WorldWideScience

Sample records for aliphatic acyclic diols

  1. Synthesis and characterizations of degradable aliphatic-aromatic copolyesters from lactic acid, dimethyl terephthalate and diol: Effects of diol type and monomer feed ratio

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available Lactic acid-based aliphatic/aromatic copolyesters are synthesized to incorporate the degradability of polylactic acid and good mechanical properties of aromatic species by using polycondensation of lactic acid (LA, dimethyl terephthalate (DMT, and various diols. Effects of diol lengths and comonomer feed ratios on structure and properties of the resulting copolymers are investigated. Three types of diols with different methylene lengths are employed, i.e., ethylene glycol (EG, 1,3-propanediol (PD and 1,4-butanediol (BD. LA/DMT/diol feed ratios of 2:1:2, 1:1:2, and 1:2:4 are used in each diol system. It is found that types of the diols play an important role in the properties of the copolyester, where an increase in diol length results in an increase in the copolymers molecular weight, and a decrease in Tg, Tm and crystallinity, when a constant monomer feed ratio is employed. Monomer feed ratio also has a significant effect on properties of the copolymers, where an increase in the aromatic content leads to formation of copolymers with higher molecular weight, longer aromatic block sequence and high aromatic to aliphatic ratio in the chain structure. These, in turn, lead to an increase in Tg, Tm, crystallinity and thermal stability of the copolymer samples, and a reduction in their solubility.

  2. Molecular orbital studies on the Wagner-Meerwein migration in some acyclic pinacol-pinacolone rearrangements

    Indian Academy of Sciences (India)

    Zodinpuia Pachuau; R H Duncan Lyngdoh

    2004-03-01

    The semi-empirical PM3 SCF-MO method is used to investigate the Wagner-Meerwein migration of various groups during the pinacol-pinacolone rearrangement of some acyclic systems. Pinacol first protonates and dehydrates to form a carbocation that undergoes a 1,2-migration to form a protonated ketone, which then deprotonates to yield the pinacolone product. We study the Wagner-Meerwein migration of hydride, methyl, ethyl, isopropyl, t-butyl, phenyl and heterocylic 2-, 3- and 4-pyridyl groups in various acyclic 1,2-diol (pinacol) systems as they rearrange to pinacolones. This 1,2-migration involves a three-centred moiety in the cationic transition state. The migratory aptitude predicted here follows the order: hydride -butyl > isopropyl > ethyl > methyl > phenyl, which accords well with available experimental data and/or chemical intuition, reflecting also on the ability of the group involved to carry positive charge in the transition state. The structure of the migrating group (whether aliphatic or aromatic) within the transition state also supports the stabilising role of delocalisation of positive charge for reaction feasibility. Geometrical and thermodynamic considerations coincide in assigning the following order to relative ``earliness” of the transition state along the reaction pathway: -butyl > isopropyl > phenyl > methyl > 2-pyridyl > 4-pyridyl.

  3. Counting acyclic hypergraphs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Acyclic hypergraphs are analogues of forests in graphs. They arevery useful in the design of databases. The number of distinct acyclic uniform hypergraphs with n labeled vertices is studied. With the aid of the principle of inclusion-exclusion, two formulas are presented. One is the explicit formula for strict (d)-connected acyclic hypergraphs, the other is the recurrence formula for linear acyclic hypergraphs.

  4. A biocatalytic approach towards sustainable furanic-aliphatic polyesters

    NARCIS (Netherlands)

    Jiang, Yi; Woortman, Albert J. J.; van Ekenstein, Gert O. R. Alberda; Loos, Katja

    2015-01-01

    An eco-friendly approach towards furanic-aliphatic polyesters as sustainable alternatives to aromatic-aliphatic polyesters is presented. In this approach, biobased dimethyl 2,5-furandicarboxylate (DMFDCA) is polymerized with various (potentially) renewable aliphatic diols via Candida antarctica Lipa

  5. Acyclic social welfare

    OpenAIRE

    Lahiri, Somdeb

    2009-01-01

    In this paper we show that if the Pareto relation is acyclic then the set of all Pareto optimal social states coincides with chosen social states of acyclic Paretian social welfare relations. Subsequently we show that given an acyclic Paretian social welfare relations the set of all social states chosen by it coincides with the set of all states chosen by strict Paretian extensions whose strict extension is the given social welfare relation.

  6. Alternating polyesteramides based on 1,4-butylene terephthalamide: 2. alternating polyesteramides based on a single, linear diol (4NTm)

    NARCIS (Netherlands)

    Serrano, P.J.M.; Thuss, E.H.L.; Gaymans, R.J.

    1997-01-01

    Strictly alternating polyesteramides consisting of 1,4-butylene terephthalamide and aliphatic diols have been synthesized in the melt in the presence of a titanium catalyst. The influence of diol length on the thermal and mechanical properties was studied. Depending on its structure, the diol took p

  7. Subquivers of mutation-acyclic quivers are mutation-acyclic

    CERN Document Server

    Warkentin, Matthias

    2011-01-01

    Quiver mutation plays a crucial role in the definition of cluster algebras by Fomin and Zelevinsky. It induces an equivalence relation on the set of all quivers without loops and two-cycles. A quiver is called mutation-acyclic if it is mutation-equivalent to an acyclic quiver. The aim of this note is to show that full subquivers of mutation-acyclic quivers are mutation-acyclic.

  8. Enumeration of Maximum Acyclic Hypergraphs

    Institute of Scientific and Technical Information of China (English)

    Jian-fang Wang; Hai-zhu Li

    2002-01-01

    Acyclic hypergraphs are analogues of forests in graphs. They are very useful in the design of databases. In this article, the maximum size of an acyclic hypergraph is determined and the number of maximum r-uniform acyclic hypergraphs of order n is shown to be ( n t-1 )(n(r-1)-r2 +2r)n-r-1.

  9. Acyclic Nucleoside Phosphonates

    Czech Academy of Sciences Publication Activity Database

    Holý, Antonín; Jansa, Petr

    Beijing: -, 2009. s. 119-119. [BIT's Annual World Summit of Antivirals 2009 /2./. 18.07.2009-20.07.2009, Beijing] R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * tenofovir * adefovir Subject RIV: CC - Organic Chemistry

  10. ON ACYCLIC AND CYCLIC HYPERGRAPHS

    Institute of Scientific and Technical Information of China (English)

    LI Haizhu; WANG Jianfang

    2002-01-01

    So far, the acyclic hypergraph has two different definitions. One is based onthe cyclomatic number of the hypergraph, whereas the other arises from the acyclic schemaof the relational database in the computer science. In this paper, it is first proved thatthese two definitions coincide with each other completely. Then we prove that a hypergraphH is not acyclic, or cyclic, if and only if it contains a special partial hypergraph namedhypercircuit. In addition, we show that H has l(H) different hypercircuits, where l(H) isa parameter used to decide whether H is acyclic or cyclic.

  11. Backdoors to Acyclic SAT

    CERN Document Server

    Gaspers, Serge

    2011-01-01

    Backdoor sets, a notion introduced by Williams et al. in 2003, are certain sets of "key" variables of a CNF formula F that make it easy to solve the formula; by assigning truth values to the variables in a backdoor set, the formula gets reduced to one or several polynomial-time solvable formulas. More specifically, a weak backdoor set of F is a set X of variables such that there exits a truth assignment t to X that reduces F to a satisfiable formula F[t] that belongs to a polynomial-time decidable base class C. A strong backdoor set is a set X of variables such that for all assignments t to X, the reduced formula F[t] belongs to C. We study the problem of finding backdoor sets of size at most k with respect to the base class of CNF formulas with acyclic incidence graphs, taking k as the parameter. We show that 1. the detection of weak backdoor sets is W[2]-hard in general but fixed-parameter tractable for r-CNF formulas, for any fixed r>=3, and 2. the detection of strong backdoor sets is fixed-parameter appro...

  12. Some inequalities for orderings of acyclic digraphs

    CERN Document Server

    Bier, Thomas

    2011-01-01

    For any acyclic ordering $g$ of a finite acyclic digraph $D$ we obtain a lower bound inequality for the inner product of its $e-$vector and $g.$ Here the $e-$vector is defined to be the difference of the indegree and the outdegree of the underlying acyclic digraph. This gives a lower bound on the functional $ T_e(f) = ,$ defined on the set of all acyclic orderings of $D.$ The class of acyclic digraphs which admit an acyclic ordering attaining the lower bound is determined as the class of posets of order dimension two.

  13. Elastic Compositions Based on Polyurethane/ Aliphatic Polyesters

    International Nuclear Information System (INIS)

    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

  14. Convex sets in acyclic digraphs

    CERN Document Server

    Balister, P; Gutin, G

    2007-01-01

    A non-empty set $X$ of vertices of an acyclic digraph is called connected if the underlying undirected graph induced by $X$ is connected and it is called convex if no two vertices of $X$ are connected by a directed path in which some vertices are not in $X$. The set of convex sets (connected convex sets) of an acyclic digraph $D$ is denoted by $\\sco(D)$ ($\\scc(D)$) and its size by $\\co(D)$ ($\\cc(D)$). Gutin, Johnstone, Reddington, Scott, Soleimanfallah, and Yeo (Proc. ACiD'07) conjectured that the sum of the sizes of all (connected) convex sets in $D$ equals $\\Theta(n \\cdot \\co(D))$ ($\\Theta(n \\cdot \\cc(D))$) where $n$ is the order of $D$. In this paper we exhibit a family of connected acyclic digraphs with $\\sum_{C\\in \\sco(D)}|C| = o(n\\cdot \\co(D))$ and $\\sum_{C\\in \\scc(D)}|C| = o(n\\cdot \\cc(D))$. We also show that the number of connected convex sets of order $k$ in any connected acyclic digraph of order $n$ is at least $n-k+1$. This is a strengthening of a theorem by Gutin and Yeo.

  15. Ruthenium(salen)-catalyzed aerobic oxidative desymmetrization of meso-diols and its kinetics.

    Science.gov (United States)

    Shimizu, Hideki; Onitsuka, Satoaki; Egami, Hiromichi; Katsuki, Tsutomu

    2005-04-20

    Chiral (nitrosyl)ruthenium(salen) complexes were found to be efficient catalysts for aerobic oxidative desymmetrization of meso-diols under photoirradiation to give optically active lactols. The scope of the applicability of this reaction ranges widely from acyclic diols to mono-cyclic diols, although fine ligand-tuning of the ruthenium(salen) complexes was required to attain high enantioselectivity (up to 93% ee). In particular, the nature of the apical ligand was found to affect not only enantioselectivity but also kinetics of the desymmetrization reaction. Spectroscopic analysis of the oxidation disclosed that irradiation of visible light is indispensable not only for dissociation of the nitrosyl ligand but also for single electron transfer from the alcohol-bound ruthenium ion to dioxygen. PMID:15826178

  16. Direct β-C(sp(3))-H Functionalization of Aliphatic Amines to α,β-Unsaturated Imines, Aldehydes, and Chromenes.

    Science.gov (United States)

    Mandal, Sumana; Mahato, Sujit; Jana, Chandan K

    2015-08-01

    A metal-free method for direct β-C(sp(3))-H functionalization of aliphatic amine was developed. The method is based on a reaction that yields enamine directly from the corresponding aliphatic amine, which otherwise requires the aid of metallic reagent and/or external oxidant. The reaction is operationally simple, general, and highly efficient in functionalizing both cyclic and acyclic amines. Structurally diverse unsaturated imines were obtained from N-heterocycles, while acyclic amines provided 2-alkyl cinnamaldehyde and benzopyran derivatives with excellent E/Z-selectivity. PMID:26204435

  17. Synthetic approaches to novel acyclic nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

    Janeba, Zlatko

    Riga: -, 2013. s. 31-31. [Conference on Heterocycles in Bio-organic Chemistry /15./. 27.05.2013-30.05.2013, Riga] Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * antiviral * anticancer Subject RIV: CC - Organic Chemistry

  18. Algorithms for Junctions in Directed Acyclic Graphs

    CERN Document Server

    Ferreira, Carlos Eduardo

    2012-01-01

    Given a pair of distinct vertices u, v in a graph G, we say that s is a junction of u, v if there are in G internally vertex disjoint directed paths from s to u and from s to v. We show how to characterize junctions in directed acyclic graphs. We also consider the two problems in the following and derive efficient algorithms to solve them. Given a directed acyclic graph G and a vertex s in G, how can we find all pairs of vertices of G such that s is a junction of them? And given a directed acyclic graph G and k pairs of vertices of G, how can we preprocess G such that all junctions of k given pairs of vertices could be listed quickly? All junctions of k pairs problem arises in an application in Anthropology and we apply our algorithm to find such junctions on kinship networks of some brazilian indian ethnic groups.

  19. Alternating polyesteramides based on 1,4-butylene terephthalamide: 3. Alternating polyesteramides based on mixtures of linear diols (4NTm,p)

    NARCIS (Netherlands)

    Serrano, P.J.M.; Werff, van der B.A.; Gaymans, R.J.

    1998-01-01

    Strictly alternating polyesteramides consisting of 1,4-butylene terephthalamide diester and mixtures of aliphatic diols have been synthesised in the melt in the presence of a titanium catalyst. To increase the molecular weight a solid state post condensation was applied. The composition was determin

  20. Categorification of acyclic cluster algebras: an introduction

    OpenAIRE

    Keller, Bernhard

    2008-01-01

    This is a concise introduction to Fomin-Zelevinsky's cluster algebras and their links with the representation theory of quivers in the acyclic case. We review the definition of cluster algebras (geometric, without coefficients), construct the cluster category and present the bijection between cluster variables and rigid indecomposable objects of the cluster category.

  1. The Algebra of Directed Acyclic Graphs

    OpenAIRE

    Fiore, Marcelo; Campos, Marco Devesas

    2013-01-01

    We give an algebraic presentation of directed acyclic graph structure, introducing a symmetric monoidal equational theory whose free PROP we characterise as that of finite abstract dags with input/output interfaces. Our development provides an initial-algebra semantics for dag structure.

  2. 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...

  3. 3000 Horsepower super conductive field acyclic motor

    International Nuclear Information System (INIS)

    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/cm2. 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

  4. Direct Copolymerization of CO2 and Diols

    Science.gov (United States)

    Tamura, Masazumi; Ito, Kazuki; Honda, Masayoshi; Nakagawa, Yoshinao; Sugimoto, Hiroshi; Tomishige, Keiichi

    2016-04-01

    Direct polymerization of CO2 and diols is promising as a simple and environmental-benign method in place of conventional processes using high-cost and/or hazardous reagents such as phosgene, carbon monoxide and epoxides, however, there are no reports on the direct method due to the inertness of CO2 and severe equilibrium limitation of the reaction. Herein, we firstly substantiate the direct copolymerization of CO2 and diols using CeO2 catalyst and 2-cyanopyridine promotor, providing the alternating cooligomers in high diol-based yield (up to 99%) and selectivity (up to >99%). This catalyst system is applicable to various diols including linear C4-C10 α,ω-diols to provide high yields of the corresponding cooligomers, which cannot be obtained by well-known methods such as copolymerization of CO2 and cyclic ethers and ring-opening polymerization of cyclic carbonates. This process provides us a facile synthesis method for versatile polycarbonates from various diols and CO2 owing to simplicity of diols modification.

  5. Acyclic 6-choosability of planar graphs without adjacent short cycles

    Institute of Scientific and Technical Information of China (English)

    WANG WeiFan; ZHANG Ge; CHEN Min

    2014-01-01

    A proper vertex coloring of a graph G is acyclic if G contains no bicolored cycles.Given a list assignment L={L(v)|v∈V}of G,we say that G is acyclically L-colorable if there exists a proper acyclic coloringπof G such thatπ(v)∈L(v)for all v∈V.If G is acyclically L-colorable for any list assignment L with|L(v)|k for all v∈V(G),then G is acyclically k-choosable.In this paper,we prove that every planar graph G is acyclically 6-choosable if G does not contain 4-cycles adjacent to i-cycles for each i∈{3,4,5,6}.This improves the result by Wang and Chen(2009).

  6. Acyclic Edge Coloring of Planar Graphs without Adjacent Triangles

    Institute of Scientific and Technical Information of China (English)

    Dezheng XIE; Yanqing WU

    2012-01-01

    An acyclic edge coloring of a graph G is a proper edge coloring such that there are no bichromatic cycles.The acyclic edge chromatic number of a graph G is the minimum number k such that there exists an acyclic edge coloring using k colors and is denoted by x'a(G).In this paper we prove that x'a(G)≤ Δ(G)+ 5 for planar graphs G without adjacent triangles.

  7. On network coding for acyclic networks with delays

    CERN Document Server

    Prasad, K

    2011-01-01

    Problems related to network coding for acyclic, instantaneous networks (where the edges of the acyclic graph representing the network are assumed to have zero-delay) have been extensively dealt with in the recent past. The most prominent of these problems include (a) the existence of network codes that achieve maximum rate of transmission, (b) efficient network code constructions, and (c) field size issues. In practice, however, networks have transmission delays. In network coding theory, such networks with transmission delays are generally abstracted by assuming that their edges have integer delays. Note that using enough memory at the nodes of an acyclic network with integer delays can effectively simulate instantaneous behavior, which is probably why only acyclic instantaneous networks have been primarily focused on thus far. In this work, we elaborate on issues ((a), (b) and (c) above) related to network coding for acyclic networks with integer delays, which have till now been overlooked. We show that the...

  8. Bayesian Discovery of Linear Acyclic Causal Models

    CERN Document Server

    Hoyer, Patrik O

    2012-01-01

    Methods for automated discovery of causal relationships from non-interventional data have received much attention recently. A widely used and well understood model family is given by linear acyclic causal models (recursive structural equation models). For Gaussian data both constraint-based methods (Spirtes et al., 1993; Pearl, 2000) (which output a single equivalence class) and Bayesian score-based methods (Geiger and Heckerman, 1994) (which assign relative scores to the equivalence classes) are available. On the contrary, all current methods able to utilize non-Gaussianity in the data (Shimizu et al., 2006; Hoyer et al., 2008) always return only a single graph or a single equivalence class, and so are fundamentally unable to express the degree of certainty attached to that output. In this paper we develop a Bayesian score-based approach able to take advantage of non-Gaussianity when estimating linear acyclic causal models, and we empirically demonstrate that, at least on very modest size networks, its accur...

  9. Biotransformation of (-)-α-pinene and geraniol to α-terpineol and p-menthane-3,8-diol by the white rot fungus, Polyporus brumalis.

    Science.gov (United States)

    Lee, Su-Yeon; Kim, Seon-Hong; Hong, Chang-Young; Park, Se-Yeong; Choi, In-Gyu

    2015-07-01

    In this study, the monoterpenes, α-pinene and geraniol, were biotransformed to synthesize monoterpene alcohol compounds. Polyporus brumalis which is classified as a white rot fungus was used as a biocatalyst. Consequently α-terpineol was synthesized from α-pinene by P. brumalis mycelium, after three days. Moreover, another substrate, the acyclic monoterpenoids geraniol was transformed into the cyclic compound, p-menthane-3, 8-diol (PMD). The main metabolites, i.e., α-terpineol and PMD, are known to be bioactive monoterpene alcohol compounds. This study highlights the potential of fungal biocatalysts for monoterpene transformation. PMID:26115995

  10. Homology cylinders and the acyclic closure of a free group

    OpenAIRE

    Sakasai, Takuya

    2005-01-01

    We give a Dehn-Nielsen type theorem for the homology cobordism group of homology cylinders by considering its action on the acyclic closure, which was defined by Levine, of a free group. Then we construct an additive invariant of those homology cylinders which act on the acyclic closure trivially. We also describe some tools to study the automorphism group of the acyclic closure of a free group generalizing those for the automorphism group of a free group or the homology cobordism group of ho...

  11. Acyclic archaebacterial ether lipids in swamp sediments

    Science.gov (United States)

    Pauly, George G.; Van Vleet, Edward S.

    1986-06-01

    Acyclic phytanyl diether glycerol and biphytanyl ether lipids have been quantified in two modern swamp sediment cores in concentrations ranging up to 360 μg/ml porewater. Methanogenic bacteria are the only known source organisms which can inhabit the swamp sediments. Variations in relative abundance between these lipids may reflect taxonomic changes in methanogen populations or the stage of growth. Maxima in methanogen lipid concentrations coincide with local maxima of 13C of organic matter, possibly the result of a pool effect on CO 2 or acetate. Methane production estimates calculated from lipid concentrations in swamp sediments range from 0.1 to 1.3 mmol cm -2 yr -1, values which are consistent with published methane fluxes.

  12. Approximating acyclicity parameters of sparse hypergraphs

    CERN Document Server

    Fomin, Fedor V; Thilikos, Dimitrios M

    2008-01-01

    The notions of hypertree width and generalized hypertree width were introduced by Gottlob, Leone, and Scarcello in order to extend the concept of hypergraph acyclicity. These notions were further generalized by Grohe and Marx, who introduced the fractional hypertree width of a hypergraph. All these width parameters on hypergraphs are useful for extending tractability of many problems in database theory and artificial intelligence. In this paper, we study the approximability of (generalized, fractional) hyper treewidth of sparse hypergraphs where the criterion of sparsity reflects the sparsity of their incidence graphs. Our first step is to prove that the (generalized, fractional) hypertree width of a hypergraph H is constant-factor sandwiched by the treewidth of its incidence graph, when the incidence graph belongs to some apex-minor-free graph class. This determines the combinatorial borderline above which the notion of (generalized, fractional) hypertree width becomes essentially more general than treewidth...

  13. Sustainable Pathways to Pyrroles through Iron-Catalyzed N-Heterocyclization from Unsaturated Diols and Primary Amines.

    Science.gov (United States)

    Yan, Tao; Barta, Katalin

    2016-09-01

    Pyrroles are prominent scaffolds in pharmaceutically active compounds and play an important role in medicinal chemistry. Therefore, the development of new, atom-economic, and sustainable catalytic strategies to obtain these moieties is highly desired. Direct catalytic pathways that utilize readily available alcohol substrates have been recently established; however, these approaches rely on the use of noble metals such as ruthenium or iridium. Here, we report on the direct synthesis of pyrroles using a catalyst based on the earth-abundant and inexpensive iron. The method uses 2-butyne-1,4-diol or 2-butene-1,4-diol that can be directly coupled with anilines, benzyl amines, and aliphatic amines to obtain a variety of N-substituted pyrroles in moderate-to-excellent isolated yields. PMID:27493031

  14. Acyclic Preference Systems in P2P Networks

    CERN Document Server

    Gai, Anh-Tuan; Mathieu, Fabien; De Montgolfier, Fabien; Reynier, Julien; Viennot, Laurent

    2007-01-01

    In this work we study preference systems natural for the Peer-to-Peer paradigm. Most of them fall in three categories: global, symmetric and complementary. All these systems share an acyclicity property. As a consequence, they admit a stable (or Pareto efficient) configuration, where no participant can collaborate with better partners than their current ones. We analyze the representation of the such preference systems and show that any acyclic system can be represented with a symmetric mark matrix. This gives a method to merge acyclic preference systems and retain the acyclicity. We also consider such properties of the corresponding collaboration graph, as clustering coefficient and diameter. In particular, studying the example of preferences based on real latency measurements, we observe that its stable configuration is a small-world graph.

  15. On the Existence of Undominated Elements of Acyclic Relations

    OpenAIRE

    Hannu Salonen; Hannu Vartiainen

    2005-01-01

    We study the existence of undominated elements of acyclic and irreflexive relations. A sufficient condition for the existence is given in the general case without any topological assumptions. Sufficient conditions are also given when the relation in question is defined on a compact Hausdorff space. We study the existence of fixed points of acyclic correspondences, the existence of stable sets, and the possibility of representing the relation by a real valued function.

  16. Physiology and methodology of intermittent resistance training for acyclic sports

    OpenAIRE

    Casas, Adrián

    2008-01-01

    Resistance training for acyclic sports has traditionally been carried out using training methods developed for cyclic sports. These methods were developed from the study of the physiological bases of maximum oxygen consumption (VO2max), prioritising “central” cardiovascular factors (cardiac) above “peripheral” factors (muscular) and omitting in-depth analysis of muscular behaviour during acyclic resistance. This article intends to: a) analyse certain physiological aspects needed to understand...

  17. Acyclic edge colorings of planar graphs and series parallel graphs

    Institute of Scientific and Technical Information of China (English)

    HOU JianFeng; WU JianLiang; LIU GuiZhen; LIU Bin

    2009-01-01

    A proper edge coloring of a graph G is called acyclic if there is no 2-colored cycle in G.The acyclic edge chromatic number of G,denoted by a'(G),is the least number of colors in an acyclic edge coloring of G.Alon et al.conjectured that a'(G) ≤△(G) +2 for any graphs.For planar graphs G with girth g(G),we prove that a'(G) ≤ max{2△(G)-2,△(G) +22} if g(G) ≥3,a'(G)≤△(G)+2if g(G) ≥ 5,a'(G) ≤△(G)+1 if g(G) ≥ 7,and a'(G)=△(G) if g(G) ≥ 16 and △(G) ≥ 3.For series-parallel graphs G,we have a'(G) ≤ △(G) +1.

  18. Inverse Eigenvalue Problems for Two Special Acyclic Matrices

    Directory of Open Access Journals (Sweden)

    Debashish Sharma

    2016-03-01

    Full Text Available In this paper, we study two inverse eigenvalue problems (IEPs of constructing two special acyclic matrices. The first problem involves the reconstruction of matrices whose graph is a path, from given information on one eigenvector of the required matrix and one eigenvalue of each of its leading principal submatrices. The second problem involves reconstruction of matrices whose graph is a broom, the eigen data being the maximum and minimum eigenvalues of each of the leading principal submatrices of the required matrix. In order to solve the problems, we use the recurrence relations among leading principal minors and the property of simplicity of the extremal eigenvalues of acyclic matrices.

  19. 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.

  20. Guided desaturation of unactivated aliphatics

    Science.gov (United States)

    Voica, Ana-Florina; Mendoza, Abraham; Gutekunst, Will R.; Fraga, Jorge Otero; Baran, Phil S.

    2012-08-01

    The excision of hydrogen from an aliphatic carbon chain to produce an isolated olefin (desaturation) without overoxidation is one of the most impressive and powerful biosynthetic transformations for which there are no simple and mild laboratory substitutes. The versatility of olefins and the range of reactions they undergo are unsurpassed in functional group space. Thus, the conversion of a relatively inert aliphatic system into its unsaturated counterpart could open new possibilities in retrosynthesis. In this article, the invention of a directing group to achieve such a transformation under mild, operationally simple, metal-free conditions is outlined. This ‘portable desaturase’ (TzoCl) is a bench-stable, commercial entity (Aldrich, catalogue number L510092) that is facile to install on alcohol and amine functionalities to ultimately effect remote desaturation, while leaving behind a synthetically useful tosyl group.

  1. Aliphatic hydrocarbons of the fungi.

    Science.gov (United States)

    Weete, J. D.

    1972-01-01

    Review of studies of aliphatic hydrocarbons which have been recently detected in the spores of phytopathogenic fungi, and are found to be structurally very similar to the alkanes of higher plants. It appears that the hydrocarbon components of the few mycelial and yeast forms reported resemble the distribution found in bacteria. The occurence and distribution of these compounds in the fungi is discussed. Suggested functional roles of fungal spore alkanes are presented.

  2. Combinatorics of aliphatic amino acids.

    Science.gov (United States)

    Grützmann, Konrad; Böcker, Sebastian; Schuster, Stefan

    2011-01-01

    This study combines biology and mathematics, showing that a relatively simple question from molecular biology can lead to complicated mathematics. The question is how to calculate the number of theoretically possible aliphatic amino acids as a function of the number of carbon atoms in the side chain. The presented calculation is based on earlier results from theoretical chemistry concerning alkyl compounds. Mathematical properties of this number series are highlighted. We discuss which of the theoretically possible structures really occur in living organisms, such as leucine and isoleucine with a chain length of four. This is done both for a strict definition of aliphatic amino acids only involving carbon and hydrogen atoms in their side chain and for a less strict definition allowing sulphur, nitrogen and oxygen atoms. While the main focus is on proteinogenic amino acids, we also give several examples of non-proteinogenic aliphatic amino acids, playing a role, for instance, in signalling. The results are in agreement with a general phenomenon found in biology: Usually, only a small number of molecules are chosen as building blocks to assemble an inconceivable number of different macromolecules as proteins. Thus, natural biological complexity arises from the multifarious combination of building blocks. PMID:21120449

  3. Rhenium-Catalyzed Deoxydehydration of Diols and Polyols

    DEFF Research Database (Denmark)

    Dethlefsen, Johannes Rytter; Fristrup, Peter

    2015-01-01

    heniumcatalyzeddeoxydehydration (DODH) of a vicinal diol into analkene; this is a model system for abundant polyols like glyceroland sugar alcohols. The present contribution includesa review of early investigations of stoichiometric reactions involvingrhenium, diols, and alkenes followed by a discussion ofthe various catalytic...... systems that have been developed withemphasis on the nature of the reductant, the substrate scope,and mechanistic investigations....

  4. 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 benzopheno

  5. 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. PMID:21213966

  6. Novel types of acyclic nucleoside phosphonates: Chemistry and biology

    Czech Academy of Sciences Publication Activity Database

    Janeba, Zlatko

    La Habana: Cuban Chemical Society, 2015. LO009. [Quimicuba 2015. Congress of Chemical Sciences, Technology and Innovation /9./. 13.10.2015-16.10.2015, La Habana] R&D Projects: GA ČR GAP207/11/0108; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * malaria * tuberculosis * inhibitors * 6-oxopurine phosphoribosyltransferases Subject RIV: CC - Organic Chemistry

  7. Thermotropic liquid crystalline polyesters derived from bis-(4-hydroxybenzoyloxy)-2-methyl-1,4-benzene and aliphatic dicarboxylic acid chlorides

    Indian Academy of Sciences (India)

    Khudbudin Mulani; Mohasin Momin; Nitin Ganjave; Nayaku Chavan

    2015-09-01

    A series of thermotropic liquid crystalline polyesters derived from bis-(4-hydroxybenzoyloxy)-2-methyl-1,4-benzene (BHBOMB) and aliphatic dicarboxylic acid chlorides were investigated. All these polyesters were synthesized by interfacial polycondensation method and characterized by differential scanning calorimetry and wide-angle X-ray diffractometer. These polyesters consist of BHBOMB as a mesogenic diol and aliphatic diacid chlorides were used as flexible spacers. The length of oligomethylene units in polymer was varied from the trimethylene to the dodecamethylene groups. The transition temperatures and thermodynamic properties were studied for all these polymers. All these polyesters were soluble in chlorinated solvents such as chloroform, dichloromethane, dichloroethane, etc. More importantly, all these polyesters exhibited very large mesophase stability.

  8. Understanding Model Counting for beta-acyclic CNF-formulas

    OpenAIRE

    Brault-Baron, Johann; Capelli, Florent; Mengel, Stefan

    2015-01-01

    We show that SAT on beta-acyclic CNF-formulas can be solved in polynomial time. In contrast to previous algorithms for other structurally restricted classes of formulas, our algorithm does not proceed by dynamic programming. Instead, it works along an elimination order, solving a weighted version of constraint satisfaction. We give evidence that this deviation from more standard algorithms is no coincidence by showing that it is outside of the framework recently proposed by Saether et al. (SA...

  9. Tyrosine-based prodrugs of acyclic nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

    Tichý, Tomáš; Pomeisl, Karel; Krečmerová, Marcela; McKenna, Ch. E.

    Praha : Institute of Organic Chemistry and Biochemistry AS CR, v. v. i, 2014 - (Hocek, M.), s. 126-128 ISBN 978-80-86241-50-0. - (Collection Symposium Series. 14). [Symposium on Chemistry of Nucleic Acid Components /16./. Český Krumlov (CZ), 08.06.2014-13.06.2014] R&D Projects: GA ČR(CZ) GA14-00522S Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * prodrug * tyrosine Subject RIV: CC - Organic Chemistry

  10. Synthesis of chiral open-ring acyclic nucleoside bisphosphonates

    Czech Academy of Sciences Publication Activity Database

    Doláková, Petra; Masojídková, Milena; Dračínský, Martin; Holý, Antonín

    Napoli : University of Napoli, 2006. s. 73. [International Symposium on Applied Bioinorganic Chemistry /9./. 02.12.2006-05.12.2006, Napoli] R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Grant ostatní: René Descartes Prize(XE) HPAW-2002-100096 Institutional research plan: CEZ:AV0Z40550506 Keywords : purine * acyclic nucleoside bisphosphonates Subject RIV: CC - Organic Chemistry

  11. Acyclic Nucleoside Phosphonates as Potential Anti-Malarial Agents

    Czech Academy of Sciences Publication Activity Database

    Janeba, Zlatko; Hocková, Dana; Holý, Antonín; Česnek, Michal; Baszczyňski, Ondřej; Tichý, Tomáš; Krečmerová, Marcela; Naesens, L.; Skinner-Adams, T. S.; Edstein, M.; Keough, D. T.; de Jersey, J.; Guddat, L. W.

    Riviera Maya: -, 2011. s. 21-21. [Zing Conferences 2011. Drug Discovery - Tropical Diseases Conference. 11.12.2011-15.12.2011, Riviera Maya] R&D Projects: GA ČR GAP207/11/0108; GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * HGXPRT * malaria * Plasmodium Subject RIV: CC - Organic Chemistry

  12. Extending Acyclicity Notions for Existential Rules (\\emph{long version})

    OpenAIRE

    Baget, Jean-Francois; Garreau, Fabien; Mugnier, Marie-Laure; Rocher, Swan

    2014-01-01

    Existential rules have been proposed for representing ontological knowledge, specifically in the context of Ontology-Based Query Answering. Entailment with existential rules is undecidable. We focus in this paper on conditions that ensure the termination of a breadth-first forward chaining algorithm known as the chase. First, we propose a new tool that allows to extend existing acyclicity conditions ensuring chase termination, while keeping good complexity properties. Second, we consider the ...

  13. Trends and challenges in chemistry of acyclic nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

    Krečmerová, Marcela

    Rehovot : European Federation for Medicinal Chemistry, 2015. s. 164. [International Symposium on Advances in Synthetic and Medicinal Chemistry (EFMC-ASMC'15) /6./ and Annual Meeting of the Medicinal Chemistry Section of the Israel Chemical Society /13./. 15.11.2015-18.11.2015, Rehovot] R&D Projects: GA MPO(CZ) FR-TI4/625 Institutional support: RVO:61388963 Keywords : 5-azacytosine * PME-azaC * acyclic nucleoside phosphonate * antivirals * prodrug Subject RIV: CC - Organic Chemistry

  14. Oligonucleotides modified with acyclic nucleoside phosphonate (HPEP) units

    Czech Academy of Sciences Publication Activity Database

    Kaiser, Martin Maxmilian; Novák, Pavel; Rosenbergová, Šárka; Poštová Slavětínská, Lenka; Rosenberg, Ivan; Janeba, Zlatko

    Praha: Institute of Organic Chemistry and Biochemistry AS CR, v. v. i, 2014 - (Hocek, M.), s. 293-294. (Collection Symposium Series. 14). ISBN 978-80-86241-50-0. [Symposium on Chemistry of Nucleic Acid Components /16./. Český Krumlov (CZ), 08.06.2014-13.06.2014] R&D Projects: GA TA ČR TA03010598 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonate * HPEP * oligonucleotides Subject RIV: CC - Organic Chemistry

  15. Acyclic Preference Systems in P2P Networks

    OpenAIRE

    Gai, Anh-Tuan; Lebedev, Dmitry; Mathieu, Fabien; de Montgolfier, Fabien; Reynier, Julien; Viennot, Laurent

    2007-01-01

    The original publication is available at www.springerlink.com International audience In this work we study preference systems suitable for the Peer-to-Peer paradigm. Most of them fall in one of the three following categories: global, symmetric and complementary. All these systems share an acyclicity property. As a consequence, they admit a stable (or Pareto efficient) configuration, where no participant can collaborate with better partners than their current ones. We analyze the represe...

  16. LAYERWIDTH: Analysis of a New Metric for Directed Acyclic Graphs

    OpenAIRE

    Hopkins, Mark

    2012-01-01

    We analyze a new property of directed acyclic graphs (DAGs), called layerwidth, arising from a class of DAGs proposed by Eiter and Lukasiewicz. This class of DAGs permits certain problems of structural model-based causality and explanation to be tractably solved. In this paper, we first address an open question raised by Eiter and Lukasiewicz - the computational complexity of deciding whether a given graph has a bounded layerwidth. After proving that this problem is NP-complete, we proceed by...

  17. Directed acyclic graphs with edge-specific bounds

    OpenAIRE

    VanderWeele, Tyler J; Tan, Zhiqiang

    2011-01-01

    We give a definition of a bounded edge within the causal directed acyclic graph framework. A bounded edge generalizes the notion of a signed edge and is defined in terms of bounds on a ratio of survivor probabilities. We derive rules concerning the propagation of bounds. Bounds on causal effects in the presence of unmeasured confounding are also derived using bounds related to specific edges on a graph. We illustrate the theory developed by an example concerning estimating the effect of antih...

  18. Chemical characterization of fatty acids, alkanes, n-diols and alkyl esters produced by a mixed culture of Trichoderma koningii and Penicillium janthinellum grown aerobically on undecanoic acid, potatoe dextrose and their mixture.

    Science.gov (United States)

    Monreal, Carlos M; Chahal, Amarpreet; Schnitzer, Morris; Rowland, Owen

    2016-05-01

    Little is known about the mixed fungal synthesis of high-value aliphatics derived from the metabolism of simple and complex carbon substrates. Trichoderma koningii and Penicillium janthinellum were fed with undecanoic acid (UDA), potatoe dextrose broth (PDB), and their mixture. Pyrolysis Field Ionization Mass Spectrometry (Py-FIMS) together with (1)H and (13)C Nuclear Magnetic Resonance (NMR) characterized CHCl3 soluble aliphatics in the fungal cell culture. Data from NMR and Py-FIMS analysis were complementary to each other. On average, the mixed fungal species produced mostly fatty acids (28% of total ion intensity, TII) > alkanes (2% of TII) > n-diols (2% of TII) > and alkyl esters (0.8% of TII) when fed with UDA, PDB or UDA+PDB. The cell culture accumulated aliphatics extracellularly, although most of the identified compounds accumulated intracellularly. The mixed fungal culture produced high-value chemicals from the metabolic conversion of simple and complex carbon substrates. PMID:26852878

  19. Anaerobic digestion of aliphatic polyesters.

    Science.gov (United States)

    Šmejkalová, Pavla; Kužníková, Veronika; Merna, Jan; Hermanová, Soňa

    2016-01-01

    Anaerobic processes for the treatment of plastic materials waste represent versatile and effective approach in environmental protection and solid waste management. In this work, anaerobic biodegradability of model aliphatic polyesters, poly(L-lactic acid) (PLA), and poly(ɛ-caprolactone) (PCL), in the form of powder and melt-pressed films with varying molar mass, was studied. Biogas production was explored in batch laboratory trials at 55 ± 1°C under a nitrogen atmosphere. The inoculum used was thermophilic digested sludge (total solids concentration of 2.9%) from operating digesters at the Central Waste Water Treatment Plant in Prague, Czech Republic. Methanogenic biodegradation of PCLs typically yielded from 54 to 60% of the theoretical biogas yield. The biodegradability of PLAs achieved from 56 to 84% of the theoretical value. High biogas yield (up to 677 mL/g TS) with high methane content (more than 60%), comparable with conventionally processed materials, confirmed the potential of polyester samples for anaerobic treatment in the case of their exploitation in agriculture or as a packaging material in the food industry. PMID:27191559

  20. Multifunctional aliphatic polyester nanofibers for tissue engineering

    OpenAIRE

    Zhan, Jianan; Singh, Anirudha; Zhang, Zhe; Huang, Ling; Elisseeff, Jennifer H.

    2012-01-01

    Electrospun fibers based on aliphatic polyesters, such as poly(ε-caprolactone) (PCL), have been widely used in regenerative medicine and drug delivery applications due to their biocompatibility, low cost and ease of fabrication. However, these aliphatic polyester fibers are hydrophobic in nature, resulting in poor wettability, and they lack functional groups for decorating the scaffold with chemical and biological cues. Current strategies employed to overcome these challenges include coating ...

  1. Modelling discrete longitudinal data using acyclic probabilistic finite automata

    DEFF Research Database (Denmark)

    Anantharama Ankinakatte, Smitha; Edwards, David

    2015-01-01

    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 algorith...... 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...

  2. Path-equivalent developments in acyclic weighted automata

    OpenAIRE

    Giraud, Mathieu; Veber, Philippe; Lavenier, Dominique

    2007-01-01

    Weighted finite automata (WFA) are used with FPGA accelerating hardware to scan large genomic banks. Hardwiring such automata raises surface area and clock frequency constraints, requiring efficient ε-transitions-removal techniques. In this paper, we present bounds on the number of new transitions for the development of acyclic WFA, which is a special case of the ε-transitions-removal problem. We introduce a new problem, a partial removal of ε-transitions while accepting short chains of ε-transi...

  3. A Distributed Algorithm for Determining Minimal Covers of Acyclic Database Schemes

    Institute of Scientific and Technical Information of China (English)

    叶新铭

    1994-01-01

    Acyclic databases possess several desirable properties for their design and use.A distributed algorithm is proposed for determining a minimal cover of an alpha-,beta-,gamma-,or Berge-acyclic database scheme over a set of attributes in a distributed environment.

  4. Studying the structure of complex networks by the transition to acyclic networks

    CERN Document Server

    Shevchuk, R

    2010-01-01

    The directed acyclic networks is the fundamental class of networks which include network citation, food chains, family trees and other networks with similar structure. In this paper we present an algorithm for transforming an ordinary undirected complex network into acyclic one and further analysis of the structure of a complex network.

  5. Worst-case Behaviour of History Based Pivot Rules on Acyclic Unique Sink Orientations of Hypercubes

    CERN Document Server

    Aoshima, Yoshikazu; Deering, Theresa; Matsumoto, Yoshitake; Moriyama, Sonoko

    2011-01-01

    An acyclic USO on a hypercube is formed by directing its edges in such as way that the digraph is acyclic and each face of the hypercube has a unique sink and a unique source. A path to the global sink of an acyclic USO can be modeled as pivoting in a unit hypercube of the same dimension with an abstract objective function, and vice versa. In such a way, Zadeh's 'least entered rule' and other history based pivot rules can be applied to the problem of finding the global sink of an acyclic USO. In this paper we present some theoretical and empirical results on the worst case behaviour of various history based pivot rules for this problem. In particular, we investigate whether or not they can follow a Hamiltonian path on an acyclic USO.

  6. 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.

  7. 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.

  8. 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

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

    DEFF Research Database (Denmark)

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

    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...

  10. The Existence Condition of γ-Acyclic Database Schemes with MVDs Constraints

    Institute of Scientific and Technical Information of China (English)

    郝忠孝; 姚春龙

    2002-01-01

    It is very important to use database technology for a large-scale system such as ERP and MIS. A good database design may improve the performance of the system. Some researches show that a γ-acyclic database scheme has many good properties, e.g., each connected join expression is monotonous, which helps to improve query performance of the database system. Thus what conditions are needed to generate a γ-acyclic database scheme for a given relational scheme? In this paper, the sufficient and necessary condition of the existence of γ-acyclic, join-lossless and dependencies-preserved database schemes meeting 4NF is given.

  11. Isolation of a Stable, Acyclic, Two-Coordinate Silylene

    OpenAIRE

    Rekken, Brian; Brown, Thomas; Fettinger, James; Tuononen, Heikki; Power, Philip

    2012-01-01

    The synthesis and characterization of a stable, acyclic two-coordinate silylene, Si(SArMe6)2, (ArMe6 = C6H3-2,6(C6H2-2,4,6-Me3)2) by reduction of Br2Si(SArMe6)2 with a magnesium(I) reductant is described. It features a v-shaped silicon coordination with a S-Si-S angle of 90.519(2)° and an average Si-S distance of 2.158(3) Å. Although it reacts readily with an alkyl halide, it does not react with hydrogen under ambient conditions probably as a result of the ca. 4.3 e...

  12. CCN activity of aliphatic amine secondary aerosol

    Directory of Open Access Journals (Sweden)

    X. Tang

    2014-01-01

    Full Text Available Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g. hydroxyl radical and nitrate radical. The particle composition can contain both secondary organic aerosol (SOA and inorganic salts. The fraction of organic to inorganic materials in the particulate phase influences aerosol hygroscopicity and cloud condensation nuclei (CCN activity. SOA formed from trimethylamine (TMA and butylamine (BA reactions with hydroxyl radical (OH is composed of organic material of low hygroscopicity (single hygroscopicity parameter, κ ≤ 0.25. Secondary aerosol formed from the tertiary aliphatic amine (TMA with N2O5 (source of nitrate radical, NO3, contains less volatile compounds than the primary aliphatic amine (BA aerosol. TMA + N2O5 form semi-volatile organics in low RH conditions that have κ ~ 0.20, indicative of slightly soluble organic material. As RH increases, several inorganic amine salts are formed as a result of acid-base reactions. The CCN activity of the humid TMA-N2O5 aerosol obeys Zdanovskii, Stokes, and Robinson (ZSR ideal mixing rules. Higher CCN activity (κ > 0.3 was also observed for humid BA+N2O5 aerosols compared with dry aerosol (κ ~ 0.2, as a result of the formation of inorganic salts such as NH4NO3 and butylamine nitrate (C4H11N · HNO3. Compared with TMA, BA+N2O5 reactions produce more volatile aerosols. The BA+N2O5 aerosol products under humid experiments were found to be very sensitive to the temperature within the stream-wise continuous flow thermal gradient CCN counter. The CCN counter, when set above a 21 °C temperature difference, evaporates BA+N2O5 aerosol formed at RH ≥ 30%; κ ranges from 0.4 to 0.7 and is dependent on the instrument supersaturation (ss settings. The aerosol behaves non-ideally, hence simple ZSR rules cannot be applied to the CCN results from the primary aliphatic amine system. Overall, aliphatic amine aerosol systems κ ranges from 0.2 < κ < 0.7. This work indicates that

  13. A sufficient condition for acyclic social choice in a single-profile world

    OpenAIRE

    Lahiri, Somdeb

    2009-01-01

    In this paper we provide a sufficient condition for a social welfare relation to be a social decision relation (i.e. an acyclic social welfare relation) when the profile of individual preferences is given.

  14. A xanthanolide diol and a dimeric xanthanolide from Xanthium species.

    Science.gov (United States)

    Ahmed, A A; Mahmoud, A A; El-Gamal, A A

    1999-06-01

    Extracts of the aerial parts of Xanthium strumarium and fruit of X. pungens afforded a new Xanthanolide diol derivative, 11alpha,13-dihydroxyxanthatin and a new dimeric xanthanolide sesquiterpene lactone, pungiolide C, in addition to some known compounds. The structures of the new compounds were determined by spectroscopic methods particularly high resolution (1)H-, (13)C-NMR and 2D (1)H- (1)H and (1)H- (13)C COSY NMR analysis. PMID:17260271

  15. 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

  16. The ERβ ligand 5α-androstane, 3β,17β-diol (3β-diol) regulates hypothalamic oxytocin (Oxt) gene expression.

    Science.gov (United States)

    Sharma, Dharmendra; Handa, Robert J; Uht, Rosalie M

    2012-05-01

    The endocrine component of the stress response is regulated by glucocorticoids and sex steroids. Testosterone down-regulates hypothalamic-pituitary-adrenal (HPA) axis activity; however, the mechanisms by which it does so are poorly understood. A candidate testosterone target is the oxytocin gene (Oxt), given that it too inhibits HPA activity. Within the paraventricular nucleus of the hypothalamus, oxytocinergic neurons involved in regulating the stress response do not express androgen receptors but do express estrogen receptor-β (ERβ), which binds the dihydrotestosterone metabolite 3β,17β-diol (3β-diol). Testosterone regulation of the HPA axis thus appears to involve the conversion to the ERβ-selective ligand 5α-androstane, 3β-diol. To study mechanisms by which 3β-diol could regulate Oxt expression, we used a hypothalamic neuronal cell line derived from embryonic mice that expresses Oxt constitutively and compared 3β-diol with estradiol (E2) effects. E2 and 3β-diol elicited a phasic response in Oxt mRNA levels. In the presence of either ligand, Oxt mRNA levels were increased for at least 60 min and returned to baseline by 2 h. ERβ occupancy preceded an increase in Oxt mRNA levels in the presence of 3β-diol but not E2. In tandem with ERβ occupancy, 3β-diol increased occupancy of the Oxt promoter by cAMP response element-binding protein and steroid receptor coactivator-1 at 30 min. At the same time, 3β-diol led to the increased acetylation of histone H4 but not H3. Taken together, the data suggest that in the presence of 3β-diol, ERβ associates with cAMP response element-binding protein and steroid receptor coactivator-1 to form a functional complex that drives Oxt gene expression. PMID:22434086

  17. Structural Interactions within Lithium Salt Solvates. Acyclic Carbonates and Esters

    Energy Technology Data Exchange (ETDEWEB)

    Afroz, Taliman [North Carolina State Univ., Raleigh, NC (United States); Seo, D. M. [North Carolina State Univ., Raleigh, NC (United States); Han, Sang D. [North Carolina State Univ., Raleigh, NC (United States); Boyle, Paul D. [North Carolina State Univ., Raleigh, NC (United States); Henderson, Wesley A. [North Carolina State Univ., Raleigh, NC (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-06

    Solvate crystal structures serve as useful models for the molecular-level interactions within the diverse solvates present in liquid electrolytes. Although acyclic carbonate solvents are widely used for Li-ion battery electrolytes, only three solvate crystal structures with lithium salts are known for these and related solvents. The present work, therefore, reports six lithium salt solvate structures with dimethyl and diethyl carbonate: (DMC)2:LiPF6, (DMC)1:LiCF3SO3, (DMC)1/4:LiBF4, (DEC)2:LiClO4, (DEC)1:LiClO4 and (DEC)1:LiCF3SO3 and four with the structurally related methyl and ethyl acetate: (MA)2:LiClO4, (MA)1:LiBF4, (EA)1:LiClO4 and (EA)1:LiBF4.

