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Sample records for acyclic diols triols

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

    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

  2. Perfluoroalkylated Derivatives of Diols and Triols. Selectivity in the Reaction of Primary and Secondary Hydroxy Groups with Perfluoroalkylepoxides. Hemocompatibility and Effect on Perfluorocarbon Emulsion

    Církva, Vladimír; Polák, R.; Paleta, O.; Kodíček, K.; Forman, S.

    2002-01-01

    Roč. 67, č. 10 (2002), s. 1436-1448. ISSN 0010-0765 R&D Projects: GA ČR GA203/98/1174; GA MŠk LB98233 Keywords : perfluoroalkyl epoxides * fluoroalkylations * fluorophilic triols Subject RIV: CC - Organic Chemistry Impact factor: 0.848, year: 2002

  3. Counting acyclic hypergraphs

    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. Acyclic social welfare

    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.

  5. Cycloartane-3,24,25-triol inhibits MRCKα kinase and demonstrates promising anti prostate cancer activity in vitro

    Lowe Henry I C

    2012-11-01

    Full Text Available Abstract Background Given the high occurrence of prostate cancer worldwide and one of the major sources of the discovery of new lead molecules being medicinal plants, this research undertook to investigate the possible anti-cancer activity of two natural cycloartanes; cycloartane-3,24,25-diol (extracted in our lab from Tillandsia recurvata and cycloartane-3,24,25-triol (purchased. The inhibition of MRCKα kinase has emerged as a potential solution to restoring the tight regulation of normal cellular growth, the loss of which leads to cancer cell formation. Methods Kinase inhibition was investigated using competition binding (to the ATP sites assays which have been previously established and authenticated and cell proliferation was measured using the WST-1 assay. Results Cycloartane-3,24,25-triol demonstrated strong selectivity towards the MRCKα kinase with a Kd50 of 0.26 μM from a total of 451 kinases investigated. Cycloartane-3,24,25-triol reduced the viability of PC-3 and DU145 cell lines with IC50 values of 2.226 ± 0.28 μM and 1.67 ± 0.18 μM respectively. Conclusions These results will prove useful in drug discovery as Cycloartane-3,24,25-triol has shown potential for development as an anti-cancer agent against prostate cancer.

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

    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.

  7. Enumeration of Maximum Acyclic Hypergraphs

    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.

  8. Acyclic Nucleoside Phosphonates

    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

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

    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})

  10. ON ACYCLIC AND CYCLIC HYPERGRAPHS

    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

    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

    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. Convex sets in acyclic digraphs

    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.

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

    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

  15. Semisynthesis and biological evaluation of ganodermanontriol and its stereoisomeric triols.

    Kennedy, Erin M; P'Pool, Steven J; Jiang, Jiahua; Sliva, Daniel; Minto, Robert E

    2011-11-28

    The first synthesis of ganodermanontriol, a bioactive lanostane triterpene from the medicinal mushroom Ganoderma lucidum, has been achieved in 15.3% yield over nine steps, along with its three stereoisomeric triols and ganoderol A. The key steps leading to this family of isomers involve the reconstruction of the trisubstituted alkene by stereoselective and chemoselective phosphonate reactions and the formation of the unusual Δ7,9(11)-diene core by the mild acidic opening of a lanosterone-derived epoxide. Ganodermanontriol showed promising activity on the inhibition and proliferation of breast cancer cells. The effect of ganodermanontriol and its isomers on cell proliferation was assayed; IC50 values of 5.8 and 9.7 μM on breast cancer cell lines MCF-7 and MDA-MB-231, respectively, were found for ganodermanontriol. PMID:22044278

  16. Synthetic approaches to novel acyclic nucleoside phosphonates

    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

  17. Cholestane-3β, 5α, 6β-triol suppresses proliferation, migration, and invasion of human prostate cancer cells.

    Ching-Yu Lin

    Full Text Available Oxysterols are oxidation products of cholesterol. Cholestane-3β, 5α, 6β-triol (abbreviated as triol is one of the most abundant and active oxysterols. Here, we report that triol exhibits anti-cancer activity against human prostate cancer cells. Treatment of cells with triol dose-dependently suppressed proliferation of LNCaP CDXR-3, DU-145, and PC-3 human prostate cancer cells and reduced colony formation in soft agar. Oral administration of triol at 20 mg/kg daily for three weeks significantly retarded the growth of PC-3 xenografts in nude mice. Flow cytometric analysis revealed that triol treatment at 10-40 µM caused G1 cell cycle arrest while the TUNEL assay indicated that triol treatment at 20-40 µM induced apoptosis in all three cell lines. Micro-Western Arrays and traditional Western blotting methods indicated that triol treatment resulted in reduced expression of Akt1, phospho-Akt Ser473, phospho-Akt Thr308, PDK1, c-Myc, and Skp2 protein levels as well as accumulation of the cell cycle inhibitor p27(Kip. Triol treatment also resulted in reduced Akt1 protein expression in PC-3 xenografts. Overexpression of Skp2 in PC-3 cells partially rescued the growth inhibition caused by triol. Triol treatment suppressed migration and invasion of DU-145, PC-3, and CDXR-3 cells. The expression levels of proteins associated with epithelial-mesenchymal transition as well as focal adhesion kinase were affected by triol treatment in these cells. Triol treatment caused increased expression of E-cadherin protein levels but decreased expression of N-cadherin, vimentin, Slug, FAK, phospho-FAK Ser722, and phospho-FAK Tyr861 protein levels. Confocal laser microscopy revealed redistribution of β-actin and α-tubulin at the periphery of the CDXR-3 and DU-145 cells. Our observations suggest that triol may represent a promising therapeutic agent for advanced metastatic prostate cancer.

  18. QSPR models based on molecular mechanics and quantum chemical calculations. 1. Construction of Boltzmann averaged descriptors for alkanes, alcohols, diols, ethers and cyclic compounds

    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...

  19. Algorithms for Junctions in Directed Acyclic Graphs

    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.

  20. Categorification of acyclic cluster algebras: an introduction

    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

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

    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. Rapid synthesis of macrocycles from diol precursors

    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...

  4. 3000 Horsepower super conductive field acyclic motor

    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

  5. Direct Copolymerization of CO2 and Diols

    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.

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

    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).

  7. Acyclic Edge Coloring of Planar Graphs without Adjacent Triangles

    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.

  8. Estudo da biocompatibilidade da blenda de poli(L-ácido láctico/policaprolactona-triol Biocompatibility study of poly(L-acid-lactic/polycaprolactone triol blend

    Mauricio K. Minata

    2013-01-01

    Full Text Available Polímeros biorreabsorvíveis têm sido estudados para aplicações médicas especialmente nas áreas de ortopedia e traumatologia. Dentre os mais promissores destaca-se o poli(L- ácido láctico, devido a sua elevada resistência e boa biocompatibilidade. Apesar dessas características os dispositivos obtidos a partir do PLLA têm baixa elongação e um caráter hidrofóbico, fatores que dificultam seu emprego em aplicações onde a interação tecido/implante seja um fator importante. O objetivo do trabalho foi obter membranas de PLLA e melhorar suas propriedades pela adição de 10% de poli(e-caprolactone (PCL-triol, um polímero semicristalino. Para isso membranas foram implantadas no tecido subcutâneo de ratos Wistar, e análises histológicas dos segmentos das áreas implantadas foram realizadas nos tempos de 2, 7, 15, 30, 60, 90, 180 dias a fim de se avaliarem as interações polímero/tecido. Não foram observadas respostas inflamatórias exacerbadas em nenhum tempo estudado. Verificou-se a formação de cápsula fibrosa envolvendo a área implantada com presença de fibroblastos, fibrócitos e células gigantes multinucleadas. Concluímos que as membranas de PLLA contendo PCL-triol apresentaram resistência ao processo de degradação, podendo ainda ser observadas após 180 dias de estudo.Bioabsorbable polymers have been studied for medical applications, especially for orthopedics and traumatology area. Among these promising polymers there is great emphasis on Poly (l-lactic acid, PLLA, due to its high strength and good biocompatibility. In spite of these characteristics, the devices obtained from the PLLA have low elongation and a hydrophobic character, which hamper its use in applications in which the tissue/implant interaction is an important factor. The aim of this work is to obtain PLLA membranes and to improve its properties adding 10% of poly (e-caprolactone (PCL-triol, a semicrystalline polymer. For this proposal membranes were

  9. On network coding for acyclic networks with delays

    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...

  10. Bayesian Discovery of Linear Acyclic Causal Models

    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...

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

    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

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

    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...

  13. Acyclic archaebacterial ether lipids in swamp sediments

    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.

  14. Approximating acyclicity parameters of sparse hypergraphs

    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...

  15. Acyclic Preference Systems in P2P Networks

    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.

  16. 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.

    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

  17. On the Existence of Undominated Elements of Acyclic Relations

    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.

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

    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...

  19. Intervertebral disk-like biphasic scaffold—demineralized bone matrix cylinder and poly(polycaprolactone triol malate)—for interbody spine fusion

    Li Jin; Yuqing Wan; Shimer, Adam L.; Shen, Francis H.; Li, Xudong J

    2012-01-01

    Interbody fusion is an established procedure to preserve disk height and anterior fusion, but fusion with autografts, allografts, and metallic cages has its endogenous shortcomings. The objective of this study is to investigate whether a biphasic scaffold model, the native demineralized bone matrix cylinder in conjunction with degradable biomaterial poly(polycaprolactone triol malate), can be employed as a biological graft for interbody fusion. The poly(polycaprolactone triol malate) was synt...

  20. Anti-apoptotic phenotypes of cholestan-3β,5α,6β-triol-resistant human cholangiocytes: characteristics contributing to the genesis of cholangiocarcinoma

    Jusakul, Apinya; Loilome, Watcharin; Namwat, Nisana; Techasen, Anchalee; Kuver, Rahul; Ioannou, George; Savard, Christopher; Haigh, W. Geoffrey; Yongvanit, Puangrat

    2013-01-01

    The oxysterols cholestan-3β, 5α, 6β-triol (Triol) and 3-keto-cholest-4-ene (3K4) are increased in Opisthorchis viverrini-associated hamster cholangiocarcinoma and induce DNA damage and apoptosis via a mitochondria-dependent mechanism in MMNK-1 human cholangiocytes. Based on these observations, we hypothesized that chronic exposure of cholangiocytes to these pathogenic oxysterols may allow a growth advantage to a subset of these cells through selection for resistance to apoptosis, thereby cont...

  1. Cell transfection with a β-cyclodextrin-PEI-propane-1,2,3-triol nanopolymer.

    Wing-Fu Lai

    Full Text Available Successful gene therapy necessitates safe and efficient gene transfer. This article describes the use of a cationic polymer, which was synthesized by cross-linking low molecular weight branched poly(ethylenimine (PEI with both β-cyclodextrin and propane-1,2,3-triol, for efficient and safe non-viral gene delivery. Experimentation demonstrated that the polymer had a pH buffering capacity and DNA condensing ability comparable to those of PEI 25 kDa. In B16-F0 cells, the polymer increased the transfection efficiency of naked DNA by 700-fold and yielded better transfection efficiencies than Fugene HD (threefold higher and PEI 25 kDa (fivefold higher. The high transfection efficiency of the polymer was not affected by the presence of serum during transfection. In addition to B16-F0 cells, the polymer enabled efficient transfection of HepG2 and U87 cells with low cytotoxicity. Our results indicated that our polymer is a safe and efficient transfection reagent that warrants further development for in vitro, in vivo and clinical applications.

  2. Anti-apoptotic phenotypes of cholestan-3β,5α,6β-triol-resistant human cholangiocytes: characteristics contributing to the genesis of cholangiocarcinoma.

    Jusakul, Apinya; Loilome, Watcharin; Namwat, Nisana; Techasen, Anchalee; Kuver, Rahul; Ioannou, George N; Savard, Christopher; Haigh, W Geoffrey; Yongvanit, Puangrat

    2013-11-01

    The oxysterols cholestan-3β,5α,6β-triol (Triol) and 3-keto-cholest-4-ene (3K4) are increased in Opisthorchis viverrini-associated hamster cholangiocarcinoma and induce DNA damage and apoptosis via a mitochondria-dependent mechanism in MMNK-1 human cholangiocytes. Based on these observations, we hypothesized that chronic exposure of cholangiocytes to these pathogenic oxysterols may allow a growth advantage to a subset of these cells through selection for resistance to apoptosis, thereby contributing to cholangiocarcinogenesis. To test this hypothesis, we cultured MMNK-1 cells long-term in the presence of Triol. Alteration in survival and apoptotic factors of Triol-exposed cells were examined. Cells cultured long-term in the presence of Triol were resistant to H2O2-induced apoptosis, and demonstrated an increase in the phosphorylation of p38-α, CREB, ERK1/2 and c-Jun. Elevations in the ratio of Bcl-2/Bax and in the protein levels of anti-apoptotic factors including cIAP2, clusterin, and survivin were detected. These results show that long-term exposure of MNNK-1 cells to low doses of Triol selects for kinase-signaling molecules which regulate resistance to apoptosis and thereby enhance cell survival. Clonal expansion of such apoptosis-resistant cells may contribute to the genesis of cholangiocarcinoma. PMID:23959098

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

    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.

  4. Inverse Eigenvalue Problems for Two Special Acyclic Matrices

    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.

  5. Synthesis of some novel hydrazono acyclic nucleoside analogues

    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.

  6. Rhenium-Catalyzed Deoxydehydration of Diols and Polyols

    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....

  7. Synthesis and complexation characteristics of phenanthroline and bipyridine diols

    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

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

    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

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

    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

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

    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...

  11. Tyrosine-based prodrugs of acyclic nucleoside phosphonates

    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

  12. Synthesis of chiral open-ring acyclic nucleoside bisphosphonates

    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

  13. Acyclic Nucleoside Phosphonates as Potential Anti-Malarial Agents

    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

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

    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 ...

  15. Trends and challenges in chemistry of acyclic nucleoside phosphonates

    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

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

    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

  17. Acyclic Preference Systems in P2P Networks

    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...

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

    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...

  19. Directed acyclic graphs with edge-specific bounds

    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...

  20. Modelling discrete longitudinal data using acyclic probabilistic finite automata

    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...

  1. Path-equivalent developments in acyclic weighted automata

    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...

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

    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.

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

    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.

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

    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.

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

    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.

  6. On Event Detection and Localization in Acyclic Flow Networks

    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.

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

    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...

  8. Mechanical Properties of Membranes of Poly(L-co-DL-lactic acid) with Poly(caprolactone triol) and Study In Vivo

    Marcia Adriana Tomaz Duarte; Adriana Cristina Motta; Eliana Aparecida Rezende Duek

    2014-01-01

    There is increasing interest in aliphatic polyesters from lactones and lactides because of their biodegradability and biocompatibility. Among these compounds, poly(lactide), and poly(glycolide), poly(ε-caprolactone) and their copolymers are especially interesting because of their potential applications as biomedical materials. The aim of this study was to examine the properties of membranes of poly(L-co-D,L lactic acid) (PLDLA) with poly(caprolactone triol) (PCL-T) obtained by solvent evapora...

  9. Bioassay guided isolation of a new C18-polyacetylene, (+)-9(Z),17-octadecadiene-12,14-diyne-1,11,16-triol, from Cassonia barteri.

    Papajewski, S; Guse, J H; Klaiber, I; Roos, G; Süssmuth, R; Vogler, B; Walter, C U; Kraus, W

    1998-06-01

    A novel C18-polyacetylene, (+)-9( Z),17-octadecadiene-12,14-diyne-1,11,16-triol, has been isolated from the ethyl acetate extract of Cassonia barteri (Araliaceae) leaves collected in Cameroon. The structure determination was achieved by NMR, mass, IR, and UV spectroscopy. The new polyenyne shows antibacterial activity against Bacillus subtilis and Pseudomonas fluorescens, antifungal activity against Cladosporium cucumerinum, moiluscicidal activity against Biomphalaria glabrata at low concentrations, and in addition it possesses haemolytic activity. PMID:17253268

  10. Evaluation of plasma cholestane-3β,5α,6β-triol and 7-ketocholesterol in inherited disorders related to cholesterol metabolism.

    Boenzi, Sara; Deodato, Federica; Taurisano, Roberta; Goffredo, Bianca Maria; Rizzo, Cristiano; Dionisi-Vici, Carlo

    2016-03-01

    Oxysterols are intermediates of cholesterol metabolism and are generated from cholesterol via either enzymatic or nonenzymatic pathways under oxidative stress conditions. Cholestan-3β,5α,6β-triol (C-triol) and 7-ketocholesterol (7-KC) have been proposed as new biomarkers for the diagnosis of Niemann-Pick type C (NP-C) disease, representing an alternative tool to the invasive and time-consuming method of fibroblast filipin test. To test the efficacy of plasma oxysterol determination for the diagnosis of NP-C, we systematically screened oxysterol levels in patients affected by different inherited disorders related with cholesterol metabolism, which included Niemann-Pick type B (NP-B) disease, lysosomal acid lipase (LAL) deficiency, Smith-Lemli-Opitz syndrome (SLOS), congenital familial hypercholesterolemia (FH), and sitosterolemia (SITO). As expected, NP-C patients showed significant increase of both C-triol and 7-KC. Strong increase of both oxysterols was observed in NP-B and less pronounced in LAL deficiency. In SLOS, only 7-KC was markedly increased, whereas in both FH and in SITO, oxysterol concentrations were normal. Interestingly, in NP-C alone, we observed that plasma oxysterols correlate negatively with patient's age and positively with serum total bilirubin, suggesting the potential relationship between oxysterol levels and hepatic disease status. Our results indicate that oxysterols are reliable and sensitive biomarkers of NP-C. PMID:26733147

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

    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.

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

    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...

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

    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.

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

    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

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

    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.

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

    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.

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

    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.

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

    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

    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

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

    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...

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

    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

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

    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

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

    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

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

    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

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

    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

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

    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

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

    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.

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

    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.

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

    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

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

    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.

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

    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

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

    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

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

    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

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

    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

  17. (24S)-ergostane-3β,5α,6β-triol from Hedyotis chrysotricha with inhibitory activity on migration of SK-HEP-1 human hepatocarcinoma cells.

    Ye, Miao; Su, Jing-Jing; Liu, Shu-Ting; Cao, Lei; Xiong, Juan; Zhao, Yun; Fan, Hui; Yang, Guo-Xun; Xia, Gang; Hu, Jin-Feng

    2013-01-01

    The methanol extract of the whole plant of Hedyotis chrysotricha demonstrated cytotoxicity against SK-HEP-1 human hepatocarcinoma cells in a primary screening for novel antitumour agents. Bioassay-guided fractionation and purification led to an active principle (24S)-ergostane-3β,5α,6β-triol (1) along with four inactive compounds (2-5). The in vitro transwell migration assay showed that compound 1 remarkably reduced the migration of SK-HEP-1 cells by 78.9% at a dose of 30 µM, without any apoptotic effect on this cell line. Moreover, all the isolated compounds were further evaluated for their cytotoxicities against another four human cancer cell lines (MCF-7, NUGC3, SH-SY5Y and PC-3). PMID:22889249

  18. 5-Androstene-3β,7β,17β-triol (β-AET slows thermal injury induced osteopenia in mice: relation to aging and osteoporosis.

    Ajay K Malik

    Full Text Available 5-Androstene-3β,7β,17β-triol (β-AET, an active metabolite of dehydroepiandrosterone (DHEA, reversed glucocorticoid (GC-induced suppression of IL-6, IL-8 and osteoprotegerin production by human osteoblast-like MG-63 cells and promoted osteoblast differentiation of human mesenchymal stem cells (MSCs. In a murine thermal injury model that includes glucocorticoid-induced osteopenia, β-AET significantly (p<0.05 preserved bone mineral content, restored whole body bone mineral content and endochondral growth, suggesting reversal of GC-mediated decreases in chondrocyte proliferation, maturation and osteogenesis in the growth plate. In men and women, levels of β-AET decline with age, consistent with a role for β-AET relevant to diseases associated with aging. β-AET, related compounds or synthetic derivatives may be part of effective therapeutic strategies to accelerate tissue regeneration and prevent or treat diseases associated with aging such as osteoporosis.

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

    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)

  20. Self-microemulsifying drug-delivery system for improved oral bioavailability of 20(S-25-methoxyl-dammarane-3β, 12β, 20-triol: preparation and evaluation

    Cai S

    2014-02-01

    Full Text Available Shuang Cai,1,* Cai-Hong Shi,2,* Xiangrong Zhang,2 Xiaojiao Tang,2 Hao Suo,2 Li Yang,2 Yuqing Zhao2 1Department of Pharmacy, The First Affiliated Hospital of China Medical University, 2Shenyang Pharmaceutical University, Shenyang, People's Republic of China *These authors contributed equally to this work Abstract: The objective of this study was to develop a self-microemulsifying drug delivery system (SMEDDS to enhance the oral bioavailability of the poorly water-soluble compound 20(S-25-methoxydammarane-3β;12β;20-triol (25-OCH3-PPD. Optimized SMEDDS formulations for 25-OCH3-PPD contained Cremophor® EL (50% as the surfactant, glycerin (20% as the cosurfactant, and Labrafil® M1944 (30% as the oil. The SMEDDS were characterized by morphological observation and mean droplet size. The pharmacokinetics and bioavailability of the 25-OCH3-PPD suspension and SMEDDS were evaluated and compared in rats. The plasma concentrations of 25-OCH3-PPD and its main metabolite, 25-OH-PPD, were determined by ultra performance liquid chromatography-tandem mass spectrometry. The relative bioavailability of SMEDDS was dramatically enhanced by an average of 9.8-fold compared with the suspension. Improved solubility and lymphatic transport may contribute to this enhanced bioavailability. Our studies highlight the promise of SMEDDS for the delivery of 25-OCH3-PPD via the oral route. Keywords: 25-methoxydammarane-3β;12β;20-triol (25-OCH3-PPD, 25-OH-PPD, self-microemulsifying drug delivery system, bioavailability, pharmacokinetics

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

    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.

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

    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

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

    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

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

    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

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

    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.

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

    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

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

    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

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

    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

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

    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...

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

    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 ...

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

    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

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

    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...

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

    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

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

    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

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

    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

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

    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.

  17. Cholestane-3β,5α,6β-triol: high levels in Niemann-Pick type C, cerebrotendinous xanthomatosis, and lysosomal acid lipase deficiency.

    Pajares, Sonia; Arias, Angela; García-Villoria, Judit; Macías-Vidal, Judit; Ros, Emilio; de las Heras, Javier; Girós, Marisa; Coll, Maria J; Ribes, Antonia

    2015-10-01

    Niemann-Pick type C (NPC) is a progressive neurodegenerative disease characterized by lysosomal/endosomal accumulation of unesterified cholesterol and glycolipids. Recent studies have shown that plasma cholestane-3β,5α,6β-triol (CT) and 7-ketocholesterol (7-KC) could be potential biomarkers for the diagnosis of NPC patients. We aimed to know the sensitivity and specificity of these biomarkers for the diagnosis of NPC compared with other diseases that can potentially lead to oxysterol alterations. We studied 107 controls and 122 patients including 16 with NPC, 3 with lysosomal acid lipase (LAL) deficiency, 8 with other lysosomal diseases, 5 with galactosemia, 11 with cerebrotendinous xanthomatosis (CTX), 3 with Smith-Lemli-Opitz, 14 with peroxisomal biogenesis disorders, 19 with unspecific hepatic diseases, 13 with familial hypercholesterolemia, and 30 with neurological involvement and no evidence of an inherited metabolic disease. CT and 7-KC were analyzed by HPLC-ESI-MS/MS as mono-dimethylglycine derivatives. Levels of 7-KC were high in most of the studied diseases, whereas those of CT were only high in NPC, LAL, and CTX patients. Consequently, although CT is a sensitive biomarker of NPC disease, including those cases with doubtful filipin staining, it is not specific. 7-KC is a very unspecific biomarker. PMID:26239048

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

    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

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

    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.

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

    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

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

    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.

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

    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.

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

    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.

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

    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.

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

    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

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

    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

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

    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.

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

    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.

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

    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 ...

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

    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

  11. Oral subchronic toxicity evaluation of a novel antitumor agent 25-methoxydammarane-3, 12, 20-triol from Panax notoginseng in Sprague-Dawley rats.

    Li, Wei; Zhang, Xiangrong; Xin, Yanfei; Xuan, Yaoxian; Liu, Jinping; Li, Pingya; Zhao, Yuqing

    2016-06-01

    Panax notoginseng and its main active ingredients ginsenosides have long been used as medicines and food additives in China. Comparing with the extensive uses and active researches of P. notoginseng and its products, the side effect and probable toxicity were rare. 25-Methoxydammarane-3,12,20-triol (25-OCH3-PPD), a novel dammarane-type triterpene sapogenin that was first isolated from the extract of P. notoginseng, was proven to have strong antitumor activities against prostate cancer, breast cancer and lung cancer. The aim of the present study was to investigate the potential subchronic toxicity of 25-OCH3-PPD after it was repeatedly orally administered to Sprague-Dawley rats (5/sex/group/each time-point) at dose levels of 0, 150, 300 or 600 mg/kg/day for 13 weeks and 4-week recovery. No mortality and treatment-related toxicity effects were observed as a result of the administration of 25-OCH3-PPD at any dose level (150, 300 and 600 mg/kg) for 92 consecutive days. Although there were some statistical changes, such as increased weights in female rats and decreased organ weights and coefficients of the liver, spleen, kidney, and adrenal gland compared with the control group at the corresponding time, the autopsy and histopathological examination of the target organs did not show any abnormal responses. As a result, 25-OCH3-PPD was well tolerated by SD rat at doses of up to 600 mg/kg and that it is a potential candidate for therapeutic use. PMID:27002186

  12. Pulse radiolysis study of the spectral and kinetic properties of the solvated electron in liquid hexane-1,2,6-triol

    The optical absorption spectrum of the solvated electron (es-) in liquid hexane-1,2,6-triol has been measured by nanosecond pulse radiolysis at different temperatures (10-40 deg C) to investigate the influence of high solvent viscosity values on the spectral and kinetic properties of es-. The wavelength at the absorption maximum, λmax, is equal to 560 nm, and its variation with temperature is less than the experimental error. At 20 deg C and 150 ns, the value of the product Gε of the yield of es-and the molar extinction coefficient at λmax is 2.55 x 104 molecule/(M cm 100 eV). In the context of this work, we have compared results obtained with both a linear accelerator and a Febetron, a comparison that has allowed to evaluate the influence of variations of the dose per pulse, and to extend measurements to short times. In the case of experiments performed with the linear accelerator, es- is is found to decay at all wavelengths by a first-order (or pseudo first-order) reaction with an activation energy of ∼45 kJ mol-1. By contrast, kinetic curves obtained with the Febetron seem to show a competition in which a second-order law is followed at short times. The fact that the shape of the spectra seems to vary with dose per pulse indicates the possible intervention of another, short lived, species. The kinetics of electron solvation does not seem to be controlled by solvent viscosity under the conditions studied. (author). 20 refs., 5 figs

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

    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.

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

    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.

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

    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

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

    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....

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

    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...

  18. 211At-Rh(16-S4-diol) complex as a precursor for astatine radiopharmaceuticals

    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

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

    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

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

    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...

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

    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.

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

    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

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

    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

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

    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

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

    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.

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

    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.

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

    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

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

    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

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

    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.

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

    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.

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

    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

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

    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...

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

    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

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

    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...

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

    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.

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

    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...

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

    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.

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

    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.

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

    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.

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

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

    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

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

    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

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

    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

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

    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

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

    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

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

    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

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

    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

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

    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

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

    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

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

    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

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

    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 \\...

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

    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...

  13. Comprehensive Evaluation of Plasma 7-Ketocholesterol and Cholestan-3β,5α,6β-Triol in an Italian Cohort of Patients Affected by Niemann-Pick Disease due to NPC1 and SMPD1 Mutations.

    Romanello, Milena; Zampieri, Stefania; Bortolotti, Nadia; Deroma, Laura; Sechi, Annalisa; Fiumara, Agata; Parini, Rossella; Borroni, Barbara; Brancati, Francesco; Bruni, Amalia; Russo, Cinzia V; Bordugo, Andrea; Bembi, Bruno; Dardis, Andrea

    2016-04-01

    Niemann-Pick C disease (NPCD) is a rare autosomal recessive neurovisceral disorder with a heterogeneous clinical presentation. Cholestan-3β,5α,6β-triol and 7-ketocholesterol have been proposed as biomarkers for the screening of NPCD. In this work, we assessed oxysterols levels in a cohort of Italian patients affected by NPCD and analyzed the obtained results in the context of the clinical, biochemical and molecular data. In addition, a group of patients affected by Niemann-Pick B disease (NPBD) were also analyzed. NPC patients presented levels of both oxysterols way above the cut off value, except for 5 siblings presenting the variant biochemical phenotype who displayed levels of 3β,5α,6β-triol below or just above the cut-off value; 2 of them presented also normal levels of 7-KC. Both oxysterols were extremely high in a patient presenting the neonatal systemic lethal phenotype. All NPB patients showed increased oxysterols levels. In conclusion, the reported LC-MS/MS assay provides a robust non-invasive screening tool for NPCD. However, false negative results can be obtained in patients expressing the variant biochemical phenotype. These data strengthen the concept that the results should always be interpreted in the context of the patients' clinical picture and filipin staining and/or genetic studies might still be undertaken in patients with normal levels of oxysterols if symptoms are highly suggestive of NPCD. Both oxysterols are significantly elevated in NPB patients; thus a differential diagnosis should always be performed in patients presenting isolated hepatosplenomegaly, a common clinical sign of both NPCD and NPBD. PMID:26790753

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

    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

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

    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.

