zia, M. Zuber, I.A. Bhatti, M. Barikani, M.A. Sheikh, Int. J. Biol. Macromol. 44 (2009) 18-22].

  5. Formation of monochloropropane-1,2-diol and its esters in biscuits during baking.

    Science.gov (United States)

    Mogol, Burçe Ataç; Pye, Céline; Anderson, Warwick; Crews, Colin; Gökmen, Vural

    2014-07-23

    The formation of free monochloropropane-1,2-diol (3-MCPD and 2-MCPD) and its esters (bound-MCPD) was investigated in biscuits baked with various time and temperature combinations. The effect of salt as a source of chloride on the formation of these processing contaminants was also determined. Kinetic examination of the data indicated that an increasing baking temperature led to an increase in the reaction rate constants for 3-MCPD, 2-MCPD, and bound-MCPD. The activation energies of formation of 3-MCPD and 2-MCPD were found to be 29 kJ mol(-1). Eliminating salt from the recipe decreased 3-MCPD and 2-MCPD formation rate constants in biscuits by 57.5 and 85.4%, respectively. In addition, there was no formation of bound-MCPD in biscuits during baking without salt. Therefore, lowering the thermal load or limiting the chloride concentration should be considered a means of reducing or eliminating the formation of these contaminants in biscuits. Different refined oils were also used in the recipe to test their effect on the occurrence of free MCPD and its esters in biscuits. Besides the baking process, the results also confirmed the role of refined oil in the final concentration of these contaminants in biscuits.

  6. Setting the anomeric effect against steric effects in simple acyclic acetals. Non-anomeric non-classical conformations. An n.m.r. and molecular mechanics investigation

    DEFF Research Database (Denmark)

    Anderson, J. Edgar; Heki, Katsuhiko; Hirota, Minoru

    1987-01-01

    N.m.r. parameters for a series of simple aliphatic acetals indicate that the preferred conformation changes from the anomeric one found in formaldehyde dimethyl acetal (formal), to a new one whose structure is suggested by molecular mechanics calculations.......N.m.r. parameters for a series of simple aliphatic acetals indicate that the preferred conformation changes from the anomeric one found in formaldehyde dimethyl acetal (formal), to a new one whose structure is suggested by molecular mechanics calculations....

  7. Kinetic analysis of the reactivity of aliphatic cyclic alcohols and carboxylic acids in the T-for-H exchange reaction

    International Nuclear Information System (INIS)

    Tamura, Kiyoshi; Imaizumi, Hiroshi; Kano, Naoki

    2007-01-01

    In order to quantitatively evaluate the influence of tritium ( 3 He or T) on various functional groups in environment, the hydrogen isotope exchange reaction (T-for-H exchange reaction) between tritium-labeled poly-(vinyl alcohol) and each aliphatic cyclic alcohol (or carboxylic acid) has been dynamically observed in the range of 50 to 90degC. Consequently, the activities of the aliphatic cyclic alcohol and carboxylic acid increased with increasing reaction time. Applying in A''-McKay plot method to the observed data, the rate constants (k) for these materials were obtained. Using the k, the relation between the number of carbon atoms in the ring in each alcohol and the reactivity of the alcohol was quantitatively compared. Then, to clarify the effect of relative atomic charge of O atom (connected with the H atom in the hydroxy (or carboxy) group in the material) on the reactivity of the material, the MOPAC method was used. From both the above-mentioned and the obtained previously, the following nine items were found as to aliphatic cyclic alcohols (and carboxylic acids) in the T-for-H exchange reaction. (1) The reactivity of aliphatic cyclic alcohols (and carboxylic acids) depends on the temperature. (2) The reactivity of the cyclic materials decreases with increasing number of carbon atoms in the ring. (3) The reactivity of the aliphatic cyclic carboxylic acid seems to be smaller than that of aliphatic cyclic alcohol, and be larger than that of aliphatic cyclic amine. (4) For aliphatic cyclic alcohols, correlation exists between k and relative atomic charges of O atom obtained by the MOPAC method, but the tendency for aliphatic cyclic carboxylic acid is not clear. (5) As to having the same number of carbon atoms in each ring, the reactivity of the aliphatic cyclic carboxylic acid including the side chain is smaller than of the aliphatic cyclic carboxylic acid including no side chain. (6) The reactivity of aliphatic cyclic carboxylic acid is larger than that of

  8. Human N6-Methyl-AMP/dAMP aminohydrolase (abacavir 5’-monophosphate deaminase) is capable of metabolizing N6-substituted purine acyclic nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

    Schinkmanová, Markéta; Votruba, Ivan; Shibata, R.; Han, B.; Liu, X.; Cihlař, T.; Holý, Antonín

    2008-01-01

    Roč. 73, č. 2 (2008), s. 275-291 ISSN 0010-0765 R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Institutional research plan: CEZ:AV0Z40550506 Keywords : guanine * acyclic nucleoside phosphonates * cPrPMEDAP * abacavir 5'-phosphate Subject RIV: CC - Organic Chemistry Impact factor: 0.784, year: 2008

  9. Synthesis of new acadesine (AICA-riboside) analogues having acyclic D-ribityl or 4-hydroxybutyl chains in place of the ribose.

    Science.gov (United States)

    D'Errico, Stefano; Oliviero, Giorgia; Borbone, Nicola; Amato, Jussara; Piccialli, Vincenzo; Varra, Michela; Mayol, Luciano; Piccialli, Gennaro

    2013-08-06

    The antiviral activity of certain acyclic nucleosides drew our attention to the fact that the replacement of the furanose ring by an alkyl group bearing hydroxyl(s) could be a useful structural modification to modulate the biological properties of those nucleosides. Herein, we report on the synthesis of some novel acadesine analogues, where the ribose moiety is mimicked by a D-ribityl or by a hydroxybutyl chain.

  10. Synthesis of Aliphatic Symmetric Diphosphonium Salts and Bactericidal Activity of Selected Products

    Directory of Open Access Journals (Sweden)

    Bin Yuan

    2017-06-01

    Full Text Available Eight new aliphatic symmetrical diphosphonium salts were synthesized by reacting ω,ω´-dibromoalkanes with triphenylphosphine or tributylphosphine using N,N-dimethyl acetamide as a solvent at 140~150°C for 16~20 h under a nitrogen atmosphere.

  11. Phenolic and short-chained aliphatic organic acid constituents of wild oat (Avena fatua L.) seeds.

    Science.gov (United States)

    Gallagher, R S; Ananth, R; Granger, K; Bradley, B; Anderson, J V; Fuerst, E P

    2010-01-13

    The objective of this research was to identify and quantify the phenolic and short-chained aliphatic organic acids present in the seeds of three wild-type populations of wild oat and compare these results to the chemical composition of seeds from two commonly utilized wild oat isolines (M73 and SH430). Phenolic acids have been shown to serve as germination inhibitors, as well as protection for seeds from biotic and abiotic stress factors in other species, whereas aliphatic organic acids have been linked to germination traits and protection against pathogens. Wild oat populations were grown under a "common garden" environment to remove maternal variation, and the resulting seeds were extracted to remove the readily soluble and chemically bound phenolic and aliphatic organic acid components. Compounds were identified and quantified using gas chromatography-mass spectrometry. Ferulic and p-coumaric acid comprised 99% of the total phenolic acids present in the seeds, of which 91% were contained in the hulls and 98% were in the chemically bound forms. Smaller quantities of OH benzoic and vanillic acid were also detected. Soluble organic acids concentrations were higher in the M73 isoline compared to SH430, suggesting that these chemical constituents could be related to seed dormancy. Malic, succinic, fumaric and azelaic acid were the dominant aliphatic organic acids detected in all seed and chemical fractions.

  12. Recovery of Aliphatic Hydrocarbons from Oil Field Sludge using Bacillus sp

    Directory of Open Access Journals (Sweden)

    Rizwan Ahmed Bhutto

    2015-04-01

    Full Text Available Bioremediation of aliphatic HC (Hydrocarbons in the oily sludge of Kunnar oil and gas field, Pakistan was attempted by means of previously isolated and developed Bacillus sp. Both autoclaved and non-autoclaved sludge samples were analyzed for a reaction time of 30 days with pH 7 and temperature of 380C in 50 ml MSM growth media for the sludge concentration of 5, 10 and 50% with 2, 4 and 6ml of Bacillus sp. relatively, in air atmosphere. Stabilization of the samples by microbial activity resulted in the decrease in TPH (Total Petroleum Hydrocarbon concentration by 60, 69 and 87% in autoclaved samples in contrast to the decrease of 70, 84 and 94% observed in non-autoclaved samples, relatively. Hydrocarbon degradation in oily sludge was investigated via GC which transpired that 97 and 99% concentration of aliphatic hydrocarbons in autoclaved and non-autoclaved samples was removed at 5% of TPH concentration, relatively. However, with 10% TPH concentration aliphatic hydrocarbons reduction was 68% in autoclaved samples to that of 87% in non-autoclaved samples. Further increase in the hydrocarbons concentration by 50% yielded in the removal of aliphatic hydrocarbons by 65% in autoclaved samples as compared to 98% decrease in non-autoclaved samples.

  13. PcMtr, an aromatic and neutral aliphatic amino acid permease of Penicillium chrysogenum

    NARCIS (Netherlands)

    Trip, H; Evers, ME; Driessen, AJM

    2004-01-01

    The gene encoding an aromatic and neutral aliphatic amino acid permease of Penicillium chrysogenum was cloned, functionally expressed and characterized in Saccharomyces cerevisiae M4276. The permease, designated PcMtr, is structurally and functionally homologous to Mtr of Neurospora crassa, and

  14. Pseudomonas sax genes overcome aliphatic isothiocyanate-mediated non-host resistance in Arabidopsis

    Science.gov (United States)

    Jun Fan; Casey Crooks; Gary Creissen; Lionel Hill; Shirley Fairhurst; Peter Doerner; Chris Lamb

    2011-01-01

    Most plant-microbe interactions do not result in disease; natural products restrict non-host pathogens. We found that sulforaphane (4-methylsulfinylbutyl isothiocyanate), a natural product derived from aliphatic glucosinolates, inhibits growth in Arabidopsis of non-host Pseudomonas bacteria in planta. Multiple sax genes (saxCAB/F/D/G) were identified in Pseudomonas...

  15. 40 CFR Table 2b to Subpart E of... - Reactivity Factors for Aliphatic Hydrocarbon Solvent Mixtures

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Reactivity Factors for Aliphatic Hydrocarbon Solvent Mixtures 2B Table 2B to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Averageboiling point * (degrees F) Criteria Reactivityfactor 1 80-205 Alkanes...

  16. Degradation of halogenated aliphatic compounds by the ammonia- oxidizing bacterium Nitrosomonas europaea.

    OpenAIRE

    Vannelli, T; Logan, M; Arciero, D M; Hooper, A B

    1990-01-01

    Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane, Tetrachloromethane (carbon tetrachloride),...

  17. High-resolution gas chromatographic analysis of polycyclic aromatic hydrocarbons and aliphatic hydrocarbons

    International Nuclear Information System (INIS)

    Perez, M.; Gonzalez, D.

    1988-01-01

    A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons and aliphatic hydrocarbons is presented. The separation has been carried out by glass and fused silica capillary column in two different polar stationary phases OV-1 and SE-54. The limitation and the advantages of the procedure are discussed in terms of separation, sensitivity and precision. (Author) 20 refs

  18. Evaluation of Efficient and Practical Methods for the Preparation of Functionalized Aliphatic Trifluoromethyl Ethers

    Directory of Open Access Journals (Sweden)

    Taras M. Sokolenko

    2017-05-01

    Full Text Available The “chlorination/fluorination” technique for aliphatic trifluoromethyl ether synthesis was investigated and a range of products with various functional groups was prepared. The results were compared with oxidative desulfurization-fluorination of xanthates with the same structure.

  19. OCCUPATIONAL ASTHMA CAUSED BY A HARDENER CONTAINING AN ALIPHATIC AND A CYCLOALIPHATIC DIAMINE

    NARCIS (Netherlands)

    ALEVA, RM; AALBERS, R; KOETER, GH; DEMONCHY, JGR

    An otherwise healthy 44-yr-old man experienced a serious attack of bronchial obstruction after working with resins and hardeners, releasing fumes of a mixture of an aliphatic and a cycloaliphatic diamine hardener. Eight hours after deliberate challenge with the hardener a large increase of airway

  20. Modification of eucalyptus pulp fiber using silane coupling agents with aliphatic side chains of different length

    Science.gov (United States)

    The objective of this work was to evaluate the effect of three silane coupling agents with different aliphatic chain lengths on the hydrophobicity of eucalyptus pulp fiber. The three silanes coupling agents used (isobutyltrimethoxysilane, methyltrimethoxysilane, and n-octyltriethoxysilane [OTES]) we...

  1. Sorption and desorption of naphthalene by soil organic matter: importance of aromatic and aliphatic components.

    Science.gov (United States)

    Gunasekara, Amrith S; Xing, Baoshan

    2003-01-01

    Nonlinear isotherm behavior has been reported for the sorption of hydrophobic organic compounds (HOCs) in soil organic matter (SOM), but the exact mechanisms are unknown. Our objective was to provide insight into the sorption mechanism of HOCs in SOM by studying the sorption-desorption processes of naphthalene in a mineral soil, its humic fractions, and lignin. Additionally, humin and lignin were used for studying the effects of temperature and cosolvent on HOC sorption. All isotherms were nonlinear. The humin and lignin isotherms became more linear at elevated temperatures and with the addition of methanol indicating a condensed to expanded structural phase transition. Isotherm nonlinearity and hysteresis increased in the following order: soil humic acid (HA) soil soil humin. Of the samples, aliphatic-rich humin exhibited the largest degree of nonlinearity and had the highest sorption capacity for naphthalene. High nonlinearity and hysteresis in humin were most likely caused by its condensed structure. A novel aliphatic, amorphous condensed conformation is proposed. This conformation can account for both high sorption capacities and increased nonlinearity observed for aliphatic-rich samples and can explain many sorption disparities discussed in the literature. This study clearly illustrates the importance of both aliphatic and aromatic moieties for HOC sorption in SOM.

  2. Cobalt-catalysed C-H carbonylative cyclisation of aliphatic amides.

    Science.gov (United States)

    Williamson, Patrick; Galván, Alicia; Gaunt, Matthew J

    2017-04-01

    A cobalt-catalysed C-H carbonylation of aliphatic carboxamide derivatives is described, employing commercially available Co(ii)-salts in the presence of a silver oxidant. This operationally simple process utilises an atmospheric pressure of CO and generates a range of substituted succinimide products bearing diverse functional groups that can be successfully accessed via this methodology.

  3. Aromatic-aliphatic copolyesters based on waste poly(ethylene terephthalate) and their biodegradability

    Czech Academy of Sciences Publication Activity Database

    Prokopová, I.; Vlčková, E.; Šašek, Václav; Náhlík, J.; Soukupová-Chaloupková, V.; Skolil, J.

    -, 052 (2008), s. 1-9 ISSN 1618-7229 R&D Projects: GA ČR GA203/03/0508; GA ČR GA203/06/0528 Institutional research plan: CEZ:AV0Z50200510 Keywords : aromatic-aliphatic colpolyesters * rhodococcus erythropolis * biodegradability Subject RIV: EE - Microbiology, Virology Impact factor: 0.661, year: 2008

  4. Abscisic (ABA)-aldehyde is a precursor to, and 1 prime ,4 prime -trans-ABA-diol a catabolite of, ABA in apple. [Malus domestica

    Energy Technology Data Exchange (ETDEWEB)

    Rock, C.D.; Zeevaart, J.A.D. (Michigan State Univ., East Lansing (USA))

    1990-07-01

    Previous {sup 18}O labeling studies of abscisic acid (ABA) have shown that apple (Malus domestica Borkh. cv Granny Smith) fruits synthesize a majority of ({sup 18}O)ABA with the label incorporated in the 1{prime}-hydroxyl position and unlabeled in the carboxyl group (JAD Zeevaart, TG Heath, DA Gage (1989) Plant Physiol 91: 1594-1601). It was proposed that exchange of {sup 18}O in the side chain with the medium occurred at an aldehyde intermediate stage of ABA biosynthesis. We have isolated ABA-aldehyde and 1{prime}-4{prime}-trans-ABA-diol (ABA-trans-diol) from {sup 18}O-labeled apple fruit tissue and measured the extent and position of {sup 18}O incorporation by tandem mass spectrometry. {sup 18}O-Labeling patterns of ABA-aldehyde, ABA-trans-diol, and ABA indicate that ABA-aldehyde is a precursor to, and ABA-trans-diol a catabolite of, ABA. Exchange of {sup 18}O in the carbonyl of ABA-aldehyde can be the cause of loss of {sup 18}O from the side chain of ({sup 18}O)ABA. Results of feeding experiments with deuterated substrates provide further support for the precursor-product relationship of ABA-aldehyde {yields} ABA {yields} ABA-trans-diol. The ABA-aldehyde and ABA-trans-diol contents of fruits and leaves were low, approximately 1 and 0.02 nanograms per gram fresh weight for ABA-aldehyde and ABA-trans-diol, respectively, while ABA levels in fruits ranged from 10 to 200 nanograms per gram fresh weight. ABA biosynthesis was about 10-fold lower in fruits than in leaves. In fruits, the majority of ABA was conjugated to {beta}-D-glucopyranosyl abscisate, whereas in leaves ABA was mainly hydroxylated to phaseic acid. Parallel pathways for ABA and trans-ABA biosynthesis and conjugation in fruits and leaves are proposed.

  5. Enthalpy of cooperative hydrogen bonding in complexes of tertiary amines with aliphatic alcohols: Calorimetric study

    International Nuclear Information System (INIS)

    Zaitseva, Ksenia V.; Varfolomeev, Mikhail A.; Novikov, Vladimir B.; Solomonov, Boris N.

    2011-01-01

    Research highlights: → Solution enthalpies of aliphatic alcohols in tertiary amines and vice versa were measured. → The enthalpies of specific interaction of amines in aliphatic alcohols are lower than the enthalpies of hydrogen bonding in 1:1 complexes amine-alcohol determined in base media. → Hydrogen bond cooperativity factors in multi-particle complexes of alcohols with aromatic amines are approximately equal for all alcohols. → Hydrogen bond cooperativity factors in multi-particle complexes of alcohols with trialkylamines decrease with increasing of alkyl radical length in alcohol and amine molecules. - Abstract: The work is devoted to the investigation of thermodynamics of specific interaction of the tertiary aliphatic and aromatic amines with associated solvents as which aliphatic alcohols were taken. Solution enthalpies of aliphatic alcohols in amines (tri-n-propylamine, 2-methylpyridine, 3-methylpyridine, N-methylimidazole) as well as amines in alcohols were measured at infinite dilution. The enthalpies of specific interaction (H-bonding) in systems studied were determined based on experimental data. The enthalpies of specific interaction of amines in aliphatic alcohols significantly lower than the enthalpies of hydrogen bonding in complexes amine-alcohol of 1:1 composition determined in base media due to the reorganization of aliphatic alcohols as solvents. The determination of solvent reorganization contribution makes possible to define the hydrogen bonding enthalpies of amines with clusters of alcohols. Obtained enthalpies of hydrogen bonding in multi-particle complexes are sensitive to the influence of cooperative effect. It was shown, that hydrogen bond cooperativity factors in multi-particle complexes of alcohols with amines are approximately equal for all alcohols when pyridines and N-methylimidazole as solutes are used. At the same time, H-bonding cooperativity factors in complexes of trialkylamines with associative species of alcohols

  6. The carriers of the unidentified infrared emission features: Clues from polycyclic aromatic hydrocarbons with aliphatic sidegroups

    Science.gov (United States)

    Yang, X. J.; Glaser, R.; Li, Aigen; Zhong, J. X.

    2017-04-01

    The unidentified infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, 11.3 and 12.7 μ m are ubiquitously seen in a wide variety of astrophysical regions in the Milky Way and nearby galaxies as well as distant galaxies at redshifts z ≳ 4. The UIE features are characteristic of the stretching and bending vibrations of aromatic hydrocarbon materials. The 3.3 μ m feature which results from the C-H stretching vibration in aromatic species is often accompanied by a weaker feature at 3.4 μ m. The 3.4 μ m feature is often thought to result from the C-H stretch of aliphatic groups attached to the aromatic systems. The ratio of the observed intensity of the 3.3 μ m aromatic C-H feature (I3.3) to that of the 3.4 μ m aliphatic C-H feature (I3.4) allows one to estimate the aliphatic fraction (e.g., NC, aliph/NC, arom, the number of C atoms in aliphatic units to that in aromatic rings) of the carriers of the UIE features, provided that the intrinsic oscillator strengths (per chemical bond) of the 3.3 μ m aromatic C-H stretch (A3.3) and the 3.4 μ m aliphatic C-H stretch (A3.4) are known. In this review we summarize the computational results on A3.3 and A3.4 and their implications for the aromaticity and aliphaticity of the UIE carriers. We use density functional theory and second-order perturbation theory to derive A3.3 and A3.4 from the infrared vibrational spectra of seven polycyclic aromatic hydrocarbon (PAH) molecules with various aliphatic substituents (e.g., methyl-, dimethyl-, ethyl-, propyl-, butyl-PAHs, and PAHs with unsaturated alkyl chains). The mean band strengths of the aromatic (A3.3) and aliphatic (A3.4) C-H stretches are derived and then employed to estimate the aliphatic fraction of the carriers of the UIE features by comparing the ratio of the intrinsic band strength of the two stretches (A3.4/A3.3) with the ratio of the observed intensities (I3.4/I3.3). We conclude that the UIE emitters are predominantly aromatic, as revealed by the observationally

  7. Salt loading increases urinary excretion of linoleic acid diols and triols in healthy human subjects.

    Science.gov (United States)

    Dreisbach, Albert W; Rice, Janet C; Japa, Shanker; Newman, John W; Sigel, Aster; Gill, Rajan S; Hess, Arthur E; Cemo, Angela C; Fonseca, Juan P; Hammock, Bruce D; Lertora, Juan J L; Hamm, L Lee

    2008-03-01

    Increased dietary linoleic acid has been associated with reduced blood pressure in clinical and animal studies possibly mediated by prostaglandins. Urinary linoleate and prostaglandin metabolite excretion were investigated in subjects exposed to a salt-loading/salt-depletion regimen. Twelve healthy subjects were recruited from the New Orleans population (before Hurricaine Katrina) and admitted to the Tulane-Louisiana State University-Charity Hospital General Clinical Research Center after a 5-day outpatient lead-in phase on a 160-mmol sodium diet. On inpatient day 1, the subjects were maintained on the 160-mmol sodium diet, and a 24-hour urine specimen was collected. On day 2, the subjects received 2 L of IV normal saline over 4 hours and continued on a 160-mmol Na(+) diet (total: 460 mmol of sodium). Two 12-hour urine collections were obtained. On day 3, the subjects received three 40-mg oral doses of furosemide, two 12-hour urine collections were obtained, and the subjects were given a 10-mmol sodium diet. Urinary oxidized lipids were measured by high-performance liquid chromatography-tandem quadrupole mass spectroscopy. The excretion of the urinary linoleate metabolites, dihydroxyoctadecamonoenoic acids, and trihydroxyoctadecamonoenoic acids increased significantly during intravenous salt loading as compared with day 1 and the salt-depleted periods. The urinary excretion of 6-keto- prostaglandin F1alpha was unaffected by salt loading but was dramatically increased 7- to 10-fold by salt depletion. Prostaglandin E2 excretion was positively correlated with sodium excretion. The salt-stimulated production of linoleic acid diols and triols may inhibit tubular sodium reabsorption, thereby assisting in the excretion of the sodium load.

  8. Synthesis, spectroscopic and biological activities studies of acyclic and macrocyclic mono and binuclear metal complexes containing a hard-soft Schiff base

    Science.gov (United States)

    Abou-Hussein, Azza A. A.; Linert, Wolfgang

    Mono- and bi-nuclear acyclic and macrocyclic complexes with hard-soft Schiff base, H2L, ligand derived from the reaction of 4,6-diacetylresorcinol and thiocabohydrazide, in the molar ratio 1:2 have been prepared. The H2L ligand reacts with Co(II), Ni(II), Cu(II), Zn(II), Mn(II) and UO2(VI) nitrates, VO(IV) sulfate and Ru(III) chloride to get acyclic binuclear complexes except for VO(IV) and Ru(III) which gave acyclic mono-nuclear complexes. Reaction of the acyclic mono-nuclear VO(IV) and Ru(III) complexes with 4,6-diacetylresorcinol afforded the corresponding macrocyclic mono-nuclear VO(IV) and Ru(IIII) complexes. Template reactions of the 4,6-diacetylresorcinol and thiocarbohydrazide with either VO(IV) or Ru(III) salts afforded the macrocyclic binuclear VO(IV) and Ru(III) complexes. The Schiff base, H2L, ligand acts as dibasic with two NSO-tridentate sites and can coordinate with two metal ions to form binuclear complexes after the deprotonation of the hydrogen atoms of the phenolic groups in all the complexes, except in the case of the acyclic mononuclear Ru(III) and VO(IV) complexes, where the Schiff base behaves as neutral tetradentate chelate with N2S2 donor atoms. The ligands and the metal complexes were characterized by elemental analysis, IR, UV-vis 1H-NMR, thermal gravimetric analysis (TGA) and ESR, as well as the measurements of conductivity and magnetic moments at room temperature. Electronic spectra and magnetic moments of the complexes indicate the geometries of the metal centers are either tetrahedral, square planar or octahedral. Kinetic and thermodynamic parameters were calculated using Coats-Redfern equation, for the different thermal decomposition steps of the complexes. The ligands and the metal complexes were screened for their antimicrobial activity against Staphylococcus aureus as Gram-positive bacteria, and Pseudomonas fluorescens as Gram-negative bacteria in addition to Fusarium oxysporum fungus. Most of the complexes exhibit mild

  9. Wavelet entropy and directed acyclic graph support vector machine for detection of patients with unilateral hearing loss in MRI scanning

    Directory of Open Access Journals (Sweden)

    Shuihua Wang

    2016-10-01

    Full Text Available (Aim Sensorineural hearing loss (SNHL is correlated to many neurodegenerative disease. Now more and more computer vision based methods are using to detect it in an automatic way. (Materials We have in total 49 subjects, scanned by 3.0T MRI (Siemens Medical Solutions, Erlangen, Germany. The subjects contain 14 patients with right-sided hearing loss (RHL, 15 patients with left-sided hearing loss (LHL, and 20 healthy controls (HC. (Method We treat this as a three-class classification problem: RHL, LHL, and HC. Wavelet entropy (WE was selected from the magnetic resonance images of each subjects, and then submitted to a directed acyclic graph support vector machine (DAG-SVM. (Results The 10 repetition results of 10-fold cross validation shows 3-level decomposition will yield an overall accuracy of 95.10% for this three-class classification problem, higher than feedforward neural network, decision tree, and naive Bayesian classifier. (Conclusions This computer-aided diagnosis system is promising. We hope this study can attract more computer vision method for detecting hearing loss.

  10. Associations of anabolic-androgenic steroid use with other behavioral disorders: an analysis using directed acyclic graphs.

    Science.gov (United States)

    Kanayama, Gen; Pope, Harrison G; Hudson, James I

    2018-03-01

    Anabolic-androgenic steroid (AAS) use is known to be associated with other psychiatric disorders, such as body image disorders, conduct disorder/sociopathy, and other substance use disorders (SUD) - but the causal pathways among these conditions remain poorly delineated. We created a directed acyclic graph to diagram hypothesized relationships among AAS use and dependence, body image disorder (BID), conduct disorder/sociopathy, and other SUD. Using proportional hazards models, we then assessed potentially causal relationships among these variables, using a dataset of 233 male weightlifters, of whom 102 had used AAS. BID and conduct disorder/sociopathy both strongly contributed to the development of AAS use, but did not appear to contribute further to the progression from AAS use to AAS dependence. Other SUD beginning prior to first AAS use - whether broadly defined or restricted only to opioids - failed to show an effect on AAS use or progression to AAS dependence. Conversely, AAS use contributed significantly to the subsequent first-time development of opioid use disorders but did not significantly increase the risk for first-time development of non-opioid SUD, taken as a whole. Our analysis suggests that AAS use and other SUD are mutually attributable to underlying conduct disorder/sociopathy. SUD do not appear to represent a 'gateway' to subsequent AAS use. AAS use may represent a gateway to subsequent opioid use disorder, but probably not to other SUD.

  11. Acyclic retinoid in chemoprevention of hepatocellular carcinoma: Targeting phosphorylated retinoid X receptor-α for prevention of liver carcinogenesis

    Directory of Open Access Journals (Sweden)

    Masahito Shimizu

    2012-01-01

    Full Text Available One of the key features of hepatocellular carcinoma (HCC is the high rate of intrahepatic recurrence that correlates with poor prognosis. Therefore, in order to improve the clinical outcome for patients with HCC, development of a chemopreventive agent that can decrease or delay the incidence of recurrence is a critical issue for urgent investigation. Acyclic retinoid (ACR, a synthetic retinoid, successfully improves HCC patient survival by preventing recurrence and the formation of secondary tumors. A malfunction of the retinoid X receptor-α (RXRα due to phosphorylation by the Ras-MAPK signaling pathway plays a critical role in liver carcinogenesis, and ACR exerts chemopreventive effects on HCC development by inhibiting RXRα phosphorylation. Here, we review the relationship between retinoid signaling abnormalities and liver disease, the mechanisms of how RXRα phosphorylation contributes to liver carcinogenesis, and the detailed effects of ACR on preventing HCC development, especially based on the results of our basic and clinical research. We also outline the concept of "clonal deletion and inhibition" therapy, which is defined as the removal and inhibition of latent malignant clones from the liver before they expand into clinically detectable HCC, because ACR prevents the development of HCC by implementing this concept. Looking toward the future, we discuss "combination chemoprevention" using ACR as a key drug since it can generate a synergistic effect, and may thus be an effective new strategy for the prevention of HCC.

  12. Acyclic cucurbit[n]uril-type molecular containers: influence of glycoluril oligomer length on their function as solubilizing agents.

    Science.gov (United States)

    Gilberg, Laura; Zhang, Ben; Zavalij, Peter Y; Sindelar, Vladimir; Isaacs, Lyle

    2015-04-07

    We present the synthesis of a series of six new glycoluril derived molecular clips and acyclic CB[n]-type molecular containers (1–3) that all feature SO3(−) solubilizing groups but differ in the number of glycoluril rings between the two terminal dialkoxyaromatic sidewalls. We report the X-ray crystal structure of 3b which shows that its dialkoxynaphthalene sidewalls actively define a hydrophobic cavity with high potential to engage in π–π interactions with insoluble aromatic guests. Compounds 1–3 possess very good solubility characteristics (≥38 mM) and undergo only very weak self-association (Ks containers 3a and 3b which feature three glycoluril rings between the terminal dialkoxy-o-xylylene and dialkoxynaphthalene sidewalls are less efficient solubilizing agents than 4a and 4b because of their smaller hydrophobic cavities. Containers 1 and 2 behave as molecular clip type receptors and therefore possess the ability to bind to and thereby solubilize aromatic drugs like camptothecin, ziprasidone, and PBS-1086.

  13. The fluxional amine gold(III) complex as an excellent catalyst and precursor of biologically active acyclic carbenes.

    Science.gov (United States)

    Montanel-Pérez, Sara; Herrera, Raquel P; Laguna, Antonio; Villacampa, M Dolores; Gimeno, M Concepción

    2015-05-21

    A new amine gold(III) complex [Au(C6F5)2(DPA)]ClO4 with the di-(2-picolyl)amine (DPA) ligand has been synthesised. In the solid state the complex has a chiral amine nitrogen because the ligand coordinates to the gold centre through one nitrogen atom from a pyridine and through the NH moiety, whereas in solution it shows a fluxional behaviour with a rapid exchange between the pyridine sites. This complex can be used as an excellent synton to prepare new gold(III) carbene complexes by the reaction with isocyanide CNR. The resulting gold(III) derivatives have unprecedented bidentate C^N acyclic carbene ligands. All the complexes have been spectroscopically and structurally characterized. Taking advantage of the fluxional behaviour of the amine complex, its catalytic properties have been tested in several reactions with the formation of C-C and C-N bonds. The complex showed excellent activity with total conversion, without the presence of a co-catalyst, and with a catalyst loading as low as 0.1%. These complexes also present biological properties, and cytotoxicity studies have been performed in vitro against three tumour human cell lines, Jurkat (T-cell leukaemia), MiaPaca2 (pancreatic carcinoma) and A549 (lung carcinoma). Some of them showed excellent cytotoxic activity compared with the reference cisplatin.

  14. Fingerprinting of traditional Chinese medicines on the C18-Diol mixed-mode column in online or offline two-dimensional liquid chromatography on the single column modes.

    Science.gov (United States)

    Wang, Qing; Tong, Ling; Yao, Lin; Zhang, Peng; Xu, Li

    2016-06-05

    In the present study, a mixed-mode stationary phase, C18-Diol, was applied for fingerprint analysis of traditional Chinese medicines. Hydrophobic, hydrogen bonding and electrostatic interactions were demonstrated to contribute the retention separately or jointly, which endowed the C18-Diol stationary phase with distinct selectivity compared to the bare C18 one. The separation of total alkaloids extracted from Fritillaria hupehensis was compared on the C18-Diol and conventional C18 column with the greater resolving power and better symmetry responses on the former one. Besides, a novel two-dimensional liquid chromatography on the single column (2D-LC-1C) was realized on C18-Diol with the offline mode for the alcohol extract of Fritillaria hupehensis and online mode for Ligusticum chuanxiong Hort. The early co-eluted extracted components with great polarity on the first dimension were reinjected on the same column and well separated on the second dimension. The results exhibited that the two complementary RPLC and HILIC modes on C18-Diol stationary phase enhanced the separation capacity and revealed more abundant chemical information of the sample, which was a powerful tool in analyzing complex herbal medicines. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Oxyfunctionalization of the Remote C-H Bonds of Aliphatic Amines by Decatungstate Photocatalysis.

    Science.gov (United States)

    Schultz, Danielle M; Lévesque, François; DiRocco, Daniel A; Reibarkh, Mikhail; Ji, Yining; Joyce, Leo A; Dropinski, James F; Sheng, Huaming; Sherry, Benjamin D; Davies, Ian W

    2017-11-27

    Aliphatic amines, oxygenated at remote positions within the molecule, represent an important class of synthetic building blocks to which there are currently no direct means of access. Reported herein is an efficient and scalable solution that relies upon decatungstate photocatalysis under acidic conditions using either H 2 O 2 or O 2 as the terminal oxidant. By using these reaction conditions a series of simple and unbiased aliphatic amine starting materials can be oxidized to value-added ketone products. Lastly, NMR spectroscopy using in situ LED-irradiated samples was utilized to monitor the kinetics of the reaction, thus enabling direct translation of the reaction into flow. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Distribution and sources of aliphatic hydrocarbons in surface sediments of Sergipe River estuarine system.

    Science.gov (United States)

    Lima, Manoel B; Feitosa, Elaine A; Emídio, Elissandro S; Dórea, Haroldo S; Alexandre, Marcelo R

    2012-08-01

    The assessment of aliphatic hydrocarbons was performed in the Sergipe River estuarine system, northeastern Brazil. Aliphatic hydrocarbons concentration ranged from 9.9 ug g⁻¹ up to 30.8 ug g⁻¹ of dry sediment. The carbon preference index (CPI, based on nC₂₄ to nC₃₄ range), indicated predominance of petrogenic input in two of the sites analyzed (P4 and P5). The unresolved complex mixture (UCM) was found to be present in seven of the nine sites sampled (except for P4 and P5). Overall, the results of this work suggest that there is a mix of organic matter sources to the sediment. Although the coast of Sergipe has an intense off shore petroleum exploration and the Sergipe River crosses the entire city of Aracaju, the capital city of Sergipe, non-significant anthropogenic fingerprint was assessed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Palladium-catalyzed aryl C-H olefination with unactivated, aliphatic alkenes.