  18. Kinetics and mechanism of the oxidation of some diols by benzyltrimethylammonium tribromide

    Indian Academy of Sciences (India)

    Garima Goswami; Seema Kothari; Kalyan K Banerji

    2001-02-01

    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 3:7 (/) acetic acid-water mixture. The vicinal diols yield the carbonyl compounds arising out of the glycol bond fission while the other diols give the hydroxycarbonyl compounds. The reaction is first-order with respect to BTMAB. 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 isotope effect. A mechanism involving a glycol-bond fission has been proposed for the oxidation of the vicinal diols. The other diols are oxidized by a hydride ion transfer to the oxidant, as are the monohydric alcohols.

  19. Acyclic edge colorings of planar graphs and series-parallel graphs

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A proper edge coloring of a graph G is called acyclic if there is no 2-colored cycle in G. The acyclic edge chromatic number of G, denoted by a (G), is the least number of colors in an acyclic edge coloring of G. Alon et al. conjectured that a (G) Δ(G) + 2 for any graphs. For planar graphs G with girth g(G), we prove that a (G) max{2Δ(G) + 2, Δ(G) + 22} if g(G) 3, a (G) Δ(G) + 2 if g(G) 5, a (G) Δ(G) + 1 if g(G) 7, and a (G) = Δ(G) if g(G) 16 and Δ(G) 3. For series-parallel graphs G, we have a (G) Δ(G) + 1.

  20. 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

    2012-06-01

    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.

  1. An Upper Bound for the Adjacent Vertex Distinguishing Acyclic Edge Chromatic Number of a Graph

    Institute of Scientific and Technical Information of China (English)

    Xin-sheng Liu; Ming-qiang An; Yang Gao

    2009-01-01

    A proper k-edge coloring of a graph G is called adjacent vertex distinguishing acyclic edge coloring if there is no 2-colored cycle in G and the color set of edges incident to u is not equal to the color set of edges incident to v,where uv ∈ E(G).The adjacent vertex distinguishing acyclic edge chromatic number of G,denoted by χαα(G),is the minimal number of colors in an adjacent vertex distinguishing acyclic edge coloring of G.In this paper we prove that if G(V,E)is a graph with no isolated edges,then χαα(G)≤32△.

  2. Corrosion inhibition of brass by aliphatic amines

    International Nuclear Information System (INIS)

    Aliphatic amines hexylamine (HCA), octylamine (OCA) and decylamine (DCA) have been used as corrosion inhibitors for (70/30) brass in 0.I M HCIO4. The inhibitor efficiency (%P) calculated using weight loss, Tafel extrapolation, linear polarization and impedance methods was found to be in the order DCA> OCA> HCA. These adsorb on brass surface following bockris-swinkels' isotherm. DCA, OCA and HCA displaced 4, 3 and 2 molecules of water from interface respectively. Displacement of water molecules brought a great reorganization of double layer at the interface. These amines during corrosion form complexes with dissolved zinc and copper ions.(Author)

  3. 75 FR 39520 - Certain New Chemicals; Receipt and Status Information

    Science.gov (United States)

    2010-07-09

    ... diisocyanate, aliphatic dicarboxylic acid, aliphatic diol, polyether diol, and dihydroxy aliphatic carboxylic... generating derivative systems ] In Table II of this unit, EPA provides the following information (to...

  4. 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...

  5. Olfactory responses of blowflies to aliphatic aldehydes.

    Science.gov (United States)

    DETHIER, V G

    1954-07-20

    The response of the blowfly Phormia regina to stimulation by aldehydes in the vapor phase has been studied by means of a specially designed olfactometer. The median rejection threshold and the maximum acceptance threshold were selected as criteria of response. For both acceptance and rejection the distribution of thresholds in the population is normal with respect to the logarithm of concentration. When thresholds are expressed as molar concentrations, the values decrease progressively as chain length is increased. There is no attraction beyond decanal and no rejection beyond dodecanal. When thresholds are expressed as activities, most members of the aldehyde series are approximately equally stimulating at rejection and equally stimulating at acceptance. The relationship is most exact over the middle range of chain lengths. There is a tendency for the terminal members to stimulate at higher activities. These relationships are in close agreement with those which were found earlier to apply to the normal aliphatic alcohols. The similarity between the relative actions of the members of the two series suggests that the relation of equal olfactory stimulation at equal thermodynamic activities by homologous aliphatic compounds at least for homologues of intermediate chain length may be of rather general application in olfaction. PMID:13174780

  6. Synthesis of side-chain gem-difluorinated acyclic nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

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

    London: Elsevier, 2014. P1.68. [Tetrahedron Symposium. Challenges in Bioorganic and Organic Medicinal Chemistry /15./. 24.06.2014-27.06.2014, London] Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * difluoromethylation * FPMPA * diethyldifluoromethylphosphonate Subject RIV: CC - Organic Chemistry

  7. Pyrimidine acyclic nucleoside phosphonates and their phosphorylated analogs as potential multisubstrate inhibitors of thymidine phosphorylase

    Czech Academy of Sciences Publication Activity Database

    Pomeisl, Karel; Votruba, Ivan; Holý, Antonín; Pohl, Radek; Blažek, Jiří; Krečmerová, Marcela

    Ottawa : -, 2012. -. [Ottawa 2012 International Symposium On Biochemistry and Biophysics. 24.10.2012-25.10.2012, Ottawa] R&D Projects: GA MPO FR-TI4/625 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * thymidine phosphorylase * phosphorylation * pyrimidines Subject RIV: CC - Organic Chemistry

  8. 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

  9. Parallel simulation algorithm for maintenance optimization based on directed Acyclic Graph

    International Nuclear Information System (INIS)

    An efficient simulation algorithm for the quantification of reliability performance indicators of a complex system is demonstrated in the paper that is based on Monte Carlo method. A directed Acyclic Graph is used as a useful system representation. A parallel simulation technique is used in the algorithm which is based on the construction of the special course of life sequence of transformed transition times subjected to the corresponding part of the Acyclic Graph. The parts of the Acyclic Graph represent individual subsystems of a given system and may be effectively evaluated from the reliability point of view. The wide range of models for both deterministic and stochastic processes applied on the terminal nodes of the Acyclic Graph is allowed in the algorithm. The use of the algorithm for comparative theoretical calculations as well as for industrial applications is shown by a visual demonstration. A cost-optimization problem is shortly introduced which may be fully solved by the algorithm using additional genetic algorithms as an applicable optimization technique. The problem takes into account also additional objective that is defined as a prescribed constraint of a selected reliability performance indicator. The solution of the cost-optimization problem is demonstrated on two practical examples

  10. 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

  11. Algebraic modelling and performance evaluation of acyclic fork-join queueing networks

    OpenAIRE

    Krivulin, Nikolai K.

    2012-01-01

    Simple lower and upper bounds on mean cycle time in stochastic acyclic fork-join queueing networks are derived using a (max,+)-algebra based representation of network dynamics. The behaviour of the bounds under various assumptions concerning the service times in the networks is discussed, and related numerical examples are presented.

  12. Bounds on mean cycle time in acyclic fork-join queueing networks

    OpenAIRE

    Krivulin, Nikolai K.

    2012-01-01

    Simple lower and upper bounds on mean cycle time in stochastic acyclic fork-join networks are derived using the $(\\max,+)$-algebra approach. The behaviour of the bounds under various assumptions concerning the service times in the networks is discussed, and related numerical examples are presented.

  13. 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

  14. CAUSALITY AMONG FED CATTLE MARKET VARIABLES: DIRECTED ACYCLIC GRAPHS ANALYSIS OF CAPTIVE SUPPLY

    OpenAIRE

    Lee, Andrew C.; Kim, Man-Keun

    2004-01-01

    In quantitative research, direction of causality among the variables is often assumed without a rigorous test. In this study, the directed acyclic graph (DAG) method was used to illuminate causal relationships among fed cattle industry variables, in particular, it was shown that captive supply causes spot market price to change.

  15. Novel class of acyclic nucleoside phosphonates: (S)-3-hydroxy-2-(phosphonoethoxy)propyl analogues

    Czech Academy of Sciences Publication Activity Database

    Kaiser, Martin Maxmilian; Dračínský, Martin; Poštová Slavětínská, Lenka; Hocková, Dana; Keough, D. T.; Guddat, L. W.; Janeba, Zlatko

    Riga: -, 2013. s. 180-180. [Conference on Heterocycles in Bio-organic Chemistry /15./. 27.05.2013-30.05.2013, Riga] R&D Projects: GA ČR GAP207/11/0108 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * antiparasitic * HPEP * Plasmodium Subject RIV: CC - Organic Chemistry

  16. 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

  17. 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: 3.562, year: 2014

  18. 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

  19. Thermal stability of aliphatic hyperbranched polyesters

    Directory of Open Access Journals (Sweden)

    Vuković Jasna

    2002-01-01

    Full Text Available The influence of the molar mass (generation, number and type of end groups on the thermal stability of aliphatic hyperbranched polyesters are presented in this study. Different end groups were obtained by modification of the samples with chlorides of propionic acid and stearic acid. The thermal stability of the hyperbranched polyesters was determined by thermogravimetry using a NET-ZSCH TG 209 instrument in nitrogen atmosphere at a heating rate of 10°C/min. A comparison of the temperatures obtained for mass losses of 5 20 and 40 wt% for unmodified samples showed that the thermal stability increased up to the fourth generation and then remained practically constant. An increase in the thermal stability of modified samples of the second, third and fourth generation was observed.

  20. Polyimide nanofoams from aliphatic polyester based copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Hedrick, J.L.; Carter, K.R.; Richter, R.; Russell, T.P. [Almaden Research Center, San Jose, CA (United States)] [and others

    1996-10-01

    High temperature polymer foams were prepared using microphase separated block copolymers where the major component is thermally stable block and the minor component is thermally labile. Upon thermal treatment, the dispersed minor component undergoes thermolysis leaving pores the size and shape of which are dictated by the initial copolymer morphology. The driving force behind the survey of aliphatic polyesters as possible labile blocks stems from their quantitative degradation into low boiling, polar degradation products via a backbiting process. Block copolymers were prepared using either a monofunctional caprolactone or a valerolactone oligomer and a high T. polyimide. Microphase morphologies were observed in each case. Thermal decomposition of the polyester blocks was accomplished by a thermal treatment at 370{degrees}C for 5 h. Significant density reductions were measured, and the resulting foams showed pore sizes in the 60-70 {Angstrom} range.

  1. Synthesis, stability constants and electronic spectral studies of ternary complexes of Pr(III) with histidine and diols

    International Nuclear Information System (INIS)

    The mixed ligand complexes of the type MAB, MA2B and MaB2 where M = Pr(III), A = histidine and B = ethanediol, prop-1,2-diol, 2-butene-1, 4-diol, but-2,3-diol, pent-1,5-diol and hex-1,6-diol have been investigated by alkalimetric titrations. The overall stability constants have been evaluated at 30+1degC (μ = 0.2MKNO3). The absorption spectra of some praseodymium(III) ternary complexes in solution have been used to calculate energy interaction and intensity parameters. The low intensity of the pseudohypersensitive transition suggests higher coordination number. (author)

  2. 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.

  3. Regioselective Acylation of Diols and Triols: The Cyanide Effect.

    Science.gov (United States)

    Peng, Peng; Linseis, Michael; Winter, Rainer F; Schmidt, Richard R

    2016-05-11

    Central topics of carbohydrate chemistry embrace structural modifications of carbohydrates and oligosaccharide synthesis. Both require regioselectively protected building blocks that are mainly available via indirect multistep procedures. Hence, direct protection methods targeting a specific hydroxy group are demanded. Dual hydrogen bonding will eventually differentiate between differently positioned hydroxy groups. As cyanide is capable of various kinds of hydrogen bonding and as it is a quite strong sterically nondemanding base, regioselective O-acylations should be possible at low temperatures even at sterically congested positions, thus permitting formation and also isolation of the kinetic product. Indeed, 1,2-cis-diols, having an equatorial and an axial hydroxy group, benzoyl cyanide or acetyl cyanide as an acylating agent, and DMAP as a catalyst yield at -78 °C the thermodynamically unfavorable axial O-acylation product; acyl migration is not observed under these conditions. This phenomenon was substantiated with 3,4-O-unproteced galacto- and fucopyranosides and 2,3-O-unprotected mannopyranosides. Even for 3,4,6-O-unprotected galactopyranosides as triols, axial 4-O-acylation is appreciably faster than O-acylation of the primary 6-hydroxy group. The importance of hydrogen bonding for this unusual regioselectivity could be confirmed by NMR studies and DFT calculations, which indicate favorable hydrogen bonding of cyanide to the most acidic axial hydroxy group supported by hydrogen bonding of the equatorial hydroxy group to the axial oxygen. Thus, the "cyanide effect" is due to dual hydrogen bonding of the axial hydroxy group which enhances the nucleophilicity of the respective oxygen atom, permitting an even faster reaction for diols than for mono-ols. In contrast, fluoride as a counterion favors dual hydrogen bonding to both hydroxy groups leading to equatorial O-acylation. PMID:27104625

  4. Design, Synthesis and Characterisation of Novel Biodegradable Aliphatic Copolyesters- Poly(ethylene sebacate-co-butylene succinate and Poly(ethylene sebacate-co-butylene adipate

    Directory of Open Access Journals (Sweden)

    L. SOWBAGYALAKSHMI PRABHA

    2012-12-01

    Full Text Available Synthesis of novel aliphatic biodegradable copolyesters namely Poly (ethylene sebacate-co-butylene succinate and Poly (ethylene sebacate-co-butylene adipate were carried out using Poly (butylene Succinate, Poly (Butylene Adipate and Poly (Ethylene Sebacate in presence of Poly Phosphoric acid. Synthesis of Poly (Butylene Succinate, Poly (Butylene Adipate and Poly (Ethylene Sebacate were carried out using respective diols and diacids in presence of titanium tetrabutoxide as catalyst. Newly synthesized copolyesters were characterized by solubility studies, viscosity measurements, thermal analysis, IR Spectroscopy and Nuclear Magnetic Resonance Spectroscopy (1H-NMR and 13C-NMR. The characteristic peaks present in the homopolyesters were recorded in the copolymers as well. DSC analysis of the copolyesters showed multiple melting peaks, while increase of methylene units in the di-acid decreased the Tg.

  5. The radiation chemistry of symmetric aliphatic polyesters

    International Nuclear Information System (INIS)

    Full text: Naturally occurring, symmetric polyesters, including polyglycolic acid, polylactic acid and polyhydroxybutyrate, have found biomedical applications in areas as diverse as the controlled release of pharmaceuticals and the manufacture of surgical sutures. As biomedical products, the materials require sterilization by high energy radiation. This has provided the motivation for the present work. D'Alelio et al. have reported that linear, asymmetric polyesters undergo scission on irradiation, but that branched polyesters containing a methyl group in the diol segments undergo crosslinking. However, for the symmetric polyhydroxybutyrate, Carswell-Pomerantz et al. have reported that only scission occurs on radiolysis, with the evolution of CO and CO2 as a result of the loss of ester linkages. These workers also found that G(CO + CO2) was approximately equal to G(S) for this polyester. By contrast, Collett et al. have reported that G(S) = 1.26 and G(X) = 0.53 for polylactic acid, which indicates that the polymer undergoes nett crosslinking on radiolysis to form a gel. They have also reported that poly(lactic-co-glycolic acid) should form a gel on radiolysis, since G(S) = 1.66 and G(X) = 0.65 for a 1:1 copolymer composition. In the present work the radiolysis of polylactic acid and poly(lactic-co-glycolic acid) have been reinvestigated in order to resolve the differences between the work of Collett et al. and that of Carswell-Pomerantz et al. In these studies, ESR has been used to study the radicals formed, GPC has been used to investigate scission and crosslinking, GC has been used to study the small molecule volatile products and NMR spectroscopy has been used to identify and measure the new chemical structures formed in the polymers

  6. The radiation chemistry of symmetric aliphatic polyesters

    Energy Technology Data Exchange (ETDEWEB)

    Babanalbandi, A.; Hill, D.J.T.; Pomery, P.J.; Whittaker, A.K. [Queensland Univ., St. Lucia, QLD (Australia). Dept. of Chemistry

    1996-12-31

    Full text: Naturally occurring, symmetric polyesters, including polyglycolic acid, polylactic acid and polyhydroxybutyrate, have found biomedical applications in areas as diverse as the controlled release of pharmaceuticals and the manufacture of surgical sutures. As biomedical products, the materials require sterilization by high energy radiation. This has provided the motivation for the present work. D`Alelio et al. have reported that linear, asymmetric polyesters undergo scission on irradiation, but that branched polyesters containing a methyl group in the diol segments undergo crosslinking. However, for the symmetric polyhydroxybutyrate, Carswell-Pomerantz et al. have reported that only scission occurs on radiolysis, with the evolution of CO and CO{sub 2} as a result of the loss of ester linkages. These workers also found that G(CO + CO{sub 2}) was approximately equal to G(S) for this polyester. By contrast, Collett et al. have reported that G(S) = 1.26 and G(X) = 0.53 for polylactic acid, which indicates that the polymer undergoes nett crosslinking on radiolysis to form a gel. They have also reported that poly(lactic-co-glycolic acid) should form a gel on radiolysis, since G(S) = 1.66 and G(X) = 0.65 for a 1:1 copolymer composition. In the present work the radiolysis of polylactic acid and poly(lactic-co-glycolic acid) have been reinvestigated in order to resolve the differences between the work of Collett et al. and that of Carswell-Pomerantz et al. In these studies, ESR has been used to study the radicals formed, GPC has been used to investigate scission and crosslinking, GC has been used to study the small molecule volatile products and NMR spectroscopy has been used to identify and measure the new chemical structures formed in the polymers. 4 refs.

  7. Acyclic nucleoside phosphonates as inhibitors of Mycobacterium tuberculosis hypoxanthine-guanine phosphoribosyltransferase: Crystal structures and antituberculosis activity

    Czech Academy of Sciences Publication Activity Database

    Hocková, Dana; Eng, W. S.; Špaček, Petr; Janeba, Zlatko; West, N. P.; Woods, K.; Naesens, L. M. J.; Keough, D. T.; Guddat, L. W.

    Praha: Czech Chemical Society, 2015. s. 74. [Liblice 2015. Advances in Organic, Bioorganic and Pharmaceutical Chemistry /50./. 06.11.2015-08.11.2015, Olomouc] Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * phosphoribosyltransferase * prodrugs Subject RIV: CC - Organic Chemistry

  8. Natural attenuation of diesel aliphatic hydrocarbons in contaminated agricultural soil

    International Nuclear Information System (INIS)

    A diesel fuel spill at a concentration of 1 L m-2 soil was simulated on a 12 m2 plot of agricultural land, and natural attenuation of aliphatic hydrocarbons was monitored over a period of 400 days following the spill after which the aliphatic hydrocarbon concentrations were found to be below the legal contamination threshold for soil. The main fraction of these compounds (95%) remained at the surface layer (0-10 cm). Shortly after the spill (viz. between days 0 and 18), evaporation was the main origin of the dramatic decrease in pollutant concentrations in the soil. Thereafter, soil microorganisms used aliphatic hydrocarbons as sources of carbon and energy, as confirmed by the degradation ratios found. Soil quality indicators, soil microbial biomass and dehydrogenase activity, regained their original levels about 200 days after the spill. - The effect of aliphatic hydrocarbons contamination on soil quality was monitored over a period of 400 days after a Diesel fuel spill

  9. ANAEROBIC AND AEROBIC TREATMENT OF CHLORINATED ALIPHATIC COMPOUNDS

    Science.gov (United States)

    Biological degradation of 12 chlorinated aliphatic compounds (CACs) was assessed in bench-top reactors and in serum bottle tests. Three continuously mixed daily batch-fed reactor systems were evaluated: anaerobic, aerobic, and sequential-anaerobic-aerobic (sequential). Glucose,...

  10. Regulation of the survival and differentiation of hepatic stem/progenitor cells by acyclic retinoid.

    Science.gov (United States)

    Kamiya, Akihide

    2015-01-01

    During embryonic liver development, hepatic stem/progenitor cells (HpSCs) have a high proliferative ability and bipotency to differentiate into hepatocytes and cholangiocytes. Retinoic acid is a derivative of vitamin A and is involved in the proliferation and differentiation of stem/progenitor cells in several tissues. However, whether retinoic acid regulates the characteristics of HpSCs in the normal liver is still unknown. A recent study has shown that acyclic retinoid regulates the survival and proliferation of HpSCs derived from mouse foetal liver. Acyclic retinoid suppressed the expansion of CD29(+)CD49f(+) HpSCs through the induction of hepatocytic differentiation and progression of apoptosis. PMID:26021438

  11. [Synthesis of acyclic 1,3-polyols and its application to structural study of natural products].

    Science.gov (United States)

    Mori, Y

    1993-06-01

    A 1,3-polyhydroxylated chain is often found on the backbone of biologically important natural products. The acyclic nature and the regular array of many hydroxyl groups are main obstacles to structural and synthetic studies, and many efforts have been made to this end. We have developed a new general synthetic method of 1,3-polyols based on the coupling of a chiral dithiane, a four-carbon unit, and an epoxide, followed by 1,3-diastereoselective reduction. We applied the method to the synthesis of polymethoxy-1-alkenes isolated from blue-green algae to establish their absolute stereochemistry. Moreover, a general procedure for assigning the absolute stereochemistry of acyclic 1,3-polyols by the difference circular dichroism (CD) method have been established. Combination of the method and a reiterative degradation enables one to determine the absolute configuration of 1,3-polyols, even if the relative stereochemistry is unknown. PMID:8355146

  12. Fixed parameter algorithms for restricted coloring problems: acyclic, star, nonrepetitive, harmonious and clique colorings

    CERN Document Server

    Campos, Victor; Maia, Ana Karolinna; Martins, Nicolas; Sampaio, Rudini Menezes

    2011-01-01

    In this paper, we obtain polynomial time algorithms to determine the acyclic chromatic number, the star chromatic number, the Thue chromatic number, the harmonious chromatic number and the clique chromatic number of $P_4$-tidy graphs and $(q,q-4)$-graphs, for every fixed $q$. These classes include cographs, $P_4$-sparse and $P_4$-lite graphs. All these coloring problems are known to be NP-hard for general graphs. These algorithms are fixed parameter tractable on the parameter $q(G)$, which is the minimum $q$ such that $G$ is a $(q,q-4)$-graph. We also prove that every connected $(q,q-4)$-graph with at least $q$ vertices is 2-clique-colorable and that every acyclic coloring of a cograph is also nonrepetitive.

  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 ostatní: 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. Synthesis and properties of chiral open-ring acyclic nucleoside bisphosphonates

    Czech Academy of Sciences Publication Activity Database

    Doláková, Petra; Dračínský, Martin; Holý, Antonín

    Elsevier. Roč. 74, č. 3 (2007), A72. ISSN 0166-3542. [Conference on Antiviral Research. 29.04.2007-03.05.2007, Palm Springs] R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Grant ostatní: René Descartes Prize-2001(XE) HPAW-2002-100096 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonate * bisphosphonate * pyrimidine Subject RIV: CC - Organic Chemistry

  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 ostatní: GA ČR(CZ) GAP207/11/0365 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * antivirals * antineoplastics * permeation enhancer * topical skin application * transdermal delivery Subject RIV: CC - Organic Chemistry Impact factor: 4.093, year: 2011

  16. Regulation of the survival and differentiation of hepatic stem/progenitor cells by acyclic retinoid

    OpenAIRE

    Kamiya, Akihide

    2015-01-01

    During embryonic liver development, hepatic stem/progenitor cells (HpSCs) have a high proliferative ability and bipotency to differentiate into hepatocytes and cholangiocytes. Retinoic acid is a derivative of vitamin A and is involved in the proliferation and differentiation of stem/progenitor cells in several tissues. However, whether retinoic acid regulates the characteristics of HpSCs in the normal liver is still unknown. A recent study has shown that acyclic retinoid regulates the surviva...

  17. Palladium-Catalyzed Enantioselective Heck Alkenylation of Acyclic Alkenols Using a Redox-Relay Strategy

    OpenAIRE

    Patel, Harshkumar H.; Sigman, Matthew S.

    2015-01-01

    We report a highly enantioselective intermolecular Heck reaction of alkenyl triflates and acyclic primary or racemic secondary alkenols. The mild reaction conditions permit installation of a wide range of alkenyl groups at positions β, γ or δ to a carbonyl group in high enantioselectivity. The success of this reaction is attributed to the use of electron-withdrawing alkenyl triflates, which offer selective β-hydride elimination followed by migration of the catalyst through the alkyl chain to ...

  18. 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

  19. Stability of 47Sc-complexes with acyclic polyamino-polycarboxylate ligands

    OpenAIRE

    Połosak, Magdalena; Piotrowska, Agata; Krajewski, Seweryn; Bilewicz, Aleksander

    2012-01-01

    The aim of this study was to evaluate acyclic ligands which can be applied for labeling proteins such as monoclonal antibodies and their fragments with scandium radionuclides. Recently, scandium isotopes (47Sc, 44Sc) are more available and their properties are convenient for radiotherapy or PET imaging. They can be used together as “matched pair” in theranostic approach. Because proteins denaturize at temperature above 42 °C, ligands which efficiently form complexes at room temperature, are n...

  20. Affinity capillary electrophoresis applied to investigation of complexes of acyclic nucleoside phosphonates with beta-cyclodextrin

    Czech Academy of Sciences Publication Activity Database

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

    Ljubljana: National Institute of Chemistry, 2015 - (Vovk, I.; Glavnik, V.; Albreht, A.). s. 127 ISBN 978-961-6104-28-9. [ISSS 2015. International Symposium on Separation Sciences /21./. 30.06.2015-03.07.2015, Ljubljana] R&D Projects: GA ČR(CZ) GA13-17224S; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * complexes * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  1. Determination of apparent binding constants of complexes of acyclic nucleoside phosphonates with cyclodextrins by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

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

    Salzburg: Society of Analytical Chemistry, 2014. P510. [ISC 2014. International Symposium on Chromatography /30./. 14.09.2014-18.09.2014, Salzburg] 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 * capillary electrophoresis * binding constant Subject RIV: CB - Analytical Chemistry, Separation

  2. Synthesis and properties of chiral open-ring acyclic nucleoside bisphosphonates

    Czech Academy of Sciences Publication Activity Database

    Doláková, Petra; Masojídková, Milena; Holý, Antonín

    Praha : ÚOCHB AV ČR, 2005 - (Hocek, M.), s. 395-396 ISBN 80-86241-25-4. - (Collection Symposium Series. 7). [Chemistry of Nucleic Acid Components /13./. Špindlerův Mlýn (CZ), 03.09.2005-09.09.2005] R&D Projects: GA MŠk(CZ) 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonate * pyrimidine * antiviral activity Subject RIV: CC - Organic Chemistry

  3. 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)

    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, γ13∞, 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, [N1112OH][NTf2] 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, ΔG1E,∞, enthalpy ΔH1E,∞, and entropy term TrefΔS1E,∞ were calculated from the experimental γ13∞ values obtained over the temperature range. The density of [N1112OH][NTf2] was measured within temperature range (313.15 to 353.15) K. The (gas + liquid) partition coefficient KL 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 γ13∞ 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 [N1112OH][NTf2] 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 [N1112OH][NTf2] IL may be proposed as an alternative solvent for the

  4. Synthesis of an Antitumoral Diarylheptanoid Containing 1,3-Diol Functionality%Synthesis of an Antitumoral Diarylheptanoid Containing 1,3-Diol Functionality

    Institute of Scientific and Technical Information of China (English)

    张少敏; 伍贻康

    2011-01-01

    A bioactive derivative of a natural diarylheptanoid containing a 1,3-anti diol motif was synthesized with the oxygen-carrying stereogenic centers taken from an enantiopure epoxy chiral building block derived from inexpensive and readily available D-glucolactone.

  5. A role for the androgen metabolite, 5alpha androstane 3beta, 17beta diol (3β-diol) in the regulation of the hypothalamo-pituitary-adrenal axis.

    Science.gov (United States)

    Handa, Robert J; Sharma, Dharmendra; Uht, Rosalie

    2011-01-01

    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 (PVN) of the hypothalamus. Within the PVN, corticotrophin-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 adrenocorticotropic hormone (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 (DHT) and its subsequent binding to the androgen receptor, whereas E2 effects were thought to be mediated by estrogen receptors alpha (ERalpha) and beta (ERbeta). However, DHT has been shown to be metabolized to the ERbeta agonist, 5α- androstane 3β, 17β Diol (3β-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 ability 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 has been shown to occur by 3β-Diol binding to ERbeta and this is thought to occur through alternate pathways of gene regulation. Based on available data, a novel and important role of 3β-Diol in

  6. 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.

  7. A Role for the Androgen Metabolite, 5alpha Androstane 3beta, 17beta Diol (3β-Diol) in the Regulation of the Hypothalamo-Pituitary–Adrenal Axis

    Science.gov (United States)

    Handa, Robert J.; Sharma, Dharmendra; Uht, Rosalie

    2011-01-01

    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 (PVN) of the hypothalamus. Within the PVN, corticotrophin-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 adrenocorticotropic hormone (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 (DHT) and its subsequent binding to the androgen receptor, whereas E2 effects were thought to be mediated by estrogen receptors alpha (ERalpha) and beta (ERbeta). However, DHT has been shown to be metabolized to the ERbeta agonist, 5α- androstane 3β, 17β Diol (3β-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 ability 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 has been shown to occur by 3β-Diol binding to ERbeta and this is thought to occur through alternate pathways of gene regulation. Based on available data, a novel and important role of 3β-Diol

  8. Differential effects of indole and aliphatic glucosinolates on lepidopteran herbivores.

    Science.gov (United States)

    Müller, René; de Vos, Martin; Sun, Joel Y; Sønderby, Ida E; Halkier, Barbara A; Wittstock, Ute; Jander, Georg

    2010-08-01

    Glucosinolates are a diverse group of defensive secondary metabolites that is characteristic of the Brassicales. Arabidopsis thaliana (L.) Heynh. (Brassicaceae) lines with mutations that greatly reduce abundance of indole glucosinolates (cyp79B2 cyp79B3), aliphatic glucosinolates (myb28 myb29), or both (cyp79B2 cyp79B3 myb28 myb29) make it possible to test the in vivo defensive function of these two major glucosinolate classes. In experiments with Lepidoptera that are not crucifer-feeding specialists, aliphatic and indole glucosinolates had an additive effect on Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) larval growth, whereas Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) and Manduca sexta (L.) (Lepidoptera: Sphingidae) were affected only by the absence of aliphatic glucosinolates. In the case of two crucifer-feeding specialists, Pieris rapae (L.) (Lepidoptera: Pieridae) and Plutella xylostella (L.) (Lepidoptera: Plutellidae), there were no major changes in larval performance due to decreased aliphatic and/or indole glucosinolate content. Nevertheless, choice tests show that aliphatic and indole glucosinolates act in an additive manner to promote larval feeding of both species and P. rapae oviposition. Together, these results support the hypothesis that a diversity of glucosinolates is required to limit the growth of multiple insect herbivores. PMID:20617455

  9. Experimental and DFT study of cyclodehydration and acetylation of ferrocenyl diols

    Science.gov (United States)

    Lapić, Jasmina; Višnjevac, Aleksandar; Cetina, Mario; Djaković, Senka; Vrček, Valerije; Rapić, Vladimir

    2012-07-01

    Racemic ferrocenyl diols, i.e. ferrocenyl(2-hydroxymethylphenyl)methanol (2), ferrocenyl-2-(2-hydroxymethylphenyl)ethanol (7), and ferrocenyl(2-(2-hydroxyethyl)phenyl)methanol (9) have been prepared by reduction of corresponding ketoesters using NaBH4 in a mixture EtOH and Et2O. In the course of these reactions new cyclic ethers 1-ferrocenyl-2-oxaindane (3), 3-ferrocenylisochromane (8), and 1-ferrocenylisochromane (10) have been isolated as side-products. Intramolecular cyclizations of ferrocenyl diols occur in both acidic and neutral medium. Density functional theory (BP86) calculations were used to explain the mechanism of these cyclodehydrations. Acid catalyzed reaction follows the classical SN1 mechanism, whereas the cyclodehydration in neutral medium is described as an SN2 reaction. X-ray diffraction analysis of new cyclic ether products has been performed. Monoacetates 11, 13 and 15 have been obtained in the reaction of ferrocenyl diols 2, 7, and 9, respectively, and acetic anhydride. Stereoselective acylation of racemic diols by vinyl acetate have been catalyzed by various lipases, and the best stereoselectivity has been observed for the diol 2 in the presence of Penicillium camembertii lipase.

  10. In silico stereo-electronic analysis of PMD (p-Menthane-3-8-Diol) and its derivatives for pharmacophore development may aid discovery of novel insect repellents.

    Science.gov (United States)

    Bhattacharjee, Apurba K

    2013-09-01

    PMD (p-menthane-3-8-diol) is an insect repellent that can be synthesized chemically or derived from a steam distillate residue of the leaves of lemon eucalyptus, Corymbia citriodora. It is one of the few natural product endorsed by the Center for Disease Control (USA) for topical application to protect against mosquitoes though it is not as effective as the common repellent DEET (N,N -diethyl-1,3-toluamide). However, DEET has several undesirable side effects and toxicity too. Thus, although PMDs are comparatively safer than DEET, no quantitative structure activity relationship (QSAR) and pharmacophore modeling studies have been reported in literature to improve efficacy and aid further development of more effective PMD analogues. In this study, we report results of quantum chemical analysis of stereoelectronic properties and pharmacophore modeling of PMD and eight of its synthetic derivatives to aid discovery and design of more effective PMD analogues. Stereo-electronic analysis indicates that lower aqueous stabilization (favorable lipophilicity) and larger separation of electrostatic potential energy together with a large localized negative electrostatic potential region by the oxygen atom play important roles for repellent activity. Consistent to these properties, the generated pharmacophore model of the PMDs showed two aliphatic hydrophobic and a hydrogen-bond donor features for potent activity. These results aided us to design more effective PMD repellents which are currently under further investigations. PMID:24010930

  11. Evaluation of follicular oxidant-antioxidant balance and oxidative damage during reproductive acyclicity in water buffalo (Bubalus bubalis)

    Institute of Scientific and Technical Information of China (English)

    M H Jan; G Singh; M Sarkar; G K Das; F A Khan; J Singh; S T Bashir; S Khan; J K Prasad; S Mehrotra; M C Pathak

    2014-01-01

    Objective:To investigate changes in follicular fluid concentrations of reactive oxygen species (ROS) and total antioxidant capacity(TAC) and degree of oxidative damage to follicular cells, using protein carbonyl(PC) as marker of oxidative stress, were investigated during reproductive acyclicity in buffalo.Methods:Follicular fluid was aspirated from follicles grouped into three classes depending upon their diameter [small(5.0-7.0 mm), medium(7.1-10.0 mm), and large (>10.0 mm)].Progesterone and estradiol were estimated to determine functional status(P:E ratio) of the follicles.Results:Acyclic buffaloes had greater concentrations ofROS(P<0.001) andPC (P=0.0412) and lower concentrations ofTAC(P=0.0280) than cyclic buffaloes.An interesting novel finding was the complete absence of lowP:E functionally active follicles in acyclic buffaloes. Results indicated a pronounced follicular fluid oxidant-antioxidant imbalance and oxidative damage to follicular cells during acyclicity in buffalo.Conclusion:In conclusion, this study provided evidence about role of oxidative stress in pathogenesis of reproductive acyclicity.

  12. 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)

  13. An ab initio study of three (ethane-1,2 diol/water) complexes

    Science.gov (United States)

    Manivet, Philippe; Masella, Michel

    1998-05-01

    Three (ethane-1,2 diol/water) complexes have been studied using ab initio calculations at the MP2 level. In two complexes, the ethane-1,2 diol structure is close to its gas phase experimental structure (presence of an intramolecular hydrogen bond HB and the O-C-C-O dihedral angle is gauche) while the intramolecular HB is disrupted by the presence of a water molecule in the third ( tGg'a). Computations have shown that most of the experimental observations regarding the solvation of ethane-1,2 diol in water may be reproduced only by considering the tGg'a complex (absence of intramolecular HB, O-C-C-O dihedral angle of 72-74°), which is also more stable than the other two by 2 kcal mol -1.

  14. 平面图的无圈边染色%Acyclic Edge Colouring of Pianar Graphs

    Institute of Scientific and Technical Information of China (English)

    段娟娟; 丁伟

    2011-01-01

    Let G=(V,E) be any finite graph.A mapping C:E→[k]is called an acyclic edge colouring of G,if any two adjacent edges have different colours and there are no bichromatic cycles in G.In other words,the subgraph induced by the union of any two colour classes is a forest.The minimum number k of colours,such that G has an acyclic edge k-colouring is called the acyclic chromatic index of G,denoted by X′a(G).Alon et al.conjectured that for any graph G it holds that X′a(G)≤Δ(G)+2;here Δ(G) stands for the maximum degree of G.In this paper weprove the planar graphs with girth at least 4,then X′a≤Δ(G)+4.%利用差值转移的方法证明了,如果g(G)≥4则有X′a≤Δ(G)+4.图G=(V,E)是简单图,映射C:E→[k],被称作是图G的一个无圈k边染色.如果任意相邻的两个边染有不同的颜色,以及图G中不含有2-色圈,换句话说即图G中任何染两种颜色的边的导出子图是一棵森林.

  15. The gnyRDBHAL Cluster Is Involved in Acyclic Isoprenoid Degradation in Pseudomonas aeruginosa

    Science.gov (United States)

    Díaz-Pérez, A. L.; Zavala-Hernández, A. N.; Cervantes, C.; Campos-García, J.

    2004-01-01

    Pseudomonas aeruginosa PAO1 mutants affected in the ability to degrade acyclic isoprenoids were isolated with transposon mutagenesis. The gny cluster (for geranoyl), which encodes the enzymes involved in the lower pathway of acyclic isoprenoid degradation, was identified. The gny cluster is constituted by five probable structural genes, gnyDBHAL, and a possible regulatory gene, gnyR. Mutations in the gnyD, gnyB, gnyA, or gnyL gene caused inability to assimilate acyclic isoprenoids of the citronellol family of compounds. Transcriptional analysis showed that expression of the gnyB gene was induced by citronellol and repressed by glucose, whereas expression of the gnyR gene had the opposite behavior. Western blot analysis of citronellol-grown cultures showed induction of biotinylated proteins of 70 and 73 kDa, which probably correspond to 3-methylcrotonoyl-coenzyme A (CoA) carboxylase and geranoyl-CoA carboxylase (GCCase) alpha subunits, respectively. The 73-kDa biotinylated protein, identified as the α-GCCase subunit, is encoded by gnyA. Intermediary metabolites of the isoprenoid pathway, citronellic and geranic acids, were shown to accumulate in gnyB and gnyA mutants. Our data suggest that the protein products encoded in the gny cluster are the β and α subunits of geranoyl-CoA carboxylase (GnyB and GnyA), the citronelloyl-CoA dehydrogenase (GnyD), the γ-carboxygeranoyl-CoA hydratase (GnyH), and the 3-hydroxy-γ-carboxygeranoyl-CoA lyase (GnyL). We conclude that the gnyRDBHAL cluster is involved in isoprenoid catabolism. PMID:15345388

  16. Thermoresponsive Polymers and Inverse Opal Hydrogels for the Detection of Diols.

    Science.gov (United States)

    Couturier, Jean-Philippe; Wischerhoff, Erik; Bernin, Robert; Hettrich, Cornelia; Koetz, Joachim; Sütterlin, Martin; Tiersch, Brigitte; Laschewsky, André

    2016-05-01

    Responsive inverse opal hydrogels functionalized by boroxole moieties were synthesized and explored as sensor platforms for various low molar mass as well as polymeric diols and polyols, including saccharides, glycopolymers and catechols, by exploiting the diol induced modulation of their structural color. The underlying thermoresponsive water-soluble copolymers and hydrogels exhibit a coil-to-globule or volume phase transition, respectively, of the LCST-type. They were prepared from oligoethylene oxide methacrylate (macro)monomers and functionalized via copolymerization to bear benzoboroxole moieties. The resulting copolymers represent weak polyacids, which can bind specifically to diols within an appropriate pH window. Due to the resulting modulation of the overall hydrophilicity of the systems and the consequent shift of their phase transition temperature, the usefulness of such systems for indicating the presence of catechols, saccharides, and glycopolymers was studied, exploiting the diol/polyol induced shifts of the soluble polymers' cloud point, or the induced changes of the hydrogels' swelling. In particular, the increased acidity of benzoboroxoles compared to standard phenylboronic acids allowed performing the studies in PBS buffer (phosphate buffered saline) at the physiologically relevant pH of 7.4. The inverse opals constructed of these thermo- and analyte-responsive hydrogels enabled following the binding of specific diols by the induced shift of the optical stop band. Their highly porous structure enabled the facile and specific optical detection of not only low molar mass but also of high molar mass diol/polyol analytes such as glycopolymers. Accordingly, such thermoresponsive inverse opal systems functionalized with recognition units represent attractive and promising platforms for the facile sensing of even rather big analytes by simple optical means, or even by the bare eye. PMID:27108735

  17. A Practical Approach for Scalable Conjunctive Query Answering on Acyclic {EL}^+ Knowledge Base

    Science.gov (United States)

    Mei, Jing; Liu, Shengping; Xie, Guotong; Kalyanpur, Aditya; Fokoue, Achille; Ni, Yuan; Li, Hanyu; Pan, Yue

    Conjunctive query answering for {EL}^{++} ontologies has recently drawn much attention, as the Description Logic {EL}^{++} captures the expressivity of many large ontologies in the biomedical domain and is the foundation for the OWL 2 EL profile. In this paper, we propose a practical approach for conjunctive query answering in a fragment of {EL}^{++}, namely acyclic {EL}^+, that supports role inclusions. This approach can be implemented with low cost by leveraging any existing relational database management system to do the ABox data completion and query answering. We conducted a preliminary experiment to evaluate our approach using a large clinical data set and show our approach is practical.

  18. A nice acyclic matching on the nerve of the partition lattice

    CERN Document Server

    Donau, Ralf

    2012-01-01

    The author has already proven that the space \\Delta(\\Pi_n)/G is homotopy equivalent to a wedge of spheres of dimension n-3 for all natural numbers n>=3 and all subgroups Gacyclic matching on \\Delta(\\Pi_n)/G that allows us to give a basis of its cohomology. This is also a more elementary approach to determining the number of spheres. Furthermore we give a description of the group action by an action on the spheres. We also obtain another result that we call Equivariant Patchwork Theorem.

  19. Formula Periodic Table for the Isomer Classes of Acyclic Hydrocarbons - Enumerative and Asymptotic Characteristics

    OpenAIRE

    Bytautas, Laimutis; Klein, Douglas J.

    2000-01-01

    The overall set of acyclic hydrocarbons CnH2m with classical valence structures is considered, the structural isomers are enumerated, and the results displayed in the form of a »periodic table« with the C atom count n and H atom half-count m respectively identifying rows and columns. Asymptotic n → ∞ behaviors of these enumerations are developed, first for fixed degree u ≡ n + 1 - m of unsaturation and second for fixed number 2m of H-atoms. The first-set isomer classes increase ...

  20. Facile syntheses of pyrimidine acyclic nucleoside phosphonates and their potential evaluation for biomedical applications

    Czech Academy of Sciences Publication Activity Database

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

    Praha : Institute of Organic Chemistry and Biochemistry ASCR, 2008 - (Hocek, M.), s. 201-205 ISBN 978-80-86241-29-6. - (Collection Symposium Series. 10). [Symposium on Chemistry of Nucleic Acid Components /14./. Český Krumlov (CZ), 08.06.2008-13.06.2008] R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * thymidine phosphorylase * dUTPpase Subject RIV: CC - Organic Chemistry

  1. Crystallization and glass transition of the diols and aminoalcohols, according to DSC data

    Science.gov (United States)

    Solonina, I. A.; Rodnikova, M. N.; Kiselev, M. P.; Khoroshilov, A. V.

    2015-05-01

    Overcooling, crystallization, and glass transition of the diol series and aminoalcohols which are the liquids with spatial hydrogen-bond networks, which are the along with the overcooling of dioxane, dimethylsulfoxide, and acetonitrile, which do not have such networks were studied by DSC. The observed phenomena are explained by the stability of H-bond networks. It was concluded that changes in the stability of the networks in and between series of diols and aminoalcohols are due to differences between their molecular structures, the energies of their hydrogen bonds, and their network topologies.

  2. 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.

  3. Selective stabilization of aliphatic organic carbon by iron oxide

    Science.gov (United States)

    Adhikari, Dinesh; Yang, Yu

    2015-06-01

    Stabilization of organic matter in soil is important for natural ecosystem to sequestrate carbon and mitigate greenhouse gas emission. It is largely unknown what factors govern the preservation of organic carbon in soil, casting shadow on predicting the response of soil to climate change. Iron oxide was suggested as an important mineral preserving soil organic carbon. However, ferric minerals are subject to reduction, potentially releasing iron and decreasing the stability of iron-bound organic carbon. Information about the stability of iron-bound organic carbon in the redox reaction is limited. Herein, we investigated the sorptive interactions of organic matter with hematite and reductive release of hematite-bound organic matter. Impacts of organic matter composition and conformation on its sorption by hematite and release during the reduction reaction were analyzed. We found that hematite-bound aliphatic carbon was more resistant to reduction release, although hematite preferred to sorb more aromatic carbon. Resistance to reductive release represents a new mechanism that aliphatic soil organic matter was stabilized by association with iron oxide. Selective stabilization of aliphatic over aromatic carbon can greatly contribute to the widely observed accumulation of aliphatic carbon in soil, which cannot be explained by sorptive interactions between minerals and organic matter.

  4. A thermostable transketolase evolved for aliphatic aldehyde acceptors.

    Science.gov (United States)

    Yi, Dong; Saravanan, Thangavelu; Devamani, Titu; Charmantray, Franck; Hecquet, Laurence; Fessner, Wolf-Dieter

    2015-01-11

    Directed evolution of the thermostable transketolase from Geobacillus stearothermophilus based on a pH-based colorimetric screening of smart libraries yielded several mutants with up to 16-fold higher activity for aliphatic aldehydes and high enantioselectivity (>95% ee) in the asymmetric carboligation step. PMID:25415647

  5. Introducing Aliphatic Substitution with a Discovery Experiment Using Competing Electrophiles

    Science.gov (United States)

    Curran, Timothy P.; Mostovoy, Amelia J.; Curran, Margaret E.; Berger, Clara

    2016-01-01

    A facile, discovery-based experiment is described that introduces aliphatic substitution in an introductory undergraduate organic chemistry curriculum. Unlike other discovery-based experiments that examine substitution using two competing nucleophiles with a single electrophile, this experiment compares two isomeric, competing electrophiles…

  6. 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 ...

  7. Chemical consequences of long-range orbital interaction in perhydronaphtalene-1,4 diol monosulfonate esters.

    NARCIS (Netherlands)

    Orru, R.V.A.

    1994-01-01

    In this thesis the base-induced reactions of perhydronaphthalene-1,4-diol monosulfonate esters are described. These compounds undergo smoothly, typical carbocationic processes upon treatment with sodium tert -amylate in refluxing benzene. The product outcome, product ratio, and (relative) rate of th

  8. 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

    is believed to involve dehydrogenation of the 1,2‐diol to the α‐hydroxy aldehyde, which condenses with the amine to form the α‐hydroxy imine. The latter rearranges to the corresponding α‐amino carbonyl compound, which then reacts with another amine followed by reduction of the resulting imine....

  9. In Situ Spectroscopic Investigation of the Rhenium-Catalyzed Deoxydehydration of Vicinal Diols

    DEFF Research Database (Denmark)

    Dethlefsen, Johannes Rytter; Fristrup, Peter

    2015-01-01

    rhenium(V) complex (the rate-limiting step), 2) condensation of the diol and the rhenium(V) complex to a rhenium(V) diolate, and 3) extrusion of the alkene accompanied by oxidation of the Re center and thus regeneration of CH3ReO3. The reaction follows zero-order kinetics initially but, unexpectedly...

  10. 211At-Rh(16-S4-diol) complex as a precursor for astatine radiopharmaceuticals

    International Nuclear Information System (INIS)

    211At is one of the most promising radionuclides in α-radioimmunotherapy (α-RIT). Unfortunately, biomolecules labeled by direct electrophilic astatination are unstable due to the rapid loss of 211At under both in vitro and in vivo conditions. The present paper describes the results of our studies on attaching At- to the rhodium(III) complex with thioether ligand: 1,5,9,13-etrathiacyclohexadecane-3,11-diol (16-S4-diol). Rh3+ was chosen as a moderately soft metal cation which should form very strong bonds with soft At- anions, but first of all because of the kinetic inertness of low spin rhodium(III) d6 complexes. The 16-S4-diol ligand was selected due to formation of stable complexes with Rh3+. The experiments related to optimization of the reaction conditions were performed with the 131I, basing on a chemical similarity of I- to At-. The experiments with 211At were then carried out under the conditions found optimal for I-. The preliminary results are promising, and indicate a possibility for astatination of biomolecules by using the 211At-Rh(16-S4-diol) complex

  11. 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 m

  12. BENZO(A)PYRENE DIOL EPOXIDE I BINDS TO DNA AT REPLICATION FORKS (JOURNAL VERSION)

    Science.gov (United States)

    The distribution in replication forks of DNA lesions caused by the treatment of S phase calls with benzo(a)pyrene-diol-epoxide-1 (BPDE-1) was studied in synchronized C3H10T1/2 cells. Sites of carcinogen modification of DNA were identified by polyclonal rabbit antibodies that were...