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

    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...

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

    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.

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

    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.

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

    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

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

    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

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

    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

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

    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.

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

    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

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

    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.

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

    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

  6. 2-[(5-Chloro-2-oxidobenzylideneazaniumyl]-2-methylpropane-1,3-diol

    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.

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

    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.

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

    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.

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

    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

  10. 6-Methyl-1,3,5-triazine-2,4-diamine butane-1,4-diol monosolvate

    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.

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

    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...

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

    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

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

    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

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

    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

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

    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 ...

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

    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

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

    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

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

    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

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

    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...

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

    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

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

    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)

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

    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

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

    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...

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

    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

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

    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...

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

    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...

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

    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

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

    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

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

    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

  10. 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

    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.)

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

    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

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

    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...

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

    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.

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

    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)

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

    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.

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

    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

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

    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

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

    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

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

    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...

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

    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...

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

    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

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

    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

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

    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.

  4. 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

    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...

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

    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....

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

    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

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

    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.

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

    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.

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

    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

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

    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

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

    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.

    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.

    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.

    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

    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

    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.

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

    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

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

    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

  20. 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

    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

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

    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

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

    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

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

    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

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

    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

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

    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

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

    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.

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

    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

  8. Two natural products, trans-phytol and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol, inhibit the biosynthesis of estrogen in human ovarian granulosa cells by aromatase (CYP19)

    Aromatase is the only enzyme in vertebrates to catalyze the biosynthesis of estrogens. Although inhibitors of aromatase have been developed for the treatment of estrogen-dependent breast cancer, the whole-body inhibition of aromatase causes severe adverse effects. Thus, tissue-selective aromatase inhibitors are important for the treatment of estrogen-dependent cancers. In this study, 63 natural products with diverse structures were examined for their effects on estrogen biosynthesis in human ovarian granulosa-like KGN cells. Two compounds—trans-phytol (SA-20) and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol (SA-48)—were found to potently inhibit estrogen biosynthesis (IC50: 1 μM and 0.5 μM, respectively). Both compounds decreased aromatase mRNA and protein expression levels in KGN cells, but had no effect on the aromatase catalytic activity in aromatase-overexpressing HEK293A cells and recombinant expressed aromatase. The two compounds decreased the expression of aromatase promoter I.3/II. Neither compound affected intracellular cyclic AMP (cAMP) levels, but they inhibited the phosphorylation or protein expression of cAMP response element-binding protein (CREB). The effects of these two compounds on extracellular regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinases (MAPKs), and AKT/phosphoinositide 3-kinase (PI3K) pathway were examined. Inhibition of p38 MAPK could be the mechanism underpinning the actions of these compounds. Our results suggests that natural products structurally similar to SA-20 and SA-48 may be a new source of tissue-selective aromatase modulators, and that p38 MAPK is important in the basal control of aromatase in ovarian granulosa cells. SA-20 and SA-48 warrant further investigation as new pharmaceutical tools for the prevention and treatment of estrogen-dependent cancers. - Highlights: • Two natural products inhibited estrogen biosynthesis in human ovarian granulosa cells. • They inhibited

  9. Two natural products, trans-phytol and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol, inhibit the biosynthesis of estrogen in human ovarian granulosa cells by aromatase (CYP19)

    Guo, Jiajia [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Yuan, Yun [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang (China); Lu, Danfeng; Du, Baowen [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Xiong, Liang; Shi, Jiangong [State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Yang, Lijuan [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Liu, Wanli [MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084 (China); Yuan, Xiaohong [School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang (China); Zhang, Guolin, E-mail: zhanggl@cib.ac.cn [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu (China); Wang, Fei, E-mail: wangfei@cib.ac.cn [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu (China); Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu (China)

    2014-08-15

    Aromatase is the only enzyme in vertebrates to catalyze the biosynthesis of estrogens. Although inhibitors of aromatase have been developed for the treatment of estrogen-dependent breast cancer, the whole-body inhibition of aromatase causes severe adverse effects. Thus, tissue-selective aromatase inhibitors are important for the treatment of estrogen-dependent cancers. In this study, 63 natural products with diverse structures were examined for their effects on estrogen biosynthesis in human ovarian granulosa-like KGN cells. Two compounds—trans-phytol (SA-20) and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol (SA-48)—were found to potently inhibit estrogen biosynthesis (IC{sub 50}: 1 μM and 0.5 μM, respectively). Both compounds decreased aromatase mRNA and protein expression levels in KGN cells, but had no effect on the aromatase catalytic activity in aromatase-overexpressing HEK293A cells and recombinant expressed aromatase. The two compounds decreased the expression of aromatase promoter I.3/II. Neither compound affected intracellular cyclic AMP (cAMP) levels, but they inhibited the phosphorylation or protein expression of cAMP response element-binding protein (CREB). The effects of these two compounds on extracellular regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinases (MAPKs), and AKT/phosphoinositide 3-kinase (PI3K) pathway were examined. Inhibition of p38 MAPK could be the mechanism underpinning the actions of these compounds. Our results suggests that natural products structurally similar to SA-20 and SA-48 may be a new source of tissue-selective aromatase modulators, and that p38 MAPK is important in the basal control of aromatase in ovarian granulosa cells. SA-20 and SA-48 warrant further investigation as new pharmaceutical tools for the prevention and treatment of estrogen-dependent cancers. - Highlights: • Two natural products inhibited estrogen biosynthesis in human ovarian granulosa cells. • They

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

    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.

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

    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

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

    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

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

    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

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

    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).

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

    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.

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

    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)

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

    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

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

    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...

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

    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...

  20. Preparation and surface active properties of oxypropylated diol monoesters of fatty acids with an amide oxime terminal group

    Eissa, A. M.F.

    1994-10-01

    Full Text Available Locally produced non-edible oil, namely, rice bran oil (R.B.O. was utilized as starting materials for preparing new nonionic surfactant. Oxypropylated diol monoesters of linoleic and rice bran oil fatty acids were prepared. Also amide oxime derivatives were obtained. Surface active properties of these compounds were measured. Under neutral condition amide eximes served as nonionic surfactants and their properties were similar to other oxypropylated monoesters.

    Se ha utilizado un aceite no comestible de producción local, denominado, aceite de salvado de arroz (R.B.O. como materia prima para la preparación de nuevos tensioactivos no iónicos. Se prepararon diol monoésteres oxipropilados de ácido linoleico y ácidos grasos de aceite de salvado de arroz. También se obtuvieron los derivados de amido oxima. Se midieron las propiedades de tensión superficial de estos compuestos. Bajo condiciones neutras las amido eximas sirvieron como tensioactivos no iónicos y sus propiedades fueron similares a los de otros monoésteres oxipropilados.

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

    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.

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

    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

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

    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

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

    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

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

    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

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

    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.

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

    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

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

    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.

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

    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

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

    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-...

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

    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...

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

    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

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

    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...

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

    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.

  15. Myeloperoxidase - 463A variant reduces benzo(a)pyrene diol epoxide DNA adducts in skin of coal tar treated patients

    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.

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

    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

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

    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

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

    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

  19. Counting acyclic hypergraphs

    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.

  20. 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

    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

  1. 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

    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

  2. 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

    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.

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

    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.

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

    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

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

    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

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

    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

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

    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.

  8. 2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

    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.

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

    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

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

    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

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

    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.

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

    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

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

    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

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

    The efficiency of 1,9- Nonane-diol-diacrylate (NDDA) as a radiation vulcanization accelerator (RVA) for natural rubber latex (NRL) was investigated. Both gamma rays and electron beam (EB) were used for vulcanizing NRL with NDDA. The radiation dose of gamma rays, concentration of NDDA required to vulcanize the latex were optimized. 20 kGy radiation dose of gamma rays and 5 phr concentration of NDDA were found optimum to get maximum tensile and related properties. NRL was vulcanized under EB to find out the optimum condition of irradiation with this RVA. The defoamer concentrations, length of irradiation time under EB, concentration of RVA were optimizer by changing various parameters of the EB machine with a constant set of the others. 0.2 phr defoamer concentration, 30 minutes irradiation time and 5 phr concentration of NDDA were found optimum for irradiation of NRL under the EB machine. Effect of low current and optimum volume of latex charged in the reaction vessel suitable for vulcanization at a time were found out. (author)

  15. Organometallic Methods for Forming and Cleaving Carbon-Carbon Bonds

    Christensen, Stig Holden

    lipophilic anchors and performing the dehydrogenative decarbonylation with the anchor monools proceeded well, while the corresponding anchor triols were unstable at the elevated temperatures. Of the simple primary alcohols investigated, 2-(2-naphthyl)ethanol, hexane-1,6-diol and dodecane-1,12-diol were found...

  16. Preparation and surface active properties of oxypropylated α-hydroxyacids, α-hydroxyesters and α-, β-alkane diols

    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.

  17. CHARACTERIZATION AND FUNCTIONAL STUDY OF A PUTATIVE JUVENILE HORMONE DIOL KINASE IN THE COLORADO POTATO BEETLE Leptinotarsa decemlineata (Say).

    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

  18. Two-step biocatalytic route to biobased functional polyesters from omega-carboxy fatty acids and diols.

    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

  19. 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.

    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

  20. Small angle neutron scattering study on the aggregation behaviour of PEO–PPO–PEO copolymers in the presence of a hydrophobic diol

    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.

  1. Acaricidal effects of Corymbia citriodora oil containing para-menthane-3,8-diol against nymphs of Ixodes ricinus (Acari: Ixodidae)

    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...

  2. 5-Cholesten-3β,25-Diol 3-Sulfate Decreases Lipid Accumulation in Diet-Induced Nonalcoholic Fatty Liver Disease Mouse Model

    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...

  3. Steviamine, a new class of indolizidine alkaloid [(1R,2S,3R,5R,8aR-3-hydroxymethyl-5-methyloctahydroindolizine-1,2-diol hydrobromide

    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.

  4. Synthesis and characterization of new polyesters based on 2,5-bis[(4-chloro carboxyanilino)carbonyl]pyridine and aromatic diols

    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...

  5. 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

    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.)

  6. Synthesis, spectroscopic studies and inhibitory activity against bactria and fungi of acyclic and macrocyclic transition metal complexes containing a triamine coumarine Schiff base ligand

    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.

  7. Synthetic incorporation of Nile Blue into DNA using 2′-deoxyriboside substitutes: Representative comparison of (R- and (S-aminopropanediol as an acyclic linker

    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.

  8. Development and validation of SPE-HPLC method for the determination of carbamazepine and its metabolites carbamazepine epoxide and carbamazepine trans-diol in plasma

    Spasić Mirjana

    2012-01-01

    Full Text Available SPE-HPLC method has been developed and validated for rapid analysis of carbamazepine and its two metabolites carbamazepine epoxide and carbamazepine trans-diol in human plasma. The analysis was performed using C18 Bakerbond-BDC analytical column (250 mm x 4.6 mm i.d., particle size 5 μm. The optimal conditions for the separation were established with the mobile phase acetonitrile - 10 mM phosphate buffer, pH 7.0 (30:70, v/v at the flow rate of 1.5 mL min-1, temperature 35°C, and UV detection at 210 nm. Total run time was about 8 minutes. SPE procedure for extraction of the analytes from plasma sample was developed using Oasis HLB cartridges and subsequently eluate was injected into the HPLC system for analysis. Afterwards, SPE-HPLC method was subjected to validation. Linearity was obtained over the concentration range of 0.2-25 μg/mL for carbamazepine, carbamazepine epoxide and carbamazepine trans-diol with correlation coefficients higher than 0.995. The method showed good intra-day and inter-day precision with relative standard deviation below 7.96%, while accuracy ranged from 92.09% to 108.5% for all analytes. Finally, the method was successfully applied to analysis of plasma samples of epileptic patients in monotherapy and polytherapy. [Acknowledgments. Projekat Ministarstva nauke Republike Srbije, br. OI 172033].

  9. Diacyltransferase Activity and Chain Length Specificity of Mycobacterium tuberculosis PapA5 in the Synthesis of Alkyl β-Diol Lipids

    Touchette, Megan H.; Bommineni, Gopal R.; Delle Bovi, Richard J.; Gadbery, John; Nicora, Carrie D.; Shukla, Anil K.; Kyle, Jennifer E.; Metz, Thomas O.; Martin, Dwight W.; Sampson, Nicole S.; Miller, W. T.; Tonge, Peter J.; Seeliger, Jessica C.

    2015-09-08

    Although classified as Gram-positive bacteria, Corynebacterineae possess an asymmetric outer membrane that imparts structural and thereby physiological similarity to more distantly related Gram-negative bacteria. Like lipopolysaccharide in Gram-negative bacteria, lipids in the outer membrane of Corynebacterineae have been associated with the virulence of pathogenic species such as Mycobacterium tuberculosis (Mtb). For example, Mtb strains that lack long, branched-chain alkyl esters known as dimycocerosates (DIMs) are significantly attenuated in model infections. The resultant interest in the biosynthetic pathway of these unusual virulence factors has led to the elucidation of many of the steps leading to the final esterification of the alkyl beta-diol, phthiocerol, with branched-chain fatty acids know as mycocerosates. PapA5 is an acyltransferase implicated in these final reactions. We here show that PapA5 is indeed the terminal enzyme in DIM biosynthesis by demonstrating its dual esterification activity and chain-length preference using synthetic alkyl beta-diol substrate analogues. Applying these analogues to a series of PapA5 mutants, we also revise a model for the substrate binding within PapA5. Finally, we demonstrate that the Mtb Ser/Thr kinase PknB modifies PapA5 on three Thr residues, including two (T196, T198) located on an unresolved loop. These results clarify the DIM biosynthetic pathway and suggest possible mechanisms by which DIM biosynthesis may be regulated by the post-translational modification of PapA5.

  10. Enhancement effect of p-menthane-3,8-diol on in vitro permeation of antipyrine and indomethacin through Yucatan micropig skin.

    Fujii, Makiko; Takeda, Yasuhiro; Yoshida, Minako; Matsumoto, Mitsuo; Watanabe, Yoshiteru

    2004-07-01

    The enhancing effect of p-Menthane-3,8-diol (MDO) on skin permeation of antipyrine (ANP) and indomethacin (IM) through Yucatan micropig skin in vitro was compared with 1-menthol. p-Menthane-3,8-diol is a metabolite of 1-menthol and has little odor. It is easy to combine the vehicle because of lower lipophilicity than 1-menthol. All formulations contained 40% (v/v) ethanol. The permeation of ANP increased with MDO about three times that without enhancer by increasing ANP concentration in the skin. However, the MDO effect was about a quarter that of 1-menthol. The permeation of IM with MDO was about 15 times that with no enhancer and it was almost the same as that with 1-menthol. The lag time of permeation was not significantly changed by MDO, which was not so in the case of 1-menthol. Skin concentration of IM increased about 11 times and six times with MDO and 1-menthol, respectively. MDO and 1-menthol partitioned to the skin relatively high concentrations, 5.9 and 2.5 mg/ cm3, respectively. The solubility of IM in the skin was improved by MDO, and consequently, the permeation of IM was enhanced. PMID:15285341

  11. Experimental Study of Structure-Energy Changes in Molecules and Crystals of 2,2-Dinitropropane-1,3-diol Caused by Temperature Variations

    Golovina, N. I.; Raevskii, A. V.; Fedorov, B. S.; Gusakovskaya, I. G.; Trofimova, R. F.; Chukanov, N. V.; Vozchikova, S. A.; Shilov, G. V.; Tarasov, V. P.; Erofeev, L. N.; Atovmyan, L. O.

    2001-03-01

    Crystals of 2,2-dinitropropane-1,3-diol were prepared and grown at different temperatures. An X-ray analysis was used to study the structure of three phases (1, 2 and 3) of the 2,2-dinitropropane-1,3-diol crystals. The calorimetric study of the crystals temperature behavior (1) showed the presence of two phase transitions in the regions of T=309 K and T=340 K, as well as crystals (2) with a phase transition at T=340 K. Observations in a hot stage with the optical microscope phase transitions for separate crystals were made. X-ray diffraction studies of polycrystalline samples (1) for temperatures increasing up to the temperatures of phase transitions I and II demonstrated that phase transition I is followed by conversion of crystals 1 into 2, and transition II is connected with conversion of crystals 2 into a disordered body-centered structure. The temperature behavior of the bands of symmetric N-O stretching vibrations of nitro groups and stretching vibrations of O-H groups was studied by IR spectroscopy. The temperature dependence of hydrogen bonds redistribution and nitro group reorientational dynamics was examined. Data on the structure-dynamic rearrangement in the crystal lattice of the examined compound were obtained by the NMR pulse method in the solid phase using relaxational free induction decay of protons. The kinetic parameters of the process were obtained.

  12. Selective Enrichment and MALDI-TOF MS Analysis of Small Molecule Compounds with Vicinal Diols by Boric Acid-Functionalized Graphene Oxide

    Zhang, Jing; Zheng, Xiaoling; Ni, Yanli

    2015-08-01

    In this study, a 4-vinylphenylboronic acid-functionalized graphene oxide (GO) material was prepared via atom-transfer radical polymerization (ATRP) method and applied for the first time as a novel matrix for the selective enrichment and analysis of small-molecule compounds with vicinal diols, which have been the focus of intense research in the field of life science, by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in positive-ion mode. There are two main factors playing a decisive role in assisting laser D/I process comparing to some traditional matrices: (1) GO provides π-conjugated system by itself for laser absorption and energy transfer; (2) the modified 4-vinylphenylboronic acid can selectively capture small-molecule compounds with vicinal diols. The results demonstrate that the novel material has distinct advantages over previously reported matrices in enriching and assisting the highly efficient ionization of target molecules for mass spectrometry analysis. This work indicates a new application branch for graphene-based matrices and provides an alternative solution for small-molecules analysis.

  13. Acyclic Cucurbit[n]uril-Type Molecular Container Enables Systemic Delivery of Effective Doses of Albendazole for Treatment of SK-OV-3 Xenograft Tumors.

    Hettiarachchi, Gaya; Samanta, Soumen K; Falcinelli, Shane; Zhang, Ben; Moncelet, Damien; Isaacs, Lyle; Briken, Volker

    2016-03-01

    Approximately, 40-70% of active pharmaceutical ingredients (API) are severely limited by their extremely poor aqueous solubility, and consequently, there is a high demand for excipients that can be used to formulate clinically relevant doses of these drug candidates. Here, proof-of-concept studies demonstrate the potential of our recently discovered acyclic cucurbit[n]uril-type molecular container Motor1 (M1) as a solubilizing agent for insoluble drugs. M1 did not induce significant rates of mutations in various Salmonella typhimurium test strains during the Ames test, suggesting low genotoxicity. M1 also has low risk of causing cardiac toxicity in humans since it did not inhibit the human Ether-à-go-go-Related Gene channel as tested on transfected CHO cell lines via patch clamp analysis. Albendazole (ABZ) is a widely used antihelminthic agent but that has also shown promising efficacy against cancerous cells in vitro. However, due to its low aqueous solubility (2.7 μM) and poor pharmacokinetics, ABZ is clinically limited as an anticancer agent. Here we investigated the potential of M1 as a solubilizing excipient for ABZ formulation. A pharmacokinetic study indicated that ABZ escapes the peritoneal cavity resulting in 78% absolute bioavailability, while its active intermediate metabolite, albendazole sulfoxide, achieved 43% absolute bioavailability. The daily dosing of 681 mg/kg M1 complexed with 3.2 mg/kg of ABZ for 14 days did not result in significant weight loss or pathology in Swiss Webster mice. In vivo efficacy studies using this M1·ABZ inclusion complex showed significant decreases in tumor growth rates and increases in survival of mice bearing SK-OV-3 xenograft tumors. In conclusion, we provide substantial new evidence demonstrating that M1 is a safe and efficient excipient that enables in vivo parenteral delivery of poorly water-soluble APIs. PMID:26756920

  14. BENZO[A]PYRENE AND ITS K-REGION DIOL INDUCE DNA DAMAGE IN C3H10T1/2C18 CELLS AS MEASURED BY THE ALKALINE SINGLE CELL GEL (COMET) ASSAY

    160. Benzo[a]pyrene and its K-region diol induce DNA damage in C3HlOTl/2Cl8 cells as measured by the alkaline single cell gel (Comet) assay In a continuing series of studies on the genotoxicity ofK-region dihydrodiols of polycyclic aromatic hydrocarbons, we have repo...

  15. Anti-inflammatory and Immune Regulatory Properties of 5-Androsten-3{beta}, 17{beta}-Diol (HE2100), and Synthetic Analogue HE3204: Implications for Treatment of Autoimmune Diseases.

    Auci, D.; Nicoletti, F.; Mangano, K.; Pieters, R.; Nierkens, S.; Morgan, L.; Offner, H.; Frincke, J.; Reading, C.

    2005-01-01

    5-Androsten-3beta, 17beta-diol (HE2100), and a synthetic analogue HE3204 are regarded as immune-regulating hormones, because both induce changes in the reporter antigen-popliteal lymph node assay (RA-PLNA). Mice were injected in the footpad with either HE2100 or HE3204 (0.01-3 mg), and a nonsensitiz

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

    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

  17. 17a-Ethynyl-5a-androstane-3a, 17 β-diol Treatment of MNU-Induced Mammary Cancer in Rats

    N-methyl-N-nitrosourea (MNU) induces estrogen-dependent mammary tumors in female Lewis rats. We explored the antineoplastic activity of a synthetic androstane derivative, 17 a-ethynyl-5a-androstane-3a, 17β-diol (HE3235), as a single agent or in combination with docetaxel compared to tamoxifen, anastrazole, and docetaxel mono therapies against MNU-induced mammary tumors in female Lewis rats. Treatment with HE3235 alone rapidly reduced tumor burden, similar in effect to tamoxifen and anastrozole. The combination of HE3235 with docetaxel was more effective than any single agent, although without apparent toxicity. Only HE3235 or HE3235 plus docetaxel continued to suppress tumor growth after cessation of treatment. HE3235 treatment increased immunohistochemical markers of apoptosis and expression of pro apoptotic genes and estrogen receptor beta and decreased expression of anti apoptotic genes, androgen receptor, and estrogen receptor alpha. These data warrant clinical investigation of HE3235 for breast cancer treatment.

  18. Binding, distribution, and clearance of 3H-benzo(a)pyrene-7,8-diol-9,10-epoxide from chromosomes of CHO cells

    The purpose of this study was to determine if the binding of a chemical carcinogen was random both within and between chromosomes. Chinese hamster ovary cells were exposed to 3H-labeled +/- anti[G-3H]-benzo(a)pyrene-7,8-diol-9,10-epoxide (3H-BPDE) and serially harvested. Autoradiographs were prepared and the distribution of silver grains over metaphase chromosomes was determined. The 3H-BPDE was randomly distributed down the length of the chromosome. The 3H-BPDE was rapidly removed from the chromosomes with 6% of the initial label remaining at 9 h after exposure. The distribution of silver grains between chromatids was nonrandom at 3 and 6 h after exposure, suggesting a differential removal of 3H-BPDE. 4 references, 4 figures

  19. Labeling internalizing anti-epidermal growth factor receptor variant III monoclonal antibody with 177Lu: in vitro comparison of acyclic and macrocyclic ligands

    Introduction: The monoclonal antibody (mAb) L8A4, reactive with the epidermal growth factor receptor variant III (EGFRvIII), internalizes rapidly in glioma cells after receptor binding. Combining this tumor-specific mAb with the low-energy β-emitter 177Lu would be an attractive approach for brain tumor radioimmunotherapy, provided that trapping of the radionuclide in tumor cells after mAb intracellular processing could be maximized. 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), 2-(4-isothiocyanatobenzyl)-diethylenetriaminepenta-acetic acid (pSCN-Bz-DTPA) and 2-(4-isothiocyanatobenzyl)-6-methyldiethylenetriaminepentaacetic 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 internalization and cellular processing assays were performed on EGFRvIII-expressing U87.ΔEGFR glioma cells over 24 h to directly compare 177Lu-labeled L8A4 to L8A4 labeled with 125I using either iodogen or N-succinimidyl 4-guanidinomethyl-3-[125I]iodobenzoate ([125I]SGMIB). In order to facilitate comparison of labeling methods, the primary parameter evaluated was the ratio of 177Lu to 125I activity retained in U87.ΔEGFR cells. Results: All chelates demonstrated higher retention of internalized activity compared with mAb labeled using iodogen, with 177Lu/125I ratios of >20 observed for the three DTPA chelates at 24 h. When compared to L8A4 labeled using SGMIB, except for MeO-DOTA, internalized activity for 125I was higher than 177Lu from 1-8 h with the opposite behavior observed thereafter. At 24 h, 177Lu/125I ratios were between 1.5 and 3, with higher values observed for the three DTPA chelates. Conclusions: The nature of the chelate used to

  20. Design and Synthesis of Novel Antimicrobial Acyclic and Heterocyclic Dyes and Their Precursors for Dyeing and/or Textile Finishing Based on 2-N-Acylamino-4,5,6,7-tetrahydro-benzo[b]thiophene Systems

    Rafat Milad Mohareb

    2011-07-01

    Full Text Available A series of novel polyfunctionalized acyclic and heterocyclic dye precursors and their respective azo (hydrazone counterpart dyes and dye precursors based on conjugate enaminones and/or enaminonitrile moieties were synthesized. The dyes and their precursors are based on 2-cyano-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide, 2-ethoxycarbonyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide or 2-phenylcarbamoyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl-acetamide systems as precursors. The latter compounds were used to synthesize polyfunctional thiophene-, thiazole-, pyrazole, pyridine-, pyrimidine-, oxazine-, as well as acyclic moieties. The dyes and dye precursors were characterized by elemental analysis and spectral methods. All dyes and their precursors were screened in vitro and evaluated for both their antibacterial and antifungal activities. MIC data of the novel dye systems and their respective precursors showed significant antimicrobial activity against most tested organisms. Some compounds exhibited comparable or even higher efficiency than selected standards. Dyes were applied at 5% depth for disperse dyeing of nylon, acetate and polyester fabrics. Their spectral characteristics and fastness properties were measured and evaluated.

  1. Synthesis and in vitro evaluation of (R), (S) and (R/S)-2-hexyne-1,4-diol, a natural product produced by fungus Clitocybe catinus, and related analogs as potential anticancer agents.

    Princival, Iza Mirela R G; Ferreira, Jeiely G; Silva, Teresinha G; Aguiar, Jaciana S; Princival, Jefferson L

    2016-06-15

    The search for natural products and related analogs as potential anticancer agents has seen a significant growth worldwide. Since small sized propargylic diols can be found in nature and chemically synthesized, their evaluation against cancer cells has been of great interest, being a topic of relevance to be investigated. For this purpose, a scalable approach aiming at the synthesis of several propargylic diols and their bioactivity against seven tumor cell lines were evaluated. Interestingly, when the compound 1a, a natural product produced by fungus Clitocybe catinus, was tested in its racemic mixture a more effective activity was observed if compared when enantiopure R-1a or S-1a were tested separately. PMID:27142752

  2. DNA polymerase eta participates in the mutagenic bypass of adducts induced by benzo[a]pyrene diol epoxide in mammalian cells.

    Alden C Klarer

    Full Text Available Y-family DNA-polymerases have larger active sites that can accommodate bulky DNA adducts allowing them to bypass these lesions during replication. One member, polymerase eta (pol eta, is specialized for the bypass of UV-induced thymidine-thymidine dimers, correctly inserting two adenines. Loss of pol eta function is the molecular basis for xeroderma pigmentosum (XP variant where the accumulation of mutations results in a dramatic increase in UV-induced skin cancers. Less is known about the role of pol eta in the bypass of other DNA adducts. A commonly encountered DNA adduct is that caused by benzo[a]pyrene diol epoxide (BPDE, the ultimate carcinogenic metabolite of the environmental chemical benzo[a]pyrene. Here, treatment of pol eta-deficient fibroblasts from humans and mice with BPDE resulted in a significant decrease in Hprt gene mutations. These studies in mammalian cells support a number of in vitro reports that purified pol eta has error-prone activity on plasmids with site-directed BPDE adducts. Sequencing the Hprt gene from this work shows that the majority of mutations are G>T transversions. These data suggest that pol eta has error-prone activity when bypassing BPDE-adducts. Understanding the basis of environmental carcinogen-derived mutations may enable prevention strategies to reduce such mutations with the intent to reduce the number of environmentally relevant cancers.

  3. DEET (N,N-diethyl-meta-toluamide)/PMD (para-menthane-3,8-diol) repellent-treated mesh increases Culicoides catches in light traps.

