Synthesis of [diene-"1"4C] curcumin at high specific activity

International Nuclear Information System (INIS)

Filer, Crist N.; Lacy, James M.; Wright, Christopher

2016-01-01

An efficient method is described to label curcumin with "1"4C at high specific activity. - Highlights: • This paper describes the synthesis of ["1"4C] Curcumin at the highest specific activity and total activity amount yet reported. • The "1"4C label was installed in the diene framework of Curcumin. • This paper also describes the characterization of ["1"4C] Curcumin by HPLC and mass spectrometry.

Copper-Catalyzed Heteroarylboration of 1,3-Dienes with 3-Bromopyridines: A cine Substitution.

Science.gov (United States)

Smith, Kevin B; Huang, Yuan; Brown, M Kevin

2018-04-26

A method for the heteroarylboration of 1,3-dienes is presented. The process involves an unusual cine substitution of 3-bromopyridine derivatives to deliver highly functionalized heterocyclic products. Mechanistic studies are included that clarify the details of this unusual process. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dien Hoetink. 'Bij benadering'. Biografie van een landbouw-juriste in crisis- en oorlogstijd

NARCIS (Netherlands)

Kamp, van J.E.

2005-01-01

A woman with a university degree who makes a career outside of the home was rather exceptional in the first half of the twentieth century. This biography about Dien Hoetink (1904-1945) describes her legal work in Dutch agriculture between 1933 and 1945.It attemps to answer the

Dienes AEM as an alternative mathematics teaching aid to enhance Indonesian students’ understanding of algebra concept

Science.gov (United States)

Soro, S.; Maarif, S.; Kurniawan, Y.; Raditya, A.

2018-01-01

The aim of this study is to find out the effect of Dienes AEM (Algebra Experience Materials) on the ability of understanding concept of algebra on the senior high school student in Indonesia. This research is an experimental research with subject of all high school students in Indonesia. The samples taken were high school students in three provinces namely DKI Jakarta Province, West Java Province and Banten Province. From each province was taken senior high school namely SMA N 9 Bekasi West Java, SMA N 94 Jakarta and SMA N 5 Tangerang, Banten. The number of samples in this study was 114 high school students of tenth grade as experimental class and 115 high school students of tenth grade as control class. Learning algebra concept is needed in learning mathematics, besides it is needed especially to educate students to be able to think logically, systematically, critically, analytically, creatively, and cooperation. Therefore in this research will be developed an effective algebra learning by using Dienes AEM. The result of this research is that there is a significant influence on the students’ concept comprehension ability taught by using Dienes AEM learning as an alternative to instill the concept of algebra compared to the students taught by conventional learning. Besides, the students’ learning motivation increases because students can construct the concept of algebra with props.

A kinetics and mechanistic study of the OH and NO₂ initiated oxidation of cyclohexa-1,3-diene in the gas phase

DEFF Research Database (Denmark)

Jenkin, M. E.; Andersen, Mads Peter Sulbæk; Hurley, M. D.

2005-01-01

The kinetics and products of the OH and NO2-initiated oxidation of cyclohexa-1,3-diene have been investigated at 296 K and 700 Torr using long path FTIR spectroscopy. Relative rate methods were employed using the photolysis of cyclohexa-1,3-diene/CH3ONO/NO/air mixtures to measure k(OH + cyclohexa...

Classical Example of Total Kinetic and Thermodynamic Control: The Diels-Alder Reaction between DMAD and Bis-furyl Dienes.

Science.gov (United States)

Borisova, Kseniya K; Kvyatkovskaya, Elizaveta A; Nikitina, Eugeniya V; Aysin, Rinat R; Novikov, Roman A; Zubkov, Fedor I

2018-04-20

A rare example of chemospecificity in the tandem Diels-Alder reaction of activated alkynes and bis-dienes has been revealed. The reaction between bis-furyl dienes and DMAD occurs at 25-80 °C and leads to kinetically controlled "pincer" adducts, 4a,8a-disubstituted 1,4:5,8-diepoxynaphthalenes. On the contrary, only thermodynamically controlled "domino" adducts (2,3-disubstituted 1,4:5,8-diepoxynaphthalenes) are formed in the same reaction at 140 °C. The "pincer" adducts can be transformed to the "domino" adducts at heating. The rate constants for reactions of both types were calculated using dynamic 1 H NMR spectroscopy.

Nickel-catalyzed cyclization of alpha, omega-dienes: formation vs. cleavage of C-C bonds

Czech Academy of Sciences Publication Activity Database

Nečas, D.; Turský, M.; Tišlerová, I.; Kotora, Martin

2006-01-01

Roč. 30, č. 4 (2006), s. 671-674 ISSN 1144-0546 R&D Projects: GA MŠk 1M0508; GA ČR GD203/03/H140 Institutional research plan: CEZ:AV0Z40550506 Keywords : catalysis * nickel * cyclization * diene * cyclopentane Subject RIV: CC - Organic Chemistry Impact factor: 2.647, year: 2006

Assessment of the role of in situ generated (E)-2,4-diene-valproic acid in the toxicity of valproic acid and (E)-2-ene-valproic acid in sandwich-cultured rat hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Surendradoss, Jayakumar; Chang, Thomas K.H.; Abbott, Frank S., E-mail: frank.abbott@ubc.ca

2012-11-01

Valproic acid (VPA) undergoes cytochrome P450-mediated desaturation to form 4-ene-VPA, which subsequently yields (E)-2,4-diene-VPA by β-oxidation. Another biotransformation pathway involves β-oxidation of VPA to form (E)-2-ene-VPA, which also generates (E)-2,4-diene-VPA by cytochrome P450-mediated desaturation. Although the synthetic form of (E)-2,4-diene-VPA is more hepatotoxic than VPA as shown in various experimental models, there is no conclusive evidence to implicate the in situ generated (E)-2,4-diene-VPA in VPA hepatotoxicity. The present study investigated the effects of modulating the in situ formation of (E)-2,4-diene-VPA on markers of oxidative stress (formation of 2′,7′-dichlorofluorescein; DCF), steatosis (accumulation of BODIPY 558/568 C{sub 12}), necrosis (release of lactate dehydrogenase; LDH), and on cellular total glutathione (GSH) levels in sandwich-cultured rat hepatocytes treated with VPA or (E)-2-ene-VPA. Treatment with either of these chemicals alone increased each of the toxicity endpoints. In VPA-treated hepatocytes, (E)-2,4-diene-VPA was detected only at trace levels, even after phenobarbital (PB) pretreatment and there was no effect on the toxicity of VPA. Furthermore, pretreatment with a cytochrome P450 enzyme inhibitor, 1-aminobenzotriazole (1-ABT), did not influence the extent of VPA toxicity in both PB-pretreated and vehicle-pretreated hepatocytes. However, in (E)-2-ene-VPA-treated hepatocytes, PB pretreatment greatly enhanced the levels of (E)-2,4-diene-VPA and this was accompanied by a further enhancement of the effects of (E)-2-ene-VPA on DCF formation, BODIPY accumulation, LDH release, and GSH depletion. Pretreatment with 1-ABT reduced the concentrations of (E)-2,4-diene-VPA and the extent of (E)-2-ene-VPA toxicity; however, this occurred in PB-pretreated hepatocytes, but not in control hepatocytes. In conclusion, in situ generated (E)-2,4-diene-VPA is not responsible for the hepatocyte toxicity of VPA, whereas it

Effect of lanthanide contraction on the mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien): Syntheses and characterizations of lanthanide complexes with a tetraelenidoantimonate ligand

International Nuclear Information System (INIS)

Zhao Jing; Liang Jingjing; Pan Yingli; Zhang Yong; Jia Dingxian

2011-01-01

Mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) (Ln=lanthanide, en=ethylenediamine, dien=diethylenetriamine, trien=triethylenetetramine) were investigated under solvothermal conditions, and novel mixed-coordinated lanthanide(III) complexes [Ln(en) 2 (dien)(η 2 -SbSe 4 )] (Ln=Ce(1a), Nd(1b)), [Ln(en) 2 (dien)(SbSe 4 )] (Ln=Sm(2a), Gd(2b), Dy(2c)), [Ln(en)(trien)(μ-η 1 ,η 2 -SbSe 4 )] ∞ (Ln=Ce(3a), Nd(3b)) and [Sm(en)(trien)(η 2 -SbSe 4 )] (4a) were prepared. Two structural types of lanthanide selenidoantimonates were obtained across the lanthanide series in both en+dien and en+trien systems. The tetrahedral anion [SbSe 4 ] 3- acts as a monodentate ligand mono-SbSe 4 , a bidentate chelating ligand η 2 -SbSe 4 or a tridentate bridging ligand μ-η 1 ,η 2 -SbSe 4 to the lanthanide(III) center depending on the Ln 3+ ions and the mixed ethylene polyamines, indicating the effect of lanthanide contraction on the structures of the lanthanide(III) selenidoantimonates. The lanthanide selenidoantimonates exhibit semiconducting properties with E g between 2.08 and 2.51 eV. - Graphical Abstract: Two structural types of lanthanide(III) selenidoantimonates are formed in both en-dien and en-trien mixed polyamines across lanthanide series, indicating the lanthanide contraction effect on the structures of the lanthanide(III) selenidoantimonates. Highlights: → Two structural types of lanthanide selenidoantimonates are prepared across the lanthanide series in both Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) systems. → The [SbSe 4 ] 3- anion acts as a mono-SbSe 4 , a η 2 -SbSe 4 or a μ-η 1 ,η 2 -SbSe 4 ligand to the Ln 3+ ions. → The soft base ligand [SbSe 4 ] 3- can be controlled to coordinate to the Ln 3+ ions with en+dien and en+trien as co-ligands.

Method for upgrading diene-containing hydrocarbon mixtures

Energy Technology Data Exchange (ETDEWEB)

Kidwell, L.E. Jr.; Holcomb, D.E.

1984-05-22

There is disclosed a method for upgrading of hydrocarbon mixtures, so as to reduce their content of gum precursors such as diolefins and pseudo-diolefins, and provide a resulting product mixture suitable for mild hydrogenation, for use as a motor fuel or as a feed stock to an extraction unit. The process comprises obtaining a hydrocarbon mixture containing about 60-90 wt. % of aromatic components, about 3-40 wt. % of dienes and pseudodienes, and monoolefins, and up to about 6 wt. % of relatively unreactive organic compounds, reacting this mixture with elemental sulfur in the approximate weight ratio of about 5-95 wt. % of the hydrocarbon mixture with about 95-5 wt. % of elemental sulfur, the reaction being carried out at a temperature in the range of 100/sup 0/-150/sup 0/ C. for about 10 minutes to 24 hours with good mixing, removing the unreacted materials by distillation and separating a sulfur-hydrocarbon reaction product to provide the upgraded hydrocarbon mixture.

FEMA expert panel review of p-mentha-1,8-dien-7-al genotoxicity testing results

NARCIS (Netherlands)

Cohen, Samuel M.; Fukushima, Shoji; Gooderham, Nigel J.; Guengerich, F.P.; Hecht, Stephen S.; Rietjens, Ivonne M.C.M.; Smith, Robert L.; Bastaki, Maria; Harman, Christie L.; McGowen, Margaret M.; Taylor, Sean V.

2016-01-01

p-Mentha-1,8-dien-7-al is a naturally occurring cyclic alpha,beta-unsaturated aldehyde that is used as a flavoring substance throughout the world. Due to the chemical structure and the potential DNA reactivity of the alpha,beta-unsaturated carbonyl moiety, a battery of genotoxicity assays was

Oxidative cycloaddition of hydroxamic acids with dienes or guaiacols mediated by iodine(III) reagents.

Science.gov (United States)

Shimizu, Hisato; Yoshimura, Akira; Noguchi, Keiichi; Nemykin, Victor N; Zhdankin, Viktor V; Saito, Akio

2018-01-01

[Bis(trifluoroacetoxy)iodo]benzene (BTI) and (diacetoxyiodo)benzene (DIB) efficiently promote the formation of acylnitroso species from hydroxamic acids in the presence of various dienes to give the corresponding hetero-Diels-Alder (HDA) adducts in moderate to high yields. The present method could be applied to the HDA reactions of acylnitroso species with o -benzoquinones generated by the oxidative dearomatization of guaiacols.

Effect of three 2-allyl-p-mentha-6,8-dien-2-ols on inhibition of mild steel corrosion in 1 M HCl

Directory of Open Access Journals (Sweden)

S. Kharchouf

2014-11-01

Full Text Available 2-Allyl-p-mentha-6,8-dien-2-ols P1−P3 synthesized from carvone P are tested as corrosion inhibitors of steel in 1 M HCl using weight loss measurements, potentiodynamic polarisation and impedance spectroscopy (EIS methods. The addition of 2-allyl-p-mentha-6,8-dien-2-ols reduced the corrosion rate. Potentiodynamic polarisation studies clearly reveal that the presence of inhibitors does not change the mechanism of hydrogen evolution and that they act essentially as cathodic inhibitors. 2-Allyl-p-mentha-6,8-dien-2-ols tested adsorb on the steel surface according to Langmuir isotherm. From the adsorption isotherm some thermodynamic data for the adsorption process are calculated and discussed. EIS measurements show the increase of the charge-transfer resistance with the inhibitor concentration. The highest inhibition efficiency (92% is obtained for P1 at 3 g/L. The corrosion rate decreases with the rise of temperature. The corresponding activation energies are determined.

Electrochemical oxidation of cholesterol in acetonitrile leads to the formation of cholesta-4,6-dien-3-one

International Nuclear Information System (INIS)

Hosokawa, Yu-Ya; Hakamata, Hideki; Murakami, Tomonori; Aoyagi, Sakae; Kuroda, Minpei; Mimaki, Yoshihiro; Ito, Ayumi; Morosawa, Sayaka; Kusu, Fumiyo

2009-01-01

Cholesterol was shown to be oxidized at the glassy carbon electrode in an acetonitrile-2-propanol mixture and this oxidation reaction was applied to the determination of serum total cholesterol by high-performance liquid chromatography with electrochemical detection (K. Hojo, H. Hakamata, A. Ito, A. Kotani, C. Furukawa, Y.Y. Hosokawa, F. Kusu, J. Chromatogr. A 1166 (2007) 135-141). To gain insight into the detection mechanisms of cholesterol, an electrolytic product of cholesterol was collected and characterized by infrared spectroscopy, one- and two-dimensional nuclear magnetic resonance, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The three techniques, together with comparisons of literature spectral data, confirmed the formation of cholesta-4,6-dien-3-one. The conversion of cholesterol to cholesta-4,6-dien-3-one, a four-electron, four-proton electrochemical process, has been proposed as an electrochemical oxidation mechanism of cholesterol in acetonitrile.