  13. Kinetics and mechanism of the oxidation of some vicinal and non-vicinal diols by tetrabutylammonium tribromide

    Indian Academy of Sciences (India)

    Jaya Gosain; Pradeep K Sharma

    2003-04-01

    Kinetics of oxidation of five vicinal and four non-vicinal diols, and two of their monoethers, by tetrabutylammonium tribromide (TBATB) has been studied. The vicinal diols yield products arising out of glycol-bond fission, while the non-vicinal diols produce the hydroxycarbonyl compounds. The reaction is first-order with respect to TBATB. Michaelis-Menten type kinetics is observed with respect to diols. The reaction fails to induce the polymerization of acrylonitrile. There is no effect of tetrabutylammonium chloride on the reaction rate. The proposed reactive oxidizing species is the tribromide ion. The effect of solvent composition indicates that the rate increases with increase in the polarity of the solvent. The oxidation of [1,1,2,2-2H4] ethanediol shows the absence of any primary kinetic isotope effect. Values of solvent isotope effect, (H2O)/(D2O), at 288 K for the oxidation of ethanediol, propane-1,3-diol and 3-methoxybutan-1-ol are 3.41, 0.98 and 1.02 respectively. A mechanism involving a glycol-bond fission has been proposed for the oxidation of vicinal diols. Non-vicinal diols are oxidised by a hydride-transfer mechanism, as they are monohydric alcohols.

  14. 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: 2.968, year: 2014

  15. Novel type of acyclic nucleoside phosphonates derived from 2-(phosphonomethoxy)-and 2-(phosphonoethoxy)propanoic acid

    Czech Academy of Sciences Publication Activity Database

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

    Amsterdam : Elsevier, 2012. -. [Tetrahedron Symposium: Challenges in Bioorganic & Organic Medicinal Chemistry /13./. 26.06.2012-29.06.2012, Amsterdam] R&D Projects: GA MV VG20102015046; GA ČR GAP207/11/0108 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * antiparasitic * 2-(phosphonomethoxy)propanoic acid * HG(X)PRTase Subject RIV: CC - Organic Chemistry

  16. Aliphatics hydrocarbon content in surface sediment from Jakarta Bay, Indonesia

    Science.gov (United States)

    YAzis, M.; Asia, L.; Piram, A.; Doumenq, P.; Syakti, A. D.

    2016-02-01

    Sedimentary aliphatic hydrocarbons content have been studied quantitatively and qualitatively using GC/MS method in eight coastal stations located in the Jakarta Bay, North of Jakarta, Indonesia. The total concentrations n-alkanes have ranged from 480 μg.kg-1to 1,935 μg.kg-1sediment dry weight. Several ratios (e.g. CPI24-32, NAR, TAR, Pr/Phy, n-C17/Pr, n- C18/Phyt,n-C29/n-C17, Ʃn-alkanes/n-C16LMW/HMW, Paq and TMD) were used to evaluate the possible sources of terrestrial-marine inputs of these hydrocarbons in the sediments. The various origins of aliphatic hydrocarbons were generally biogenic, including both terrigenous and marine, with an anthropogenic pyrolytic contribution (petrogenic and biogenic combustion). Two stations (G,H) were thehighest concentration and had potential risk to environment

  17. Effect of solvents on reactions of oxidation with aliphatic peroxyacids

    OpenAIRE

    Natalia Matsyuk, Mariya Matsyuk; Volodymur Dutka

    2013-01-01

    Organic solvents effect on the reactions of oxidation involving aliphatic peroxyacids was studied. It was found the kinetic and activation parameters of the oxidation of aniline. It is shown that the reaction medium has a significant effect on the rate of the process. The epoxidation reaction of ?-pinene and ?3-karen by peroxydecanoic acid was studied. It was obtain the equation of correlation that connecting speed reaction with the basic physicochemical properties of solvents.

  18. 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.

  19. Reactions of aliphatic free radicals with transition metal complexes

    International Nuclear Information System (INIS)

    A pulse radiolytic study of the reactions of copper ions with free aliphatic radicals was carried out. It was found that all the aliphatic radicals studied react with Cusub(aq)sup(+) and Cusub(aq)sup(2+), forming an unstable compound, with a carbon-copper σ bond, according to the reaction Mnsub(aq)sup(n+)+ . CR1R2R3 → M-CR1R2Rsub(3)sup(n+). It was also found that the rates of formation of the intermediate compounds, their half-lives and their decomposition mechanism depend on the properties of the radical and the cation. Experiments for the determination of the influence of macrocyclic ligands of the Curtis type on the stability of intermediate compounds failed because of insufficient concentrations of these ligands. The processes of ligand hydridization, isomerization and decomposition for the macrocylic complexes Cusup(I)L were also studied. These complexes, which are unstable, are formed as a result of the reaction of the stable Cusup(II)L complexes with certain free aliphatic radicals

  20. 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. PMID:26787457

  1. 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.

  2. Consensus pursuit of heterogeneous multi-agent systems under a directed acyclic graph

    Institute of Scientific and Technical Information of China (English)

    Yan Jing; Guan Xin-Ping; Luo Xiao-Yuan

    2011-01-01

    This paper is concerned with the cooperative target pursuit problem by multiple agents based on directed acyclic graph. The target appears at a random location and moves only when sensed by the agents, and agents will pursue the target once they detect its existence. Since the ability of each agent may be different, we consider the heterogeneous multi-agent systems.According to the topology of the multi-agent systems, a novel consensus-based control law is proposed, where the target and agents are modeled as a leader and followers, respectively. Based on Mason's rule and signal flow graph analysis, the convergence conditions are provided to show that the agents can catch the target in a finite time. Finally, simulation studies are provided to verify the effectiveness of the proposed approach.

  3. Chiral analysis and characterization of acyclic nucleoside phosphonates-based antiviral drugs by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Šolínová, Veronika; Sázelová, Petra; Mikysková, Hana; Koval, Dušan; Břehová, Petra; Krečmerová, Marcela; Janeba, Zlatko; Holý, Antonín

    Bratislava: Slovenská vákuová spoločnosť, 2013 - (Bodor, R.; Okenicová, L.; Staňová, A.), s. 14-17 ISBN 978-80-971179-1-7. [Analytické metódy a zdravie človeka. Medzinárodná konferencia /19./. Rajecké Teplice (SK), 24.06.2013-27.06.2013] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR GA13-17224S; GA MŠk(CZ) ME10040; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * chiral analysis * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  4. The mixed diol-dithiol 2,2-bis(sulfanylmethyl)propane-1,3-diol: characterization of key intermediates on a new synthetic pathway.

    Science.gov (United States)

    Simmons, Trevor R; Pickett, Christopher J; Wright, Joseph A

    2011-01-01

    A new synthetic route to 2,2-bis(sulfanylmethyl)propane-1,3-diol, (II), is described starting from the commercially available 2,2-bis(hydroxymethyl)propane-1,3-diol. The structures of two intermediates on this route are described. 5,5-Dimethenyl-2,2-dimethyl-1,3-dioxane bis(thiocyanate) (systematic name: {[5-(cyanosulfanyl)-2,2-dimethyl-1,3-dioxan-5-yl]sulfanyl}formonitrile), C(10)H(14)N(2)O(2)S(2), (X), crystallizes in the space group P2(1)/c with no symmetry relationship between the two thiocyanate groups. There is a short intramolecular N...S contact for one thiocyanate group, while the second group is positioned such that this type of interaction is not possible. 1,3-(Hydroxymethyl)propane-1,3-diyl bis(thiocyanate), C(7)H(10)N(2)O(2)S(2), (XI), also features a single short N···S contact in the solid state. Hydrogen bonding between two molecules of compound (XI) results in the formation of dimers in the crystal, which are then linked together by a second hydrogen-bond interaction between the dimers. In addition, the structures of two intermediates from an unsuccessful alternative synthesis of (II) are reported. 2,2-Bis(chloromethyl)propane-1,3-diol, C(5)H(10)Cl(2)O(2), (VI), crystallized as an inversion twin with a minor twin fraction of 0.43 (6). It forms a zigzag structure as a result of intermolecular hydrogen bonding. The structure of 9,9-dimethyl-2,4,8,10-tetraoxa-3λ(4)-thiaspiro[5.5]undecan-3-one, C(8)H(14)O(5)S, (VII), shows evidence for a weak S···O contact with a distance of 3.2529 (11) Å. PMID:21206075

  5. Acyclic hydrocarbon environments ⩾ n-C 18 on the early terrestrial planets

    Science.gov (United States)

    Marcano, Vicente; Benitez, Pedro; Palacios-Prü, Ernesto

    2003-03-01

    The possible occurrence on the surface of the early Earth, Mars and Venus of hydrocarbon environments mainly composed by acyclic alkane molecules ⩾ n-C 18 has been revised. These hydrocarbons could be accumulated from the contribution of endogenous Fischer-Tropsh-type reactions and post-impact recombination reactions, as well as from exogenous sources such as comets, meteorites and dust particles. Such heavy alkane environments could offer protection for the synthesis and survival of biomolecules on the early terrestrial planets. Amounts of heavy n-alkanes delivered by large impactors, dust particles or produced by post-impact recombination on Venus would have been higher than those delivered or produced by the same sources on Earth and Mars before 3600 Myr ago. However, the high values of the total frequency of impacts by bolides >14-km in diameter estimated in this time period (viz. 3.9×10 3, Mars; 2.2×10 4, Earth, and 3.8×10 4 Venus) and the high surface temperatures generated by those impactors suggest the existence of very unstable conditions on the early terrestrial planets for the survival and long-term accumulation of acyclic hydrocarbons. Therefore, the most significant accumulation of n-alkanes could have occurred only during the longer intervals (10 5- 10 7 yr) between each impact through the contribution mainly of IDPs, and thereby a high decomposition rate would be expected for the accumulated n-alkanes by successive impacts. Amounts of n-alkanes accumulated from IDPs in these intervals have been estimated between 2.3×10 9 and 2.2×10 10 kg 3600- 3800 Myr ago. These processes are expected to occur on other planetary bodies or satellites belonging to our solar system and probably in analogs of the early solar system.

  6. Cost-Benefit Analysis for Alternatives to Aliphatic Isocyanate Polyurethanes

    Science.gov (United States)

    Lewis, Pattie

    2007-01-01

    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 Cost-Benefit Analysis (CBA) quantifies the estimated capital and process costs of coating alternatives and cost savings relative to the current coatings. The estimates in this CBA are to be used for assessing the relative merits of the selected alternatives. The actual economic effects at any specific facility will depend on the alternative material or technology implemented, the number of actual applications converted, future workloads, and other factors . The participants initially considered eighteen (18) alternative coatings as described in the Potential Alternatives Report entitled Potential Alternatives Report for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes, prepared by ITB. Of those, 8 alternatives were selected for testing in accordance with the Joint Test Protocol entitled Joint Test Protocol for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes, and the Field Test Plan entitled Field Evaluations Test Plan for Validation of Alternatives 10 Aliphatic Isocyanate Polyurethanes, both of which were prepared by ITB. A joint Test Report entitled Joint Test Report for Validation of Alternatives to Aliphatic Isocyanate Polyurethanes, prepared by ITB, documents the results of the laboratory and field testing, as well as any

  7. Asymmetric reduction of α-hydroxy aromatic ketones to chiral aryl vicinal diols using carrot enzymes system

    Institute of Scientific and Technical Information of China (English)

    Xiang Liu; Yi Wang; Hai Yan Gao; Jian He Xu

    2012-01-01

    Asymmetric reduction of α-hydroxy aromatic ketones was carried out by using carrot enzymes system,yielding corresponding chiral vicinal diols with special functional groups.The optimum reaction conditions were obtained after investigation of various influencing factors.Chiral aryl vicinal diols were produced with good yields and excellent enantiomeric excesses under appropriate conditions,Meanwhile,the steric factors and electronic effects of the substituents on the aromatic ring were shown to have an interesting influence on both yield and enantioselectivity.

  8. Percutaneous absorption of an insect repellent p-menthane-3,8-DIOL: a model for human dermal absorption.

    Science.gov (United States)

    Reifenrath, William G; Olson, James J; Vedula, Usha; Osimitz, Thomas G

    2009-01-01

    p-Menthane-3,8-diol(38DIOL) was recently introduced as a natural topical insect repellent in the commercial product "OFF! Botanicals" lotion. The objective of this study was to provide an estimate of the potential for 38DIOL systemic absorption in humans. Carbon-14-labeled 38DIOL formulated in the lotion and in an ethanol solution was applied to excised pig skin in an in vitro flow-through test system predictive of skin absorption in humans. Twenty-four hours after application, radiolabel recovered from the dermis and receptor fluid was summed to determine percent absorption. At a dose of approximately 80 microg/cm(2) of 38DIOL in the lotion, a value of 3.5 +/- 0.8% of applied dose was obtained with pig skin. The corresponding value for 38DIOL in ethanol (90 microg/cm(2)) was not significantly different (3.0 +/- 1.2%). Most of the applied dose of 38DIOL was found to evaporate from pig skin (77 +/- 8% for the lotion and 87 +/- 1% for ethanol solution), thus limiting percutaneous absorption values. For reference purposes, the pig skin absorptions of piperonyl butoxide (PBO) at 100 microg/cm(2) in isopropanol, N,N-diethyl-m-toluamide (DEET) at 500 microg/cm(2) in ethanol, and neat isododecane at 650 microg/cm(2) (in order of increasing volatility) were 15 +/- 6%, 23 +/- 3%, and 0.09 +/- 0.05% of applied dose respectively. Isododecane was lost almost exclusively from the skin surface by evaporation. For additional reference, absorptions of PBO, DEET, and 38DIOL were found to be higher with excised rat skin. PMID:19557607

  9. Polyols Prepared from Ring-Opening Epoxidized Soybean Oil by a Castor Oil-Based Fatty Diol

    OpenAIRE

    Jing Zhang; Ji Jun Tang; Jiao Xia Zhang

    2015-01-01

    Several biorenewable vegetable oil-based polyols with different molecular weights and various hydroxyl functionalities were successfully prepared by ring-opening epoxidized soybean oil with a castor oil-based fatty diol. It was found that several factors, including reaction time, reaction temperature, and molar ratios between epoxidized soybean oil and castor oil diol, affect structures and rheology behaviors of the final polyols. Proton NMR, FT-IR, GPC, and rheometry results revealed that th...

  10. Absolute Configuration Determination of Azulenyl Diols Isolated From Asymmetric Pinacol Coupling.

    Science.gov (United States)

    Dragu, Eugenia Andreea; Naubron, Jean-Valere; Hanganu, Anamaria; Razus, Alexandru C; Nica, Simona

    2015-11-01

    A convenient enantioselective approach for the pinacol coupling of 1-acetylazulene involving easily accessible (R)- or (S)-BINOLs as chiral additive is reported. This supposes the preformation of the chiral titanium-BINOL complex in 1:2 ratio and subsequent reduction with zinc when, 2,3-di(azulen-1-yl)butane-2,3-diol can be isolated in around 60% enantiomeric excess. The absolute configuration of the isolated enantiomers was assigned by comparison of the experimental and Boltzmann-weighted calculated VCD and ECD spectra and assigned as (+)-(2S;3S)-di(azulen-1-yl)butane-2,3-diol. Chirality 27:826-834, 2015. © 2015 Wiley Periodicals, Inc. PMID:26364568

  11. Antibacterial action of 2-bromo-2-nitropropane-1,3-diol (bronopol).

    OpenAIRE

    Shepherd, J A; Waigh, R D; Gilbert, P

    1988-01-01

    Patterns of growth inhibition of Escherichia coli in the presence of 2-bromo-2-nitropropane-1,3-diol (bronopol) indicate a period of biocide-induced bacteriostasis followed by growth at an inhibited rate. The length of the bacteriostatic period, but not the subsequent growth inhibition, was reduced by the addition of excess cysteine. Patterns of growth inhibition were unaffected by catalase or superoxide dismutase. The bactericidal concentrations (100 to 500 micrograms/ml) were considerably i...

  12. NMR solution structures of adducts derived from the binding of polycyclic aromatic diol epoxides to DNA

    Energy Technology Data Exchange (ETDEWEB)

    Cosman, M.; Patel, D.J. [Memorial Sloan Kettering Cancer Center, New York, NY (United States). Cellular Biochemistry and Biophysics Program; Hingerty, B.E. [Oak Ridge National Lab., TN (United States). Health and Safety Research Div.; Amin, S. [American Health Foundation, Valhalla, NY (United States); Broyde, S.; Geacintov, N.E. [New York Univ., NY (United States)

    1995-12-31

    Site-specifically modified oligonucleotides were derived from the reactions of stereoisomeric polycyclic aromatic diol epoxide metabolite model compounds with oligonucleotides of defined base composition and sequence. The NMR solution structures of ten different adducts studied so far are briefly described, and it is shown that stereochemical factors and the nature of the oligonucleotide context of the complementary strands, exert a powerful influence on the conformational features of these adducts.

  13. Colloidal and Chemical Properties of Polyesters Based on Glutamic acid and Diols of Different Nature

    OpenAIRE

    Puzko N.V.; Varvarenko S.S.; Voronov A.S.; Dron I.A.; Tarnavchyk I.T.; Nosova N.G.; Samaryk V.J.; Voronov S.A.

    2012-01-01

    The paper describes synthesis method and colloid-chemical properties of novel α-amino acid based polyesters with controllable hydrophilic-lipophillic balance. Glutamic acid and diols of different nature based polyesters were obtained via low-temperature activated polyesterefication. Such polymers are able to form micellar structures in self-stabilized water dispersion. Solubilization of water insoluble dyes Sudan and toluene in polymer water solution was studied. Due to micelle forming abilit...

  14. Preparation for Supramolecular Complexes of Chiral Diols BDPDD, DMBDPD and BINOL with Some Prochiral Compounds

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Interaction between chiral diols BDPDD, DMBDPD and BINOL with prochiral compounds was examined and some new supramolecular complexes were prepared. It was found that these chiral hosts could include prochiral guests,α,β-unsaturated compounds or piper- azinedione derivatives to give inclusion crystals in different molar ratio. Formations of these supramolecular complexes were characterized by the data of IR and 1H NMR spectra.

  15. 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})

  16. Synthesis and characterization of biodegradable materials: PDLLA-(MAh-Diol)n-PDLLA copolymer

    Institute of Scientific and Technical Information of China (English)

    Jia Chen; Yuan Liang Wang; Mei Na Huang

    2007-01-01

    The novel biodegradable copolymer PDLLA-(MAH-Diol)n-PDLLA with unsaturated bond was synthesized by copolymerizing lactide and prepolymer, which was prepared by the polycondensation of maleic anhydride and poly(ethylene glycol), using ptoluene sulphonic acid as catalyst. The new copolymer has improved hydrophilicity and flexibility. The structure and properties of the novel polymers were studied by FTIR, NMR, GPC-MALLS and DSC.

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

    OpenAIRE

    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 inexpensive personal computer (Apple Macintosh Plus). The program is described and the scope for its application is surveyed.

  18. Comparison of finishing application for aliphatic polyurethane dispersions and polyurethane/polyacrylate composite emulsions

    OpenAIRE

    Chai, S; Zhang, Zhongyi

    2010-01-01

    Aliphatic and aromatic cationic aqueous polyurethane (PU-1, PU-2), aliphatic anionic aqueous polyurethanes (PU-3, PU-4) were prepared with polyether glycol, polyether polyol, toluene diisocyanate and isophorone diisocyanate as raw materials. The core-shell polyurethane/polyacrylate composite emulsions (PUA-5, PUA-6) as well as interpenetrating PUA composite emulsions (PUA-7,PUA-8) were prepared by seeded emulsion polymerization, the aliphatic anionic aqueous PU dispersions were used as seed p...

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

    OpenAIRE

    Agnieszka Mironowicz; Krystyna Kukułczanka; Antoni Siewiński

    2014-01-01

    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.

  20. Uptake of Hydrocarbons in Aqueous Solution by Encapsulation in Acyclic Cucurbit[n]uril-Type Molecular Containers.

    Science.gov (United States)

    Lu, Xiaoyong; Isaacs, Lyle

    2016-07-01

    The ability of two water-soluble acyclic cucurbit[n]uril (CB[n]) type containers, whose hydrophobic cavity is defined by a glycoluril tetramer backbone and terminal aromatic (benzene, naphthalene) sidewalls, to act as solubilizing agents for hydrocarbons in water is described. (1) H NMR spectroscopy studies and phase-solubility diagrams establish that the naphthalene-walled container performs as well as, or better than, CB[7] and CB[8] in promoting the uptake of poorly soluble hydrocarbons into aqueous solution through formation of host-hydrocarbon complexes. The naphthalene-walled acyclic CB[n] container is able to extract large hydrocarbons from crude oil into aqueous solution. PMID:27169688

  1. Synthesis and Characterization of Aliphatic-Aromatic Hyperbranched Polyesters

    Institute of Scientific and Technical Information of China (English)

    唐黎明; 张晓龙; 邱藤; 刘德山

    2002-01-01

    Hyperbranched polymers possess special architectures and have potential applications in various areas. In this study, two AB2 monomers, dipropyl 5-(hydroxyethoxy) isophthalate (I) and 5-hydroxyethoxyisophthaic acid (II), were prepared. By bulk polycondensation of each monomer, two aliphatic-aromatic hyperbranched polyesters were prepared and characterized by 1H-nuclear magnetic resonance (1H-NMR), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), and scanning electron microscopy (SEM). Compared with all-aromatic hyperbranched polyesters, the prepared polymers showed lower glass transition temperatures in connection with the moderate decrease in their decomposition temperatures.

  2. 5α-Estrane-3β,17β-diol and 5β-estrane-3α,17β-diol: definitive screening biomarkers to sign nandrolone abuse in cattle?

    Science.gov (United States)

    Dervilly-Pinel, Gaud; Rambaud, Lauriane; Sitthisack, Parina; Monteau, Fabrice; Hewitt, S Armstrong; Kennedy, D Glenn; Le Bizec, Bruno

    2011-09-01

    17β-Nandrolone (17β-NT) is one of the most frequently misused anabolic steroids in meat producing animals. As a result of its extensive metabolism combined with the possibility of interferences with other endogenous compounds, detection of its illegal use often turns out to be a difficult issue. In recent years, proving the illegal administration of 17β-NT became even more challenging since the presence of endogenous presence of 17β-NT or some of its metabolite in different species was demonstrated. In bovines, 17α-NT can occur naturally in the urine of pregnant cows and recent findings reported that both forms can be detected in injured animals. Because efficient control must both take into account metabolic patterns and associated kinetics of elimination, the purpose of the present study was to investigate further some estranediols (5α-estrane-3β,17β-diol (abb), 5β-estrane-3α,17β-diol (bab), 5α-estrane-3β,17α-diol (aba), 5α-estrane-3α,17β-diol (aab) and 5β-estrane-3α,17α-diol (baa)) as particular metabolites of 17β-NT on a large number of injured (n=65) or pregnant (n=40) bovines. Whereas the metabolites abb, bab, aba and baa have previously been detected in urine up to several days after 17β-NT administration, the present study showed that some of the isomers abb (5α-estrane-3β,17β-diol) and bab (5β-estrane-3α,17β-diol) could not be detected in injured or pregnant animals, even at very low levels. This result may open a new way for the screening of anabolic steroid administration considering these 2 estranediols as biomarkers to indicate nandrolone abuse in cattle. PMID:21621615

  3. 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 ostatní: 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

  4. 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 ostatní: 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

  5. 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 ostatní: Descartes Prize(XE) HPAW-CT-2002-9001 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * thymidine phosphorylase * pyrimidines * FPMP derivatives * fluorination Subject RIV: CC - Organic Chemistry Impact factor: 0.723, year: 2007

  6. Estimation of apparent binding constant of complexes of selected acyclic nucleoside phosphonates with -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: 3.028, year: 2014

  7. Acyclic nucleoside phosphonates as inhibitors of hypoxanthine-guanine-(xanthine) phosphoribosyltransferase: new anti-malarial chemotherapy leads

    Czech Academy of Sciences Publication Activity Database

    Hocková, Dana; Holý, Antonín; Česnek, Michal; Baszczyňski, Ondřej; Tichý, Tomáš; Krečmerová, Marcela; Janeba, Zlatko; Skinner-Adams, T.; Naesens, L.; Keough, D. T.; de Jersey, J.; Guddat, L. W.

    Praha : ČSCH, 2011. s. 21-21. [Pokroky v organické, bioorganické a farmaceutické chemii - "Liblice 2011" /46./. 11.11.2011-13.11.2011, Lázně Bělohrad] R&D Projects: GA ČR GAP207/11/0108; GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : nucleotide analogues * antiviral activity * antiplasmodial activity * acyclic nucleoside phosphonates Subject RIV: CC - Organic Chemistry

  8. 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 * cyclodextrin s * nucleotide analogs Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.737, year: 2014

  9. 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: 1.000, year: 2014

  10. Assessment of chiral purity of acyclic nucleoside phosphonates-based anti-AIDS drugs by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Sázelová, Petra; Šolínová, Veronika; Kašička, Václav; Holý, Antonín

    Baltimore Inner Harbor, MD, 2010. s. 74-75. [International Symposium on Electro- and Liquid Phase-separation Techniques /17./. 29.08.2010-01.09.2010, Baltimore Inner Harbor, MD] R&D Projects: GA ČR(CZ) GA203/08/1428; GA ČR(CZ) GA203/09/0675 Institutional research plan: CEZ:AV0Z40550506 Keywords : chiral analysis * acyclic nucleoside phosphonates * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  11. 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 ostatní: 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

  12. Energies for cyclic and acyclic aggregations of adamantane and diamantane units sharing vertices, edges, or six-membered rings

    CERN Document Server

    Balaban, Alexandru T; Klein, Douglas J; Ortiz, Yenni P

    2015-01-01

    Diamondoids are hydrocarbons having a carbon scaffold comprised from polymer-like composites of adamantane cages. The present paper describes computed total energies and "SWB-tension" energies (often referred to as "strain" energies) for species having $n$ adamantane or diamantane units sharing pairwise: one carbon atom (spiro-[n]adamantane or spiro-[$n$]diamantane); one C-C bond (one-bond-sharing-[$n$]adamantane or one-bond-sharing-[$n$]diamantane); or one chair-shaped hexagon of carbon atoms (1234-helical-cata-[$n$]diamantanes). Each of the five investigated polymer-like types is considered either as an acyclic or a cyclic chain of adamantane- or diamantane-unit cages. With increasing $n$ values, SWB-tension energies for acyclic aggregates are found to increase linearly, while the net SWB-tension energies of cyclic aggregates often go thru a minimum at a suitable value of $n$. In all five cases, a limiting common energy per unit ($E/n$ ) is found to be approached by both cyclic and acyclic chains as $n\\to \\...

  13. Mutagenicity and tumorigenicity of the four enantiopure bay-region 3,4-diol-1,2-epoxide isomers of dibenz[a,h]anthracene

    OpenAIRE

    Chang, Richard L.; Wood, Alexander W.; Huang, Mou Tuan; Xie, Jian Guo; Cui, Xiao Xing; Reuhl, Kenneth R.; Boyd, D. R.; Lin, Yong; Shih, Weichung Joe; Balani, Suresh K.; Yagi, Haruhiko; Jerina, Donald M.; Conney, Allan H.

    2013-01-01

    Each enantiomer of the diastereomeric pair of bay-region dibenz[a,h]anthracene 3,4-diol-1,2-epoxides in which the benzylic 4-hydroxyl group and epoxide oxygen are either cis (isomer 1) or trans (isomer 2) were evaluated for mutagenic activity. In strains TA 98 and TA 100 of Salmonella typhimurium, the diol epoxide with (1S,2R,3S,4R) absolute configuration [(–)-diol epoxide-1] had the highest mutagenic activity. In Chinese hamster V-79 cells, the diol epoxide with (1R,2S,3S,4R) absolute con...

  14. Tailoring NO donors metallopharmaceuticals: ruthenium nitrosyl ammines and aliphatic tetraazamacrocycles.

    Science.gov (United States)

    Tfouni, E; Doro, F G; Figueiredo, L E; Pereira, J C M; Metzker, G; Franco, D W

    2010-01-01

    The discovery of the involvement of nitric oxide (NO) in several physiological and pathophysiological processes launched a spectacular increase in studies in areas such as chemistry, biochemistry, and pharmacology. As a consequence, the development of NO donors or scavengers for regulation of its concentration and bioavailability in vivo is required. In this sense, ruthenium nitrosyl ammines and aliphatic tetraazamacrocyles have attracted a lot of attention due to their unique chemical properties. These complexes are water soluble and stable in solution, not to mention that they can deliver NO when photochemically or chemically activated by the reduction of the coordinated nitrosonium (NO+). The tuning of the energies of the charge transfer bands, the redox potential, and the specific rate constants of NO liberation, in both solution and matrices, is desirable for the achievement of selective NO delivery to biological targets, hence making the ruthenium ammines and aliphatic tetraazamacrocyles a quite versatile platform for biological application purposes. These ruthenium nitrosyls have shown to be active in firing neurons in mouse hippocampus, performing redox reactions in mitochondria, acting in blood pressure control, exhibiting cytotoxic activities against trypanosomatids (T.cruzi and L.major) and tumor cells. This tailoring approach is explored here, being heavily supported by the accumulated knowledge on the chemistry and photochemistry of ruthenium complexes, which allows NO donors/scavengers systems to be custom made designed. PMID:20846113

  15. Polarized Raman spectra and intensities of aliphatic amino acids

    Science.gov (United States)

    Himmler, Hans J.; Eysel, Hans H.

    1989-01-01

    Raman spectra of aliphatic α- L-amino acids, glycine, alanine, and valine were re-investigated both in aqueous solution and deuterium oxide solution. The spectra were taken of the zwitterionic and of the completely deprotonated form of the amino acids. Spectra of leucine and isoleucine were studied in water at the isoelectric point. Spectra were recorded both with parallel and perpendicular polarization and the isotropic and anisotropic scattering components were isolated. The integrated intensities of CH stretch, CC stretch and carboxylate bend vibrations are discussed. Linear relations between the number of CC and CH bonds and the total scattered intensity in the appropriate spectral regions are observed. The sum over the carboxylate modes shows characteristic intensities for the first three members of the aliphatic amino acids. An increase of isotropic scattering of ϱ co 2 near 510 cm -1 with increasing chain length of the amino acid (or with increasing concentration) is interpreted as the result of micelle formation.

  16. Study on the Synthesis and Biodegradation of Aliphatic Polyester

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An aliphatic polyester, poly(hexalene adipate) (PHA) and an aliphatic copolyester, poly (hexalene adipate succinate) (PHAS) were synthesized by direct condensation of corresponding binary acid and binary alcohol in the presence of a catalyst, p-toluene sulfonic acid. The biodegradation of these polyesters were studied in the laboratory by enzyme attack and outdoor soil burial. The results show that these polyesters have good biodegradability and the copolyester PHAS, even displayed a better biodegradability than the polyester PHA. In the presence of Penicillium chrysogenum the weight loss reached 18.3% for the PHAS (film thickness 1.0 mm)and 9.1% for the PHA (film thickness 1.0 mm) after 28 days. Outdoor soil burial tests indicate that these polyesters also have good biodegradability in natural conditions. The weight loss reached 14.2% for PHAS (film thickness 0.1 mm) and 6.7% for PHA (film thickness 0.1mm) after burying in soil for 36 days.

  17. Short-chain aliphatic ester synthesis using Thermobifida fusca cutinase.

    Science.gov (United States)

    Su, Lingqia; Hong, Ruoyu; Guo, Xiaojie; Wu, Jing; Xia, Yongmei

    2016-09-01

    Short-chain aliphatic esters are commonly used as fruit flavorings in the food industry. In this study, Thermobifida fusca (T. fusca) cutinase was used for the synthesis of aliphatic esters, and the maximum yield of ethyl caproate reached 99.2% at a cutinase concentration of 50U/ml, 40°C, and water content of 0.5%, representing the highest ester yield to date. The cutinase-catalyzed esterification displayed strong tolerance for water content (up to 8%) and acid concentration (up to 0.8M). At substrate concentrations ⩽0.8M, the ester yield remained above 80%. Moreover, ester yields of more than 98% and 95% were achieved for acids of C3-C8 and alcohols of C1-C6, respectively, indicating extensive chain length selectivity of the cutinase. These results demonstrate the superior ability of T. fusca cutinase to catalyze the synthesis of short-chain esters. This study provides the basis for industrial production of short-chain esters using T. fusca cutinase. PMID:27041308

  18. Samarium-153 and lutetium-177 chelation properties of selected macrocyclic and acyclic ligands

    International Nuclear Information System (INIS)

    We describe a simple in vitro characterization of chelation that is useful when choosing an appropriate ligand-metal combination for clinical applications. These properties include the effect of concentration on chelation efficiency, time to maximum chelation, and stability in acidic and serum environments. The macrocyclic ligands nitro-DOTA and nitro-PADOTA, the acyclic ligands nitro-CHX-A-DTPA, nitro-MX-DTPA, DTPA, and a novel terpyridine ligand, TMT-amine, were evaluated as chelate complexes of both intermediate energy β-emitting lanthanides lutetium-177 and samarium-153. The data were compared to results obtained in a previously published study with yttrium-90. Acid lability, time to achieve maximum chelation, and stability in human serum are properties unique to each ligand-metal combination and should be evaluated prior to choosing an appropriate combination for therapeutic applications. Concentration dependence and duration of chelation are general properties of lanthanide and yttrium chelation that can be applied to an appropriate ligand-metal combination to achieve optimum chelation efficiencies

  19. 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.

  20. Z/p-acyclic resolutions in the strongly countable Z/p-dimensional case

    CERN Document Server

    Rubin, Leonard R

    2011-01-01

    We prove the following Theorem: Let X be a nonempty compact metrizable space, let $l_1 \\leq l_2 \\leq...$ be a sequence of natural numbers, and let $X_1 \\subset X_2 \\subset...$ be a sequence of nonempty closed subspaces of X such that for each k in N, $dim_{Z/p} X_k \\leq l_k < \\infty$. Then there exists a compact metrizable space Z, having closed subspaces $Z_1 \\subset Z_2 \\subset...$, and a surjective cell-like map $\\pi: Z \\to X$, such that for each k in N, (a) $dim Z_k \\leq l_k$, (b) $\\pi (Z_k) = X_k$, and (c) $\\pi | {Z_k}: Z_k \\to X_k$ is a Z/p-acyclic map. Moreover, there is a sequence $A_1 \\subset A_2 \\subset...$ of closed subspaces of Z, such that for each k, $dim A_k \\leq l_k$, $\\pi|{A_k}: A_k\\to X$ is surjective, and for k in N, $Z_k\\subset A_k$ and $\\pi|{A_k}: A_k\\to X$ is a UV^{l_k-1}-map. It is not required that X be the union of all X_k, nor that Z be the union of all Z_k. This result generalizes the Z/p-resolution theorem of A. Dranishnikov, and runs parallel to a similar theorem of S. Ageev, R...

  1. 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.

  2. Computing the SKT Reliability of Acyclic Directed Networks Using Factoring Method

    Institute of Scientific and Technical Information of China (English)

    KONG Fanjia; WANG Guangxing

    1999-01-01

    This paper presents a factoringalgorithm for computing source-to-K terminal (SKT) reliability, the probability that a source s can send message to a specified set of terminals K, in acyclic directed networks (AD-networks) in which bothnodes and edges can fail. Based on Pivotal decomposition theorem, a newformula is derived for computing the SKT reliability of AD-networks. By establishing a topological property of AD-networks, it is shown that the SKT reliability of AD-networks can be computed by recursively applying this formula. Two new Reliability-Preserving Reductions are alsointroduced. The recursion tree generated by the presented algorithm hasat most 2(|V| - |K|- |C|) leaf nodes, where |V| and |K| are the numbers of nodes and terminals, respectively, while |C| is the number of the nodes satisfying some specified conditions. The computation complexity of the new algorithm is O (|E||V|2(|V| -|K| -|C|)) in the worst case, where |E| is the number of edges. Forsource-to-all-terminal (SAT) reliability, its computation complexity is O (|E|). Comparison of the new algorithm with the existing ones indicates that the new algorithm is more efficient for computing the SKT reliability of AD-networks.

  3. Biosynthesis of unnatural bacteriochlorophyll c derivatives esterified with α,ω-diols in the green sulfur photosynthetic bacterium Chlorobaculum tepidum.

    Science.gov (United States)

    Nishimori, Risato; Mizoguchi, Tadashi; Tamiaki, Hitoshi; Kashimura, Shigenori; Saga, Yoshitaka

    2011-09-13

    Unnatural bacteriochlorophyll (BChl) c derivatives possessing a hydroxy group at the terminus of a hydrocarbon chain at the 17-propionate were biosynthesized in the green sulfur photosynthetic bacterium Chlorobaculum tepidum. Addition of exogenous 1,8-octanediol, 1,12-dodecanediol, and 1,16-hexadecanediol in acetone to liquid cultures resulted in accumulation of BChl c monoesterified with the corresponding diols. The relative ratios of the novel BChl c derivatives esterified with 1,8-, 1,12-, and 1,16-diols to totally producing BChl c were 8.2, 50.2, and 57.6% in the cells grown with additive α,ω-diols at concentrations of 1.5, 0.06, and 0.06 mM, respectively, at the final concentration. The homologue composition of BChl c derivatives esterified with these α,ω-diols was similar to that of original, coexisting BChl c esterified with farnesol (BChl c(F)), suggesting that esterification of α,ω-diols occurred at the last step of the BChl c biosynthetic pathway by BChl c synthase, BchK, in the same manner as in BChl c(F). Chlorosomes, which were isolated from cells grown in the presence of exogenous α,ω-diols, contained a ratio and a composition of BChl c derivatives esterified with the diols similar to those in the whole cells, indicating that these BChl c derivatives were actually present in chlorosomes. Q(y) absorption bands of C. tepidum cells containing the novel BChl c derivatives were shifted to a shorter wavelength, although their bandwidths were analogous to those of cells obtained by normal cultivation. Circular dichroism spectra of cells that had BChl c derivatives esterified with α,ω-diols exhibited S-shaped signals in the Q(y) region, whose polarities were the reverse of those of cells grown in the normal medium and by supplementation with neat acetone as a control experiment. These spectral features of C. tepidum possessing BChl c derivatives esterified with α,ω-diols imply that the novel BChl c derivatives possessing a hydroxy group at the

  4. Analyses of effects of α-cembratrien-diol on cell morphology and transcriptome of Valsa mali var. mali.

    Science.gov (United States)

    Yan, Ning; Du, Yongmei; Liu, Xinmin; Zhang, Hongbo; Liu, Yanhua; Shi, John; Xue, Sophia Jun; Zhang, Zhongfeng

    2017-01-01

    The objective of this work was to study the underlying mechanisms of growth inhibition of Valsa mali var. mali, the causative pathogen of apple tree canker disease, by α-cembratrien-diol. The half maximal inhibitory concentration of α-cembratrien-diol against V. mali var. mali is 18.0mg/L. Treatment of V. mali var. mali with α-cembratrien-diol resulted in various mycelial and cellular abnormalities, and the up- and down-regulation of 94 and 170 differentially expressed genes, respectively. Gene Ontology term enrichment analysis revealed that α-cembratrien-diol substantially altered the expression of genes involved in the redox process, tetrapyrrole binding, coenzyme binding, heme binding, and iron binding. Kyoto Encyclopedia of Genes and Genomes enrichment analysis also showed significant enrichment of specific metabolic pathways involving the set of differentially expressed genes. The present study will assist in the development of alternative α-cembratrien-diol-based biological control agents and ultimately facilitate organic apple production. PMID:27507455

  5. 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...

  6. A Theoretical Study on the Vibrational Spectra of PAH Molecules with Aliphatic Sidegroups

    CERN Document Server

    Sadjadi, SeyedAbdolreza; Kwok, Sun

    2015-01-01

    The role of aliphatic side groups on the formation of astronomical unidentified infrared emission (UIE) features is investigated by applying the density functional theory (DFT) to a series of molecules with mixed aliphatic-aromatic structures. The effects of introducing various aliphatic groups to a fixed polycyclic aromatic hydrocarbon (PAH) core (ovalene) are studied. Simulated spectra for each molecule are produced by applying a Drude profile at $T$=500 K while the molecule is kept at its electronic ground state. The vibrational normal modes are classified using a semi-quantitative method. This allows us to separate the aromatic and aliphatic vibrations and therefore provide clues to what types of vibrations are responsible for the emissions bands at different wavelengths. We find that many of the UIE bands are not pure aromatic vibrational bands but may represent coupled vibrational modes. The effects of aliphatic groups on the formation of the 8 $\\mu$m plateau are qua ntitatively determined. The vibratio...

  7. On the mechanism of radical fragmentation of α-dioles and some of their derivatives

    International Nuclear Information System (INIS)

    Studied is the composition of radiolysis products of deluted deaerated aqueous solutions of 1.2-dimethoxyethane and some of 1.3-dioxolanes. The solutions were leached (pH 12-13) to prevent hydrolysis of both initial and final products. Cs137 was used as a source of γ-radiation. Absorbed dose rate is equal to 4x1015 eV/mlxs. On the basis of the results obtained and literary data on radical fragmentation of α-dioles a possibility of ROCHCH2OR' particle decomposition according to the coordinated mechanism is discussed

  8. Colloidal and Chemical Properties of Polyesters Based on Glutamic acid and Diols of Different Nature

    Directory of Open Access Journals (Sweden)

    Puzko N.V.

    2012-08-01

    Full Text Available The paper describes synthesis method and colloid-chemical properties of novel α-amino acid based polyesters with controllable hydrophilic-lipophillic balance. Glutamic acid and diols of different nature based polyesters were obtained via low-temperature activated polyesterefication. Such polymers are able to form micellar structures in self-stabilized water dispersion. Solubilization of water insoluble dyes Sudan and toluene in polymer water solution was studied. Due to micelle forming ability and prognosticated biodegradability to non-toxic products, obtained polymers are promising materials for formation of novel dispersed drug delivery systems.

  9. Kinetics of complexation and oxidation of ethanolamine and diols by silver(II)

    International Nuclear Information System (INIS)

    The oxidation of ethanolamine (EtA), ethylene glycol, and several other diols by Ag(II) has been studied at pH approx. 8.5. In the basic pH range, complexation of the substrate by Ag(II) has been found to take place in two steps by successive ligand uptake. Complexation rates are higher by 1 order of magnitude in the basic pH range as compared to the acidic pH range. Oxidation then takes place through intramolecular electron transfer from substrate to Ag(II) within the complex. Oxidation rates for cis- and trans-1,2-cyclohexanediols are quite similar

  10. A Facile and Efficient Synthesis of (15R)-Latanoprost from Chiral Precursor Corey Lactone Diol

    Indian Academy of Sciences (India)

    K Vijendhar; B Srinivas; Sathyanarayana Boodida

    2015-11-01

    An efficient asymmetric synthetic route for the synthesis of anti-glaucoma agent, (15R)-latanoprost using Corey lactone diol as chiral substrate under Swern oxidation, allylic reduction and Wittig reaction conditions has been developed. In this method, reduction of keto and alkene functional groups has been achieved in a single step using low cost catalyst NiCl2/NaBH4 in methanol. This new synthetic protocol is a good alternative for the synthesis of latanoprost with high stereo selectivity and improved yield.

  11. Synthesis and characterization of segmented polyurethanes based on amphiphilic polyether diols.

    Science.gov (United States)

    Lan, P N; Corneillie, S; Schacht, E; Davies, M; Shard, A

    1996-12-01

    Segmented polyurethanes (SPUs) based on polyethylene glycol (PEG), polypropylene glycol (PPG) and a series of Pluronics with different ethylene oxide/propylene oxide ratios (EO/PO) and molecular weights were prepared. Different diisocyanates were used for making SPUs: 4,4-diphenylmethane diisocyanate (MDI), 4,4-dicyclohexylmethane diisocyanate (MDCI), hexamethylene diisocyanate (HMDI) and isophorone diisocyanate (IPDI). 1,4-Butane diol (BD) and ethylene diamine (ED) were used as chain extenders. The polymers obtained were characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). The microphase morphology (phase separation and phase mixing) is discussed in more detail. PMID:8968523

  12. 2-[(5-Chloro-2-oxidobenzylideneazaniumyl]-2-methylpropane-1,3-diol

    Directory of Open Access Journals (Sweden)

    Dong-Yue Wang

    2012-02-01

    Full Text Available The title compound, C11H14ClNO3, was prepared by the condensation of equimolar quantities of 5-chlorosalicylaldehyde and 2-amino-2-methylpropane-1,3-diol in methanol. In the crystal, it exists in the zwitterionic form, with nominal proton transfer from the phenol group to the imine N atom. This results in the formation of an intramolecular N—H...O hydrogen bond, which generates an S(6 ring. Intermolecular O—H...O hydrogen bonds arise from the hydroxy groups, forming (001 sheets.

  13. The impact of the absence of aliphatic glucosinolates on insect herbivory in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Jules Beekwilder

    Full Text Available Aliphatic glucosinolates are compounds which occur in high concentrations in Arabidopsis thaliana and other Brassicaceae species. They are important for the resistance of the plant to pest insects. Previously, the biosynthesis of these compounds was shown to be regulated by transcription factors MYB28 and MYB29. We now show that MYB28 and MYB29 are partially redundant, but in the absence of both, the synthesis of all aliphatic glucosinolates is blocked. Untargeted and targeted biochemical analyses of leaf metabolites showed that differences between single and double knock-out mutants and wild type plants were restricted to glucosinolates. Biosynthesis of long-chain aliphatic glucosinolates was blocked by the myb28 mutation, while short-chain aliphatic glucosinolates were reduced by about 50% in both the myb28 and the myb29 single mutants. Most remarkably, all aliphatic glucosinolates were completely absent in the double mutant. Expression of glucosinolate biosynthetic genes was slightly but significantly reduced by the single myb mutations, while the double mutation resulted in a drastic decrease in expression of these genes. Since the myb28myb29 double mutant is the first Arabidopsis genotype without any aliphatic glucosinolates, we used it to establish the relevance of aliphatic glucosinolate biosynthesis to herbivory by larvae of the lepidopteran insect Mamestra brassicae. Plant damage correlated inversely to the levels of aliphatic glucosinolates observed in those plants: Larval weight gain was 2.6 fold higher on the double myb28myb29 mutant completely lacking aliphatic glucosinolates and 1.8 higher on the single mutants with intermediate levels of aliphatic glucosinolates compared to wild type plants.

  14. Sodium hypochlorite oxidation of petroleum aliphatic contaminants in calcareous soils.

    Science.gov (United States)

    Picard, François; Chaouki, Jamal

    2016-02-01

    This research project investigated the sodium hypochlorite (NaClO) oxidation of aliphatic petroleum contaminants (C10-C50) in a calcareous soil (average 5473 ppm C10-C50, 15 wt% Ca), which had been excavated from a contaminated industrial site. The decontamination objective was to lower the C10-C50 concentration to 700 ppm. CO2 acidity was used in the project to boost the NaClO oxidation yield and seems to have played a role in desorbing the natural organic matter. The experimental conditions were a 2- to 16-h reaction time, at room temperature, with a 1 to 12.5 wt% NaClO oxidative solution and a fixed 2:1 solution-to-soil ratio. With a 3 wt% NaClO solution and with a CO2 overhead, the NaClO dosage requirement was maintained below 60 g NaClO/g of oxidized C10-C50 over the entire decontamination range. The strong chlorine smell remaining after the reaction was completed suggests that part of the NaClO requirement can be recycled. Except traces of chloroform, there were no regulation-listed organochloride contaminants detected on either the treated soil samples or leachates and the total count of chlorinated compounds in treated soil samples was below the detection limit of 250 mg/kg. The NaClO oxidation mechanism on aliphatic substrates might be triggered by transition metals, such as manganese, but no attempt has been made to investigate the oxidation mechanism. Further investigations would include a constant-fed NaClO system and other techniques to lower the required NaClO dosage. PMID:26702553

  15. 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...

  16. An asymmetric route to 2,3-epoxy-syn-1,4-cyclohexane diol derivatives using ring closing metathesis (RCM)

    Indian Academy of Sciences (India)

    Soumitra Maity; Subrata Ghosh

    2010-11-01

    An asymmetric route for the synthesis of highly functionalized 2,3-epoxy-syn-1,4-cyclohexane diol derivatives present in some polyketide natural products has been developed. The key step involves RCM of an appropriately constructed 1,7-dienol derived from D-mannitol to cyclohexane-1,4-diol followed by its stereoselective epoxidation.

  17. Selective allylic hydroxylation of acyclic terpenoids by CYP154E1 from Thermobifida fusca YX

    Directory of Open Access Journals (Sweden)

    Anna M. Bogazkaya

    2014-06-01

    Full Text Available Allylic alcohols are valuable precursors in the synthesis of pharmaceutical intermediates, agrochemicals and natural products. Regioselective oxidation of parental alkenes is a challenging task for chemical catalysts and requires several steps including protection and deprotection. Many cytochrome P450 enzymes are known to catalyse selective allylic hydroxylation under mild conditions. Here, we describe CYP154E1 from Thermobifida fusca YX that enables this type of oxidation. Several acyclic terpenoids were tested as possible substrates for CYP154E1, and the regio- and chemoselectivity of their oxidation was investigated. Using a previously established bioinformatics approach we identified position 286 in the active site of CYP154E1 which is putatively involved in substrate binding and thereby might have an effect on enzyme selectivity. To tune regio- and chemoselectivity of the enzyme three mutants at position 286 were constructed and used for substrate oxidation. All formed products were analysed with GC–MS and identified using chemically synthesised authentic samples and known compounds as references. Best regioselectivity towards geraniol and nerol was observed with the wild type enzyme mainly leading to 8-hydroxy derivatives (8-hydroxygeraniol or 8-hydroxynerol with high selectivity (100% and 96% respectively. Highest selectivities during the oxidation of geranylacetone and nerylacetone were observed with the following variants: V286F led mainly to 7-hydroxygeranylacetone (60% of the total product and V286A produced predominantly 12-hydroxynerylacetone (75% of total product. Thus, CYP154E1 and its mutants expand the tool-box for allylic hydroxylation in synthetic chemistry.