    Science.gov (United States)

    Deb, Arghya; Bag, Sukdev; Kancherla, Rajesh; Maiti, Debabrata

    2014-10-01

    Palladium-catalyzed coupling between aryl halides and alkenes (Mizoroki-Heck reaction) is one of the most popular reactions for synthesizing complex organic molecules. The limited availability, problematic synthesis, and higher cost of aryl halide precursors (or their equivalents) have encouraged exploration of direct olefination of aryl carbon-hydrogen (C-H) bonds (Fujiwara-Moritani reaction). Despite significant progress, the restricted substrate scope, in particular noncompliance of unactivated aliphatic olefins, has discouraged the use of this greener alternative. Overcoming this serious limitation, we report here a palladium-catalyzed chelation-assisted ortho C-H bond olefination of phenylacetic acid derivatives with unactivated, aliphatic alkenes in good to excellent yields with high regio- and stereoselectivities. The versatility of this operationally simple method has been demonstrated through drug diversification and sequential C-H olefination for synthesizing divinylbenzene derivatives.

  18. Stability and in vivo behavior of Rh[16aneS4-diol]211 at complex: a potential precursor for astatine radiopharmaceuticals.

    Science.gov (United States)

    Pruszyński, Marek; Łyczko, Monika; Bilewicz, Aleksander; Zalutsky, Michael R

    2015-05-01

    The heavy halogen (211)At is of great interest for targeted radiotherapy because it decays by the emission of short-range, high-energy α-particles. However, many astatine compounds that have been synthesized are unstable in vivo, providing motivation for seeking other (211)At labeling strategies. One relatively unexplored approach is to utilize prosthetic groups based on astatinated rhodium (III) complex stabilized with a tetrathioether macrocyclic ligand - Rh[16aneS(4)-diol](211)At. The purpose of the current study was to evaluate the in vitro and in vivo stability of this complex in comparison to its iodine analog - Rh[16aneS(4)-diol](131)I. Rh[16aneS(4)-diol](211)At and Rh[16aneS(4)-diol](131)I complexes were synthesized and purified by HPLC. The stability of both complexes was evaluated in vitro by incubation in phosphate-buffered saline (PBS) and human serum at different temperatures. The in vivo behavior of the two radiohalogenated complexes was assessed by a paired-label biodistribution study in normal Balb/c mice. Both complexes were synthesized in high yield and purity. Almost no degradation was observed for Rh[16aneS(4)-diol](131)I in PBS over a 72 h incubation. The astatinated analog exhibited good stability in PBS over 14 h. A slow decline in the percentage of intact complex was observed for both tracers in human serum. In the biodistribution study, retention of (211)At in most tissues was higher than that of (131)I at all time points, especially in spleen and lungs. Renal clearance of Rh[16aneS(4)-diol](211)At and Rh[16aneS(4)-diol](131)I predominated, with 84.1 ± 2.3% and 94.6 ± 0.9% of injected dose excreted via the urine at 4 h. The Rh[16aneS(4)-diol](211)At complex might be useful for constructing prosthetic groups for the astatination of biomolecules and further studies are planned to evaluate this possibility. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Enzymatic reduction of (+)-dihydroflavonols to flavan-3,4-cis-diols with flower extracts from Matthiola incana and its role in anthocyanin biosynthesis.

    Science.gov (United States)

    Heller, W; Forkmann, G; Britsch, L; Grisebach, H

    1985-08-01

    A cell-free extract from flowers of Matthiola incana catalyzes a NADPH-dependent stereospecific reduction of (+)-dihydrokaempferol to 3,4-cis-leucopelargonidin (5,7,4'-trihydroxyflavan-3,4-cis-diol). The pH-optimum of this reaction is around 6. The rate of reaction with NADH was about 50% of that found with NADPH. (+)-Dihydroquercetin and (+)-dihydromyricetin were also reduced by the enzyme preparation to the corresponding flavan-3,4-cis-diols. Correlation between the genotype of M. incana and the presence of dihydroflavonol 4-reductase is strong evidence that this enzyme is involved in anthocyanin biosynthesis.

  20. Degradation of halogenated aliphatic compounds by the ammonia- oxidizing bacterium Nitrosomonas europaea.

    Science.gov (United States)

    Vannelli, T; Logan, M; Arciero, D M; Hooper, A B

    1990-01-01

    Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane, Tetrachloromethane (carbon tetrachloride), tetrachloroethylene (perchloroethylene), and trans-dibromoethylene were not degraded. PMID:2339874

  1. The fumigant and repellent activity of aliphatic lactones against Pediculus humanus capitis (Anoplura: Pediculidae)

    OpenAIRE

    Toloza, Ariel Ceferino; Zygadlo, Julio; Mougabure-Cueto, Gastón; Zerba, Eduardo; Faillaci, Silvina; Picollo, María Inés

    2006-01-01

    New alternative insecticides are necessary for the chemical control of head lice. In this study the fumigant knockdown time 50% (KT50) and repellency index (RI) of three aliphatic lactones was compared with two essential oils and DDVP, against permethrin-resistance Pediculus humanus capitis from Argentina. In the fumigant assay, none of the lactones were effective compared to the highest activity of eucalyptus (KT50 15.53 m). In the repellency test, the three lactones were equally or more eff...

  2. Extraction-spectrophotometric determination of purine alkaloids in water solutions using aliphatic alcohols

    Directory of Open Access Journals (Sweden)

    Y. I. Korenman

    2012-01-01

    Full Text Available For extraction of caffeine, theobromin and theophylline from water solutions are applied aliphatic alcohols С3 – С9. Water concentrates analyzed method UF- spectrophotometry. Factors of distribution and extraction degree are calculated. Influence of length of a hydrocarbonic radical in a solvent and nature olecule salting-out agent on interphase distribution of alkaloids is studied. Dependence of quantitative characteristics extraction from number active groups in structure alkaloids is established.

  3. Selective Palladium(II)-Catalyzed Carbonylation of Methylene β-C-H Bonds in Aliphatic Amines.

    Science.gov (United States)

    Cabrera-Pardo, Jaime R; Trowbridge, Aaron; Nappi, Manuel; Ozaki, Kyohei; Gaunt, Matthew J

    2017-09-18

    Palladium(II)-catalyzed C-H carbonylation reactions of methylene C-H bonds in secondary aliphatic amines lead to the formation of trans-disubstituted β-lactams in excellent yields and selectivities. The generality of the C-H carbonylation process is aided by the action of xantphos-based ligands and is important in securing good yields for the β-lactam products. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. The effect of mechanical loads on the degradation of aliphatic biodegradable polyesters.

    Science.gov (United States)

    Li, Ying; Chu, Zhaowei; Li, Xiaoming; Ding, Xili; Guo, Meng; Zhao, Haoran; Yao, Jie; Wang, Lizhen; Cai, Qiang; Fan, Yubo

    2017-06-01

    Aliphatic biodegradable polyesters have been the most widely used synthetic polymers for developing biodegradable devices as alternatives for the currently used permanent medical devices. The performances during biodegradation process play crucial roles for final realization of their functions. Because physiological and biochemical environment in vivo significantly affects biodegradation process, large numbers of studies on effects of mechanical loads on the degradation of aliphatic biodegradable polyesters have been launched during last decades. In this review article, we discussed the mechanism of biodegradation and several different mechanical loads that have been reported to affect the biodegradation process. Other physiological and biochemical factors related to mechanical loads were also discussed. The mechanical load could change the conformational strain energy and morphology to weaken the stability of the polymer. Besides, the load and pattern could accelerate the loss of intrinsic mechanical properties of polymers. This indicated that investigations into effects of mechanical loads on the degradation should be indispensable. More combination condition of mechanical loads and multiple factors should be considered in order to keep the degradation rate controllable and evaluate the degradation process in vivo accurately. Only then can the degradable devise achieve the desired effects and further expand the special applications of aliphatic biodegradable polyesters.

  5. Distribution of aliphatic and polycyclic aromatic hydrocarbon in South China sea sediments

    International Nuclear Information System (INIS)

    Md Suhaimi Elias; Ab Khalik Wood; Zaleha Hashim; Wee Boon Siong; Nazaratul Ashifa; Mohd Suhaimi Hamzah; Shamsiah Ab Rahman; Ariffin Talib

    2006-01-01

    Petroleum hydrocarbon (Hcp) consist of three major components namely alkanes, cyclo-alkanes and aromatics. HCP are pollutant and can cause adverse effect to the marine organisms. The study was done to identify the source of pollution in the South China Sea coastal area. The South China Sea is one of the major oil production area in Malaysia. Sampling was done at 15 stations along the coastal area of South China Sea off Peninsular Malaysia, which involved two zone namely coastal (zone 1) and offshore (zone 2) areas. Samples were analyzed using GC-MS for determination of HCP. The results showed, that concentration of aliphatic and polycyclic aromatic hydrocarbon at coastal area, range from 0.51 - 1.31 mg/g and 0.18 - 0.42 mg/g dry weight, respectively whilst, concentration of aliphatic and polycyclic aromatic hydrocarbon at offshore area, range from 0.44 - 1.09 mg/g and 0.20 - 0.49 mg/g dry weight, respectively. SHCP (Aliphatic + PAH) concentration in the sediment at the study area range from 0.64 - 1.68 mg/g dry weight. In this study, it was found that, pollution source for the South China Sea off Peninsular Malaysia was originated from pyrolytic sources (combustion fossil fuel), while some other area had been polluted by pyrolytic or petrogenic (unburned fossil) sources. (Author)

  6. Aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil: a review.

    Science.gov (United States)

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-11-10

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research.

  7. Aliphatic, Cyclic, and Aromatic Organic Acids, Vitamins, and Carbohydrates in Soil: A Review

    Science.gov (United States)

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-01-01

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research. PMID:24319374

  8. Olfactory discrimination ability for aliphatic esters in squirrel monkeys and humans.

    Science.gov (United States)

    Laska, M; Freyer, D

    1997-08-01

    Using a behavioral paradigm designed to simulate olfactory-guided foraging, the ability of five squirrel monkeys to distinguish iso-amyl acetate from n- and iso-forms of other acetic esters (ethyl acetate to decyl acetate) and from other esters carrying the iso-amyl group (iso-amyl propionate to iso-amyl capronate) was investigated. We found (i) that all five animals were clearly able to discriminate between all odor pairs tested; (ii) a significant negative correlation between discrimination performance and structural similarity of odorants in terms of differences in carbon chain length of both the aliphatic alcohol group and the aliphatic acid group of the esters; and (iii) that iso- and n-amyl acetate were perceived as qualitatively similar despite different steric conformation. Using a triple-forced choice procedure, 20 human subjects were tested on the same tasks in parallel and showed a very similar pattern of discrimination performance compared with the squirrel monkeys. Thus, the results of this study provide evidence of well-developed olfactory discrimination ability in squirrel monkeys for aliphatic esters and support the assumption that human and non-human primates may share common principles of odor quality perception.

  9. Metabolism of isoeugenol via isoeugenol-diol by a newly isolated strain of Bacillus subtilis HS8.

    Science.gov (United States)

    Zhang, Yongmei; Xu, Ping; Han, Shuai; Yan, Haiqin; Ma, Cuiqing

    2006-12-01

    A bacterium designated as HS8 was newly isolated from soil based on its ability to degrade isoeugenol. The strain was identified as Bacillus subtilis according to its 16S rDNA sequence analysis and biochemical characteristics. The metabolic pathway for the degradation of isoeugenol was examined. Isoeugenol-diol, for the first time, was detected as an intermediate from isoeugenol to vanillin by a bacterial strain. Isoeugenol was converted to vanillin via isoeugenol-diol, and vanillin was then metabolized via vanillic acid to guaiacol by strain HS8. These metabolites, vanillin, vanillic acid, and guaiacol, are all valuable aromatic compounds in flavor production. At the same time, the bipolymerization of isoeugenol was observed, which produced dehydrodiisoeugenol and decreased the vanillin yield. High level of vanillic acid decarboxylase activity was detected in cell-free extract. These findings provided a detailed profile of isoeugenol metabolism by a B. subtilis strain for the first time, which would improve the production of valuable aromatic compounds by biotechnology.

  10. Cross-Linked Dependency of Boronic Acid-Conjugated Chitosan Nanoparticles by Diols for Sustained Insulin Release

    Directory of Open Access Journals (Sweden)

    Nabil A. Siddiqui

    2016-10-01

    Full Text Available Boronic acids have been widely investigated for their potential use as glucose sensors in glucose responsive polymeric insulin delivery systems. Interactions between cyclic diols and boronic acids, anchored to polymeric delivery systems, may result in swelling of the delivery system, releasing the drug. In this study, 4-formylphenylboronic acid conjugated chitosan was formulated into insulin containing nanoparticles via polyelectrolyte complexation. The nanoparticles had an average diameter of 140 ± 12.8 nm, polydispersity index of 0.17 ± 0.1, zeta potential of +19.1 ± 0.69 mV, encapsulation efficiency of 81% ± 1.2%, and an insulin loading capacity of 46% ± 1.8% w/w. Changes in size of the nanoparticles and release of insulin were type of sugar- and concentration-dependent. High concentration of diols resulted in a sustained release of insulin due to crosslink formation with boronic acid moieties within the nanoparticles. The formulation has potential to be developed into a self-regulated insulin delivery system for the treatment of diabetes.

  11. Studies on Poly(propylene fumarate-co-caprolactone diol Thermoset Composites towards the Development of Biodegradable Bone Fixation Devices

    Directory of Open Access Journals (Sweden)

    M. Jayabalan

    2009-01-01

    Full Text Available The effect of reinforcement in the cross-linked poly(propylene fumarate-co-caprolactone diol thermoset composites based on Kevlar fibres and hydroxyapatite was studied. Cross-linked poly(propylene fumarate-co-caprolactone diol was also studied without any reinforcement for comparison. The reinforcing fibre acts as a barrier for the curing reaction leading to longer setting time and lesser cross-link density. The fibre and HA reinforced composites have almost the same compressive strength. Nonreinforced material undergoes greater degree of swelling. Among the reinforced materials, the hydroxyapatite reinforced composite has a much higher swelling percentage than the fibre reinforced one. The studies on in vitro degradation of the cured materials reveal hydrolytic degradation in Ringer's solution and PBS medium during aging. All the three materials are found to swell initially in Ringer's solution and PBS medium during aging and then undergo gradual degradation. Compression properties of these cross-linked composites increase with aging; HA reinforced composite has the highest compressive strength and compressive modulus, whereas the aged fibre-reinforced composite has the least compressive strength and modulus.

  12. 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.

  13. A reversed-phase/hydrophilic interaction mixed-mode C18-Diol stationary phase for multiple applications.

    Science.gov (United States)

    Wang, Qing; Ye, Mao; Xu, Li; Shi, Zhi-guo

    2015-08-12

    A mixed-mode chromatographic packing material, C18 and diol groups modified silica (C18-Diol), was prepared with controllable hydrophobicity and hydrophilicity. It demonstrated excellent aqueous compatibility and stability in aqueous mobile phase; compared to the traditional C18 column, improved peak shape of basic analytes was also obtained. Additionally, it exhibited both reversed-phase liquid chromatographic (RPLC) and hydrophilic interaction chromatographic (HILIC) performance; the analyte separation scope was thus enlarged, demonstrated by simultaneous separation of twenty acids, bases and neutrals. More interestingly, a novel on-line two-dimensional liquid chromatography on the single column (2D-LC-1C) was established by modifying the high performance liquid chromatographic instrument only with the addition of an extra six-port two-position valve. The early co-eluted components of the extract of Lonicera japonica on the 1st-dimension (RPLC) were collected for the online re-injection to the 2nd-dimension (HILIC) by conveniently varying the mobile phase components. Six more peaks were obtained. The established system was simple, easy operation and low cost, which had advantages in analyzing complicated samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Using Directed Acyclic Graphs in Epidemiological Research in Psychosis: An Analysis of the Role of Bullying in Psychosis.

    Science.gov (United States)

    Moffa, Giusi; Catone, Gennaro; Kuipers, Jack; Kuipers, Elizabeth; Freeman, Daniel; Marwaha, Steven; Lennox, Belinda R; Broome, Matthew R; Bebbington, Paul

    2017-10-21

    Modern psychiatric epidemiology researches complex interactions between multiple variables in large datasets. This creates difficulties for causal inference. We argue for the use of probabilistic models represented by directed acyclic graphs (DAGs). These capture the dependence structure of multiple variables and, used appropriately, allow more robust conclusions about the direction of causation. We analyzed British national survey data to assess putative mediators of the association between bullying victimization and persecutory ideation. We compared results using DAGs and the Karlson-Holm-Breen (KHB) logistic regression commands in STATA. We analyzed data from the 2007 English National Survey of Psychiatric Morbidity, using the equivalent 2000 survey in an instant replication. Additional details of methods and results are provided in the supplementary material. DAG analysis revealed a richer structure of relationships than could be inferred using the KHB logistic regression commands. Thus, bullying had direct effects on worry, persecutory ideation, mood instability, and drug use. Depression, sleep and anxiety lay downstream, and therefore did not mediate the link between bullying and persecutory ideation. Mediation by worry and mood instability could not be definitively ascertained. Bullying led to hallucinations indirectly, via persecutory ideation and depression. DAG analysis of the 2000 dataset suggested the technique generates stable results. While causality cannot be fully determined from cross-sectional data, DAGs indicate the relationships providing the best fit. They thereby advance investigation of the complex interactions seen in psychiatry, including the mechanisms underpinning psychiatric symptoms. It may consequently be used to optimize the choice of intervention targets. © The Author 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.

  15. Synthesis and biological evaluation of novel acyclic and cyclic glyoxamide based derivatives as bacterial quorum sensing and biofilm inhibitors.

    Science.gov (United States)

    Nizalapur, Shashidhar; Kimyon, Onder; Yee, Eugene; Bhadbhade, Mohan M; Manefield, Mike; Willcox, Mark; Black, David StC; Kumar, Naresh

    2017-07-21

    Bacteria regulate the expression of various virulence factors and processes such as biofilm formation through a chemically-mediated communication mechanism called quorum sensing. Bacterial biofilms contribute to antimicrobial resistance as they can protect bacteria embedded in their matrix from the effects of antibiotics. Thus, developing novel quorum sensing inhibitors, which can inhibit biofilm formation, is a viable strategy to combat antimicrobial resistance. We report herein the synthesis of novel acyclic and cyclic glyoxamide derivatives via ring-opening reactions of N-acylisatins. These compounds were evaluated for their quorum sensing inhibition activity against P. aeruginosa MH602 and E. coli MT102. Compounds 20, 21 and 30 displayed the greatest quorum sensing inhibition activity against P. aeruginosa MH602, with 71.5%, 71.5%, and 74% inhibition, respectively, at 250 μM. Compounds 18, 20 and 21 exhibited the greatest QSI activity against E. coli MT102, with 71.5%, 72.1% and 73.5% quorum sensing inhibition activity, respectively. In addition, the biofilm inhibition activity was also investigated against P. aeruginosa and E. coli at 250 μM. The glyoxamide compounds 16, 18 and 19 exhibited 71.2%, 66.9%, and 66.5% inhibition of P. aeruginosa biofilms, respectively; whereas compounds 12, 20, and 22 showed the greatest inhibitory activity against E. coli biofilms with 87.9%, 90.8% and 89.5%, respectively. Finally, the determination of the in vitro toxicity against human MRC-5 lung fibroblast cells revealed that these novel glyoxamide compounds are non-toxic to human cells.

  16. Cationic lipids bearing succinic-based, acyclic and macrocyclic hydrophobic domains: Synthetic studies and in vitro gene transfer.

    Science.gov (United States)

    Jubeli, Emile; Maginty, Amanda B; Khalique, Nada Abdul; Raju, Liji; Nicholson, David G; Larsen, Helge; Pungente, Michael D; Goldring, William P D

    2017-01-05

    In this communication we describe the construction of four succinic-based cationic lipids, their formulation with plasmid DNA (pDNA), and an evaluation of their in vitro gene delivery into Chinese hamster ovarian (CHO-K1) cells. The cationic lipids employed in this work possess either a dimethylamine or trimethylamine headgroup, and a macrocyclic or an acyclic hydrophobic domain composed of, or derived from two 16-atom, succinic-based acyl chains. The synthesized lipids and a co-lipid of neutral charge, either cholesterol or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), were formulated in an overall 3:2 cationic-to-neutral lipid molar ratio, then complexed with plasmid DNA (pDNA). The relative transfection performance was evaluated via a comparison between matched versus mismatched formulations defined by the rigidity relationship between the lipids employed. Gel electrophoresis was used to characterize the binding of the lipid formulations with plasmid DNA and the relative degree of plasmid degradation using a DNase I degradation assay. Small angle X-ray diffraction (SAXD) was employed to characterize the packing morphology of the lipid-DNA complexes. In general, the succinic unit embedded within the hydrophobic domain of the cationic lipids was found to improve lipid hydration. The transfection assays revealed a general trend in which mismatched formulations that employed a rigid lipid combined with a non-rigid (or flexible) lipid, outperformed the matched formulations. The results from this work suggest that the design of the cationic lipid structure and the composition of the lipoplex formulation play key roles in governing the transfection performance of nonviral gene delivery agents. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Synthesis, structure and cytotoxicity of cyclic (alkyl)(amino) carbene and acyclic carbene complexes of group 11 metals.

    Science.gov (United States)

    Bertrand, Benoît; Romanov, Alexander S; Brooks, Mark; Davis, Josh; Schmidt, Claudia; Ott, Ingo; O'Connell, Maria; Bochmann, Manfred

    2017-11-21

    A series of complexes of cyclic (alkyl)(amino)carbene (CAAC) complexes of copper, silver and gold have been investigated for their antiproliferative properties. A second series of acyclic carbene (ACC) complexes of gold(i) were prepared by nucleophilic attack on isocyanide complexes by amines and amino esters, to give (ACC)AuCl, [(ACC)Au(PTA)] + (PTA = triazaphosphaadamantane), as well as mixed-carbene compounds [(CAAC)Au(ACC)] + . Representative complexes were characterised by X-ray diffraction which confirmed the mononuclear linear structures without close intermolecular contacts or aurophilic interactions. The redox properties of these complexes have been determined. The compounds were tested against a panel of human cancer cell lines including leukemia (HL 60), breast adenocarcinoma cells (MCF-7) and human lung adenocarcinoma epithelial cell lines (A549), which show varying degrees of cisplatin resistance. The pro-ligand iminium salts and the PTA complexes were non-toxic. By contrast, the CAAC complexes show high cytotoxicity, with IC 50 values in the sub-micromolar to ∼100 nanomolar range, even against cisplatin-insensitive MCF-7 and A549 cells. Cationic bis-carbene complexes [( Me2 CAAC) 2 M] + (6-8, M = Cu, Ag and Au) proved particularly effective. The mechanism of cell growth control by these complexes remains to be established, although possible modes of action such as inhibition of thioredoxin reductase (TrxR), which is a common pathway for gold NHC compounds, or the formation of reactive oxygen species (ROS) through redox processes, could be ruled out as primary pathways.

  18. Chemistry of formation and properties of sapropelitic coals. III. Extraction of aliphatic carboxylic acids and ketones of normal structure

    Energy Technology Data Exchange (ETDEWEB)

    Bodoev, N.V.; Rokosov, Y.V.; Koptyug, V.A.

    1989-05-01

    Aliphatic carboxylic acids and ketones of normal structure produced in high yields by the reaction of Taimylyr boghead or Matagan gagat with water and sodium hydroxide at elevated pressure and at temperatures from 400 to 450 degrees C have been investigated. The compositions of these compounds have been studied by IRS, NMR and chromato-mass-spectrometry. The possible ways of formation of aliphatic carboxylic acids and ketones during the fossilization process have been discussed. 14 refs., 6 figs.

  19. Mechanisms of inhibition of CaV3.1 T-type calcium current by aliphatic alcohols

    OpenAIRE

    Eckle, Veit-Simon; Todorovic, Slobodan M

    2010-01-01

    Many aliphatic alcohols modulate activity of various ion channels involved in sensory processing and also exhibit anesthetic capacity in vivo. Although the interaction of one such compound, 1-octanol (octanol) with different T-type calcium channels (T-channels) has been described, the mechanisms of current modulation and its functional significance are not well studied. Using patch-clamp technique, we investigated the mechanisms of inhibition of T-currents by a series of aliphatic alcohols in...

  20. Marine organic pollutants of the Eastern Aegean: aliphatic and polycyclic aromatic hydrocarbons in Candarli Gulf surficial sediments.

    Science.gov (United States)

    Kucuksezgin, Filiz; Pazi, Idil; Gonul, L Tolga

    2012-11-01

    Aliphatics and PAHs were determined in sediments from the Candarli Gulf in 2009. Aliphatics ranged from 3.88 to 24.7 μg g(-1) while aromatics varied between hydrocarbon contamination is via oil and its products. PAH levels at all sites were below the ERL and ERM except fluorene. The results indicated that the sediments should have no potential biological impact except stations 6 and 14. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. A Fast Computation for the State Vector in a Max-Plus Algebraic System with an Adjacency Matrix of a Directed Acyclic Graph

    Science.gov (United States)

    Goto, Hiroyuki

    We provide a useful method for calculating the state vector of a state equation efficiently in a max-plus algebraic system. For a discrete event system whose precedence relationships are represented by a directed acyclic graph, computing the transition matrix, which includes the Kleene star operation of a weighted adjacency matrix, is occasionally the bottleneck. On the other hand, the common objective is to compute the state equation, rather than the transition matrix itself. Since the state equation is essentially the multiplication of the transition matrix and vector, we propose algorithms for efficiently calculating the multiplication and left division of the Kleene star of an adjacency matrix and a vector.

  2. Synthesis and antimicrobial activity of new 1-[(tetrazol-5-yl)methyl] indole derivatives, their 1,2,4-triazole thioglycosides and acyclic analogs.

    Science.gov (United States)

    El-Sayed, Weal A; Abdel Megeid, Randa E; Abbas, Hebat-Allah S

    2011-07-01

    New 1-[(tetrazol-5-yl)methyl]indole derivatives, their acyclic nucleoside analogs and the corresponding glycoside derivatives were synthesized. Furthermore, the [)(1,2,4-triazol-3-yl)methyl])-2H-tetrazole derivative as well as the corresponding thioglucoside were prepared. The synthesized compounds were tested for their antimicrobial activity against Aspergillus Niger, Penicillium sp, Candida albican, Bacillus subtilis, Streptococcus lacti, Escherichia coli, Pseudomonas sp., and streptomyces sp. Compounds 3, 5 and 19b exhibited potent antibacterial activity and compounds 4, 5 and 10 exhibited high activities against the tested fungi compared with fusidic acid.

  3. Lipase AKG mediated resolutions of alpha,alpha-disubstituted 1,2-diols in organic solvents; Remarkably high regio- and enantio-selectivity

    NARCIS (Netherlands)

    Hof, RP; Kellogg, RM

    1996-01-01

    Diols 1, which contain adjacent tertiary and primary hydroxy groups, can be selectively mono-acylated at the primary hydroxy group by many lipases in organic solvents, Since the reaction does not take place at the chiral tertiary centre itself, observed enantioselectivities are usually low. Only the

  4. (E-2-((4R,5R-5-((Benzyloxymethyl-2,2-dimethyl-1,3-dioxolan-4-ylbut-2-ene-1,4-diol

    Directory of Open Access Journals (Sweden)

    Carlos R. Carreras

    2010-04-01

    Full Text Available The synthesis of (E-2-((4R,5R-5-((benzyloxymethyl-2,2-dimethyl-1,3-dioxolan-4-ylbut-2-ene-1,4-diol by a one-step reduction of the appropriate 2-substituted butenolide is reported. Product characterization was carried out by IR, 1H NMR, 13C NMR, MS, elemental analysis and optical rotation.

  5. Synthesis and thermal behavior of telechelic poly(butadiene)diols with azobenzene-based liquid-crystalline units in side chains

    Czech Academy of Sciences Publication Activity Database

    Poláková, Lenka; Sedláková, Zdeňka; Látalová, Petra

    2010-01-01

    Roč. 64, č. 4 (2010), s. 315-326 ISSN 0170-0839 R&D Projects: GA ČR GA202/09/2078 Institutional research plan: CEZ:AV0Z40500505 Keywords : azobenzene mesogens * radical addition * poly(butadiene)diols Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.215, year: 2010

  6. Chiral separation of synthetic vicinal diol compounds by capillary zone electrophoresis with borate buffer and beta-cyclodextrin as buffer additive.

    Science.gov (United States)

    Zhao, Yan; Yang, Xingbin; Jiang, Ru; Sun, Xiaoli; Liu, Wenmin; Zhang, Shengyong

    2006-05-01

    The investigation on capillary electrophoretic enantioseparation of six synthetic compounds containing vicinal diol groups has been undertaken to acquire the optimum conditions using native beta-cyclodextrin (beta-CD) as chiral selector and borate as a background electrolyte. The separation was carried out in an uncoated capillary (58.5 cm x 75 microm i.d., effective length 48.5 cm) and the effects of several important factors were investigated in detail. The results showed that beta-CD as a chiral selector exhibited good enantioselectivity and that the enantioseparation was greatly influenced by the structure of the diols, the borate concentration and the buffer pH. The optimum performance was obtained for the chiral vicinal diols under the conditions of 200 mM borate buffer of pH 9.8 containing 1.7% beta-CD at an applied voltage of 15 kV and a capillary temperature of 20 degrees C. Under the conditions, four diols were baseline separated with fast analysis time and the good theoretical plate numbers (above 10 x 10(4)) and favorable migration-time reproducibilities (RSDs below 3.0%) were obtained. The separation results were satisfactory.

  7. Metabolism of estradiol-17β, 5-androstene-3β,17β-diol and testosterone in human breast cancer cells in long-term culture

    NARCIS (Netherlands)

    Rademaker, B.; Vossenberg, J.B.J.; Poortman, J.; Thijssen, J.H.H.

    The human breast cancer cell line MCF-7 is able to metabolize steroids, which are added in order to study the growth rate of these cells. The following steroids: estradiol-17β, 5-androstene-3β,17β-diol and testosterone were incubated with these cells for 48 h under identical conditions used for

  8. Hydroformylation of olefins and reductive carbonylation of aryl halides with syngas formed ex situ from dehydrogenative decarbonylation of hexane-1,6-diol

    DEFF Research Database (Denmark)

    Christensen, Stig Holden; Olsen, Esben Paul Krogh; Rosenbaum, Jascha

    2014-01-01

    and then consumed in the other chamber in either a rhodium-catalysed hydroformylation of olefins or a palladium-catalysed reductive carbonylation of aryl halides. Hexane-1,6-diol was found to be the optimum alcohol for both reactions where moderate to excellent yields were obtained of the product aldehydes...

  9. Cork suberin molecular structure: stereochemistry of the C18 epoxy and vic-diol ω-hydroxyacids and α,ω-diacids analyzed by NMR.

    Science.gov (United States)

    Santos, Sara; Cabral, Vanessa; Graça, José

    2013-07-24

    Suberin is the biopolyester that protects the secondary tissues of plants against environmental variability and aggressions. Cork suberin is composed mostly of C18 ω-hydroxyacids and α,ω-diacids, 9,10-substituted with an unsaturation, an epoxide ring, or a vic-diol group. Although determinant for suberin macromolecular structure, the stereochemistry of these monomers is poorly studied, sometimes with contradictory results. An NMR technique was used here to assign the configuration of the 9,10-epoxy and 9,10-diol groups in C18 suberin acids, comparing the chemical shifts of diagnostic (1)H and (13)C signals with the ones of model compounds, before and after conversion of the vic-diol group into benzylidene acetal derivatives. The relative configuration was proved to be cis in the C18 9,10-epoxy and threo in the C18 9,10-diol suberin acids. These monomers were present in suberin probably as racemic mixtures, as shown by polarimetry. The revealed stereochemistry allows the suberin macromolecule to be built as an ordered array of midchain kinked C18 acids, reinforced by intramolecular hydrogen bonding.

  10. Self-assembly of short peptides composed of only aliphatic amino acids and a combination of aromatic and aliphatic amino acids.

    Science.gov (United States)

    Subbalakshmi, Chilukuri; Manorama, Sunkara V; Nagaraj, Ramakrishnan

    2012-05-01

    The morphology of structures formed by the self-assembly of short N-terminal t-butyloxycarbonyl (Boc) and C-terminal methyl ester (OMe) protected and Boc-deprotected hydrophobic peptide esters was investigated. We have observed that Boc-protected peptide esters composed of either only aliphatic hydrophobic amino acids or aliphatic hydrophobic amino acids in combination with aromatic amino acids, formed highly organized structures, when dried from methanol solutions. Transmission and scanning electron microscopic images of the peptides Boc-Ile-Ile-OMe, Boc-Phe-Phe-Phe-Ile-Ile-OMe and Boc-Trp-Ile-Ile-OMe showed nanotubular structures. Removal of the Boc group resulted in disruption of the ability to form tubular structures though spherical aggregates were formed. Both Boc-Leu-Ile-Ile-OMe and H-Leu-Ile-Ile-OMe formed only spherical nanostructures. Dynamic light scattering studies showed that aggregates of varying dimensions were present in solution suggesting that self-assembly into ordered structures is facilitated by aggregation in solution. Fourier transform infrared spectroscopy and circular dichroism spectroscopy data show that although all four of the protected peptides adopt well-defined tertiary structures, upon removal of the Boc group, only H-Phe-Phe-Phe-Ile-Ile-OMe had the ability to adopt β-structure. Our results indicate that hydrophobic interaction is a very important determinant for self-assembly and presence of charged and aromatic amino acids in a peptide is not necessary for self-assembly. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.

  11. The C32 alkane-1,15-diol as a proxy of late Quaternary riverine input in coastal margins

    Science.gov (United States)

    Lattaud, Julie; Dorhout, Denise; Schulz, Hartmut; Castañeda, Isla S.; Schefuß, Enno; Sinninghe Damsté, Jaap S.; Schouten, Stefan

    2017-08-01

    The study of past sedimentary records from coastal margins allows us to reconstruct variations in terrestrial input into the marine realm and to gain insight into continental climatic variability. There are numerous organic proxies for tracing terrestrial input into marine environments but none that strictly reflect the input of river-produced organic matter. Here, we test the fractional abundance of the C32 alkane 1,15-diol relative to all 1,13- and 1,15-long-chain diols (FC32 1, 15) as a tracer of input of river-produced organic matter in the marine realm in surface and Quaternary (0-45 ka) sediments on the shelf off the Zambezi and nearby smaller rivers in the Mozambique Channel (western Indian Ocean). A Quaternary (0-22 ka) sediment record off the Nile River mouth in the eastern Mediterranean was also studied for long-chain diols. For the Mozambique Channel, surface sediments of sites most proximal to Mozambique rivers showed the highest F1, 15 - C32 (up to 10 %). The sedimentary record shows high (15-35 %) pre-Holocene F1, 15 - C32 and low (soil and river-produced organic matter in the marine environment, which declines from 0.25 to 0.60 for the pre-Holocene to sea level, which caused the Zambezi River mouth to become more distal to our study site, thereby decreasing riverine input at the core location. Some small discrepancies are observed between the records of the BIT index and FC32 1, 15 for Heinrich Event 1 (H1) and the Younger Dryas (YD), which may be explained by a change in soil sources in the catchment area rather than a change in river influx. Like for the Mozambique Channel, a significant correlation between FC32 1, 15 and the BIT index (r2 = 0.38, p sea level rise. In general, the differences between the BIT index and FC32 1, 15 eastern Mediterranean Nile records can be explained by the fact that the BIT index is not only affected by riverine runoff but also by vegetation cover with increasing cover leading to lower soil erosion. Our results

  12. Tamoxifen synergizes with 4-(E)-{(4-hydroxyphenylimino)-methylbenzene, 1,2-diol} and 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol}, novel azaresveratrol analogs, in inhibiting the proliferation of breast cancer cells

    Science.gov (United States)

    Ronghe, Amruta; Chatterjee, Anwesha; Bhat, Nimee K.; Padhye, Subhash; Bhat, Hari K.