Isolation of stigmast-5,24-dien-3-ol from marine brown algae Sargassum tenerrimum and its antipredatory activity

Digital Repository Service at National Institute of Oceanography (India)

Majik, M.S.; Adel, H.; Shirodkar, D.; Tilvi, S.; Furtado, J.

In recent years many sterols with potent biological activity have been identified from marine sources. Here we report the isolation of stigmast-5,24-dien-3-ol (fucosterol) as a major metabolite from the bioactive hexane-fraction of Sargassum...

The direct oxidative diene cyclization and related reactions in natural product synthesis

Directory of Open Access Journals (Sweden)

Juliane Adrian

2016-09-01

Full Text Available The direct oxidative cyclization of 1,5-dienes is a valuable synthetic method for the (diastereoselective preparation of substituted tetrahydrofurans. Closely related reactions start from 5,6-dihydroxy or 5-hydroxyalkenes to generate similar products in a mechanistically analogous manner. After a brief overview on the history of this group of transformations and a survey on mechanistic and stereochemical aspects, this review article provides a summary on applications in natural product synthesis. Moreover, current limitations and future directions in this area of chemistry are discussed.

Asymmetric aza-Diels-Alder reaction of Danishefsky's diene with imines in a chiral reaction medium

Directory of Open Access Journals (Sweden)

Pégot Bruce

2006-09-01

Full Text Available Abstract The asymmetric aza-Diels-Alder reaction of chiral imines with Danishefsky's diene in chiral ionic liquids provides the corresponding cycloadduct with moderate to high diastereoselectivity. The reaction has proved to perform better at room temperature in ionic liquids without either Lewis acid catalyst or organic solvent. Chiral ionic liquids are recycled while their efficiency is preserved.

Ruthenium-catalyzed intramolecular metathesis of dienes and its application in the synthesis of bridged and spiro azabicycles

Science.gov (United States)

Kuznetsov, N. Yu; Bubnov, Yu N.

2015-07-01

The review presents a historical excursion into catalytic alkene metathesis, covering the problems of history of the discovery of this process, as well as investigations on the properties, structure and reactivity of the most popular ruthenium catalysts for metathesis, mechanism of their action and decomposition. The main part covers studies devoted to the syntheses of bridged azabicyclic and 1-azaspirocyclic compounds comprising the intramolecular metathesis of dienes as the key step. The formation of a bicyclic skeleton of a series of natural bridged (cocaine, ferruginine, calystegines, and anatoxin-a) and spiro (pinnaic acids, halichlorine, hystrionicotoxin, and cephalotaxine) azabicycles, as well as their analogues and compounds with larger rings is demonstrated. The methods for the synthesis of diene precursors and the conditions for final assembling of the bicyclic compounds are considered in detail. The generalization of the literature data allows one to efficiently carry out the mentioned process taking into account the most important features. The bibliography includes 129 references.

Ruthenium-catalyzed intramolecular metathesis of dienes and its application in the synthesis of bridged and spiro azabicycles

International Nuclear Information System (INIS)

Kuznetsov, N Yu; Bubnov, Yu N

2015-01-01

The review presents a historical excursion into catalytic alkene metathesis, covering the problems of history of the discovery of this process, as well as investigations on the properties, structure and reactivity of the most popular ruthenium catalysts for metathesis, mechanism of their action and decomposition. The main part covers studies devoted to the syntheses of bridged azabicyclic and 1-azaspirocyclic compounds comprising the intramolecular metathesis of dienes as the key step. The formation of a bicyclic skeleton of a series of natural bridged (cocaine, ferruginine, calystegines, and anatoxin-a) and spiro (pinnaic acids, halichlorine, hystrionicotoxin, and cephalotaxine) azabicycles, as well as their analogues and compounds with larger rings is demonstrated. The methods for the synthesis of diene precursors and the conditions for final assembling of the bicyclic compounds are considered in detail. The generalization of the literature data allows one to efficiently carry out the mentioned process taking into account the most important features. The bibliography includes 129 references

A novel 3α-p-Nitrobenzoylmultiflora-7:9(11)-diene-29-benzoate and two new triterpenoids from the seeds of zucchini (Cucurbita pepo L).

Science.gov (United States)

Tanaka, Reiko; Kikuchi, Takashi; Nakasuji, Saori; Ue, Yasuhiro; Shuto, Daisuke; Igarashi, Keishi; Okada, Rina; Yamada, Takeshi

2013-06-26

Three novel multiflorane-type triterpenoids, 3α-p-nitrobenzoylmultiflora-7:9(11)-diene-29-benzoate (1), 3α-acetoxymultiflora-7:9(11)-diene-29-benzoate (2), and 3α-acetoxymultiflora-5(6):7:9(11)-triene-29-benzoate (3), along with two known related compounds 4 and 5 were isolated from the seeds of zucchini (Cucurbita pepo L). Their structures were determined on the basis of 1D and 2D NMR spectroscopy and HREIMS. Triterpenoids possessing a nitro group were not isolated previously.

Sulfonation of vulcanized ethylene-propylene-diene terpolymer membranes

International Nuclear Information System (INIS)

Barroso-Bujans, F.; Verdejo, R.; Lozano, A.; Fierro, J.L.G.; Lopez-Manchado, M.A.

2008-01-01

In the present work, sulfonation of previously vulcanized ethylene propylene diene terpolymer (EPDM) membranes was developed in a swelling solvent with acetyl sulfate. This procedure avoids the need to pre-dissolve the raw polymer. The reaction conditions were optimized in terms of solvent type, reaction time, acetyl sulfate concentration and film thickness to obtain the maximum degree of sulfonation of the polymer. The sulfonation procedure presented in this study yields a degree of sulfonation comparable to the chlorosulfonic acid procedure. Sulfonic acid groups were detected by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, and quantified by titrations. Proton conductivity and water uptake were measured by means of impedance spectroscopy and swelling measurements, respectively, and were correlated with the degree of sulfonation. Tensile strength and Young's modulus of sulfonated EPDM increased with the degree of sulfonation, while elongation at break remained constant. Thermal stability of the sulfonated EPDM was studied by simultaneous thermogravimetry-mass spectroscopy

Mechanism, reactivity, and selectivity of nickel-catalyzed [4 + 4 + 2] cycloadditions of dienes and alkynes.

Science.gov (United States)

Hong, Xin; Holte, Dane; Götz, Daniel C G; Baran, Phil S; Houk, K N

2014-12-19

Density functional theory (DFT) calculations with B3LYP and M06 functionals elucidated the reactivities of alkynes and Z/E selectivity of cyclodecatriene products in the Ni-catalyzed [4 + 4 + 2] cycloadditions of dienes and alkynes. The Ni-mediated oxidative cyclization of butadienes determines the Z/E selectivity. Only the oxidative cyclization of one s-cis to one s-trans butadiene is facile and exergonic, leading to the observed 1Z,4Z,8E-cyclodecatriene product. The same step with two s-cis or s-trans butadienes is either kinetically or thermodynamically unfavorable, and the 1Z,4E,8E- and 1Z,4Z,8Z-cyclodecatriene isomers are not observed in experiments. In addition, the competition between the desired cooligomerization and [2 + 2 + 2] cycloadditions of alkynes depends on the coordination of alkynes. With either electron-deficient alkynes or alkynes with free hydroxyl groups, the coordination of alkynes is stronger than that of dienes, and alkyne trimerization prevails. With alkyl-substituted alkynes, the generation of alkyne-coordinated nickel complex is much less favorable, and the [4 + 4 + 2] cycloaddition occurs.

Le carcinome parathyroïdien: à propos d’un cas et revue de la literature

Science.gov (United States)

kolsi, Naourez; Jellali, Sondos; Koubaa, Jamel

2017-01-01

Le carcinome parathyroïdien est une tumeur maligne, très rare, de la glande parathyroïde. Cliniquement, ce cancer se présente souvent par un tableau d'hyperparathyroïdie primaire sévère. Le diagnostic est histologique mais n'est pas toujours aisé. Le traitement est basé sur la chirurgie. Femme âgée de 59 ans, aux antécédents d'hypertension artérielle, et de lithiases rénales récidivantes, consultait pour des douleurs osseuses diffuses avec asthénie. L'examen du cou a trouvé une tuméfaction basi-cervicale dure et à bord inférieur non palpable. A la biologie: hypercalcémie à 4,1 mmol/l, une hyperparathyroïdie avec valeur de parathormone (PTH) très élevée à 1088 pg/ml soit 13 fois la normale. La scintigraphie au Technétium-99m-sestamibi a montré une plage de fixation anormale de MIBI en projection de la parathyroïde inférieure gauche. Une parathyroïdectomie inférieure gauche, avec évidement médiastino-récurrentiel homolatéral ont été réalisés. Les suites opératoires étaient marquées par la normalisation de la calcémie et de la PTH. L'anatomopathologie était en faveur d'un carcinome parathyroïdien. Le diagnostic de carcinome parathyroïdien est généralement établi sur la conjonction de signes radiologiques biologiques et histologiques. La gravité de cette pathologie est due à l'hypercalcémie sévère et au risque de récidive et de métastases à distance justifiant la surveillance prolongée. PMID:28819506

Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation

Directory of Open Access Journals (Sweden)

Mohamad Irfan Fathurrohman

2015-07-01

Full Text Available The vulcanization kinetics of Ethylene-propylene diene monomer (EPDM rubber thermal insulation was studied by using rheometer under isothermal condition at different temperatures. The rheometry analysis was used to determining the cure kinetic parameters and predicting the cure time of EPDM thermal insulation. The experimental results revealed that the curing curves of EPDM thermal insulation were marching and the optimum curing time decreased with increasing the temperature. The kinetic parameters were determined from the autocatalytic model showed close fitting with the experimental results, indicating suitability of autocatalytic model in characterizing the cure kinetics. The activation energy was determined from the autocatalytic model is 46.3661 kJ mol-1. The cure time were predicted from autocatalytic model and the obtained kinetic parameter by using the relationship among degree of conversion, cure temperature, and cure time. The predictions of cure time provide information for the actual curing characteristic of EPDM thermal insulation. The mechanical properties of EPDM thermal insulation with different vulcanization temperatures showed the same hardness, tensile strength and modulus at 300%, except at temperature 70 °C, while the elongation at breaking point decreased with increasing temperature of vulcanization. © 2015 BCREC UNDIP. All rights reservedReceived: 8th April 2014; Revised: 7th January 2015; Accepted: 16th January 2015How to Cite: Fathurrohman, M.I., Maspanger, D.R., Sutrisno, S. (2015. Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation. Bulletin of Chemi-cal Reaction Engineering & Catalysis, 10 (2, 104-110. (doi:10.9767/bcrec.10.2.6682.104-110Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.6682.104-110 

A Simple and Efficient Approach to the Synthesis of Endo and Exo Bicyclo[6.1.0]nona-3,5-diene-9-carboxaldehyde

Directory of Open Access Journals (Sweden)

Gholamreza Mashayekhi

2007-10-01

Full Text Available Monobromination of 1,5-cyclooctadiene, followed by cyclopropanation with ethyl diazoacetate, led to the formation of endo and exo ethyl 4,5-dibromobicyclo[6.1.0]nonane-9-carboxylates 3a and 3b. Bis-dehydrobromination of 3a and 3b using 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU afforded the endo and exo ethyl bicyclo[6.1.0]nona-3,5-diene-9-carboxylates 4a and 4b. Reduction of these compounds to the corresponding alcohols 5a and 5b and subsequent oxidation with pyridinium chlorochromate (PCC resulted in the formation of the target compounds endo and exo bicyclo[6.1.0]nona-3,5-diene-9-carboxaldehydes 6a and 6b.

Evaluation of some antioxidants in radiation vulcanized ethylene-propylene diene (EPDM) rubber

Energy Technology Data Exchange (ETDEWEB)

Abdel-Aziz, M.M.; Basfar, A.A. E-mail: abasfar@kacst.edu.sa

2001-12-01

Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) have been used to study the oxidation of {gamma}-ray vulcanized ethylene-propylene diene rubber (EPDM) stabilized with various types of antioxidants. The antioxidants used were pentaerythrityl tetrakis(3,5-di-tert-butyl(-4-hydroxyphenyl))propionate (Irganox 1010), Irganox 1035, Irganox 1520D, as primary antioxidants; Irganox B561 and Irganox B900, as synergistic blends; hindered amine light stabilizer (HALS), i.e. Tinuvin 622 LD; N-isopropyl-N-phenyl-p-phenylene diamine (IPPD) and trimethyl quinoline (TMQ) and their mixtures. The measurements were carried out under atmospheric conditions. The effects of antioxidant type and its selected concentration were determined and mechanism of reaction proposed.

Stereo- and regioselectivity of the hetero-Diels-Alder reaction of nitroso derivatives with conjugated dienes.

Science.gov (United States)

Brulíková, Lucie; Harrison, Aidan; Miller, Marvin J; Hlaváč, Jan

2016-01-01

The hetero-Diels-Alder reaction between a nitroso dienophile and a conjugated diene to give the 3,6-dihydro-2 H -1,2-oxazine scaffold is useful for the synthesis of many biologically interesting molecules due to the diverse opportunities created by subsequent transformations of the resulting 1,2-oxazine ring. This review discusses the rationale for the observed regio- and stereoselectivity and the methods developed in recent years used to control and improve the stereo- and regioselectivity for the synthesis of 1,2-oxazine scaffolds.

Synthesis of 17α-[(E)-2-[125I]iodoethenyl]androsta-4-6-dien-17β-o l-3-one, an active -site-directed photoaffinity radiolabel for androgen-binding proteins

International Nuclear Information System (INIS)

Diaz Cruz, P.J.; Smith, H.E.; Vanderbilt Univ., Nashville, TN; Danzo, B.J.; Clanton, J.A.; Mason, N.S.