  18. Synergistic growth inhibition by acyclic retinoid and phosphatidylinositol 3-kinase inhibitor in human hepatoma cells

    International Nuclear Information System (INIS)

    A malfunction of RXRα due to phosphorylation is associated with liver carcinogenesis, and acyclic retinoid (ACR), which targets RXRα, can prevent the development of hepatocellular carcinoma (HCC). Activation of PI3K/Akt signaling plays a critical role in the proliferation and survival of HCC cells. The present study examined the possible combined effects of ACR and LY294002, a PI3K inhibitor, on the growth of human HCC cells. This study examined the effects of the combination of ACR plus LY294002 on the growth of HLF human HCC cells. ACR and LY294002 preferentially inhibited the growth of HLF cells in comparison with Hc normal hepatocytes. The combination of 1 μM ACR and 5 μM LY294002, in which the concentrations used are less than the IC50 values of these agents, synergistically inhibited the growth of HLF, Hep3B, and Huh7 human HCC cells. These agents when administered in combination acted cooperatively to induce apoptosis in HLF cells. The phosphorylation of RXRα, Akt, and ERK proteins in HLF cells were markedly inhibited by treatment with ACR plus LY294002. Moreover, this combination also increased RXRE promoter activity and the cellular levels of RARβ and p21CIP1, while decreasing the levels of cyclin D1. ACR and LY294002 cooperatively increase the expression of RARβ, while inhibiting the phosphorylation of RXRα, and that these effects are associated with the induction of apoptosis and the inhibition of cell growth in human HCC cells. This combination might therefore be effective for the chemoprevention and chemotherapy of HCC

  19. 6-Methyl-1,3,5-triazine-2,4-diamine butane-1,4-diol monosolvate

    Directory of Open Access Journals (Sweden)

    Rajni M. Bhardwaj

    2012-12-01

    Full Text Available The title co-crystal, C4H7N5·C4H10O2, crystallizes with one molecule of 6-methyl-1,3,5-triazine-2,4-diamine (DMT and one molecule of butane-1,4-diol in the asymmetric unit. The DMT molecules form ribbons involving centrosymmetric R22(8 dimer motifs between DMT molecules along the c-axis direction. These ribbons are further hydrogen bonded to each other through butane-1,4-diol, forming sheets parallel to (121.

  20. 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

    does not require any stoichiometric additives and only produces water and dihydrogen as byproducts. Anilines containing methyl, methoxy, chloro and fluoro substituents can participate in the cyclocondensation. Meta-substituted anilines give good regioselectivity for 6-substituted indoles, while...... unsymmetrical diols afford excellent regioselectivity for the indole isomer with an aryl or large alkyl group in the 2-position. The mechanism for the cyclocondensation presumably involves initial formation of the alpha-hydroxyketone from the diol. The ketone subsequently reacts with aniline to generate the...

  1. 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 treatment period compared to pretreatment levels in four of five 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 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. PMID:25314824

  2. 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 ostatní: 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

  3. Acyclic Nucleoside Phosphonates as Inhibitors of Hypoxanthine-Guanine-Xanthine Phosphoribosyltransferase: New Anti-Malarial Chemotherapy Leads

    Czech Academy of Sciences Publication Activity Database

    Hocková, Dana; Holý, Antonín; Česnek, Michal; Baszczyňski, Ondřej; Tichý, Tomáš; Krečmerová, Marcela; Janeba, Zlatko; Skinner-Adams, T. S.; Naesens, L.; Keough, D. T.; de Jersey, J.; Guddat, L. W.

    Praha : Institute of Organic Chemistry and Biochemistry AS CR, v. v. i., 2011 - (Hocek, M.), s. 171-174 ISBN 978-80-86241-37-1. - (Collection Symposium Series. 12). [Chemistry of Nucleic Acid Components /15./. Český Krumlov (CZ), 05.06.2011-10.06.2011] R&D Projects: GA MŠk 1M0508; GA ČR GAP207/11/0108 Institutional research plan: CEZ:AV0Z40550506 Keywords : ANPs * acyclic nucleoside phosphonates * anti-malarial * Plasmodium * HGXPRTase Subject RIV: CC - Organic Chemistry

  4. Applying the Directed Acyclic Graph to Examine the Factors Related to the Adoption of E-Learning

    OpenAIRE

    Quang Linh Huynh; Thuy Lan Le Thi

    2014-01-01

    This research explores the causal relationships among the attitude toward using e-learning, the perception on the usefulness of e-learning and the adoption of e-learning as well as the mediating role of the attitude toward using e-learning and the moderating role of the perceived usefulness of e-learning. We use an advanced method known as the directed acyclic graph to investigate the causal associations. Then we use Sobel’s technique and hierarchical regressions to examine the mediating and ...

  5. Enantiopurity analysis of anti-AIDS drugs and related acyclic nucleoside phosphonates-based antivirotics by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Šolínová, Veronika; Sázelová, Petra; Mikysková, Hana; Koval, Dušan; Holý, Antonín

    Alphaville: AlphaGraphics, 2013 - (Guzman, N.; Tavares, M.). s. 32-32 [LACE 2013. Latin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology /19./. 29.11.2013-03.12.2013, Lima] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA MŠk(CZ) ME10040; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * capillary electrophoresis * chiral analysis Subject RIV: CB - Analytical Chemistry, Separation

  6. The atu and liu Clusters Are Involved in the Catabolic Pathways for Acyclic Monoterpenes and Leucine in Pseudomonas aeruginosa†

    Science.gov (United States)

    Aguilar, J. A.; Zavala, A. N.; Díaz-Pérez, C.; Cervantes, C.; Díaz-Pérez, A. L.; Campos-García, J.

    2006-01-01

    Evidence suggests that the Pseudomonas aeruginosa PAO1 gnyRDBHAL cluster, which is involved in acyclic isoprenoid degradation (A. L. Díaz-Pérez, N. A. Zavala-Hernández, C. Cervantes, and J. Campos-García, Appl. Environ. Microbiol. 70:5102-5110, 2004), corresponds to the liuRABCDE cluster (B. Hoschle, V. Gnau, and D. Jendrossek, Microbiology 151:3649-3656, 2005). A liu (leucine and isovalerate utilization) homolog cluster was found in the PAO1 genome and is related to the catabolism of acyclic monoterpenes of the citronellol family (AMTC); it was named the atu cluster (acyclic terpene utilization), consisting of the atuCDEF genes and lacking the hydroxymethyl-glutaryl-coenzyme A (CoA) lyase (HMG-CoA lyase) homolog. Mutagenesis of the atu and liu clusters showed that both are involved in AMTC and leucine catabolism by encoding the enzymes related to the geranyl-CoA and the 3-methylcrotonyl-CoA pathways, respectively. Intermediary metabolites of the acyclic monoterpene pathway, citronellic and geranic acids, were accumulated, and leucine degradation rates were affected in both atuF and liuD mutants. The alpha subunit of geranyl-CoA carboxylase and the alpha subunit of 3-methylcrotonyl-CoA carboxylase (α-MCCase), encoded by the atuF and liuD genes, respectively, were both induced by citronellol, whereas only the α-MCCase subunit was induced by leucine. Both citronellol and leucine also induced a LacZ transcriptional fusion at the liuB gene. The liuE gene encodes a probable hydroxy-acyl-CoA lyase (probably HMG-CoA lyase), an enzyme with bifunctional activity that is essential for both AMTC and leucine degradation. P. aeruginosa PAO1 products encoded by the liuABCD cluster showed a higher sequence similarity (77.2 to 79.5%) with the probable products of liu clusters from several Pseudomonas species than with the atuCDEF cluster from PAO1 (41.5%). Phylogenetic studies suggest that the atu cluster from P. aeruginosa could be the result of horizontal transfer from

  7. 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 0.19μgg(-1) and 8.5μgg(-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. PMID:26837270

  8. Nucleoside and Nucleotide Analogues for the Treatment of Herpesvirus Infections: Current Stage and New Prospects in the Field of Acyclic Nucleoside Phosphonates

    Czech Academy of Sciences Publication Activity Database

    Krečmerová, Marcela

    Rijeka : InTech, 2012 - (Magel, G.; Tyring, S.), s. 245-270 ISBN 978-953-51-0186-4 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * acyclic nucleoside analogue * antimetabolite * DHPA * 5-azacytosine * cidofovir * HPMPDAP * prodrugs * animal herpesviruses Subject RIV: CC - Organic Chemistry http://www.intechopen.com/books/herpesviridae-a-look-into-this-unique-family-of-viruses/nucleoside-and-nucleotide-analogues-for-the-treatment-of-herpesvirus-infections-current-stage-and-ne

  9. 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 pr...

  10. The influence of hard segment content on dynamic mechanical properties of segmented polyurethanes based on polycarbonate diols

    Czech Academy of Sciences Publication Activity Database

    Bera, O.; Pavličević, J.; Špírková, Milena; Strachota, Adam; Poreba, Rafal; Jovičić, M.; Budinski-Simendic, J.

    Belgrade : Institute of Technical Sciences of the Serbian Academy of Sciences & Arts, 2010 - (Uskoković, D.). s. 125 [Annual Conference /12./ YUCOMAT 2010. 06.09.2010-10.09.2010, Herceg Novi] R&D Projects: GA ČR GAP108/10/0195 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyurethane * polycarbonate diol Subject RIV: CD - Macromolecular Chemistry

  11. Electrocatalytic oxidation of alcohols and diols in a biphasic medium using CeIV methanesulfonate as mediator

    International Nuclear Information System (INIS)

    Some alcohols and diols were oxidized electro-catalytically in a biphasic system using cerium methanesulphonate as mediator. A mixture of methanesulphonic acid solution and benzene was used and aldehydes, ketones and diacids were some of the principal products obtained with yield varying from 27 to 98%. In several cases selectivity was obtained. (author)

  12. 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

  13. THE PHASE BEHAVIOR OF FLUORINATED DIOLS, DIVINYL ADIPATE, AND A FLUORINATED POLYESTER IN SUPERCRITICAL CARBON DIOXIDE. (R828131)

    Science.gov (United States)

    The use of supercritical carbon dioxide as a reaction medium for polyester synthesis is hindered by the low solubility of diols in CO2. However, it has been previously demonstrated that fluorinated compounds can exhibit greater miscibility with carbon dioxide than t...

  14. Boronate Affinity Fluorescent Nanoparticles for Förster Resonance Energy Transfer Inhibition Assay of cis-Diol Biomolecules.

    Science.gov (United States)

    Wang, Shuangshou; Ye, Jin; Li, Xinglin; Liu, Zhen

    2016-05-17

    Förster resonance energy transfer (FRET) has been essential for many applications, in which an appropriate donor-acceptor pair is the key. Traditional dye-to-dye combinations remain the working horses but are rather nonspecifically susceptive to environmental factors (such as ionic strength, pH, oxygen, etc.). Besides, to obtain desired selectivity, functionalization of the donor or acceptor is essential but usually tedious. Herein, we present fluorescent poly(m-aminophenylboronic acid) nanoparticles (poly(mAPBA) NPs) synthesized via a simple procedure and demonstrate a FRET scheme with suppressed environmental effects for the selective sensing of cis-diol biomolecules. The NPs exhibited stable fluorescence properties, resistance to environmental factors, and a Förster distance comparable size, making them ideal donor for FRET applications. By using poly(mAPBA) NPs and adenosine 5'-monophosphate modified graphene oxide (AMP-GO) as a donor and an acceptor, respectively, an environmental effects-suppressed boronate affinity-mediated FRET system was established. The fluorescence of poly(mAPBA) NPs was quenched by AMP-GO while it was restored when a competing cis-diol compounds was present. The FRET system exhibited excellent selectivity and improved sensitivity toward cis-diol compounds. Quantitative inhibition assay of glucose in human serum was demonstrated. As many cis-diol compounds such as sugars and glycoproteins are biologically and clinically significant, the FRET scheme presented herein could find more promising applications. PMID:27089186

  15. 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

    Chemical processes capable of reducing the high oxygen content of biomass-derived polyols are in demand in order to produce renewable substitutes for chemicals of fossil origin. Deoxydehydration (DODH) is an attractive reaction that in a single step transforms a vicinal diol into an alkene, but the...

  16. 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.; Blobstein, S.H.; Harvey, R.G.; Harris, C.; Autrup, Herman; Kasai, H.; Nakanishi, K.

    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...

  17. 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 ostatní: COST(XE) CM1201 Institutional support: RVO:61388963 Keywords : synthetic methods * reduction * diastereoselectivity * diols * ketones Subject RIV: CC - Organic Chemistry Impact factor: 3.065, year: 2014

  18. 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

    2016-01-01

    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. PMID:26729717

  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. Project Summary. IN-SITU AQUIFER RESTORATION OF CHLORINATED ALIPHATICS BY METHANOTROPHIC BACTERIA

    Science.gov (United States)

    This project evaluated the potential of an innovative approach to aquifer restoration: enhanced in-situ biotransformation of chlorinated aliphatic solvents by a bacterial community grown on methane under aerobic conditions. The target chlorinated compounds were trichloroethene (...

  1. 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.

  2. 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

  3. Studies on reactions of cerium(4) reduction with alcohols. Part 3. Reactions of cerium(4) reduction with butane-2,3-diol, butane-1,3-diol and cis-butene-2-diol-1,4 in aqueous solutions of perchloric acid

    International Nuclear Information System (INIS)

    The basic study of the red-ox reaction kinetics of cerium ions -diols-water systems in presence of the perchloric acid is given. Dependence of the various agents and its concentrations on equilibrium constants the complex formation reactions and complex stability are discussed and compared. (B.Cz.)

  4. Interaction of ferroceneboronic acid with diols at aqueous and non-aqueous conditions - signalling and binding abilities of an electrochemical probe for saccharides

    International Nuclear Information System (INIS)

    Highlights: • Electrochemical characterisation of ferroceneboronic acid-diol interactions in non-aqueous solutions. • Elucidation of the signalling process and signalling mechanism of the ferroceneboronic acid upon interaction with diols in aqueous and non-aqueous solutions. • Effect of coordination of boron atom on electrochemistry of ferroceneboronic acid in free and bound forms with diols. - Abstract: Ferroceneboronic acid (FcBA) was employed as a model compound for clarification of binding and signalling properties of molecular probe for saccharides. As the simplest electrochemically active boronic acid, its interactions with diverse diols were studied in homogeneous phase under aqueous and non-aqueous conditions. The FcBA-diol system was examined by cyclic voltammetry resulting in two redox pairs corresponding to free and bound forms of FcBA. Redox potential of the bound form of FcBA was shifted in the cathodic direction in aqueous conditions due to coordination of the hydroxyl group to the boron atom. Oppositely, the anodic shift of the redox potential was observed upon the interaction of FcBA with diols in non-aqueous solvents. The binding properties and signalling mechanism of electrochemically active boronic acids were deduced and the assumptions resulting from the electrochemical behaviour were confirmed by 1H and 11B NMR spectroscopies. The binding constants of the tested diols in aqueous and non-aqueous media were determined and compared

  5. Novel five- to ten-membered organoselenium heterocycles from the selenation of aromatic diols

    OpenAIRE

    Hua, Guoxiong; Fuller, Amy; Slawin, Alexandra M. Z.; Woollins, J. Derek

    2010-01-01

    This work is funded by the EPSRC UK Reaction of Woollins' reagent ― WR , 2,4-bis(phenyl)-1,3-diselenadiphosphetane 2,4-diselenide [{PhP(Se)(μ-Se)}2] ― with aromatic diols in refluxing toluene afforded a series of novel five- to ten-membered phosphorus-selenium heterocycles 1 – 10 with an O–P(Se)–O or O–P(Se)–Se–P(Se)–O or O–P(Se)–O–P(Se)–O linkage in 12–74 % isolated yields. It was found that the diphosphorus species O–P(Se)–Se–P(Se)–O rings could be readily reduced into the monophosphorus...

  6. Isolation and Crystal Structure of 1′,4′-Trans-diol of Abscisic Acid

    Institute of Scientific and Technical Information of China (English)

    WANG Tian-Shan; ZHOU Jin-Yan; TAN Hong

    2006-01-01

    1 ′,4′-Trans-diol of abscisic acid was isolated from botrytis cinerea as a colorless crystal. The molecular and crystal structures have been determined by X-ray diffraction analysis. It crystallizes in orthorhombic system, space group P212121 with a = 6.724(3), b = 17.559(6), c =12.265(2) (A), a = β = y = 90°, V = 1448.1(8) (A)3, Z = 4, Dx = 1.222 g/cm3, F(000) = 576 and μ(MoKa) = 0.087 mm-1. The final R = 0.0628 and wR = 0.1604 for 2501 independent reflections with Rint = 0.0160 and 1679 observed reflections with I >2σ(Ⅰ). There are three intermolecular hydrogen bonds in a unit cell.

  7. Bifunctional Nb/Ti-MCM-41 catalyst in oxidative acidic reaction of cyclohexene to diol

    International Nuclear Information System (INIS)

    Bifunctional oxidative and acidic catalyst was prepared by incorporating titanium ion (Ti4+) and niobic acid in meso porous molecular sieves MCM-41 structure. The catalyst is active both in oxidation, and acid-catalyzed reaction of olefin to diol. Nb/ Ti-MCM-41 catalyst was prepared by first synthesizing Ti-MCM-41 by hydrothermal method, followed by subsequent impregnation of niobic acid (Nb) into Ti-MCM-41 at various % wt Nb loading. The framework structure of Ti-MCM-41 collapsed after incorporation of Nb but the tetrahedral form of Ti4+ still maintained with octahedral Nb species. Both Bronsted and Lewis acid sites are present in all Nb/ Ti-MCM-41 samples. The formation of cyclohexanediol in the epoxidation of cyclohexene proved the bifunctional oxidative and acidic catalyst through the formation of cyclohexane oxide. The yield increased with the increase amount of the Bronsted acid sites provided by niobium species. (author)

  8. A NEW POLYMER-BOUND 1,2-DIOL AS A PROTECTING AGENT FOR SYMMETRICAL DIALDEHYDE

    Institute of Scientific and Technical Information of China (English)

    REN Qisheng; HUANG Wenqiang; ZHAO Fengzhi; Ho Binglin

    1989-01-01

    A novel polymer- bound 1,2 - diol, 3 - polystyrylsulfonyl- 1,2 - propanediol (6) had ben prepared by the reaction of sodium polystyrylsulfinate with allyl bromide, followed by oxidation and. hydrolysis or directly with 3 - chloro - 1,2 - propanediol in the presence of a phase transfer catalyst ,n - tetrabutylammonium iodide. The capacity of resin 6 for terephthaldehyde reached 1.43 mmol/g. The aldehydic groups attached to polymer 6 reacted with hydroxylamine hydrochloride or reduced by sodium borohydride giving p-formylbenzaldoxime (yield:89%)and p-formyl -benzalcohol (yield:73 A % ), respectively. The high yields of these polymer-supported reactions showed that the polymer 6 possessed the effective isolation of its reactive sites.

  9. 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: 2.587, year: 2014 http://www.stem-art.com/Library/Science/Structure%20and%20properties%20of%20porous%20films%20based%20on%20aliphatic%20copolyamide%20developed%20for%20cellular%20technologies.pdf

  10. Heterologous expression, purification, and properties of diol dehydratase, an adenosylcobalamin-dependent enzyme of Klebsiella oxytoca.

    Science.gov (United States)

    Tobimatsu, T; Sakai, T; Hashida, Y; Mizoguchi, N; Miyoshi, S; Toraya, T

    1997-11-01

    Recombinant adenosylcobalamin-dependent diol dehydratase of Klebsiella oxytoca overexpressed in Escherichia coli was purified to homogeneity. The enzyme has a low solubility and was extracted from the crude membrane fraction with 1% Brij 35 in a high recovery. Subsequent chromatography on DEAE-cellulose resulted in 4.9-fold purification of the enzyme in an overall yield of 65%. The enzyme thus obtained showed specific activity comparable to that of the wild-type enzyme of K. oxytoca. The apparent molecular weight determined by nondenaturing gel electrophoresis on a gradient gel was 220,000. The enzyme consists of equimolar amounts of the three subunits with apparent Mr of 60,000 (alpha), 30,000 (beta), and 19,000 (gamma). Therefore, the subunit structure of the enzyme is most likely alpha2beta2gamma2. The recombinant enzyme was also separated into components F and S upon DEAE-cellulose chromatography in the absence of substrate. Components F and S were identified as the beta subunit and alpha2gamma2 complex, respectively. Apparent Km for adenosylcobalamin, 1,2-propanediol, glycerol, and 1,2-ethanediol were 0.83 microM, 0.08 mM, 0.73 mM, and 0.56 mM, respectively. The three genes encoding the subunits of diol dehydratase were overexpressed individually or in various combinations in Escherichia coli. The alpha and gamma subunits mutually required each other for correct folding forming the soluble, active alpha2gamma2 complex (component S). Expression of the beta subunit in a soluble, active form (component F) was promoted by coexpression with both the alpha and gamma subunits, probably by coexistence with component S. These lines of evidence indicate that each subunit mutually affects the folding of the others in this heterooligomer enzyme. PMID:9344474

  11. The waterborne polyurethane dispersions based on polycarbonate diol: Effect of ionic content

    International Nuclear Information System (INIS)

    Three water-based polyurethane dispersions (PUD) were synthesized by modified dispersing procedure using polycarbonate diol (PCD), isophorone diisocyanate (IPDI), dimethylolpropionic acid (DMPA), triethylamine (TEA) and ethylenediamine (EDA). The ionic group content in the polyurethane-ionomer structure was varied by changing the amount of the internal emulsifier, DMPA (4.5, 7.5 and 10 wt.% to the prepolymer weight). The expected structures of obtained materials were confirmed by FTIR spectroscopy. The effect of the DMPA content on the thermal properties of polyurethane films was measured by TGA, DTA, DSC and DMTA methods. Increased DMPA amounts result in the higher hard segment contents and in the increase of the weight loss corresponding to the degradation of the hard segments. The reduction of hard segment content led to the elevated temperature of decomposition and to the decrease of the glass transition temperature and thermoplasticity. The atomic force microscopy (AFM), results indicated that phase separation between hard and soft segment of PUD with higher DMPA content is more significant than of PUD with lower DMPA content. The physico-mechanical properties, such as hardness, adhesion test and gloss of the dried films were also determined considering the effect of DMPA content on coating properties. Highlights: ► Polyurethane dispersions (PUD) were synthesized from polycarbonate diol. ► The effect of the DMPA content on the thermal properties of PUD films was measured. ► The thermal stability of PUD was increased by decreasing the DMPA content. ► Tg values of PUD were increased by increasing ionic content. ► The PUD with the highest content of DMPA showed more significant phase separation confirmed by AFM results

  12. On the Aliphatic versus Aromatic Content of the Carriers of the "Unidentified" Infrared Emission Features

    CERN Document Server

    Yang, Xuejuan; Li, Aigen; Zhong, Jianxin

    2016-01-01

    Although it is generally accepted that the so-called "unidentified" infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, and 11.3 micrometer are characteristic of the stretching and bending vibrations of aromatic hydrocarbon materials, the exact nature of their carriers remains unknown: whether they are free-flying, predominantly aromatic gas-phase molecules, or amorphous solids with a mixed aromatic/aliphatic composition are being debated. Recently, the 3.3 and 3.4 micrometer features which are commonly respectively attributed to aromatic and aliphatic C-H stretches have been used to place an upper limit of ~2\\% on the aliphatic fraction of the UIE carriers (i.e. the number of C atoms in aliphatic chains to that in aromatic rings). Here we further explore the aliphatic versus aromatic content of the UIE carriers by examining the ratio of the observed intensity of the 6.2 micrometer aromatic C-C feature (I6.2) to that of the 6.85 micrometer aliphatic C-H deformation feature (I6.85). To derive the intrinsic...

  13. Synthesis of novel naphthoquinone aliphatic amides and esters and their anticancer evaluation.

    Science.gov (United States)

    Kongkathip, Boonsong; Akkarasamiyo, Sunisa; Hasitapan, Komkrit; Sittikul, Pichamon; Boonyalai, Nonlawat; Kongkathip, Ngampong

    2013-02-01

    Fourteen new naphthoquinone aliphatic amides and seventeen naphthoquinone aliphatic esters were synthesized in nine to ten steps from 1-hydroxy-2-naphthoic acid with 9-25% overall yield for the amides, and 16-21% overall yield for the esters. The key step of the amide synthesis is a coupling reaction between amine and various aliphatic acids using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling agent while for the ester synthesis, DCC/DMAP or CDI was used as the coupling reagent between aliphatic acids and naphthoquinone alcohol. Both naphthoquinone amides and esters were evaluated for their anticancer activity against KB cells. It was found that naphthoquinone aliphatic amides showed stronger anticancer activity than those of the esters when the chains are longer than 7-carbon atoms. The optimum chain of amides is expected to be 16-carbon atoms. In addition, naphthoquinone aliphatic esters with α-methyl on the ester moiety possessed much stronger anticancer activity than the straight chains. Decatenation assay revealed that naphthoquinone amide with 16-carbon atoms chain at 15 μM and 20 μM can completely inhibit hTopoIIα activity while at 10 μM the enzyme activity was moderately inhibited. Molecular docking result also showed the same trend as the cytotoxicity and decatenation assay. PMID:23313636

  14. Synthesis of a precursor for the preparation of 9 alpha,11 alpha-tritiated 5 alpha-androstane-3 alpha,17 beta-diol 17-glucuronide

    International Nuclear Information System (INIS)

    Starting from 11 beta-hydroxytestosterone, the synthesis of a strategic precursor, C-9 (11) unsaturated 5 alpha-androstane-3 alpha, 17 beta-diol 17-glucuronide (9a), for the preparation of 9 alpha,11 alpha-tritiated 5 alpha-androstane-3 alpha, 17 beta-diol 17-glucuronide has been achieved. The authors optimized the reaction conditions for catalytic reduction employing hydrogen and subsequent base hydrolysis followed by purification on Amberlite XAD-2 resin to obtain the saturated 5 alpha-androstane-3 alpha, 17 beta-diol 17-glucuronide

  15. Preferential binding of benzo[a]pyrene diol epoxide to the linker DNA of human foreskin fibroblasts in S phase in the presence of benzamide.

    OpenAIRE

    Kurian, P.; Jeffrey, A M; Milo, G E

    1985-01-01

    Addition of benzamide (BZ) at the onset of S phase inhibited expression of the neoplastic phenotype in human foreskin fibroblasts treated in vitro with (+/-)-7 alpha,8 beta-dihydroxy-9 beta,10 beta-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (B[a]P diol epoxide) in early S phase. Analysis of the specific B[a]P diol epoxide-DNA adducts revealed that ca. 65% of the total adducts in BZ and non-BZ carcinogen-treated cells was the B[a]P diol epoxide-deoxyguanine adduct. Limited micrococcal nuclease di...

  16. Role of diaxial versus diequatorial hydroxyl groups in the tumorigenic activity of a benzo[a]pyrene bay-region diol epoxide.

    OpenAIRE

    Chang, R L; Wood, A.W.; Conney, A H; Yagi, H.; Sayer, J M; Thakker, D R; Jerina, D M; Levin, W

    1987-01-01

    Tumorigenic activities of the (7R,8S,9S,10R)-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydro derivatives of benzo[a]pyrene [(+)-B[a]P diol epoxide-2] and 6-fluorobenzo[a]pyrene (6-FB[a]P diol epoxide-2) were evaluated in newborn CD-1 mice. A total dose of 14 nmol of either diol epoxide was administered to preweanling mice, and tumorigenic activity was determined when the mice were 32 to 36 weeks old. At the termination of the study, 13% of solvent-treated control mice had developed lung tumors w...

  17. Synthesis of acyclic nucleoside phosphonates bearing (N-methyl)anthraniloyl substituent as potential inhibitors of adenylate cyclase toxin from Bordetella Pertussis

    Czech Academy of Sciences Publication Activity Database

    Břehová, Petra; Šmídková, Markéta; Mertlíková-Kaiserová, Helena; Dračínský, Martin; Janeba, Zlatko

    Praha: Czech Chemical Society, 2015. s. 61. [Liblice 2015. Advances in Organic , Bioorganic and Pharmaceutical Chemistry /50./. 06.11.2015-08.11.2015, Olomouc] R&D Projects: GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * adenylate cyclase toxin * prodrugs Subject RIV: CC - Organic Chemistry

  18. 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. PMID:25340465

  19. Secondary aerosol formation from atmospheric reactions of aliphatic amines

    Directory of Open Access Journals (Sweden)

    S. M. Murphy

    2007-01-01

    Full Text Available Although aliphatic amines have been detected in both urban and rural atmospheric aerosols, little is known about the chemistry leading to particle formation or the potential aerosol yields from reactions of gas-phase amines. We present here the first systematic study of aerosol formation from the atmospheric reactions of amines. Based on laboratory chamber experiments and theoretical calculations, we evaluate aerosol formation from reaction of OH, ozone, and nitric acid with trimethylamine, methylamine, triethylamine, diethylamine, ethylamine, and ethanolamine. Entropies of formation for alkylammonium nitrate salts are estimated by molecular dynamics calculations enabling us to estimate equilibrium constants for the reactions of amines with nitric acid. Though subject to significant uncertainty, the calculated dissociation equilibrium constant for diethylammonium nitrate is found to be sufficiently small to allow for its atmospheric formation, even in the presence of ammonia which competes for available nitric acid. Experimental chamber studies indicate that the dissociation equilibrium constant for triethylammonium nitrate is of the same order of magnitude as that for ammonium nitrate. All amines studied form aerosol when photooxidized in the presence of NOx with the majority of the aerosol mass present at the peak of aerosol growth consisting of aminium (R3NH+ nitrate salts, which repartition back to the gas phase as the parent amine is consumed. Only the two tertiary amines studied, trimethylamine and triethylamine, are found to form significant non-salt organic aerosol when oxidized by OH or ozone; calculated organic mass yields for the experiments conducted are similar for ozonolysis (15% and 5% respectively and photooxidation (23% and 8% respectively. The non-salt organic aerosol formed appears to be more stable than the nitrate salts and does not quickly repartition back to the gas phase.

  20. Separation and conductimetric detection of C1-C7 aliphatic monocarboxylic acids and C1-C7 aliphatic monoamines on unfunctionized polymethacrylate resin columns.

    Science.gov (United States)

    Ohta, Kazutoku; Towata, Atsuya; Ohashi, Masayoshi; Takeuchi, Toyohide

    2004-06-11

    The application of unfunctionized polymethacrylate resin (TSKgel G3000PWXL) as a stationary phase in liquid chromatography with conductimetric detection for C1-C7 aliphatic monocarboxylic acids (formic acid, acetic acid, propionic acid, butyric acid, isovaleric acid, valeric acid, 3,3-dimethylbutyric acid, 4-methylvaleric acid, hexanoic acid, 2-methylhexanoic acid, 5-methylhexanoic acid and heptanoic acid) and C1-C7 aliphatic monoamines (methylamine, ethylamine, propylamine, isobutylamine, butylamine, isoamylamine, amylamine, 1,3-dimethylbutylamine, hexylamine, 2-heptylamine and heptylamine) was attempted with C8 aliphatic monocarboxylic acids (2-propylvaleric acid, 2-ethylhexanoic acid, 2-methylheptanoic acid and octanoic acid) and C8 aliphatic monoamines (1,5-dimethylhexylamine, 2-ethylhexylamine, 1-methylheptylamine and octylamine) as eluents, respectively. Using 1 mM 2-methylheptanoic acid at pH 4.0 as the eluent, excellent separation and relatively high sensitive detection for these C1-C7 carboxylic acids were achieved on a TSKgel G3000PWXL column (150 mm x 6 mm i.d.) in 60 min. Using 2 mM octylamine at pH 11.0 as the eluent, excellent separation and relatively high sensitive detection for these C1-C7 amines were also achieved on the TSKgel G3000PWXL column in 60 min. PMID:15250420

  1. The separation and synthesis of lipidic 1,2- and 1,3-diols from natural phenolic lipids for the complexation and recovery of boron.

    Science.gov (United States)

    Tyman, John H P; Mehet, Satinderjit K

    2003-12-01

    A study has been made of the semi-synthesis of 1,3-diols (anacardic alcohols) from natural phenolic lipid resources from Anacardium occidentale and Anacardium giganteum which have given C15 and C11 derivatives, respectively. An isomeric 1,3-diol (isoanacardic alcohol) has been obtained from cardanol separated from technical cashew nut-shell liquid. Homologous 1,3-diols have been synthesised from a range of synthetic 2-alkyl-, 3-alkyl- and 4-alkylphenols and from 6-alkylsalicylic acids. The natural 1,2-diol, urushiol, from Rhus vernicifera has been purified. All these lipidic compounds have been studied for their complexation and the potential recovery of boron as boric acid. PMID:14623453

  2. Long chain diol index (LDI) as an organic-based sea surface temperature proxy in the Korean East Sea (NW Pacific)

    Science.gov (United States)

    Gal, Jong-Ku; Kim, Jung-Hyun; Kang, Su-Jin; Lee, Dong-Hun; Shin, Kyung-Hoon

    2016-04-01

    Long chain diol index (LDI) was introduced as an organic-based sea surface temperature (SST) proxy. LDI is expressed as the C30 1,15-diol abundance relative to those of C28 1,13-, C30 1,13- and C30 1,15-diols. There were a few studies which accessed the potential of LDI based on the culture, core top sediments, suspended particulate organic matters, and down-core sediments. However it is still unknown about the source of the diols and robustness as the SST proxy in the various marine environments. In the current study, we examined the applicability of the LDI in the East Sea of Korea where productivity and thus sedimentation rates are high. We will compare the LDI data with those of alkenone-based UK'37 by analyzing two multicores covering the last 100 year.

  3. Preferential Glutathione Conjugation of a Reverse Diol Epoxide Compared to a Bay Region Diol Epoxide of Phenanthrene in Human Hepatocytes: Relevance to Molecular Epidemiology Studies of Glutathione-S-Transferase Polymorphisms and Cancer

    OpenAIRE

    Hecht, Stephen S.; Berg, Jeannette Zinggeler; Hochalter, J. Bradley

    2009-01-01

    Bay region diol epoxides are recognized ultimate carcinogens of polycyclic aromatic hydrocarbons (PAH), and in vitro studies have demonstrated that they can be detoxified by conjugation with glutathione, leading to the widely investigated hypothesis that individuals with low activity forms of glutathione-S-transferases are at higher risk of PAH induced cancer, a hypothesis that has found at most weak support in molecular epidemiology studies. A weakness in this hypothesis was that the mercapt...

  4. 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....

  5. Enantioseparation of newly synthesized acyclic nucleoside phosphonates-based antivirals by capillary electrophoresis using cyclodextrins as chiral selectors

    Czech Academy of Sciences Publication Activity Database

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

    Bratislava : Slovenská vákuová spoločnosť, 2013 - (Bodor, R.; Okenicová, L.; Staňová, A.), s. 245-247 ISBN 978-80-971179-1-7. [Analytické metódy a zdravie človeka. Medzinárodná konferencia /19./. Rajecké Teplice (SK), 24.06.2013-27.06.2013] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR GA13-17224S; GA MV VG20102015046 Grant ostatní: AV ČR CSIC(CZ) 2008CZ0019 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * chiral analysis * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation

  6. 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.

  7. Ring Expansion of Cyclic 1,2-Diols to form Medium Sized Rings via Ruthenium Catalyzed Transfer Hydrogenative [4+2] Cycloaddition

    OpenAIRE

    Kasun, Zachary A.; Geary, Laina M.; Krische, Michael J.

    2014-01-01

    A new method for the ring expansion of cyclic diols is described. Using improved conditions for the ruthenium(0) catalyzed cycloaddition of cyclic 1,2-diols with 1,3-dienes, fused [n.4.0] bicycles 3a–3r (n = 3–6) are formed, which upon exposure to iodosobenzene diacetate engage in oxidative cleavage to form the 9–12 membered rings 4a–4r.

  8. [Diol column as stationary phase for high performance liquid chromatographic analysis of carbohydrates in drinks with evaporative light scattering detection].

    Science.gov (United States)

    Wei, Y; Guo, L; Ding, M Y

    2001-11-01

    A high performance liquid chromatographic method with a diol column and evaporative light scattering detector (ELSD) was established for the direct analysis of fructose, glucose, sucrose, maltose and raffinose in mixture. A separation column (Lichrospher 100 Diol, 250 mm x 4.0 mm i.d., 5 microns, Hewlett-Packard, USA) and a guard column (Zorbax Rx-SIL, 12.5 mm x 4.6 mm i.d., 5 microns) were used. The mobile phase was a mixture of dichloromethane-methanol (3.2:1, volume ratio). Regression equations revealed linear relationship (correlation coefficients: 0.995-0.999) between the mass of carbohydrates injected and the peak area of carbohydrates detected by ELSD. The detection limits of ELSD (S/N = 3) were about 0.20 microgram for all carbohydrates. This system could be used for the routine analysis of simple carbohydrates in some common drinks on market. PMID:12545463

  9. Swift heavy ion induced modification of aliphatic polymers

    International Nuclear Information System (INIS)

    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 1010 - 5 x 1012 ions/cm2). 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 the

  10. Aliphatic hydrocarbons in surface sediments from South China Sea off Kuching Division, Sarawak

    International Nuclear Information System (INIS)

    Eighteen surface sediment samples collected from South China Sea off Kuching Division, Sarawak were analyzed for aliphatic hydrocarbons. These hydrocarbons were recovered from sediment by Soxhlet extraction method and then analyzed using gas chromatography equipped with mass spectrometer (GC/ MS). Total concentrations of aliphatic hydrocarbons in surface sediments from South China Sea off Kuching division are ranged from 35.6 μg/ g to 1466.1 μg/ g dry weights. The sediments collected from Bako Bay, Kuching showed high concentrations of total aliphatic hydrocarbons. Several molecular indices were used to predict the predominant sources of hydrocarbons. Carbon preference index (CPI) value revealed widespread anthropogenic input in this study area (CPI= 0 to 4.1). The ratio of C31/ C19and C29/ C31indicated that major input of aliphatic hydrocarbon mostly transfer by lateral input to the marine environment than atmospheric movements. Generally, the concentrations of aliphatic hydrocarbons in sediment from South China Sea off Kuching division are generally higher compare to other area in the world. (author)

  11. Preferential binding of benzo[a]pyrene diol epoxide to linker DNA of human foreskin fibroblasts in S phase in the presence of benzamide

    International Nuclear Information System (INIS)

    Addition of benzamide (BZ) at the onset of S phase inhibited expression of the neoplastic phenotype of human foreskin fibroblasts treated in vitro with (+/-)-7α,8β-dihydroxy-9β,10β-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (B[a]P diol epoxide) in early S phase. Analysis of the specific B[a]P diol epoxide-DNA adducts revealed that ca. 65% of the total adducts in BZ and non-BZ carcinogen-treated cells was the B[a]P diol epoxide-deoxyguanine adduct. Limited micrococcal nuclease digestion of the early S phase nuclei from cells treated with B[a]P diol epoxide indicated that the carcinogen binds equally to linker and core DNA. However, when the cells were predominantly in S phase, in the presence of BZ, there was ca. three times more binding of B[a]P diol epoxide to the linker DNA compared to the core region. These data indicate that pretreatment of the cells with BZ at the onset of S phase established a preferential binding pattern in the linker DNA similar to that observed in the cells treated with B[a]P diol epoxide in G1 arrest

  12. Synthesis of bio-based thermoplastic polyurethane elastomers containing isosorbide and polycarbonate diol and their biocompatible properties.

    OpenAIRE

    Oh, S. Y.; Kang, M. S.; Knowles, J. C.; Gong, M. S.

    2015-01-01

    A new family of highly elastic polyurethanes (PUs) partially based on renewable isosorbide were prepared by reacting hexamethylene diisocyanate with a various ratios of isosorbide and polycarbonate diol 2000 (PCD) via a one-step bulk condensation polymerization without catalyst. The influence of the isorsorbide/PCD ratio on the properties of the PU was evaluated. The successful synthesis of the PUs was confirmed by Fourier transform-infrared spectroscopy and (1)H nuclear magnetic resonance. T...

  13. Juvenile hormone diol kinase, a calcium-binding protein with kinase activity, from the silkworm, Bombyx mori.

    Science.gov (United States)

    Li, Sheng; Zhang, Qi-Rui; Xu, Wei-Hua; Schooley, David A

    2005-11-01

    Juvenile hormone (JH) diol kinase (JHDK) is an important enzyme involved in the JH degradation pathway. Bombyx mori (Bommo)-JHDK cDNA (637bp) contains an open reading frame encoding a 183-amino acid protein, which reveals a high degree of identity to the two previously reported JHDKs. JHDK is similar to GTP-binding proteins with three conserved sequence elements involved in purine nucleotide binding, contains eight alpha-helices and three EF-hand motifs, and resembles the three-dimensional model of 2SCP and some other calcium-binding proteins. The Bommo-JHDK gene has only a single copy in the silkworm haploid genome, contains only one exon, and its 5'-upstream sequence does not have a JH response element. Although Bommo-JHDK is highly expressed in the gut of the silkworm, its mRNA expression remains at a constant level during larval development suggesting this enzyme is constitutive and not regulated by JH, at least at the transcriptional level. Recombinant Bommo-JHDK catalyzed the conversion of 10S-JH diol into JH diol phosphate, confirming its enzymatic function. Recombinant enzyme formed a dimer and had biochemical characteristics similar to other JHDKs. Bommo-JHDK, a calcium-binding protein with kinase activity, provides unique insights on how JH levels are regulated in the silkworm. PMID:16203205

  14. 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. PMID:26478126

  15. Binding site for the adenosyl group of coenzyme B12 in diol dehydrase

    International Nuclear Information System (INIS)

    The binding of cob(II)alamin (CblII) and 5'-deoxyadenosine to diol dehydrase was studied spectroscopically and with [U-14C]5'-deoxyadenosine. CblII was bound to this enzyme forming a tight 1:1 complex which was resistant to oxidation by O2 even in the presence of CN-. An irreversible 1:1:1 ternary complex was formed between enzyme, CblII, and 5'-deoxyadenosine, when the enzyme was incubated first with the nucleoside and then with CblII. When this order of addition of the constituents was reversed, no 5'-deoxyadenosine was bound to the enzyme-CblII complex. Hydroxocobalamin could also bind to the enzyme together with the nucleoside, while other cob(III)alamins bearing a bulkier Co beta ligand displaced the nucleoside upon binding to the enzyme. The binding of [U-14C]5'-deoxyadenosine was strongly inhibited by unlabeled 5'-deoxy-ara-adenosine, 4',5'-anhydroadenosine, adenosine, adenine, and 5',8-cyclic adenosine, in this order, but not by 5'-deoxyuridine. These results constitute direct evidence for the presence of the binding site for the adenosyl group of adenosylcobalamin, which is spatially limited to and highly specific for adenine nucleosides. The binding of 5'-deoxyadenosine to the apoenzyme was reversible

  16. Urinary 5α-androstane-3α,17β-diol radioimmunoassay: a new clinical evaluation

    International Nuclear Information System (INIS)

    A rapid specific and reliable RIA for urinary 5α-androstane-3α, 17β-diol (Adiol) is described using chromatographical purification and a specific antibody. Values are reported under some physiological and pathological conditions in 179 individuals. In 43 normal adult men the mean (+- SD) urinary Adiol excretion was 193 +- 77 μg/24 h, and in 29 normal women it was 44 +- 23 μg/24 h. These values are significantly different (P < 0.01). In 49 hirsute women, urinary Adiol Excretion was elevated (137 +- 51 μg/24 h) and significantly different from this value in normal women (P < 0.01). The urinary Adiol excretion in 10 postmenopausal women was very low (< 5 μg/24 h). In normal adult subjects, the theoretical contribution to urinary Adiol of the major secreted androgens was calculated. Whereas dehydroisoandrosterone and dehydroisoandrosterone sulfate yield the same amount of urinary Adiol in both sexes, testosterone is the main precursor of Adiol in men and androstenedione is the main precursor in normal premenopausal and hirsute women. However, the amount of Adiol recovered in the 24-h urine depends not only on the secretion rate of androstenedione and testosterone but is also related to the testosterone 5α-reductase activity present in androgen target cells, especially in sexual skin

  17. Mussel-inspired soft-tissue adhesive based on poly(diol citrate) with catechol functionality.

    Science.gov (United States)

    Ji, Yali; Ji, Ting; Liang, Kai; Zhu, Lei

    2016-02-01

    Marine mussels tightly adhering to various underwater surfaces inspires human to design adhesives for wet tissue adhesion in surgeries. Characterization of mussel adhesive plaques describes a matrix of proteins containing 3,4-dihydroxyphenylalanine (DOPA), which provides strong adhesion in aquatic conditions. Several synthetic polymer systems have been developed based on this DOPA chemistry. Herein, a citrate-based tissue adhesives (POEC-d) was prepared by a facile one-pot melt polycondensation of two diols including 1,8-octanediol and poly(ethylene oxide) (PEO), citric acid (CA) and dopamine, and the effects of hydrophilic and soft PEO on the properties of adhesives were studied. It was found that the obtained adhesives exhibited water-soluble when the mole ratio of PEO to 1,8-octanediol was 70%, and the equilibrium swelling percentage of cured adhesive was about 144%, and degradation rate was in the range of 1-2 weeks. The cured adhesives demonstrated soft rubber-like behavior. The lap shear adhesion strength measured by bonding wet pig skin was in the range of 21.7-33.7 kPa, which was higher than that of commercial fibrin glue (9-15 kPa). The cytotoxicity tests showed the POEC-d adhesives had a low cytotoxicity. Our results supports that POEC-d adhesives, which combined strong wet adhesion with good biodegradability, acceptable swelling ratio, good elasticity and low cytotoxicity, have potentials in surgeries where surgical tissue adhesives, sealants, and hemostatic agents are used. PMID:26704547

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

    International Nuclear Information System (INIS)

    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 H2O molecules. These structural not necessary H2O 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

  19. Swift heavy ion induced modification of aliphatic polymers

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Umme Habiba

    2015-01-15

    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{sup 10} - 5 x 10{sup 12} ions/cm{sup 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

  20. Aliphatic and aromatic hydrocarbons in Candiota coal samples: novel series of bicyclic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, A.C.M.L.; Loureiro, M.R.B.; Cardoso, J.N. [Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil). Inst. de Quimica

    1999-07-01

    Gas chromatography - mass spectrometry was used to analyse aliphatic and aromatic fractions obtained from nine samples taken from two different seams of five boreholes in the Candiota coalfield (Lower Permian). The occurrence of certain tetracyclic diterpenoids among the aliphatic hydrocarbons, and the tricyclic diterpenoids simonellite and retene in the aromatic hydrocarbon concentrates, suggest an important input from conifers to the sedimentary biomass. This may explain the origin of a novel series of saturated and aromatic bicyclic compounds detected in the extracts which may be structurally related to the same precursor, possibly a conifer resin-derived tricyclic diterpenoid.

  1. Oxymer - a new class of aliphatic polycarbonate oligomers improving the properties of radiation curable systems

    International Nuclear Information System (INIS)

    In this paper a new class of aliphatic polycarbonate oligomers that greatly improves the properties of radiation curable systems is presented. Through the use of these oligomers hydrolytic stability and outdoor durability can be achieved without compromising any other aspect of the coating performance making it deal for many interior as well as exterior applications such as automotive coatings and UV adhesives. In addition, the chemical constituents of this new class of aliphatic polycarbonates awards low surface energy making them suitable for coating of low surface energy substrates e.g within the field of graphic arts. (Author)

  2. 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; Jørgensen, Flemming Steen

    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....

  3. Intercalation of 1,n-diols into strontium phenylphosphonate: how the shape of the host layers influences arrangement of the guest molecules.