    2016-01-01

    We have recently shown that 4-(E)-{(4-hydroxyphenylimino)-methylbenzene, 1,2-diol} (HPIMBD) and 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol} (TIMBD), novel analogs of resveratrol (Res), selectively inhibited the proliferation of breast cancer cells. In the current study, we tested HPIMBD and TIMBD individually in combination with tamoxifen (Tam) for inhibition of growth of breast cancer cells. Tamoxifen was first tested on non-neoplastic breast epithelial cell lines and its dose that does not inhibit their growth was determined. A combination of this low dose of Tam with either of the Res analogs HPIMBD or TIMBD, resulted in synergistic inhibition of proliferation of breast cancer cells. Both estrogen receptor (ER)-positive and negative breast cancer cell lines responded to the combination. The combination resulted in a substantial decrease in IC50 values of Res analogs in all breast cancer cell lines tested. Mechanistic studies showed a synergistic increase in apoptosis and autophagy genes (beclin-1 and LC3BII/I) with the combination in ER-negative MDA-MB-231 cells. In ER-positive MCF-7 and T47D cells, the mechanism of synergy was found to be inhibition of expression of ERα and oncogene c-Myc. The combination treatment had a synergistic effect in inhibiting the colony forming and spheroid forming ability of cancer cells. Taken together, our findings indicate that a combination of Tam and Res analogs HPIMBD or TIMBD represents a novel approach to enhancing the use of Tam in therapy for breast cancers. Considering the urgent need for novel therapeutic strategies to treat ER-negative breast cancers and overcoming resistance in ER-positive cancers, this combinatorial approach is worthy of continued investigation. PMID:27351134

  13. Homoeologous GSL-ELONG gene replacement for manipulation of aliphatic glucosinolates in Brassica rapa L. by marker assisted selection

    Directory of Open Access Journals (Sweden)

    Arvind H. Hirani

    2013-03-01

    Full Text Available Aliphatic glucosinolates are the predominant sulphur-rich plant secondary metabolites in economically important Brassica crops. Glucosinolates and their hydrolysis products are involved in plant-microbe, plant-insect, plant-animal and plant-human interactions. It is, therefore, important to manipulate glucosinolate profiles and contents in Brassica species. In this study, aliphatic glucosinolates were genetically manipulated through homoeologous recombination in backcross lines followed by marker assisted selection in B. rapa. A resynthesized B. napus line, from a cross between B. rapa and B. oleracea, was backcrossed with Chinese cabbage doubled haploid line, RI16. Marker assisted selection for non-functional gene was performed in each backcross generations. Advanced backcross progenies (BC3F2 were developed to identify homoeologous gene replacement and/or introgression. Reduction in 5C aliphatic glucosinolates (gluconapoleiferin, glucoalyssin and glucobrassicanapin was observed in BC3F2 progenies of the recurrent parent that carried the GSL-ELONG gene. The GSL-ELONG positive backcross progenies were also screened by the A-genome and BraGSL-ELONG gene specific marker, which linked with 5C aliphatic glucosinolates. The A-genome specific marker was absent in the plants of advanced backcross progenies which showed reduction in 5C aliphatic glucosinolates. The results suggest that the functional allele had been replaced by the non-functional GSL-ELONG allele from B. oleracea. Some advanced backcross progenies (BC3F2 positive for the GSL-ELONG allele and the A-genome specific SCAR marker BraMAM1-1 did not show reduction in 5C aliphatic glucosinolates, suggesting that GSL-ELONG allele is recessive. Replacement of the functional locus in the A genome by non-functional counterpart in the C genome reduced the content of 5C aliphatic glucosinolates in B. rapa seeds with 20 micromoles per gram.

  14. Universal reaction mechanism of boronic acids with diols in aqueous solution: kinetics and the basic concept of a conditional formation constant.

    Science.gov (United States)

    Furikado, Yuki; Nagahata, Tomomi; Okamoto, Takuya; Sugaya, Tomoaki; Iwatsuki, Satoshi; Inamo, Masahiko; Takagi, Hideo D; Odani, Akira; Ishihara, Koji

    2014-10-06

    To establish a detailed reaction mechanism for the condensation between a boronic acid, RB(OH)2, and a diol, H2L, in aqueous solution, the acid dissociation constants (Ka(BL)) of boronic acid diol esters (HBLs) were determined based on the well-established concept of conditional formation constants of metal complexes. The pKa values of HBLs were 2.30, 2.77, and 2.00 for the reaction systems, 2,4-difluorophenylboronic acid and chromotropic acid, 3-nitrophenylboronic acid and alizarin red S, and phenylboronic acid and alizarin red S, respectively. A general and precise reaction mechanism of RB(OH)2 with H2L in aqueous solution, which can serve as a universal reaction mechanism for RB(OH)2 and H2L, was proposed on the basis of (a) the relative kinetic reactivities of the RB(OH)2 and its conjugate base, that is, the boronate ion, toward H2L, and (b) the determined pKa values of HBLs. The use of the conditional formation constant, K', based on the main reaction: RB(OH)2 + H2L (K1)⇌ RB(L)(OH)(-) + H3O(+) instead of the binding constant has been proposed for the general reaction of uncomplexed boronic acid species (B') with uncomplexed diol species (L') to form boronic acid diol complex species (esters, BL') in aqueous solution at pH 5-11: B' + L' (K')⇌ BL'. The proposed reaction mechanism explains perfectly the formation of boronic acid diol ester in aqueous solution. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Highly sensitive determination of 2,4,6-trinitrotoluene and related byproducts using a diol functionalized column for high performance liquid chromatography.

    Directory of Open Access Journals (Sweden)

    Burcu Gumuscu

    Full Text Available In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT; 2,4-dinitrotoluene (2,4-DNT; 2,6-dinitrotoluene (2,6-DNT; 2-aminodinitrotoluene (2-ADNT and 4-aminodinitrotoluene (4-ADNT molecules in high-performance liquid-chromatography (HPLC with UV sensor has been developed using diol column. This approach improves on cost, time, and sensitivity over the existing methods, providing a simple and effective alternative. Total analysis time was less than 13 minutes including column re-equilibration between runs, in which water and acetonitrile were used as gradient elution solvents. Under optimized conditions, the minimum resolution between 2,4-DNT and 2,6-DNT peaks was 2.06. The recovery rates for spiked environmental samples were between 95-98%. The detection limits for diol column ranged from 0.78 to 1.17 µg/L for TNT and its byproducts. While the solvent consumption was 26.4 mL/min for two-phase EPA and 30 mL/min for EPA 8330 methods, it was only 8.8 mL/min for diol column. The resolution was improved up to 49% respect to two-phase EPA and EPA 8330 methods. When compared to C-18 and phenyl-3 columns, solvent usage was reduced up to 64% using diol column and resolution was enhanced approximately two-fold. The sensitivity of diol column was afforded by the hydroxyl groups on polyol layer, joining the formation of charge-transfer complexes with nitroaromatic compounds according to acceptor-donor interactions. Having compliance with current requirements, the proposed method demonstrates sensitive and robust separation.

  16. Ovarian acyclicity in zoo African elephants (Loxodonta africana) is associated with high body condition scores and elevated serum insulin and leptin.

    Science.gov (United States)

    Morfeld, Kari A; Brown, Janine L

    2016-04-01

    The purpose of the present study was to determine whether excessive body fat and altered metabolic hormone concentrations in the circulation were associated with ovarian acyclicity in the world's largest land mammal, the African elephant. We compared body condition, glucose, insulin and leptin concentrations and the glucose-to-insulin ratio (G:I) between cycling (n=23; normal 14-16 week cycles based on serum progestagens for at least 2 years) and non-cycling (n=23; consistent baseline progestagen concentrations for at least 2 years) females. A validated body condition score (BCS) index (five-point scale; 1=thinnest, 5=fattest) was used to assess the degree of fatness of the study elephants. The mean BCS of non-cycling elephants was higher than that of their cycling counterparts. There were differences in concentrations of serum metabolic biomarkers, with non-cycling elephants in the BCS 5 category having higher leptin and insulin concentrations and a lower G:I ratio than cycling BCS 5 females. Using 'non-cycling' as the outcome variable in regression models, high BCS was a strong predictor of a non-cycling status. This study provides the first evidence that ovarian acyclicity in zoo African elephants is associated with body condition indicative of obesity, as well as elevated, perturbed biomarkers of metabolic status.

  17. Acyclic cucurbit[n]uril-type molecular containers: influence of aromatic walls on their function as solubilizing excipients for insoluble drugs.

    Science.gov (United States)

    Zhang, Ben; Isaacs, Lyle

    2014-11-26

    We studied the influence of the aromatic sidewalls on the ability of acyclic CB[n]-type molecular containers (1a-1e) to act as solubilizing agents for 19 insoluble drugs including the developmental anticancer agent PBS-1086. All five containers exhibit good water solubility and weak self-association (Ks ≤ 624 M(-1)). We constructed phase solubility diagrams to extract Krel and Ka values for the container·drug complexes. The acyclic CB[n]-type containers generally display significantly higher Ka values than HP-β-CD toward drugs. Containers 1a-1e bind the steroidal ring system and aromatic moieties of insoluble drugs. Compound 1b displays highest affinity toward most of the drugs studied. Containers 1a and 1b are broadly applicable and can be used to formulate a wider variety of insoluble drugs than was previously possible with cyclodextrin technology. For drugs that are solubilized by both HP-β-CD and 1a-1e, lower concentrations of 1a-1e are required to achieve identical [drug].

  18. Synthesis, Characterizations and Investigation of Electrochemical Behaviours of 4-[(2-Hydroxyphenyliminomethyl]benzene-1,3-diol

    Directory of Open Access Journals (Sweden)

    Aysen D. Mulazimoglu

    2009-01-01

    Full Text Available This Schiff base ligand, 4-[(2-hydroxyphenylimino methyl]benzene-1,3-diol (HIBD was synthesized by reaction of 2-aminophenol and 2,4-dihydroxybenzaldehyde. The ligand was characterized by elemental analysis, FT-IR and 1H-NMR. Electrochemical behaviors were investigated on the glassy carbon electrode (GC surface with cyclic voltammetry (CV. The modification of HIBD on the GC was performed in +0.3 V and +2,8 V potential range using 100 mV s-1 scanning rate having 5 cycle. For the characterization of the modified surfaces 1 mM ferrocene redox probe in 0,1 M tetrabutylammonium tetrafluoroborate (TBATFB and 1 mM ferricyanide redox probe in 0.1 M H2SO4 were used.

  19. Myeloperoxidase - 463A variant reduces benzo(a)pyrene diol epoxide DNA adducts in skin of coal tar treated patients

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, M.; Godschalk, R.; Alexandrov, K.; Cascorbi, I.; Kriek, E.; Ostertag, J.; Van Schooten, F.J.; Bartsch, H. [German Cancer Research Center, Heidelberg (Germany). Div. of Toxicology & Cancer Risk Factors

    2001-07-01

    The skin of atopic dermatitis patients provides an excellent model to study the role of inflammation in benzo(a)pyrene (BaP) activation, since these individuals are often topically treated with ointments containing high concentrations of BaP. The authors determined, by HPLC with fluorescence detection, the BaP diol epoxide (BPDE)-DNA adduct levels in human skin after topical treatment with coal tar and their modulation by the -453G into A myeloperoxidase (MPO) polymorphism, which reduces MPO mRNA expression. The data show for the first time: (i) the in vivo formation of BPDE-DNA adducts in human skin treated with coal tar; (ii) that the MPO-463AA/AG genotype reduced BPDE-DNA adduct levels in human skin.

  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. Biocatalytic production of enantiopure cyclohexane-trans-1,2-diol using extracellular lipases from Bacillus subtilis.

    Science.gov (United States)

    Detry, Jean; Rosenbaum, Thorsten; Lütz, Stephan; Hahn, Doris; Jaeger, Karl-Erich; Müller, Michael; Eggert, Thorsten

    2006-10-01

    Two extracellular lipases from Bacillus subtilis, B. subtilis lipase A and lipase B, have been expressed in the heterologous host Escherichia coli, biochemically characterized and used for the kinetic resolution of (rac)-trans-1,2-diacetoxycyclohexane. Both enzymes were selectively acting on the (R,R)-enantiomer of the racemic substrate, highly specifically hydrolyzing only one of the two ester groups present, thus allowing the preparation of enantiopure (R,R)- and (S,S)-cyclohexane-trans-1,2-diol. The reaction conditions for the use of purified enzyme and crude cell lyophilizate were optimized and reactions in batch and repetitive batch modes were carried out on a preparative scale to yield enantiopure product (>99% enantiomeric excess).

  2. Laboratory Study of Aliphatic Organic Spectral Signatures and Applications to Ceres and Primitive Asteroids

    Science.gov (United States)

    Kaplan, H. H.; Milliken, R.

    2017-12-01

    Aliphatic organics were recently discovered on the surface of Ceres with Dawn's Visible and InfraRed (VIR) mapping spectrometer, which has implications for prebiotic chemistry of Ceres and other asteroids. An absorption in the spectrum at 3.4 µm was used to identify and provide initial estimates of the amount of organic material. We have studied the 3.4 µm absorption in reflectance spectra of bulk rock and meteorite powders and isolated organic materials in the NASA RELAB facility at Brown University to determine how organic composition and abundance affects absorption strength. Reflectance spectra of insoluble organic matter (IOM) extracted from carbonaceous chondrites were measured from 0.35 - 25 µm. These IOM have known elemental (H, C, N, O) and isotopic compositions that were compared with spectral properties. Bulk meteorites were measured as chips and particulates over the same wavelength range. Despite overall low reflectance values (albedo specifically those with a H/C ratio greater than 0.4. The absorption strength (band depth) increases with increasing H/C ratio, which corroborates similar findings in our previous study of sedimentary rocks and isolated kerogens. The absorption strength in the bulk meteorites reflects both H/C of the IOM and the concentration of IOM in the inorganic (mineral) matrix. Overlapping absorptions from carbonates and phyllosilicates (OH/H2O) can also influence the aliphatic organic bands in bulk rocks and meteorites. This laboratory work provides a foundation that can be used to constrain the composition of Ceres' aliphatic organic matter using band depth as a proxy for H/C. Reflectance spectra collected for this work will also be used to model the Dawn VIR data and obtain abundance and H/C estimates assuming that the organic material on Ceres' surface is similar to carbonaceous chondrite IOM. These spectra and findings can aid interpretation of reflectance data from Ceres and other asteroid missions, such as OSIRIS-REx and

  3. Palladium-catalysed C-H activation of aliphatic amines to give strained nitrogen heterocycles

    Science.gov (United States)

    McNally, Andrew; Haffemayer, Benjamin; Collins, Beatrice S. L.; Gaunt, Matthew J.

    2014-06-01

    The development of new chemical transformations based on catalytic functionalization of unactivated C-H bonds has the potential to simplify the synthesis of complex molecules dramatically. Transition metal catalysis has emerged as a powerful tool with which to convert these unreactive bonds into carbon-carbon and carbon-heteroatom bonds, but the selective transformation of aliphatic C-H bonds is still a challenge. The most successful approaches involve a `directing group', which positions the metal catalyst near a particular C-H bond, so that the C-H functionalization step occurs via cyclometallation. Most directed aliphatic C-H activation processes proceed through a five-membered-ring cyclometallated intermediate. Considering the number of new reactions that have arisen from such intermediates, it seems likely that identification of distinct cyclometallation pathways would lead to the development of other useful chemical transformations. Here we report a palladium-catalysed C-H bond activation mode that proceeds through a four-membered-ring cyclopalladation pathway. The chemistry described here leads to the selective transformation of a methyl group that is adjacent to an unprotected secondary amine into a synthetically versatile nitrogen heterocycle. The scope of this previously unknown bond disconnection is highlighted through the development of C-H amination and carbonylation processes, leading to the synthesis of aziridines and β-lactams (respectively), and is suggestive of a generic C-H functionalization platform that could simplify the synthesis of aliphatic secondary amines, a class of small molecules that are particularly important features of many pharmaceutical agents.

  4. Aliphatic and polycyclic aromatic hydrocarbons in sediments of Kaohsiung Harbour and Adjacent Coast, Taiwan.

    Science.gov (United States)

    Lee, Chon-Lin; Hsieh, Ming-Tsuen; Fang, Meng-Der

    2005-01-01

    Surficial sediment samples collected from Kaohsiung Harbour and its nearby coast were analyzed for aliphatic hydrocarbons and parent polycyclic aromatic hydrocarbons (PAHs). According to our results, the average total concentrations of n-alkanes (n-C12 to C35) and aromatics (15 PAHs) were 4.33 microg g(-1) dry weight (ranged 0.46-22.60) and 0.59 microg g(-1) dry weight (ranged 0.09-1.75), respectively. The highest concentrations of aliphatic and aromatic hydrocarbons were recorded in stations near the estuaries of Qianzhen River and Love River, respectively. Aliphatic hydrocarbons in the samples indicate that there has been significant non-petrogenic, possibly terrestrial, contribution in the sediment of the open coast of Kaohsiung Harbour and that there has been dominant contribution from petrogenic sources in the sediment of the inner harbour. PAHs, detected in the samples, however, indicated a higher pyrolytic contribution in open-coast samples and a higher petrogenic contribution in the inner harbour. Overall, sediment concentrations of total alkanes in this study were comparable to those found in Victoria Harbour, Hong Kong and are higher than those found in Xiamen Harbour, China. Concentrations of total PAHs in inner Kaohsiung Harbour sediments were relatively lower than those found in Victoria Harbour, Hong Kong and Xiamen Harbour, China, but comparable to those found in Hsin-ta Harbour, Taiwan and Incheon Harbour, Korea. In comparison with several effect-based sediment quality guidelines, most PAH concentrations found in samples taken from inner harbour stations exceeded the Threshold Effect Level of Florida indicating a slight possibility of adverse effects.

  5. Simultaneous determination of aliphatic hydrocarbons, PCBs and PCTs in pork liver by gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Barros, C. [Dept. de Quimica Analitica, Nutricion y Bromatologia, Area Nutricion y Bromatologia, Facultad de Farmacia, Santiago de Compostela (Spain); Alvarez Pineiro, M.E. [Inst. de Investigacion y Analisis Alimentarios, Lab. de Bromatologia, Facultad de Farmacia, Santiago de Compostela (Spain); Simal Lozano, J. [Dept. de Quimica Analitica, Nutricion y Bromatologia, Area Nutricion y Bromatologia, Facultad de Farmacia, Santiago de Compostela (Spain); Lage Yusty, M.A. [Inst. de Investigacion y Analisis Alimentarios, Lab. de Bromatologia, Facultad de Farmacia, Santiago de Compostela (Spain)

    1996-10-01

    A multicomponent extraction/concentration procedure has been developed for the enrichment of PCBs, PCTs and aliphatic hydrocarbons (pristane, C{sub 18}, C{sub 19}, C{sub 20}, C{sub 22}, C{sub 24}, C{sub 28}, C{sub 32} and C{sub 36}) in pork liver. These components of the enriched extract were then simultaneously determined by gas chromatography. Mean recoveries ranged from 81.5% for pristane to 93% for PCBs; CV % (0.9-6.7) indicated the method to be both precise and reproducible. (orig.)

  6. The kinetics of reductive dehalogenation of a set of halogenated aliphatic hydrocarbons in anaerobic sediment slurries.

    Science.gov (United States)

    Peijnenburg, W; Eriksson, L; de Groot, A; Sjöström, M; Verboom, H

    1998-01-01

    Disappearance rate constants are reported for the reductive transformation of 17 halogenated aliphatic hydrocarbons in anaerobic sediment-water samples. Statistical experimental design in combination with multivariate chemical characterization of their chemical properties was used to select the compounds. Degradation followed pseudo first-order kinetics through at least two half-lives for 15 of the 17 compounds. Of all the compounds investigated, 1,2,3-trichloropropane and dichloromethane were unique in that they were dehalogenated according to zero-order kinetics. Reductive dehalogenation was the sole transformation reaction taking place.

  7. The fumigant and repellent activity of aliphatic lactones against Pediculus humanus capitis (Anoplura: Pediculidae

    Directory of Open Access Journals (Sweden)

    Ariel Ceferino Toloza

    2006-02-01

    Full Text Available New alternative insecticides are necessary for the chemical control of head lice. In this study the fumigant knockdown time 50% (KT50 and repellency index (RI of three aliphatic lactones was compared with two essential oils and DDVP, against permethrin-resistance Pediculus humanus capitis from Argentina. In the fumigant assay, none of the lactones were effective compared to the highest activity of eucalyptus (KT50 15.53 m. In the repellency test, the three lactones were equally or more effective (RI ranging from 60.50 to 76.68 than the positive control (piperonal. These lactones are promising as head lice repellents.

  8. The fumigant and repellent activity of aliphatic lactones against Pediculus humanus capitis (Anoplura: Pediculidae).

    Science.gov (United States)

    Toloza, Ariel Ceferino; Zygadlo, Julio; Mougabure-Cueto, Gastón; Zerba, Eduardo; Faillaci, Silvina; Picollo, María Inés

    2006-02-01

    New alternative insecticides are necessary for the chemical control of head lice. In this study the fumigant knockdown time 50% (KT50) and repellency index (RI) of three aliphatic lactones was compared with two essential oils and DDVP, against permethrin-resistance Pediculus humanus capitis from Argentina. In the fumigant assay, none of the lactones were effective compared to the highest activity of eucalyptus (KT50 15.53 m). In the repellency test, the three lactones were equally or more effective (RI ranging from 60.50 to 76.68) than the positive control (piperonal). These lactones are promising as head lice repellents.

  9. New Aliphatic Esters and Pyran Derivatives isolated from stem bark of Dalbergia Sissoo Roxb

    International Nuclear Information System (INIS)

    Trag, A. R.; Siddiqui, T. O.; Mahmooduzzafar; Iqbal, M.; Ali, M.

    2005-01-01

    Phytochemical investigation of the ethanolic extract of the stem bark of Dalbergia Sissoo led to the isolation of two new aliphatic esters and two new pyran derivatives and their structures have been elucidated as n-hexacosan-5-ol-1-yl propionate, n-tetracosan-5-ol-yl propionate, 7-hydroxy-8-methoxy-4-(2'-hydroxyphenyl1)-[4H]-benzopyran (dalbergyl pyran) and 10, 12, 13-trihydroxy-11-methoxyanthracenyl-15-18[2H]pyran(anthracenyl pyran) on the basis of spectral data analyses and chemical reactions. (author)

  10. Brominated aliphatic hydrocarbons and sterols from the sponge Xestospongia testudinaria with their bioactivities.

    Science.gov (United States)

    Zhou, Xuefeng; Lu, Yanan; Lin, Xiuping; Yang, Bin; Yang, Xianwen; Liu, Yonghong

    2011-10-01

    Four brominated aliphatic hydrocarbons (1-4), including a novel brominated ene-tetrahydrofuran named as mutafuran H (1), and five sterols (5-9) were isolated from the South China Sea sponge Xestospongia testudinaria. The structure of 1 was determined on the basis of NMR ((1)H, (13)C NMR, HSQC, HMBC, (1)H-(1)H COSY, and NOESY), MS, and optical rotation analysis. Known compounds were identified by comparison of their NMR data with those reported in the literature. Compounds 1-4, and 6-9 were evaluated for their toxicity against Artemia salina larvae, and anti-acetylcholinesterase activity. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  11. Selective Palladium(II)-Catalyzed Carbonylation of Methylene β-C-H Bonds in Aliphatic Amines.

    OpenAIRE

    Cabrera-Pardo, Jaime R; Trowbridge, Aaron; Nappi, Manuel; Ozaki, Kyohei; Gaunt, Matthew James

    2017-01-01

    Pd(II)-catalyzed C–H carbonylation of methylene C–H bonds in secondary aliphatic amines leads to the formation trans-disubstituted β-lactams in excellent yields and selectivities. The generality of the C–H carbonylation process is aided by the action of xantphos-based ligands and is important in securing good yields of the β-lactam products. EPSRC (EP/100548X/1), ERC (ERC-STG-259711), Royal Society (Wolfson Award), Marie Curie Foundation and Herchel Smith Foundation.

  12. Molecular Characterization of MYB28 Involved in Aliphatic Glucosinolate Biosynthesis in Chinese Kale (Brassica oleracea var. alboglabra Bailey

    Directory of Open Access Journals (Sweden)

    Ling Yin

    2017-06-01

    Full Text Available Glucosinolates are Brassicaceae-specific secondary metabolites that act as crop protectants, flavor precursors, and cancer-prevention agents, which shows strong evidences of anticarcinogentic, antioxidant, and antimicrobial activities. MYB28, the R2R3-MYB28 transcription factor, directly activates genes involved in aliphatic glucosinolate biosynthesis. In this study, the MYB28 homology (BoaMYB28 was identified in Chinese kale (Brassica oleracea var. alboglabra Bailey. Analysis of the nucleotide sequence indicated that the cDNA of BoaMYB28 was 1257 bp with an ORF of 1020 bp. The deduced BoaMYB28 protein was a polypeptide of 339 amino acid with a putative molecular mass of 38 kDa and a pI of 6.87. Sequence homology and phylogenetic analysis showed that BoaMYB28 was most closely related to MYB28 homologs from the Brassicaceae family. The expression levels of BoaMYB28 varies across the tissues and developmental stages. BoaMYB28 transcript levels were higher in leaves and stems compared with those in cotyledons, flowers, and siliques. BoaMYB28 was expressed across all developmental leaf stages, with higher transcript accumulation in mature and inflorescence leaves. Over-expression and RNAi studies showed that BoaMYB28 retains the basic MYB28 gene function as a major transcriptional regulator of aliphatic glucosinolate pathway. The results indicated that over-expression and RNAi lines showed no visible difference on plant morphology. The contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes increased in over-expression lines and decreased in RNAi lines. In over-expression lines, aliphatic glucosinolate contents were 1.5- to 3-fold higher than those in the wild-type, while expression levels of aliphatic glucosinolate biosynthesis genes were 1.5- to 4-fold higher than those in the wild-type. In contrast, the contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate

  13. Evaluation of Novel Acyclic Nucleoside Phosphonates against Human and Animal Gammaherpesviruses Revealed an Altered Metabolism of Cyclic Prodrugs upon Epstein-Barr Virus Reactivation in P3HR-1 Cells

    Czech Academy of Sciences Publication Activity Database

    Coen, N.; Duraffour, S.; Naesens, L.; Krečmerová, Marcela; Van Den Oord, J.; Snoeck, R.; Andrei, G.

    2013-01-01

    Roč. 87, č. 22 (2013), s. 12422-12432 ISSN 0022-538X R&D Projects: GA MPO FR-TI4/625 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonate * gammaherpesvirus * Epstein-Barr virus * Kaposi's sarcoma * HPMP-5-azaC * cidofovir Subject RIV: EE - Microbiology, Virology Impact factor: 4.648, year: 2013

  14. Two new aliphatic lactones from the fruits of Coriandrum sativum L.

    Science.gov (United States)

    2012-01-01

    Background The present paper describes the isolation and characterization of two new aliphatic δ-lactones along with three glycerides and n-nonadecanyl cetoleate from the fruits of Coriandrum sativum L. (Apiaceae). The structures of all the isolated phytoconstituents have been established on the basis of spectral data analysis and chemical reactions. Results Phytochemical investigation of the methanolic extract of C. sativum L. (Apiaceae) fruits resulted in the isolation of two new aliphatic δ-lactones characterized as 2α-n-heptatriacont-(Z)-3-en-1,5-olide (1) (coriander lactone) and 2α-n-tetracont-(Z,Z)-3,26-dien-18α-ol-1,5-olide (2) (hydroxy coriander lactone) together with glyceryl-1,2-dioctadec-9,12-dienoate-3-octadec-9-enoate (3); glyceryl-1,2,3-trioctadecanoate (4); n-nonadecanyl-n-docos-11-enoate (5) and oleiyl glucoside (6). Conclusions Phytochemical investigation of the methanolic extract of C. sativum gave coriander lactone and hydroxy coriander lactone as the new phytoconstituents. PMID:22800677

  15. Nanostructure to microstructure self-assembly of aliphatic polyurethanes: the effect on mechanical properties.

    Science.gov (United States)

    Mishra, Abhinay; Aswal, Vinod K; Maiti, Pralay

    2010-04-29

    We report the step by step self-assembly from nanostructure to microstructure (bottom-up approach through X-ray diffraction (1.6 nm), small angle neutron scattering (SANS) (11.6 nm), atomic force microscopy (70 nm smaller crystallite from enlarged image and 450 nm greater crystallites), and polarizing optical microscope (2 microm)) of aliphatic polyurethanes (PU) in contrast to aromatic polyurethanes depending on hard segment content (HSC). Polyurethanes of 10 to 80% HSC have been synthesized by using appropriate amount of polyol and chain extender. The effect of self-assembled patterns on mechanical properties both in solid and liquid state has been established exhibiting structure-property relationship of supramolecular polyurethanes. The crystallinity enhances but the degradation temperature decreases with increasing HSC. The characteristic length (measure of gap between lamellar crystallites), as revealed from SANS, gradually decreases with increasing HSC suggesting compactness of the crystallites through extensive hydrogen bonding. The Young's modulus increases with increasing HSC with a percolation threshold of hard segment (50%) while the toughness improves up to 30% HSC followed by gradual decrease in presence of bigger crystallites which promote brittle fracture. The origin of self-assembly in aliphatic PUs has been demonstrated through electronic structure calculations to form a loop structure with minimum intermolecular distance (2.2 A) while that distance is quite large in aromatic polyurethanes (4.6 A) that cannot form hydrogen bonds. The unique splintering of domain structure and its subsequent reformation under dynamic shear experiment has been established.

  16. N-hydroxysuccinimide-mediated photoelectrooxidation of aliphatic alcohols based on cadmium telluride nanoparticles decorated graphene nanosheets

    International Nuclear Information System (INIS)

    Navaee, Aso; Salimi, Abdollah

    2013-01-01

    A simple nonenzymatic electrochemical protocol is proposed for the oxidation of aliphatic alcohols using formed N-hydroxysuccinimide (NHS) radical cation on the graphene nanosheets/L-cysteine/cadmium telluride quantum dot (QD) nanocomposite (GNs/Cys/CdTe) modified glassy carbon (GC) electrode. At first, graphene oxide (GO) is chemically synthesized from graphite after which Cys is covalently functionalized to GO through formation of amide bonds between carboxylic acid groups of GO and amine groups of Cys. The resulting GNs/Cys is used as a capping agent to synthesize CdTe QD nanoparticles. After the characterization of the as-made nanocomposite which confirmed the successful attachment of CdTe nanoparticles to the GNs, the ability of the GNs/Cys/CdTe modified GC electrode toward the nonenzymatic ethanol electrooxidation is examined in the presence of NHS as an effective mediating system. Our results revealed that the proposed system possess a good activity to NHS electrooxidation and subsequently, ethanol oxidation. Moreover, the GNs/Cys/CdTe modified electrode displayed a significant photoelectrocatalytic activity toward the ethanol oxidation upon illumination by visible light. The photoactive GNs/Cys/CdTe nanohybrid presented here showing favorable photoelectrochemical features for nonenzymatic aliphatic alcohols oxidation may hold great promise to the development of electrochemical sensors and biofuel cells

  17. Evaluation of 10 aliphatic halogenated hydrocarbons in the mouse bone marrow micronucleus test.

    Science.gov (United States)

    Crebelli, R; Carere, A; Leopardi, P; Conti, L; Fassio, F; Raiteri, F; Barone, D; Ciliutti, P; Cinelli, S; Vericat, J A

    1999-03-01

    Ten halogenated aliphatic hydrocarbons (carbon tetrachloride, 1-chlorohexane, 2,3-dichlorobutane, 1,2-dichloroethane, 1,2-dichloroethylene, 1,3-dichloropropane, hexachloroethane, 1,1,2-trichloroethane, 1,2,3-trichloropropane and 1,1,3-trichloropropene), previously assayed in genetic assays in fungi, were evaluated in the mouse bone marrow micronucleus test in order to assess their genotoxicity in vivo. All chemicals were administered once i.p. at 40 and 70-80% of their respective LD50 to male and female CD-1 mice, 24 and 48 h before killing. All treatments produced evident clinical symptoms, but no marked depression of bone marrow proliferation. No statistically significant increases in the incidence of micronucleated polychromatic erythrocytes over the control values were observed at any sampling time with any of the 10 halogenated hydrocarbons assayed. The comparison of the results obtained in this study with the findings provided by in vitro micronucleus assays on the same chemicals, reported by other authors, indicate that mouse bone marrow is weakly sensitive to the genotoxic effects induced by halogenated hydrocarbons in other test systems. This suggests that the role of such an assay in carcinogen screening may be questionable for this chemical class. An examination of mouse bone marrow micronucleus test results with the halogenated aliphatic hydrocarbons classified as carcinogens by IARC supports this conclusion.

  18. Phase diagrams in blends of poly(3-hydroxybutyric acid with various aliphatic polyesters

    Directory of Open Access Journals (Sweden)

    2011-07-01

    Full Text Available Phase behavior with immiscibility, miscibility, crystalline morphology, and kinetic analysis in blends of poly(3-hydroxybutyric acid (PHB with aliphatic polyesters such as poly(butylene adipate (PBA, poly(ethylene adipate (PEA, poly(trimethylene adipate (PTA, or poly(ethylene succinate (PESu, respectively, were explored mainly using differential scanning calorimeter (DSC and polarized-light optical microscopy (POM. Immiscibility phase behavior with reversible upper-critical-solution-temperature (UCST is common in the PHB/polyester blends. The polyester/polyester blend of PHB/PTA is partially miscible with no UCST in melt and amorphous glassy states within a composition range of PTA less than 50 wt%. The miscible crystalline/crystalline blend exhibits ring-banded spherulites at Tc = 50~100°C, with inter-ring spacing dependent on Tc. All immiscible or partially miscible PHB/polyester blends, by contrast, exhibit disrupted ringbanded spherulites or discrete spherical phase domains upon cooling from UCST to crystallization. The blends of PHB with all other aliphatic polyesters, such as PESu, PEA, PBA, etc. are only partially miscible or immiscible with an upper critical solution temperature (UCST at 180~221°C depending on blend composition. UCST with reversibility was verified.

  19. Assay of Aliphatic Phthalates in Polymer Products by Sensitive Polarographic Method: Health and Environmental Issue

    Directory of Open Access Journals (Sweden)

    Munawar Saeed

    2010-06-01

    Full Text Available A faster, simpler and sensitive method was developed for determination of aliphatic phthalates using differential pulse polarography (DPP as standard technique. The choice and concentration of base electrolyte, solvent, initial potential, effect of water addition and interference by other phthalates were the main parameters to optimize for enhancement of peak current and to obtain well-defined polarogram with lower background current using 1.3 x 10-4 M di-butyl phthalate (DBP solution. Best results were obtained in the presence of tetra methyl ammonium bromide (TMAB as electrolyte in methanol solvent with initial potential, -1.4 V. A linear calibration plot was observed in the range of 3 x 10-7 – 1.6 x 10-4 M DBP solution as aliphatic phthalates with lower detection limit of 5.9 x 10-8 M and linear regression coefficient of 0.9987. The developed polarographic method was successfully applied for analysis of aliphtaic phthalates in various samples of locally available polymer products such as baby toys, nipples, teethers, infusion blood bags and shopping bags. The results of the current method were compared with those obtained by a reported method and good agreement was found between them.

  20. A comprehensive evaluation of the toxicology of cigarette ingredients: aliphatic and aromatic carboxylic acids.

    Science.gov (United States)

    Coggins, Christopher R E; Liu, Jianmin; Merski, Jerome A; Werley, Michael S; Oldham, Michael J

    2011-06-01

    Aromatic and aliphatic carboxylic acids are present in tobacco and tobacco smoke. A battery of tests was used to compare the toxicity of mainstream smoke from experimental cigarettes containing eight aromatic and aliphatic carboxylic acids and the salt of one acid that were added individually at three different levels (lowest and highest target inclusions were 100 and 90,000 ppm, respectively). Mainstream smoke from cigarettes containing each of the test ingredients was evaluated using analytical chemistry and assays to measure in vitro cytotoxicity (neutral red uptake) and Salmonella (five strains) mutagenicity. For four of the compounds (citric, lactic, benzoic acids, and sodium benzoate), 90-day rodent inhalation studies were also performed. Although sporadic statistically significant differences in some experimental cigarette smoke constituents occurred, none resulted in significant changes in mutagenicity or cytotoxicity responses, nor in responses measured in the inhalation studies, except for lactic acid (LA). Inclusion of LA resulted in dose-dependent increase in water and caused a dose-dependent decrease in cytotoxicity. Incorporation of LA into cigarettes resulted in several dose-related reductions in histopathology, which were largely restricted to the nasal passages. Incorporation of LA also ameliorated some of the typical decrease in body weight gain seen in cigarette smoke-exposed rats. Inclusion of these ingredients at exaggerated use levels resulted in sporadic dose-related and treatment effects for some smoke constituents, but no toxicological response was noted in the in vitro and in vivo tests performed.