1993-01-01

The active-site-directed photoaffinity radiolabel for androgen-binding proteins, 17α-[(E)-2-[ 125 I]iodoethenyl]androsta-4,6-dien-17β-ol-3-one, was prepared by reaction of 17α-[(E)-2-tributyltin(IV)ethenyl]androsta-4,6-dien-17β-ol-3-one with carrier added sodium iodide-125 in the presence of hydrogen peroxide and acetic acid. Purification by HPLC gave the radiolabeled steroid in 52% radiochemical yield with a specific activity of 27 Ci/mmol and 100% radiochemical purity. (author)

Morphology-properties relationship on nanocomposite films based on poly(styrene-block-diene-block-styrene copolymers and silver nanoparticles

Directory of Open Access Journals (Sweden)

2011-02-01

Full Text Available A comparative study on the self-assembled nanostructured morphology and the rheological and mechanical properties of four different triblock copolymers, based on poly(styrene-block-diene-block-styrene and poly(styrene-block-diene-block-styrene matrices, and of their respective nanocomposites with 1 wt% silver nanoparticles, is reported in this work. In order to obtain well-dispersed nanoparticles in the block copolymer matrix, dodecanethiol was used as surfactant, showing good affinity with both nanoparticles and the polystyrene phase of the matrices as predicted by the solubility parameters calculated based on Hoftyzer and Van Krevelen theory. The block copolymer with the highest PS content shows the highest tensile modulus and tensile strength, but also the smallest elongation at break. When silver nanoparticles treated with surfactant were added to the block copolymer matrices, each system studied shows higher mechanical properties due to the good dispersion and the good interface of Ag nanoparticles in the matrices. Furthermore, it has been shown that semiempirical models such as Guth and Gold equation and Halpin-Tsai model can be used to predict the tensile modulus of the analyzed nanocomposites.

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

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Lucie Brulíková

2016-09-01

Full Text Available The hetero-Diels–Alder reaction between a nitroso dienophile and a conjugated diene to give the 3,6-dihydro-2H-1,2-oxazine scaffold is useful for the synthesis of many biologically interesting molecules due to the diverse opportunities created by subsequent transformations of the resulting 1,2-oxazine ring. This review discusses the rationale for the observed regio- and stereoselectivity and the methods developed in recent years used to control and improve the stereo- and regioselectivity for the synthesis of 1,2-oxazine scaffolds.

Surface characterisation of ethylene-propylene-diene rubber upon exposure to aqueous acidic solution

DEFF Research Database (Denmark)

Mitra, S.; Ghanbari-Siahkali, Afshin; Kingshott, P.

2006-01-01

but significantly different with respect to molar mass and the presence of long chain branching. Both rubbers contained 5-ethylidene-2-norbomene (ENB) as diene. Solution cast films of pure EPDM samples were exposed in two different acidic solutions, viz. chromosulphuric (Cr (VI)/H2SO4) and sulphuric acid (H2SO4....... Furthermore, 20% Cr (VI)/H2SO4 also attacked the allylic carbon-hydrogen (C-H) bonds of ENB resulting in more oxygenated species on the surface compared to 20% H2SO4 under identical conditions. Cr (VI) in the 20% Cr (VI)/H2SO4 was found to play an important role in alteration of surface chemistry. Studies...

Ludwig, un roi sur la lune : l’histoire d’un roi fou jouée par des comédien.ne.s en situation de handicap mental

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Marie Astier

2017-12-01

Full Text Available Ludwig, un roi sur la lune, spectacle mis en scène par Madeleine Louarn avec les comédien.ne.s professionnels en situation de handicap mental de l’Atelier Catalyse et présenté lors de la dernière édition du Festival d’Avignon n’est pas une reconstitution historique de la vie de Louis II de Bavière, roi du XIXe siècle diagnostiqué paranoïaque et destitué pour être interné, mais une tentative de transcrire théâtralement la perception du monde d’un homme amoureux de l’Art, de la nature et des hommes, mais qui devait être Roi. Ce n’est ni un personnage ni des comédien.ne.s « handicapé.e.s » que nous sommes invités à voir, mais les visions de Ludwig incarnées par des comédien.ne.s qui se trouvent être en situation de handicap mental. Dans ce spectacle, la « folie » devenue plus tard « handicap mental » apparaît sous les traits de la non-conformité bien plus que sous ceux de la pathologie.

Regio-, Diastereo-, and Enantioselective Nitroso-Diels-Alder Reaction of 1,3-Diene-1-carbamates Catalyzed by Chiral Phosphoric Acids.

Science.gov (United States)

Pous, Jonathan; Courant, Thibaut; Bernadat, Guillaume; Iorga, Bogdan I; Blanchard, Florent; Masson, Géraldine

2015-09-23

Chiral phosphoric acid-catalyzed asymmetric nitroso-Diels-Alder reaction of nitrosoarenes with carbamate-dienes afforded cis-3,6-disubstituted dihydro-1,2-oxazines in high yields with excellent regio-, diastereo-, and enantioselectivities. Interestingly, we observed that the catalyst is able not only to control the enantioselectivity but also to reverse the regioselectivity of the noncatalyzed nitroso-Diels-Alder reaction. The regiochemistry reversal and asynchronous concerted mechanism were confirmed by DFT calculations.

Structural determination of ethylene-propylene-diene rubber (EPDM) containing high degree of controlled long-chain branching

DEFF Research Database (Denmark)

Mitra, Susanta; Jørgensen, Mikkel; Pedersen, Walther Batsberg

2009-01-01

findings and the available theories, an attempt was made to identify the chemical nature and degree of LCB. This study reveals the possibility of detailed characterization of molecular architecture of EPDM containing LCB by comparing with an essentially linear EPDM in light of an existing theory. © 2009...... mass and the presence of LCB. Both rubbers contained 5-ethylidene-2-norbornene (ENB) as diene. Solution cast films of pure EPDM samples were used for different characterization techniques. 1H-NMR, and 13C-NMR were used for assessing the comonomer ratios and LCB. Size exclusion chromatography (SEC...

Diethylenetriamine/diamines/copper (II complexes [Cu(dien(NN]Br2: Synthesis, solvatochromism, thermal, electrochemistry, single crystal, Hirshfeld surface analysis and antibacterial activity

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Fatima Abu Saleemh

2017-09-01

Full Text Available Two dicationic water soluble mixed triamine/diamine copper (II complexes, of general formula [Cu(dienNN]Br2 (1–2 [dien = diethelenetriamine and NN is en = ethylenediamine or Me4en = N,N′,N,N′-tetramethylethylenediamine] were prepared under ultrasonic mode with a relatively high yield. These complexes were characterized by elemental microanalysis, UV visible IR spectroscopy, and thermal and electrochemical techniques. In addition, complex 2 structure was solved by X-ray single crystal and Hirshfeld surface analysis. The complex exhibits a distorted square pyramidal coordination environment around Cu(II centre. The solvatochromism of the desired complexes was investigated in water and other suitable organic solvents. The results show that the Guttmann’s DN parameter values of the solvents have mainly contributed to the shift of the d–d absorption band towards the linear increase in the wavelength of the absorption maxima of the complexes. The complex 1 showed higher antibacterial activity against the studied microorganisms compared to complex 2. Both complexes revealed promising antibacterial activities.

Abcès thyroïdien révélant un basedow: à propos d'un cas et revue ...

African Journals Online (AJOL)

Une radiographie thoracique a été demandée montrant un foyer alvéolaire pulmonaire apical droit. L'étude cytobactériologique des crachats ont isolé le bacille de koch. Le bilan biologique thyroïdien était en faveur d'un Basedow. La prise en charge était médicale comprenait une tri-antibiothérapie par voie parentérale, ...

Structure aggregation of carbon black in ethylene-propylene diene polymer

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2009-03-01

Full Text Available The modulus of filled and unfilled Ethylene-propylene diene rubber (EPDM vulcanizates was used to predict the shape-factor of carbon black aggregation in the polymer. Four types of carbon black that vary in particle size and structure were used in this study. Quadratic curves relating the carbon black volume concentration and the modulus ratio of filled and unfilled rubber vulcanizates were used to adopt the shape factor of certain carbon black type. The shape factor of MT, HAF, SRF and Lampblack were 3, 3.75, 4 and 4.25 respectively. X-ray diffraction technique (XRD was also used to evaluate the relative size of crystallite on the filler surface to that of the rubber and correlating it to the shape factor of carbon black aggregation in the polymer. Effect of the pH values and structure of carbon blacks used on the shape factor of filler aggregates were also studied. It was found that the shape factor is independent on the particle size while it is dependent on the pH value and structure of carbon black. Also the crystallites size of the filler is proportional to the shape factor.

An investigation on changes in chemical properties of pure ethylene-propylene-diene rubber in aqueous acidic environments

DEFF Research Database (Denmark)

Mitra, S.; Ghanbari-Siahkali, Afshin; Kingshott, Peter

2006-01-01

The influence of two aqueous acidic environments on two types of pure ethylene-propylene-diene (EPDM) rubber (i.e., elastomer) thin films is studied. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) results revealed the formation of several oxygenated species...... formation on the surface of EPDM rubbers compared to 20% H2SO4 under identical conditions. Complex formation on the surface of EPDM samples exposed to 20% Cr(VI)/H2SO4 through reactions of carboxylic groups (generated due to EPDM degradation) with Cr(III) (formed due to reduction of Cr(VI)) was also evident...

Novel UTP derivative with diene-containing spacer arm for Diels-Alder reaction: potential tool for radioactive or fluorescent detection upon its incorporation into ribonucleic acid

Czech Academy of Sciences Publication Activity Database

Točík, Zdeněk; Krásný, Libor; Kovačková, Soňa; Rejman, Dominik; Rosenberg, Ivan

2007-01-01

Roč. 6, č. 5 (2007), s. 357 ISSN 1535-3508. [International Conference of the European Society for Molecular Imaging /2./. 14.06.2007-15.06.2007, Naples] Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520701 Keywords : UTP derivative * Diels - Alder reaction * diene * spacer arm Subject RIV: CC - Organic Chemistry

Crystal structure of chloridobis[(1,2,5,6-η-cycloocta-1,5-diene]iridium(I

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A. K. Fazlur Rahman

2017-02-01

Full Text Available The title complex, [IrCl(C8H122], was synthesized directly from the reaction of IrCl3·3H2O with a large excess of cod (cod = cycloocta-1,5-diene in alcoholic solvent. Large yellow needles were obtained by the slow cooling of a hot solution. Based on the positions of the chloride ligand and the mid-points of the four C=C bonds, the molecule adopts a five-coordinate geometry that is midway between square pyramidal and trigonal bipyramidal. The material crystallizes in the orthorhombic space group Pbca with one molecule per asymmetric unit in a general position and shows no significant intermolecular interactions. Individual molecules are aligned along [010], and these rows form a pseudo-hexagonal packing arrangement.

Stereo-controlled synthesis of polyheterocycles via the diene-transmissive hetero-Diels-Alder reaction of β,γ-unsaturated α-keto esters.

Science.gov (United States)

Otani, Takashi; Tamai, Yumiko; Seki, Kazunori; Kikuchi, Tomohiro; Miyazawa, Taiichiro; Saito, Takao

2015-06-07

We describe the stereoselective synthesis of polyring-fused heterocyclic compounds based on diene-transmissive hetero-Diels-Alder reactions utilizing β,γ-unsaturated α-keto esters. This protocol involves the initial endo- or exo-selective Diels-Alder (DA) reactions with electron-rich dienophiles, methylenation of the ester carbonyl groups with the Tebbe reagent, and a stereoselective second DA reaction with electron-deficient dienophiles. The use of enantioselective DA reactions in the initial reaction enables access to chiral polyring-fused heterocyclic compounds with multiple chiral centres.

Absolute rate constants for the reaction of NO₃ radicals with a series of dienes at 295 K

DEFF Research Database (Denmark)

Ellermann, T.; Nielsen, O.J.; Skov, H.

1992-01-01

The rate constants for the reaction of NO3 radicals with a series of 7 dienes, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, trans-1,3-pentadiene, cis-1,3-pentadiene, trans,trans-2,4-hexadiene, and 1,3-cyclohexadiene, were measured at 295 K and at a total pressure of 1 atm. The rate consta...... were obtained using the absolute technique of pulse radiolysis combined with kinetic UV-VIS spectroscopy. The results are discussed in terms of reactivity trends and previous literature data....

Synthesis and Characterization of Pyridino(1,4-Η-cyclohexa-1,3-dieneDerivatives of Iron Tricarbonyl Complexes

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T. I. Odiaka

2011-01-01

Full Text Available In this synthesis, we have been able to show that, the addition of x- substituted pyridines, (X = H, 2- Me, 3- Me 4- Me, 4-NH2 and 4-N(CH32 to the dienyl ring of the organometallic cation, [(Fe(CO3 (1-5- η-2-Me0C3H6]BF4 and [(Fe(CO3(1-5-η-C6H7]BF4 gives ionic substituted diene products, (X C5H4-C6H6Y (Fe(CO3] BF4,Y=H or 2-MeO. The reaction takes place at ordinary room temperature. The resulting products were isolated and characterized.

Crystal structure of 4,4-dibromo-1-(3,4-dimethoxyphenyl-2-azabuta-1,3-diene-1-carbonitrile

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Marwa Chaabene

2016-08-01

Full Text Available The title compound, C12H10Br2N2O2, represents an example of a planar π-conjugated 2-azabutadiene molecule, which is both an interesting starting material for further organic transformations and a potential ligand in organometallic coordination chemistry. Its metric molecular parameters are typical for the family of 2-azabuta-1,3-dienes not substituted at the (CH 3-position. In the crystal, the almost planar (r.m.s. deviation = 0.0658 Å azadiene molecules form one-dimensional double-wide ribbons through intermolecular halogen bonds (C—Br...O and C—Br...Br—C, which then stack in a slipped manner through weak C—H...Br and π–π interactions to generate a three-dimensional network.

Six years of experience in connection with the performance of ethylene-propylene-diene terpolymer Rubber (EPDM) geo membranes used in waterproofing reservoirs; Sesis anos de experiencia en el empleo de geomembranas de etileno-propileno-monomero dienico (EPDM) en la impermeabilizacion de balsas

Energy Technology Data Exchange (ETDEWEB)

Blanco, M.; Aguiar, E.; Cea, J. C. de; Soriano, J.; Castillo, F.; Garcia, F.; Crespo, M. A.