    Science.gov (United States)

    Melánová, Klára; Kovář, Petr; Beneš, Ludvík; Svoboda, Jan; Veteška, Marek; Pospíšil, Miroslav; Zima, Vítězslav

    2015-12-15

    Strontium phenylphosphonate intercalates with 1,n diols (n=2-4, 6-8) having general formula SrC6H5PO3⋅x(HO(CH2)nOH)⋅yH2O were prepared by precipitation from strontium phenylphosphonate solution and the corresponding diols. Prepared compounds exhibit a very good stability at ambient conditions. The intercalates were characterized by X-ray diffraction, thermogravimetry and elemental analysis. Thanks to the existence of free spaces among the benzene rings the diols exhibit a peculiar intercalation behavior. This behavior is explained on the basis of molecular simulation, which facilitated to elucidate the arrangement of the diol (guest) molecules in the specifically shaped space between the layers of the host material. From the structural point of view the intercalates can be divided into two subgroups: (i) intercalates with 1,2- to 1,4-diols and (ii) intercalates with 1,6- to 1,8-diols. The alkanediols of the first group are immersed in the free spaces among the benzene groups, their molecules adopt a horseshoe shape meaning cis conformation and are bonded by both of their OH groups to one host layer. The longer alkanediol chains of the second group allow anchoring to both neighboring layers of the host forming a kind of pillared structure in the interlayer space. The diol molecules are in this case bonded to the host layers by their OH groups to the oxygen atoms of the host layers and to water molecules present in the interlayer space through hydrogen bonds. The values of the basal spacing obtained from the experimental powder X-ray patterns are in a very good agreement with the basal spacing values calculated from the models. The molecular simulation of a 1,5-pentanediol intercalate, which we were not be able to synthesize, explained why this intercalate cannot be stable. PMID:26319335

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

    International Nuclear Information System (INIS)

    Previous 18O labeling studies of abscisic acid (ABA) have shown that apple (Malus domestica Borkh. cv Granny Smith) fruits synthesize a majority of [18O]ABA with the label incorporated in the 1'-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 18O in the side chain with the medium occurred at an aldehyde intermediate stage of ABA biosynthesis. We have isolated ABA-aldehyde and 1'-4'-trans-ABA-diol (ABA-trans-diol) from 18O-labeled apple fruit tissue and measured the extent and position of 18O incorporation by tandem mass spectrometry. 18O-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 18O in the carbonyl of ABA-aldehyde can be the cause of loss of 18O from the side chain of [18O]ABA. Results of feeding experiments with deuterated substrates provide further support for the precursor-product relationship of ABA-aldehyde → ABA → 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 β-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. Synthesis of branched 9-[2-(2-phosphonoethoxy)ethyl]purines as a new class of acyclic nucleoside phosphonates which inhibit Plasmodium falciparum hypoxanthine-guanine-xanthine phosphoribosyltransferase

    Czech Academy of Sciences Publication Activity Database

    Hocková, Dana; Holý, Antonín; Masojídková, Milena; Keough, D. T.; de Jersey, J.; Guddat, L. W.

    2009-01-01

    Roč. 17, č. 17 (2009), s. 6218-6232. ISSN 0968-0896 R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * drug design * phosphoribosyltransferase * enzyme inhibitors * purine salvage pathway Subject RIV: CC - Organic Chemistry Impact factor: 2.822, year: 2009

  6. Pd-catalyzed Suzuki-Miyaura coupling reaction in the synthesis of 5-aryl substituted pyrimidine acyclic nucleoside phosphonates as potential multisubstrate inhibitors of thymidine phosphorylase

    Czech Academy of Sciences Publication Activity Database

    Pomeisl, Karel; Holý, Antonín; Pohl, Radek

    Dublin : University College Dublin, 2007. s. 329. [European Symposium on Organic Chemistry /15./. 08.07.2007-13.07.2007, Dublin] R&D Projects: GA MŠk 1M0508 Grant ostatní: Descartes Prize(XE) HPAW-CT-2002-9001 Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * thymidine phosphorylase * Suzuki coupling Subject RIV: CC - Organic Chemistry

  7. Sonogashira cross-coupling in the synthesis of acyclic nucleoside phosphonates: preparation of 6-[(phosphonomethoxy)alkynyl]- and 6-[(phosphonomethoxy)alkyl]pyrimidines

    Czech Academy of Sciences Publication Activity Database

    Hocková, Dana; Masojídková, Milena; Holý, Antonín

    2005-01-01

    Roč. 70, č. 2 (2005), 247-257. ISSN 0010-0765 R&D Projects: GA AV ČR(CZ) IBS4055109 Grant ostatní: René Descartes Prize 2001(XE) HPAW-2002-90001 Institutional research plan: CEZ:AV0Z40550506 Keywords : nucleotide analogues * acyclic nucleoside phosphonates * pyrimidines Subject RIV: CC - Organic Chemistry Impact factor: 0.949, year: 2005

  8. Phenylalanine Ammonia-Lyase-Catalyzed Deamination of an Acyclic Amino Acid: Enzyme Mechanistic Studies Aided by a Novel Microreactor Filled with Magnetic Nanoparticles.

    Science.gov (United States)

    Weiser, Diána; Bencze, László Csaba; Bánóczi, Gergely; Ender, Ferenc; Kiss, Róbert; Kókai, Eszter; Szilágyi, András; Vértessy, Beáta G; Farkas, Ödön; Paizs, Csaba; Poppe, László

    2015-11-01

    Phenylalanine ammonia-lyase (PAL), found in many organisms, catalyzes the deamination of l-phenylalanine (Phe) to (E)-cinnamate by the aid of its MIO prosthetic group. By using PAL immobilized on magnetic nanoparticles and fixed in a microfluidic reactor with an in-line UV detector, we demonstrated that PAL can catalyze ammonia elimination from the acyclic propargylglycine (PG) to yield (E)-pent-2-ene-4-ynoate. This highlights new opportunities to extend MIO enzymes towards acyclic substrates. As PG is acyclic, its deamination cannot involve a Friedel-Crafts-type attack at an aromatic ring. The reversibility of the PAL reaction, demonstrated by the ammonia addition to (E)-pent-2-ene-4-ynoate yielding enantiopure l-PG, contradicts the proposed highly exothermic single-step mechanism. Computations with the QM/MM models of the N-MIO intermediates from L-PG and L-Phe in PAL show similar arrangements within the active site, thus supporting a mechanism via the N-MIO intermediate. PMID:26345352

  9. Anti-EGFRvIII monoclonal antibody armed with {sup 177}Lu: in vivo comparison of macrocyclic and acyclic ligands

    Energy Technology Data Exchange (ETDEWEB)

    Hens, Marc; Vaidyanathan, Ganesan; Zhao Xiaoguang [Department of Radiology, Duke University Medical Center, Durham, NC 27710 (United States); Bigner, Darell D. [Department of Pathology, Duke University Medical Center, Durham, NC 27710 (United States); Zalutsky, Michael R., E-mail: zalut001@mc.duke.ed [Department of Radiology, Duke University Medical Center, Durham, NC 27710 (United States)

    2010-10-15

    Introduction: Monoclonal antibody (mAb) L8A4 binds specifically to the epidermal growth factor receptor variant III (EGFRvIII) that is present on gliomas but not on normal tissues, and is internalized rapidly after receptor binding. Because of the short range of its {beta}-emissions, labeling this mAb with {sup 177}Lu would be an attractive approach for the treatment of residual tumor margins remaining after surgical debulking of brain tumors. Materials and Methods: L8A4 mAb was labeled with {sup 177}Lu using the acyclic ligands [(R)-2-amino-3-(4-isothiocyanatophenyl)propyl]-trans-(S,S)-cyclohexane-1, 2-diamine-pentaacetic acid (CHX-A''-DTPA) and 2-(4-isothiocyanatobenzyl)-6-methyldiethylene-triaminepentaacetic acid (1B4M-DTPA), and the macrocyclic ligands S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-tetraacetic acid (C-DOTA) and {alpha}-(5-isothiocyanato-2-methoxyphenyl)-1,4,7,10-tetraazacyclododecane-1,4,7, 10-tetraacetic acid (MeO-DOTA). Paired-label tissue distribution experiments were performed in athymic mice bearing subcutaneous EGFRvIII-expressing U87.{Delta}EGFR glioma xenografts over a period of 1 to 8 days to directly compare {sup 177}Lu-labeled L8A4 to L8A4 labeled with {sup 125}I using N-succinimidyl 4-guanidinomethyl-3-[{sup 125}I]iodobenzoate ([{sup 125}I]SGMIB). Results: Except with C-DOTA, tumor uptake for the {sup 177}Lu-labeled mAb was significantly higher than the co-administered radioiodinated preparation; however, this was also the case for spleen, liver, bone and kidneys. Tumor/normal tissue ratios for {sup 177}Lu-1B4M-DTPA-L8A4 and, to an even greater extent, {sup 177}Lu-MeO-DOTA-L8A4 were higher than those for [{sup 125}I]SGMIB-L8A4 in most other tissues. Conclusions: Tumor and normal tissue distribution patterns for this anti-EGFRvIII mAb were dependent on the nature of the bifunctional chelate used for {sup 177}Lu labeling. Optimal results were obtained with 1B4M-DTPA and MeO-DOTA, suggesting no clear advantage

  10. Design and synthesis of novel 5-substituted acyclic pyrimidine nucleosides as potent and selective inhibitors of hepatitis B virus.

    Science.gov (United States)

    Kumar, Rakesh; Nath, Mahendra; Tyrrell, D Lorne J

    2002-05-01

    A novel class of 5-substituted acyclic pyrimidine nucleosides, 1-[(2-hydroxyethoxy)methyl]-5-(1-azidovinyl)uracil (9a), 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl]-5-(1-azidovinyl)uracil (9b), and 1-[4-hydroxy-3-(hydroxymethyl)-1-butyl]-5-(1-azidovinyl)uracil (9c), were synthesized by regiospecific addition of bromine azide to the 5-vinyl substituent of the respective 5-vinyluracils (2a-c) followed by treatment of the obtained 5-(1-azido-2-bromoethyl) compounds (3a-c) with t-BuOK, to affect the base-catalyzed elimination of HBr. Thermal decomposition of 9b and 9c at 110 degrees C in dioxane yielded corresponding 5-[2-(1-azirinyl)]uracil analogues (10b,c). The 5-(1-azidovinyl)uracil derivatives 9a-c were found to exhibit potent and selective in vitro anti-HBV activity against duck hepatitis B virus (DHBV) infected primary duck hepatocytes at low concentrations (EC(50) = 0.01-0.1 microg/mL range). The most active anti-DHBV agent (9c), possessing a [4-hydroxy-3-(hydroxymethyl)-1-butyl] substituent at N-1, exhibited an activity (EC(50) of 0.01-0.05 microg/mL) comparable to that of reference compound (-)-beta-L-2',3'-dideoxy-3'-thiacytidine (3-TC) (EC(50) = 0.01-0.05 microg/mL). In contrast, related 5-[2-(1-azirinyl)]uracil analogues (10b,c) were devoid of anti-DHBV activity, indicating that an acyclic side chain at C-5 position of the pyrimidine ring is essential for anti-HBV activity. The pyrimidine nucleosides (9a-c, 10b,c) exhibited no cytotoxic activity against a panel of 60 human cancer cell lines. All of the compounds investigated did not show any detectable toxicity to several stationary and proliferating host cell lines or to mitogen stimulated proliferating human T lymphocytes, up to the highest concentration tested. PMID:11985471

  11. Anti-EGFRvIII monoclonal antibody armed with 177Lu: in vivo comparison of macrocyclic and acyclic ligands

    International Nuclear Information System (INIS)

    Introduction: Monoclonal antibody (mAb) L8A4 binds specifically to the epidermal growth factor receptor variant III (EGFRvIII) that is present on gliomas but not on normal tissues, and is internalized rapidly after receptor binding. Because of the short range of its β-emissions, labeling this mAb with 177Lu would be an attractive approach for the treatment of residual tumor margins remaining after surgical debulking of brain tumors. Materials and Methods: L8A4 mAb was labeled with 177Lu using the acyclic ligands [(R)-2-amino-3-(4-isothiocyanatophenyl)propyl]-trans-(S,S)-cyclohexane-1, 2-diamine-pentaacetic acid (CHX-A''-DTPA) and 2-(4-isothiocyanatobenzyl)-6-methyldiethylene-triaminepentaacetic acid (1B4M-DTPA), and the macrocyclic ligands S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-tetraacetic acid (C-DOTA) and α-(5-isothiocyanato-2-methoxyphenyl)-1,4,7,10-tetraazacyclododecane-1,4,7, 10-tetraacetic acid (MeO-DOTA). Paired-label tissue distribution experiments were performed in athymic mice bearing subcutaneous EGFRvIII-expressing U87.ΔEGFR glioma xenografts over a period of 1 to 8 days to directly compare 177Lu-labeled L8A4 to L8A4 labeled with 125I using N-succinimidyl 4-guanidinomethyl-3-[125I]iodobenzoate ([125I]SGMIB). Results: Except with C-DOTA, tumor uptake for the 177Lu-labeled mAb was significantly higher than the co-administered radioiodinated preparation; however, this was also the case for spleen, liver, bone and kidneys. Tumor/normal tissue ratios for 177Lu-1B4M-DTPA-L8A4 and, to an even greater extent, 177Lu-MeO-DOTA-L8A4 were higher than those for [125I]SGMIB-L8A4 in most other tissues. Conclusions: Tumor and normal tissue distribution patterns for this anti-EGFRvIII mAb were dependent on the nature of the bifunctional chelate used for 177Lu labeling. Optimal results were obtained with 1B4M-DTPA and MeO-DOTA, suggesting no clear advantage for acyclic vs. macrocyclic ligands for this application.

  12. Gene-specific repair of benzo[a]pyrene diol epoxide DNA damage in human cells

    International Nuclear Information System (INIS)

    Gene-specific preferential repair of UV damage has been well documented in a variety of organisms. Less is known about many other types of critical DNA lesions, the data available being not numerous and contradictory. To date, the majority of observations with UV were obtained by using T4 endonuclease V system. Recent report questions the applicability of UvrABC nuclease incision method for detecting gene-specific repair. This has stimulated our search for simple and sensitive approach based on a different principle. We have employed the idea of detection by the Southern hybridization of restriction cleavage inhibition at rare sites and developed a method for the analysis of benzo[a]pyrene diol epoxide (anti-BPDE) DNA damage in human H-ras proto-oncogene. Damage-dependent induction of individual facultative bands resulting from cleavage inhibition was observed in in vitro modified (4-50 adducts/103kb) p220-ras plasmid DNA digested with EcoRI/NotI, Xhol/Xbal/PstI, and SstI/XbaI/Pst/I. In vivo lesion formation and removal was monitored at several PstI sites distributed along the 6.4 kb single copy ras sequence. Rapid gene-specific repair was seen in primary culture of normal human fibroblasts and in SV40 transformed GM00637 cells. Surprisingly, SV40 transformed XP12BE (complementation group A) GM4429 fibroblasts also repaired anti-BPDE DNA damage at comparable levels. All investigated sites within ras sequence were repaired faster than the genome overall. The results show the utility of the above approach for fine mapping of anti-BPDE DNA lesions. Data suggests that the xeroderma pigmentosum (group A) fibroblasts have a capacity of removing these bulky adducts at least from the active genes

  13. 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...

  14. 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

  15. Hydrogenation of Aliphatic Alkenes in a High-Temperature High-Pressure Packed-Bed Microreactor

    Czech Academy of Sciences Publication Activity Database

    Stavárek, Petr; Vajglová, Zuzana; Křišťál, Jiří; Herbstritt, F.; Heck, J.; Jiřičný, Vladimír

    Praha : Orgit, 2012, P1.164. ISBN 978-80-905035-1-9. [International Congress of Chemical and Process Engineering CHISA 2012 and 15th Conference PRES 2012 /20./. Prague (CZ), 25.08.2012-29.08.2012] Institutional support: RVO:67985858 Keywords : microreactor * hydrogenation reactions * aliphatic alkenes Subject RIV: CI - Industrial Chemistry, Chemical Engineering www.chisa.cz/2012

  16. IN-SITU AQUIFER RESTORATION OF CHLORINATED ALIPHATICS BY METHANOTROPHIC BACTERIA

    Science.gov (United States)

    This project evaluated the potential of enhanced in-situ biotransformation of chlorinated aliphatic solvents by a bacterial community grown on methane under aerobic conditions. The target chlorinated compounds were trichloroethene (TCE), cis-and trans-1,2-dichloroethene (DCE), an...

  17. PATTERN RECOGNITION ANALYSIS OF A SET OF MUTAGENIC ALIPHATIC N-NITROSAMINES

    Science.gov (United States)

    A set of 21 mutagenic aliphatic N-nitrosamines were subjected to a pattern recognition analysis using ADAPT software. Four descriptors based on molecular connectivity, geometry and sigma charge on nitrogen were capable of achieving a 100% classification using the linear learning ...

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

    International Nuclear Information System (INIS)

    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

  19. Preparation and characterization of aliphatic diphenyl esters intended as precursors for polyesters

    DEFF Research Database (Denmark)

    Hvilsted, S.; Andruzzi, F.; Cerrai, P.; Tricoli, M.

    1991-01-01

    An extensive number of aliphatic diphenyl esters, C6H5OOC(CH2)nCOOC6H5 (n = O,...,8,10,11,12,14), have been prepared in pure form. The crystalline melting points these esters exhibit an odd-even temperature behaviour, with the higher-melting even series (n even) displaying a minimum for n = 8 whi...

  20. Synthesis and characterization of biodegradable aliphatic polyesters using dibutylmagnesium as initiator

    Institute of Scientific and Technical Information of China (English)

    Lian Liu; Zhi Yong Wei; Min Qi

    2007-01-01

    Aliphatic polyesters were synthesized via the ring opening polymerization of the corresponding lactones initiated with dibutylmagnesium both in bulk and in solution.The resulting polymers were characterized by 1H, 13C NMR, GPC and XRD.The results indicated that dibutylmagnesium is an effective initiator for the ring opening polymerization of lactones.

  1. 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.

  2. STUDY ON THE PHASE TRANSITION KINETICS OF THERMOTROPIC LIQUID CRYSTALLINE AROMATIC-ALIPHATIC COPOLYESTER

    Institute of Scientific and Technical Information of China (English)

    LI Minhui; WANG Xiaogong; LIU Deshan; ZHOU Qixiang

    1991-01-01

    The phase transition kinetics of thermotropic liquid crystalline aromatic-aliphatic regular copolyester:(X) were studied by DSC. By means of Kissinger's method the kinetic equation and parameters including activation energy, rate order and preexponential factor for phase transition from nematic to isotropic were obtained. The activation energy from crystal to nematic was also presented.

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

    International Nuclear Information System (INIS)

    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

  4. 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.

  5. Repellent activities of stereoisomers of p-menthane-3,8-diols against Anopheles gambiae (Diptera: Culicidae).

    Science.gov (United States)

    Barasa, Stephen S; Ndiege, Isaiah O; Lwande, Wilber; Hassanali, Ahmed

    2002-09-01

    Four stereoisomers of p-menthane-3,8-diol, which make up the natural product obtained from Eucalyptus citriodora, were synthesized through stereoselective procedures. Repellency assays showed that all the four were equally active against Anopheles gambiae s.s. Racemic blends and the diastereoisomeric mixture of all the four isomers were also equally repellent. 1-alpha-terpeneol, with a single hydroxyl function at C-8 and unsaturation at C-8, and menthol, with a single hydroxyl function at C-3, were not repellent. The practical implication of these results is discussed. PMID:12349856

  6. (Enantio)selective Hydrogen Autotransfer: Ruthenium-Catalyzed Synthesis of Oxazolidin-2-ones from Urea and Diols.

    Science.gov (United States)

    Peña-López, Miguel; Neumann, Helfried; Beller, Matthias

    2016-06-27

    A novel strategy for the synthesis of oxazolidin-2-ones from vicinal diols and urea is described. In this heterocycle synthesis, two different C-O and C-N bonds are sequentially formed in a domino process consisting of nucleophilic substitution and alcohol amination. The use of readily available starting materials and the good atom economy render this process environmentally benign. While this transformation is already highly chemo- and regioselective, we also developed the first asymmetric version of this method using (R)-(+)-MeO-BIPHEP as the chiral ligand. PMID:27072612

  7. Improved straightforward chemical synthesis of dihydroxyacetone phosphate through enzymatic desymmetrization of 2,2-dimethoxypropane-1,3-diol.

    Science.gov (United States)

    Charmantray, Franck; El Blidi, Lahssen; Gefflaut, Thierry; Hecquet, Laurence; Bolte, Jean; Lemaire, Marielle

    2004-12-24

    Dihydroxyacetone phosphate (DHAP) was synthesized in high purity and yield in four steps starting from dihydroxyacetone dimer (DHA) (47% overall yield). DHA was converted into 2,2-dimethoxypropane-1,3-diol, which was desymmetrized by acetylation with lipase AK. The alcohol function was phosphorylated to give dibenzyl phosphate ester 4. From 4, two routes were investigated for large-scale synthesis of DHAP. First, acetate hydrolysis was performed prior to hydrogenolysis of the phosphate protective groups. The acetal hydrolysis was finally catalyzed by the phosphate group itself. Second, acetate and acetal hydrolysis were performed in one single step after hydrogenolysis. PMID:15609974

  8. New thermally stable polyesters based on 2,5-pyridinedicarbonyl dichloride and aromatic diols: Synthesis and characterization

    Institute of Scientific and Technical Information of China (English)

    Hossein Nasr Isfahani; Khalil Faghihi

    2009-01-01

    Six new thermally stable polyesters (4a-f) were synthesized through the solution polycondensation reaction of 2,5-pyridine dicarbonyldichloride (2) with six aromatic diols in N,N'-dimethyl acetamide (DMAc) solution and in the presence of pyridine as a base. The polycondensation reactions produce a series of new polyesters (4a-f) in high yields, and inherent viscosity between 0.30 and 0.55 dL/g. The resulting polyesters were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA and DTG), solubility test, Fourier transform infrared (FT-IR) spectroscopy and gel permeation chromatography (GPC).

  9. Conglomerate formative precursor of chiral drug timolol: 3-(4-Morpholino-1,2,5-thiadiazol-3-yloxy)-propane-1,2-diol

    Science.gov (United States)

    Bredikhin, Alexander A.; Zakharychev, Dmitry V.; Fayzullin, Robert R.; Bredikhina, Zemfira A.; Gubaidullin, Aidar T.

    2015-05-01

    Solid state properties of 3-(4-N-morpholino-1,2,5-thiadiazol-3-yloxy)-propane-1,2-diol 3, the synthetic precursor of popular drug timolol, have been investigated. The original solubility test, the data of X-ray diffraction and DSC methods indicate that the compound is prone to spontaneous resolution. Diol 3 crystallizing from both enantiopure or racemic feed material forms "guaifenesin-like" crystal packing in which the classic H-bonded bilayers, framed in both sides by hydrophobic molecular fragments, act as the basic supramolecular motif. The main chain conformation of the molecules in the crystals of diol 3 differs from that in the guaifenesin crystals, and this fact changes the absolute configuration of spiral columns formed by intermolecular hydrogen bonds in crystals of 3 as compared with guaifenesin crystals.

  10. The mixed-ligand ternary complexes of neodymium(III) with L-histidine and L-cysteine with various diols

    International Nuclear Information System (INIS)

    The stability constants of the ternary complexes of the type MAB, MA2B, MAB2 where M = Neodymium(III), A = amino acids and B = diols, have been investigated by pH-metric technique (μ = 0.2, KNO3 at 30 +- 1degC) with both amino acids used as primary ligand. Stability constant data indicates that MA2B species were more stable than MAB and MAB2. The diols are responsible for the change in stability. The stability constants were correlated with basicities of different ligands present in the complexes. (author)

  11. Stability and in vivo behavior of Rh[16aneS4-diol]211At complex: A potential precursor for astatine radiopharmaceuticals

    International Nuclear Information System (INIS)

    Introduction: The heavy halogen 211At 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 211At labeling strategies. One relatively unexplored approach is to utilize prosthetic groups based on astatinated rhodium (III) complex stabilized with a tetrathioether macrocyclic ligand – Rh[16aneS4-diol]211At. 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[16aneS4-diol]131I. Methods: Rh[16aneS4-diol]211At and Rh[16aneS4-diol]131I 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. Results: Both complexes were synthesized in high yield and purity. Almost no degradation was observed for Rh[16aneS4-diol]131I 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 211At in most tissues was higher than that of 131I at all time points, especially in spleen and lungs. Renal clearance of Rh[16aneS4-diol]211At and Rh[16aneS4-diol]131I predominated, with 84.1 ± 2.3% and 94.6 ± 0.9% of injected dose excreted via the urine at 4 h. Conclusions: The Rh[16aneS4-diol]211At complex might be useful for constructing prosthetic groups for the astatination of biomolecules and further studies are planned to evaluate this possibility

  12. Organocatalyzed direct aldol condensation using L-proline and BINAM-prolinamides: regio-, diastereo-, and enantioselective controlled synthesis of 1,2-diols

    OpenAIRE

    Guillena Townley, Gabriela; Hita López, María del Carmen; Nájera Domingo, Carmen

    2006-01-01

    Recoverable BINAM-prolinamide derivatives, as well as L-proline, give results complementary to antibodies when used as organocatalysts for aldol eactions between aldehydes and α-alkoxyacetones driving regioselectively to anti/syn-1,2-diols. The formation of the iso-regioisomer is suppressed using α-hydroxyacetone in DMSO at rt, achieving the corresponding anti-1,2-diol with ee’s up to 85%. For α-alkoxyacetones (methoxy, benzyloxy, and tert-butyldimethylsilyloxy), the highest regio- and dia...

  13. Mechanism of the inhibition of mutagenicity of a benzo[a]pyrene 7,8-diol 9,10-epoxide by riboflavin 5'-phosphate.

    OpenAIRE

    Wood, A.W.; Sayer, J M; Newmark, H L; Yagi, H.; Michaud, D P; Jerina, D M; Conney, A H

    1982-01-01

    Riboflavin 5'-phosphate (flavin mononucleotide; FMN) inhibits the mutagenicity of (+/-)-7 beta, 8 alpha-dihydroxy-9 alpha, 10 alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (B[a]P diol epoxide), the only known ultimate carcinogenic metabolite of benzo[a]pyrene. Coincubation of 10, 25, and 50 nmol of FMN with strain TA100 of histidine-dependent Salmonella typhimurium inhibits the mutagenicity of 0.05 nmol of the diol epoxide by 50, 70, and 90%, respectively. Ribose 5-phosphate and riboflavin sh...

  14. 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.

  15. Superparamagnetic Ironoxide Nanoparticles via Ligand Exchange Reactions: Organic 1,2-Diols as Versatile Building Blocks for Surface Engineering

    Directory of Open Access Journals (Sweden)

    Robert Sachsenhofer

    2008-09-01

    Full Text Available A method for the preparation of ligand-covered superparamagnetic iron oxide nanoparticles via exchange reactions is described. 1,2-diol-ligands are used to provide a stable binding of the terminally modified organic ligands onto the surface of γ-Fe2O3-nanoparticles (r∼4 nm. The 1,2-diol-ligands are equipped with variable terminal functional groups (i.e., hydrogen bonding moieties, azido- bromo-, fluorescent moieties and can be easily prepared via osmium tetroxide-catalyzed 1,2-dihydroxylation reactions of the corresponding terminal alkenes. Starting from octylamine-covered Î��-Fe2O3-nanoparticles, ligand exchange was effected at 50∘C over 24–48 hours, whereupon complete ligand exchange is taking place as proven by thermogravimetric (TGA- and IR-spectroscopic measurements. A detailed kinetic analysis of the ligand exchange reaction was performed via TGA analysis, demonstrating a complete ligand exchange after 24 hours. The method offers a simple approach for the generation of various γ-Fe2O3-nanoparticles with functional organic shells in a one-step procedure.

  16. 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. PMID:22431418

  17. New acyclic bis phenylpropanoid and neolignans, from Myristica fragrans Houtt., exhibiting PARP-1 and NF-κB inhibitory effects.

    Science.gov (United States)

    Muñoz Acuña, Ulyana; Carcache, Peter J Blanco; Matthew, Susan; Carcache de Blanco, Esperanza J

    2016-07-01

    The bioassay-guided fractionation of the aril of Myristica fragrans (mace spice) yielded five phenolic compounds, one new acyclic bis phenylpropanoid (1) and four previously known phenolic compounds: compounds (1) (S) 1-(3,4,5-trimethoxyphenyl)-2-(3-methoxy-5-(prop-1-yl) phenyl)-propan-1-ol, (2) benzenemethanol; α-[1-[2,6-dimethoxy-4-(2-propen-1-yl)phenoxy]ethyl]-3,4-dimethoxy-1-acetate, (3) odoratisol A, phenol, 4-[(2S,3S)-2,3-dihydro-7-methoxy-3-methyl-5-(1E)-1-propenyl-2-benzofuranyl]-2,6-dimethoxy, (4) 1,3-benzodioxate-5-methanol,α-[1-[2,6-dimethoxy-4-(2-propenyl)phenoxy]ethyl]-acetate, (5) licarin C; benzofuran,2,3-dihydro-7-methoxy-3-methyl-5-(1E)-1-yl-2-(3,4,5-trimethoxyphenyl). An NMR tube Mosher ester reaction was used in an approach to characterize and determine the assignment of the absolute configuration of the new isolated chiral alcohol (1). The PARP-1 inhibitory activity was evaluated for compound (1) (IC50=3.04μM), compound (2) (IC50=0.001μM), compound (4) (IC50=22.07μM) and compound (5) (IC50=3.11μM). Furthermore, the isolated secondary metabolites were tested for NF-κB and K-Ras inhibitory activities. When tested in the p65 assay, compounds (2) and (4) displayed potent NF-κB inhibition (IC50=1.5 nM and 3.4nM, respectively). PMID:26920294

  18. Acyclic Cucurbit[n]uril-Type Molecular Containers: Influence of Linker Length on Their Function as Solubilizing Agents.

    Science.gov (United States)

    Sigwalt, David; Moncelet, Damien; Falcinelli, Shane; Mandadapu, Vijaybabu; Zavalij, Peter Y; Day, Anthony; Briken, Volker; Isaacs, Lyle

    2016-05-01

    Two acyclic cucurbit[n]uril (CB[n])-type molecular containers that differ in the length of the (CH2 )n linker (M2C2: n=2, M2C4: n=4) between their aromatic sidewalls and sulfonate solubilizing groups were prepared and studied. The inherent solubilities of M2C2 (68 mm) and M2C4 (196 mm) are higher than the analogue with a (CH2 )3 linker (M2, 14 mm) studied previously. (1) H NMR dilution experiments show that M2C2 and M2C4 do not self-associate in water, which enables their use as solubilizing excipients. We used phase solubility diagrams (PSDs) to compare the solubilizing capacities of M2, M2C2, M2C4, hydroxypropyl-β-cyclodextrin (HP-β-CD), and sulfobutylether-β-cyclodextrin (SBE-β-CD) toward 15 insoluble drugs. We found that M2C2 and M2C4-as gauged by the slope of their PSDs-are less potent solubilizing agents than M2. However, the higher inherent solubility of M2C2 allows higher concentrations of drug to be formulated using M2C2 than with M2 in several cases. The solubilizing ability of M2C2 and SBE-β-CD were similar in many cases, with Krel values averaging 23 and 12, respectively, relative to HP-β-CD. In vitro cytotoxicity and in vivo maximum tolerated dose studies document the biocompatibility of M2C2. PMID:26990780

  19. Peretinoin, an acyclic retinoid, improves the hepatic gene signature of chronic hepatitis C following curative therapy of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    The acyclic retinoid, peretinoin, has been shown to be effective for suppressing hepatocellular carcinoma (HCC) recurrence after definitive treatment in a small-scale randomized clinical trial. However, little has been documented about the mechanism by which peretinoin exerts its inhibitory effects against recurrent HCC in humans in vivo. Twelve hepatitis C virus-positive patients whose HCC had been eradicated through curative resection or ablation underwent liver biopsy at baseline and week 8 of treatment with either a daily dose of 300 or 600 mg peretinoin. RNA isolated from biopsy samples was subjected to gene expression profile analysis. Peretinoin treatment elevated the expression levels of IGFBP6, RBP1, PRB4, CEBPA, G0S2, TGM2, GPRC5A, CYP26B1, and many other retinoid target genes. Elevated expression was also observed for interferon-, Wnt-, and tumor suppressor-related genes. By contrast, decreased expression levels were found for mTOR- and tumor progression-related genes. Interestingly, gene expression profiles for week 8 of peretinoin treatment could be classified into two groups of recurrence and non-recurrence with a prediction accuracy rate of 79.6% (P<0.05). In the liver of patients with non-recurrence, expression of PDGFC and other angiogenesis genes, cancer stem cell marker genes, and genes related to tumor progression was down-regulated, while expression of genes related to hepatocyte differentiation, tumor suppression genes, and other genes related to apoptosis induction was up-regulated. Gene expression profiling at week 8 of peretinoin treatment could successfully predict HCC recurrence within 2 years. This study is the first to show the effect of peretinoin in suppressing HCC recurrence in vivo based on gene expression profiles and provides a molecular basis for understanding the efficacy of peretinoin

  20. Study on Aromatization of C6 Aliphatic Hydrocarbons on ZRP Zeolite Catalyst

    Institute of Scientific and Technical Information of China (English)

    Wang Yongjun; Xie Chaogang

    2004-01-01

    The performance of ZRP zeolite catalysts for aromatization of C6 aliphatic hydrocarbons was investigated in a pulsed microreactor. The influence of metal modified ZRP zeolites on aromatization reaction was also studied, coupled with comparison of aromatization tendencies of olefins, paraffins and paraffins with different degrees of chain branching. Test results had shown that the lower the silicon/aluminum ratio in the ZRP zeolite, the higher the aromatization reactivity of aliphatic hydrocarbons. Modification of ZRP zeolite by zinc and its zinc content had apparent impact on the yield and distribution of aromatics. The aromatization tendency of olefins was apparently better than paraffins, while the aromatization tendency of monomethyl paraffins was better than that of straight-chain paraffins with the exception of dimethyl paraffins, which had worse aromatization tendency because of their steric hindrance.

  1. A study of aliphatic amino acids using simulated vibrational circular dichroism and Raman optical activity spectra

    CERN Document Server

    Ganesan, Aravindhan; Wang, Feng

    2013-01-01

    Vibrational optical activity (VOA) spectra, such as vibrational circular dichroism (VCD) and Raman optical activity (ROA) spectra, of aliphatic amino acids are simulated using density functional theory (DFT) methods in both gas phase (neutral form) and solution (zwitterionic form), together with their respective infrared (IR) and Raman spectra of the amino acids. The DFT models, which are validated by excellent agreements with the available experimental Raman and ROA spectra of alanine in solution, are employed to study other aliphatic amino acids. The inferred (IR) intensive region (below 2000 cm-1) reveals the signature of alkyl side chains, whereas the Raman intensive region (above 3000 cm-1) contains the information of the functional groups in the amino acids. Furthermore, the chiral carbons of the amino acids (except for glycine) dominate the VCD and ROA spectra in the gas phase, but the methyl group vibrations produce stronger VCD and ROA signals in solution. The C-H related asymmetric vibrations domina...

  2. Biodegradation of aliphatic hydrocarbons in the presence of hydroxy cucurbit[6]uril.

    Science.gov (United States)

    Pasumarthi, Rajesh; Kumar, Vikash; Chandrasekharan, Sivaraman; Ganguly, Anasuya; Banerjee, Mainak; Mutnuri, Srikanth

    2014-11-15

    Aliphatic hydrocarbons are one of the major environmental pollutants with reduced bioavailability. The present study focuses on the effect of hydroxy cucurbit[6]uril on the bioavailability of hydrocarbons. A bacterial consortium was used for biodegradation studies under saline and non-saline conditions. Based on denaturing gradient gel electrophoresis results it was found that the consortium under saline conditions had two different strains. The experiment was conducted in microcosms with tetradecane, hexadecane, octadecane and mixture of the mentioned hydrocarbons as the sole carbon source. The residual hydrocarbon was quantified using gas chromatography every 24h. It was found that biodegradation of tetradecane and hexadecane, as individual carbon source increased in the presence of hydroxy CB[6], probably due to the increase in their bioavailability. In case of octadecane this did not happen. Bioavailability of all three aliphatic hydrocarbons was increased when provided as a mixture to the consortium under saline conditions. PMID:25277552

  3. Determination of aliphatic organic acids by high-performance liquid chromatography with pulsed electrochemical detection.

    Science.gov (United States)

    Casella, Innocenzo G; Gatta, Maria

    2002-01-01

    A new ion exclusion HPLC procedure accomplished with a pulsed electrochemical detection for the determination of several common aliphatic acids is described. A triple-step waveform of the applied potentials, based on the formation/inhibition of PtOH species on the electrode surface, is successfully used for sensitive detection of several aliphatic acids in flowing systems avoiding pre- or postcolumn derivatization and/or cleanup procedures. Under optimal chromatographic conditions (i.e., 50 mM HClO(4)) the proposed method allowed detection limits between 0.5 and 7 microM for all investigated acids, and the dynamic linear range spanned generally over 1 or 2 orders of magnitude. Determination of citric, malic, tartaric, lactic, formic, and acetic acids in several foods and beverages was performed, in approximately 15 min, without the necessity of any sample pretreatment. PMID:11754537

  4. Unique gas and hydrocarbon adsorption in a highly porous metal-organic framework made of extended aliphatic ligands.

    Science.gov (United States)

    Li, Kunhao; Lee, Jeongyong; Olson, David H; Emge, Thomas J; Bi, Wenhua; Eibling, Matthew J; Li, Jing

    2008-12-14

    High and unique gas and hydrocarbon adsorption in a highly stable guest-free microporous metal-organic framework constructed on rigid aliphatic ligands, H(2)bodc and ted, is reported in this work. PMID:19082093

  5. Cyclo-Aliphatic Epoxide Based Photo Cured Gelled Electrolytes for Secondary Li Battery Applications. Electrochemical Kinetic Studies

    Science.gov (United States)

    Nagasubramanian, G.; Surampudi, S.; Halpert, G.

    1993-01-01

    Cyclo aliphatic epoxide based thin gelled fils prepared by UV photo curing were characterized electrochemically. Thylene carbonate (EC) mixed with different organic liquids in different volume ratios were used as solvents.

  6. Development and Characterization of Novel Interpenetrating Network (IPN) Foams from Epoxy Ester and Aliphatic Epoxy Resin

    OpenAIRE

    Patel, Kanuprasad; Desai, Dhirubhai; Bhuva, Santosh

    2009-01-01

    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 per...

  7. Hydrogenation of Aliphatic Alkenes in a High-Temperature High-Pressure Packed-Bed Microreactor

    OpenAIRE

    Stavárek, Petr

    2012-01-01

    This contribution presents results of the characterization of a new high-temperature high-pressure integrated packed-bed microreactor (MCTU 600 from Ehrfeld Mikrotechnik BTS GmbH) for lab-scale catalyst testing. As the model reaction we used the hydrogenation of C4-C5 aliphatic alkenes heterogeneously catalyzed by Pt/Al2O3 or Pd/Al2O3.

  8. Pattern recognition analysis of a set of mutagenic aliphatic N-nitrosamines.

    OpenAIRE

    Nesnow, S; Langenbach, R; Mass, M J

    1985-01-01

    A set of 21 mutagenic aliphatic N-nitrosamines were subjected to a pattern recognition analysis using ADAPT software. Four descriptors based on molecular connectivity, geometry and sigma charge on nitrogen were capable of achieving a 100% classification using the linear learning machine or iterative least squares algorithms. Three descriptors were capable of a 90.5% and two descriptors of a 85.7% overall correct classification. Three of the four descriptors were each capable of classifying 15...

  9. Gas phase heterogeneous catalytic oxidation of alkanes to aliphatic ketones and/or other oxygenates

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Manhua; Wang, Xiang; Yeom, Younghoon

    2015-09-29

    A catalyst, its method of preparation and its use for producing aliphatic ketones by subjecting alkanes C.sub.3 to C.sub.9 to a gas phase catalytic oxidation in the presence of air or oxygen, and, optionally, steam and/or one or more diluting gases. The catalyst comprises a catalytically active mixed metal oxide phase and a suitable support material onto and/or into which the active catalytic phase is dispersed.

  10. Gas phase heterogeneous catalytic oxidation of alkanes to aliphatic ketones and/or other oxygenates

    Science.gov (United States)

    Lin, Manhua; Wang, Xiang; Yeom, Younghoon

    2015-03-17

    A catalyst, its method of preparation and its use for producing aliphatic ketones by subjecting alkanes C.sub.3 to C.sub.9 to a gas phase catalytic oxidation in the presence of air or oxygen, and, optionally, steam and/or one or more diluting gases. The catalyst comprises a catalytically active mixed metal oxide phase and a suitable support material onto and/or into which the active catalytic phase id dispersed.

  11. Computation of Bond Dissociation Energies for Removal of Nitrogen Dioxide Groups in Certain Aliphatic Nitro Compounds

    Institute of Scientific and Technical Information of China (English)

    SHAO Ju-Xiang; CHENG Xin-Lu; YANG Xiang-Dong; XIANG Shi-Kai

    2006-01-01

    @@ Bond dissociation energies for removal of nitrogen dioxide groups in 10 aliphatic nitro compounds, including nitromethane, nitroethylene, nitroethane, dinitromethane, 1-nitropropane, 2-nitropropane, 1-nitrobutane,2-methyl-2-nitropropane, nitropentane, and nitrohexane, are calculated using the highly accurate complete basis set (CBS-Q) and the three hybrid density functional theory (DFT) methods B3LYP, B3PW91 and B3P86 with 6-31G** basis set.

  12. Assay of Aliphatic Phthalates in Polymer Products by Sensitive Polarographic Method: Health and Environmental Issue

    OpenAIRE

    Munawar Saeed; Sirajuddin; Abdul Niaz2,; Afzal Shah; Abdul Rauf; Jiri Barek

    2010-01-01

    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. Bes...

  13. Production of aliphatic carboxylic acids during the alkali catalysed decomposition of cellulose

    OpenAIRE

    Efhil, Mohamed

    2013-01-01

    The degradation of cellulosic materials under alkaline condition (sodium hydroxide) using High performance ion exclusion chromatography (HPIEC) Dionex ICS‐3000 to analyse the samples at different temperatures (at room, at 50 °C, at 90 °C), under atmosphere of N2 during 188 hours, by using acrylic acid as internal standard, resulted in complex mixture of compounds, including isosaccharinic acid. The retention time of aliphatic organic acids measured under the conditions outlined i...

  14. A QSPR STUDY OF NORMAL BOILING POINT OF ORGANIC COMPOUNDS (ALIPHATIC ALKANES) USING MOLECULAR DESCRIPTORS

    OpenAIRE

    B. Souyei; M. Korichi

    2013-01-01

    A quantitative structure–property relationship (QSPR) study is carried out to develop correlations that relate the molecular structures of organic compounds (Aliphatic Alkanes) to their normal boiling point (NBP) and two correlations were proposed for constitutionals and connectivity indices Models. The correlations are simple in application with good accuracy, which provide an easy, direct and relatively accurate way to calculate NBP. Such calculation gives us a model that gives results in r...

  15. Modification of nano-sized layered double hydroxides by long-chain organic aliphatic surfactants

    OpenAIRE

    RAMASAMY ANBARASAN; SEUNG SOON IM; WANDUC LEE

    2008-01-01

    The inter-layer anion of layered double hydroxides (LDH) with a hydrotalcite (HT)-like structure was ion-exchanged with various organic surfactants, particularly with long chain aliphatic surfactants. After the ion-exchange process, the basal spacing of the LDH was increased and the increase of the basal spacing depended on various factors, such as the intercalation capacity functionality and orientation capability of the surfactant. Of the employed surfactants, stearic acid intercalated LDH ...

  16. Coefficients of caffeine distribution in aliphatic alcohol-ammonium sulfate-water systems

    Science.gov (United States)

    Korenman, Ya. I.; Krivosheeva, O. A.; Mokshina, N. Ya.

    2012-11-01

    The extraction of caffeine with aliphatic alcohols C3-C9 from aqueous solutions in the presence of a salting-out agent (ammonium sulfate) is studied. Quantitative characteristics of extraction are calculated: the distribution coefficients ( D) and the degree of recovery ( R, %). Relations are found between log D of caffeine and the length of the hydrocarbon radical in the alcohol molecule, along with certain physicochemical properties of the extragents.

  17. Abilities of some higher plants to hydrolyze the acetates of phenols and aromatic-aliphatic alcohols

    OpenAIRE

    Agnieszka Mironowicz; Krystyna Kromer; Paweł Pawłowicz; Antoni Siewiński

    2014-01-01

    In the biotransformations carried out under the same conditions, the whole intact plants of Spirodela punctata, Nephrolepis exaltata, Cyrtomium falcatum, Nephrolepis cordifolia and the suspension cultures of Helianthus tuberosus, Daucus carota and Petunia hybrida hydrolyze (partially or totally) the ester bonds of the acetates of phenols and aromatic-aliphatic alcohols and also the menthyl acetate. Nevertheless, the methyl esters of aromatic acids, structurally similar to the former substrate...

  18. Synthesis and reactivity of aliphatic sulfur pentafluorides from substituted (pentafluorosulfanyl)benzenes

    OpenAIRE

    Vida, Norbert; Václavík, Jiří; Beier, Petr

    2016-01-01

    Oxidation of 3- and 4-pentafluorosulfanyl-substituted anisoles and phenols with hydrogen peroxide and sulfuric acid provided a mixture of SF5-substituted muconolactone, maleic, and succinic acids. A plausible mechanism for the formation of the aliphatic SF5 compounds was presented and their chemical reactivity was investigated. SF5-substituted para-benzoquinone was synthesized; its oxidation led to an improved yield of 2-(pentafluorosulfanyl)maleic acid. The reaction of SF5-substituted maleic...

  19. Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

    OpenAIRE

    Q. G. J. Malloy; Li Qi; B. Warren; Cocker III, D. R.; M. E. Erupe; Silva, P J

    2009-01-01

    Primary aliphatic amines are an important class of nitrogen containing compounds emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with O3 and NO3 have been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of ...

  20. Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

    OpenAIRE

    M. E. Erupe; Cocker III, D. R.; B. Warren; Li Qi; Q. G. J. Malloy; Silva, P J

    2008-01-01

    Primary aliphatic amines are an important class of nitrogen containing compounds found to be emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with NO3 has been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by ext...

  1. Secondary Organic Aerosol Formation from Primary Aliphatic Amines with Nitrate Radical

    OpenAIRE

    Q. G. J. Malloy; Qi, L; B. Warren; Cocker III, D. R.; M. E. Erupe; Silva, P J

    2009-01-01

    Primary aliphatic amines are an important class of nitrogen containing compounds emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CECERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with O3 and NO3 have been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by extensio...

  2. Structure-property relationship of aliphatic segmented poly(ester amide)s

    OpenAIRE

    Garg, Priya

    2010-01-01

    This thesis focuses on the synthesis, characterization and applications of aliphatic segmented poly(ester amide)s (PEA)s for use as potential biomaterials. Three different series of PEAs with different microstructures containing isolated, two and three adjacent amide groups within a polybutylene adipate (PBA) chain have been synthesized. Analytical techniques such as NMR (liquid and solid-state), SEC, DSC, FT-IR, WAXD and microscopy (AFM, SEM, optical) have been extensively used to characteri...

  3. Kinetics of aerobic cometabolic biodegradation of chlorinated and brominated aliphatic hydrocarbons: A review.

    Science.gov (United States)

    Jesus, João; Frascari, Dario; Pozdniakova, Tatiana; Danko, Anthony S

    2016-05-15

    This review analyses kinetic studies of aerobic cometabolism (AC) of halogenated aliphatic hydrocarbons (HAHs) from 2001-2015 in order to (i) compare the different kinetic models proposed, (ii) analyse the estimated model parameters with a focus on novel HAHs and the identification of general trends, and (iii) identify further research needs. The results of this analysis show that aerobic cometabolism can degrade a wide range of HAHs, including HAHs that were not previously tested such as chlorinated propanes, highly chlorinated ethanes and brominated methanes and ethanes. The degree of chlorine mineralization was very high for the chlorinated HAHs. Bromine mineralization was not determined for studies with brominated aliphatics. The examined research period led to the identification of novel growth substrates of potentially high interest. Decreasing performance of aerobic cometabolism were found with increasing chlorination, indicating the high potential of aerobic cometabolism in the presence of medium- and low-halogenated HAHs. Further research is needed for the AC of brominated aliphatic hydrocarbons, the potential for biofilm aerobic cometabolism processes, HAH-HAH mutual inhibition and the identification of the enzymes responsible for each aerobic cometabolism process. Lastly, some indications for a possible standardization of future kinetic studies of HAH aerobic cometabolism are provided. PMID:26874310

  4. Assay of aliphatic phthalates in polymer products by sensitive polarographic method: health and environmental issue

    International Nuclear Information System (INIS)

    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 polarograms with lower background current using 1.3 x 10/sup -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/sup -7/ - 1.6 x 10/sup -4/ M DBP solution as aliphatic phthalates with lower detection limit of 5.9 x 10/sup -8/ M and linear regression coefficient of 0.9987. The developed polarographic method was successfully applied for analysis of aliphatic 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. (author)

  5. Exploring mild enzymatic sustainable routes for the synthesis of bio-degradable aromatic-aliphatic oligoesters.

    Science.gov (United States)

    Pellis, Alessandro; Guarneri, Alice; Brandauer, Martin; Acero, Enrique Herrero; Peerlings, Henricus; Gardossi, Lucia; Guebitz, Georg M

    2016-05-01

    The application of Candida antarctica lipase B in enzyme-catalyzed synthesis of aromatic-aliphatic oligoesters is here reported. The aim of the present study is to systematically investigate the most favorable conditions for the enzyme catalyzed synthesis of aromatic-aliphatic oligomers using commercially available monomers. Reaction conditions and enzyme selectivity for polymerization of various commercially available monomers were considered using different inactivated/activated aromatic monomers combined with linear polyols ranging from C2 to C12 . The effect of various reaction solvents in enzymatic polymerization was assessed and toluene allowed to achieve the highest conversions for the reaction of dimethyl isophthalate with 1,4-butanediol and with 1,10-decanediol (88 and 87% monomer conversion respectively). Mw as high as 1512 Da was obtained from the reaction of dimethyl isophthalate with 1,10-decanediol. The obtained oligomers have potential applications as raw materials in personal and home care formulations, for the production of aliphatic-aromatic block co-polymers or can be further functionalized with various moieties for a subsequent photo- or radical polymerization. PMID:26762794

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

    Science.gov (United States)

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-01-01

    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

  7. 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. PMID:9279468

  8. Kinetics of acid-catalyzed aldol condensation reactions of aliphatic aldehydes

    Science.gov (United States)

    Casale, Mia T.; Richman, Aviva R.; Elrod, Matthew J.; Garland, Rebecca M.; Beaver, Melinda R.; Tolbert, Margaret A.