    Murchie, A K; Clawson, S; Rea, I; Forsythe, I W N; Gordon, A W; Jess, S

    2016-09-01

    Biting midges (Culicoides spp.) are vectors of bluetongue and Schmallenberg viruses. Treatment of mesh barriers is a common method for preventing insect-vectored diseases and has been proposed as a means of limiting Culicoides ingression into buildings or livestock transporters. Assessments using animals are costly, logistically difficult and subject to ethical approval. Therefore, initial screening of test repellents/insecticides was made by applying treatments to mesh (2 mm) cages surrounding Onderstepoort light traps. Five commercial treatments were applied to cages as per manufacturers' application rates: control (water), bendiocarb, DEET/p-menthane-3,8-diol (PMD) repellent, Flygo (a terpenoid based repellent) and lambda-cyhalothrin. The experimental design was a 5 × 5 Latin square, replicated in time and repeated twice. Incongruously, the traps surrounded by DEET/PMD repellent-treated mesh caught three to four times more Obsoletus group Culicoides (the commonest midge group) than the other treatments. A proposed hypothesis is that Obsoletus group Culicoides are showing a dose response to DEET/PMD, being attracted at low concentrations and repelled at higher concentrations but that the strong light attraction from the Onderstepoort trap was sufficient to overcome close-range repellence. This study does not imply that DEET/PMD is an ineffective repellent for Culicoides midges in the presence of an animal but rather that caution should be applied to the interpretation of light trap bioassays. PMID:27179956

  4. Stereochemical effects in the gas-phase pinacol rearrangement. 2. Ring contraction versus methyl migration in cis- and trans-1,2-dimethylcyclohexane-1,2-diol

    The gas-phase pinacol rearrangement of cis- and trans-1,2-dimethylcyclohexane-1,2-diols, promoted by D3+, CH5+/C2H5+ and t-C4H9+ ions, was studied by mass spectrometric and radiolytic methods in the pressure range 0.5-760 Torr. When product isomerization is inhibited, by using N(CH3)3 as a trapping reagent at high pressure, mixtures of 2,2-dimethylcyclohexanone and 1-acetyl-1-methylcyclopentane were recovered from the reaction. In methane, the trend of the measured relative rates for ring contraction (k5), methyl or hydroxyl group migration (k6) versus the rearrangement rate of pincaol itself (k/sub p/), is k6(trans) ∼ k5(trans) ≥ k5(cis) > k6(cis) ≥ k/sub p/. No evidence for the formation of an intermediate carbenium ion was found. Stereochemical aspects of the mechanism are discussed and compared with solution data

  5. Acaricidal effects of Corymbia citriodora oil containing para-menthane-3,8-diol against nymphs of Ixodes ricinus (Acari: Ixodidae).

    Elmhalli, Fawzeia H; Pålsson, Katinka; Orberg, Jan; Jaenson, Thomas G T

    2009-07-01

    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 of exposure with a distinct effect after 3.5 h. From the results obtained by methods A, C and E, the LC(50) range was 0.035-0.037 mg PMD/cm(2) and the LC(95) range was 0.095-0.097 mg PMD/cm(2) at 4 h of exposure; the LT(50) range was 2.1-2.8 h and the LT(95) range was 3.9-4.2 h at 0.1 mg PMD/cm(2). To determine the duration of toxic activity of PMD, different concentrations (0.002, 0.01, 0.1 mg PMD/cm(2)) were tested and mortality was recorded at each concentration after 1 h; thereafter new ticks were tested. This test revealed that the lethal activity of PMD remained for 24 h but appeared absent after 48 h. The overall results show that PMD is toxic to nymphs of I. ricinus and may be useful for tick control. PMID:19169833

  6. 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.

    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

  7. MALDI-TOF MS Imaging evidences spatial differences in the degradation of solid polycaprolactone diol in water under aerobic and denitrifying conditions.

    Rivas, Daniel; Ginebreda, Antoni; Pérez, Sandra; Quero, Carmen; Barceló, Damià

    2016-10-01

    Degradation of solid polymers in the aquatic environment encompasses a variety of biotic and abiotic processes giving rise to heterogeneous patterns across the surface of the material, which cannot be investigated using conventional Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) that only renders an "average" picture of the sample. In that context, MALDI-TOF MS Imaging (MALDI MSI) provides a rapid and efficient tool to study 2D spatial changes occurred in the chemical composition of the polymer surface. Commercial polycaprolactone diol (average molecular weight of 1250Da) was selected as test material because it had been previously known to be amenable to biological degradation. The test oligomer probe was incubated under aerobic and denitrifying conditions using synthetic water and denitrifying mixed liquor obtained from a wastewater treatment plant respectively. After ca. seven days of exposure the mass spectra obtained by MALDI MSI showed the occurrence of chemical modifications in the sample surface. Observed heterogeneity across the probe's surface indicated significant degradation and suggested the contribution of biotic processes. The results were investigated using different image processing tools. Major changes on the oligomer surface were observed when exposed to denitrifying conditions. PMID:27213667

  8. INFLUENCE OF 2-BUTYNE-1, 4-DIOL ON THE STRUCTURE AND PERFORMANCE OF THE Co-Ni ALLOY PLATED BY ELECTRODEPOSITION

    S.L. Wang; L.L. Hong; W.W. Yu

    2008-01-01

    The effect of 2-butyne-1, 4-diol (BD) on the deposition behavior of the Co-Ni alloy was investigated by linear sweep voltammetry. The results showed that BD could prevent the deposition of the Co-Ni alloy. The elect of BD concentration in the sulfate plating bath, on the structure of the Co-Ni deposit was studied by energy dispersive x-ray spectroscopy, scanning electron microscope, and X-ray diffraction, respectively. As a result, BD could smoothen the deposit surface and decrease the diameter of the grain, but too much of BD was not good for the size of the grain. In general, a hexagonal close-packed (hcp) phase of the Co-Ni alloy, with a preferentially oriented (110) plane, was prepared by electrodeposition in the presence of BD. The Co-Ni alloy as a catalyst for the electro-oxidation of ethanol in alkaline medium was investigated by cyclic voltammetry. The deposit plated from the bath containing BD possessed better electro-oxidation of ethanol performance compared with that of the deposit plated from only the sulfate plating bath, but too much of BD was not beneficial for catalytic activity. The Co-Ni film was suitable as a magnetic recording material.

  9. Thermo-Responsive Polyurethane Hydrogels Based on Poly(ε-caprolactone Diol and Amphiphilic Polylactide-Poly(Ethylene Glycol Block Copolymers

    Shan-hui Hsu

    2016-07-01

    Full Text Available Waterborne polyurethane (PU based on poly(ε-caprolactone (PCL diol and an amphiphilic polylactide-poly(ethylene glycol (PLA-PEG diblock copolymer was synthesized. The molar ratio of PCL/PLA-PEG was 9:1 with different PLA chain lengths. The PU nanoparticles were characterized by dynamic light scattering (DLS, small angle X-ray scattering (SAXS and rheological analysis. The water contact angle measurement, infrared spectroscopy, wide angle X-ray scattering (WAXS, thermal and mechanical analyses were conducted on PU films. Significant changes in physio-chemical properties were observed for PUs containing 10 mol % of amphiphilic blocks. The water contact angle was reduced to 12°–13°, and the degree of crystallinity was 5%–10%. The PU dispersions underwent sol-gel transition upon the temperature rise to 37 °C. The gelation time increased as the PLA chain length increased. In addition, the fractal dimension of each gel was close to that of a percolation cluster. Moreover, PU4 with a solid content of 26% could support the proliferation of human mesenchymal stem cells (hMSCs. Therefore, thermo-responsive hydrogels with tunable properties are promising injectable materials for cell or drug delivery.

  10. Optically active helical polyurethane-attapulgite composites: Effect of optical purity of S-1,1'-binaphthyl-2,2'-diol on infrared emissivity

    Wang Zhiqiang [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Zhou Yuming, E-mail: ymzhou@seu.edu.cn [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Sun Yanqing; Mei Zhenyu; Miao Yuee [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China)

    2009-05-15

    Helical polyurethane-attapulgite (HPU-ATT) composites were prepared after the surface modification of the rod-like attapulgite (ATT). HPU-ATT composites based on S-1,1'-binaphthyl-2,2'-diol (S-BINOL) with different optical purity (O.P.) were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The results indicate that the helical polyurethane has been successfully grafted onto the surfaces of the modified ATT without destroying the original crystalline structure of ATT. The rod-like nanoparticles were confirmed by transmission electron microscopy (TEM). Infrared emissivity values of HPU-ATT composites have been investigated, and the results indicate that the optical purity of monomer plays a very important role in the infrared emissivity for HPU-ATT owing to the effect of helical conformation and interchain hydrogen bonds. Along with the increased optical purity of S-BINOL, the infrared emissivity of HPU-ATT is reduced evidently. Infrared emissivity value of HPU-ATT based on S-BINOL with 100% optical purity is the lowest one (0.431).

  11. Optically active helical polyurethane-attapulgite composites: Effect of optical purity of S-1,1'-binaphthyl-2,2'-diol on infrared emissivity

    Helical polyurethane-attapulgite (HPU-ATT) composites were prepared after the surface modification of the rod-like attapulgite (ATT). HPU-ATT composites based on S-1,1'-binaphthyl-2,2'-diol (S-BINOL) with different optical purity (O.P.) were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The results indicate that the helical polyurethane has been successfully grafted onto the surfaces of the modified ATT without destroying the original crystalline structure of ATT. The rod-like nanoparticles were confirmed by transmission electron microscopy (TEM). Infrared emissivity values of HPU-ATT composites have been investigated, and the results indicate that the optical purity of monomer plays a very important role in the infrared emissivity for HPU-ATT owing to the effect of helical conformation and interchain hydrogen bonds. Along with the increased optical purity of S-BINOL, the infrared emissivity of HPU-ATT is reduced evidently. Infrared emissivity value of HPU-ATT based on S-BINOL with 100% optical purity is the lowest one (0.431).

  12. 5-Androstene-3{beta},17{beta}-diol Promotes Recovery of Immature Hematopoietic Cells Following Myelosuppressive Radiation and Synergizes With Thrombopoietin

    Aerts-Kaya, Fatima S.F.; Visser, Trudi P.; Arshad, Shazia [Department of Hematology, Erasmus University Medical Center, Rotterdam (Netherlands); Frincke, James; Stickney, Dwight R.; Reading, Chris L. [Harbor Therapeutics, Inc, San Diego, California (United States); Wagemaker, Gerard, E-mail: g.wagemaker@erasmusmc.nl [Department of Hematology, Erasmus University Medical Center, Rotterdam (Netherlands)

    2012-11-01

    Purpose: 5-Androstene-3{beta},17{beta}-diol (5-AED) stimulates recovery of hematopoiesis after exposure to radiation. To elucidate its cellular targets, the effects of 5-AED alone and in combination with (pegylated) granulocyte colony-stimulating factor and thrombopoietin (TPO) on immature hematopoietic progenitor cells were evaluated following total body irradiation. Methods and Materials: BALB/c mice were exposed to radiation delivered as a single or as a fractionated dose, and recovery of bone marrow progenitors and peripheral blood parameters was assessed. Results: BALB/c mice treated with 5-AED displayed accelerated multilineage blood cell recovery and elevated bone marrow (BM) cellularity and numbers of progenitor cells. The spleen colony-forming unit (CFU-S) assay, representing the life-saving short-term repopulating cells in BM of irradiated donor mice revealed that combined treatment with 5-AED plus TPO resulted in a 20.1-fold increase in CFU-S relative to that of placebo controls, and a 3.7 and 3.1-fold increase in comparison to 5-AED and TPO, whereas no effect was seen of Peg-G-CSF with or without 5-AED. Contrary to TPO, 5-AED also stimulated reconstitution of the more immature marrow repopulating (MRA) cells. Conclusions: 5-AED potently counteracts the hematopoietic effects of radiation-induced myelosuppression and promotes multilineage reconstitution by stimulating immature bone marrow cells in a pattern distinct from, but synergistic with TPO.

  13. Inhibitory effect of sesquiterpene lactones and the sesquiterpene alcohol aromadendrane-4β,10α-diol on memory impairment in a mouse model of Alzheimer.

    Amoah, Solomon K S; Dalla Vecchia, Maria Tereza; Pedrini, Beatriz; Carnhelutti, Gabriela Lazzarotto; Gonçalves, Ana Elisa; Dos Santos, Diogo Adolfo; Biavatti, Maique W; de Souza, Márcia Maria

    2015-12-15

    Alzheimer's disease (AD), a progressive neurodegenerative disorder of the aged brain with no known cause or cures, has become a major medical and social problem for industrialized countries. Cerebral deposition of amyloid-β peptide (Aβ) is a critical feature of AD. The use of medicinal plants as an alternative form of prevention, or even as a possible treatment of AD, is therefore interesting areas of research. Sesquiterpene lactones and a sesquiterpene alcohol are compounds found in H. brasiliense that have several anti-oxidative and anti-inflammatory effects. In the present study, we investigated whether these compounds have neuroprotective effects in an amyloid-β peptide-induced Alzheimer's disease mouse model. Mice were injected with Aβ1-42 peptide intracerebroventricularly and were subsequently injected (i.c.v.) with 1µg/site of IGM-A (15-acetoxy-isogermafurenolide), IGM-H (15-hydroxy-isogermafurenolide), PDA (Podoandin), EHP (1,2-epoxy-10α-hydroxy-podoandin), HDS (13-hydroxy-8,9-dehydroshizukanolide), and ARD (aromadendrane-4β,10α-diol). Seven days after treatments the animals had their memory tested in the inhibitory avoidance. After the behavioral testing of animals the brains were removed and subjected to biochemical tests for oxidative stress. The results showed that ARD, HDS and PDA significantly ameliorated the Aβ1-42 peptide-induced memory impairment in the passive avoidance task (Panimals induced peptide amyloid and may be potential candidates for Alzheimer's disease therapy. PMID:26593432

  14. Serum Level of Antibody against Benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA Adducts in People Dermally Exposed to PAHs

    Lenka Borska

    2014-01-01

    Full Text Available Some specific antibodies indicate the presence of antigenic structures on DNA (DNA adducts that can play an important role in the process of mutagenesis and/or carcinogenesis. They indicate the presence of increased genotoxic potential (hazard prior to the formation of disease (primary prevention. The present study was focused on the serum level of benzo[a]pyrene 7,8-diol-9,10-epoxide-DNA adducts antibodies (anti-BPDE-DNA in psoriatic patients (n=55 dermally exposed to different levels of polycyclic aromatic hydrocarbons (PAHs. The general goal of the study was to contribute to better understanding of the value of the assumed biomarker (anti-BPDE-DNA for evaluation of the organism's answer to genotoxic exposure to PAHs. Elevated level of exposure to PAHs resulted in the increased level of anti-BPDE-DNA. However, almost all levels of anti-BPDE-DNA ranged within the field of low values. Both variants of GT (CCT-3% and CCT-5% induced higher expression of anti-BPDE-DNA in the group of nonsmokers. Significant relations between the level of anti-BPDE-DNA and PASI score, total duration of the therapy, or time of UVR exposure were not found. Further studies are needed to reduce interpretation uncertainty of this promising bioindicator.

  15. The solid-matrix phosphorescence of (±)-anti-dibenzo[a,l]pyrene diol epoxide-DNA adducts and benzo[e]pyrene

    New solid-matrix phosphorescence (SMP) methods for (±)-anti-DB[a,l]PDE-DNA adducts and B[e]P were developed. The methods can be used to detect and characterize (±)-anti-DB[a,l]PDE-DNA adducts and B[e]P by employing SMP spectra, intensities, and lifetimes acquired with the heavy-atom salt, TlNO3, on Whatman 1PS paper. With the SMP data, a number of photophysical parameters were calculated such as biexponential SMP decay curves, pre-exponential factors, and fractional contribution to SMP decay curves. The SMP results were compared with earlier SMP data for (±)-anti-BPDE-DNA adducts and tetrol I-1. The SMP results show that small molecular-weight compounds like B[e]P can be readily detected and characterized by SMP. For example, the limit of detection for B[e]P was 0.60 pmol. Comparison of the SMP properties of the (±)-anti-DB[a,l]PDE-DNA adducts with earlier SMP data for the (±)-anti-BPDE-DNA adducts showed major differences in the SMP spectra, intensities, and lifetimes. The methods developed are important for the comparison of the SMP properties of different diol epoxides of PAH bonded to DNA

  16. Inhibition of benzopyrene-diol-epoxide (BPDE)-induced bax and caspase-9 by cadmium: Role of mitogen activated protein kinase

    Cadmium, a major metal constituent of tobacco smoke, elicits synergistic enhancement of cell transformation when combined with benzo[a]pyrene (BP) or other polynuclear aromatic hydrocarbons (PAHs). The mechanism underlying this synergism is not clearly understood. Present study demonstrates that (+/-)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE), an ultimate carcinogen of BP, induces apoptosis in human leukemic HL-60 cells and others, and cadmium at non-cytotoxic concentration inhibits BPDE-induced apoptosis. We observed that BPDE treatment also activates all three MAP kinases e.g. ERK1/2, p38 and JNK in HL-60 cells, and inhibition of BPDE-induced apoptosis by cadmium is associated with down-regulation of pro-apoptotic bax induction/caspase-9 activation and up-regulation of ERK phosphorylation, whereas p38 MAP kinase and c-Jun phosphorylation (indicative of JNK activation) remain unaffected. Inhibition of ERKs by prior treatment of cells with 10 μM U0126 relieves cadmium-mediated inhibition of apoptosis/bax induction/caspase-9 activation. Our results suggest that cadmium inhibits BPDE-induced apoptosis by modulating apoptotic signaling through up-regulation of ERK, which is known to promote cell survival

  17. 5-Androstene-3β,17β-diol Promotes Recovery of Immature Hematopoietic Cells Following Myelosuppressive Radiation and Synergizes With Thrombopoietin

    Purpose: 5-Androstene-3β,17β-diol (5-AED) stimulates recovery of hematopoiesis after exposure to radiation. To elucidate its cellular targets, the effects of 5-AED alone and in combination with (pegylated) granulocyte colony-stimulating factor and thrombopoietin (TPO) on immature hematopoietic progenitor cells were evaluated following total body irradiation. Methods and Materials: BALB/c mice were exposed to radiation delivered as a single or as a fractionated dose, and recovery of bone marrow progenitors and peripheral blood parameters was assessed. Results: BALB/c mice treated with 5-AED displayed accelerated multilineage blood cell recovery and elevated bone marrow (BM) cellularity and numbers of progenitor cells. The spleen colony-forming unit (CFU-S) assay, representing the life-saving short-term repopulating cells in BM of irradiated donor mice revealed that combined treatment with 5-AED plus TPO resulted in a 20.1-fold increase in CFU-S relative to that of placebo controls, and a 3.7 and 3.1-fold increase in comparison to 5-AED and TPO, whereas no effect was seen of Peg-G-CSF with or without 5-AED. Contrary to TPO, 5-AED also stimulated reconstitution of the more immature marrow repopulating (MRA) cells. Conclusions: 5-AED potently counteracts the hematopoietic effects of radiation-induced myelosuppression and promotes multilineage reconstitution by stimulating immature bone marrow cells in a pattern distinct from, but synergistic with TPO.

  18. Diastereo- and Enantioselective Iridium Catalyzed Coupling of Vinyl Aziridines with Alcohols: Site-Selective Modification of Unprotected Diols and Synthesis of Substituted Piperidines.

    Wang, Gang; Franke, Jana; Ngo, Chinh Q; Krische, Michael J

    2015-06-24

    The chiral cyclometalated π-allyliridium ortho-C,O-benzoate complex (R)-Ir-VIb derived from [Ir(cod)Cl]2, allyl acetate, 4-cyano-3-nitro-benzoic acid, and (R)-MeO-BIPHEP catalyzes the coupling of N-(p-nitrophenylsulfonyl) protected vinyl aziridine 3a with primary alcohols 1a-1l to furnish branched products of C-C bond formation 4a-4l with good levels of anti-diastereo- and enantioselectivity. In the presence of 2-propanol, but under otherwise identical conditions, vinyl aziridine 3a and aldehydes 2a-2l engage in reductive coupling to furnish an equivalent set of adducts 4a-4l with roughly equivalent levels of anti-diastereo- and enantioselectivity. Using enantiomeric iridium catalysts, vinyl aziridine 3a reacts with unprotected chiral 1,3-diols 1m-1o in a site-selective manner to deliver the diastereomeric products of C-allylation syn-4m, -4n, -4o and anti-4m, -4n, -4o, respectively, with good isolated yields and excellent levels of catalyst-directed diastereoselectivity. These adducts were directly converted to the diastereomeric 2,4,5-trisubstituted piperidines syn-5m, -5n, -5o and anti-5m, -5n, -5o. PMID:26074091

  19. Enhanced binding capacity of boronate affinity adsorbent via surface modification of silica by combination of atom transfer radical polymerization and chain-end functionalization for high-efficiency enrichment of cis-diol molecules

    Wang, Wei; He, Maofang; Wang, Chaozhan; Wei, Yinmao, E-mail: ymwei@nwu.edu.cn

    2015-07-30

    Boronate affinity materials have been widely used for specific separation and preconcentration of cis-diol molecules, but most do not have sufficient capacity due to limited binding sites on the material surface. In this work, we prepared a phenylboronic acid-functionalized adsorbent with a high binding capacity via the combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and chain-end functionalization. With this method, the terminal chlorides of the polymer chains were used fully, and the proposed adsorbent contains dense boronic acid polymers chain with boronic acid on the chain end. Consequently, the proposed adsorbent possesses excellent selectivity and a high binding capacity of 513.6 μmol g{sup −1} for catechol and 736.8 μmol g{sup −1} for fructose, which are much higher than those of other reported adsorbents. The dispersed solid-phase extraction (dSPE) based on the prepared adsorbent was used for extraction of three cis-diol drugs (i.e., epinephrine, isoprenaline and caffeic acid isopropyl ester) from plasma; the eluates were analyzed by HPLC-UV. The reduced amount of adsorbent (i.e., 2.0 mg) could still eliminate interferences efficiently and yielded a recovery range of 85.6–101.1% with relative standard deviations ranging from 2.5 to 9.7% (n = 5). The results indicated that the proposed strategy could serve as a promising alternative to increase the density of surface functional groups on the adsorbent; thus, the prepared adsorbent has the potential to effectively enrich cis-diol substances in real samples. - Highlights: • Boronate adsorbent is prepared via ATRP and chain-end functionalization. • The adsorbent has quite high binding capacity for cis-diols. • Binding capacity is easily manipulated by ATRP condition. • Chain-end functionalization can improve binding capacity significantly. • Reduced adsorbent is consumed in dispersed solid-phase extraction of cis-diols.

  20. Enhanced binding capacity of boronate affinity adsorbent via surface modification of silica by combination of atom transfer radical polymerization and chain-end functionalization for high-efficiency enrichment of cis-diol molecules

    Boronate affinity materials have been widely used for specific separation and preconcentration of cis-diol molecules, but most do not have sufficient capacity due to limited binding sites on the material surface. In this work, we prepared a phenylboronic acid-functionalized adsorbent with a high binding capacity via the combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and chain-end functionalization. With this method, the terminal chlorides of the polymer chains were used fully, and the proposed adsorbent contains dense boronic acid polymers chain with boronic acid on the chain end. Consequently, the proposed adsorbent possesses excellent selectivity and a high binding capacity of 513.6 μmol g−1 for catechol and 736.8 μmol g−1 for fructose, which are much higher than those of other reported adsorbents. The dispersed solid-phase extraction (dSPE) based on the prepared adsorbent was used for extraction of three cis-diol drugs (i.e., epinephrine, isoprenaline and caffeic acid isopropyl ester) from plasma; the eluates were analyzed by HPLC-UV. The reduced amount of adsorbent (i.e., 2.0 mg) could still eliminate interferences efficiently and yielded a recovery range of 85.6–101.1% with relative standard deviations ranging from 2.5 to 9.7% (n = 5). The results indicated that the proposed strategy could serve as a promising alternative to increase the density of surface functional groups on the adsorbent; thus, the prepared adsorbent has the potential to effectively enrich cis-diol substances in real samples. - Highlights: • Boronate adsorbent is prepared via ATRP and chain-end functionalization. • The adsorbent has quite high binding capacity for cis-diols. • Binding capacity is easily manipulated by ATRP condition. • Chain-end functionalization can improve binding capacity significantly. • Reduced adsorbent is consumed in dispersed solid-phase extraction of cis-diols

  1. A role for the androgen metabolite, 5alpha-androstane-3beta,17beta-diol, in modulating oestrogen receptor beta-mediated regulation of hormonal stress reactivity.

    Handa, R J; Weiser, M J; Zuloaga, D G

    2009-03-01

    Activation of the hypothalamic-pituitary-adrenal (HPA) axis is a basic response of animals to environmental perturbations that threaten homeostasis. These responses are regulated by neurones in the paraventricular nucleus of the hypothalamus (PVN) that synthesise and secrete corticotrophin-releasing hormone (CRH). Other PVN neuropeptides, such as arginine vasopressin and oxytocin, can also modulate activity of CRH neurones in the PVN and enhance CRH secretagogue activity of the anterior pituitary gland. In rodents, sex differences in HPA reactivity are well established; females exhibit a more robust activation of the HPA axis after stress than do males. These sex differences primarily result from opposing actions of sex steroids, testosterone and oestrogen, on HPA function. Ostreogen enhances stress activated adrenocorticotrophic hormone (ACTH) and corticosterone (CORT) secretion, whereas testosterone decreases the gain of the HPA axis and inhibits ACTH and CORT responses to stress. Data show that androgens can act directly on PVN neurones in the male rat through a novel pathway involving oestrogen receptor (ER)beta, whereas oestrogen acts predominantly through ERalpha. Thus, we examined the hypothesis that, in males, testosterone suppresses HPA function via an androgen metabolite that binds ERbeta. Clues to the neurobiological mechanisms underlying such a novel action can be gleaned from studies showing extensive colocalisation of ERbeta in oxytocin-containing cells of the PVN. Hence, in this review, we address the possibility that testosterone inhibits HPA reactivity by metabolising to 5alpha-androstane-3beta,17beta-diol, a compound that binds ERbeta and regulates oxytocin containing neurones of the PVN. These findings suggest a re-evaluation of studies examining pathways for androgen receptor signalling. PMID:19207807

  2. A Role for the Androgen Metabolite, 5α-Androstane-3β,17β-Diol, in Modulating Oestrogen Receptor β-Mediated Regulation of Hormonal Stress Reactivity

    Handa, R. J.; Weiser, M. J.; Zuloaga, D. G.

    2009-01-01

    Activation of the hypothalamic-pituitary-adrenal (HPA) axis is a basic response of animals to environmental perturbations that threaten homeostasis. These responses are regulated by neurones in the paraventricular nucleus of the hypothalamus (PVN) that synthesise and secrete corticotrophin-releasing hormone (CRH). Other PVN neuropeptides, such as arginine vasopressin and oxytocin, can also modulate activity of CRH neurones in the PVN and enhance CRH secretagogue activity of the anterior pituitary gland. In rodents, sex differences in HPA reactivity are well established; females exhibit a more robust activation of the HPA axis after stress than do males. These sex differences primarily result from opposing actions of sex steroids, testosterone and oestrogen, on HPA function. Ostreogen enhances stress activated adrenocorticotrophic hormone (ACTH) and corticosterone (CORT) secretion, whereas testosterone decreases the gain of the HPA axis and inhibits ACTH and CORT responses to stress. Data show that androgens can act directly on PVN neurones in the male rat through a novel pathway involving oestrogen receptor (ER)β, whereas oestrogen acts predominantly through ERα. Thus, we examined the hypothesis that, in males, testosterone suppresses HPA function via an androgen metabolite that binds ERβ. Clues to the neurobiological mechanisms underlying such a novel action can be gleaned from studies showing extensive colocalisation of ERβ in oxytocin-containing cells of the PVN. Hence, in this review, we address the possibility that testosterone inhibits HPA reactivity by metabolising to 5α-androstane-3β,17β-diol, a compound that binds ERβ and regulates oxytocin containing neurones of the PVN. These findings suggest a re-evaluation of studies examining pathways for androgen receptor signalling. PMID:19207807

  3. (Eco)toxicological effects of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (TMDD) in zebrafish (Danio rerio) and permanent fish cell cultures.

    Vincze, Krisztina; Gehring, Martin; Braunbeck, Thomas

    2014-01-01

    2,4,7,9-tetramethyl-5-decyne-4,7-diol (TMDD) is a high-production volume chemical used in paper, ink, pesticide, and adhesive industries as a wetting and anti-foaming agent. The physicochemical properties and slow biodegradation rate of TMDD indicate a low bioaccumulation potential but a high prevalence in the environment. As a consequence, TMDD has been detected in several European rivers in the nanogram per liter and lower microgram per liter range; however, its environmental risk to aquatic organisms is considered low. Recent studies almost exclusively focused on acute effects by TMDD, little is known about cytotoxic and genotoxic effects, reproduction and developmental toxicity, endocrine disruption, and any kind of long-term toxicity and carcinogenicity so far. The present study aims to provide more specific baseline information on the ecotoxicological effects of TMDD in fish. For this end, cyto- and genotoxicity assays were carried out in vitro with the permanent fish cell line RTL-W1; in addition, in vivo studies were conducted with the early life stages of zebrafish (Danio rerio) in order to fill the data gaps in developmental toxicity and endocrine disruption. TMDD showed a cytotoxic and slight genotoxic potential in fish cell lines; moreover, various sublethal and lethal effects could be detected in developing zebrafish embryos. There was no evidence of endocrine-disrupting effects by TMDD; however, mortality following prolonged exposure to TMDD during fish sexual development test was clearly higher than mortality in the fish embryo test after 96-h exposure. Our results thus confirmed previous findings of laboratory screening tests, suggesting short-term toxic effects of TMDD in the intermediate, and long-term effects in the lower milligram per liter range. PMID:24687796

  4. 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol}, 1 a novel resveratrol analog, differentially regulates estrogen receptors α and β in breast cancer cells.

