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Sample records for acyclic diols triols

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

    Science.gov (United States)

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

    2016-05-11

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

  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

    Czech Academy of Sciences Publication Activity Database

    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. Solvatochromic effect studies on the absorption spectra of 4-((2-ethylphenyl)diazenyl)benzene-1,3-diol and 2-((2-ethylphenyl)diazenyl)benzene-1,3,5-triol molecules

    Energy Technology Data Exchange (ETDEWEB)

    Guelseven, Yadigar; Tasal, Erol; Sidir, Isa [Department of Physics, Faculty of Arts and Sciences, Eskisehir Osmangazi University, Eskisehir 26480 (Turkey); Guengoer, Tayyar [Department of Physics, Faculty of Arts and Sciences, Akdeniz University, Antalya (Turkey); Berber, Halil [Department of Chemistry, Faculty of Sciences, Anadolu University, Eskisehir (Turkey); Oegretir, Cemil [Department of Chemistry, Faculty of Arts and Sciences, Eskisehir Osmangazi University, Eskisehir (Turkey)

    2009-06-15

    The electronic absorption spectra of 4-((2-ethylphenyl)diazenyl)benzene-1,3-diol and 2-((2-ethylphenyl)diazenyl)benzene-1,3,5-triol molecules in the nine different solvent variable electronic characters have been recorded. The solvent dependent maximum absorption band ({pi}-{pi}* transitions) shifts, {nu}{sub max}, were analyzed using a wide range of parameters such as refractive index, dielectric constant and Kamlet-Taft parameters [hydrogen bond donating ability ({alpha}) and hydrogen bond accepting ability ({beta})]. The electronic transitions are assigned and the solvent-induced spectral shifts have been analyzed in relation to the different solute-solvent interaction mechanism using computational chemistry. The intermolecular interaction types in the azobenzene derivatives solutions have been established on the basis of a multiple linear regression analysis. The fitting coefficients obtained from this analysis allowed us to estimate the contribution of each type of interactions to the total spectral shifts in the studied solutions. (author)

  4. Acyclic models

    CERN Document Server

    Barr, Michael

    2002-01-01

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

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

    DEFF Research Database (Denmark)

    Dyekjær, Jane Dannow; Rasmussen, Kjeld; Jonsdottir, Svava Osk

    2002-01-01

    Values for nine descriptors for QSPR (quantitative structure-property relationships) modeling of physical properties of 96 alkanes, alcohols, ethers, diols, triols and cyclic alkanes and alcohols in conjunction with the program Codessa are presented. The descriptors are Boltzmann-averaged by sele......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...

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

    International Nuclear Information System (INIS)

    Voisin, Maud; Silvente-Poirot, Sandrine; Poirot, Marc

    2014-01-01

    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 [ 14 C]-cholestane-3β,5α,6β-triol and [ 14 C]-6-oxo-cholestan-3β,5α-diol. In the present study we report the one-step synthesis of [ 14 C]-cholestane-3β,5α,6β-triol and [ 14 C]-6-oxo-cholestan-3β,5α-diol by oxidation of [ 14 C]-cholesterol with iodide metaperiodate (HIO 4 )

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    2012-01-01

    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. PMID:23151005

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

    Science.gov (United States)

    Lowe, Henry I C; Watson, Charah T; Badal, Simone; Toyang, Ngeh J; Bryant, Joseph

    2012-11-14

    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. 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. 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. 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.

  10. (Citric acid–co–polycaprolactone triol) polyester

    Science.gov (United States)

    Thomas, Lynda V.; Nair, Prabha D.

    2011-01-01

    Tissue engineering holds enormous challenges for materials science, wherein the ideal scaffold to be used is expected to be biocompatible, biodegradable and possess mechanical and physical properties that are suitable for target application. In this context, we have prepared degradable polyesters in different ratios by a simple polycondensation technique with citric acid and polycaprolactone triol. Differential scanning calorimetry indicated that the materials were amorphous based the absence of a crystalline melting peak and the presence of a glass transition temperature below 37°C. These polyesters were found to be hydrophilic and could be tailor-made into tubes and films. Porosity could also be introduced by addition of porogens. All the materials were non-cytotoxic in an in vitro cytotoxicity assay and may degrade via hydrolysis to non-toxic degradation products. These polyesters have potential implications in the field of soft tissue engineering on account of their similarity of properties. PMID:23507730

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-11

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

  12. Acyclicity in edge-colored graphs

    DEFF Research Database (Denmark)

    Gutin, Gregory; Jones, Mark; Sheng, Bin

    2017-01-01

    A walk W in edge-colored graphs is called properly colored (PC) if every pair of consecutive edges in W is of different color. We introduce and study five types of PC acyclicity in edge-colored graphs such that graphs of PC acyclicity of type i is a proper superset of graphs of acyclicity of type...

  13. On Acyclicity of Games with Cycles

    DEFF Research Database (Denmark)

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

    2009-01-01

    We study restricted improvement cycles (ri-cycles) in finite positional n-person games with perfect information modeled by directed graphs (digraphs) that may contain cycles. We obtain criteria of restricted improvement acyclicity (ri-acyclicity) in two cases: for n = 2 and for acyclic digraphs. We...

  14. 3000 Horsepower super conductive field acyclic motor

    International Nuclear Information System (INIS)

    Marshall, R.

    1983-01-01

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

  15. Acyclicity in edge-colored graphs

    DEFF Research Database (Denmark)

    Gutin, Gregory; Jones, Mark; Sheng, Bin

    2017-01-01

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

  16. Rapid synthesis of macrocycles from diol precursors

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  17. Impossibility of an acyclic relativistic electric motor

    Energy Technology Data Exchange (ETDEWEB)

    Spavieri, G [Universidad de Los Andes, Merida (Venezuela); Cavalleri, G [Milan Univ. (Italy). Ist. di Fisica; Spinelli, G [Padua Univ. (Italy). Ist. di Matematica Applicata

    1981-02-11

    The relativistic torque acting on a circuit carrying a current and having a uniform translatory motion in a constant and uniform electric field would seem to suggest the possibility of an acyclic relativistic electric motor. However, the net effect on the side parallel to the rotation axis is exactly balanced by the variation of the angular momentum (in the case of an insulating circuit transporting electric charges) or by the external moment due to the magnetic field (in the case of a conducting circuit) acting on the two sides perpendicular to the rotation axis.

  18. Iridium catalysed synthesis of piperazines from diols

    DEFF Research Database (Denmark)

    Nordstrøm, Lars Ulrik Rubæk; Madsen, Robert

    2007-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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

  20. On Event Detection and Localization in Acyclic Flow Networks

    KAUST Repository

    Suresh, Mahima Agumbe; Stoleru, Radu; Zechman, Emily M.; Shihada, Basem

    2013-01-01

    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

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

    Indian Academy of Sciences (India)

    Abstract. 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 (v/v) acetic acid–water mixture. The vicinal diols yield the carbonyl compounds arising out of the glycol bond fission while the other diols give.

  2. Antiviral acyclic nucleoside phosphonates: New structures and prodrugs

    Czech Academy of Sciences Publication Activity Database

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

    2016-01-01

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

  3. Polynomial kernels for deletion to classes of acyclic digraphs

    NARCIS (Netherlands)

    Mnich, Matthias; van Leeuwen, E.J.

    2017-01-01

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

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

    NARCIS (Netherlands)

    Duval, F.L.

    2015-01-01

    Florine Duval - New applications of the interaction between diols and boronic acids – Summary

    Chapter 1 introduces the theory and known applications of the interaction between boronic acids and diols, and explains the context of this thesis. Diagnosis of

  5. Synthesis and complexation characteristics of phenanthroline and bipyridine diols

    NARCIS (Netherlands)

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

    2004-01-01

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

  6. On Event Detection and Localization in Acyclic Flow Networks

    KAUST Repository

    Suresh, Mahima Agumbe

    2013-05-01

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

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

    KAUST Repository

    Agumbe Suresh, Mahima

    2012-01-03

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

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    within few seconds prior to reaching a steady state. Exchange between the acyclic intermediates increases at conditions that favor epimerization. Species accounting for less than 0.05% of total glucose can be monitored with sub-second time resolution to allow kinetic analysis of intermediate formation...... and catalytic conversion. Epimerization occurs 2-3 orders of magnitude-fold faster than the binding of acyclic glucose to the catalyst at near-optimum reaction conditions. The current study brings insight in to the nature of acyclic intermediate-catalyst complexes of very low population and into experimental...... strategies for characterizing very minor intermediates in carbohydrate conversion to value-added compounds....

  9. An Algorithm for Determining Minimal Reduced—Coverings of Acyclic Database Schemes

    Institute of Scientific and Technical Information of China (English)

    刘铁英; 叶新铭

    1996-01-01

    This paper reports an algoritm(DTV)for deermining the minimal reducedcovering of an acyclic database scheme over a specified subset of attributes.The output of this algotithm contains not only minimum number of attributes but also minimum number of partial relation schemes.The algorithm has complexity O(|N|·|E|2),where|N| is the number of attributes and |E|the number of relation schemes.It is also proved that for Berge,γ or β acyclic database schemes,the output of algorithm DTV maintains the acyclicity correspondence.

  10. Highly selective Ba2+ separations with acyclic, lipophilic di-[N-(X)sulfonyl carbamoyl] polyethers.

    Science.gov (United States)

    Elshani, Sadik; Chun, Sangki; Amiri-Eliasi, Bijan; Bartsch, Richard A

    2005-01-14

    New lipophilic acyclic polyethers with two N-(X)sulfonyl carbamoyl groups of "tunable" acidity exhibit remarkable selectivity for Ba2+ over other alkaline earth metal ions in competitive solvent extraction and transport across polymer inclusion membranes.

  11. Outstanding effects on antithrombin activity of modified TBA diastereomers containing an optically pure acyclic nucleotide analogue.

    Science.gov (United States)

    Scuotto, M; Persico, M; Bucci, M; Vellecco, V; Borbone, N; Morelli, E; Oliviero, G; Novellino, E; Piccialli, G; Cirino, G; Varra, M; Fattorusso, C; Mayol, L

    2014-07-28

    Herein, we report optically pure modified acyclic nucleosides as ideal probes for aptamer modification. These new monomers offer unique advantages in exploring the role played in thrombin inhibition by a single residue modification at key positions of the TBA structure.

  12. Comparison of construction algorithms for minimal, acyclic, deterministic, finite-state automata from sets of strings

    NARCIS (Netherlands)

    Daciuk, J; Champarnaud, JM; Maurel, D

    2003-01-01

    This paper compares various methods for constructing minimal, deterministic, acyclic, finite-state automata (recognizers) from sets of words. Incremental, semi-incremental, and non-incremental methods have been implemented and evaluated.

  13. Selective discrimination of cyclodextrin diols using cyclic sulfates

    DEFF Research Database (Denmark)

    Petrillo, Marta; Marinescu, Lavinia; Rousseau, Cyril

    2009-01-01

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

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

    Science.gov (United States)

    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. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

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

    Science.gov (United States)

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

    2016-01-01

    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

  16. Decomposition of 2-((2-methoxyphenyl)diazenyl)benzene-1,3,5-triol molecule by an argon plasma jet

    Science.gov (United States)

    Tanışlı, Murat; Taşal, Erol

    2018-05-01

    In this study, we have presented the effects of the argon plasma on a 2-((2-methoxyphenyl)diazenyl)benzene-1,3,5-triol molecule—AZO compound (abbreviated as 2MDB)—under atmospheric pressure. In order to do this, the validated molecule has been considered and plasma has been used to modify it. The atmospheric pressure plasma jet system was specially designed for performing decomposing processes of the 2MDB molecule. The characterizations before and after the application of plasma—which takes only 3 minutes under atmospheric pressure conditions, to dissolve the 2MDB molecule in ethanol and methanol solutions—were examined using the Fourier transform infrared and Ultraviolet-Visible (UV-Vis) spectroscopies. After the plasma treatment, the molecule was broken at -C-N=N-C-C bond. Accurate and important changes are seen clearly from the results. In addition, according to UV-Vis spectra, π-π* electronic transitions related to -N=N- AZO bridge for the 2MDB molecule in polar-aprotic solvents such as ethanol and methanol were recorded as strong transitions. The new photoproducts such as -C-N-N=C and C=O were obtained from the 2MDB molecule.

  17. Measurement and modelling of urea solubility in aqueous propane-1,2,3-triol and prop-2-enoic acid solutions

    International Nuclear Information System (INIS)

    Santos, Jéssica dos J; Rocha, João A.A.B.; Costa, Glória M.N.; Cabral-Albuquerque, Elaine C.M.; Alves, Tito L.M.; Pinto, José C.; Fialho, Rosana L.

    2016-01-01

    Highlights: • Solubilities were shown to increase with temperature and to decrease with the increasing organic solvent content. • The UNIFAC method provided good fitting of the available data, after the estimation of a single model parameter. • The empirical method showed to be more efficient to describe several solution concentrations however, it is not predictive. - Abstract: The aim of the present study is to measure the solubility of urea in aqueous solutions of prop-2-enoic acid and propane-1,2,3-triol, as these compounds are used as co-monomers to produce urea base co-polymers. Experimental values have been obtained at several concentrations and temperatures. Solubility results were modelled with the help of an exponential empirical correlation, ideal solid-liquid equilibrium correlation and the Universal Functional Activity Coefficient (UNIFAC) method, used to describe the activity coefficient in the liquid phase. The empirical correlation requires two empirical parameters for each solvent and leads to the best fit for the available data. The UNIFAC method correlation also has a good numerical performance and is completely predictive, and it does not require the estimation of additional parameters.

  18. Learning directed acyclic graphs from large-scale genomics data.

    Science.gov (United States)

    Nikolay, Fabio; Pesavento, Marius; Kritikos, George; Typas, Nassos

    2017-09-20

    In this paper, we consider the problem of learning the genetic interaction map, i.e., the topology of a directed acyclic graph (DAG) of genetic interactions from noisy double-knockout (DK) data. Based on a set of well-established biological interaction models, we detect and classify the interactions between genes. We propose a novel linear integer optimization program called the Genetic-Interactions-Detector (GENIE) to identify the complex biological dependencies among genes and to compute the DAG topology that matches the DK measurements best. Furthermore, we extend the GENIE program by incorporating genetic interaction profile (GI-profile) data to further enhance the detection performance. In addition, we propose a sequential scalability technique for large sets of genes under study, in order to provide statistically significant results for real measurement data. Finally, we show via numeric simulations that the GENIE program and the GI-profile data extended GENIE (GI-GENIE) program clearly outperform the conventional techniques and present real data results for our proposed sequential scalability technique.

  19. Specific acyclic isoprenoids as biological markers of methanogenic bacteria in marine sediments.

    Science.gov (United States)

    Brassell, S C; Wardroper, A M; Thomson, I D; Maxwell, J R; Eglinton, G

    1981-04-23

    The widespread occurrence of extended hopanoids in sediments and petroleums illustrates the importance of bacterial lipid contributions to geological materials. In archaebacteria, however, hopanoids are absent; their role as structural components of biomembranes is fulfilled by acyclic isoprenoids. Recent studies of the lipid constituents of archaebacteria have greatly extended the range of acyclic isoprenoid skeletons known in organisms (Fig. 1). In particularly, isoprenoids with head-to-head linkages have been identified, and such compounds (for example, 3,7,11,15,18,22,26,30-octamethyldotriacontane, I) have been recognized in petroleum and as degradation products of Messel shale kerogen. Here we report the first recognition of 2,6,10,15,19-pentamethyleicosane (II), a known component of methanogens, in marine sediments of Recent to Cretaceous age (Table 1) and suggest that it and certain other acyclic isoprenoids may be used as biological markers for methanogens.

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

    Science.gov (United States)

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

    2017-06-07

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2007-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

    Elbert, Tomáš; Břehová, Petra; Holý, Antonín

    2010-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2009-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2016-01-01

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

  6. Existence principles for inclusions of Hammerstein type involving noncompact acyclic multivalued maps

    Directory of Open Access Journals (Sweden)

    Jean-Francois Couchouron

    2002-01-01

    Full Text Available We apply Monch type fixed point theorems for acyclic multivalued maps to the solvability of inclusions of Hammerstein type in Banach spaces. Our approach makes possible to unify and improve the existence theories for nonlinear evolution problems and abstract integral inclusions of Volterra and Fredholm type.

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

    Czech Academy of Sciences Publication Activity Database

    Zídek, Zdeněk; Kmoníčková, Eva; Holý, Antonín

    2007-01-01

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

  8. A new recursive incremental algorithm for building minimal acyclic deterministic finite automata

    NARCIS (Netherlands)

    Watson, B.W.; Martin-Vide, C.; Mitrana, V.

    2003-01-01

    This chapter presents a new algorithm for incrementally building minimal acyclic deterministic finite automata. Such minimal automata are a compact representation of a finite set of words (e.g. in a spell checker). The incremental aspect of such algorithms (where the intermediate automaton is

  9. Metabolism of acyclic and cyclic N-nitroamines by cultured human colon

    DEFF Research Database (Denmark)

    Autrup, Herman; Harris, Curtis C.; Trump, Benjamin F.

    1978-01-01

    Cultured human colon mucosa was found to metabolize both acyclic and cyclic N-nitrosamines as measured by 14C-CO2 formation and reaction of the activated moieties with cellular macromolecules. Dimethylnitrosamine and N-nitrosopyrrolidine were metabolized by explants from all patients studied. A p...

  10. Determination of 3-Monochloropropane-1,2-diol and 2-Monochloropropane-1,3-diol (MCPD) Esters and Glycidyl Esters by Microwave Extraction in Different Foodstuffs.

    Science.gov (United States)

    Marc, Corinne; Drouard-Pascarel, Valérie; Rétho, Cécile; Janvion, Patrice; Saltron, Frédéric

    2016-06-01

    This paper describes a method for the determination of 3-monochloropropane-1,2-diol and 2-monochloropropane-1,3-diol (MCPD) esters and glycidyl esters in various foodstuffs, which are isolated using microwave extraction. The next step is based on alkaline-catalyzed ester cleavage. The released glycidol is transformed into monobromopropanediol (MBPD). All compounds are derivatized in free diols (MCPD and MBPD) with phenylboronic acid and analyzed by gas chromatography-mass spectrometry (GC-MS). The method was validated for oils with a limit of quantitation (LOQ) of 0.1 mg/kg, for chips and crisps with a LOQ of 0.02 mg/kg, and for infant formula with a LOQ of 0.0025 mg/L. Recoveries of each sample were controlled by standard addition on extracts before derivatization. Quantitation was performed by the addition of isotopically labeled glycidyl and 3-monochloropropane-1,2-diol (3-MCPD) esters.

  11. Design and Synthesis of 2-Alkylpyrimidine-4,6-diol and 6-Alkylpyridine-2,4-diol as Potent GPR84 Agonists.

    Science.gov (United States)

    Liu, Yang; Zhang, Qing; Chen, Lin-Hai; Yang, Hui; Lu, Wei; Xie, Xin; Nan, Fa-Jun

    2016-06-09

    A series of alkylpyrimidine-4,6-diol derivatives were designed and synthesized as novel GRP84 agonists based on a high-throughput screening (HTS) hit 1. 6-Nonylpyridine-2,4-diol was identified as the most potent agonist of GPR84 reported so far, with an EC50 of 0.189 nM. These novel GPR84 agonists will provide valuable tools for the study of the physiological functions of GPR84.

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

    Science.gov (United States)

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

    2017-12-01

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

  13. Ultrasound-assisted catalytic synthesis of acyclic imides in the presence of p-toluenesulfonic acid under solvent free conditions

    Directory of Open Access Journals (Sweden)

    Nasr-Esfahani Masoud

    2012-01-01

    Full Text Available A rapid and convenient preparation of acyclic imides by the reaction of aliphatic and aromatic nitriles with acyclic carboxylic anhydride in the presence of catalytic amounts of p-toluenesulfonic acid under thermal or ultrasonic conditions is reported. The advantages of this procedure are moderate reaction times, good to excellent yields, use of inexpensive and ecofriendly catalyst. The reaction of nitriles with aliphatic anhydrides proceeds in thermal conditions, while by the use of ultrasound irradiations these reactions get accelerated.

  14. Acyclic Ketones in the Defensive Secretion of a “Daddy Longlegs” (Leiobunum vittatum)

    Science.gov (United States)

    Meinwald, J.; Kluge, A. F.; Carrel, J. E.; Eisner, T.

    1971-01-01

    The defensive secretion of the “daddy longlegs” Leiobunum vittatum was analyzed and found to contain the acyclic ketones 4-methylheptan-3-one and E-4,6-dimethyl-6-octen-3-one as its major organic components. Although 4-methylheptan-3-one has been found previously as an alarm substance in certain ant genera, the second component, whose structure is confirmed by synthesis, is new. PMID:5283937

  15. Acyclic ketones in the defensive secretion of a "daddy longlegs" (Leiobunum vittatum).

    Science.gov (United States)

    Meinwald, J; Kluge, A F; Carrel, J E; Eisner, T

    1971-07-01

    The defensive secretion of the "daddy longlegs" Leiobunum vittatum was analyzed and found to contain the acyclic ketones 4-methylheptan-3-one and E-4,6-dimethyl-6-octen-3-one as its major organic components. Although 4-methylheptan-3-one has been found previously as an alarm substance in certain ant genera, the second component, whose structure is confirmed by synthesis, is new.

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

    International Nuclear Information System (INIS)

    Mahajan, J.R.; Resck, I.S.; Braz Filho, R.; Carvalho, M.G. de

    1995-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2011-01-01

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

  18. Synthesis of alpha-Branched Acyclic Nucleoside Phosphonates as Potential Inhibitors of Bacterial Adenylate Cyclases

    Czech Academy of Sciences Publication Activity Database

    Frydrych, Jan; Skácel, Jan; Šmídková, Markéta; Mertlíková-Kaiserová, Helena; Dračínský, Martin; Gnanasekaran, Ramachandran; Lepšík, Martin; Soto-Velasquez, M.; Watts, V. J.; Janeba, Zlatko

    2018-01-01

    Roč. 13, č. 2 (2018), s. 199-206 ISSN 1860-7179 R&D Projects: GA MV VG20102015046; GA ČR(CZ) GBP208/12/G016; GA MŠk LO1302 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonates * adenylate cyclase toxin * bisamidates * Bordetella pertussis * prodrugs Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 3.225, year: 2016

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

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

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

  20. Synthesis, structural studies and biological properties of new TBA analogues containing an acyclic nucleotide.

    Science.gov (United States)

    Coppola, Teresa; Varra, Michela; Oliviero, Giorgia; Galeone, Aldo; D'Isa, Giuliana; Mayol, Luciano; Morelli, Elena; Bucci, Maria-Rosaria; Vellecco, Valentina; Cirino, Giuseppe; Borbone, Nicola

    2008-09-01

    A new modified acyclic nucleoside, namely N(1)-(3-hydroxy-2-hydroxymethyl-2-methylpropyl)-thymidine, was synthesized and transformed into a building block useful for oligonucleotide (ON) automated synthesis. A series of modified thrombin binding aptamers (TBAs) in which the new acyclic nucleoside replaces, one at the time, the thymidine residues were then synthesized and characterized by UV, CD, MS, and (1)H NMR. The biological activity of the resulting TBAs was tested by Prothrombin Time assay (PT assay) and by purified fibrinogen clotting assay. From a structural point of view, nearly all the new TBA analogues show a similar behavior as the unmodified counterpart, being able to fold into a bimolecular or monomolecular quadruplex structure depending on the nature of monovalent cations (sodium or potassium) coordinated in the quadruplex core. From the comparison of structural and biological data, some important structure-activity relationships emerged, particularly when the modification involved the TT loops. In agreement with previous studies we found that the folding ability of TBA analogues is more affected by modifications involving positions 4 and 13, rather than positions 3 and 12. On the other hand, the highest anti-thrombin activities were detected for aptamers containing the modification at T13 or T12 positions, thus indicating that the effects produced by the introduction of the acyclic nucleoside on the biological activity are not tightly connected with structure stabilities. It is noteworthy that the modification at T7 produces an ON being more stable and active than the natural TBA.

  1. Preparation and biological characteristics of 99mTc-diol a renal agent

    International Nuclear Information System (INIS)

    Castanheira, I.; Paulo, A.; Neves, M.; Patricio, L.; Sawas-Dimopoulou, C.

    1993-01-01

    The present work concerns the production of 1,2-dihydroxypropyl-1-phosphonic acid (diol) by acid hydrolysis of (-cis) 1,2-epoxypropylphosphonic acid (phosphomycin), and its formation as a kit easily labeled with [ 99m Tc]pertechnetate. Biodistribution studies and whole-body autoradiographies in mice show that 99m Tc-diol has a specific affinity for the kidneys: it is rapidly cleared from the blood and excreted in urine. Part of the injected activity remains in the kidney cortex sufficiently long to permit kidney imaging. In comparison with other agents which also localize in the kidney cortex, such as 99m Tc-DMSA and 99m Tc-glucoheptonate ( 99m Tc-GHA), the main differences are the following: the peak of renal activity is reached early in the 5 min post-injection period for 99m Tc-diol, only at about 10 min post-injection for 99m Tc-GHA and after 3 h post-injection for 99m Tc-DMSA. The uptake of 99m Tc-diol by other organs, especially by bones, is much smaller than in the case of 99m Tc-DMSA. Unlike 99m Tc-DMSA, the biodistribution of 99m Tc-diol is not significantly influenced by acid-base imbalance. Moreover, the retention effect of hyperuricemia on 99m Tc-diol blood clearance and kidney excretion could be the result of a competition mechanism between this radiopharmaceutical and uric acid for a common transport system. The above biological characteristics suggest that 99m Tc-diol is a kidney radiopharmaceutical with an ability for functional and imaging studies. (author)

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  3. Diurnal rhythms in gonadotropins and progesterone in lactating and photoperiod induced acyclic hamsters

    International Nuclear Information System (INIS)

    Bridges, R.S.; Goldman, B.D.

    1975-01-01

    Levels of LH, FSH, and progesterone in serum were measured in lactating hamsters and in hamsters in which acyclicity was induced with altered photoperiod. Lactating hamsters were found to have low titers of LH, FSH, and progesterone in serum at 0900 (lights on 0500--1900) on Days 4, 9, 14, and 19 of lactation and increased levels of these hormones at 1600. Levels of LH and FSH in serum at both 0900 and 1600 remained relatively constant throughout lactation. In contrast, levels of progesterone in serum obtained at both 0900 and 1600 sampling times increased as lactation progressed. Ovariectomy on Day 9 of lactation reduced serum levels of progesterone at both 0900 and 1600 and eliminated the afternoon surge in progesterone in animals bled 5 days after surgery. The levels and pattern of LH in serum remained unchanged after ovariectomy in lactating hamsters. However, serum FSH levels in the ovariectomized, lactating animals were elevated at both 0900 and 1600 when compared to levels present in intact, lactating hamsters bled at the same times. Females which were acyclic due to altered photoperiod displayed similar patterns of LH, FSH, and progesterone in serum. Levels of LH, FSH, and progesterone in serum were low at 1000 (lights on 0500--1500) and were increased 2 to 10 fold at 1500. Ovariectomy was followed by lower progesterone levels in serum at 1000 and 1500 and eliminated the afternoon rise of this hormone. Serum levels of LH were unaffected by ovariectomy. As in lactating hamsters, levels of FSH in serum were elevated 3--4 days following ovariectomy at both bleeding times, but the levels were higher at 1500. These results indicate that acyclicity induced by lactation or exposure to a short photoperiod is characterized by similar diurnal patterns of circulating hormones in the hamster

  4. Reaction of acyclic enaminones with methoxymethylene meldrum's acid: synthetic and structural implications

    OpenAIRE

    Cunha,Silvio; Silva,Viviane C. da; Napolitano,Hamilton B.; Lariucci,Carlito; Vencato,Ivo

    2003-01-01

    The reaction of acyclic enaminones with methoxymethylene Meldrum's acid afforded N-adduct and/or C-adduct of enaminones in moderate to good yields. The regiochemistry of this reaction depends on the N-amino substituent of the enaminone. The C-adduct is a precursor to 2-pyridones. X-ray analysis of two N-adducts were investigated and the Z-s-Z configuration assigned. A reação de enaminonas com o derivado metoximetilênico do ácido de Meldrum forneceu N-adutos e/ou C-adutos das enaminonas, em...

  5. Competitive solvent extraction of alkaline-earth cations into chloroform by lipophilic acyclic polyether dicarboxylic acids

    International Nuclear Information System (INIS)

    Kang, S.I.; Czech, A.; Czech, B.P.; Stewart, L.E.; Bartsch, R.A.

    1985-01-01

    Competitive solvent extraction of alkaline-earth cations from aqueous solutions into chloroform by a series of lipophilic acyclic polyether dicarboxylic acids is reported. The influence of polyether chain length and of terminal carboxylic acid group variation upon extraction selectivity and efficiency is assessed. In the competitive extraction of concentrated magnesium, calcium, strontium and barium chloride solutions, one complexing agent exhibits pronounced selectivity for barium with Ba 2+ /S 2+ = 50, Ba 2+ /Ca 2+ = 250, and no detectable Mg 2+ extraction. 20 references, 3 figures, 1 table

  6. The use of positron annihilation to study polyacrylamide and polymethylmethacrylate-Alcohols and diols mixture

    International Nuclear Information System (INIS)

    Mostafa, N.

    2007-01-01

    The effect of addition of both alcohols and diols to polyacrylamide (PAA) and polymethylmethacrylate (PMMA) forming polymer mixtures was studied using positron annihilation lifetime (PAL) and Doppler broadening of annihilation radiation (DBAR) techniques. It was found that, by increasing chain length of alcohols, PAA-alcohols contain free volume with small size V and low fraction f, while PMMA-alcohols contain free volume with large size and high fraction. On the other hand, S-parameter increases and W-parameter decreases in PAA-diols according to the number of carbon and hydrogen atoms in the chain. In addition, the electrical conductivity measurements are performed on the above two polymer mixtures. The results showed that both PAA and PMMA exhibit semiconducting properties by the addition of alcohols and diols. Correlation between the macroscopic conductivity properties and the microstructures such as free volume and microdefects are established

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

    Science.gov (United States)

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

    2014-09-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2016-05-03

    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.

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

    Science.gov (United States)

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

    2014-11-01

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

  11. Anti-1,2-Diols via Ni-Catalyzed Reductive Coupling of Alkynes and α-Oxyaldehydes

    Science.gov (United States)

    Luanphaisarnnont, Torsak; Ndubaku, Chudi O.; Jamison, Timothy F.

    2008-01-01

    Ni-catalyzed reductive coupling of aryl alkynes (1) and enantiomerically enriched α-oxyaldehydes (2) afford differentiated anti-1,2-diols (3) with high diastereoselectivity and regioselectivity, despite the fact that the methoxymethyl (MOM) and para-methoxybenzyl (PMB) protective groups typically favor syn-1,2-diol formation in carbonyl addition reactions of this family of aldehydes. PMID:15987174

  12. Regioselective Benzoylation of Diols and Carbohydrates by Catalytic Amounts of Organobase.

    Science.gov (United States)

    Lu, Yuchao; Hou, Chenxi; Ren, Jingli; Xin, Xiaoting; Xu, Hengfu; Pei, Yuxin; Dong, Hai; Pei, Zhichao

    2016-05-17

    A novel metal-free organobase-catalyzed regioselective benzoylation of diols and carbohydrates has been developed. Treatment of diol and carbohydrate substrates with 1.1 equiv. of 1-benzoylimidazole and 0.2 equiv. of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in MeCN under mild conditions resulted in highly regioselective benzoylation for the primary hydroxyl group. Importantly, compared to most commonly used protecting bulky groups for primary hydroxyl groups, the benzoyl protective group offers a new protection strategy.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    is believed to involve dehydrogenation of the 1,2‐diol to the α‐hydroxy aldehyde, which condenses with the amine to form the α‐hydroxy imine. The latter rearranges to the corresponding α‐amino carbonyl compound, which then reacts with another amine followed by reduction of the resulting imine.......A straightforward procedure is described for the synthesis of piperazines from amines and 1,2‐diols. The heterocyclization is catalyzed by [Cp*IrCl2]2 and sodium hydrogen carbonate and can be achieved with either toluene or water as solvent. The transformation does not require any stoichiometric...

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

    Directory of Open Access Journals (Sweden)

    Sanjay Kumar Singh

    2011-09-01

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

  15. Interaction of phosphates of the acyclic nucleoside phosphonates with nucleoside diphosphate kinase from yeast and bovine liver

    Czech Academy of Sciences Publication Activity Database

    Horská, Květoslava; Votruba, Ivan; Holý, Antonín

    2006-01-01

    Roč. 71, č. 1 (2006), s. 35-43 ISSN 0010-0765 R&D Projects: GA AV ČR(CZ) IBS4055109 Institutional research plan: CEZ:AV0Z40550506 Keywords : enzymatic phosphorylation * acyclic nucleotide analogs * NTP analogues Subject RIV: CC - Organic Chemistry Impact factor: 0.881, year: 2006

  16. The efficient synthesis of 2-arylpyrimidine acyclic nucleoside phosphonates using Liebeskind-Srogl cross-coupling reaction

    Czech Academy of Sciences Publication Activity Database

    Břehová, Petra; Česnek, Michal; Dračínský, Martin; Holý, Antonín; Janeba, Zlatko

    2011-01-01

    Roč. 67, č. 38 (2011), s. 7379-7385 ISSN 0040-4020 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : Liebeskind-Srogl cross - coupling * acyclic nucleoside phosphonates * pyrimidines * arylboronic acids * microwave Subject RIV: CC - Organic Chemistry Impact factor: 3.025, year: 2011

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

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2011-04-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Cuihong Wen

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

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

    Science.gov (United States)

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

    2016-01-01

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

  1. Polystyrene-Supported Acyclic Diaminocarbene Palladium Complexes in Sonogashira Cross-Coupling: Stability vs. Catalytic Activity

    Directory of Open Access Journals (Sweden)

    Vladimir N. Mikhaylov

    2018-04-01

    Full Text Available Two types of immobilized on the amino-functionalized polystyrene-supported acyclic diaminocarbene palladium complexes (ADC-PdII are investigated under Sonogashira cross-coupling conditions. Depending on substituents in the diaminocarbene fragment immobilized ADC-PdII, systems are found to have different catalytic activity and stability regarding Pd-leaching. PdII-diaminocarbenes possessing protons at both nitrogen atoms smoothly decompose into Pd0-containing species providing a catalytic “cocktail system” with high activity and ability to reuse within nine runs. Polymer-supported palladium (II complex bearing NBn–Ccarbene–NH-moiety exhibits greater stability while noticeably lower activity under Sonogashira cross-coupling. Four molecular ADC-PdII complexes are also synthesized and investigated with the aim of confirming proposed base-promoted pathway of ADC-PdII conversion through carbodiimide into an active Pd0 forms.

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

    Science.gov (United States)

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

    2017-10-02

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

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

    Directory of Open Access Journals (Sweden)

    Pramod K. Sahu

    2017-07-01

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

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

    Science.gov (United States)

    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 polyurethane provided a total sacrifice of 107–108 colony forming units per milliliter of Staphylococcus aureus (Gram-positive bacteria), Escherichia coli (Gram-negative bacteria), and Candida albicans (fungi) within 10 min and successfully prevented bacterial and fungal biofilm formation. The antimicrobial and biofilm-controlling effects were both durable and rechargeable, pointing to great potentials of the new acyclic N-halamine-immobilized polyurethane for a broad range of related applications. PMID:26089593

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-05-23

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

  6. Theoretic derivation of directed acyclic subgraph algorithm and comparisons with message passing algorithm

    Science.gov (United States)

    Ha, Jeongmok; Jeong, Hong

    2016-07-01

    This study investigates the directed acyclic subgraph (DAS) algorithm, which is used to solve discrete labeling problems much more rapidly than other Markov-random-field-based inference methods but at a competitive accuracy. However, the mechanism by which the DAS algorithm simultaneously achieves competitive accuracy and fast execution speed, has not been elucidated by a theoretical derivation. We analyze the DAS algorithm by comparing it with a message passing algorithm. Graphical models, inference methods, and energy-minimization frameworks are compared between DAS and message passing algorithms. Moreover, the performances of DAS and other message passing methods [sum-product belief propagation (BP), max-product BP, and tree-reweighted message passing] are experimentally compared.

  7. Pd-Catalyzed N-Arylation of Secondary Acyclic Amides: Catalyst Development, Scope, and Computational Study

    Science.gov (United States)

    Hicks, Jacqueline D.; Hyde, Alan M.; Cuezva, Alberto Martinez; Buchwald, Stephen L.

    2009-01-01

    We report the efficient N-arylation of acyclic secondary amides and related nucleophiles with aryl nonaflates, triflates, and chlorides. This method allows for easy variation of the aromatic component in tertiary aryl amides. A new biaryl phosphine with P-bound 3,5-(bis)trifluoromethylphenyl groups was found to be uniquely effective for this amidation. The critical aspects of the ligand were explored through synthetic, mechanistic, and computational studies. Systematic variation of the ligand revealed the importance of (1) a methoxy group on the aromatic carbon of the “top ring” ortho to the phosphorus and (2) two highly electron-withdrawing P-bound 3,5-(bis)trifluoromethylphenyl groups. Computational studies suggest the electron-deficient nature of the ligand is important in facilitating amide binding to the LPd(II)(Ph)(X) intermediate. PMID:19886610

  8. The effect of maturation on the configurations of acyclic isoprenoid acids in sediments

    Science.gov (United States)

    Mackenzie, A. S.; Patience, R. L.; Yon, D. A.; Maxwell, J. R.

    1982-05-01

    Within a variety of sedimentary rocks of differing maturity, the configurations of a suite of acyclic isoprenoid acids have been examined by gas Chromatographic (in a few cases also by combined gas chromatography-mass spectrometry) analysis of their diastereoisomeric methyl and (-)-menthyl esters. The samples include the Eocene Messel (Germany) and Green River (U.S.) shales, the Permian Irati shale (Brazil) and a number of Lower Toarcian shales from the Paris Basin. The isomer distributions show that isomerisation occurs at the chiral centres with increasing maturation (to increase the number of isomers) and that the rate of isomerisation increases for centres (C-2,C-3) closest to the carboxyl group. These results suggest that adsorption of the carboxyl group to a catalyst surface may control the isomerisation rates by way of access to the catalyst.

  9. Influence of Two Acyclic Homoterpenes (Tetranorterpenes) on the Foraging Behavior of Anthonomus grandis Boh.

    Science.gov (United States)

    Magalhães, D M; Borges, M; Laumann, R A; Woodcock, C M; Pickett, J A; Birkett, M A; Blassioli-Moraes, Maria Carolina

    2016-04-01

    Previous studies have shown that the boll weevil, Anthonomus grandis, is attracted to constitutive and conspecific herbivore-induced cotton volatiles, preferring the blend emitted by cotton at the reproductive over the vegetative stage. Moreover, this preference was paralleled by the release of the acyclic homoterpenes (tetranorterpenes) (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) in Delta Opal cotton being higher at the vegetative than at the reproductive stage. Here, we evaluated whether this difference in release of acyclic homoterpenes also occurred in other cotton varieties, and if boll weevils could recognize these compounds as indicators of a specific cotton phenological stage. Results showed that cotton genotypes CNPA TB-90, BRS-293 and Delta Opal all produced higher levels of DMNT and TMTT at the vegetative stage than at the reproductive stage and that these homoterpenes allowed for principal component analysis separation of volatiles produced by the two phenological stages. Electroantennograms confirmed boll weevil antennal responses to DMNT and TMTT. Behavioral assays, using Y-tube olfactometers, showed that adding synthetic homoterpenes to reproductive cotton volatiles (mimicking cotton at the vegetative stage in terms of homoterpene levels) resulted in reduced attraction to boll weevils compared to that to unmodified reproductive cotton. Weevils showed no preference when given a choice between plants at the vegetative stage and the vegetative stage-mimicked plant. Altogether, the results show that DMNT and TMTT are used by boll weevils to distinguish between cotton phenological stages.

  10. New acyclic secondary metabolites from the biologically active fraction of Albizia lebbeck flowers.

    Science.gov (United States)

    Al-Massarani, Shaza M; El Gamal, Ali A; Abd El Halim, Mohamed F; Al-Said, Mansour S; Abdel-Kader, Maged S; Basudan, Omer A; Alqasoumi, Saleh I

    2017-01-01

    The total extract of Albizia lebbeck flowers was examined in vivo for its possible hepatoprotective activity in comparison with the standard drug silymarin at two doses. The higher dose expressed promising activity especially in reducing the levels of AST, ALT and bilirubin. Fractionation via liquid-liquid partition and reexamination of the fractions revealed that the n -butanol fraction was the best in improving liver biochemical parameters followed by the n -hexane fraction. However, serum lipid parameters were best improved with CHCl 3 fraction. The promising biological activity results initiated an intensive chromatographic purification of A. lebbeck flowers fractions. Two compounds were identified from natural source for the first time, the acyclic farnesyl sesquiterpene glycoside1-O-[6-O- α -l-arabinopyranosyl- β -d-glucopyranoside]-(2 E ,6 E -)-farnesol ( 6 ) and the squalene derivative 2,3-dihydroxy-2,3-dihydrosqualene ( 9 ), in addition to eight compounds reported here for the first time from the genus Albizia ; two benzyl glycosides, benzyl 1-O- β -d-glucopyranoside ( 1 ) and benzyl 6-O- α -l-arabinopyranosyl β -d-glucopyranoside ( 2 ); three acyclic monoterpene glycosides, linalyl β -d-glucopyranoside ( 3 ) and linalyl 6-O- α -l-arabinopyranosyl- β -d-glucopyranoside ( 4 ); (2 E )-3,7-dimethylocta-2,6-dienoate-6-O- α -l arabinopyranosyl- β -d-glucopyranoside ( 5 ), two oligoglycosides, n -hexyl- α -l arabinopyranosyl-(1 → 6)- β -d-glucopyranoside (creoside) ( 7 ) and n -octyl α -l-arabinopyranosyl-(1 → 6)- β -d-glucopyranoside (rhodiooctanoside) ( 8 ); and ethyl fructofuranoside ( 10 ). The structures of the isolated compounds were elucidated based on extensive examination of their spectroscopic 1D and 2D-NMR, MS, UV, and IR data. It is worth mentioning that, some of the isolated linalol glycoside derivatives were reported as aroma precursors.

  11. New acyclic secondary metabolites from the biologically active fraction of Albizia lebbeck flowers

    Directory of Open Access Journals (Sweden)

    Shaza M. Al-Massarani

    2017-01-01

    Full Text Available The total extract of Albizia lebbeck flowers was examined in vivo for its possible hepatoprotective activity in comparison with the standard drug silymarin at two doses. The higher dose expressed promising activity especially in reducing the levels of AST, ALT and bilirubin. Fractionation via liquid–liquid partition and reexamination of the fractions revealed that the n-butanol fraction was the best in improving liver biochemical parameters followed by the n-hexane fraction. However, serum lipid parameters were best improved with CHCl3 fraction. The promising biological activity results initiated an intensive chromatographic purification of A. lebbeck flowers fractions. Two compounds were identified from natural source for the first time, the acyclic farnesyl sesquiterpene glycoside1-O-[6-O-α-l-arabinopyranosyl-β-d-glucopyranoside]-(2E,6E--farnesol (6 and the squalene derivative 2,3-dihydroxy-2,3-dihydrosqualene (9, in addition to eight compounds reported here for the first time from the genus Albizia; two benzyl glycosides, benzyl 1-O-β-d-glucopyranoside (1 and benzyl 6-O-α-l-arabinopyranosyl β-d-glucopyranoside (2; three acyclic monoterpene glycosides, linalyl β-d-glucopyranoside (3 and linalyl 6-O-α-l-arabinopyranosyl-β-d-glucopyranoside (4; (2E-3,7-dimethylocta-2,6-dienoate-6-O-α-l arabinopyranosyl-β-d-glucopyranoside (5, two oligoglycosides, n-hexyl-α-l arabinopyranosyl-(1 → 6-β-d-glucopyranoside (creoside (7 and n-octyl α-l-arabinopyranosyl-(1 → 6-β-d-glucopyranoside (rhodiooctanoside (8; and ethyl fructofuranoside (10. The structures of the isolated compounds were elucidated based on extensive examination of their spectroscopic 1D and 2D-NMR, MS, UV, and IR data. It is worth mentioning that, some of the isolated linalol glycoside derivatives were reported as aroma precursors.

  12. Enzymatic monoesterification of symmetric diols: restriction of molecular conformations influences selectivity.

    Science.gov (United States)

    Tomer, Sanjiv O; Soni, Hemant P

    2017-10-31

    We have experimentally demonstrated that by 'locking' the molecular conformation through the introduction of a double or triple bond in the center of a symmetric diol, enzymatic monoesterification can be achieved selectively. The enzyme Candida antarctica lipase B, generally used for the transesterification of diols, can be effectively used for the monoesterification of symmetrical diols in an unbuffered system also. By varying the chain length of a carboxylic acid moiety, we have established that optimum selectivity and efficiency can be achieved in the range of 4.8 to 5.0 pK a values. Selectivity can be improved up to 98.75% for a monoester in an overall 73% yield (mixture of a monoester and a diester) when but-2-yne-1,4-diol reacted with hexanoic acid. Water, a by-product, provides an interfacial environment for the enzyme to work in the organic reaction medium. The uniqueness of the reported monoesterification protocol is that it involves only the mechanical stirring of the reaction mixture at room temperature in the presence of the enzyme for 24 h. High percentage yield with selectivity for a monoester, easier product isolation and overall, environmental sustainability are added advantages. The synthesized monoesters are characterized by using HNMR and high resolution mass spectrometry (HRMS).

  13. Synthesis of enantiomerically pure thiocrown ethers derived from 1,1'-binaphthalene-2,2'-diol

    NARCIS (Netherlands)

    Stock, H. Thijs; Kellogg, Richard M.

    1996-01-01

    Synthetic methodology is given for the preparation of two different types of thiocrown ethers from optically pure 1,1'-binaphthalene-2,2'-diol (10). The conceptually simplest approach starts from optically pure 10 itself, which is alkylated (4 equiv of K2CO3 in DMF at 110 degrees C) with

  14. Thermoplastic poly(urethane urea)s from novel, bio-based amorphous polyester diols

    NARCIS (Netherlands)

    Tang, D.; Noordover, B.A.J.; Sablong, R.J.; Koning, C.E.

    2012-01-01

    In this study, two novel, bio-based, amorphous polyester diols, namely poly(1,2-dimethylethylene adipate) (PDMEA) and poly(1,2-dimethylethylene succinate) (PDMES) are used to prepare thermoplastic poly(urethane urea)s (TPUUs). Interestingly, the TPUUs based on PDMEA show similar thermal and

  15. 211At-Rh(16-S4-diol) complex as a precursor for astatine radiopharmaceuticals

    International Nuclear Information System (INIS)

    Pruszynski, M.; Bilewicz, A.

    2006-01-01

    211 At 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 211 At 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). Rh 3+ 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) d 6 complexes. The 16-S4-diol ligand was selected due to formation of stable complexes with Rh 3+ . The experiments related to optimization of the reaction conditions were performed with the 131 I, basing on a chemical similarity of I - to At - . The experiments with 211 At 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 211 At-Rh(16-S4-diol) complex

  16. Microbial Stereoselective One-Step Conversion of Diols to Chiral Lactones in Yeast Cultures

    Directory of Open Access Journals (Sweden)

    Filip Boratyński

    2015-12-01

    Full Text Available It has been shown that whole cells of different strains of yeast catalyze stereoselective oxidation of meso diols to the corresponding chiral lactones. Among screening-scale experiments, Candida pelliculosa ZP22 was selected as the most effective biocatalyst for the oxidation of monocyclic diols 3a–b with respect to the ratio of high conversion to stereoselectivity. This strain was used in the preparative oxidation, affording enantiomerically-enriched isomers of lactones: (+-(3aR,7aS-cis-hexahydro-1(3H -isobenzofuranone (2a and (+-(3aS,4,7,7aR-cis-tetrahydro-1(3H-isobenzofuranone (2b. Scaling up the culture growth, as well as biotransformation conditions has been successfully accomplished. Among more bulky substrates, bicyclic diol 3d was totally converted into enantiomerically-pure exo-bridged (+-(3aR,4S,7R,7aS-cis-tetrahydro-4,7-methanoisobenzofuran -1(3H-one (2d by Yarrovia lipolytica AR71. Microbial oxidation of diol 3f by Candida sake AM908 and Rhodotorula rubra AM4 afforded optically-pure cis-3-butylhexahydro-1(3H -isobenzofuranone (2f, however with low conversion.