    Field observations of atmospheric aerosols have established that organic compounds compose a large fraction of the atmospheric aerosol mass. However, the physical/chemical pathway by which organic compounds are incorporated into atmospheric aerosols remains unclear. The potential role of acid-catalyzed reactions of organic compounds on acidic aerosols has been explored as a possible chemical pathway for the incorporation of organic material into aerosols. In the present study, ultraviolet-visible (UV-vis) spectroscopy was used to monitor the kinetics of formation of the products of the acid-catalyzed aldol condensation reaction of a range of aliphatic aldehydes (C 2-C 8). The experiments were carried out at various sulfuric acid concentrations and a range of temperatures in order to estimate the rate constants of such reactions on sulfuric acid aerosols under tropospheric conditions. The rate constants were generally found to decrease as the chain length of the aliphatic aldehyde increased (except for acetaldehyde, which had an unusually small rate constant), increase as a function of sulfuric acid concentration as predicted by excess acidity theory, and showed normal Arrhenius behavior as a function of temperature. While the kinetic data are generally consistent with previous laboratory reports of aldehyde reactivity in various sulfuric acid media, the aldol condensation reactions involving aliphatic aldehydes do not appear fast enough to be responsible for significant transfer of organic material into atmospheric aerosols.

  9. Identification of micro-pollutant sources in urban areas. Advantage of aliphatic hydrocarbons

    International Nuclear Information System (INIS)

    In urban areas, important amounts of hydrocarbons are released in the environment and a significant part of these pollutants concentrate in the sewage system leading to environmental problems. Many studies are based only on the study of polycyclic aromatic hydrocarbons (PAH) to identify the origin of environmental contamination. This work aims at demonstrating the advantage of aliphatic hydrocarbons (n-alkanes) in the identification of pollutant sources in urban environments. Their specificity and relative distribution allow the identification and follow up of many hydrocarbon generating sources. The analysis of aliphatic hydrocarbon pathways has permitted to build up an important database for the signature of these pollutants. The coarse fraction of the sewage sludges is mainly contaminated by exhaust particulates and lubricating oils, while the organic fraction and the bio-film concentrate the biological and petroleum product contributions. The estimation of the level of degradation of aliphatic hydrocarbons indicates a shorter residence time in the organic and bio-film layer with respect to the coarse deposit. (J.S.)

  10. Mechanisms and modeling of halogenated aliphatic contaminant adsorption by carbon nanotubes.

    Science.gov (United States)

    Apul, Onur Guven; Zhou, Yang; Karanfil, Tanju

    2015-09-15

    This paper examines the adsorption of environmentally relevant halogenated aliphatic compounds using single-walled (SWCNT) and multi-walled carbon nanotubes (MWCNT), and the development of linear solvation-energy relationships (LSER) to examine those adsorption mechanisms. The poly-parameter LSER model was also compared to those previously generated for the adsorption of aromatic compounds by CNTs. The adsorption affinity of aliphatic compounds was greater on the SWCNT than MWCNT with similar oxygen contents. This was attributed to the pore-filling mechanism that was enhanced by higher micropore volume of the SWCNT bundles over the MWCNT bundles. LSER models showed that, at higher concentrations, B (the hydrogen bond accepting ability) was the most influential descriptor for both SWCNT and MWCNT. Other important descriptors were V followed by P, both of which exhibited a positive correlation with adsorption, indicating that their size and polarizability favors adsorption. The contribution of these descriptors to overall adsorption was 2-3 times less than the B. In comparison, V was the most important descriptor in the aromatic compound LSER models. This difference indicates that adsorbate hydrophobicity greatly affects the adsorption of aromatic compounds by CNTs, whereas, aliphatic compounds are affected by both the hydrophobic driving force and other interactions. PMID:25897695

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

    International Nuclear Information System (INIS)

    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)

  12. A study of aliphatic amino acids using simulated vibrational circular dichroism and Raman optical activity spectra*

    Science.gov (United States)

    Ganesan, Aravindhan; Brunger, Michael J.; Wang, Feng

    2013-11-01

    Vibrational optical activity (VOA) spectra, such as vibrational circular dichroism (VCD) and Raman optical activity (ROA) spectra, of aliphatic amino acids are simulated using density functional theory (DFT) methods in both gas phase (neutral form) and solution (zwitterionic form), together with their respective infrared (IR) and Raman spectra of the amino acids. The DFT models, which are validated by excellent agreements with the available experimental Raman and ROA spectra of alanine in solution, are employed to study other aliphatic amino acids. The inferred (IR) intensive region (below 2000 cm-1) reveals the signature of alkyl side chains, whereas the Raman intensive region (above 3000 cm-1) contains the information of the functional groups in the amino acids. Furthermore, the chiral carbons of the amino acids (except for glycine) dominate the VCD and ROA spectra in the gas phase, but the methyl group vibrations produce stronger VCD and ROA signals in solution. The C-H related asymmetric vibrations dominate the VOA spectra (i.e., VCD and ROA) > 3000 cm-1 reflecting the side chain structures of the amino acids. Finally the carboxyl and the C(2)H modes of aliphatic amino acids, together with the side chain vibrations, are very active in the VCD/IR and ROA/Raman spectra, which makes such the vibrational spectroscopic methods a very attractive means to study biomolecules.

  13. CYP79F1 and CYP79F2 have distinct functions in the biosynthesis of aliphatic glucosinolates in Arabidopsis.

    Science.gov (United States)

    Chen, Sixue; Glawischnig, Erich; Jørgensen, Kirsten; Naur, Peter; Jørgensen, Bodil; Olsen, Carl-Erik; Hansen, Carsten H; Rasmussen, Hasse; Pickett, John A; Halkier, Barbara A

    2003-03-01

    Cytochromes P450 of the CYP79 family catalyze the conversion of amino acids to oximes in the biosynthesis of glucosinolates, a group of natural plant products known to be involved in plant defense and as a source of flavor compounds, cancer-preventing agents and bioherbicides. We report a detailed biochemical analysis of the substrate specificity and kinetics of CYP79F1 and CYP79F2, two cytochromes P450 involved in the biosynthesis of aliphatic glucosinolates in Arabidopsis thaliana. Using recombinant CYP79F1 and CYP79F2 expressed in Escherichia coli and Saccharomyces cerevisiae, respectively, we show that CYP79F1 metabolizes mono- to hexahomomethionine, resulting in both short- and long-chain aliphatic glucosinolates. In contrast, CYP79F2 exclusively metabolizes long-chain elongated penta- and hexahomomethionines. CYP79F1 and CYP79F2 are spatially and developmentally regulated, with different gene expression patterns. CYP79F2 is highly expressed in hypocotyl and roots, whereas CYP79F1 is strongly expressed in cotyledons, rosette leaves, stems, and siliques. A transposon-tagged CYP79F1 knockout mutant completely lacks short-chain aliphatic glucosinolates, but has an increased level of long-chain aliphatic glucosinolates, especially in leaves and seeds. The level of long-chain aliphatic glucosinolates in a transposon-tagged CYP79F2 knockout mutant is substantially reduced, whereas the level of short-chain aliphatic glucosinolates is not affected. Biochemical characterization of CYP79F1 and CYP79F2, and gene expression analysis, combined with glucosinolate profiling of knockout mutants demonstrate the functional role of these enzymes. This provides valuable insights into the metabolic network leading to the biosynthesis of aliphatic glucosinolates, and into metabolic engineering of altered aliphatic glucosinolate profiles to improve nutritional value and pest resistance. PMID:12609033

  14. Total synthesis of cis-hydroazulene sesquiterpenes. Base-induced and -directed elimination and rearrangement reactions of perhydronaphthalene-1,4-diol monosulfonate esters.

    NARCIS (Netherlands)

    Jenniskens, L.H.D.

    1992-01-01

    The total synthesis of a number of cis-fused hydroazulene sesquiterpenes is described in this thesis. In this synthetic study, ample attention is paid to the mechanistic aspects of the base- induced and -directed rearrangement and elimination reactions of perhydronaphthalene-1,4-diol monosulfonate e

  15. (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.

  16. Crystallization and preliminary X-ray analysis of molecular chaperone-like diol dehydratase-reactivating factor in ADP-bound and nucleotide-free forms

    International Nuclear Information System (INIS)

    The molecular chaperone-like reactivating factor for adenosylcobalamin (coenzyme B12) dependent diol dehydratase was crystallized in ADP-bound and nucleotide-free forms. Preliminary X-ray analysis indicated that crystals are orthorhombic and diffract to 2.0 Å. Adenosylcobalamin (coenzyme B12) dependent diol dehydratase (EC 4.2.1.28) catalyzes the conversion of 1,2-diols and glycerol to the corresponding aldehydes. It undergoes mechanism-based inactivation by glycerol. The diol dehydratase-reactivating factor (DDR) reactivates the inactivated holoenzymes in the presence of adenosylcobalamin, ATP and Mg2+ by mediating the release of a damaged cofactor. This molecular chaperone-like factor was overexpressed in Escherichia coli, purified and crystallized in the ADP-bound and nucleotide-free forms by the sandwich-drop vapour-diffusion method. The crystals of the ADP-bound form belong to the orthorhombic system, with space group P212121 and unit-cell parameters a = 83.26, b = 84.60, c = 280.09 Å, and diffract to 2.0 Å. In the absence of nucleotide, DDR crystals were orthorhombic, with space group P212121 and unit-cell parameters a = 81.92, b = 85.37, c = 296.99 Å and diffract to 3.0 Å. Crystals of both forms were suitable for structural analysis

  17. Fluorine-containing terpene analogs. IV. 9,9,9,10,10,10-Hexafluoro-p-menthane-1,8-diol (hexafluoroterpine)

    Energy Technology Data Exchange (ETDEWEB)

    Zalesskaya, I.M.; Fialkov, Yu.A.; Parakhnenko, A.I.; Yagupol' skii, I.M.

    1988-03-10

    The oxidation of trans-e,e-4-(2-hydroxyperfluoroisopropyl)cyclohexanol with pyridinium chlorochromate gave the corresponding cyclohexanone. The reaction of this product with methylmagnesium iodide gave cis- and trans-9,9,9,10,10,10-hexafluoro-p-menthane-1,8-diol, which is fluorinated analog of natural terpine.

  18. SEPARATION OF 32P-LABELED 3',5'-BISPHOSPHATE NUCLEOTIDES OF POLYCYCLIC AROMATIC HYDROCARBON ANTI-DIOL-EPOXIDES AND DERIVATIVES

    Science.gov (United States)

    23P-Postlabeling/HPLC is a highly sensitive analytical method for identification of chemical-modified DNA adducts isolated from experimental animals and human samples. o determine the optimal 32P-postlabeling/HPLC conditions for efficient separation, we employed ten diol-epoxide-...

  19. BENZO[A]PYRENE AND BENZO[C]PHENANTHRENE: THE EFFECT OF STRUCTURE ON THE BINDING OF WATER MOLECULES TO THE DIOL EPOXIDES

    Science.gov (United States)

    ABSTRACTThe interaction with water of the diol epoxides (DEs) of both a planar and a non-planar PAH have been examined using molecular dynamics. To determine probable water locations around the DE for later use in the study of DE protonation, molecular dynamics simulations u...

  20. Effects of 3-beta-diol, an androgen metabolite with intrinsic estrogen-like effects, in modulating the aquaporin-9 expression in the rat efferent ductules

    Directory of Open Access Journals (Sweden)

    Hess Rex A

    2006-10-01

    Full Text Available Abstract Background Fluid homeostasis is critical for normal function of the male reproductive tract and aquaporins (AQP play an important role in maintenance of this water and ion balance. Several AQPs have been identified in the male, but their regulation is not fully comprehended. Hormonal regulation of AQPs appears to be dependent on the steroid in the reproductive tract region. AQP9 displays unique hormonal regulation in the efferent ductules and epididymis, as it is regulated by both estrogen and dihydrotestosterone (DHT in the efferent ductules, but only by DHT in the initial segment epididymis. Recent data have shown that a metabolite of DHT, 5-alpha-androstane-3-beta-17-beta-diol (3-beta-diol, once considered inactive, is also present in high concentrations in the male and indeed has biological activity. 3-beta-diol does not bind to the androgen receptor, but rather to estrogen receptors ER-alpha and ER-beta, with higher affinity for ER-beta. The existence of this estrogenic DHT metabolite has raised the possibility that estradiol may not be the only estrogen to play a major role in the male reproductive system. Considering that both ER-alpha and ER-beta are highly expressed in efferent ductules, we hypothesized that the DHT regulation of AQP9 could be due to the 3-beta-diol metabolite. Methods To test this hypothesis, adult male rats were submitted to surgical castration followed by estradiol, DHT or 3-beta-diol replacement. Changes in AQP9 expression in the efferent ductules were investigated by using immunohistochemistry and Western blotting assay. Results Data show that, after castration, AQP9 expression was significantly reduced in the efferent ductules. 3-beta-diol injections restored AQP9 expression, similar to DHT and estradiol. The results were confirmed by Western blotting assay. Conclusion This is the first evidence that 3-beta-diol has biological activity in the male reproductive tract and that this androgen metabolite has

  1. Monolayer behaviour of chiral compounds at the air-water interface: 4-hexadecyloxy-butane-1,2-diol

    DEFF Research Database (Denmark)

    Rietz, R.; Rettig, W.; Brezesinski, G.;

    1996-01-01

    Monolayers of the pure S-enantiomer (x(S) = 1) and of two mixtures x(S) = 0.75 and x(S) = 0.5 (racemate) of 4-hexadecyloxy-butane-1,2-diol (C16H33-O-CH2-CH2-CHOH-CH2OH) (HOBD) have been studied at the air-water interface by thermodynamic measurements, fluorescence microscopy and X-ray diffraction....... The isotherms depend only slightly on chirality. Above the transition pressure pi(c) condensed domains with a polygonal shape are formed. In all cases the domains start to destabilize from the notch. The branches of the S-enantiomer turn only clockwise, whereas domains of the mixtures show branches...

  2. 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.

  3. 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.

  4. Antitenascin antibody 81C6 armed with 177Lu: in vivo comparison of macrocyclic and acyclic ligands

    International Nuclear Information System (INIS)

    Introduction: When labeled with iodine-131, the antitenascin monoclonal antibody (mAb) 81C6 has shown promise as a targeted radiotherapeutic in patients with brain tumors. Because of its more favorable γ-ray properties, lutetium-177 might be a better low-energy β-emitter for this type of therapy. Materials and Methods: Chimeric 81C6 (ch81C6) was labeled with 177Lu using the acyclic 1B4M ligand and the macrocyclic ligands NHS-DOTA and MeO-DOTA and evaluated for binding to tenascin. Three paired-label tissue distribution experiments were performed in normal mice receiving one of the 177Lu-labeled immunoconjugates plus 125I-labeled ch81C6 labeled using Iodogen. Paired-label experiments in athymic mice bearing subcutaneous D54 MG human glioma xenografts were done to directly compare the biodistribution of ch81C6-1B4M-177Lu and 125I-labeled ch81C6, and ch81C6-MeO-DOTA-177Lu and 125I-labeled ch81C6. Similar comparisons were done using murine (mu) instead of ch81C6. The primary parameter utilized for evaluation was the 177Lu/125I uptake ratio in each tissue. Results: In the studies performed in normal mice, the NHS-DOTA ligand yielded the highest 177Lu/125I uptake ratios in tissues indicative of loss of label from the chelate; for this reason, only 1B4M and MeO-DOTA were evaluated further. The 177Lu/125I ratio in bone increased gradually with time for the chimeric conjugates; however, there were no significant differences between ch81C6-1B4M-DTPA-177Lu and ch81C6-MeO-DOTA-177Lu. In contrast, mu81C6-1B4M-DTPA-177Lu and mu81C6-MeO-DOTA-177Lu showed a more dramatic increase in the 177Lu/125I ratio in bone - from 2.4±0.3 and 1.7±0.2 at Day 1 to 8.5±1.1 and 4.2±0.5 at Day 7, respectively. Conclusion: With these antitenascin constructs, the nature of the mAb had a profound influence on the relative degree of loss of 177Lu from these immunoconjugates. MeO-DOTA shows promise as a bifunctional chelate for labeling 81C6 mAbs with 177Lu

  5. Flexible Acyclic Polyol-Chloride Anion Complexes and Their Characterization by Photoelectron Spectroscopy and Variable Temperature Binding Constant Determinations.

    Science.gov (United States)

    Shokri, Alireza; Wang, Xue-Bin; Wang, Yanping; O'Doherty, George A; Kass, Steven R

    2016-03-17

    Flexible acyclic alcohols with one to five hydroxyl groups were bound to a chloride anion and these complexes were interrogated by negative ion photoelectron spectroscopy and companion density functional theory computations. The resulting vertical detachment energies are reproduced on average to 0.10 eV by M06-2X/aug-cc-pVTZ predictions and range from 4.45-5.96 eV. These values are 0.84-2.35 eV larger than the adiabatic detachment energy of Cl(-) as a result of the larger hydrogen bond networks in the bigger polyols. Adiabatic detachment energies of the alcohol-Cl(-) clusters are more difficult to determine both experimentally and computationally. This is due to the large geometry changes that occur upon photodetachment and the large bond dissociation energy of H-Cl which enables the resulting chlorine atom to abstract a hydrogen from any of the methylene (CH2) or methine (CH) positions. Both ionic and nonionic hydrogen bonds (i.e., OH···Cl(-) and OH···OH···Cl(-)) form in the larger polyols complexes and are found to be energetically comparable. Subtle structural differences, consequently can lead to the formation of different types of hydrogen bonds, and maximizing the ionic ones is not always preferred. Solution equilibrium binding constants between the alcohols and tetrabutylammonium chloride (TBACl) in acetonitrile at -24.2, +22.0, and +53.6 °C were also determined. The free energies of association are nearly identical for all of the substrates (i.e., ΔG° = -2.8 ± 0.7 kcal mol(-1)). Compensating enthalpy and entropy values reveal, contrary to expectation and the intrinsic gas-phase preferences, that the bigger systems with more hydroxyl groups are entropically favored and enthalpically disfavored relative to the smaller species. This suggests that more solvent molecules are released upon binding TBACl to alcohols with more hydroxyl groups and is consistent with the measured negative heat capacities. These quantities increase with molecular

  6. Flexible Acyclic Polyol-Chloride Anion Complexes and Their Characterization by Photoelectron Spectroscopy and Variable Temperature Binding Constant Determinations

    Energy Technology Data Exchange (ETDEWEB)

    Shokri, Alireza; Wang, Xue B.; Wang, Yangping; O' Doherty, George A.; Kass, Steven R.

    2016-03-17

    Flexible acyclic alcohols with 1–5 hydroxyl groups were bound to chloride anion and these complexes were interrogated by negative ion photoelectron spectroscopy and companion density functional theory computations. The resulting vertical detachment energies are reproduced on average to 0.10 eV by M06-2X/aug-cc-pVTZ predictions and range from 4.45 – 5.96 eV. These values are 0.84 – 2.35 eV larger than the adiabatic detachment energy of Cl– as a result of the larger hydrogen bond networks in the bigger polyols. Adiabatic detachment energies of the alcohol–Cl– clusters are more difficult to determine both experimentally and computationally. This is due to the large geometry changes that occur upon photodetachment and the large bond dissociation energy of H–Cl which enables the resulting chlorine atom to abstract a hydrogen from any of the methylene (CH2) or methine (CH) positions. Both ionic and non-ionic hydrogen bonds (i.e., OH•••Cl– and OH•••OH•••Cl–) form in the larger polyols complexes, and are found to be energetically comparable. Subtle structural differences, consequently can lead to the formation of different types of hydrogen bonds and maximizing the ionic ones is not always preferred. Solution equilibrium binding constants between the alcohols and tetrrabuylammonium chloride (TBACl) in acetonitrile at -24.2, 22.0, and 53.6 °C were also determined. The free energies of association are nearly identical for all of the substrates (i.e., ΔG° = -2.8 ± 0.7 kcal mol–1). Compensating enthalpy and entropy values reveal, contrary to expectation and the intrinsic gas-phase preferences, that the bigger systems with more hydroxyl groups are entropically favored and enthalpically disfavored relative to the smaller species. This suggests that more solvent molecules are released upon binding TBACl to alcohols with more hydroxyl groups and is consistent with the measured negative heat capacities. These quantities increase with

  7. 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.

  8. Analysis of TPH and Aliphatic and Aromatic Hydrocarbons Fractions in Environmental Interest Matrices

    International Nuclear Information System (INIS)

    Analytical methods to analyze TPH and several aliphatic and aromatic fractions present in soil and groundwater samples contaminated by hydrocarbons are showed. As a part of BIOXISOIL project, analyzing these parameters is fundamental and indispensable to know the initial contamination level, design an adequate method to decontaminate it and eventually assess decontamination accomplished. Analysis of both matrices involve different extraction stages such as microwave radiation, clean up steps based on solid phase extraction and finally a chromatograph analysis with flame ion detector. Analytical procedures have showed satisfactory analytical quality parameters and have been validated against several certified reference materials. (Author)

  9. Preparation and characterization of aliphatic diphenyl esters intended as precursors for polyesters

    DEFF Research Database (Denmark)

    Hvilsted, S.; Andruzzi, F.; Cerrai, P.; Tricoli, M.

    1991-01-01

    An extensive number of aliphatic diphenyl esters, C6H5OOC(CH2)nCOOC6H5 (n = O,...,8,10,11,12,14), have been prepared in pure form. The crystalline melting points these esters exhibit an odd-even temperature behaviour, with the higher-melting even series (n even) displaying a minimum for n = 8 whi...... chloroform points to specific phenyl ester-solvent interactions, which obscure a potential s.e.c. conformational analysis of the diphenyl esters....

  10. Distribution of aliphatic and aromatic hydrocarbon in dated sediment cores of the Gulf of Thailand

    International Nuclear Information System (INIS)

    In this study sediment core samples from 8 stations in the Gulf of Thailand were collected during September 1992 - August 1994. Sediment cores have been dated by 210Pb dating method. Aliphatic and aromatic hydrocarbon have been analyzed by GC and GC/Ms technique. Total n-alkane in surface sediment were 0.237 - 2.210, 0.672, 0.458, and 0.118 - 0.171 μg/g dry weight with the average of 0.940, 0.672, 0.458, and 0.144 μg/g dry weight for area 1,2,4 and 3 respectively

  11. A QSPR STUDY OF NORMAL BOILING POINT OF ORGANIC COMPOUNDS (ALIPHATIC ALKANES USING MOLECULAR DESCRIPTORS

    Directory of Open Access Journals (Sweden)

    B. Souyei

    2013-12-01

    Full Text Available A quantitative structure–property relationship (QSPR study is carried out to develop correlations that relate the molecular structures of organic compounds (Aliphatic Alkanes to their normal boiling point (NBP and two correlations were proposed for constitutionals and connectivity indices Models. The correlations are simple in application with good accuracy, which provide an easy, direct and relatively accurate way to calculate NBP. Such calculation gives us a model that gives results in remarkable correlations with the descriptors of blokes constitutionals (CON, and connectivity indices (CI (R2 = 0.950, δ = 0.766 (R2 = 0.969, δ = 0.782 respectively.

  12. Abilities of some higher plants to hydrolyze the acetates of phenols and aromatic-aliphatic alcohols

    Directory of Open Access Journals (Sweden)

    Agnieszka Mironowicz

    2014-02-01

    Full Text Available In the biotransformations carried out under the same conditions, the whole intact plants of Spirodela punctata, Nephrolepis exaltata, Cyrtomium falcatum, Nephrolepis cordifolia and the suspension cultures of Helianthus tuberosus, Daucus carota and Petunia hybrida hydrolyze (partially or totally the ester bonds of the acetates of phenols and aromatic-aliphatic alcohols and also the menthyl acetate. Nevertheless, the methyl esters of aromatic acids, structurally similar to the former substrates, do not undergo hydrolysis. At the same time, the viability of first four plants was observed for different levels of acetate concentration. The method of continuous preparative hydrolysis of the same acetates was worked out in Cyrtomium falcatum culture.

  13. QSAR analysis and data extrapolation among mammals in a series of aliphatic alcohols.

    OpenAIRE

    Tichý, M.; Trcka, V; Roth, Z; Krivucová, M

    1985-01-01

    Concepts of QSAR analysis and biological similarity models are combined for use in extrapolation of LD50 values after IP application of a series of aliphatic alcohols (C1-C5) to mouse, hamster, rat, and guinea pig and rabbit. It has been found that although close correlation exists between LD50 values after IP and IV applications for mouse and rat, the QSARs obtained with LD50 after IV application are not suitable for a prediction of LD50 values after IP application for rabbit. Different tran...

  14. 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.)

  15. Photocycloaddition of aromatic and aliphatic aldehydes to isoxazoles: Cycloaddition reactivity and stability studies

    Directory of Open Access Journals (Sweden)

    Hidehiro Kotaka

    2011-01-01

    Full Text Available The first photocycloadditions of aromatic and aliphatic aldehydes to methylated isoxazoles are reported. The reactions lead solely to the exo-adducts with high regio- and diastereoselectivities. Ring methylation of the isoxazole substrates is crucial for high conversions and product stability. The 6-arylated bicyclic oxetanes 9a–9c were characterized by X-ray structure analyses and showed the highest thermal stabilities. All oxetanes formed from isoxazoles were highly acid-sensitive and also thermally unstable. Cleavage to the original substrates is dominant and the isoxazole derived oxetanes show type T photochromism.

  16. Design, Synthesis and Cytotoxic Activities of Novel Aliphatic Amino-Substituted Flavonoids

    OpenAIRE

    Guannan Liu; Zhen Ge; Mengdan Zhao; Yifeng Zhou

    2013-01-01

    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 ag...

  17. Using the Griess colorimetric nitrite assay for measuring aliphatic β-nitroalcohols

    OpenAIRE

    Wen, Quan; Paik, David C

    2012-01-01

    Our recent studies suggest that aliphatic β-nitroalcohols (BNAs) may represent a useful class of compounds for topical therapeutic corneoscleral cross-linking agents. Thus, this study was undertaken in order to standardize a simple method for nitroalcohol quantitation based on a denitration step followed by colorimetric Griess nitrite assay. Conditions necessary for denitration included a pH of 7-9 and heating for 1 hour at 100°C. Standard curves for two mono-nitroalcohols (2-nitroethanol and...

  18. Kinetics and mechanism of the selective oxidation of primary aliphatic alcohols under phase transfer catalysis

    Directory of Open Access Journals (Sweden)

    K. Bijudas

    2014-03-01

    Full Text Available Kinetics of the oxidation of primary aliphatic alcohols has been carried out using phase transferred monochromate in benzene. Tetrabutylammonium bromide (TBAB and tetrabutylphosphonium bromide (TBPB are used as phase transfer catalysts (PT catalyst. The reaction shows first order dependence on both [alcohol] and [monochromate ion]. The oxidation leads to the formation of corresponding aldehyde and no traces of carboxylic acid has been detected. The reaction mixture failed to induce the polymerization of added acrylonitrile which rules out the presence radical intermediates in the reaction. Various thermodynamic parameters have been evaluated and a suitable mechanism has been proposed.

  19. Amination of ω-Functionalized Aliphatic Primary Alcohols by a Biocatalytic Oxidation–Transamination Cascade

    OpenAIRE

    Pickl, Mathias; Fuchs, Michael; Glueck, Silvia. M.; Faber, Kurt

    2015-01-01

    Amination of non-activated aliphatic fatty alcohols to the corresponding primary amines was achieved through a five-enzyme cascade reaction by coupling a long-chain alcohol oxidase from Aspergillus fumigatus (LCAO_Af) with a ω-transaminase from Chromobacterium violaceum (ω-TA_Cv). The alcohol was oxidized at the expense of molecular oxygen to yield the corresponding aldehyde, which was subsequently aminated by the PLP-dependent ω-TA to yield the final primary amine product. The overall cascad...

  20. Alteration and release of aliphatic compounds by the polychaete Nereis virens (Sars) experimentally fed with hydrocarbons

    OpenAIRE

    Gilbert, Franck; Stora, Georges; Desrosiers, Gaston; Deflandre, Bruno; Bertrand, Jean-Claude; Poggiale, Jean-Christophe; Gagne, Jean-Pierre

    2001-01-01

    In the laboratory, marine worms were fed with a mixture of algae and several aliphatic hydrocarbons for 15 days. After ingestion by the worms, 34.9% of hydrocarbons are found in the faeces and only 3.1% accumulated in the gut. The comparison between the initial mixture and the faeces shows that the worm’s digestive process lead to changes in the distribution of the n-alkane mixture. These changes are different from those only due to physical processes in the experimental conditions. In our ...

  1. The C--H Stretching Features at 3.2--3.5 Micrometer of Polycyclic Aromatic Hydrocarbons with Aliphatic Sidegroups

    CERN Document Server

    Yang, Xuejuan; Glaser, Rainer; Zhong, Jianxin

    2016-01-01

    The so-called unidentified infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, and 11.3 micrometer are ubiquitously seen in a wide variety of astrophysical regions. The UIE features are characteristic of the stretching and bending vibrations of aromatic hydrocarbon materials, e.g., polycyclic aromatic hydrocarbon (PAH) molecules. The 3.3 micrometer aromatic C--H stretching feature is often accompanied by a weaker feature at 3.4 micrometer. The latter 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 micrometer aromatic C--H feature to that of the 3.4 micrometer aliphatic C--H feature allows one to estimate the aliphatic fraction of the UIE carriers, provided that the intrinsic oscillator strengths of the 3.3 micrometer aromatic C--H stretch (A3.3) and the 3.4 micrometer aliphatic C--H stretch (A3.4) are known. While previous studies on the aliphatic fraction of the UIE carriers were mostly based on the A3.4...

  2. Aliphatic and polycyclic aromatic hydrocarbons in sediments of the Slovenian coastal area (Gulf of Trieste, northern Adriatic).

    Science.gov (United States)

    Bajt, Oliver

    2012-12-01

    The distribution and sources of aliphatic and polycyclic aromatic hydrocarbons (PAH) were determined in sediments at seven sites around the Slovenian coastal area. The potential toxicological significance was also assessed using biological thresholds. The results of the analyses showed higher concentrations of hydrocarbons in the Port of Koper and in the Marina of Portoroz. The influence of pollution was also evident in rather higher concentrations of hydrocarbons in the surrounding area in the Bays of Koper and Piran. Concentrations of hydrocarbons decrease toward the central part of the Gulf of Trieste. The major component of the aliphatic fraction was the unresolved complex mixture. Concentrations of the total resolved aliphatic hydrocarbons were in a range from 689 to 3,164 ng g(-1). Concentrations of the total PAHs were between 330 and 1,173 ng g(-1). Polycyclic aromatic hydrocarbons are primarily of pyrolytic origin with some smaller contributions of the petrogenic, while the aliphatic are mostly of petrogenic origin with significant amounts of biogenic derived compounds of terrestrial and marine origin. Strong evidence of the diagenetic origin of perylene in the investigated area was also found. Quite a good linear relationship between PAH concentration and TOC and between aliphatic hydrocarbon concentrations and TOC was observed. The principal component analysis showed differences between the nearshore and offshore sites. In general, the investigated area is moderately contaminated by hydrocarbons. Concentrations of PAHs, hydrocarbons of high concern, are below the levels (effects range low and the effects range median) associated with adverse biological effects. PMID:22270593

  3. Counting acyclic hypergraphs

    Institute of Scientific and Technical Information of China (English)

    WANG; Jianfang

    2001-01-01

    [1]Harker, P. T., Pang, J. S., Finite-dimensional variational inequality and nonlinear complementarity problems: A survey of theory, algorithm, and applications, Mathematical Programming, 1990, 48(2): 161.[2]Eaves, B. C., The linear complementarity problem, Management Science, 1971, 17(3): 612.[3]Eaves, B. C., On the basic theorem of complementarity problem, Math. Programming, 1971, 1(1): 68.[4]Karamardian, S., Generalized complementarity problem, J. Optim. Theory Appl., 1971, 8(1): 161.[5]Kojima, M., A unification of the existence theorems of the nonlinear complementarity problem, Math. Programming, 1975, 9(2): 257.[6]Moré, J. J., Classes of functions and feasibility conditions in nonlinear complementarity problems, Math. Programming, 1974, 6(2): 327.[7]Moré, J. J., Coercivity conditions in nonlinear complementarity problems, SIAM Rev., 1974, 16(1): 1.[8]Smith, T. E., A solution condition for complementarity problems, with an application to spatial price equilibrium, Appl. Math. Computation, 1984, 15(1): 61.[9]Isac, G., Bulavaski, V., Kalashnikov, V., Exceptional families, topological degree and complementarity problems, J. Global Optim., 1997, 10(2): 207.[10]Zhao, Y. B., Han, J. Y., Qi, H. D., Exceptional families and existence theorems for variational inequality problems, J. Optim. Theory Appl., 1999, 101(2): 475.[11]Zhao, Y. B., Han, J. Y., Exceptional family of elements for a variational inequality problem and its applications, Journal of Global Optimization, 1999, 14(2): 313.[12]Zhao, Y. B., Exceptional families and finite dimensional variational inequalities over polyhedral convex sets, Appl. Math. Computation, 1997, 87(1): 111.[13]Lloyd, N. Q., Degree Theory, Cambridge: Cambridge University Press, 1978, 6—54.[14]Ortega, J. M., Rheinholdt, W. C., Iterative Solution of Nonlinear Equations in Several Variables, New York: Academic Press, 1970, 30—45.[15]Isac, G., Obuchowska, W. T., Functions without exceptional family of elements and complementarity problems, J. Optim. Theory Appl., 1998, 99(1): 147.[16]Hartman, P., Stampacchia, G., On some nonlinear elliptic differentiable functional equation, Acta Math., 1966, 115(2): 271.

  4. 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

  5. Acyclic nucleoside phosphonates as a new class of anti-malarial compounds: Inhibition of Plasmodium falciparum hypoxanthine-guanine-xanthine phosphoribosyltransferase by 9-[2-(2-phosphonoethoxy)ethyl]-purines and their branched derivatives

    Czech Academy of Sciences Publication Activity Database

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

    Praha : -, 2009. -. ISBN 978-80-02-02160-5. [ESOC 2009. European Symposium on Organic Chemistry /16./. 12.07.2009-16.07.2009, Praha] Institutional research plan: CEZ:AV0Z40550506 Keywords : acyclic nucleoside phosphonates * anti-malarial compounds Subject RIV: CC - Organic Chemistry

  6. Phase behavior and crystal structure of 3-(1-naphthyloxy)- and 3-(4-indolyloxy)-propane-1,2-diol, synthetic precursors of chiral drugs propranolol and pindolol

    Science.gov (United States)

    Bredikhin, Alexander A.; Gubaidullin, Aidar T.; Bredikhina, Zemfira A.; Fayzullin, Robert R.; Samigullina, Aida I.; Zakharychev, Dmitry V.

    2013-08-01

    Valuable precursors of popular chiral drugs propranolol and pindolol, 3-(1-naphthyloxy)-propane-1,2-diol 3 and 3-(4-indolyloxy)-propane-1,2-diol 4 were investigated by IR spectroscopy, DSC, and X-ray diffraction methods. Both compounds, crystallizing from enantiopure feed material, form "guaifenesin-like" crystal packing in which the classic H-bonded bilayers, framed in both sides by hydrophobic fragments of the molecules, acts as the basic crystal-forming motif. Diol 4 prone to spontaneous resolution and conserves its packing pattern crystallizing from racemate. Under the same conditions, diol 3 forms weakly stable solid racemic compound. Some reasons for such a behavior are identified and discussed.

  7. Effect of electron beam irradiation on the biodegradability of aromatic aliphatic copolyester film and their blend with corn starch

    International Nuclear Information System (INIS)

    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 (EcobrasR) irradiated presented a bigger biodegradability than the aromatic aliphatic copolyester (EcoflexR) film in both methods studied. (author)

  8. Halides with Fifteen Aliphatic C–H···Anion Interaction Sites

    Science.gov (United States)

    Shi, Genggongwo; Aliakbar Tehrani, Zahra; Kim, Dongwook; Cho, Woo Jong; Youn, Il-Seung; Lee, Han Myoung; Yousuf, Muhammad; Ahmed, Nisar; Shirinfar, Bahareh; Teator, Aaron J.; Lastovickova, Dominika N.; Rasheed, Lubna; Lah, Myoung Soo; Bielawski, Christopher W.; Kim, Kwang S.

    2016-07-01

    Since the aliphatic C–H···anion interaction is relatively weak, anion binding using hydrophobic aliphatic C–H (Cali–H) groups has generally been considered not possible without the presence of additional binding sites that contain stronger interactions to the anion. Herein, we report X-ray structures of organic crystals that feature a chloride anion bound exclusively by hydrophobic Cali–H groups. An X-ray structure of imidazolium-based scaffolds using Cali–H···A‑ interactions (A‑ = anion) shows that a halide anion is directly interacting with fifteen Cali–H groups (involving eleven hydrogen bonds, two bidentate hydrogen-bond-type binding interactions and two weakly hydrogen-bonding-like binding interactions). Additional supporting interactions and/or other binding sites are not observed. We note that such types of complexes may not be rare since such high numbers of binding sites for an anion are also found in analogous tetraalkylammonium complexes. The Cali–H···A‑ interactions are driven by the formation of a near-spherical dipole layer shell structure around the anion. The alternating layers of electrostatic charge around the anion arise because the repulsions between weakly positively charged H atoms are reduced by the presence of the weakly negatively charged C atoms connected to H atoms.

  9. Halides with Fifteen Aliphatic C-H···Anion Interaction Sites.

    Science.gov (United States)

    Shi, Genggongwo; Aliakbar Tehrani, Zahra; Kim, Dongwook; Cho, Woo Jong; Youn, Il-Seung; Lee, Han Myoung; Yousuf, Muhammad; Ahmed, Nisar; Shirinfar, Bahareh; Teator, Aaron J; Lastovickova, Dominika N; Rasheed, Lubna; Lah, Myoung Soo; Bielawski, Christopher W; Kim, Kwang S

    2016-01-01

    Since the aliphatic C-H···anion interaction is relatively weak, anion binding using hydrophobic aliphatic C-H (Cali-H) groups has generally been considered not possible without the presence of additional binding sites that contain stronger interactions to the anion. Herein, we report X-ray structures of organic crystals that feature a chloride anion bound exclusively by hydrophobic Cali-H groups. An X-ray structure of imidazolium-based scaffolds using Cali-H···A(-) interactions (A(-) = anion) shows that a halide anion is directly interacting with fifteen Cali-H groups (involving eleven hydrogen bonds, two bidentate hydrogen-bond-type binding interactions and two weakly hydrogen-bonding-like binding interactions). Additional supporting interactions and/or other binding sites are not observed. We note that such types of complexes may not be rare since such high numbers of binding sites for an anion are also found in analogous tetraalkylammonium complexes. The Cali-H···A(-) interactions are driven by the formation of a near-spherical dipole layer shell structure around the anion. The alternating layers of electrostatic charge around the anion arise because the repulsions between weakly positively charged H atoms are reduced by the presence of the weakly negatively charged C atoms connected to H atoms. PMID:27444513

  10. Quantitative separation of aliphatic and aromatic hydrocarbons using silver ion--silica solid-phase extraction

    Science.gov (United States)

    Bennett; Larter

    2000-03-01

    A solid-phase extraction (SPE) method employing silver nitrate impregnated silica has been developed and evaluated for the separation of defined aliphatic and aromatic hydrocarbons from crude oils. The versatility of the SPE method is demonstrated using a light crude oil from the North Sea and a heavy crude oil from Orcutt field (Monterey, California, U.S.A.). The coefficients of variation for a number of geochemical parameters measured on both aliphatic and aromatic hydrocarbons were excellent. The separation efficiency of SPE is demonstrated using quantification of monoaromatic steroid hydrocarbons which are notoriously difficult to efficiently sequester into the aromatic hydrocarbon fraction using traditional liquid chromatographic procedure. The selectivity and efficiency of the SPE technique is comparable with that of silica gel TLC. However, losses of volatile compounds such as naphthalene are limited during SPE since the sample remains in solvent. We conclude that solid-phase extraction affords rapid sample turnover suitable for processing large sample numbers with high reproducibility. PMID:10739209

  11. 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.

  12. Using of mass spectrum for prognosis of melting temperature of monatomic aliphatic spirits

    International Nuclear Information System (INIS)

    In present article researching possibility of prediction of melting temperature (MT) of monatomic aliphatic spirits with using mass-spectra as descriptors structure of molecules. Mass-spectra of 84 aliphatic spirits were used. Mass-spectra were preliminarily transformed on special formula before calculations for receiving work dates of descriptors. Calculations fulfilled with help of the computer program PROGROC. Quality of prediction characterized by coefficient of R-correlation between predicted and experimental dates MT and standard s-deviation. Coefficient of R-correlation between experimental and calculated dates account for 0.9785, standard s-deviation = 11.25 deg. C. Singly R and S for training and control excerpt equally 0.9789 and 11.31 deg. C, 0,9789 and 8.87 deg. C accordingly. Advantage of workable by us method lie in that, what on comparable with literature data of accuracy for prediction property is enough to have only mass-spectrum of substance

  13. Effect of Functional Group and Carbon Chain Length on the Odor Detection Threshold of Aliphatic Compounds

    Directory of Open Access Journals (Sweden)

    Manuel Zarzo

    2012-03-01

    Full Text Available Odor detection thresholds (ODTs are used for assessing outdoor and indoor air quality. They are obtained experimentally by olfactometry and psychophysical methods, and large compilations are available in the literature. A non-linear regression equation was fitted to describe the ODT variability of 114 aliphatic compounds based on the alkyl chain length for different homologous series (carboxylic acids, aldehydes, 2-ketones, esters, 1-alcohols, amines, thiols, thioethers and hydrocarbons. The resulting equation reveals an effect of the functional group, molecular size and also an interaction between both factors. Although the mechanistic interpretation of results is uncertain, the relatively high goodness-of-fit (R2 = 0.90 suggests that ODT values of aliphatic compounds can be predicted rather accurately, which is not the case for rigid molecules. This equation may serve as a basis for the development of more complex ODT models taking into account diverse structural features of odorants. The variability of power-law exponents was also investigated for the homologous series.

  14. The distribution and source apportionment of aliphatic hydrocarbons in soils from the outskirts of Beijing

    Energy Technology Data Exchange (ETDEWEB)

    Youfeng Zhu; Hui Liu; Zhiqun Xi; Xiufeng Liu; Xiaobai Xu [Chinese Academy of Sciences, Research Center for Eco-Environmental Sciences, Beijing (China); Hangxing Cheng [Institute of Geochemical and Geophysical Exploration, Beijing (China)

    2005-03-15

    We report the first extensive study of the spatial distribution and source apportionment of aliphatic hydrocarbons in soils from the Beijing outskirts. Mixed soil samples (5-30 cm depth) were collected for the quantitative determination of n-alkanes, isoprenoids, unresolved complex mixtures and the qualitative determination of hopanes and steranes. The total concentrations, including n-alkanes from C{sub 13} to C{sub 36}, pristane and phytane, were in the range of 0.60-39.92 {mu}g/g, with a median value of 1.97 {mu}g/g. No correlation between soil organic matter content or the percentage of clay and the concentrations was found. Carbon preference index (CPI) values for the whole range of n-alkanes varied between 0.73 and 4.27, with a median value of 1.64, and a contour map of CPI was drawn. A predominance of odd/even carbon n-alkanes and unresolved complex mixtures with different shapes and range were frequently observed. Factor analysis reduced the data set to two principal components explaining 82.82% of the total variation among samples and confirming contributions from low molecular weight species (63.66%) and long-chain n-alkanes (19.27%), respectively. Based on the principal component analysis, the concentration profiles and molecular markers, it was concluded that the aliphatic hydrocarbons were from both biogenic and anthropogenic sources. (Author)

  15. Aliphatic esters as targets of esterase activity in the parsnip webworm (Depressaria pastinacella).

    Science.gov (United States)

    Zangerl, Arthur R; Liao, Ling-Hsiu; Jogesh, Tania; Berenbaum, May R

    2012-02-01

    As a specialist on the reproductive structures of Pastinaca sativa and species in the related genus Heracleum, the parsnip webworm (Depressaria pastinacella) routinely encounters a distinctive suite of phytochemicals in hostplant tissues. Little is known, however, about the detoxification mechanisms upon which this species relies to metabolize these compounds. In this study, larval guts containing hostplant tissues were homogenized, and metabolism was determined by incubating reactions with and without NADPH and analyzing for substrate disappearance and product appearance by gas chromatography-mass spectrometry. Using this approach, we found indications of carboxylesterase activity, in the form of appropriate alcohol metabolites for three aliphatic esters in hostplant tissues-octyl acetate, octyl butyrate, and hexyl butyrate. Involvement of webworm esterases in hostplant detoxification subsequently was confirmed with metabolism assays with pure compounds. This study is the first to implicate esterases in lepidopteran larval midgut metabolism of aliphatic esters, ubiquitous constituents of flowers and fruits. In addition, this method confirmed that webworms detoxify furanocoumarins and myristicin in their hostplants via cytochrome P450-mediated metabolism, and demonstrated that these enzymes also metabolize the coumarin osthol and the fatty acid derivative palmitolactone. PMID:22350520

  16. Extraction and solubility characteristics of metal aliphatic carboxylates in a hexane medium

    International Nuclear Information System (INIS)

    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 (pH1/2) 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)

  17. New aliphatic glycerophosphoryl-containing polyurethanes: synthesis, platelet adhesion and elution cytotoxicity studies.

    Science.gov (United States)

    Acetti, Daniela; D'Arrigo, Paola; Giordano, Carmen; Macchi, Piero; Servi, Stefano; Tessaro, Davide

    2009-04-01

    in this study new poly(ether)urethanes (PeUs) based on aliphatic diisocyanates were synthesized with phospholipid-like residues as chain extenders. The primary objective was to prepare new polyurethanes from diisocyanates that are less toxic than the aromatic ones widely used in medical-grade polyurethanes, in order to investigate the effect of the different aromatic or aliphatic hard segment content on the final properties of the materials. Some glycerophospho residues were simultaneously introduced to enhance the hemocompatibility of these materials. Polymers were prepared by a conventional two-step solution polymerization procedure using hexamethylene diisocyanate (HDi) and dodecametilendiisocyanate (DDi) and poly(1,4-butanediol) with molecular weight 1000 to form prepolymers, which were subsequently polymerized with 1-glycerophosphorylcholine (1-GPC) or glycerophosphorylserine (GPS) to act as chain extenders. The reference polymers bearing 1,4-butandiol (BD) were also synthesized. The polymers obtained were characterized by fourier transform infrared spectroscopy (fT-iR), nuclear magnetic resonance (1H nmR), and differential scanning calorimetry (DSC). The hemocompatibility of synthesized segmented polyurethanes was preliminarily investigated by platelet-rich plasma contact studies and related scanning electron microscopy (Sem) photographs as well as by cell viability assay after cell exposure to material elutions to assess the effect of any toxic leachables coming out from the samples. Two of the polymers gave interesting results, suggesting the desirability of further investigation into their possible use in biomedical devices. PMID:19569028

  18. Structure-property relationship in aliphatic polyamide/polyaniline surface layered composites

    Energy Technology Data Exchange (ETDEWEB)

    Fatyeyeva, K., E-mail: kateryna.fatyeyeva@univ-rouen.fr [Institute of Bioorganic Chemistry and Petrochemistry of National Academy of Science of Ukraine, 50 Kharkivske shose, Kyiv 02160 (Ukraine); Laboratoire de Physique de l' Etat Condense, UMR CNRS 6087, Universite du Maine, Av. Olivier Messiaen, 72085 Le Mans cedex 9 (France); Laboratoire Polymeres, Biopolymeres et Surfaces, UMR 6270 and FR 3038 CNRS, Universite de Rouen, Bd. Maurice de Broglie, 76821 Mont Saint Aignan cedex (France); Pud, A.A. [Institute of Bioorganic Chemistry and Petrochemistry of National Academy of Science of Ukraine, 50 Kharkivske shose, Kyiv 02160 (Ukraine); Bardeau, J.-F.; Tabellout, M. [Laboratoire de Physique de l' Etat Condense, UMR CNRS 6087, Universite du Maine, Av. Olivier Messiaen, 72085 Le Mans cedex 9 (France)

    2011-10-17

    Highlights: {yields} Synthesis of surface conducting polymers based on aliphatic polyamides and polyaniline. {yields} The study revealed the layered structure of the surface conductive composites. {yields} Different dielectric relaxation processes were found as a function of doping agent and polyaniline oxidation state. {yields} Conductivity value (10{sup -4}-10{sup -11} S cm{sup -1}) enables the use of such composites as antistatic/electrostatic discharge materials. - Abstract: Conducting polymer composite films based on different aliphatic polyamides (PA) (PA-6, PA-11 and PA-12) have been synthesized by in situ aniline polymerization inside a surface layer of the PA host matrix. Dielectric permittivity and dielectric loss of these films are explained in terms of the interfacial polarization. The real part of permittivity is found to be higher in the PA/polyaniline (PANI) composite films than in the virgin PA polymer matrix. Such behaviour is attributed to the interaction between PA and PANI molecular chains and to the conductivity increase after the aniline polymerization. The performed confocal Raman spectrometry and X-ray diffraction studies also confirmed the presence of interactions between PA and PANI molecular chains.

  19. Anaerobic biotransformation of chlorinated aliphatic hydrocarbons: Ugly duckling to beautiful swan

    Energy Technology Data Exchange (ETDEWEB)

    Parkin, G.F.