    Ronghe, Amruta; Chatterjee, Anwesha; Singh, Bhupendra; Dandawate, Prasad; Abdalla, Fatma; Bhat, Nimee K; Padhye, Subhash; Bhat, Hari K

    2016-06-15

    Breast cancer is a public health concern worldwide. Prolonged exposure to estrogens has been implicated in the development of breast neoplasms. Epidemiologic and experimental evidence suggest a chemopreventive role of phytoestrogens in breast cancers. Resveratrol, a naturally occurring phytoestrogen, has been shown to have potent anti-cancer properties. However, poor efficacy and bioavailability have prevented the use of resveratrol in clinics. In order to address these problems, we have synthesized a combinatorial library of azaresveratrol analogs and tested them for their ability to inhibit the proliferation of breast cancer cells. We have recently shown that 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol} (TIMBD), has better anti-cancer properties than resveratrol and any other resveratrol analog we have synthesized so far. The objective of this study was to investigate the regulation of estrogen receptors (ERs) α and β by TIMBD in breast cancer cell lines. We demonstrate that TIMBD significantly induces the mRNA and protein expression levels of ERβ and inhibits that of ERα. TIMBD inhibits mRNA and protein expression levels of oncogene c-Myc, and cell cycle protein cyclin D1, which are important regulators of cellular proliferation. TIMBD significantly induces protein expression levels of tumor suppressor genes p53 and p21 in MCF-7 cells. TIMBD inhibits c-Myc in an ERβ-dependent fashion in MCF-10A and ERβ1-transfected MDA-MB-231 cells, suggesting regulation of ERs as an important upstream mechanism of this analog. ERβ plays a partial role in inhibition of proliferation by TIMBD while ERα overexpression does not significantly affect TIMBD's inhibition. PMID:26970359

  5. Benzo[a]pyrene diol epoxide suppresses retinoic acid receptor-β2 expression by recruiting DNA (cytosine-5--methyltransferase 3A

    Xu Xiao-Chun

    2010-04-01

    Full Text Available Abstract Tobacco smoke is an important risk factor for various human cancers, including esophageal cancer. How benzo [a]pyrene diol epoxide (BPDE, a carcinogen present in tobacco smoke as well as in environmental pollution, induces esophageal carcinogenesis has yet to be defined. In this study, we investigated the molecular mechanism responsible for BPDE-suppressed expression of retinoic acid receptor-beta2 (RAR-β2 in esophageal cancer cells. We treated esophageal cancer cells with BPDE before performing methylation-specific polymerase chain reaction (MSP to find that BPDE induced methylation of the RAR-β2 gene promoter. We then performed chromatin immunoprecipitation (ChIP assays to find that BPDE recruited genes of the methylation machinery into the RAR-β2 gene promoter. We found that BPDE recruited DNA (cytosine-5--methyltransferase 3 alpha (DNMT3A, but not beta (DNMT3B, in a time-dependent manner to methylate the RAR-β2 gene promoter, which we confirmed by reverse transcription-polymerase chain reaction (RT-PCR analysis of the reduced RAR-β2 expression in these BPDE-treated esophageal cancer cell lines. However, BPDE did not significantly change DNMT3A expression, but it slightly reduced DNMT3B expression. DNA methylase inhibitor 5-aza-2'-deoxycytidine (5-Aza and DNMT3A small hairpin RNA (shRNA vector antagonized the effects of BPDE on RAR-β2 expressions. Transient transfection of the DNMT3A shRNA vector also antagonized BPDE's effects on expression of RAR-β2, c-Jun, phosphorylated extracellular signal-regulated protein kinases 1/2 (ERK1/2, and cyclooxygenase-2 (COX-2, suggesting a possible therapeutic effect. The results of this study form the link between the esophageal cancer risk factor BPDE and the reduced RAR-β2 expression.

  6. Protection of rats against 3-butene-1,2-diol-induced hepatotoxicity and hypoglycemia by N-acetyl-L-cysteine

    3-Butene-1,2-diol (BDD), an allylic alcohol and major metabolite of 1,3-butadiene, has previously been shown to cause hepatotoxicity and hypoglycemia in male Sprague-Dawley rats, but the mechanisms of toxicity were unclear. In this study, rats were administered BDD (250 mg/kg) or saline, ip, and serum insulin levels, hepatic lactate levels, and hepatic cellular and mitochondrial GSH, GSSG, ATP, and ADP levels were measured 1 or 4 h after treatment. The results show that serum insulin levels were not causing the hypoglycemia and that the hypoglycemia was not caused by an enhancement of the metabolism of pyruvate to lactate because hepatic lactate levels were either similar (1 h) or lower (4 h) than controls. However, both hepatic cellular and mitochondrial GSH and GSSG levels were severely depleted 1 and 4 h after treatment and the mitochondrial ATP/ADP ratio was also lowered 4 h after treatment relative to controls. Because these results suggested a role for hepatic cellular and mitochondrial GSH in BDD toxicity, additional rats were administered N-acetyl-L-cysteine (NAC; 200 mg/kg) 15 min after BDD administration. NAC treatment partially prevented depletion of hepatic cellular and mitochondrial GSH and preserved the mitochondrial ATP/ADP ratio. NAC also prevented the severe depletion of serum glucose concentration and the elevation of serum alanine aminotransferase activity after BDD treatment without affecting the plasma concentration of BDD. Thus, depletion of hepatic cellular and mitochondrial GSH followed by the decrease in the mitochondrial ATP/ADP ratio was likely contributing to the mechanisms of hepatotoxicity and hypoglycemia in the rat

  7. Epoxidation and Reduction of DHEA, 1,4,6-Androstatrien-3-one and 4,6-Androstadien-3β,17β-diol

    Eunjeong Kim

    2005-05-01

    Full Text Available Dehydroepiandrosterone (DHEA reacted with m-chloroperoxybenzoic acid(m-CPBA to form 3β-hydroxy-5α,6α-epoxyandrostan-17-one (1, but it did not reactwith 30% H2O2. 1,4,6-Androstatrien-3,17-dione (2 was obtained from DHEA and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in dioxane. Compound 2 was reacted with 30%H2O2 and 5% NaOH in methanol to give 1α,2α-epoxy-4,6-androstadien-3,17-dione (3,which was stereoselectively reduced with NaBH4 to form 1α,2α-epoxy-4,6-androstadien-3β,17β-diol (7 and reacted with Li metal in absolute ethanol-tetrahydrofuran mixture togive 2-ethoxy-1,4,6-androstatrien-3,17-dione (8. Compound 2 was also epoxidized withm-CPBA in dichloromethane to afford 6α,7α-epoxy-1,4-androstadien-3,17-dione (4,which was reacted with NaBH4 to synthesize 6α,7α-epoxy-4-androsten-3β,17β-diol (9.Compound 4 was reduced with Li metal in absolute ethanol-tetrahydrofuran mixture toform 7β-ethoxy-6α-hydroxy-1,4-androstadien-3,17-dione (10. Compound 2 was reducedwith NaBH4 in absolute ethanol to form 4,6-androstadien-3β,17β-diol (5, which wasreacted with 30% H2O2 to give the original compound, but which reacted with m-CPBAto give 4β,5β-epoxy-6-androsten-3β,17β-diol (6.

  8. Dose-Response on the Chemopreventive Effects of Sarcophine-Diol on UVB-Induced Skin Tumor Development in SKH-1 Hairless Mice

    Chandradhar Dwivedi

    2012-09-01

    Full Text Available Sarcophine-diol (SD is a lactone ring-opened analogue of sarcophine. It has shown chemopreventive effects on chemically-induced skin tumor development in female CD-1 mice, as well as in a UVB-induced skin tumor development model in hairless SKH-1 mice at a dose of 30 μg SD applied topically and 180 mJ/cm2 UVB. The objective of this study was to determine the dose-response on the chemopreventive effects of SD on SKH-1 hairless mice when exposed to a UVB radiation dose of 30 mJ/cm2. This UVB dose better represents chronic human skin exposure to sunlight leading to skin cancer than previous studies applying much higher UVB doses. Carcinogenesis was initiated and promoted by UVB radiation. Female hairless SKH-1 mice were divided into five groups. The control group was topically treated with 200 μL of acetone (vehicle, and the SD treatment groups were topically treated with SD (30 μg, 45 μg, and 60 μg dissolved in 200 μL of acetone 1 h before UVB radiation (30 mJ/cm2. The last group of animals received 60 μg SD/200 μL acetone without UVB exposure. These treatments were continued for 27 weeks. Tumor multiplicity and tumor volumes were recorded on a weekly basis for 27 weeks. Weight gain and any signs of toxicity were also closely monitored. Histological characteristics and the proliferating cell nuclear antigen (PCNA were evaluated in the mice skin collected at the end of the experiment. The dose-response study proved a modest increase in chemopreventive effects with the increase in SD dose. SD reduced the number of cells positively stained with PCNA proliferation marker in mice skin. The study also showed that SD application without UVB exposure has no effect on the structure of skin. The results from this study suggest that broader range doses of SD are necessary to improve the chemopreventive effects.

  9. Optical and relaxometric properties of monometallic (Eu(III), Tb(III), Gd(III)) and heterobimetallic (Re(I)/Gd(III)) systems based on a functionalized bipyridine-containing acyclic ligand.

    Leygue, Nadine; Boulay, Alexandre; Galaup, Chantal; Benoist, Eric; Laurent, Sophie; Vander Elst, Luce; Mestre-Voegtlé, Béatrice; Picard, Claude

    2016-05-17

    A series of lanthanide complexes of [LnL(H2O)](2-) composition where Ln = Eu(III), Tb(III) or Gd(III) has been studied for determining their photophysical and relaxometric properties in aqueous solution. The bifunctional ligand L (H5BPMNTA) is an acyclic chelator based on a central functionalized 2,2'-bipyridine core and two iminodiacetate coordinating arms. The mono-aqua Eu(III) and Tb(III) complexes display attractive spectroscopic properties with an excitation wavelength at 316 nm, similar excited state lifetimes and overall quantum yields (in the ranges 0.5-0.6 ms and 10-13%, respectively) in Tris buffer (pH 7.4). The proton longitudinal relaxivity, r1, of the Gd(III) complex is 4.4 mM(-1) s(-1) at 20 MHz and 310 K, which is comparable to that of the clinically used Gd-DTPA (Magnevist®). Interestingly, the water exchange rate between the coordination site and the bulk solvent is very fast (Kex = 2.6 × 10(8) s(-1) at 310 K). The ability of the complex to bind non-covalently to human serum albumin (HSA) was also examined by relaxometric measurements. We also report the synthesis and properties of a bimetallic complex based on Gd-BPMNTA and Re(I)(bpy)(CO)3 components. In this system, the Re core exhibits interesting photophysical properties (λem = 588 nm, Φ = 1.4%) and the Gd-BPMNTA core displays improved relaxivity (r1 = 6.6 mM(-1) s(-1) at 20 MHz and 310 K), due to an increase of the rotational correlation time. Besides these appealing optical and relaxometric properties, the presence of a reactive function on the structure proposes this potential dual imaging probe for conjugation to biomolecules or nanomaterials. PMID:27109253

  10. 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.

    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

  11. The role of hRev7, the accessory subunit of hPolζ, in translesion synthesis past DNA damage induced by benzo[a]pyrene diol epoxide (BPDE

    Maher Veronica M

    2010-12-01

    Full Text Available Abstract Background DNA polymerase zeta (Polζ is a specialized DNA polymerase that, unlike classical replicative polymerases, is capable of replicating past DNA lesions, i.e. of performing translesion synthesis (TLS. The catalytic subunit of hPolζ, hRev3, has been shown to play a critical role in DNA damage-induced mutagenesis in human cells, but less is known about the role of hRev7, the accessory subunit of hPolζ, in such mutagenesis. To address this question, we recently generated human fibroblasts with very significantly reduced levels of hRev7 protein and demonstrated that hRev7 is required to protect cells from ultraviolet(254 nm (UV radiation-induced cytotoxicity and mutagenesis (McNally et al., DNA Repair 7 (2008 597-604. The goal of the present study was to determine whether hRev7 is similarly involved in the tolerance of DNA damage induced by benzo[a]pyrene diol epoxide (BPDE, the reactive form of the widespread environmental carcinogen benzo[a]pyrene. Methods To determine whether hRev7 also plays a role in protecting human cells from the cytotoxicity and mutagenesis induced by benzo[a]pyrene diol epoxide (BPDE, cell strains with reduced hRev7 were compared to their parental strain and a vector control strain for the effect of BPDE on cell survival, induction of mutations, and the ability to progress through the cell cycle. Results The results show that cell strains with reduced hRev7 are more sensitive to the cytotoxic effect of BPDE than the control strains, and progress through S-phase at a slower rate than the control cells following BPDE treatment, indicating that hRev7, and likely hPolζ, is required for efficient bypass of BPDE-induced DNA lesions. However, neither the frequency nor kinds of mutations induced by BPDE in cells with reduced hRev7 differ significantly from those induced in the control strains, suggesting that hPolζ is not essential for inserting nucleotides opposite BPDE-induced DNA damage. Conclusions Taken

  12. Equity valuation in cyclical and acyclical industries

    Shuqair, Rand

    2012-01-01

    This dissertation provides an overview of various valuation approaches, mainly the multiples-based approach, the Dividend Discount Model, Discounted Cash Flow Model, Residual Income Valuation Model and the Abnormal Earnings Growth Model. In addition, it highlights the advantages and disadvantages of each, and follows with a discussion of the models and evidence of empirical research. It then takes the angle of assessing the performance of selected valuation models (Price to Ear...

  13. Therapeutic potential of acyclic nucleoside phosphonates

    Janeba, Zlatko

    Lima: Peruvian Chemical Society, 2014. [Latin American Chemistry Congress /31./ and Peruvian Chemistry Congress /27./. 14.10.2014-17.10.2014, Lima] Institutional support: RVO:61388963 Keywords : ANPs * malaria * antivirals Subject RIV: CC - Organic Chemistry

  14. Oxidation of acyclic terpenoids by Corynebacterium sp.

    Yamada, Y; Seo, C W; Okada, H.

    1985-01-01

    Squalene analogs such as lycopersene, geranylfarnesyl, digeranyl, and 2-hydroxy-2,3-dihydrosqualene and terpene alcohol derivatives such as farnesyl benzyl ether, farnesyl pivalate, geranylgeranyl pivalate, geranyl pivalate, and geranyl benzyl ether were oxidized by Corynebacterium sp. strain SY-79, which was isolated from soil by using squalene as a carbon source. Lycopersene and geranylfarnesyl gave no major product. Digeranyl, geranyl benzyl ether, and geranyl pivalate gave terminal oxidat...

  15. Synthesis and Crystal Structure of(3S,4R,Z)-3,6-dimethyl-2-(3-methylbut-2-enylidene)-2,3,3a,4,7,7a-hexahydrobenzofuran-3,4-diol

    CHEN Lei; FANG Hu-Biao; HUANG Nian-Yu; WANG Jun-Zhi; ZOU Kun

    2011-01-01

    The title compound of(3S,4R,Z)-3,6-dimethyl-2-(3-methylbut-2-enylidene)-2,3,3a,4,7,7a-hexahydrobenzofuran-3,4-diol,C15H22O3,as a potential gastric cytoprotective agent has been synthesized by the reduction of bisabolangelone in methanol with sodium borohydride.The title compound was characterized by IR and NMR spectra.Meanwhile,the crystal was obtained and determined by X-ray single-crystal diffraction.Crystal data:monoclinic system,space group P21 with a = 6.0692(12),b = 8.9954(18),c = 13.182(3) ,β = 92.59(3)°,V = 718.9(2) 3,Z = 2,F(000) = 272,Dc = 1.156 g/cm3,μ = 0.633 mm-1,R = 0.0362 and wR = 0.1051 for 9490 independent reflections(Rint = 0.0172) and 2461 observed reflections(I 2σ(I)).Intermolecular O-H…O interactions link the molecules into one-dimensional infinite chains running along the b axis,which contributes to the stability of the crystal structure.

  16. Synthesis and Characterization of (Na0.sK0.5)NbO3 (NKN) Thin Films Formed by a Diol-based Sol-gel Process

    SeSastian Wiegandt; Stefan Flege; Olaf Baake; Wolfgang Ensinger

    2012-01-01

    Lead-free (Na0.sK0.5)Nb03 (NKN) thin films were fabricated by spin coating on Pt/Ti/SiO2/Si substrates by a diol-based sol-gel process. Na-acetate, K-acetate, Nb-pentaethoxide and 1,3 propanediol were used to prepare the NKN precursor solution. Thermal analysis showed two characteristic temperatures of 360 and 600℃. Based on these temperatures, a heat treatment program with pyrolysis at 360℃ and calcination at 600℃ after every layer was used. To avoid inhomogeneities and secondary phases, an excess of sodium and potassium was necessary. To evaluate the proper excess amount of sodium and potassium secondary ion mass spectrometry (SIMS) lateral element maps and X-ray diffraction (XRD) patterns were recorded. An excess amount of 20% led to homogeneous distribution of the elements and to single phase perovskite NKN films with random crystal orientation. Scanning electron microscopy (SEMI images showed a pore free surface with 100 nm grains. The leakage current measurements showed a current of lx10-3 A/cm2 at 150 kV/cm.

  17. Determination of boron in waters and in water extracts from wastes by molecular and atomic absorption spectrometry following preliminary boron separation by extraction of its complex with 2-ethylhexane-1,3-diol

    Two methods for boron determination were developed and tested. The analysis is based on boron separation and preconcentration by extraction from an acid aqueous solution into a chloroform solution of 2-ethylhexane-1,3-diol followed by reextraction into aqueous sodium hydroxide, and subsequent molecular absorption spectroscopic determination with curcumine at 543 nm or atomic absorption spectroscopic determination at 249.8 nm in a nitrous oxide-acetylene flame. The limits of determination (3s criterion) for the two methods are 0.002 and 0.1 mg/l, respectively. The methods were compared with the conventional procedure based on the use of azomethine-H. While the sensitivities of the methods are comparable (the limit of determination for the azomethine-H method is 0.02 mg/l), the proposed methods exhibit a better reliability and are widely applicable to the determination of total boron in all types of water and water extracts. (author) 3 tabs., 37 refs

  18. Synthesis, receptor binding, and tissue distribution of (17α,20E)- and (17α20Z)-21[125I]iodo-11β-methoxy-19-norpregna-1,3,5,(10),20-tetraene-3,17-diol

    The isomeric (17α,20E)- and (17α,20Z)-21-Iodo-11β-methoxy-19-norpregna-1,3,5,(10),20-tetraene-3,17-diols 1 and 2, respectively, and their no-carrier-added (NCA) [125I]iodo-vinyl analogues were tested for their binding affinity for the estrogen receptor, their relative target tissue retention and their in vivo stability. The (iodovinyl)-11β -methoxygestradiols 3 and 6 were prepared with retention of the configuration about C-20 via destannylation of the tributylstannyl precursors in a similar manner as recently described for the analogous 20E isomer 3 and 20Z isomer 4 of (iodovinyl)estradiol (J. Med. Chem., 31, 1946, 1988). Although both isomeric 11β-methoxyestradiols 1 and 2 showed similar relative binding affinities for estrogen receptors as compared to 3 and 6, the former showed substantial higher receptor-mediated target tissue uptake. Differences in biological properties between the 20E (1) and 20Z isomer (2) are insignificant. However, the 20Z isomer 2 exhibited higher in vivo instability, as judged by iodine uptake in the thyroid, which is in accordance with its relative low chemical stability

  19. Reextraction rays and their use in multicomponent systems of the B2O3-Na2O-H2O-β-diol/solvent type for characteristic of B2O3 reextraction from organic into aqueous phase

    THE SYSTEM B2O3-Na2O-H2O - β-diol/diluent is studied with the aim of choosing the optimal conditions for the reextraction of B2O3 to the aqueous phase. In order to model the process of the B2O3 transition from the organic to the aqueous phase, a concept ''the reextraction beam'' is introduced by analogy with ''the extraction beam''. The method is exemplified by the isothermal section (25 deg C) of the system Na2O-B2O3-H2O-2.6-dimethyloctanediol-4.6/toluol, which describes the reextration of B2O3 to the aqueous phase from the extracts obtained in the system B2O3-H2O-2.6-dimethyloctanediol-4.6/toluol. The data obtained were plotted on the diagram describing the composition of the ternary system Na2O-H2O-B2O3. The treatment of the extract with the varying amounts of NaOH of the same concentration gives a number of points for the aqueus phase composition, forming a straight line, the so called ''reextraction beam''. A diagram was constructed for each reextraction beam on the basis of experimental data: the degree of reextraction of Er (%) as a function of the molar ratio Na2O/B2/3. The practically complete reextraction of B2O3 is attained at the beams 1-3 at Na2O/B2O3 = 2

  20. Transetherification on polyols by intra- and intermolecular nucleophilic substitutions.

    Takahiro Muraoka

    Full Text Available Transetherification on polyols involving intra- and intermolecular nucleophilic substitutions is reported. Di- or trialkoxide formation of propane-1,3-diol or 2-(hydroxymethylpropane-1,3-diol derivatives by NaH triggers the reaction via oxetanes formation, where the order to add NaH and a polyol significantly influences the yields of products. It was demonstrated that the protective group on the pentaerythritol skeleton is apparently transferred to the hydrophilic and hydrophobic chain molecules bearing a leaving group in one-step, and a protective group conversion from tosyl to benzyl was successful using a benzyl-appending triol to afford a desired product in 67% yield.

  1. Efficient synthesis of 1,3,5-oxygenated synthons from dimethyl 3-oxoglutarate: first use of borane-dimethyl sulfide complex as a regioselective reducing agent of 3-oxygenated glutarate derivatives

    The selective reduction of dimethyl 3-oxoglutarate was accomplished in different levels. A high yielding sodium borohydride reduction of the keto group is fully described leading to dimethyl 3-hydroxyglutarate. When borane-dimethyl sulfide (BMS) complex was used, a diol or a triol compound can be obtained by selective or total reduction of 3-hydroxy- or 3-oxoglutarate, respectively, allowing an efficient and practical route to 1,3,5-oxygenated compounds. (author)

  2. Matrix metalloproteinase-13 downregulation and potential cartilage protective action of the Korean Red Ginseng preparation

    Lee, Je Hyeong; Shehzad, Omer; Ko, Sung Kwon; Kim, Yeong Shik; Kim, Hyun Pyo

    2014-01-01

    Background The present study was designed to prepare and find the optimum active preparation or fraction from Korea Red Ginseng inhibiting matrix metalloproteinase-13 (MMP-13) expression, because MMP-13 is a pivotal enzyme to degrade the collagen matrix of the joint cartilage. Methods From total red ginseng ethanol extract, n-BuOH fraction (total ginsenoside-enriched fraction), ginsenoside diol-type-enriched fraction (GDF), and ginsenoside triol-type-enriched fraction (GTF) were prepared, and...

  3. 对(艹孟)烷-3,8-二醇的合成与应用研究进展%Research Progress on Synthesis and Application of p-Menthane-3,8-diol

    何丽芝; 赵振东; 毕良武; 王鹏

    2012-01-01

    对(艹孟)烷-3,8-二醇是一种具有生物活性的化合物,主要来源于柠檬桉精油,可直接用于香水、杀虫剂和药品等.通常采用化学和生物化学的方法合成对(艹孟)烷-3,8-二醇,以替代从柠檬桉叶油分离得到的天然产品.以香茅醛为原料通过Prins环缩合和水解,或者通过Solanum aviculare悬浮培养方式进行生物转化得到对(艹孟)烷-3,8-二醇;通过薄荷醇的氧化,或者以2-丁烯醛为原料与甲基锂、NaClO2等试剂经过较长步骤也可合成对(艹孟)烷-3,8-二醇.对(艹孟)烷-3,8-二醇可应用于制造驱虫剂、凉味剂、药物或者化妆品的添加剂以及海水防护涂料添加剂等.%p-Menthane-3,8-diol (PMD) is a bioactive compound, which is first found in essential oil of leaves of Eucalyptus citriodora and often used as an active composition for perfume, insecticide, and medicine. It is usually synthesized by chemical or biological approaches instead of the direct isolation from the E. citriodora oil. PMD can be synthesized from citronellal through a prins reaction and a hydration,or be transformed from citronellal through a Solarium avwulare suspension culture. It can also be produced from menthol with an oxidation,or synthesized from 2-butenal by a long step reactions with reagents such as MeIi,NaClO2,etc.PMD can be used as repellent,coolant,pharmaceutical,cosmetics,and coatings.

  4. 注射用磷霉素钠中磷霉素钠二醇物含量测定方法的研究%Study on the determination of fosfomycin sodium diol substance in fosfomycin sodium for injection

    邹宇; 刘珂; 姜雯; 张亚杰; 刘亚威

    2012-01-01

    Objectives;To establish LC - MS/MS and HPLC - RID methods to determine fosfomycin sodium diol substance in fosfomycin sodium for injection, and compare with the method in Chinese Pharmacopoeia to improve the quality control of fosfomycin sodium. Methods: LC - MS/MS method was achieved on Promosil CN column (2S0 mm x4. 6 mm,5 p,m)with mobile phase consisting of 5 mmol · L"1 ammonium acetate solution - methanol (82:18). The analytes were detected in the negative ion mode. Multiple reaction monitoring using the precursor to product ion combinations of m/z 154. 9 ->80. 9 and m/z 120. 9 ->77. 1 was performed to quantify fosfomycin diol substance and the internal standard benzoic acid, respectively. HPLC - RID method was achieved on Agilent Zorbax NH2 column(250 mm x4. 6 mm,5 (xm) utilizing a mobile phase of 10. 89 g · L-1 potassium dihydrogen phosphate solution at the flow rate of 1. 0 mL · min"1. The column temperature was 36℃and the temperature of RID detector was set at 35℃. Results;The LC - MS/MS method;The standard curve was linear in the concentration range of 22. 46 - 359. 4 ng · mL-1. The lower limit of quantification was 4. 492 ng · mL-1,each sample was chromatographed within 5 min. The HPLC - RID method;The standard curve was linear in the concentration range of 0. 104 - 5. 205 mg · mL-1 , the method precision was 0. 7% . Conclusions; The two methods are specific, simple and reliable, and can be applied to quality research and control of fosfomycin sodium for injection.%目的:建立液相色谱串联质谱法和高效液相色谱-示差折光法测定注射用磷霉素钠中的磷霉素钠二醇物含量,并与现行中国药典方法比较,提高对药品的质量控制.方法:液相色谱串联质谱法采用Promosil CN(250 mm×4.6mm,5μm)色谱柱,流动相为5 mmol·L-1醋酸铵-甲醇(82:18),采用(-)ESI电离源,多反应监测(MRM)扫描方式,用于定量分析的离子分别为m/z 154.9→80.9(磷霉素二醇物)和m/z 120.9 →77.1(内标

  5. Steroidal saponins from Tribulus terrestris.

    Kang, Li-Ping; Wu, Ke-Lei; Yu, He-Shui; Pang, Xu; Liu, Jie; Han, Li-Feng; Zhang, Jie; Zhao, Yang; Xiong, Cheng-Qi; Song, Xin-Bo; Liu, Chao; Cong, Yu-Wen; Ma, Bai-Ping

    2014-11-01

    Sixteen steroidal saponins, including seven previously unreported compounds, were isolated from Tribulus terrestris. The structures of the saponins were established using 1D and 2D NMR spectroscopy, mass spectrometry, and chemical methods. They were identified as: 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-2α,3β,22α,26-tetrol-12-one (terrestrinin C), 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-22α,26-diol-3,12-dione (terrestrinin D), 26-O-β-d-glucopyranosyl-(25S)-furost-4-en-22α,26-diol-3,6,12-trione (terrestrinin E), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-3β,22α,26-triol-12-one (terrestrinin F), 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-12β,22α,26-triol-3-one (terrestrinin G), 26-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl-(25R)-furost-4-en-22α,26-diol-3,12-dione (terrestrinin H), and 24-O-β-d-glucopyranosyl-(25S)-5α-spirostan-3β,24β-diol-12-one-3-O-β-d-glucopyranosyl-(1→4)-β-d-galactopyranoside (terrestrinin I). The isolated compounds were evaluated for their platelet aggregation activities. Three of the known saponins exhibited strong effects on the induction of platelet aggregation. PMID:25172515

  6. 2,3-Diols versus 3,4-diols in the bean second internode

    Šíša, Miroslav; Swaczynová, Jana; Kohout, Ladislav

    Bialystok : University of Bialystok, 2005, s. 95. [Conference on Isoprenoids /21./. Bialowieza (PL), 23.09.2005-29.09.2005] R&D Projects: GA AV ČR(CZ) IBS4055304 Institutional research plan: CEZ:AV0Z40550506 Keywords : brassinolide analogues * cholestane * internode bioassay Subject RIV: CC - Organic Chemistry

  7. Two New Monoterpenes from the Fruits of Illicium lanceolatum

    Yan-Bing Zhang; Meng-Qi Liu; Yue-Feng Bi; Li-Xia Wang; Hui-Juan Li; Ji-Feng Liu

    2013-01-01

    Two new monoterpenes, p-mentha-1(7),8-dien-2-O-b-d-glucoside (1) and trans-2,4-dihydroxy-2,4-dimethyl-trans-1-acetic acid g-lactone (2) were isolated from the fruits of Illicium lanceolatum along with trans-2,4-dihydroxy-2,4-dimethyl-cis-1-acetic acid g-lactone (3), (1R,2R,4R)-8-p-menthen-1,2-diol (4), trans-sobrerol (5), (1S,2S,4R)-p-menthane-1,2,8-triol (6) and (1S, 2S, 4R, 8R)-p-menthane-1,2,9-triol (7). The structures of the isolates were confirmed by spectroscopic analysis and they showe...