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

    NARCIS (Netherlands)

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2015-04-01

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

  19. Chiral 1,2- and 1,3-diol-functionalized chromophores as Lego building blocks for coupled structures.

    Science.gov (United States)

    Spange, Stefan; Hofmann, Katja; Walfort, Bernhard; Rüffer, Tobias; Lang, Heinrich

    2005-10-14

    Chiral nitroanilines containing 1,2- or 1,3-diol functionalities have been synthesized by nucleophilic aromatic substitution of fluoronitroanilines with 1-aminopropane-2,3-diols and 2-aminopropane-1,3-diol in the melt. X-ray structure analyses confirm retention of the configuration of the chiral center. The novel chromophores are suitable to link reversibly to various substituted arylboronic acids which allows the construction of new solvatochromic sensor molecules suitable to response to solvent and anion coordination by fluoride. The solvatochromism of the new compounds has been studied using the Kamlet-Taft LSE relationship.

  20. Investigating temporary acyclicity in a captive group of Asian elephants (Elephas maximus): Relationship between management, adrenal activity and social factors.

    Science.gov (United States)

    Edwards, Katie L; Trotter, Jessica; Jones, Martin; Brown, Janine L; Steinmetz, Hanspeter W; Walker, Susan L

    2016-01-01

    Routine faecal steroid monitoring has been used to aid the management of five captive Asian elephant (Elephas maximus) females at Chester Zoo, UK, since 2007. Progestagen analysis initially revealed synchronised oestrous cycles among all females. However, a 14- to 20-week period of temporary acyclicity subsequently occurred in three females, following several management changes (increased training, foot-care and intermittent matriarch removal for health reasons) and the initiation of pregnancy in another female. The aim of this study was to retrospectively investigate whether these management changes were related to increased adrenal activity and disruption of ovarian activity, or whether social factors may have been involved in the temporary cessation of cyclicity. Faecal samples collected every other day were analysed to investigate whether glucocorticoid metabolites were related to reproductive status (pregnant, cycling, acyclic) or management (training, foot-care, matriarch presence). Routine training and foot-care were not associated with adrenal activity; however, intensive foot-care to treat an abscess in one female was associated with increased glucocorticoid concentration. Matriarch presence influenced adrenal activity in three females, being lower when the matriarch was separated from the group at night compared to being always present. However, in the females that exhibited temporary acyclicity, there was no consistent relationship between glucocorticoids and cyclicity state. Although the results of this study do not fully explain this occurrence, the highly synchronised nature of oestrous cycles within this group, and the concurrent acyclicity in three females, raises the question of whether social factors could have been involved in the temporary disruption of ovarian activity. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    Czech Academy of Sciences Publication Activity Database

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

    2009-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2016-01-01

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

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

    KAUST Repository

    Bruno, Mark

    2016-09-29

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

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

    KAUST Repository

    Bruno, Mark; Koschmieder, Julian; Wuest, Florian; Schaub, Patrick; Fehling-Kaschek, Mirjam; Timmer, Jens; Beyer, Peter; Al-Babili, Salim

    2016-01-01

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

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

    Science.gov (United States)

    Bruno, Mark; Koschmieder, Julian; Wuest, Florian; Schaub, Patrick; Fehling-Kaschek, Mirjam; Timmer, Jens; Beyer, Peter; Al-Babili, Salim

    2016-01-01

    The Arabidopsis carotenoid cleavage dioxygenase 4 (AtCCD4) is a negative regulator of the carotenoid content of seeds and has recently been suggested as a candidate for the generation of retrograde signals that are thought to derive from the cleavage of poly-cis-configured carotene desaturation intermediates. In this work, we investigated the activity of AtCCD4 in vitro and used dynamic modeling to determine its substrate preference. Our results document strict regional specificity for cleavage at the C9–C10 double bond in carotenoids and apocarotenoids, with preference for carotenoid substrates and an obstructing effect on hydroxyl functions, and demonstrate the specificity for all-trans-configured carotenes and xanthophylls. AtCCD4 cleaved substrates with at least one ionone ring and did not convert acyclic carotene desaturation intermediates, independent of their isomeric states. These results do not support a direct involvement of AtCCD4 in generating the supposed regulatory metabolites. In contrast, the strigolactone biosynthetic enzyme AtCCD7 converted 9-cis-configured acyclic carotenes, such as 9-cis-ζ-carotene, 9'-cis-neurosporene, and 9-cis-lycopene, yielding 9-cis-configured products and indicating that AtCCD7, rather than AtCCD4, is the candidate for forming acyclic retrograde signals. PMID:27811075

  8. 4 Birds 1 Stone to Inhibit 5androstane-3alpha,17beta-diol Conversion to DHT

    Science.gov (United States)

    2016-09-01

    Award Number: W81XWH-15-1-0409 TITLE: 4 Birds 1 Stone to Inhibit 5androstane-3alpha,17beta-diol Conversion to DHT PRINCIPAL INVESTIGATOR...SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-04094 Birds 1 Stone to Inhibit 5androstane-3alpha,17beta-diol Conversion to DHT 5c...testicular androgens, testosterone or dihydrotestosterone ( DHT ). Men diagnosed with advanced prostate cancer or failure potentially curative therapy are

  9. Isomerization of 2-butene-1,4-diol in aqueous solutions catalyzed by palladium(II) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Kalabin, S.M.; Novikov, N.A.; Belov, A.P.

    1989-02-01

    The authors studied the isomerization of 2-butene-1,4-diol into 3-butene-1,2-diol at 18-25/degree/C. The concentrations of the diol and PdCl/sub 2/ were (1.0-5.0) /times/ 10/sup /minus/2/ mole/liter at 5-10-fold excess amounts of HCl and NaCl. These additives were used because of their inhibiting action on the oxidation of olefinic compounds. 3-Butene-1,2-diol was identified by /sup 1/H NMR method directly in the reaction solutions in which the reaction solutions in which the reactions in D/sub 2/O were carried out. It was found that palladium(II) complexes catalyze the isomerization of 2-butene-1,4-diol into 3-butene-1,2-diol. A mechanism is proposed for the reaction, which includes the intermediate formation of /eta//sup 3/-allyl complex of palladium with a coordinated hydroxyl group.

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

    Czech Academy of Sciences Publication Activity Database

    Bubnov, Alexej; Kašpar, Miroslav; Sedláková, Zdeňka

    2010-01-01

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

  11. Crystallization of DNA fragments from water-salt solutions, containing 2-methylpentane-2,3-diol.

    Science.gov (United States)

    Osica, V D; Sukharevsky, B Y; Vasilchenko, V N; Verkin, B I; Polyvtsev, O F

    1976-09-01

    Fragments of calf thymus DNA have been crystallized by precipitation from water-salt solutions, containing 2-methylpentane-2,3-diol (MPD). DNA crystals usually take the form either of spherulites up to 100 mu in diameter or of needles with the length up to 50 mu. No irreversible denaturation of DNA occurs during the crystallization process. X-ray diffraction from dense slurries of DNA crystals yields crystalline powder patterns.

  12. Directed acyclic graphs (DAGs): an aid to assess confounding in dental research.

    Science.gov (United States)

    Merchant, Anwar T; Pitiphat, Waranuch

    2002-12-01

    Confounding, a special type of bias, occurs when an extraneous factor is associated with the exposure and independently affects the outcome. In order to get an unbiased estimate of the exposure-outcome relationship, we need to identify potential confounders, collect information on them, design appropriate studies, and adjust for confounding in data analysis. However, it is not always clear which variables to collect information on and adjust for in the analyses. Inappropriate adjustment for confounding can even introduce bias where none existed. Directed acyclic graphs (DAGs) provide a method to select potential confounders and minimize bias in the design and analysis of epidemiological studies. DAGs have been used extensively in expert systems and robotics. Robins (1987) introduced the application of DAGs in epidemiology to overcome shortcomings of traditional methods to control for confounding, especially as they related to unmeasured confounding. DAGs provide a quick and visual way to assess confounding without making parametric assumptions. We introduce DAGs, starting with definitions and rules for basic manipulation, stressing more on applications than theory. We then demonstrate their application in the control of confounding through examples of observational and cross-sectional epidemiological studies.

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

    Directory of Open Access Journals (Sweden)

    Kazuhisa Murai

    2018-01-01

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

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

    Science.gov (United States)

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

    2004-05-07

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

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

    Science.gov (United States)

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

    2012-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Vangelis Smyrniotopoulos

    2017-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Kata Tuza

    2014-12-01

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

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

    International Nuclear Information System (INIS)

    Levitin, Gregory

    2002-01-01

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

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

    International Nuclear Information System (INIS)

    Levitin, Gregory

    2002-01-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

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

    OpenAIRE

    Batt , Frédéric

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-01

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

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

    Science.gov (United States)

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

    2015-04-21

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

  4. Simultaneous determination of cysteine, uric acid and tyrosine using Au-nanoparticles/poly(E)-4-(p-tolyldiazenyl)benzene-1,2,3-triol film modified glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Taei, M., E-mail: m.taei@ch.iut.ac.ir; Hasanpour, F.; Salavati, H.; Banitaba, S.H.; Kazemi, F.

    2016-02-01

    A novel Au nanoparticles/poly(E)-4-(p-tolyldiazenyl)benzene-1,2,3-triol (AuNPs/PTAT) film modified glassy carbon electrode (AuNPs/PTAT/GCE) was fabricated for the simultaneous determination of three antioxidants named, cysteine (Cys), uric acid (UA) and tyrosine (Tyr). The bare glassy carbon electrode (GCE) fails to separate the oxidation peak potentials of these molecules, while PTAT film modified electrode can resolve them. Electrochemical impedance spectroscopy (EIS) study indicates that the charge transfer resistance of bare electrode increased as (E)-4-(p-tolyldiazenyl)benzene-1,2,3-triol was electropolymerized at the bare electrode. Furthermore, EIS exhibits enhancement of electron transfer kinetics between analytes and electrode after electrodeposition of Au nanoparticles. Differential pulse voltammetry results show that the electrocatalytic current increases linearly in the ranges of 2–540 μmol L{sup −1} for Cys, 5–820 μmol L{sup −1} for UA and 10–560 μmol L{sup −1} for Tyr with detection limits (S/N = 3) of 0.04 μmol L{sup −1}, 0.1 μmol L{sup −1} and 2 μmol L{sup −1} for Cys, UA and Tyr, respectively. The proposed method was successfully applied for simultaneous determination of Cys, UA and Tyr in human urine samples. - Highlights: • AuNPs/PTAT/GCE was fabricated by electrodeposition and electropolymerization. • The sensor reduced the overpotential for oxidation of Cys. • This electrode was successfully used for simultaneous sensing of Cys, UA and Tyr. • This sensor was effectively used for detection Cys, UA and Tyr in real samples.

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

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

    2018-02-16

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

  7. Zirconium-doped magnetic microspheres for the selective enrichment of cis-diol-containing ribonucleosides.

    Science.gov (United States)

    Fan, Hua; Chen, Peihong; Wang, Chaozhan; Wei, Yinmao

    2016-05-27

    Zirconium-doped magnetic microspheres (Zr-Fe3O4) for the selective enrichment of cis-diol-containing biomolecules were easily synthesized via a one-step hydrothermal method. Characterization of the microspheres revealed that zirconium was successfully doped into the lattice of Fe3O4 at a doping level of 4.0 at%. Zr-Fe3O4 possessed good magnetic properties and high specificity towards cis-diol molecules, as shown using 28 compounds. For ribonucleosides, the adsorbent not only has favorable anti-interferential abilities but also has a high adsorption capacity up to 159.4μmol/g. As an example of a real application, four ribonucleosides in urine were efficiently enriched and detected via magnetic solid-phase extraction coupled with high-performance liquid chromatography. Under the optimized extraction conditions, the detection limits were determined to be between 0.005 and 0.017μg/mL, and the linearities ranged from 0.02 to 5.00μg/mL (R≥0.996) for these analytes. The accuracy of the analytical method was examined by studying the relative recoveries of the analytes in real urine samples, with recoveries varying from 77.8% to 119.6% (RSDs<10.6%, n=6). The results indicate that Zr-Fe3O4 is a suitable adsorbent for the analysis of cis-diol-containing biomolecules in practical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Ultrasonicated Synthesis of N-Benzyl-2,3-substituted Morpholines, via the Mitsunobu Diol Cyclisation

    Directory of Open Access Journals (Sweden)

    B. Jayachandra Reddy

    2010-01-01

    Full Text Available A facile five step synthesis of N-benzyl-2,3-substituted morpholines (i-iii was performed. The key steps were microwave assisted Friedel-crafts acylation and diol cyclization carried out via an ultra sonication of Mitsunobu reaction using DEAD (diethylazodicarboxylate, TPP in THF for 1 h. The morpholine products were generated as diasteriomers (ii andiii which has been separated by the column chromatography to good yield. The structure of compounds (i-iii has been characterized by the spectral and chemical studies.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  10. Correlation analysis of reactivity in the oxidation of some organic diols by tripropylammonium fluorochromate in non-aqueous media

    Directory of Open Access Journals (Sweden)

    S. Sheik Mansoor

    2016-09-01

    Full Text Available The kinetics of oxidation of some organic diols by tripropylammonium fluorochromate (TriPAFC have been studied in dimethylsulfoxide (DMSO. The main product of oxidation is the corresponding hydroxy aldehydes. The reaction is first order with respect to TriPAFC and exhibited Michaelis-Menten type kinetics with respect to organic diols. The reaction is catalyzed by hydrogen ions. The hydrogen ion dependence has the form: kobs = a + b[H+]. Various thermodynamic parameters for the oxidation have been reported and discussed along with the validity of isokinetic relationship. Oxidation of diols was studied in 18 different organic solvents. The rate data are showing satisfactory correlation with Kamlet–Taft solvotochromic parameters (α, β and π∗. A suitable mechanism of oxidation has been proposed.

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

    Directory of Open Access Journals (Sweden)

    Xian-Yang Qin

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

  12. Comparative reactivity of different types of stable cyclic and acyclic mono- and diamino carbenes with simple organic substrates.

    Science.gov (United States)

    Martin, David; Canac, Yves; Lavallo, Vincent; Bertrand, Guy

    2014-04-02

    A series of stable carbenes, featuring a broad range of electronic properties, were reacted with simple organic substrates. The N,N-dimesityl imidazolylidene (NHC) does not react with isocyanides, whereas anti-Bredt di(amino)carbene (pyr-NHC), cyclic (alkyl)(amino)carbene (CAAC), acyclic di(amino)carbene (ADAC), and acyclic (alkyl)(amino)carbene (AAAC) give rise to the corresponding ketenimines. NHCs are known to promote the benzoin condensation, and we found that the CAAC, pyr-NHC, and ADAC react with benzaldehyde to give the ketone tautomer of the Breslow intermediate, whereas the AAAC first gives the corresponding epoxide and ultimately the Breslow intermediate, which can be isolated. Addition of excess benzaldehyde to the latter does not lead to benzoin but to a stable 1,3-dioxolane. Depending on the electronic properties of carbenes, different products are also obtained with methyl acrylate as a substrate. The critical role of the carbene electrophilicity on the outcome of reactions is discussed.

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

    Czech Academy of Sciences Publication Activity Database

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

    2010-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2016-01-01

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

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

    NARCIS (Netherlands)

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

    2017-01-01

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

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

    DEFF Research Database (Denmark)

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

    1976-01-01

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

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

    DEFF Research Database (Denmark)

    Monrad, Rune Nygaard; Madsen, Robert

    2011-01-01

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

  18. Femtosecond double proton transfer dynamics in [2,2'-bipyridyl]-3,3'-diol in sol-gel glasses

    NARCIS (Netherlands)

    Prosposito, P.; Marks, D.R.A.; Zhang, H.; Glasbeek, M.

    1998-01-01

    Abstract: Intramolecular excited state double proton-transfer dynamics has been studied for [2,2'-bipyridyl]-3,3'-diol (BP(OH)2) in sol-gel glass. By means of the femtosecond fluorescence up-conversion technique, the spectral dependence of the fluorescence transients obtained for BP(OH)2 in a few

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

    Czech Academy of Sciences Publication Activity Database

    Marek, Aleš; Klepetářová, Blanka; Elbert, Tomáš

    2011-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

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

  1. Further characterization of benzo[a]pyrene diol-epoxide (BPDE)-induced comet assay effects.

    Science.gov (United States)

    Bausinger, Julia; Schütz, Petra; Piberger, Ann Liza; Speit, Günter

    2016-03-01

    The present study aims to further characterize benzo[a]pyrene diol-epoxide (BPDE)-induced comet assay effects. Therefore, we measured DNA effects by the comet assay and adduct levels by high-performance liquid chromatography (HPLC) in human lymphocytes and A549 cells exposed to (±)-anti-benzo[a]pyrene-7,8-diol 9,10-epoxide [(±)-anti-BPDE] or (+)-anti-benzo[a]pyrene-7,8-diol 9,10-epoxide [(+)-anti-BPDE]. Both, the racemic form and (+)-anti-BPDE, which is the most relevant metabolite with regard to mutagenicity and carcinogenicity, induced DNA migration in cultured lymphocytes in the same range of concentrations to a similar extent in the alkaline comet assay after exposure for 2h. Nevertheless, (+)-anti-BPDE induced significantly enhanced DNA migration after 16 and 18h post-cultivation which was not seen in response to (±)-anti-BPDE. Combination of the comet assay with the Fpg (formamidopyrimidine-DNA glycosylase) protein did not enhance BPDE-induced effects and thus indicated the absence of Fpg-sensitive sites (oxidized purines, N7-guanine adducts, AP-sites). The aphidicolin (APC)-modified comet assay suggested significant excision repair activity of cultured lymphocytes during the first 18h of culture after a 2 h-exposure to BPDE. In contrast to these repair-related effects measured by the comet assay, HPLC analysis of stable adducts did not reveal any significant removal of (+)-anti-BPDE-induced adducts from lymphocytes during the first 22h of culture. On the other hand, HPLC measurements indicated that A549 cells repaired about 70% of (+)-anti-BPDE-induced DNA-adducts within 22h of release. However, various experiments with the APC-modified comet assay did not indicate significant repair activity during this period in A549 cells. The conflicting results obtained with the comet assay and the HPLC-based adduct analysis question the real cause for BPDE-induced DNA migration in the comet assay and the reliability of the APC-modified comet assay for the

  2. ARA-aldehyde and ABA-trans-diol in apple fruits

    International Nuclear Information System (INIS)

    Rock, C.D.; Zeevaart, J.A.D.

    1989-01-01

    We have isolated ABA-aldehyde and ABA-t-diol from postharvest apple fruits, cv. Granny Smith and confirmed their structure by GC-MS. These putative ABA biosynthetic precursors incorporate 18 O to a similar degree as ABA during 48 hours under 18 O 2 atmospheres. The presence of significant amounts of ABA-aldehyde can explain the unique 18 O labeling pattern of ABA in this tissue, where a majority of ABA molecules containing 18 O is labeled in the 1'-hydroxyl group and not in the side chain carboxyl group, the primary site of incorporation for stressed leaves. Exchange of the carbonyl oxygen of ABA-aldehyde with water would decrease 18 O enrichment in the side chain. Results of 18 O 2 experiments and feeding studies using hexadeutero-ABA-aldehyde will be presented and the biosynthetic relationship of these compounds discussed

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

    Science.gov (United States)

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

    2008-10-01

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

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

    International Nuclear Information System (INIS)

    Vijayaraj, A.; Prabu, R.; Suresh, R.; Narayanan, V.; Sangeetha Kumari, R.; Kaviyarasan, V.

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-15

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

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

    Directory of Open Access Journals (Sweden)

    Tahmina Haque

    2015-03-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

  8. Preparation and characterization of fluorophenylboronic acid-functionalized affinity monolithic columns for the selective enrichment of cis-diol-containing biomolecules.

    Science.gov (United States)

    Li, Qianjin; Liu, Zhen

    2015-01-01

    Boronate affinity monolithic columns have been developed into an important means for the selective recognition and capture of cis-diol-containing biomolecules, such as glycoproteins, nucleosides and saccharides. The ligands of boronic acids are playing an important role in boronate affinity monolithic columns. Although several boronate affinity monoliths with high affinity toward cis-diol-containing biomolecules have been reported, only few publications are focused on their detailed procedures for preparation and characterization. This chapter describes in detail the preparation and characterization of a boronate affinity monolithic column applying 2,4-difluoro-3-formyl-phenylboronic acid (DFFPBA) as a ligand. The DFFPBA-functionalized monolithic column not only exhibited an ultrahigh boronate affinity toward cis-diol-containing biomolecules, but also showed great potential for the selective enrichment of cis-diol-containing biomolecules in real samples.

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

    KAUST Repository

    Chen, Zuliang

    2016-07-12

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

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

    KAUST Repository

    Yin, Dongdong

    2017-01-05

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

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

    Directory of Open Access Journals (Sweden)

    Santi Kulsiriswad

    2017-10-01

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

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

    Science.gov (United States)

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

    2017-02-01

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

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

    Science.gov (United States)

    Weinstein, I B; Jeffrey, A M; Jennette, K W; Blobstein, S H; Harvey, R G; Harris, C; Autrup, H; Kasai, H; Nakanishi, K

    1976-08-13

    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 formed between position 10 of this derivative and the 2-amino group of guanine.

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

    DEFF Research Database (Denmark)

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

    1996-01-01

    Monolayers of the pure S-enantiomer (x(S) = 1) and of two mixtures x(S) = 0.75 and x(S) = 0.5 (racemate) of 4-hexadecyloxy-butane-1,2-diol (C16H33-O-CH2-CH2-CHOH-CH2OH) (HOBD) have been studied at the air-water interface by thermodynamic measurements, fluorescence microscopy and X-ray diffraction...

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

    Czech Academy of Sciences Publication Activity Database

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

    2003-01-01

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

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

    Science.gov (United States)

    Rainis, Guido; Ternes, Waldemar

    2014-01-08

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

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

    Science.gov (United States)

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

    2018-04-01

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

  18. Synthesis of New Acadesine (AICA-riboside Analogues Having Acyclic d-Ribityl or 4-Hydroxybutyl Chains in Place of the Ribose

    Directory of Open Access Journals (Sweden)

    Gennaro Piccialli

    2013-08-01

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

  19. 20(S)-25-methoxyl-dammarane-3β, 12β, 20-triol negatively regulates activation of STAT3 and ERK pathways and exhibits anti-cancer effects in HepG2 cells.

    Science.gov (United States)

    Ai, Hui-Han; Zhou, Zi-Long; Sun, Lu-Guo; Yang, Mei-Ting; Li, Wei; Yu, Chun-Lei; Song, Zhen-Bo; Huang, Yan-Xin; Wu, Yin; Liu, Lei; Yang, Xiao-Guang; Zhao, Yu-Qing; Bao, Yong-Li; Li, Yu-Xin

    2017-11-01

    The pro-inflammatory cytokine interleukin 6 (IL-6), via activating its downstream JAK/STAT3 and Ras/ERK signaling pathways, is involved in cell growth, proliferation and anti-apoptotic activities in various malignancies. To screen inhibitors of IL-6 signaling, we constructed a STAT3 and ERK dual-pathway responsive luciferase reporter vector (Co.RE). Among several candidates, the natural compound 20(S)-25-methoxyl-dammarane-3β, 12β, 20-triol (25-OCH 3 -PPD, GS25) was identified to clearly inhibit the luciferase activity of Co.RE. GS25 was confirmed to indeed inhibit activation of both STAT3 and ERK pathways and expression of downstream target genes of IL-6, and to predominantly decrease the viability of HepG2 cells via induction of cell cycle arrest and apoptosis. Interestingly, GS25 showed preferential inhibition of HepG2 cell viability relative to normal liver L02 cells. Further investigation showed that GS25 could not induce apoptosis and block activation of STAT3 and ERK pathways in L02 cells as efficiently as in HepG2 cells, which may result in differential effects of GS25 on malignant and normal liver cells. In addition, GS25 was found to potently suppress the expression of endogenous STAT3 at a higher concentration and dramatically induce p38 phosphorylation in HepG2 cells, which could mediate its anti-cancer effects. Finally, we demonstrated that GS25 also inhibited tumor growth in HepG2 xenograft mice. Taken together, these findings indicate that GS25 elicits its anti-cancer effects on HepG2 cells through multiple mechanisms and has the potential to be used as an inhibitor of IL-6 signaling. Thus, GS25 may be developed as a treatment for hepatocarcinoma with low toxicity on normal liver tissues as well as other inflammation-associated diseases.

  20. Novel approaches to analysis of 3-chloropropane-1,2-diol esters in vegetable oils.

    Science.gov (United States)

    Moravcova, Eliska; Vaclavik, Lukas; Lacina, Ondrej; Hrbek, Vojtech; Riddellova, Katerina; Hajslova, Jana

    2012-03-01

    A sensitive and accurate method utilizing ultrahigh performance liquid chromatography (U-HPLC) coupled to high resolution mass spectrometry based on orbitrap technology (orbitrapMS) for the analysis of nine 3-chloropropane-1,2-diol (3-MCPD) diesters in vegetable oils was developed. To remove the interfering triacylglycerols that induce strong matrix effects, a clean-up step on silica gel column was used. The quantitative analysis was performed with the use of deuterium-labeled internal standards. The lowest calibration levels estimated for the respective analytes ranged from 2 to 5 μg kg(-1). Good recovery values (89-120%) and repeatability (RSD 5-9%) was obtained at spiking levels of 2 and 10 mg kg(-1). As an alternative, a novel ambient desorption ionization technique, direct analysis in real time (DART), hyphenated with orbitrapMS, was employed for no separation, high-throughput, semi-quantitative screening of 3-MCPD diesters in samples obtained by chromatographic fractionation. Additionally, the levels of 3-MCPD diesters measured in reallife vegetable oil samples (palm oil, sunflower oil, rapeseed oil) using both methods are reported. Relatively good agreement of the data generated by U-HPLC-orbitrapMS and DART-orbitrapMS were observed. With regard to a low ionization yield achieved for 3-MCPD monoesters, the methods presented in this paper were not yet applicable for the analysis of these contaminants at the naturally occurring levels.

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

    Science.gov (United States)

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

    2014-07-23

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

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

    International Nuclear Information System (INIS)

    Toraya, T.

    1985-01-01

    The binding of cob(II)alamin (CblII) and 5'-deoxyadenosine to diol dehydrase was studied spectroscopically and with [U- 14 C]5'-deoxyadenosine. CblII was bound to this enzyme forming a tight 1:1 complex which was resistant to oxidation by O 2 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- 14 C]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

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

    International Nuclear Information System (INIS)

    Wright, F.; Mowszowicz, I.; Mauvais-Jarvis, P.

    1978-01-01

    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

  4. Selective hydrodeoxygenation of cyclic vicinal diols to cyclic alcohols over tungsten oxide-palladium catalysts.

    Science.gov (United States)

    Amada, Yasushi; Ota, Nobuhiko; Tamura, Masazumi; Nakagawa, Yoshinao; Tomishige, Keiichi

    2014-08-01

    Hydrodeoxygenation of cyclic vicinal diols such as 1,4-anhydroerythritol was conducted over catalysts containing both a noble metal and a group 5-7 transition-metal oxide. The combination of Pd and WOx allowed the removal of one of the two OH groups selectively. 3-Hydroxytetrahydrofuran was obtained from 1,4-anhydroerythritol in 72 and 74% yield over WOx -Pd/C and WOx -Pd/ZrO2 , respectively. The WOx -Pd/ZrO2 catalyst was reusable without significant loss of activity if the catalyst was calcined as a method of regeneration. Characterization of WOx -Pd/C with temperature-programmed reduction, X-ray diffraction, and transmission electron microscopy/energy-dispersive X-ray spectroscopy suggested that Pd metal particles approximately 9 nm in size were formed on amorphous tungsten oxide particles. A reaction mechanism was proposed on the basis of kinetics, reaction results with tungsten oxides under an atmosphere of Ar, and density functional theory calculations. A tetravalent tungsten center (W(IV) ) was formed by reduction of WO3 with the Pd catalyst and H2 , and this center served as the reductant for partial hydrodeoxygenation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Exposure assessment of 3-monochloropropane-1, 2-diol esters from edible oils and fats in China.

    Science.gov (United States)

    Li, Chang; Nie, Shao-Ping; Zhou, Yong-Qiang; Xie, Ming-Yong

    2015-01-01

    3-monochoropropane-1, 2-diol (3-MCPD) esters from edible oils are considered to be a possible risk factor for adverse effects in human. In the present study, the exposure assessment of 3-MCPD esters to Chinese population was performed. A total of 143 edible oil and fat samples collected from Chinese markets were determined for the concentrations of 3-MCPD esters. The concentration data together with the data of fats consumed were analyzed by the point evaluation and probabilistic assessment for the exposure assessment. The point evaluation showed that the mean daily intake (DI) of 3-MCPD esters were lower than the value of provisional maximum tolerable daily intake (PMTDI) of 3-MCPD (2 µg/kg BW/d). The mean DI values in different age groups obtained from probabilistic assessment were similar to the results of the point evaluation. However, in high percentiles (95th, 97.5th, 99th), the DI values in all age groups were undesirably higher than the value of PMTDI. Overall, the children and adolescents exposed more to 3-MCPD esters than the adults. Uncertainty was also analyzed for the exposure assessment. Decreasing the level of 3-MCPD esters in edible oils and consuming less oil were top priority to minimize the risk of 3-MCPD esters. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. HILIC separation and quantitation of water-soluble vitamins using diol column.

    Science.gov (United States)

    Karatapanis, Andreas E; Fiamegos, Yiannis C; Stalikas, Constantine D

    2009-04-01

    Hydrophilic interaction liquid-chromatography (HILIC) in conjunction with diode array detection has been applied for the separation of selected-water-soluble vitamins using an end-capped HILIC-diol column. Vitamins with significant biological importance, such as thiamine (B(1)), riboflavin (B(2)), nicotinic acid (B(3)), nicotinamide (B(3)), pyridoxine (B(6)), folic acid (B(9)), cyanocobalamin (B(12)) and ascorbic acid (vitamin C) were simultaneously separated. Chromatographic conditions including type and percentage of organic modifier in the mobile phase, pH, type and concentration of buffer salt and flow rate were investigated. ACN was shown to offer superior separation for the compounds tested as compared to methanol, isopropanol and THF. Isocratic separation and analysis were achieved for six vitamins (B(1), B(2), nicotinic acid/nicotinamide, B(6) and C) at ACN-H(2)O 90:10, containing ammonium acetate 10 mM, triethylamine 20 mM, pH 5.0, using a flow rate of 0.8 mL/min, while a gradient was necessary to resolve a mixture of all eight water-soluble vitamins. The HILIC method was validated and successfully applied to the analysis of a pharmaceutical formulation and an energy drink negating the need for time consuming clean-up steps.

  7. Toxicological assessment of 3-chloropropane-1,2-diol and glycidol fatty acid esters in food.

    Science.gov (United States)

    Bakhiya, Nadiya; Abraham, Klaus; Gürtler, Rainer; Appel, Klaus Erich; Lampen, Alfonso

    2011-04-01

    Fatty acid esters of 3-chloropropane-1,2-diol (3-MCPD) and glycidol are a newly identified class of food process contaminants. They are widespread in refined vegetable oils and fats and have been detected in vegetable fat-containing products, including infant formulas. There are no toxicological data available yet on the 3-MCPD and glycidol esters, and the primary toxicological concern is based on the potential release of 3-MCPD or glycidol from the parent esters by lipase-catalyzed hydrolysis in the gastrointestinal tract. Although 3-MCPD is assessed as a nongenotoxic carcinogen with a tolerable daily intake (TDI) of 2 μg/kg body weight (bw), glycidol is a known genotoxic carcinogen, which induces tumors in numerous organs of rodents. The initial exposure estimates, conducted by Federal Institute for Risk Assessment (BfR) under the assumption that 100% of the 3-MPCD and glycidol are released from their esters, revealed especially that infants being fed commercial infant formula could ingest harmful amounts of 3-MCPD and glycidol. However, the real oral bioavailability may be lower. As this gives rise for toxicological concern, the currently available toxicological data of 3-MCPD and glycidol and their esters are summarized in this review and discussed with regard to data gaps and further research needs. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. 3-Monochloropropane-1,2-diol fatty acid esters in commercial deep-fat fried foods.

    Science.gov (United States)

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

    2015-01-01

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

  9. [Occurrence of 3-monochloropropane-1,2-diol (3-MCPD) in food products].

    Science.gov (United States)

    Gawarska, Halina; Sawilska-Rautenstrauch, Dorota; Starski, Andrzej; Karłowski, Kazimierz

    2009-01-01

    3-Monochloropropane-1,2-diol (3-MCPD) is a contaminant belongs to a group of chemicals called chloropropanols. 3-MCPD can be formed in foods as result of processing or storage condition. At the beginning 3-MCPD was identified as a contaminant of the acid-hydrolysed vegetable protein, which is produced using hydrochloric acid and high temperature. Studies have shown that 3-MCPD is carcinogenic for rats, however genotoxic adverse effect was not observed in vivo. The purpose of this studies was determination of 3-MCPD amounts in retail food products and comparison with the EC legislative limit. 99 samples of foodstuffs was tested: soya sauce, hydrolysed vegetable protein (HVP), sugar, instant soups, stock cubes, bakery products, chips and edible fats. 3-MCPD was detected at levels below 10 microg/kg in 15% of the tested samples, and above 10 microg/kg in 63%. 3-MCPD was not occurred in 22% of the tested samples. The samples were analysed by gas chromatography-mass spectrometry (GC/MS).

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

    Science.gov (United States)

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

    2015-11-11

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

  11. Influence of dough ingredients on 3-chloropropane-1,2-diol (3-MCPD) formation in toast.

    Science.gov (United States)

    Breitling-Utzmann, C M; Hrenn, H; Haase, N U; Unbehend, G M

    2005-02-01

    The influence of different dough ingredients such as fat, salt, sourdough, emulsifiers, and sugar on the formation of 3-chloropropane-1,2-diol (3-MCPD) during toast preparation under domestic conditions was investigated. In comparison with a fat-free recipe, addition of 1% peanut fat considerably increased 3-MCPD formation, but varying the fat (2-5%) or salt (1.6-2.4%) contents within technological acceptable limits did not show any significant differences. A baking agent, which is usually commercially applied by many toast bakers or industrial toast manufacturers, increased 3-MCPD formation in toasted bread slices. Considerable evidence was found that the baking agent's main component sucrose had the major part in increasing 3-MCPD levels. Emulsifiers containing monoacylglycerols moderately increased 3-MCPD levels, but the addition of lecithin did not have any significant influence. 3-MCPD levels showed a good correlation with the lightness (L* value) of the bread slices; their 3-MCPD content increased exponentially towards dark coloured toasts. The relation between 3-MCPD and 2-MCPD was an average of 3:1 in all samples. Dichloropropanols such as, for example, 1,3-dichloropropanol could not be detected.

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

    Science.gov (United States)

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

    2015-04-07

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

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

    Directory of Open Access Journals (Sweden)

    Shuihua Wang

    2016-10-01

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

  14. Reversible Twisting of Primary Amides via Ground State N-C(O) Destabilization: Highly Twisted Rotationally Inverted Acyclic Amides.

    Science.gov (United States)

    Meng, Guangrong; Shi, Shicheng; Lalancette, Roger; Szostak, Roman; Szostak, Michal

    2018-01-17

    Since the seminal studies by Pauling in 1930s, planarity has become the defining characteristic of the amide bond. Planarity of amides has central implications for the reactivity and chemical properties of amides of relevance to a range of chemical disciplines. While the vast majority of amides are planar, nonplanarity has a profound effect on the properties of the amide bond, with the most common method to restrict the amide bond relying on the incorporation of the amide function into a rigid cyclic ring system. In a major departure from this concept, here, we report the first class of acyclic twisted amides that can be prepared, reversibly, from common primary amides in a single, operationally trivial step. Di-tert-butoxycarbonylation of the amide nitrogen atom yields twisted amides in which the amide bond exhibits nearly perpendicular twist. Full structural characterization of a range of electronically diverse compounds from this new class of twisted amides is reported. Through reactivity studies we demonstrate unusual properties of the amide bond, wherein selective cleavage of the amide bond can be achieved by a judicious choice of the reaction conditions. Through computational studies we evaluate structural and energetic details pertaining to the amide bond deformation. The ability to selectively twist common primary amides, in a reversible manner, has important implications for the design and application of the amide bond nonplanarity in structural chemistry, biochemistry and organic synthesis.

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

    Directory of Open Access Journals (Sweden)

    Masahito Shimizu

    2012-01-01

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

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

    Science.gov (United States)

    Abou-Hussein, Azza A A; Linert, Wolfgang

    2012-09-01

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

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

    International Nuclear Information System (INIS)

    Rock, C.D.; Zeevaart, J.A.D.

    1990-01-01

    Previous 18 O labeling studies of abscisic acid (ABA) have shown that apple (Malus domestica Borkh. cv Granny Smith) fruits synthesize a majority of [ 18 O]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 18 O in the side chain with the medium occurred at an aldehyde intermediate stage of ABA biosynthesis. We have isolated ABA-aldehyde and 1'-4'-trans-ABA-diol (ABA-trans-diol) from 18 O-labeled apple fruit tissue and measured the extent and position of 18 O incorporation by tandem mass spectrometry. 18 O-Labeling patterns of ABA-aldehyde, ABA-trans-diol, and ABA indicate that ABA-aldehyde is a precursor to, and ABA-trans-diol a catabolite of, ABA. Exchange of 18 O in the carbonyl of ABA-aldehyde can be the cause of loss of 18 O from the side chain of [ 18 O]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

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

    Science.gov (United States)

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

    2016-06-05

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

  19. 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)

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    International Nuclear Information System (INIS)

    Honda, Masao; Yamashita, Taro; Yamashita, Tatsuya; Arai, Kuniaki; Sakai, Yoshio; Sakai, Akito; Nakamura, Mikiko; Mizukoshi, Eishiro; Kaneko, Shuichi

    2013-01-01

    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

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    A straightforward and atom-economical method is described for the synthesis of 2,3-disubstituted indoles. Anilines and 1,2-diols are condensed under neat conditions with catalytic amounts of either [Cp*IrCl2](2)/MsOH or RuCl3 center dot xH(2)O/phosphine (phosphine = PPh3 or xantphos). The reactio...... the alpha-hydroxyimine which rearranges to the corresponding alpha-aminoketone. Acid-or metal-catalysed electrophilic ring-closure with the release of water then furnishes the indole product....

  2. Influence of oil composition on the formation of fatty acid esters of 2-chloropropane-1,3-diol (2-MCPD) and 3-chloropropane-1,2-diol (3-MCPD) under conditions simulating oil refining.

    Science.gov (United States)

    Ermacora, Alessia; Hrncirik, Karel

    2014-10-15

    The toxicological relevance and widespread occurrence of fatty acid esters of 2-chloropropane-1,3-diol (2-MCPD) and 3-chloropropane-1,2-diol (3-MCPD) in refined oils and fats have recently triggered an interest in the mechanism of formation and decomposition of these contaminants during oil processing. In this work, the effect of the main precursors, namely acylglycerols and chlorinated compounds, on the formation yield of MCPD esters was investigated in model systems simulating oil deodorization. The composition of the oils was modified by enzymatic hydrolysis, silica gel purification and application of various refining steps prior to deodorization (namely degumming, neutralization, bleaching). Partial acylglycerols showed greater ability, than did triacylglycerols, to form MCPD esters. However, no direct correlation was found between these two parameters, since the availability of chloride ions was the main limiting factor in the formation reaction. Polar chlorinated compounds were found to be the main chloride donors, although the presence of reactive non-polar chloride-donating species was also observed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Synthesis and characterization of biodegradable poly (ethylene glycol) and poly (caprolactone diol) end capped poly (propylene fumarate) cross linked amphiphilic hydrogel as tissue engineering scaffold material.

    Science.gov (United States)

    Krishna, Lekshmi; Jayabalan, Muthu

    2009-12-01

    Biodegradable poly (caprolactone diol-co-propylene fumarate-co-ethylene glycol) amphiphilic polymer with poly (ethylene glycol) and poly (caprolactone diol) chain ends (PCL-PPF-PEG) was prepared. PCL-PPF-PEG undergoes fast setting with acrylamide (aqueous solution) by free radical polymerization and produces a crosslinked hydrogel. The cross linked and freeze-dried amphiphilic material has porous and interconnected network. It undergoes higher degree of swelling and water absorption to form hydrogel with hydrophilic and hydrophobic domains at the surface and appreciable tensile strength. The present hydrogel is compatible with L929 fibroblast cells. PCL-PPF-PEG/acrylamide hydrogel is a candidate scaffold material for tissue engineering applications.

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

    Science.gov (United States)

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

    2006-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Nabil A. Siddiqui

    2016-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Eissa, A. M.F.

    1994-10-01

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

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

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

    Directory of Open Access Journals (Sweden)

    M. Jayabalan

    2009-01-01

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

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

    Science.gov (United States)

    Jayabalan, M

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-17

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

  10. Acyclic cucurbit[n]uril-type molecular containers: influence of aromatic walls on their function as solubilizing excipients for insoluble drugs.

    Science.gov (United States)

    Zhang, Ben; Isaacs, Lyle

    2014-11-26

    We studied the influence of the aromatic sidewalls on the ability of acyclic CB[n]-type molecular containers (1a-1e) to act as solubilizing agents for 19 insoluble drugs including the developmental anticancer agent PBS-1086. All five containers exhibit good water solubility and weak self-association (Ks ≤ 624 M(-1)). We constructed phase solubility diagrams to extract Krel and Ka values for the container·drug complexes. The acyclic CB[n]-type containers generally display significantly higher Ka values than HP-β-CD toward drugs. Containers 1a-1e bind the steroidal ring system and aromatic moieties of insoluble drugs. Compound 1b displays highest affinity toward most of the drugs studied. Containers 1a and 1b are broadly applicable and can be used to formulate a wider variety of insoluble drugs than was previously possible with cyclodextrin technology. For drugs that are solubilized by both HP-β-CD and 1a-1e, lower concentrations of 1a-1e are required to achieve identical [drug].

  11. Conformational analysis of an acyclic tetrapeptide: ab-initio structure determination from X-ray powder diffraction, Hirshfeld surface analysis and electronic structure.

    Science.gov (United States)

    Das, Uday; Naskar, Jishu; Mukherjee, Alok Kumar

    2015-12-01

    A terminally protected acyclic tetrapeptide has been synthesized, and the crystal structure of its hydrated form, Boc-Tyr-Aib-Tyr-Ile-OMe·2H2O (1), has been determined directly from powder X-ray diffraction data. The backbone conformation of tetrapeptide (1) exhibiting two consecutive β-turns is stabilized by two 4 → 1 intramolecular N-H · · · O hydrogen bonds. In the crystalline state, the tetrapeptide molecules are assembled through water-mediated O-H · · · O hydrogen bonds to form two-dimensional molecular sheets, which are further linked by intermolecular C-H · · · O hydrogen bonds into a three-dimensional supramolecular framework. The molecular electrostatic potential (MEP) surface of (1) has been used to supplement the crystallographic observations. The nature of intermolecular interactions in (1) has been analyzed quantitatively through the Hirshfeld surface and two-dimensional fingerprint plot. The DFT optimized molecular geometry of (1) agrees closely with that obtained from the X-ray structure analysis. The present structure analysis of Boc-Tyr-Aib-Tyr-Ile-OMe·2H2 O (1) represents a case where ab-initio crystal structure of an acyclic tetrapeptide with considerable molecular flexibility has been accomplished from laboratory X-ray powder diffraction data. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

  12. Letter to the Editor: About "Studies of Viscosity and Excess Molar Volume of Binary Mixtures of Propane-1,2 diol with Water at Various Temperatures"

    Czech Academy of Sciences Publication Activity Database

    Linek, Jan

    2003-01-01

    Roč. 208, 1-2 (2003), s. 261-263 ISSN 0378-3812 R&D Projects: GA ČR GA203/02/1098 Institutional research plan: CEZ:AV0Z4072921 Keywords : water * propane-1,2-diol * physical properties Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.165, year: 2003

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

    Directory of Open Access Journals (Sweden)

    Carlos R. Carreras

    2010-04-01

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

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

    Czech Academy of Sciences Publication Activity Database

    Poláková, Lenka; Sedláková, Zdeňka; Látalová, Petra

    2010-01-01

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

  15. Human hair follicle benzo(a)pyrene and benzo(a)pyrene 7, 8-diol metabolism: effect of exposure to a coal tar-containing shampoo

    Energy Technology Data Exchange (ETDEWEB)

    Merk, H.F.; Mukhtar, H.; Kaufmann, I.; Das, M.; Bickers, D.R.

    1987-01-01

    Hair follicles are a readily available source of human epithelial tissue and offer an excellent system with which to study carcinogen metabolism in human populations. In this study hair follicles were employed to measure the metabolism of benzo(a)pyrene (BP), benzo(a)pyrene - 7,8-diol (BP 7,8-diol) and the enzyme mediated binding of /sup 3/H-BP to DNA. The effect of human exposure to a crude coal tar (CCT) - containing shampoo, a preparation rich in polycyclic aromatic hydrocarbons (PAHs on these parameters was also evaluated. It was found that aryl hydrocarbon hydroxylase (AHH) activity increased after use of the shampoo and enhancement of enzyme-mediated binding of BP to DNA was detected in most subjects. Hair follicles were shown to convert BP to several metabolic species and BP, 7,8-diol was also metabolised. Clotrimazole, a known inhibitor of the metabolism of BP was found to inhibit AHH and the metabolism of BP and BP 7,8-diol in human hair follicles, as were other imidazole compounds. The studies show that hair follicles represent an accessible tissue suitable for assessing the extent of PAH carcinogen metabolism in human subjects. Furthermore enzyme activity critical to cancer induction by PAHs was shown to be inducible following the use of a CCT-containing shampoo. Imidazole compounds were shown to be possible effective anti-carcinogens in human populations. 29 refs.

  16. High-Throughput Assay for Enantiomeric Excess Determination in 1,2- and 1,3-Diols and Direct Asymmetric Reaction Screening.

    Science.gov (United States)

    Shcherbakova, Elena G; Brega, Valentina; Lynch, Vincent M; James, Tony D; Anzenbacher, Pavel

    2017-07-26

    A simple and efficient method for determination of the yield, enantiomeric/diasteriomeric excess (ee/de), and absolute configuration of crude chiral diols without the need of work-up and product isolation in a high throughput setting is described. This approach utilizes a self-assembled iminoboronate ester formed as a product by dynamic covalent self-assembly of a chiral diol with an enantiopure fluorescent amine such as tryptophan methyl ester or tryptophanol and 2-formylphenylboronic acid. The resulting diastereomeric boronates display different photophysical properties and allow for fluorescence-based ee determination of molecules containing a 1,2- or 1,3-diol moiety. This method has been utilized for the screening of ee in a number of chiral diols including atorvastatin, a statin used for the treatment of hypercholesterolemia. Noyori asymmetric hydrogenation of benzil was performed in a highly parallel fashion with errors products from the parallel asymmetric synthesis in real time and in a high-throughput screening (HTS) fashion. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Science.gov (United States)

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

    2006-05-01

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

  18. Glass transition and the rigid amorphous phase in semicrystalline blends of bacterial polyhydroxybutyrate PHB with low molecular mass atactic R,S-PHB-diol

    NARCIS (Netherlands)

    Hoehne, G.W.H.

    2004-01-01

    The glass transition and the crystallinity of blends of isotactic bacterial PHB and low molecular mass atactic R, S-PHB-diols was investigated by means of differential scanning calorimetry (DSC), temperature-modulated DSC and dielectric spectroscopy. It was found that (i) Tg of crystallized blends

  19. Speed of sound in saturated aliphatic alcohols (propan-2-ol, butan-2-ol, and 2-methylpropan-1-ol) and alkanediols (ethane-1,2-diol, propane-1,2- and -1,3-diol) at temperature between 253.15 K and 353.15 K and pressures up to 30 MPa

    International Nuclear Information System (INIS)

    Dávila, María J.; Gedanitz, Holger; Span, Roland

    2016-01-01

    Highlights: • Speed of sound measurements were made in aliphatic alcohols and alkanediols. • Speeds of sound were measured in a wide temperature and pressure range. • A pulse-echo method with a double path type sensor operating at 8 MHz was employed. • A double polynomial equation was used to fit the experimental speed of sound data. • The accurate results were compared with available literature sources. - Abstract: Speeds of sound have been measured in three saturated aliphatic alcohols (propan-2-ol, butan-2-ol, and 2-methylpropan-1-ol) and three alkanediols (ethane-1,2-diol, propane-1,2- and -1,3-diol) in the temperature range from (253.15 to 353.15) K and pressures up to 30 MPa by use of a pulse-echo method with a double path type sensor operating at 8 MHz. The expanded overall uncertainties (k = 2) in the speed of sound measurements are estimated to be 0.013% for propan-2-ol, 0.019% for butan-2-ol, 0.01% for 2-methylpropan-1-ol, 0.009% for ethane-1,2-diol, 0.02% for propane-1,2-diol, and 0.07% for propane-1,3-diol. Experimental speeds of sound data were correlated with the temperature and pressure with an empirical double polynomial equation. Our results were also compared with the available literature data and a satisfactory agreement was found.