2008-07-01

This paper provides to show the performance of synthetic geo membranes based on ethylene-propylene-diene terpolymer rubber (EPDM). Results after six years one applied are presented. The samples of geo membranes came from eight Spanish reservoirs: Bigastro, Bullas, La Casa de las Chumberas, el Boqueron, El Golfo, Los Dos Pinos, Los Pozos (La Torrecilla) and El Saltadero (experimental field). Characteristics of ethylene-propylene-diene terpolymer rubber were evaluated: tensile properties, impact resistance, static perforation, low temperature folding, joint strength (shear and peeling test), optic microscopy and electron microscopy scanner. (Author) 13 refs.

ADMET Polymerization Activities of Electrochemically Reduced W-Based Active Species for Ge- and Sn-Containing Dienes

Science.gov (United States)

Imamoglu, Yavuz; Aydogdu, Cemil; Karabulut, Solmaz; Düz, Bülent

In the last 20 years metal atom-containing polymers have become important classes of polymers [1]. Properties like high thermic stability, electric, and photo conductometry make them very interesting for producing films, fibers, and coating [2]. Many of these compounds can be synthesized by conventional methods [3]. For producing metal-containing polymers anionic, cationic, and radicalic polymerizations were used [4-6]. Metal-containing polymers were also synthesized via acyclic diene metathesis (ADMET) polymerization that is facilitated by Schrock’s molybdenum alkylidene, or Grubbs’ ruthenium carbene catalyst [7-9]. In 1979, Gilet and coworkers succeeded in synthesizing metathetically active species from electrochemical reduction of WCl6 and MoCl5 [10,11]. In the light of these works, we have showed that electrochemically generated tungsten-based active species (WCl6-e--Al-CH2Cl2) catalyzes various metathesis-related reactions [12-16].

New catalysts for selective hydrogenation of diene and acetylene hydrocarbons into olefins

Energy Technology Data Exchange (ETDEWEB)

Frolov, V.M.; Parenago, O.P.; Shuikina, L.P.

1978-12-01

New catalysts for selective hydrogenation of diene and acetylene hydrocarbons into olefins were obtained by reacting aqueous palladium, rhodium, or nickel chloride (0.005-0.05 mole/l.) at 50/sup 0/C, in an argon atmosphere with chelating nitrogen compounds, i.e., o-phenanthroline, ..cap alpha..,..cap alpha..'-dipyridyl, sodium ethylenediaminetetracetate, morpholine, branched polyethylene imines, or amino acids such as glycine, ..cap alpha..-alanine, ..beta..-phenyl-..cap alpha..-alanine, tyrosine, or histidine, and treating the complexes so obtained with sodium borohydride at 1:1-1:5 NaBH/sub 4/-metal ratios, in an aqueous medium. Palladium-based complexes showed the highest activities (20-98Vertical Bar3< conversion) and selectivities (98-100Vertical Bar3<) in heterogeneous hydrogenation of cyclopentadiene, butadiene, 1-hexyne, 1,3-cyclohexadiene, or 1,3-cyclooctadiene at 20/sup 0/-60/sup 0/C and 0.5-15 atm hydrogen, carried out in a kinetic circulation reactor or a metallic autoclave. Thus, a catalytic system based on PdCl/sub 2/ and ..beta..-phenyl-..cap alpha..-alanine converted 98Vertical Bar3< of cyclopentadiene to cyclopentene with 99Vertical Bar3< selectivity. The palladium-based catalyst did not deactivate on the contact with air.

Response of ethylene propylene diene monomer rubber (EPDM) to simulant Hanford tank waste

Energy Technology Data Exchange (ETDEWEB)

NIGREY,PAUL J.

2000-02-01

This report presents the findings of the Chemical Compatibility Program developed to evaluate plastic packaging components that may be incorporated in packaging mixed-waste forms for transportation. Consistent with the methodology outlined in this report, the author performed the second phase of this experimental program to determine the effects of simulant Hanford tank mixed wastes on packaging seal materials. That effort involved the comprehensive testing of five plastic liner materials in an aqueous mixed-waste simulant. The testing protocol involved exposing the materials to {approximately}143, 286, 571, and 3,670 krad of gamma radiation and was followed by 7-, 14-, 28-, 180-day exposures to the waste simulant at 18, 50, and 60 C. Ethylene propylene diene monomer (EPDM) rubber samples subjected to the same protocol were then evaluated by measuring seven material properties: specific gravity, dimensional changes, mass changes, hardness, compression set, vapor transport rates, and tensile properties. The author has determined that EPDM rubber has excellent resistance to radiation, this simulant, and a combination of these factors. These results suggest that EPDM is an excellent seal material to withstand aqueous mixed wastes having similar composition to the one used in this study.

Rhodium/chiral diene-catalyzed asymmetric 1,4-addition of arylboronic acids to chromones: a highly enantioselective pathway for accessing chiral flavanones.

Science.gov (United States)

He, Qijie; So, Chau Ming; Bian, Zhaoxiang; Hayashi, Tamio; Wang, Jun

2015-03-01

Chromone has been noted to be one of the most challenging substrates in the asymmetric 1,4-addition of α,β-unsaturated carbonyl compounds. By employing the rhodium complex associated with a chiral diene ligand, (R,R)-Ph-bod*, the 1,4-addition of a variety of arylboronic acids was realized to give high yields of the corresponding flavanones with excellent enantioselectivities (≥97% ee, 99% ee for most substrates). Ring-opening side products, which would lead to erosion of product enantioselectivity, were not observed under the stated reaction conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The divergent synthesis of nitrogen heterocycles by rhodium(II)-catalyzed cycloadditions of 1-sulfonyl 1,2,3-triazoles with 1,3-dienes.

Science.gov (United States)

Shang, Hai; Wang, Yuanhao; Tian, Yu; Feng, Juan; Tang, Yefeng

2014-05-26

The first rhodium(II)-catalyzed aza-[4+3] cycloadditions of 1-sulfonyl 1,2,3-triazoles with 1,3-dienes have been developed, and enable the efficient synthesis of highly functionalized 2,5-dihydroazepines from readily available precursors. In some cases, the reaction pathway could divert to formal aza-[3+2] cycloadditions, thus leading to 2,3-dihydropyrroles. In this context, the titled reaction represents a capable tool for the divergent synthesis of two types of synthetically valuable aza-heterocycles from common rhodium(II) iminocarbene intermediates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

60Co-labeling in 59Co(n,γ)60Co reaction and γ-ray irradiation of [Co(dien)2]3+ and [Co(en)3]3+ in crystals and/or in polyvinyl alcohol

International Nuclear Information System (INIS)

Sasaki, K.; Iiyoshi, N.; Watanabe, J.; Yamatera, H.

1982-01-01

Three isomers (sym-fac, unsym-fac, and mer forms) of [Co(dien) 2 ]Cl 3 were irradiated in a reactor in the form of crystals and in amorphous solids, where the ions were dissolved in polyvinyl alcohol (PVA) or adsorbed on an SP-Sephadex ion exchanger. The distribution of produced 60 Co among the isomers of the Co(III) complex and the Co(II) species was determined. The preferential labeling on the parent isomer was observed in crystals but not in PVA. In the Sephadex, no marked labeling occurred. For comparison with reactor-irradiated samples, mixed solutions of [Co(dien) 2 ]Cl 3 and 60 Co-labeled cobalt (II) chloride dissolved in PVA films ([Co(III)]/[Co(II)] = 2 - 3) were irradiated by γ-rays. Significant labeling was observed after the irradiation. Comparison of the results from the above experiments showed that the labeling was enhanced by radiation chemical reactions, and that the preferential labeling on the parent isomer of crystal samples resulted from the stiffness of the crystal matrix. (orig.)

5-Methyl-3,8-di-(2-amino-4-bromophenyl-4,9-dioxa-1,2,6,7-tetraaza-5λ5-phosphaspiro[4.4]nona-2,7-diene

Directory of Open Access Journals (Sweden)

Sławomir Kasperowicz

2018-01-01

Full Text Available 5-Methyl-3,8-di-(2-amino-4-bromophenyl-4,9-dioxa-1,2,6,7-tetraaza-5λ5-phosphaspiro[4.4]nona-2,7-diene was obtained by condensation of 2-amino-5-bromobenzohydrazide and methylphosphonyl dichloride in the presence of triethylamine. An initial biological screening was performed for the resulting product. The synthesized compound showed relatively strong cytotoxic activity, which was, however, similar for cancer and non-cancer cell lines.

Limitations of using Raman microscopy for the analysis of high-content-carbon-filled ethylene propylene diene monomer rubber

DEFF Research Database (Denmark)

Ghanbari-Siahkali, A.; Almdal, K.; Kingshott, P.

2003-01-01

The effects of laser irradiation on changes to the surface chemistry and structure of a commercially available ethylene propylene diene monomer (EPDM) rubber sample after Raman microscopy analysis was investigated. The Raman measurements were carried out with different levels of laser power...... on the sample, ranging from 4.55 mW to 0.09 mW. The surface of the EPDM was analyzed before and after laser exposure using X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The techniques have surface probe depths of approximately less...... than or equal to10 nm and 1 mum, respectively. Both sets of analysis show that ingredients of the blended EPDM rubber "bloom" to the surface as a result of local heating that takes place due to the absorption of laser by carbon black during the Raman analysis. Scanning electron microscopy (SEM...

Synthesis of [14α, 15α-3H]-17α-cyanomethyl-17β-hydroxyestra-4.9-diene-3-one - a specifically tritium labelled gestagen

International Nuclear Information System (INIS)

Roemer, J.; Wagner, H.

1978-05-01

Synthesis of [14α, 15α- 3 H 2 ]-17α-cyanomethyl-17β-hydroxyestra-4.9-diene-3-one from quantitativly tritiated [14α, 15α- 3 H 2 ]-3-methoxyestra-1,3,5(10),8-tetraene-17β-ol is described. The determination of the radiochemical purity and chemical yield was carried out by thin-layer chromatography. Preparative thin-layer chromatography was used for purifying the final product. By-products formed in the course of synthesis could be detected by determining and comparing specific activities of the intermediate products. Radiolytic investigations revealed the instability of the tritium labelled dienone system. (author)

Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

International Nuclear Information System (INIS)

Basak, Ganesh C.; Bandyopadhyay, Abhijit; Neogi, Sudarsan; Bhowmick, Anil K.

2011-01-01

Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

Energy Technology Data Exchange (ETDEWEB)

Basak, Ganesh C. [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India); Bandyopadhyay, Abhijit [Department of Polymer Science and Technology, University of Calcutta, Calcutta 700 009 (India); Neogi, Sudarsan [Department of Chemical Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Bhowmick, Anil K., E-mail: anilkb@rtc.iitkgp.ernet.in [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India)

2011-01-15

Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

General patterns in the photochemistry of pregna-1,4-dien-3,20-diones.

Science.gov (United States)

Ricci, Andrea; Fasani, Elisa; Mella, Mariella; Albini, Angelo

2003-05-30

The photochemistry of six pregna-1,4-dien-3,20-diones has been compared and found to involve both the cyclohexadienone moiety in ring A and the isolated ketone at C-20. The two reactions take place proportionally to the fraction of light absorbed by each chromophore. The cross-conjugated ketone absorbs predominantly or exclusively at both 254 and 366 nm and undergoes the "lumi" rearrangement to bicyclo[3.1.0]hex-3-en-2-one. The quantum yield of the reaction diminished somewhat with increasing lambda(exc), e.g., for prednisolone Phi(254) (nm) = 0.42, Phi(366) (nm) = 0.3. A much stronger lowering is caused by halogen substitution in position 9 (by a factor of 3 for F, >50 for Cl), apparently due to a shortened triplet lifetime caused by heavy atom effect. At 310 nm, both chromophores absorb to a comparable degree and both may react. The reaction at C(20) ketone involves either quite efficient alpha-cleavage (C(17)-C(20)) for compounds bearing an acetal or hydroxyl function at C(17) or less effective (by a factor of ca. 10) hydrogen abstraction from the 18-methyl group in the other cases (finally resulting in Norrish II fragmentation or Yang cyclization). The results allow generalizing how the substitution pattern surrounding each chromophore affects the photoreactivity at that site and the competition between the two modes, allowing predicting the photochemistry of this family of antiinflammatory drugs.

Process for Biotransformation of Androsta-4-ene-3, 17-Dione (4-AD) to Androsta-1,4-Diene-3,17-Dione (ADD).

Science.gov (United States)

Prakash, Surya; Bajaj, Abhay

2017-01-01

Androsta-1,4-diene-3,17-dione (androstadienedione, ADD) is key intermediate for the organic synthesis of a variety of female sex hormones such as estrone, estradiol, estriol and other related derivatives. De novo synthesis of this molecule is not yet reported in any form of living system, i.e., microbial, plant, and animal. The structural complexities due to presence of several chiral carbon centers create significant hurdles in chemical synthesis of such molecules. Microbe-mediated biotransformation offer a highly reliable, cost-effective, and relatively non hazardous way for commercial manufacturing of steroidal key intermediates. Currently microbial biotransformations are extensively being exploited for large-scale production of basic intermediates such as androstenedione (AD), ADD, and several types of hydroxylated derivatives of androstane compounds. In this chapter several aspects of microbial biotransformation process of AD to ADD are discussed.

Increased Yield of Biotransformation of Androsta-1, 4-Dien-3, 17-Dione from Β-Sitosterol by Using Sulfobutyl Ether-Β-Cyclodextrin Complexation Technique

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Wang Jingwen

2016-01-01

Full Text Available Substrate solubility in steroid biotransformation is critical for enhancing the biotransformation of hydrophobic compounds. In this study, the sulfobutyl ether-β-cyclodextrin (SBE-β-CD complexation technique was used for the biotransformation of β-sitosterol to androsta-1, 4-diene-3, 17-dione with Mycobacterium ATCC25795. The production yield was increased by 26.72%, and the biotransformation course was shortened by 24h using β-sitosterol/SBE-β-CD inclusion complexes as substrates (1.0 g/L. Fourier transform infrared spectroscopy and differential scanning calorimetry indicated that an inclusion complex was formed between SBE-β-CD and β-sitosterol. The complex significantly increased the solubility of β-sitosterol and improved the biotransformation efficiency of the substrate.