  8. Acyclic nucleoside bisphosphonates as inhibitors of 6-oxopurine phosphoribosyltransferases

    Hocková, Dana; Keough, D. T.; Špaček, Petr; Janeba, Zlatko; Naesens, L.; Edstein, M. D.; Chavchich, M.; Wang, T. H.; de Jersey, J.; Guddat, L. W.

    Kanagawa : Kanagawa University, 2013. P004-P004. [ISNAC 2013. The International Symposium on Nucleic Acid Chemistry /40./. 13.11.2013-15.11.2013, Yokohama] R&D Projects: GA ČR GAP207/11/0108 Grant ostatní: NHMRC(AU) 1030353 Institutional support: RVO:61388963 Keywords : nucleotide analogues * enzyme inhibitors * plasmodium Subject RIV: CC - Organic Chemistry

  9. Efficient synthesis of "open-ring" acyclic nucleoside phosphonates

    Jansa, Petr; Holý, Antonín; Masojídková, Milena

    Marburg : University of Marburg, 2006. s. 111. ISBN 3-89703-685-1. [Joint Meeting of the Czech, German and Hungarian Pharmaceutical Societies. 04.10.2006-07.10.2006, Marburg] R&D Projects: GA MŠk(CZ) 1M0508 Grant ostatní: Descartes Prize(XE) HPAW-2002-100096 Institutional research plan: CEZ:AV0Z40550506 Keywords : open-ring ANPs * pyrimidines Subject RIV: CC - Organic Chemistry

  10. Pillar switchings and acyclic embedding in mapping class group

    Jeong, Chan-Seok

    2012-01-01

    The braid group $B_g$ is embedded in the ribbon braid group that is defined to be the mapping class group $\\Gamma_{0,(g),1}$. By gluing two copies of surface $S_{0,g+2}$ along $g+1$ holes, we get surface $S_{g,1}$. A pillar switching is a self-homeomorphism of $S_{g,1}$ which switches two pillars of surfaces by $180{}^\\circ$ horizontal rotation. We analyze the actions of pillar switchings on $\\pi_1 S_{g,1}$ and then give concrete expressions of pillar switchings in terms of standard Dehn twists. The map $\\psi: B_g \\rightarrow \\Gamma_{g,1}$ sending the generators of $B_g$ to pillar switchings on $S_{g,1}$ is defined by extending the embedding $B_g \\hookrightarrow \\Gamma_{0,(g+1),1}$. We show that this map is injective by analyzing the actions of pillar switchings on $\\pi_1 S_{g,1}$. The second part of this paper is to prove that this map induces a trivial homology homomorphism in the stable range. For the proof we use the categorical delooping. We construct a suitable monoidal 2-functor from tile category to s...

  11. Novel oligonucleotides modified with acyclic nucleoside phosphonate units

    Janeba, Zlatko; Hocková, Dana; Kaiser, Martin Maxmilian; Ménová, Petra; Novák, Pavel; Rosenbergová, Šárka; Páv, Ondřej; Pohl, Radek; Poštová Slavětínská, Lenka; Rosenberg, Ivan

    Newport : Gordon Research Conference, 2015. [Nucleosides, Nucleotides & Oligonucleotides. Gordon Research Conference 2015. 28.06.2015-03.07.2015, Newport] R&D Projects: GA ČR GA13-26526S Institutional support: RVO:61388963 Keywords : nucleotide analogues * modified oligonucleotides Subject RIV: CC - Organic Chemistry

  12. Schur complements of matrices with acyclic bipartite graphs

    Britz, Thomas Johann; Olesky, D.D.; van den Driessche, P.

    2005-01-01

    Bipartite graphs are used to describe the generalized Schur complements of real matrices having nos quare submatrix with two or more nonzero diagonals. For any matrix A with this property, including any nearly reducible matrix, the sign pattern of each generalized Schur complement is shown...

  13. Enumeration of Golomb Rulers and Acyclic Orientations of Mixed Graphs

    Beck, Matthias; Pham, Tu

    2011-01-01

    A \\emph{Golomb ruler} is a sequence of distinct integers (the \\emph{markings} of the ruler) whose pairwise differences are distinct. Golomb rulers can be traced back to additive number theory in the 1930s and have attracted recent research activities on existence problems, such as the search for \\emph{optimal} Golomb rulers (those of minimal length given a fixed number of markings). Our goal is to enumerate Golomb rulers in a systematic way: we study [g_m(t) := # {\\x \\in \\Z^{m+1} : \\, 0 = x_0 < x_1 < ... < x_{m-1} < x_m = t, \\text{all} x_j - x_k \\text{distinct}},] the number of Golomb rulers with $m+1$ markings and length $t$. Our main result is that $g_m(t)$ is a quasipolynomial in $t$ which satisfies a combinatorial reciprocity theorem: $(-1)^{m-1} g_m(-t)$ equals the number of rulers $\\x$ of length $t$ with $m+1$ markings, each counted with its \\emph{Golomb multiplicity}, which measures how many combinatorially different Golomb rulers are in a small neighborhood of $\\x$. Our reciprocity theorem...

  14. Acyclic Nucleotide Analogues Derived from 2-(Aminomethyl) Purine Bases

    Holý, Antonín; Hocek, Michal; Snoeck, R.; Balzarini, J.; De Clercq, E.

    Santa Fe : Sweeney Convention Center , 1995. s. 25. [International Conference on Antiviral Research /8./. 23.04.1995-28.04.1995, Santa Fe] R&D Projects: GA AV ČR IAA455407 Grant ostatní: American Foundation for AIDS Research ERBCIPDCT930194; Gilead Sciences 001682-13-RGR Source of funding: US ; US

  15. On the cluster multiplication theorem for acyclic cluster algebras

    Xu, Fan

    2007-01-01

    In \\cite{CK2005} and \\cite{Hubery2005}, the authors proved the cluster multiplication theorems for finite type and affine type. We generalize their results and prove the cluster multiplication theorem for arbitrary type by using the properties of 2--Calabi--Yau (Auslander--Reiten formula) and high order associativity.

  16. Medicinal Chemistry of Fluorinated Cyclic and Acyclic Nucleoside Phosphonates

    Baszczyňski, Ondřej; Janeba, Zlatko

    2013-01-01

    Roč. 33, č. 6 (2013), s. 1304-1344. ISSN 0198-6325 Institutional support: RVO:61388963 Keywords : nucleoside phosphosphonates * fluorine * antiviral * anticancer * antiparasitic Subject RIV: CC - Organic Chemistry Impact factor: 8.131, year: 2013

  17. [Acyclic analogs of ribavirin. Synthesis and antiviral activity].

    Tsilevich, T L; Shchaveleva, I L; Nosach, L N; Zhovnovataia, V L; Smirnov, I P

    1988-05-01

    Activity of several ribavirin analogues, viz.1-(2-hydroxyethoxymethyl)-, 1-(3-hydroxypropoxymethyl)-, 1-(4-hydroxybutoxymethyl)- and 1-(2,3-dihydroxypropyl)-1,2,4-triazole 5- and 3-carboxamides, against human adenovirus type 2 in the Hep-2 cell culture has been studied. The ether oxygen atom imitating the ribose O4' was shown to be essential for the antiviral activity. 1-(2-Hydroxyethoxymethyl)-1,2,4-triazole 3-carboxamide, a structural analogue of ribavirin in which the hydroxyl group is apparently equivalent to the ribose 5'-OH, possesses the highest activity among the compounds studied. Lengthening of the alkyl side chain reduces essentially the antiviral activity. PMID:3422011

  18. Hyperprolactinemia-induced ovarian acyclicity is reversed by kisspeptin administration

    Sonigo, Charlotte; Bouilly, Justine; Carré, Nadège; Tolle, Virginie; Caraty, Alain; Tello, Javier; Simony-Conesa, Fabian-Jesus; Millar, Robert; Young, Jacques; Binart, Nadine

    2012-01-01

    Hyperprolactinemia is the most common cause of hypogonadotropic anovulation and is one of the leading causes of infertility in women aged 25-34. Hyperprolactinemia has been proposed to block ovulation through inhibition of GnRH release. Kisspeptin neurons, which express prolactin receptors, were recently identified as major regulators of GnRH neurons. To mimic the human pathology of anovulation, we continuously infused female mice with prolactin. Our studies demonstrated that hyperprolactinem...

  19. Hyperprolactinemia-induced ovarian acyclicity is reversed by kisspeptin administration

    Sonigo, Charlotte; Bouilly, Justine; Carré, Nadège; Tolle, Virginie; Caraty, Alain; Tello, Javier; Simony-Conesa, Fabian-Jesus; Millar, Robert; Young, Jacques; Binart, Nadine

    2012-01-01

    Hyperprolactinemia is the most common cause of hypogonadotropic anovulation and is one of the leading causes of infertility in women aged 25–34. Hyperprolactinemia has been proposed to block ovulation through inhibition of GnRH release. Kisspeptin neurons, which express prolactin receptors, were recently identified as major regulators of GnRH neurons. To mimic the human pathology of anovulation, we continuously infused female mice with prolactin. Our studies demonstrated that hyperprolactinem...

  20. Acyclic nucleoside phosphonates: A key class of antiviral drugs

    De Clercq, E.; Holý, Antonín

    2005-01-01

    Roč. 4, č. 13 (2005), 928-940. ISSN 1474-1776 Institutional research plan: CEZ:AV0Z4055905 Keywords : tenofovir * adefovir * cidofovir Subject RIV: CC - Organic Chemistry Impact factor: 18.775, year: 2005

  1. Two New Furostanol Glycosides from Asparagus cochinchinensis

    2002-01-01

    Two new furostanol oligoglycosides named as aspacochioside A (1) and B (2) were isolated from the roots of Asparagus cochinchinensis (Lour.) Merr.. Their structures were elucidated to be 3-O-[{α-L-rhamnopyranosyl-(1→4)}{β-D-glucopyranosyl}]-26-O-[β-D-glucopy- ranosyl]-(25S)-5β-furostane-3β,22α,26-triol 1 and 3-O-[{α-L-rhamnopyranosyl-(1→4)}{(-D-glu- copyranosyl}]-26-O-[β-D-glucopyranosyl]-22α-methoxy-(25S)-5β-furostane-3β,26-diol 2 on the basis of spectroscopic techniques and chemical methods.

  2. Substituted silane-diol polymers have improved thermal stability

    Byrd, J. D.; Curry, J. E.

    1966-01-01

    Organosilicon polymers were synthesized to produce improved physical and chemical properties, including high thermal stability. Of the polymers produced, poly/4, 4 prime-bisoxybi- phenylene/diphenylsilane, formed from bis/anilino/diphenylsilane and p, p prime-biphenol, was found to have the most desirable properties.

  3. The antigluconeogenic activity of cucurbitacins from Momordica charantia.

    Chen, Jian-Chao; Lau, Clara Bik-San; Chan, Judy Yuet-Wa; Fung, Kwok-Pui; Leung, Ping-Chung; Liu, Jie-Qing; Zhou, Lin; Xie, Ming-Jin; Qiu, Ming-Hua

    2015-03-01

    Five new cucurbitacins, kuguacins II-VI (1-5), along with five known analogues (6-10), were obtained from the fruit of Momordica charantia. Structures of the new compounds were elucidated as 5β,19-epoxycucurbit-23-en-7-on-3β,25-diol (1), 5β,19-epoxycucurbit-7,23-dion-3β,25-diol (2), 5β,19-epoxycucurbit-6-en-19,23-dion-3β,25-diol (3), 5β,19-epoxy-23,24,25,26,27-pentanorcucurbit-6-en-7,19-dion-3β,22-diol (4), and cucurbit-5-en-7,23-dion-3β,19,25-triol (5) by extensive spectroscopic and single-crystal X-ray diffraction analyses. Some cucurbitane compounds from this species were screened for their potential antidiabetic properties in terms of antigluconeogenic activity. As a result, compounds 1, 10, 11, and 12 (at 25-100 µM) showed concentration-dependent inhibition on glucose production from liver cells. In addition, compounds 11 and 12 (at 100 µM) showed around 20-30 % inhibition on PEPCK activity. PMID:25760384

  4. Preparative isolation and purification of five steroid saponins from Dioscorea zingiberensis C.H.Wright by counter-current chromatography coupled with evaporative light scattering detector.

    Zhang, Xinxin; Ito, Yoichiro; Liang, Jinru; Su, Qi; Zhang, Yongmin; Liu, Jianli; Sun, Wenji

    2013-10-01

    A counter-current chromatography (CCC) method was successfully applied to separate and purify steroid saponins from the traditional Chinese medicine Dioscorea zingiberensis C.H.Wright for the first time. Ethyl acetate-n-butanol-methanol-water (4:1:2:4, v/v) was used as the two-phase solvent system, and evaporative light scattering detector (ELSD) was used as the detector in this method. The method separated in a single run the following five steroid saponins: 26-O-β-d-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[β-d-glucopyranosyl-(1→3)-β-d-glucopyranol-(1→4)-α-l-rhamnopyranosyl-(1→2)]-β-d-glucopyranoside (Compound A); 26-O-β-d-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[β-d-glucopyranosyl(1→3)-α-l-rhamnopyranosyl(1→2)]-β-d-glucopyranoside (Compound B); 26-O-β-d-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranoside (Compound C); 26-O-β-d-glucopyranosyl-(25R)-furost-5, 20(22)-diene-3β, 26-diol-3-O-{α-l-rhamnopyranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)-β-d-glucopyranosyl-(1→2)]}-β-d-glucopyranoside (Compound D); and 26-O-β-d-glucopyranosyl-(25R)-furost-5, 20(22)-diene-3β, 26-diol-3-O-[β-d-glucopyranosyl-(1→4)-α-l-rhamnopyranosyl(1→2)]-β-d-glucopyranoside (Compound E). Their structural identification of the five steroid saponins was performed by means of ESI-MS, and (13)C NMR. PMID:23831486

  5. The conversion of 16β hydroxyldehydroepiandrosterone in human serum.

    Ke, Yuyong; Gonthier, Renaud; Labrie, Fernand

    2016-05-01

    The circulating levels of 16β hydroxydehydroepiandrosterone (16β OH-DHEA) are at the limit of detection (less than 10pg/mL), unlike the serum concentrations of 16α-hydroxydehydroepiandrosterone (16α OH-DHEA, 10-300pg/mL) in premenopausal, postmenopausal and male serum. A major reason could be the rapid conversion of 16β OH-DHEA to 5-androstene-3beta, 17beta-diol 16 one (3β, 17β-diol 16-oxo) in serum due to the stereospecific structure of 16β OH-DHEA. In ultrapure H2O, there is no apparent conversion observed while 16β OH-DHEA (10ng/mL) spiked in stripped or unstripped serum is quickly converted to 3β, 17β-diol 16-oxo at room temperature. During this conversion, a further converted product was observed with a difference in molecular weight of 16Da from that of 16β OH-DHEA and 3β, 17β-diol 16-oxo, which could be their hydroxylation product, i.e. triol-ketone. Under basic conditions, further conversion occurs. The present data can explain the practically undetectable concentration of serum 16β OH-DHEA while 3β, 17β-diol 16-oxo is at the level of less than 50pg/mL. Serum concentrations of (0.0-9.9pg/mL for 16β OH-DHEA, 8.9-50.7pg/mL for 3β, 17β-diol 16-oxo and 10.0-285.0pg/mL for 16α OH-DHEA are measured in sera of premenopausal, postmenopausal women and men over 50years of age. PMID:26896786

  6. Carotenoid composition and vitamin A value of an Argentinian squash (Cucurbita moschata).

    González, E; Montenegro, M A; Nazareno, M A; López de Mishima, B A

    2001-12-01

    The carotenoid composition of butternut squash (Cucurbita moschata) cultivated in the province of Santiago del Estero, Argentina, was determined. The main carotenoids isolated were identified as beta-carotene (beta,beta-carotene), alpha-carotene (beta,epsilon-carotene), and lutein (beta,epsilon-carotene-3,3'-diol) and the minor carotenoids, as phytofluene (7,8,11,12,7',8'-hexahydro-psi,psi-carotene), zeta-carotene (7,8,7',8'-tetrahydro-psi,psi-carotene), neurosporene (7,8-dihydro-psi,psi-carotene), violaxanthin (5,6,5',6'- diepoxy-5,6,5',6'-tetrahydro-beta,beta-carotene-3,3'-diol) and neoxanthin (5,6-epoxy-6,7-didehydro-5,6,5',6'-tetrahydro-beta,beta- carotene-3,5,3'-triol). In some samples, 5,6,5',6'-beta-carotene diepoxide, (5,6,5',6'-diepoxy-5,6,5',6'-tetrahydro-beta,beta-carotene) and flavoxanthin (5,8-epoxy-5,8-dihydro-beta,epsilon-carotene-3,3'-diol) were detected. The presence of cis-isomers of beta,beta-carotene was also detected by HPLC. The vitamin A value obtained was 432 micrograms RE/100 g fresh sample, which indicates that this vegetable is an important source of provitamin A. PMID:12012567

  7. Structures and Absolute Configurations of Sulfate-Conjugated Triterpenoids Including an Antifungal Chemical Defense of the Green Macroalga Tydemania expeditionis

    Jiang, Ren-Wang; Lane, Amy L.; Mylacraine, Lauren; Hardcastle, Kenneth I.; Fairchild, Craig R.; Aalbersberg, William; Hay, Mark E.; Kubanek, Julia

    2012-01-01

    Cytotoxicity-guided fractionation of the green macroalga Tydemania expeditionis led to isolation of four sulfate-conjugated triterpenoids including one new lanostane-type triterpenoid disulfate, lanosta-8-en-3,29-diol-23-oxo-3,29-disodium sulfate (1), and three known cycloartane-type triterpenoid disulfates, cycloartan-3,29-diol-23-one 3,29-disodium sulfate (2), cycloart-24-en-3,29-diol-23-one 3,29-disodium sulfate (3), and cycloartan-3,23,29-triol 3,29-disodium sulfate (4). Extensive 1D and 2D NMR analyses in combination with X-ray crystallography established the structure and absolute configuration of 1 and allowed determination of the absolute configurations of 2–4 with a revision of previously assigned configuration at C-5. Each natural product was moderately cytotoxic in tumor cell and invertebrate toxicity assays. Of the natural products, only 4 exhibited significant antifungal activity at whole-tissue natural concentrations against the marine pathogen Lindra thalassiae. Comparison of the biological activities of natural products with their desulfated derivatives indicated that sulfation does not appear to confer cytotoxicity or antifungal activity. PMID:18763828

  8. The Chemical Constituents of Diterpenoids from Kaempferia marginata Carey

    YuJingguang; YuDonglei; SunLan; ZhangShu; ZhengCaicheng; ChenYuheng

    2001-01-01

    Marginatol (1), a new isopimarene diterpenoid, and five known compounds 8(14),15-sandera-copimaradiene-1α,9α-diol (2), 8(14), 15-sanderacopimaradene-1α 6β,9α-triol (3), germacrone (4), trans-ethyl p-methoxycinnamate (5) and n-pentadecane (6) were isolated from the hexane extract of Kaempferia marginata Carey.The structure of marginatol (1) was established as 8(14),15-isopimaradiene-6α-ol on the basis of spectral data (IR,MS,1h--1H 13C-1H NOESY and HMBC). Compounds 2, 3 and 4 were isolated for the first time from thisplant.

  9. New Cucurbitane Triterpenoids and Steroidal Glycoside from Momordica charantia

    Cui-Fang Wang

    2009-11-01

    Full Text Available Three new cucurbitane triterpenoids 1–3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia. The structures of new compounds were determined to be 19(R-n-butanoxy-5β,19-epoxycucurbita-6,23-diene-3β,25-diol 3-O-β-glucopyranoside (1, 23-O-β-allopyranosylecucurbita-5,24-dien-7α,3β,22(R,23(S-tetraol 3-O-β-allopyranoside. (2, 23(R,24(S,25-trihydroxycucurbit-5-ene 3-O-{[β-glucopyranosyl(1→6]-O-β-glucopyranosyl}-25-O-β-glucopyranoside (3, and 24(R-stigmastan-3β,5α,6β-triol-25-ene 3-O-β-glucopyranoside (4, respectively. Their structures were elucidated by the combination of mass spectrometry (MS, one and two-dimensional NMR experiments and chemical reactions.

  10. Two New Steroidal Glycosides from Fermented Leaves of Agave americana

    JianMingJIN; XiKuiLIU; 等

    2002-01-01

    Two new spirostanol glycosides named agamenoside A and B, ere isolated from the fermented leaves of Agave americana. Their structures were elucidated as (23S,25R)-5α-spirostan-3β,6α,23-triol 3-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside(1) and (25R)-5α-spiro-stan-3β,6α-diol 3-O-β-D-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyra-nosyl-(1→4)-β-D-galactopyranoside(2) by a combination of chemical and spectral methods.

  11. Two New Steroidal Glycosides from Fermented Leaves of Agave americana

    2002-01-01

    Two new spirostanol glycosides named agamenoside A and B, were isolated from the fcrmcnted leaves of Agave americana. Their structures were elucidated as (23S, 25R)-5α-spirostan-3β, 6α, 23-triol 3-O-α-L-rhamnopyranosyl-(1→3)- β-D-glucopyranosyl-(l→2)-[β-D-xylopyranosyl-( 1 →3)]-β-D-glucopyranosyl-( l →4)-β-D-galactopyranoside (1) and (25R)-5α-spiro stan-3β, 6α-diol 3-O-β-D-glucopyranosyl-(l→2)-[ β-D-xylopyranosyl-(l→3)]- β-D-glucopyra nosyl-(1→4)- β-D-galactopyranoside (2) by a combination of chemical and spectral methods.

  12. Synthesis, kinetics of photo-dimerization/photo-cleavage and physical properties of coumarin-containing branched polyurethanes based on polycaprolactones

    R. Seoane Rivero

    2016-02-01

    Full Text Available A series of coumarin-containing branched polyurethanes based on polycaprolactones, hexamethylene diisocyanate and a monohydroxylated coumarin monomer with 5 and 10% content by weight of coumarin units were successfully prepared. Chain architecture was controlled by combination of polycaprolactone (PCL triol or tetrol with PCL diol. Terminal coumarin units segregated from the polyurethane matrix as measured by differential scanning calorimetry (DSC. Photo-dimerization with 313 nm lamps presented an anomalous behavior in two steps with high irreversibility at high conversions. Photo-dimerization/photo-cleavage reactions showed an increase in irreversibility with the increase in cycles. It was demonstrated that conversion measured by Raman spectroscopy gave the same results than conversion measured by ultraviolet (UV spectroscopy. Photo-dimerization produced an elastomeric material with much better mechanical properties than non-irradiated material as a consequence of the crosslinking produced. Photo-cleavage decreased the mechanical properties and repeated photo-dimerization increased mechanical properties again.

  13. Di-and tri-hydroxylated Kaurane derivatives from microbial transformation of Ent-Kaur-16-En-19-Ol by Cephalosporium aphidicola and their allelopathic activity on Lactuca sativa (lettuce)

    The use of microorganisms to induce chemical modifications in organic molecules is a very useful tool in organic synthesis, to obtain biologically active substances. The fungus Cephalosporium aphidicola is known by its ability to hydroxylate several skeleton positions of many classes of organic compounds. In this work, the microbial transformation of ent-kaur-16-en-19-01 (1) by C. aphidicola, afforded two hydroxylated compounds, ent-kauran-16β,19-diol (2) and ent-kauran-16β,17,19-triol (3). Their structures were established by 1D and 2D-NMR studies. Both compounds were tested for their action on the growth of radical and shoot of Lactuca sativa. (author)

  14. Five new cyotoxic steroidal glycosides from the fruits of Solanum torvum.

    Li, Jinsheng; Zhang, Lu; Huang, Cheng; Guo, Fujiang; Li, Yiming

    2014-03-01

    The fruits of Solanum torvum Swartz, commonly known as Turkey berry, are edible and commonly used as a vegetable in the South Indian population's diet and as an essential ingredient in Thai cuisine. Five new steroidal glycosides together with five known ones were isolated from the fruits of S. torvum Swartz. Based on chemical and spectral evidence, the five new compounds were identified to be 25(S)-26-O-β-D-glucopyranosyl-5α-furost-22(20)-en-3β,6α,26-triol-6-O-[α-L-rhamnopyranosyl-(1→3)-O-β-D-quinovopyranoside] (1), 25(S)-26-O-β-D-glucopyranosyl-5α-furost-22(20)-en-3-one-6α,26-diol-6-O-[α-L-rhamnopyranosyl-(1→3)-O-β-D-quinovopyranoside] (2), 25(S)-26-O-β-D-glucopyranosyl-5α-furost-22(20)-en-3β,6α,26-triol-6-O-β-D-quinovopyranoside (3), 5α-pregn-16-en-20-one-3β,6α-diol-6-O-[α-L-rhamnopyranosyl-(1→3)-β-D-quinovopyranoside] (4), and 5α-pregn-16-en-3,20-dione-6α-ol-6-O-[α-L-rhamnopyranosyl-(1→3)-β-D-quinovopyranoside] (5). These new compounds were assayed for cytotoxicities in vitro, and 1 to 4 showed cyotoxic activity against the human melanoma cell line A375, with IC50 values of 30 μM to 260 μM. PMID:24444891

  15. Studies of the Raman spectra of cyclic and acyclic molecules: Combination and prediction spectrum methods

    Kim, Taejin; Assary, Rajeev S.; Marshall, Christopher L.; Gosztola, David J.; Curtiss, Larry A.; Stair, Peter C.

    2012-04-01

    A combination of Raman spectroscopy and density functional methods was employed to investigate the spectral features of selected molecules: furfural, 5-hydroxymethyl furfural (HMF), methanol, acetone, acetic acid, and levulinic acid. The computed spectra and measured spectra are in excellent agreement, consistent with previous studies. Using the combination and prediction spectrum method (CPSM), we were able to predict the important spectral features of two platform chemicals, HMF and levulinic acid. The results have shown that CPSM is a useful alternative method for predicting vibrational spectra of complex molecules in the biomass transformation process.

  16. Cell Tracking Accuracy Measurement Based on Comparison of Acyclic Oriented Graphs

    Matula, Pavel; Maška, M.; Sorokin, D.V.; Matula, Pe.; Ortiz de Solorzano, C.; Kozubek, M.

    2015-01-01

    Roč. 10, č. 12 (2015). E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) EE2.3.30.0030 Institutional support: RVO:68081707 Keywords : FLUORESCENCE MICROSCOPY IMAGES * LINEAGE CONSTRUCTION * MANUAL VALIDATION Subject RIV: BO - Biophysics Impact factor: 3.234, year: 2014

  17. Acyclic nucleoside bisphosphonates as inhibitors of 6-oxopurine phosphoribosyltransferases: Potential antimalarial and antibacterial agents

    Hocková, Dana; Keough, D. T.; Špaček, Petr; Janeba, Zlatko; Edstein, M. D.; Chavchich, M.; Wang, T. H.; Eng, W. S.; West, N. P.; de Jersey, J.; Guddat, L. W.

    Praha: Institute of Organic Chemistry and Biochemistry AS CR, v. v. i, 2014 - (Hocek, M.), s. 107-110. (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 ČR GAP207/11/0108 Institutional support: RVO:61388963 Keywords : nucleotide analogues * enzyme inhibitors * Plasmodium Subject RIV: CC - Organic Chemistry

  18. Acyclic nucleoside phosphonates with 5-azacytosine moiety: A new class of antiviral agents

    Krečmerová, Marcela; Holý, Antonín; Pískala, Alois; Masojídková, Milena; Andrei, G.; Snoeck, R.; Naesens, L.; Balzarini, J.; Neyts, J.; De Clercq, E.