  20. Highly Sensitive Determination of 2,4,6-Trinitrotoluene and Related Byproducts Using a Diol Functionalized Column for High Performance Liquid Chromatography

    Science.gov (United States)

    Gumuscu, Burcu; Erdogan, Zeynep; Guler, Mustafa O.; Tekinay, Turgay

    2014-01-01

    In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT); 2,4-dinitrotoluene (2,4-DNT); 2,6-dinitrotoluene (2,6-DNT); 2-aminodinitrotoluene (2-ADNT) and 4-aminodinitrotoluene (4-ADNT) molecules in high-performance liquid-chromatography (HPLC) with UV sensor has been developed using diol column. This approach improves on cost, time, and sensitivity over the existing methods, providing a simple and effective alternative. Total analysis time was less than 13 minutes including column re-equilibration between runs, in which water and acetonitrile were used as gradient elution solvents. Under optimized conditions, the minimum resolution between 2,4-DNT and 2,6-DNT peaks was 2.06. The recovery rates for spiked environmental samples were between 95–98%. The detection limits for diol column ranged from 0.78 to 1.17 µg/L for TNT and its byproducts. While the solvent consumption was 26.4 mL/min for two-phase EPA and 30 mL/min for EPA 8330 methods, it was only 8.8 mL/min for diol column. The resolution was improved up to 49% respect to two-phase EPA and EPA 8330 methods. When compared to C-18 and phenyl-3 columns, solvent usage was reduced up to 64% using diol column and resolution was enhanced approximately two-fold. The sensitivity of diol column was afforded by the hydroxyl groups on polyol layer, joining the formation of charge-transfer complexes with nitroaromatic compounds according to acceptor-donor interactions. Having compliance with current requirements, the proposed method demonstrates sensitive and robust separation. PMID:24905826

  1. Highly sensitive determination of 2,4,6-trinitrotoluene and related byproducts using a diol functionalized column for high performance liquid chromatography.

    Science.gov (United States)

    Gumuscu, Burcu; Erdogan, Zeynep; Guler, Mustafa O; Tekinay, Turgay

    2014-01-01

    In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT); 2,4-dinitrotoluene (2,4-DNT); 2,6-dinitrotoluene (2,6-DNT); 2-aminodinitrotoluene (2-ADNT) and 4-aminodinitrotoluene (4-ADNT) molecules in high-performance liquid-chromatography (HPLC) with UV sensor has been developed using diol column. This approach improves on cost, time, and sensitivity over the existing methods, providing a simple and effective alternative. Total analysis time was less than 13 minutes including column re-equilibration between runs, in which water and acetonitrile were used as gradient elution solvents. Under optimized conditions, the minimum resolution between 2,4-DNT and 2,6-DNT peaks was 2.06. The recovery rates for spiked environmental samples were between 95-98%. The detection limits for diol column ranged from 0.78 to 1.17 µg/L for TNT and its byproducts. While the solvent consumption was 26.4 mL/min for two-phase EPA and 30 mL/min for EPA 8330 methods, it was only 8.8 mL/min for diol column. The resolution was improved up to 49% respect to two-phase EPA and EPA 8330 methods. When compared to C-18 and phenyl-3 columns, solvent usage was reduced up to 64% using diol column and resolution was enhanced approximately two-fold. The sensitivity of diol column was afforded by the hydroxyl groups on polyol layer, joining the formation of charge-transfer complexes with nitroaromatic compounds according to acceptor-donor interactions. Having compliance with current requirements, the proposed method demonstrates sensitive and robust separation.

  2. Highly sensitive determination of 2,4,6-trinitrotoluene and related byproducts using a diol functionalized column for high performance liquid chromatography.

    Directory of Open Access Journals (Sweden)

    Burcu Gumuscu

    Full Text Available In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT; 2,4-dinitrotoluene (2,4-DNT; 2,6-dinitrotoluene (2,6-DNT; 2-aminodinitrotoluene (2-ADNT and 4-aminodinitrotoluene (4-ADNT molecules in high-performance liquid-chromatography (HPLC with UV sensor has been developed using diol column. This approach improves on cost, time, and sensitivity over the existing methods, providing a simple and effective alternative. Total analysis time was less than 13 minutes including column re-equilibration between runs, in which water and acetonitrile were used as gradient elution solvents. Under optimized conditions, the minimum resolution between 2,4-DNT and 2,6-DNT peaks was 2.06. The recovery rates for spiked environmental samples were between 95-98%. The detection limits for diol column ranged from 0.78 to 1.17 µg/L for TNT and its byproducts. While the solvent consumption was 26.4 mL/min for two-phase EPA and 30 mL/min for EPA 8330 methods, it was only 8.8 mL/min for diol column. The resolution was improved up to 49% respect to two-phase EPA and EPA 8330 methods. When compared to C-18 and phenyl-3 columns, solvent usage was reduced up to 64% using diol column and resolution was enhanced approximately two-fold. The sensitivity of diol column was afforded by the hydroxyl groups on polyol layer, joining the formation of charge-transfer complexes with nitroaromatic compounds according to acceptor-donor interactions. Having compliance with current requirements, the proposed method demonstrates sensitive and robust separation.

  3. Synthesis, Characterizations and Investigation of Electrochemical Behaviours of 4-[(2-Hydroxyphenyliminomethyl]benzene-1,3-diol

    Directory of Open Access Journals (Sweden)

    Aysen D. Mulazimoglu

    2009-01-01

    Full Text Available This Schiff base ligand, 4-[(2-hydroxyphenylimino methyl]benzene-1,3-diol (HIBD was synthesized by reaction of 2-aminophenol and 2,4-dihydroxybenzaldehyde. The ligand was characterized by elemental analysis, FT-IR and 1H-NMR. Electrochemical behaviors were investigated on the glassy carbon electrode (GC surface with cyclic voltammetry (CV. The modification of HIBD on the GC was performed in +0.3 V and +2,8 V potential range using 100 mV s-1 scanning rate having 5 cycle. For the characterization of the modified surfaces 1 mM ferrocene redox probe in 0,1 M tetrabutylammonium tetrafluoroborate (TBATFB and 1 mM ferricyanide redox probe in 0.1 M H2SO4 were used.

  4. Formation and reduction of 3-monochloropropane-1,2-diol esters in peanut oil during physical refining.

    Science.gov (United States)

    Li, Chang; Li, Linyan; Jia, Hanbing; Wang, Yuting; Shen, Mingyue; Nie, Shaoping; Xie, Mingyong

    2016-05-15

    In the present study, lab-scale physical refining processes were investigated for their effects on the formation of 3-monochloropropane-1,2-diol (3-MCPD) esters. The potential precursors, partial acylglycerols and chlorines were determined before each refining step. 3-MCPD esters were not detected in degummed and bleached oil when the crude oils were extracted by solvent. While in the hot squeezed crude oils, 3-MCPD esters were detected with low amounts. 3-MCPD esters were generated with maximum values in 1-1.5h at a certain deodorizing temperature (220-260°C). Chlorine seemed to be more effective precursor than partial acylglycerol. By washing bleached oil before deodorization with ethanol solution, the precursors were removed partially and the content of 3-MCPD esters decreased to some extent accordingly. Diacetin was found to reduce 3-MCPD esters effectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Occurrence of 3-chloro-propane-1,2-diol (3-MCPD) and related compounds in foods: a review.

    Science.gov (United States)

    Hamlet, C G; Sadd, P A; Crews, C; Velísek, J; Baxter, D E

    2002-07-01

    A critical review of the occurrence of 3-chloro-propane-1,2-diol (3-MCPD) in foods not known to contain hydrolysed vegetable proteins is presented. The review covers the properties and chemistry of 3-MCPD and the current methods of analysis in foodstuffs. The results of UK surveys of 3-MCPD occurrence in both retail foods and commercial food ingredients are discussed with particular reference to cereal, meat and dairy products. The possible mechanisms for the formation and decay of 3-MCPD in foods are suggested. The review does not cover the detailed toxicology of 3-MCPD and its occurrence in hydrolysed vegetable proteins, which have been considered elsewhere, nor possible issues such as in-vivo formation.

  6. Antitenascin antibody 81C6 armed with {sup 177}Lu: in vivo comparison of macrocyclic and acyclic ligands

    Energy Technology Data Exchange (ETDEWEB)

    Yordanov, Alexander T. [Department of Radiology, Duke University Medical Center Durham, NC 27710 (United States); Hens, Marc [Department of Radiology, Duke University Medical Center Durham, NC 27710 (United States); Pegram, Charles [Department of Pathology, 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. [Department of Radiology, Duke University Medical Center Durham, NC 27710 (United States)]. E-mail: zalut001@mc.duke.edu

    2007-02-15

    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 {gamma}-ray properties, lutetium-177 might be a better low-energy {beta}-emitter for this type of therapy. Materials and Methods: Chimeric 81C6 (ch81C6) was labeled with {sup 177}Lu 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 {sup 177}Lu-labeled immunoconjugates plus {sup 125}I-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-{sup 177}Lu and {sup 125}I-labeled ch81C6, and ch81C6-MeO-DOTA-{sup 177}Lu and {sup 125}I-labeled ch81C6. Similar comparisons were done using murine (mu) instead of ch81C6. The primary parameter utilized for evaluation was the {sup 177}Lu/{sup 125}I uptake ratio in each tissue. Results: In the studies performed in normal mice, the NHS-DOTA ligand yielded the highest {sup 177}Lu/{sup 125}I uptake ratios in tissues indicative of loss of label from the chelate; for this reason, only 1B4M and MeO-DOTA were evaluated further. The {sup 177}Lu/{sup 125}I ratio in bone increased gradually with time for the chimeric conjugates; however, there were no significant differences between ch81C6-1B4M-DTPA-{sup 177}Lu and ch81C6-MeO-DOTA-{sup 177}Lu. In contrast, mu81C6-1B4M-DTPA-{sup 177}Lu and mu81C6-MeO-DOTA-{sup 177}Lu showed a more dramatic increase in the {sup 177}Lu/{sup 125}I 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 {sup 177}Lu from these

  7. Evaluation of Novel Acyclic Nucleoside Phosphonates against Human and Animal Gammaherpesviruses Revealed an Altered Metabolism of Cyclic Prodrugs upon Epstein-Barr Virus Reactivation in P3HR-1 Cells

    Czech Academy of Sciences Publication Activity Database

    Coen, N.; Duraffour, S.; Naesens, L.; Krečmerová, Marcela; Van Den Oord, J.; Snoeck, R.; Andrei, G.

    2013-01-01

    Roč. 87, č. 22 (2013), s. 12422-12432 ISSN 0022-538X R&D Projects: GA MPO FR-TI4/625 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonate * gammaherpesvirus * Epstein-Barr virus * Kaposi's sarcoma * HPMP-5-azaC * cidofovir Subject RIV: EE - Microbiology, Virology Impact factor: 4.648, year: 2013

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

    Science.gov (United States)

    Chen, Lu; Hatti-Kaul, Rajni

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    R. V. Parish

    2001-10-01

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

  10. Isolation and Characterization of an Acyclic Isoprenoid from Semecarpus anacardium Linn. and its Antibacterial Potential in vitro - Antimicrobial Activity of Semecarpus anacardium Linn. Seeds -

    Directory of Open Access Journals (Sweden)

    Ayyakkannu Purushothaman

    2017-06-01

    Full Text Available Objectives: Semecarpus anacardium Linn. is a plant well-known for its antimicrobial, antidiabetic and anti-arthritic properties in the Ayurvedic and Siddha system of medicine. This has prompted the screening of this plant for antibacterial activity. The main aims of this study were to isolate compounds from the plant’s seeds and to evaluate their antibacterial effects on clinical bacterial test strains. Methods: The n-butanolic concentrate of the seed extract was subjected to thin layer chromatography (TLC and repeated silica gel column chromatography followed by elution with various solvents. The compound was identified based on observed spectral (IR, 1H NMR, 13C NMR and high-resolution mass spectrometry data. The well diffusion method was employed to evaluate the antibacterial activities of the isolated acyclic isoprenoid compound (final concentration: 5 - 15 μg/mL on four test bacterial strains, namely, Staphylococcus aureus (MTCC 96, Bacillus cereus

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

    Energy Technology Data Exchange (ETDEWEB)

    Kiwamoto, R., E-mail: reiko.kiwamoto@wur.nl; Spenkelink, A.; Rietjens, I.M.C.M.; Punt, A.

    2015-01-01

    Acyclic α,β-unsaturated aldehydes present in food raise a concern because the α,β-unsaturated aldehyde moiety is considered a structural alert for genotoxicity. However, controversy remains on whether in vivo at realistic dietary exposure DNA adduct formation is significant. The aim of the present study was to develop physiologically based kinetic/dynamic (PBK/D) models to examine dose-dependent detoxification and DNA adduct formation of a group of 18 food-borne acyclic α,β-unsaturated aldehydes without 2- or 3-alkylation, and with no more than one conjugated double bond. Parameters for the PBK/D models were obtained using quantitative structure–activity relationships (QSARs) defined with a training set of six selected aldehydes. Using the QSARs, PBK/D models for the other 12 aldehydes were defined. Results revealed that DNA adduct formation in the liver increases with decreasing bulkiness of the molecule especially due to less efficient detoxification. 2-Propenal (acrolein) was identified to induce the highest DNA adduct levels. At realistic dietary intake, the predicted DNA adduct levels for all aldehydes were two orders of magnitude lower than endogenous background levels observed in disease free human liver, suggesting that for all 18 aldehydes DNA adduct formation is negligible at the relevant levels of dietary intake. The present study provides a proof of principle for the use of QSAR-based PBK/D modelling to facilitate group evaluations and read-across in risk assessment. - Highlights: • Physiologically based in silico models were made for 18 α,β-unsaturated aldehydes. • Kinetic parameters were determined by in vitro incubations and a QSAR approach. • DNA adduct formation was negligible at levels relevant for dietary intake. • The use of QSAR-based PBK/D modelling facilitates group evaluations and read-across.

  12. Metabolites of the PAH diol epoxide pathway and other urinary biomarkers of phenanthrene and pyrene in workers with and without exposure to bitumen fumes.

    Science.gov (United States)

    Lotz, Anne; Pesch, Beate; Dettbarn, Gerhard; Raulf, Monika; Welge, Peter; Rihs, Hans-Peter; Breuer, Dietmar; Gabriel, Stefan; Hahn, Jens-Uwe; Brüning, Thomas; Seidel, Albrecht

    2016-11-01

    This study investigates the diol epoxide pathway of phenanthrene (PHE) together with phenolic metabolites of PHE and pyrene (PYR) in workers with and without exposure to bitumen fumes. The metabolite concentrations were determined in urine samples collected from 91 mastic asphalt workers and 42 construction workers as reference group before and after shift. During shift, vapours and aerosols of bitumen were measured according to a German protocol in the workers' breathing zone. The median concentration of vapours and aerosols of bitumen in mastic asphalt workers was 6.3 mg/m 3 . Metabolite concentrations were highest in post-shift urines of smokers with bitumen exposure and showed an increase during shift. The Spearman correlations between the creatinine-adjusted concentrations of metabolites and vapours and aerosols of bitumen in non-smokers were weak (e.g. sum of Di-OH-PYR: 0.28) or negligible (e.g. 1,2-PHE-diol: 0.08; PHE-tetrol: 0.12). Metabolites from the diol epoxide pathway of PHE were excreted in higher concentrations than phenolic metabolites (post-shift, non-smoking asphalt workers: 1,2-PHE-diol 2.59 µg/g crea vs. sum of all OH-PHE 1.87 µg/g crea). 1,2-PHE-diol was weakly correlated with PHE-tetrol (Spearman coefficient 0.30), an endpoint of the diol epoxide pathway. By contrast, we found a close correlation between the sum of 1,6-DiOH-PYR and 1,8-DiOH-PYR with 1-OH-PYR (Spearman coefficient 0.76). Most urinary PAH metabolites were higher after shift in bitumen-exposed workers, although the association with bitumen was weak or negligible likely due to the small PAH content. The additional metabolites of PHE and PYR complete the picture of the complex metabolic pathways. Nevertheless, none of the PAH metabolites can be considered to be a specific biomarker for bitumen exposure.

  13. 2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi Meresht, E. [Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, 1411713114, Tehran (Iran, Islamic Republic of); Shahrabi Farahani, T., E-mail: tshahrabi34@modares.ac.ir [Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, 1411713114, Tehran (Iran, Islamic Republic of); Neshati, J. [Research Institute of Petroleum Industry, RIPI, 1485733111, Tehran (Iran, Islamic Republic of)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Corrosion of API 5L X65 is effectively reduced by the addition of the inhibitor. Black-Right-Pointing-Pointer The techniques include weight loss, potentiodynamic polarization, EIS and AFM. Black-Right-Pointing-Pointer 2-Butyne-1,4-diol acts as a mixed-type inhibitor. Black-Right-Pointing-Pointer The adsorption of 2-butyne-1,4-diol obeys Langmuir adsorption isotherm. - Abstract: The inhibition effects of 2-butyne-1,4-diol on the corrosion susceptibility of grade API 5L X65 steel pipeline in 2 M Na{sub 2}CO{sub 3}/1 M NaHCO{sub 3} solution were studied by electrochemical techniques and weight loss measurements. The results indicated that this inhibitor was a mixed-type inhibitor, with a maximum percentage inhibition efficiency of approximately 92% in the presence of 5 mM inhibitor. Atomic force microscopy revealed that a protective film was formed on the surface of the inhibited sample. The adsorption of the inhibitor was found to conform to the Langmuir isotherm with the standard adsorption free energy of -21.08 kJ mol{sup -1}.

  14. 2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

    International Nuclear Information System (INIS)

    Sadeghi Meresht, E.; Shahrabi Farahani, T.; Neshati, J.

    2012-01-01

    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 Na 2 CO 3 /1 M NaHCO 3 solution were studied by electrochemical techniques and weight loss measurements. The results indicated that this inhibitor was a mixed-type inhibitor, with a maximum percentage inhibition efficiency of approximately 92% in the presence of 5 mM inhibitor. Atomic force microscopy revealed that a protective film was formed on the surface of the inhibited sample. The adsorption of the inhibitor was found to conform to the Langmuir isotherm with the standard adsorption free energy of −21.08 kJ mol −1 .

  15. Isolation of endosulfan sulfate-degrading Rhodococcus koreensis strain S1-1 from endosulfan contaminated soil and identification of a novel metabolite, endosulfan diol monosulfate

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Koji; Kawashima, Fujimasa [Department of Applied Biology and Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502 (Japan); Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); Takagi, Kazuhiro, E-mail: ktakagi@affrc.go.jp [Department of Applied Biology and Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502 (Japan); Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); Kataoka, Ryota [Department of Environmental Science, University of Yamanashi, 41-4-37 Takeda, Kofu, Yamanashi (Japan); Kotake, Masaaki [Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai 981-8555 (Japan); Kiyota, Hiromasa [Graduate School of Environmental & Life Science, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530 (Japan); Yamazaki, Kenichi [Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); Sakakibara, Futa [Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 (Japan); The Japan Society for the Promotion of Science(JSPS), 1-8 Chiyoda-ku, Tokyo (Japan); Okada, Sanae [Department of Applied Biology and Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502 (Japan)

    2016-05-13

    An aerobic endosulfan sulfate-degrading bacterium, Rhodococcus koreensis strain S1-1, was isolated from soil to which endosulfan had been applied annually for more than 10 years until 2008. The strain isolated in this work reduced the concentration of endosulfan sulfate (2) from 12.25 μM to 2.11 μM during 14 d at 30 °C. Using ultra performance liquid chromatography-electrospray ionization-mass spectroscopy (UPLC-ESI-MS), a new highly water-soluble metabolite possessing six chlorine atoms was found to be endosulfan diol monosulfate (6), derived from 2 by hydrolysis of the cyclic sulfate ester ring. The structure of 6 was elucidated by chemical synthesis of the candidate derivatives and by HR-MS and UPLC-MS analyses. Therefore, it was suggested that the strain S1-1 has a new metabolic pathway of 2. In addition, 6 was expected to be less toxic among the metabolites of 1 because of its higher water-solubility. -- Highlights: •A novel endosulfan sulfate-degrading bacterium was isolated and named strain S1-1. •Strain S1-1 degraded endosulfan sulfate into a novel metabolite endosulfan diol monosulfate. •Endosulfan diol monosulfate showed higher polarity than other known metabolites of endosulfan. •We proposed the plausible metabolic pathway of endosulfan in terms of organic chemistry.

  16. Isolation of endosulfan sulfate-degrading Rhodococcus koreensis strain S1-1 from endosulfan contaminated soil and identification of a novel metabolite, endosulfan diol monosulfate

    International Nuclear Information System (INIS)

    Ito, Koji; Kawashima, Fujimasa; Takagi, Kazuhiro; Kataoka, Ryota; Kotake, Masaaki; Kiyota, Hiromasa; Yamazaki, Kenichi; Sakakibara, Futa; Okada, Sanae

    2016-01-01

    An aerobic endosulfan sulfate-degrading bacterium, Rhodococcus koreensis strain S1-1, was isolated from soil to which endosulfan had been applied annually for more than 10 years until 2008. The strain isolated in this work reduced the concentration of endosulfan sulfate (2) from 12.25 μM to 2.11 μM during 14 d at 30 °C. Using ultra performance liquid chromatography-electrospray ionization-mass spectroscopy (UPLC-ESI-MS), a new highly water-soluble metabolite possessing six chlorine atoms was found to be endosulfan diol monosulfate (6), derived from 2 by hydrolysis of the cyclic sulfate ester ring. The structure of 6 was elucidated by chemical synthesis of the candidate derivatives and by HR-MS and UPLC-MS analyses. Therefore, it was suggested that the strain S1-1 has a new metabolic pathway of 2. In addition, 6 was expected to be less toxic among the metabolites of 1 because of its higher water-solubility. -- Highlights: •A novel endosulfan sulfate-degrading bacterium was isolated and named strain S1-1. •Strain S1-1 degraded endosulfan sulfate into a novel metabolite endosulfan diol monosulfate. •Endosulfan diol monosulfate showed higher polarity than other known metabolites of endosulfan. •We proposed the plausible metabolic pathway of endosulfan in terms of organic chemistry.

  17. Infrared, Raman and density functional characterization and structural study of 2-Nitro-2-phenyl-propane-1,3-diol

    Science.gov (United States)

    Kaya, Mehmet Fatih; Bağlayan, Özge; Kaya, Esma Güneş; Alver, Özgür

    2017-12-01

    Nitro compound and nitro derivatives are industrially important to produce rubber and agricultural chemicals. In this study, one of the promising derivatives of nitro compound 2-Nitro-2-phenyl-propane-1,3-diol (2NPP) is examined in detail. FT-Infrared and dispersive Raman spectra of 2NPP (C9H11NO4) were respectively recorded in 4000-10 cm-1 and 4000-100 cm-1. The bond distances and angles, conformational distributions, vibrational frequencies and the assignment of each mode, some thermodynamic parameters and reactivity descriptors: total energy, hardness, chemical potential, electrophilicity index, electronegativity, frontier orbitals energy gap of 2NPP were investigated by using DFT/B3LYP method with 6-31++G (d,p) basis set. In order to locate the global minimum on the potential energy surface of 2NPP, a beforehand conformational examinations were carried out using Spartan 10 along with semi-emprical PM6 method. The results of conformational analyses showed that there are five possible conformations having energies under 2 kcal/mol. Comparison of the theoretical and experimental results clearly indicates that density functional hybrid B3LYP/6-31++G (d,p) level of theory can be used to predict vibrational frequencies and structural parameters of 2NPP. Further, C1 geometry is considered to be the global minimum conformation of 2NPP.

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

    International Nuclear Information System (INIS)

    Haque, M.E.

    2003-09-01

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

  19. Toxic mechanisms of 3-monochloropropane-1,2-diol on progesterone production in R2C rat leydig cells.

    Science.gov (United States)

    Sun, Jianxia; Bai, Shun; Bai, Weibin; Zou, Feiyan; Zhang, Lei; Su, Zhijian; Zhang, Qihao; Ou, Shiyi; Huang, Yadong

    2013-10-16

    3-Monochloropropane-1,2-diol (3-MCPD) is a well-known food processing contaminant that has been shown to impede the male reproductive function. However, its mechanism of action remains to be elucidated. In this study, the effects of 3-MCPD on progesterone production were investigated using R2C Leydig cells. 3-MCPD caused concentration-dependent inhibition of cell viability at the IC25, IC50, and IC75 levels of 1.027, 1.802, and 3.160 mM, respectively. Single cell gel/comet assay and atomic force microscopy assay showed that 3-MCPD significantly induced early apoptosis. In addition, 3-MCPD significantly reduced progesterone production by reducing the expression of cytochrome P450 side-chain cleavage enzyme, steroidogenic acute regulatory protein, and 3β-hydroxysteroid dehydrogenase in R2C cells. The change in steroidogenic acute regulatory protein expression was highly consistent with progesterone production. Furthermore, the mitochondrial membrane potential and cAMP significantly decreased.

  20. Structural and vibrational study of a neurotransmitter molecule: Dopamine [4-(2-aminoethyl) benzene-1,2-diol].

    Science.gov (United States)

    Jha, Omkant; Yadav, T K; Yadav, R A

    2018-01-15

    Structural and vibrational studies for the most stable conformer of dopamine {4-(2-Aminoethyl) benzene-1, 2-diol} have been carried out at the DFT/B3LYP/6-311++G** level using the Gaussian 09 software. The IR and Raman spectra have been recorded and analyzed in light of the computed vibrational parameters using the DFT and the PEDs computed with the help of the GAR2PED software. Some of the fundamentals have considerably changed frequencies in going from benzene to dopamine. Except the rocking and wagging modes of the NH 2 group the other four modes are pure group modes. The rocking and wagging modes of the NH 2 group show mixing with the other modes. The two OH stretching vibrations are highly localized modes. The Kekule phenyl ring stretching mode is found to remain almost unchanged. The HOMO-LUMO study suggests the existence of charge transfer within the molecule and the energy gap supports the pharmacological active property of the dopamine molecule. The NBO analysis has been carried out to understand the proper and improper hydrogen bonding. Copyright © 2017. Published by Elsevier B.V.

  1. Dietary exposure of Hong Kong adults to fatty acid esters of 3-monochloropropane-1,2-diol.

    Science.gov (United States)

    Chung, H Y; Chung, Stephen W C; Chan, B T P; Ho, Yuk Yin; Xiao, Ying

    2013-01-01

    A total of 290 individual food samples were collected in Hong Kong, China, for 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters analysis. Most samples were processed food and in ready-to-eat form. The results show that the levels of 3-MCPD fatty acid esters were high in biscuits, fats and oils, snacks and Chinese pastry with mean bound 3-MCPD levels of 440, 390, 270 and 270 μg kg⁻¹, respectively. The dietary exposures to bound 3-MCPD of average and high adult consumers were estimated to be 0.20 and 0.53 μg kg bw⁻¹ day⁻¹, respectively. The primary toxicological concern of 3-MCPD fatty acid esters is its potential to release 3-MCPD in vivo during digestion in the gastrointestinal tract. 3-MCPD would affect the kidney, the central nervous system and the male reproductive system of rats. Assuming that 100% of the 3-MCPD was released from 3-MCPD fatty acid esters by hydrolysis in the digestive system, the dietary exposures to 3-MCPD for average and high adult consumers were only 10% and 26% of the provisional maximum tolerable daily intake (PMTDI) of 3-MCPD established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) (2 μg kg bw⁻¹ day⁻¹), respectively. The results suggest that both average and high adult consumers are unlikely to experience major toxicological effects of 3-MCPD.

  2. Lack of effect on rat testicular organogenesis after in utero exposure to 3-monochloropropane-1,2-diol (3-MCPD).

    Science.gov (United States)

    El Ramy, Rosy; Ould Elhkim, Mostafa; Poul, Martine; Forest, Maguelone G; Leduque, Patrick; Le Magueresse-Battistoni, Brigitte

    2006-10-01

    3-Monochloropropane-1,2-diol (3-MCPD) is a food-born contaminant known to display toxic effects on male reproduction, producing infertility in rats and humans. Using the rat as a model, we investigated whether or not testicular organogenesis, which, in the rat species, occurs during the second half of gestation, was at particular risk regarding 3-MCPD toxicity. Pregnant rats were given daily doses of 5, 10 or 25 mg/kg BW of 3-MCPD from days 11.5-18.5 postcoitum (dpc). On 19.5 dpc, testes were removed from fetuses for histological examination and testosterone analysis. Eight genes were selected among the differentiation markers of testicular cell lineages, and their expression was studied by RT-PCR. The levels of 3-MCPD and its main metabolite, beta-chlorolactic acid, were assayed in fetal tissues and dam plasma. Our results show a statistically significant decrease in the mean body weight gain of pregnant rats treated with 10 and 25 mg/kg BW of 3-MCPD. Fetal testes exposed to 3-MCPD exhibited normal histology and produced testosterone at levels that were similar to controls. In addition, 3-MCPD did not alter gene expression in the fetal testes. This lack of effect occurred under conditions where 3-MCPD and beta-chlorolactic acid were found to readily cross the placental barrier and diffuse throughout the fetal tissues. Our findings indicate that 3-MCPD has minimal effect on rat testicular organogenesis.

  3. Optimization of palm oil physical refining process for reduction of 3-monochloropropane-1,2-diol (3-MCPD) ester formation.

    Science.gov (United States)

    Zulkurnain, Musfirah; Lai, Oi Ming; Tan, Soo Choon; Abdul Latip, Razam; Tan, Chin Ping

    2013-04-03

    The reduction of 3-monochloropropane-1,2-diol (3-MCPD) ester formation in refined palm oil was achieved by incorporation of additional processing steps in the physical refining process to remove chloroester precursors prior to the deodorization step. The modified refining process was optimized for the least 3-MCPD ester formation and acceptable refined palm oil quality using response surface methodology (RSM) with five processing parameters: water dosage, phosphoric acid dosage, degumming temperature, activated clay dosage, and deodorization temperature. The removal of chloroester precursors was largely accomplished by increasing the water dosage, while the reduction of 3-MCPD esters was a compromise in oxidative stability and color of the refined palm oil because some factors such as acid dosage, degumming temperature, and deodorization temperature showed contradictory effects. The optimization resulted in 87.2% reduction of 3-MCPD esters from 2.9 mg/kg in the conventional refining process to 0.4 mg/kg, with color and oil stability index values of 2.4 R and 14.3 h, respectively.

  4. Indole-3-acetic acid/diol based pH-sensitive biological macromolecule for antibacterial, antifungal and antioxidant applications.

    Science.gov (United States)

    G, Chitra; D S, Franklin; S, Sudarsan; M, Sakthivel; S, Guhanathan

    2017-02-01

    Indole-3-acetic acid (IAA)/diol based pH-sensitive biopolymeric hydrogels with tunable biological properties (cytotoxicity, anti-oxidant and anti-fungal) have been synthesized via condensation polymerization. The present study focused on the synthesis of heterocyclic hydrogel using citric acid (CA), indole-3-acetic acid (IAA) and diethylene glycol (DEG) by condensation polymerization. The hydrogels revealed a pH-sensitive swelling behaviour, with increased swelling in acidic media, then turns to decreased the swelling in the basic media. The hydrogel samples were tested for antifungal activity against Aspergillus fumigates, Rhizopusoryzae and Candida albicans at different concentrations using ketoconazole as positive control and DMSO as negative control for antifungal activity. Antioxidant activity increasing nature in DPPH than NO radical compared with rutin and confirmed non toxic property using cytotoxicity analysis. The biopolymeric hydrogels were characterized by Fourier transform infrared (FT-IR) spectroscopy, 1 H NMR, 13 C NMR, TGA, DSC followed by scanning electron microscopy (SEM). Such hydrogels with antioxidant properties is recommended for medical applications such as bandages, catheters, drains and tubes to prevent infection. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. The resolution of acyclic P-stereogenic phosphine oxides via the formation of diastereomeric complexes: A case study on ethyl-(2-methylphenyl)-phenylphosphine oxide.

    Science.gov (United States)

    Bagi, Péter; Varga, Bence; Szilágyi, András; Karaghiosoff, Konstantin; Czugler, Mátyás; Fogassy, Elemér; Keglevich, György

    2018-04-01

    As an example of acyclic P-chiral phosphine oxides, the resolution of ethyl-(2-methylphenyl)-phenylphosphine oxide was elaborated with TADDOL derivatives, or with calcium salts of the tartaric acid derivatives. Besides the study on the resolving agents, several purification methods were developed in order to prepare enantiopure ethyl-(2-methylphenyl)-phenylphosphine oxide. It was found that the title phosphine oxide is a racemic crystal-forming compound, and the recrystallization of the enantiomeric mixtures could be used for the preparation of pure enantiomers. According to our best method, the (R)-ethyl-(2-methylphenyl)-phenylphosphine oxide could be obtained with an enantiomeric excess of 99% and in a yield of 47%. Complete racemization of the enantiomerically enriched phosphine oxide could be accomplished via the formation of a chlorophosphonium salt. Characterization of the crystal structures of the enantiopure phosphine oxide was complemented with that of the diastereomeric intermediate. X-ray analysis revealed the main nonbonding interactions responsible for enantiomeric recognition. © 2018 Wiley Periodicals, Inc.

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

    Directory of Open Access Journals (Sweden)

    Daniel Lachmann

    2010-02-01

    Full Text Available The Nile Blue chromophore was incorporated into oligonucleotides using “click” chemistry for the postsynthetic modification of oligonucleotides. These were synthesized using DNA building block 3 bearing an alkyne group and reacted with the azide 4. (R-3-amino-1,2-propanediol was applied as the linker between the phosphodiester bridges. Two sets of DNA duplexes were prepared. One set carried the chromophore in an A-T environment, the second set in a G-C environment. Both were characterized by optical spectroscopy. Sequence-dependent fluorescence quenching was applied as a sensitive tool to compare the stacking interactions with respect to the chirality of the acyclic linker attachment. The results were compared to recent results from duplexes that carried the Nile Blue label in a sequentially and structurally identical context, except for the opposite chirality of the linker ((S-3-amino-1,2-propandiol. Only minor, negligible differences were observed. Melting temperatures, UV–vis absorption spectra together with fluorescence quenching data indicate that Nile Blue stacks perfectly between the adjacent base pairs regardless of whether it has been attached via an S- or R-configured linker. This result was supported by geometrically optimized DNA models.

  7. Formation of diastereomeric benzo[a]pyrene diol epoxide-guanine adducts in p53 gene-derived DNA sequences.

    Science.gov (United States)

    Matter, Brock; Wang, Gang; Jones, Roger; Tretyakova, Natalia

    2004-06-01

    G --> T transversion mutations in the p53 tumor suppressor gene are characteristic of smoking-related lung tumors, suggesting that these genetic changes may result from exposure to tobacco carcinogens. It has been previously demonstrated that the diol epoxide metabolites of bay region polycyclic aromatic hydrocarbons present in tobacco smoke, e.g., benzo[a]pyrene diol epoxide (BPDE), preferentially bind to the most frequently mutated guanine nucleotides within p53 codons 157, 158, 248, and 273 [Denissenko, M. F., Pao, A., Tang, M., and Pfeifer, G. P. (1996) Science 274, 430-432]. However, the methodology used in that work (ligation-mediated polymerase chain reaction in combination with the UvrABC endonuclease incision assay) cannot establish the chemical structures and stereochemical identities of BPDE-guanine lesions. In the present study, we employ a stable isotope-labeling HPLC-MS/MS approach [Tretyakova, N., Matter, B., Jones, R., and Shallop, A. (2002) Biochemistry 41, 9535-9544] to analyze the formation of diastereomeric N(2)-BPDE-dG lesions within double-stranded oligodeoxynucleotides representing p53 lung cancer mutational hotspots and their surrounding DNA sequences. (15)N-labeled dG was placed at defined positions within DNA duplexes containing 5-methylcytosine at all physiologically methylated sites, followed by (+/-)-anti-BPDE treatment and enzymatic hydrolysis of the adducted DNA to 2'-deoxynucleosides. Capillary HPLC-ESI(+)-MS/MS was used to establish the amounts of (-)-trans-N(2)-BPDE-dG, (+)-cis-N(2)-BPDE-dG, (-)-cis-N(2)-BPDE-dG, and (+)-trans-N(2)-BPDE-dG originating from the (15)N-labeled bases. We found that all four N(2)-BPDE-dG diastereomers were formed preferentially at the methylated CG dinucleotides, including the frequently mutated p53 codons 157, 158, 245, 248, and 273. The contributions of individual diastereomers to the total adducts number at a given site varied between 70.8 and 92.9% for (+)-trans-N(2)-BPDE-dG, 5.6 and 16.7% for

  8. A glucose-responsive pH-switchable bioelectrocatalytic sensor based on phenylboronic acid-diol specificity

    International Nuclear Information System (INIS)

    Gao, Peiyi; Wang, Zhihua; Yang, Lele; Ma, Tengfei; Yang, Ling; Guo, Qianqiong; Huang, Shasheng

    2015-01-01

    Graphical abstract: A pH-switchable bioelectrocatayltic sensor was developed, which exhibited an obvious anodic current in acidic conditions as “ON” state, yet a prohibited signal in alkaline conditions as “OFF” state. With the change of pH and/or the presence of glucose, our proposed biosensor produced the corresponding amplified signal, providing a better sensitivity. - Abstract: Aminophenylboronic acid moieties were covalently grafted onto mercaptobenzoic acid moieties, and glucose oxidase was then immobilized through boronic acid-diol specific recognition to form a pH-sensitive electrosensor switching between pH 5.8 and pH 8.0 base solution. Using potassium ferricyanide as electroactive probe, the response was intensified in acidic condition while hindered in alkaline condition. The sharp and stable contrast in current was performed alternately upon the change of pH like a “pH switch”. In the presence of glucose, the response to glucose was further amplified catalytically by glucose oxidase on “ON” state, while electron transfer was inhibited on “OFF” state. Furthermore, when our sensor was on “ON” state, it showed a good linearity ranging from 0 to 30 μmol L −1 of glucose, with a detection limit of 348 nmol L −1 (S/B = 3) and a dynamic range extending to 50 μmol L −1 . Glucose-responsive, pH-switchable and catalytically-amplified, our biosensor provided a new method for the detection of glucose in the form of pH switch in human serum sample, and was promising to more complicated environment

  9. Novel Magnetic Microprobe with Benzoboroxole-Modified Flexible Multisite Arm for High-Efficiency cis-Diol Biomolecule Detection.

    Science.gov (United States)

    Chen, Guosheng; Huang, Siming; Kou, Xiaoxue; Zhang, Jin'ge; Wang, Fuxin; Zhu, Fang; Ouyang, Gangfeng

    2018-03-06

    With regard to regulating a variety of biological events, including molecular recognition, signal transduction, cell adhesion, and immune response, cis-diol biomolecules, such as saccharides and glycoproteins, play vital roles. However, saccharides and glycoproteins in living systems usually exist in very low abundance, along with abundant interfering components. High-efficiency detection of saccharides and glycoproteins is a challenging yet highly impactful area of research. Herein, we reported a novel magnetic microprobe with a benzoboroxole-modified flexible multisite arm (PEG 2000-grafted PAMAM dendrimers; the microprobe was denoted as BFMA-MNP) for high-efficiency saccharides detection. The extraction capacity was significantly improved by ∼2 orders of magnitude, because of the integration of the enhanced hydrophilicity and multivalency effects in benzoboroxoles and the enhanced accessibility of the binding sites within the PEG 2000-grafted PAMAM dendrimers. As a result, the proposed approach possessed several advantages, compared with previous boronic acid-based methods, including ultrahigh sensitivity (limit of detection was <1 ng/mL), wide linear range (ranged from 0.5 μM to 2000 μM), and applicable in physiological pH condition. Furthermore, we established a general BFMA-MNP/glycoproteins/AuNPs sandwich assay to realize the visual glycoprotein qualitative screening for the first time. The unique sandwich assay possessed the dual nature of the magnetic separation by BFMA-MNPs and specific coloration by citrate-coated AuNPs. This visual sandwich assay enabled fast differentiation of the existence of glycoproteins in complicated samples without any advanced instruments. We believe the proposed BFMA-MNP microprobe herein will advance the ideas to detect and identify trace saccharides and glycoproteins in important fields such as glycomics and glycoproteomics.

  10. Altered susceptibility of an obese rat model to 13-week subchronic toxicity induced by 3-monochloropropane-1,2-diol.

    Science.gov (United States)

    Toyoda, Takeshi; Cho, Young-Man; Akagi, Jun-Ichi; Mizuta, Yasuko; Matsushita, Kohei; Nishikawa, Akiyoshi; Imaida, Katsumi; Ogawa, Kumiko

    2017-01-01

    3-Monochloropropane-1,2-diol (3-MCPD) is a heat-induced food contaminant that has been shown to be a nongenotoxic renal carcinogen. Although the toxicity of 3-MCPD has been widely investigated for decades, there is a further concern that 3-MCPD might exert more potent toxicity in high-risk population with underlying diseases such as hyperlipidemia associated with obesity. In the present study, we performed a 13-week subchronic toxicity study for 3-MCPD using an obesity rat model to investigate the differences in susceptibility between obese and normal individuals. Male F344 and obese Zucker (lean and fatty) rats were administered 0, 9, 28.5, 90, 285, or 900 ppm 3-MCPD in drinking water for 13 weeks. 3-MCPD treatment decreased body weight gain, increased relative kidney weights, induced anemia, and induced epithelial cell necrosis in epididymal ducts in all 3 strains. The degrees of epididymal damage were higher in F344 and lean rats than in fatty rats, while renal toxicity was most potent in F344 rats and comparable in lean and fatty rats. In contrast, the hematology data indicated that anemia was worse in fatty rats than in F344 and lean rats, and a significant decrease in hematopoietic cells in the bone marrow was observed only in fatty rats. The no-observed-adverse-effect level was estimated to be 28.5 ppm in all 3 strains for 3-MCPD. These results suggested that obese Zucker rats may be more susceptible to 3-MCPD-dependent toxicity in the hematopoietic tissues than their lean counterparts.

  11. Partial molar volumes of organic solutes in water. XXIV. Selected alkane-α,ω-diols at temperatures T = 298 K to 573 K and pressures up to 30 MPa

    International Nuclear Information System (INIS)

    Cibulka, Ivan; Hnědkovský, Lubomír

    2013-01-01

    Highlights: • Standard molar volumes of three alkane-α,ω-diols (C 5 , C 8 , C 9 ) in water are presented. • Data were obtained in the range T from (298 to 573) K and p up to 30 MPa. • Dependences on carbon atom number, temperature, and pressure are analysed. -- Abstract: Density data for dilute aqueous solutions of three alkane-α,ω-diols (pentane-1,5-diol, octane-1,8-diol, nonane-1,9-diol) are presented together with standard molar volumes (partial molar volumes at infinite dilution) calculated from the experimental data. The measurements were performed at temperatures from T = 298 K up to T = 573 K. Experimental pressures were slightly above the saturation vapour pressure of water, and (15 and 30) MPa. The data were obtained using a high-temperature high-pressure flow vibrating-tube densimeter. Measured standard molar volumes were combined with data previously published for other members of the homologous series and discussed. Experimental standard molar volumes were correlated as a function of temperature and pressure using an empirical polynomial function. Dependences of standard molar volumes on temperature and pressure were analysed. Contributions of the methylene group to the standard molar volume were also evaluated and discussed

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

    Directory of Open Access Journals (Sweden)

    Amber L. Thompson

    2009-11-01

    Full Text Available X-ray crystallographic analysis of the title hydrobromide salt, C10H20N+·Br−, of (1R,2S,3R,5R,8aR-3-hydroxymethyl-5-methyloctahydroindolizine-1,2-diol defines the absolute and relative stereochemistry at the five chiral centres in steviamine, a new class of polyhydroxylated indolizidine alkaloid isolated from Stevia rebaudiana (Asteraceae leaves. In the crystal structure, molecules are linked by intermolecular O—H...Br and N—H...Br hydrogen bonds, forming double chains around the twofold screw axes along the b-axis direction. Intramolecular O—H...O interactions occur.

  13. Multipoint attachment to a support protects enzyme from inactivation by organic solvents: alpha-Chymotrypsin in aqueous solutions of alcohols and diols.

    Science.gov (United States)

    Mozhaev, V V; Sergeeva, M V; Belova, A B; Khmelnitsky, Y L

    1990-03-25

    Inactivation of alpha-chymotrypsin in aqueous solutions of alcohols and diols proceeds both reversibly and irreversibly. Reversible loss of the specific enzyme activity results from conformational changes (unfolding) of the enzyme detected by fluorescence spectroscopy. Multipoint covalent attachment to the matrix of polyacryl-amide gel by copolymerization method stabilizes alpha-chymotrypsin from denaturation by alcohols, the stabilizing effect increasing with the number of bonds between the protein and the support. Immobilization protects the enzyme also from irreversible inactivation by organic solvents resulting from bimolecular aggregation and autolysis.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    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 consumed in the other chamber in either a rhodium-catalysed hydroformylation of olefins or a palladium-catalysed reductive carbonylation of aryl halides. Hexane-1,6-diol was found to be the optimum alcohol for both reactions where moderate to excellent yields were obtained of the product aldehydes...

  15. Development of analytical methods for the gas chromatographic determination of 1,2-epoxy-3-butene, 1,2:3,4-diepoxybutane, 3-butene-1,2-diol, 3,4-epoxybutane-1,2-diol and crotonaldehyde from perfusate samples of 1,3-butadiene exposed isolated mouse and rat livers

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, S.; Schuster, A.; Filser, J.G.

    2003-07-01

    Mutagenicity and carcinogenicity of 1,3-butadiene (BD) highly probably results from epoxide metabolites as 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB) and 3,4-epoxybutane-1,2-diol (EBD). A further metabolite crotonaldehyde (CA) has also been discussed to be relevant. So far, in BD exposed rodents only EB and DEB concentrations had been quantified. However, the methods used were either not very sensitive or instrumentally expensive. Therefore, the goal of the present work was to establish simple analytical methods selective and sensitive enough to determine all of these compounds and a further secondary BD intermediate, 3-butene-1,2-diol (B-diol), in BD exposed rodent livers. The once-through perfused liver system was chosen for testing the applicability of the methods to be developed, since it enables BD exposures of this quantitatively most relevant metabolising organ near to the in-vivo situation. All the metabolites were extracted from the aqueous perfusion medium and analysed using a gas chromatograph equipped with a mass selective detector (GC/MS) in the PCI mode. (orig.)

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

    Science.gov (United States)

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

    2016-03-07

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

  17. Transition from androgenic to neurosteroidal action of 5α-androstane-3α, 17β-diol through the type A γ-aminobutyric acid receptor in prostate cancer progression.

    Science.gov (United States)

    Xia, Ding; Lai, Doan V; Wu, Weijuan; Webb, Zachary D; Yang, Qing; Zhao, Lichao; Yu, Zhongxin; Thorpe, Jessica E; Disch, Bryan C; Ihnat, Michael A; Jayaraman, Muralidharan; Dhanasekaran, Danny N; Stratton, Kelly L; Cookson, Michael S; Fung, Kar-Ming; Lin, Hsueh-Kung

    2018-04-01

    Androgen ablation is the standard of care prescribed to patients with advanced or metastatic prostate cancer (PCa) to slow down disease progression. Unfortunately, a majority of PCa patients under androgen ablation progress to castration-resistant prostate cancer (CRPC). Several mechanisms including alternative intra-prostatic androgen production and androgen-independent androgen receptor (AR) activation have been proposed for CRPC progression. Aldo-keto reductase family 1 member C3 (AKR1C3), a multi-functional steroid metabolizing enzyme, is specifically expressed in the cytoplasm of PCa cells; and positive immunoreactivity of the type A γ-aminobutyric acid receptor (GABA A R), an ionotropic receptor and ligand-gated ion channel, is detected on the membrane of PCa cells. We studied a total of 72 radical prostatectomy cases by immunohistochemistry, and identified that 21 cases exhibited positive immunoreactivities for both AKR1C3 and GABA A R. In the dual positive cancer cases, AKR1C3 and GABA A R subunit α 1 were either expressed in the same cells or in neighboring cells. Among several possible substrates, AKR1C3 reduces 5α-dihydrotesterone (DHT) to form 5α-androstane-3α, 17β-diol (3α-diol). 3α-diol is a neurosteroid that acts as a positive allosteric modulator of the GABA A R in the central nervous system (CNS). We examined the hypothesis that 3α-diol-regulated pathological effects in the prostate are GABA A R-dependent, but are independent of the AR. In GABA A R-positive, AR-negative human PCa PC-3 cells, 3α-diol significantly stimulated cell growth in culture and the in ovo chorioallantoic membrane (CAM) xenograft model. 3α-diol also up-regulated expression of the epidermal growth factor (EGF) family of growth factors and activation of EGF receptor (EGFR) and Src as measured by quantitative polymerase chain reaction and immunoblotting, respectively. Inclusion of GABA A R antagonists reversed 3α-diol-stimulated tumor cell growth, expression of EGF

  18. The Analysis Methods Of 3-Monochloropropane-1,2-Diol and Glycydyl Esters in Foods, Mitigation Studies, and Current Developments About their Effects on Health

    Directory of Open Access Journals (Sweden)

    Aslı Yıldırım

    2017-12-01

    Full Text Available Chloropropanols are known as undesired food contaminants liberated during the processing of various food products. When the adverse effects of chloropropanols, especially 3-monochloropropane-1,2-diol (3-MCPD, 2-monochloropropane-1,3-diol (2-MCPD and glycidols along with their esters were first understood, the studies about the detection and mitigation of these compounds were accelerated. 3-MCPD, which was detected in food products in higher amounts when compared to other chloropropanols, usually occurs during refining process of vegetable oils, especially in deodorisation step. The novel methods in terms of the analysis of 3-MCPD and other chloropropanols are continuously updated. However, there are two basic methods today namely direct and indirect methods. Direct methods enable to detect all of the esters individually, yet, due to the necessity of a huge number of reference standards, indirect methods are currently more preferred. The first essential step of reducing chloropropanols in food products is to determine the proper analysis method. In this review, general information, new developments in analysis methods, mitigation studies and the toxigolocial data about various chloropropanols were summarized.