  1. Extraction and solubility characteristics of metal aliphatic carboxylates in a hexane medium

    International Nuclear Information System (INIS)

    Moriya, Yoshio; Sugai, Mikio; Ohshima, Yozo; Ogawa, Nobuaki; Matsuo, Shigeki.

    1994-01-01

    Extractions of 30 metal ions with aliphatic carboxylic acids into hexane were carried out to understand their extraction behavior. Results were expressed in an area-graph form for metal partitions among the three (aqueous, organic and/or solid) phases in the range pH 1-9. The difference in half-extraction pH (pH 1/2 ) between various metals can be explained by the electrostatic effect (hard acids) and the polarizability. According to the solubility of the metal complexes into organic phase, the thirty metal ions were divided into two groups. The metal ions with high ionic potential (group A) were generally extractable by every carboxylic acid tested. The large size metal ions (group B) precipitated at the liquid/liquid interface by n-aliphatic carboxylic acids and were perfectly extracted by 2-ethylhexanoic acid. We propose that this difference in the group B is caused by interface-coagulation through inter-molecular hydrophobic bond formation in the former, while the branched chain in the carboxylic acid weakens the interaction in the latter. For group A, therefore, most of the extracted species would be origomers so that no coagulation would occur. (author)

  2. Pd-catalysed ligand-enabled carboxylate-directed highly regioselective arylation of aliphatic acids

    Science.gov (United States)

    Zhu, Yan; Chen, Xiaolan; Yuan, Chunchen; Li, Guobao; Zhang, Jingyu; Zhao, Yingsheng

    2017-04-01

    α-amino acids bearing aromatic side chains are important synthetic units in the synthesis of peptides and natural products. Although various β-C-H arylation methodologies for amino acid derivatives involving the assistance of directing groups have been extensively developed, syntheses that directly employ N-protected amino acids as starting materials remain rare. Herein, we report an N-acetylglycine-enabled Pd-catalysed carboxylate-directed β-C(sp3)-H arylation of aliphatic acids. In this way, various non-natural amino acids can be directly prepared from phthaloylalanine in one step in good to excellent yields. Furthermore, a series of aliphatic acids have been shown to be amenable to this transformation, affording β-arylated propionic acid derivatives in moderate to good yields. More importantly, this ligand-enabled direct β-C(sp3)-H arylation could be easily scaled-up to 10 g under reflux conditions, highlighting the potential utility of this synthetic method.

  3. Radiolytic crosslinking and chain scission in aliphatic and alkyl-aromatic polyamides: Pt. 2

    International Nuclear Information System (INIS)

    Lyons, B.J.; Glover, L.C. Jr.

    1991-01-01

    Regression analysis of the radiation parameters of nine aliphatic polyamides exposed to ionizing radiation leads to the conclusion that the decline in the ratio of chain scission to crosslinking in higher aliphatic polyamides is best related to the linear increase in the methylene content of, or the number of methylene groups in, the polyamide repeat unit. G(crosslink)[G(X)] and G(chain scission) [G(CS)] values, however, do not correlate well with either of these parameters. Rather it is found that the major determinant of yields [about 80-85% of the variation for G(X), 70% for G(CS)] is the number of hydrogen atoms or methylene groups in the amine residue. Although, logically, the yields of crosslinks and chain scissions in polyamides would be expected to tend to that of polyethylene as the number of methylene groups in the repeat unit increases, use of two models assuming an exponential trend to the G(X) value characteristic of polyethylene in the analysis did not provide better fits to the data than the simple linear model referred to above. Indeed, the assumption of a significant exponential trend factor led to a marked drop in the goodness of fit. (author)

  4. Effect of electron beam irradiation on the biodegradability of aromatic aliphatic copolyester film and their blend with corn starch

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Leonardo G. Andrade e; Poveda, Patricia N.S., E-mail: lgasilva@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Rezende, Maira L.; Rosa, Derval S. [Universidade Sao Francisco, Itatiba, SP (Brazil)

    2009-07-01

    Biodegradable and green plastics have been studied in the last years. The aim of this paper is to study the effect of electron beam irradiation on the biodegradability of aromatic aliphatic copolyester film and their blend with corn starch. The samples were irradiated at different doses 10 and 40 kGy in a linear accelerator. The biodegradability of the materials was evaluated by two methods: soil simulated and enzymatic. In the method enzymatic when it was used alpha-amylase, the irradiated samples presented faster biodegradation than the references non irradiated. The blend of aromatic aliphatic copolyester with corn starch (Ecobras{sup R}) irradiated presented a bigger biodegradability than the aromatic aliphatic copolyester (Ecoflex{sup R}) film in both methods studied. (author)

  5. Effect of electron beam irradiation on the biodegradability of aromatic aliphatic copolyester film and their blend with corn starch

    International Nuclear Information System (INIS)

    Silva, Leonardo G. Andrade e; Poveda, Patricia N.S.; Rezende, Maira L.; Rosa, Derval S.

    2009-01-01

    Biodegradable and green plastics have been studied in the last years. The aim of this paper is to study the effect of electron beam irradiation on the biodegradability of aromatic aliphatic copolyester film and their blend with corn starch. The samples were irradiated at different doses 10 and 40 kGy in a linear accelerator. The biodegradability of the materials was evaluated by two methods: soil simulated and enzymatic. In the method enzymatic when it was used α-amylase, the irradiated samples presented faster biodegradation than the references non irradiated. The blend of aromatic aliphatic copolyester with corn starch (Ecobras R ) irradiated presented a bigger biodegradability than the aromatic aliphatic copolyester (Ecoflex R ) film in both methods studied. (author)

  6. Metabolites of the PAH diol epoxide pathway and other urinary biomarkers of phenanthrene and pyrene in workers with and without exposure to bitumen fumes.

    Science.gov (United States)

    Lotz, Anne; Pesch, Beate; Dettbarn, Gerhard; Raulf, Monika; Welge, Peter; Rihs, Hans-Peter; Breuer, Dietmar; Gabriel, Stefan; Hahn, Jens-Uwe; Brüning, Thomas; Seidel, Albrecht

    2016-11-01

    This study investigates the diol epoxide pathway of phenanthrene (PHE) together with phenolic metabolites of PHE and pyrene (PYR) in workers with and without exposure to bitumen fumes. The metabolite concentrations were determined in urine samples collected from 91 mastic asphalt workers and 42 construction workers as reference group before and after shift. During shift, vapours and aerosols of bitumen were measured according to a German protocol in the workers' breathing zone. The median concentration of vapours and aerosols of bitumen in mastic asphalt workers was 6.3 mg/m 3 . Metabolite concentrations were highest in post-shift urines of smokers with bitumen exposure and showed an increase during shift. The Spearman correlations between the creatinine-adjusted concentrations of metabolites and vapours and aerosols of bitumen in non-smokers were weak (e.g. sum of Di-OH-PYR: 0.28) or negligible (e.g. 1,2-PHE-diol: 0.08; PHE-tetrol: 0.12). Metabolites from the diol epoxide pathway of PHE were excreted in higher concentrations than phenolic metabolites (post-shift, non-smoking asphalt workers: 1,2-PHE-diol 2.59 µg/g crea vs. sum of all OH-PHE 1.87 µg/g crea). 1,2-PHE-diol was weakly correlated with PHE-tetrol (Spearman coefficient 0.30), an endpoint of the diol epoxide pathway. By contrast, we found a close correlation between the sum of 1,6-DiOH-PYR and 1,8-DiOH-PYR with 1-OH-PYR (Spearman coefficient 0.76). Most urinary PAH metabolites were higher after shift in bitumen-exposed workers, although the association with bitumen was weak or negligible likely due to the small PAH content. The additional metabolites of PHE and PYR complete the picture of the complex metabolic pathways. Nevertheless, none of the PAH metabolites can be considered to be a specific biomarker for bitumen exposure.

  7. Aliphatic alcohols of illegally produced spirits can act synergistically on superoxide-anion production by human granulocytes.

    Science.gov (United States)

    Arnyas, Ervin M; Pál, László; Kovács, Csilla; Adány, Róza; McKee, Martin; Szűcs, Sándor

    2012-10-01

    Aliphatic alcohols present in illegally produced spirits in a large number of low and middle income countries have been implicated in the etiology of chronic liver disease and cirrhosis. Previous studies have confirmed that chronic alcoholism can lead to increased susceptibility to infectious diseases. Reduced superoxide-anion (O(2)·(-)) production by granulocytes could provide a mechanism by which antimicrobial defense is impaired in alcoholics. In vitro experiments have also demonstrated that ethanol can inhibit granulocyte O(2)·(-) generation. Aliphatic alcohols consumed as contaminants of illicit spirits may also influence O(2)·(-) production thereby contributing to a decrease in microbicidal activity. The aim of this study was to investigate this possibility. It measured the O(2)·(-) production by human granulocytes following treatment of the cells with aliphatic alcohol contaminants found in illicit spirits. Granulocytes were isolated from human buffy coats with centrifugal elutriation and then treated with individual aliphatic alcohols and their mixture. The O(2)·(-) production was stimulated with phorbol-12-13-dibutyrate and N-formyl-methionyl-leucyl-phenylalanine (FMLP) and measured by superoxide dismutase inhibitable reduction of ferricytochrome c. Aliphatic alcohols of illegally produced spirits inhibited the FMLP-induced O(2)·(-) production in a concentration dependent manner. They suppressed O(2)·(-) generation at 2.5-40 times lower concentrations when combined than when tested individually. Aliphatic alcohols found in illegally produced spirits can inhibit FMLP-induced O(2)·(-) production by granulocytes in a concentration-dependent manner. Due to their synergistic effects, it is possible that, in combination with ethanol, they may inhibit O(2)·(-) formation in heavy episodic drinkers.

  8. Microwave-Assisted Kinetic Resolution of Homochiral (Z-Cyclooct-5-ene-1,2-diol and (Z-2-Acetoxycyclooct-4-enyl Acetate Using Lipases

    Directory of Open Access Journals (Sweden)

    Hervé Rouillard

    2014-07-01

    Full Text Available Over the last decade, the use of biocatalysts has become an attractive alternative to conventional chemical methods, especially for organic synthesis, due to their unusual properties. Among these enzymes, lipases are the most widely used, because they are cheap, easily available, cofactor-free, and have broad substrate specificity. Combined to microwave heating in non-aqueous medium, recent results suggest that irradiation may influence the enzyme activity. This Communication reports the benefits of lipases and the microwave irradiation on the kinetic resolution of racemic homochiral (Z-cyclooct-5-ene-1,2-diol and (Z-2-acetoxycyclooct-4-enyl acetate. In order to best achieve the kinetic resolution, different parameters were studied including the type of lipase, the temperature, the impact of microwave power compared to conventional heating. Optimization of the reaction parameters lead to the obtainment of highly enriched or enantiopure diols and diesters in a clean, efficient and safe way.

  9. Time-resolved resonance Raman study of proton transferring systems in the excited triplet state: 2,2'-bipyridine and 2,2'-bipyridine-3,3'-diol

    DEFF Research Database (Denmark)

    Langkilde, F.W.; Mordzinski, A.; Wilbrandt, R.

    1992-01-01

    Time-resolved resonance Raman (RR) spectra of the excited triplet state T1 of 2,2'-bipyridine (BP), 2,2'-bipyridine-3,3'-diol BP(OH)2, and 5,5'-dimethyl-2,2'-bipyridine-3,3'-diol Me2BP(OH)2 are obtained. and interpreted by comparison with their ground-state Raman spectra and the T1 spectrum...... of biphenyl. The BP T1 RR spectrum is assigned assuming C2h molecular symmetry. The T1 RR spectra of BP(OH)2 and Me2BP(OH)2 are ascribed to diketo tautomers that are products of double proton transfer in the S1 state....

  10. Mortality of Bemisia tabaci biotype B (sternorrhyncha: aleyrodidae adults by aliphatic and aromatic synthetic sucrose esters

    Directory of Open Access Journals (Sweden)

    Mariangela Alves

    2008-12-01

    Full Text Available The B-strain of Bemisia tabaci Gennadius is a key pest of several crops and chemical control is the main control method used by growers, although reduction in efficacy due to insecticide resistance has already been reported. The aim of this work was to investigate the insecticidal effect of an array of synthetic sucrose esters with the aliphatic and aromatic groups on whitefly adults. Sucrose butyrate, caprate, octanoate, palmitate, oleate, octaacetate, phthalate, benzoate, and sucrose diacetate hexaisobutyrate were tested. The solutions were prepared and applied on the adults caught on yellow sticky traps using the Potter spray tower. Long-chains sucrose aliphatic esters were more effective against the silverleaf whiteflies and the highest mortality was obtained with sucrose oleate and sucrose octanoate. Since these compounds were tensoactive, sodium dodecylsulphate was also tested for the comparison but no effect was observed. Sucrose butyrate and other aliphatic and aromatic sucrose polyesters showed negligible effect on the silverleaf whiteflies.O biótipo B de B. tabaci Gennadius tem se destacado como uma praga-chave de diversas culturas. O controle químico tem sido a principal tática de controle utilizada, embora já se tenha observado redução na eficiência dos produtos devido ao desenvolvimento de resistência. Assim, o objetivo do presente trabalho foi avaliar o efeito de diversos ésteres de sacarose com grupos alifáticos ou aromáticos sobre adultos de mosca-branca. Butirato de sacarose, caprato, octanoato, palmitato, oleato, actaacetato, ftlato, benzoato e diacetato hexaisobutirato de sacarose foram testados. Soluções de éster de sacarose foram preparadas e aplicadas sobre adultos capturados em armadilhas adesivas utilizando Torre de Potter. Ésteres alifáticos de sacarose com longas cadeias foram mais efetivos contra mosca-branca e as maiores taxas de mortalidade foram obtidas com oleato e octanoato de sacarose. Uma vez que

  11. Characterization of aliphatic and polycyclic aromatic hydrocarbons in environmental tobacco smokes

    International Nuclear Information System (INIS)

    Mohammad Fais Fadzil; Norhayati Mohd Tahir

    2007-01-01

    A study has been conducted to investigate the distribution of aliphatic and polycyclic aromatic hydrocarbons in Environmental Tobacco Smoke (ETS). ETS is the smoke that is present in the ambient air due to smoking of tobacco. Types of cigarettes (C1R1 and C6R1) were chosen based on a result of a simple survey carried out to determine the consumer choice of cigarette brand. In analyzing the ETS, volunteers were asked to smoke each brand of cigarette in a closed room and the ETS was then collected using the high Volume Air Sampler fitted with a glass fiber filter. Smoke samples from the glass fiber filter were then extracted using Ultrasonic Agitation and fractionated into aliphatic and aromatic fraction using silica-alumina column. Identification and quantification was done using gas chromatography with flame ionization detector. Results indicated the presence of n-alkanes in ETS, ranging from C 13 to C 36 with an odd to even carbon number predominance with Carbon Preference Index(CPI) values ranging from 3.34 to 4.90. Total identified resolved aliphatic hydrocarbons (TIRAH) concentration found in ETS ranged from 590 μg m -3 to 591 μg m -3 with the percentage of plant wax n-alkanes ranging from 61% to 64% of the TIRAH found in ETS samples. In source apportionment, CPI > 1 and high percentage of plant wax n-alkanes has generally been associated with the contribution of terrestrial plant source, thus this result indicates that even after curing process and smoking of tobacco, the overall signature of the source of n-alkanes is still preserved. Amount of PAHs detected in all ETS samples ranged from 11.7 ng m -3 to 56.1 ng m -3 . Results also indicated the presence of medium to high molecular weight PAHs with dominant presence of benzo(g, h, i)perylene compound. This result seems to support the contention that smoking process involves a high temperature burning with an oxygen deficient zone in the cigarette itself. Although the concentrations were low, the

  12. An integrated QSAR-PBK/D modelling approach for predicting detoxification and DNA adduct formation of 18 acyclic food-borne α,β-unsaturated aldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Kiwamoto, R., E-mail: reiko.kiwamoto@wur.nl; Spenkelink, A.; Rietjens, I.M.C.M.; Punt, A.

    2015-01-01

    Acyclic α,β-unsaturated aldehydes present in food raise a concern because the α,β-unsaturated aldehyde moiety is considered a structural alert for genotoxicity. However, controversy remains on whether in vivo at realistic dietary exposure DNA adduct formation is significant. The aim of the present study was to develop physiologically based kinetic/dynamic (PBK/D) models to examine dose-dependent detoxification and DNA adduct formation of a group of 18 food-borne acyclic α,β-unsaturated aldehydes without 2- or 3-alkylation, and with no more than one conjugated double bond. Parameters for the PBK/D models were obtained using quantitative structure–activity relationships (QSARs) defined with a training set of six selected aldehydes. Using the QSARs, PBK/D models for the other 12 aldehydes were defined. Results revealed that DNA adduct formation in the liver increases with decreasing bulkiness of the molecule especially due to less efficient detoxification. 2-Propenal (acrolein) was identified to induce the highest DNA adduct levels. At realistic dietary intake, the predicted DNA adduct levels for all aldehydes were two orders of magnitude lower than endogenous background levels observed in disease free human liver, suggesting that for all 18 aldehydes DNA adduct formation is negligible at the relevant levels of dietary intake. The present study provides a proof of principle for the use of QSAR-based PBK/D modelling to facilitate group evaluations and read-across in risk assessment. - Highlights: • Physiologically based in silico models were made for 18 α,β-unsaturated aldehydes. • Kinetic parameters were determined by in vitro incubations and a QSAR approach. • DNA adduct formation was negligible at levels relevant for dietary intake. • The use of QSAR-based PBK/D modelling facilitates group evaluations and read-across.

  13. The effect of winter length on duration of dormancy and survival of specialized herbivorous Rhagoletis fruit flies from high elevation environments with acyclic climatic variability.

    Science.gov (United States)

    Rull, J; Tadeo, E; Lasa, R; Aluja, M

    2017-09-19

    Dormancy can be defined as a state of suppressed development allowing insects to cope with adverse conditions and plant phenology. Among specialized herbivorous insects exploiting seasonal resources, diapause frequently evolves as a strategy to adjust to predictable plant seasonal cycles. To cope with acyclic and unpredictable climatic events, it has been found for some insects that a proportion of the population undergoes prolonged dormancy. We compared the response of three species in the Rhagoletis cingulata species group exploiting plants differing in fruiting phenology from environments varying in frequency and timing of acyclic climatic catastrophic events (frost during flowering and fruit set) and varying also in the time of the onset of the rainy season. Small proportions (10 months), and large proportions of pupae died without emerging as adults. The number of days elapsed from the end of artificial winter and adult eclosion was longer for R. cingulata exploiting late fruiting Prunus serotina in Northeastern Mexico than for flies recovered from earlier fruiting plants in the central Altiplano. Rhagoletis turpiniae and northeastern R. cingulata pupae suffered high proportions of parasitism. Large proportions of R. cingulata from central Mexico engaging in prolonged dormancy may be explained by the fact that flowering and fruit set for its host, P. serotina var capuli, driven by the timing of maximum precipitation, matches a period of highest probability of frost often resulting in large areas with fruitless trees at unpredictable time intervals. As a consequence of differences in host plant fruiting phenology, central and northeastern Mexican R. cingulata were found to be allochronically isolated. Prolonged dormancy may have resulted in escape from parasitism.

  14. Diastereoselective Synthesis of 2-Phenylselenenyl-1,3-anti-Diols and 2-Phenylselenenyl-1,3-anti-Azido-Alcohols via Hydroxyand Azido-Selenenylation Reactions

    Directory of Open Access Journals (Sweden)

    Renato Noto

    2005-02-01

    Full Text Available A method to synthesize 2-phenylselenenyl-1,3-anti-diols and 2-phenyl- selenenyl-1,3-anti-azidoalcohols via hydroxy- or azido-selenenylation of trans-allylic alcohols is reported. Moreover, the first example of hydroxyl-selenenylation of an allylic azide is presented. Yields ranging from moderate to good and diastereomeric ratios up to 95:5 are achieved.

  15. Synthesis and evaluation of borates derived from boric acid and diols for the protection of wood against fungal decay and thermal degradation

    Science.gov (United States)

    George C. Chen

    2004-01-01

    N,N-dimethyl amino carbinol catechol borate(1). N,N-dimethyl amino carbinol-4-methyl catechol borate(2), N,N-dimethyl amino carbinol-4-t- butyl catechol borate(3). N,N-dimethyl amino carbinol-2,3-naphthyl borate 4) were synthesized by refluxing boric acid and diol in DMF(N,N-dimethyl formamide). The borates were characterized by NMR. Wood impregnated with borate 1,2 or...

  16. Preparation of organic-silica hybrid boronate affinity monolithic column for the specific capture and separation of cis-diol containing compounds.

    Science.gov (United States)

    Li, Qianjin; Lü, Chenchen; Li, Hengye; Liu, Yunchun; Wang, Heye; Wang, Xin; Liu, Zhen

    2012-09-21

    A new boronate-silica hybrid monolithic column was prepared using a one-pot approach with 3-acrylamidophenylboronic acid (AAPBA) as the boronate affinity ligand. The AAPBA-silica monolith exhibited several attractive advantages. First, it is highly hydrophilic, providing excellent specificity and avoiding the presence of organic solvent in the mobile phase. Second, due to its large surface area, it exhibited a high binding capacity, 49.5 μmol/mL, the highest among the boronate affinity monolithic columns appeared in the literature. Third, the monolith can bind with cis-diol containing compounds at pH as low as 6.5, which not only avoids the use of basic pH conditions at which the silica monolith may hydrolysis but also facilitates the applications to wider sample range. Finally, the hybrid monolithic column exhibited apparent secondary separation capability, which allows for two-dimensional (2D) separation of cis-diol compounds in a single column. Due to these merits, the AAPBA-silica hybrid monolithic column can be a promising separation medium for the analysis of cis-diol containing compounds. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Isolation of endosulfan sulfate-degrading Rhodococcus koreensis strain S1-1 from endosulfan contaminated soil and identification of a novel metabolite, endosulfan diol monosulfate

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Koji; Kawashima, Fujimasa [Department of Applied Biology and Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502 (Japan); Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); Takagi, Kazuhiro, E-mail: ktakagi@affrc.go.jp [Department of Applied Biology and Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502 (Japan); Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); Kataoka, Ryota [Department of Environmental Science, University of Yamanashi, 41-4-37 Takeda, Kofu, Yamanashi (Japan); Kotake, Masaaki [Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai 981-8555 (Japan); Kiyota, Hiromasa [Graduate School of Environmental & Life Science, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530 (Japan); Yamazaki, Kenichi [Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); Sakakibara, Futa [Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); The Japan Society for the Promotion of Science(JSPS), 1-8 Chiyoda-ku, Tokyo (Japan); Okada, Sanae [Department of Applied Biology and Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502 (Japan)

    2016-05-13

    An aerobic endosulfan sulfate-degrading bacterium, Rhodococcus koreensis strain S1-1, was isolated from soil to which endosulfan had been applied annually for more than 10 years until 2008. The strain isolated in this work reduced the concentration of endosulfan sulfate (2) from 12.25 μM to 2.11 μM during 14 d at 30 °C. Using ultra performance liquid chromatography-electrospray ionization-mass spectroscopy (UPLC-ESI-MS), a new highly water-soluble metabolite possessing six chlorine atoms was found to be endosulfan diol monosulfate (6), derived from 2 by hydrolysis of the cyclic sulfate ester ring. The structure of 6 was elucidated by chemical synthesis of the candidate derivatives and by HR-MS and UPLC-MS analyses. Therefore, it was suggested that the strain S1-1 has a new metabolic pathway of 2. In addition, 6 was expected to be less toxic among the metabolites of 1 because of its higher water-solubility. -- Highlights: •A novel endosulfan sulfate-degrading bacterium was isolated and named strain S1-1. •Strain S1-1 degraded endosulfan sulfate into a novel metabolite endosulfan diol monosulfate. •Endosulfan diol monosulfate showed higher polarity than other known metabolites of endosulfan. •We proposed the plausible metabolic pathway of endosulfan in terms of organic chemistry.

  18. Generation and Stability of the gem-Diol Forms in Imidazole Derivatives Containing Carbonyl Groups. Solid-State NMR and Single-Crystal X-ray Diffraction Studies.

    Science.gov (United States)

    Crespi, Ayelén Florencia; Byrne, Agustín Jesús; Vega, Daniel; Chattah, Ana Karina; Monti, Gustavo Alberto; Lázaro-Martínez, Juan Manuel

    2018-01-18

    The stability of gem-diol forms in imidazolecarboxaldehyde isomers was studied by solid-state nuclear magnetic resonance (ss-NMR) combined with single-crystal X-ray diffraction studies. These methodologies also allowed determining the factors governing the occurrence of such rare functionalization in carbonyl moieties. Results indicated that the position of the carbonyl group is the main factor that governs the generation of geminal diols, having a clear and direct effect on hydration, since, under the same experimental conditions, only 36% of 5-imidazolecarboxaldehydes and 5% of 4-imidazolecarboxaldehydes were hydrated, as compared to 2-imidazolecarboxaldehydes, with which a 100% hydration was achieved. Not only did trifluoroacetic acid favor the addition of water to the carbonyl group but also it allowed obtaining single crystals. Single crystals of the gem-diol and the hemiacetal forms 2-imidazolecarboxaldehyde and N-methyl-2-imidazolecarboxaldehyde, respectively, were isolated and studied through 1 H ss-NMR. Mass spectrometry and solution-state NMR experiments were also performed to study the hydration process.

  19. 2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi Meresht, E. [Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, 1411713114, Tehran (Iran, Islamic Republic of); Shahrabi Farahani, T., E-mail: tshahrabi34@modares.ac.ir [Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, 1411713114, Tehran (Iran, Islamic Republic of); Neshati, J. [Research Institute of Petroleum Industry, RIPI, 1485733111, Tehran (Iran, Islamic Republic of)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Corrosion of API 5L X65 is effectively reduced by the addition of the inhibitor. Black-Right-Pointing-Pointer The techniques include weight loss, potentiodynamic polarization, EIS and AFM. Black-Right-Pointing-Pointer 2-Butyne-1,4-diol acts as a mixed-type inhibitor. Black-Right-Pointing-Pointer The adsorption of 2-butyne-1,4-diol obeys Langmuir adsorption isotherm. - Abstract: The inhibition effects of 2-butyne-1,4-diol on the corrosion susceptibility of grade API 5L X65 steel pipeline in 2 M Na{sub 2}CO{sub 3}/1 M NaHCO{sub 3} solution were studied by electrochemical techniques and weight loss measurements. The results indicated that this inhibitor was a mixed-type inhibitor, with a maximum percentage inhibition efficiency of approximately 92% in the presence of 5 mM inhibitor. Atomic force microscopy revealed that a protective film was formed on the surface of the inhibited sample. The adsorption of the inhibitor was found to conform to the Langmuir isotherm with the standard adsorption free energy of -21.08 kJ mol{sup -1}.

  20. Design, Synthesis and Cytotoxic Activities of Novel Aliphatic Amino-Substituted Flavonoids

    Directory of Open Access Journals (Sweden)

    Guannan Liu

    2013-11-01

    Full Text Available A series of flavonoids 9a–f, 13b, 13d, 13e and 14a–f bearing diverse aliphatic amino moieties were designed, synthesized and evaluated for their cytotoxic activities against the ECA-109, A-549, HL-60, and PC-3 cancer cell lines. Most of the compounds exhibited moderate to good activities. The structure-activity relationships were studied, revealing that the chalcone skeleton is the most preferable for cytotoxic activities. Chalcone 9d was the most promising compound due to its high potency against the examined cancer cell lines (its IC50 values against ECA-109, A549, HL-60 and PC-3 cells were 1.0, 1.5, 0.96 and 3.9 μM, respectively.

  1. Hydrocarbons (aliphatic and aromatic) in the snow-ice cover in the Arctic

    International Nuclear Information System (INIS)

    Nemirovskaya, I.A.; Novigatsky, A.N.; Kluvitkin, A.A.

    2002-01-01

    This paper presented the concentration and composition of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in snow and ice-infested waters in the France-Victoria trough in the northern Barents Sea and in the Mendeleev ridge in the Amerasian basin of the Arctic Ocean. Extreme conditions such as low temperatures, ice sheets and the polar nights render the arctic environment susceptible to oil spills. Hydrocarbons found in these northern seas experience significant transformations. In order to determine the sources, pathways and transformations of the pollutants, it is necessary to know their origin. Hydrocarbon distributions is determined mostly by natural hydrobiological and geochemical conditions. The regularity of migration is determined by natural factors such as formation and circulation of air and ice drift. There is evidence suggesting that the hydrocarbons come from pyrogenic sources. It was noted that hydrocarbons could be degraded even at low temperatures. 17 refs., 1 tab

  2. A nitrilase from a metagenomic library acts regioselectively on aliphatic dinitriles.

    Science.gov (United States)

    Bayer, Sally; Birkemeyer, Claudia; Ballschmiter, Meike

    2011-01-01

    Several novel nitrilases were selected from metagenomic libraries using cinnamonitrile and a mixture of six different nitriles as substrates. The nitrilase gene nit1 was expressed in Escherichia coli and the resulting protein was further examined concerning its biochemical properties. Nit1 turned out to be an aliphatic nitrilase favoring dinitriles over mononitriles. Stereochemical analysis revealed that Nit1 converted the dinitrile 2-methylglutaronitrile regioselectively. Hydrolysis at the ω-nitrile group of a dinitrile, such as catalyzed by Nit1, leads to ω-cyanocarboxylic acids, which are important precursors for chemical and pharmaceutical products. Nit1 metabolized 2-methylglutaronitrile to the corresponding ω-cyanocarboxylic acid 4-cyanopentanoic acid can be used for the production of the fine chemical 1,5-dimethyl-2-piperidone.

  3. Purification of wet process phosphoric acid by solvent extraction with long-chain aliphatic amines

    International Nuclear Information System (INIS)

    Stenstroem, S.

    1986-09-01

    Purification of phosphoric acid by solvent extraction with long-chain aliphatic amines is investigated. Extraction of cadmium is extensively examined regarding the importance of the aqueous phase, the diluent and the amine. The solubility of tri-n-octyl-amine is determined in water and phosphoric acid solutions. Properties of valuable constituent such as uranium and yttrium are screened. Modelling of the system is performed by adapting Bromley's model for electrolytes to the different dissociation/association equilibria in the aqueous phase. In the organic phase simple expressions are used for the non-ideal behaviour. Amine-acid equilibria are investigated for all acids present in industrial phosphoric acid. New extraction constants are calculated for phosphoric and hydro- fluosilic acid. Calculations are compared with experiments both from binary and multicomponent acid mixtures

  4. Synthesis, characterization and antimicrobial studies of new bispyrazolines linked via 3-aryl ring with aliphatic chains

    Science.gov (United States)

    Yusuf, Mohamad; Jain, Payal

    2012-10-01

    The bispyrazolines 4a(a'-f') and 4b(a'-f') built around the aliphatic chains of varying lengths have been prepared by refluxing bischalcones 3a(a'-f') and 3b(a'-f') with phenyl hydrazine in alcoholic medium. The reactions of chalcones 2a and 2b with suitable 1,ω-dibromoalkanes in the presence of anhydrous K2CO3/dry acetone and Bu4N+I- (PTC) provided 3a(a'-f') and 3b(a'-f'), respectively. The antibacterial and antifungal activities of the synthesized compounds were evaluated against five bacterial and four fungal strains. The compounds 3ba', 3bc', 3bd', 3be', 3af', 4aa' and 4ba' showed better MIC (μg/mL) against the tested microorganisms.

  5. Gas-Phase Reactions of Dimethyl Disulfide with Aliphatic Carbanions - A Mass Spectrometry and Computational Study

    Science.gov (United States)

    Franczuk, Barbara; Danikiewicz, Witold

    2018-03-01

    Ion-molecule reactions of Me2S2 with a wide range of aliphatic carbanions differing by structure and proton affinity values have been studied in the gas phase using mass spectrometry techniques and DFT calculations. The analysis of the spectra shows a variety of product ions formed via different reaction mechanisms, depending on the structure and proton affinity of the carbanion. Product ions of thiophilic reaction ( m/z 47), SN2 ( m/z 79), and E2 elimination - addition sequence of reactions ( m/z 93) can be observed. Primary products of thiophilic reaction can undergo subsequent SN2 and proton transfer reactions. Gibbs free energy profiles calculated for experimentally observed reactions using PBE0/6-311+G(2d,p) method show good agreement with experimental results.

  6. Supercritical fluid extraction of triterpenes and aliphatic hydrocarbons from olive tree derivatives

    Directory of Open Access Journals (Sweden)

    Aimen Issaoui

    2017-05-01

    Full Text Available Olive leaves and tree bark were extracted through supercritical fluid extraction (SFE and the chemical composition of the extracted mixture was determined by Gas Chromatography–Mass Spectrometry (GC–MS. Both samples contain a great number of triterpenes as squalene, which were used since 1997 as a main constituent of the flu vaccine (FLUAD, and the alpha-tocopherol the most biologically active form of vitamin E. We also underline the presence of many aliphatic compounds such nonacosane and heptacosane in low concentrations. The extractions were carried out at 313 and 333 K, at a pressure varying from 90 to 250 bars and using pure carbon dioxide in its supercritical phase. Therefore, their solubilities at equilibrium were numerically optimized via two assumptions and compared with the experimental values. Indeed, a good agreement between several results was shown.

  7. Development and Characterization of Novel Interpenetrating Network (IPN Foams from Epoxy Ester and Aliphatic Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Kanuprasad Patel

    2009-01-01

    Full Text Available Diglycidyl ether of bisphenol-A (DGEBA was reacted with acrylate monomer at variable molar ratios. The reaction between glycerine and epichlorohydrine form glycidyl ether of polyol aliphatic epoxy resin. The resultant resins were characterized duly. Both the resins were mixed at different ratios with constant high shear stirring. The obtained mixture and suitable additives were heated at 150oC for one and half hour. The so called Interpenetrating Network (IPN transformed into foams. The performance of foams was evaluated by testing for compression in both parallel and perpendicular to rise direction. The tests were carried out at room temperature and at the elevated temperature. The compression properties showed a decreasing trend for increasing amounts of glycerine resin. The density and thermal properties of epoxy foams were also evaluated. The relation between the composition, density and properties of the foam was analyzed.

  8. Liquid-phase synthesis of bridged peptides using olefin metathesis of a protected peptide with a long aliphatic chain anchor.

    Science.gov (United States)

    Aihara, Keisuke; Komiya, Chiaki; Shigenaga, Akira; Inokuma, Tsubasa; Takahashi, Daisuke; Otaka, Akira

    2015-02-06

    Bridged peptides including stapled peptides are attractive tools for regulating protein-protein interactions (PPIs). An effective synthetic methodology in a heterogeneous system for the preparation of these peptides using olefin metathesis and hydrogenation of protected peptides with a long aliphatic chain anchor is reported.

  9. NMR studies on the mechanism of structural destabilization of the globular proteins and DNA by aliphatic alcohols

    International Nuclear Information System (INIS)

    Lubas, B.; Witman, B.; Wieniewska, T.; Soltysik, M.