    Bern : DCB University of Bern, 2006. s. 340. [IRT-International Roundtable on Nucleosides, Nucleotides and Nucleic Acids /17./. 03.09.2006-07.09.2006, Bern] R&D Projects: GA MŠk(CZ) 1M0508; GA AV ČR(CZ) 1QS400550501 Grant ostatní: Descartes Prize(XE) HPAW-2002-100096; NIAID/NIH(US) UC1AI062540-01 Institutional research plan: CEZ:AV0Z40550506 Keywords : HPMP-5-azaC * 5-azacytosine * antiviral activity Subject RIV: CC - Organic Chemistry

  19. Acyclic nucleoside phosphonates containing O-substituted hydroxypyridineamines and diamines as nucleobases

    Otmar, Miroslav; Masojídková, Milena; Holý, Antonín

    Praha : ÚOCHB AV ČR, 2005 - (Hocek, M.), s. 283-285 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 Grant ostatní: René Descartes Prize 2001(XE) HPAW-2002-100096 Institutional research plan: CEZ:AV0Z40550506 Keywords : pyridine nucleotides * antivirals * nucleophilic aromatic substitution Subject RIV: CC - Organic Chemistry

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

    Krečmerová, Marcela; Holý, Antonín; Masojídková, Milena

    Marburg : University of Marburg, 2006. s. 111. ISBN 3-89703-685-1. [Joint Meeting of the Czech, German and Hungarian Pharmaceutical Societies. 04.10.2006-07.10.2006, Marburg] R&D Projects: GA AV ČR(CZ) 1QS400550501 Grant ostatní: Descartes Prize(XE) HPAW-2002-100096 Institutional research plan: CEZ:AV0Z40550506 Keywords : HPMPC analogues * 5-phenylcytosine derivative * antivirals Subject RIV: CC - Organic Chemistry

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

    Kata Tuza; László Jicsinszky; Tamás Sohajda; István Puskás; Éva Fenyvesi

    2014-01-01

    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-modif...

  2. On acyclic decomposition problem of hypergraph%超图的无圈分解问题

    段广森; 薛春善; 田冲

    2008-01-01

    引入了超图的无圈分解的荫度的概念,研究了n阶r-完全超图Krn的无圈分解问题,给出了n阶r-完全超图Krn的荫度的一个下界Y(Krn)≥n!/r!(n-r+1)!.并提出猜想T(Krn)={n!/r!(n-r+1)!当[n!/r!(n-r+1)!]=n!/r!(n-r+1)!;n!/r!(n-r+1)!+1,当n!/r!(n-r+1)!≠n!/r!(n-r+1)!.这里[x]表示x的整数部分.

  3. Acyclic Alkanes in the Soil over Heshang Cave in Qingjiang, Hubei Province

    Pu Yang; Huang Junhua; Huang Xianyu; Cui Jingwei; Hu Chaoyong

    2006-01-01

    The reports that relate to the biomarker's fate and characteristics of the modern soil in the karst area are very lacking. By using gas chromatography-mass spectrometry (GC-MS), a series of biomaximum at C31. They have a strong odd-over-even carbon number predominance. These characteristics represent an input mainly from higher plants. The lipid parameters, including CPIh (carbon preference index), Rh/1 (ratio of lower- to higher-molecular-weight homologues) and ACL (average chain length),show comparable trends with depth, probably reflecting vegetation change and microbial degradation.Series of monomethylalkanes and dipioptene are present in the extractable organic matter; they might be derived from soil microbes, cyanobacteria in particular.

  4. In Vivo Modulation of Angiogenic Genes Expression by Acyclic Nucleoside Phosphonates PMEDAP and PMEG

    Otová, B.; Hrdý, J.; Votruba, Ivan; Holý, Antonín

    2009-01-01

    Roč. 29, č. 4 (2009), s. 1295-1302. ISSN 0250-7005 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : PMEDAP * PMEG * proangiogenic genes Subject RIV: CC - Organic Chemistry Impact factor: 1.428, year: 2009

  5. New in vitro method for evaluating antiviral activity of acyclic nucleoside phosphonates against plant viruses

    Špak, Josef; Holý, Antonín; Pavingerová, Daniela; Votruba, Ivan; Špaková, Vlastimila; Petrzik, Karel

    2010-01-01

    Roč. 88, č. 3 (2010), s. 296-303. ISSN 0166-3542 R&D Projects: GA ČR GA522/09/0707 Institutional research plan: CEZ:AV0Z50510513; CEZ:AV0Z40550506 Keywords : Brassica * Chemotherapy * Turnip yellow mosaic virus * Ribavirin Subject RIV: CE - Biochemistry Impact factor: 4.439, year: 2010

  6. Acyclic N-halamine-immobilized polyurethane: Preparation and antimicrobial and biofilm-controlling functions

    Luo, Jie; Porteous, Nuala; Lin, Jiajin; Sun, Yuyu

    2015-01-01

    Hydroxyl groups were introduced onto polyurethane surfaces through 1,6-hexamethylene diisocyanate activation, followed by diethanolamine hydroxylation. Polymethacrylamide was covalently attached to the hydroxylated polyurethane through surface grafting polymerization of methacrylamide using cerium (IV) ammonium nitrate as an initiator. After bleach treatment, the amide groups of the covalently bound polymethacrylamide chains were transformed into N-halamines. The new N-halamine-immobilized po...

  7. Potential role of acyclic nucleoside phosphonates in the treatment of malaria

    Janeba, Zlatko; Hocková, Dana; Keough, D. T.; Guddat, L. W.

    Nerja: -, 2014. [Zing Drug Discovery Conference 2014 /4./. 17.02.2014-20.02.2014, Nerja] R&D Projects: GA ČR GAP207/11/0108 Institutional support: RVO:61388963 Keywords : ANPs * prodrugs * malaria Subject RIV: CC - Organic Chemistry

  8. Antimalarial activity of prodrugs of N-branched acyclic nucleoside phosphonate inhibitors of 6-oxopurine phosphoribosyltransferases

    Hocková, Dana; Janeba, Zlatko; Naesens, L.; Edstein, M. D.; Chavchich, M.; Keough, D. T.; Guddat, L. W.

    2015-01-01

    Roč. 23, č. 17 (2015), s. 5502-5510. ISSN 0968-0896 R&D Projects: GA ČR GAP207/11/0108 Institutional support: RVO:61388963 Keywords : nucleotide analogues * enzyme inhibitors * malaria * HG(X)PRT * ANP Subject RIV: CC - Organic Chemistry Impact factor: 2.793, year: 2014

  9. Crystal structures of novel bis-NO-acyclic Schiff base compounds

    Khalaji, A.D.; Fejfarová, Karla; Dušek, Michal

    2015-01-01

    Roč. 56, č. 7 (2015), s. 1405-1409. ISSN 0022-4766 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : Schiff base * single crystal structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.508, year: 2014

  10. Timing analysis of First-Come First-Served scheduled interval-timed Directed Acyclic Graphs

    Frijns, R.M.W.; Adyanthaya, S.; Stuijk, S.; Voeten, J.P.M.; Geilen, M.C.W.; Schiffelers, R.R.H.; Corporaal, H.

    2014-01-01

    Analyzing worst-case application timing for systems with shared resources is difficult, especially when non-monotonic arbitration policies like First-Come-First-Served (FCFS) scheduling are used in combination with varying task execution times. Analysis methods that conservatively analyze these syst

  11. Novel acyclic nucleoside phosphonate analogues with potent anti-hepatitis B virus activities

    Ying, C.; Holý, Antonín; Hocková, Dana; Havlas, Zdeněk; De Clercq, E.; Neyts, J.

    2005-01-01

    Roč. 49, č. 3 (2005), 1177-1180. ISSN 0066-4804 R&D Projects: GA AV ČR(CZ) IBS4055109 Grant ostatní: FWO(BE) G.0267.04 Institutional research plan: CEZ:AV0Z4055905 Keywords : antivirals * hepatitis B * ANP Subject RIV: CC - Organic Chemistry Impact factor: 4.379, year: 2005

  12. Macrophage activation by antiviral acyclic nucleoside phosphonates in dependence on priming immune stimuli

    Zídek, Zdeněk; Franková, Daniela; Holý, Antonín

    2000-01-01

    Roč. 22, č. 12 (2000), s. 1121-1129. ISSN 0192-0561 R&D Projects: GA ČR GA305/00/0048; GA ČR GV203/96/K001 Institutional research plan: CEZ:AV0Z5008914 Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 1.142, year: 2000

  13. Acyclicity Notions for Existential Rules and Their Application to Query Answering in Ontologies

    Grau, BC; Horrocks, I.; Krötzsch, M; Kupke, C.; Magka, D; Motik, B; Wang, Z.

    2014-01-01

    Answering conjunctive queries (CQs) over a set of facts extended with existential rules is a prominent problem in knowledge representation and databases. This problem can be solved using the chase algorithm, which extends the given set of facts with fresh facts in order to satisfy the rules. If the chase terminates, then CQs can be evaluated directly in the resulting set of facts. The chase, however, does not terminate necessarily, and checking whether the chase terminates on a given set of r...

  14. Enzymatic synthesis of ester prodrugs of acyclic nucleoside analogues by Candida antarctica lipase

    Lamatová, Nikola; Krečmerová, Marcela; Spiwok, V.; Brabcová, Jana

    Praha: Czech Chemical Society, 2015. s. 106. [Liblice 2015. Advances in Organic, Bioorganic and Pharmaceutical Chemistry /50./. 06.11.2015-08.11.2015, Olomouc] R&D Projects: GA ČR(CZ) GA14-00522S Institutional support: RVO:61388963 Keywords : vinil esters * lipase * enzymatic esterification Subject RIV: CC - Organic Chemistry

  15. Chiral analysis of acyclic nucleoside phosphonates-based anti-aids drugs by capillary electrophoresis

    Kašička, Václav; Šolínová, Veronika; Sázelová, Petra; Mikysková, Hana; Jansa, Petr; Krečmerová, Marcela; Holý, Antonín

    2012-01-01

    Roč. 106, - (2012), s604-s604. ISSN 0009-2770. [EuCheMS Chemistry Congress /4./. 26.08.2012-30.08.2012, Prague] R&D Projects: GA MŠk 1M0508; GA ČR(CZ) GA203/08/1428 Institutional research plan: CEZ:AV0Z40550506 Keywords : analytical methods * electrophoresis * enentioselectivity Subject RIV: CC - Organic Chemistry

  16. Acyclic nucleoside phosphonates: a study on cytochrome P450 gene expression

    Nekvindová, J.; Contreras, J. A.; Juvan, P.; Tacer, K. F.; Anzenbacher, P.; Zídek, Zdeněk; Zapletalová, M.; Rozman, D.; Anzenbacherová, E.

    2014-01-01

    Roč. 44, č. 8 (2014), s. 708-715. ISSN 0049-8254 Grant ostatní: GA MŠk(CZ) CZ.1.07/2.3.00/20.0019; GA MŠk(CZ) CZ.1.05/2.1.00/01.003 Institutional support: RVO:68378041 Keywords : induction * drug metabolism * antiviral Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 2.199, year: 2014

  17. Mononuclear and oligonuclear transition metal complexes with acyclic and macrocyclic ligands

    Rösel, Pirmin

    2009-01-01

    Chapter 1 describes an efficient multi-step synthesis of an endotopic but sterically un¬hindered biisoquinoline decorated with long alkyl groups for better solubility. This chelate is ideally suited for macrocycle formation around transition metal ions and therefore a valuable new building block for topological chemistry. Sokolov’s concept to use an octahedral metal template for the syntheses of macrocycles and molecular knots is discussed in Chapter 2. The concept was successfully realise...

  18. Enantioselective, Stereodivergent Hydroazidation and Hydroamination of Allenes Catalyzed by Acyclic Diaminocarbene (ADC) Gold(I) Complexes

    Khrakovsky, Dimitri A.; Tao, Chuanzhou; Johnson, Miles W.; Thornbury, Richard T.; Shevick, Sophia L.; Toste, F. Dean

    2016-01-01

    The gold-catalyzed enantioselective hydroazidation and hydroamination reactions of allenes are presented herein. ADC gold(I) catalysts derived from BINAM were critical for achieving high levels of enantioselectivity in both transformations. The sense of enantioinduction is reversed for the two different nucleophiles, allowing access to both enantiomers of the corresponding allylic amines using the same catalyst enantiomer.

  19. Acyclic nucleoside bis-phosphonates as potent inhibitors of 6-oxopurine phosphoribosyltransferases

    Špaček, Petr; Keough, D. T.; Vrbková, Silvie; Slavětínská, Lenka; Janeba, Zlatko; Naesens, L.; Edstein, M. D.; Chavchich, M.; Wang, T. H.; de Jersey, J.; Guddat, L. W.; Hocková, Dana

    Praha : Institute of Organic Chemistry and Biochemistry AS CR, v. v. i, 2014 - (Hocek, M.), s. 375-376 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 GAP207/11/0108 Institutional support: RVO:61388963 Keywords : nucleotide analogues * enzyme inhibitors * Plasmodium Subject RIV: CC - Organic Chemistry

  20. The unique impact of microwave irradiation on the chemistry of acyclic nucleoside phosphonates

    Jansa, Petr; Holý, Antonín; Dračínský, Martin; Baszczyňski, Ondřej; Česnek, Michal; Janeba, Zlatko

    Praha : Institute of Organic Chemistry and Biochemistry AS CR, v. v. i., 2011 - (Hocek, M.), s. 347-348 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 Institutional research plan: CEZ:AV0Z40550506 Keywords : ANPs * hydrolysis * microwave * Michaelis -Arbuzov reaction * haloalkylphosphonates Subject RIV: CC - Organic Chemistry

  1. Brassinolide activities of 2alpha,3alpha-diols versus 3alpha,4alpha-diols in the bean second internode bioassay: Explanation by molecular modeling methods

    Šíša, Miroslav; Vilaplana-Polo, M.; Ballesteros, C. B.; Kohout, Ladislav

    2007-01-01

    Roč. 72, 11/12 (2007), s. 740-750. ISSN 0039-128X R&D Projects: GA AV ČR 1QS510680561; GA MŠk 1M06030 Institutional research plan: CEZ:AV0Z40550506 Keywords : 3D-SAR * 3D-QSAR * biologically active steroids * brassinosteroids Subject RIV: CC - Organic Chemistry Impact factor: 2.143, year: 2007

  2. Brassinolide activities 2alpha, 3alpha - diols versus 3alpha, 4alpha - diols in the bean second internode bioassay: explanation by molecular modeling methods

    Šíša, Miroslav; Vilaplana-Polo, M.; Ballesteros, C. B.; Kohout, Ladislav

    Brno : Mendelova zemědělská a lesnická univerzita v Brně, 2007. s. 7. ISBN 978-80-7375-090-9. [Funkční genomika a proteomika ve šlechtění rostlin. 24.09.2007-25.09.2007, Křtiny] Institutional research plan: CEZ:AV0Z40550506 Keywords : brassinolid * plant stress * molecular modeling Subject RIV: CC - Organic Chemistry

  3. Seasonal lake surface water temperature trends reflected by heterocyst glycolipid-based molecular thermometers

    Bauersachs, T.; Rochelmeier, J.; Schwark, L.

    2015-06-01

    It has been demonstrated that the relative distribution of heterocyst glycolipids (HGs) in cultures of N2-fixing heterocystous cyanobacteria is largely controlled by growth temperature, suggesting a potential use of these components in paleoenvironmental studies. Here, we investigated the effect of environmental parameters (e.g., surface water temperatures, oxygen concentrations and pH) on the distribution of HGs in a natural system using water column filtrates collected from Lake Schreventeich (Kiel, Germany) from late July to the end of October 2013. HPLC-ESI/MS (high-performance liquid chromatography coupled to electrospray ionization-mass spectrometry) analysis revealed a dominance of 1-(O-hexose)-3,25-hexacosanediols (HG26 diols) and 1-(O-hexose)-3-keto-25-hexacosanol (HG26 keto-ol) in the solvent-extracted water column filtrates, which were accompanied by minor abundances of 1-(O-hexose)-3,27-octacosanediol (HG28 diol) and 1-(O-hexose)-3-keto-27-octacosanol (HG28 keto-ol) as well as 1-(O-hexose)-3,25,27-octacosanetriol (HG28 triol) and 1-(O-hexose)-3-keto-25,27-octacosanediol (HG28 keto-diol). Fractional abundances of alcoholic and ketonic HGs generally showed strong linear correlations with surface water temperatures and no or only weak linear correlations with both oxygen concentrations and pH. Changes in the distribution of the most abundant diol and keto-ol (e.g., HG26 diol and HG26 keto-ol) were quantitatively expressed as the HDI26 (heterocyst diol index of 26 carbon atoms) with values of this index ranging from 0.89 in mid-August to 0.66 in mid-October. An average HDI26 value of 0.79, which translates into a calculated surface water temperature of 15.8 ± 0.3 °C, was obtained from surface sediments collected from Lake Schreventeich. This temperature - and temperatures obtained from other HG indices (e.g., HDI28 and HTI28) - is similar to the one measured during maximum cyanobacterial productivity in early to mid-September and suggests that HGs

  4. Seasonal lake surface water temperature trends reflected by heterocyst glycolipid based molecular thermometers

    Bauersachs, T.; Rochelmeier, J.; Schwark, L.

    2015-01-01

    It has been demonstrated that the relative distribution of heterocyst glycolipids (HGs) in cultures of N2-fixing heterocystous cyanobacteria is largely controlled by growth temperature, suggesting a potential use of these components in paleoenvironmental studies. Here, we investigated the effect of environmental parameters (e.g. surface water temperatures, oxygen concentrations and pH) on the distribution of HGs in a natural system using water column filtrates collected from Lake Schreventeich (Kiel, Germany) from late July to the end of October 2013. HPLC-ESI/MS analysis revealed a dominance of 1-(O-hexose)-3,25-hexacosanediols (HG26 diols) and 1-(O-hexose)-3-keto-25-hexacosanol (HG26 keto-ol) in the solvent extracted water column filtrates, which were accompanied by minor abundances of 1-(O-hexose)-3,27-octacosanediol (HG28 diol) and 1-(O-hexose)-3-keto-27-octacosanol (HG28 keto-ol) as well as 1-(O-hexose)-3,25,27-octacosanetriol (HG28 triol) and 1-(O-hexose)-3-keto-25,27-octacosanediol (HG28 keto-diol). Fractional abundances of alcoholic and ketonic HGs generally showed strong linear correlations with surface water temperatures and no or only weak linear correlations with both oxygen concentrations and pH. Changes in the distribution of the most abundant diol and keto-ol (e.g., HG26 diol and HG26 keto-ol) were quantitatively expressed as the HDI26 (heterocyst diol index of 26carbon atoms) with values of this index ranging from 0.89 in mid-August to 0.66 in mid-October. An average HDI26 value of 0.79, which translates into a calculated surface water temperature of 15.8 ± 0.3 °C, was obtained from surface sediments collected from Lake Schreventeich. This temperature - and temperatures obtained from other HG indices (e.g., HDI28 and HTI28) - is similar to the one measured during maximum cyanobacterial productivity in early to mid-September and suggests that HGs preserved in Lake Schreventeich sediments record summer surface water temperatures. As N2-fixing

  5. Illegitimate recombination induced by benzo[a]pyrene diol epoxide in Escherichia coli

    Duplex DNA oligomer constructs (32 base pairs) were paired that contained a single benzo[a]pyrene (BP) adduct at a specific deoxyadenosine or deoxyguanosine site in either one or both strands. These constructs were inserted into M13 replicative form viral DNA, and the DNA from progeny virus generated by transfection of Escherichia coli was examined by sequence analysis at the site of oligomer insertion. With nonalkylated constructs, and with constructs containing only one BP adduct, no sequence alterations were found in progeny viral DNAs. With constructs containing two BP adducts, one in each strand and closely spaced, some progeny DNAs showed the original oligomer sequence, whereas others exhibited large deletions and illegitimate (non-homologous) recombination, both of which removed the damage construct. Increasing the distance between BP adducts in the construct reduced the frequency of recombinant events. These sequence alterations occurred in both recA+ and recA- host cells. The authors speculate that the closely spaced adducts in opposite construct strands cause a rare distortion in DNA structure, which activates the recombinant machinery, and that mutagenic and carcinogenic agents other than polycyclic aromatic hydrocarbons may cause similar DNA distortions, which induce illegitimate recombination

  6. Laterally substituted naphthalene-2,7-diol-based bent-shaped liquid crystals

    Kozmík, V.; Kuchař, M.; Svoboda, J.; Novotná, Vladimíra; Glogarová, Milada; Baumeister, U.; Diele, S.; Pelzl, G.

    2005-01-01

    Roč. 32, č. 9 (2005), s. 1151-1160. ISSN 0267-8292 R&D Projects: GA ČR(CZ) GA202/02/0840; GA ČR(CZ) GA202/05/0431; GA MŠk(CZ) 1P04OCD14.60 Grant ostatní: EU(XE) COST D14 WG 00015 Institutional research plan: CEZ:AV0Z1010914 Keywords : naphthalene - based liquid crystals * x-ray Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.432, year: 2005

  7. The waterborne polyurethane dispersions based on polycarbonate diol: effect of ionic content

    Cakić, S. M.; Špírková, Milena; Ristić, I. S.; B-Simendić, J. K.; M-Cincović, M.; Poreba, Rafal

    2013-01-01

    Roč. 138, č. 1 (2013), s. 277-285. ISSN 0254-0584 R&D Projects: GA ČR GAP108/10/0195 Institutional research plan: CEZ:AV0Z40500505 Keywords : coatings * chemical synthesis * thermogravimetric analysis (TGA) Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.129, year: 2013

  8. The investigation of the reactions of some pyrazole-3-carboxylic acids with various diamines and diols

    Rahmi Kasımoğulları

    2012-06-01

    Full Text Available In this study, some new derivatives were synthesized of 4-benzoyl-1-(3-nitrophenyl-5-phenyl-1H-pyrazole-3-carboxylic acid (1 and 4-(ethoxycarbonyl-1-(3-nitrophenyl-5-phenyl-1H-pyrazole-3-carboxylic acid (2 that they were pyrazole carboxylic acid derivatives. Firstly, 1 and 2 reacted with SOCl2 to transform them into acyl chlorides (3, 4. Then various bis-carboxamide derivatives (5–8 were obtained from the reaction of 3 and 4 with various diamines and also a ;#946;-hydroxy ester (9 derivative was obtained from the reaction of 3 with ethylene glycol. The structures of synthesized compounds were elucidated with using FT-IR, 1H NMR, 13C NMR and elemental analysis methods.

  9. The investigation of the reactions of some pyrazole-3-carboxylic acids with various diamines and diols

    Rahmi Kasımoğulları; Makbule Maden; Samet Mert

    2012-01-01

    In this study, some new derivatives were synthesized of 4-benzoyl-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid (1) and 4-(ethoxycarbonyl)-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid (2) that they were pyrazole carboxylic acid derivatives. Firstly, 1 and 2 reacted with SOCl2 to transform them into acyl chlorides (3, 4). Then various bis-carboxamide derivatives (58) were obtained from the reaction of 3 and 4 with various diamines and also a ;#946;-hydroxy ester (9) deri...

  10. The investigation of the reactions of some pyrazole-3-carboxylic acids with various diamines and diols

    Kasımoğulları, Rahmi; Maden, Makbule; Mert, Samet

    2012-01-01

    In this study, some new derivatives were synthesized of 4-benzoyl-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid (1) and 4-(ethoxycarbonyl)-1-(3-nitrophenyl)-5-phenyl-1H-pyrazole-3-carboxylic acid (2) that they were pyrazole carboxylic acid derivatives. Firstly, 1 and 2 reacted with SOCl2 to transform them into acyl chlorides (3, 4). Then various bis-carboxamide derivatives (5–8) were obtained from the reaction of 3 and 4 with various diamines and also a β-hydroxy ester (9)...

  11. A novel fluorescent vesicular sensor for saccharides based on boronic acid-diol interaction.

    Zhang, Yujian; He, Zhenfeng; Li, Guowen

    2010-04-15

    A novel amphiphile containing two functional groups of both naphthalene and boronic acid, 2-(hexadecyloxy)-naphthalene-6-boronic acid (HNBA), has been synthesized. Scanning electron microscopy (SEM) indicated the formation of bilayer vesicles in the ethanol/water solution (Phi=0.6). Differential scanning calorimetry (DSC) established the presence of crystal-to-liquid crystal transition at 63.36 degrees C. The vesicular fluorescence properties upon binding with carbohydrates have been studied in ethanol/water buffer at pH 7.4. Addition of saccharides to the vesicular solution, the fluorescent intensities of naphthalene in HNBA vesicles centered at 348 nm decreased dramatically with increasing concentration of saccharides. The change tendency of fluorescent intensities of the HNAB vesicles with concentration of saccharides followed in the order of fructose>galactose>maltose>glucose. The pH profiles of the fluorescence intensity were studied in the absence and in the presence of sugars. Also, the urine sample induced spectral changes of the HNBA vesicles were studied. These results suggest that the HNBA vesicles may be developed as a continuous monitoring and implantable fluorescence vesicular sensor, which might be applied in the practical field. PMID:20188967

  12. Surface characteristics of UV-irradiated polyurethane elastomers extended with α, ω-alkane diols

    Polyurethane elastomers (PUEs) based on 4,4'-diphenylmethane diisocyanate (MDI), poly (ε-caprolactone) (PCL) and extended with series of chain extender (CE) were synthesized via two step polymerization technique. The synthesized samples were irradiated for 50, 100 and 200 h in an UV exposure unit as such the spectral distribution of the light is good match for terrestrial solar radiation. The modifications in the chemical structures of the PU before and after irradiation were characterized using Fourier transform infrared (FT-IR) technique. The effect of irradiation time and chain extenders length on surface properties were studied and investigated. Photo-oxidation of PU surface leads to fast increase in surface free energy and its polar component. Simultaneously, the work of water adhesion to polymer increases significantly during UV-irradiation. The higher changes in surface properties, observed by water absorption (%), equilibrium degree of swelling, as well as monitored by ATR-FT-IR and contact angle measurement, were found for the PU samples extended with higher number of methylene unit and irradiation time

  13. Chiral selection in the formation of borates from racemic binaphthols and related diols

    Raskatov, Jevgenij A.; Brown, John M.; Amber L. Thompson

    2011-01-01

    A series of racemic or stereochemically labile chiral borate anions based on the 2,2′-biphenol motif was investigated. All borates were homochiral in the solid state, although in some cases the heterochiral diastereomers were computed to be thermodynamically preferred (DFT). The crystallographic preference for the homochiral diastereomer was attributed to its lower bulk, higher molecular symmetry, and the therewith associated better packing ability.

  14. PROPERTIES OF POLYURETHANE ELASTOMERS BASED ON POLY (OXYETHYLENE-co-OXYTETRAMETHYLENE) DIOL

    Chen-yu Su; Guang-li Zhang; Hong-zhi Zhang

    2001-01-01

    Polyurethane elastomers derived from 4,4′-methylene bis(phenyl isocyanate), butylene glycol and the low oxyethylene moiety content copolyether of tetrahydrofuran and ethylene oxide, obtained by copolymerization using heteropolyacid-ethylene oxide initiator system, were prepared. The polyurethanes exhibited an increased water absorption and much better low temperature resilience, which remained high even at a temperature of-3℃, while that of polyurethane based upon poly(tetramethylene ether) glycol of the same molecular weight, I.e. Being 2000, and molecular weight distribution, I.e. In the range of 1.4-1.5, starts to decrease dramatically at 5℃.``

  15. MONOALLYLATION OF DIOLS THROUGH RUTHENIUM-CATALYZED REACTION WITH HOMOALLYL ALCOHOLS. (R822668)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  16. (E-(25S-23-Acetyl-5β-furost-22-ene-3β,26-diol

    Sylvain Bernès

    2008-03-01

    Full Text Available The title steroid, C29H46O4, is a furostene derivative with a C=C double-bond length of 1.353 (3 Å and an E configuration. The side chain is oriented toward the α face of the A–E steroidal nucleus and presents a disordered terminal CH2—OH group [occupancies for resolved sites are 0.591 (9 and 0.409 (9]. The methyl group at C20 attached to ring E is also oriented toward the α face, avoiding steric hindrance with the carbonyl O atom of the acetyl group. The furostene and acetyl functionalities form an α,β-unsaturated ketone system, with an s-cis configuration. All hydroxy and carbonyl groups are involved in weak intermolecular hydrogen bonds. The absolute configuration was assigned from the synthesis.

  17. Poitediol, a new nonisoprenoid sesquiterpene diol from the marine alga Laurencial poitei

    The compound was isolated from ethanol extracts of the red seaweed Laurencia poitei(Lamouroux) Howe by extensive liquid chromatography on μ-Porasil. The structure of the compound, established by x-ray crystallography, belongs to the chiral, monoclinic space group P2 with a = 9.412(6), b = 17.489(8), c = 9.721(3)A, and β = 114.69(4)0. A calculated and observed density of 1.09 g/cm3 (Z = 4) indicated that two molecules of C15H26O2 form the asymmetric unit. Poitediol is an unusual sesquiterpene with a trans-fused bicyclo(6.30)undecane. The five-membered ring is in the envelope conformation with C(8) as the flap(0.615A) removed from the plane of atoms C(1), C(11), C(10), and C(9). The eight-membered ring does not assume any simple conformation. Molecular distances and angles are generally in agreement with accepted values. A computer-generated perspective drawing is also included

  18. 1,4-Dibromo­naphthalene-2,3-diol

    Gao, Qinghe; Zhu, Yanping

    2011-01-01

    In the title compound (r.m.s. deviation for the non-H atoms = 0.020 Å), C10H6Br2O2, an intra­molecular O—H⋯O hydrogen bond generates an S(6) ring. In the crystal, the same H atom also forms an inter­molecular O—H⋯O hydrogen bond, generating a C(2) chain propagating in [100]. The other O—H hydrogen forms a weak O—H⋯π inter­action, and short Br⋯Br contacts [3.5972 (9) Å] also occur.