  19. Pyriculins A and B, two monosubstituted hex-4-ene-2,3-diols and other phytotoxic metabolites produced by Pyricularia grisea isolated from buffelgrass (Cenchrus ciliaris).

    Science.gov (United States)

    Masi, Marco; Meyer, Susan; Górecki, Marcin; Mandoli, Alessandro; Di Bari, Lorenzo; Pescitelli, Gennaro; Cimmino, Alessio; Cristofaro, Massimo; Clement, Suzette; Evidente, Antonio

    2017-11-01

    Pyricularia grisea has been identified as a foliar pathogen on buffelgrass (Cenchrus ciliaris) in North America and was studied as a potential source of phytotoxins for buffelgrass control. Two monosubstituted hex-4-ene-2,3-diols, named pyriculins A and B, were isolated from its culture filtrate organic extract together with (10S,11S)-(-)-epipyriculol, trans-3,4-dihydro-3,4,8-trihydroxy-1(2H)-napthalenone, and (4S)-(+)-isosclerone. Pyriculins A and B were characterized by spectroscopic (essentially nuclear magnetic resonance [NMR], High-resolution electrospray ionization mass spectrometry [HRESIMS]) and chemical methods such as (4E)-1-(4-hydroxy-1,3-dihydroisobenzofuran-1-yl)hex-4-ene-2,3-diols. The relative and absolute configuration of these compounds was determined by a combination of spectroscopic (NMR, electronic circular dichroism [ECD]) and computational tools. When bioassayed in a buffelgrass coleoptile and radicle elongation test, (10S,11S)-(-)-epipyriculol proved to be the most toxic compound. Seed germination was much reduced and slowed with respect to the control and radicles failed to elongate. All five compounds delayed germination, but only (10S,11S)-(-)-epipyriculol was able to prevent radicle development of buffelgrass seedlings. It had no effect on coleoptile elongation, while the other four compounds caused significantly increased coleoptile development relative to the control. © 2017 Wiley Periodicals, Inc.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-08

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

  1. Sterol synthesis. A novel reductive rearrangement of an alpha,beta-unsaturated steroidal epoxide; a new chemical synthesis of 5alpha-cholest-8(14)-en-3beta, 15alpha-diol.

    Science.gov (United States)

    Parish, E J; Schroepfer, G J

    1977-04-01

    Reduction of 3beta-benzoyloxy-14alpha,15alpha-epoxy-5alpha-cholest-7-ene with either lithium triethylboro-hydride or lithium aluminum hydride (4 molar excess) gave 5-alpha-cholest-8(14)-en-3beta,15alpha-diol in high yield. Reduction of the epoxy ester with lithium triethylborodeuteride or lithium aluminum deuteride (4 molar excess) gave [7alpha-2-H]-5alpha-cholest-8(14)-en-3beta,15alpha-diol. Reduction of 2beta-benzoyloxy-14alpha,15alpha-epoxy-5alpha-cholest-7-ene with a large excess (24 molar excess) of lithium aluminum hydride gave, in addition to the expected 5alpha-cholest-8(14)-en-3beta,15alpha-diol, a significant yield (33%) of 5alpha-cholest-8(14)-en-3beta-o1. Reduction of the epoxy ester with a large excess (24 molar excess) of lithium aluminum deuteride gave [7alpha-2H]-5alpha-cholest-8(14)-en-3beta,15alpha-diol and 5alpha-cholest-8(14)-en-3beta-o1 which contained two atoms of stably bound deuterium.

  2. Transfer and control of molecular chirality in the 1 : 2 host-guest supramolecular complex consisting of Mg(II)bisporphyrin and chiral diols: the effect of H-bonding on the rationalization of chirality.

    Science.gov (United States)

    Ikbal, Sk Asif; Brahma, Sanfaori; Rath, Sankar Prasad

    2014-11-21

    A clear rationalization of the origin of chirality transfer from an optically active diol guest to an achiral Mg(ii)bisporphyrin host in a series of 1 : 2 host-guest supramolecular complexes has been reported here that has so far remained the most outstanding issue for the chirogenic process.

  3. 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

    Science.gov (United States)

    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...

  4. Ruthenium-complex catalyzed N-(cyclo)alkylation of aromatic amines with diols. Selective synthesis of N-(n-hydroixyalkyl)anilines of type PhNH(CH2)nOH and of some bioactive arylpiperazines,

    NARCIS (Netherlands)

    Koten, G. van; Abbenhuis, R.A.T.M.; Boersma, J.

    1998-01-01

    A new class of well-defined neutral mono-, and dicationic ruthenium(II) complexes containing a neutral terdentate donor system [C5H3N(CH2E)(2)-2,6] (E = PPh2 (PNP) or NMe2 (NN'N)) has been found effective as catalyst precursor in N-(cyclo)alkylation reactions of aromatic amines with diols

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

    Directory of Open Access Journals (Sweden)

    Rafat Milad Mohareb

    2011-07-01

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

  6. Purification and identification of 4-allylbenzene-1,2-diol: an antilisterial and biofilm preventing compound from the leaves of Piper betle L. var Pachaikodi.

    Science.gov (United States)

    Kavitha, Sekar; HariKrishnan, Adhikesavan; Jeevaratnam, Kadirvelu

    2017-12-22

    Antibiotic-resistant food-borne Listeriosis has been rising with up to 30% mortality threat in humans since several decades. Hence, discovering antilisterial from the extracts of ethnomedicinal plants may be of value as a novel antidote. In our preceding study, we reported that ethanolic extract of Piper betle L. var Pachaikodi leaves exhibited antibacterial activity towards Listeria monocytogenes MTCC 657. Consequently in the present study, the bioactive molecule responsible for anti-Listeria activity was purified and identified as 4-allylbenzene-1,2-diol. This identified bioactive compound may have significance while used as antimicrobials and/or food additives in food processing sector as evidenced by dual action: biofilm inhibition and pore formation on cell membrane.

  7. Asymmetric Diels-Alder Reaction of α,β-Unsaturated Oxazolidin-2-one Derivatives Catalyzed by a Chiral Fe(III)-Bipyridine Diol Complex.

    Science.gov (United States)

    Li, Mao; Carreras, Virginie; Jalba, Angela; Ollevier, Thierry

    2018-02-16

    An asymmetric Fe III -bipyridine diol catalyzed Diels-Alder reaction of α,β-unsaturated oxazolidin-2-ones has been developed. Among various Fe II /Fe III salts, Fe(ClO 4 ) 3 ·6H 2 O was selected as the Lewis acid of choice. The use of a low catalyst loading (2 mol % of Fe(ClO 4 ) 3 ·6H 2 O and 2.4 mol % of Bolm's ligand) afforded high yields (up to 99%) and high enantiomeric excesses (up to 98%) of endo-cycloadducts for the Diels-Alder reaction between cyclopentadiene and substituted acryloyloxazolidin-2-ones. Other noncyclic dienes led to decreased enantioselectivities. A proposed model supports the observed stereoinduction.

  8. Bis(1,10-phenanthroline-κ2N,N′(sulfato-κ2O,O′cobalt(II propane-1,3-diol solvate

    Directory of Open Access Journals (Sweden)

    Kai-Long Zhong

    2010-03-01

    Full Text Available The title compound, [Co(SO4(C12H8N22]·C3H8O2, was obtained unexpectedly as a by-product during an attempt to synthesize a mixed-ligand complex of CoII with 1,10-phenanthroline (phen and melamine via a solvothermal reaction. The CoII metal ions are in a distorted octahedral coordination environment formed by four N atoms from two chelating phen ligands and two O atoms from a bidentate sulfate ligand. The two chelating N2C2 groups are almost perpendicular to each other [dihedral angle = 80.06 (8°]. A twofold rotation axis passes through the Co and S atoms, and also through the central C atom of the propane-1,3-diol solvent molecule. Intermolecular O—H...O hydrogen bonds help to stabilize the structure.

  9. Synthesis of omega-hydroxy carboxylic acids and alpha,omega-dimethyl ketones using alpha,omega-diols as alkylating agents.

    Science.gov (United States)

    Iuchi, Yosuke; Hyotanishi, Megumi; Miller, Brittany E; Maeda, Kensaku; Obora, Yasushi; Ishii, Yasutaka

    2010-03-05

    Synthesis of omega-hydroxy carboxylic acids and alpha,omega-dimethyl diketones was successfully achieved by using alpha,omega-diols as alkylating agents under the influence of an iridium catalyst. For example, the alkylation of butyl cyanoacetate with 1,13-tridecanediol in the presence of [IrCl(cod)](2) or [IrCl(coe)(2)](2) gave rise to butyl 2-cyano-15-hydroxypentadecanoate in good yield which is easily converted to cyclopentadecanolide (CPDL). In addition, the alkylation of acetone with 1,10-decanediol in the presence of [IrCl(cod)](2) and KOH resulted in an important muscone precursor, 2,15-hexadecanedione (HDDO), in good yield.

  10. Synthesis, properties and applications of biodegradable polymers derived from diols and dicarboxylic acids: from polyesters to poly(ester amide)s.

    Science.gov (United States)

    Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

    2014-04-25

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

  11. High-throughput and sensitive analysis of 3-monochloropropane-1,2-diol fatty acid esters in edible oils by supercritical fluid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Hori, Katsuhito; Matsubara, Atsuki; Uchikata, Takato; Tsumura, Kazunobu; Fukusaki, Eiichiro; Bamba, Takeshi

    2012-08-10

    We have established a high-throughput and sensitive analytical method based on supercritical fluid chromatography (SFC) coupled with triple quadrupole mass spectrometry (QqQ MS) for 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters in edible oils. All analytes were successfully separated within 9 min without sample purification. The system was precise and sensitive, with a limit of detection less than 0.063 mg/kg. The recovery rate of 3-MCPD fatty acid esters spiked into oil samples was in the range of 62.68-115.23%. Furthermore, several edible oils were tested for analyzing 3-MCPD fatty acid ester profiles. This is the first report on the analysis of 3-MCPD fatty acid esters by SFC/QqQ MS. The developed method will be a powerful tool for investigating 3-MCPD fatty acid esters in edible oils. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. 17a-Ethynyl-5a-androstane-3a, 17 β-diol Treatment of MNU-Induced Mammary Cancer in Rats

    International Nuclear Information System (INIS)

    Ahlem, C.N.; Frincke, J.M.; White, S.K.; Reading, Ch.L.; Trauger, R.J.; Lakshmanaswamy, R.

    2011-01-01

    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.

  13. Simultaneous determination of testosterone, 5α-androstan-17β-ol-3-one, 5α-androstane-3α,17β-diol and 5α-androstane-3β,17β-diol in plasma of adult male rabbits by radioimmunoassay

    International Nuclear Information System (INIS)

    Schanbacher, B.D.; Ewing, L.L.

    1975-01-01

    A simultaneous radioimmunoassay procedure for plasma testosterone (T), 5alpha-androstan-17beta-ol-3-one (DHT), 5alpha- androstane-3alpha,17beta-diol (3alphaol), and 5alpha-androstan- 3beta,17beta-diol (3betaol) is described in this report. Peripheral plasma concentrations of T, DHT, 3alphaol, and 3βol were 1.61 +- 0.26, 0.49 +- 0.15, 0.17 +- 0.03, and 0.24 +- 0.04 ng/ml, respectively, in adult male rabbits. In contrast, T, DHT, 3αol, and 3βol peripheral plasma concentrations in dexamethasone-treated castrate rabbits were 0.07 +- 0.001, 0.02 +- 0.01, 0.07 +- 0.01, and 0.05 +- 0.01 ng/ml, respectively. These results represent the first simultaneous measurement of T, DHT, 3αol, and 3βol in peripheral plasma of any male vertebrate. Moreover, we suggest that DHT, 3αol, and 3βol represent the unidentified immunoreactive material found in peripheral plasma of male rabbits by Falvo and Nalbandov. (auth)

  14. Voltammetric Response of Alizarin Red S-Confined Film-Coated Electrodes to Diol and Polyol Compounds: Use of Phenylboronic Acid-Modified Poly(ethyleneimine) as Film Component.

    Science.gov (United States)

    Takahashi, Shigehiro; Suzuki, Iwao; Ojima, Takuto; Minaki, Daichi; Anzai, Jun-Ichi

    2018-01-22

    Alizarin red S (ARS) was confined in layer-by-layer (LbL) films composed of phenylboronic acid-modified poly(ethyleneimine) (PBA-PEI) and carboxymethylcellulose (CMC) to study the voltammetric response to diol and polyol compounds. The LbL film-coated gold (Au) electrode and quartz slide were immersed in an ARS solution to uptake ARS into the film. UV-visible absorption spectra of ARS-confined LbL film suggested that ARS formed boronate ester (ARS-PBS) in the film. The cyclic voltammetry of the ARS-confined LbL film-coated electrodes exhibited oxidation peaks at -0.50 and -0.62 V, which were ascribed to the oxidation reactions of ARS-PBS and free ARS, respectively, in the LbL film. The peak current at -0.62 V increased upon the addition of diol or polyol compounds such as L-dopa, glucose, and sorbitol into the solution, depending on the concentration, whereas the peak current at -0.50 V decreased. The results suggest a possible use of ARS-confined PBA-PEI/CMC LbL film-coated Au electrodes for the construction of voltammetric sensors for diol and polyol compounds.

  15. Transformações químicas do (+-10b,14-diol-allo-aromadendrano, isolado de duguetia glabriuscula r. e. fries (r. e. fries (annonaceae e avaliações biológicas de alguns derivados obtidos Chemical modifications of (+-allo-aromadendrane-10b,14-diol isolated from duguetia glabriuscula r. e. fries (r. e. fries (annonaceae and biological evaluation of some obtained derivatives

    Directory of Open Access Journals (Sweden)

    Dênis Pires de Lima

    1997-12-01

    Full Text Available The sesquiterpene (+-allo-aromadendrane-10b-14-diol 1 was the lead compound to the preparation of several derivatives in order to test their biological activity against A. salina, C. sphaerospermum, E. coli and S. aureus. In this way the monoalcohols (+-viridiflorol 4, 9 and 11 were synthesized from 1 together with the acetal 6, the ketal 7, and the ketone 8. The oxirane 3 and nitrile 5 were also prepared using as an intermediate the tosylate derivative 2.

  16. Simultaneous determination of 3-monochloropropane-1,2-diol and acrylamide in food by gas chromatography-triple quadrupole mass spectrometry with coupled column separation.

    Science.gov (United States)

    Xu, Xiao-min; He, Hua-li; Zhu, Yan; Feng, Liang; Ying, Ying; Huang, Bai-fen; Shen, Hai-tao; Han, Jian-long; Ren, Yi-ping

    2013-01-14

    Both 3-monochloropropane-1,2-diol (3-MCPD) and acrylamide are contaminants found in heat-processed foods and their related products. A quantitative method was developed for the simultaneous determination of both contaminants in food by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). The analytes were purified and extracted by the matrix solid-phase dispersion extraction (MSPDE) technique with Extrelut NT. A coupled column (a 3 m Innowax combined with a 30 m DB-5 ms) was developed to separate both compounds efficiently without derivatization. Triple quadrupole mass spectrometry in multiple reaction monitoring mode (MRM) was applied to suppress matrix interference and obtain good sensitivity in the determination of both analytes. The limit of detection (LOD) in the sample matrix was 5 μg kg(-1) for 3-MCPD or acrylamide. The average recoveries for 3-MCPD and acrylamide in different food matrices were 90.5-107% and 81.9-95.7%, respectively, with the intraday relative standard deviations (RSDs) of 5.6-13.5% and 5.3-13.4%, respectively. The interday RSDs were 6.1-12.6% for 3-MCPD and were 5.0-12.8% for acrylamide. Both contaminants were found in samples of bread, fried chips, fried instant noodles, soy sauce, and instant noodle flavoring. Neither 3-MCPD nor acrylamide was detected in the samples of dairy products (solid or liquid samples) and non-fried instant noodles. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. IN0523 (Urs-12-ene-3α,24β-diol) a plant based derivative of boswellic acid protect Cisplatin induced urogenital toxicity

    International Nuclear Information System (INIS)

    Singh, Amarinder; Arvinda, S; Singh, Surjeet; Suri, Jyotsna; Koul, Surinder; Mondhe, Dilip M.; Singh, Gurdarshan; Vishwakarma, Ram

    2017-01-01

    The limiting factor for the use of Cisplatin in the treatment of different type of cancers is its toxicity and more specifically urogenital toxicity. Oxidative stress is a well-known phenomenon associated with Cisplatin toxicity. However, in Cisplatin treated group, abnormal animal behavior, decreased body weight, cellular and sub-cellular changes in the kidney and sperm abnormality were observed. Our investigation revealed that Cisplatin when administered in combination with a natural product derivative (Urs-12-ene-3α,24β-diol, labeled as IN0523) resulted in significant restoration of body weight and protection against the pathological alteration caused by Cisplatin to kidney and testis. Sperm count and motility were significantly restored near to normal. Cisplatin caused depletion of defense system i.e. glutathione peroxidase, catalase and superoxide dismutase, which were restored close to normal by treatment of IN0523. Reduction in excessive lipid peroxidation induced by Cisplatin was also found by treatment with IN0523. The result suggests that IN0523 is a potential candidate for ameliorating Cisplatin induced toxicity in the kidney and testes at a dose of 100 mg/kg p.o. via inhibiting the oxidative stress/redox status imbalance and may be improving the efflux mechanism. - Highlights: • Synthesis of a novel boswellic acid derivative (IN0523) • Counter oxidative stress induced due to Cisplatin • Protect against urogenital toxicity induced by Cisplatin

  18. Bis(1,10-phenanthroline-κ2N,N′(sulfato-κ2O,O′cobalt(II butane-2,3-diol monosolvate

    Directory of Open Access Journals (Sweden)

    Shi-Juan Wang

    2011-04-01

    Full Text Available In the title compound, [Co(SO4(C12H8N22]·C4H10O2, the Co2+ ion has a distorted octahedral coordination environment composed of four N atoms from two chelating 1,10-phenanthroline ligands and two O atoms from an O,O′-bidentate sulfate anion. The dihedral angle between the two chelating N2C2 groups is 83.48 (1°. The Co2+ ion, the S atom and the mid-point of the central C—C bond of the butane-2,3-diol solvent molecule are situated on twofold rotation axes. The molecules of the complex and the solvent molecules are held together by pairs of symmetry-related O—H...O hydrogen bonds with the uncoordinated O atoms of the sulfate ions as acceptors. The solvent molecule is disordered over two sets of sites with site occupancies of 0.40 and 0.60.

  19. Synthesis of boronate-functionalized organic-inorganic hybrid monolithic column for the separation of cis-diol containing compounds at low pH.

    Science.gov (United States)

    Zhao, Heqing; Lyu, Haixia; Qin, Wenfei; Xie, Zenghong

    2018-04-01

    In this work, an organic-inorganic hybrid boronate affinity monolithic column was prepared via "one-pot" process using 4-vinylphenylboronic acid as organic monomer and divinylbenzene as cross-linker. The effects of reaction temperature, solvents and composition of organic monomers on the column properties (e.g. morphology, permeability, and mechanical stability) were investigated. A series of test compounds including small neutral molecules, aromatic amines, and cis-diol compounds were used to evaluate the retention behaviors of the prepared hybrid monolithic column. The results demonstrated that the prepared hybrid monolith exhibited mixed-interactions including hydrophilicity, cation exchange, and boronate affinity interaction. The run-to-run, day-to-day and batch-to-batch reproducibilities of the prepared hybrid monolith for thiourea's retention time were satisfactory with the relative standard deviations (RSDs) less than 0.09, 1.45 and 4.05% (n = 3), respectively, indicating the effectiveness and practicability of the proposed method. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Production of 7,8-Dihydroxy Unsaturated Fatty Acids from Plant Oils by Whole Recombinant Cells Expressing 7,8-Linoleate Diol Synthase from Glomerella cingulata.

    Science.gov (United States)

    Seo, Min-Ju; Kang, Woo-Ri; Shin, Kyung-Chul; Oh, Deok-Kun

    2016-11-16

    The reaction conditions for the production of 7S,8S-dihydroxy-9,12(Z,Z)-octadecadienoic acid from linoleic acid by recombinant Escherichia coli expressing 7,8-linoleate diol synthase from Glomerella cingulata were optimized using response surface methodology. The optimal reaction conditions were pH 7.0, 18.6 °C, 10.8% (v/v) dimethyl sulfoxide, 44.9 g/L cells, and 14.3 g/L linoleic acid, with agitation at 256 rpm. Under these conditions, recombinant cells produced 7,8-dihydroxy unsaturated fatty acids in the range of 7.0-9.8 g/L from 14.3 g/L linoleic acid, 14.3 g/L oleic acid, and plant oil hydrolysates such as waste oil and olive oil containing 14.3 g/L linoleic acid or oleic acid. To the best of the authors' knowledge, this is the first report on the biotechnological production of 7,8-dihydroxy unsaturated fatty acids.

  2. 5-Androstene-3{beta},17{beta}-diol Promotes Recovery of Immature Hematopoietic Cells Following Myelosuppressive Radiation and Synergizes With Thrombopoietin

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. [Field efficacy of repellent formulation containing para-menthane-3,8-diol and lemongrass against Culicoides pachymerus (Diptera: Ceratopogonidae) in Colombia].

    Science.gov (United States)

    Santamaría, Erika; Cabrera, Olga Lucía; Zipa, Yaneth; Pardo, Raúl Hernando

    2012-09-01

    Culicoides pachymerus is a major pest species for the inhabitants of the western Boyacá province of Colombia. The effect of a repellent lotion based on p-menthane-3,8-diol (16%) and lemongrass oil (2%) was evaluated against the bites of C. pachymerus. The repellent lotion was compared simultaneously with a control (no treatment) by human landing catches of C. pachymerus on the forearms of paired volunteers situated near human dwellings. Protection percentage and protection time for 3 to 6 h after repellent application was calculated. The test was repeated ten times. Only two females of C. pachymerus were collected on arms with the repellent treatment. In contrast, the mean biting rate in the untreated control was 47.7 midges/person/10 min. Mean protection percentage of the repellent was 100% up to 4 h and 99.5% up to 5 h. Protection time was 332.2 and 338.2 min in the two replicates where bites of C. pachymerus were confirmed. In the remaining eight replicates protection time exceeded the test duration. The repellent showed high efficacy against C. pachymerus, up to 5 h post-application.

  4. Synthesis, characterization and computational studies of 3-{(E)-[(2-hydroxyphenyl)imino]methyl}benzene-1,2-diol and molecular structure of its zwitterionic form

    Science.gov (United States)

    Ezeorah, Julius Chigozie; Ossai, Valentine; Obasi, Lawrence Nnamdi; Elzagheid, Mohamed I.; Rhyman, Lydia; Lutter, Michael; Jurkschat, Klaus; Dege, Necmi; Ramasami, Ponnadurai

    2018-01-01

    The Schiff base 3-{(E)-[(2-hydroxyphenyl)imino]methyl}benzene-1,2-diol was synthesized by the condensation of 2,3-dihydroxybenzaldehyde and 2-aminophenol in water at room temperature. The crystal was grown using two solvents (dry methanol and 60% methanol). The compound was characterized using elemental microanalysis, IR, NMR, UV spectroscopies and single-crystal X-ray diffraction crystallography. The X-ray structure reveals that the Schiff base crystallizes as a methanol solvate in dry methanol with triclinic crystal system, space group P-1 and Z = 2 in the unit cell and as a non-methanol solvate in 60% methanol with triclinic crystal system, space group P-1 and Z = 4 in the unit cell. The compound showed absorption bands at 272, 389, 473 and 602 nm in DMSO. These bands were assigned as π → π ∗, n → π∗ and n-σ∗ transitions. The 473 and 602 nm bands in DMSO reveal that the compound exists in tautomeric forms. The presence of N-H, C-O and Cdbnd N stretching vibrations in the IR spectrum indicates that the compound is zwitterionic in the solid state. This study was supplemented using density functional theory method.

  5. [Determination of 3-monochloropropane-1,2-diol in grease food by solid phase extraction-derivatization-gas chromatography-mass spectrometry].

    Science.gov (United States)

    Xiang, Xiaoling; Wang, Liyuan; Shen, Xianghong; Li, Chunsong; Shen, Jianfu; Wu, Pinggu

    2017-09-01

    To establish the method of determination of 3-monochloropropane-1,2-diol( 3-MCPD) in grease food by gas chromatography-mass spectrometry( GC-MS). 3-MCPD in grease food represented by bean paste was extracted by ultrasound,purified by alkaline earth solid phase extraction column,derivatived using phenylboronic acid( PBA) and detected by GC-MS. The linearity of 3-MCPD ranged from 1-100 ng/mL,with correlation coefficient at 0. 9993.The limits of quantitation( LOQ) in soy sauce,bean paste,pepper oil were 0. 6,0. 5 and7. 0 μg/kg and limits of detection( LOD) were 1. 9,1. 6 and 18. 8 μg/kg,respectively.Average recovery rate and relative standard deviation was 78. 3%-106. 7% and 1. 9%-11. 6%( n = 6), when 3-MCPD was added in grease food at 2. 5-1000 μg/kg. The method has good purification effect and the detection sensitivity and accuracy,and can be used for the determination of 3-MCPD in grease food.

  6. New Insights on Degumming and Bleaching Process Parameters on The Formation of 3-Monochloropropane-1,2-Diol Esters and Glycidyl Esters in Refined, Bleached, Deodorized Palm Oil.

    Science.gov (United States)

    Sim, Biow Ing; Muhamad, Halimah; Lai, Oi Ming; Abas, Faridah; Yeoh, Chee Beng; Nehdi, Imededdine Arbi; Khor, Yih Phing; Tan, Chin Ping

    2018-04-01

    This paper examines the interactions of degumming and bleaching processes as well as their influences on the formation of 3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters in refined, bleached and deodorized palm oil by using D-optimal design. Water degumming effectively reduced the 3-MCPDE content up to 50%. Acid activated bleaching earth had a greater effect on 3-MCPDE reduction compared to natural bleaching earth and acid activated bleaching earth with neutral pH, indicating that performance and adsorption capacities of bleaching earth are the predominant factors in the removal of esters, rather than its acidity profile. The combination of high dosage phosphoric acid during degumming with the use of acid activated bleaching earth eliminated almost all glycidyl esters during refining. Besides, the effects of crude palm oil quality was assessed and it was found that the quality of crude palm oil determines the level of formation of 3-MCPDE and glycidyl esters in palm oil during the high temperature deodorization step of physical refining process. Poor quality crude palm oil has strong impact towards 3-MCPDE and glycidyl esters formation due to the intrinsic components present within. The findings are useful to palm oil refining industry in choosing raw materials as an input during the refining process.

  7. Measurement of micronuclei and internal dose in mice demonstrates that 3-monochloropropane-1,2-diol (3-MCPD) has no genotoxic potency in vivo.

    Science.gov (United States)

    Aasa, Jenny; Törnqvist, Margareta; Abramsson-Zetterberg, Lilianne

    2017-11-01

    In this study 3-monochloropropane-1,2-diol (3-MCPD), a compound that appears as contaminant in refined cooking oils, has been studied with regard to genotoxicity in vivo (mice) with simultaneous measurement of internal dose using state-of-the-art methodologies. Genotoxicity (chromosomal aberrations) was measured by flow cytometry with dual lasers as the frequency of micronuclei in erythrocytes in peripheral blood from BalbC mice intraperitoneally exposed to 3-MCPD (0, 50, 75, 100, 125 mg/kg). The internal doses of 3-MCPD in the mice were calculated from N-(2,3-dihydroxypropyl)-valine adducts to hemoglobin (Hb), quantified at very low levels by high-resolution mass spectrometry. Convincing evidence for absence of genotoxic potency in correlation to measured internal doses in the mice was demonstrated, despite relatively high administered doses of 3-MCPD. The results are discussed in relation to another food contaminant that is formed as ester in parallel to 3-MCPD esters in oil processing, i.e. glycidol, which has been studied previously by us in a similar experimental setup. Glycidol has been shown to be genotoxic, and in addition to have ca. 1000 times higher rate of adduct formation compared to that observed for 3-MCPD. The conclusion is that at simultaneous exposure to 3-MCPD and glycidol the concern about genotoxicity would be glycidol. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Carcinogenicity study of 3-monochloropropane-1, 2-diol (3-MCPD) administered by drinking water to B6C3F1 mice showed no carcinogenic potential.

    Science.gov (United States)

    Jeong, Jayoung; Han, Beom Seok; Cho, Wan-Seob; Choi, Mina; Ha, Chang-Su; Lee, Byoung-Seok; Kim, Yong-Bum; Son, Woo-Chan; Kim, Choong-Yong

    2010-09-01

    3-Monochloropropane-1, 2-diol (or 3-chloro-1,2-propanediol, 3-MCPD) is a well-known food processing contaminant found in a wide range of foods and ingredients. It has been classified as non-genotoxic carcinogen but its carcinogenic potential in the rodents has been controversial. The carcinogenicity to B6C3F1 mice by drinking water administration was assessed over a period of 104 weeks. Three groups, each comprising 50 male and 50 female mice received 3-MCPD at dosages of 30, 100 or 300 ppm up to Day 100 and 200 ppm onward (4.2, 14.3 and 33.0 mg/kg for males; 3.7, 12.2, and 31.0 mg/kg for females), were allocated. Survival was good, with at least 80% of males and 72% of females in each group surviving 104 weeks. Body weights and body weight gain were decreased in males and females receiving 200 ppm. Water and food consumptions of both sexes at 300/200 ppm were lowered. Emaciated or crouching position was observed for animals of both sexes exposed to 200 ppm. There were some differences in hematology and serum biochemistry compared with controls, although there was no histopathological evidence to support those changes. Histopathological examination did not reveal any neoplastic or non-neoplastic findings attributable to treatment with 3-MCPD. It is concluded that drinking water administration of 3-MCPD for 104 weeks revealed no evidence of carcinogenic potential.

  9. Experimental exposure to 3-monochloropropane-1,2-diol from the pre-puberty causes damage in sperm production and motility in adulthood

    Directory of Open Access Journals (Sweden)

    Kátia Cristina Melo Tavares Vieira

    2017-06-01

    Full Text Available 3-Monochloropropane-1,2-diol (3-MCPD is a food contaminant that can be formed during the thermic processing of various foodstuffs. Studies of reproductive toxicology of 3-MCPD are mainly concentrated in the evaluation of possible insults caused by exposure of adult animals. However, the prepuberty might be a period of different susceptibility to chemicals. The aim of this study was to evaluate the effects on reproductive endpoints of the 3-MCPD-exposure prepubertal male rats. Wistar male rats were assigned to 4 groups: control and exposed to 2.5; 5 or 10 mg kg-1 day-1 of 3-MCPD for 30 days by gavage. Testis and epididymis were used for sperm counts and histology analysis. Sertoli cell number and dynamic of the spermatogenesis were evaluated. Sperm were collected from the vas deferens for evaluation of the sperm motility and morphology. Number of sperm with progressive movement, number of Sertoli cells and germ cells and relative daily sperm production were decreased in the groups exposed to 5 and 10 mg kg-1 day-1 of 3-MCPD. Sperm morphology, testicular and epididymal histology were comparable among groups. Results show that 3-MCPD-exposure of rats from prepuberty might cause alterations in spermatogenesis and sperm maturation, similarly to exposure in adulthood.

  10. 3-Monochloropropane-1,2-diol (alpha-chlorohydrin) disrupts spermatogenesis and causes spermatotoxicity in males of the Egyptian fruit-bat (Rousettus aegyptiacus).

    Science.gov (United States)

    Mahmoud, Y I; Taha, A; Soliman, S

    2018-03-29

    We evaluated the sterilizing effect of 3-monochloropropane-1, 2-diol (3-MCPD) in male Egyptian fruit bats (Rousettus aegyptiacus). We used three groups. One was treated with 70 mg/kg 3-MCPD for 4 days. The second group was treated with 3-MCPD as a bait formulation (known concentration of 3-MCPD mixed with a known amount of food). The third group was untreated controls. We compared the weights of the reproductive organs, histology of the testes, occurrence of spermatogenesis, and the count, motility and abnormalities of epididymal sperm of treated males with those of the untreated control group. 3-MCPD caused significantly decreased weights of reproductive organs, several testicular histological alterations and spermatogenic arrest accompanied by significant decreases in sperm count and motility, and significantly increased number of abnormal sperm. 3-MCPD bait was readily accepted by the animals. 3-MCPD, even in low doses and after limited exposure, disrupted spermatogenesis in males of the Egyptian fruit bat. Our findings have potential value for public health and agricultural authorities, and for vertebrate pest managers. 3-MCPD may have application for control of this pest.

  11. The effects of physical refining on the formation of 3-monochloropropane-1,2-diol esters in relation to palm oil minor components.

    Science.gov (United States)

    Zulkurnain, Musfirah; Lai, Oi Ming; Latip, Razam Abdul; Nehdi, Imededdine Arbi; Ling, Tau Chuan; Tan, Chin Ping

    2012-11-15

    The formation of 3-monochloropropane-1,2-diol (3-MCPD) esters in refined palm oil during deodorisation is attributed to the intrinsic composition of crude palm oil. Utilising D-optimal design, the effects of the degumming and bleaching processes on the reduction in 3-MCPD ester formation in refined palm oil from poor-quality crude palm oil were studied relative to the palm oil minor components that are likely to be their precursors. Water degumming remarkably reduced 3-MCPD ester formation by up to 84%, from 9.79 mg/kg to 1.55 mg/kg. Bleaching with synthetic magnesium silicate caused a further 10% reduction, to 0.487 mg/kg. The reduction in 3-MCPD ester formation could be due to the removal of related precursors prior to the deodorisation step. The phosphorus content of bleached palm oil showed a significant correlation with 3-MCPD ester formation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. A 4-week study of four 3-monochloropropane-1,2-diol diesters on lipid metabolism in C57BL/6J mice.

    Science.gov (United States)

    Lu, Jing; Wang, Zhenning; Ren, Mengrou; Feng, Guangxin; Ye, Beining; Wang, Yi; Fang, Baochen; Deng, Xuming; Guan, Shuang

    2015-09-01

    3-Monochloropropane-1,2-diol (3-MCPD) esters have been detected in many foods, which have become a new safety issue worldwide. In the study, we investigated the effect of four 3-MCPD diesters (palmitate diester: CDP; stearate diester: CDS; oleate diester: CDO; linoleate diester: CDL) on lipid metabolism in C57BL/6J mice. The results showed that CDP, CDS, CDO and CDL significantly increased the serum TC, LDL-C levels and liver TG, TC levels at dose of 16.5μmol/kg/day. These results indicated that 3-MCPD diesters could potentially cause hyperlipidemia in C57BL/6J mice. Moreover, oil red O staining confirmed fat accumulation in liver induced by 3-MCPD diesters. Our work will provide more information for safety evaluation of 3-MCPD diesters. However, whether free 3-MCPD or free fatty acids or combined action compensates for the hyperlipidemia effects should be elucidated in the future. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Effects of 3-monochloropropane-1,2-diol (3-MCPD) and its metabolites on DNA damage and repair under in vitro conditions.

    Science.gov (United States)

    Ozcagli, Eren; Alpertunga, Buket; Fenga, Concettina; Berktas, Mehmet; Tsitsimpikou, Christina; Wilks, Martin F; Tsatsakis, Αristidis M

    2016-03-01

    3-monochloropropane-1,2-diol (3-MCPD) is a food contaminant that occurs during industrial production processes and can be found mainly in fat and salt containing products. 3-MCPD has exhibited mutagenic activity in vitro but not in vivo, however, a genotoxic mechanism for the occurrence of kidney tumors has not so far been excluded. The main pathway of mammalian 3-MCPD metabolism is via the formation of β--chlorolactatic acid and formation of glycidol has been demonstrated in bacterial metabolism. The aim of this study was to investigate genotoxic and oxidative DNA damaging effects of 3-MCPD and its metabolites, and to provide a better understanding of their roles in DNA repair processes. DNA damage was assessed by alkaline comet assay in target rat kidney epithelial cell lines (NRK-52E) and human embryonic kidney cells (HEK-293). Purine and pyrimidine base damage, H2O2 sensitivity and DNA repair capacity were assessed via modified comet assay. The results revealed in vitro evidence for increased genotoxicity and H2O2 sensitivity. No association was found between oxidative DNA damage and DNA repair capacity with the exception of glycidol treatment at 20 μg/mL. These findings provide further insights into the mechanisms underlying the in vitro genotoxic potential of 3-MCPD and metabolites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. IN0523 (Urs-12-ene-3α,24β-diol) a plant based derivative of boswellic acid protect Cisplatin induced urogenital toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Amarinder [Academy of Scientific & Innovative Research (AcSIR), New Delhi (India); PK-PD-Toxicology and Formulation Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, J& K (India); Arvinda, S [Deptt. of Pathology, Govt. Medical College, Jammu 180001, J& K (India); Singh, Surjeet [PK-PD-Toxicology and Formulation Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, J& K (India); Suri, Jyotsna [Deptt. of Pathology, Govt. Medical College, Jammu 180001, J& K (India); Koul, Surinder [Bio-Organic Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, J& K (India); Mondhe, Dilip M. [Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, J& K (India); Singh, Gurdarshan, E-mail: singh_gd@iiim.ac.in [PK-PD-Toxicology and Formulation Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, J& K (India); Vishwakarma, Ram [Bio-Organic Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, J& K (India)

    2017-03-01

    The limiting factor for the use of Cisplatin in the treatment of different type of cancers is its toxicity and more specifically urogenital toxicity. Oxidative stress is a well-known phenomenon associated with Cisplatin toxicity. However, in Cisplatin treated group, abnormal animal behavior, decreased body weight, cellular and sub-cellular changes in the kidney and sperm abnormality were observed. Our investigation revealed that Cisplatin when administered in combination with a natural product derivative (Urs-12-ene-3α,24β-diol, labeled as IN0523) resulted in significant restoration of body weight and protection against the pathological alteration caused by Cisplatin to kidney and testis. Sperm count and motility were significantly restored near to normal. Cisplatin caused depletion of defense system i.e. glutathione peroxidase, catalase and superoxide dismutase, which were restored close to normal by treatment of IN0523. Reduction in excessive lipid peroxidation induced by Cisplatin was also found by treatment with IN0523. The result suggests that IN0523 is a potential candidate for ameliorating Cisplatin induced toxicity in the kidney and testes at a dose of 100 mg/kg p.o. via inhibiting the oxidative stress/redox status imbalance and may be improving the efflux mechanism. - Highlights: • Synthesis of a novel boswellic acid derivative (IN0523) • Counter oxidative stress induced due to Cisplatin • Protect against urogenital toxicity induced by Cisplatin.

  15. IN0523 (Urs-12-ene-3α,24β-diol) a plant based derivative of boswellic acid protect Cisplatin induced urogenital toxicity.

    Science.gov (United States)

    Singh, Amarinder; Arvinda, S; Singh, Surjeet; Suri, Jyotsna; Koul, Surinder; Mondhe, Dilip M; Singh, Gurdarshan; Vishwakarma, Ram

    2017-03-01

    The limiting factor for the use of Cisplatin in the treatment of different type of cancers is its toxicity and more specifically urogenital toxicity. Oxidative stress is a well-known phenomenon associated with Cisplatin toxicity. However, in Cisplatin treated group, abnormal animal behavior, decreased body weight, cellular and sub-cellular changes in the kidney and sperm abnormality were observed. Our investigation revealed that Cisplatin when administered in combination with a natural product derivative (Urs-12-ene-3α,24β-diol, labeled as IN0523) resulted in significant restoration of body weight and protection against the pathological alteration caused by Cisplatin to kidney and testis. Sperm count and motility were significantly restored near to normal. Cisplatin caused depletion of defense system i.e. glutathione peroxidase, catalase and superoxide dismutase, which were restored close to normal by treatment of IN0523. Reduction in excessive lipid peroxidation induced by Cisplatin was also found by treatment with IN0523. The result suggests that IN0523 is a potential candidate for ameliorating Cisplatin induced toxicity in the kidney and testes at a dose of 100mg/kg p.o. via inhibiting the oxidative stress/redox status imbalance and may be improving the efflux mechanism. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Vasodilator effects and putative guanylyl cyclase stimulation by 2-nitro-1-phenylethanone and 2-nitro-2-phenyl-propane-1,3-diol on rat aorta.

    Science.gov (United States)

    Vasconcelos, Thiago Brasileiro de; Ribeiro-Filho, Helder Veras; Lahlou, Saad; Pereira, José Geraldo de Carvalho; Oliveira, Paulo Sérgio Lopes de; Magalhães, Pedro Jorge Caldas

    2018-07-05

    Compounds containing a nitro group may reveal vasodilator properties. Several nitro compounds have a NO 2 group in a short aliphatic chain connected to an aromatic group. In this study, we evaluated in rat aorta the effects of two nitro compounds, with emphasis on a putative recruitment of the soluble guanylate cyclase (sGC) pathway to induce vasodilation. Isolated aortic rings were obtained from male Wistar rats to compare the effects induced by 2-nitro-1-phenylethanone (NPeth) or 2-nitro-2-phenyl-propane-1,3-diol (NPprop). In aortic preparations contracted with phenylephrine or KCl, NPeth and NPprop induced vasorelaxant effects that did not depend on the integrity of vascular endothelium. NPeth had a lesser vasorelaxant efficacy than NPprop and only the NPprop effects were inhibited by pretreatment with the sGC inhibitors, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) or methylene blue. In an ODQ-preventable manner, NPprop inhibited the contractile component of the phenylephrine-induced response mediated by intracellular Ca 2+ release or by extracellular Ca 2+ recruitment through receptor- or voltage-operated Ca 2+ channels. In contrast, NPprop was inert against the transient contraction induced by caffeine in Ca 2+ -free medium. In an ODQ-dependent manner, NPprop inhibited the contraction induced by the protein kinase C activator phorbol 12,13-dibutyrate or by the tyrosine phosphatase inhibitor sodium orthovanadate. In silico docking analysis of a sGC homologous protein revealed preferential site for NPprop. In conclusion, the nitro compounds NPeth and NPprop induced vasorelaxation in rat aortic rings. Aliphatic chain substituents selectively interfered in the ability of these compounds to induce vasorelaxant effects, and only NPprop relaxed aortic rings via a sGC pathway. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol}, 1 a novel resveratrol analog, differentially regulates estrogen receptors α and β in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Ronghe, Amruta; Chatterjee, Anwesha [Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO 64108 (United States); Singh, Bhupendra [Department of Genetics, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Dandawate, Prasad [ISTRA, Department of Chemistry, Abeda Inamdar Senior College, University of Pune (India); Abdalla, Fatma; Bhat, Nimee K. [Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO 64108 (United States); Padhye, Subhash [ISTRA, Department of Chemistry, Abeda Inamdar Senior College, University of Pune (India); Bhat, Hari K., E-mail: bhath@umkc.edu [Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO 64108 (United States)

    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-10 A 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. - Highlights: • Resveratrol analog TIMBD inhibits growth of breast cancer cells. • TIMBD induces protein expression levels of ERβ and inhibits that of ERα. • TIMBD inhibits c-Myc and cyclin D1, and induces p53 and p21. • TIMBD suppresses c-Myc in an ER-dependent fashion.

  20. 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol}, 1 a novel resveratrol analog, differentially regulates estrogen receptors α and β in breast cancer cells

    International Nuclear Information System (INIS)

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

    2016-01-01

    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-10 A 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. - Highlights: • Resveratrol analog TIMBD inhibits growth of breast cancer cells. • TIMBD induces protein expression levels of ERβ and inhibits that of ERα. • TIMBD inhibits c-Myc and cyclin D1, and induces p53 and p21. • TIMBD suppresses c-Myc in an ER-dependent fashion.

  1. A 13-week repeated dose study of three 3-monochloropropane-1,2-diol fatty acid esters in F344 rats.

    Science.gov (United States)

    Onami, Saeko; Cho, Young-Man; Toyoda, Takeshi; Mizuta, Yasuko; Yoshida, Midori; Nishikawa, Akiyoshi; Ogawa, Kumiko

    2014-04-01

    3-monochloropropane-1,2-diol (3-MCPD), a rat renal and testicular carcinogen, has been reported to occur in various foods and food ingredients as free or esterified forms. Since reports about toxicity of 3-MCPD esters are limited, we conducted a 13-week rat subchronic toxicity study of 3-MCPD esters (palmitate diester: CDP, palmitate monoester: CMP, oleate diester: CDO). We administered a carcinogenic dose (3.6 × 10(-4) mol/kg B.W./day) of 3-MCPD or these esters at equimolar concentrations and two 1/4 lower doses by gavage with olive oil as a vehicle five times a week for 13 weeks to F344 male and female rats. As a result, five out of ten 3-MCPD-treated females died from acute renal tubular necrosis, but none of the ester-treated rats. Decreased HGB was observed in all high-dose 3-MCPD fatty acid ester-treated rats, except CDO-treated males. The absolute and relative kidney weights were significantly increased in the ester-treated rats at medium and high doses. Relative liver weights were significantly increased in the esters-treated rat at high dose, except for CMP females. Significant increase in apoptotic epithelial cells in the initial segment of the epididymis of high-dose ester-treated males was also observed. The results suggested that although acute renal toxicity was lower than 3-MCPD, these three 3-MCPD fatty acid esters have the potential to exert subchronic toxicity to the rat kidneys and epididymis, to a similar degree as 3-MCPD under the present conditions. NOAELs (no-observed-adverse-effect levels) of CDP, CMP and CDO were suggested to be 14, 8 and 15 mg/kg B.W./day, respectively.

  2. Occurrence of bound 3-monochloropropan-1,2-diol content in commonly consumed foods in Hong Kong analysed by enzymatic hydrolysis and GC-MS detection.

    Science.gov (United States)

    Chung, Stephen W C; Chan, Benny T P; Chung, H Y; Xiao, Ying; Ho, Y Y

    2013-01-01

    The aim of this study was to determine the level of bound 3-monochloropropan-1,2-diol in foodstuffs commonly consumed in Hong Kong, China, by an enzymatic hydrolysis indirect method which proved to be free from interferences. A total of 290 samples were picked up randomly from the local market and analysed. About 73% of these samples were found to contain detectable amounts of bound 3-MCPD. Amongst the 73 food items, bound 3-MCPD was not detected in 13 food items, including extra virgin olive oil, beef ball/salami, beef flank, ham/Chinese ham, nuts, seeds, soy sauce, oyster sauce, butter, yoghurt, cream, cheese and milk. For those found to contain detectable bound 3-MCPD, the content ranged up to 2500 µg kg(-1). The highest mean bound 3-MCPD content among the 14 food groups was in biscuits (440 [50-860] µg kg(-1)), followed by fats and oils (390 [n.d.-2500] µg kg(-1)), snacks (270 [9-1000] µg kg(-1)), and Chinese pastry (270 [n.d.-1200] µg kg(-1)). Among the samples, the highest bound 3-MCPD content was in a grape seed oil (2500 µg kg(-1)), followed by a walnut flaky pastry (1200 µg kg(-1)) and a grilled corn (1000 µg kg(-1)). Basically, the results of this study agreed well with other published results in peer-reviewed journals, except for cheese, cream, ham, nuts and seeds.

  3. Effect of the Topical Repellent para-Menthane-3,8-diol on Blood Feeding Behavior and Fecundity of the Dengue Virus Vector Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Jugyeong Lee

    2018-06-01

    Full Text Available Dengue fever is an acute disease caused by the dengue virus and transmitted primarily by the mosquito Aedes aegypti. The current strategy for dengue prevention is vector control including the use of topical repellents to reduce mosquito biting. Although N,N-diethyl-m-methylbenzamide (DEET is the most common active ingredient in topical repellent products, para-menthane-3,8-diol (PMD is also used commercially. Studies have indicated PMD reduced biting by 90–95% for up to 6–8 h, similar to the efficacy of DEET, depending on the testing environment. The purpose of this study was to evaluate the behavioral effects of PMD on Ae. aegypti blood feeding and fecundity to explore the potential impact of PMD on downstream mosquito life-history traits. Two experiments were performed. In both experiments, cohorts of female Ae. aegypti (Belize strain were exposed to 20% PMD or ethanol for 10 min in a closed system and introduced to an artificial membrane feeding system. Following a 30min feed time, mosquitoes of Experiment 1 were killed and weighed as a proxy measure of blood meal, whereas mosquitoes of Experiment 2 were monitored for oviposition, a measure of fecundity. Results showed a statistically significant reduction (p < 0.001 in the percentage of Ae. aegypti that blood-fed when exposed to PMD (38% compared to those non-exposed (49%. No significant difference in fecundity between test populations was indicated. These findings suggest that exposure of Ae. aegypti to 20% PMD may influence the probability of subsequent blood feeding but of those mosquitoes that do blood feed, egg-lay density is not affected. Further studies are warranted to investigate the full range of effects of PMD exposure on other Ae. aegypti life-history traits such as mating, to continue characterizing the potential effects of PMD to impact overall vector population dynamics.