Calorimetric study of alternating copolymer of bicyclo[2,2,1]-hepta-2,5-diene and carbon monoxide in the range from T->0 to 510K

International Nuclear Information System (INIS)

Smirnova, N.N.; Nikishchenkova, L.V.; Bykova, T.A.; Kulagina, T.G.; Belov, G.P.; Novikova, E.V.

2006-01-01

By adiabatic vacuum and dynamic calorimetry, the temperature dependence of heat capacity for alternating copolymer of bicyclo[2,2,1]-hepta-2,5-diene and carbon monoxide has been determined over the 6-510K range with an uncertainty of 0.2-0.5% between 6 and 350K and 0.5-1.5% from 330 to 510K. In the above temperature ranges, the physical transformations of the copolymer have been detected and their thermodynamic characteristics have been estimated. In a calorimeter with a static bomb and an isothermal shield, the energy of combustion of the copolymer has been measured at 298.15K. Based on the experimental data, the thermodynamic functions of the copolymer, namely, the heat capacity C p - bar (T), enthalpy H o (T)-H o (0), entropy S o (T)-S o (0) and Gibbs function G o (T)-H o (0) have been determined for the range from T->0 to 400K. The enthalpy of combustion Δ c H o and the thermodynamic parameters Δ f H o , Δ f S o , Δ f G o and lnK f - bar of reaction of formation of the copolymer from simple substances at T=298.15K and p=0.1MPa have been calculated. The data cited in the present work and literature data were used to calculate the thermodynamic characteristics of the alternating copolymerization in bulk of bicyclo[2,2,1]-hepta-2,5-diene and CO in the 0-340K range at standard pressure as well as to compare them with the thermodynamic characteristics of the synthesis of isomeric polyketone

Radiation processed polychloroprene-co-ethylene-propene diene terpolymer blends: Effect of radiation vulcanization on solvent transport kinetics

Energy Technology Data Exchange (ETDEWEB)

Dubey, K.A. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Room No. S-1, HIRUP Building, Trombay, Mumbai 400 085 (India); Bhardwaj, Y.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Room No. S-1, HIRUP Building, Trombay, Mumbai 400 085 (India)], E-mail: ykbhard@barc.gov.in; Chaudhari, C.V.; Kumar, Virendra; Goel, N.K.; Sabharwal, S. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Room No. S-1, HIRUP Building, Trombay, Mumbai 400 085 (India)

2009-03-15

Blends of polychloroprene rubber (PCR) and ethylene propylene diene terpolymer rubber (EPDM) of different compositions were made and exposed to different gamma radiation doses. The radiation sensitivity and radiation vulcanization efficiency of blends was estimated by gel-content analysis, Charlesby-Pinner parameter determination and crosslinking density measurements. Gamma radiation induced crosslinking was most efficient for EPDM (p{sub 0}/q{sub 0} {approx} 0.08), whereas it was the lowest for blends containing 40% PCR (p{sub 0}/q{sub 0} {approx} 0.34). The vulcanized blends were characterized for solvent diffusion characteristics by following the swelling dynamics. Blends with higher PCR content showed anomalous swelling. The sorption and permeability of the solvent were not strictly in accordance with each other and the extent of variation in two parameters was found to be a function of blend composition. The {delta}G values for solvent diffusion were in the range -2.97 to -9.58 kJ/mol and indicated thermodynamically favorable sorption for all blends. These results were corroborated by dynamic swelling, experimental as well as simulated profiles and have been explained on the basis of correlation between crosslinking density, diffusion kinetics, thermodynamic parameters and polymer-polymer interaction parameter.

Enhancing the thermal stability of natural rubber/recycled ethylene–propylene–diene rubber blends by means of introducing pre-vulcanised ethylene–propylene–diene rubber and electron beam irradiation

International Nuclear Information System (INIS)

Nabil, H.; Ismail, H.

2014-01-01

Highlights: • New route of processing was introduced to optimise the thermal stability of NR/R-EPDM blends. • Pre-vulcanised EPDM and EB irradiation were introduced into NR/R-EPDM blends. • Thermal stability is obviously enhanced by applying these two techniques. • Applying new route of processing methods is clearly successful to NR/R-EPDM blends. - Abstract: Most rubber materials are subjected to oxidation. The rate of oxidation depends on the type of rubber, processing method, and end-use conditions. The oxidation of rubber can result in the loss of physical properties, such as tensile strength, elongation, and flexibility. Hence, the service life is determined by oxidation stability. Thermal properties are relevant to the potential use of polymeric materials in many consumer oriented applications. Thermo-oxidative ageing and thermogravimetric analysis (TGA) have been proven to be successful techniques in determining the thermal stability of polymers and polymer blends. In this article, preparation of a series of natural rubber/recycled ethylene–propylene–diene rubber (NR/R-EPDM) blends is described. Processing of the blends, by means of introducing pre-vulcanised EPDM and electron beam (EB) irradiation, was carried out. Two thermal analysis methods, namely thermo-oxidative ageing and thermogravimetric analysis, were conducted. The results indicated that pre-vulcanising EPDM for 1.45 min (ts − 2) is sufficient to gain the optimum retained tensile and elongation at break. It was simultaneously observed that the introduction of pre-vulcanised EPDM increased decomposition temperature and activation energy by showing optimum values at a pre-vulcanising time of 3.45 min (ts). In the latter study, the retained properties increased after EB irradiation. The results can be verified by the thermal decomposition temperature and their activation energy. The obtained TG profiles and the calculated kinetic parameters indicated that introducing EB irradiation

Enhanced Production of Androst-1,4-Diene-3,17-Dione by Mycobacterium neoaurum JC-12 Using Three-Stage Fermentation Strategy

Science.gov (United States)

Shao, Minglong; Zhang, Xian; Rao, Zhiming; Xu, Meijuan; Yang, Taowei; Li, Hui; Xu, Zhenghong

2015-01-01

To improve the androst-1,4-diene-3,17-dione (ADD) production from phytosterol by Mycobacterium neoaurum JC-12, fructose was firstly found favorable as the initial carbon source to increase the biomass and eliminate the lag phase of M. neoaurum JC-12 in the phytosterol transformation process. Based on this phenomenon, two-stage fermentation by using fructose as the initial carbon source and feeding glucose to maintain strain metabolism was designed. By applying this strategy, the fermentation duration was decreased from 168 h to 120 h with the ADD productivity increased from 0.071 g/(L·h) to 0.108 g/(L·h). Further, three-stage fermentation by adding phytosterol to improve ADD production at the end of the two-stage fermentation was carried out and the final ADD production reached 18.6 g/L, which is the highest reported ADD production using phytosterol as substrate. Thus, this strategy provides a possible way in enhancing the ADD production in pharmaceutical industry. PMID:26352898

Enhanced Production of Androst-1,4-Diene-3,17-Dione by Mycobacterium neoaurum JC-12 Using Three-Stage Fermentation Strategy.

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Minglong Shao

Full Text Available To improve the androst-1,4-diene-3,17-dione (ADD production from phytosterol by Mycobacterium neoaurum JC-12, fructose was firstly found favorable as the initial carbon source to increase the biomass and eliminate the lag phase of M. neoaurum JC-12 in the phytosterol transformation process. Based on this phenomenon, two-stage fermentation by using fructose as the initial carbon source and feeding glucose to maintain strain metabolism was designed. By applying this strategy, the fermentation duration was decreased from 168 h to 120 h with the ADD productivity increased from 0.071 g/(L·h to 0.108 g/(L·h. Further, three-stage fermentation by adding phytosterol to improve ADD production at the end of the two-stage fermentation was carried out and the final ADD production reached 18.6 g/L, which is the highest reported ADD production using phytosterol as substrate. Thus, this strategy provides a possible way in enhancing the ADD production in pharmaceutical industry.

An intermolecular Diels-Alder cycloaddition under various condition between 1,3-cyclohexadiene and 7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate

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Özgür Yılmaz

2017-10-01

Full Text Available The reaction between 1,3-cyclohexadiene and dimethyl 7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate both without a catalyst and with different catalysts, in both atmospheric and at high pressure, over 20 days were studied. At the end of the reactions, different products (retro Diels-Alder addition product 5 and Diels-Alder addition product 6 were obtained in different yields. When we look at the percentage of the addition product, it is observed that the yield of reaction at high pressure in water is the highest. All structures of these products were characterized by 1H-NMR, 13C-NMR, MS, and IR spectroscopy.

Calorimetric study of alternating copolymer of bicyclo[2,2,1]-hepta-2,5-diene and carbon monoxide in the range from T->0 to 510K

Energy Technology Data Exchange (ETDEWEB)

Smirnova, N.N. [Research Institute of Chemistry, Nizhny Novgorod University, Gagarin Prospekt 23/5, 603950 Nizhny Novgorod (Russian Federation)]. E-mail: smirnova@ichem.unn.runnet.ru; Nikishchenkova, L.V. [Research Institute of Chemistry, Nizhny Novgorod University, Gagarin Prospekt 23/5, 603950 Nizhny Novgorod (Russian Federation); Bykova, T.A. [Research Institute of Chemistry, Nizhny Novgorod University, Gagarin Prospekt 23/5, 603950 Nizhny Novgorod (Russian Federation); Kulagina, T.G. [Research Institute of Chemistry, Nizhny Novgorod University, Gagarin Prospekt 23/5, 603950 Nizhny Novgorod (Russian Federation); Belov, G.P. [Institute of Problems of Chemical Physics of Russian Academy Sciences, 142432 Chernogolovka, Moscow Region (Russian Federation); Novikova, E.V. [Institute of Problems of Chemical Physics of Russian Academy Sciences, 142432 Chernogolovka, Moscow Region (Russian Federation)

2006-12-01

By adiabatic vacuum and dynamic calorimetry, the temperature dependence of heat capacity for alternating copolymer of bicyclo[2,2,1]-hepta-2,5-diene and carbon monoxide has been determined over the 6-510K range with an uncertainty of 0.2-0.5% between 6 and 350K and 0.5-1.5% from 330 to 510K. In the above temperature ranges, the physical transformations of the copolymer have been detected and their thermodynamic characteristics have been estimated. In a calorimeter with a static bomb and an isothermal shield, the energy of combustion of the copolymer has been measured at 298.15K. Based on the experimental data, the thermodynamic functions of the copolymer, namely, the heat capacity C{sub p}{sup -}bar (T), enthalpy H{sup o}(T)-H{sup o}(0), entropy S{sup o}(T)-S{sup o}(0) and Gibbs function G{sup o}(T)-H{sup o}(0) have been determined for the range from T->0 to 400K. The enthalpy of combustion {delta}{sub c}H{sup o} and the thermodynamic parameters {delta}{sub f}H{sup o}, {delta}{sub f}S{sup o}, {delta}{sub f}G{sup o} and lnK{sub f}{sup -}bar of reaction of formation of the copolymer from simple substances at T=298.15K and p=0.1MPa have been calculated. The data cited in the present work and literature data were used to calculate the thermodynamic characteristics of the alternating copolymerization in bulk of bicyclo[2,2,1]-hepta-2,5-diene and CO in the 0-340K range at standard pressure as well as to compare them with the thermodynamic characteristics of the synthesis of isomeric polyketone.

{2-[Bis(2,4-di-tert-butylphenoxyphosphanyloxy-κP]-3,5-di-tert-butylphenyl-κC1}[(1,2,5,6-η-cycloocta-1,5-diene]rhodium(I toluene monosolvate

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Detlef Selent

2012-02-01

Full Text Available The reaction of (η3-allyl[(1,2,5,6-η-cycloocta-1,5-diene]rhodium(I with tris(2,4-di-tert-butylphenylphosphite in toluene produces the title compound, [Rh(C42H62O3P(C8H12]·C7H8, by spontaneous metallation at one of the nonsubstituted phenyl ortho-C atoms of the phosphite molecule. The coordination geometry at the RhI ion is distorted square-planar. The toluene solvent molecule is disordered over two different orientations, with site-occupation factors of 0.810 (2 and 0.190 (2.

Ethylene–propylene–diene terpolymer/hexa fluoropropylene–vinylidinefluoride dipolymer rubber blends: Thermal and mechanical properties

International Nuclear Information System (INIS)

Balachandran Nair, Ajalesh; Kurian, Philip; Joseph, Rani

2012-01-01

Highlights: ► The EPDM/MA-g-EPDM/FKM blends show good mechanical properties. ► In compatibilized blends, better thermal and swelling resistance was obtained. ► Random nucleation mechanism is the rate controlling process in degradation. ► Good phase morphology is obtained in the case of compatibilized blends. -- Abstract: Hexa fluoropropylene–vinylidinefluoride dipolymer, fluoroelastomer (FKM) and ethylene propylene diene rubber (EPDM) blends with and without compatibilizer (MA-g-EPDM) were prepared by two-roll mill mixing. The effects of blend ratio and amount of compatibilizer on mechanical properties and thermal stability were investigated. The cure characteristics and mechanical properties of EPDM, FKM and their blends of varying compositions were studied for unaged and aged samples. The 50:50 (w/w) FKM/EPDM showed highest mechanical properties. The tensile properties of all the composites, especially those with higher proportion of FKM increased with aging. Swelling of the blends was reduced after aging. The thermal stability of FKM/EPDM rubber blends was studied using thermogravimetric analysis (TGA). The incorporation of FKM rubber improved the thermal stability of EPDM rubber. The apparent degradation activation energy (E) of EPDM/FKM reactive blends was calculated by the Coats–Redfern method. The results showed that the EPDM/FKM reactive blends had higher thermal stability but lower E than FKM. The thermal degradation process of both EPDM/FKM reactive blends and FKM were determined by nucleation and growth mechanism. The differential scanning calorimetry (DSC) results suggest that glass transition temperature (T g ) peak for EPDM region is shifted to FKM phase, due to improved compatibility on addition of compatibilizer. The morphology of blends was investigated using scanning electron microscopy (SEM).

Evaluasi terhadap Pelaksanaan Komunikasi Pemasaran Sosial Non-Goverment Organization (NGO) untuk Isu-Isu Anti Kekerasan terhadap Perempuan (Studi Kasus Kampanye Anti Kekerasan Terhadap Perempuan Cut Nyak Dien Yogyakarta dan Solidaritas Perempuan untuk Ha

OpenAIRE

Tri Hastuti Nur R

2013-01-01

Abstract: This paper explains how social marketing communication used by Cut Nyak Dien, Yogyakarta and Spekham, Surakarta–those are non goverment organization (NGO)– to sosialize issues about anti-violences to women. The result of research show evaluation fase in the social marekting fases were not done. They were not evaluate the messages were received or not;and they were not identify the level of target audiens’ behaviour changes. The media that they used were variatives. Having soci...