    1999-10-01

    For many years anaerobic biological processes were reputed to be more sensitive than aerobic processes to toxic substances such as chlorinated aliphatic hydrocarbons (CAH) and thus a poor choice for treating water containing these compounds. This was especially true for water containing perchloroethylene (PCE) or trichloroethylene (TCE) because vinyl chloride, a human carcinogen, is produced when these two compounds are degraded anaerobically. Aerobic treatment with organisms containing oxygenase enzyme systems, which could fortuitously degrade a wide variety of chlorinated aliphatics (but not PCE), was favored. Recently, however, several enrichments and organisms have been isolated that will convert PCE and TCE into ethene and ethane, as shown by field data. Because of this evidence, anaerobic processes are now considered a significant alternative treatment for CAH contamination. Recent work at the University of Iowa, Iowa City, has focused on the effect of mixtures of CAHs on biotransformation of individual organic compounds and the potential for a combined methanogen-iron (Fe(0)) system to improve CAH bioremediation. At the concentration ranges tested, the presence of a mixture of CAHs seems to decrease rate of transformation of individual organics. However, there are important exceptions; in some cases a mixture of CAHs seems to facilitate transformation of an individual organic compound. Combination of an active methanogenic population with Fe(0) increases the rate and extent of transformation of carbon tetrachloride and chloroform. Results with PCE and 1,1,1-trichloroethane are less clear.

  20. Determination of aliphatic aldehydes by liquid chromatography with pulsed amperometric detection.

    Science.gov (United States)

    Casella, Innocenzo G; Contursi, Michela

    2005-01-21

    An electrochemical detection method for short-chain saturated and unsaturated aliphatic aldehydes separated by liquid chromatography in moderately acidic medium is described. A triple-step waveform of the potentials applied to the polycrystalline platinum electrode, is proposed for sensitive detection of aliphatic aldehydes in flowing streams avoiding tedious pre- or post-column derivatization and/or cleanup procedures. The influences of the perchloric acid concentration and dissolved oxygen in the mobile phase, on the amperometric and chromatographic performance were evaluated and considered in terms of sensitivity and selectivity. Under the optimised experimental conditions (i.e., deoxygenated 50mM HClO4) the proposed analytical method allowed detection limits between 0.2 microM for acrolein and 2.5 microM for valeraldehyde. Regression analysis of calibration data indicates that responses for all investigated compounds are linear over about 2 orders of magnitude above the LOD, with correlation coefficients >0.990. The method was successfully applied to the determination of formaldehyde, acetaldehyde, propionaldehyde and acrolein in real matrices such as spiked water and red wines with good mean recoveries (81-97%). PMID:15700464

  1. 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.

  2. Branched aliphatic alkanes of shell bar section in Qarhan Lake, Qaidam Basin and their paleoclimate significance

    Institute of Scientific and Technical Information of China (English)

    ZHANG HuCai; CHANG FengQin; LI Bin; LEI GuoLiang; CHEN Yue; ZHANG WenXiang; NIU Jie; FAN HongFang; YANG MingSheng

    2007-01-01

    Biomarkers of paleolake deposits from Qarhan Salt Lake in Qaidam Basin, northwest China were systematically analyzed and the A-C series compounds of branched aliphatic alkanes with quaternary substituted carbon atom (BAQCs) were identified. The homologous distinguished three series, A-C,were identified as 5,5-diethylalkanes, 6,6-diethylalkanes and 5-butyl, 5-ethylalkanes series, and their relative abundance was A > B > C. Series A and C were characterized by odd carbon numbers, whereas series B was characterized by even carbon numbers. The high values of series A corresponded with the high values of series B and C. Therefore, it can be concluded that series A, B and C possess a similar biological origin. The abundance of series A was relatively Iow in the lower part of the section compared with that in the upper part, implying that these series originated from bacteria and/or algae more prevalent in fresh-mesohaline water, and such kinds of bacteria and/or algae are most likely to be thermophilous species. The A25/nC25 ratio differences in the section show that such branched aliphatic alkanes can be treated as one kind of environmental change proxy for paleolake evolution and may provide important information for the climate reconstruction of the Late Pleistocene.

  3. Prediction of liquid−liquid equilibria of (aromatic + aliphatic + ionic liquid) systems using the Cosmo-SAC model

    International Nuclear Information System (INIS)

    Highlights: ► Aromatic/aliphatic hydrocarbons separation by ionic liquids. ► Cosmo-SAC thermodynamic model for prediction of LLE by quantum chemical calculations. ► Predictions successful for some ionic liquids. ► Correlation by single parameter for other ionic liquids. ► Preliminary screening of additional ionic liquids for aromatic/aliphatic separation. - Abstract: The extraction of aromatic hydrocarbons from aliphatic hydrocarbons is an important problem. This process can be used to enhance the capacity of ethylene crackers by prior removal of aromatics that cannot be cracked. Ionic liquids have been investigated extensively for liquid–liquid extraction of aromatics from aliphatics. The choice of a suitable ionic liquid may be made by measuring liquid−liquid equilibria. However, the large number of ionic liquids, formed by the various cation and anion combinations, makes the experimental measurements expensive and time consuming. Hence, a predictive thermodynamic model called Cosmo-SAC that uses quantum chemical calculations for calculating liquid−liquid equilibria has been evaluated. A priori predictions are accurate for some ionic liquids and inaccurate for some ionic liquids. However, it has been shown that even when a priori predictions are inaccurate, the data can be correlated using a single parameter that is characteristic of the ionic liquid and accurate predictions can be made for additional aromatic/aliphatic combinations for the same ionic liquid. A comparison with the NRTL and UNIQUAC models has also been carried out. In addition, a preliminary screening of ionic liquids for aromatic/aliphatic separations has been carried out using the Cosmo-SAC model. Finally, the “Cosmo” files for eight cations and sixteen anions corresponding to 128 potential ionic liquids have been provided for the use of the general scientific community to predict any thermodynamic equilibria involving ionic liquids without the use of any molecular modeling

  4. Supramolecular Arrangement in Styphnic Acid and Naphthalene-1,4-diol (1 : 1 through a Novel Synthetic Rote for Styphnic Acid

    Directory of Open Access Journals (Sweden)

    Moamen S. Refat

    2013-01-01

    Full Text Available The chemical preparation and crystal structure of styphnic acid and naphthalene-1,4-diol (1 : 1 (I have been reported. The compound crystallizes in the orthorhombic system in space group Pnma and cell parameters a=6.6712(2, b=16.8267(7, c=13.6450(5 Å and V=1531.71(10 Å3, and Z=4. Crystal structure has been determined and refined to R=0.0576. The crystal structure of I, the asymmetric unit, contains C6H2N3O7, C10H7O, and it is a half portion of both styphnic acid and naphthalene-1,4-diol. The O1–H1⋯O2 intramolecular hydrogen bond was found between the O–H and a nitro group in the styphnic acid unit.

  5. Characterization of the SgcF epoxide hydrolase supporting an (R)-vicinal diol intermediate for enediyne antitumor antibiotic C-1027 biosynthesis.

    Science.gov (United States)

    Lin, Shuangjun; Horsman, Geoffrey P; Chen, Yihua; Li, Wenli; Shen, Ben

    2009-11-18

    C-1027 is a chromoprotein antitumor antibiotic consisting of an apoprotein and the C-1027 chromophore. The C-1027 chromophore possesses four distinct structural moieties-an enediyne core, a deoxy aminosugar, a benzoxazolinate, and an (S)-3-chloro-5-hydroxy-beta-tyrosine-the latter two of which are proposed to be appended to the enediyne core via a convergent biosynthetic strategy. Here we report the in vitro characterization of SgcF, an epoxide hydrolase from the C-1027 biosynthetic gene cluster that catalyzes regio- and stereospecific hydrolysis of styrene oxide, serving as an enediyne core epoxide intermediate mimic, to form a vicinal diol. Abolishment of C-1027 production in the DeltasgcF mutant strain Streptomyces globisporus SB1010 unambiguously establishes that sgcF plays an indispensable role in C-1027 biosynthesis. SgcF efficiently hydrolyzes (S)-styrene oxide, displaying an apparent K(m) of 0.6 +/- 0.1 mM and k(cat) of 48 +/- 1 min(-1), via attack at the alpha-position to exclusively generate the (R)-phenyl vicinal diol, consistent with the stereochemistry of the C-1027 chromophore. These findings support the role of SgcF in the proposed convergent pathway for C-1027 biosynthesis, unveiling an (R)-vicinal diol as a key intermediate. Interestingly, SgcF can also hydrolyze (R)-styrene oxide to afford preferentially the (R)-phenyl vicinal diol via attack at the beta-position, albeit with significantly reduced efficiency (apparent K(m) of 2.0 +/- 0.4 mM and k(cat) = 4.3 +/- 0.3 min(-1)). Although the latter activity unlikely contributes to C-1027 biosynthesis in vivo, such enantioconvergence arising from complementary regioselective hydrolysis of a racemic substrate could be exploited to engineer epoxide hydrolases with improved regio- and/or enantiospecificity. PMID:19856960

  6. Carbonate phosphonium salts as catalysts for the transesterification of dialkyl carbonates with diols. The competition between cyclic carbonates and linear dicarbonate products.

    Science.gov (United States)

    Selva, Maurizio; Caretto, Alessio; Noè, Marco; Perosa, Alvise

    2014-06-28

    At 90-120 °C, in the presence of methylcarbonate and bicarbonate methyltrioctylphosphonium salts as catalysts ([P8881][A]; [A] = MeOCO2 and HOCO2), the transesterification of non-toxic dimethyl- and diethyl-carbonate (DMC and DEC, respectively) with 1,X-diols (2 ≤ X ≤ 6) proceeds towards the formation of cyclic and linear products. In particular, 1,2-propanediol and ethylene glycol afford propylene- and ethylene-carbonate with selectivity and yields up to 95 and 90%, respectively; while, the reaction of DMC with higher diols such 1,3-butanediol, 2-methyl-1,3-propanediol, 1,3-propanediol, 2,2-dimethyl, 1,3-propanediol, 1,4-butanediol and 1,6-hexanediol produce linear C8-C10 dicarbonates of general formula MeOC(O)O∼∼∼OC(O)OMe as the almost exclusive products. Of note, these dicarbonate derivatives are not otherwise accessible in good yields by other conventional base catalyzed methods. Among 1,3-diols, the only exception was 2-methyl 2,4-pentandiol that yields the corresponding cyclic carbonate, i.e. 4,4,6-trimethyl-1,3-dioxan-2-one. In no one case, polycarbonates are observed. Such remarkable differences of product distributions are ascribed to the structure (branching and relative position of OH groups) of diols and to the role of cooperative (nucleophilic and electrophilic) catalysis which has been proved for onium salts. The investigated carbonate salts are not only effective in amounts as low as 0.5 mol%, but they are highly stable and recyclable. PMID:24825024

  7. 2-aminopyrimidine-4,6-diol as an efficient ligand for solvent-free copper-catalyzed N-arylations of imidazoles with aryl and heteroaryl halides.

    Science.gov (United States)

    Xie, Ye-Xiang; Pi, Shao-Feng; Wang, Jian; Yin, Du-Lin; Li, Jin-Heng

    2006-10-13

    Efficient and solvent-free copper-catalyzed N-arylations of imidazoles with aryl and heteroaryl halides have been demonstrated. In the presence of CuBr, 2-aminopyrimidine-4,6-diol, and TBAF (n-Bu4NF), a variety of imidazoles underwent the N-arylation reaction with aryl and heteroaryl halides smoothly in moderate to excellent yields. Noteworthy is that the reaction is conducted under solvent-free conditions. PMID:17025338

  8. Synthesis and Crystal Structure Determination of a Nickel(II Complex of an Acyclic Pentadentate (N5 Mono Schiff Base Ligand

    Directory of Open Access Journals (Sweden)

    R. V. Parish

    2001-10-01

    Full Text Available The asymmetrical tripodal tetraamine ligand N[(CH23NH2]2[(CH22NH2] (ppe was condensed with 2-acetylpyridine in the presence of nickel(II ion. In ethanolwater solution the reaction stops after the first stage of condensation, and a new nickel(II complex of an acyclic pentadentate (N5 mono Schiff base ligand was obtained. X-ray structure analysis of the resulting complex, [Ni(ppe-py(H2O](ClO42, indicates that condensation with 2-acetylpyridine is at the propylene chain of ppe. The geometry around the nickel ion is distorted octahedral in which the sixth co-ordination group is a solvent molecule.

  9. 2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

    International Nuclear Information System (INIS)

    Highlights: ► Corrosion of API 5L X65 is effectively reduced by the addition of the inhibitor. ► The techniques include weight loss, potentiodynamic polarization, EIS and AFM. ► 2-Butyne-1,4-diol acts as a mixed-type inhibitor. ► 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 Na2CO3/1 M NaHCO3 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−1.

  10. Preliminary neutron and ultrahigh-resolution X-ray diffraction studies of the aspartic proteinase endothiapepsin cocrystallized with a gem-diol inhibitor

    International Nuclear Information System (INIS)

    Three data sets have been collected on endothiapepsin complexed with the gem-diol inhibitor PD-135,040: a high-resolution synchrotron X-ray data set, a room-temperature X-ray data set and a neutron diffraction data set. Until recently, it has been impossible to grow large protein crystals of endothiapepsin with any gem-diol inhibitor that are suitable for neutron diffraction. Endothiapepsin has been cocrystallized with the gem-diol inhibitor PD-135,040 in a low solvent-content (39%) unit cell, which is unprecedented for this enzyme–inhibitor complex and enables ultrahigh-resolution (1.0 Å) X-ray diffraction data to be collected. This atomic resolution X-ray data set will be used to deduce the protonation states of the catalytic aspartate residues. A room-temperature neutron data set has also been collected for joint refinement with a room-temperature X-ray data set in order to locate the H/D atoms at the active site

  11. An integrated QSAR-PBK/D modelling approach for predicting detoxification and DNA adduct formation of 18 acyclic food-borne α,β-unsaturated aldehydes

    International Nuclear Information System (INIS)

    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

  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. Preparation and characterization of bifunctional oxidative and acidic catalysts Nb2O5/TS-1 for synthesis of diols

    International Nuclear Information System (INIS)

    Bifunctional oxidative and acidic catalyst was prepared by incorporation of titanium ion (Ti4+) and niobic acid in zeolite molecular-sieve. The catalysts being active both in oxidation reactions due to the presence of tetrahedral Ti4+, and acid-catalyzed reactions due to the presence of niobic acid. Nb/TS-1 was prepared by hydrothermal synthesis of TS-1, calcination in air and subsequent impregnation of niobium into TS-1. The sample was characterized by XRD, FTIR, UV-vis DR, TPR and pyridine adsorption techniques. The XRD analysis of Nb/TS-1 revealed that the MFI structure of the TS-1 support was found to be intact upon incorporation of niobium. The infrared spectra showed that the tetrahedral titanium in the TS-1 is still remained after impregnation with niobium while based on the UV-vis DR result, the niobium species are in the octahedral structure. On the basis TPR and infrared of hydroxyl groups results, it is concluded that niobium species interacted with the silanols on the surface of TS-1. Pyridine adsorption study shows both Bronsted and Lewis acid sites are present in Nb/TS-1. The catalytic results in the transformation of 1-octene to 1,2-octanediol through the formation of 1,2-epoxyoctane by using Nb/TS-1 indicate that the production of epoxide and diol was correlated with the presence of oxidative and Bronsted acidic sites in the catalyst

  14. Synthesis of bio-based thermoplastic polyurethane elastomers containing isosorbide and polycarbonate diol and their biocompatible properties.

    Science.gov (United States)

    Oh, So-Yeon; Kang, Min-Sil; Knowles, Jonathan C; Gong, Myoung-Seon

    2015-09-01

    A new family of highly elastic polyurethanes (PUs) partially based on renewable isosorbide were prepared by reacting hexamethylene diisocyanate with a various ratios of isosorbide and polycarbonate diol 2000 (PCD) via a one-step bulk condensation polymerization without catalyst. The influence of the isorsorbide/PCD ratio on the properties of the PU was evaluated. The successful synthesis of the PUs was confirmed by Fourier transform-infrared spectroscopy and (1)H nuclear magnetic resonance. The resulting PUs showed high number-average molecular weights ranging from 56,320 to 126,000 g mol(-1) and tunable Tg values from -34 to -38℃. The thermal properties were determined by differential scanning calorimetry and thermogravimetric analysis. The PU films were flexible with breaking strains from 955% to 1795% at from 13.5 to 54.2 MPa tensile stress. All the PUs had 0.9-2.8% weight lost over 4 weeks and continual slow weight loss of 1.1-3.6% was observed within 8 weeks. Although the cells showed a slight lower rate of proliferation than that of the tissue culture polystyrene as a control, the PU films were considered to be cytocompatible and nontoxic. These thermoplastic PUs were soft, flexible and biocompatible polymers, which open up a range of opportunities for soft tissue augmentation and regeneration. PMID:26055962

  15. Efficiency of 1,9- Nonane-diol-diacrylate as a radiation vulcanization accelerator for natural rubber latex

    International Nuclear Information System (INIS)

    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)

  16. Aliphatic and polycyclic aromatic hydrocarbons characterisation of Coimbra and Oporto PM2.5 urban aerosol

    Science.gov (United States)

    Rocha, A. C.; Mirante, F.; Gonçalves, C.; Nunes, T.; Alves, C.; Evtyugina, M.; Kowacz, M.; Pio, C.; Rocha, C.; Vasconcelos, T.

    2009-04-01

    The concentration of organic pollutants in urban areas is mostly due to incomplete combustion from vehicles, industries and domestic heating. Some of these compounds, principally the aliphatic (ALIPH) and polycyclic aromatic hydrocarbons (PAHs) promote harmful effects in human health. The determination of the ALIPH and PAHs concentration levels and their possible emission sources are useful for air quality management and source apportionment studies. In order to estimate and compare the ambient concentrations and establish the main sources of these compounds, the fine fraction of the atmospheric particulate matter (PM2.5) was collected simultaneously in Oporto and Coimbra during summer and winter seasons using a high volume sampler. The organic compounds were extracted from the particulate matter, under reflux with dichloromethane and the total organic extract (TOE) was fractionated by flash chromatography using five different eluents with increasing polarity. The hydrocarbon fractions were analysed by gas chromatography/mass spectrometry (GC/MS). Here we present and discuss the qualitative and quantitative composition of the aliphatic and aromatic fractions present in PM2.5 samples from both cities. The homologous series of C14 to C34 n-alkanes, isoprenoid hydrocarbons (pristane and phytane), PAHs and some petroleum markers have been identified and quantified. With the purpose of identifying the possible sources, various molecular diagnostic ratios were calculated. The global carbon preference index (CPI) closer to the unity, the large concentration of the unresolved complex mixture (UCM) and the presence of PAHs indicate that motor vehicle exhaust was the main emission source of the aliphatic and polycyclic aromatic fractions of Oporto and Coimbra aerosol, especially in the first city. Also, the remarkable presence of petroleum biomarkers such, as hopanes, confirms the previous results. Concentration ratios between PAHs were calculated and used to assign emission

  17. Vertical fluxes of aromatic and aliphatic hydrocarbons in the Northwestern Mediterranean Sea

    International Nuclear Information System (INIS)

    Aliphatic and aromatic hydrocarbon fluxes were measured in time series sediment trap samples at 200 m and at 1000 m depths in the open Northwestern Mediterranean Sea, from December 2000 to July 2002. Averaged fluxes of n-alkanes, UCM and T-PAH35 were 2.96 ± 2.60 μg m-2 d-1, 64 ± 60 μg m-2 d-1 and 0.68 ± 0.59 μg m-2 d-1, respectively. Molecular compositions of both hydrocarbon classes showed a contamination in petrogenic hydrocarbons well above the background levels of such an open site, whereas pyrolytic hydrocarbons stand in the range of other open Mediterranean locations. Fluxes displayed ample interannual and seasonal variabilities, mainly related to mass flux variation while concentration evolutions trigger secondary changes in pollutant fluxes. High lithogenic flux events exported particles with a larger pollutant load than biogenic particles formed during the spring bloom and during the summer. Sinking hydrocarbons were efficiently transported from 200 m to 1000 m. - Highlights: → PAH composition, plots of diagnostic PAH ratios and the UCM abundance indicate that non aromatic and aromatic hydrocarbons in sinking particles in the Ligurian Sea were mainly of petrogenic origin. → Fluxes of T-PAH35, n-alkanes and UCM transported downward at 200 m during the year 2001 were 269, 1218 and 26 910 mg m-2 yr-1, respectively. → Vertical fluxes of aliphatic and aromatic hydrocarbons displayed ample seasonal and inter-annual variabilities, mainly related to mass flux variation. Concentration variation triggered smaller changes in pollutant fluxes. → High fluxes of lithogenic particles occurring from early January to early March 2001 transported about 45% of the annual vertical export of contaminants. In April-May, high fluxes of biogenic particles also transported a significant fraction of pollutants, despite the dilution of petrogenic and pyrolytic PAHs by biogenic material. - Vertical fluxes of aliphatic and aromatic hydrocarbons in the Ligurian Sea show

  18. Vertical fluxes of aromatic and aliphatic hydrocarbons in the Northwestern Mediterranean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Deyme, Remi; Bouloubassi, Ioanna; Taphanel-Valt, Marie-Helene [Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques (LOCEAN/IPSL), Universite Pierre et Marie Curie-CNRS-IRD-MNHN, UMR 7159, 4 Place Jussieu, 75252 Paris Cedex 05 (France); Miquel, Juan-Carlos [Environment Laboratories, International Atomic Energy Agency, 4 Quai Antoine 1er, MC98000 Monaco, Principality of Monaco (Monaco); Lorre, Anne [Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques (LOCEAN/IPSL), Universite Pierre et Marie Curie-CNRS-IRD-MNHN, UMR 7159, 4 Place Jussieu, 75252 Paris Cedex 05 (France); Marty, Jean-Claude [CNRS- Universite Pierre et Marie Curie, UMR 7093, LOV, Observatoire oceanographique, 06234 Villefranche/mer (France); Mejanelle, Laurence, E-mail: laurence.mejanelle@upmc.fr [Laboratoire d' ECObiogeochimie Benthique, FRE3350, CNRS-Universite Pierre et Marie Curie, Avenue du Fontaule, 66650 Banyuls Sur Mer (France)

    2011-12-15

    Aliphatic and aromatic hydrocarbon fluxes were measured in time series sediment trap samples at 200 m and at 1000 m depths in the open Northwestern Mediterranean Sea, from December 2000 to July 2002. Averaged fluxes of n-alkanes, UCM and T-PAH{sub 35} were 2.96 {+-} 2.60 {mu}g m{sup -2} d{sup -1}, 64 {+-} 60 {mu}g m{sup -2} d{sup -1} and 0.68 {+-} 0.59 {mu}g m{sup -2} d{sup -1}, respectively. Molecular compositions of both hydrocarbon classes showed a contamination in petrogenic hydrocarbons well above the background levels of such an open site, whereas pyrolytic hydrocarbons stand in the range of other open Mediterranean locations. Fluxes displayed ample interannual and seasonal variabilities, mainly related to mass flux variation while concentration evolutions trigger secondary changes in pollutant fluxes. High lithogenic flux events exported particles with a larger pollutant load than biogenic particles formed during the spring bloom and during the summer. Sinking hydrocarbons were efficiently transported from 200 m to 1000 m. - Highlights: > PAH composition, plots of diagnostic PAH ratios and the UCM abundance indicate that non aromatic and aromatic hydrocarbons in sinking particles in the Ligurian Sea were mainly of petrogenic origin. > Fluxes of T-PAH35, n-alkanes and UCM transported downward at 200 m during the year 2001 were 269, 1218 and 26 910 mg m{sup -2} yr{sup -1}, respectively. > Vertical fluxes of aliphatic and aromatic hydrocarbons displayed ample seasonal and inter-annual variabilities, mainly related to mass flux variation. Concentration variation triggered smaller changes in pollutant fluxes. > High fluxes of lithogenic particles occurring from early January to early March 2001 transported about 45% of the annual vertical export of contaminants. In April-May, high fluxes of biogenic particles also transported a significant fraction of pollutants, despite the dilution of petrogenic and pyrolytic PAHs by biogenic material. - Vertical fluxes of

  19. Characterization of aliphatic and polycyclic aromatic hydrocarbons in environmental tobacco smokes

    International Nuclear Information System (INIS)

    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 C13 to C36 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 carcinogenic and

  20. 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

  1. Radiolytic crosslinking and chain scission in aliphatic and alkyl-aromatic polyamides—II

    Science.gov (United States)

    Lyons, Bernard J.; Glover, Leon C.

    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. A minor determinant [15% of the variation for G(X) and 30% for G(CS)] is the number of hydrogen atoms or methylene groups in the acid residue of the repeat unit. Significantly, although there was little sign of a decrease in G(CS) in the higher aliphatic homologues (up to 11 methylene residues per amide group), G(CS) is found to be positively related to the number of methylene groups in the amine residue but negatively related to the number of methylene groups in the acid residue. Thus although the amine residue dominates the radiolytic response, the acid residue plays a critical if lesser role in determining chain scission yields in polyamides. Thus a polyamide with the repeat unit —(CH 2) 3 nCONH(CH 2) nNHCO— would be predicted to have a very low or zero G(CS) and, if n is 10 or more, a G(X) comparable to that of polyethylene. 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

  2. A systems biology approach identifies a R2R3 MYB gene subfamily with distinct and overlapping functions in regulation of aliphatic glucosinolates.

    Directory of Open Access Journals (Sweden)

    Ida Elken Sønderby

    Full Text Available BACKGROUND: Glucosinolates are natural metabolites in the order Brassicales that defend plants against both herbivores and pathogens and can attract specialized insects. Knowledge about the genes controlling glucosinolate regulation is limited. Here, we identify three R2R3 MYB transcription factors regulating aliphatic glucosinolate biosynthesis in Arabidopsis by combining several systems biology tools. METHODOLOGY/PRINCIPAL FINDINGS: MYB28 was identified as a candidate regulator of aliphatic glucosinolates based on its co-localization within a genomic region controlling variation both in aliphatic glucosinolate content (metabolite QTL and in transcript level for genes involved in the biosynthesis of aliphatic glucosinolates (expression QTL, as well as its co-expression with genes in aliphatic glucosinolate biosynthesis. A phylogenetic analysis with the R2R3 motif of MYB28 showed that it and two homologues, MYB29 and MYB76, were members of an Arabidopsis-specific clade that included three characterized regulators of indole glucosinolates. Over-expression of the individual MYB genes showed that they all had the capacity to increase the production of aliphatic glucosinolates in leaves and seeds and induce gene expression of aliphatic biosynthetic genes within leaves. Analysis of leaves and seeds of single knockout mutants showed that mutants of MYB29 and MYB76 have reductions in only short-chained aliphatic glucosinolates whereas a mutant in MYB28 has reductions in both short- and long-chained aliphatic glucosinolates. Furthermore, analysis of a double knockout in MYB28 and MYB29 identified an emergent property of the system since the absence of aliphatic glucosinolates in these plants could not be predicted by the chemotype of the single knockouts. CONCLUSIONS/SIGNIFICANCE: It seems that these cruciferous-specific MYB regulatory genes have evolved both overlapping and specific regulatory capacities. This provides a unique system within which to

  3. Structural characterisation of aliphatic, non-hydrolyzable biopolymers in freshwater algae and a leaf cuticle by ruthenium tetroxide degradation

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Schouten, S.; Moerkerken, P.; Gelin, F.; Baas, M.; Leeuw, J.W. de

    1998-01-01

    Aliphatic, non-hydrolyzable biopolymers were subjected to RuO4-oxidation in order to examine the potential of this method in revealing details on their structures. The method was tested on model compounds first and found to cleave alkyl chains of aromatic moieties, double bonds and ether bonds. Oxid

  4. Amperometric detection and electrochemical oxidation of aliphatic amines and ammonia on silver-lead oxide thin-film electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Jisheng

    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.

  5. Metalloradical-Catalyzed Selective 1,2-Rh-H Insertion into the Aliphatic Carbon-Carbon Bond of Cyclooctane

    NARCIS (Netherlands)

    Y.W. Chan; B. de Bruin; K.S. Chan

    2015-01-01

    The selective aliphatic carboncarbon activation of cyclo-octane (c-octane) was achieved via the Rh-II(ttp)-catalyzed 1,2-addition of Rh(ttp)H to give Rh(ttp)(n-octyl) (ttp = tetratolylporphyrinato dianion) in good yield under mild reaction conditions. This mechanism is further supported by DFT calcu

  6. The impact of the absence of aliphatic glucosinolates on water transport under salt stress in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Mcarmen eMartinez-Ballesta

    2015-07-01

    Full Text Available Members of the Brassicaceae are known for their contents of nutrients and health-promoting phytochemicals, including glucosinolatesExposure to salinity increases the levels of several of these compounds, but their role in abiotic stress response is unclear. The effect of aliphatic glucosinolates on plant water balance and growth under salt stress, involving aquaporins, was investigated by means of Arabidopsis thaliana mutants impaired in aliphatic glucosinolate biosynthesis, which is controlled by two transcription factors: Myb28 and Myb29. The double mutant myb28myb29, completely lacking aliphatic glucosinolates, was compared to wild type Col-0 (WT and the single mutant myb28. A greater reduction in the hydraulic conductivity of myb28myb29 was observed under salt stress, when compared to the WT and myb28; this correlated with the abundance of both PIP1 and PIP2 aquaporin subfamilies. Also, changes in root architecture in response to salinity were genotype dependent. Treatment with NaCl altered glucosinolates biosynthesis in a similar way in WT and the single mutant and differently in the double mutant. The results indicate that short-chain aliphatic glucosinolates may contribute to water saving under salt stress

  7. Sources and distribution of aliphatic and polyaromatic hydrocarbons in coastal sediments from the Ushuaia Bay (Tierra del Fuego, Patagonia, Argentina).

    Science.gov (United States)

    Commendatore, Marta G; Nievas, Marina L; Amin, Oscar; Esteves, José L

    2012-03-01

    The environmental quality of Ushuaia Bay, located at the southernmost tip of South America, is affected by the anthropogenic pressure of Ushuaia city. In this study, levels and sources of hydrocarbons in coastal sediments were assessed. Aliphatic hydrocarbon fractions ranged between 5.5 and 1185.3 μg/g dry weight and PAHs from not detected to 360 ng/g. Aliphatic diagnostic indices, the nalkanes homologous series occurrence, Aliphatic Unresolved Complex Mixtures (AliUCMs), and pristane and phytane isoprenoids indicated a petrogenic input. Some sites showed biogenic features masked by the anthropogenic signature. Particularly in port areas biodegradation processes were evident. PAH ratios showed a mixture of petrogenic and pyrogenic sources. Aliphatic and aromatic UCMs were strongly correlated, reflecting chronic pollution. Three areas were distinguished inside the bay: (1) east, with low hydrocarbons impact; (2) central, where hydrocarbons accumulation was related to source proximity and sediment characteristics; (3) south-west, where sediment characteristics and current circulation favour hydrocarbons accumulation. PMID:22189069

  8. Selective preparation of terminal alkenes from aliphatic carboxylic acids by a palladium-catalysed decarbonylation-eliminiation reaction

    NARCIS (Netherlands)

    Notre, le J.E.L.; Scott, E.L.; Franssen, M.C.R.; Sanders, J.P.M.

    2010-01-01

    Trialkylamines were used as additives in the decarbonylation–elimination reaction catalysed by the combination of palladium(II) chloride and DPE-Phos. Aliphatic carboxylic acids were transformed at relatively low temperature into terminal alkenes in high yield and high selectivity, without the need

  9. Ru/Me-BIPAM-Catalyzed Asymmetric Addition of Arylboronic Acids to Aliphatic Aldehydes and α-Ketoesters

    Directory of Open Access Journals (Sweden)

    Momoko Watanabe

    2011-06-01

    Full Text Available A ruthenium-catalyzed asymmetric arylation of aliphatic aldehydes and α-ketoesters with arylboronic acids has been developed, giving chiral alkyl(arylmethanols and α-hydroxy esters in good yields. The use of a chiral bidentate phosphoramidite ligand (Me-BIPAM achieved excellent enantioselectivities.

  10. NMR studies on the mechanism of structural destabilization of the globular proteins and DNA by aliphatic alcohols

    International Nuclear Information System (INIS)

    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)

  11. STUDY ON THE SEQUENCE STRUCTURE OF SBR BY 13C- NMR METHOD Ⅱ . PEAK ASSIGNMENT FOR ALIPHATIC CARBONS SPECTRA

    Institute of Scientific and Technical Information of China (English)

    JIAO Shuke; CHEN Xiaonong; HU Liping; YAN Baozhen

    1990-01-01

    The study on 13C-NMR spectra of aliphatic carbon region of emulsion-processed and solution-processed ( by lithium catalyst ) SBR was carried out. The assignments for more than thirty odd peaks observed experimentally were made by using " corresponding analysis " method, combined with the empirical parameters reported in literature. The peak intensities were calculated based on Bernoullian statistic assumption.

  12. Effects of aliphatic acids, furfural, and phenolic compounds on Debaryomyces hansenii CCMI 941.

    Science.gov (United States)

    Duarte, Luís C; Carvalheiro, Florbela; Neves, Inês; Gírio, Francisco M

    2005-01-01

    Debaryomyces hansenii is a polyol overproducing yeast that can have a potential use for upgrading lignocellulosic hydrolysates. Therefore, the establishment of its tolerance to metabolic inhibitors found in hydrolysates is of major interest. We studied the effects of selected aliphatic acids, phenolic compounds, and furfural. Acetic acid favored biomass production for concentrations toxic than acetic acid and induced xylitol accumulation (maximum yield of 0.21 g/g of xylose). All tested phenolics strongly decreased the specific growth rate. Increased toxicity was found for hydroquinone, syringaldehyde, and 4-methylcatechol and was correlated to the compound's hydrophobicity. Increasing the amount of furfural led to longer lag phases and had a detrimental effect on specific growth rate and biomass productivity. PMID:15917618

  13. Direct optical observation of the formation of some aliphatic alcohol radicals. A pulse radiolysis study

    Indian Academy of Sciences (India)

    E Janata

    2002-12-01

    The kinetics of the reactions of hydroxyl radicals and hydrogen atoms with some aliphatic alcohols in aqueous solutions were studied using pulse radiolysis. Based on the increase in optical absorption in the UV region, the rate constants for the reaction of hydroxyl radicals and hydrogen atoms with methanol, ethanol, 2-propanol or -butyl alcohol were determined to be 9.0 × 108, 2.2 × 109, 2.0 × 109, 6.2 × 108 and 1.1 × 106, 1.8 × 107, 5.3 × 107, 2.3 × 105 dm3 mol-1 s-1 respectively. The bimolecular decay rate constants for the alcohol radicals produced in methanol and ethanol were evaluated to be 2 .4 × 109 and 1.5 × 109 dm3 mol-1 s-1. The values observed are in fairly good agreement with those reported earlier.

  14. Interaction of Calix[4]arene and aliphatic amines: a combined NMR, spectrophotometric and conductimetric investigation

    Energy Technology Data Exchange (ETDEWEB)

    Nachtigall, Francine F.; Lazzarotto, Marcio [Universidade Estadual de Ponta Grossa, PR (Brazil). Dept. de Quimica]. E-mail: mlazzaro@uepg.br; Nome, Faruk [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Quimica

    2002-06-01

    The constants related to the equilibria between calix[4]arene and aliphatic amines in acetonitrile were measured by conductimetric and spectrophotometric methods, and the structures of the salts studied by NMR spectroscopy. In concentrations about 10{sup -4} mol L{sup -1}, free ions are at higher proportion, whereas at 10{sup -2} mol L{sup -1} there is an increase of ion-pairs proportion. The values of the constants found for acid-base reactions allow an evaluation of the value of pKa for calix[4]arene in acetonitrile as 16.6 pKa units. The analysis of data agrees with a proposal of exo-calix ammonium ion. (author)

  15. Interaction of Calix[4]arene and aliphatic amines: a combined NMR, spectrophotometric and conductimetric investigation

    International Nuclear Information System (INIS)

    The constants related to the equilibria between calix[4]arene and aliphatic amines in acetonitrile were measured by conductimetric and spectrophotometric methods, and the structures of the salts studied by NMR spectroscopy. In concentrations about 10-4 mol L-1, free ions are at higher proportion, whereas at 10-2 mol L-1 there is an increase of ion-pairs proportion. The values of the constants found for acid-base reactions allow an evaluation of the value of pKa for calix[4]arene in acetonitrile as 16.6 pKa units. The analysis of data agrees with a proposal of exo-calix ammonium ion. (author)

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

    Indian Academy of Sciences (India)

    Sonu Saraswat; Vinita Sharma; K K Banerji

    2003-02-01

    Oxidation of nine aliphatic primary alcohols by quinolinium bromochromate (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 form: obs = + [H+]. The oxidation of [1,1-2H2]ethanol (MeCD2OH) exhibits a substantial primary kinetic isotope effect. The reaction has been studied in nineteen different organic solvents. The solvent effect was analysed using Taft’s and Swain's multiparametric equations. The rate of oxidation is susceptible to both polar and steric effects of the substituents. A suitable mechanism has been proposed.

  17. Modification of nano-sized layered double hydroxides by long-chain organic aliphatic surfactants

    Directory of Open Access Journals (Sweden)

    RAMASAMY ANBARASAN

    2008-03-01

    Full Text Available The inter-layer anion of layered double hydroxides (LDH with a hydrotalcite (HT-like structure was ion-exchanged with various organic surfactants, particularly with long chain aliphatic surfactants. After the ion-exchange process, the basal spacing of the LDH was increased and the increase of the basal spacing depended on various factors, such as the intercalation capacity functionality and orientation capability of the surfactant. Of the employed surfactants, stearic acid intercalated LDH showed the highest increase of the basal spacing, which was confirmed by XRD analysis. FTIR results supported the interaction of the surfactants with the LDH. In addition, an increase in the thermal stability of the dodecanedioic acid intercalated HT was evidenced by the TGA method.

  18. Synthesis and Characterization of Aromatic–Aliphatic Polyamide Nanocomposite Films Incorporating a Thermally Stable Organoclay

    Directory of Open Access Journals (Sweden)

    Zulfiqar Sonia

    2009-01-01

    Full Text Available Abstract Nanocomposites were synthesized from reactive thermally stable montmorillonite and aromatic–aliphatic polyamide obtained from 4-aminophenyl sulfone and sebacoyl chloride. Carbonyl chloride terminal chain ends were generated using 1% extra sebacoyl chloride that could interact chemically with the organoclay. The distribution of clay in the nanocomposites was investigated by XRD, SEM, and TEM. Mechanical and thermal properties of these materials were monitored using tensile testing, TGA, and DSC. The results revealed delaminated and intercalated nanostructures leading to improved tensile strength and modulus up to 6 wt% addition of organoclay. The elongation at break and toughness of the nanocomposites decreased with increasing clay contents. The nanocomposites were thermally stable in the range 400–450 °C. The glass transition temperature increased relative to the neat polyamide due to the interfacial interactions between the two phases. Water uptake of the hybrids decreased upon the addition of organoclay depicting reduced permeability.

  19. Low-temperature microchip nonaqueous capillary electrophoresis of aliphatic primary amines: applications to Titan chemistry.

    Science.gov (United States)

    Cable, Morgan L; Stockton, Amanda M; Mora, Maria F; Willis, Peter A

    2013-01-15

    We demonstrate microchip nonaqueous capillary electrophoresis (μNACE) analysis of primary aliphatic amines (C1-C18) in ethanol down to -20 °C as a first step in adapting microfluidic protocols for in situ analysis on Titan. To our knowledge, this is the first report of a nonaqueous separation at -20 °C on-chip. Limits of detection (LODs) ranged from 1.0 nM to 2.6 nM, and we identified several primary amines ranging in length from C2 to C16 in Titan aerosol analogue (tholin) samples; new amines were also detected in a tholin sample exposed to oxygen and liquid water. This preliminary work validates the sensitivity and efficacy of microfluidic chemical analysis of complex organics with relevance to Titan aerosols and surface deposits. PMID:23214444

  20. Synthesis and Characterization of Aromatic-Aliphatic Polyamide Nanocomposite Films Incorporating a Thermally Stable Organoclay

    Science.gov (United States)

    Zulfiqar, Sonia; Sarwar, Muhammad Ilyas

    2009-05-01

    Nanocomposites were synthesized from reactive thermally stable montmorillonite and aromatic-aliphatic polyamide obtained from 4-aminophenyl sulfone and sebacoyl chloride. Carbonyl chloride terminal chain ends were generated using 1% extra sebacoyl chloride that could interact chemically with the organoclay. The distribution of clay in the nanocomposites was investigated by XRD, SEM, and TEM. Mechanical and thermal properties of these materials were monitored using tensile testing, TGA, and DSC. The results revealed delaminated and intercalated nanostructures leading to improved tensile strength and modulus up to 6 wt% addition of organoclay. The elongation at break and toughness of the nanocomposites decreased with increasing clay contents. The nanocomposites were thermally stable in the range 400-450 °C. The glass transition temperature increased relative to the neat polyamide due to the interfacial interactions between the two phases. Water uptake of the hybrids decreased upon the addition of organoclay depicting reduced permeability.

  1. Synthesis and Characterization of Aromatic–Aliphatic Polyamide Nanocomposite Films Incorporating a Thermally Stable Organoclay

    Science.gov (United States)

    2009-01-01

    Nanocomposites were synthesized from reactive thermally stable montmorillonite and aromatic–aliphatic polyamide obtained from 4-aminophenyl sulfone and sebacoyl chloride. Carbonyl chloride terminal chain ends were generated using 1% extra sebacoyl chloride that could interact chemically with the organoclay. The distribution of clay in the nanocomposites was investigated by XRD, SEM, and TEM. Mechanical and thermal properties of these materials were monitored using tensile testing, TGA, and DSC. The results revealed delaminated and intercalated nanostructures leading to improved tensile strength and modulus up to 6 wt% addition of organoclay. The elongation at break and toughness of the nanocomposites decreased with increasing clay contents. The nanocomposites were thermally stable in the range 400–450 °C. The glass transition temperature increased relative to the neat polyamide due to the interfacial interactions between the two phases. Water uptake of the hybrids decreased upon the addition of organoclay depicting reduced permeability. PMID:20596518

  2. Investigating the structure-property relationship of aromatic-aliphatic polyamide/layered silicate hybrid films

    Science.gov (United States)

    Zulfiqar, Sonia; Sarwar, Muhammad Ilyas

    2009-07-01

    Surface treated montmorillonite was used to prepare nanocomposites with aromatic-aliphatic polyamide by solution intercalation technique. The polyamide chains were produced through polycondensation of 4-aminophenyl sulfone with sebacoyl chloride in dimethyl acetamide. Compatibility between the polymer and organoclay was achieved through carbonyl chloride end-capped amide chains prepared by adding extra sebacoyl chloride near the end of polymerization reaction. The nanocomposites morphology and clay dispersion were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Delaminated and intercalated morphologies were observed for different loading of organoclay. Tensile strength and modulus improved for nanocomposites with optimum organoclay content (10-wt.%). Thermal stability and glass transition temperature of nanocomposites increased relative to pristine polyamide with augmenting organoclay content. Water uptake of these materials decreased as compared to the neat polyamide indicating reduced permeability.

  3. 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.

  4. Synthesis and reactivity of aliphatic sulfur pentafluorides from substituted (pentafluorosulfanyl)benzenes.

    Science.gov (United States)

    Vida, Norbert; Václavík, Jiří; Beier, Petr

    2016-01-01

    Oxidation of 3- and 4-pentafluorosulfanyl-substituted anisoles and phenols with hydrogen peroxide and sulfuric acid provided a mixture of SF5-substituted muconolactone, maleic, and succinic acids. A plausible mechanism for the formation of the aliphatic SF5 compounds was presented and their chemical reactivity was investigated. SF5-substituted para-benzoquinone was synthesized; its oxidation led to an improved yield of 2-(pentafluorosulfanyl)maleic acid. The reaction of SF5-substituted maleic anhydride and para-benzoquinone with cyclopentadiene afforded the Diels-Alder adducts. Decomposition of 3-(pentafluorosulfanyl)muconolactone in acidic, neutral and basic aqueous media was investigated and the decarboxylation of 2-(pentafluorosulfanyl)maleic acid provided 3-(pentafluorosulfanyl)acrylic acid. PMID:26877813

  5. Kinetics and mechanism of oxidation of aliphatic alcohols by tetrabutylammonium tribromide

    Indian Academy of Sciences (India)

    Manju Baghmar; Pradeep K Sharma

    2001-04-01

    Oxidation of nine primary aliphatic alcohols by tetrabutylammonium tribromide (TBATB) in aqueous acetic acid leads to the formation of the corresponding aldehydes. The reaction is first order with respect to TBATB. Michaelis-Menten type kinetics is observed with respect to alcohols. The reaction failed to induce the polymerization of acrylonitrile. Tetrabutylammonium chloride has no effect on the reaction rate. The proposed reactive oxidizing species is the tribromide ion. The oxidation of [1,1-2H2]ethanol exhibits a substantial kinetic isotope effect. The effect of solvent composition indicates that the rate increases with increase in the polarity of the solvent. The reaction is susceptible to both polar and steric effects of substituents. A mechanism involving transfer of a hydride ion in the ratedetermining step has been proposed.

  6. Aromatic-aliphatic polyamide/montmorillonite clay nanocomposite materials: Synthesis, nanostructure and properties

    International Nuclear Information System (INIS)

    New type of aromatic-aliphatic polyamide/montmorillonite nanocomposites were produced using solution intercalation technique in dimethylacetamide. The modification of clay was carried out with ammonium salt of long chain alkyl amine. The nanocomposites were probed for organoclay dispersion, mechanical, thermal and water absorption measurements. Formation of delaminated and intercalated nanostructures was confirmed by X-ray diffraction and TEM studies. Improvement in tensile strength and modulus was observed for nanocomposites with optimum organoclay content (8-wt.%). Thermogravimetric analysis indicated an increase in thermal stability of nanocomposites as compared to pristine polyamide. Differential scanning calorimetric results revealed increase in glass transition temperatures (Tg) with augmenting organoclay in the nanocomposites. Water uptake of the nanocomposites reduced than the neat polyamide rendering decreased permeability.

  7. Catalytic activity of carbon nanotubes in the conversion of aliphatic alcohols

    Science.gov (United States)

    Zhitnev, Yu. N.; Tveritinova, E. A.; Chernyak, S. A.; Savilov, S. V.; Lunin, V. V.

    2016-06-01

    Carbon nanotubes (CNTs) obtained via the catalytic pyrolysis of hexane at 750°C were studied as the catalysts in conversion of C2-C4 alcohols. The efficiency of CNTs as catalysts in dehydration and dehydrogenation of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and tert-butanol was studied by means of pulse microcatalysis. The surface and structural characteristics of CNTs are investigated via SEM, TEM, DTA, BET, and XPS. CNTs are shown to be effective catalysts in the conversion of alcohols and do not require additional oxidative treatment. The regularities of the conversion of aliphatic alcohols, related to the properties of the CNTs surface and the structure of the alcohols are identified.

  8. Purification of wet process phosphoric acid by solvent extraction with long-chain aliphatic amines

    International Nuclear Information System (INIS)

    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

  9. Amination of ω-Functionalized Aliphatic Primary Alcohols by a Biocatalytic Oxidation–Transamination Cascade

    Science.gov (United States)

    Pickl, Mathias; Fuchs, Michael; Glueck, Silvia M; Faber, Kurt

    2015-01-01

    Amination of non-activated aliphatic fatty alcohols to the corresponding primary amines was achieved through a five-enzyme cascade reaction by coupling a long-chain alcohol oxidase from Aspergillus fumigatus (LCAO_Af) with a ω-transaminase from Chromobacterium violaceum (ω-TA_Cv). The alcohol was oxidized at the expense of molecular oxygen to yield the corresponding aldehyde, which was subsequently aminated by the PLP-dependent ω-TA to yield the final primary amine product. The overall cascade was optimized with respect to pH, O2 pressure, substrate concentration, decomposition of H2O2 (derived from alcohol oxidation), NADH regeneration, and biocatalyst ratio. The substrate scope of this concept was investigated under optimized conditions by using terminally functionalized C4–C11 fatty primary alcohols bearing halogen, alkyne, amino, hydroxy, thiol, and nitrile groups. PMID:26583050

  10. Analysis of aliphatic carboxylic acids in anaerobic digestion process waters by ion-exclusion chromatography

    Institute of Scientific and Technical Information of China (English)

    Kazuaki ITO; Kazuhiko TANAKA; Jun SAKAMOTO; Kazuya NAGAOKA; Yohichi TAKAYAMA; Takashi KANAHORI; Hiroshi SUNAHARA; Tsuneo HAYASHI; Shinji SATO; Takeshi HIROKAWA

    2012-01-01

    The analysis of seven aliphatic carboxylic acids ( formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents (benzoic acid,perfluorobutyric acid (PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet (UV) detection.The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column ( TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column ( TSKgel Super IC-A/C ).Good separation was performed on the TSKgel SCX in shorter retention times.For the TSKgel Super IC-A/C,peak shape of the acids was sharp and symmetrical in spite of longer retention times.In addition,the mutual separation of the acids was good except for iso- and n-butyric acids.The better separation and good detection was achieved by using the two columns (TSKgel SCX and TSKgel Super IC-A/C connected in series),lower concentrations of PFBA and sulfuric acid as eluents,non-suppressed conductivity detection and UV detection at 210 nm.This analysis was applied to anaerobic digestion process waters.The chromatograms with conductivity detection were relatively simpler compared with those of UV detection.The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.