  4. Synthesis and Characterization of Acyclic and Cyclic Azabridged Ligands Incorporating 2,2'-Bipyridine Subunits and Their Complexes With Copper(II, Cobalt(II, and Nickel(II

    Directory of Open Access Journals (Sweden)

    Andrea Pappalardo

    2003-07-01

    Full Text Available The synthesis of a series of N,N'-disubstituted acyclic (AL and cyclic (CL aza-bridged ligands incorporating 2,2-pipryidine subunits is described. 1H-NMR and IR spectral data support the proposed ligand structures. Dynamic 1H-NMR studies on diurea and diamide derivatives point to the presence of slowly interconverting conformers on the 1H-NMR time-scale, owing to N−H···N hydrogen bonding and/or a restricted rotation around the amide bonds. The ligands synthesized form 1:1 complexes with divalent transition metal ions. Upon complexation, bis-ester derivatives AL5 and CL5 undergo a metal-induced hydrolysis of the ester groups to carboxyl functions, which act as additional binding sites for the metal ion, as well as hydrogen-bonding donor-acceptor binding site to produce dimeric complexes.

  5. Influence of gamma radiation on the crosslinking properties of oligo-butadiene-base polyurethane elastomers

    International Nuclear Information System (INIS)

    Dedgaonkar, V.G.

    1994-01-01

    Liquid oligo-butadiene-base diol was cured by gammas when a diisocyanate and a triol were present. The NCO/OH ratio was at unity. Radiation brought about crosslink networks through urethane linkages and among polybutadiene segments. (author). 5 refs., 1 tab

  6. Synthesis, structural, spectroscopic, anti-cancer and molecular docking studies on novel 2-[(Anthracene-9-ylmethylene)amino]-2-methylpropane-1,3-diol using XRD, FTIR, NMR, UV-Vis spectra and DFT

    Science.gov (United States)

    Pavitha, P.; Prashanth, J.; Ramu, G.; Ramesh, G.; Mamatha, K.; Venkatram Reddy, Byru

    2017-11-01

    The novel titled compound 2-[(Anthracene-9-ylmethylene)amino]-2-methylpropane-1,3-diol (AMD) has been synthesized by slow evaporation technique from mixed solvent system of methanol with anthracene-9-carbaldehyde and 2-amino-2-methylpropane-1,3-diol. The synthesized molecule AMD was characterized experimentally by single crystal XRD, FTIR, NMR and UV-Vis spectra and density functional theory (DFT) computations. The structure of the crystal has been determined as orthorhombic system with space group P 21 21 21 and the cell parameters are obtained using XRD data. The optimized ground state geometry of the molecule is determined by evaluating torsional potentials as a function of angle of free rotation around Csbnd C bonds of functional groups by DFT method employing B3LYP functional with 6-311++G(d,p) basis set. All the fundamental vibrations of the molecule are assigned unambiguously using potential energy distribution (PED) obtained in the DFT computations. The rms error between the observed and scaled frequencies is 6.20 cm-1. The values of dipole moment, polarizability and hyperpolarizability are evaluated to study the NLO behavior of the molecule. The HOMO-LUMO energies and thermodynamic parameters are also determined. The molecular electrostatic surface potential (MESP) is mapped to obtain the charge density distribution. The 1H and 13C NMR chemical shifts of the molecule are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. UV-visible spectrum of the compound is also recorded in the region 200-800 nm to know the type of electronic transitions involved. The anti-cancer activity of AMD is determined against human breast cancer cell line MCF-7 and human prostate cancer cell line PC-3 and correlated the results with study of molecular docking against pharmacological protein IDO-1 receptor.

  7. 3,3′,4,4′,5-Pentachlorobiphenyl (PCB 126) Decreases Hepatic and Systemic Ratios of Epoxide to Diol Metabolites of Unsaturated Fatty Acids in Male Rats

    Science.gov (United States)

    Wu, Xianai; Yang, Jun; Morisseau, Christophe; Robertson, Larry W.; Hammock, Bruce; Lehmler, Hans-Joachim

    2016-01-01

    Disruption of the homeostasis of oxygenated regulatory lipid mediators (oxylipins), potential markers of exposure to aryl hydrocarbon receptor (AhR) agonists, such as 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126), is associated with a range of diseases, including nonalcoholic fatty liver disease and nonalcoholic steatohepatitis. Here we test the hypothesis that PCB 126 exposure alters the levels of oxylipins in rats. Male Sprague-Dawley rats (5-weeks old) were treated over a 3-month period every 2 weeks with intraperitoneal injections of PCB 126 in corn oil (cumulative doses of 0, 19.8, 97.8, and 390 µg/kg b.w.; 6 injections total). PCB 126 treatment caused a reduction in growth rates at the highest dose investigated, a dose-dependent decrease in thymus weights, and a dose-dependent increase in liver weights. Liver PCB 126 levels increased in a dose-dependent manner, while levels in plasma were below or close to the detection limit. The ratios of several epoxides to diol metabolites formed via the cytochrome P450 (P450) monooxygenase/soluble epoxide hydrolase (sEH) pathway from polyunsaturated fatty acids displayed a dose-dependent decrease in the liver and plasma, whereas levels of oxylipins formed by other metabolic pathways were generally not altered by PCB 126 treatment. The effects of PCB 126 on epoxide-to-diol ratios were associated with an increased CYP1A activity in liver microsomes and an increased sEH activity in liver cytosol and peroxisomes. These results suggest that oxylipins are potential biomarkers of exposure to PCB 126 and that the P450/sEH pathway is a therapeutic target for PCB 126-mediated hepatotoxicity that warrants further attention. PMID:27208083

  8. Synthesis and complexation of acyclic dithiolate ligands

    International Nuclear Information System (INIS)

    Ashford, L.

    1999-11-01

    Four approaches to ring substituted and unsubstituted N,N'-bis(o-mercaptobenzyliden)propylenediaminate ligands are described using N,N-dimethylcarbamate as a thiolate protecting group. Of the four basic methods, substitution, reduction, rearrangement and oxidation, the latter two successfully synthesise the aldehyde precursor. Rearrangement of the thiocarbamoyl group to the protected thiophenol is shown to be facilitated by a para-nitro substiuent. Ni(II) and Cu(II) complexes of N,N'-bis(p-nitro-o-mercaptobenzyliden)-propylenediaminate are synthesised by reaction of 2-formyl-4-nitro-N,N-dimethylcarbamoyI thiophenol, [Ni(OAc) 2 ].4(H 2 O) and 1,3-diaminopropane. The para-unsubstituted Ni(II) complex, Nickel-[N,N'-bis(o-mercaptobenzyliden) propylenediaminate] is prepared via reaction of the aldehyde, 2-formyl-N,N-dimethylcarbamoyl thiophenol with [Ni(OAc) 2 ].4(H 2 O) and 1,3-diaminopropane. The analogous carbamoyl-protected amine ligands, N,N'-dimethyl-N.N'-di[2-(N'',N''-dimethylcarbamyl)mercapto] benzyl-1,3-propane-diamine and N,N'-dimethyl-N,N'-di[2-(N'',N''-dimethylcarbamyl)mercapto] benzyl-1,2-ethane-diamine are also studied. The tertiary-butyl-protected diimine ligand, N,N'-bis-(o-mercaptobenzylidene)-propylenediaminate is prepared from 2-(tert-butylsulfanyl)benzaldehyde and 1,3-diaminopropane. Reaction with [Ni(H 2 O) 6 ]Cl 2 gives Nickel-[N,N'-bis(o-mercaptobenzyliden)-propylenediaminate], the crystal structure showing a distorted square-planar Ni(II) centre. Reaction with ZnCl 2 gives Zinc-[N,N'-bis(o-mercaptobenzyliden)propylenediaminate]dichloride. The crystal structure shows the thiolate donors remain protected and uncoordinated. The Zn(II) ion is coordinated by two imine donors and two chloride ions in a tetrahedral environment. In reactions with Ag(I) and Hg(II), N,N'-bis-(o-mercaptobenzylidene)-propylenediaminate acts as a reductant giving the free metals. Structural data and NMR and IR spectroscopic data for Nickel-[N,N'-bis(p-nitro-o-mereaptobenzyliden)propylenediaminate, Copper- [N,N'-bis(p-nitro-o-mercaptobenzyliden)propylenediaminate and Nickel-[N,N'-bis(o-mercaptobenzyliden)propylenediaminate] are analysed. Comparison of the data of the Ni(II) species show the major effects of the para-nitro group arise from electron withdrawal from the thiolate donors. The synthesis and complexation of the (2-mercaptomethyl)thiophenolato series of ligands, via the corresponding (2-hydroxymethyl)thiophenolato compounds, is detailed. Removal of β-elimination pathways by use of an o-xylyl linker allows the synthesis of α,α'-di[(2-mercaptomethyl)thiophenolato]-o-xylene. Reaction of α,α'-di[(2-mercaptomethyl)thiophenolato]-o-xylene with Group 10 metal ions Ni(II) and Pd(ll) monomers and a Pt(ll) trinuclear complex. Potential causes of the broad and featureless resonances in the 1 H NMR spectra of the complexes are investigated. The Ni(II) and Pd(ll) monomers are reacted with Pt(ll) salts to give trinuclear species. (author)

  9. On acyclicity of games with cycles

    DEFF Research Database (Denmark)

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

    2010-01-01

    We study restricted improvement cycles (ri-cycles) in finite positional n-person games with perfect information modeled by directed graphs (di-graphs) that may contain directed cycles (di-cycles). We assume that all these di-cycles form one outcome c, for example, a draw. We obtain criteria...

  10. Comparison of solvation dynamics of electrons in four polyols

    Energy Technology Data Exchange (ETDEWEB)

    Lampre, I.; Pernot, P.; Bonin, J. [Laboratoire de Chimie Physique/ELYSE, Universite Paris-Sud 11, UMR 8000, Bat. 349, Orsay F-91405 (France); CNRS, Orsay F-91405 (France); Mostafavi, M. [Laboratoire de Chimie Physique/ELYSE, Universite Paris-Sud 11, UMR 8000, Bat. 349, Orsay F-91405 (France); CNRS, Orsay F-91405 (France)], E-mail: mehran.mostafavi@lcp.u-psud.fr

    2008-10-15

    Using pump-probe transient absorption spectroscopy, we studied the solvation dynamics of the electron in liquid polyalcohols: ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol and propane-1,2,3-triol. Time-resolved absorption spectra ranging from 440 to 720 nm were measured. Our study shows that the excess electron in the diols presents an intense and wide absorption band in the visible and near-IR spectral domain at early time after two-photon ionization of the neat solvent. Then, for the first tens of picoseconds, the electron spectrum shifts toward the blue domain and its bandwidth decreases as the red part of the initial spectrum rapidly drops, while the blue part hardly evolves. In contrast, in the triol, the absorption spectrum of the electron is early situated in the visible range after the pump pulse and then solely evolves in the red part. The Bayesian data analysis of the observed picosecond solvation dynamics with different models is in favor of a heterogeneous continuous relaxation. That is corroborated by the analogy between the change in the absorption band with increasing time or decreasing temperature. That tends to indicate a similar organization disorder of the solvent. Moreover, the electron solvation dynamics is very fast in propane-1,2,3-triol despite its high viscosity and highlight the role of the OH-group in that process.

  11. Synthesis and crystal structures of two α-bromoamides, (2'R,1S,2S)-N(2-bromopropanoyl)-2-amino-1-phenylpropane-1,3-diol and (2'S,5S,6S)-N(2-bromopropanoyl)-5-amino-6-phenyl-2-oxo-1,3,2-dioxathiane

    International Nuclear Information System (INIS)

    English, R.B.; Liddell, R.J.; Whiteley, C.G.

    1987-01-01

    One pair of diastereomeric bromoamides, (2'R,1S,2S)- and (2'S,1S,2S)-N(2-bromopropanoyl)-2-amino-1-phenylpropane-1,3-diol have been synthesized from ethyl 2-bromopropionate and an optically active amino-diol. The crystal structures of both were determined from single-crystal X-ray analyses. Both compounds are orthorhombic with space group P2 1 2 1 2 1 with Z = 4 in a unit cell of dimensions a 22,124(5),b 12,812(5), and c 4,886(5)A and a 15,510(5), b 9,707(5), and c 9,457(5)A. The proton chemical shifts of the groups attached to the asymmetric centre C(2'), and consequently, the identification of the configuration of the molecules, were resolved with the help of high-resolution nuclear magnetic resonance

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

    Directory of Open Access Journals (Sweden)

    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

  13. Marine Bromophenol Derivative 3,4-Dibromo-5-(2-bromo-3,4-dihydroxy-6-isopropoxymethyl benzylbenzene-1,2-diol Protects Hepatocytes from Lipid-Induced Cell Damage and Insulin Resistance via PTP1B Inhibition

    Directory of Open Access Journals (Sweden)

    Jiao Luo

    2015-07-01

    Full Text Available 3,4-Dibromo-5-(2-bromo-3,4-dihydroxy-6-isopropoxymethyl benzylbenzene-1,2-diol (HPN is a bromophenol derivative from the marine red alga Rhodomela confervoides. We have previously found that HPN exerted an anti-hyperglycemic property in db/db mouse model. In the present study, we found that HPN could protect HepG2 cells against palmitate (PA-induced cell death. Data also showed that HPN inhibited cell death mainly by blocking the cell apoptosis. Further studies demonstrated that HPN (especially at 1.0 μM significantly restored insulin-stimulated tyrosine phosphorylation of IR and IRS1/2, and inhibited the PTP1B expression level in HepG2 cells. Furthermore, the expression of Akt was activated by HPN, and glucose uptake was significantly increased in PA-treated HepG2 cells. Our results suggest that HPN could protect hepatocytes from lipid-induced cell damage and insulin resistance via PTP1B inhibition. Thus, HPN can be considered to have potential for the development of anti-diabetic agent that could protect both hepatic cell mass and function.

  14. Serum Level of Antibodies (IgG, IgM Against Benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA Adducts in Children Dermatologically Exposed to Coal Tar

    Directory of Open Access Journals (Sweden)

    Pavel Borský

    2017-06-01

    Full Text Available Crude coal tar (CCT contains polycyclic aromatic hydrocarbons (PAHs. Benzo[a]pyrene (BaP is metabolized into a highly reactive metabolite benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE that is able to bind to DNA and creates BPDE-DNA adducts. Adducted DNA becomes immunogenic and induces immune response by production of antibodies against BPDE-DNA adducts (Ab-BPDE-DNA. Circulating Ab-BPDE-DNA was proposed as potential biomarker of genotoxic exposure to BaP (PAHs. Goeckerman therapy (GT of psoriasis uses dermal application of CCT ointment (PAHs. In presented study (children with psoriasis treated by GT; n = 19 the therapy significantly increased the level of Ab-BPDE-DNA (EI = 0.29/0.19–0.34 vs. 0.31/0.25–0.40; median/lower–upper quartile; p < 0.01. The results support the idea of Ab-BPDE-DNA level as a possible tentative indicator of exposure, effects and susceptibility of the organism to the exposure of BaP (PAHs.

  15. Evaluation of the genotoxic potential of 3-monochloropropane-1,2-diol (3-MCPD) and its metabolites, glycidol and beta-chlorolactic acid, using the single cell gel/comet assay.

    Science.gov (United States)

    El Ramy, R; Ould Elhkim, M; Lezmi, S; Poul, J M

    2007-01-01

    3-monochloropropane-1,2-diol (3-MCPD) is a member of a group of chemicals known as chloropropanols. It is found in many foods and food ingredients as a result of food processing. 3-MCPD is regarded as a rat carcinogen known to induce Leydig-cell and mammary gland tumours in males and kidney tumours in both genders. The aim of our study was to clarify the possible involvement of genotoxic mechanisms in 3-MCPD induced carcinogenicity at the target organ level. For that purpose, we evaluated DNA damages in selected target (kidneys and testes) and non-target (blood leukocytes, liver and bone marrow) male rat organs by the in vivo alkaline single cell gel electrophoresis (comet) assay, 3 and 24 h after 3-MCPD oral administration to Sprague-Dawley and Fisher 344 adult rats. 3-MCPD may be metabolised to a genotoxic intermediate, glycidol, whereas the predominant urinary metabolite in rats following 3-MCPD administration is beta-chlorolactic acid. Therefore, we also studied the DNA damaging effects of 3-MCPD and its metabolites, glycidol and beta-chlorolactic acid, in the in vitro comet assay on CHO cells. Our results show the absence of genotoxic potential of 3-MCPD in vivo in the target as well as in the non-target organs. Glycidol, the epoxide metabolite, induced DNA damages in CHO cells. beta-Chlorolactic acid, the main metabolite of 3-MCPD in rats, was shown to be devoid of DNA-damaging effects in vitro in mammalian cells.

  16. Effects of DK-002, a synthesized (6aS,cis)-9,10-Dimethoxy-7,11b-dihydro-indeno[2,1-c]chromene-3,6a-diol, on platelet activity.

    Science.gov (United States)

    Lee, Ki-Seon; Khil, Lee-Yong; Chae, Sang-Ho; Kim, Deukjoon; Lee, Byung-Hoon; Hwang, Gwi-Seo; Moon, Chang-Hyun; Chang, Tong-Shin; Moon, Chang-Kiu

    2006-02-02

    In the present study, the mechanism of antiplatelet activity of DK-002, a synthesized (6aS,cis)-9,10-Dimethoxy-7,11b-dihydro-indeno[2,1-c]chromene-3,6a-diol, was investigated. DK-002 inhibited the thrombin, collagen, and ADP-induced rat platelet aggregation in a concentration-dependent manner, with IC50 values of 120, 27, and 47 microM, respectively. DK-002 also inhibited thrombin-induced dense granule secretion, thromboxane A2 synthesis, and [Ca2+]i elevation in platelets. DK-002 did not show any significant effect on ADP-induced inhibition of cyclic AMP elevation by prostaglandin E1, but DK-002 was confirmed to inhibit ADP-induced [Ca2+]i elevation and shape change. DK-002 inhibited 4-bromo-A23187-induced [Ca2+]i elevation in the presence of creatine phosphate/creatine phosphokinase (CP/CPK, a ADP scavenging system) and indomethacin (a specific inhibitor of cyclooxygenase). DK-002 also inhibited Ca2+ mobilization in thrombin- or 4-bromo-A23187-stimulated platelets through its inhibitory effects on both Ca2+ release from intracellular stores and Ca2+ influx, in the presence of CP/CPK and indomethacin. Taken together, the present study shows that DK-002 has inhibitory effects on stimulation of platelets, and suggests that its antiplatelet activity might be related to the inhibitory mechanism on Ca2+ mobilization in stimulated platelets.

  17. Dispersive microextraction based on water-coated Fe₃O₄ followed by gas chromatography-mass spectrometry for determination of 3-monochloropropane-1,2-diol in edible oils.

    Science.gov (United States)

    Zhao, Qin; Wei, Fang; Xiao, Neng; Yu, Qiong-Wei; Yuan, Bi-Feng; Feng, Yu-Qi

    2012-06-01

    In the present work, we developed a novel dispersive microextraction technique by combining the advantages of liquid-phase microextraction (LPME) and magnetic solid-phase extraction (MSPE). In this method, trace amount of water directly absorbed on bare Fe₃O₄ to form water-coated Fe₃O₄ (W-Fe₃O₄) and rapid extraction can be achieved while W-Fe₃O₄ dispersed in the sample solution. The analyte adsorbed W-Fe₃O₄ can be easily collected and isolated from sample solution by application of a magnet. It was worth noting that in the proposed method water was used as extractant and Fe₃O₄ served as the supporter and retriever of water. The performance of the method was evaluated by extraction of 3-monochloropropane-1,2-diol (3-MCPD) from edible oils. The extracted 3-MCPD was then derived by a silylanization reagent (1-trimethylsilylimidazole) before gas chromatography-mass spectrometry (GC-MS) analysis. Several parameters that affected the extraction and derivatization efficiency were investigated. Our results showed that the limit of detection for 3-MCPD was 1.1 ng/g. The recoveries in spiked oil samples were in the range of 70.0-104.9% with the RSDs less than 5.6% (intra-day) and 6.4% (inter-day). Taken together, the simple, rapid and cost-effective method developed in current study, offers a potential application for the extraction and preconcentration of hydrophilic analytes from complex fatty samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Vasorelaxant and Hypotensive Effects of an Ethanolic Extract of Eulophia macrobulbon and Its Main Compound 1-(4′-Hydroxybenzyl-4,8-Dimethoxyphenanthrene-2,7-Diol

    Directory of Open Access Journals (Sweden)

    Sutthinee Wisutthathum

    2018-05-01

    Full Text Available Background: Ethnopharmacological studies demonstrated the potential for Eulophia species to treat inflammation, cancer, and cardio-metabolic diseases. The aim of the study was to investigate the vasorelaxant effect of ethanolic Eulophia macrobulbon (EM extract and its main phenanthrene on rat isolated mesenteric artery and to investigate the hypotensive effect of EM.Methods: The vasorelaxant effects of EM extract or phenanthrene and the underlying mechanisms were evaluated on second-order mesenteric arteries from Sprague Dawley rats. In addition, the acute hypotensive effect was evaluated in anesthetized rats infused with cumulative concentrations of the EM extract.Results: Both EM extract (10-4–1 mg/ml and phenanthrene (10-7–10-4 M relaxed endothelium-intact arteries, an effect that was partly reduced by endothelium removal (p < 0.001. A significant decrease in the relaxant effect of the extract and the phenanthrene was observed with L-NAME and apamin/charybdotoxin in endothelium-intact vessels, and with iberiotoxin in denuded vessels. SNP (sodium nitroprusside-induced relaxation was significantly enhanced by EM extract and phenanthrene. By contrast, ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one, 4-aminopyridine and glibenclamide (endothelium-denuded vessels and indomethacin (endothelium-intact vessels had no effect. In calcium-free solution, both the EM extract and phenanthrene inhibited extracellular Ca2+-induced contraction in high KCl and phenylephrine (PE pre-contracted rings. They also inhibited the intracellular Ca2+ release sensitive to PE. The acute infusion of EM extract (20 and 70 mg/kg induced an immediate and transient dose-dependent hypotensive effect.Conclusion: The ethanolic extract of EM tubers and its main active compound, 1-(4′-hydroxybenzyl-4,8-dimethoxyphenanthrene-2,7-diol (phenanthrene induced vasorelaxant effects on rat resistance vessels, through pleiotropic effects including endothelium-dependent effects (NOS

  19. Absence of in vivo genotoxicity of 3-monochloropropane-1,2-diol and associated fatty acid esters in a 4-week comprehensive toxicity study using F344 gpt delta rats.

    Science.gov (United States)

    Onami, Saeko; Cho, Young-Man; Toyoda, Takeshi; Horibata, Katsuyoshi; Ishii, Yuji; Umemura, Takashi; Honma, Masamitsu; Nohmi, Takehiko; Nishikawa, Akiyoshi; Ogawa, Kumiko

    2014-07-01

    3-Monochloropropane-1,2-diol (3-MCPD) is regarded as a rat renal and testicular carcinogen and has been classified as a possible human carcinogen (group 2B) by International Agency for Research on Cancer. This is potentially of great importance given that esters of this compound have recently found to be generated in many foods and food ingredients as a result of food processing. There have been a few reports about their toxicity, although we have recently found that the toxicity profile of 3-MCPD esters was similar to that of 3-MCPD in a rat 13-week repeated dose study, except for the acute renal toxicity seen in 3-MCPD-treated females. In the present study, to examine in vivo genotoxicity we administered equimolar doses of 3-MCPD or 3-MCPD fatty acid esters (palmitate diester, palmitate monoester and oleate diester) to 6-week-old male F344 gpt delta rats carrying a reporter transgene for 4 weeks by intragastric administration. In vivo micronucleus, Pig-a mutation and gpt assays were performed, as well as investigations of major toxicological parameters including histopathological features. As one result, the relative kidney weights of the 3-MCPD and all three ester groups were significantly increased compared with the vehicle control group. However, the frequency of micronucleated reticulocytes and Pig-a mutant red blood cells did not differ among groups. Moreover, no changes were observed in mutant frequencies of gpt and red/gam (Spi(-)) genes in the kidney and the testis of 3-MCPD and 3-MCPD-fatty-acid-esters-treated rats. In histopathological analyses, no treatment related changes were observed, except for decrease of eosinophilic bodies in the kidneys of all treated groups. These results suggest that 3-MCPD and its fatty acid esters are not in vivo genotoxins, although they may exert renal toxicity. © The Author 2014. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e

  20. Steroidal saponins from Tribulus terrestris.

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Schur complements of matrices with acyclic bipartite graphs

    DEFF Research Database (Denmark)

    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 to be ...

  2. Acyclic diastereoselection in prochiral radical addition to prochiral olefins.

    Science.gov (United States)

    Sibi, Mukund P; Rheault, Tara R; Chandramouli, Sithamalli V; Jasperse, Craig P

    2002-03-27

    The stereochemical preference (syn or anti) when prochiral radicals add to prochiral acceptors is of fundamental interest. The primary focus of this research was to determine which factors influence the relative stereochemistry between the beta and gamma chiral centers when these are formed concurrently. While moderate diastereoselectivity was found for addition of alkyl (6a-d) and alpha-alkoxy radicals (16a-c) (15:1 anti). Steric influence in alkyl radical additions was difficult to evaluate due to decreased reactivity when using bulky reaction partners; however, more reactive alpha-alkoxy radicals, it was found that increasing steric bulk leads to moderate increases in selectivity. In addition, higher selectivity was observed when employing lanthanide Lewis acids whose environment (reactivity) was modified using achiral additives, suggesting a potentially simple means for selectivity enhancements in radical reactions. Overall these results indicate that significant stereoelectronic effects are necessary to achieve high levels of selectivity in prochiral radical additions to prochiral acceptors.

  3. Dissociation kinetics of acyclic and macrocyclic polyaminopolycarboxylate complexes of yttrium

    International Nuclear Information System (INIS)

    Pathak, P.N.; Manchanda, V.K.

    2000-01-01

    Dissociation kinetics of Y III complexes of a linear as well as two macrocyclic polyaminopolycarboxylates, ethylenediamine diacetic acid (EDDA), 1,7-diaza-4,10,13-trioxacyclopentadecane-N,N'-diacetic acid (K21DA) and 1,10-diaza-4,7,13,16-tetraoxacyclooctadecane-N,N'-diacetic acid (K22DA) have been studied at a constant ionic strength (0.1 M) under varying (H + ) and temperatures. Cu II ion acts as the scavenger of the free ligand. Dissociation rate of Y III -K21DA is insensitive to Cu II and acetate (used as buffer anion) concentrations. Kinetic stability of the three complexes follow the order : Y III -K22DA>Y III -K21DA>Y III -EDDA. Enthalpies of activation for K21DA and K22DA complexes of Y III are also evaluated. Thermodynamic stability constant (log K) for Y III -K22DA complex is 10.81 ± 0.04. (author)

  4. Synthesis of acyclic nucleoside 5-o-carboranyl uracil derivative ...

    African Journals Online (AJOL)

    carboranyl uracil 7 as potentially antiviral agent and a suitable candidate for BNCT is described starting from 5,5- dihydroxymethyl-1,3-dioxane 1, an intermediate 2,2,2-triacetoxymethyl ethoxymethyl acetyl 2 was synthesized and coupled with ...

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

    Czech Academy of Sciences Publication Activity Database

    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

  6. A novel acyclic diterpenic alcohol isolated from antioxidant active ...

    African Journals Online (AJOL)

    Background: Isolation and characterization of a new compound from the antioxidant active ethanol extract of leaves of an endemic plant Centaurothamnus maximus. Methods: The air dried powdered leaves of the plant was extracted successively with n-hexane, dichloromethane, ethyl acetate and ethanol. The obtained ...

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

    KAUST Repository

    Agumbe Suresh, Mahima; Stoleru, Radu; Denton, Ron; Zechman, Emily; Shihada, Basem

    2012-01-01

    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

  8. Synthesis of acyclic adenine 8,N-anhydronucleosides

    Czech Academy of Sciences Publication Activity Database

    Meszárosová, Kateřina; Holý, Antonín; Masojídková, Milena

    2000-01-01

    Roč. 65, č. 7 (2000), s. 1109-1125 ISSN 0010-0765 R&D Projects: GA ČR GV203/96/K001 Institutional research plan: CEZ:AV0Z4055905 Subject RIV: CC - Organic Chemistry Impact factor: 0.960, year: 2000

  9. Efficient synthesis and biological properties of the 2‘-trifluoromethyl analogues of acyclic nucleosides and acyclic nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

    Jansa, Petr; Kolman, Viktor; Kostinová, Alexandra; Dračínský, Martin; Mertlíková-Kaiserová, Helena; Janeba, Zlatko

    2011-01-01

    Roč. 76, č. 10 (2011), s. 1187-1198 ISSN 0010-0765 R&D Projects: GA MV VG20102015046 Institutional research plan: CEZ:AV0Z40550506 Keywords : nucleosides * nucleotides * phosphorus * fluorine * biological activity * antibiotics Subject RIV: CC - Organic Chemistry Impact factor: 1.283, year: 2011

  10. Six new ergostane-type steroids from king trumpet mushroom (Pleurotus eryngii) and their inhibitory effects on nitric oxide production.

    Science.gov (United States)

    Kikuchi, Takashi; Maekawa, Yukina; Tomio, Arisa; Masumoto, Yuki; Yamamoto, Taishi; In, Yasuko; Yamada, Takeshi; Tanaka, Reiko

    2016-11-01

    Six new ergostane-type steroids; (22E)-3β,5α,6α,11-tetrahydroxy-9(11)-seco-ergosta-7,22-dien-9-one (1), (22E)-8,14-epoxyergosta-6,22-diene-3β,5α,9α-triol (2), (22E)-4α,5α-epoxyergosta-7,22-diene-3β,6β-diol (3), (22E)-3β,4β,5α-trihydroxyergosta-7,22-dien-6-one (4), (22E)-ergosta-7,22-diene-3β,5β,6α-triol (5), and (22E)-6β-methoxyergosta-7,22-diene-3β,5α-diol 3-O-β-d-glucopyranoside (6) were isolated from the fruiting bodies of king trumpet mushroom (Pleurotus eryngii), along with fourteen known compounds (7-20). All isolated compounds were evaluated for their inhibitory effects on macrophage activation using a nitric oxide production inhibition assay. Copyright © 2016. Published by Elsevier Inc.

  11. Novel 1,3-dioxanes from apple juice and cider.

    Science.gov (United States)

    Kavvadias, D; Beuerle, T; Wein, M; Boss, B; König, T; Schwab, W

    1999-12-01

    Extracts obtained by XAD solid-phase extraction of apple juice and cider were separated by liquid chromatography on silica gel. Several new 1,3-dioxanes including the known 2-methyl-4-pentyl-1,3-dioxane and 2-methyl-4-[2'(Z)-pentenyl]-1,3-dioxane, were identified in the nonpolar fractions by GC/MS analysis and confirmed by chemical synthesis. The enantioselective synthesis of the stereoisomers of the 1,3-dioxanes was performed using (R)- and (R,S)-octane-1,3-diol and (R)- and (R,S)-5(Z)-octene-1,3-diol as starting material. Comparison with the isolated products indicated that the natural products consisted of a mixture of (2S,4R) and (2R,4R) stereoisomers in the ratio of approximately 10:1, except for 1,3-dioxanes generated from acetone and 2-butanone. It is assumed that the 1, 3-dioxanes are chemically formed in the apples and cider from the natural apple ingredients (R)-octane-1,3-diol, (R)-5(Z)-octene-1, 3-diol, (3R,7R)- and (3R,7S)-octane-1,3,7-triol, and the appropriate aldehydes and ketones, which are produced either by the apples or by yeast during fermentation of the apple juice.

  12. Steroidal saponins from the roots of Asparagus cochinchinensis.

    Science.gov (United States)

    Zhu, Guo-Lei; Hao, Qian; Li, Rong-Tao; Li, Hai-Zhou

    2014-03-01

    To study the chemical constituents of the roots of Asparagus cochinchinensis (Asparagaceae). The compounds were isolated with Diaion HP20, silica gel, and ODS chromatography, and their structures were determined on the basis of chemical methods, HR-ESI-MS, and 1D- and 2D-NMR techniques. Seven compounds were isolated from the n-butanol fraction of the roots of A. cochinchinensis, and their structures were elucidated as (25S)-26-O-β-D-glucopyranosyl-5β-furostan-3β, 22α, 26-triol-12-one-3-O-β-D-glucopyranoside (1), (25S)-26-O-β-D-glucopyranosyl-22α-methoxy-5β-furostan-3β, 26-diol-12-one-3-O-β-D-glucopyranoside (2), (25S)-26-O-β-D-glucopyranosyl-5β-furostan-3β, 22α, 26-triol (3), (25S)-26-O-β-D-glucopyranosyl-5β-furstan-3β, 22α, 26-triol-3-O-β-D-glucopyranoside (4), (25S)-26-O-β-D-glucopyranosyl-5β-furostan-3β, 22α, 26-triol-3-O-α-L-rhamnopyranosyl-(1, 4)-β-D-glucopyranoside (5), (25S)-5β-spirostan-3β-ol-3-O-α-L-rhamnopyranoside (6), and (25S)-5β-spirostan-3β-ol-3-O-β-D-glucopyranoside (7). Compounds 1 and 2 were two new furostanol saponins. Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  13. C5 glycolipids of heterocystous cyanobacteria track symbiont abundance in the diatom Hemiaulus hauckii across the tropical North Atlantic

    Science.gov (United States)

    Bale, Nicole J.; Villareal, Tracy A.; Hopmans, Ellen C.; Brussaard, Corina P. D.; Besseling, Marc; Dorhout, Denise; Sinninghe Damsté, Jaap S.; Schouten, Stefan

    2018-03-01

    Diatom-diazotroph associations (DDAs) include marine heterocystous cyanobacteria found as exosymbionts and endosymbionts in multiple diatom species. Heterocysts are the site of N2 fixation and have thickened cell walls containing unique heterocyst glycolipids which maintain a low oxygen environment within the heterocyst. The endosymbiotic cyanobacterium Richelia intracellularis found in species of the diatom genus Hemiaulus and Rhizosolenia makes heterocyst glycolipids (HGs) which are composed of C30 and C32 diols and triols with pentose (C5) moieties that are distinct from limnetic cyanobacterial HGs with predominantly hexose (C6) moieties. Here we applied a method for analysis of intact polar lipids to the study of HGs in suspended particulate matter (SPM) and surface sediment from across the tropical North Atlantic. The study focused on the Amazon plume region, where DDAs are documented to form extensive surface blooms, in order to examine the utility of C5 HGs as markers for DDAs as well as their transportation to underlying sediments. C30 and C32 triols with C5 pentose moieties were detected in both marine SPM and surface sediments. We found a significant correlation between the water column concentration of these long-chain C5 HGs and DDA symbiont counts. In particular, the concentrations of both the C5 HGs (1-(O-ribose)-3,27,29-triacontanetriol (C5 HG30 triol) and 1-(O-ribose)-3,29,31-dotriacontanetriol (C5 HG32 triol)) in SPM exhibited a significant correlation with the number of Hemiaulus hauckii symbionts. This result strengthens the idea that long-chain C5 HGs can be applied as biomarkers for marine endosymbiotic heterocystous cyanobacteria. The presence of the same C5 HGs in surface sediment provides evidence that they are effectively transported to the sediment and hence have potential as biomarkers for studies of the contribution of DDAs to the paleo-marine N cycle.

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

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    Sep 15, 2009 ... microscope analyses, the compounds were confirmed to have ability in promoting apoptosis. However, ... Some of them have cytostatic properties and the others ..... rescent images of untreated cells, 2',3'-epoxyisocapno-.

  15. Rhenium-Catalyzed Deoxydehydration of Diols and Polyols

    DEFF Research Database (Denmark)

    Dethlefsen, Johannes Rytter; Fristrup, Peter

    2015-01-01

    The substitution of platform chemicals of fossil origin by biomass-derived analogues requires the development of chemicaltransformations capable of reducing the very high oxygen contentof biomass. One such reaction, which has received increasingattention within the past five years, is the heniumc......The substitution of platform chemicals of fossil origin by biomass-derived analogues requires the development of chemicaltransformations capable of reducing the very high oxygen contentof biomass. One such reaction, which has received increasingattention within the past five years...... systems that have been developed withemphasis on the nature of the reductant, the substrate scope,and mechanistic investigations....

  16. The synthesis and pyrolysis of polycyclic organic sulphites

    International Nuclear Information System (INIS)

    Venter, H.J.

    1988-01-01

    The syntheses and thermolyses of model sulphite substrates were investigated: Lithium aluminium hidride reductions via the formation of a cyclic transition state lead to the formation of an endo-endo-diol as the main product. In contrast with the above, sodium borohidride reductions proceded via the formation of an acyclic transition state, which gave rise to different end products. The influence of specific reaction mechanisms on the product distribution of hidride reductions is discussed. The pinacoles required for the syntheses of certain substrates were obtained by means of the Clemmensen reductions. An unusual alcohol was formed during one of Clemmensen reductions. A mechanisms for ring cleavage and pinacole formation is presented, while a modified mechanism is proposed for the Clemmensen reduction of ketones. Treatment of some of the pinacoles with thionyl chloride lead to the formation of specific sulphites. A cyclic sulphite was derived from a diol obtained via a lithium aluminium hidride reduction reaction. In contrast a specific diketone was converted to a specific hemiketal when treated with zinc and acetic acid. Attempts to convert the diketone to the corresponding diol were unsuccessful. The pyrolytic behaviour of some sulphites as well as some of the diols were investigated. The pyrolysis of γ-diols and the corresponding sulphites proceded similarly. Various structures were derived from extensive comparative 1 H- and 13 C- studies

  17. Single-Atom Mn Active Site in a Triol-Stabilized β-Anderson Manganohexamolybdate for Enhanced Catalytic Activity towards Adipic Acid Production

    Directory of Open Access Journals (Sweden)

    Jianhui Luo

    2018-03-01

    Full Text Available Adipic acid is an important raw chemical for the commercial production of polyamides and polyesters. The traditional industrial adipic acid production utilizes nitric acid to oxidize KA oil (mixtures of cyclohexanone and cyclohexanol, leading to the emission of N2O and thus causing ozone depletion, global warming, and acid rain. Herein, we reported an organically functionalized β-isomer of Anderson polyoxometalates (POMs nanocluster with single-atom Mn, β-{[H3NC(CH2O3]2MnMo6O18}− (1, as a highly active catalyst to selectively catalyze the oxidation of cyclohexanone, cyclohexanol, or KA oil with atom economy use of 30% H2O2 for the eco-friendly synthesis of adipic acid. The catalyst has been characterized by single crystal and powder XRD, XPS, ESI-MS, FT-IR, and NMR. A cyclohexanone (cyclohexanol conversion of >99.9% with an adipic acid selectivity of ~97.1% (~85.3% could be achieved over catalyst 1 with high turnover frequency of 2427.5 h−1 (2132.5 h−1. It has been demonstrated that the existence of Mn3+ atom active site in catalyst 1 and the special butterfly-shaped topology of POMs both play vital roles in the enhancement of catalytic activity.

  18. 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)

    International Nuclear Information System (INIS)

    Rocha, D.; Takahashi, J.A.; Boaventura, M.A.D.

    2009-01-01

    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)

  19. 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)

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, D.; Takahashi, J.A.; Boaventura, M.A.D. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Quimica], e-mail: dianadb@netuno.lcc.ufmg.br

    2009-01-15

    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-16{beta},19-diol (2) and ent-kauran-16{beta},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)

  20. A new ceramide from Suillus luteus and its cytotoxic activity against human melanoma cells.

    Science.gov (United States)

    León, Francisco; Brouard, Ignacio; Torres, Fernando; Quintana, José; Rivera, Augusto; Estévez, Francisco; Bermejo, Jaime

    2008-01-01

    A new phytosphingosine-type ceramide, suillumide (1), was isolated from the EtOH extract of the basidiomycete Suillus luteus (L.) S. F. Gray, along with ten known compounds: ergosta-4,6,8(14),22-tetraen-3-one, ergosterol, ergosterol peroxide, suillin, (E)-3,4,5-trimethoxycinnamic alcohol, 5 alpha,6 alpha-epoxyergosta-8,22-diene-3beta,7 beta-diol, (R)-1-palmitoylglycerol, ergosta-7,9(11),22-triene-3beta,5 alpha,6 beta-triol, cerevisterol, and 4-hydroxybenzoic acid. The structure of 1 was determined on the basis of spectroscopic and mass-spectrometric analyses, as well as by chemical methods. Compound 1 and its synthetic diacetyl derivative 2 were tested for their cytotoxic activities against the human melanoma cell line SK-MEL-1. Both drugs showed IC(50) values of ca. 10 microM after 72 h of exposure.

  1. Two new sesquiterpenoids produced by halophilic Nocardiopsis chromatogenes YIM 90109.

    Science.gov (United States)

    Sun, Ming-Wei; Zhang, Xiao-Mei; Bi, Hui-Li; Li, Wen-Jun; Lu, Chun-Hua

    2017-01-01

    Two new germacradiene-type sesquiterpenoids, including 1(10)E,5E-germacradiene-9β,11-diol (or 9β-hydroxyl germacradienol) (1) and 11-hydroxy-1(10)E,5E-germacradien-2-one (2-oxygermacradienol) (2), together with a known geosmin-type sesquiterpenoid (1β,4β,4aβ,7α,8aα)-4,8a-dimethyloctahydronaphthalene-1,4a,7(2H)-triol (3), were elucidated by their NMR spectroscopic data, HR-ESI-MS and single-crystal X-ray diffraction from the halophilic strain Nocardiopsis chromatogenes YIM 90109. The antimicrobial activities were evaluated by paper diffusion method.

  2. Chemical Constituents of Schisandra rubriflora Rehd.et Wils.

    Institute of Scientific and Technical Information of China (English)

    Gan-Peng LI; Jing-Feng ZHAO; Yong-Qiang TU; Xiao-Dong YANG; Hong-Bin ZHANG; Liang LI

    2005-01-01

    Schisandra rubriflora Rehd. et Wils. is a traditional Chinese medicine. To search for new and bioactive components from traditional Chinese medicines and provide scientific evidence for taxonomy, the chemical constituents ofthe plant were investigated by various column chromatography methods (silica gel,Sephadex LH-20, and RP-18). From the aerial parts ofS. rubriflora, three new megastigmane glycosides,namely (3S, 5R, 6S, 9R)-megastigmane-3, 9-diol 3-O-[α-L-arabionfuranosyl-(1→6)-β-D-glucopyranoside](1), 7-megastigmene-3-ol-9-one 3-O-[o-L-arabionfuranosyl-(1→6)-β-D-glucopyranoside] (2), and megastigmane-3α, 4β, 9ξ-triol 3-O-β-D-glucopyranoside (3), along with 14 known compounds, were isolated.The structures of the new compounds were elucidated by a combination of spectroscopic and chemical methods.

  3. Kinetics of hydrogen peroxide decomposition by catalase: hydroxylic solvent effects.

    Science.gov (United States)

    Raducan, Adina; Cantemir, Anca Ruxandra; Puiu, Mihaela; Oancea, Dumitru

    2012-11-01

    The effect of water-alcohol (methanol, ethanol, propan-1-ol, propan-2-ol, ethane-1,2-diol and propane-1,2,3-triol) binary mixtures on the kinetics of hydrogen peroxide decomposition in the presence of bovine liver catalase is investigated. In all solvents, the activity of catalase is smaller than in water. The results are discussed on the basis of a simple kinetic model. The kinetic constants for product formation through enzyme-substrate complex decomposition and for inactivation of catalase are estimated. The organic solvents are characterized by several physical properties: dielectric constant (D), hydrophobicity (log P), concentration of hydroxyl groups ([OH]), polarizability (α), Kamlet-Taft parameter (β) and Kosower parameter (Z). The relationships between the initial rate, kinetic constants and medium properties are analyzed by linear and multiple linear regression.

  4. Cucurbitane-type triterpenoids from the stems and leaves of Momordica charantia.

    Science.gov (United States)

    Zhao, Gao-Ting; Liu, Jie-Qing; Deng, Yuan-Yuan; Li, Hai-Zhou; Chen, Jian-Chao; Zhang, Zhi-Run; Zhou, Lin; Qiu, Ming-Hua

    2014-06-01

    Six new cucurbitane-type triterpenoids, karavilagenin F (1), karavilosides XII and XIII (2, 3), momordicines VI, VII, and VIII (4, 5 and 6), along with four known ones, 5β,19-epoxy-25-methoxycucurbita-6,23-diene-3β,19-diol (7), 5β,19-epoxycucurbita-6, 23-diene-3β,19,25-triol (8), kuguacin R (9), and (19R,23E)-5β,19-epoxy-19-methoxycucurbita-6,23,25-trien-3β-ol (10), were isolated from the stems and leaves of Momordica charantia L. Their chemical structures were elucidated by extensive 1D NMR and 2D NMR (HSQC, HMBC, COSY, and ROESY), MS experiments, and CD spectrum. Compound 6 showed weak cytotoxicity against five human cancer cells lines with IC50 values of 14.3-20.5μmol/L. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Structure Odour Relationship Study of Acyclic Monoterpene Alcohols, their Acetates and Synthesized Oxygenated Derivatives

    OpenAIRE

    Elsharif, Shaimaa

    2017-01-01

    The replacement of synthetic conventional compounds by natural ingredients; whether in medicine, food, or cosmetics; has been increasingly requested by consumers, especially since the last decade. Terpenes in general and monoterpenes in particular are secondary metabolites in plants, and they may be a promising natural alternative. Monoterpenes, the main constituents of plants’ essential oils, are odorous compounds that play a significant ecological role in plant evolution. The...

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

    Czech Academy of Sciences Publication Activity Database

    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 - others: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

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

    Czech Academy of Sciences Publication Activity Database

    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

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

    Czech Academy of Sciences Publication Activity Database

    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: 3.057, year: 2015

  9. Crystal Structures of Acyclic Nucleoside Phosphonates in Complex with Escherichia coli Hypoxanthine Phosphoribosyltransferase

    Czech Academy of Sciences Publication Activity Database

    Eng, W. S.; Hocková, Dana; Špaček, Petr; Baszczyňski, Ondřej; Janeba, Zlatko; Naesens, L.; Keough, D. T.; Guddat, L. W.

    2016-01-01

    Roč. 1, č. 19 (2016), s. 6267-6276 ISSN 2365-6549 R&D Projects: GA ČR(CZ) GA16-06049S Institutional support: RVO:61388963 Keywords : enzyme inhibitors * nucleotide analogues * HPRT Subject RIV: CC - Organic Chemistry

  10. Can acyclic conformational control be achieved via a sulfur-fluorine gauche effect?

    Science.gov (United States)

    Thiehoff, C; Holland, M C; Daniliuc, C; Houk, K N; Gilmour, R

    2015-06-01

    The gauche conformation of the 1,2-difluoroethane motif is known to involve stabilising hyperconjugative interactions between donor (bonding, σ C-H ) and acceptor (antibonding, σ *C-F) orbitals. This model rationalises the generic conformational preference of F-C β -C α -X systems ( φ FCCX ≈ 60°), where X is an electron deficient substituent containing a Period 2 atom. Little is known about the corresponding Period 3 systems, such as sulfur and phosphorus, where multiple oxidation states are possible. Conformational analyses of β-fluorosulfides, -sulfoxides and -sulfones are disclosed here, thus extending the scope of the fluorine gauche effect to the 3rd Period (F-C-C-S(O) n ; φ FCCS ≈ 60°). Synergy between experiment and computation has revealed that the gauche effect is only pronounced in structures bearing an electropositive vicinal sulfur atom (S + -O - , SO 2 ).

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

    OpenAIRE

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

    2004-01-01

    A novel 13-residue peptide Mo1659 has been isolated from the venom of a vermivorous cone snail, Conus monile. HPLC fractions of the venom extract yielded an intense UV absorbing fraction with a mass of 1659 Da. De novo sequencing using both matrix assisted laser desorption and ionization and electrospray MS/MS methods together with analysis of proteolytic fragments successfully yielded the amino acid sequence, HGGSWYRFPWGY-NH2. This was further confirmed by comparison with the chemically synt...