Evaluasi Terhadap Pelaksanaan Komunikasi Pemasaran Sosial Non-Goverment Organization (NGO) Untuk Isu-Isu Anti Kekerasan Terhadap Perempuan (Studi Kasus Kampanye Anti Kekerasan Terhadap Perempuan Cut Nyak Dien YOGYAKARTA Dan Solidaritas Perempuan Untuk Ha

OpenAIRE

Nur R, Tri Hastuti

2006-01-01

This paper explains how social marketing communication used by Cut Nyak Dien, Yogyakarta and Spekham, Surakarta–those are non goverment organization (NGO)– to sosialize issues about anti-violences to women. The result of research show evaluation fase in the social marekting fases were not done. They were not evaluate the messages were received or not;and they were not identify the level of target audiens’ behaviour changes. The media that they used were variatives. Having social marketi...

Effects of carbon blacks with various structures on vulcanization and reinforcement of filled ethylene-propylene-diene rubber

Directory of Open Access Journals (Sweden)

2008-10-01

Full Text Available The effects of carbon blacks on vulcanization and mechanical properties of filled ethylene-propylene-diene rubber (EPDM are investigated, by comparing with five types of rubber-grade carbon blacks. Curing kinetics is studied by rheometer and the results indicate that the curing characteristics are influenced by combination of surface area of carbon black and sulphur content on the filler surface, because the former one enhances the physical cross-linking and the latter one introduces the additional chemical cross-linking. Both the degree of cross-linking and cure rate increase with increasing surface area and sulphur content, whereas the optimum cure time and scorch time decrease. The reinforcing nature of the carbon black is assessed from mechanical measurements. It is suggested that the surface area of carbon blacks strongly affects the physical properties of EPDM/carbon black composites. Conductive carbon black (N472 can be used as desirable reinforcing filler due to the higher degree of cross-linking of EPDM with N472 than other EPDM/carbon black composites. The morphology and distribution of particles are studied by using scanning electron microscope. The sound reinforcing ability of N472 is also supported by scanning electron microscope due to the notable dispersibility of N472 within EPDM matrix. N472 ensures the EPDM/N472 composite the most conductive sample among the five composites.

Effect of material and processing parameters on mechanical properties of Polypropylene/Ethylene-Propylene-Diene-Monomer/clay nanocomposites

International Nuclear Information System (INIS)

Hejazi, Iman; Sharif, Farhad; Garmabi, Hamid

2011-01-01

Highlights: → Improved mechanical properties over a broad range of processing conditions. → Moderate levels of clay and processing parameters lead to higher toughness of TPO. → Significant improvement of tensile strength and modulus of TPO materials. -- Abstract: Polypropylene/Ethylene-Propylene-Diene-Monomer (PP/EPDM) blends are well known for having a combination of favourable mechanical properties. In this paper, addition of organoclay to PP/EPDM to make PP/EPDM nanocomposites with enhanced mechanical properties is studied. PP/EPDM/organoclay nanocomposites were prepared using a lab scale twin-screw extruder. Maleic anhydride grafted polypropylene (PP-g-MA) was used to enhance the intercalation/exfoliation process and to create good adhesion at the polymer/polymer and polymer/filler interfaces. Taguchi method was employed to deign the experiments and optimize material and processing parameters for optimized mechanical properties. Organoclay (NC) and compatibilizer content were selected as material parameters and the main processing variables were feeding rate and average shear rate (RPM). X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to study the microstructure of the nanocomposites samples. It was observed that NC content and shear rate in extruder improved the tensile strength and modulus. Another important result was the insignificant effect of NC content on impact strength while increasing shear rate first increased and then decreased the impact strength.

Comparison of Current Chemical and Stereochemical Tests for the Identification and Differentiation of Pelargonium graveolens L'Hér. (Geraniaceae Essential Oils: Analytical Data for (--(1S, 4R, 5S-Guaia-6,9-diene and (--(7R,10S-10-epi-γ-Eudesmol

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Mei Wang

2014-07-01

Full Text Available Commercial geranium oil samples, steam-distilled oils of authenticated plant samples, and a reference sample were investigated by GC/MS to determine the validity and applicability of a series of chemical and stereochemical tests that have been proposed in the literature to identify the country of origin, phytochemical identity or authenticity of geranium oils. The chemical tests evaluated include the ratio of the concentrations of geraniol to citronellol and the presence or absence of certain sesquiterpenes, viz., (-- guaia-6,9-diene and (--10-epi-γ-eudesmol. The stereochemical tests include the stereochemical distribution of i citronellol, ii menthone and isomenthone, and iii rose oxides. The most reliable chemical test was the presence or absence of the sesquiterpene probes. The stereochemical tests proved to be less reliable. Most of the tests could be used to classify geranium oils into general types; however, none of the tests provided a foolproof method to distinguish cultivars or country of origin. During this study, the ambiguity in the absolute stereochemistry of (--10-epi-γ-eudesmol and (--guaia-6,9-diene was addressed, and these two sesquiterpenes could serve as effective markers for the authentication of P. graveolens essential oils.

Effect of cork loading on mechanical and thermal properties of silica-Ethylene-propylene-diene monomer composite

International Nuclear Information System (INIS)

Gul, J.; Mirza, S.

2011-01-01

Ethylene-propylene diene ter-monomer (EPDM) filled with asbestos are widely used as thermal insulation in space vehicles because of its low specific gravity, low temperature flexibility, high ozone and oxygen resistant, superior thermal and ablation characteristics. However, asbestos has been banned worldwide because of its carcinogenic nature. This study was aimed to replace asbestos by environmental friendly and low specific gravity filler, cork in thermal insulation for space vehicles. Various batches of cork filled EPDM were obtained by compounding 0, 10, 20, 40, 50, 60, 70 and 100 Phr (parts per hundred parts of rubber) of cork powder with EPDM in Two-roll-mill in presence of other necessary compounding ingredients. The resulted vulcanizates were characterized for mechanical, thermal and ablation performances. It was observed that cork loadings significantly enhanced tensile strength and hardness of EPDM. However, elongation at break of EPDM decreased with the increase of cork concentration. Moreover, no significant reduction in density of EPDM was obtained instead of compounding with lower specific gravity cork powder. Temperatures cures in Thermo-gravimetric analysis shifted to lower temperature with increasing of cork percentage in the formulation. Furthermore, char formation of the EPDM composites decreased with the increase of cork Phr in the composition which was the indication of degrading thermal stability of EPDM by cork powders. It can be concluded that on the basis of mechanical properties asbestos can be replaced by cork powder however, cork filled EPDM exhibited inferior thermal properties as compared to asbestos filled EPDM. (author)

Evaluasi terhadap Pelaksanaan Komunikasi Pemasaran Sosial Non-Goverment Organization (NGO untuk Isu-Isu Anti Kekerasan terhadap Perempuan (Studi Kasus Kampanye Anti Kekerasan Terhadap Perempuan Cut Nyak Dien Yogyakarta dan Solidaritas Perempuan untuk Ha

Directory of Open Access Journals (Sweden)

Tri Hastuti Nur R

2013-12-01

Full Text Available Abstract: This paper explains how social marketing communication used by Cut Nyak Dien, Yogyakarta and Spekham, Surakarta–those are non goverment organization (NGO– to sosialize issues about anti-violences to women. The result of research show evaluation fase in the social marekting fases were not done. They were not evaluate the messages were received or not;and they were not identify the level of target audiens’ behaviour changes. The media that they used were variatives. Having social marketing communication, they always do with advocacy activities.

Highly toughened polypropylene/ethylene–propylene-diene monomer/zinc dimethacrylate ternary blends prepared via peroxide-induced dynamic vulcanization

Energy Technology Data Exchange (ETDEWEB)

Chen, Yukun, E-mail: cyk@scut.edu.cn [The Key Laboratory of Polymer Processing Engineering, Ministry of Education, South China University of Technology, Guangzhou 510640 (China); School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Xu, Chuanhui [College of Material Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Cao, Liming [The Key Laboratory of Polymer Processing Engineering, Ministry of Education, South China University of Technology, Guangzhou 510640 (China); School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Cao, Xiaodong [College of Material Science and Engineering, South China University of Technology, Guangzhou 510640 (China)

2013-02-15

Polypropylene (PP)/ethylene–propylene-diene monomer (EPDM)/zinc dimethacrylate (ZDMA) blends with remarkable toughness and extensibility were successfully prepared via peroxide dynamical vulcanization. A unique structure with the EPDM particles surrounded by a transition zone containing numerous polymerized ZDMA (PZDMA) nano-particles was observed for the first time by using transmission electron microscopy (TEM) examination, which contributed to the dramatically increase of Izod impact strength. Dynamic mechanical analysis (DMA) confirmed that the possible PZDMA graft products resulted from peroxide dynamical vulcanization improved the compatibility between EPDM and PP phases. The specific morphology of the PP/EPDM/ZDMA blends indicated that ZDMA can lead to size reduction and good distribution uniformity of the crosslinked rubber particles and the increase of adhesion between PP matrix and EPDM phases during deformation. The synergic effect of the increase in the effective volume of the EPDM phase, the improved compatibility and adhesion between EPDM and PP phases and the deformation of those fine rubber particles is believed to result in the remarkable high toughness and extensibility of the PP/EPDM/ZDMA blends. Particularly for the PP/EPDM ratio of 70/30, the PP/EPDM/ZDMA (70/30/9, w/w/w) ternary blends with the Izod impact strength nearly 2 times higher than PP/EPDM (70/30, w/w) binary blends and 15–20 times higher than PP are achieved; besides, the elongation at break of PP/EPDM/ZDMA ternary blends is 4–5 times higher than that of PP/EPDM binary blends. - Highlights: ► ZDMA largely toughen peroxide dynamically vulcanized PP/EPDM blend. ► PZDMA graft products improved the compatibility and adhesion between EPDM and PP. ► Size reduction and good distribution uniformity of crosslinked rubber particles.

Highly toughened polypropylene/ethylene–propylene-diene monomer/zinc dimethacrylate ternary blends prepared via peroxide-induced dynamic vulcanization

International Nuclear Information System (INIS)

Chen, Yukun; Xu, Chuanhui; Cao, Liming; Cao, Xiaodong

2013-01-01

Polypropylene (PP)/ethylene–propylene-diene monomer (EPDM)/zinc dimethacrylate (ZDMA) blends with remarkable toughness and extensibility were successfully prepared via peroxide dynamical vulcanization. A unique structure with the EPDM particles surrounded by a transition zone containing numerous polymerized ZDMA (PZDMA) nano-particles was observed for the first time by using transmission electron microscopy (TEM) examination, which contributed to the dramatically increase of Izod impact strength. Dynamic mechanical analysis (DMA) confirmed that the possible PZDMA graft products resulted from peroxide dynamical vulcanization improved the compatibility between EPDM and PP phases. The specific morphology of the PP/EPDM/ZDMA blends indicated that ZDMA can lead to size reduction and good distribution uniformity of the crosslinked rubber particles and the increase of adhesion between PP matrix and EPDM phases during deformation. The synergic effect of the increase in the effective volume of the EPDM phase, the improved compatibility and adhesion between EPDM and PP phases and the deformation of those fine rubber particles is believed to result in the remarkable high toughness and extensibility of the PP/EPDM/ZDMA blends. Particularly for the PP/EPDM ratio of 70/30, the PP/EPDM/ZDMA (70/30/9, w/w/w) ternary blends with the Izod impact strength nearly 2 times higher than PP/EPDM (70/30, w/w) binary blends and 15–20 times higher than PP are achieved; besides, the elongation at break of PP/EPDM/ZDMA ternary blends is 4–5 times higher than that of PP/EPDM binary blends. - Highlights: ► ZDMA largely toughen peroxide dynamically vulcanized PP/EPDM blend. ► PZDMA graft products improved the compatibility and adhesion between EPDM and PP. ► Size reduction and good distribution uniformity of crosslinked rubber particles

Polymeric membrane neodymium(III)-selective electrode based on 11,13-diaza-4,7,12-trioxo-2(3),8(9)-dibenzoyl- cyclotetridecane-1,11-diene

Energy Technology Data Exchange (ETDEWEB)

Chandra, Sulekh [Department of Chemistry, Zakir Husain College, University of Delhi, J.L.N. Marg, New Delhi, 110002 (India)], E-mail: schandra_00@yahoo.com; Singh, Dev Raj [Department of Chemistry, Zakir Husain College, University of Delhi, J.L.N. Marg, New Delhi, 110002 (India)

2009-02-25

We found that 11, 13-diaza-4, 7, 12-trioxo-2(3), 8(9)-dibenzoyl-cyclotetridecane-1, 11-diene (DATODBCT) can be used as an excellent ionophore in the construction of a novel neodymium(III) poly(vinylchloride) (PVC)-based membrane sensor. A membrane composition of 29% poly(vinylchloride), 59% dibutylphthalate (DBP), 9% DATODBCT and 3% sodiumtetrakis (p-chlorophenyl) borate (NaTpClPB), led to the optimum results. The Nd(III)-selectivity of the sensor, is relatively better as compared to a large number of lanthanide metal ions, such as lanthanum, gadolinium, samarium, dysprosium, praseodymium and ytterbium ions. The sensor response is Nernstian (with slope of 19.4 {+-} 0.3 mV per decade for the triply charged ion) over a wide concentration range (1.0 x 10{sup -8} to 1.0 x 10{sup -1} mol L{sup -1}) with a detection limit of 8.0 x 10{sup -7} mol L{sup -1}, a relatively fast response time, in the whole concentration range (<15 s), and a considerable life time at least for seven weeks in the pH range of 3.0-7.0.