  19. Epoxide compounds. III. Synthesis of amino-β-diols and their PMR spectra

    The reactions of 2,2,3-trimethyl-5,6-epoxy-3-hexanol with ammonia and primary and secondary amines was studied. A comprehensive NMR spectral analysis was performed and extensive data on spin-spin coupling constants, chemical shift, and line structure are given. Yields and boiling points of the reaction products are tabulated

  20. Access to enantiopure aromatic epoxides and diols using epoxide hzdrolases derived from total biofilter DNA

    Kotík, Michael; Štěpánek, Václav; Grulich, Michal; Kyslík, Pavel; Archelas, A.

    2010-01-01

    Roč. 65, 1-4 (2010), s. 41-48. ISSN 1381-1177 R&D Projects: GA ČR GA204/06/0458 Institutional research plan: CEZ:AV0Z50200510 Keywords : Chiral resolution * Enantioconvergent reaction * Enantioselectivity Subject RIV: CE - Biochemistry Impact factor: 2.330, year: 2010

  1. A Striking Exception to the Chelate Model for Acyclic Diastereocontrol: Efficient Access to a Versatile Propargyl Alcohol for Chemical Synthesis

    Clark, Ronald J.; Gregory B. Dudley; Tlais, Sami F

    2009-01-01

    The four-step, asymmetric synthesis of a chiral propargyl alcohol 1 from (R)-pantolactone is described. A key feature of the synthesis is a diastereoselective acetylide addition to a chiral α-alkoxy-aldehyde 7, in which unusual Felkin selectivity is observed, despite the potential for chelation control. Crystalline propargyl alcohol 1 is valuable for complex molecule synthesis, and is easy to prepare in multi-gram quantities and high diastereomeric purity.

  2. A Striking Exception to the Chelate Model for Acyclic Diastereocontrol: Efficient Access to a Versatile Propargyl Alcohol for Chemical Synthesis

    Ronald J. Clark

    2009-12-01

    Full Text Available The four-step, asymmetric synthesis of a chiral propargyl alcohol 1 from (R-pantolactone is described. A key feature of the synthesis is a diastereoselective acetylide addition to a chiral α-alkoxy-aldehyde 7, in which unusual Felkin selectivity is observed, despite the potential for chelation control. Crystalline propargyl alcohol 1 is valuable for complex molecule synthesis, and is easy to prepare in multi-gram quantities and high diastereomeric purity.

  3. Acyclic nucleoside phosphonates with branched 2-(2-phosphonoethoxy)ethyl chain: efficient synthesis and biological activity

    Hocková, Dana; Holý, Antonín; Andrei, G.; Snoeck, R.; Balzarini, J.; Keough, D. T.; de Jersey, J.; Guddat, L. W.

    Crete : University of Crete, 2011. [ESOC 2011. European Symposium on Organic Chemistry /17./. 10.07.2011-15.07.2011, Crete] R&D Projects: GA MŠk 1M0508; GA ČR GAP207/11/0108 Institutional research plan: CEZ:AV0Z40550506 Keywords : nucleotide analogues * antiviral activity * antiplasmodial activity Subject RIV: CC - Organic Chemistry

  4. Acyclic nucleoside phosphonates containing a second phosphonate group as potent inhibitors of 6-oxopurine phosphoribosyltransferases with antimalarial activity

    Špaček, Petr; Keough, D. T.; Hocková, Dana; Tichý, Tomáš; Vrbková, Silvie; Slavětínská, Lenka; Janeba, Zlatko; Naesens, L.; Edstein, M. D.; Chavchich, M.; Wang, T.; de Jersey, J.; Guddat, L. W.

    Marseille : -, 2013. s. 183-183. [ESOC 2013. European Symposium on Organic Chemistry /18./. 07.07.2013-12.07.2013, Marseille] R&D Projects: GA ČR GAP207/11/0108 Institutional support: RVO:61388963 Keywords : nucleotide analogues * enzyme inhibitors * Plasmodium Subject RIV: CC - Organic Chemistry

  5. Acyclic nucleoside bisphosphonates as inhibitors of hypoxanthine-guanine-(xanthine) phosphoribosyltransferases: Potential new anti-malarial compounds

    Špaček, Petr; Hocková, Dana; Janeba, Zlatko; Vrbková, Silvie; Edstein, M.; de Jersey, J.; Keough, D. T.; Guddat, L. W.

    Amsterdam : Elsevier, 2012. P2.24-P2.24. [Tetrahedron Symposium: Challenges in Bioorganic & Organic Medicinal Chemistry /13./. 26.06.2012-29.06.2012, Amsterdam] Institutional research plan: CEZ:AV0Z40550506 Keywords : nucleoside phosphonates * biophosphonates Subject RIV: CC - Organic Chemistry

  6. Activity of novel acyclic pyrimidine nucleoside phosphonates against different DNA polymerase mutants of herpes simplex virus type 1 (HSV-1)

    Andrei, G.; Holý, Antonín; Fiten, P.; Opdenakker, G.; De Clercq, E.; Snoeck, R.

    Chicago, 2003. s. 490. [Interscience Conference on Antimicrobial Agents and Chemotherapy /43./. 14.09.2003-17.09.2003, Chicago] Institutional research plan: CEZ:AV0Z4055905 Keywords : pyrimidine nucleoside phosphonates Subject RIV: CC - Organic Chemistry

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

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

    Newport: Gordon Research Conference, 2015. [Nucleosides, Nucleotides & Oligonucleotides. Gordon Research Conference 2015. 28.06.2015-03.07.2015, Newport] Institutional support: RVO:61388963 Keywords : nucleotide analogues * enzyme inhibitors * tuberculosis Subject RIV: CC - Organic Chemistry

  8. Glycosylation of Acyclic and Cyclic Aglycone Substrates by Macrolide Glycosyltransferase DesVII/DesVIII: Analysis and Implications

    Borisova, Svetlana A.; Kim, Hak Joong; Pu, Xiaotao; Liu, Hung-wen

    2008-01-01

    Studies of the macrolide glycosyltransferase, DesVII/DesVIII, showed that it can process a variety of linear substrates and cyclic substrates of different ring size. When multiple hydroxyl groups are present, no regiospecificity of glycosylation is observed for the linear substrates. In contrast, when cyclic substrates with multiple glycosylation sites were tested, it displayed excellent regiospecificity in most cases. These results clearly indicate that this enzyme pair is a valuable tool fo...

  9. Aldol condensation of acyclic ketones with benzaldehyde and subsequent cyclodehydration to form indenes over halide cluster catalysts

    黒川, 秀樹; 千原, 貞次

    2006-01-01

    When a molecular halide cluster [(Ta6Cl12)C-12(H2O)(4)]-4H(2)O (1)/SiO2 was treated in a helium stream above 200 degrees C, it catalyzed the aldol condensation of acetone with benzaldehyde to yield E-4-phenyl-3-buten-2-one. The bromide cluster of Ta and chloride clusters of Nb, Mo, and W of the same octahedral metal framework also catalyzed the reaction. 3,3-Dimethyl-2-butanone combined with benzaldehyde similarly yielded the corresponding aldol condensation product over 1/SiO2 at 400 degrees...

  10. Antiviral activity of acyclic nucleoside phosphonates PMEA, (S)-HPMPC, PMEDAP and ribavirin against Cauliflower mosaic virus in Brassica pekinensis

    Špak, Josef; Votruba, Ivan; Pavingerová, Daniela; Holý, Antonín; Špaková, Vlastimila; Petrzik, Karel

    2012-01-01

    Roč. 10, č. 1 (2012), s. 63-68. ISSN 0167-6857 R&D Projects: GA ČR GA522/09/0707 Institutional research plan: CEZ:AV0Z50510513; CEZ:AV0Z40550506 Keywords : Caulimovirus * Chemotherapy * Pararetrovirus * dsDNA Subject RIV: EE - Microbiology, Virology Impact factor: 3.633, year: 2012

  11. Acyclic Nucleoside Phosphonates Containing a Second Phosphonate Group Are Potent Inhibitors of 6-Oxopurine Phosphoribosyltransferases and Have Antimalarial Activity

    Keough, D. T.; Špaček, Petr; Hocková, Dana; Tichý, Tomáš; Vrbková, S.; Slavětínská, Lenka; Janeba, Zlatko; Naesens, L.; Edstein, M. D.; Chavchich, M.; Wang, T. H.; de Jersey, J.; Guddat, L. W.

    2013-01-01

    Roč. 56, č. 6 (2013), s. 2513-2526. ISSN 0022-2623 R&D Projects: GA ČR GAP207/11/0108 Institutional support: RVO:61388963 Keywords : enzyme inhibitors * ANPs * malaria * bisphosphonates Subject RIV: CC - Organic Chemistry Impact factor: 5.480, year: 2013

  12. Novel Type of Acyclic Nucleoside Phosphonates as Inhibitors of 6-Oxopurine Phosphoribosyltransferases: New Potential Antimalarial Chemotherapy Leads

    Hocková, Dana; Keough, D. T.; Janeba, Zlatko; Wang, T.; de Jersey, J.; Guddat, L. W.

    Montreal: International Society of Nucleosides, Nucleotides and Nucleic Acids, 2012. -. [International Round Table on Nucleosides Nucleotides and Nucleic Acids /20./. 05.08.2012-09.08.2012, Montreal] R&D Projects: GA ČR GAP207/11/0108 Grant ostatní: National Health and Medical Research Council(AU) NHMRC 1030353 Institutional research plan: CEZ:AV0Z40550506 Keywords : nucleotide analogues * enzyme inhibitors * Plasmodium Subject RIV: CC - Organic Chemistry

  13. Results on Differential and Dependent Measurement Error of the Exposure and the Outcome Using Signed Directed Acyclic Graphs

    VanderWeele, Tyler J; Hernán, Miguel A.

    2012-01-01

    Measurement error in both the exposure and the outcome is a common problem in epidemiologic studies. Measurement errors in the exposure and the outcome are said to be independent of each other if the measured exposure and the measured outcome are statistically independent conditional on the true exposure and true outcome (and dependent otherwise). Measurement error is said to be nondifferential if measurement of the exposure does not depend on the true outcome conditional on the true exposure...

  14. Acyclic nucleoside phosphonates containing a second phosphonate group as potent inhibitors of 6-oxopurine phosphoribosyltransferases with antimalarial activity

    Špaček, Petr; Keough, D. T.; Janeba, Zlatko; Edstein, M. D.; Chavchich, M.; Wang, T. H.; Guddat, L. W.; Hocková, Dana

    Santa Barbara : International Society of Heterocyclic Chemistry, 2015. 0166. [International Society of Heterocyclic Chemistry Congress /25./. 23.08.2015-28.08.2015, Santa Barbara] Institutional support: RVO:61388963 Keywords : nucleotide analogues * enzyme inhibitors * Plasmodium Subject RIV: CC - Organic Chemistry

  15. Diameters of Permutation Groups on Graphs, Multi-agent Path Planning, and Integer Multiflow on Directed Acyclic Graphs

    Yu, Jingjin

    2012-01-01

    Let $G$ be an $n$-vertex connected, undirected, simple graph. The vertices of $G$ are populated with $n$ uniquely numbered agents, one on each vertex. Allowing agents on cycles of $G$ to rotate (synchronous rotations along multiple disjoint cycles are allowed), the resulting agent permutations form a group $\\G$. Let $diam(\\G)$ (the diameter of $\\G$) denote the length of the longest product of (cycle) generators required to reach an element of $G$, we show that $diam(\\G) = O(n^2)$. Given any initial and goal (agent) configurations, the algorithm from our constructive proofs computes in $O(n^2)$ time whether the goal configuration is reachable and reports such a generator sequence if this is the case. Combined with the results from Kornhauser, Miller, and Spirakis \\cite{KorMilSpi84}, we obtain a complete and efficient algorithm for solving a very general version of the multi-agent path planning problem on graphs. The above result is strengthened as we continue to establish that: 1. There exist graphs of which t...

  16. Drug Design and Analysis In Silico of Sapelenin G, an Acyclic Triterpenoid as Potential Anti-Inflammatory

    Ngabireng Marie. Claude; Menye Cyrille; Kouam F.Simeon; Ntede N .Hyppolite; Tagoudjeu Jacques; Awono Onana

    2013-01-01

    Diverse non-steriodal anti-inflammatory drugs and COX-2 inhibitors are a class of drugs which selectively inhibit COX-2, provide relief from pain and inflammation. However, they lack anti-thrombotic activity and hence lead to cardiovascular and renal liabilities apart from gastrointestinal irritation. To ameliorate this situation, research can be foccuss on the products originating from natural products that could offer better relief from inflammation than the currently used co...

  17. A Great Barrier Reef Sinularia sp. Yields Two New Cytotoxic Diterpenes

    Cherie A. Motti

    2012-07-01

    Full Text Available The methanol extract of a Sinularia sp., collected from Bowden Reef, Queensland, Australia, yielded ten natural products. These included the new nitrogenous diterpene (4R*,5R*,9S*,10R*,11Z-4-methoxy-9-((dimethylamino-methyl-12,15-epoxy-11(13-en-decahydronaphthalen-16-ol (1, and the new lobane, (1R*,2R*,4S*,15E-loba-8,10,13(14,15(16-tetraen-17,18-diol-17-acetate (2. Also isolated were two known cembranes, sarcophytol-B and (1E,3E,7E-11,12-epoxycembratrien-15-ol, and six known lobanes, loba-8,10,13(15-triene-16,17,18-triol, 14,18-epoxyloba-8,10,13(15-trien-17-ol, lobatrientriol, lobatrienolide, 14,17-epoxyloba-8,10,13(15-trien-18-ol-18-acetate and (17R-loba-8,10,13(15-trien-17,18-diol. Structures of the new compounds were elucidated through interpretation of spectra obtained after extensive NMR and MS investigations and comparison with literature values. The tumour cell growth inhibition potential of 1 and 2 along with loba-8,10,13(15-triene-16,17,18-triol, 14,17-epoxyloba-8,10,13(15-trien-18-ol-18-acetate, lobatrienolide, (1E,3E,7E-11,12-epoxycembratrien-15-ol and sarcophytol-B were assessed against three human tumour cell lines (SF-268, MCF-7 and H460. The lobanes and cembranes tested demonstrated 50% growth inhibition in the range 6.8–18.5 µM, with no selectivity, whilst 1 was less active (GI50 70–175 µM.

  18. Preparation of Polyurethane Foam for Filling the Thawing Holes of Railway Roadbed in High Cold Area%高寒带铁路路基融洞填充用单组分聚氨酯泡沫填缝剂

    张世泽; 姜志国; 张瑶; 刘唯平; 王乐然; 刘伟斌

    2015-01-01

    The influences of polyether triol/diol ratio,isocyanate index, the amount of catalyst on properties of one⁃component polyurethane foam were studied. The better usage of raw materials was obtained as below. The mix⁃ture of propane/butane mixture and dimethyl ether with mass ratio 1/1 was used as an aerosol propellant. The mass ratio of polyurethane and aerosol propellant was 4/1. The mole ratio polyether triol MN 700 and polyether diol DDL⁃1000D was between 3/2 and 1/1. The isocyanate index was 4. 25~4. 50, and the mass ratio of the catalyst DMDEE and polyether polyols was (2~3)/100. The prepared polyurethane foam had the following properties: the foaming ratio ≥15, the compressive strength(10%)≥0. 85 MPa, the shear strength to soil≥0. 85 MPa, the thermal con⁃ductivity ≤0. 05 W/( m·K) . The polyurethane foam could basically satisfy the use requirement of filling the tha⁃wing holes of railyway bedroad in high cold area.%研究了聚醚多元醇品种及其配比、异氰酸酯指数、催化剂用量对聚氨酯泡沫填缝剂材料性能的影响,确定了较佳的原料配比为:采用丙丁烷混合气和DME混合物(质量比1/1)作为抛射剂、料气质量比4/1、聚醚三醇MN⁃700与聚醚二醇DDL⁃1000D的摩尔比在3/2~1/1之间、异氰酸酯指数4.25~4.50、催化剂DMDEE的用量2~3份(相对于100份聚醚多元醇)。制备的聚氨酯泡沫材料达到如下性能:发泡倍率≥15,压缩强度(10%)≥0.85 MPa,土壤粘接剪切强度≥0.85 MPa,导热系数≤0.05 W/( m·K),基本满足高寒带铁路路基融洞填充使用要求。

  19. Experimental and Theoretical Studies of the Acid-Catalyzed Conversion of Furfuryl Alcohol to Levulinic Acid in Aqueous Solution

    Gonzalez Maldonado, Gretchen M.; Assary, Rajeev S.; Dumesic, James A.; Curtiss, Larry A.

    2012-02-14

    The conversion of furfuryl alcohol (FAL) to levulinic acid over Amberlyst TM 15 in aqueous media was investigated using a combination of liquid chromatography-mass spectrometry (LC-MS) measurements, isotopic labeling studies, nuclear magnetic resonance (NMR) spectroscopy, and ab initio quantum chemical calculations using the G4MP2 method. The results of these combined studies showed that one of the major reaction pathways takes place via a geminal diol species (4,5,5- trihydroxypentan-2-one, denoted as intermediate A), formed by the addition of two water molecules to FAL, where two of the oxygen atoms from FAL are retained. This geminal diol species can also be produced from another intermediate found to be a dimer-like species, denoted as intermediate B. This dimer-like species is formed at the early stages of reaction, and it can also be converted to intermediate A, indicating that intermediate B is the product of the reaction of FAL with another early intermediate. Quantum chemical calculations suggested this to be a protonated acyclic species. Reaction of this early intermediate with water produces intermediate A, while reaction with FAL produces intermediate B.

  20. Skin of the male African catfish, Clarias gariepinus: a source of steroid glucuronides

    Steroid metabolism in the skin of mature male African catfish, Clarias gariepinus, reared in the laboratory, was studied in vitro by tissue incubations with [3H]pregnenolone, [3H]dehydroepiandrosterone, [3H]17 alpha-hydroxyprogesterone, [3H]androstenedione, [14C]11 beta-hydroxyandrostenedione, and [3H]testosterone as precursors. While pregnenolone was not converted to any other steroid, dehydroepiandrosterone was transformed mainly to 5-androstene-3 beta, 17 beta-diol. The products of 17 alpha-hydroxyprogesterone incubations were 5 beta-pregnane-3 alpha,17 alpha-diol-20-one, 5 beta-pregnane-3 alpha,17 alpha, 20 beta-triol, and 5 beta-pregnan-17 alpha-o1-3,20-dione. The major steroids of androstenedione incubations were etiocholanolone, testosterone, and androsterone. Testosterone was converted mainly to etiocholanolone and androstenedione, and only small quantities of 11 beta-hydroxytestosterone, 11-ketotestosterone, and 11-ketoandrostenedione were the metabolites found in 11 beta-hydroxyandrostenedione incubation. These results demonstrated the presence of the enzymes 5 alpha- and 5 beta-reductases and 3 alpha-, 11 beta-, 17 beta-, and 20 beta-hydroxysteroid dehydrogenases in the skin. From enzymehistochemical results it appeared that the steroid conversions take place in the epithelial cells. Moreover, the presence of UDP-glucose dehydrogenase, an enzyme involved in the synthesis of glucuronic acid, in these cells indicates the possibility of steroid glucuronide formation. Indeed significant amounts of water-soluble steroid conjugates, particularly 5 beta-dihydrotestosterone- and testosterone-glucuronide, were found in the incubations with androstenedione and testosterone, indicating the presence of the UDP-glucuronosyl transferase in the catfish skin

  1. The Synthesis of Tritium-Labelled Adrenal and Gonadal Hormones

    Partial, catalytic hydrogenation of 1.4-diene-3-ketosteroids yields among other products the adrenal and/or gonadal 4- ene-3-ketones. The Cortisol (4-pregnene-11 β, 17 α, 21-triol-3.20-dione) and several of its derivatives labelled with tritium on carbons 1 and 2 have been prepared previously by this method in good yield and high specific activity. The technique of reduction has been adapted to the quantities of substrate of the order of 0.1 mmole. This affords better utilization of tritium and easier purification of the final product. The description is given of the preparation of starting material for the synthesis of corticosterone (4-pregnene-11 β, 21-diol-3.20-dione), Reichstein's compound ''S'' (4-pregnene-17 α, 21-diol- 3.20 dione), desoxycorticosterone (4-pregnene-21-ol-3.20-dione), testosterone (4-androstene-17 β-ol-3-one) and androstenedione (4-androstene-3.17-dione). Several solvent systems are described as appropriate for paper chromatographic separation of hydrogénation products. Using tritium gas, all the above-mentioned compounds have been prepared with specific activities of 5 —10 mc/mg. The influence of molecular structure on reaction yield is discussed. Some observations are noted concerning the isotopic effect during the catalytic hydrogenation. Further work is reported on the stability of the label, particularly in the second position and during biological reactions involving ring A reduction. The principal applications are indicated in which this type of labelling can be used successfully. (author)

  2. Quantitation and bitter taste contribution of saponins in fresh and cooked white asparagus (Asparagus officinalis L.).

    Dawid, Corinna; Hofmann, Thomas

    2014-02-15

    A sensitive HPLC-MS/MS method was developed enabling the simultaneous quantification of bitter-tasting mono- and bidesmosidic saponins in fresh and processed asparagus (Asparagus officinalis L.). Based on quantitative data and bitter taste recognition thresholds, dose-over-threshold factors were determined for the first time to determine the bitter impact of the individual saponins. Although 3-O-[α-L-rhamnopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranosyl]-(25R/S)-spirost-5-ene-3β-ol was found based on dose-over-threshold factors to be the predominant bitter saponin in raw asparagus spears, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-{α-L-rhamnopyranosyl-(1 → 4)}-β-D-glucopyranosyl]-26-O-[β-D-glucopyranosyl]-(25R)-22-hydroxyfurost-5-ene-3β,26-diol, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-{α-L-rhamnopyranosyl-(1 → 4)}-β-D-glucopyranosyl]-26-O-[β-D-glucopyranosyl]-(25S)-22-hydroxyfurost-5-ene-3β,26-diol, and (25R)- and (25S)-furost-5-en-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1 → 4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside were found as key bitter contributors after cooking. Interestingly, the monodesmosidic saponins 5a/b were demonstrated for the first time to be the major contributor to the bitter taste of fresh asparagus spears, while the bidesmosides 1a/b and 2a/b may be considered the primary determinants for the bitter taste of cooked asparagus. PMID:24128498

  3. Formulation and properties of ADN/GAP propellants

    Menke, Klaus; Heintz, Thomas; Schweikert, Wenka; Keicher, Thomas; Krause, Horst [Fraunhofer-Institut fuer Chemische Technologie ICT, Pfinztal (Germany)

    2009-06-15

    In this contribution two ways are described, how it is possible to achieve perfectly cured and processible propellants with prilled ADN, low amounts of HMX 5{mu}m mps and a binder system based on GAP diole and GAP triole oligomers with and without TMETN as a nitrate ester plasticizer. It was shown how it will be possible to suppress the strongly gas forming reaction between ADN and reactive isocyanates by a mixture of stabilizers. In this way it was possible to create minimum smoke ADN/HMX/GAP/TMETN propellants cured with the triisocyanate N100. In the second part an unconventional binder system based on the 1.3 dipolar cycloaddition reaction of azido groups with acetylene compounds forming 1,2,3-triazole heterocyclic rings has been applied for ADN/GAP and AP/GAP propellants. Together with small parts of HMX formulations with ADN/HMX/GAP and the corresponding AP/HMX/GAP exhibit high thermodynamic performance, are easily processible, and cure successfully at 60 C. Their basic properties consisting of burning behavior and mechanical properties, at ambient temperature, chemical stability, and sensitivity have been investigated and are compared to each other. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  4. Electrochemical corrosion protection studies of aniline-capped aniline trimer-based electroactive polyurethane coatings

    In this paper, the successful preparation of electroactive polyurethane (EPU) coatings containing amine-capped aniline trimer (ACAT) is presented for the first time. To accomplish this, ACAT was synthesized by carrying out oxidative coupling reactions between aniline and para-phenylenediamine, after which it was characterized through Fourier-transformation infrared and UV–vis spectroscopy. Subsequently, a polyurethane (PU) prepolymer was prepared by polymerizing diisocyanate of 4,4-methylene-bis(cyclohexylisocyanate), diol of polycaprolactone, and triol of phloroglucinol at 60 °C for 3 h. EPU was then produced by allowing the as-prepared polyurethane prepolymer to react with ACAT under suitable conditions. Non-electroactive polyurethane (NEPU) coating was also prepared for the control experiments. Based on a series of electrochemical corrosion measurements, EPU in the form of a coating was found to possess a clearly enhanced corrosion protection effect when compared to PU. The observed enhancement of the anticorrosion effect of EPU on a metallic substrate when compared to that of NEPU may have been caused by the redox catalytic capability of ACAT present in EPU, inducing the formation of a densely passive metal oxide layer (i.e., Fe2O3 and Fe3O4), as indicated by the results of scanning electron microscopy and electron spectroscopy for chemical analysis. The redox behavior of the EPU coatings was further analyzed and compared to that of the NEPU coating by cyclic voltammetric (CV) studies.

  5. 液体古马隆改性双组分聚氨酯涂料的制备和性能%Preparation and properties of liquid coumarone modified two-component polyurethane coating

    冯涛; 韩胜利; 杨足明; 周柳

    2012-01-01

    The liquid coumarone modified two-component polyurethane coating was prepared,among which the component A is the prepolymcr containing NCO groups and the component B is the curing agent containing mixed diamine and liquid coumarone.The effects of ratio of triol and diol,NCO group content,liquid coumarone amount etc.,on the film properties were discussed and the optimal formulation was obtained.The tensile strength is 2.5 MPa.the elongation at break is 750% and the solid content is over 99%,that can achieve the requirements,in standard GB/T 19250-2003.%制备了液体古马隆改性的双组分聚氨酯涂料,其中A组分为含-NCO的预聚物,B组分为含混合二元胺和液体古马隆的固化剂.分别讨论了三元醇和二元醇的比例、-NCO含量、液体古马隆添加量等对涂膜性能的影响,得到最优化的配方.胶膜强度为2.5 MPa,断裂伸长率为750%.涂料固含量大于99%,可以达到《GB/T 19250-2003聚氨酯防水涂料》规定的指标要求.

  6. Two new triterpenoid glycosides from the stems of Camellia oleifera Abel.

    Yan, Qing-Wei; Fu, Hui-Zheng; Luo, Yue-Hua; Zhou, Guo-Ping; Wan, Kai-Hua; Zhong, Rui-Jian

    2016-07-01

    Two new oleanane-type triterpenoid glycosides, 3-O-β-D-xylopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→3)-[β-D-glucuronopyranosyl-(1→2)]-β-D-glucuronopyranosyl-22α-angeloyloxyolean-12-ene-15α,16α,28-triol(1) and 3-O-β-D-xylopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→3)-[β-D-glucuronopyranosyl-(1→2)]-β-D-glucuronopyranosyl-21β-acetyl-22α-angeloyloxyolean-12-ene-16α,28-diol (2) were isolated from the stems of Camellia oleifera Abel. Their structures were elucidated by means of spectroscopic methods and chemical evidence. The cytotoxic activities of compounds 1-2 were evaluated against five human tumour cell lines (HCT-8, BGC-823, A5049, and A2780). Compounds 1-2 showed cytotoxic activity against five human cancer cell lines, with IC50 values ranging from 3.15 to 7.32 μM. PMID:26610161

  7. Bis(1,10-phenanthroline-κ2N,N′(sulfato-Ocopper(II ethane-1,2-diol monosolvate

    Kai-Long Zhong

    2011-09-01

    Full Text Available In the title compound, [Cu(SO4(C12H8N22]·C2H6O2, the CuII ion is five-coordinated in a distorted square-pyramidal manner by four N atoms from two chelating 1,10-phenanthroline (phen ligands and one O atom from a monodentate sulfate anion. The four N atoms comprise a square and the one O atom the apex of a square pyramid. The two chelating N2C2 groups are oriented at 71.1 (2°. In the crystal, the components are connected by intermolecular O—H...O hydrogen bonding. The presence of pseudosymmetry in the structure suggests the higher symmetry space group C2/c, but attempts to refine the structure in this space group resulted in an unsatisfactory model.

  8. High efficient acetalization of carbonyl compounds with diols catalyzed by novel carbon-based solid strong acid catalyst

    2007-01-01

    The novel carbon-based acid catalyst has been applied to catalyzing the acetalization and ketalization. The results showed that the catalyst was very efficient with the average yield over 93%. The novel heterogeneous catalyst has the advantages of high activity, wide applicability even to 7-membered ring acetals, strikingly simple workup procedure, non-pollution, and reusability, which will contribute to the green process greatly.