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

    Czech Academy of Sciences Publication Activity Database

    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 - others: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

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

    Czech Academy of Sciences Publication Activity Database

    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

  14. Mapping and Scheduling of Directed Acyclic Graphs on An FPFA Tile

    NARCIS (Netherlands)

    Guo, Y.; Smit, Gerardus Johannes Maria

    2002-01-01

    An architecture for a hand-held multimedia device requires components that are energy-efficient, flexible, and provide high performance. In the CHAMELEON [4] project we develop a coarse grained reconfigurable device for DSP-like algorithms, the so-called Field Programmable Function Array (FPFA). The

  15. Configurations and conformations in acyclic, unsaturated hydrocarbons. A 13C NMR study

    NARCIS (Netherlands)

    Haan, de J.W.; Ven, van de L.J.M.

    1973-01-01

    13C NMR (CMR) spectra of a number of di- and trisubstituted ethylenes have been measured. Very consistent values are found for the differential shieldings of allylic carbons in a number of linear, (Z)- and (E)-disubstituted ethylenes. The discrepancies between the several structural elements are

  16. Studies of the Raman Spectra of Cyclic and Acyclic Molecules: Combination and Prediction Spectrum Methods

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-02

    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.

  17. Antiretrovirus activity of a novel class of acyclic pyrimidine nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

    Balzarini, J.; Pannecouque, C.; De Clercq, E.; Aquaro, S.; Perno, C. F.; Egberink, H.; Holý, Antonín

    2002-01-01

    Roč. 46, č. 7 (2002), s. 2185-2193 ISSN 0066-4804 R&D Projects: GA ČR GV203/96/K001 Institutional research plan: CEZ:AV0Z4055905 Keywords : nucleoside phosphonates Subject RIV: CC - Organic Chemistry Impact factor: 4.215, year: 2002

  18. Phytotoxicity of acyclic nucleoside phosphonates in Brassica pekinensis and Solanum lycopersicum

    Czech Academy of Sciences Publication Activity Database

    Špak, Josef; Janeba, Zlatko; Jansa, Petr; Baszczyňski, Ondřej; Pavingerová, Daniela; Špaková, Vlastimila

    2016-01-01

    Roč. 125, č. 2 (2016), s. 375-379 ISSN 0167-6857 Institutional support: RVO:60077344 ; RVO:61388963 Keywords : Chemotherapy * Virus eradication * Phytotoxicity Subject RIV: EE - Microbiology, Virology; CC - Organic Chemistry (UOCHB-X) Impact factor: 2.002, year: 2016

  19. Highly stable acyclic bifunctional chelator for {sup 64}Cu PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Abada, S.; Lecointre, A.; Christine, C.; Charbonniere, L. [CNRS/UDS, EPCM, Strasbourg (France). Lab. d' Ingenierie Appliquee a l' Analyse; Dechamps-Olivier, I. [Univ. de Reims Champagne Ardenne, Reims (France). Group Chimie de Coordination; Platas-Iglesias, C. [Univ. da Coruna (Spain). Dept. de Quimica Fundamental; Elhabiri, M. [CNRS/UDS, EPCM, Strasbourg (France). Lab. de Physico-Chimie Bioinorganique

    2011-07-01

    Ligand L{sup 1}, based on a pyridine scaffold, functionalized by two bis(methane phosphonate)aminomethyl groups, was shown to display a very high affinity towards Cu(II) (log K{sub CuL}=22.7) and selectivity over Ni(II), Co(II), Zn(II) and Ga(III) ({delta} log K{sub ML}>4) as shown by the values of the stability constants obtained from potentiometric measurements. Insights into the coordination mode of the ligand around Cu(II) cation were obtained by UV-Vis absorption and EPR spectroscopies as well as density functional theory (DFT) calculations (B3LYP model) performed in aqueous solution. The results point to a pentacoordination pattern of the metal ion in the fully deprotonated [CuL{sup 1}]{sup 6-} species. Considering the beneficial thermodynamic parameters of this ligand, kinetic experiments were run to follow the formation of the copper(II) complexes, indicating a very rapid formation of the complex, appropriate for {sup 64}Cu complexation. As L{sup 1} represents a particularly interesting target within the frame of {sup 64}Cu PET imaging, a synthetic protocol was developed to introduce a labeling function on the pyridyl moiety of L{sup 1}, thereby affording L{sup 2}, a potential bifunctional chelator (BFC) for PET imaging.

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

    Czech Academy of Sciences Publication Activity Database

    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: 2.923, year: 2015

  1. A rapid reliability estimation method for directed acyclic lifeline networks with statistically dependent components

    International Nuclear Information System (INIS)

    Kang, Won-Hee; Kliese, Alyce

    2014-01-01

    Lifeline networks, such as transportation, water supply, sewers, telecommunications, and electrical and gas networks, are essential elements for the economic and societal functions of urban areas, but their components are highly susceptible to natural or man-made hazards. In this context, it is essential to provide effective pre-disaster hazard mitigation strategies and prompt post-disaster risk management efforts based on rapid system reliability assessment. This paper proposes a rapid reliability estimation method for node-pair connectivity analysis of lifeline networks especially when the network components are statistically correlated. Recursive procedures are proposed to compound all network nodes until they become a single super node representing the connectivity between the origin and destination nodes. The proposed method is applied to numerical network examples and benchmark interconnected power and water networks in Memphis, Shelby County. The connectivity analysis results show the proposed method's reasonable accuracy and remarkable efficiency as compared to the Monte Carlo simulations

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

    DEFF Research Database (Denmark)

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

    1977-01-01

    The metabolism of carcinogenic N-nitrosamines was studied in normal-appearing bronchial specimens obtained from 4 patients. Explants of bronchi were cultured in a chemically defined medium for 7 days. N-Nitrosamines [N-nitrosodimethylamine (DMN), N-nitrosodiethylamine (DEN), N,N'-dinitrosopiperaz...

  3. Identification of a carotenoid oxygenase synthesizing acyclic xanthophylls: combinatorial biosynthesis and directed evolution.

    Science.gov (United States)

    Mijts, Benjamin N; Lee, Pyung Cheon; Schmidt-Dannert, Claudia

    2005-04-01

    A carotenoid desaturase homolog from Staphylococcus aureus (CrtOx) was identified. When expressed in engineered E. coli cells synthesizing linear C(30) carotenoids, polar carotenoid products were generated, identified as aldehyde and carboxylic acid C(30) carotenoid derivatives. The major product in this engineered pathway is the fully desaturated C(30) dialdehyde carotenoid 4,4'-diapolycopen-4,4'-dial. Very low carotenoid yields were observed when CrtOx was complemented with the C(40) carotenoid lycopene pathway. But extension of an in vitro evolved pathway of the fully desaturated 2,4,2',4'-tetradehydrolycopene produced the structurally novel fully desaturated C(40) dialdehyde carotenoid 2,4,2',4'-tetradehydrolycopendial. Directed evolution of CrtOx by error-prone PCR resulted in a number of variants with higher activity on C(40) carotenoid substrates and improved product profiles. These findings may provide new biosynthetic routes to highly polar carotenoids with unique spectral properties desirable for a number of industrial and pharmaceutical applications.

  4. Systematic investigations on acyclic organic carbonate solvents for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, J.; Peter, S.; Novak, P.

    2003-03-01

    Electrochemical cycling tests on cells with graphite electrodes and several alkyl methyl carbonates were performed. Experiments with mixed binary solvent electrolytes with ethylene carbonate (EC) showed that the alkyl methyl carbonates H{sub 3}CO(CO)O(CH{sub 2}){sub n}H (n = 3-5) are suitable as co-solvents in lithium-ion batteries. Ternary mixtures of EC, BMC, and propylene carbonate (PC) showed better overall performances than EC/PC electrolytes. The branched isobutyl methyl carbonate (i-BMC) outperforms its linear isomer (BMC) in terms of electrochemical performance. LiPF{sub 6} is superior to LiClO{sub 4} as conducting salt in both EC/BMC and EC/i-BMC mixtures in terms of electrolyte conductivity, rate capability, and cycling stability. (author)

  5. Stereochemical studies of acyclic isoprenoids-XII. Lipids of methanogenic bacteria and possible contributions to sediments

    Science.gov (United States)

    Risatti, J.B.; Rowland, S.J.; Yon, D.A.; Maxwell, J.R.

    1984-01-01

    Abundant volatile lipids of Methanobacterium thermoautotrophicum and Methanosarcina barkeri include isoprenoid hydrocarbons (??? C30), and C15, C20 and C25 isoprenoid alcohols. M. barkeri contains 2,6,10,15,19-pentamethyleicosane, whose relative stereochemistry is the same as found in marine sediments, indicating that it is a marker of methanogenic activity. The C20, C30 and C25 alkenes in M. thermoautotrophicum also have a preferred sterochemistry; the latter have the 2,6,10,14,18-pentamethyleicosanyl skeleton, suggesting that the alkane in marine sediments may derive from methanogens. The stereochemistry of squalane in a marine sediment is also compatible with an origin in methanogens; in contrast, the stereochemistry of pristane in M. thermoautotrophicum indicates a fossil fuel contaminant origin, suggesting that this and certain other alkanes reported in archaebacteria might also be of contaminant origin. There is, therefore, little evidence at present that the pristane in immature marine sediments originates in methanogens. The C15 and C20 saturated alcohols in M. thermoautotrophicum have mainly the all-R configuration. If this is generally true for methanogens, the C20 alcohol in the Messel shale may originate mainly from methanogens, whereas that in the Green River shale may originate mainly from photosynthetic organisms. ?? 1984.

  6. Distributions of Heterocyst Glycolipids in Settling Particulate Matter Record Ecological and Environmental Parameters in a Tropical Lake

    Science.gov (United States)

    Meegan Kumar, D.; Hopmans, E.; S Sinninghe Damsté, J.; Schouten, S.; Bauersachs, T.; Werne, J. P.

    2017-12-01

    Temperature is a critical component of paleoenvironmental reconstructions, yet it is notoriously difficult to measure in terrestrial archives. Presented here is an investigation of unique glycolipids produced by heterocystous cyanobacteria, so-called heterocyst glycolipids (HGs), in the water column of Lake Malawi (East Africa). The goal of the study is to evaluate the potential of HGs to function as a paleotemperature proxy in tropical lacustrine environments. HGs in Lake Malawi were extracted from settling particulate matter (SPM) collected at bi-monthly intervals from 2011 - 2013. Sediment traps were moored in the metalimnion of both the north and south basins of the lake in order to evaluate the spatial and the temporal trends in lipid production and export. This study is the first to analyze HGs in SPM and contains the longest time-series of HG production in a natural environment to date. HGs are consistently present throughout the three-year study period, but maximum fluxes occur annually in December, coincident with the timing of cyanobacterial blooms in the lake. HGs in SPM appear to be sourced from living cyanobacteria populations, indicating rapid export of the lipids through the water column. Temperatures reconstructed with published HG-based indices, which are derived from the relative abundances of HG diols and triols to HG keto-(di)ols, do not accurately reflect the seasonal variability in measured surface water temperatures. Rather, the production of C28 HG keto-ols appears to be related to the timing of heterocyst differentiation. Heterocystous cyanobacteria in Lake Malawi may instead respond to growth temperatures by elongating the alkyl side chain of HG diols, as indicated by increases in the abundance of the C28 HG diol relative to the C26 HG diol with warmer surface water temperatures. Distributions of HGs thus may indeed provide a novel tool for paleotemperature reconstructions in tropical lakes.

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

    Science.gov (United States)

    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

  8. Lipid metabolites with free-radical scavenging activity from Euphorbia helioscopia L.

    Science.gov (United States)

    Cateni, F; Zilic, J; Altieri, T; Zacchigna, M; Procida, G; Gaggeri, R; Rossi, D; Collina, S

    2014-07-01

    The methanolic extract of the plant Euphorbia helioscopia L. exhibited an interesting free-radical scavenging activity. From the aerial parts of Euphorbia helioscopia L. (Euphorbiaceae), a complex mixture of seven cerebrosides together with glucoclionasterol, a digalactosyldiacylglycerol and a diacylmonogalactosylglycerol were identified. The structures of the cerebrosides were characterized as 1-O-β-D-glucosides of phytosphingosines, which comprised (2S, 3S, 4E, 8E)-2-amino-4(E),8(E)-octadecadiene-1,3-diol, (2S, 3S, 4E, 8Z)-2-amino-4(E),8(Z)-octadecadiene-1,3-diol, (2S, 3S, 4R, 8Z)-2-amino-8(Z)-octadecene-1,3,4-triol as long chain bases with seven 2-hydroxy fatty acids of varying chain lengths (C16, C24:1, C26:1, C24, C26, C28:1) linked to the amino group. The glycosylglycerides were characterized as (2S)-2,3-O-di-(9,12,15-octadecatrienoyl)-glyceryl-6-O-(α-D-galactopyranosyl)-β-D-galactopyranoside and (2S)-2,3-O-di-(9,12,15-octadecatrienoyl)-glyceryl-1-O-β-D-galactopyranoside. The structures were established on the basis of spectroscopic data and chemical reactions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. The epoxide-diol pathway in the metabolism of vinylbital in rat and man

    NARCIS (Netherlands)

    Vermeulen, N P; Bakker, B H; Eylers, D; Breimer, D D

    1. In urine of rats given vinylbital (5-vinyl-5-(1'-methylbutyl)barbituric acid) i.p., unchanged vinylbital and its devinylated metabolite, 5-(1'-methylbutyl)barbituric acid, were identified. Rats synthetic 1',2'-epoxyvinylbital excreted the same compound as a major metabolite. No unchanged epoxide,

  10. Electrooxidation of activated alpha,omega-diols to cyclic tetramethylene acetals of the corresponding dials

    Czech Academy of Sciences Publication Activity Database

    Hlavatý, Jaromír; Polášek, Miroslav

    2006-01-01

    Roč. 47, č. 44 (2006), s. 7789-7791 ISSN 0040-4039 R&D Projects: GA ČR GA203/03/0825 Institutional research plan: CEZ:AV0Z40400503 Keywords : anodic oxidation * cyclic tetramethylene acetals * 2,7-dioxepyl derivatives Subject RIV: CG - Electrochemistry Impact factor: 2.509, year: 2006

  11. Oxidative C-C bond cleavage of 1,2-diols by silver(II)

    International Nuclear Information System (INIS)

    Kumar, A.

    1981-01-01

    Oxidation of ethylene glycol and related compounds by Ag(II) has been investigated. Complexation of these substrates by Ag(II) precedes their oxidation. Oxidation occurs through electron transfer from an OH group to the Ag(II) within the complex resulting in the formation of alkoxyl-type radicals. The radicals thus formed undergo β-scission to give cleavage products. For ethylene glycol a complexation rate 1.3 x 10 6 M -1 s -1 and oxidation rate approx. 3 x 10 3 s -1 were observed. A general trend for the type of the substrates which would undergo C-C bond scission by Ag(II) is discussed

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

    Czech Academy of Sciences Publication Activity Database

    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

  13. A model for the calculation of lanthanide induced shifts of bidentate ligands - 1,3-diols

    International Nuclear Information System (INIS)

    Hofer, O.; Griengl, H.; Nowak, P.

    1978-01-01

    The NMR-LIS data of the four diastereomeric 2-(hydroxyphenylmethyl) cyclohexanols 1-4 are used to test two possible computational models for bidentate Eu(dpm)B 3 complexes. A model taking into account the presence of two equivalent coordinaton centers by averaging the corresponding dipolar fields of both centers proved to be superior to the simpler one assuming only one dipolar field with a fictive coordination center at a point equidistant between the two actual coordination sites. (author)

  14. Solvent free oxidation of primary alcohols and diols using thymine iron(III) catalyst.

    Science.gov (United States)

    Al-Hunaiti, Afnan; Niemi, Teemu; Sibaouih, Ahlam; Pihko, Petri; Leskelä, Markku; Repo, Timo

    2010-12-28

    In this study, we developed an efficient and selective iron-based catalyst system for the synthesis of ketones from secondary alcohols and carboxylic acids from primary alcohol. In situ generated iron catalyst of thymine-1-acetate (THA) and FeCl(3) under solvent-free condition exhibits high activity. As an example, 1-octanol and 2-octanol were oxidized to 1-octanoic acid and 2-octanone with 89% and 98% yields respectively.

  15. (E-1,1,4,4-Tetraphenylbut-2-yne-1,4-diol

    Directory of Open Access Journals (Sweden)

    P. L. Nilantha Lakshman

    2010-03-01

    Full Text Available The molecule of the title compound, C28H22O2, is centrosymmetric with the inversion centre located at the mid-point of the C[triple-bond]C bond [1.178 (5 Å]. The hydroxyl groups therefore lie on either side of the molecule. The crystal structure is stabilized by O—H...O hydrogen bonds, leading to the formation of a linear supramolecular chain along the b axis.

  16. 1,3,5-Tri-p-tolylpentane-1,5-diol

    Directory of Open Access Journals (Sweden)

    A. Thiruvalluvar

    2014-02-01

    Full Text Available In the title compound, C26H30O2, the central benzene ring forms dihedral angles of 14.85 (15 and 28.17 (14° with the terminal benzene rings. The dihedral angle between the terminal benzene rings is 32.14 (13°. The crystal packing exhibits two strong intermolecular O—H...O hydrogen bonds, forming directed four-membered co-operative rings. A region of disordered electron density, most probably disordered ethyl acetate solvent molecules, occupying voids of ca 519 Å3 for an electron count of 59, was treated using the SQUEEZE routine in PLATON [Spek (2009. Acta Cryst. D65, 148–155]. Their formula mass and unit-cell characteristics were not taken into account during refinement. The structure was refined as an inversion twin [absolute structure parameter = −0.3 (4].

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Thermoreversible covalent crosslinking of maleated ethylene/propylene copolymers with diols

    NARCIS (Netherlands)

    Mee, van der M.A.J.; Goossens, J.G.P.; Duin, van M.

    2008-01-01

    Maleated ethylene/propylene copolymer (MAn-g-EPM) was thermoreversibly cross-linked using different routes, i.e. ionic interactions (ionomers), hydrogen bonding and a combination thereof. Microphase separation into polar MAn-rich aggregates occurs for MAn-g-EPM and all cross-linked materials, which

  19. Total synthesis of broussonetine F: the orthoamide Overman rearrangement of an allylic diol.

    Science.gov (United States)

    Hama, Naoto; Aoki, Toshihiro; Miwa, Shohei; Yamazaki, Miki; Sato, Takaaki; Chida, Noritaka

    2011-02-18

    A first total synthesis of broussonetine F from diethyl L-tartrate was achieved. The cornerstone of our synthesis was an orthoamide Overman rearrangement, which provided an allylic amino alcohol with complete diastereoselectivity.

  20. Inert Reassessment Document for 3,6-Diemthyl-4-octyn-3,6-diol

    Science.gov (United States)

    These chemicals are used as surfactants in pesticide formulations applied to growing crops, raw agricultural commodities, and animals with use limitations of not more than 2.5 in formulation and application to soil prior to planting.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    , and extrusion of the alkene. We have compared the proposed pathway with several alternatives, and the results have been corroborated by comparison with the molybdenum- catalyzed sulfoxide reduction recently published by Sanz et al. and with experimental observations for the DODH itself. Improved understanding...

  2. Synthesis and Evaluation of Asymmetric Acyclic Nucleoside Bisphosphonates as Inhibitors of Plasmodium falciparum and Human Hypoxanthine-Guanine-(Xanthine) Phosphoribosyltransferase

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

    Roč. 60, č. 17 (2017), s. 7539-7554 ISSN 0022-2623 R&D Projects: GA ČR(CZ) GA16-06049S Institutional support: RVO:61388963 Keywords : hypoxanthine-guanine phosphoribosyltransferase * 2nd phosphonate group * 6-oxopurine phosphoribosyltransferases Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 6.259, year: 2016

  3. Synthesis and Properties of a Novel Type of Acyclic Nucleoside Phosphonates: 2-(Purin-9-yl)ethoxyphenylphosphonic Acids

    Czech Academy of Sciences Publication Activity Database

    Hocková, Dana; Dračínský, Martin; Holý, Antonín

    -, č. 15 (2010), s. 2885-2892 ISSN 1434-193X R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : nucleotides * phosphonates * cross-coupling Subject RIV: CC - Organic Chemistry Impact factor: 3.206, year: 2010

  4. Synthesis of analogues of acyclic nucleoside diphosphates containing a (phosphonomethyl)phosphanyl moiety and studies of their phosphorylation

    Czech Academy of Sciences Publication Activity Database

    Doláková, Petra; Dračínský, Martin; Fanfrlík, Jindřich; Holý, Antonín

    -, č. 7 (2009), s. 1082-1092 ISSN 1434-193X R&D Projects: GA AV ČR 1QS400550501 Grant - others:NIH(US) 1UC1AI062540-01 Institutional research plan: CEZ:AV0Z40550506 Keywords : antiviral agents * nucleotides * phosphorylation * dUTPase Subject RIV: CC - Organic Chemistry Impact factor: 3.096, year: 2009

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

    Czech Academy of Sciences Publication Activity Database

    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

  6. Iminium-ion formation and deuterium exchange by acetone in the presence of pyrrolidine, pyrazolidine, isoxazolidine, and their acyclic analogues

    International Nuclear Information System (INIS)

    Hine, J.; Evangelista, R.A.

    1980-01-01

    Equilibrium constants for iminium-ion-formation in the reaction of in acetone in aqueous solution at 35 0 C with pyrazolidinium, isoxazolidinium, O,N-dimethylhydroxylammonium, and N,N'-dimethylhydrazinium ions were found to be 9.33, 8.96, 0.117, and 0.057 M -1 , respectively. The kinetics of hydrolysis of the iminium ions were studied in every case except that of the N-isopropylidene-O,N-dimethylhydroxylammonium ion, whose hydrolysis is too fast to follow by the techniques used with the other iminium ions. The rate of hydrolysis of the N-isopropylidenepyrazolidinium ion is independent of the pH from about pH 3 to 6; it is hydrogen ion catalyzed at lower pHs and hydroxide ion catalyzed at higher pHs. The rate of hydrolysis of N-isopropylidenisoxazolidinium ions is Ph independent from pH 0.5 to about 2, increases until about pH 4, remains pH independent until pH 6.5, and has become too fast to measure above pH 8. Both reactions are general base catalyzed in all the buffers studied. A mechanism is described to fit the kinetics of each of these reactions. The dedeuteration of acetone-d 6 was studied pyridine buffers in the presence of each of the four hydrazine and hydroxylamine derivatives and also in the presence of the dimethylammonium and pyrrolidinium ion. All six of these secondary ammonium ions catalyze the dedeuteration by transforming the acetone-d 6 to an iminium ion that is dedeuterated by pyridine more rapidly than the ketone is. The iminium-ion formation is a relatively rapid equilibrium in all cases except that of pyrrolidinium ions, where the intermediate iminium ion loses deuterium and hydrolyzes at comparable rates, and possibly the case of dimethylammonium ions, where the amount of catalysis via iminium-ion formation is too small to reveal mechanistic details. The effect of structure on the efficiency of catalysis of dedeuteration via iminium-ion formation is discussed. 3 figures, 7 tables

  7. Acyclic Nucleoside Phosphonates Containing 9-Deazahypoxanthine and a Five-Membered Heterocycle as Selective Inhibitors of Plasmodial 6-Oxopurine Phosphoribosyltransferases

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

    Roč. 12, č. 14 (2017), s. 1133-1141 ISSN 1860-7179 R&D Projects: GA ČR(CZ) GA16-06049S Institutional support: RVO:61388963 Keywords : inhibitors * nucleosides * malaria * phosphonates * purine salvage Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 3.225, year: 2016

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

    Czech Academy of Sciences Publication Activity Database

    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

  9. Antimicrobial metabolites from the plant endophytic fungus Penicillium sp.

    Science.gov (United States)

    Yang, Ming-Hua; Li, Tian-Xiao; Wang, Ying; Liu, Rui-Huan; Luo, Jun; Kong, Ling-Yi

    2017-01-01

    Five rare dichloro aromatic polyketides (1-5) were obtained from an endophytic fungus Penicillium sp., along with five known metabolites (6-10). Their structures were elucidated by extensive spectroscopic analysis, Mosher methods, as well as [Rh 2 (OCOCF 3 ) 4 ]-induced electronic circular dichroism (ECD) experiments. Compounds 2-4 and 6 structurally involved acyclic 1.3-diols, the uneasy configuration determinations of which were well carried out by double-derivation NMR methods. Compounds 1-10 were evaluated for their antibacterial and antifungal activities against five strains of human pathogenic microorganisms. Helvolic acid (7) showed potent inhibitory effects against Staphylococcus aureus and Pseudomonas aeruginosa with MIC (minimum inhibitory concentration) values of 5.8 and 4.6μg/mL, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Isolation, structural determination, and evaluation of the biological activity of 20(S)-25-methoxyl-dammarane-3beta, 12beta, 20-triol [20(S)-25-OCH3-PPD], a novel natural product from Panax notoginseng.

    Science.gov (United States)

    Zhao, Y; Wang, W; Han, L; Rayburn, E R; Hill, D L; Wang, H; Zhang, R

    2007-01-01

    Ginseng has been used extensively for medicinal purposes, with suggested utility for indications as diverse as diabetes, cardiovascular disease and cancer. Herein we report the discovery and characterization of 20(S)-25-OCH3-PPD, a ginsenoside that inhibits growth and survival of cancer cells. The novel dammarane triterpene sapogenin (C31H56O4; molecular weight 492) was isolated from the total hydrolyzed saponins extracted from the leaves of Panax notoginseng using conventional and reverse-phase silica gel chromatography. Based on physicochemical characteristics and NMR data, the compound was identified as 20(S)-25-OCH3-PPD. The biological activities of 20(S)-25-OCH3-PPD and its known analogs, 20(S)-PPD and Rg3, were evaluated in 12 human cancer cell lines. In all cell lines, the order of cytotoxicity of the test compounds was 20(S)-25-OCH3-PPD > 20(S)-PPD > Rg3. 20(S)-25-OCH3-PPD also induced apoptosis and cell cycle arrest in the G1 phase, and inhibited proliferation in breast cancer cell lines, demonstrating its potent biological effects. In regard to cytotoxicity, the IC50 values of 20(S)-25-OCH3-PPD for most cell lines were in the lower microM range, a 5-15-fold greater cytotoxicity relative to 20(S)-PPD and a 10-100-fold increase over Rg3. These findings suggest a structure-activity relationship among dammarane-type sapogenins. The data presented here may provide a basis for the future development of 20(S)-25-OCH3-PPD as a novel anti-cancer agent.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-01

    The conversion of furfuryl alcohol (FAL) to levulinic acid over AmberlystTM 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.

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

    Science.gov (United States)

    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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Cholesterol autoxidation in phospholipid membrane bilayers

    International Nuclear Information System (INIS)

    Sevanian, A.; McLeod, L.L.

    1987-01-01

    Lipid peroxidation in unilamellar liposomes of known cholesterol-phospholipid composition was monitored under conditions of autoxidation or as induced by a superoxide radical generating system, gamma-irradiation or cumene hydroperoxide. Formation of cholesterol oxidation products was indexed to the level of lipid peroxidation. The major cholesterol oxidation products identified were 7-keto-cholesterol, isomeric cholesterol 5,6-epoxides, isomeric 7-hydroperoxides and isomeric 3,7-cholestane diols. Other commonly encountered products included 3,5-cholestadiene-7-one and cholestane-3 beta, 5 alpha, 6 beta-triol. Superoxide-dependent peroxidation required iron and produced a gradual increase in 7-keto-cholesterol and cholesterol epoxides. Cholesterol oxidation was greatest in liposomes containing high proportions of unsaturated phospholipid to cholesterol (4:1 molar ratio), intermediate with low phospholipid to cholesterol ratios (2:1) and least in liposomes prepared with dipalmitoylphosphatidylcholine and cholesterol. This relationship held regardless of the oxidizing conditions used. Cumene hydroperoxide-dependent lipid peroxidation and/or more prolonged oxidations with other oxidizing systems yielded a variety of products where cholesterol-5 beta,6 beta-epoxide, 7-ketocholesterol and the 7-hydroperoxides were most consistently elevated. Oxyradical initiation of lipid peroxidation produced a pattern of cholesterol oxidation products distinguishable from the pattern derived by cumene hydroperoxide-dependent peroxidation

  15. Formulation and properties of ADN/GAP propellants

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  16. Solvated electrons at elevated temperatures in different alcohols: Temperature and molecular structure effects

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yu [Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Lin, Mingzhang [Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1195 (Japan); Katsumura, Yosuke, E-mail: katsu@n.t.u-tokyo.ac.j [Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Nuclear Professional School, Graduate School of Engineering, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); Fu, Haiying; Muroya, Yusa [Nuclear Professional School, Graduate School of Engineering, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan)

    2010-12-15

    The absorption spectra of solvated electrons in pentanol, hexanol and octanol are measured from 22 to 200, 22 to 175 and 50 to150 {sup o}C, respectively, at a fixed pressure of 15 MPa, using nanosecond pulse radiolysis technique. The results show that the peak positions of the absorption spectra have a red-shift (shift to longer wavelengths) as temperature increases, similar to water and other alcohols. Including the above mentioned data, a compilation of currently available experimental data on the energy of absorption maximum (E{sub max}) of solvated electrons changed with temperature in monohydric alcohols, diols and triol is presented. E{sub max} of solvated electron is larger in those alcohols that have more OH groups at all the temperatures. The molecular structure effect, including OH numbers, OH position and carbon chain length, is investigated. For the primary alcohols with same OH group number and position, the temperature coefficient increases with increase in chain length. For the alcohols with same chain length and OH numbers, temperature coefficient is larger for the symmetric alcohols than the asymmetric ones.

  17. Inelastic neutron scattering investigation of the α-β crossover in glass-formers as a function of molecular architecture

    International Nuclear Information System (INIS)

    Levelut, C.; Faivre, A.; Pelous, J.; Durand, D.

    1999-01-01

    Complete text of publication follows. An experimental investigation of the relaxational processes related to the glass transition in several glass formers with more or less complex molecular architecture is presented. This inelastic neutron scattering study concentrates on the region around 1.1 to 1.5 T g where the two relaxation processes usually identified in most glass formers, the α and the β relaxations, are expected to merge or cross. A recent study comparing the dynamics of Sorbitol and Maltitol (two low molecular and complementary glasses) seems to show that the way on which the α and β processes merge depends on the differences in the chemical architecture of these polyols [1]. In the present work, linear diols, three-arm-star triols and crosslinked polyurethanes, synthesized from the latter are studied. This work is an extension of a previous study of the relaxational processes in cross-linked polyurethanes [2]. For such series of samples of similar chemical composition but with increasing complexity in the architecture, the influence of the molecular complexity on the type of merging between α and β processes is tested. This allows to discuss the α-β cross-over on molecular level. (author)

  18. Radical Additions to Fluoroolefins. Photochemical Fluoroalkylation of Alkanols and Alkane Diols with Perfluoro Vinyl Ethers; Photo-Supported O-Alkylation of Butane-1,4-Diol with Hexafluoropropene

    Czech Academy of Sciences Publication Activity Database

    Církva, Vladimír; Polák, R.; Paleta, O.

    1996-01-01

    Roč. 80, č. 2 (1996), s. 135-144 ISSN 0022-1139 Institutional research plan: CEZ:AV0Z4072921 Keywords : radical addition * regioselectivity * perfluoroolefins Subject RIV: CC - Organic Chemistry Impact factor: 0.689, year: 1996

  19. Synthesis of novel lidocaine-releasing poly(diol-co-citrate) elastomers by using deep eutectic solvents.

    Science.gov (United States)

    Serrano, M Concepción; Gutiérrez, María C; Jiménez, Ricardo; Ferrer, M Luisa; del Monte, Francisco

    2012-01-14

    Poly(octanediol-co-citrate) elastomers containing high loading of lidocaine were synthesized at temperatures below 100 °C by means of using deep eutectic mixtures of 1,8-octanediol and lidocaine. The preservation of lidocaine integrity resulted in high-capacity drug-eluting elastomers. This journal is © The Royal Society of Chemistry 2012

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

    NARCIS (Netherlands)

    Yan, Tao; Barta, Katalin

    2016-01-01

    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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    %. The DODH of erythritol yields 39% 2,5-dihydrofuran, while the DODH of the proposed intermediate 1,4-anhydroerythritol yields 75%. The mechanism of the DODH of 1,4-anhydroerythritol was investigated by means of density functional theory (DFT), and the rate-determining step (24.1 kcal/mol) was found...

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

    Czech Academy of Sciences Publication Activity Database

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  4. The synthesis of amphipathic prodrugs of 1,2-diol drugs with saccharide conjugates by high regioselective enzymatic protocol.

    Science.gov (United States)

    Quan, Jing; Chen, Zhichun; Han, Chengyou; Lin, Xianfu

    2007-02-15

    A facile, high regioselective enzymatic synthesis approach for the preparation of amphipathic prodrugs with saccharides of mephenesin and chlorphenesin was developed. Firstly, transesterification of two drugs with divinyl dicarboxylates with different carbon chain length was performed under the catalysis of Candida antarctica lipase acrylic resin and Lipozyme in anhydrous acetone at 50 degrees C, respectively. A series of lipophilic derivatives with vinyl groups of mephenesin and chlorphenesin were prepared. The influences of different organic solvents, enzyme sources, reaction time, and the acylation reagents on the synthesis of vinyl esters were investigated. And then, protease-catalyzed high regioselective acylation of D-glucose and D-mannose with vinyl esters of mephenesin and chlorphenesin gave drug-saccharide derivatives in good yields. The studies of lipophilicity and hydrolysis in vitro of prodrugs verified that drug-saccharide derivatives had amphipathic properties, and both lipophilic and amphipathic drug derivatives had obvious controlled release characteristics.

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Dissolution patterns of biocompatible glasses in 2-amino-2-hydroxymethyl-propane-1,3-diol (Tris) buffer.

    Science.gov (United States)

    Fagerlund, S; Hupa, L; Hupa, M

    2013-02-01

    A continuous flow measurement system with sensitive on-line ion analysis has been applied to study the initial dissolution behaviour of biocompatible glasses in Tris. Altogether 16 glasses with widely varying compositions were studied. The measurement system allowed for quantitative determination of the time-dependent rates of dissolution of sodium, potassium, calcium, magnesium, silicon and phosphorus during the first 10-15 min in contact with Tris solution. The dissolution rates of the different ions showed significant glass to glass variations, but all glasses studied showed one of four distinct dissolution patterns. The ion dissolution rates after an exposure of 1000 s, expressed as the normalized surface-specific mass loss rates, were compared with the in vitro and in vivo reactivity of the glasses as predicted by models in the literature. The results showed a clear correlation between the dissolution rates of the glasses in Tris and their reactivity as measured by other different methods. Consequently, the measured short-term dissolution patterns could be used to determine which glasses are suitable as bioactive, biodegradable, or inert biomaterials for medical devices. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

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

    KAUST Repository

    Yin, Dongdong; Li, Chuang; Ren, Hangxing; Shekhah, Osama; Liu, Jinxuan; Liang, Changhai

    2017-01-01

    Pd@MIL-101(Cr) hetero-catalysts have been successfully prepared using the metal-organic chemical vapour deposition (MOCVD) approach, by choosing [Pd(η-CH)(η-CH)] as a volatile precursor, and the hydrothermally stable metal-organic framework, MIL-101

  8. 2 : 2 Fe(III): ligand and "adamantane core" 4 : 2 Fe(III): ligand (hydr)oxo complexes of an acyclic ditopic ligand

    DEFF Research Database (Denmark)

    Ghiladi, Morten; Larsen, Frank B.; McKenzie, Christine J.

    2005-01-01

    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-ray struct......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...

  9. Synthesis and investigation of the structure and chemical properties of acyclic compounds of bicoordinated phosphorus with a phosphorus-carbon (p-p)/sub π/ bond

    International Nuclear Information System (INIS)

    Markovskii, L.N.; Romanenko, V.D.

    1987-01-01

    Five types of reactions of phosphoalkenes can be distinguished according to the nature of the change in the coordination number and valence of the phosphorus atom in the course of chemical conversions. There are: reactions of cyclodimerization, cycloaddition, and 1,2-addition at the P-C double bond; formation of compounds of tricoordinated pentavalent phosphorus; formation of tetracoordinated phosphorus compounds; reactions of functionalization occurring without a change in the valence and coordination number of the phosphorus atom; and reactions of 1,2-elimination, leading to compounds of monocoordinated phosphorus. This paper reviews each of these reactions in detail, using double-resonance hydrogen 1 and phosphorus 31 NMR spectra and analyzing the acquired chemical shift and spin-spin coupling constants, and also demonstrates the complexation of phosphorus with several metals

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

    KAUST Repository

    Vummaleti, Sai V. C.; Falivene, Laura; Poater, Albert; Cavallo, Luigi

    2014-01-01

    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.

  11. A computational study on Lewis acid-catalyzed diastereoselective acyclic radical allylation reactions with unusual selectivity dependence on temperature and epimer precursor.

    Science.gov (United States)

    Georgieva, Miglena K; Santos, A Gil

    2014-12-05

    In stereoselective radical reactions, it is accepted that the configuration of the radical precursor has no impact on the levels of stereoinduction, as a prochiral radical intermediate is planar, with two identical faces, independently of its origin. However, Sibi and Rheault (J. Am. Chem. Soc. 2000, 122, 8873-8879) remarkably obtained different selectivities in the trapping of radicals originated from two epimeric bromides, catalyzed by chelating Lewis acids. The selectivity rationalization was made on the basis of different conformational properties of each epimer. However, in this paper we show that the two epimers have similar conformational properties, which implies that the literature proposal is unable to explain the experimental results. We propose an alternative mechanism, in which the final selectivity is dependent on different reaction rates for radical formation from each epimer. By introducing a different perspective of the reaction mechanism, our model also allows the rationalization of different chemical yields obtained from each epimer, a result not rationalized by the previous model. Adaptation to other radical systems, under different reaction conditions, is also possible.

  12. Synthesis and Biological Evaluation of a New Acyclic Pyrimidine Derivative as a Probe for Imaging Herpes Simplex Virus Type 1 Thymidine Kinase Gene Expression

    Directory of Open Access Journals (Sweden)

    Simon M. Ametamey

    2013-07-01

    Full Text Available With the idea of finding a more selective radiotracer for imaging herpes simplex virus type 1 thymidine kinase (HSV1-tk gene expression by means of positron emission tomography (PET, a novel [18F]fluorine radiolabeled pyrimidine with 4-hydroxy-3-(hydroxymethylbutyl side chain at N-1 (HHB-5-[18F]FEP was prepared and evaluated as a potential PET probe. Unlabeled reference compound, HHB-5-FEP, was synthesized via a five-step reaction sequence starting from 5-(2-acetoxyethyl-4-methoxypyrimidin-2-one. The radiosynthesis of HHB-[18F]-FEP was accomplished by nucleophilic radiofluorination of a tosylate precursor using [18F]fluoride-cryptate complex in 45% ± 4 (n = 4 radiochemical yields and high purity (>99%. The biological evaluation indicated the feasibility of using HHB-5-[18F]FEP as a PET radiotracer for monitoring HSV1-tk expression in vivo.

  13. Synthesis of 8-amino and 8-substituted amino derivatives of acyclic purine nucleoside and nucleotide analogs. Alkylation of 8-substituted purine bases

    Czech Academy of Sciences Publication Activity Database

    Janeba, Zlatko; Holý, Antonín

    2001-01-01

    Roč. 20, 4-7 (2001), s. 1103-1106 ISSN 1525-7770 R&D Projects: GA ČR GV203/96/K001 Institutional research plan: CEZ:AV0Z4055905 Keywords : nucleotide analogs Subject RIV: CC - Organic Chemistry Impact factor: 0.508, year: 2001

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

    KAUST Repository

    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.

  15. New 2-alkynyl derivatives of the acyclic nucleoside 9-(2,3-dihydroxypropyl)adenine and their 6-guanidinopurine counterparts as potential effectors of adenosine receptors

    Czech Academy of Sciences Publication Activity Database

    Česnek, Michal; Holý, Antonín; Masojídková, Milena

    2003-01-01

    Roč. 68, č. 11 (2003), s. 2201-2218 ISSN 0010-0765 R&D Projects: GA AV ČR IBS4055109; GA MŠk OC D13.20 Institutional research plan: CEZ:AV0Z4055905 Keywords : adenosine receptors * alkynes * purines Subject RIV: CC - Organic Chemistry Impact factor: 1.041, year: 2003

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

    DEFF Research Database (Denmark)

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

    1987-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

    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: 5.589, year: 2015

  18. Evidence for the formation of acyclic ions from the radical cations and cyclic ions from the protonated molecules of ¿,¿-diamines upon loss of ammonia

    NARCIS (Netherlands)

    Fernandes, Ana M.; Correia, A.J. Ferrer; Fokkens, R.H.; Nibbering, N.M.M.

    2002-01-01

    The structural characterization of the ions generated by the electron ionization-induced loss of ammonia from the molecular ions of α,ω-diamines, using ion/molecule reactions in combination with collision-induced dissociation (CID) studies, is described. The results of the experiments of

  19. Acyclic peptides incorporating the d-Phe-2-Abz turn motif: Investigations on antimicrobial activity and propensity to adopt β-hairpin conformations.

    Science.gov (United States)

    Cameron, Alan J; Varnava, Kyriakos G; Edwards, Patrick J B; Harjes, Elena; Sarojini, Vijayalekshmi

    2018-06-14

    Three linear peptides incorporating d-Phe-2-Abz as the turn motif are reported. Peptide 1, a hydrophobic β-hairpin, served as a proof of principle for the design strategy with both NMR and CD spectra strongly suggesting a β-hairpin conformation. Peptides 2 and 3, designed as amphipathic antimicrobials, exhibited broad spectrum antimicrobial activity, with potency in the nanomolar range against Staphylococcus aureus. Both compounds possess a high degree of selectivity, proving non-haemolytic at concentrations 500 to 800 times higher than their respective minimal inhibitory concentrations (MICs) against S. aureus. Peptide 2 induced cell membrane and cell wall disintegration in both S. aureus and Pseudomonas aeruginosa as observed by transmission electron microscopy. Peptide 2 also demonstrated moderate antifungal activity against Candida albicans with an MIC of 50 μM. Synergism was observed with sub-MIC levels of amphotericin B (AmB), leading to nanomolar MICs against C. albicans for peptide 2. Based on circular dichroism spectra, both peptides 2 and 3 appear to exist as a mixture of conformers with the β-hairpin as a minor conformer in aqueous solution, and a slight increase in hairpin population in 50% trifluoroethanol, which was more pronounced for peptide 3. NMR spectra of peptide 2 in a 1:1 CD 3 CN/H 2 O mixture and 30 mM deuterated sodium dodecyl sulfate showed evidence of an extended backbone conformation of the β-strand residues. However, inter-strand rotating frame Overhauser effects (ROE) could not be detected and a loosely defined divergent hairpin structure resulted from ROE structure calculation in CD 3 CN/H 2 O. The loosely defined hairpin conformation is most likely a result of the electrostatic repulsions between cationic strand residues which also probably contribute towards maintaining low haemolytic activity. Copyright © 2018 European Peptide Society and John Wiley & Sons, Ltd.

  20. Interactions with selected drug renal transporters and transporter-mediated cytotoxicity in antiviral agents from the group of acyclic nucleoside phosphonates

    Czech Academy of Sciences Publication Activity Database

    Mandíková, J.; Volková, M.; Pávek, P.; Česnek, Michal; Janeba, Zlatko; Kubíček, V.; Trejtnar, F.

    2013-01-01

    Roč. 311, č. 3 (2013), s. 135-146 ISSN 0300-483X Institutional support: RVO:61388963 Keywords : hOAT1 * hCNTs * MDR1 * BCRP * nephrotoxicity * transmembrane transport Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 3.745, year: 2013

  1. Synthesis and evaluation of symmetric acyclic nucleoside bisphosphonates as inhibitors of the Plasmodium falciparum, Plasmodium vivax and human 6-oxopurine phosphoribosyltransferases and the antimalarial activity of their prodrugs

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

    Roč. 25, č. 15 (2017), s. 4008-4030 ISSN 0968-0896 R&D Projects: GA ČR(CZ) GA16-06049S Institutional support: RVO:61388963 Keywords : enzyme inhibitors * nucleotide analogues * malaria Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 2.930, year: 2016

  2. 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

    Czech Academy of Sciences Publication Activity Database

    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: 5.589, year: 2015

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

    Czech Academy of Sciences Publication Activity Database

    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 - others: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

  4. Synthesis of some potent immunomodulatory and anti-inflammatory metabolites by fungal transformation of anabolic steroid oxymetholone

    Directory of Open Access Journals (Sweden)

    Khan Naik Tameen

    2012-12-01

    Full Text Available Abstract Background Biotransformation of organic compounds by using microbial whole cells provides an efficient approach to obtain novel analogues which are often difficult to synthesize chemically. In this manuscript, we report for the first time the microbial transformation of a synthetic anabolic steroidal drug, oxymetholone, by fungal cell cultures. Results Incubation of oxymetholone (1 with Macrophomina phaseolina, Aspergillus niger, Rhizopus stolonifer, and Fusarium lini produced 17β-hydroxy-2-(hydroxy-methyl-17α-methyl-5α-androstan-1-en-3-one (2, 2α,17α-di(hydroxyl-methyl-5α-androstan-3β,17β-diol (3, 17α-methyl-5α-androstan-2α,3β,17β-triol (4, 17β-hydroxy-2-(hydroxymethyl-17α-methyl-androst-1,4-dien-3-one (5, 17β-hydroxy-2α-(hydroxy-methyl-17α-methyl-5α-androstan-3-one (6, and 2α-(hydroxymethyl-17α-methyl-5α-androstan-3β-17β-diol (7. Their structures were deduced by spectral analyses, as well as single-crystal X-ray diffraction studies. Compounds 2–5 were identified as the new metabolites of 1. The immunomodulatory, and anti-inflammatory activities and cytotoxicity of compounds 1–7 were evaluated by observing their effects on T-cell proliferation, reactive oxygen species (ROS production, and normal cell growth in MTT assays, respectively. These compounds showed immunosuppressant effect in the T-cell proliferation assay with IC50 values between 31.2 to 2.7 μg/mL, while the IC50 values for ROS inhibition, representing anti-inflammatory effect, were in the range of 25.6 to 2.0 μg/mL. All the compounds were found to be non-toxic in a cell-based cytotoxicity assay. Conclusion Microbial transformation of oxymetholone (1 provides an efficient method for structural transformation of 1. The transformed products were obtained as a result of de novo stereoselective reduction of the enone system, isomerization of double bond, insertion of double bond and hydroxylation. The transformed products, which showed significant

  5. Biodegradable shape-memory block co-polymers for fast self-expandable stents.

    Science.gov (United States)

    Xue, Liang; Dai, Shiyao; Li, Zhi

    2010-11-01

    Block co-polymers PCTBVs (M(n) of 36,300-65,300 g/mol, T(m) of 39-40 and 142 degrees C) containing hyperbranched three-arm poly(epsilon-caprolactone) (PCL) as switching segment and microbial polyester PHBV as crystallizable hard segment were designed as biodegradable shape-memory polymer (SMP) for fast self-expandable stent and synthesized in 96% yield by the reaction of three-arm PCL-triol (M(n) of 4200 g/mol, T(m) of 47 degrees C) with methylene diphenyl 4,4'-diisocyanate isocynate (MDI) to form the hyperbrached MDI-linked PCL (PTCM; M(n) of 25,400 g/mol and a T(m) of 38 degrees C), followed by further polymerization with PHBV-diol (M(n) of 2200 g/mol, T(m) of 137 and 148 degrees C). The polymers were characterized by (1)H NMR, GPC, DSC, tensile test, and cyclic thermomechanical tensile test. PCTBVs showed desired thermal properties, mechanical properties, and ductile nature. PCTBV containing 25 wt% PHBV (PCTBV-25) demonstrated excellent shape-memory property at 40 degrees C, with R(f) of 94%, R(r) of 98%, and shape recovery within 25s. PCTBV-25 was also shown as a safe material with good biocompatibility by cytotoxicity tests and cell growth experiments. The stent made from PCTBV-25 film showed nearly complete self-expansion at 37 degrees C within only 25 s, which is much better and faster than the best known self-expandable stents. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  6. Biosynthesis of bioactive diterpenoids in the medicinal plant Vitex agnus-castus.