Polymeric membrane neodymium(III)-selective electrode based on 11,13-diaza-4,7,12-trioxo-2(3),8(9)-dibenzoyl- cyclotetridecane-1,11-diene

International Nuclear Information System (INIS)

Chandra, Sulekh; Singh, Dev Raj

2009-01-01

We found that 11, 13-diaza-4, 7, 12-trioxo-2(3), 8(9)-dibenzoyl-cyclotetridecane-1, 11-diene (DATODBCT) can be used as an excellent ionophore in the construction of a novel neodymium(III) poly(vinylchloride) (PVC)-based membrane sensor. A membrane composition of 29% poly(vinylchloride), 59% dibutylphthalate (DBP), 9% DATODBCT and 3% sodiumtetrakis (p-chlorophenyl) borate (NaTpClPB), led to the optimum results. The Nd(III)-selectivity of the sensor, is relatively better as compared to a large number of lanthanide metal ions, such as lanthanum, gadolinium, samarium, dysprosium, praseodymium and ytterbium ions. The sensor response is Nernstian (with slope of 19.4 ± 0.3 mV per decade for the triply charged ion) over a wide concentration range (1.0 x 10 -8 to 1.0 x 10 -1 mol L -1 ) with a detection limit of 8.0 x 10 -7 mol L -1 , a relatively fast response time, in the whole concentration range (<15 s), and a considerable life time at least for seven weeks in the pH range of 3.0-7.0

The Labdane Ent-3-Acetoxy-Labda-8(17), 13-Dien-15-Oic Decreases Blood Pressure In Hypertensive Rats

Energy Technology Data Exchange (ETDEWEB)

Simplicio, Janaina A. [Programa de Pós-Graduação em Farmacologia - Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, SP (Brazil); Departamento de Enfermagem Psiquiátrica e Ciências Humanas - Laboratório de Farmacologia - Escola de Enfermagem de Ribeirão Preto (USP), Ribeirão Preto, SP (Brazil); Simão, Marilia R.; Ambrosio, Sergio R. [Núcleo de Pesquisa em Ciências e Tecnologia - Universidade de Franca (UNIFRAN), Franca, SP (Brazil); Tirapelli, Carlos R., E-mail: crtirapelli@eerp.usp.br [Departamento de Enfermagem Psiquiátrica e Ciências Humanas - Laboratório de Farmacologia - Escola de Enfermagem de Ribeirão Preto (USP), Ribeirão Preto, SP (Brazil)

2016-06-15

Labdane-type diterpenes induce lower blood pressure via relaxation of vascular smooth muscle; however, there are no studies describing the effects of labdanes in hypertensive rats. The present study was designed to investigate the cardiovascular actions of the labdane-type diterpene ent-3-acetoxy-labda-8(17), 13-dien-15-oic acid (labda-15-oic acid) in two-kidney 1 clip (2K-1C) renal hypertension. Vascular reactivity experiments were performed in aortic rings isolated from 2K-1C and normotensive (2K) male Wistar rats. Nitrate/nitrite (NOx) measurement was performed in aortas by colorimetric assay. Blood pressure measurements were performed in conscious rats. Labda-15-oic acid (0.1-300 µmol/l) and forskolin (0.1 nmol/l - 1 µmol/l) relaxed endothelium-intact and endothelium-denuded aortas from both 2K-1C and 2K rats. Labda-15-oic acid was more effective at inducing relaxation in endothelium-intact aortas from 2K pre-contracted with phenylephrine when compared to the endothelium-denuded ones. Forskolin was more potent than labda-15-oic acid at inducing vascular relaxation in arteries from both 2K and 2K-1C rats. Labda-15-oic acid-induced increase in NOx levels was lower in arteries from 2K-1C rats when compared to 2K rats. Intravenous administration of labda-15-oic acid (0.3-3 mg/kg) or forskolin (0.1-1 mg/kg) induced hypotension in conscious 2K-1C and 2K rats. The present findings show that labda-15-oic acid induces vascular relaxation and hypotension in hypertensive rats.

Structure-Activity Relationships for Some Diamine, Triamine and Schiff Base Derivatives and Their Copper(II) Complexes

OpenAIRE

Bolos, C. A.; Nikolov, G. St.; Ekateriniadou, L.; Kortsaris, A.; Kyriakidis, D. A.

1998-01-01

Ethylenediamine (en), putrescine (pu), diethylenetriamine (dien), dipropylenetriamine (dpta), spermidine (spmd) and their CuII compounds as well as the Schiff bases with 2-furaldehyde (dienOO), 2- thiophenecarboxaldehyde (dienSS) and pyrrole-2-carboxaldehyde (dienNN) of dien and that of dpta with 2- thiophenecarboxaldehyde (dptaSS), were prepared and characterised. They were tested against Bacillus substilis, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Proteus vulgaris and Xanth...

Computational Investigation of the Competition between the Concerted Diels-Alder Reaction and Formation of Diradicals in Reactions of Acrylonitrile with Non-Polar Dienes

Science.gov (United States)

James, Natalie C.; Um, Joann M.; Padias, Anne B.; Hall, H. K.; Houk, K. N.

2013-01-01

The energetics of the Diels-Alder cycloaddition reactions of several 1,3-dienes with acrylonitrile, and the energetics of formation of diradicals, were investigated with density functional theory (B3LYP and M06-2X) and compared to experimental data. For the reaction of 2,3-dimethyl-1,3-butadiene with acrylonitrile, the concerted reaction is favored over the diradical pathway by 2.5 kcal/mol using B3LYP/6-31G(d); experimentally this reaction gives both cycloadduct and copolymer. The concerted cycloaddition of cyclopentadiene with acrylonitrile is preferred computationally over the stepwise pathway by 5.9 kcal/mol; experimentally, only the Diels-Alder adduct is formed. For the reactions of (E)-1,3-pentadiene and acrylonitrile, both cycloaddition and copolymerization were observed experimentally; these trends were mimicked by the computational results, which showed only a 1.2 kcal/mol preference for the concerted pathway. For the reactions of (Z)-1,3-pentadiene and acrylonitrile, the stepwise pathway is preferred by 3.9 kcal/mol, in agreement with previous experimental findings that only polymerization occurs. M06-2X is known to give more accurate activation and reaction energetics but the energies of diradicals are too high. PMID:23758325

Quantum chemical investigations on the molecular structure, FTIR, UV-Vis and HOMO-LUMO analysis of 15-16-epoxy-7b, 9a dihydroxylabdane 13(16), 14-dien-6-one

Science.gov (United States)

Uppal, Anshul; Pathania, Kamni; Khajuria, Yugal

2018-05-01

The structural, spectroscopic (Fourier Transform Infrared (FT-IR), Ultra-Violet Visible (UV-VIS)) and thermodynamic properties of 15, 16-epoxy-7b, 9a dihydroxylabdane-13(16), 14-dien-6-one were studied by using both experimental techniques and theoretical methods. The FTIR spectrum of the title compound was recorded in the spectral range 4000-400 cm-1. The UV-VIS spectrum was measured in the spectral range 190-800 nm. The quantum chemistry calculations have been performed to compute optimized geometry, molecular parameters, vibrational frequencies along with intensities using Hartree Fock (HF) theory and Density Functional Theory (DFT) with 6-31G basis set. The calculated HOMO-LUMO energies show that the charge transfer occurs within the molecule. The temperature dependence of the thermodynamic properties like heat capacity, entropy and enthalpy of the optimized structure were obtained. Finally, a comparison between the experimental data and the calculated results presented a good agreement.

The Presence of Amorpha-4, 11-Diene Synthase, a Key Enzyme in Artemisinin Production in Ten Artemisia Species

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GA. Garoosi

2011-12-01

Full Text Available Background and the purpose of the study: Artemisinin is one of the most effective medicine against malaria, which is produced naturally by Artemisia annua in low yield. It is produced in a metabolic pathway, in which several genes and gene products are involved. One of the key genes in this pathway is am1, which encodes amorpha-4, 11-diene synthase (ADS, a key enzyme in artemisinin biosynthesis pathway. The aim of this study was to determine the presence of this gene in ten Artemisia species in order to increase the yield of production of Artemisinin. Methods : The experiments were carried out using PCR. Specific primers were designed based on the published am1 gene sequence obtained from A. annua (NCBI, accession number AF327527. Results: The amplification of this gene by the specific primers was considered as a positive sign for the potentiality of artemisinin production. Since the entire am1 gene was not amplified in any of the 10 species used, four parts of the gene, essential in ADS enzyme function, corresponding to a pair site of Arg10-Pro12 in the first 100 amino acids, b aspartate rich motif (DDXXD, c active site final lid and d active site including farnesyl diphosphate (FDP ionization sites and catalytic site in the ADS enzyme, were investigated. Major conclusion: The sequence corresponding to ADS active site was amplified only in A. annua, A. aucheri and A. chamaemelifolia. The negative results obtained with other species could be due to some sequence alteration, such as point mutations or INDELs. We propose A. aucheri and A. chamaemelifolia as two potential candidate species for further characterization, breeding and transferring am1 gene for artemisinin overproduction.

Triterpenos da resina de Protium heptaphyllum March (B0urseraceae: caracterização em misturas binárias

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Maia Robinson Magalhães

2000-01-01

Full Text Available Eight triterpenes, maniladiol, breine, ursa-9(11:12-dien-3beta-ol, oleana-9(11:12-dien-3beta-ol, 3alpha-hydroxy-tirucalla-8,24-dien-21-oic acid, 3alpha-hydroxy-tirucalla-7,24-dien-21-oic, alpha and beta amyrines were isolated as binary mixtures obtained from the chloroform extract of the oil-resin of Protium heptaphyllum March. The identification of the compounds was based mainly in 13C NMR data and mass spectra. The diene and the tetracyclic acid triterpenes were not reported before in the literature as constituents of the studied resin.

Structure-Activity Relationships for Some Diamine, Triamine and Schiff Base Derivatives and Their Copper(II) Complexes.

Science.gov (United States)

Bolos, C A; Nikolov, G S; Ekateriniadou, L; Kortsaris, A; Kyriakidis, D A

1998-01-01

Ethylenediamine (en), putrescine (pu), diethylenetriamine (dien), dipropylenetriamine (dpta), spermidine (spmd) and their Cu(II) compounds as well as the Schiff bases with 2-furaldehyde (dienOO), 2- thiophenecarboxaldehyde (dienSS) and pyrrole-2-carboxaldehyde (dienNN) of dien and that of dpta with 2- thiophenecarboxaldehyde (dptaSS), were prepared and characterised. They were tested against Bacillus substilis, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Proteus vulgaris and Xanthomonas campestris as antibacterial reagents, the highest activity being exhibited by Cu(dptaSS)(NO(3))(2) complex, which acts as antibiotic. In the antiproliferative tests (vs. T(47)D,L(929) and BHK(21/c13) cell lines) the best results were obtained with Cu(dptaSS)(2+) and Cu(dienSS)(2+). Electronic structure calculations gave for dptaSS and dienSS the higher negative charges on the N atoms. The counter-ions (Br(-), NO(3) (-) and SO(4) (2-)) play an important role by modulating the reagent's selectivity versus the bacteria [Gram(+) or Gram(-)], but they have no effect on the antiproliferative activity.

Antifungal isopimaranes from Hypoestes serpens.

Science.gov (United States)

Rasoamiaranjanahary, L; Guilet, D; Marston, A; Randimbivololona, F; Hostettmann, K

2003-09-01

Five isopimarane diterpenes (7beta-hydroxyisopimara-8,15-dien-14-one, 14alpha-hydroxyisopimara-7,15-dien-1-one, 1beta,14alpha-dihydroxyisopimara-7,15-diene, 7beta-hydroxyisopimara-8(14),15-dien-1-one and 7beta-acetoxyisopimara-8(14),15-dien-1-one) have been isolated from the leaves of Hypoestes serpens (Acanthaceae). All compounds exhibited antifungal activity against both the plant pathogenic fungus Cladosporium cucumerinum and the yeast Candida albicans; two of them also displayed an acetylcholinesterase inhibition. The structures of the compounds were determined by means of spectrometric methods, including 1D and 2D NMR experiments and MS analysis.

Optimisation of accelerators and vulcanising systems on thermal stability of natural rubber/recycled ethylene–propylene–diene-monomer blends

International Nuclear Information System (INIS)

Nabil, H.; Ismail, H.; Azura, A.R.

2014-01-01

Highlights: • Accelerator types and vulcanising systems were optimised in NR/R-EPDM blends. • Two methods of thermal analysis namely thermal ageing and TGA were employed. • EV and peroxide provided superior thermal stability due to stable –S–S and –C–C– linkages. • Crosslinking of the blends is a major concern on the retained properties of the blends. • A CBS-vulcanised using EV system is highly recommended for NR/R-EPDM blends. - Abstract: The present paper concerns the thermal stability of natural rubber/recycled ethylene–propylene–diene-monomer (NR/R-EPDM) blends. The blends were prepared using various accelerators and vulcanising systems. Four types of accelerators were selected, i.e., N-tert-butyl-2-benzothiazyl-sulphonamide (TBBS), N-cyclohexyl-benzothiazyl-sulphenamide (CBS), tetramethylthiuram disulphide (TMTD) and 2-mercaptobenzothiazol (MBT). Subsequently, semi-efficient vulcanisation (semi-EV), efficient vulcanisation (EV), peroxide and mixed sulphur/peroxide vulcanising systems (semi-EV/Peroxide and EV/Peroxide) were observed in the latter study. Two methods of thermal analysis namely, thermo-oxidative ageing and thermogravimetric analysis were conducted. The results indicated that TMTD and MBT-vulcanised blends showed slightly higher thermal stability than that of CBS and TBBS vulcanised blends however, CBS-vulcanised blends exhibited satisfactory overall mechanical and thermal stability in comparison to the other accelerators used. In the case of optimisation of vulcanising systems, semi-EV showed the highest un-aged tensile strength when compared against semi-EV/Peroxide, EV, EV/Peroxide and peroxide vulcanising systems, respectively. However, EV, EV/Peroxide and peroxide vulcanising systems provided slightly higher thermal stability, due to the blends consisted of more stable monosulphidic and carbon–carbon linkages in the vulcanised network. The activation energies of degradation of the blends were determined by applying

Assessment of the Thermodynamic Properties of DL-p-Mentha-1,8-diene, 4-Isopropyl-1-Methylcyclohexene (DL-limonene) by Inverse Gas Chromatography (IGC).