    1977-01-01

    The concept that the mechanism of structural destabilization of the biologically active macromolecules by typical denaturing agents should find a reflection in the NMR spectra of the denaturants themselves has been followed by proton NMR for some aliphatic alcohols in the system containing the serum albumin of DNA. (author)

  10. Amperometric detection and electrochemical oxidation of aliphatic amines and ammonia on silver-lead oxide thin-film electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Jisheng [Iowa State Univ., Ames, IA (United States)

    1996-01-08

    This thesis comprises three parts: Electrocatalysis of anodic oxygen-transfer reactions: aliphatic amines at mixed Ag-Pb oxide thin-film electrodes; oxidation of ammonia at anodized Ag-Pb eutectic alloy electrodes; and temperature effects on oxidation of ethylamine, alanine, and aquated ammonia.

  11. Study of the electron beam irradiation effect on some properties of aromatic aliphatic copolyester films

    International Nuclear Information System (INIS)

    Poveda, Patricia Negrini Siqueira

    2008-01-01

    Biodegradable and green plastics are the new tendency in the world. The effect of the electron beam irradiation in aromatic aliphatic copolyester and the blend with corn starch films (Ecoflex R and Ecobras R ) were studied by tensile strength at break, elongation at break, Scanning Electronic Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), crosslinking degree and biodegradability. The measurements in both, the machine direction and the transverse direction were made for mechanical tests. It was found that, the electron irradiation caused an increase in the strength at break of the blend with corn starch film, when doses of up to 10 kGy were applied. A significant decrease of the elongation at break of the blend with corn starch was observed at doses of 10 kGy and 40 kGy. It was not found important change in tensile properties for aromatic aliphatic copolyester. Structural changes of the samples (crosslinking or degradation) by SEM were not observed. The FT-IR identified the characteristic peaks of each involved functional group (copolyester and corn starch). However, it was not found bands of oxidation of the samples. In the DSC, changes in the melting temperature of the irradiated Ecoflex R and Ecobras R samples, was not identified when compared with the samples of reference. However, it was verified a reduction in the melting enthalpy of the Ecobras R samples after irradiation. The Ecobras R material presented crosslinking, when submitted to doses of 10 kGy and 40 kGy. The Ecoflex R material did not present crosslinking when submitted to these doses. The biodegradability of the materials was evaluated by two methods of test: soil simulated and enzymatic. In both methods, the irradiated samples presented faster biodegradation than the references not irradiated. (author)

  12. Biosynthesis of aliphatic polyketides by type III polyketide synthase and methyltransferase in Bacillus subtilis.

    Science.gov (United States)

    Nakano, Chiaki; Ozawa, Hiroki; Akanuma, Genki; Funa, Nobutaka; Horinouchi, Sueharu

    2009-08-01

    Type III polyketide synthases (PKSs) synthesize a variety of aromatic polyketides in plants, fungi, and bacteria. The bacterial genome projects predicted that probable type III PKS genes are distributed in a wide variety of gram-positive and -negative bacteria. The gram-positive model microorganism Bacillus subtilis contained the bcsA-ypbQ operon, which appeared to encode a type III PKS and a methyltransferase, respectively. Here, we report the characterization of bcsA (renamed bpsA, for Bacillus pyrone synthase, on the basis of its function) and ypbQ, which are involved in the biosynthesis of aliphatic polyketides. In vivo analysis demonstrated that BpsA was a type III PKS catalyzing the synthesis of triketide pyrones from long-chain fatty acyl-coenzyme A (CoA) thioesters as starter substrates and malonyl-CoA as an extender substrate, and YpbQ was a methyltransferase acting on the triketide pyrones to yield alkylpyrone methyl ethers. YpbQ thus was named BpsB because of its functional relatedness to BpsA. In vitro analysis with histidine-tagged BpsA revealed that it used broad starter substrates and produced not only triketide pyrones but also tetraketide pyrones and alkylresorcinols. Although the aliphatic polyketides were expected to localize in the membrane and play some role in modulating the rigidity and properties of the membrane, no detectable phenotypic changes were observed for a B. subtilis mutant containing a whole deletion of the bpsA-bpsB operon.

  13. Enzymatic Degradation of Aromatic and Aliphatic Polyesters by P. pastoris Expressed Cutinase 1 from Thermobifida cellulosilytica

    Directory of Open Access Journals (Sweden)

    Caroline Gamerith

    2017-05-01

    Full Text Available To study hydrolysis of aromatic and aliphatic polyesters cutinase 1 from Thermobifida cellulosilytica (Thc_Cut1 was expressed in P. pastoris. No significant differences between the expression of native Thc_Cut1 and of two glycosylation site knock out mutants (Thc_Cut1_koAsn and Thc_Cut1_koST concerning the total extracellular protein concentration and volumetric activity were observed. Hydrolysis of poly(ethylene terephthalate (PET was shown for all three enzymes based on quantification of released products by HPLC and similar concentrations of released terephthalic acid (TPA and mono(2-hydroxyethyl terephthalate (MHET were detected for all enzymes. Both tested aliphatic polyesters poly(butylene succinate (PBS and poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV were hydrolyzed by Thc_Cut1 and Thc_Cut1_koST, although PBS was hydrolyzed to significantly higher extent than PHBV. These findings were also confirmed via quartz crystal microbalance (QCM analysis; for PHBV only a small mass change was observed while the mass of PBS thin films decreased by 93% upon enzymatic hydrolysis with Thc_Cut1. Although both enzymes led to similar concentrations of released products upon hydrolysis of PET and PHBV, Thc_Cut1_koST was found to be significantly more active on PBS than the native Thc_Cut1. Hydrolysis of PBS films by Thc_Cut1 and Thc_Cut1_koST was followed by weight loss and scanning electron microscopy (SEM. Within 96 h of hydrolysis up to 92 and 41% of weight loss were detected with Thc_Cut1_koST and Thc_Cut1, respectively. Furthermore, SEM characterization of PBS films clearly showed that enzyme tretment resulted in morphological changes of the film surface.

  14. Efficiency of 1,9- Nonane-diol-diacrylate as a radiation vulcanization accelerator for natural rubber latex

    International Nuclear Information System (INIS)

    Haque, M.E.

    2003-09-01

    The efficiency of 1,9- Nonane-diol-diacrylate (NDDA) as a radiation vulcanization accelerator (RVA) for natural rubber latex (NRL) was investigated. Both gamma rays and electron beam (EB) were used for vulcanizing NRL with NDDA. The radiation dose of gamma rays, concentration of NDDA required to vulcanize the latex were optimized. 20 kGy radiation dose of gamma rays and 5 phr concentration of NDDA were found optimum to get maximum tensile and related properties. NRL was vulcanized under EB to find out the optimum condition of irradiation with this RVA. The defoamer concentrations, length of irradiation time under EB, concentration of RVA were optimizer by changing various parameters of the EB machine with a constant set of the others. 0.2 phr defoamer concentration, 30 minutes irradiation time and 5 phr concentration of NDDA were found optimum for irradiation of NRL under the EB machine. Effect of low current and optimum volume of latex charged in the reaction vessel suitable for vulcanization at a time were found out. (author)

  15. [Research on the modification of Kevlar fiber by polypropylene glycol and cis-2-butene-1,4-diol].

    Science.gov (United States)

    Zheng, Yu-ying; Wang, Can-yao; Fu, Ming-lian; Cai, Wei-long; Wang, Liang-en

    2005-03-01

    The mechanism of the modification of Kevlar fiber by polypropylene glycol(PPG) and cis-2-butene-1, 4-diol was studied in the paper, the authors learned the esterification of toluene-2, 4-diisocyanate (TDI) onto Kevlar fiber by infrared spectrum. In the mean time, the infrared spectrograms of the productions which steadily disposed by PPG and butendiol were analysed respectively, the result showed that the intensity of the bands was reinforced at about 1700-1720 cm(-1) after the samples were steadily disposed, that is to say, the group of --NCO has been stabilized into --NHCO group, the effect of steady disposal was obvious; but the disposal effect of butendiol was apparently better than PPG's at the same condition. Finally, the authors compared the influence of different mol rates between TDI and butendiol on the productions. Based onthe consequence, excessive butendiol would prevent the Kevlar fiber from farther reaction, therefore, the mol rate between TDI and butendiol should approach 1:1.

  16. Structural and vibrational study of a neurotransmitter molecule: Dopamine [4-(2-aminoethyl) benzene-1,2-diol

    Science.gov (United States)

    Jha, Omkant; Yadav, T. K.; Yadav, R. A.

    2018-01-01

    Structural and vibrational studies for the most stable conformer of dopamine {4-(2-Aminoethyl) benzene-1, 2-diol} have been carried out at the DFT/B3LYP/6-311 ++G** level using the Gaussian 09 software. The IR and Raman spectra have been recorded and analyzed in light of the computed vibrational parameters using the DFT and the PEDs computed with the help of the GAR2PED software. Some of the fundamentals have considerably changed frequencies in going from benzene to dopamine. Except the rocking and wagging modes of the NH2 group the other four modes are pure group modes. The rocking and wagging modes of the NH2 group show mixing with the other modes. The two Osbnd H stretching vibrations are highly localized modes. The Kekule phenyl ring stretching mode is found to remain almost unchanged. The HOMO-LUMO study suggests the existence of charge transfer within the molecule and the energy gap supports the pharmacological active property of the dopamine molecule. The NBO analysis has been carried out to understand the proper and improper hydrogen bonding.

  17. Indole-3-acetic acid/diol based pH-sensitive biological macromolecule for antibacterial, antifungal and antioxidant applications.

    Science.gov (United States)

    G, Chitra; D S, Franklin; S, Sudarsan; M, Sakthivel; S, Guhanathan

    2017-02-01

    Indole-3-acetic acid (IAA)/diol based pH-sensitive biopolymeric hydrogels with tunable biological properties (cytotoxicity, anti-oxidant and anti-fungal) have been synthesized via condensation polymerization. The present study focused on the synthesis of heterocyclic hydrogel using citric acid (CA), indole-3-acetic acid (IAA) and diethylene glycol (DEG) by condensation polymerization. The hydrogels revealed a pH-sensitive swelling behaviour, with increased swelling in acidic media, then turns to decreased the swelling in the basic media. The hydrogel samples were tested for antifungal activity against Aspergillus fumigates, Rhizopusoryzae and Candida albicans at different concentrations using ketoconazole as positive control and DMSO as negative control for antifungal activity. Antioxidant activity increasing nature in DPPH than NO radical compared with rutin and confirmed non toxic property using cytotoxicity analysis. The biopolymeric hydrogels were characterized by Fourier transform infrared (FT-IR) spectroscopy, 1 H NMR, 13 C NMR, TGA, DSC followed by scanning electron microscopy (SEM). Such hydrogels with antioxidant properties is recommended for medical applications such as bandages, catheters, drains and tubes to prevent infection. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Waste-free and facile solid-state protection of diamines, anthranilic acid, diols, and polyols with phenylboronic acid.

    Science.gov (United States)

    Kaupp, Gerd; Naimi-Jamal, M Reza; Stepanenko, Vladimir

    2003-09-05

    Phenylboronic acid (2) reacts quantitatively by ball-milling in the solid state with o-phenylendiamine, 1,8-diaminonaphthalene, anthranilic acid, pyrocatechol, pyrogallol, pinacol, bicyclic cis-diols, mannitol, and inositol to form the five- or six-membered cyclic phenylboronic amides or esters. Catalysts or other auxiliaries are strictly excluded as they are not required and would have to be removed after the reactions. These varied model reactions provide pure protected products without the necessity of further purifying workup and the potential for protection chemistry is demonstrated. Some of the reactions can also be quantitatively performed if stoichiometric mixtures of the reactants are co-ground or co-milled and heated to appropriate temperatures either below the eutectics or above the melting points. The temperatures are much higher in the latter case. Similar reactions in solution suffer from less than 100 % yield of the mostly sensitive compounds that are difficult to purify and thus create much waste. The hydrolysis (deprotection) conditions of the products are rather mild in most cases. Therefore, this particularly easy access to heteroboroles, heteroborolanes, heteroborinones, heteroborines, and heteroborinines is highly valuable for their more frequent use in protective syntheses.

  19. Preparation and surface active properties of oxypropylated α-hydroxyacids, α-hydroxyesters and α-, β-alkane diols

    Directory of Open Access Journals (Sweden)

    Shaker, N. O.

    1994-10-01

    Full Text Available A series of a-hydroxyacids RCH(OHCO2H, α-hydroxyesters RCH(OHCO2CH3 and α, β-alkane diols was synthetized and condensed with 5-20 moles propylene oxide to obtain nonionic surfactants. Some of the physicochemical properties and the biodegradability of these products were examined. The results showed that the best wetting properties were obtained by the addition of 15 oxypropylene groups to methyl α-hydroxymyristate. The α-hydroxymyristic acid with 20 moles of propylene oxide gave the highest foam. Biodegradation studies indicated that increasing both the chain length of the hydrophobic alkyl chain or the number of oxypropylene groups in the adduct decreased biodegradation.

    Una serie de α-hidroxiácidos RCH(OHCO2H, α-hidroxiésteres RCH(OHCO2CH3 y α, β-alcanodioles se sintetizaron y condensaron con 5-20 moles de óxido de propileno para obtener tensioactivos no iónicos. Se examinaron algunas propiedades fisicoquímicas y de biodegradabilidad de estos productos. Los resultados mostraron que las mejores propiedades humectantes se obtuvieron por adición de 15 grupos oxipropilenos a α-hidroximiristato de metilo.
    El ácido α-hidroximirístico con 20 moles de óxido de propileno dio la espuma más poderosa. Estudios de biodegradación indicaron que tanto el aumento de la longitud de cadena de los grupos alquilo hidrofóbicos como el número de grupos oxipropilenos en el aducto disminuyeron la biodegradación.

  20. Enhancing productivity for cascade biotransformation of styrene to (S)-vicinal diol with biphasic system in hollow fiber membrane bioreactor.

    Science.gov (United States)

    Gao, Pengfei; Wu, Shuke; Praveen, Prashant; Loh, Kai-Chee; Li, Zhi

    2017-03-01

    Biotransformation is a green and useful tool for sustainable and selective chemical synthesis. However, it often suffers from the toxicity and inhibition from organic substrates or products. Here, we established a hollow fiber membrane bioreactor (HFMB)-based aqueous/organic biphasic system, for the first time, to enhance the productivity of a cascade biotransformation with strong substrate toxicity and inhibition. The enantioselective trans-dihydroxylation of styrene to (S)-1-phenyl-1,2-ethanediol, catalyzed by Escherichia coli (SSP1) coexpressing styrene monooxygenase and an epoxide hydrolase, was performed in HFMB with organic solvent in the shell side and aqueous cell suspension in the lumen side. Various organic solvents were investigated, and n-hexadecane was found as the best for the HFMB-based biphasic system. Comparing to other reported biphasic systems assisted by HFMB, our system not only shield much of the substrate toxicity but also deflate the product recovery burden in downstream processing as the majority of styrene stayed in organic phase while the diol product mostly remained in the aqueous phase. The established HFMB-based biphasic system enhanced the production titer to 143 mM, being 16-fold higher than the aqueous system and 1.6-fold higher than the traditional dispersive partitioning biphase system. Furthermore, the combination of biphasic system with HFMB prevents the foaming and emulsification, thus reducing the burden in downstream purification. HFMB-based biphasic system could serve as a suitable platform for enhancing the productivity of single-step or cascade biotransformation with toxic substrates to produce useful and valuable chemicals.

  1. Seasonal variation of aliphatic amines in marine sub-micrometer particles at the Cape Verde islands

    Directory of Open Access Journals (Sweden)

    H. Herrmann

    2009-12-01

    Full Text Available Monomethylamine (MA, dimethylamine (DMA and diethylamine (DEA were detected at non-negligible concentrations in sub-micrometer particles at the Cap Verde Atmospheric Observatory (CVAO located on the island of São Vicente in Cape Verde during algal blooms in 2007. The concentrations of these amines in five stage impactor samples ranged from 0–30 pg m−3 for MA, 130–360 pg m−3 for DMA and 5–110 pg m−3 for DEA during the spring bloom in May 2007 and 2–520 pg m−3 for MA, 100–1400 pg m−3 for DMA and 90–760 pg m−3 for DEA during an unexpected winter algal bloom in December 2007. Anomalously high Saharan dust deposition and intensive ocean layer deepening were found at the Atmospheric Observatory and the associated Ocean Observatory during algal bloom periods. The highest amine concentrations in fine particles (impactor stage 2, 0.14–0.42 μm indicate that amines are likely taken up from the gas phase into the acidic sub-micrometer particles. The contribution of amines to the organic carbon (OC content ranged from 0.2–2.5% C in the winter months, indicating the importance of this class of compounds to the carbon cycle in the marine environment. Furthermore, aliphatic amines originating from marine biological sources likely contribute significantly to the nitrogen content in the marine atmosphere. The average contribution of the amines to the detected nitrogen species in sub-micrometer particles can be non-negligible, especially in the winter months (0.1% N–1.5% N in the sum of nitrate, ammonium and amines. This indicates that these smaller aliphatic amines can be important for the carbon and the nitrogen cycles in the remote marine environment.

  2. Development of technology for the alkylation of hydroquinone with aliphatic alcohols

    Directory of Open Access Journals (Sweden)

    V. M. Bolotov

    2017-01-01

    Full Text Available The paper presents the results of research of technology of alkylation of hydroquinone, propyl, isopropyl, isobutyl and tert-butyl alcohols in the presence of concentrated phosphoric acid. The temperature of the alkylation reaction was maintained between 70–72 °С. On the basis of literature data and preliminary investigations the reaction was performed for 4 hours. Upon completion of the reaction, we removed the unreacted hydroquinone, aliphatic alcohol and phosphoric acid are added to a solution of distilled water (solvent corresponding connections and sodium bicarbonate to slightly acidic (pH 5–6. For separation from the reaction medium of alkylhydroquinones in the reaction mixture was added benzene in which the original hydroquinone dissolves much less. Concentration of the benzene extract alkylhydroquinones conducted by Stripping the solvent under vacuum at temperatures above 70 °С in air atmosphere. Higher temperature vacuum distillation AIDS in the oxidation of alkylhydroquinones to alkylphenones. Precipitated after crystallization, alkylhydroquinones were dried under vacuum in a drying pistol at 56 °С. Dried products were identified by defining the melting temperature, the study of spectral characteristics and qualitative reactions with FeCl3. We also studied the solubility of alkylhydroquinones in various solvents, which showed low solubility of alkylhydroquinones in water, benzene, toluene and higher solubility in propyl and isopropyl alcohols and in acetone. Analysis of the results shows that the obtained alkylhydroquinones are not chemically pure compounds, and contain in their composition of admixture source of hydroquinone. Qualitative reactions of solutions of alkylhydroquinones with FeCl3 solution differ from the corresponding reaction of a solution of hydroquinone. The results of investigations of electronic absorption spectra of alkylhydroquinones and source of hydroquinone in isopropyl alcohol solution did not

  3. Syntheses of Enantiopure Aliphatic Secondary Alcohols and Acetates by Bioresolution with Lipase B from Candida antarctica

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    Richele P. Severino

    2012-07-01

    Full Text Available The lipase B from Candida antarctica (Novozym 435®, CALB efficiently catalyzed the kinetic resolution of some aliphatic secondary alcohols: (±-4-methylpentan-2-ol (1, (±-5-methylhexan-2-ol (3, (±-octan-2-ol (4, (±-heptan-3-ol (5 and (±-oct-1-en-3-ol (6. The lipase showed excellent enantioselectivities in the transesterifications of racemic aliphatic secondary alcohols producing the enantiopure alcohols (>99% ee and acetates (>99% ee with good yields. Kinetic resolution of rac-alcohols was successfully achieved with CALB lipase using simple conditions, vinyl acetate as acylating agent, and hexane as non-polar solvent.

  4. Hofmeister effect on the interfacial free energy of aliphatic and aromatic surfaces studied by chemical force microscopy.

    Science.gov (United States)

    Patete, Jonathan; Petrofsky, John M; Stepan, Jeffery; Waheed, Abdul; Serafin, Joseph M

    2009-01-15

    This work describes chemical force microscopy (CFM) studies of specific-ion effects on the aqueous interfacial free energy of hydrophobic monolayers. CFM measurements allow for the characterization of interfacial properties on length scales below 100 nm. The ions chosen span the range of the Hofmeister series, from the kosmotropic Na(2)SO(4) to the chaotropic NaSCN. The salt concentrations used are typical of many laboratory processes such as protein crystallization, 2-3 M. Both aliphatic (terminal methyl) and aromatic (terminal phenyl) monolayers were examined, and rather pronounced differences were observed between the two cases. The specific-ion dependence of the aliphatic monolayer closely follows the Hofmeister series, namely the chaotropic ions lowered the interfacial free energy and the kosmotropic ions increased the interfacial free energy. However, the aromatic monolayer had significant deviations from the Hofmeister series. Possible origins for this difference are discussed.

  5. Topsoil drying combined with increased sulfur supply leads to enhanced aliphatic glucosinolates in Brassica juncea leaves and roots.

    Science.gov (United States)

    Tong, Yu; Gabriel-Neumann, Elke; Ngwene, Benard; Krumbein, Angelika; George, Eckhard; Platz, Stefanie; Rohn, Sascha; Schreiner, Monika

    2014-01-01

    The decrease of water availability is leading to an urgent demand to reduce the plants' water supply. This study evaluates the effect of topsoil drying, combined with varying sulfur (S) supply on glucosinolates in Brassica juncea in order to reveal whether a partial root drying may already lead to a drought-induced glucosinolate increase promoted by an enhanced S supply. Without decreasing biomass, topsoil drying initiated an increase in aliphatic glucosinolates in leaves and in topsoil dried roots supported by increased S supply. Simultaneously, abscisic acid was determined, particularly in dehydrated roots, associated with an increased abscisic acid concentration in leaves under topsoil drying. This indicates that the dehydrated roots were the direct interface for the plants' stress response and that the drought-induced accumulation of aliphatic glucosinolates is related to abscisic acid formation. Indole and aromatic glucosinolates decreased, suggesting that these glucosinolates are less involved in the plants' response to drought. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. One-Step Preparation of Phenyl Boron-Modified Magnetic Mesoporous Silica for Selective Enrichment of cis-Diol-Containing Substances

    Directory of Open Access Journals (Sweden)

    Hua Fu

    2018-03-01

    Full Text Available For enrichment and separation of cis-diol-containing compounds from biomatrix, a new type of magnetic nanoparticles named MS-48-PBSC, whichwas facilely prepared in a one-step heterogeneous reaction. The morphology results demonstrated that the MS-48-PBSC was a spherical nanomaterial containing a core of silica-coated magnetic particle with a diameter of about 200 nm, and a cover layer of mesoporous silica with a thickness of approximate 50 nm. The characterization results showed that MS-48-PBSC presented a pore size of 4.2 nm, a surface area of 548 m2·g−1, and a pore volume of 0.30 cm3·g−1. The MS-48-PBSC also exhibited magnetism of 42 emu·g−1 that contributed to the easy separation of magnetic nanomaterial within 30 s from the matrix with the aid of the external magnetic field. In addition, the MS-48-PBSC exhibited high adsorption capacity for adenosine, xanthosine, uridine, sialic acid, and teicoplanin with 0.60, 0.51, 0.42, 0.75, and 1.26 mg/g, respectively, and showed a high selectivity for the cis-diol structure compounds, relative to interferences of bovine serum albumin, guanine, uric acid, and xanthine. The recoveries of adenosine, xanthosine, uridine, sialic acid, and teicoplanin were 71.8–114.1% with relative standard deviation (RSD ≤ 8.6%, and the enrichment factors of them were 8–11. MS-48-PBSC exhibited quick separation capability from matrix, high adsorption capacity and size exclusion for bovine serum albumin, which could meet the requirements of separation and enrichment for substances with a cis-diol structure.

  7. Photodetachment, electron cooling, and recombination, in a series of neat aliphatic room temperature ionic liquids.

    Science.gov (United States)

    Molins i Domenech, Francesc; Healy, Andrew T; Blank, David A

    2015-08-14

    Transient absorption following photodetachment of a series of neat methyl-alkyl-pyrrolidinium bis(trifluoromethylsulfonyl)amides at 6.20 eV was measured with sub-picosecond time resolution in the visible and near-IR portions of the spectrum. This series spans the onset of structuring in the liquids in the form of polarity alternation. Excitation promotes the electron into a delocalized state with a very large reactive radius. Strong transient absorption is observed in the visible spectrum with a ∼700 fs lifetime, and much weaker, long-lived absorption is observed in the near-IR spectrum. Absorption in the visible is shown to be consistent with the hole, and absorption in the near-IR is assigned to the free solvated electron. Yield of free electrons is estimated at ∼4%, is insensitive to the size of the cation, and is determined in less than 1 ps. Solvation of free electrons depends strongly on the size of the cation and correlates well with the viscosity of the liquid. In addition to radiolytic stability of the aliphatic cations, ultrafast, efficient recombination of separated charge in NTf2 (-) based ionic liquids following photo-excitation near the band-gap may prevent subsequent reactive damage associated with anions.

  8. Biomass-based production of low-molecular-mass aliphatic carboxylic acids - BioHap

    Energy Technology Data Exchange (ETDEWEB)

    Alen, R.; Paloheimo, T.; Markkanen, E.; Louhelainen, J. (Jyvaeskylae Univ. (Finland). Dept. of Chemistry), Email: raimo.j.alen@jyu.fi; Viikari, L.; Martikainen, J. (Helsinki Univ. (Finland). Dept. of Applied Chemsitry and Microbiology), Email: liisa.viikari@helsinki.fi

    2010-10-15

    The suitability of the Propionibacterium acidipropionici (ATCC 4875) strain was studied for producing aliphatic carboxylic acids (mainly propionic acid) from wood-derived monosaccharides as carbon sources by fermentation. The optimal treatment conditions based on the separate experiments with model substrates (glucose and xylose) were applied to a mixture of carbohydrates (about 75% of the dry solids) in various hydrolysates from the hot-water treatment (at 150 deg C for 120 min) of pine and birch chips (the total dissolved material 10-15% of the feedstock dry solids) prior to kraft pulping. In the latter case, the oligo- and polysaccharides were first hydrolysed by enzymes to fermentable monosaccharides (hexoses and pentoses). The results indicated that a yield of about 50% of the consumed sugars (theoretical yield 54%) could be obtained and the fermentation was not significantly disturbed, for example, by the presence of possible inhibitors (i.e., lignin-derived aromatics, extractives and furans) present in small amounts in all hydrolysates. This preliminary study offers useful data for the forthcoming studies aiming at a fullscale application. (orig.)

  9. Aliphatic alcohol contaminants of illegally produced spirits inhibit phagocytosis by human granulocytes.

    Science.gov (United States)

    Pál, László; Árnyas, Ervin M; Tóth, Béla; Ádám, Balázs; Rácz, Gábor; Ádány, Róza; McKee, Martin; Szűcs, Sándor

    2013-04-01

    Unregulated production of spirits in many countries leads to products containing appreciable levels of aliphatic alcohols (AAs) and is the main source of human exposure to these substances worldwide. Previous studies have confirmed that alcohol abuse can lead to ethanol-induced immunosuppression and thereby increased susceptibility to infectious diseases. Granulocytes, as professional phagocytic cells, play a crucial role in engulfment and killing of pathogenic microorganisms. Thus, a decrease in their phagocytic activity has been invoked as a factor in the impaired antimicrobial defense observed in alcoholics. However, AAs consumed as contaminants of illicit spirits may also influence phagocytosis, thereby contributing to a further decrease in microbicidal activity but, so far, this has not been studied. Therefore, the aim of this study was to measure granulocyte phagocytosis following treatment of granulocytes with those higher alcohols found in illegal spirits. Granulocytes were isolated from human peripheral blood. Then phagocytosis of opsonized zymosan particles by granulocytes treated with AAs individually and in combination was determined. These alcohols inhibited phagocytosis in a concentration-dependent manner and at lower concentrations when combined than when tested individually. Due to their synergistic effects, it is possible that, in combination with ethanol, they may inhibit phagocytosis in a clinically meaningful way in episodic heavy drinkers.

  10. Synthesis of Carbon Nanotubes of Few Walls Using Aliphatic Alcohols as a Carbon Source

    Directory of Open Access Journals (Sweden)

    Francisco Espinosa-Magaña

    2013-06-01

    Full Text Available Carbon nanotubes with single and few walls are highly appreciated for their technological applications, regardless of the limited availability due to their high production cost. In this paper we present an alternative process that can lead to lowering the manufacturing cost of CNTs of only few walls by means of the use of the spray pyrolysis technique. For this purpose, ferrocene is utilized as a catalyst and aliphatic alcohols (methanol, ethanol, propanol or butanol as the carbon source. The characterization of CNTs was performed by scanning electron microscopy (SEM and transmission electron microscopy (TEM. The study of the synthesized carbon nanotubes (CNTs show important differences in the number of layers that constitute the nanotubes, the diameter length, the quantity and the quality as a function of the number of carbons employed in the alcohol. The main interest of this study is to give the basis of an efficient synthesis process to produce CNTs of few walls for applications where small diameter is required.

  11. Contact allergy to aliphatic polyisocyanates based on hexamethylene-1,6-diisocyanate (HDI).

    Science.gov (United States)

    Aalto-Korte, Kristiina; Pesonen, Maria; Kuuliala, Outi; Alanko, Kristiina; Jolanki, Riitta

    2010-12-01

    Aliphatic polyisocyanates based on hexamethylene 1,6-diisocyanate (HDI) are components of lacquers, coatings, and spray paints. They are mainly composed of HDI trimers, but also contain larger oligomers, and minute amounts of HDI monomers (paints. The patients were examined at the Finnish Institute of Occupational Health in 2000-2009. The first two patients were diagnosed by testing with their own polyurethane hardeners and ingredients of the hardeners. In 2002, HDI isocyanurate (HDI-IC) trimer was added to our isocyanate series, and the last two patients were screened with the series. Patient no. 1 was exposed and sensitized to HDI biuret trimer, patient no. 2 to HDI-IC trimer, and patient no. 4 to HDI asymmetrical trimer. Patient no. 3 was positive with HDI-IC trimer. He had been handling several paint hardeners containing HDI-based polyisocyanates, but the subtypes of the trimers remained unidentified. All 4 patients were negative with HDI monomer. HDI trimers are novel contact allergens in workers who handle polyurethane paints. The allergic reactions cannot be explained by sensitization to HDI monomer. © 2010 John Wiley & Sons A/S.

  12. Comparison of decomposition characteristics between aromatic and aliphatic VOCs using electron beam

    International Nuclear Information System (INIS)

    Kim, Jo-Chun

    2011-01-01

    The removal efficiency of n-decane (C 10 H 22 ) by electron beam was the highest among aliphatic VOCs of concern, and that of n-hexane (C 6 H 14 ), n-butane (C 4 H 10 ), and methane (CH 4 ) followed. On the other hand, in terms of aromatic VOC decomposition efficiencies, benzene (C 6 H 6 ) decomposition was the lowest and that of toluene (C 7 H 8 ), ethylbenzene (C 8 H 10 ), and p-xylene (C 8 H 10 ) were similar. It was also found that there was increase in by-product (untreated VOC, CO, CO 2 , O 3 , and other compounds) formation as well as all VOC removal efficiencies. It was demonstrated that the removal efficiency of VOC increased as its concentration decreased and the irradiation dose increased. In addition, low removal efficiency was observed because helium was relatively stable compared to the other gases, and nothing but electrons produced by electron accelerator reacted with VOC. It was also found that relative humidity had some effects on the decomposition rates of VOC. The removal efficiency at the 100% RH condition was slightly higher than that at 7.4% RH (dry condition) due to OH radical formation. (author)

  13. Clustering of comb and propolis waxes based on the distribution of aliphatic constituents

    Directory of Open Access Journals (Sweden)

    Custodio Angela R.

    2003-01-01

    Full Text Available Chemical composition data for 41 samples of propolis waxes and 9 samples of comb waxes of Apis mellifera collected mainly in Brazil were treated using Principal Component Analysis (PCA and Hierarchical Cluster Analysis (HCA. For chemometrical analysis, the distribution of hydrocarbons and residues of alcohols and carboxylic acids of monoesters were considered. The clustering obtained revealed chemical affinities and differences not previously grasped by simple eye-inspection of the data. No consistent differences were detected between comb and propolis waxes. These and previous results suggest that hydrocarbons, carboxylic acids, aliphatic alcohols and esters from both comb and propolis waxes are bee-produced compounds and, hence, the differences detected between one and another region are dependent on genetic factors related to the insects rather than the local flora. The samples analyzed were split into two main clusters, one of them comprising exclusively material collected in the State of São Paulo. The results are discussed with respect to the africanization of honeybees that first took place in that State and therefrom irradiated to other parts of Brazil.

  14. New regioselective multicomponent reaction: one pot synthesis of spiro heterobicyclic aliphatic rings.

    Science.gov (United States)

    Byk, G; Gottlieb, H E; Herscovici, J; Mirkin, F

    2000-01-01

    In the context of our high-throughput organic synthesis program, we have studied the reactivity of special beta-keto esters toward the Biginelli reaction. We have found that a cyclic beta-keto ester reacts with one molecule of urea and two molecules of aldehyde to give a new family of spiro heterobicyclic aliphatic rings in good yields. Interestingly, the Biginelli product was not detected. After analysis of products using HPLC, 1H NMR, and 13C NMR, we have found that the reaction is driven by a regio-specific condensation of two molecules of aldehyde with the other reagents to afford only products harboring substituents exclusively in cis configuration. Monte Carlo minimization studies using MM2 force field suggest that cis products are energetically more stable than the trans counterparts. Together with previously reported data, these results suggest that the trans products were not obtained as result of steric hindrance produced by the equatorial position of one of the ring substituents. This new reaction is useful for high-throughput organic synthesis. Indeed, the new scaffold can be used to introduce additional groups in the molecules through remaining functional groups by a "domino strategy".

  15. Biological evaluation of porous aliphatic polyurethane/hydroxyapatite composite scaffolds for bone tissue engineering.

    Science.gov (United States)

    Yang, Wanxun; Both, Sanne K; Zuo, Yi; Birgani, Zeinab Tahmasebi; Habibovic, Pamela; Li, Yubao; Jansen, John A; Yang, Fang

    2015-07-01

    Biomaterial scaffolds meant to function as supporting structures to osteogenic cells play a pivotal role in bone tissue engineering. Recently, we synthesized an aliphatic polyurethane (PU) scaffold via a foaming method using non-toxic components. Through this procedure a uniform interconnected porous structure was created. Furthermore, hydroxyapatite (HA) particles were introduced into this process to increase the bioactivity of the PU matrix. To evaluate the biological performances of these PU-based scaffolds, their influence on in vitro cellular behavior and in vivo bone forming capacity of the engineered cell-scaffold constructs was investigated in this study. A simulated body fluid test demonstrated that the incorporation of 40 wt % HA particles significantly promoted the biomineralization ability of the PU scaffolds. Enhanced in vitro proliferation and osteogenic differentiation of the seeded mesenchymal stem cells were also observed on the PU/HA composite. Next, the cell-scaffold constructs were implanted subcutaneously in a nude mice model. After 8 weeks, a considerable amount of vascularized bone tissue with initial marrow stroma development was generated in both PU and PU/HA40 scaffold. In conclusion, the PU/HA composite is a potential scaffold for bone regeneration applications. © 2014 Wiley Periodicals, Inc.

  16. Separation of Aliphatic and Aromatic Carboxylic Acids by Conventional and Ultra High Performance Ion Exclusion Chromatography.

    Science.gov (United States)

    Mansour, Fotouh R; Kirkpatrick, Christine L; Danielson, Neil D

    2013-06-01

    An ion exclusion chromatography (IELC) comparison between a conventional ion exchange column and an ultra-high performance liquid chromatography (UHPLC) dynamically surfactant modified C18 column for the separation of an aliphatic carboxylic acid and two aromatic carboxylic acids is presented. Professional software is used to optimize the conventional IELC separation conditions for acetylsalicylic acid and the hydrolysis products: salicylic acid and acetic acid. Four different variables are simultaneously optimized including H 2 SO 4 concentration, pH, flow rate, and sample injection volume. Thirty different runs are suggested by the software. The resolutions and the time of each run are calculated and feed back to the software to predict the optimum conditions. Derringer's desirability functions are used to evaluate the test conditions and those with the highest desirability value are utilized to separate acetylsalicylic acid, salicylic acid, and acetic acid. These conditions include using a 0.35 m M H 2 SO 4 (pH 3.93) eluent at a flow rate of 1 mL min -1 and an injection volume of 72 μL. To decrease the run time and improve the performance, a UHPLC C18 column is used after dynamic modification with sodium dodecyl sulfate. Using pure water as a mobile phase, a shorter analysis time and better resolution are achieved. In addition, the elution order is different from the IELC method which indicates the contribution of the reversed-phase mode to the separation mechanism.