    Science.gov (United States)

    Heskes, Allison M; Sundram, Tamil C M; Boughton, Berin A; Jensen, Niels B; Hansen, Nikolaj L; Crocoll, Christoph; Cozzi, Federico; Rasmussen, Simon; Hamberger, Britta; Hamberger, Björn; Staerk, Dan; Møller, Birger L; Pateraki, Irini

    2018-03-01

    Vitex agnus-castus L. (Lamiaceae) is a medicinal plant historically used throughout the Mediterranean region to treat menstrual cycle disorders, and is still used today as a clinically effective treatment for premenstrual syndrome. The pharmaceutical activity of the plant extract is linked to its ability to lower prolactin levels. This feature has been attributed to the presence of dopaminergic diterpenoids that can bind to dopamine receptors in the pituitary gland. Phytochemical analyses of V. agnus-castus show that it contains an enormous array of structurally related diterpenoids and, as such, holds potential as a rich source of new dopaminergic drugs. The present work investigated the localisation and biosynthesis of diterpenoids in V. agnus-castus. With the assistance of matrix-assisted laser desorption ionisation-mass spectrometry imaging (MALDI-MSI), diterpenoids were localised to trichomes on the surface of fruit and leaves. Analysis of a trichome-specific transcriptome database, coupled with expression studies, identified seven candidate genes involved in diterpenoid biosynthesis: three class II diterpene synthases (diTPSs); three class I diTPSs; and a cytochrome P450 (CYP). Combinatorial assays of the diTPSs resulted in the formation of a range of different diterpenes that can account for several of the backbones of bioactive diterpenoids observed in V. agnus-castus. The identified CYP, VacCYP76BK1, was found to catalyse 16-hydroxylation of the diol-diterpene, peregrinol, to labd-13Z-ene-9,15,16-triol when expressed in Saccharomyces cerevisiae. Notably, this product is a potential intermediate in the biosynthetic pathway towards bioactive furan- and lactone-containing diterpenoids that are present in this species. © 2018 The Authors The Plant Journal published by John Wiley & Sons Ltd and Society for Experimental Biology.

  7. Hydroxy protons as structural probes to reveal hydrogen bonding properties of polyols in aqueous solution by NMR spectroscopy

    Science.gov (United States)

    Oruc, Gizem; Varnali, Tereza; Bekiroglu, Somer

    2018-05-01

    The solution properties of ethylene glycol (ethane-1,2-diol), glycerol (propane-1,2,3-triol), erythritol ((2R,3S)-butane-1,2,3,4-tetraol), D-xylitol ((2R,3r,4S)-pentane-1,2,3,4,5-pentaol), D-mannitol ((2R,3R,4R,5R)-hexane-1,2,3,4,5,6-hexaol), and D-sorbitol ((2S,3R,4R,5R)-hexane-1,2,3,4,5,6-hexaol), constituting a subgroup of polyalcohols/polyols of maximum six carbon atoms have been investigated using 1H NMR chemical shifts, coupling constants, temperature coefficients, and chemical exchange rates of hydroxy protons in aqueous medium. Relative within a molecule, minimum two-fold difference in rate of exchange values and higher temperature dependence of chemical shifts of the hydroxy protons on terminal carbon atoms confirm that sustainable hydrogen bonding interactions is accentuated for the hydroxyl groups on secondary carbons. Compared to the primary carbons i.e. terminal ones, the hydroxy protons on second and third carbon atoms exhibit much lower rate of exchange and smaller temperature coefficients, indicating that they are further involved in transient hydrogen bonding interactions. Scalar 3JOH,CH-couplings ranging between 3.9 and 7.2 Hz imply that the hydroxyl groups are practically in free rotation regime. Examination of the chemical shift differences with respect to the shift of glycol hydroxy proton reveals that the disparity between terminal and inner hydroxyl groups disclosed by the exchange rates and temperature coefficients is sustained with the exception of 0.003 and 0.053 ppm for O(3)H of mannitol and O(5)H of sorbitol respectively. The experimental findings have been augmented by quantum chemical calculations targeting theoretical NMR chemical shifts, as well as the conformational analysis of the structures.

  8. DNA functionalization by dynamic chemistry

    Directory of Open Access Journals (Sweden)

    Zeynep Kanlidere

    2016-10-01

    Full Text Available Dynamic combinatorial chemistry (DCC is an attractive method to efficiently generate libraries of molecules from simpler building blocks by reversible reactions under thermodynamic control. Here we focus on the chemical modification of DNA oligonucleotides with acyclic diol linkers and demonstrate their potential for the deoxyribonucleic acid functionalization and generation of libraries of reversibly interconverting building blocks. The syntheses of phosphoramidite building blocks derived from D-threoninol are presented in two variants with protected amino or thiol groups. The threoninol building blocks were successfully incorporated via automated solid-phase synthesis into 13mer oligonucleotides. The amino group containing phosphoramidite was used together with complementary single-strand DNA templates that influenced the Watson–Crick base-pairing equilibrium in the mixture with a set of aldehyde modified nucleobases. A significant fraction of all possible base-pair mismatches was obtained, whereas, the highest selectivity (over 80% was found for the guanine aldehyde templated by the complementary cytosine containing DNA. The elevated occurrence of mismatches can be explained by increased backbone plasticity derived from the linear threoninol building block as a cyclic deoxyribose analogue.

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

    Czech Academy of Sciences Publication Activity Database

    Melánová, Klára; Kovář, P.; Beneš, L.; Svoboda, Jan; Veteška, M.; Pospíšil, M.; Zima, Vítězslav

    2015-01-01

    Roč. 460, 15 December (2015), s. 181-188 ISSN 0021-9797 R&D Projects: GA ČR(CZ) GA14-13368S Institutional support: RVO:61389013 Keywords : intercalation * phosphonates * alkaline- earth Subject RIV: CA - Inorganic Chemistry Impact factor: 3.782, year: 2015

  10. Síntesis y caracterización de poliuretanos termoplásticos basados en policarbonato dioles. Relación estructura/propiedades.

    OpenAIRE

    Félix de Castro, Paula

    2012-01-01

    Los poliuretanos son una familia de polímeros muy versátil, utilizados en un amplio rango de aplicación, desde las espumas rígidas-flexibles, materiales elastómeros, recubrimientos, adhesivos, hasta materiales con aplicaciones biomédicas. Esta gran versatilidad es debida a que los reactivos utilizados en la síntesis de los poliuretanos son muy variados, permitiendo la gran versatilidad en la formulación del poliuretano y en las propiedades del mismo. Los poliuretanos termoplásticos el...

  11. Crystal structures of 2-(N,N-dimethylaminoalkyl)ferroceneboronic acids and their diol derivatives. The quest for a B-N intramolecular bond in the solid state

    DEFF Research Database (Denmark)

    Norrild, Jens Chr.; Søtofte, Inger

    2001-01-01

    The crystal structures of (S,S)-2-(N,N-dimethyl-1-aminoethyl)ferroceneboronic acid (2), (S,S)-1-(N,N-dimethyl-1-aminoethyl)-2-(4,4,5,5-tetraphenyl-1,3,2-dioxaborolan-2-yl)ferrocene (3), rac-2-(N,N-dimethylaminomethyl)-ferroceneboronic acid (rac-4), (S)-[(1S,2S,3R,5S)-pinane-1,2-diyl] 2-(N...

  12. Determination of 3-monochloropropane-1,2-diol fatty acid esters in Brazilian vegetable oils and fats by an in-house validated method.

    Science.gov (United States)

    Arisseto, A P; Marcolino, P F C; Vicente, E

    2014-01-01

    An in-house validated GC-MS method preceded by acid-catalysed methanolysis was applied to 97 samples of vegetable oils and fats marketed in Brazil. The levels of the compounds ranged from not detected (limit of detection = 0.05 mg kg(-1)) to 5.09 mg kg(-1), and the highest concentrations were observed in samples containing olive pomace oil and in products used for industrial applications, such as palm oil and its fractions (olein and stearin). The content of diesters and monoesters was also investigated by employing solid-phase extraction on silica cartridges, indicating that the majority of the compounds were present as diesters. This study provides the first occurrence data on these contaminants in Brazil and the results are comparable with those reported in other countries.

  13. Determination of the radioimmunologic concentration of 5-androstene-3β-17β-diole in the blood plasma of patients suffering from common psoriasis

    International Nuclear Information System (INIS)

    Ehlen, M.

    1979-01-01

    A new radioimmunologic method for the determination of ADIOL in the blood plasma was developed. The author produced the antiserum herself and she examined it on cross-reactions. This method resulted to be very sensitive and in the standard curve a linear range of 0.04 ng to 1.5 ng was obtained. Moreover, the ADIOL concentration was determined in the blood plasma of 16 control subjects and of 35 patients suffering from psoriasis. The result was a far-reaching correlation with the results described in literature, although they were obtained by means of differing determination procedures. (orig./MG) [de

  14. Crystal structure of (1S,2R,4S-1-[(morpholin-4-ylmethyl]-4-(prop-1-en-2-ylcyclohexane-1,2-diol

    Directory of Open Access Journals (Sweden)

    Rachid Outouch

    2015-01-01

    Full Text Available The asymmetric unit of the title compound, C14H25NO3, contains two independent molecules with similar geometry. The morpholine and cyclohexane rings of both molecules adopt a chair conformation. Intramolecular O—H...N hydrogen bonds are observed. In the crystal, molecules are linked by O—H...O hydrogen bonds into chains parallel to the [101] direction. The chains are further connected through C—H...O hydrogen bonds forming undulating layers parallel to the (-101 plane. The absolute configuration was assigned by reference to an unchanging chiral centre in the synthetic procedure.

  15. Reaction of a chemotherapeutic agent, 6-mercaptopurine, with a direct-acting, electrophilic carcinogen, benzo[a]pyrene-7,8-diol 9,10-epoxide.

    Science.gov (United States)

    MacLeod, M C; Stewart, E; Daylong, A; Lew, L K; Evans, F E

    1991-01-01

    The chemotherapeutic agent 6-mercaptopurine (6-MP) has been shown to react covalently with the ultimate carcinogenic metabolite of benzo[a]pyrene, 7-r,8-t-dihydroxy-9-t,10-t-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE), in aqueous solution, forming a single adduct. NMR studies of the HPLC-purified product were consistent with its identification as 10(S)-(6'-mercaptopurinyl)-7,8,9-trihydroxy-7,8,9,10- tetrahydrobenzo[a]pyrene. Reaction kinetics were analyzed by using both HPLC separation of the products formed and a spectrophotometric assay for adduct formation. A simple model in which direct reaction between 6-MP and BPDE takes place without formation of a physical complex was found to adequately predict the dependence of product ratios on 6-MP concentration. Variations in the observed rate constant for this reaction with changes in temperature, pH, and buffer concentration were determined and compared to the effects of these variables on the observed rate constant for BPDE hydrolysis. In each case, the processes were affected quite differently, suggesting that different rate-determining steps are involved. The data suggest that the reaction mechanism involves SN2 attack of the anion of 6-MP, formed by ionization of the sulfhydryl group, on carbon 10 of BPDE, resulting in a trans-9,10 reaction product.

  16. Covalent binding of benzo(a)pyrene-diol-epoxide to histone H2A in rat liver nuclei: target site specificity

    International Nuclear Information System (INIS)

    Kurokawa, M.; MacLeod, M.C.

    1986-01-01

    The authors have recently found that 7r,8t-dihydroxy-9t,10t-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BPDE-I), a strong carcinogen, binds selectively to histone H2A-2 variant in rat liver nuclei, using a high performance liquid chromatography (HPLC) system which can separate H4, H2B, 3 different fractions of H2A variants and 3 different H3 variants in an hour. Here the authors examined the binding site of BPDE-I to the H2A-2 variant. The H2A-2 variants were purified from the acid extracted core histones of rat liver nuclei treated with ( 3 H)-BPDE-I by the HPLC system with a semi-preparative Aquapore RP-300 column. HPLC analysis of cyanogen bromide treated-H2A-2, which has one methionine residue, showed that the binding site is located in C-terminal half of H2A-2. In addition, digestions with V8-protease, trypsin and different types of carboxypeptides suggested that there are some target amino acid residues for BPDE-I in the V8-proteolytic C-terminal octapeptide which contains 2 histadine and 3 lysine residues. Currently identification of the target amino acid is proceeding, using amino acid-BPDE adducts prepared in vitro

  17. Highly Sensitive Determination of 2,4,6-Trinitrotoluene and Related Byproducts Using a Diol Functionalized Column for High Performance Liquid Chromatography

    NARCIS (Netherlands)

    Gümüscü, B.; Erdogan, Zeynep; Guler, Mustafa O.; Tekinay, Turgay

    2016-01-01

    In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT); 2,4-dinitrotoluene (2,4-DNT); 2,6-dinitrotoluene (2,6-DNT); 2-aminodinitrotoluene (2-ADNT) and 4-aminodinitrotoluene (4-ADNT) molecules in high-performance liquid-chromatography (HPLC) with UV sensor has

  18. Bis(2,2′-bipyridyl-κ2N,N′(sulfato-κ2O,O′cobalt(II ethane-1,2-diol monosolvate

    Directory of Open Access Journals (Sweden)

    Lin Chen

    2011-01-01

    Full Text Available The title compound, [Co(SO4(C10H8N22]·C2H6O2, has the Co2+ ion in a distorted octahedral CoN4O2 coordination geometry. A twofold rotation axis passes through the Co and S atoms, and through the mid-point of the C—C bond of the ethanediol molecule. In the crystal, the [CoSO4(C10H8N22] and C2H6O2 units are held together by a pair of O—H...O hydrogen bonds.

  19. Efficient Synthesis of Differentiated syn-1,2-Diol Derivatives by Asymmetric Transfer Hydrogenation-Dynamic Kinetic Resolution of α-Alkoxy-Substituted β-Ketoesters.

    Science.gov (United States)

    Monnereau, Laure; Cartigny, Damien; Scalone, Michelangelo; Ayad, Tahar; Ratovelomanana-Vidal, Virginie

    2015-08-10

    Asymmetric transfer hydrogenation was applied to a wide range of racemic aryl α-alkoxy-β-ketoesters in the presence of well-defined, commercially available, chiral catalyst Ru(II) -(N-p-toluenesulfonyl-1,2-diphenylethylenediamine) and a 5:2 mixture of formic acid and triethylamine as the hydrogen source. Under these conditions, dynamic kinetic resolution was efficiently promoted to provide the corresponding syn α-alkoxy-β-hydroxyesters derived from substituted aromatic and heteroaromatic aldehydes with a high level of diastereoselectivity (diastereomeric ratio (d.r.)>99:1) and an almost perfect enantioselectivity (enantiomeric excess (ee)>99 %). Additionally, after extensive screening of the reaction conditions, the use of Ru(II) - and Rh(III) -tethered precatalysts extended this process to more-challenging substrates that bore alkenyl-, alkynyl-, and alkyl substituents to provide the corresponding syn α-alkoxy-β-hydroxyesters with excellent enantiocontrol (up to 99 % ee) and good to perfect diastereocontrol (d.r.>99:1). Lastly, the synthetic utility of the present protocol was demonstrated by application to the asymmetric synthesis of chiral ester ethyl (2S)-2-ethoxy-3-(4-hydroxyphenyl)-propanoate, which is an important pharmacophore in a number of peroxisome proliferator-activated receptor α/γ dual agonist advanced drug candidates used for the treatment of type-II diabetes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. hREV3 is essential for error-prone translesion synthesis past UV or benzo[a]pyrene diol epoxide-induced DNA lesions in human fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Li Ziqiang; Zhang Hong; McManus, Terrence P.; McCormick, J. Justin; Lawrence, Christopher W.; Maher, Veronica M

    2002-12-29

    In S. cerevisiae, the REV3 gene, encoding the catalytic subunit of polymerase zeta, is involved in translesion synthesis and required for the production of mutations induced by ultraviolet radiation (UV) photoproducts and other DNA fork-blocking lesions, and for the majority of spontaneous mutations. To determine whether hREV3, the human homolog of yeast REV3, is similarly involved in error-prone translesion synthesis past UV photoproducts and other lesions that block DNA replication, an hREV3 antisense construct under the control of the TetP promoter was transfected into an infinite life span human fibroblast cell strain that expresses a high level of tTAk, the activator of that promoter. Three transfectant strains expressing high levels of hREV3 antisense RNA were identified and compared with their parental cell strain for sensitivity to the cytotoxic and mutagenic effects of UV. The three hREV3 antisense-expressing cell strains were not more sensitive than the parental strain to the cytotoxic effect of UV, but the frequency of mutants induced by UV in their HPRT gene was significantly reduced, i.e. to 14% that of the parent. Two of these hREV3 antisense-expressing cell strains were compared with the parental strain for sensitivity to ({+-})-7{beta},8{alpha}-dihydroxy-9{alpha},10{alpha}-epoxy-7,8,9,10-tetrahydro= benzo[a]pyrene (BPDE). They were not more sensitive than the parent strain to the cytotoxic effect of BPDE, but the frequency of mutants induced was significantly reduced, i.e. in one strain, to 17% that of the parent, and in the other, to 24%. DNA sequencing showed that the kinds of mutations induced by BPDE in the parental and the derivative strains did not differ and were similar to those found previously with finite life span human fibroblasts. The data strongly support the hypothesis that hRev3 plays a critical role in the induction of mutations by UV or BPDE. Because the level of hRev3 protein in human fibroblasts is below the level of antibody detection, it was not possible to demonstrate that the decrease in mutagenesis reflected decreased hRev3 protein. However, the conclusion is supported by the fact that in a similar study with a strain expressing a high level of antisense hREV1, a very similar result was obtained, i.e. UV or BPDE mutagenesis was virtually eliminated.

  1. hREV3 is essential for error-prone translesion synthesis past UV or benzo[a]pyrene diol epoxide-induced DNA lesions in human fibroblasts

    International Nuclear Information System (INIS)

    Li Ziqiang; Zhang Hong; McManus, Terrence P.; McCormick, J. Justin; Lawrence, Christopher W.; Maher, Veronica M.

    2002-01-01

    In S. cerevisiae, the REV3 gene, encoding the catalytic subunit of polymerase zeta, is involved in translesion synthesis and required for the production of mutations induced by ultraviolet radiation (UV) photoproducts and other DNA fork-blocking lesions, and for the majority of spontaneous mutations. To determine whether hREV3, the human homolog of yeast REV3, is similarly involved in error-prone translesion synthesis past UV photoproducts and other lesions that block DNA replication, an hREV3 antisense construct under the control of the TetP promoter was transfected into an infinite life span human fibroblast cell strain that expresses a high level of tTAk, the activator of that promoter. Three transfectant strains expressing high levels of hREV3 antisense RNA were identified and compared with their parental cell strain for sensitivity to the cytotoxic and mutagenic effects of UV. The three hREV3 antisense-expressing cell strains were not more sensitive than the parental strain to the cytotoxic effect of UV, but the frequency of mutants induced by UV in their HPRT gene was significantly reduced, i.e. to 14% that of the parent. Two of these hREV3 antisense-expressing cell strains were compared with the parental strain for sensitivity to (±)-7β,8α-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE). They were not more sensitive than the parent strain to the cytotoxic effect of BPDE, but the frequency of mutants induced was significantly reduced, i.e. in one strain, to 17% that of the parent, and in the other, to 24%. DNA sequencing showed that the kinds of mutations induced by BPDE in the parental and the derivative strains did not differ and were similar to those found previously with finite life span human fibroblasts. The data strongly support the hypothesis that hRev3 plays a critical role in the induction of mutations by UV or BPDE. Because the level of hRev3 protein in human fibroblasts is below the level of antibody detection, it was not possible to demonstrate that the decrease in mutagenesis reflected decreased hRev3 protein. However, the conclusion is supported by the fact that in a similar study with a strain expressing a high level of antisense hREV1, a very similar result was obtained, i.e. UV or BPDE mutagenesis was virtually eliminated.

  2. Twenty-six-week oral carcinogenicity study of 3-monochloropropane-1,2-diol in CB6F1-rasH2 transgenic mice.

    Science.gov (United States)

    Lee, Byoung-Seok; Park, Sang-Jin; Kim, Yong-Bum; Han, Ji-Seok; Jeong, Eun Ju; Son, Hwa-Young; Moon, Kyoung-Sik

    2017-01-01

    The carcinogenic potential of 3-monochloro-1,2-propanediol (3-MCPD) was evaluated in a short-term carcinogenicity testing study using CB6F1 rasH2-Tg (rasH2-Tg) mice. 3-MCPD is found in many foods and food ingredients as a result of storage or processing and is regarded as a carcinogen since it is known to induce Leydig cell and kidney tumors in rats. Male and female rasH2-Tg mice were administered 3-MCPD once daily by oral gavage at doses of 0, 10, 20, and 40 mg/kg body weight (bw) per day for 26 weeks. As a positive control, N-methyl-N-nitrosourea (MNU) was administered as a single intraperitoneal injection (75 mg/kg). In 3-MCPD-treated mice, there was no increase in the incidence of neoplastic lesions compared to the incidence in vehicle control mice. However, 3-MCPD treatment resulted in an increased incidence of tubular basophilia in the kidneys and germ cell degeneration in the testes, with degenerative germ cell debris in the epididymides of males at 20 and 40 mg/kg bw per day. In 3-MCPD-treated females, vacuolation of the brain and spinal cord was observed at 40 mg/kg bw per day; however, only one incidence of vacuolation was observed in males. Forestomach and cutaneous papilloma and/or carcinoma and lymphoma were observed in most rasH2 mice receiving MNU treatment. We concluded that 3-MCPD did not show carcinogenic potential in the present study using rasH2-Tg mice. The findings of this study suggest that the carcinogenic potential of 3-MCPD is species specific.

  3. Diols and anions can control the formation of an exciplex between a pyridinium boronic acid with an aryl group connected via a propylene linker.

    Science.gov (United States)

    Huang, Yan-Jun; Jiang, Yun-Bao; Bull, Steven D; Fossey, John S; James, Tony D

    2010-11-21

    The exciplex formation between a pyridinium boronic acid and phenyl group connected via a propylene linker can be monitored using fluorescence. Addition of pinacol affords a cyclic boronate ester with enhanced Lewis acidity that increases the strength of its cation-π stacking interaction causing a four-fold fluorescence enhancement.

  4. 17α-Ethyl-5β-estrane-3α,17β-diol, a biological marker for the abuse of norethandrolone and ethylestrenol in slaughter cattle

    NARCIS (Netherlands)

    Puymbroeck, M. van; Kuilman, M.E.M.; Maas, R.F.M.; Witkamp, R.F.; Leyssens, L.; Miert, A.S.J.P.A.M. van; Hendriks, L.; Zande, D.J.M. van der; Adriaensens, P.; Jacobs, M.-P.; Raus, J.

    1999-01-01

    The metabolism of the illegal growth promoter ethylestrenol (EES) was evaluated in bovine liver cells and subcellular fractions of bovine liver preparations. Incubations with bovine microsomal preparations revealed that EES is extensively biotransformed into norethandrolone (NE), another illegal

  5. TPX2 in malignantly transformed human bronchial epithelial cells by anti-benzo[a]pyrene-7,8-diol-9,10-epoxide

    International Nuclear Information System (INIS)

    Zhang Lijuan; Huang He; Deng Luyao; Chu Ming; Xu Lan; Fu Juanling; Zhu Yunlan; Zhang Xiuchun; Liu Shulin; Zhou Zongcan; Wang Yuedan

    2008-01-01

    In order to elucidate the function of the targeting protein for Xenopus kinesin-like protein 2 (Xklp2) (TPX2) in the malignant transformation of human bronchial epithelial cells induced by anti-benzo[a]pyrene-trans-7, 8-dihydrodiol-9, 10-epoxide (anti-BPDE), TPX2 was characterized in cells at both the gene and the protein levels. TPX2 was present at higher levels in 16HBE-C cells than in 16HBE cells as demonstrated by two-dimensional gel electrophoresis, immunocytochemistry, Western blot analysis and RT-PCR. TPX2 was also detected in lung squamous-cell carcinoma tissues by immunohistochemistry, but not in normal lung tissues. Depression of TPX2 by RNA interference in 16HBE-C cells led to a decrease in cell proliferation, S-phase cell cycle arrest and cell apoptosis. Abnormal TPX2 tyrosine phosphorylation was detected in 16HBE-C cells, and this could be inhibited, to different degrees, by tyrosine kinase inhibitors. Inhibiting tyrosine phosphorylation in 16HBE-C cells by three selected tyrosine protein kinase inhibitors, tyrphostin 47, AG112 and AG555, caused G 0 /G 1 -phase cell cycle arrest. Our results suggest that anti-BPDE can cause the over-expression of TPX2 and its aberrant tyrosine phosphorylation. Misregulation of TPX2 affects the cell cycle state, proliferation rates and apoptosis

  6. Synthesis, thermolysis and pyrolysis of group IV metal pinacolates: The impact of a vicinal diol as a supporting ligand for molecular precursors

    Science.gov (United States)

    Zechmann, Cecilia A.

    In an effort to investigate the suitability of an alternative ligand class for molecular precursors, the following studies were carried out: (1) New zirconium species were obtained by reaction of zirconium isopropoxide alcoholate, Zr2(OiPr)8(HOiPr) 2, with pinacol (HOCMe2CMe2OH). Control of reaction stoichiometries followed by azeotropic distillation of evolved isopropanol led to the successful preparation of a range of homo- and heteroleptic trinuclear species, Zr3(OCMe2CMe2O)2(O iPr)8(HOiPr)2, Zr3(OCMe 2CMe2O)4(OCMe2CMe2OH) 2(OiPr)2, and Zr3(OCMe2CMe 2O)4(OCMe2CMe2OH)4. Dinuclear products could be obtained by carrying out the reactions at room temperature or by addition of excess pinacol (in which case Zr2(OCMe2 CMe2O)2(OCMe2CMe2OH) 4 was the product). (2) Similar reactions between Ti(Oi Pr)4 and pinacol gave dinuclear products under all conditions. Both homo- (Ti2(OiPr)2(OCMe2CMe 2O)2(OCMe2CMe2OH)2) and heterometallic complexes (Ti2(OCMe2CMe2O) 2(OCMe2CMe2OH)4) were characterized. (3) Controlled addition of water to either of the isolated titanium pinacolates gave Ti3(mu3-O)(OCMe2CMe2O) 4(OCMe2CMe2OH)2. (4) Reaction of zirconium pinacolates with water led to the isolation of Zr4(mu 2-O)(OCMe2CMe2O)4(OCMe2CMe 2OH)6 and Zr6(mu3-O)4(H 2O)2(OCMe2CMe2O)5(OCMe 2CMe2OH)5. 17O NMR studies aided in the investigation of active equilibria and reversibility of hydrolysis. (5) The thermolysis of Zr2(OCMe2CMe2O) 2(OCMe2CMe2OH)4 gave ZrO2 in a mixture of crystalline phases. GC-MS and NMR analysis of the volatiles revealed 4 C6 products as well as two ligand coupled products. Isotope-labeling studies were carried out to probe the mechanisms by which the organic products were formed. (6) Reaction of Zr2(OCMe 2CMe2O)2(OCMe2CMe2OH) 4 with Ti(OiPr)4 gives (OiPr) 2TiZr2(OCMe2CMe2O)4(OCMe 2CMe2OH)2 which reacts with a second equivalent of Ti(OiPr)4 to give (OiPr) 4Ti2Zr2(OCMe2CMe2O) 6. (7) Reaction of Li{N(SiMe3)2}·Et 2O or Na{N(SiMe3)2}·x THF with Zr2(OCMe2CMe2O)2(OCMe 2CMe2OH)4 gave (THF)LiZr2(OCMe 2CMe2O)3(OCMe2CMe2OH) 3 or (HOCMe2CMe2OH)2Na2Zr 2(OCMe2CMe2O)4(OCMe2CMe 2OH)2 respectively. Similar reactions with larger +1 or +2 metals led to the formation of insoluble precipitates.

  7. 5,7,12,14-Tetrahydro-5,14:7,12-bis([1,2]benzenopentacene-6,13-diol dimethylformamide disolvate

    Directory of Open Access Journals (Sweden)

    Mohammad Nozari

    2016-07-01

    Full Text Available The crystal lattice of the title compound, C34H22O2·2C3H7NO, at 173 K has monoclinic (P21/n symmetry. Molecules are located on crystallographic centers of symmetry and have approximate non-crystallographic mmm symmetry, indicating that in solution the chemical and spectroscopic behavior would be that of a D2h molecule. The compound has applications in gas-separation membranes fabricated from polymers of intrinsic microporosity (PIM. The compound is the product of reduction of the corresponding quinone by Na2S2O4 in DMF/NaHCO3.

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

    Czech Academy of Sciences Publication Activity Database

    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: 3.926, year: 2015

  9. Determination of thermal stability of specific biomarker lipids of the freshwater fern Azolla through hydrous pyrolysis

    Science.gov (United States)

    Sap, Merel; Speelman, Eveline N.; Lewan, Michael D.; Sinninghe Damsté, Jaap S.; Reichart, Gert-Jan

    2010-05-01

    Enormous blooms of the free-floating freshwater fern Azolla occurred within the Arctic Basin during an extended period of ~1.2 Ma during the middle Eocene (Brinkhuis et al. 2006; Speelman et al., GB, 2009). The sustained growth of Azolla, currently ranking among the fastest growing plants on Earth, in a major anoxic basin may have substantially contributed to decreasing atmospheric CO2 levels by burial of Azolla-derived organic matter. Speelman et al. (OG, 2009) reported biomarkers for Azolla (1,w20 C32 - C36 diols, structurally related C29 ω20,ω21 diols, C29 1,20,21 triols, C29 dihydroxy fatty acids as well as a series of wax esters containing these mono- and dihydroxy lipids), which can be used to reconstruct palaeo-environmental conditions. Here we assess the thermal stability of these compounds, to extend their biomarker potential. We specifically focused on the thermal stability of the Azolla biomarkers using hydrous pyrolysis in order to determine which burial conditions allow reconstruction of past occurrences of Azolla. In addition, hydrous pyrolysis was also performed on samples from the Eocene Arctic Ocean (ACEX core), to test if and how the biomarkers change under higher temperatures and pressures in situ. During hydrous pyrolysis, the biomass was heated under high pressure at temperatures ranging between 220 and 365°C for 72 hours. Four experiments were also run using different durations to explore the kinetics of biomarker degradation at specific temperatures. First results indicate that the Azolla specific diols are still present at 220°C, while the corresponding wax esters are already absent. At 300°C all Azolla specific biomarkers are destroyed. More specific determination of the different biomarkers' stability and kinetics would potentially allow the reconstruction of the temperature and pressure history of Azolla deposits. Literature: • Brinkhuis, H., Schouten, S., Collinson, M. E., Sluijs, A., Sinninghe Damste, J. S., Dickens, G. R., Huber

  10. Chiral analysis of anti-acquired immunodeficiency syndrome drug, 9-(R)-[2-(phosphonomethoxy)propyl]adenine (tenofovir), and related antiviral acyclic nucleoside phosphonates by CE using beta-CD as chiral selector

    Czech Academy of Sciences Publication Activity Database

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

    2009-01-01

    Roč. 30, č. 12 (2009), s. 2245-2254 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA203/06/1044; GA ČR(CZ) GA203/08/1428; GA AV ČR 1QS400550501; GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : antiviral drugs * capillary electrophoresis * enantioseparation Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.077, year: 2009

  11. Extent of Intramolecular pi Stacks in Aqueous Solution in Mixed-Ligand Copper(II) Complexes Formed by Heteroaromatic Amines and 1-[2-(Phosphonomethoxy)ethyl]cytosine (PMEC), a Relative of Antivirally Active Acyclic Nucleotide Analogues (Part 72)

    Czech Academy of Sciences Publication Activity Database

    Blindauer, C. A.; Sigel, A.; Operschall, B. P.; Holý, Antonín; Sigel, H.

    2013-01-01

    Roč. 639, 8-9 (2013), s. 1661-1673 ISSN 0044-2313 Institutional support: RVO:61388963 Keywords : nucleotide analogues * antivirals * complex stabilities * isomers * equilibria * mixed ligand complexes Subject RIV: CC - Organic Chemistry Impact factor: 1.251, year: 2013

  12. Synthesis and Comparison of In Vitro Leishmanicidal Activity of 5-(Nitroheteroaryl-1, 3, 4-Thiadiazols Containing Cyclic Amine of Piperidin-4-ol at C-2 with Acyclic Amine Analogues against Iranian Strain of Leishmania major (MRHO/IR/75/ER

    Directory of Open Access Journals (Sweden)

    Azar Tahghighi

    2017-04-01

    Full Text Available Background: Cutaneous Leishmaniasis (CL is endemic in many tropical and subtropical regions of the world. Due to the prolonged duration of therapy, adverse effect and resistance to current drugs in the treatment of CL, the dis­covery of novel, efficient, and safe leishmanicidal drugs is required. The aims of the present study was to synthesis of new compounds based on the active compounds of 5-(5-nitrofuran-2-yl- and 5-(5-nitrothiophen-2-yl-1,3,4-thia­diazole bearing the linear amino alcohol of 3-aminopropan-1-ol in the C-2 position of thiadiazole ring and evaluation of their activity against the promastigote and amastigote forms of Leishmania major.Methods: Reaction between the solution of 5-(5-nitro heteroaryl-2-chloro-1, 3, 4-thiadiazole and piperidin-4-ol in absolute ethanol was performed and the resulting products were evaluated against promastigotes form of L. major with MTT assay and amastigote form of L. major in murine peritoneal macrophages. In addition, the toxicity of these compounds was assessed against mouse peritoneal macrophages with MTT assay.Results: New synthetic compounds 5a-b showed moderate in vitro antileishmanial activity against L. major pro­mastigotes with IC50 values of 68.9 and 27 µM, respectively. These compounds have also demonstrated a good antiamastigote activity in terms of amastigote number per macrophage, the percentage of macrophage infectivity and infectivity index.Conclusion: Novel cyclic compounds 5a-b were synthesized and exhibited less antipromastigote and antiamastigote activity compared to linear analogues.

  13. Stereo-selectivity and regio-selectivity in the metabolism of 7,8-dihydrobenzo[a]pyrene by cytochrome P450, epoxide hydrolase and hepatic microsomes from 3-methylcholanthrene-treated rats.

    Science.gov (United States)

    Adams, J D; Yagi, H; Levin, W; Jerina, D M

    1995-03-30

    The active site of cytochrome P450 1A1 has been probed with the substrate 7,8-dihydrobenzo[a]pyrene using a purified, reconstituted system composed of cytochrome P450 1A1, NADPH-cytochrome c reductase and lipid in the presence or absence of epoxide hydrolase. The turnover of the substrate was found to be 38 nmol/nmol of cytochrome P450/min. The metabolic products that were identified are: a phenolic 7,8-dihydrobenzo[a]pyrene (20-29%); 9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (17-28%); benzo[a]pyrene (12-19%); 7-hydroxy-7,8-dihydrobenzo[a]pyrene (13-16%); 8-hydroxy-7,8-dihydrobenzo[a]pyrene (7-15%); 3-hydroxybenzo[a]pyrene (7-15%); 4,5-epoxy-4,5,7,8-tetrahydrobenzo[a]pyrene (0-4%); and a triol of 7,8,9,10-tetrahydrobenzo[a]pyrene (0-4%). 9,10-Epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene undergoes rapid hydrolysis to cis- and trans-9,10-dihydroxy-dihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (2:1) by benzylic attack of water at C-10. Approximately 71% of the trans diols are derived from (+)-(9S,10R)-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene, indicating that cytochrome P450 1A1 has more than a 2:1 preference for selective epoxidation of an enantiotopic face of 7,8-dihydrobenzo[a]pyrene. This stereo-selectivity agrees with the postulated stereo-selectivity predicted by a previously described active site model for cytochrome P450 1A1. Epoxide hydrolase in pure form or in hepatic microsomes catalyzes the hydrolysis of 9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene, which is inhibited by 1,1,1-trichloropropane 2,3-oxide. The (+)-(9S,10R)-isomer of the epoxide is slightly preferred as a substrate over its enantiomer and is cleaved by benzylic and nonbenzylic attack. Only benzylic attack was found with (-)-(9R,10S)-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene.

  14. Effects of sex and time of day on metabolism and excretion of corticosterone in urine and feces of mice.

    Science.gov (United States)

    Touma, Chadi; Sachser, Norbert; Möstl, Erich; Palme, Rupert

    2003-02-15

    Non-invasive techniques to monitor stress hormones in small animals like mice offer several advantages and are highly demanded in laboratory as well as in field research. Since knowledge about the species-specific metabolism and excretion of glucocorticoids is essential to develop such a technique, we conducted radiometabolism studies in mice (Mus musculus f. domesticus, strain C57BL/6J). Each mouse was injected intraperitoneally with 740 kBq of 3H-labelled corticosterone and all voided urine and fecal samples were collected for five days. In a first experiment 16 animals (eight of each sex) received the injection at 9 a.m., while eight mice (four of each sex) were injected at 9 p.m. in a second experiment. In both experiments radioactive metabolites were recovered predominantly in the feces, although males excreted significantly higher proportions via the feces (about 73%) than females (about 53%). Peak radioactivity in the urine was detected within about 2h after injection, while in the feces peak concentrations were observed later (depending on the time of injection: about 10h postinjection in experiment 1 and about 4h postinjection in experiment 2, thus proving an effect of the time of day). The number and relative abundance of fecal [3H]corticosterone metabolites was determined by high performance liquid chromatography (HPLC). The HPLC separations revealed that corticosterone was extensively metabolized mainly to more polar substances. Regarding the types of metabolites formed, significant differences were found between males and females, but not between the experiments. Additionally, the immunoreactivity of these metabolites was assessed by screening the HPLC fractions with four enzyme immunoassays (EIA). However, only a newly established EIA for 5alpha-pregnane-3beta,11beta,21-triol-20-one (measuring corticosterone metabolites with a 5alpha-3beta,11beta-diol structure) detected several peaks of radioactive metabolites with high intensity in both sexes, while

  15. Experiments and simulations of NOx formation in the combustion of hydroxylated fuels

    KAUST Repository

    Bohon, Myles

    2015-06-01

    This work investigates the influence of molecular structure in hydroxylated fuels (i.e. fuels with one or more hydroxyl groups), such as alcohols and polyols, on NOx formation. The fuels studied are three lower alcohols (methanol, ethanol, and n-propanol), two diols (1,2-ethanediol and 1,2-propanediol), and one triol (1,2,3-propanetriol); all of which are liquids at room temperature and span a wide range of thermophysical properties. Experimental stack emissions measurements of NO/NO2, CO, and CO2 and flame temperature profiles utilizing a rake of thermocouples were obtained in globally lean, swirling, liquid atomized spray flames inside a refractory-lined combustion chamber as a function of the atomizing air flow rate and swirl number. These experiments show significantly lower NOx formation with increasing fuel oxygen content despite similarities in the flame temperature profiles. By controlling the temperature profiles, the contribution to NOx formation through the thermal mechanism were matched, and variations in the contribution through non-thermal NOx formation pathways are observed. Simulations in a perfectly stirred reactor, at conditions representative of those measured within the combustion region, were conducted as a function of temperature and equivalence ratio. The simulations employed a detailed high temperature chemical kinetic model for NOx formation from hydroxylated fuels developed based on recent alcohol combustion models and extended to include polyol combustion chemistry. These simulations provide a qualitative comparison to the range of temperatures and equivalence ratios observed in complex swirling flows and provide insight into the influence of variations in the fuel decomposition pathways on NOx formation. It is observed that increasing the fuel bound oxygen concentration ultimately reduces the formation of NOx by increasing the proportion of fuel oxidized through formaldehyde, as opposed to acetylene or acetaldehyde. The subsequent

  16. Catalytic asymmetric dihydroxylation of olefins with reusable OsO(4)(2-) on ion-exchangers: the scope and reactivity using various cooxidants.

    Science.gov (United States)

    Choudary, Boyapati M; Chowdari, Naidu S; Jyothi, Karangula; Kantam, Mannepalli L

    2002-05-15

    Exchanger-OsO(4) catalysts are prepared by an ion-exchange technique using layered double hydroxides and quaternary ammonium salts covalently bound to resin and silica as ion-exchangers. The ion-exchangers with different characteristics and opposite ion selectivities are specially chosen to produce the best heterogeneous catalyst that can operate using the various cooxidants in the asymmetric dihydroxylation reaction. LDH-OsO(4) catalysts composed of different compositions are evaluated for the asymmetric dihydroxylation of trans-stilbene. Resin-OsO(4) and SiO(2)-OsO(4) designed to overcome the problems associated with LDH-OsO(4) indeed show consistent activity and enantioselectivity in asymmetric dihydroxylation of olefins using K(3)Fe(CN)(6) and molecular oxygen as cooxidants. Compared to the Kobayashi heterogeneous systems, resin-OsO(4) is a very efficient catalyst for the dihydroxylation of a wide variety of aromatic, aliphatic, acyclic, cyclic, mono-, di-, and trisubstituted olefins to afford chiral vicinal diols with high yields and enantioselectivities irrespective of the cooxidant used. Resin-OsO(4) is recovered quantitatively by a simple filtration and reused for a number of cycles with consistent activity. The high binding ability of the heterogeneous osmium catalyst enables the use of an equimolar ratio of ligand to osmium to give excellent enantioselectives in asymmetric dihydroxylation in contrast to the homogeneous osmium system in which excess molar quantities of the expensive chiral ligand to osmium are invariably used. The complexation of the chiral ligand (DHQD)(2)PHAL, having very large dimension, a prerequisite to obtain higher ee, is possible only with the OsO(4)(2-) located on the surface of the supports.

  17. Kultuurkapitali preemiad

    Index Scriptorium Estoniae

    2000-01-01

    Eesti Kultuurkapitali aastapreemia U. Lippusele, Helikunsti aastapreemiad J. Leitenile, M. Martinile, J. Reinverele, V. Sarvele, A. Volmerile, Uus Tallinna Triole, Duole Kai Ratassepp, Mati Mikali; Rahvakultuuri Sihtkapitali aastapreemia J. Rent, V. Sarv

  18. Metabolic studies of oxyguno in horses

    International Nuclear Information System (INIS)

    Wong, April S.Y.; Ho, Emmie N.M.; Wan, Terence S.M.; Lam, Kenneth K.H.; Stewart, Brian D.

    2015-01-01

    Oxyguno (4-chloro-17α-methyl-17β-hydroxy-androst-4-ene-3,11-dione) is a synthetic oral anabolic androgenic steroid commercially available without a prescription. Manufacturers of oxyguno claim that its anabolic effect in metabolic enhancement exceeds that of the classic anabolic steroid testosterone by seven times, but its androgenic side-effects are only twelve percent of testosterone. Like other anabolic androgenic steroids, oxyguno is prohibited in equine sports. The metabolism of oxyguno in either human or horse has not been reported and therefore little is known about its metabolic fate. This paper describes the in vitro and in vivo metabolic studies of oxyguno in racehorses with an objective to identify the most appropriate target metabolites for detecting oxyguno administration. In vitro studies of oxyguno were performed using horse liver microsomes. Metabolites in the incubation mixtures were isolated by liquid–liquid extraction and analysed by gas chromatography-mass spectrometry in the EI mode after trimethylsilylation. In vitro metabolites identified include the stereoisomers of 4-chloro-17α-methyl-androst-4-ene-3-keto-11,17β-diol (M1a & M1b); 20-hydroxy-oxyguno (M2); and 4-chloro-17α-methyl-androst-4-ene-3-keto-11,17β,20-triol (M3). These novel metabolites were resulted from hydroxylation at C20, and/or reduction of the keto group at C11. For the in vivo studies, two geldings were each administered orally with a total dose of 210 mg oxyguno (52.5 mg twice daily for 2 days). Pre- and post-administration urine and blood samples were collected for analysis. The parent drug oxyguno was detected in both urine and blood, while numerous novel metabolites were detected in urine. The stereoisomers (M1a & M1b) observed in the in vitro studies were also detected in post-administration urine samples. Three other metabolites (M4 - M6) were detected. M4, 4-chloro-17α-methyl-androstane-11-keto-3,17β-diol, was resulted from reductions of the olefin

  19. Metabolic studies of oxyguno in horses

    Energy Technology Data Exchange (ETDEWEB)

    Wong, April S.Y., E-mail: april.sy.wong-rl@hkjc.org.hk [Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong (China); Ho, Emmie N.M. [Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong (China); Wan, Terence S.M., E-mail: terence.sm.wan@hkjc.org.hk [Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong (China); Lam, Kenneth K.H.; Stewart, Brian D. [Veterinary Regulation & International Liaison, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T, Hong Kong (China)

    2015-09-03

    Oxyguno (4-chloro-17α-methyl-17β-hydroxy-androst-4-ene-3,11-dione) is a synthetic oral anabolic androgenic steroid commercially available without a prescription. Manufacturers of oxyguno claim that its anabolic effect in metabolic enhancement exceeds that of the classic anabolic steroid testosterone by seven times, but its androgenic side-effects are only twelve percent of testosterone. Like other anabolic androgenic steroids, oxyguno is prohibited in equine sports. The metabolism of oxyguno in either human or horse has not been reported and therefore little is known about its metabolic fate. This paper describes the in vitro and in vivo metabolic studies of oxyguno in racehorses with an objective to identify the most appropriate target metabolites for detecting oxyguno administration. In vitro studies of oxyguno were performed using horse liver microsomes. Metabolites in the incubation mixtures were isolated by liquid–liquid extraction and analysed by gas chromatography-mass spectrometry in the EI mode after trimethylsilylation. In vitro metabolites identified include the stereoisomers of 4-chloro-17α-methyl-androst-4-ene-3-keto-11,17β-diol (M1a & M1b); 20-hydroxy-oxyguno (M2); and 4-chloro-17α-methyl-androst-4-ene-3-keto-11,17β,20-triol (M3). These novel metabolites were resulted from hydroxylation at C20, and/or reduction of the keto group at C11. For the in vivo studies, two geldings were each administered orally with a total dose of 210 mg oxyguno (52.5 mg twice daily for 2 days). Pre- and post-administration urine and blood samples were collected for analysis. The parent drug oxyguno was detected in both urine and blood, while numerous novel metabolites were detected in urine. The stereoisomers (M1a & M1b) observed in the in vitro studies were also detected in post-administration urine samples. Three other metabolites (M4 - M6) were detected. M4, 4-chloro-17α-methyl-androstane-11-keto-3,17β-diol, was resulted from reductions of the olefin

  20. The C

    NARCIS (Netherlands)

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

    2017-01-01

    Long chain alkyl diols are lipids that occur ubiquitously in marine sediments and are used as a proxy for sea surface temperature (SST), using the Long chain Diol Index (LDI), and for upwelling intensity/high nutrient conditions. The distribution of 1,13- and 1,15-diols has been documented in open

  1. elucidating the mechanism of the adsorption of mucin

    African Journals Online (AJOL)

    dcu user

    Kinetic and mechanistic studies of electron transfer reaction of butane-1,3-diol and Cr(VI) ion in ... The oxidation of diols other than. 1,2-diols by transition metal ions and their complexes has received little attention. An increased interest in these reactions was noticed after the oxidation of propane-1,3-, butane-1,3- and ...

  2. Kinetics and mechanism of the oxidation of some vicinal and non ...

    Indian Academy of Sciences (India)

    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 ...

  3. Producció enantioselectiva de diols vicinals i αhidroxicetones amb oxidoreductases de llevat. Aplicació de tècniques d’autoclonació per la generación d’enzims i soques modificades

    OpenAIRE

    Calam Cervera, Eduard

    2015-01-01

    Les transformacions catalitzades per enzims s'utilitzen cada cop més per a la síntesis d'intermediaris útils destinats a les indústries farmacèutiques, agroalimentàries i de química fina. La utilització d'enzims en síntesi química compleix amb els principis de la "química verda", com per exemple en la utilització de solvents més segurs (les reaccions enzimàtiques són realitzades usualment, en medi aquós), en el disseny de reaccions amb millor eficiència energètica (les reaccions enzimàtiques ...

  4. Flow cytometric analysis of mitotic cycle perturbation by chemical carcinogens in cultured epithelial cells. [Effects of benzo(a)pyrene-diol-epoxide on mitotic cycle of cultural mouse liver epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Pearlman, Andrew Leonard [Univ. of California, Berkeley, CA (United States)

    1978-08-01

    A system for kinetic analysis of mitotic cycle perturbation by various agents was developed and applied to the study of the mitotic cycle effects and dependency of the chemical carcinogen benzo(a)pyrene-diolepoxide, DE, upon a mouse lever epithelial cell line, NMuLi. The study suggests that the targets of DE action are not confined to DNA alone but may include cytoplasmic structures as well. DE was found to affect cells located in virtually every phase of the mitotic cycle, with cells that were actively synthesizing DNA showing the strongest response. However, the resulting perturbations were not confined to S-phase alone. DE slowed traversal through S-phase by about 40% regardless of the cycle phase of the cells exposed to it, and slowed traversal through G2M by about 50%. When added to G1 cells, DE delayed recruitment of apparently quiescent (G0) cells by 2 hours, and reduced the synchrony of the cohort of cells recruited into active proliferation. The kinetic analysis system consists of four elements: tissue culture methods for propagating and harvesting cell populations; an elutriation centrifugation system for bulk synchronization of cells in various phases of the mitotic cycle; a flow cytometer (FCM), coupled with appropriate staining protocols, to enable rapid analysis of the DNA distribution of any given cell population; and data reduction and analysis methods for extracting information from the DNA histograms produced by the FCM. The elements of the system are discussed. A mathematical analysis of DNA histograms obtained by FCM is presented. The analysis leads to the detailed implementation of a new modeling approach. The new modeling approach is applied to the estimation of cell cycle kinetic parameters from time series of DNA histograms, and methods for the reduction and interpretation of such series are suggested.