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

    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

  10. Mechanism of formation of 3-chloropropan-1,2-diol (3-MCPD) esters under conditions of the vegetable oil refining.

    Šmidrkal, Jan; Tesařová, Markéta; Hrádková, Iveta; Berčíková, Markéta; Adamčíková, Aneta; Filip, Vladimír

    2016-11-15

    3-MCPD esters are contaminants that can form during refining of vegetable oils in the deodorization step. It was experimentally shown that their content in the vegetable oil depends on the acid value of the vegetable oil and the chloride content. 3-MCPD esters form approximately 2-5 times faster from diacylglycerols than from monoacylglycerols. It has been proved that the higher fatty acids content in the oil caused higher 3-MCPD esters content in the deodorization step. Neutralization of free fatty acids in the vegetable oil before the deodorization step by alkaline carbonates or hydrogen carbonates can completely suppress the formation of 3-MCPD esters. Potassium salts are more effective than sodium salts. PMID:27283615

  11. Cyclopentadienyl-based Trioxo-rhenium Complexes for the Catalytic Deoxydehydration of Diols and Bio-based Polyols to Olefins

    RAJU, S

    2015-01-01

    Renewable sources like biomass, which mainly consists of materials derived from trees and plants, are currently considered as a key and future feedstock in the chemical industry for the sustainable production of chemicals. After the pre-treatment of biomass, lignocellulosic biomass is obtained as the major component. This contains various polymeric compounds such as starch, cellulose and lignin. By breaking these polymers into smaller monomeric molecules, sugars, polyols and aromatic compound...

  12. (20S)-Dammar-24-ene-3β,20-diol monohydrate from the bark of Aglaia exima (Meliaceae)

    Agus Safariari; Asep Supriadin; Unang Supratman4); Khalijah Awang; Seik Weng Ng

    2012-01-01

    In the title compound {systematic name: (1R,2R,5R,7R,10R,11R,14S,15R)-14-[(2S)-2-hydroxy-6-methylhept-5-en-2-yl]-2,6,6,10,11-pentamethyltetracyclo[8.7.0.02,7.011,15]heptadecan-5-ol monohydrate}, C30H52O2·H2O, the three fused cyclohexane rings adopt chair conformations and the hydroxy substituent of one of these occupies an axial position. The fused cyclopentane ring adopts an envelope conformation (with the flap atom being the C atom bearing the methyl group) and the 3-methylbut-2-en...

  13. (20S-Dammar-24-ene-3β,20-diol monohydrate from the bark of Aglaia exima (Meliaceae

    Agus Safariari

    2012-09-01

    Full Text Available In the title compound {systematic name: (1R,2R,5R,7R,10R,11R,14S,15R-14-[(2S-2-hydroxy-6-methylhept-5-en-2-yl]-2,6,6,10,11-pentamethyltetracyclo[8.7.0.02,7.011,15]heptadecan-5-ol monohydrate}, C30H52O2·H2O, the three fused cyclohexane rings adopt chair conformations and the hydroxy substituent of one of these occupies an axial position. The fused cyclopentane ring adopts an envelope conformation (with the flap atom being the C atom bearing the methyl group and the 3-methylbut-2-enyl portion of its substituent is disordered over three sets of sites in a 0.413 (7:0.250 (7:0.337 (7 ratio. The O atoms of both water molecules occupy special positions of 2 site symmetry. In the crystal, Os—H...Ow and Ow—H...Os (s = steroid and w = water hydrogen bonds link hydroxy groups and water molecules, forming a three-dimensional network. The crystal studied was found to be a non-merohedral twin with a 0.518 (1:0.482 (1 component ratio.

  14. Synthesis of 7-ω-Amidoalkyl-substituted 6,7-Dehydroestra-3,17β-diols

    Inohae, Eiko; Thiemann, Thies; Mataka, Shuntaro; Melo'e Silva, M. Cristina; Patricio Catela, Luciana

    1999-01-01

    The entry to the novel C7-alkylsubstituted 6,7-dehydroestrones 10 by addition of C-nucleophiles on the enolate of suitably protected 6-ketoestrone derivative 3, reduction of the 6-keto group in 7, dehydration of 6-hydroxy group in 8 with a subsequent deprotection step is presented. An exemplary transformation of 10 to the 17α-iodoethynylestradiol 12 is shown.

  15. Gene expression profiles and genetic damage in benzo(a)pyrene diol epoxide-exposed TK6 cells

    Microarray analysis is a powerful tool to identify the biological effects of drugs or chemicals on cellular gene expression. In this study, we compare the relationships between traditional measures of genetic toxicology and mutagen-induced alterations in gene expression profiles. TK6 cells were incubated with 0.01, 0.1, or 1.0 μM ±anti-benzo(a)pyrene-trans-7,8-dihydrodiol-9,10-epoxide (BPDE) for 4 h and then cultured for an additional 20 h. Aliquots of the exposed cells were removed at 4 and 24 h in order to quantify DNA adduct levels by 32P post-labeling and measure cell viability by cloning efficiency and flow cytometry. Gene expression profiles were developed by extracting total RNA from the control and exposed cells at 4 and 24 h, labeling with Cy3 or Cy5 and hybridizing to a human 350 gene array. Mutant frequencies in the Thymidine Kinase and Hypoxanthine Phosphoribosyl Transferase genes were also determined. The 10α-(deoxyguanosin-N2-yl)-7α,8β,9β-trihydroxy-7,8,9,10-tetrahydrobenzo(a) pyrene (dG-N2-BPDE) adduct increased as a function of dose and was the only adduct identified. A dose-related decrease in cell viability was evident at 24 h, but not at 4 h. Cell death occurred by apoptosis. At 4 h, analysis of the gene expression profiles revealed that Glutathione Peroxidase and Gadd45 were consistently upregulated (greater than 1.5-fold and significantly (P<0.001) greater than the control in two experiments) in response to 1.0 μM BPDE exposure. Fifteen genes were consistently down-regulated (less than 0.67-fold and significantly (P<0.001) lower than the control in two experiments) at 4 h in cultures exposed to 1.0 μM BPDE. Genes with altered expression at 4 h included genes important in the progression of the cell-cycle and those that inhibit apoptosis. At 24 h post-exposure, 16 genes, involved in cell-cycle control, detoxification, and apoptosis were consistently upregulated; 10 genes were repressed in cultures exposed to the high dose of BPDE. Real-time quantitative PCR confirmed the differential expression of selected genes. These data suggest that changes in gene expression will help to identify effects of drugs and chemicals on molecular pathways in cells, and will provide useful information about the molecular responses associated with DNA damage. Of the endpoints evaluated, DNA adduct formation was the most sensitive indicator of DNA damage. DNA adduct formation was clearly evident at low doses, but the number of genes with significantly altered expression (P<0.001) was minimal. Alterations in gene expression were more robust at doses associated with cellular toxicity and induction of mutations.

  16. 5-Methylchrysene metabolism in mouse epidermis in vivo, diol epoxide--DNA adduct persistence, and diol epoxide reactivity with DNA as potential factors influencing the predominance of 5-methylchrysene-1,2-diol-3,4-epoxide--DNA adducts in mouse epidermis

    5-Methylchrysene (5-MeC) can form two bay region dihydrodiol epoxides: 1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydro-5-methylchrysene (DE-I) which has the methyl group and the epoxide ring in the same bay region, and 7,8-dihydroxy-9,10-epoxy-7,8,10-tetrahydro-5-methylchrysene (DE-II). In a previous study, we observed that the ratio of DE-I:DNA adducts to DE-II:DNA adducts in mouse epidermis, 24 h after application of [3H]5-MeC metabolites was 2.7 to 1. To investigate the basis for this observation we have now studies: (i) the formation of [3H]5-MeC in mouse epidermis in vivo at various time intervals from 0.33 to 24 h; (ii) the persistence of DE-I:DNA adducts and DE-II:DNA adducts in mouse epidermis at 4-48 h after application of [3H]5-MeC; and (iii) the reactions of DE-I and DE-II with calf thymus DNA in vitro. In contrast to results obtained with mouse liver 9000 grams supernatant, the dihydrodiol precursors of DE-I and DE-II were present in equivalent quantities in mouse epidermis in vivo at every time point studied. The ratio of DE-I:DNA adducts to DE-II:DNA adducts in mouse epidermis was constant throughout the time period studied. However, the extent of formation of DE-I:DNA adducts was greater than that of DE-II:DNA adducts upon reaction of DE-I or DE-II with calf thymus DNA in vitro. These results suggest that differences in reactivity with DNA of DE-I and DE-II may bw responsible for the higher levels in mouse epidermis of DE-I:DNA adducts compared with DE-II:DNA adducts and provide a possible basis for the observed enhancing effect of a bay region methyl group on the carcinogenicity of polynuclear aromatic hydrocarbons

  17. Antiproliferative and anti-inflammatory polyhydroxylated spirostanol saponins from Tupistra chinensis.

    Xiang, Limin; Yi, Xiaomin; Wang, Yihai; He, Xiangjiu

    2016-01-01

    Tupistra chinensis is widely distributed in southwestern China and its rhizome is a famous folk medicine for the treatment of carbuncles and pharyngitis. Its chemical identity of potent antiproliferative and anti-inflammatory constituents has been carried out in this study. Twenty-three polyhydroxylated spirostanol saponins, including nine novels, were isolated and identified. The new spirostanol saponins were elucidated as spirost-25(27)-en-1β,2β,3β,4β,5β-pentol-2-O-β-D-xylopyranoside (1), spirost-25(27)- en-1β,2β,3β,4β,5β-pentol-2-O-α-L-arabinopyranoside (2), spirost-25(27)-en- 1β,3α,5β-triol (12), spirost-25(27)-en-1β,3α,4β,5β,6β-pentol (13), spirost-25(27)-en- 1β,2β,3β,5β-tetraol-5-O-β-D-glucopyranoside (16), 5β-spirost-25(27)-en-1β,3β-diol- 3-O-β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranoside (17), (25R)-5β-spirostan- 1β,3β-diol-3-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside (18), (25R)-5β- spirostan-1β,3β-diol-3-O-β-D-fructofuranosyl-(2 → 6)-β-D-glucopyranoside (19), 5β-spirost-25(27)-en-3β-ol-3-O-β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranoside (20). The antiproliferative effects against seven human cancer cell lines and inhibitory activities on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in a macrophage cell line RAW 264.7 were assayed for all the isolated compounds. Compounds 17, 19 and 21 exhibited potential antiproliferative activities against all of human cancer cell lines tested. Compounds 21 showed significant inhibition on NO production with IC50 values of 11.5 μM. These results showed that the spirostanol saponins isolated from the dried rhizomes of T. chinensis have potent antiproliferative and anti-inflammatory activities and T. chinensis might be used as anticancer and.anti-inflammatory supplement. PMID:27530890

  18. Phytotoxic steroidal saponins from Agave offoyana leaves.

    Pérez, Andy J; Simonet, Ana M; Calle, Juan M; Pecio, Łukasz; Guerra, José O; Stochmal, Anna; Macías, Francisco A

    2014-09-01

    A bioassay-guided fractionation of Agave offoyana leaves led to the isolation of five steroidal saponins (1-5) along with six known saponins (6-11). The compounds were identified as (25R)-spirost-5-en-2α,3β-diol-12-one 3-O-{α-l-rhamnopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (1), (25R)-spirost-5-en-3β-ol-12-one 3-O-{α-l-rhamnopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (2), (25R)-spirost-5-en-3β-ol-12-one 3-O-{β-d-xylopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (3), (25R)-26-O-β-d-glucopyranosylfurost-5-en-3β,22α,26-triol-12-one 3-O-{α-l-rhamnopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (4) and (25R)-26-O-β-d-glucopyranosylfurost-5-en-3β,22α,26-triol-12-one 3-O-{β-d-xylopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (5) by comprehensive spectroscopic analysis, including one- and two-dimensional NMR techniques, mass spectrometry and chemical methods. The phytotoxicity of the isolated compounds on the standard target species Lactuca sativa was evaluated. PMID:24939800

  19. 6-[2-(Phosphonomethoxy)alkoxy]-2,4-diaminopyrimidines: A new class of acyclic pyrimidine nucleoside phosphonates with antiviral activity

    Balzarini, J.; Pannecouque, C.; Naesens, L.; Andrei, G.; Snoeck, R.; De Clercq, E.; Hocková, Dana; Holý, Antonín

    2004-01-01

    Roč. 23, 8/9 (2004), s. 1321-1327. ISSN 1525-7770 R&D Projects: GA AV ČR IBS4055109 Grant ostatní: GWOV(BE) G.0104.98; GOA (BE) 00/12 Institutional research plan: CEZ:AV0Z4055905 Keywords : herpesviruses * poxviruses * hepadnaviruses Subject RIV: CC - Organic Chemistry Impact factor: 0.429, year: 2004

  20. Deconstructing selectivity in the gold-promoted cyclization of alkynyl benzothioamides to six-membered mesoionic carbene or acyclic carbene complexes

    Vummaleti, Sai V. C.

    2014-05-02

    We demonstrate that the experimentally observed switch in selectivity from 5-exo-dig to 6-endo-dig cyclization of an alkynyl substrate, promoted by Au I and AuIII complexes, is connected to a switch from thermodynamic to kinetic reaction control. The AuIII center pushes alkyne coordination toward a single Au-C(alkyne) σ-bond, conferring carbocationic character (and reactivity) to the distal alkyne C atom. © 2014 American Chemical Society.

  1. 2 : 2 Fe(III): ligand and "adamantane core" 4 : 2 Fe(III): ligand (hydr)oxo complexes of an acyclic ditopic ligand

    Ghiladi, Morten; Larsen, Frank B.; McKenzie, Christine J.; Søtofte, Inger; Tuchagues, Jean-Pierre

    -ray structure of the dinuclear complex [{( Hbpbp) Fe(mu-OH)}(2)](ClO4)(4) center dot 2C(3)H(6)O ( 1 center dot 2C(3)H(6)O) shows that only one of the metal-binding cavities of each ligand is occupied by an iron( III) atom and two [Fe(Hbpbp)](3+) units are linked together by two hydroxo bridging groups to form a......A bis-hydroxo-bridged diiron(III) complex and a bis-mu-oxo-bis-mu-hydroxo-bridged tetrairon( III) complex are isolated from the reaction of 2,6-bis((N, N'-bis-(2-picolyl) amino) methyl)-4-tert-butylphenol (Hbpbp) with iron perchlorate in acidic and neutral solutions respectively. The X...... bond lengths of the two different octahedral iron sites: Fe -mu-OH, 1.953( 5), 2.013( 5) angstrom and Fe-mu-O, 1.803( 5), 1.802( 5) angstrom. The difference in ligand environment is too small for allowing Mossbauer spectroscopy to distinguish between the two crystallographically independent Fe sites...

  2. RELATIVE SPECIFICITIES OF A SERIES OF BETA-LACTAM-RECOGNIZING ENZYMES TOWARDS THE SIDE-CHAINS OF PENICILLINS AND OF ACYCLIC THIOLDEPSIPEPTIDES

    SOTO, G; ADACHI, H; VANDERLINDEN, MPG; KECK, W; PRATT, RF

    1994-01-01

    In an attempt to understand more: of the subtle differences between bacterial beta-lactamases and DD-peptidases. comparisons have been made between the specificities of these enzymes towards the phenylacetyl side chain, generally thought to be favoured by beta-lactamases, and the NN'-diacetyl-L-lysy

  3. New Anti-malarial Drug Leads: N-Branched Acyclic Nucleoside Phosphonates as Inhibitors of the Plasmodium falciparum and vivax 6-Oxopurine Phosphoribosyltransferases

    Hocková, Dana; Keough, D. T.; Janeba, Zlatko; Naesens, L.; Edstein, M. D.; Chavchich, M.; Wang, T. H.; de Jersey, J.; Guddat, L. W.

    Istanbul : IUPAC, 2013. s. 1629-1629. [World Chemistry Congress /44./. 11.08.2013-16.08.2013, Istanbul] R&D Projects: GA ČR GAP207/11/0108 Grant ostatní: NHMRC(AU) 1030353 Institutional support: RVO:61388963 Keywords : nucleotide analogues * enzyme inhibitors * Plasmodium Subject RIV: CC - Organic Chemistry

  4. First Crystal Structures of Mycobacterium tuberculosis 6-Oxopurine Phosphoribosyltransferase: Complexes with GMP and Pyrophosphate and with Acyclic Nucleoside Phosphonates Whose Prodrugs Have Antituberculosis Activity

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

    2015-01-01

    Roč. 58, č. 11 (2015), s. 4822-4838. ISSN 0022-2623 R&D Projects: GA ČR GAP207/11/0108; GA MV VG20102015046 Institutional support: RVO:61388963 Keywords : enzyme inhibitors * nucleotide analogues * tuberculosis * crystal structures Subject RIV: CC - Organic Chemistry Impact factor: 5.447, year: 2014

  5. Biologische Untersuchungen zum „lower acyclic terpene utilisation (atu) pathway“ in Pseudomonas aeruginosa und chemische Synthese wichtiger Intermediate dieses Stoffwechselweges

    Randel, Nadine

    2012-01-01

    Der Abbau von Citronellol und verwandten azyklischen Terpenoiden ist aufgrund einer Methylgruppe in beta-Position schwierig und nicht weit verbreitet. Die Organismen P. aeruginosa und P. citronellolis umgehen die Blockierung der beta-Oxidation durch Carboxylierung dieser Methylgruppe auf Stufe des CoenzymA-Esters 19 (Geranyl-CoA). Durch Wasseranlagerung an die Doppelbindung wird die Voraussetzung für die Abspaltung der Acetat-Funktionalität geschaffen, wobei die resultierende Verbindung 23 (7...

  6. DOCTOR OF PHILOSOPHY In the field of Chimie organique Application of the Radical Chemistry of Xanthates to the Synthesis of Cyclic or Acyclic Amines

    Han, Songzhe

    2014-01-01

    In chapter 1, general aspects of radical chemistry are briefly introduced. Improvements and applications of the Barton radical decarboxylation, the Barton-McCombie radical deoxygenation and the radical chemistry of xanthates are also described in this chapter. In chapter 2, various methods for the construction of amines and especially radical hydroaminomethylation reaction developed in our group are described. In chapter 3, based on our previous experiences of radical hydroaminomethylation re...

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

    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....

  8. Synthesis of Novel N-Branched Acyclic Nucleoside Phosphonates As Potent and Selective Inhibitors of Human, Plasmodium falciparum and Plasmodium vivax 6-Oxopurine Phosphoribosyltransferases

    Hocková, Dana; Keough, D. T.; Janeba, Zlatko; Wang, T.; de Jersey, J.; Guddat, L. W.

    2012-01-01

    Roč. 55, č. 13 (2012), s. 6209-6223. ISSN 0022-2623 R&D Projects: GA ČR GAP207/11/0108; GA MŠk 1M0508 Grant ostatní: NHMRC(AU) 569703; NHMRC(AU) 1030353 Institutional support: RVO:61388963 Keywords : enzyme inhibitors * aza-ANPs * malaria Subject RIV: CC - Organic Chemistry Impact factor: 5.614, year: 2012

  9. Aza-acyclic Nucleoside Phosphonates Containing a Second Phosphonate Group As Inhibitors of the Human, Plasmodium falciparum and vivax 6-Oxopurine Phosphoribosyltransferases and Their Prodrugs As Antimalarial Agents

    Keough, D. T.; Hocková, Dana; Janeba, Zlatko; Wang, T. H.; Naesens, L.; Edstein, M. D.; Chavchich, M.; Guddat, L. W.

    2015-01-01

    Roč. 58, č. 2 (2015), s. 827-846. ISSN 0022-2623 R&D Projects: GA ČR GAP207/11/0108 Institutional support: RVO:61388963 Keywords : enzyme inhibitors * ANPs * Plasmodium * malaria Subject RIV: CC - Organic Chemistry Impact factor: 5.447, year: 2014

  10. Furan-Oxidation-Triggered Inducible DNA Cross-Linking: Acyclic Versus Cyclic Furan-Containing Building Blocks-On the Benefit of Restoring the Cyclic Sugar Backbone

    Stevens, K.; Claeys, D. D.; Catak, S.; Figaroli, S.; Hocek, Michal; Tromp, J. M.; Schürch, S.; Speybroeck, V. V.; Madder, A.

    2011-01-01

    Roč. 17, č. 25 (2011), s. 6940-6953. ISSN 0947-6539 R&D Projects: GA MŠk LC512; GA AV ČR IAA400550902 Institutional research plan: CEZ:AV0Z40550506 Keywords : bioorganic chemistry * DNA * molecular modeling * nucleosides * oxidation Subject RIV: CC - Organic Chemistry Impact factor: 5.925, year: 2011

  11. Chemical constituents of Papulaspora immersa, an endophyte from Smallanthus sonchifolius (Asteraceae), and their cytotoxic activity.

    Gallo, Margareth Borges Coutinho; Cavalcanti, Bruno Coêlho; Barros, Francisco Washington Araújo; Odorico de Moraes, Manoel; Costa-Lotufo, Letícia Veras; Pessoa, Cláudia; Bastos, Jairo Kenupp; Pupo, Mônica Tallarico

    2010-12-01

    Papulaspora immersa H. H. Hotson was isolated from roots and leaves of Smallanthus sonchifolius (Poepp. and Endl.) H. Rob. (Asteraceae), traditionally known as Yacon. The fungus was cultured in rice, and, from the AcOEt fraction, 14 compounds were isolated. Among them, (22E,24R)-8,14-epoxyergosta-4,22-diene-3,6-dione (4), 2,3-epoxy-1,2,3,4-tetrahydronaphthalene-c-1,c-4,8-triol (10), and the chromone papulasporin (13) were new secondary metabolites. The spectral data of the known natural products were compared with the literature data, and their structures were established as the (24R)-stigmast-4-en-3-one (1), 24-methylenecycloartan-3β-ol (2), (22E,24R)-ergosta-4,6,8(14),22-tetraen-3-one (3), (-)-(3R,4R)-4-hydroxymellein (5), (-)-(3R)-5-hydroxymellein (6), 6,8-dihydroxy-3-methylisocoumarin (7), (-)-(4S)-4,8-dihydroxy-α-tetralone (8), naphthalene-1,8-diol (9), 6,7,8-trihydroxy-3-methylisocoumarin (11), 7-hydroxy-2,5-dimethylchromone (12), and tyrosol (14). Compound 4 showed the highest cytotoxic activity against the human tumor cell lines MDA-MB435 (melanoma), HCT-8 (colon), SF295 (glioblastoma), and HL-60 (promyelocytic leukemia), with IC₅₀ values of 3.3, 14.7, 5.0 and 1.6 μM, respectively. Strong synergistic effects were also observed with compound 5 and some of the isolated steroidal compounds. PMID:21162007

  12. 南海北部1,3,4-C27-29三醇化合物的检出及其指示%Detection and indication of 1,3,4-C27-29 triol in the sediment of northern South China Sea

    朱小畏; 茅晟懿; 吴能友; 贾国东; 孙永革; 管红香; 邬黛黛

    2016-01-01

    继长链三醇化合物(1,20,21-C29)在部分沉积物和淡水蕨类植物中检出后,本文在南海北部Site4B岩芯沉积物中检出了与1,20,21-C29三醇不同羟基位置和碳链长度的新的长链三醇同系物(1,3,4-C27-29).通过对其分子分布和单体碳同位素测试发现1,3,4-C29三醇与n-C26-30偶碳长链脂肪醇含量具有良好相关性,R2 (n=68)分别为0.905、0.929和0.903,并且碳同位素组成(-32.3±1.9‰)与n-C26-30偶碳长链脂肪醇(分别为-29.13±0.87‰、-32.98±1.28‰和-32.98±1.28‰)较为接近.Site4B岩芯沉积物中1,3,4-C29三醇和陆源长链脂肪醇(n-C26-34)在整个剖面中的分布趋势高度一致,可以作为陆源输入的替代性指标.鉴于以往研究1,20,21-C29三醇专属于满江红属(Azolla)淡水蕨类植物,此次报道的1,3,4-C27-29三醇可能具有相似的生物来源,通过对其生源区及生长环境的判定可以为南海北部陆源输入途径和来源提供潜在的有机地球化学依据.

  13. Caracterização de pinos da blenda poli(L-co-D,L ácido láctico)/poli(caprolactona triol) (PLDLA/PCL-T) e análise das propriedade mecânicas dos pinos durante degradação in vitro

    Marcia Adriana Tomaz Duarte; Adriana Cristina Motta; Eliana Aparecida Rezende Duek

    2016-01-01

    Resumo Os dispositivos de fixação óssea, metálicos convencionais, usados em cirurgia crâniomaxilofacial têm apresentado alguns problemas, tais como, corrosão, inflamação e infecção, além de neoformação de estrutura óssea mecanicamente inferior devido à atrofia gerada pela diferença de módulo elástico entre metal e osso, razões que têm levado ao aumento do interesse por dispositivos poliméricos bioarreabsorvíveis. Os polímeros biorreabsorvíveis mais utilizados nesta aplicação pertencem à famíl...

  14. 75 FR 39520 - Certain New Chemicals; Receipt and Status Information

    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...

  15. Epigallocatechin-3-gallate reduces DNA damage induced by benzo[a]pyrene diol epoxide and cigarette smoke condensate in human mucosa tissue cultures.

    Baumeister, Philipp; Reiter, Maximilian; Kleinsasser, Norbert; Matthias, Christoph; Harréus, Ulrich

    2009-06-01

    Although epidemiological studies indicate cancer preventive effects of diets rich in fruit and vegetables, large clinical intervention studies conducted to evaluate dietary supplementation with micronutrients, mostly vitamins, showed disappointing results in large parts. In contrast, there is encouraging epidemiologic data indicating great chemopreventive potential of a large group of phytochemicals, namely polyphenols. This study shows the DNA protective effect epigallocatechin-3-gallate, a tea catechin, and one of the best-studied substances within this group, on carcinogen-induced DNA fragmentation in upper aerodigestive tract cells. Cell cultures from fresh oropharyngeal mucosa biopsies were preincubated with epigallocatechin-3-gallate in different concentrations before DNA damage was introduced with the metabolically activated carcinogen benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide or cigarette smoke condensate. Effects on resulting DNA fragmentation were measured using the alkaline single-cell microgel electrophoresis (comet assay). Epigallocatechin-3-gallate significantly reduced benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide-induced DNA damage by up to 51% (Pculture model. PMID:19491610

  16. Analysis of 1,2-diol diesters in vernix caseosa by high-performance liquid chromatography - atmospheric pressure chemical ionization mass spectrometry

    Šubčíková, L.; Hoskovec, Michal; Vrkoslav, Vladimír; Čmelíková, T.; Háková, Eva; Míková, Radka; Coufal, P.; Doležal, A.; Plavka, R.; Cvačka, Josef

    2015-01-01

    Roč. 1378, Jan 23 (2015), s. 8-18. ISSN 0021-9673 R&D Projects: GA ČR GAP206/12/0750 Institutional support: RVO:61388963 Keywords : skin lipids * neutral lipids * lipidomics * mass spectrometry * double-bond position Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.169, year: 2014

  17. Study on Waterborne Polycarbonate Diols-based Polyurethane%聚碳酸酯型水性聚氨酯的研究

    王全杰; 朱先义; 侯立杰; 蒋艳云; 杜丹华

    2009-01-01

    以聚碳酸酯二醇(PCDL)和4,4'-二苯基甲烷二异氰酸酯(MDI )为主要原料合成水性聚碳酸酯型聚氨酯树脂(PCU).研究了软段分子量、软段用量对PCU力学性能和微观相分离结构的影响.结果表明,随着软段用量的增加,PCU的断裂强度迅速下降,断裂伸长率也有所下降.但相同软段用量,随着分子量的增加,断裂强度非但没有下降,反而有所上升;断裂伸长率略有下降.同时聚碳酸酯二醇可以明显提高聚氨酯的耐黄变性.

  18. Grubbs's Cross Metathesis of Eugenol with cis-2-butene-1, 4-diol to Make a Natural Product: An Organometallic Experiment for the Undergraduate Lab

    Taber, Douglass F.; Frankowski, Kevin J.

    2006-01-01

    A modified experimental procedure for the one-step synthesis that is suitable for the undergraduate organic lab is presented. In the course of work towards the more routine use of air-sensitive organometallic complexes such as the Grubb's catalyst, the natural product (E)-4-(4-hydroxy-3-methoxyphenyl) but-2-en-ol, 4, was synthesized.

  19. Detection of benzo[a]pyrene diol epoxide-DNA adducts in peripheral blood lymphocytes and antibodies to the adducts in serum from coke oven workers.

    Harris, C. C.; Vahakangas, K.; Newman, M J; Trivers, G E; Shamsuddin, A; Sinopoli, N; Mann, D L; Wright, W. E.

    1985-01-01

    Coke oven workers are exposed to high levels of carcinogenic polycyclic aromatic hydrocarbons, including benzo[a]pyrene (B[a]P), and are at increased risk of lung cancer. Since B[a]P is enzymatically activated to 7 beta,8 alpha-dihydroxy(9 alpha, 10 alpha)epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (B[a]PDE) that forms adducts with DNA, the presence of these adducts was measured in DNA from peripheral blood lymphocytes by synchronous fluorescence spectrophotometry and enzyme radioimmunoassay. App...

  20. Hydroformylation of olefins and reductive carbonylation of aryl halides with syngas formed ex situ from dehydrogenative decarbonylation of hexane-1,6-diol

    Christensen, Stig Holden; Olsen, Esben Paul Krogh; Rosenbaum, Jascha;

    2014-01-01

    A variety of primary alcohols have been investigated as convenient substrates for the ex situ delivery of carbon monoxide and molecular hydrogen in a two-chamber reactor. The gaseous mixture is liberated in one chamber by an iridium-catalysed dehydrogenative decarbonylation of the alcohol and then...