  17. Odor Detection by Humans of Lineal Aliphatic Aldehydes and Helional as Gauged by Dose–Response Functions

    OpenAIRE

    Cometto-Muñiz, J. Enrique; Abraham, Michael H.

    2010-01-01

    We have measured concentration detection (i.e., psychometric) functions to determine the odor detectability of homologous aliphatic aldehydes (propanal, butanal, hexanal, octanal, and nonanal) and helional. Subjects (16 ≤ n ≤ 18) used a 3-alternative forced-choice procedure against carbon-filtered air (blanks), under an ascending concentration approach. Generation, delivery, and control of each vapor were achieved via an 8-station vapor delivery device. Gas chromatography served to quantify t...

  18. Continuous-flow synthesis of primary amines: Metal-free reduction of aliphatic and aromatic nitro derivatives with trichlorosilane

    Directory of Open Access Journals (Sweden)

    Riccardo Porta

    2016-12-01

    Full Text Available The metal-free reduction of nitro compounds to amines mediated by trichlorosilane was successfully performed for the first time under continuous-flow conditions. Aromatic as well as aliphatic nitro derivatives were converted to the corresponding primary amines in high yields and very short reaction times with no need for purification. The methodology was also extended to the synthesis of two synthetically relevant intermediates (precursors of baclofen and boscalid.

  19. Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments from the Eastern Aegean: assessment and source recognition of petroleum hydrocarbons.

    Science.gov (United States)

    Gonul, L Tolga; Kucuksezgin, Filiz

    2012-01-01

    Aliphatic and polycyclic aromatic hydrocarbons (PAHs) were determined in surficial sediments from the Aegean Sea in the Eastern Mediterranean in 2008. Total aliphatic hydrocarbons (n-C12 to n-C35) ranged from 330 to 2,660 ng g(-1) dry weight (dwt), while aromatics (19 PAHs) varied between 73.5 and 2,170 ng g(-1) dwt. Total concentrations of both aliphatic hydrocarbons and PAHs ranged from a relatively low to a moderate PAHs pollution compared to other urbanized coastal areas worldwide. PAH consisted mainly of pyrolytic four- to five-ring compounds. Both pyrolytic and petrogenic PAHs are present in most samples, although petroleum-derived PAH are dominant at Izmir Inner Bay (IIB) and Dardanelles Strait, and pyrolytic sources are prevalent in other sampling sites. A high contribution of perylene, a diagenetic originated PAH, to the total penta PAHs was found greater than 70% in Meric River Estuary, Dikili Bay, Candarli Bay, and Gokova Bay sites. The spatial distributions of aliphatic hydrocarbons and PAHs indicated that urban runoff and transport from the continental shelf is the major input pathway of anthropogenic and biogenic hydrocarbons from terrestrial sources in the near-shore area. PAH levels at all sites were below the effects range-low (ERL) and effects range-median (ERM) values except fluorene. The average and maximum fluorene concentrations exceeded ERL, but below ERM, in the IIB. Meanwhile, the concentration levels of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, benzo[a]anthracene, and chrysene were higher than threshold effect level values at the same site, but all these compounds were significantly lower than the probable effect level values. The results indicated that the sediments should have potential biological impact.

  20. Liquid chromatographic separation and indirect detection of non-absorbing aliphatic compounds using m-nitrophenol as a detection agent

    International Nuclear Information System (INIS)

    Lee, Seung Seok; Kang, Sam Woo; Moon, Young Ja

    1991-01-01

    m-Nitrophenol(m-NP) was a detection agent for the use of the detection and separation of non-absorbing compounds such as aliphatic acids, alcohols, amines and tetraalkylammonium salts by indirect photometric detection in reversed-phase liquid chromatography. Response of samples was investigated to the several factors such as pH, temperature, and concentration of MeOH as well as concentration of detection reagent in mobile phase. The separation of several mixtures were attempted under optimum condition. (Author)

  1. In-situ micro-FTIR Study of Thermal Changes of Organics in Tagish Lake Meteorite: Behavior of Aliphatic Oxygenated Functions and Effects of Minerals

    Science.gov (United States)

    Kebukawa, Yoko; Nakashima, Satoru; Nakamura-Messenger, Keiko; Zolensky, Michael E.

    2007-01-01

    Systematic in-situ FTIR heating experiments of Tagish Lake meteorite grains have been performed in order to study thermal stability of chondritic organics. Some aliphatic model organic substances have also been used to elucidate effects of hydrous phyllosilicate minerals on the thermal stability of organics. The experimental results indicated that organic matter in the Tagish Lake meteorite might contain oxygenated aliphatic hydrocarbons which are thermally stable carbonyls such as ester and/or C=O in ring compounds. The presence of hydrous phyllosilicate minerals has a pronounced effect on the increase of the thermal stability of aliphatic and oxygenated functions. These oxygenated aliphatic organics in Tagish Lake can be formed during the aqueous alteration in the parent body and the formation temperature condition might be less than 200 C, based especially on the thermal stability of C-O components. The hydrous phyllosilicates might provide sites for organic globule formation and protected some organic decomposition

  2. Steviamine, a new class of indolizidine alkaloid [(1R,2S,3R,5R,8aR-3-hydroxymethyl-5-methyloctahydroindolizine-1,2-diol hydrobromide

    Directory of Open Access Journals (Sweden)

    Amber L. Thompson

    2009-11-01

    Full Text Available X-ray crystallographic analysis of the title hydrobromide salt, C10H20N+·Br−, of (1R,2S,3R,5R,8aR-3-hydroxymethyl-5-methyloctahydroindolizine-1,2-diol defines the absolute and relative stereochemistry at the five chiral centres in steviamine, a new class of polyhydroxylated indolizidine alkaloid isolated from Stevia rebaudiana (Asteraceae leaves. In the crystal structure, molecules are linked by intermolecular O—H...Br and N—H...Br hydrogen bonds, forming double chains around the twofold screw axes along the b-axis direction. Intramolecular O—H...O interactions occur.

  3. Aliphatic polycarbonate-based polyurethane elastomers and nanocomposites. I. The influence of hard-segment content and macrodiol-constitution on bottom-up self-assembly

    Czech Academy of Sciences Publication Activity Database

    Špírková, Milena; Poreba, Rafal; Pavličevič, Jelena; Kobera, Libor; Baldrian, Josef; Pekárek, Michal

    2012-01-01

    Roč. 126, č. 3 (2012), s. 1016-1030 ISSN 0021-8995 R&D Projects: GA ČR GAP108/10/0195 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyurethane elastomer * polycarbonate diol * nanocomposite Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.395, year: 2012

  4. Quantitative structure-activity relationships for toxicity and genotoxicity of halogenated aliphatic compounds: wing spot test of Drosophila melanogaster.

    Science.gov (United States)

    Chroust, Karel; Pavlová, Martina; Prokop, Zbynek; Mendel, Jan; Bozková, Katerina; Kubát, Zdenek; Zajícková, Veronika; Damborský, Jiri

    2007-02-01

    Halogenated aliphatic compounds were evaluated for toxic and genotoxic effects in the somatic mutation and recombination test employing Drosophila melanogaster. The tested chemicals included chlorinated, brominated and iodinated; mono-, di- and tri-substituted; saturated and unsaturated alkanes: 1,2-dibromoethane, 1-bromo-2-chloroethane, 1-iodopropane, 2,3-dichloropropene, 3-bromo-1-propene, epibromohydrin, 2-iodobutane, 3-chloro-2-methylpropene, 1,2,3-trichloropropane, 1,2-dichloroethane, 1,2-dichlorobutane, 1-chloro-2-methylpropane, 1,3-dichloropropane, 1,2-dichloropropane, 2-chloroethymethylether, 1-bromo-2-methylpropane and 1-chloropentane. N-methyl-N-nitrosourea served as the positive and distilled water as the negative control. The set of chemicals for the toxicological testing was selected by the use of statistical experiment design. Group of unsaturated aliphatic hydrocarbons were generally more toxic than saturated analogues. The genotoxic effect was observed with 14 compounds in the wing spot test, while 3 substances did not show any genotoxicity by using the wing spot test at 50% lethal concentration. The highest number of wing spots was observed in genotoxicity assay with 1-bromo-2-chloroethane, 1,2-dichloroethane, 1,2-dibromoethane and 1-iodopropane. Nucleophilic superdelocalizability calculated by quantum mechanics appears to be a good parameter for prediction of both toxicity and genotoxicity effects of halogenated aliphatic compounds.

  5. Purification and characterization of a novel nitrilase of Rhodococcus rhodochrous K22 that acts on aliphatic nitriles.

    Science.gov (United States)

    Kobayashi, M; Yanaka, N; Nagasawa, T; Yamada, H

    1990-01-01

    A novel nitrilase that preferentially catalyzes the hydrolysis of aliphatic nitriles to the corresponding carboxylic acids and ammonia was found in the cells of a facultative crotononitrile-utilizing actinomycete isolated from soil. The strain was taxonomically studied and identified as Rhodococcus rhodochrous. The nitrilase was purified, with 9.08% overall recovery, through five steps from a cell extract of the stain. After the last step, the purified enzyme appeared to be homogeneous, as judged by polyacrylamide gel electrophoresis, analytical centrifugation, and double immunodiffusion in agarose. The relative molecular weight values for the native enzyme, estimated from the ultracentrifugal equilibrium and by high-performance liquid chromatography, were approximately 604,000 +/- 30,000 and 650,000, respectively, and the enzyme consisted of 15 to 16 subunits identical in molecular weight (41,000). The enzyme acted on aliphatic olefinic nitriles such as crotononitrile and acrylonitrile as the most suitable substrates. The apparent Km values for crotononitrile and acrylonitrile were 18.9 and 1.14 mM, respectively. The nitrilase also catalyzed the direct hydrolysis of saturated aliphatic nitriles, such as valeronitrile, 4-chlorobutyronitrile, and glutaronitrile, to the corresponding acids without the formation of amide intermediates. Hence, the R. rhodochrous K22 nitrilase is a new type distinct from all other nitrilases that act on aromatic and related nitriles. Images PMID:2394676

  6. Thermally induced degradation of sulfur-containing aliphatic glucosinolates in broccoli sprouts (Brassica oleracea var. italica) and model systems.

    Science.gov (United States)

    Hanschen, Franziska S; Platz, Stefanie; Mewis, Inga; Schreiner, Monika; Rohn, Sascha; Kroh, Lothar W

    2012-03-07

    Processing reduces the glucosinolate (GSL) content of plant food, among other aspects due to thermally induced degradation. Since there is little information about the thermal stability of GSL and formation of corresponding breakdown products, the thermally induced degradation of sulfur-containing aliphatic GSL was studied in broccoli sprouts and with isolated GSL in dry medium at different temperatures as well as in aqueous medium at different pH values. Desulfo-GSL have been analyzed with HPLC-DAD, while breakdown products were estimated using GC-FID. Whereas in the broccoli sprouts structural differences of the GSL with regard to thermal stability exist, the various isolated sulfur-containing aliphatic GSL degraded nearly equally and were in general more stable. In broccoli sprouts, methylsulfanylalkyl GSL were more susceptible to degradation at high temperatures, whereas methylsulfinylalkyl GSL were revealed to be more affected in aqueous medium under alkaline conditions. Besides small amounts of isothiocyanates, the main thermally induced breakdown products of sulfur-containing aliphatic GSL were nitriles. Although they were most rapidly formed at comparatively high temperatures under dry heat conditions, their highest concentrations were found after cooking in acidic medium, conditions being typical for domestic processing.

  7. Derivatization and detection of small aliphatic and lipid-bound carbonylated lipid peroxidation products by ESI-MS.

    Science.gov (United States)

    Milic, Ivana; Fedorova, Maria

    2015-01-01

    Double bonds in polyunsaturated fatty acids (PUFA) and lipids are one of the major targets of reactive oxygen species (ROS). The resulting lipid peroxidation products (LPP) represent a group of chemically diverse compounds formed by several consecutive oxidative reactions. Oxidative cleavage leads to the formation of small aliphatic and lipid-bound aldehydes and ketones (oxoLPPs). These strong electrophiles can readily react with nucleophilic substrates, for example, side chains in proteins which can alter structure, function, and cellular distribution of the modified proteins. Despite growing interest in the field of oxidative lipidomics, only a few dominantly formed oxoLPP were identified. Due to the chemical and physical properties, aliphatic oxoLPPs are usually analyzed using gas chromatography-mass spectrometry (GC- MS), while nonvolatile lipid-bound oxoLPPs require liquid chromatography-mass spectrometry (LC-MS). To overcome the need for the two analyses, we have developed a new derivatization strategy to capture all oxoLPP independent to their properties with electrospray ionization (ESI) MS allowing simultaneous detection of aliphatic and lipid-bound oxoLPPs. Thus, the 7-(diethylamino)coumarin-3-carbohydrazide (CHH) derivatization reagent allowed us to identify 122 carbonyl compounds in a mixture of four PUFA and phosphatidylcholines (PC) oxidized in vitro.

  8. Arabidopsis thaliana plants with different levels of aliphatic- and indolyl-glucosinolates affect host selection and performance of Bemisia tabaci.

    Science.gov (United States)

    Markovich, Oshry; Kafle, Dinesh; Elbaz, Moshe; Malitsky, Sergey; Aharoni, Asaph; Schwarzkopf, Alexander; Gershenzon, Jonathan; Morin, Shai

    2013-12-01

    Generalist insects show reduced selectivity when subjected to similar, but not identical, host plant chemical signatures. Here, we produced transgenic Arabidopsis thaliana plants that over-express genes regulating the aliphatic- and indolyl- glucosinolates biosynthetic pathways with either a constitutive (CaMV 35S) or a phloem-specific promoter (AtSUC2). This allowed us to examine how exposure to high levels of aliphatic- or indolyl-glucosinolates in homogenous habitats (leaf cage apparatus containing two wild-type or two transgenic leaves) and heterogeneous habitats (leaf cage apparatus containing one wild-type and one transgenic leaf) affects host selection and performance of Bemsia tabaci, a generalist phloem-feeding insect. Data from homogenous habitats indicated that exposure to A. thaliana plants accumulating high levels of aliphatic- or indolyl-glucosinolates negatively affected the performance of both adult females and nymphs of B. tabaci. Data from heterogeneous habitats indicated that B. tabaci adult females selected for oviposition plants on which their offspring perform better (preference-performance relationship). However, the combinations of wild-type and transgenic plants in heterogeneous habitats increased the period of time until the first choice was made and led to increased movement rate on transgenic plants, and reduced fecundity on wild-type plants. Overall, our findings are consistent with the view that both performance and selectivity of B. tabaci decrease in heterogeneous habitats that contain plants with closely-related chemical signatures.

  9. Development of analytical methods for the gas chromatographic determination of 1,2-epoxy-3-butene, 1,2:3,4-diepoxybutane, 3-butene-1,2-diol, 3,4-epoxybutane-1,2-diol and crotonaldehyde from perfusate samples of 1,3-butadiene exposed isolated mouse and rat livers

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, S.; Schuster, A.; Filser, J.G.

    2003-07-01

    Mutagenicity and carcinogenicity of 1,3-butadiene (BD) highly probably results from epoxide metabolites as 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB) and 3,4-epoxybutane-1,2-diol (EBD). A further metabolite crotonaldehyde (CA) has also been discussed to be relevant. So far, in BD exposed rodents only EB and DEB concentrations had been quantified. However, the methods used were either not very sensitive or instrumentally expensive. Therefore, the goal of the present work was to establish simple analytical methods selective and sensitive enough to determine all of these compounds and a further secondary BD intermediate, 3-butene-1,2-diol (B-diol), in BD exposed rodent livers. The once-through perfused liver system was chosen for testing the applicability of the methods to be developed, since it enables BD exposures of this quantitatively most relevant metabolising organ near to the in-vivo situation. All the metabolites were extracted from the aqueous perfusion medium and analysed using a gas chromatograph equipped with a mass selective detector (GC/MS) in the PCI mode. (orig.)

  10. A rapid and sensitive method for the simultaneous analysis of aliphatic and polar molecules containing free carboxyl groups in plant extracts by LC-MS/MS

    OpenAIRE

    Kallenbach, Mario; Baldwin, Ian T; Bonaventure, Gustavo

    2009-01-01

    Abstract Background Aliphatic molecules containing free carboxyl groups are important intermediates in many metabolic and signalling reactions, however, they accumulate to low levels in tissues and are not efficiently ionized by electrospray ionization (ESI) compared to more polar substances. Quantification of aliphatic molecules becomes therefore difficult when small amounts of tissue are available for analysis. Traditional methods for analysis of these molecules require purification or enri...

  11. Synthesis, spectroscopic studies and inhibitory activity against bactria and fungi of acyclic and macrocyclic transition metal complexes containing a triamine coumarine Schiff base ligand

    Science.gov (United States)

    Abou-Hussein, A. A.; Linert, Wolfgang

    2015-04-01

    Two series of new mono and binuclear complexes with a Schiff base ligand derived from the condensation of 3-acetylcoumarine and diethylenetriamine, in the molar ratio 2:1 have been prepared. The ligand was characterized by elemental analysis, IR, UV-visible, 1H-NMR and mass spectra. The reaction of the Schiff base ligand with cobalt(II), nickel(II), copper(II), zinc(II) and oxovanadium(IV) lead to mono or binuclear species of cyclic or macrocyclic complexes, depending on the mole ratio of metal to ligand and as well as on the method of preparation. The Schiff base ligand behaves as a cyclic bidentate, tetradendate or pentaentadentae ligand. The formation of macrocyclic complexes depends significantly on the dimension of the internal cavity, the rigidity of the macrocycles, the nature of its donor atoms and on the complexing properties of the anion involved in the coordination. Electronic spectra and magnetic moments of the complexes indicate that the geometries of the metal centers are either square pyramidal or octahedral for acyclic or macro-cyclic complexes. The structures are consistent with the IR, UV-visible, ESR, 1H-NMR, mass spectra as well as conductivity and magnetic moment measurements. The Schiff base ligand and its metal complexes were tested against two pathogenic bacteria as Gram-positive and Gram-negative bacteria as well as one kind of fungi. Most of the complexes exhibit mild antibacterial and antifungal activities against these organisms.

  12. Cyclohexane/benzene organic glasses and ethylene/styrene copolymers behaviour under ionizing radiations: energy and species transfers between aliphatic and aromatic moieties

    International Nuclear Information System (INIS)

    Ferry, M.

    2008-11-01

    The aim of this study is to understand how aliphatic and aromatic groups interact under ionizing radiations. Three research orientations were explored: the determination of the relative contribution of energy and radical transfers, the determination of the intermolecular and intra-chain relative contribution, and the influence of the repartition of the aliphatic and aromatic units inside the polymer chain. Three systems composed of aromatic and aliphatic units were studied: the cyclohexane/benzene organic glasses (intermolecular reactions), the ethylene/styrene random copolymers (inter-chain and intra-chain reactions) and ethylene/styrene di-blocs copolymers (influence of the repartition of the aliphatic and aromatic units in the material). Considering the results obtained, we have concluded that energy transfers are important in the radiation protection effect of the aliphatic moiety by the aromatic one, although radical transfers are also contributing. Intermolecular transfers are efficient in the solid state and their efficiency seems equivalent to that of the intra-chain ones. Thanks to the use of infrared spectroscopy, we have shown an important effect of radiation sensitization of the aromatic moiety, whatever the irradiation temperature and the system studied: energy transfers to the aromatic moiety are carried out at the detriment of its stability. Finally, the repartition of the aliphatic and aromatic units in the polymer chain is not an important factor in the effects induced by the energy transfers. (author)

  13. Plasma oxylipin profiling identifies polyunsaturated vicinal diols as responsive to arachidonic acid and docosahexaenoic acid intake in growing piglets.

    Science.gov (United States)

    Bruins, Maaike J; Dane, Adrie D; Strassburg, Katrin; Vreeken, Rob J; Newman, John W; Salem, Norman; Tyburczy, Cynthia; Brenna, J Thomas

    2013-06-01

    The dose-responsiveness of plasma oxylipins to incremental dietary intake of arachidonic acid (20:4n-6; ARA) and docosahexaenoic acid (22:6n-3; DHA) was determined in piglets. Piglets randomly received one of six formulas (n = 8 per group) from days 3 to 27 postnatally. Diets contained incremental ARA or incremental DHA levels as follows (% fatty acid, ARA/DHA): (A1) 0.1/1.0; (A2) 0.53/1.0; (A3-D3) 0.69/1.0; (A4) 1.1/1.0; (D1) 0.66/0.33; and (D2) 0.67/0.62, resulting in incremental intake (g/kg BW/day) of ARA: 0.07 ± 0.01, 0.43 ± 0.03, 0.55 ± 0.03, and 0.82 ± 0.05 at constant DHA intake (0.82 ± 0.05), or incremental intake of DHA: 0.27 ± 0.02, 0.49 ± 0.03, and 0.81 ± 0.05 at constant ARA intake (0.54 ± 0.04). Plasma oxylipin concentrations and free plasma PUFA levels were determined at day 28 using LC-MS/MS. Incremental dietary ARA intake dose-dependently increased plasma ARA levels. In parallel, ARA intake dose-dependently increased ARA-derived diols 5,6- and 14,15-dihydroxyeicosatrienoic acid (DiHETrE) and linoleic acid-derived 12,13-dihydroxyoctadecenoic acid (DiHOME), downstream metabolites of cytochrome P450 expoxygenase (CYP). The ARA epoxide products from CYP are important in vascular homeostatic maintenance. Incremental DHA intake increased plasma DHA and most markedly raised the eicosapentaenoic acid (EPA) metabolite 17,18-dihydroxyeicosatetraenoic acid (DiHETE) and the DHA metabolite 19,20-dihydroxydocosapentaenoic acid (DiHDPE). In conclusion, increasing ARA and DHA intake dose-dependently influenced endogenous n-6 and n-3 oxylipin plasma concentrations in growing piglets, although the biological relevance of these findings remains to be determined.

  14. A series of silver(I) coordination polymers with saccarinate and flexible aliphatic diamines

    Energy Technology Data Exchange (ETDEWEB)

    Yeşilel, Okan Zafer, E-mail: yesilel@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Karamahmut, Bingül [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Semerci, Fatih [Department of Energy Systems Engineering, Faculty of Technology, Kırklareli University, 39000 Kırklareli (Turkey); Darcan, Cihan [Department of Molecular Biology and Genetic, Faculty of Arts and Sciences, Bilecik Şeyh Edebali University, Gülümbe-Bilecik (Turkey); Yılmaz, Filiz [Department of Chemistry, Faculty of Sciences, Anadolu University, Eskişehir (Turkey)

    2017-05-15

    A series of Ag(I) complexes with aliphatic diamines having a different chain length (NH{sub 2}-(CH{sub 2}){sub n}-NH{sub 2}, n=4–9), with the formulas, [Ag(μ-sac)(μ-db){sub 0.5}]{sub n} (1), ([Ag{sub 4}(sac){sub 4}(μ-dp){sub 2}]·4H{sub 2}O){sub n} (2){sub ,} ([Ag{sub 2}(sac){sub 2}(μ-dz)]·2H{sub 2}O){sub n} (3), ([Ag{sub 2}(sac){sub 2}(μ-dh)]·H{sub 2}O){sub n} (4), ([Ag{sub 2}(sac){sub 2}(μ-do)]·H{sub 2}O){sub n} (5a), [Ag{sub 2}(sac){sub 2}(μ-do){sub 2}] (5b) and [Ag{sub 4}(sac){sub 4}(μ-dn){sub 2}]·2H{sub 2}O (6), where sac=saccharinate, db=1,4-diaminobutane, dp=1,5-diaminopentane, dz=1,6-diaminohexane, dh=1,7-diaminoheptane, do=1,8-diaminooctane and dn=1,9-diaminononane, were synthesized and characterized by elemental analysis, infrared spectra and single-crystal X-ray diffraction analysis. In 1, the sac ligand bridges adjacent Ag(I) ions through the nitrogen and carbonyl oxygen atoms to form eight-membered bimetallic rings with the Ag···Ag distance being 3.897 Å, which are linked by db ligands to give a 1D zigzag chain. The complexes 2–5a consist of a one-dimensional (1D) linear cationic chains and discrete mononuclear anions. The discreet complex units are further connected by ligand unsupported argentophilic interactions. In 6, the dn ligands bridge adjacent silver centers to form 24-membered macrometallacyclic rings, which are further connected to the anionic [Ag(sac){sub 2}]{sup -} units by argentophilic Ag1···Ag2 interactions to form a tetranuclear structure. The adjacent dinuclear units are further linked together through ligand-unsupported argentophilic Ag···Ag (3.207(1) Å) interactions, generating a one-dimensional linear chain. The most striking feature of complexes is the presence of the rare intermolecular C-H···Ag interactions. In 5b, the do ligand bridges two Ag(I) ions to form a dinuclear with a 22-membered macrometallacyclic ring. Furthermore, biological activities, luminescence properties and thermal analysis (TG

  15. Interaction of benzo[a]pyrene diol epoxide isomers with human serum albumin: Site specific characterisation of adducts and associated kinetics

    Science.gov (United States)

    Motwani, Hitesh V.; Westberg, Emelie; Törnqvist, Margareta

    2016-11-01

    Carcinogenicity of benzo[a]pyrene {B[a]P, a polycyclic aromatic hydrocarbon (PAH)} involves DNA-modification by B[a]P diol epoxide (BPDE) metabolites. Adducts to serum albumin (SA) are not repaired, unlike DNA adducts, and therefore considered advantageous in assessment of in vivo dose of BPDEs. In the present work, kinetic experiments were performed in relation to the dose (i.e. concentration over time) of different BPDE isomers, where human SA (hSA) was incubated with respective BPDEs under physiological conditions. A liquid chromatography (LC) tandem mass spectrometry methodology was employed for characterising respective BPDE-adducts at histidine and lysine. This strategy allowed to structurally distinguish between the adducts from racemic anti- and syn-BPDE and between (+)- and (-)-anti-BPDE, which has not been attained earlier. The adduct levels quantified by LC-UV and the estimated rate of disappearance of BPDEs in presence of hSA gave an insight into the reactivity of the diol epoxides towards the N-sites on SA. The structure specific method and dosimetry described in this work could be used for accurate estimation of in vivo dose of the BPDEs following exposure to B[a]P, primarily in dose response studies of genotoxicity, e.g. in mice, to aid in quantitative risk assessment of PAHs.

  16. Pyriculins A and B, two monosubstituted hex-4-ene-2,3-diols and other phytotoxic metabolites produced by Pyricularia grisea isolated from buffelgrass (Cenchrus ciliaris).

    Science.gov (United States)

    Masi, Marco; Meyer, Susan; Górecki, Marcin; Mandoli, Alessandro; Di Bari, Lorenzo; Pescitelli, Gennaro; Cimmino, Alessio; Cristofaro, Massimo; Clement, Suzette; Evidente, Antonio

    2017-11-01

    Pyricularia grisea has been identified as a foliar pathogen on buffelgrass (Cenchrus ciliaris) in North America and was studied as a potential source of phytotoxins for buffelgrass control. Two monosubstituted hex-4-ene-2,3-diols, named pyriculins A and B, were isolated from its culture filtrate organic extract together with (10S,11S)-(-)-epipyriculol, trans-3,4-dihydro-3,4,8-trihydroxy-1(2H)-napthalenone, and (4S)-(+)-isosclerone. Pyriculins A and B were characterized by spectroscopic (essentially nuclear magnetic resonance [NMR], High-resolution electrospray ionization mass spectrometry [HRESIMS]) and chemical methods such as (4E)-1-(4-hydroxy-1,3-dihydroisobenzofuran-1-yl)hex-4-ene-2,3-diols. The relative and absolute configuration of these compounds was determined by a combination of spectroscopic (NMR, electronic circular dichroism [ECD]) and computational tools. When bioassayed in a buffelgrass coleoptile and radicle elongation test, (10S,11S)-(-)-epipyriculol proved to be the most toxic compound. Seed germination was much reduced and slowed with respect to the control and radicles failed to elongate. All five compounds delayed germination, but only (10S,11S)-(-)-epipyriculol was able to prevent radicle development of buffelgrass seedlings. It had no effect on coleoptile elongation, while the other four compounds caused significantly increased coleoptile development relative to the control. © 2017 Wiley Periodicals, Inc.

  17. Diacyltransferase Activity and Chain Length Specificity of Mycobacterium tuberculosis PapA5 in the Synthesis of Alkyl β-Diol Lipids

    Energy Technology Data Exchange (ETDEWEB)

    Touchette, Megan H.; Bommineni, Gopal R.; Delle Bovi, Richard J.; Gadbery, John; Nicora, Carrie D.; Shukla, Anil K.; Kyle, Jennifer E.; Metz, Thomas O.; Martin, Dwight W.; Sampson, Nicole S.; Miller, W. T.; Tonge, Peter J.; Seeliger, Jessica C.

    2015-09-08

    Although classified as Gram-positive bacteria, Corynebacterineae possess an asymmetric outer membrane that imparts structural and thereby physiological similarity to more distantly related Gram-negative bacteria. Like lipopolysaccharide in Gram-negative bacteria, lipids in the outer membrane of Corynebacterineae have been associated with the virulence of pathogenic species such as Mycobacterium tuberculosis (Mtb). For example, Mtb strains that lack long, branched-chain alkyl esters known as dimycocerosates (DIMs) are significantly attenuated in model infections. The resultant interest in the biosynthetic pathway of these unusual virulence factors has led to the elucidation of many of the steps leading to the final esterification of the alkyl beta-diol, phthiocerol, with branched-chain fatty acids know as mycocerosates. PapA5 is an acyltransferase implicated in these final reactions. We here show that PapA5 is indeed the terminal enzyme in DIM biosynthesis by demonstrating its dual esterification activity and chain-length preference using synthetic alkyl beta-diol substrate analogues. Applying these analogues to a series of PapA5 mutants, we also revise a model for the substrate binding within PapA5. Finally, we demonstrate that the Mtb Ser/Thr kinase PknB modifies PapA5 on three Thr residues, including two (T196, T198) located on an unresolved loop. These results clarify the DIM biosynthetic pathway and suggest possible mechanisms by which DIM biosynthesis may be regulated by the post-translational modification of PapA5.

  18. Molecular Connectivity Predefines Polypharmacology: Aliphatic Rings, Chirality, and sp3 Centers Enhance Target Selectivity

    Directory of Open Access Journals (Sweden)

    Stefania Monteleone

    2017-08-01

    Full Text Available Dark chemical matter compounds are small molecules that have been recently identified as highly potent and selective hits. For this reason, they constitute a promising class of possible candidates in the process of drug discovery and raise the interest of the scientific community. To this purpose, Wassermann et al. (2015 have described the application of 2D descriptors to characterize dark chemical matter. However, their definition was based on the number of reported positive assays rather than the number of known targets. As there might be multiple assays for one single target, the number of assays does not fully describe target selectivity. Here, we propose an alternative classification of active molecules that is based on the number of known targets. We cluster molecules in four classes: black, gray, and white compounds are active on one, two to four, and more than four targets respectively, whilst inactive compounds are found to be inactive in the considered assays. In this study, black and inactive compounds are found to have not only higher solubility, but also a higher number of chiral centers, sp3 carbon atoms and aliphatic rings. On the contrary, white compounds contain a higher number of double bonds and fused aromatic rings. Therefore, the design of a screening compound library should consider these molecular properties in order to achieve target selectivity or polypharmacology. Furthermore, analysis of four main target classes (GPCRs, kinases, proteases, and ion channels shows that GPCR ligands are more selective than the other classes, as the number of black compounds is higher in this target superfamily. On the other side, ligands that hit kinases, proteases, and ion channels bind to GPCRs more likely than to other target classes. Consequently, depending on the target protein family, appropriate screening libraries can be designed in order to minimize the likelihood of unwanted side effects early in the drug discovery process

  19. In Vivo Genotoxic Evaluation of D-003, a Mixture of Very Long Chain Aliphatic Acids.

    Science.gov (United States)

    Gámez, Rafael; González, Jorge E.; Rodeiro, Idania; Fernández, Ivonne; Alemán, Celia; Rodríguez, María D.; Acosta, Pilar C.; García, Haydee

    2001-01-01

    D-003 is a mixture of very long chain aliphatic acids purified from sugar cane wax with cholesterol-lowering effects. The present study was undertaken to investigate the in vivo cytotoxic and genotoxic potential of D-003 using three established assays: bone marrow micronucleus, sperm morphology, and single cell gel electrophoresis (Comet) assay. In a first experimental series, CEN/NMRI mice (6-8 animals per sex per group) were administered D-003 by gastric gavage at 5, 50, or 500 mg/kg for 90 days, then sacrificed 24 hours after the last administration. The effects on bone marrow micronucleus were evaluated only in female mice. D-003 (5-500 mg/kg) did not increase the frequency of micronucleated polychromatic erythrocytes, nor the ratio of polychromatic to normochromatic erythrocytes, compared with the controls. The assessment of the effects on sperm morphology showed that D-003 did not change the sperm count or the frequency of all types of abnormal head shapes, compared with the controls. In a second series, the micronucleus assay was performed in mice of both sexes given 2,000 mg/kg for 6 days. Likewise, in this series, neither cytotoxic nor genotoxic effects were found. Finally, five male Sprague-Dawley rats were treated with D-003 (1,250 mg/kg) by oral gavage for 90 days, and Comet assay on liver cells was performed. No single-strand breaks or alkali-labile site induction on DNA was observed. These results indicate that D-003 does not show evidence of cytotoxic or genotoxic activity on either somatic or germ cells in rodents.

  20. Kinetics of aluminum and sulfate release from forest soil by mono- and diprotic aliphatic acids

    Energy Technology Data Exchange (ETDEWEB)

    Evans, A. Jr.; Zelazny, L.W. (Virginia Polytechnic Institute and State Univ., Blacksburg (USA))

    1990-06-01

    A batch equilibration study evaluated the influence of naturally occurring low-molecular-weight mono- and diprotic aliphatic acids on the rate of Al and SO{sub 4}{sup 2{minus}} release in a Cecil soil (Typic Hapludult). The authors adjusted the pH of the organic acids (OAs) and of the soil suspension (3.8% w/w) to pH 4.0 and allowed them to equilibrate thermally before the experiment. After rapid addition of OAs to the soil suspension, they took solution samples at various time intervals and analyzed for Al, SO{sub 4}{sup 2{minus}}, and OA concentration. The initial concentration of OA in suspension was 1 {times} 10{sup {minus}5} mol liter{sup {minus}1}. Both Al and SO{sub 4}{sup 2{minus}} release followed pseudo-first-order kinetics, whereas OA adsorption obeyed simple first-order kinetics. The rate of Al release (k{sub 1}) was more rapid for the diprotic OA treatment (20.4 {times} 10{sup {minus}8} mol s{sup {minus}1}), as was SO{sub 4}{sup 2{minus}} release (1.63 {times} 10{sup {minus}8} mol s{sup {minus}1}), compared to the monoprotic OA treatment. The rate of Al release varied inversely with OA chain length and the distance between -COOH functional groups. The addition of substituent -OH groups between the -COOH groups further reduced K{sub 1}. A similar trend was observed for the rate of SO{sub 4}{sup 2{minus}} release (k{sub 1}) into solution. Monoprotic OAs were more rapidly adsorbed to the particle surfaces than were diprotic OAs. The authors postulate that removal of Al and SO{sub 4}{sup 2{minus}} from solution occurs via selective mineral precipitation.