  5. Radical Addition Reactions of Fluorinated Species. Part 8. Rigioselectivity of Radical Additions to Perfluoroalkylethylenes and Quantum Chemical Calculations. Highly Selective Two-Step Synthesis of 4-(Perfluoroalkyl)Butane-1,2-diols

    Czech Academy of Sciences Publication Activity Database

    Církva, Vladimír; Böhm, S.; Paleta, O.

    2000-01-01

    Roč. 102, - (2000), s. 159-168 ISSN 0022-1139 R&D Projects: GA ČR GA203/98/1174; GA MŠk LB98233 Institutional research plan: CEZ:AV0Z4072921 Subject RIV: CC - Organic Chemistry Impact factor: 0.851, year: 2000

  6. A Multidisciplinary Approach Toward the Rapid and Preparative-Scale Biocatalytic Synthesis of Chiral Amino Alcohols: A Concise Transketolase-/omega-Transaminase-Mediated Synthesis of (2S,3S)-2-Aminopentane-1,3-diol

    DEFF Research Database (Denmark)

    Smith, M.E.B; Chen, B.H.; Hibbert, E.G

    2010-01-01

    Chiral amino alcohols represent an important class of value-added biochemicals and pharmaceutical intermediates. Chemical routes to such compounds are generally step intensive, requiring environmentally unfriendly catalysts and solvents. This work describes a multidisciplinary approach to the rapid...... the bioconversions were subsequently scaled up to preparative scales in batch stirred-tank reactors. The microwell methods thus provide process chemists and engineers with a valuable tool for the rapid and early evaluation of potential synthetic strategies. Overall, this work describes a concise and efficient...... biocatalytic route to chiral amino alcohols and illustrates an integrated multidisciplinary approach to bioconversion process design and scale-up....

  7. CCDC 838941: Experimental Crystal Structure Determination : 3,3,3',3'-Tetramethyl-5,5'-dinitro-2,2',3,3'-tetrahydro-1,1'-spirobi[indene]-6,6'-diol dichloromethane solvate

    KAUST Repository

    Ma, Xiaohua; Swaidan, R.; Belmabkhout, Youssef; Zhu, Yihan; Litwiller, E.; Jouiad, M.; Pinnau, I.; Han, Yu

    2013-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  8. Crystal structure of 5,5′-dibromo-3,3′-di-tert-butyl-6,6′-dimethylbiphenyl-2,2′-diol

    Directory of Open Access Journals (Sweden)

    Rika Obata

    2015-05-01

    Full Text Available The whole molecule of the title compound, C22H28Br2O2, is generated by twofold rotation symmetry. The dihedral angle of the biphenyl moiety is 85.05 (11°. The hydroxy groups show intramolecular O—H...π interactions without any other hydrogen-bond acceptors. In the crystal, there are no other significant intermolecular interactions present.

  9. Synthesis, spectral, antitumor, antioxidant and antimicrobial studies on Cu(II), Ni(II) and Co(II) complexes of 4-[(1H-Benzoimidazol-2-ylimino)-methyl]-benzene-1,3-diol.

    Science.gov (United States)

    El-wakiel, Nadia; El-keiy, Mai; Gaber, Mohamed

    2015-08-05

    A new Schiff base of 2-aminobenzimidazole with 2,4-dihydroybezaldehyde (H₃L), and its Cu(II), Ni(II) and Co(II) complexes have been synthesized and characterized by elemental analyses, molar conductance, thermal analysis (TGA), inductive coupled plasma (ICP), magnetic moment measurements, IR, EI-mass, UV-Vis. and ESR spectral studies. On the basis of spectral studies and analytical data, it is evident that the Schiff base acts as dibasic tridentate ligand coordinating via deprotonated OH, NH and azomethine nitrogen atom. The results showed that Co(II) and Ni(II) complexes have tetrahedral structure while Cu(II) complexes has octahedral geometry. The kinetic and thermodynamic parameters of the thermal decomposition stages have been evaluated. The studied complexes were tested for their in vitro antimicrobial activities against some bacterial strains. The anticancer activity of the ligand and its metal complexes is evaluated against human liver Carcinoma (HEPG2) cell. These compounds exhibited a moderate and weak activity against the tested HEPG2 cell lines with IC₅₀ of 9.08, 18.2 and 19.7 μg/ml for ligand, Cu(II) and Ni(II) complexes, respectively. In vitro antioxidant activity of the newly synthesized compounds has also been evaluated. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: Synthesis, spectral characterization, antimicrobial and nuclease studies

    Science.gov (United States)

    Subbaraj, P.; Ramu, A.; Raman, N.; Dharmaraja, J.

    2014-01-01

    A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA = Schiff base and B = 2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, 1H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, 1H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique.

  11. A 28-day oral gavage toxicity study of 3-monochloropropane-1,2-diol (3-MCPD) in CB6F1-non-Tg rasH2 mice.

    Science.gov (United States)

    Lee, Byoung-Seok; Park, Sang-Jin; Kim, Yong-Bum; Han, Ji-Seok; Jeong, Eun-Ju; Moon, Kyoung-Sik; Son, Hwa-Young

    2015-12-01

    3-Monochloro-1,2-propanediol (3-MCPD) is a well-known contaminant of foods containing hydrolyzed vegetable protein. However, limited toxicity data are available for the risk assessment of 3-MCPD and its carcinogenic potential is controversial. To evaluate the potential toxicity and determine the dose levels for a 26-week carcinogenicity test using Tg rasH2 mice, 3-MCPD was administered once daily by oral gavage at doses of 0, 25, 50, and 100 mg/kg body weight (b.w.)/day for 28 days to male and female CB6F1-non-Tg rasH2 mice (N = 5 males and females per dose). The standard toxicological evaluations were conducted during the in-life and post-mortem phase. In the 100 mg/kg b.w./day group, 3 males and 1 female died during the study and showed clinical signs such as thin appearance and subdued behavior accompanied by significant decreases in mean b.w. Microscopy revealed tubular basophilia in the kidneys, exfoliated degenerative germ cells in the lumen of the seminiferous tubule of the testes, vacuolation in the brain, axonal degeneration of the sciatic nerve, and cardiomyopathy in the 100, ≥25, ≥50, 100, and 100 mg/kg b.w./day groups, respectively. In conclusion, 3-MCPD's target organs were the kidneys, testes, brain, sciatic nerve, and heart. The "no-observed-adverse-effect level" (NOAEL) of 3-MCPD was ≤25 and 25 mg/kg b.w./day in males and females, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Co-crystal of (R,R)-1,2-cyclohexanediol with (R,R)-tartaric acid, a key structure in resolution of the ({+-})-trans-diol by supercritical extraction, and the related ternary phase system

    Energy Technology Data Exchange (ETDEWEB)

    Thorey, Paul [Department of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Bombicz, Petra [Institute of Structural Chemistry, Chemical Research Center, Hungarian Academy of Science, H-1525 Budapest (Hungary); Szilagyi, Imre Miklos [Material Structure and Modeling Research Group, Hungarian Academy of Sciences, H-1111 Budapest (Hungary); Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Molnar, Peter; Bansaghi, Gyoergy; Szekely, Edit; Simandi, Bela [Department of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Parkanyi, Laszlo [Institute of Structural Chemistry, Chemical Research Center, Hungarian Academy of Science, H-1525 Budapest (Hungary); Pokol, Gyoergy [Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Madarasz, Janos, E-mail: madarasz@mail.bme.hu [Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1521 Budapest (Hungary)

    2010-01-10

    A novel co-crystal of trans-(R,R)-1,2-cyclohexanediol and (R,R)-tartaric acid (with 1:1 molar ratio, 1) has been found to be a key crystalline compound in the improved resolution of ({+-})-trans-1,2-cyclohexanediol by supercritical fluid extraction. The molecular and crystal structure of this co-crystal, which crystallizes in orthorhombic crystal system (space group P2{sub 1}2{sub 1}2{sub 1}, a = 6.7033(13) A, b = 7.2643(16), c = 24.863(5), Z = 4), has been solved by single crystal X-ray diffraction (R = 0.064). The packing arrangement consists of two dimensional layers of sandwich-like sheets, where the inner part is constructed by double layers of tartaric acids which hydrophilicity is 'covered' on both upper and bottom side by cyclohexanediols with the hydrophobic cyclohexane rings pointing outward. Thus, a rather complex hydrogen bonding pattern is constructed. The relatively high melting point (133 {sup o}C) observed by both simultaneous TG/DTA and DSC, and the main features of FTIR-spectrum of 1 are explained by the increased stability of this crystal structure. DSC studies on binary mixtures of co-crystal 1 with (R,R)-1,2-cyclohexanediol or (R,R)-tartaric acid, revealed eutectic temperatures of T{sub eu} = 100 or 131 {sup o}C, respectively. Between (S,S)-1,2-cyclohexanediol and (R,R)-tartaric acid a eutectic temperature of T{sub eu} = 85 {sup o}C have also been observed. The phase relations have been confirmed by powder X-ray diffraction, as well.

  13. Probabilistic Networks

    DEFF Research Database (Denmark)

    Jensen, Finn Verner; Lauritzen, Steffen Lilholt

    2001-01-01

    This article describes the basic ideas and algorithms behind specification and inference in probabilistic networks based on directed acyclic graphs, undirected graphs, and chain graphs.......This article describes the basic ideas and algorithms behind specification and inference in probabilistic networks based on directed acyclic graphs, undirected graphs, and chain graphs....

  14. Ionizable polyethers as specific metal ion carriers in liquid-liquid extraction and liquid membrane separations

    International Nuclear Information System (INIS)

    Walkowiak, W.; Charewicz, W.A.; Bartsch, R.A.; Ndip, G.M.

    1988-01-01

    Consideration is given to results of investigations into competitive extraction and penetration through a liquid membrane of alkali and alkaline earth cations from aqueous solutions by a series of lipophilic and ionizable acyclic polyethers of various molecular structure. It is shown that specificity and selectiviy of cation carriers in liquid-liquid extraction and liquid membrane separation depend on molecular structure of acyclic polyethers

  15. A Combinatorial Formula for Certain Elements of Upper Cluster Algebras

    Science.gov (United States)

    Lee, Kyungyong; Li, Li; Mills, Matthew R.

    2015-06-01

    We develop an elementary formula for certain non-trivial elements of upper cluster algebras. These elements have positive coefficients. We show that when the cluster algebra is acyclic these elements form a basis. Using this formula, we show that each non-acyclic skew-symmetric cluster algebra of rank 3 is properly contained in its upper cluster algebra.

  16. Biotransformation of (-)-dihydromyrcenyl acetate using the plant parasitic fungus Glomerella cingulata as a biocatalyst.

    Science.gov (United States)

    Miyazawa, M; Akazawa, S i; Sakai, H; Nankai, H

    2000-10-01

    The microbial transformation of (-)-dihydromyrcenyl acetate was investigated using the plant parasitic fungus Glomerella cingulata. As a result, (-)-dihydromyrcenyl acetate was converted to dihydromyrcenol, 3,7-dihydroxy-3,7-dimethyl-1-octene-7-carboxylate, 3,7-dihydroxy-3,7-dimethyl-1-octene, 3,7-dimethyloctane-1,2, 7-triol-7-carboxylate, and 3,7-dimethyloctane-1,2,7-triol. In addition, microbial transformation of dihydromyrcenol by G. cingulata was carried out. The metabolic pathway of (-)-dihydromyrcenyl acetate is discussed.

  17. Two new steroidal saponins from Tribulus terrestris L.

    Science.gov (United States)

    Liu, Tao; Lu, Xuan; Wu, Biao; Chen, Gang; Hua, Hui-Ming; Pei, Yue-Hu

    2010-01-01

    Two new steroidal saponins were isolated from the fruits of Tribulus terrestris L. Their structures were elucidated by spectroscopic and chemical analysis as (23S,24R,25R)-5alpha-spirostane-3beta,23,24-triol-3-O-{alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 4)]-beta-D-galactopyranoside} (1) and (23S,24R,25S)-5alpha-spirostane-3beta,23,24-triol-3-O-{alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 4)]-beta-D-galactopyranoside} (2).

  18. Furostanol saponins from the fruits of Tribulus terrestris.

    Science.gov (United States)

    Chen, Gang; Su, Lan; Feng, Sheng-Guang; Lu, Xuan; Wang, Haifeng; Pei, Yue-Hu

    2013-01-01

    Two new steroidal saponins were isolated from the fruits of Tribulus terrestris. Their structures were assigned by spectroscopic analysis and colour reaction as 26-O-β-D-glucopyranosyl-(25R)-5α-furostane-12-one-3β,22α,26-triol-3-O-β-D-glucopyranosyl(1 → 4)-β-D-galactopyranoside (1); 26-O-β- D-glucopyranosyl-25(R)-5α-furostan-12-one-3β,22α,26-triol-3-O-α-L-rhamnopyranosyl-(1 → 2)-O-[β-D-glucopyranosyl-(1 → 4)]-β-D-galactopyranoside (2).

  19. H3O2-, O22- and O2•- bridging ligands in cobalt(III) complexes of an acyclic phenolate-hinged dinucleating ligand

    DEFF Research Database (Denmark)

    Ghiladi, Morten; Gomez, Jonnes T.; Hazell, A.

    2003-01-01

    The dicobalt(III) complex, [Co2(bpbp)(μ-H3O2)2](ClO4)3 (bpbp− = 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-tert-butylphenolate), obtained by reaction of cobalt(II) perchlorate with Hbpbp under ambient conditions contains two μ-H3O2− bridging ligands. The H-bonded O⋯O distances in this motif are 2...

  20. Can acyclic conformational control be achieved via a sulfur–fluorine gauche effect?† †Electronic supplementary information (ESI) available. CCDC 1048074–1048078. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5sc00871a

    Science.gov (United States)

    Thiehoff, C.; Holland, M. C.; Daniliuc, C.

    2015-01-01

    The gauche conformation of the 1,2-difluoroethane motif is known to involve stabilising hyperconjugative interactions between donor (bonding, σC–H) and acceptor (antibonding, σ*C–F) orbitals. This model rationalises the generic conformational preference of F–Cβ–Cα–X systems (φFCCX ≈ 60°), where X is an electron deficient substituent containing a Period 2 atom. Little is known about the corresponding Period 3 systems, such as sulfur and phosphorus, where multiple oxidation states are possible. Conformational analyses of β-fluorosulfides, -sulfoxides and -sulfones are disclosed here, thus extending the scope of the fluorine gauche effect to the 3rd Period (F–C–C–S(O)n; φFCCS ≈ 60°). Synergy between experiment and computation has revealed that the gauche effect is only pronounced in structures bearing an electropositive vicinal sulfur atom (S+–O–, SO2). PMID:29511517

  1. Synthesis, basicity and complex properties from A ZN (II) of a acyclic purazol and pyridine proton-ionizable new receptor; Sintesis, basicidad y propiedades complejantes frente a Zn(II) de un nuevo receptor aciclico de pirazol y piridina prton-ionizable

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, J.M.; Campayo, L.; Navarro, P.; Acerete, C. [Instituto de Quimica Medica CSIC, Madrid (Spain)

    1995-12-01

    The synthesis of bis (2`-pyridylmethil) N{sub 1}-H pyrazole 3,5-dicarboxylate 1[L] is reported. The formation of its sodium pyrazolate salt 1` [L] has been studied by ``13 CNMR, and the deprotonation pKa value of the pyrazole ring of 1 and those corresponding to the protonation of their pyridine rings have been measured using potentiometric methods in H{sub 2}O-MeOH (v/v 9:1) Starting from 1[L] or 1`[L-], the formation of mono- and di-nuclear complexes 2Zn[L] and 3[Zn{sub 2}[L-

  2. Synthesis, basicity and complexation properties versus Zn (II) of a new acyclic acceptor of proton-ionizing pyrazole and pyridine; Sintesis, basicidad y propiedades complejantes frente a Zn (II) de un nuevo receptor aciclico de pirazol y piridina proton-ionizable

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, J.M.; Campayo, L.; Navarro, P.; Acerete, C. [Instituto de Quimica Medica, CSIC (Spain)

    1995-12-31

    The synthesis of bis (2`-pyridyl methyl) N{sub 1}-H pyrazole 3,5-dicarboxylate 1[L] is reported. The formation of its sodium pyrazolate salt 1`[L] has been studied by ``13 CNMR, and the deprotonation pKa value of the pyrazole ring of 1 and those corresponding to the protonation of their pyridine rings have been measured using potentiometric methods in H{sub 2}O-MeOH (v/v 9:1) Starting from 1[L] or 1`[L-], the formation of mono- and dinuclear complexes 2 Zn[L] and 3[Zn]{sub 2}[L-]``3+ respectively has been studied. (Author) 17 refs.

  3. EFSA Panel on Food Contact Material, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 201Rev1: 2-Alkylated, aliphatic, acyclic alpha,beta-unsaturated aldehydes and precursors, with or without additional double-bonds, from chemical subgroup 1.1.2 of FGE.19

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    . The Panel therefore concluded that further data are required in order to clarify the genotoxic potential of this subgroup. The Panel considers the Comet assay with [FL-no: 05.095] as test material and performed on liver, blood and first site of contact, as a preferred option to further investigate.......177 and 09.931], for which it was concluded in the previous version of this FGE that the available data were insufficient to evaluate their genotoxicity. Secondly, the Panel considers that the mutagenicity hazard could not be cleared by the endpoints evaluated in the in vivo micronucleus assay submitted...

  4. Extent of intramolecular pi stacks in aqueous solution in mixed-ligand copper(II) complexes formed by heteroaromatic amines and the anticancer and antivirally active 9[2-(phosphonomethoxy)ethyl]guanine (PMEG). A comparison with related acyclic nucleotide analogues

    Czech Academy of Sciences Publication Activity Database

    Blindauer, C. A.; Sigel, A.; Operschall, B. P.; Griesser, R.; Holý, Antonín; Sigel, H.

    2016-01-01

    Roč. 103, Jan 8 (2016), s. 248-260 ISSN 0277-5387 Institutional support: RVO:61388963 Keywords : anticancer activity * antivirals * aromatic-ring stacking * isomeric equilibria * nucleotide analogues Subject RIV: CC - Organic Chemistry Impact factor: 1.926, year: 2016

  5. Metabolic activation and DNA binding of benzo(a)pyrene in cultured human bronchus

    DEFF Research Database (Denmark)

    Yang, Shen K.; Gelboin, Harry V.; Trump, Benjamin F.

    1977-01-01

    . The predominant metabolite formed by human bronchus from the (-)-trans-7,8-diol is found by high-pressure liquid chromatographic analysis to be the diol-epoxide r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahy-drobenzo(a)pyrene. The results suggest that this diol-epoxide is the major benzo(a)pyrene metabolite bound...

  6. Humanized Androgen Receptor Mice: A Genetic Model for Differential Response to Prostate Cancer Therapy

    Science.gov (United States)

    2012-07-01

    of T, DHT and its two principal metabolites 5a-androstane-3a,17bDiol (3aDiol) and 5a-androstane- 3b,17bDiol (3bDiol) were measured in extracts of 50 ll ...intact) or 100 ll (DHT-treated) of mouse serum by liquid chromatography tandem mass spectrometry (LC–MS/MS) (Harwood and Handels- man, 2009) as...is activated by adrenal androgens and progesterone. Mol. Endocrinol. 7, 1541–1550. David, C.J., Manley , J.L., 2010. Alternative pre-mRNA splicing

  7. Three New Multiflorane-Type Triterpenes from Pumpkin (Cucurbita maxima Seeds

    Directory of Open Access Journals (Sweden)

    Reiko Tanaka

    2013-05-01

    Full Text Available Three new multiflorane-type triterpenes; 7a-methoxymultiflor-8-ene-3a,29-diol 3-acetate-29-benzoate (1, 7-oxomultiflor-8-ene-3a,29-diol 3-acetate-29-benzoate (2, and multiflora-7,9(11-diene-3a,29-diol 3-p-hydroxybenzoate-29-benzoate (3, were isolated from seeds of Cucurbita maxima, along with three known compounds. Compound 3 and multiflora-7,9(11-diene-3a-29-diol 3-benzoate (5 exhibited potent inhibitory effects on melanogenesis, with low cytotoxicities, and 2 exhibited single-digit micromolar cytotoxicity against HL-60 and P388 cells.

  8. Three new multiflorane-type triterpenes from pumpkin (Cucurbita maxima) seeds.

    Science.gov (United States)

    Kikuchi, Takashi; Takebayashi, Mika; Shinto, Mayumi; Yamada, Takeshi; Tanaka, Reiko

    2013-05-14

    Three new multiflorane-type triterpenes; 7a-methoxymultiflor-8-ene-3a,29-diol 3-acetate-29-benzoate (1), 7-oxomultiflor-8-ene-3a,29-diol 3-acetate-29-benzoate (2), and multiflora-7,9(11)-diene-3a,29-diol 3-p-hydroxybenzoate-29-benzoate (3), were isolated from seeds of Cucurbita maxima, along with three known compounds. Compound 3 and multiflora-7,9(11)-diene-3a-29-diol 3-benzoate (5) exhibited potent inhibitory effects on melanogenesis, with low cytotoxicities, and 2 exhibited single-digit micromolar cytotoxicity against HL-60 and P388 cells.

  9. Biotransformation of alpha-bulnesene using a plant pathogenic fungus, Glomerella cingulata as a biocatalyst.

    Science.gov (United States)

    Miyazawa, Mitsuo; Sugawara, Atsushi

    2005-02-01

    The biotransformation of a sesquiterpene having a guaiane skeleton, namely (+)-alpha-bulnesene was investigated using the plant pathogenic fungus, Glomerella cingulata as a biocatalyst. (+)-alpha-Bulnesene was oxidized at the double bond of the isopropenyl group and hydroxylated at the allylic methyl group to (4S,5S,7R)-1(10)-guaien-11,13,15-triol.

  10. 7 dnei / Leta Gureli

    Index Scriptorium Estoniae

    Gureli, Leta

    1996-01-01

    Iz soderzh.: 21 sentjabrja 130 let so dnja rozhdenia Gerberta Dzhordzha Uellsa; 22 sentjabrja 105 let so dnja rozhdenia Ruvim Frajerman; 24 sentjabrja 100 let so dnja rozhdenia Frensisa Skotta Fidzheralda; 24 sentjabrja 100 let so dnja rozhdenia Elzõ Triole

  11. Rapid Diagnosis of 83 Patients with Niemann Pick Type C Disease and Related Cholesterol Transport Disorders by Cholestantriol Screening

    Directory of Open Access Journals (Sweden)

    Janine Reunert

    2016-02-01

    Full Text Available Niemann Pick type C (NP-C is a rare neurodegenerative disorder caused by an impairment of intracellular lipid transport. Due to the heterogeneous clinical phenotype and the lack of a reliable blood test, diagnosis and therapy are often delayed for years. In the cell, accumulating cholesterol leads to increased formation of oxysterols that can be used as a powerful screening parameter for NP-C. In a large scale study, we evaluated the oxysterol cholestane-3β,5α,6β-triol (c-triol as potential biomarker for a rapid diagnosis of NP-C. Using GC/MS, c-triol has been analyzed in 1902 plasma samples of patients with the suspicion for NP-C. Diagnosis in patients with elevated oxysterols was confirmed by genetic analysis. 71 new NP-C patients (69 NP-C1 and two NP-C2 and 12 Niemann Pick type A/B patients were identified. 24 new mutations in NPC1, one new mutation in NPC2 and three new mutations in the SMPD1 gene were found. Cholestane-3β,5α,6β-triol was elevated in Niemann Pick type C1, type C2, type A/B and in CESD disease. No other study has ever identified so many NP-C patients, proving that c-triol is a rapid and reliable biomarker to detect patients with NP-C disease and related cholesterol transport disorders. It should replace the filipin test as the first-line diagnostic assay.

  12. Proceedings of the International Pyrotechnics Seminar (6th) Held at Estes Park, Colorado, 17-21 July 1978

    Science.gov (United States)

    1978-06-01

    ethylene glycols , neopentyl - glycol , 1,6-hexane-diol, and similar diols. Polyesters are generally preferred over polyethers because they are able to retain...contribute to adequate processing, mech- anical properties, and ballistics. The CT polydiethylene glycol adipate i cured with the multifunctional ERL

  13. Preparation of eugenol-based polyurethane

    Science.gov (United States)

    Li, Yupeng; Luo, Fang; Cheng, Chuanjie

    2018-03-01

    The regenerative eugenol was used as the starting material to prepare diol species by two steps, with a total yield of 28%. Furthermore, the prepared diol reacts with 1,6-hexadiisocyanate(HDI) to afford the corresponding polyurethane (PU). The structure of intermediates and PU are characterized by 1H-NMR or IR.

  14. One-Pot Catalyst-Free Synthesis of β- and γ-Hydroxy Sulfides using Diaryliodonium Salts and Microwave Irradiation

    Science.gov (United States)

    A facile one-pot high-yield protocol is described for the preparation of β- and γ-hydroxy sulfides directly from diaryliodonium salts, potassium thiocyanate, and ethane-1,2-diol (ethylene glycol)/propane-1,3-diol (β-propylene glycol) without the need for any additional catalyst o...

  15. Isolation and Structure Elucidation of Radical Scavengers from Thymus vulgaris Leaves

    NARCIS (Netherlands)

    Dapkevicius, A.; Beek, van T.A.; Lelyveld, G.P.; Veldhuizen, van A.; Groot, de Æ.; Linssen, J.P.H.; Venskutonis, R.

    2002-01-01

    2,2-Diphenyl-1-picrylhydrazyl radical (DPPH*) scavenging activity-guided fractionation of a leaf extract of Thymus vulgaris led to the isolation of the radical scavengers rosmarinic acid 1, eriodictyol, taxifolin, luteolin 7-glucuronide, p-cymene 2,3-diol, p-cymene 2,3-diol 6-6'-dimer, carvacrol,

  16. Estudo fitoquímico da madeira de Guarea macrophylla (Meliaceae Phytochemical study of the wood from Guarea macrophylla (Meliaceae

    Directory of Open Access Journals (Sweden)

    João Henrique G. Lago

    2009-01-01

    Full Text Available In the present work, the crude ethanol extract from wood of G. macrophylla was submitted to liquid/liquid partition between hexane, CH2Cl2, EtOAc and n-BuOH. Each phase was individually chromatographed over silica gel, Sephadex LH-20 or Amberlite XAD-2 to give eight terpene derivatives, such as five sesquiterpenoids (caryophyllene oxide, guai-6-en-10β-ol, spathulenol, aromadendrane-4β,10α-diol and aloaromadendrane-4α,10β-diol as well as three triterpenoids (cicloart-24-ene-3β,23(R*-diol, cicloart-24-ene-3β,23(S*-diol, and cicloart-23E-ene-3β,25-diol. Additionally, were isolated three fatty acids (linolenic, linoleic and stearic, two steroids (sitosterol and stigmasterol and sacarose. The structures of all these compounds were characterized by spectrometric analysis, mainly mass spectrometry and NMR and comparison of these data described in the literature.

  17. Molecular orbital studies on the Wagner–Meerwein migration in ...

    Indian Academy of Sciences (India)

    Unknown

    volves a three-centred moiety in the cationic transition state. The migratory aptitude ... positive charge in the transition state. ... col–pinacolone rearrangement in acyclic systems, which is ...... of Higher and Technical Education, Government of.

  18. Arenethiolatecopper(I) complexes as homogeneous catalysts for Michael addition reactions

    NARCIS (Netherlands)

    Koten, G. van; Klaveren, M. van; Lambert, F.; Eijkelkamp, D.J.F.M.; Grove, D.M.

    1994-01-01

    Arenethiolatocopper(I) complexes are shown to be efficient homogeneous catalysts in Michael addition reactions of several Grignard reagents to acyclic enones; the addition products are formed with excellent chemoselectivity (>99%) and good enantioselectivity (76% e.e.).

  19. Structural and Pharmacological Effects of Ring-Closing Metathesis in Peptides

    Directory of Open Access Journals (Sweden)

    Pål Rongved

    2010-09-01

    Full Text Available Applications of ring-closing alkene metathesis (RCM in acyclic α- and β-peptides and closely related systems are reviewed, with a special emphasis on the structural and pharmacological effects of cyclization by RCM.

  20. Molecular orbital studies on the Wagner-Meerwein migration in ...

    Indian Academy of Sciences (India)

    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 ...

  1. Data-driven execution of fast multipole methods

    KAUST Repository

    Ltaief, Hatem; Yokota, Rio

    2013-01-01

    time-consuming stages of the FMMs into smaller tasks. The algorithm can then be represented as a directed acyclic graph where nodes represent tasks and edges represent dependencies among them. The execution of the algorithm is performed

  2. Direct Synthesis of Medium-Bridged Twisted Amides via a Transannular Cyclization Strategy

    Science.gov (United States)

    Szostak, Michal; Aubé, Jeffrey

    2009-01-01

    The sequential RCM to construct a challenging medium-sized ring followed by a transannular cyclization across a medium-sized ring delivers previously unattainable twisted amides from simple acyclic precursors. PMID:19708701

  3. Synthesis, estrogen receptor binding, and tissue distribution of a new iodovinylestradiol derivative (17{alpha},20E)-21-[{sup 123}I]iodo-11{beta}-nitrato-19-norpregna-1,3,5(10),20-te= traene-3,17 -diol (E-[{sup 123}I]NIVE)

    Energy Technology Data Exchange (ETDEWEB)

    Rijks, Leonie J.M.; Bos, Jan C. van den; Doremalen, Peter A.P.M. van; Boer, Gerard J.; Bruin, Kora de; Doornbos, Tamme; Vekemans, Jozef A.J.M.; Posthumus, Maarten A.; Janssen, Anton G.M.; Royen, Eric A. van

    1998-05-01

    We have synthesized and evaluated E-11{beta}-nitrato-17{alpha}-iodovinylestradiol (E-NIVE; E-3c) and its {sup 123}I-labelled form, as a new potential radioligand for imaging of estrogen receptor (ER)-positive human breast tumors. E-[{sup 123}I]NIVE was prepared by stereospecific iododestannylation of the E-tri-n-butylstannylvinyl precursor (E-2c), obtained from reaction of 11{beta}-nitrato-estrone (8) with E-tributylstannylvinyllithium. In competitive binding studies, E-NIVE proved to have high binding affinity for both the rat and the human ER (K{sub i} 280-730 pM), without significant binding to human sex hormone binding globulin. Distribution studies in normal and mammary tumor-bearing rats showed specific ER-mediated uptake of E-[{sup 123}I]NIVE in the estrogen target tissues, i.e., uterus, ovaries, pituitary, and hypothalamus, but not in the mammary tumors. Selective retention in these target tissues, including tumor tissue, resulted in significant increases over time for the target tissue-to-muscle uptake ratios, but not for the target tissue-to-fat uptake ratios. The tumor-to-fat uptake ratio even appeared constantly below 1. In the primary estrogen target tissues, E-[{sup 123}I]NIVE displayed high specific ER-mediated uptake and retention, which resulted in moderate target-to-nontarget tissue uptake ratios. In contrast, in tumor tissue, E-[{sup 123}I]NIVE uptake appeared to be rather low and not ER-specific. As a consequence, E-[{sup 123}I]NIVE appears to be a less favorable radioligand for ER imaging in breast cancer than the previously studied stereoisomers of 11{beta}-methoxy-17{alpha}-[{sup 123}I]iodovinylestradiol (E- and Z-[{sup 123}I]MIVE; [{sup 123}I]E- and [{sup 123}I]Z-3b)

  4. CCDC 1436512: Experimental Crystal Structure Determination : 1,9,12,20-tetrakis(Hexyloxy)-7,10,18,21-tetramesitylbenzo[5',10']anthra[2',3':5,6]-s-indaceno[1,2-b]benzo[fg]anthracene-6,17-diol

    KAUST Repository

    Hu, Pan; Lee, Sangsu; Seng, Herng Tun; Aratani, Naoki; Zheng, Bin; Yamada, Hiroko; Huang, Kuo-Wei; Ding, Jun; Kim, Dongho; Wu, Jishan

    2016-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  5. 10,21-Dimethyl-2,7,13,18-tetraphenyl-3,6,14,17-tetraazatricyclo[17.3.1.18,12]tetracosa-1(23,2,6,8(24,9,11,13,17,19,21-decaene-23,24-diol cyclohexane 0.33-solvate

    Directory of Open Access Journals (Sweden)

    Sushil K. Gupta

    2011-10-01

    Full Text Available The title compound, C46H40N4O2·0.33C6H12, was obtained unintentionally as a product of an attempted synthesis of a cadmium(II complex of the [2,6-{PhSe(CH22N=CPh}2C6H2(4-Me(OH] ligand. The full tetraiminodiphenol macrocyclic ligand is generated by the application of an inversion centre. The macrocyclic ligand features strong intramolecular O—H...N hydrogen bonds. The dihedral angles formed between the phenyl ring incorporated within the macrocycle and the peripheral phenyl rings are 82.99 (8 and 88.20 (8°. The cyclohexane solvent molecule lies about a site of overline{3} symmetry. Other solvent within the lattice was disordered and was treated with the SQUEEZE routine [Spek (2009. Acta Cryst. D65, 148–155].

  6. Synthesis, estrogen receptor binding, and tissue distribution of a new iodovinylestradiol derivative (17α,20E)-21-[123I]iodo-11β-nitrato-19-norpregna-1,3,5(10),20-tetraene-3,17 -diol (E-[123I]NIVE)

    International Nuclear Information System (INIS)

    Rijks, Leonie J.M.; Bos, Jan C. van den; Doremalen, Peter A.P.M. van; Boer, Gerard J.; Bruin, Kora de; Doornbos, Tamme; Vekemans, Jozef A.J.M.; Posthumus, Maarten A.; Janssen, Anton G.M.; Royen, Eric A. van

    1998-01-01

    We have synthesized and evaluated E-11β-nitrato-17α-iodovinylestradiol (E-NIVE; E-3c) and its 123 I-labelled form, as a new potential radioligand for imaging of estrogen receptor (ER)-positive human breast tumors. E-[ 123 I]NIVE was prepared by stereospecific iododestannylation of the E-tri-n-butylstannylvinyl precursor (E-2c), obtained from reaction of 11β-nitrato-estrone (8) with E-tributylstannylvinyllithium. In competitive binding studies, E-NIVE proved to have high binding affinity for both the rat and the human ER (K i 280-730 pM), without significant binding to human sex hormone binding globulin. Distribution studies in normal and mammary tumor-bearing rats showed specific ER-mediated uptake of E-[ 123 I]NIVE in the estrogen target tissues, i.e., uterus, ovaries, pituitary, and hypothalamus, but not in the mammary tumors. Selective retention in these target tissues, including tumor tissue, resulted in significant increases over time for the target tissue-to-muscle uptake ratios, but not for the target tissue-to-fat uptake ratios. The tumor-to-fat uptake ratio even appeared constantly below 1. In the primary estrogen target tissues, E-[ 123 I]NIVE displayed high specific ER-mediated uptake and retention, which resulted in moderate target-to-nontarget tissue uptake ratios. In contrast, in tumor tissue, E-[ 123 I]NIVE uptake appeared to be rather low and not ER-specific. As a consequence, E-[ 123 I]NIVE appears to be a less favorable radioligand for ER imaging in breast cancer than the previously studied stereoisomers of 11β-methoxy-17α-[ 123 I]iodovinylestradiol (E- and Z-[ 123 I]MIVE; [ 123 I]E- and [ 123 I]Z-3b).

  7. Molecular and biochemical biomarkers for diagnosis and therapy monitorization of Niemann-Pick type C patients.

    Science.gov (United States)

    Hammerschmidt, Tatiane Grazieli; de Oliveira Schmitt Ribas, Graziela; Saraiva-Pereira, Maria Luiza; Bonatto, Márcia Polese; Kessler, Rejane Gus; Souza, Fernanda Timm Seabra; Trapp, Franciele; Michelin-Tirelli, Kristiane; Burin, Maira Graeff; Giugliani, Roberto; Vargas, Carmen Regla

    2018-05-01

    Niemann-Pick type C (NP-C), one of 50 inherited lysosomal storage disorders, is caused by NPC protein impairment that leads to unesterified cholesterol accumulation in late endosomal/lysosomal compartments. The clinical manifestations of NP-C include hepatosplenomegaly, neurological and psychiatric symptoms. Current diagnosis for NP-C is based on observation of the accumulated cholesterol in fibroblasts of affected individuals, using an invasive and time expensive test, called Filipin staining. Lately, two metabolites that are markedly increased in NP-C patients are arising as biomarkers for this disease screening: 7-ketocholesterol and cholestane-3β,5α,6β-triol, both oxidized cholesterol products. In this work, we aimed to evaluate the performance of cholestane-3β,5α,6β-triol analysis for the screening and monitoring of NPC patients, correlating it with chitotriosidase levels, Filipin staining and molecular analysis. It was investigated 76 non-treated individuals with NP-C suspicion and also 7 patients with previous NP-C diagnosis under treatment with miglustat, in order to verify the cholestane-3β,5α,6β-triol value as a tool for therapy monitoring. Considering molecular assay as golden standard, it was verified that cholestane-3β,5α,6β-triol analysis presented 88% of sensitivity, 96.08% of specificity, a positive and negative predictive value calculated in 91.67% and 94.23%, respectively, for the diagnosis of NP-C. Chitotriosidase levels were increased in patients with positive molecular analysis for NP-C. For Filipin staining, it was found 1 false positive, 7 false negative and 24 inconclusive cases, showing that this assay has important limitations for NP-C diagnosis. Besides, we found a significant decrease in cholestane-3β,5α,6β-triol concentrations in NP-C patients under therapy with miglustat when compared to non-treated patients. Taken together, the present data show that cholestane-3β,5α,6β-triol analysis has a high potential to be an

  8. New steroidal glycosides from Tribulus terrestris L.

    Science.gov (United States)

    Chen, Gang; Liu, Tao; Lu, Xuan; Wang, Hai-Feng; Hua, Hui-Ming; Pei, Yue-Hu

    2012-01-01

    Two new steroidal glycosides were isolated from Tribulus terrestris L. Their structures were elucidated as 26-O-β-D-glucopyranosyl-5α-furostan-12-one-20(22)-ene-3β,23,26-triol-3-O-β-D-xylopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl-(1 → 4)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-galactopyranoside (1) and 26-O-β-D-glucopyranosyl-5α-furostan-20(22)-ene-3β,23,26-triol-3-O-β-D-xylopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl-(1 → 4)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-galactopyranoside (2) by spectroscopic methods including 1D and 2D NMR experiments.

  9. Development of a Tetrathioether (S4) Bifunctional Chelate System for Rh-105

    Science.gov (United States)

    2013-07-01

    olt s...500 0 500 1000 1500 mV olt s -500 0 500 1000 1500 (B) Free Rhodium Chloride Minutes 0 2 4 6 8 10 12 mV olt s 0 2000 4000 mV olt s 0 2000 4000 (C) Rh-S4...Diol prepared in water Minutes 0 2 4 6 8 10 12 mV olts 0 2000 4000 mV olts 0 2000 4000 (D) 105 Rh-S4Diol with cold [Rh-S4(OH)2-Diol] +

  10. Carbohydrate-based Polyurethanes and Polyamides: Synthesis, Characterization and Stereocomplex Formation

    OpenAIRE

    Marín Bernabé, Romina

    2009-01-01

    Esta tesis doctoral está dirigida al desarrollo de poliuretanos a partir de dioles derivados de carbohidratos. Los poliuretanos son polímeros muy versátiles que pueden ser usados en una amplia variedad de aplicaciones que van desde espumas de relleno a artículos técnicos. Actualmente, existe un interés creciente por parte de la industria del poliuretano en la incorporación de productos procedentes de fuentes renovables. Dioles derivados de grasas naturales y aceites así como otros dioles d...

  11. Preparation of 6,6,1',1',6',6'-hexadeutero sucrose.

    Science.gov (United States)

    Gouy, Marie-Hélène; Danel, Mathieu; Gayral, Maud; Bouchu, Alain; Queneau, Yves

    2007-11-05

    The preparation of 6,6,1',1',6',6'-hexadeutero sucrose is reported. The synthesis is based on a triple oxidation of a protected sucrose 6,1',6'-triol to the corresponding 6,1',6'-tricarboxylic acid or ester, followed by reduction with lithium aluminium deuteride. This triple oxidation could be achieved either using cat. TEMPO-NaOCl (to the acid) or PDC-Ac(2)O-t-BuOH (to the t-butyl carboxylic ester).

  12. Application of a new tandem isomerization-aldolization reaction of allylic alcohols to the synthesis of three diastereoisomers of (2R)-1,2-O-isopropylidene-4-methylpentane-1,2,3,5-tetraol.

    Science.gov (United States)

    Cuperly, David; Crévisy, Christophe; Grée, René

    2003-08-08

    The tandem isomerization-aldolization reaction of (2R)-1,2-O-isopropylidene-4-penten-1,2,3-triol 3 and formaldehyde gives a mixture of two aldol products 2a and 2b. The stereoselective reduction of each compound by l-Selectride affords two diastereoisomers of (2R)-1,2-O-Isopropylidene-4-methylpentane-1,2,3,5-tetraol while a third diastereoisomer is obtained by stereoselective reduction with Me(4)NHB(OAc)(3).

  13. A new simple and rapid LC-ESI-MS/MS method for quantification of plasma oxysterols as dimethylaminobutyrate esters. Its successful use for the diagnosis of Niemann-Pick type C disease.

    Science.gov (United States)

    Boenzi, Sara; Deodato, Federica; Taurisano, Roberta; Martinelli, Diego; Verrigni, Daniela; Carrozzo, Rosalba; Bertini, Enrico; Pastore, Anna; Dionisi-Vici, Carlo; Johnson, David W

    2014-11-01

    Two oxysterols, cholestan-3β,5α,6β-triol (C-triol) and 7-ketocholesterol (7-KC), have been recently proposed as diagnostic markers of Niemann-Pick type C (NP-C) disease, representing a potential alternative diagnostic tool to the more invasive and time consuming filipin test in cultured fibroblasts. Usually, the oxysterols are detected and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using atmospheric pressure chemical ionization (APCI) or electro-spray-ionization (ESI) sources, after a variety of derivatization procedures to enhance sensitivity. We developed a sensitive LC-MS/MS method to quantify the oxysterols in plasma as dimethylaminobutyrate ester, suitable for ESI analysis. This method, with an easy liquid-phase extraction and a short derivatization procedure, has been validated to demonstrate specificity, linearity, recovery, lowest limit of quantification, accuracy and precision. The assay was linear over a concentration range of 0.5-200ng/mL for C-triol and 1.0-200ng/mL for 7-KC. Intra-day and inter-day coefficients of variation (CV%) were <15% for both metabolites. Receiver operating characteristic analysis estimates that the area under curve was 0.998 for C-triol, and 0.972 for 7-KC, implying a significant discriminatory power for the method in this patient population of both oxysterols. In summary, our method provides a simple, rapid and non-invasive diagnostic tool for the biochemical diagnosis of NP-C disease. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Chemical communication in tilapia: a comparison of Oreochromis mossambicus with O. niloticus.

    Science.gov (United States)

    Hubbard, Peter C; Mota, Vasco C; Keller-Costa, Tina; da Silva, José Paulo; Canário, Adelino V M

    2014-10-01

    In allopatric speciation species differentiation generally results from different selective pressures in different environments, and identifying the traits responsible helps to understand the isolation mechanism(s) involved. Male Mozambique tilapia (Oreochromis mossambicus) use urine to signal dominance; furthermore, 5β-pregnane-3α,17,20β-triol-3α-glucuronide (and its α-epimer, 5β-pregnane-3α,17,20α-triol-3α-glucuronide), in their urine is a potent pheromone, the concentration of which is correlated with social status. The Nile tilapia (Oreochromisniloticus) is a close relative; species divergence probably resulted from geographical separation around 6 million years ago. This raises the question of whether the two species use similar urinary chemical cues during reproduction. The olfactory potency of urine, and crude extracts, from either species was assessed by the electro-olfactogram and the presence of the steroid glucuronides in urine from the Nile tilapia by liquid-chromatography/mass-spectrometry. Both species showed similar olfactory sensitivity to urine and respective extracts from either species, and similar sensitivity to the steroid glucuronides. 5β-Pregnan-3α,17α,20β-triol-3α-glucuronide was present at high concentrations (approaching 0.5mM) in urine from Nile tilapia, with 5β-pregnan-3α,17α,20α-triol-3α-glucuronide present at lower concentrations, similar to the Mozambique tilapia. Both species also had similar olfactory sensitivity to estradiol-3-glucuronide, a putative urinary cue from females. Together, these results support the idea that reproductive chemical cues have not been subjected to differing selective pressure. Whether these chemical cues have the same physiological and behavioural roles in O. niloticus as O. mossambicus remains to be investigated. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Structural and Sensory Characterization of Bitter Tasting Steroidal Saponins from Asparagus Spears (Asparagus officinalis L.).

    Science.gov (United States)

    Dawid, Corinna; Hofmann, Thomas

    2012-12-05

    Application of sequential solvent extraction and iterative chromatographic separation in combination with taste dilution analysis recently revealed a series of steroidal saponins as the key contributors to the typical bitter taste of white asparagus spears (Asparagus officinalis L.). Besides six previously reported saponins, (25R)-furost-5-en-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, (25R)-furostane-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, and (25S)-furostane-3β,22,26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside]-26-O-β-D-glucopyranoside, and 3-O-[{α-L-rhamnopyranosyl-(1→2)}{α-L-rhamnopyranosyl-(1→4)}-β-D-glucopyranosyl]-(25S)-spirost-5-ene-3β-ol were identified for the first time as key bitter compounds in the edible spears of white asparagus by means of LC-MS/MS, LC-TOF-MS, 1D/2D-NMR spectroscopy, and hydrolysis experiments. This paper presents the isolation, structure determination, and sensory activity of these saponins. Depending on their chemical structure, the saponins identified showed human bitter recognition thresholds between 10.9 and 199.7 μmol/L (water).

  16. Kinetics and mechanism of the oxidation of some vicinal and non ...

    Indian Academy of Sciences (India)

    Unknown

    2.1 Materials. The diols and monoethers used were commercial products (BDH or Fluka) and were ..... charge separation takes place in the transition state of the reaction. ... The following mechanism (scheme 1) accounts for the observed data.

  17. Three new triterpene esters from pumpkin (Cucurbita maxima) seeds.

    Science.gov (United States)

    Kikuchi, Takashi; Ueda, Shinsuke; Kanazawa, Jokaku; Naoe, Hiroki; Yamada, Takeshi; Tanaka, Reiko

    2014-04-16

    Three new multiflorane-type triterpene esters, i.e. 7α-hydroxymultiflor-8-ene-3α,29-diol 3-acetate-29-benzoate (1), 7α-methoxymultiflor-8-ene-3α,29-diol 3,29-dibenzoate (2), and 7β-methoxymultiflor-8-ene-3α,29-diol 3,29-dibenzoate (3), were isolated from seeds of Cucurbita maxima, along with the known compound, multiflora-7,9(11)-diene-3α,29-diol 3,29-dibenzoate (4). Compound 1 exhibited melanogenesis inhibitory activities comparable with those of arbutin. In cytotoxicity assays, compounds 1 and 3 exhibited weak cytotoxicity, with IC50 values of 34.5-93.7 μM against HL-60 and P388 cells.

  18. Three New Triterpene Esters from Pumpkin (Cucurbita maxima Seeds

    Directory of Open Access Journals (Sweden)

    Takashi Kikuchi

    2014-04-01

    Full Text Available Three new multiflorane-type triterpene esters, i.e. 7α-hydroxymultiflor-8-ene-3α,29-diol 3-acetate-29-benzoate (1, 7α-methoxymultiflor-8-ene-3α,29-diol 3,29-dibenzoate (2, and 7β-methoxymultiflor-8-ene-3α,29-diol 3,29-dibenzoate (3, were isolated from seeds of Cucurbita maxima, along with the known compound, multiflora-7,9(11-diene-3α,29-diol 3,29-dibenzoate (4. Compound 1 exhibited melanogenesis inhibitory activities comparable with those of arbutin. In cytotoxicity assays, compounds 1 and 3 exhibited weak cytotoxicity, with IC50 values of 34.5–93.7 μM against HL-60 and P388 cells.

  19. Comparative Structural Analysis of ERa and ERb Bound to Selective Estrogen Agonists and Antagonists

    National Research Council Canada - National Science Library

    Greene, Geoffrey

    2001-01-01

    ...) complexed with receptor-selective estrogens and antiestrogens (SERMs) The crystallographic structures of ERalpha and ERbeta ligand binding domains complexed with cis-R,R-diethyl-tetrahydrochrysene-2,8-diol (R,R-THC...

  20. Comparative Structural Analysis of ERa and ERb Bound to Selective Estrogen Agonists and Antagonists

    National Research Council Canada - National Science Library

    Greene, Geoggrey

    2000-01-01

    ...) complexed with receptor-selective estrogens and antiestrogens (SERMs). The crystallographic structures of ERalpha and ERbeta ligand binding domains complexed with cis- R,R-diethyl-tetrahydrochrysene-2, 8 -diol (R,R-THC...