  11. Frequency of genes in aromatic and aliphatic hydrocarbon biodegradation pathways within baterial populations from Alaskan sediments

    International Nuclear Information System (INIS)

    Bacteria from sediments affected by the Exxon Valdez oil spill were examined for their ability to metabolize aliphatic and aromatic hydrocarbons and for genes in the pathways for metabolism of low molecular weight alkanes and aromatic hydrocarbons. The abilities of microorganisms from Alaskan sediments to mineralize hexadecane and naphthalene were also determined. Microorganisms were further examined for the presence of the alkB gene that codes for the alkane hydroxylase responsible for the hydroxylation of C6-12 alkanes within the pathway for alkane metabolism, and for the presence of the xylE gene that codes for catechol 2,3-dioxygenase that catalyzes the cleavage of catechols within the lower pathway of aromatic hydrocarbon metabolism. These studies were aimed at determining whether microorganisms can possess genes in the pathways for both aromatic and aliphatic hydrocarbon metabolism. It was found that a significant proportion of the naturally occurring hydrocarbon-degrading populations within Alaskan sediments affected by the Exxon Valdez oil spill had both the xylE and alkB genes and could convert hexadecane and naphthalene to CO2. A greater proportion had xylE than alkB, reflecting the composition of the residual oil at the time of sampling. Nearly equal populations with xylE alone, alkB alone, and xylE plus alkB genes together were found after exposure to fresh crude oil. Populations with xylE lacking alkB increased after enrichment on naphthalene. Thus, the genotypes of hydrocarbon-degrading populations reflected the composition of the hydrocarbons to which they were exposed. 13 refs., 3 figs., 1 tab

  12. Analysis of aliphatic waxes associated with root periderm or exodermis from eleven plant species.

    Science.gov (United States)

    Kosma, Dylan K; Rice, Adam; Pollard, Mike

    2015-09-01

    Aliphatic waxes can be found in association with suberized tissues, including roots. Non-polar lipids were isolated by rapid solvent extraction of mature regions of intact roots from eleven angiosperms, including both monocots and dicots. The majority of roots analyzed were taproots or tuberous taproots that had undergone secondary growth and thus were covered by a suberized periderm. The exceptions therein were maize (Zea mays L.) and rice (Oryza sativa L.), which present a suberized exodermis. The analysis herein focused on aliphatic waxes, with particular emphasis on alkyl hydroxycinnamates (AHCs). AHCs were widely distributed, absent from only one species, were found in both aerial and subterranean portions of tuberous taproots, and were associated with the fibrous roots of both maize and rice. Most species also contained monoacylglycerols, fatty alcohols and/or free fatty acids. Carrot (Daucus carrota L.) was the outlier, containing only free fatty acids, sterols, and polyacetylenes as identified components. Sterols were the only ubiquitous component across all roots analyzed. Monoacylglycerols of ω-hydroxy fatty acids were present in maize and rice root waxes. For species within the Brassiceae, wax compositions varied between subspecies or varieties and between aerial and subterranean portions of taproots. In addition, reduced forms of photo-oxidation products of ω-hydroxy oleate and its corresponding dicarboxylic acid (10,18-dihydroxy-octadec-8-enoate, 9,18-dihydroxy-octadec-10-enoate and 9-hydroxyoctadec-10-ene-1,18-dioate) were identified as naturally occurring suberin monomers in rutabaga (Brassica napus subsp. rapifera Metzg.) periderm tissues. PMID:26143051

  13. Aliphatic and aromatic plant biopolymer dynamics in soil particles isolated from sequential density fractionation

    Science.gov (United States)

    Caldwell, B.; Filley, T.; Sollins, P.; Lajtha, K.; Swanston, C.; Kleber, M.; Kramer, M.

    2007-12-01

    A recent multi-layer-based soil organic matter-mineral interaction mechanistic model to describe the nature of soil organic matter-mineral surface mechanism for soil organic matter stabilization predicts that proteinaceous and aliphatic materials establish the core of strong binding-interactions upon which other organic matter is layered. A key methodology providing data underpinning this hypothesis is sequential density fractionation where soil is partitioned into particles of increasing density with the assumption that a partial control on organic matter distribution through density series is the thickness of its layering. Four soils of varying mineralogy and texture were investigated for their biopolymer, isotopic, and mineralogical properties. Light fractions (plant derived biopolymers with density. Extractable lignin phenols exhibited a progressive oxidation state with density. The concentration of biopolymers roughly mirrored the C:N ratio of soil particles which dropped consistently with increasing particle density. Although, in all soils, both lignin phenols and SFA concentration generally decreased with increasing density the ratio SFA/lignin varied with density and depending upon the soil. All soils, except the oxisol, exhibited an increase in SFA with respect to lignin suggesting a selective stabilization of those material with respect to lignin. In the oxisol, which showed little variation in its hematite dominated mineralogy across density, SFA/lignin remained constant, potentially indicating a greater capacity to stabilize lignin in that system. Interestingly, the lignin oxidation state increased with density in the oxisol. Given the variation in soil character, the consistency in these trends it suggests a general phenomenon of progressive decay in plant derived material with thinness of mineral coating but an overall relative increase in aliphatic character-all consistent with the multi-layer model.

  14. Occurrence of selected aliphatic amines in source water of major cities in China

    Institute of Scientific and Technical Information of China (English)

    Haifeng Zhang; Shuoyi Ren; Jianwei Yu; Min Yang

    2012-01-01

    The formation of toxic nitrogenous disinfection byproducts (N-DBPs),such as nitrosamines,halonitromethanes and haloacetonitriles,from reactions between chlorine/chloramine and dissolved organic nitrogen in drinking water has caused great concern with regarding public health.This study revealed the occurrence of 17 aliphatic amines,some of which have been confirmed to be the precursors of N-DBPs,in source water across China.A sensitive method based on benzenesulfonyl chloride derivatization and liquid-liquid extraction followed by GC-MS analysis was established for the simultaneous analysis of the selected amines in aqueous samples.In total,37 source water samples from the capital cities of 20 provinces were collected for the survey.Among the 17 amines,14 were detected with an average frequency of detection of 36%.The most relevant amines in terms of frequency and maximum concentrations detected were dimethylamine (100%,24.82 μg/L),methylamine (78%,0.92 μg/L),N-methylethylamine (70%,8.84 μg/L),propylamine (59%,10.69 μg/L),diethylamine (54%,3.76 μg/L),N-methylbutylamine (35%,3.07 μg/L),N-ethylpropylamine (35%,0.52 μg/L),and piperidine (32%,2.35 μg/L).This is the first large scale survey of the aliphatic amines occurrence in source water in the world.The wide presence of nitrosamine precursors like dimethylamine,N-methylethylamine and diethylamine,and the precursors of haloacetonitriles and halonitromethanes like methylamine and propylamine suggests that better source water management is required to ensure the safety of drinking water.

  15. Study of the electron beam irradiation effect on some properties of aromatic aliphatic copolyester films

    International Nuclear Information System (INIS)

    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 (EcoflexR and EcobrasR) 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 EcoflexR and EcobrasR samples, was not identified when compared with the samples of reference. However, it was verified a reduction in the melting enthalpy of the EcobrasR samples after irradiation. The EcobrasR material presented crosslinking, when submitted to doses of 10 kGy and 40 kGy. The EcoflexR 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)

  16. Seasonal variation of aliphatic amines in marine sub-micrometer particles at the Cape Verde islands

    Directory of Open Access Journals (Sweden)

    C. Müller

    2009-07-01

    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 to 30 pg m−3 for MA, 130 to 360 pg m−3 for DMA and 5 to 110 pg m−3 for DEA during the spring bloom in May 2007 and 2 to 520 pg m−3 for MA, 100 to 1400 pg m−3 for DMA, 90 to 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 indicates 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 to 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 organic nitrogen in the marine atmosphere. The average contribution of the amines to the total detected nitrogen content in submicron particles can be non-negligible, especially in the winter months (0.1% N to 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.

  17. 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.

  18. CHARACTERIZATION AND FUNCTIONAL STUDY OF A PUTATIVE JUVENILE HORMONE DIOL KINASE IN THE COLORADO POTATO BEETLE Leptinotarsa decemlineata (Say).

    Science.gov (United States)

    Fu, Kai-Yun; Lü, Feng-Gong; Guo, Wen-Chao; Li, Guo-Qing

    2015-11-01

    Juvenile hormone diol kinase (JHDK) is an enzyme involved in JH degradation. In the present article, a putative JHDK cDNA (LdJHDK) was cloned from the Colorado potato beetle Leptinotarsa decemlineata. The cDNA consists of 814 bp, containing a 555 bp open reading frame encoding a 184 amino acid protein. LdJHDK reveals a high degree of identity to the previously reported insect JHDKs. It possesses three conserved purine nucleotide-binding elements, and contains three EF-hand motifs (helix-loop-helix structural domains). LdJHDK mRNA was mainly detected in hindgut and Malpighian tubules. Besides, a trace amount of LdJHDK mRNA was also found in thoracic muscles, brain-corpora cardiaca-corpora allata complex, foregut, midgut, ventral ganglia, fat body, epidermis, and hemocytes. Moreover, LdJHDK was expressed throughout all developmental stages. Within the first, second, and third larval instar, the expression levels of LdJHDK were higher just before and right after the molt, and were lower in the intermediate instar. In the fourth larval instar, the highest peak of LdJHDK occurred 56 h after ecdysis. Ingestion of double-stranded RNA (dsRNA) against LdJHDK successfully knocked down the target gene, increased JH titer, and significantly upregulated LdKr-h1 mRNA level. Knockdown of LdJHDK significantly impaired adult emergence. Thus, we provide a line of experimental evidence in L. decemlineata to support that LdJHDK encodes function protein involved in JH degradation. PMID:26280246

  19. Two-step biocatalytic route to biobased functional polyesters from omega-carboxy fatty acids and diols.

    Science.gov (United States)

    Yang, Yixin; Lu, Wenhua; Zhang, Xiaoyan; Xie, Wenchun; Cai, Minmin; Gross, Richard A

    2010-01-11

    Biobased omega-carboxy fatty acid monomers 1,18-cis-9-octadecenedioic, 1,22-cis-9-docosenedioic, and 1,18-cis-9,10-epoxy-octadecanedioic acids were synthesized in high conversion yields from oleic, erucic and epoxy stearic acids by whole-cell biotransformations catalyzed by C. tropicalis ATCC20962. Maximum volumetric yields in shake-flasks were 17.3, 14.2, and 19.1 g/L after 48 h conversion for oleic acid and 72 h conversions for erucic and epoxy stearic acids, respectively. Studies in fermentor with better control of pH and glucose feeding revealed that conversion of oleic acid to 1,18-cis-9-octadecenedioic acid by C. tropicalis ATCC20962 occurred with productivities up to 0.5 g/L/h. The conversion of omega-carboxy fatty acid monomers to polyesters was then studied using immobilized Candida antarctica Lipase B (N435) as catalyst. Polycondensations with diols were performed in bulk as well as in diphenyl ether. The retension of functionality from fatty acid, to omega-carboxy fatty acid monomer and to corresponding polyesters resulted in polymers with with unsaturated and epoxidized repeat units and M(w) values ranging from 25000 to 57000 g/mol. These functional groups along chains disrupted crystallization giving materials that are low melting (23-40 degrees C). In contrast, saturated polyesters prepared from 1,18-octadecanedioic acid and 1,8-octanediol have correspondingly higher melting transitions (88 degrees C). TGA results indicated that all synthesized polyesters showed high thermal stabilities. Thus, the preparation of functional monomers from C. tropicalis omega-oxidation of fatty acids provides a wide range of new monomer building blocks to construct functional polymers. PMID:20000460

  20. Mapping the landscape of potentially primordial informational oligomers: (3'→2')-D-phosphoglyceric acid linked acyclic oligonucleotides tagged with 2,4-disubstituted 5-aminopyrimidines as recognition elements.

    Science.gov (United States)

    Hernández-Rodríguez, Marcos; Xie, Jian; Osornio, Yazmin M; Krishnamurthy, Ramanarayanan

    2011-05-01

    The (3'→2')-phosphodiester glyceric acid backbone containing an acyclic oligomer tagged with 2,4-disubstituted pyrimidines as alternative recognition elements have been synthesized. Strong cross-pairing of a 2,4-dioxo-5-aminopyrimidine hexamer, rivaling locked nucleic acid (LNA) and peptide nucleic acid (PNA), with complementary adenine-containing DNA and RNA sequences was observed. The corresponding 2,4-diamino- and 2-amino-4-oxo-5-aminopyrimidine-tagged oligomers were synthesized, but difficulties in deprotection, purification, and isolation thwarted further investigations. The acyclic phosphate backbone structure of the protected oligomer seems to be prone to an eliminative degradation owing to the acidic hydrogen at the 2'-position--an arrangement that renders the oligomer vulnerable to the conditions used for the removal of the protecting groups on the heterocyclic recognition element. However, the free oligomers seem to be stable under the conditions investigated. PMID:21387563

  1. Small angle neutron scattering study on the aggregation behaviour of PEO–PPO–PEO copolymers in the presence of a hydrophobic diol

    Indian Academy of Sciences (India)

    B Bharatiya; V K Aswal; P Bahadur

    2008-11-01

    Small angle neutron scattering (SANS) measurements on aqueous solutions of four polyethylene oxide–polypropylene oxide–polyethylene oxide block copolymers (commercially known as Pluronic®)F88, P85, F127 and P123 in the presence of hydrophobic C14Diol (also known as Surfynol® 104) reveal information on micellization, micellar size and micellar transitions. While most hydrophilic F88 (with least PPO/PEO ratio) remained unimers in water at 30◦ C, other copolymers formed micellar solutions. Surfynol® 104 is sparingly soluble in water to only about ∼ 0.1 wt%, but on addition to pluronic solution, it gets incorporated in the micellar region of block copolymer which leads to increase in aggregation number and transformation of spherical to ellipsoidal micelles. The added diol-induced micellization in F88, though hydrophilic copolymers F88 and F127 did not show any appreciable micellar growth or shape changes as observed for P85 and P123 (which are comparatively more hydrophobic). The SANS results on copolymer pairs with same molecular weight PPO but different % PEO (viz. F88 and P85, F127 and P123) and with same molecular weight PEO but different PPO (F88 and F127) reveal that the copolymer with large PPO/PEO ratio facilitate micellar transition in the presence of diol. An increase in temperature and presence of added electrolyte (sodium chloride) in the solution further enhances these effects. The micellar parameters for these systems were found out using available software and are reported.

  2. Application of Topology Index in Aliphatic Aldehydes,Fatty Amines and Aliphatic Hydrocarbons Boiling Point%拓扑指数在脂肪醛、脂肪胺及脂肪烃沸点中的应用

    Institute of Scientific and Technical Information of China (English)

    周长会; 吴启勋; 侯庆高; 高宴梓; 李洪囡; 张瑞

    2013-01-01

    Two matrices and a topological index W were defined,then,topological index W was put into nonlinear regression with the boiling point of aliphatic aldehydes, fatty amines and aliphatic hydrocarbons, respectively, and with good results,the correlation coefficient reaches a good level. The established topological index and two kinds of matrix are easy and convenient to use, which can quickly predict the boiling point of the molecule.%定义了两种矩阵和一种拓扑指数W,将拓扑指数W分别与脂肪醛、脂肪胺及脂肪烃的沸点进行非线性回归,取得了较好的结果,相关性系数达到了良好级别.建立的拓扑指数和两种矩阵简洁方便,可以快速预测分子的沸点.

  3. Green Aza-Michael Reaction of Aliphatic Amines to á,(a)-Unsaturated Compounds in Water

    Institute of Scientific and Technical Information of China (English)

    XU Li-Wen; XIA Chun-Gu

    2004-01-01

    The hydroamination of olefins is a long-standing goal for transition metal catalysis. And the metal-catalyzed addition of amines to carbon-carbon double bonds is an unsolved, synthetically important problem. Although recent advances have made using lanthanide and precious metal complexes, there are few excellent catalyst that display broad functional group tolerance and useful rates for an intermolecular aza-Michael addition. As such, the development of efficient synthetic methods leading to a-amino carbonyl compounds and derivatives has attracted much attention in organic synthesis. Although recent advances have made this route more attractive, development of cheaper, simpler, and more efficient metal catalyst is highly desirable. We also have been interested in developing a reaction that uses catalytic quantities of minimally toxic, readily available, economic reagent should greatly contribute to the creation of environmental benign processes.The recent interest in aqueous medium metal-mediated carbon-carbon and carbon-heteroatom and formations led to the contributors for such reactions. Furthermore, development of organic reactions in water will contribute to the progress of green and quasi-nature catalysis chemistry. Surprisingly however, there is few report on conjugate additions of amines to a,a-unsaturated carbonyl compounds in water.Herein, we report a new protocol that employs air stable copper salts as efficient catalyst in the aza-Michael reaction under mild reaction conditions. Advantages of the protocol include high-yielding reactions that can be conducted at ambient temperature; the use of readily available and stable copper salts as the catalyst, and the reaction was successfully performed in environmental benign solvent, water.Finally, we have utilized a variety of aliphatic amines successfully with different á,(a)-unsaturated compounds catalyzed by simple hydrophilic ionic liquid, bmimBF4 in water. Interestingly, all the aliphatic amines gave

  4. Studies of the physical, yield and failure behavior of aliphatic polyketones

    Science.gov (United States)

    Karttunen, Nicole Renee

    This thesis describes an investigation into the multiaxial yield and failure behavior of an aliphatic polyketone terpolymer. The behavior is studied as a function of: stress state, strain rate, temperature, and sample processing conditions. Results of this work include: elucidation of the behavior of a recently commercialized polymer, increased understanding of the effects listed above, insight into the effects of processing conditions on the morphology of the polyketone, and a description of yield strength of this material as a function of stress state, temperature, and strain rate. The first portion of work focuses on the behavior of a set of samples that are extruded under "common" processing conditions. Following this reference set of tests, the effect of testing this material at different temperatures is studied. A total of four different temperatures are examined. In addition, the effect of altering strain rate is examined. Testing is performed under pseudo-strain rate control at constant nominal octahedral shear strain rate for each failure envelope. A total of three different rates are studied. An extension of the first portion of work involves modeling the yield envelope. This is done by combining two approaches: continuum level and molecular level. The use of both methods allows the description of the yield envelope as a function of stress state, strain rate and temperature. The second portion of work involves the effects of processing conditions. For this work, additional samples are extruded with different shear and thermal histories than the "standard" material. One set of samples is processed with shear rates higher and lower than the standard. A second set is processed at higher and lower cooling rates than the standard. In order to understand the structural cause for changes in behavior with processing conditions, morphological characterization is performed on these samples. In particular, the effect on spherulitic structure is important. Residual

  5. Different aliphatic dicarboxylates affected assemble of new coordination polymers constructed from flexible-rigid mixed ligands

    International Nuclear Information System (INIS)

    In this article, seven coordination polymers: [Cd(C5H6O4)(C10H8N2)]n (1), [Zn(C5H6O4)(C10H8N2)]n (2), [Cd(C6H8O4)(C10H8N2)]n (3), {[Mn(C10H8N2)(H2O)4] (C4H4O4).4H2O}n (4), [Mn5(C4H4O4)4(O)]n (5), [Cd(C4H4O4)(C10H8N2)(H2O)]n (6) and [Zn(C6H6O4)(C12H8N2)(H2O)]n (7) were synthesized and characterized by single-crystallographic X-ray diffraction. Compounds 1 and 2 are two-dimensional layers connected by glutarate anions and 4,4'-bpy. Unlike compounds 1 and 2, compound 3 is a two-fold interpenetration network. Compound 4 is a one-dimensional chain-like structure, which is further extended to two-dimensional supramolecular layer structure with hydrogen bond. During the synthesis of compound 4, to our surprise, we got compound 5; compound 5 is an interesting three-dimensional network composed of pentanuclear Mn(II) building units and succinate anions. Compound 6 is also a two-dimensional supramolecular layer structure composed of one-dimensional chain-like structure with hydrogen bonds and Π-Π interactions. Compound 7 is also a one-dimensional chain-like structure, which is further connected with the same kind of interaction to generate two-dimensional supramolecular layer structure. Furthermore, compounds 1 and 2 both exhibit fluorescent property at room temperature. - Graphical abstract: Seven complexes composed by 3D metal ions, aliphatic acid ligand and rigid bidentate nitrogen ligands: 4,4'-bpy, 2,2'-bpy and 1,10'-phen. With the change of the carbon number of the backbone of aliphatic dicarboxylate ligand, we can synthesize different complexes with various structures

  6. 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.

  7. Acaricidal effects of Corymbia citriodora oil containing para-menthane-3,8-diol against nymphs of Ixodes ricinus (Acari: Ixodidae)

    OpenAIRE

    Elmhalli, Fawzeia; Pålsson, Katinka; Örberg, Jan; Jaenson, Thomas

    2009-01-01

    The toxicity of para-menthane-3,8-diol (PMD), the main arthropod-repellent compound in the oil of the lemon eucalyptus, Corymbia citriodora, was evaluated against nymphs of Ixodes ricinus using five methods (A-E) of a contact toxicity bioassay. Mortality rates were estimated by recording numbers of dead nymphs at 30 min intervals during the first 5 h after the start of exposure and at longer intervals thereafter. The mortality rate increased with increasing concentration of PMD and duration o...

  8. 5-Cholesten-3β,25-Diol 3-Sulfate Decreases Lipid Accumulation in Diet-Induced Nonalcoholic Fatty Liver Disease Mouse Model

    OpenAIRE

    Xu, Leyuan; Kim, Jin Koung; Bai, Qianming; Zhang, Xin; Kakiyama, Genta; Min, Hae-Ki; Arun J Sanyal; Pandak, William M.; Ren, Shunlin

    2013-01-01

    Sterol regulatory element-binding protein-1c (SREBP-1c) increases lipogenesis at the transcriptional level, and its expression is upregulated by liver X receptor α (LXRα). The LXRα/SREBP-1c signaling may play a crucial role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). We previously reported that a cholesterol metabolite, 5-cholesten-3β,25-diol 3-sulfate (25HC3S), inhibits the LXRα signaling and reduces lipogenesis by decreasing SREBP-1c expression in primary hepatocytes. T...

  9. 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.

  10. QSPR models based on molecular mechanics and quantum chemical calculations. 1. Construction of Boltzmann averaged descriptors for alkanes, alcohols, diols, ethers and cyclic compounds

    DEFF Research Database (Denmark)

    Dyekjær, Jane Dannow; Rasmussen, Kjeld; Jonsdottir, Svava Osk

    2002-01-01

    Values for nine descriptors for QSPR (quantitative structure-property relationships) modeling of physical properties of 96 alkanes, alcohols, ethers, diols, triols and cyclic alkanes and alcohols in conjunction with the program Codessa are presented. The descriptors are Boltzmann-averaged by...... selection of the most relevant conformers out of a set of possible molecular conformers generated by a systematic scheme presented in this paper. Six of these descriptors are calculated with molecular mechanics and three with quantum chemical methods. Especially interesting descriptors are the relative van...

  11. Synthesis and characterization of new polyesters based on 2,5-bis[(4-chloro carboxyanilino)carbonyl]pyridine and aromatic diols

    Institute of Scientific and Technical Information of China (English)

    Khalil; Faghihi

    2010-01-01

    Six new polyesters 7a-f were synthesized through the solution polycondensation reaction of diacid chloride 5 with six aromatic diols 6a-f in N,N-dimethyl acetamide(DMAc) as solvent in the presence of pyridine as base.The polycondensation reaction produced a series of novel polyester containing pyridyl moiety in the main chain in high yields with inherent viscosities between 0.35 and 0.54 dL/g.The resulted polymers were fully characterized by means of FT-IR spectroscopy,elemental analyses,inherent viscosi...

  12. 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.)

  13. Syntheses of Enantiopure Aliphatic Secondary Alcohols and Acetates by Bioresolution with Lipase B from Candida antarctica

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. Synthetic incorporation of Nile Blue into DNA using 2′-deoxyriboside substitutes: Representative comparison of (R- and (S-aminopropanediol as an acyclic linker

    Directory of Open Access Journals (Sweden)

    Daniel Lachmann

    2010-02-01

    Full Text Available The Nile Blue chromophore was incorporated into oligonucleotides using “click” chemistry for the postsynthetic modification of oligonucleotides. These were synthesized using DNA building block 3 bearing an alkyne group and reacted with the azide 4. (R-3-amino-1,2-propanediol was applied as the linker between the phosphodiester bridges. Two sets of DNA duplexes were prepared. One set carried the chromophore in an A-T environment, the second set in a G-C environment. Both were characterized by optical spectroscopy. Sequence-dependent fluorescence quenching was applied as a sensitive tool to compare the stacking interactions with respect to the chirality of the acyclic linker attachment. The results were compared to recent results from duplexes that carried the Nile Blue label in a sequentially and structurally identical context, except for the opposite chirality of the linker ((S-3-amino-1,2-propandiol. Only minor, negligible differences were observed. Melting temperatures, UV–vis absorption spectra together with fluorescence quenching data indicate that Nile Blue stacks perfectly between the adjacent base pairs regardless of whether it has been attached via an S- or R-configured linker. This result was supported by geometrically optimized DNA models.

  16. 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

  17. Aliphatic acid-conjugated antimicrobial peptides--potential agents with anti-tumor, multidrug resistance-reversing activity and enhanced stability.

    Science.gov (United States)

    Deng, Xin; Qiu, Qianqian; Ma, Ke; Wang, Xuekun; Huang, Wenlong; Qian, Hai

    2015-07-28

    Compared with traditional therapeutics, antimicrobial peptides as novel anti-tumor agents have prominent advantages of higher specificity and circumvention of multi-drug resistance. In a previous study, we found that B1, an antimicrobial peptide derived from Cathelicidin-BF15, presented specific anti-tumor activity against several tumor cells. Since aliphatic chain-conjugated peptides have shown ameliorative activity and stability, we conjugated aliphatic acids with different lengths to the amino terminal of B1. All the conjugated peptides exhibited improved anti-tumor activity over B1. Further investigations revealed that the peptides were capable of disrupting the cell membrane, stimulating cytochrome c release into the cytosol, which results in apoptosis. The peptides also acted against multidrug resistant cells and had multidrug resistance-reversing effects. Additionally, conjugation of aliphatic acid enhanced the peptide stability in plasma. In summary, aliphatic acid-modified peptides might be promising anti-tumor agents in the future. PMID:26083110

  18. Distribution and sources of aliphatic hydrocarbons and fatty acids in surface sediments of a tropical estuary south west coast of India (Cochin estuary)

    Digital Repository Service at National Institute of Oceanography (India)

    Gireeshkumar, T.R.; Deepulal, P.M.; Chandramohanakumar, N.

    Surface sediments samples from the Cochin estuary were measured for elemental, stable isotopic and molecular biomarkers (aliphatic hydrocarbons and fatty acids) to study the sources and distribution of sedimentary organic matter. Concentrations...

  19. Synthesis of Novel Aliphatic N-sulfonylamidino Thymine Derivatives by Cu(I)-catalyzed Three-component Coupling Reaction

    OpenAIRE

    Krstulović, Luka; Ismaili, Hamit; Višnjevac, Aleksandar; Glavaš-Obrovac, Ljubica; Žinić, Biserka

    2012-01-01

    A series of new aliphatic N-sulfonylamidino thymine derivatives containing nucleobase, N-sulfonyl and amidine pharmacophores in the structure were synthesized by Cu(I)-catalyzed threecomponent coupling of 1-propargyl thymine, benzenesulfonyl azides and amines or ammonium salts. Preliminary in vitro antitumor screening (human cervix adenocarcinoma -HeLa and leukemia cells - Jurkat) revealed promising activities of N,N-diethyl- (2) and N-4-cyanobenzyl- (6) derivatives of 4-acetamido...

  20. The effect of aliphatic amines on the extraction of elements by phosphoryl-containing podands from hydrochloric acid media

    International Nuclear Information System (INIS)

    Distribution of Sc, Zn, Ga, Mo, Pd, Ag, Cd, In, Pt, Hg, Pb, Bi and U between HCl aqueous solutions and mixtures of phosphoryl-containing podands with aliphatic amines in dichloroethane is studied by the production of phosphoryl-containing podand complexes with a protonated amine molecule in the organic phase, which represent a cation section of extracted ion associates. Effect of amine and podand nature and HCl concentration on element extraction is considered. (author)

  1. Analysis of. gamma. -radiolysis products of aqueous solutions of esters of aliphatic amino acids by the PMR method

    Energy Technology Data Exchange (ETDEWEB)

    Panin, V.I.; Sidorov, P.S.; Usatyi, A.F.

    1987-09-01

    The ..gamma..-radiolysis of aqueous solutions of methyl esters of aliphatic amino acids and peptides was investigated by the method of nuclear (proton) magnetic resonance (PMR). The resonance lines appearing in the PMR spectra of the irradiated systems were identified, and a conclusion was drawn about the molecular structure of the radiolysis products. The kinetics of the accumulation of radiolysis products was studied, and the values of their radiation yields were estimated.

  2. Changes in aliphatic hydrocarbon tracer composition during the digestive process of the marine worm Nereis virens. Preliminary results

    OpenAIRE

    Gilbert, Franck; Stora, Georges; Desrosiers, Gaston; Gagne, Jean-Pierre; Deflandre, Bruno; Bertrand, Jean-Claude

    1998-01-01

    In the laboratory, marine worms were fed with a mixture of algae and several aliphatic hydrocarbons for 15 days. By comparing hydrocarbons in food and in faeces, it appeared that the worm's digestive process led to changes in the distribution of the n-alkanes mixture. These changes were different from those only due to physical processes in the experimental conditions, indicating that marine worm feeding could substantially affect the fate of hydrocarbons in the sedimentary marine ecosystem.

  3. {Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons in gas and particle phases in two sites of Mexico: MILAGRO project}

    Science.gov (United States)

    Amador-Muñoz, O.; Villalobos-Pietrini, R.; Castro, T.; Gaspariano-Larino, R.

    2009-04-01

    Aliphatic hydrocarbons are markers of anthropogenic and biogenic emission sources1; meanwhile PAHs are generated by incomplete combustion sources2. The last ones are important compounds due to their carcinogenic and mutagenic properties3,4. The aim of this study was to identify and quantify aliphatic hydrocarbons and PAHs in gas and particles phases of the atmospheric aerosol and to determine the day and night time behavior during the MILAGRO (Megacity Initiative: Local Global and Research Observations) campaign. The gas phase was collected on polyurethane foam, while particles less than 2.5 m (PM2.5) were collected on glass fiber filters covered with Teflon (TIGF, pallflex) of 8x10 in. Samplings were carried out with a high volume sampler (Tisch) with a flow of 1.13 m3 min-1 at two sites: Instituto Mexicano del Petróleo (T0) and Tecamac (T1) located at North and Northeast of Mexico City, respectively during day (7:00 am-7:00 pm) and night time (7:00 pm-7:00 am) from 1 to 29 of March, 2006. Ninteen PAHs and 23 aliphatic hydrocarbons from n-C13H28 to n-C35H72 were analyzed by gas chromatography coupled to mass spectrometry in impact mode. The samples were spiked with deuterads PAHs and aliphatics hydrocarbons before ultrasound extraction. Medians comparisons were made with Mann-Whitney U test. PAHs with molecular weight (MW) less than 228 g mol-1 were distributed in the gas phase, in both sites. Higher concentrations of PAHs ≥ 228 g mol-1 in PM2.5, were observed during night period (p

  4. Oxidation and degradation of short-chain aliphatic compounds by hyperazeotropic nitric acid

    International Nuclear Information System (INIS)

    To determine the ultimate fate of organic material present in nuclear fuel reprocessing solutions and the chemical nature of the last surviving residues, organic products of the hydrolysis/nitrolysis of tributyl phosphate were subjected to further degradation with boiling 20 M HNO3 (Iodox Process) and carbon balances were run. Except for methyl nitrate, nitrate esters were oxidized in refluxing 20 M HNO3, primarily to a mixture of carbon dioxide and the corresponding and shorter chain aliphatic acids. Typically, 40% or more of the carbon from the nitrate esters was converted to CO2. Except for formic acid, the straight-chain monobasic acids oxidized slowly. Compounds identified among those resulting from oxidation of butyric acid (e.g., from the oxidation of butyl nitrate) included succinic and oxalic acids, 3- and 4-hydroxy-butyric acids, nitrate esters of 3- and 4-hydroxybutyric acid, butyrolactone, and 3-nitrobutyric acid. The mechanisms for formation of these products are briefly discussed. Oxalic acid and the hydroxyaliphatic acids have some potential for complexing ceertain metallic fission products. These results show that traces of organic materials will always be present in actual fuel processing solutions unless special measures are taken to ensure their removal. This conclusion was reinforced by analysis of recycle acid from the Savannah River Plant. The possible implications to a reprocessing plant using 100% recycle are briefly discussed

  5. 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.

  6. Syntheses, structures, and properties of multidimensional lithium coordination polymers based on aliphatic carboxylic acids.

    Science.gov (United States)

    Cheng, Pei-Chi; Lin, Wei-Cheng; Tseng, Feng-Shuen; Kao, Ching-Che; Chang, Ting-Guang; Senthil Raja, Duraisamy; Liu, Wei-Ren; Lin, Chia-Her

    2013-02-28

    Three lithium coordination polymers, [Li4(H2O)2(EDTA)] (1), [Li4(H2O)4(BTCA)] (2), and (H2NMe2)2[Li2(H2O)2(BTCA)] (3) (H4EDTA = ethylenediaminetetraacetic acid, H4BTCA = 1,2,3,4-butane tetracarboxylic acid, H2NMe2 = dimethyl amine), have been synthesized by reacting lithium salts with aliphatic carboxylic acids using a solvothermal method. The structures of all the three complexes have been determined by single crystal X-ray diffraction studies. The single crystal structure analysis revealed that complex 1 has a three-dimensional framework, whereas complex 2 has 2D sheets and complex 3 has 1D chains. In addition, these lithium complexes contain various inorganic motifs with a tetramer in 1 and 2, and discrete tetrahedra in 3 and have further been connected through organic ligands to construct multidimensional structures. Further, the electrochemical properties of complexes 1–3 have been studied to evaluate these compounds as electrode materials for lithium ion batteries with discharge capacities of around 100 mA h g(-1) in the first thirty cycles. PMID:23235699

  7. Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

    Directory of Open Access Journals (Sweden)

    M. E. Erupe

    2008-07-01

    Full Text Available Primary aliphatic amines are an important class of nitrogen containing compounds found to be emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with NO3 has been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by extension NO3, large yields of aerosol mass loadings (~44% for butylamine are seen. Aerosol generated was determined to be organic in nature due to the small fraction of NO and NO2 in the total signal (<17% for all amines tested as detected by an aerosol mass spectrometer (AMS. We propose a reaction mechanism between carbonyl containing species and the parent amine leading to formation of particulate imine products. These findings can have significant impacts on rural communities and lead to elevated nighttime PM loadings, when significant levels on NO3 exist.

  8. Binuclear biologically active Co(II) complexes with octazamacrocycle and aliphatic dicarboxylates

    Science.gov (United States)

    Tanasković, S. B.; Vučković, G.; Antonijević-Nikolić, M.; Stanojković, T.; Gojgić-Cvijović, G.

    2012-12-01

    Four new cationic Co(II) complexes with N,N',N'',N'''-tetrakis (2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane (tpmc) and dianion of one the aliphatic dicarboxylic acids: butanedioic acid (succinic) acid = succH2, pentanedioic (glutaric) acid = gluH2, hexanedioic acid (adipic) acid = adipH2 or decanedioic acid (sebacic) acid = sebH2 of general formula [Co2(L)(tpmc)](ClO4)2ṡxY, L2- = succ, x = 1, Y = H2O; L = glu, x = 1, Y = H2O; L = adip, x = 1.5, Y = H2O; L = seb, x = 1, Y = CH3CN were isolated. The composition and charge are proposed based on elemental analyses (C, H, N) and electrical conductivity measurements. UV-Vis and FTIR spectral data and magnetic moments were in accordance with high-spin Co(II) state. It is proposed that in all complexes Co(II) is hexa-coordinated out of cyclam ring and that both carboxylic groups from dicarboxylate bridge participate in coordination. Oxygens from one group are most likely bonded to the same Co(II) ion thus forming a four-membered ring. The in vitro antibacterial/antiproliferative activities of the complexes were in some cases enhanced compared with the simple Co(II) salt and free ligands, tested as controls.

  9. Comparison of decomposition characteristics between aromatic and aliphatic VOCs using electron beam

    International Nuclear Information System (INIS)

    The removal efficiency of n-decane (C10H22) by electron beam was the highest among aliphatic VOCs of concern, and that of n-hexane (C6H14), n-butane (C4H10), and methane (CH4) followed. On the other hand, in terms of aromatic VOC decomposition efficiencies, benzene (C6H6) decomposition was the lowest and that of toluene (C7H8), ethylbenzene (C8H10), and p-xylene (C8H10) were similar. It was also found that there was increase in by-product (untreated VOC, CO, CO2, O3, 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)

  10. Solid, double-metal cyanide catalysts for synthesis of hyperbranched polyesters and aliphatic polycarbonates

    Indian Academy of Sciences (India)

    Joby Sebastian; Srinivas Darbha

    2014-03-01

    Fe-Zn and Co-Zn double-metal cyanide (DMC) complexes exhibit highly efficient and selective catalytic activity for synthesis of hyperbranched polyesters (glycerol-succinic acid (G-SA) and glycerol-adipic acid (G-AA)) and aliphatic polycarbonates (via., alternative co-polymerization of cyclohexene oxide and CO2), respectively. The influence of method of preparation of DMC, in particular the mode of addition of reagents, on its physicochemical and catalytic properties was investigated. Co-Zn DMC was found highly selective for polycarbonate (than polyethers) formation. Catalysts prepared using tert-butanol and PEG-4000 as complexing and co-complexing agents, respectively, were found superior to those prepared without these agents. Apart from its role as a coordinating ligand, tert-butanol activated the Lewis acidic Zn2+ sites for reactions in polyester and polycarbonate formation. Hydrophobicity, micro-mesoporosity, acid strength and the amount of coordinated complexing agent are some of the crucial factors influenced the catalytic activity of DMC complexes.

  11. Flow-induced Crystallization of Long Chain Aliphatic Polyamides under a Complex Flow Field

    Science.gov (United States)

    Dong, Xia; Gao, Yunyun; Wang, Lili; Wang, Dujin

    The present work deals with the flow-induced multiple orientations and crystallization structure of polymer melts under a complex flow field. This complex flow field is characteristic of the consistent coupling of extensional ``pulse'' and closely followed shear flow in a narrow channel. Utilizing an ingenious combination of an advanced micro-injection device and long chain aliphatic polyamides, the flow-induced crystallization morphology was well preserved for ex-situ synchrotron micro-focused wide angle X-ray scattering as well as small angle X-ray scattering. The experimental results clearly indicate that the effect of extensional pulse on the polymer melt is restrained and further diminished due to either the transverse tumble of fountain flow or the rapid retraction of stretched high molecular weight tails. However, the residual shish-kebab structures in the core layer of the far-end of channel suggest that the effect of extensional pulse should be considered in the small-scaled geometries or under the high strain rate condition. The authors thank the financial support from MOST (2013BAE02B02, 2014CB643600) and NSFC(21574140).

  12. Sum frequency generation image reconstruction: aliphatic membrane under spherical cap geometry.

    Science.gov (United States)

    Volkov, Victor

    2014-10-01

    The article explores an opportunity to approach structural properties of phospholipid membranes using Sum Frequency Generation microscopy. To establish the principles of sum frequency generation image reconstruction in such systems, at first approach, we may adopt an idealistic spherical cap uniform assembly of hydrocarbon molecules. Quantum mechanical studies for decanoic acid (used here as a representative molecular system) provide necessary information on transition dipole moments and Raman tensors of the normal modes specific to methyl terminal - a typical moiety in aliphatic (and phospholipid) membranes. Relative degree of localization and frequencies of the normal modes of methyl terminals make nonlinearities of this moiety to be promising in structural analysis using Sum Frequency Generation imaging. Accordingly, the article describes derivations of relevant macroscopic nonlinearities and suggests a mapping procedure to translate amplitudes of the nonlinearities onto microscopy image plane according to geometry of spherical assembly, local molecular orientation, and optical geometry. Reconstructed images indicate a possibility to extract local curvature of bilayer envelopes of spherical character. This may have practical implications for structural extractions in membrane systems of practical relevance. PMID:25296798

  13. Sum frequency generation image reconstruction: Aliphatic membrane under spherical cap geometry

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, Victor [Bereozovaya 2A, Konstantinovo, Moscow Region 140207 (Russian Federation)

    2014-10-07

    The article explores an opportunity to approach structural properties of phospholipid membranes using Sum Frequency Generation microscopy. To establish the principles of sum frequency generation image reconstruction in such systems, at first approach, we may adopt an idealistic spherical cap uniform assembly of hydrocarbon molecules. Quantum mechanical studies for decanoic acid (used here as a representative molecular system) provide necessary information on transition dipole moments and Raman tensors of the normal modes specific to methyl terminal – a typical moiety in aliphatic (and phospholipid) membranes. Relative degree of localization and frequencies of the normal modes of methyl terminals make nonlinearities of this moiety to be promising in structural analysis using Sum Frequency Generation imaging. Accordingly, the article describes derivations of relevant macroscopic nonlinearities and suggests a mapping procedure to translate amplitudes of the nonlinearities onto microscopy image plane according to geometry of spherical assembly, local molecular orientation, and optical geometry. Reconstructed images indicate a possibility to extract local curvature of bilayer envelopes of spherical character. This may have practical implications for structural extractions in membrane systems of practical relevance.

  14. Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

    Directory of Open Access Journals (Sweden)

    P. J. Silva

    2009-03-01

    Full Text Available Primary aliphatic amines are an important class of nitrogen containing compounds emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with O3 and NO3 have been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by extension NO3, large aerosol mass yields (~44% for butylamine are seen. Aerosol generated was determined to be organic in nature due to the small fraction of NO and NO2 in the total signal (<1% for all amines tested as detected by an aerosol mass spectrometer (AMS. We propose a reaction mechanism between carbonyl containing species and the parent amine leading to formation of particulate imine products. These findings can have significant impacts on rural communities with elevated nighttime PM loadings, when significant levels of NO3 exist.

  15. The androgen 5alpha-dihydrotestosterone and its metabolite 5alpha-androstan-3beta, 17beta-diol inhibit the hypothalamo-pituitary-adrenal response to stress by acting through estrogen receptor beta-expressing neurons in the hypothalamus.

    Science.gov (United States)

    Lund, Trent D; Hinds, Laura R; Handa, Robert J

    2006-02-01

    Estrogen receptor beta (ERbeta) and androgen receptor (AR) are found in high levels within populations of neurons in the hypothalamus. To determine whether AR or ERbeta plays a role in regulating hypothalamo-pituitary-adrenal (HPA) axis function by direct action on these neurons, we examined the effects of central implants of 17beta-estradiol (E2), 5alpha-dihydrotestosterone (DHT), the DHT metabolite 5alpha-androstan-3beta, 17beta-diol (3beta-diol), and several ER subtype-selective agonists on the corticosterone and adrenocorticotropin (ACTH) response to immobilization stress. In addition, activation of neurons in the paraventricular nucleus (PVN) was monitored by examining c-fos mRNA expression. Pellets containing these compounds were stereotaxically implanted near the PVN of gonadectomized male rats. Seven days later, animals were killed directly from their home cage (nonstressed) or were restrained for 30 min (stressed) before they were killed. Compared with controls, E2 and the ERalpha-selective agonists moxestrol and propyl-pyrazole-triol significantly increased the stress induced release of corticosterone and ACTH. In contrast, central administration of DHT, 3beta-diol, and the ERbeta-selective compound diarylpropionitrile significantly decreased the corticosterone and ACTH response to immobilization. Cotreatment with the ER antagonist tamoxifen completely blocked the effects of 3beta-diol and partially blocked the effect of DHT, whereas the AR antagonist flutamide had no effect. Moreover, DHT, 3beta-diol, and diarylpropionitrile treatment significantly decreased restraint-induced c-fos mRNA expression in the PVN. Together, these studies indicate that the inhibitory effects of DHT on HPA axis activity may be in part mediated via its conversion to 3beta-diol and subsequent binding to ERbeta. PMID:16452668

  16. 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

  17. Phase equilibria study of the (N-octylisoquinolinium thiocyanate ionic liquid + aliphatic and aromatic hydrocarbon, or thiophene) binary systems

    International Nuclear Information System (INIS)

    Highlights: • The LLE for n-alkanes and aromatic hydrocarbons in [C8iQuin][SCN] have been determined. • The NRTL equation was used to correlate experimental data. • The influence of the ionic liquid structure on mutual solubility was discussed. -- Abstract: Binary liquid + liquid phase equilibria for 8 systems containing N-octylisoquinolinium thiocyanate, [C8iQuin][SCN] and aliphatic hydrocarbon (n-hexane, n-heptane), cyclohexane, aromatic hydrocarbon (benzene, toluene, ethylbenzene, n-propylbenzene) and thiophene have been determined using dynamic method. The experiment was carried out from room temperature to the boiling-point of the solvent at atmospheric pressure. For the tested binary systems the mutual immiscibility with an upper critical solution temperature (UCST) for {IL + aliphatic hydrocarbon, or thiophene} were observed. The immiscibility gap with lower critical solution temperature (LCST) for the {IL + aromatic hydrocarbon} were determined. The parameters of the LLE correlation equation for the tested binary systems have been derived using NRTL equation. The phase equilibria diagrams presented in this paper are compared with literature data for the corresponding ionic liquids with N-alkylisoquinolinium, or N-alkylquinolinium cation and with thiocyanate – based ionic liquids. The influence of the ionic liquid structure on mutual solubility with aliphatic and aromatic hydrocarbons and thiophene is discussed

  18. Segregation and Alteration of Phenolic and Aliphatic Components of Root and Leaf Litter by Detritivores and Microbes

    Science.gov (United States)

    Filley, T. R.; Altmann, J.; Szlavecz, K. A.; Kalbitz, K.; Gamblin, D.; Nierop, K.

    2012-12-01

    The physical and microbial transformation of plant detritus in the litter layer and soil is accompanied by chemical separation of progressively soluble fractions and their movement into the rhizosphere driving subsequent soil processes. We investigated the combined action of specific detritivores, microbial decay, and leaching on the chemical separation of plant aromatic and aliphatic components from root, wood, and leaf tissue using 13C-TMAH thermochemolysis. This method enabled the simultaneous analysis of hydrolyzable tannin and lignin fragments, substituted fatty acids, and condensed tannin composition and revealed process-specific chemical transformations to plant secondary compounds. Long-term incubation and field sampling demonstrated how plant residues are progressively leached of the water soluble, oxidized fragments generated through decay. The residues appeared only slightly altered, in the case of brown rot wood, or enriched in aliphatic fragments, in the case of leaf and root tissue. Water extractable fractions were always selectively dominated by polyphenolics, either as demethylated lignin or tannins, and nearly devoid of aliphatic materials, despite high concentrations in the starting materials. Additionally, for plant materials with high tannin contents, such as pine needles, consumption and passage through some arthropod guts revealed what appeared to be microbially-mediated methylation of phenols, and a loss of tannins in leachates. These findings are indications for an in-situ phenol detoxification mechanism. This research provides important information regarding the links between biochemical decay and the chemical nature of organic matter removed and remaining in the soil profile.

  19. The Effect of Triton X-100 on Biodegradation of Aliphatic and Aromatic Fractions of Crude Oil in Soil

    Science.gov (United States)

    Minai-Tehrani, Dariush; Minooi, Saiid; Azari-Dehkordi, Forood; Herfatmanesh, Ali

    Crude oil is one the most common organic pollutant of the soil. The spillage of crude oil in the soil can be harmful to living organisms. Certain microorganisms are able to biodegrade crude oil and use it as sole carbon source. Some detergents were used to help the biodegradation of crude oil by microorganisms. In this study Triton X-100 was used to determine its effect in biodegradation of aliphatic and aromatic fractions of heavy crude oil in soil during 4 months. Different concentration of Triton X-100 (0 to 0.25%) was added to crude oil-contaminated soil with 2% (w/w) crude oil as final concentration. Present results demonstrated that in 0.025% of Triton X-100 the reduction of total crude oil, total aliphatic and total aromatic fractions were high, while in 0.05 to 0.25% the reduction reached to its minimum value. The higher reduction of phenanthrene, anthracene, fluoranthene and pyrene was observed in 0.025% Triton X-100 while it was lower in 0.25% followed by 0.1% Triton X-100. The low reduction of C17/pristane and C18/phytane in 0.25% Triton X-100 suggested low bioavaibility of aliphatic compounds in this concentration.

  20. An improved reagent for determination of aliphatic amines with fluorescence and online atmospheric chemical ionization-mass spectrometry identification

    International Nuclear Information System (INIS)

    An improved reagent named 2-[2-(dibenzocarbazole)-ethoxy] ethyl chloroformate (DBCEC-Cl) for the determination of aliphatic amines by high-performance liquid chromatography (HPLC) with fluorescence detection and post-column online atmospheric chemical ionization-mass spectrometry (APCI-MS) identification has been developed. DBCEC-Cl could easily and quickly label aliphatic amines. Derivatives were stable enough to be efficiently analyzed by HPLC and showed an intense protonated molecular ion corresponding m/z [M+H]+ under APCI-MS in positive-ion mode. The ratios for fluorescence responses were IDBCEC-amine/IBCEC-amine = 1.02-1.60; IDBCEC-amine/IBCEOC-amine = 1.30-2.57; and IDBCEC-amine/IFMOC-amine = 2.20-4.12 (here, I was relative fluorescence intensity). The ratios for MS responses were ICDBCEC-amine/ICBCEC-amine = 4.16-29.31 and ICDBCEC-amine/ICBCEOC-amine = 1.23-2.47 (Here, IC: APCI-MS ion current intensity). Detection limits calculated from 0.0244 pmol injection, at a signal-to-noise ratio of 3, were 0.3-3.0 fmol. The relative standard deviations for within-day determination (n = 6) were 0.045-0.081% for retention time and 0.86-1.03% for peak area for the tested aliphatic amines. The mean intra- and inter-assay precision for all amine levels were 0.9991.