  1. Transferability of aliphatic isocyanates from recently applied paints to the skin of auto body shop workers.

    Science.gov (United States)

    De Vries, Thomas T; Bello, Dhimiter; Stowe, Meredith H; Harari, Homero; Slade, Martin D; Redlich, Carrie A

    2012-01-01

    Isocyanates, the essential cross-linking chemicals used to make polyurethane, are potent sensitizers and a common cause of occupational asthma. In addition, isocyanate (NCO) skin contact may contribute to the development of isocyanate asthma. Prior work has shown that unbound NCO can persist on recently spray coated auto body parts after appearing dry. The purpose of this study was to assess whether isocyanate skin exposure can result from handling such surfaces. Quantitative surface and skin wipe sampling for total NCO was performed on test panels sprayed with aliphatic isocyanate coatings, and on paired skin samples obtained from participants who had rubbed the recently dried surfaces. Surface and skin samples, obtained from 18 workers in five auto body shops, were prepared following NIOSH method 5525 (modified for skin samples), and isocyanate species derived from hexamethylene diisocyanate and isophorone diisocyanate were analyzed using high-performance liquid chromatography with ultraviolet and fluorescence detectors. Quantifiable unbound NCO species were detected on 84.2% of all sprayed surfaces sampled after initially considered dry. Only 7 out of a total of 104 (6.7%) non-compounded skin samples obtained after contact with the recently dried coatings had detectable quantities of free NCO. The 7 positive samples, all obtained at the initial sampling time (t(0)), had a geometric mean of 0.016 μg NCO cm(-2) (range: 0.002-0.88 μg NCO cm(-2)). Only 1 of 12 (8.3%) of skin samples obtained after compounding contained detectable free NCO. The risk of substantial human isocyanate skin exposure from contact with the dry appearing (yet not fully cured) isocyanate coatings evaluated in this study appears to be low, although other isocyanate coatings and tasks may pose a greater risk of NCO skin exposure.

  2. Characterization of aliphatic hyperbranched polyesters by MALDI-TOF mass spectrometry

    Directory of Open Access Journals (Sweden)

    Vuković Jasna

    2007-01-01

    Full Text Available In this work, MALDI-TOF mass spectrometry was used for the characterization of aliphatic hyperbranched polyesters (AHBP, synthesized from 2,2-bis(hydroxymethylpropionic acid (bis-MPA and di-trimethylolpropane. From the obtained results it was concluded that it was not possible to take complete advantages of MALDI-TOF MS in this particular case, since the AHBP used in this work were polydisperse. The intensity of the signals from the high mass tail of these samples (pseudo generation higher than four was underestimated and insufficient to distinguish it from the baseline and to use it for the analysis of the spectra. As a consequence of that, lower values of the Mn were obtained. At the same time, Mw were also underestimated, which led to very low values of the polydispersity index. On the other hand, it was possible to obtain molar masses of individual molecules from the MALDI-TOF mass spectra of AHBP and to qualitatively determine the extent of cyclization (side reactions at each degree of polymerization. Using the adequate set of equations and results obtained from MALDI-TOF mass spectra of AHBP, every signal from the spectra was identified. The obtained results show that formation of poly(bis-MPA, intramolecular esterification and intramolecular etherification occurred as side reactions during the synthesis of these polyesters. The relative amount of the cycles increases with the number of pseudo generation (from the second up to the fifth pseudo generation. It was also observed that the relative proportion of the signals which represent cyclic structures increases with the increasing degree of polymerization. In this work the basic principles of MALDI-TOF MS are also presented, as well as, a review of adequate published articles.

  3. Differential effects of falcarinol and related aliphatic C(17)-polyacetylenes on intestinal cell proliferation.

    Science.gov (United States)

    Purup, Stig; Larsen, Eric; Christensen, Lars P

    2009-09-23

    Quantitative major polyacetylenes of carrots (falcarinol and falcarindiol) and American ginseng roots (falcarinol and panaxydol) were isolated and tested in human intestinal epithelial cells of normal (FHs 74 Int.) and cancer (Caco-2) origin. A hormesis effect was seen for all isolated polyacetylenes when added to Caco-2 cells in concentrations ranging from 1 ng/mL to 20 microg/mL. The relative inhibitory potency was falcarinol > panaxydol > falcarindiol. No hormesis effect was observed when adding the polyacetylenes to FHs 74 Int. cells. Instead, an inhibitory growth response was observed above 1 microg/mL. The relative inhibitory potency was panaxydol > falcarinol > falcarindiol. Maximal inhibition at 20 microg/mL corresponded to approximately 95% and 80% inhibition of cell proliferation in normal and cancer cells, respectively. Combinations of falcarinol and falcarindiol added to normal and cancer cells showed a synergistic response for the inhibition of cell growth. Furthermore, the oxidized form of falcarinol, falcarinon, showed a significantly less growth inhibitory effect in intestinal cells of both normal and cancer origin; hence, a hydroxyl group at C-3 may be important for activity of falcarinol-type polyacetylenes. Extracts of carrots, containing different amounts of falcarinol, falcarindiol, and falcarindiol 3-acetate had significant inhibitory effects on both normal and cancer cell proliferation. In cancer cells, the extract containing the highest concentration of falcarinol tended to have the highest growth inhibitory effect, in accordance with a higher potency of falcarinol than falcarindiol. The present study demonstrates that aliphatic C(17)-polyacetylenes are potential anticancer principles of carrots and related vegetables and that synergistic interaction between bioactive polyacetylenes may be important for their bioactivity.

  4. Differential Effects of Falcarinol and Related Aliphatic C17-Polyacetylenes on Intestinal Cell Proliferation

    Science.gov (United States)

    2009-01-01

    Quantitative major polyacetylenes of carrots (falcarinol and falcarindiol) and American ginseng roots (falcarinol and panaxydol) were isolated and tested in human intestinal epithelial cells of normal (FHs 74 Int.) and cancer (Caco-2) origin. A hormesis effect was seen for all isolated polyacetylenes when added to Caco-2 cells in concentrations ranging from 1 ng/mL to 20 μg/mL. The relative inhibitory potency was falcarinol > panaxydol > falcarindiol. No hormesis effect was observed when adding the polyacetylenes to FHs 74 Int. cells. Instead, an inhibitory growth response was observed above 1 μg/mL. The relative inhibitory potency was panaxydol > falcarinol > falcarindiol. Maximal inhibition at 20 μg/mL corresponded to approximately 95% and 80% inhibition of cell proliferation in normal and cancer cells, respectively. Combinations of falcarinol and falcarindiol added to normal and cancer cells showed a synergistic response for the inhibition of cell growth. Furthermore, the oxidized form of falcarinol, falcarinon, showed a significantly less growth inhibitory effect in intestinal cells of both normal and cancer origin; hence, a hydroxyl group at C-3 may be important for activity of falcarinol-type polyacetylenes. Extracts of carrots, containing different amounts of falcarinol, falcarindiol, and falcarindiol 3-acetate had significant inhibitory effects on both normal and cancer cell proliferation. In cancer cells, the extract containing the highest concentration of falcarinol tended to have the highest growth inhibitory effect, in accordance with a higher potency of falcarinol than falcarindiol. The present study demonstrates that aliphatic C17-polyacetylenes are potential anticancer principles of carrots and related vegetables and that synergistic interaction between bioactive polyacetylenes may be important for their bioactivity. PMID:19694436

  5. Biodegradable aliphatic-aromatic copolyester/corn starch blend composite reinforced with coffee parchment husk

    International Nuclear Information System (INIS)

    Silva, Valquiria A.; Teixeira, Jaciele G.; Gomes, Michelle G.; Ortiz, Angel V.; Oliveira, Rene R.; Scapin, Marcos A.; Moura, Esperidiana A.B.; Colombo, Maria A.

    2013-01-01

    In recent years, studies have shown that the addition of natural fiber or proper filler is an effective strategy for achieving improved properties in biodegradable polymer materials. Moreover, is especially important if such fibers are residues of agro-industrial processes. In this work, a promising technique to develop biodegradable polymer matrix composite based on aliphatic-aromatic copolyester/corn starch blend (Evela®) and coffee parchment husk, which is residue from coffee processing is described. The biodegradable polymeric blend (Evela®) with 5 % (w/w) of ball-milled coffee parchment husk fiber powder, with size ≤250 μm, without any modification was prepared by melt-mixing processing, using a twin screw extruder machine and then pelletized. In a second step, the pelletized Evela®)/coffee parchment (Composite) was then dried at 70 ± 2 deg C for 24 h in a circulating air oven, fed into injection molding machine and test specimens were obtained. The Composite specimen samples were irradiated using an electron beam accelerator, at radiation dose of 20 and 40 kGy, at room temperature in presence of air. The irradiated and non-irradiated samples were characterized by means of scanning electron microscopy (SEM), X-Ray diffraction (XRD), tensile tests and sol-gel analysis and the correlation between their properties was discussed. In addition, coffee parchment husk fiber characterization by SEM, EDS, XRD and WDXRF have also been carried out with a view to evaluate its importance in determining the end-use properties of the composite. (author)

  6. Catalytic pyrolysis of amino acids: Comparison of aliphatic amino acid and cyclic amino acid

    International Nuclear Information System (INIS)

    Liu, Guangyi; Wright, Mark M.; Zhao, Qingliang; Brown, Robert C.; Wang, Kaige; Xue, Yuan

    2016-01-01

    Highlights: • Catalytic pyrolysis of leucine and proline were carried out in a micro-furnace pyrolyzer. • Distributions of carbon, oxygen and nitrogen were comparatively investigated. • Leucine yielded 29.6% aromatic hydrocarbons, 34.9% olefins, and 8.1% alkanes. • Proline yielded 25.3% aromatic hydrocarbons, 14.0% olefins, and 5.5% alkanes. • Insights into the deoxygenation pathways of leucine and proline were elucidated. - Abstract: Catalytic pyrolysis (CP) of protein-rich biomass such as microalgae is a promising approach to biofuel production. CP of amino acids can help understand the cracking of protein-rich biomass in the presence of zeolite catalysts. In this study, as representatives of aliphatic amino acid and cyclic amino acid, respectively, leucine and proline were pyrolyzed with ZSM-5 catalyst in a Tandem micro-furnace reactor coupled with a MS/FID/TCD. At 650 °C, leucine produced more hydrocarbons (aromatic hydrocarbons of 29.6%, olefins of 34.9% and alkanes of 8.1%) than proline (aromatic hydrocarbons of 25.3%, olefins of 14.0% and alkanes of 5.5%) because its relatively simpler amino structure readily detached as ammonia during CP. However, with an N-cyclic structure, proline produced large quantities of nitrogen-containing heterocyclic compounds that favored coke formation in CP. Accordingly, 28.2% of the nitrogen in proline was retained in the solid residue while most of the nitrogen in leucine was converted into ammonia leaving only 4.3% in the solid residue. In addition, though decarboxylation to carbon dioxide was favored in non-catalytic pyrolysis of leucine and proline, decarbonylation to carbon monoxide became the primary deoxygenation pathway in CP. These results indicate that the chemical structures of amino acids have significant effects on product distributions during CP and N-cyclic amino acid is less favored in CP for production of hydrocarbons and ammonia.

  7. Deuterium magnetic resonance of some polymorphic liquid crystals: The conformation of the aliphatic end chains

    International Nuclear Information System (INIS)

    Hsi, S.; Zimmermann, H.; Luz, Z.

    1978-01-01

    Deuterium magnetic resonance measurements of four members of the homologous series p-alkoxybenzylidene-p-alkylaniline (noxm), perdeuterated in their alkoxy chains, are reported. The compounds studied were 40x7, 50x7, 60x7, and 70x7. For 50x7 various isotopic species specifically deuterated in the alkoxy chains, as well as in the benzylidine moiety, were prepared and their DMR studied. These measurements allowed a complete assignment of the resonances from the alkoxy chain. The spectrum of all four compounds was studied over their whole mesomorphic regions. In most phases well resolved spectra were obtained yielding the various quadrupole splittings and in many cases also the dipolar interactions within the methylene and methyl groups. Using double quantum spectroscopy dipolar splitting between different methylene deuterons could also be resolved. The methylene quadrupolar splittings and the dipolar interaction within the methylene groups decrease along the chain towards the methyl end in a characteristic stepwise manner. This behavior is attributed to chain reorientational freedom and is quantitatively interpreted in terms of two structural factors: (i) Fast dynamical equilibrium between the all-trans conformation of the alkoxy chains and chain conformations involving one or more kinks, and (ii) a molecular model in which the aliphatic chain axis is inclined with respect to the molecular long axis. The characteristic pattern of the splitting can then be reproduced by assuming a monotonically increasing kink probabilities along the chain towards its methyl end. This interpretation is used to estimate the kink probability distribution in the alkoxy chains in the various compounds and mesophases. No significant effect of the mesophase structure on the kink statistics was found

  8. Two Novel Flavin-Containing Monooxygenases Involved in Biosynthesis of Aliphatic Glucosinolates

    Directory of Open Access Journals (Sweden)

    Wenwen Kong

    2016-08-01

    Full Text Available Glucosinolates (GSLs, a class of secondary metabolites from cruciferous plants, are derived from amino acids and have diverse biological activities, such as in biotic defense, depending on their side chain modification. The first structural modification step in the synthesis of aliphatic (methionine-derived GSLs—S-oxygenation of methylthioalkyl GSLs to methylsulfinylalkyl GSLs—was found to be catalyzed by five flavin-containing monooxygenases (FMOs, FMOGS-OX1-5. Here, we report two additional FMOGS-OX enzymes, FMOGS-OX6 and FMOGS-OX7, encoded by At1g12130 and At1g12160, respectively. The overexpression of both FMOGS-OX6 and FMOGS-OX7 decreased the ratio of MT GSL to the sum of MT and MS GSL, suggesting that the introduction of the two genes converted MT GSL into MS GSL. Analysis of expression pattern revealed that the spatial expression of the two genes is quite similar and partially overlapped with the other FMOGS-OX genes, which are primarily expressed in vascular tissue. We further analyzed the responsive expression pattern of all the seven FMOGS-OX genes to exogenous treatment with abscisic acid (ABA, 1-aminocyclopropane-1-carboxylic acid (ACC, jasmonic acid (JA, salicylic acid (SA, indole-3-acetic acid (IAA, and low and high temperatures. Although these genes showed same tendency toward the changing stimulus, the sensitivity of each gene was quite different. The variety in spatial expression among the FMOGS-OX genes while responding to environmental stimulus indicated a complex and finely tuned regulation of GSL modifications. Identification of these two novel FMOGS-OX enzymes will enhance the understanding of GSL modifications and the importance of evolution of these duplicated genes.

  9. Synthesis, spectroscopic studies and inhibitory activity against bacteria and fungi of acyclic and macrocyclic transition metal complexes containing a triamine coumarine Schiff base ligand.

    Science.gov (United States)

    Abou-Hussein, A A; Linert, Wolfgang

    2015-04-15

    Two series of new mono and binuclear complexes with a Schiff base ligand derived from the condensation of 3-acetylcoumarine and diethylenetriamine, in the molar ratio 2:1 have been prepared. The ligand was characterized by elemental analysis, IR, UV-visible, (1)H-NMR and mass spectra. The reaction of the Schiff base ligand with cobalt(II), nickel(II), copper(II), zinc(II) and oxovanadium(IV) lead to mono or binuclear species of cyclic or macrocyclic complexes, depending on the mole ratio of metal to ligand and as well as on the method of preparation. The Schiff base ligand behaves as a cyclic bidentate, tetradendate or pentaentadentae ligand. The formation of macrocyclic complexes depends significantly on the dimension of the internal cavity, the rigidity of the macrocycles, the nature of its donor atoms and on the complexing properties of the anion involved in the coordination. Electronic spectra and magnetic moments of the complexes indicate that the geometries of the metal centers are either square pyramidal or octahedral for acyclic or macro-cyclic complexes. The structures are consistent with the IR, UV-visible, ESR, (1)H-NMR, mass spectra as well as conductivity and magnetic moment measurements. The Schiff base ligand and its metal complexes were tested against two pathogenic bacteria as Gram-positive and Gram-negative bacteria as well as one kind of fungi. Most of the complexes exhibit mild antibacterial and antifungal activities against these organisms. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. The Teacher, the Physician and the Person: Exploring Causal Connections between Teaching Performance and Role Model Types Using Directed Acyclic Graphs

    Science.gov (United States)

    Boerebach, Benjamin C. M.; Lombarts, Kiki M. J. M. H.; Scherpbier, Albert J. J.; Arah, Onyebuchi A.

    2013-01-01

    Background In fledgling areas of research, evidence supporting causal assumptions is often scarce due to the small number of empirical studies conducted. In many studies it remains unclear what impact explicit and implicit causal assumptions have on the research findings; only the primary assumptions of the researchers are often presented. This is particularly true for research on the effect of faculty’s teaching performance on their role modeling. Therefore, there is a need for robust frameworks and methods for transparent formal presentation of the underlying causal assumptions used in assessing the causal effects of teaching performance on role modeling. This study explores the effects of different (plausible) causal assumptions on research outcomes. Methods This study revisits a previously published study about the influence of faculty’s teaching performance on their role modeling (as teacher-supervisor, physician and person). We drew eight directed acyclic graphs (DAGs) to visually represent different plausible causal relationships between the variables under study. These DAGs were subsequently translated into corresponding statistical models, and regression analyses were performed to estimate the associations between teaching performance and role modeling. Results The different causal models were compatible with major differences in the magnitude of the relationship between faculty’s teaching performance and their role modeling. Odds ratios for the associations between teaching performance and the three role model types ranged from 31.1 to 73.6 for the teacher-supervisor role, from 3.7 to 15.5 for the physician role, and from 2.8 to 13.8 for the person role. Conclusions Different sets of assumptions about causal relationships in role modeling research can be visually depicted using DAGs, which are then used to guide both statistical analysis and interpretation of results. Since study conclusions can be sensitive to different causal assumptions, results

  11. Acyclic Cucurbit[n]uril-Type Molecular Container Enables Systemic Delivery of Effective Doses of Albendazole for Treatment of SK-OV-3 Xenograft Tumors.

    Science.gov (United States)

    Hettiarachchi, Gaya; Samanta, Soumen K; Falcinelli, Shane; Zhang, Ben; Moncelet, Damien; Isaacs, Lyle; Briken, Volker

    2016-03-07

    Approximately, 40-70% of active pharmaceutical ingredients (API) are severely limited by their extremely poor aqueous solubility, and consequently, there is a high demand for excipients that can be used to formulate clinically relevant doses of these drug candidates. Here, proof-of-concept studies demonstrate the potential of our recently discovered acyclic cucurbit[n]uril-type molecular container Motor1 (M1) as a solubilizing agent for insoluble drugs. M1 did not induce significant rates of mutations in various Salmonella typhimurium test strains during the Ames test, suggesting low genotoxicity. M1 also has low risk of causing cardiac toxicity in humans since it did not inhibit the human Ether-à-go-go-Related Gene channel as tested on transfected CHO cell lines via patch clamp analysis. Albendazole (ABZ) is a widely used antihelminthic agent but that has also shown promising efficacy against cancerous cells in vitro. However, due to its low aqueous solubility (2.7 μM) and poor pharmacokinetics, ABZ is clinically limited as an anticancer agent. Here we investigated the potential of M1 as a solubilizing excipient for ABZ formulation. A pharmacokinetic study indicated that ABZ escapes the peritoneal cavity resulting in 78% absolute bioavailability, while its active intermediate metabolite, albendazole sulfoxide, achieved 43% absolute bioavailability. The daily dosing of 681 mg/kg M1 complexed with 3.2 mg/kg of ABZ for 14 days did not result in significant weight loss or pathology in Swiss Webster mice. In vivo efficacy studies using this M1·ABZ inclusion complex showed significant decreases in tumor growth rates and increases in survival of mice bearing SK-OV-3 xenograft tumors. In conclusion, we provide substantial new evidence demonstrating that M1 is a safe and efficient excipient that enables in vivo parenteral delivery of poorly water-soluble APIs.

  12. Effect of initial GnRH and time of insemination on reproductive performance in cyclic and acyclic beef heifers subjected to a 5-d Co-synch plus progesterone protocol.

    Science.gov (United States)

    Helguera, I López; Whittaker, P; Behrouzi, A; Mapletoft, R J; Colazo, M G

    2018-01-15

    This study evaluated the effect of initial GnRH and timing of AI in a 5-d Co-synch plus CIDR (device containing 1.38 g of progesterone) protocol on pregnancy per AI (P/AI) and pregnancy loss in beef heifers. A secondary objective was to determine if the effect of initial GnRH on reproductive performance was influenced by cyclicity. Crossbred beef heifers (n = 1068; 301-514 kg of body weight, and 13-15 mo of age) at three locations were assigned to either a 5-d Co-synch plus CIDR protocol with (CIDR5G) or without (CIDR5NG) an initial injection of 100 μg of GnRH at CIDR insertion (Day 0). All heifers received a single dose of 500 μg of cloprostenol at CIDR removal (Day 5) and were divided into two groups to receive GnRH and TAI at either 66 or 72 h (Day 8) after CIDR removal. All heifers were inseminated by one technician with frozen-thawed semen from 1 of 4 sires available commercially. Transrectal ultrasonography was performed on Day 0 to determine cyclicity (presence of CL) and normalcy of the reproductive track, and 27 d after TAI to determine pregnancy status. Non-pregnant heifers (n = 470) were assigned to either a CIDR5G or a CIDR5NG protocol with TAI at 72 h after CIDR removal. Twelve days after second AI, heifers were exposure to bulls for 20 d and pregnancy diagnoses were performed approximately 30 d after second TAI and 60 d after bulls were removed to diagnose bull pregnancies and determine pregnancy loss rate. The percentage of acyclic heifers was 20.3%. Overall P/AI after first TAI was 55.6% (594/1068) and did not differ between CIDR5G and CIDR5NG (56.1 vs. 55.1%), or between TAI66 and TAI72 (55.8 vs. 55.4%). However, cyclic heifers were more likely to become pregnant than acyclic ones (59.3 vs. 41.2%; P P/AI than those subjected to CIDR5G (P P/AI after resynchronization was 55.1% and did not differ between CIDR5G and CIDR5NG (51.3 vs. 59.0%). Overall pregnancy loss after first and second TAI were 3.0% (18/594) and 3.9% (8

  13. Direct enantioseparation of underivatized aliphatic 3-hydroxyalkanoic acids with a quinine-based zwitterionic chiral stationary phase.

    Science.gov (United States)

    Ianni, Federica; Pataj, Zoltán; Gross, Harald; Sardella, Roccaldo; Natalini, Benedetto; Lindner, Wolfgang; Lämmerhofer, Michael

    2014-10-10

    While aliphatic 2-hydroxyalkanoic acids have been more or less successfully enantioseparated with various chiral stationary phases by HPLC and GC, analogous applications on underivatized aliphatic 3-hydroxyalkanoic acids are completely absent in the scientific literature. With the aim of closing this gap, the enantioseparation of 3-hydroxybutyric acid, 3-hydroxydecanoic acid and 3-hydroxymyristic acid has been performed with two ion-exchange type chiral stationary phases (CSPs): one containing the anion-exchange type tert-butyl carbamoyl quinine chiral selector motif (Chiralpak QN-AX), and the other carrying the new zwitterionic variant based on trans-(S,S)-2-aminocyclohexanesulfonic acid-derivatized quinine carbamate (Chiralpak ZWIX(+)) as the chiral selector and enantiodiscriminating element, respectively. The zwitterionic enantiorecognition material provided better results in terms of enantioselectivity and resolution compared to the anion-exchanger CSP at reduced retention times due to the intramolecular counterion effect imposed by the sulfonic acid moiety and its competition with the 3-hydroxyalkanoic acid analyte for ionic interaction at the quininium-anion exchanger site. It is thus recommended as the CSP of first choice for enantioseparations of the class of aliphatic 3-hydroxyalkanoic acids. With use of polar organic eluent composed of ACN/MeOH/AcOH - 95/5/0.05 (v/v/v), a good compromise in terms of analysis time and enantioresolution quality was accomplished. The major experimental variables have been investigated for optimization of the resolution and allowed to derive information on the enantiorecognition mechanism. Corresponding Chiralpak ZWIX(-), based on pseudo-enantiomeric selector derived from quinidine and trans-(R,R)-2-aminocyclohexanesulfonic acid with opposite configurations provided reversed enantiomer elution orders. It has further to be stressed that these separations can be obtained with mass spectrometry compatible mobile phases

  14. Characterization, Distribution, Sources and Origins of Aliphatic Hydrocarbons from Surface Sediment of Prai Strait, Penang, Malaysia: A Widespread Anthropogenic Input

    Directory of Open Access Journals (Sweden)

    Mahyar Sakari

    2008-07-01

    Full Text Available Persistent organic pollutants such as petroleum hydrocarbons are one of the most serious and important class of pollutants that face to many countries including Malaysia. Aliphatic hydrocarbons contain straight chain alkane; derive from anthropogenic and natural sources to the marine environment. The multi-purpose strait of Prai is located in the Northwest of Peninsular Malaysia plays an important economic role in the Southeast Asia. Twenty surface sediment samples were collected using Eckman dredge to measure the concentration and determine the characterization, sources and origins of the aliphatic hydrocarbons in December 2006. Samples (top 4 cm were extracted with Soxhlet, treated with activated copper and subjected to 2 steps column chromatography for purification and fractionation. Alkane fraction injected into Gas Chromatography–Flame Ionization Detector (GC-FID for instrumental analysis. The results showed that total n-alkane concentrations are ranging from 512 to 10770 ng/mg d. w. Carbon Preferences Index (CPI revealed an extreme widespread anthropogenic input and naturally derived (CPI= 0 to 4.88 hydrocarbons in the study area. The ratio of C31/C19 indicated that natural hydrocarbons are generating from terrestrial vascular plants and transferring by rivers. The characteristics of Major Hydrocarbons provided evidences that oil and its derivatives either fresh or degraded are the major contributors of the pollution in the study area. Statistical approaches also confirmed that 85% of study area affected by oil sources of pollution. It is seen that aliphatic hydrocarbons mostly transfer by lateral input to the marine environment than atmospheric movements.

  15. Assessment of the environmental risk of long-chain aliphatic alcohols.

    Science.gov (United States)

    Belanger, S E; Sanderson, H; Fisk, P R; Schäfers, C; Mudge, S M; Willing, A; Kasai, Y; Nielsen, A M; Dyer, S D; Toy, R

    2009-05-01

    An environmental assessment of long-chain alcohols (LCOH) has recently been conducted under the OECD SIDS High Production Volume (HPV) Program via the Global International Council of Chemical Associations (ICCA) Aliphatic Alcohols Consortium. LCOH are used primarily as intermediates, as a precursor to alcohol-based surfactants and as alcohol per se in a wide variety of consumer product applications. Global production volume is approximately 1.58 million metric tonnes. The OECD HPV assessment covers linear to slightly branched LCOH ranging from 6 to 22 alkyl carbons (C). LCOH biodegrade exceptionally rapidly in the environment (half-lives on the order of minutes); however, due to continuous use and distribution to wastewater treatment systems, partitioning properties, biodegradation of alcohol-based surfactants, and natural alcohol sources, LCOH are universally detected in wastewater effluents. An environmental risk assessment of LCOH is presented here by focusing on the most prevalent and toxic members of the linear alcohols, specifically, from C(12-15). The assessment includes environmental monitoring data for these chain lengths in final effluents of representative wastewater treatment plants and covers all uses of alcohol (i.e., the use of alcohol as a substance and as an intermediate for the manufacturing of alcohol-based surfactants). The 90th percentile effluent discharge concentration of 1.979microg/L (C(12)-C(15)) was determined for wastewater treatment plants in 7 countries. Chronic aquatic toxicity studies with Daphnia magna demonstrated that between C(13) and C(15) LCOH solubility became a factor and that the structure-activity relationship was characterized by a toxicity maximum between C(13) and C(14). Above C(14) the LCOH was less toxic and become un-testable due to insolubility. Risk quotients based on a toxic units (TU) approach were determined for various scenarios of exposure and effects extrapolation. The global average TU ranged from 0.048 to 0

  16. Ionic liquids as recyclable and separable reaction media in Rh-catalyzed decarbonylation of aromatic and aliphatic aldehydes

    DEFF Research Database (Denmark)

    Malcho, Phillip; Garcia-Suarez, Eduardo J.; Riisager, Anders

    2014-01-01

    Ionic liquids (ILs) have been applied as recyclable reaction media in the decarbonylation of aldehydes in the presence of a rhodium-phosphine complex catalyst. The performance of several new catalytic systems based on imidazolium-based ILs and [Rh(dppp)2]Cl (dppp: 1,3-diphenylphosphinopropane) were...... excellent in the decarbonylation of both aromatic and aliphatic aldehydes providing >99 yield of benzenes and alkanes, respectively. The catalytic performance depended, however, strongly on the employed IL and its thermal stability. In addition, the ILs afforded good catalyst immobilization as well...

  17. Physico-chemical properties of binary mixtures of aliphatic and aromatic solvents at 313 K on acoustical data

    Science.gov (United States)

    Dahire, S. L.; Morey, Y. C.; Agrawal, P. S.

    2015-12-01

    Density (ρ), viscosity (η), and ultrasonic velocity ( U) of binary mixtures of aliphatic solvents like dimethylformamide (DMF) and dimethylsulfoxide (DMSO) with aromatic solvents viz. chlorobenzene (CB), bromobenzene (BB), and nitrobenzene (NB) have been determined at 313 K. These parameters were used to calculate the adiabatic compressibility (β), intermolecular free length ( L f), molar volume ( V m), and acoustic impedance ( Z). From the experimental data excess molar volume ( V m E ), excess intermolecular free length ( L f E )), excess adiabatic compressibility (βE), and excess acoustic impedance ( Z E) have been computed. The excess values were correlated using Redlich-Kister polynomial equation to obtain their coefficients and standard deviations (σ).

  18. Ru (III Catalyzed Oxidation of Aliphatic Ketones by N-Bromosuccinimide in Aqueous Acetic Acid: A Kinetic Study

    Directory of Open Access Journals (Sweden)

    P. Giridhar Reddy

    2012-01-01

    Full Text Available Kinetics of Ru (III catalyzed oxidation of aliphatic ketones such as acetone, ethyl methyl ketone, diethyl ketone, iso-butylmethyl ketone by N-bromosuccinimide in the presence of Hg(II acetate have been studied in aqueous acid medium. The order of [N-bromosuccinimide] was found to be zero both in catalyzed as well as uncatalyzed reactions. However, the order of [ketone] changed from unity to a fractional one in the presence of Ru (III. On the basis of kinetic features, the probable mechanisms are discussed and individual rate parameters evaluated.

  19. Ruthenium-complex catalyzed N-(cyclo)alkylation of aromatic amines with diols. Selective synthesis of N-(n-hydroixyalkyl)anilines of type PhNH(CH2)nOH and of some bioactive arylpiperazines,

    NARCIS (Netherlands)

    Koten, G. van; Abbenhuis, R.A.T.M.; Boersma, J.

    1998-01-01

    A new class of well-defined neutral mono-, and dicationic ruthenium(II) complexes containing a neutral terdentate donor system [C5H3N(CH2E)(2)-2,6] (E = PPh2 (PNP) or NMe2 (NN'N)) has been found effective as catalyst precursor in N-(cyclo)alkylation reactions of aromatic amines with diols

  20. A novel synthesis and pharmacological evaluation of a potential dopamine D-1/D-2 agonist : 1-Propyl-1,2,3,4,4a,5,10,10-aoctahydrobenzo[g]quinoline-6,7-diol

    NARCIS (Netherlands)

    Liu, Danyang; Dijkstra, Durk; de Vries, Jan B.; Wikstrom, Hakan V.

    2008-01-01

    Previously, we have demonstrated that enone prodrugs of dopaminergic catecholamines represent a new type of dopamine (DA) agonist. Trans-1-propyl-1,2, 3,4,4a,5,10,10a-octahydrobenzo[g]quinoline-6,7-diol (TL-334), the active form

  1. Sterol synthesis. A novel reductive rearrangement of an alpha,beta-unsaturated steroidal epoxide; a new chemical synthesis of 5alpha-cholest-8(14)-en-3beta, 15alpha-diol.

    Science.gov (United States)

    Parish, E J; Schroepfer, G J

    1977-04-01

    Reduction of 3beta-benzoyloxy-14alpha,15alpha-epoxy-5alpha-cholest-7-ene with either lithium triethylboro-hydride or lithium aluminum hydride (4 molar excess) gave 5-alpha-cholest-8(14)-en-3beta,15alpha-diol in high yield. Reduction of the epoxy ester with lithium triethylborodeuteride or lithium aluminum deuteride (4 molar excess) gave [7alpha-2-H]-5alpha-cholest-8(14)-en-3beta,15alpha-diol. Reduction of 2beta-benzoyloxy-14alpha,15alpha-epoxy-5alpha-cholest-7-ene with a large excess (24 molar excess) of lithium aluminum hydride gave, in addition to the expected 5alpha-cholest-8(14)-en-3beta,15alpha-diol, a significant yield (33%) of 5alpha-cholest-8(14)-en-3beta-o1. Reduction of the epoxy ester with a large excess (24 molar excess) of lithium aluminum deuteride gave [7alpha-2H]-5alpha-cholest-8(14)-en-3beta,15alpha-diol and 5alpha-cholest-8(14)-en-3beta-o1 which contained two atoms of stably bound deuterium.

  2. In vitro bioactivation of 3-(N-phenylamino)propane-1,2-diol by human and rat liver microsomes and recombinant P450 enzymes. Implications for toxic oil syndrome

    NARCIS (Netherlands)

    Martinez-Cabot, A.; Morato, A.; Commandeur, J.N.M.; Vermeulen, N.P.E.; Messeguer, A.

    2007-01-01

    Toxic oil syndrome (TOS) was a massive food-borne intoxication that occurred in Spain in 1981. Epidemiological studies imputed 3-(N-phenylamino) propane-1,2-diol (PAP) derivatives as the toxic agents. The in vitro bioactivation of PAP by rat and human liver microsomes was studied. In both cases,

  3. Transfer and control of molecular chirality in the 1 : 2 host-guest supramolecular complex consisting of Mg(II)bisporphyrin and chiral diols: the effect of H-bonding on the rationalization of chirality.

    Science.gov (United States)

    Ikbal, Sk Asif; Brahma, Sanfaori; Rath, Sankar Prasad

    2014-11-21

    A clear rationalization of the origin of chirality transfer from an optically active diol guest to an achiral Mg(ii)bisporphyrin host in a series of 1 : 2 host-guest supramolecular complexes has been reported here that has so far remained the most outstanding issue for the chirogenic process.

  4. The Origin of Remarkable Chromatographic Differences in Novel Azulenyl-1,5-diols; & Synthesis and Use of Phosphinine and Phosphabarrelene Ligands for Asymmetric Catalysis

    Science.gov (United States)

    Horgen, Dana Ann

    The synthesis, characterization and analysis of novel chiral molecules advance many areas of synthetic organic chemistry, both industrially and academically. This work touches on three of the major methods for obtaining enantiomerically pure compounds. Based on the observation of a remarkably large difference in the silica TLC mobility of a pair of azulene 1,5-diol diastereomers, a series of such azulene 1,5-diols were prepared. Every pair of diastereomers was especially well separated, and X-ray crystallography revealed a conformational explanation of the large differences in mobility. The separation of the diol enantiomers was then studied on two chiral HLPC columns. The enantiomers were well-resolved, the separation appearing to benefit from the presence of the azulene ring. In addition, the more polar diastereomers on silica TLC gave dramatically better enantiomer separations on a Chiralcel-OD-H column. Very few chiral phosphinine and phosphabarrelene ligands have been reported in the literature but have shown promise as good ligands for asymmetric catalysis. Our group had previously synthesized a C2-symmetric chiral bis-camphorphosphinine and the derived bis-camphorphosphabarrelene but neither had been tested as ligands for hydroformylation. In this work, optimization of the synthesis of these two compounds was undertaken. In addition, modifications to the structure of these molecules that incorporated electron donating (N,N-dimethylaminophenyl-) or electron withdrawing (trifluoromethyl-) substituents were made in an attempt to affect the electronic nature of the phosphorus atom. Steric modifications were also done to create a more hindered environment around the phosphorus atom. The activity and selectivity of bis-camphorphosphinine, bis-camphorphosphabarrelene and other chiral phosphinine molecules serving as ligands in the rhodiumcatalyzed hydroformylation of styrene were compared to other phosphorus ligands recently published in the literature. All of

  5. EFSA Panel on Food Contact Material, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 201Rev1: 2-Alkylated, aliphatic, acyclic alpha,beta-unsaturated aldehydes and precursors, with or without additional double-bonds, from chemical subgroup 1

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider in this revision 1 of Flavouring Group Evaluation 201, the additional data on genotoxicity submitted by the Industry on two substances, 2-methylpent-2-enal....... The Panel therefore concluded that further data are required in order to clarify the genotoxic potential of this subgroup. The Panel considers the Comet assay with [FL-no: 05.095] as test material and performed on liver, blood and first site of contact, as a preferred option to further investigate...

  6. Scientific Opinion on the safety and efficacy of primary aliphatic saturated or unsaturated alcohols/aldehydes/acids/acetals/esters with a second primary, secondary or tertiary oxygenated functional group including aliphatic lactones (chemical group 9) when used as flavourings for all animal species

    OpenAIRE

    EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP)

    2012-01-01

    Chemical group 9 consists of primary aliphatic saturated or unsaturated alcohols/aldehydes/acids/acetals/esters with a second primary, secondary or tertiary oxygenated functional group including aliphatic lactones, of which 30 are currently authorised for use as flavours in food. The FEEDAP Panel was unable to perform an assessment of 2-oxopropanal because of issues related to the purity of the compound. The FEEDAP Panel concludes that lactic acid, succinic acid, fumaric acid, 4-oxov...

  7. Synthesis, properties and applications of biodegradable polymers derived from diols and dicarboxylic acids: from polyesters to poly(ester amide)s.

    Science.gov (United States)

    Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

    2014-04-25

    Poly(alkylene dicarboxylate)s 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 amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

  8. Synthesis, Properties and Applications of Biodegradable Polymers Derived from Diols and Dicarboxylic Acids: From Polyesters to Poly(ester amide)s

    Science.gov (United States)

    Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

    2014-01-01

    Poly(alkylene dicarboxylate)s 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 amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed. PMID:24776758

  9. Bis(1,10-phenanthroline-κ2N,N′(sulfato-κ2O,O′cobalt(II propane-1,3-diol solvate

    Directory of Open Access Journals (Sweden)

    Kai-Long Zhong

    2010-03-01

    Full Text Available The title compound, [Co(SO4(C12H8N22]·C3H8O2, was obtained unexpectedly as a by-product during an attempt to synthesize a mixed-ligand complex of CoII with 1,10-phenanthroline (phen and melamine via a solvothermal reaction. The CoII metal ions are in a distorted octahedral coordination environment formed by four N atoms from two chelating phen ligands and two O atoms from a bidentate sulfate ligand. The two chelating N2C2 groups are almost perpendicular to each other [dihedral angle = 80.06 (8°]. A twofold rotation axis passes through the Co and S atoms, and also through the central C atom of the propane-1,3-diol solvent molecule. Intermolecular O—H...O hydrogen bonds help to stabilize the structure.

  10. Synthesis of omega-hydroxy carboxylic acids and alpha,omega-dimethyl ketones using alpha,omega-diols as alkylating agents.

    Science.gov (United States)

    Iuchi, Yosuke; Hyotanishi, Megumi; Miller, Brittany E; Maeda, Kensaku; Obora, Yasushi; Ishii, Yasutaka

    2010-03-05

    Synthesis of omega-hydroxy carboxylic acids and alpha,omega-dimethyl diketones was successfully achieved by using alpha,omega-diols as alkylating agents under the influence of an iridium catalyst. For example, the alkylation of butyl cyanoacetate with 1,13-tridecanediol in the presence of [IrCl(cod)](2) or [IrCl(coe)(2)](2) gave rise to butyl 2-cyano-15-hydroxypentadecanoate in good yield which is easily converted to cyclopentadecanolide (CPDL). In addition, the alkylation of acetone with 1,10-decanediol in the presence of [IrCl(cod)](2) and KOH resulted in an important muscone precursor, 2,15-hexadecanedione (HDDO), in good yield.

  11. Bis(1,10-phenanthroline-κ2N,N′(sulfato-κ2O,O′nickel(II propane-1,3-diol solvate

    Directory of Open Access Journals (Sweden)

    Chao Ni

    2010-07-01

    Full Text Available In the structure of the title compound, [Ni(SO4(C12H8N22]·C3H8O2, the NiII ion (site symmetry 2 is six-coordinated in a distorted octahedral manner by four N atoms from two chelating 1,10-phenanthroline (phen ligands and two O atoms from a bidentate sulfate ligand (2 symmetry. The dihedral angle between the two chelating NCCN groups is 80.9 (1°. The central C atom of the propane-1,3-diol solvent molecule is likewise located on a twofold rotation axis. In the crystal structure, the [Ni(SO4(C12H8N22] and C3H8O2 entities are connected through intermolecular O—H...O hydrogen bonding.

  12. Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)

    Energy Technology Data Exchange (ETDEWEB)

    Alsabagh, A.M. [Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Ahmed El-Zomor Street 1, Nasr City, Cairo 11727 (Egypt); Migahed, M.A. [Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Ahmed El-Zomor Street 1, Nasr City, Cairo 11727 (Egypt)]. E-mail: mohamedatiyya707@hotmail.com; Awad, Hayam S. [Chemistry Department, Faculty of Girls for Science, Art and Education, Ain Shams University, Asmaa Fahmi Street, Helliopolis, Cairo (Egypt)

    2006-04-15

    Effect of different concentrations, 40-200 ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200 ppm). Inhibition efficiencies in the range 86-96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using Tafel extrapolation and polarisation resistance methods. It was shown that all the investigated surfactants act primarily as anodic inhibitors; however, they also affect the rate and mechanism of the cathodic reaction. These compounds function via adsorption on reactive sites on the corroding surface reducing the corrosion rate of the metal. It was revealed that the adsorption of these surfactants obey Langmuir adsorption isotherm. The inhibition effectiveness increases with the length of the aliphatic hydrocarbon chain, being a maximum in the presence of surfactant IV ({approx}96% efficiency). The corrosion inhibition feature of this compound is attributed to the presence of a long hydrocarbon chain that ensures large surface coverage as well as the presence of multiple active centers for adsorption. Scanning electron microscopy, SEM, has been applied to identify the surface morphology of carbon steel alloy in the absence and presence of the inhibitor molecules.

  13. A Comparative Study of Two Quantum Chemical Descriptors in Predicting Toxicity of Aliphatic Compounds towards Tetrahymena pyriformis

    Directory of Open Access Journals (Sweden)

    Altaf Hussain Pandith

    2010-01-01

    Full Text Available Quantum chemical parameters such as LUMO energy, HOMO energy, ionization energy (I, electron affinity (A, chemical potential (μ, hardness (η electronegativity (χ, philicity (ωα, and electrophilicity (ω of a series of aliphatic compounds are calculated at the B3LYP/6-31G(d level of theory. Quantitative structure-activity relationship (QSAR models are developed for predicting the toxicity (pIGC50 of 13 classes of aliphatic compounds, including 171 electron acceptors and 81 electron donors, towards Tetrahymena pyriformis. The multiple linear regression modeling of toxicity of these compounds is performed by using the molecular descriptor log P (1-octanol/water partition coefficient in conjunction with two other quantum chemical descriptors, electrophilicity (ω and energy of the lowest unoccupied molecular orbital (ELUMO. A comparison is made towards the toxicity predicting the ability of electrophilicity (ω versus ELUMO as a global chemical reactivity descriptor in addition to log P. The former works marginally better in most cases. There is a slight improvement in the quality of regression by changing the unit of IGC50 from mg/L to molarity and by removing the racemates and the diastereoisomers from the data set.

  14. Quantitative structure-activity relationship (QSAR) prediction of (eco)toxicity of short aliphatic protic ionic liquids.

    Science.gov (United States)

    Peric, Brezana; Sierra, Jordi; Martí, Esther; Cruañas, Robert; Garau, Maria Antonia

    2015-05-01

    Ionic liquids (ILs) are considered as a group of very promising compounds due to their excellent properties (practical non-volatility, high thermal stability and very good and diverse solving capacity). The ILs have a good prospect of replacing traditional organic solvents in vast variety of applications. However, the complete information on their environmental impact is still not available. There is also an enormous number of possible combinations of anions and cations which can form ILs, the fact that requires a method allowing the prediction of toxicity of existing and potential ILs. In this study, a group contribution QSAR model has been used in order to predict the (eco)toxicity of protic and aprotic ILs for five tests (Microtox®, Pseudokirchneriella subcapitata and Lemna minor growth inhibition test, and Acetylcholinestherase inhibition and Cell viability assay with IPC-81 cells). The predicted and experimental toxicity are well correlated. A prediction of EC50 for these (eco)toxicity tests has also been made for eight representatives of the new family of short aliphatic protic ILs, whose toxicity has not been determined experimentally to date. The QSAR model applied in this study can allow the selection of potentially less toxic ILs amongst the existing ones (e.g. in the case of aprotic ILs), but it can also be very helpful in directing the synthesis efforts toward developing new "greener" ILs respectful with the environment (e.g. short aliphatic protic ILs). Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Synthesis of Scutellarein Derivatives with a Long Aliphatic Chain and Their Biological Evaluation against Human Cancer Cells.

    Science.gov (United States)

    Ni, Guanghui; Tang, Yanling; Li, Minxin; He, Yuefeng; Rao, Gaoxiong

    2018-02-01

    Scutellarin is the major active flavonoid extracted from the traditional Chinese herbal medicine Erigeron breviscapus (Vant.) Hand-Mazz., which is widely used in China. Recently, accumulating evidence has highlighted the potential role of scutellarin and its main metabolite scutellarein in the treatment of cancer. To explore novel anticancer agents with high efficiency, a series of new scutellarein derivatives with a long aliphatic chain were synthesized, and the antiproliferative activities against Jurkat, HCT-116 and MDA-MB-231 cancer cell lines were assessed. Among them, compound 6a exhibited the strongest antiproliferative effects on Jurkat (IC 50 = 1.80 μM), HCT-116 (IC 50 = 11.50 μM) and MDA-MB-231 (IC 50 = 53.91 μM). In particular, 6a even showed stronger antiproliferative effects than the positive control NaAsO₂ on Jurkat and HCT-116 cell lines. The results showed that a proper long aliphatic chain enhanced the antiproliferative activity of scutellarein.

  16. Synthesis of Scutellarein Derivatives with a Long Aliphatic Chain and Their Biological Evaluation against Human Cancer Cells

    Directory of Open Access Journals (Sweden)

    Guanghui Ni

    2018-02-01

    Full Text Available Scutellarin is the major active flavonoid extracted from the traditional Chinese herbal medicine Erigeron breviscapus (Vant. Hand-Mazz., which is widely used in China. Recently, accumulating evidence has highlighted the potential role of scutellarin and its main metabolite scutellarein in the treatment of cancer. To explore novel anticancer agents with high efficiency, a series of new scutellarein derivatives with a long aliphatic chain were synthesized, and the antiproliferative activities against Jurkat, HCT-116 and MDA-MB-231 cancer cell lines were assessed. Among them, compound 6a exhibited the strongest antiproliferative effects on Jurkat (IC50 = 1.80 μM, HCT-116 (IC50 = 11.50 μM and MDA-MB-231 (IC50 = 53.91 μM. In particular, 6a even showed stronger antiproliferative effects than the positive control NaAsO2 on Jurkat and HCT-116 cell lines. The results showed that a proper long aliphatic chain enhanced the antiproliferative activity of scutellarein.

  17. A novel high-performance thin layer chromatography method for quantification of long chain aliphatic hydrocarbons from Cissus quadrangularis

    Directory of Open Access Journals (Sweden)

    Vandana Jain

    2016-08-01

    Full Text Available Context: A high-performance thin layer chromatography (HPTLC is an analytical technique, which can be used for the determination of constituents or marker components in various parts of the plants. Earlier studies have estimated phytoconstituents from the stem and other aerial plant parts of Cissus quadrangularis Linn. Estimation of hydrocarbons can also be successfully done using HPTLC technique using suitable derivatization. Aims: To develop and validate a simple and rapid method for the estimation of long chain aliphatic hydrocarbons from the leaves of C. quadrangularis using HPTLC technique. Methods: Precoated silica gel 60 F254 plates were used as stationary phase. The mobile phase used was hexane (100 %. The detection of spots was carried out using berberine sulphate as detecting reagent. Results: The method was validated in terms of linearity, sensitivity, accuracy, and precision. Linearity range was found to be 2-10 µg/mL, limit of detection 0.127 µg/mL, and limit of quantification 0.384 µg/mL. Conclusions: A novel, simple, accurate, precise and sensitive HPTLC method has been developed and validated for the estimation of long chain aliphatic hydrocarbons obtained from the leaves of C. quadrangularis Linn.

  18. Ion-Exclusion High-Performance Liquid Chromatography of Aliphatic Organic Acids Using a Surfactant-Modified C18 Column.

    Science.gov (United States)

    Fasciano, Jennifer M; Mansour, Fotouh R; Danielson, Neil D

    2016-07-01

    Ion exclusion chromatography (IELC) of short chain aliphatic carboxylic acids is normally done using a cation exchange column under standard HPLC conditions but not in the ultra-HPLC (UHPLC) mode. A novel IELC method for the separation of this class of carboxylic acids by either HPLC or UHPLC utilizing a C18 column dynamically modified with sodium dodecyl sulfate has been developed. The sample capacity is estimated to be near 10 mM for a 20 µL injection or 0.2 µmol using a 150 × 4.6 mm column. The optimum mobile phase determined for three standard mixtures of organic acids is 1.84 mM sulfuric acid at pH 2.43 and a flow rate of 0.6 mL/min. Under optimized conditions, a HPLC separation of four aliphatic carboxylic acids such as tartaric, malonic, lactic and acetic can be achieved in under 4 min and in C18 column can be easily extended when needed to IELC under either standard or UHPLC conditions. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Aliphatic C-C Bond Cleavage in α-Hydroxy Ketones by a Dioxygen-Derived Nucleophilic Iron-Oxygen Oxidant.

    Science.gov (United States)

    Bhattacharya, Shrabanti; Rahaman, Rubina; Chatterjee, Sayanti; Paine, Tapan K

    2017-03-17

    A nucleophilic iron-oxygen oxidant, formed in situ in the reaction between an iron(II)-benzilate complex and O 2 , oxidatively cleaves the aliphatic C-C bonds of α-hydroxy ketones. In the cleavage reaction, α-hydroxy ketones without any α-C-H bond afford a 1:1 mixture of carboxylic acid and ketone. Isotope labeling studies established that one of the oxygen atoms from dioxygen is incorporated into the carboxylic acid product. Furthermore, the iron(II) complex cleaves an aliphatic C-C bond of 17-α-hydroxyprogesterone affording androstenedione and acetic acid. The O 2 -dependent aliphatic C-C bond cleavage of α-hydroxy ketones containing no α-C-H bond bears similarity to the lyase activity of the heme enzyme, cytochrome P450 17A1 (CYP17A1). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. An amino acid at position 142 in nitrilase from Rhodococcus rhodochrous ATCC 33278 determines the substrate specificity for aliphatic and aromatic nitriles.

    Science.gov (United States)

    Yeom, Soo-Jin; Kim, Hye-Jung; Lee, Jung-Kul; Kim, Dong-Eun; Oh, Deok-Kun

    2008-11-01

    Nitrilase from Rhodococcus rhodochrous ATCC 33278 hydrolyses both aliphatic and aromatic nitriles. Replacing Tyr-142 in the wild-type enzyme with the aromatic amino acid phenylalanine did not alter specificity for either substrate. However, the mutants containing non-polar aliphatic amino acids (alanine, valine and leucine) at position 142 were specific only for aromatic substrates such as benzonitrile, m-tolunitrile and 2-cyanopyridine, and not for aliphatic substrates. These results suggest that the hydrolysis of substrates probably involves the conjugated pi-electron system of the aromatic ring of substrate or Tyr-142 as an electron acceptor. Moreover, the mutants containing charged amino acids such as aspartate, glutamate, arginine and asparagine at position 142 displayed no activity towards any nitrile, possibly owing to the disruption of hydrophobic interactions with substrates. Thus aromaticity of substrate or amino acid at position 142 in R. rhodochrous nitrilase is required for enzyme activity.

  1. Camphor-10-sulfonic acid catalyzed condensation of 2-naphthol with aromatic/aliphatic aldehydes to 14-aryl/alkyl-14H-dibenzo[a,j]xanthenes

    Directory of Open Access Journals (Sweden)

    Kundu Kshama

    2014-01-01

    Full Text Available (±-Camphor-10-sulfonic acid (CSA catalyzed condensation of 2-naphthol with both aliphatic/aromatic aldehydes at 80°C yielded 14-alkyl/aryl-dibenzoxanthenes as the sole product in high yields. However, the same condensation with benzaldehyde at 25°C afforded a mixture of intermediate 1,1-bis-(2-hydroxynaphthylphenylmethane and 14-phenyl-dibenzoxanthene while the condensation with aliphatic aldehydes at 25°C furnished the corresponding 14-alkyl-dibenzoxanthenes as the sole product. Moreover, condensation of 2-naphthol with aromatic/aliphatic aldehydes with low catalyst loading (2 mol% was greatly accelerated under microwave irradiation to afford the corresponding 14-aryl/alkyl-dibenzoxanthenes as the sole product in high yields.

  2. Effects of a melanogenic bicyclic monoterpene diol on cell cycle, p53, TNF-alpha, and PGE2 are distinct from those of UVB.

    Science.gov (United States)

    Kraus, Eliyahu; Galvin, Jason W; Boumakis, Stavroula; Boamah, Ernest K; Canning, Matthew T; Yarosh, Daniel B; Brown, David A

    2003-12-01

    Bicyclic monoterpene (BMT) diols are small-molecule compounds that mimic ultraviolet radiation (UVR) by inducing melanogenesis. The objective of this study was to compare the effects of 2,2-dimethyl-3-propanyldiol-norbornane (AGI-1140), a novel BMT diol, and ultraviolet B (UVB) on additional cellular responses. S91 mouse melanoma cells were treated with a range of concentrations of AGI-1140, and examined for induction of melanogenesis and nitric oxide (NO). The effect of AGI-1140 on dendrite outgrowth from human melanocytes was examined by quantitative microscopy. The effect of AGI-1140 and UVB on phosphorylation of p53 serine 15 in human keratinocytes was examined by Western blotting, while the release of tumor necrosis factor-alpha (TNF-alpha) and prostaglandin E2 (PGE2) was determined by enzyme-linked immunosorbent assay. The effects of AGI-1140 and UVB on cell cycle arrest of human melanocytes, keratinocytes, fibroblasts, and endothelial cells were compared using fluorescence-activated cell sorting. Similar to UVB, AGI-1140 induced both melanogenesis and NO in melanoma cells. AGI-1140 also induced dendrite outgrowth from melanocytes, indicative of differentiation. However, whereas UVB induced G2 cell cycle arrest with phosphorylation of p53 at serine 15, AGI-1140 induced G1 cell cycle arrest without this phosphorylation. Additionally, unlike UVB, AGI-1140 did not increase the secretion of TNF-alpha or PGE2, mediators of UVB-induced immunosuppressive and inflammatory responses in the skin that may contribute to carcinogenesis. This study shows that melanogenesis can be induced by AGI-1140 without many of the deleterious effects associated with UVB.

  3. Bicyclic monoterpene diols induce differentiation of S91 melanoma and PC12 pheochromocytoma cells by a cyclic guanosine-monophosphate-dependent pathway.

    Science.gov (United States)

    Brown, D A; Lesiak, K; Ren, W Y; Strzelecki, K L; Khorlin, A A

    1999-02-01

    Previously, we showed that 5-norbornene-2,2-dimethanol (5-NBene-2,2-DM) is an effective inducer of melanogenesis in cultured cells and guinea-pig skin [Brown et al. (1998) J. Invest. Dermatol., 110:428-437]. This study shows that 2,3-cis/exo-pinanediol (2,3-cs/ex-PinD) is a more effective inducer of melanogenesis than 5-NBene-2,2-DM in S91 mouse melanoma cells. Furthermore, 2,3-cs/ex-PinD appears to penetrate guinea-pig skin better than 5-NBene-2,2-DM and to induce higher levels of pigmentation. Both 5-NBene-2,2-DM and 2,3-cs/ex-PinD induce synthesis of nitric oxide (NO) in S91 cells, and the melanogenic activity of both compounds is reduced by inhibitors of the NO/cyclic guanosine monophosphate (cGMP)/protein kinase(PK) G signaling pathway, but not by inhibitors of the PKC or PKA pathways. Thus, these bicyclic monoterpene diols appear to induce melanogenesis by the same pathway in S91 cells as that shown previously for ultraviolet radiation in melanocytes (Romero-Graillet et al. (1996) J. Biol. Chem., 271:28052-28056). These compounds also induce NO synthesis, neurite outgrowth, and tyrosine hydroxylase activity in PC12 pheochromocytoma cells. Neurite outgrowth in PC12 cells is blocked by the guanylate cyclase inhibitor, LY83583 (6-anilino-2,8-quinolinequinone), indicating that, similar to S91 cells, the induction of morphological differentiation of PC12 cells by bicyclic monoterpene diols is regulated by a cGMP-dependent pathway.

  4. Modified solution calorimetry approach for determination of vaporization and sublimation enthalpies of branched-chain aliphatic and alkyl aromatic compounds at T = 298.15 K

    International Nuclear Information System (INIS)

    Varfolomeev, Mikhail A.; Novikov, Vladimir B.; Nagrimanov, Ruslan N.; Solomonov, Boris N.

    2015-01-01

    Highlights: • Solution enthalpies of 18 branching-chain alkyl aromatic and aliphatic compounds in cyclohexane were measured. • Group contributions to the enthalpy of solvation due to branching and substitution in carbon chain were evaluated. • Modified solution calorimetry based approach for determination of vaporization/sublimation enthalpies was proposed. • This approach provides vaporization/sublimation enthalpies directly at T = 298.15 K. • Vaporization/sublimation enthalpies of 35 branched-chain alkyl aromatic and aliphatic compounds were determined. - Abstract: The enthalpies of solution, solvation and vaporization/sublimation are interrelated values combined in the simplest thermodynamic circle. Hence, experimental determination of vaporization/sublimation enthalpy can be substituted by experimentally simpler determination of solution enthalpy when solvation enthalpy is known. Previously it was found that solvation enthalpies of a wide range of unbranched aliphatic and aromatic solutes in saturated hydrocarbons are in good linear correlation with their molar refraction values. This allows to estimate the vaporization/sublimation enthalpy of any unbranched organic compound from its solution enthalpy in saturated hydrocarbon and molar refraction. In the present work this approach was modified for determination of vaporization/sublimation enthalpy of branched-chain alkyl aromatic and aliphatic compounds. Group contributions to the enthalpy of solvation due to the branching of carbon chain were evaluated. Enthalpies of solution at infinite dilution of 18 branched-chain aliphatic and alkyl aromatic compounds were measured at T = 298.15 K. Vaporization/sublimation enthalpies for 35 branched aliphatic and alkyl aromatic compounds were determined by using modified solution calorimetry approach. These values are in good agreement with available literature data on vaporization/sublimation enthalpies obtained by conventional methods.

  5. Joint Test Report For Validation of Alternatives to Aliphatic Isocyanate Polyurethanes

    Science.gov (United States)

    Lewis, Pattie

    2007-01-01

    National Aeronautics and Space Administration (NASA) and Air Force Space Command (AFSPC) have similar missions and therefore similar facilities and structures in similar environments. The standard practice for protecting metallic substrates in atmospheric environments is the application of an applied coating system. The most common topcoats used in coating systems are polyurethanes that contain isocyanates. Isocyanates are classified as potential human carcinogens and are known to cause cancer in animals. The primary objective of this effort was to demonstrate and validate alternatives to aliphatic isocyanate polyurethanes resulting in one or more isocyanate-free coatings qualified for use at AFSPC and NASA installations participating in this project. This joint Test Report (JTR) documents the results of the laboratory and field testing as well as any test modifications made during the execution of the testing. The technical stakeholders agreed upon test procedure modifications documented in this document. This JTR is made available as a reference for future pollution prevention endeavors by other NASA centers, the Department of Defense and commercial users to minimize duplication of effort. All coating system candidates were tested using approved NASA and AFSPC standard coating systems as experimental controls. This study looked at eight alternative coating systems and two control coating systems and was divided into Phase I Screening Tests, Phase II Tests, and Field Testing. The Phase I Screening Tests were preliminary tests performed on all the selected candidate coating systems. Candidate coating systems that did not meet the acceptance criteria of the screening tests were eliminated from further testing. Phase I Screening Tests included: Ease of Application, Surface Appearance, Dry-To-Touch (Sanding), Accelerated Storage Stability, Pot Life (Viscosity), Cure Time (Solvent Rubs), Cleanability, Knife Test, Tensile (pull-off) Adhesion, and X-Cut Adhesion by Wet

  6. Aliphatic C-H activation with aluminium trichloride-acetyl chloride: expanding the scope of the Baddeley reaction for the functionalisation of saturated hydrocarbons.

    Science.gov (United States)

    Lyall, Catherine L; Uosis-Martin, Mario; Lowe, John P; Mahon, Mary F; Pantoş, G Dan; Lewis, Simon E

    2013-03-07

    The functionalisation of decalin by means of an "aliphatic Friedel-Crafts" reaction was reported over fifty years ago by Baddeley et al. This protocol is of current relevance in the context of C-H activation and here we demonstrate its applicability to a range of other saturated hydrocarbons. Structural elucidation of the products is described and a mechanistic rationale for their formation is presented. The "aliphatic Friedel-Crafts" procedure allows for production of novel oxygenated building blocks from abundant hydrocarbons and as such can be considered to add significant synthetic value in a single step.

  7. Design and Synthesis of Novel Antimicrobial Acyclic and Heterocyclic Dyes and Their Precursors for Dyeing and/or Textile Finishing Based on 2-N-Acylamino-4,5,6,7-tetrahydro-benzo[b]thiophene Systems

    Directory of Open Access Journals (Sweden)

    Rafat Milad Mohareb

    2011-07-01

    Full Text Available A series of novel polyfunctionalized acyclic and heterocyclic dye precursors and their respective azo (hydrazone counterpart dyes and dye precursors based on conjugate enaminones and/or enaminonitrile moieties were synthesized. The dyes and their precursors are based on 2-cyano-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide, 2-ethoxycarbonyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide or 2-phenylcarbamoyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide systems as precursors. The latter compounds were used to synthesize polyfunctional thiophene-, thiazole-, pyrazole, pyridine-, pyrimidine-, oxazine-, as well as acyclic moieties. The dyes and dye precursors were characterized by elemental analysis and spectral methods. All dyes and their precursors were screened in vitro and evaluated for both their antibacterial and antifungal activities. MIC data of the novel dye systems and their respective precursors showed significant antimicrobial activity against most tested organisms. Some compounds exhibited comparable or even higher efficiency than selected standards. Dyes were applied at 5% depth for disperse dyeing of nylon, acetate and polyester fabrics. Their spectral characteristics and fastness properties were measured and evaluated.

  8. Differences of diurnal variations of some aliphatic and polycyclic aromatic hydrocarbons concentrations in aerosols of the urban area of Madrid

    International Nuclear Information System (INIS)

    Perez, M. M.; Perez-Pastor, R. M.; Bea, F. J.; Campos, A.; Gonzalez, D.

    1991-01-01

    A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled m the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. (Author)

  9. Differences of diurnal variations of some aliphatic and polycyclic aromatic hydrocarbons concentrations in aerosol of the urban area of Madrid

    International Nuclear Information System (INIS)

    Perez Garcia, M.M.; Perez Pastor, R.M.; Bea, J.F.; Campos, A.; Gonzalez Diaz, D.

    1990-01-01

    A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled in the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. From these results, it has been tried to identify emission sources of the studied hydrocarbons. (Author). 10 refs

  10. Gold recovery from acidic leach solutions using as extractants trialkylamines of N,N'-di-alkyl-aliphatic amides

    Energy Technology Data Exchange (ETDEWEB)

    Baroncelli, F.; Carlini, D.; Gasparini, G.M.; Simonetti, E.

    1988-07-01

    TriOctylAmine (TOA) and a di-substituted aliphatic amide, N,N-Di-N-ButylOctanamide (DBOA), were examined in batch and in mini mixer-settler experiments using leachates of Peruvian and Bolivian concentrates. With these minerals, very rich in sulfur (pyrites, stybine), 90-95% gold recovery in 12-24 hours was reached by leaching with 4M aqua regia (HCl 3M nitric acid 1M) at room temperature and with 1/3 solid/liquid ratio. With these leachate solutions (2-3M total acidity, 10-60 ppm ao Au), the two processes with TOA (GAMEX PROCESS) and with DBOA (AUMIDEX PROCESS) were tested and compared. Experimental results strongly support the possibility of using TOA and DBOA on an industrial scale.

  11. Comparison of supercritical fluid extraction and Soxhlet extraction for the determination of aliphatic hydrocarbons in seaweed samples.

    Science.gov (United States)

    Punín Crespo, M O; Lage Yusty, M A

    2006-07-01

    Supercritical fluid extraction (SFE) and Soxhlet extraction methods were compared in a study of the aliphatic hydrocarbon profiles of seaweed samples. Method precision for Soxhlet extraction (Soxhlet extraction is a more suitable method. To evaluate the SFE and Soxhlet methods developed, three diverse Undaria pinnatifida samples collected at different dates and areas of the Galician coast were analyzed. n-Alkanes C18, C20, C22, C24, and C28 were found in all samples, with values lower than 7.9 microg g(-1) d.w. The total hydrocarbon content was within the range of 13.6-21.7 microg g(-1) d.w. C18 was found to be the most abundant.

  12. Size of the aliphatic chain of sodium houttuyfonate analogs determines their affinity for renin and angiotensin I converting enzyme.

    Science.gov (United States)

    Yuan, Lujiang; Wu, Jianping; Aluko, Rotimi E

    2007-08-01

    Sodium houttuyfonate analogs (SHAs), CH(3)-(CH(2))(n)-CO-CH(2)-CH(OH)SO(3)Na, (n=6-14) were synthesized and their molecular interactions with renin and angiotensin I converting enzyme (ACE) studied using fluorescence quenching techniques. Unlike renin, inhibition of ACE activity was not directly proportional to the aliphatic chain length of SHAs. Ability of SHAs to inhibit enzyme activities and quench protein fluorescence was greater with renin than with ACE. The presence of an ACE substrate (angiotensin I) did not reduce quenching ability of SHAs, suggesting that enzyme-inhibitor interactions did not involve the active site or the substrate was displaced by inhibitor molecules. The results showed that renin is a more sensitive target than ACE for the potential antihypertensive ability of SHAs.

  13. Screening and Quantification of Aliphatic Primary Alkyl Corrosion Inhibitor Amines in Water Samples by Paper Spray Mass Spectrometry.

    Science.gov (United States)

    Jjunju, Fred P M; Maher, Simon; Damon, Deidre E; Barrett, Richard M; Syed, S U; Heeren, Ron M A; Taylor, Stephen; Badu-Tawiah, Abraham K

    2016-01-19

    Direct analysis and identification of long chain aliphatic primary diamine Duomeen O (n-oleyl-1,3-diaminopropane), corrosion inhibitor in raw water samples taken from a large medium pressure water tube boiler plant water samples at low LODs (boiler plant and other related samples in the water treatment industry. This approach was applied for the analysis of three complex water samples including feedwater, condensate water, and boiler water, all collected from large medium pressure (MP) water tube boiler plants, known to be dosed with varying amounts of polyamine and amine corrosion inhibitor components. Polyamine chemistry is widely used for example in large high pressure (HP) boilers operating in municipal waste and recycling facilities to prevent corrosion of metals. The samples used in this study are from such a facility in Coventry waste treatment facility, U.K., which has 3 × 40 tonne/hour boilers operating at 17.5 bar.

  14. Escherichia coli as a potential hydrocarbon conversion microorganism. Oxidation of aliphatic and aromatic compounds by recombinant E. coli in two-liquid phase (aqueous-organic) systems

    NARCIS (Netherlands)

    Favre-Bulle, Olivier

    1992-01-01

    The increased interest in the study of hydrocarbon utilizing microorganisms in recent years has been stimulated by the possibility of using their monooxygenases in the selective oxidation of aliphatic and aromatic compounds. As an example, long chain (>C16) n-alkanes are converted to dicarboxylic

  15. Cobalt-Porphyrin-Catalysed Intramolecular Ring-Closing C-H Amination of Aliphatic Azides: A Nitrene-Radical Approach to Saturated Heterocycles

    NARCIS (Netherlands)

    Kuijpers, P.F.; Tiekink, M.J.; Breukelaar, W.B.; Broere, D.L.J.; van Leest, N.P.; van der Vlugt, J.I.; Reek, J.N.H.; de Bruin, B.

    2017-01-01

    Cobalt-porphyrin-catalysed intramolecular ring-closing C−H bond amination enables direct synthesis of various N-heterocycles from aliphatic azides. Pyrrolidines, oxazolidines, imidazolidines, isoindolines and tetrahydroisoquinoline can be obtained in good to excellent yields in a single reaction

  16. Non-Heme Iron Catalysts with a Rigid Bis-Isoindoline Backbone and Their Use in Selective Aliphatic C−H Oxidation

    NARCIS (Netherlands)

    Chen, Jianming; Lutz, Martin; Milan, Michela; Costas, Miquel; Otte, Matthias; Klein Gebbink, Bert

    2017-01-01

    Iron complexes derived from a bis-isoindoline-bis-pyridine ligand platform based on the BPBP ligand (BPBP=N,N′-bis(2-picolyl)-2,2′-bis-pyrrolidine) have been synthesized and applied in selective aliphatic C−H oxidation with hydrogen peroxide under mild conditions. The introduction of benzene

  17. The Cer-cqu gene cluster determines three key players in a β-diketone synthase polyketide pathway synthesizing aliphatics in epicuticular waxes

    DEFF Research Database (Denmark)

    Schneider, Lizette Marais; Adamski, Nikolai M.; Christensen, Caspar Elo

    2016-01-01

    alkan-2-ols. These aliphatics are present in many Triticeae as well as dicotyledons such as Eucalyptus and Dianthus. Recently developed genomic resources and mapping populations in barley defined these genes to a small region on chromosome arm 2HS. Exploiting Cer-c and -u potential functions pinpointed...

  18. Synthesis and characterization of soluble, blue-fluorescent polyamides and polyimides containing substituted p-terphenyl as well as long aliphatic segments in the main chain

    NARCIS (Netherlands)

    Mikroyannidis, JA; Tsivgoulis, GM

    1999-01-01

    A novel class of semiflexible polyamides and polyimides bearing substituted p-terphenyl as well as long aliphatic segments in the main chain were synthesized through pyrylium salts. Characterization of polymers was accomplished by inherent viscosity, elemental analysis, FT-IR, NMR, UV-vis

  19. In Situ and Laboratory Studies on the Fate of Specific Organic Compounds in an Anerobic Landfill Leachate Plume, 2. Fate of Aromatic and Chlorinated Aliphatic Compounds

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Bjarnadóttir, Helga; Winter, Pia L.

    1995-01-01

    the landfill in Fe(IIl)-reducing conditions but not in NO3-reducing conditions at 350 m from the landfill. Abiotic processes apparently contributed to the transformation of tetrachloromethane. A local variation in the transformation of the chlorinated aliphatic hydrocarbons was observed at 2 m from...

  20. Introduction of an Aliphatic Ketone into Recombinant Proteins in a Bacterial Strain that Overexpresses an Editing-Impaired Leucyl-tRNA Synthetase

    Science.gov (United States)

    Tang, Yi; Wang, Pin; Van Deventer, James A.; Link, A. James; Tirrell, David A.

    2011-01-01

    A leucine analog containing a ketone has been incorporated into proteins in E. coli. Only E. coli strains overexpressing an editing-deficient leucyl-tRNA synthetase were capable of synthesizing proteins with the aliphatic ketone amino acid. Modification of ketone-containing proteins under mild conditions has been demonstrated. PMID:19670197