Science.gov (United States)

Farshchi, Negin; Abbasian, Ali; Larijani, Kambiz

2018-05-10

Limonene is a colorless liquid hydrocarbon and had been investigated as a plasticizer for many plastics. Prediction of solubility between different materials is an advantage in many ways, one of the most convenient ways to know the compatibility of materials is to determine the degree of solubility of them in each other. The concept of "solubility parameter" can help practitioners in this way.In this study, inverse gas chromatography (IGC) method at infinite dilution was used for determination of the thermodynamic properties of DL-p-mentha-1,8-diene, 4-Isopropyl-1-methylcyclohexene (DL-limonene). The interaction between DL-limonene and 13 solvents were examined in the temperature range of 63-123°C through the assessment of the thermodynamic sorption parameters, the parameters of mixing at infinite dilution, the weight fraction activity coefficient and the Flory-Huggins interaction parameters. Additionally, the solubility parameter for DL-limonene and the temperature dependence of these parameters was investigated as well.Results show that there is a temperature dependence in solubility parameter, which increases by decreasing temperature. However, there were no specific dependence between interaction parameters and temperature, but chemical structure appeared to have a significant effect on them as well as on the type and strength of intermolecular interactions between DL-limonene and investigated solvents. The solubility parameter δ2 of DL-limonene determined to be 19.20 (J/cm3)0.5 at 25°C.

Efficient androst-1,4-diene-3,17-dione production by co-expressing 3-ketosteroid-Δ1 -dehydrogenase and catalase in Bacillus subtilis.

Science.gov (United States)

Shao, M; Sha, Z; Zhang, X; Rao, Z; Xu, M; Yang, T; Xu, Z; Yang, S

2017-01-01

3-ketosteroid-Δ 1 -dehydrogenase (KSDD), a flavin adenine dinucleotide (FAD)-dependent enzyme involved in sterol metabolism, specifically catalyses the conversion of androst-4-ene-3,17-dione (AD) to androst-1,4-diene-3,17-dione (ADD). However, the low KSDD activity and the toxic effects of hydrogen peroxide (H 2 O 2 ) generated during the biotransformation of AD to ADD with FAD regeneration hinder its application on AD conversion. The aim of this work was to improve KSDD activity and eliminate the toxic effects of the generated H 2 O 2 to enhance ADD production. The ksdd gene obtained from Mycobacterium neoaurum JC-12 was codon-optimized to increase its expression level in Bacillus subtilis, and the KSDD activity reached 12·3 U mg -1 , which was sevenfold of that of codon-unoptimized gene. To improve AD conversion, catalase was co-expressed with KSDD in B. subtilis 168/pMA5-ksdd opt -katA to eliminate the toxic effects of H 2 O 2 generated during AD conversion. Finally, under optimized bioconversion conditions, fed-batch strategy was carried out and the ADD yield improved to 8·76 g l -1 . This work demonstrates the potential to improve enzyme activity by codon-optimization and eliminate the toxic effects of H 2 O 2 by co-expressing catalase. This study showed the highest ADD productivity ever reported and provides a promising strain for efficient ADD production in the pharmaceutical industry. © 2016 The Society for Applied Microbiology.

Metal-metal bonded compounds. V. Compounds with Ir (Rh)-Hg bonds containing a bridging and a chelating triazenido group which interconvert intramolecularly

NARCIS (Netherlands)

Koten, G. van; Vliet, P.I. van; Kokkes, M.; Vrieze, K.

1980-01-01

The compounds [(Diene)(RN{3}R'){2}MHgCl]{2} (M = Ir; Diene = COD; R = CH{3}, C{2}H{5}; R' = p-CH{3}C{6}H{4} and M = Rh; Diene = COD, NOR; R = CH{3}, C{2}H{5}, p-CH{3}-C{6}H{4}; R' = p-CH{3}C{6}H{4} have been prepared by reaction of [(Diene)MCl]{2} with [Hg(RN{3}R'){2}] and by reaction of

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.

Design and synthesis of new hybrids from 2-cyano-3,12-dioxooleana- 9-dien-28-oic acid and O2-(2,4-dinitrophenyl) diazeniumdiolate for intervention of drug-resistant lung cancer.

Science.gov (United States)

Kang, Fenghua; Ai, Yong; Zhang, Yihua; Huang, Zhangjian

2018-04-10

To search for new drugs for intervention of drug-resistant lung cancer, a series of hybrids 4-15 from 2-cyano-3,12-dioxooleana-9-dien-28-oic acid (CDDO) and O 2 -(2,4-dinitrophenyl) diazeniumdiolate were designed, synthesized and biologically evaluated. The most active compound 7 produced relatively high levels of nitric oxide (NO) and reactive oxygen species (ROS) in drug-resistant lung cancer A549/Taxol cells which over-express glutathione S-transferase π (GSTπ), and significantly inhibited the cells' proliferation (IC 50  = 0.349 ± 0.051 μM), superior to the positive controls CDDO-Me, JS-K and Taxol. The inhibitory activity of 7 could be attenuated by an NO scavenger, ROS scavenger or GSTπ inhibitor. In addition, 7 suppressed the Lon protease expression as well as induced cell apoptosis and cycle arrest in A549/Taxol cells more strongly than CDDO-Me or JS-K. Together, our findings suggest that 7 may be worth studying further for intervention of drug-resistant lung cancer. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

CO2/N2 Gas Separation Using Nanocomposite Membranes Comprised of Ethylene-Propylene-Diene Monomer/Multi-Walled Carbon Nanotube (EPDM/MWCNT

Directory of Open Access Journals (Sweden)

Zeinab Rajabi

2015-07-01

Full Text Available Nanocomposite membranes of ethylene-propylene-diene monomer/multiwalled carbon nanotubes (EPDM/MWCNT were prepared by solution casting, solvent evaporation and cross-link technique to be applied in CO2/N2 gas separation. Both simple and functionalized MWCNTs have been used. The effect of incorporated different amounts multiwalled carbon nanotubes (0-4 wt%, of both simple and functionalized types, on the performance of nanocomposite membranes was studied. Fourier transform infrared (FTIR spectroscopy and field emission scanning electron microscopy (FESEM were used to evaluate the structural/morphological observations of nanocomposite membranes. Comparing the FTIR results of pure and functionalized nanotubes confirmed the presence of carboxylic groups on the functional carbon nanotubes. The FESEM images indicated that at low concentrations, carbon nanotube particles were dispersed well in the EPDM matrix, but they formed agglomerates at concentrations beyond 1 wt%. By incorporation of MWCNTs, the mechanicalproperties of nanocomposite membranes including tensile strength, Young's modulus and elongation-at-break considerably were improved. By increasing carbon nanotube loading up to 0.75 wt%, the permeability of both CO2 and N2 and the CO2/N2 selectivity increased. Further loading led to higher permeability of CO2/N2, while the selectivity ofthe system decreased that could be attributed to further agglomeration of carbon nanotube particles. Furthermore, functionalization of carbon nanotubes improved their dispersion and the mechanical properties and gas separation performance of nanocomposite membranes. Through functionalizing of MWCNTs, both the CO2 permeability and CO2/N2 selectivity of the optimum membrane (0.75 wt% MWCNTs increased from 37.95 and 18.03 Barrer to 57.57 and 23.43 Barrer, respectively. At ambient temperature, by the increase in feed pressure a slight increase in the permeability of both CO2 and N2 gases was observed, while the CO2

VOLUME 8 (2003) Sada and J. Guthrie ABSTRACT

African Journals Online (AJOL)

denise

Conjugated dienes tend to form 1:1 Diels. Alder adducts instead of copolymerizing while non - conjugated dienes can react to form 1:1 or 1:2 copolymers with vinyl groups which are cyclic15. A more extensive description of the current knowledge on the kinetics of copolymerization of maleic anhydride with dienes is found in ...

Diversity-Oriented Approaches to Polycyclics and Bioinspired Molecules via the Diels-Alder Strategy: Green Chemistry, Synthetic Economy, and Beyond.

Science.gov (United States)

Kotha, Sambasivarao; Chavan, Arjun S; Goyal, Deepti

2015-05-11

We describe diverse approaches to various dienes and their utilization in the Diels-Alder reaction to produce a variety of polycycles. The dienes covered here are prepared by simple alkylation reaction or via the Claisen rearrangement or by enyne metathesis of alkyne or enyne building blocks. Here, we have also included the Diels-Alder chemistry of dendralenes, a higher analog of cross-conjugated dienes. The present article is inclusive of o-xylylene derivatives that are generated in situ starting with benzosultine or benzosulfone derivatives. The Diels-Alder reaction of these dienes with various dienophiles gave diverse polycyclic systems and biologically important targets.

Volatile constituents of Trichothecium roseum.

Science.gov (United States)

Vanhaelen, M; Vanhaelen-Fastre, R; Geeraerts, J

1978-06-01

In the course of investigation of Trichothecium roseum (Fungi Imperfecti) for its attractancy against Tyrophagus putrescentiae (cheese mite), the twenty following volatile compounds produced at a very low concentration by the microfungus were identified by gc, gc/ms, gc/c.i.ms and tlc: 3-methyl-1-butanol, 3-octanone, 1-octen-3-one, 3-octanol, octa-1,5-dien-3 one, 1-octen-3-ol, 6-methyl-5-hepten-2-ol, octa-1,5-dien-3 ol, furfural, linalool, linalyl acetate, terpineol (alpha and beta) citronellyl acetate, nerol, citronellol, phenylacetaldehyde, benzyl alcohol geranyl acetate, 1-phenyl ethanol and nerolidol. Octa-1,5-dien-3-ol and octa-1,5-dien-3-one have not been previously isolated from fungi; octa-1,5-dien-3-ol is the most potent attractant amount the volatile compounds detected by gc.

Plasma-polymerized perfluoro(methylcyclohexane) coating on ethylene propylene diene elastomer surface: Effect of plasma processing condition on the deposition kinetics, morphology and surface energy of the film

International Nuclear Information System (INIS)

Tran, N.D.; Dutta, N.K.; Choudhury, N. Roy

2005-01-01

Plasma polymerization of perfluoro (methylcyclohexane) was carried out under cold plasma process operated at 13.56 MHz to deposit pore-free, uniform, ultra-thin film on an ethylene propylene diene terpolymer (EPDM) substrate in a view to modify the surface characteristics. The plasma fluoropolymeric films were formed at different plasma treatment times (from 20 s to 16 min), applied powers (20 to 100 W) and precursor flow rates to produce high quality films in a controllable yet tunable fashion. Scanning electron microscopy was employed successfully to characterize the evolution of the morphological feature in the film and also to determine the thickness of the coating. The surface energy of the film was determined by sessile drop method using different solvents as probe liquids. It is observed that a pore-free homogeneous plasma polymer thin film is formed within 20 s of treatment time, however, the morphology of the film depends on the plasma processing conditions, such as plasma power, precursor flow rate and deposition time. With increased time and power at a constant flow rate, the morphology of the film progressively changes from flat smooth to globular and rough. The kinetics and activation energy of the plasma polymer film deposition process were also estimated. The surface energy of the EPDM substrate decreased dramatically with plasma coating, however, it appears to be independent of the treatment time

A comparison between the effects of gamma radiation and sulfur cure system on the microstructure and crosslink network of (styrene butadiene rubber/ethylene propylene diene monomer) blends in presence of nanoclay

Science.gov (United States)

Shoushtari Zadeh Naseri, Aida; Jalali-Arani, Azam

2015-10-01

Rubber blends based on (styrene-butadiene rubber (SBR)/ethylene-propylene-diene monomer (EPDM)) with and without organoclay (OC) were prepared through a melt mixing process. The concentration ratio of the rubber phases (EPDM/SBR; 50/50 wt%) and the amount of the OC were kept constant. The samples were then vulcanized by means of gamma radiation using a Co-60 gamma source as well as sulfur cure system. The effect of absorbed dose on the formation of the crosslinks was confirmed by the Fourier transform infrared spectroscopy (FTIR). The effects of absorbed dose, sulfur cure system and OC on the gel content, and crosslink density were evaluated by the chemical tests. Applying the Charlesby-Pinner equation to estimate the radiation chemical yield, revealed that the use of OC in the blend caused 20% reduction in the degradation/crosslinking ratio. Employing the swelling test data, some thermodynamic parameters were determined. Using field emission scanning electron microscopy (FE-SEM) to investigate microstructure of the samples revealed a more homogeneous structure and also an increase in compatibility of the blend components in the sample cured by the irradiation in comparison to that cured by the sulfur curing system.

Polar Diels-Alder reactions using electrophilic nitrobenzothiophenes. A combined experimental and DFT study

Science.gov (United States)

Della Rosa, Claudia D.; Mancini, Pedro M. E.; Kneeteman, Maria N.; Lopez Baena, Anna F.; Suligoy, Melisa A.; Domingo, Luis R.

2015-01-01

The reactions between 2- and 3-nitrobenzothiophenes with three dienes of different nucleophilicity, 1-methoxy-3-trimethylsilyloxy-1,3-butadiene, 1-trimethylsilyloxy-1,3-butadiene and isoprene developed in anhydrous benzene and alternative under microwave irradiation with molecular solvents or in free solvent conditions, respectively, for produce dibenzothiophenes permit to conclude that both nitroheterocycles act as electrophile with the cited dienes. In the cases of the dienes 1-methoxy-3-trimethylsilyloxy-1,3-butadiene and 1-trimethylsilyloxy-1,3-butadiene which posses major nucleophilicity the observed product is the normal cycloaddition one. However when the diene is isoprene the product with both electrophiles follow the hetero Diels-Alder way. These reactions are considered polar cycloaddition reactions and the yields are reasonables. Moreover the polar Diels-Alder reactions of nitrobenzothiophenes with electron rich dienes 1-trimethylsilyloxy-1,3-butadiene have been theoretically studied using DFT methods.

Radiation Vulcanization of Polymeric Blends Based on Ethylene Propylene Diene Monomer Rubber/ Waste Materials in Presence of Different Additives

International Nuclear Information System (INIS)

MOHAMED, R.M.

2015-01-01

In this investigation, the mechanical blending technique was applied for preparation of elastomeric blend of ethylene propylene diene monomer rubber (EPDM)and nitrile butadiene rubber (NBR) having a fixed ratio of (50/50) by weight. The prepared blend of EPDM/NBR (50/50) was used as a rubber matrix to be loaded with waste materials, namely rice husk (RH) as a natural waste filler and then with ground tire rubber (GTR) as an artificial one. The degree of loading varied from 5 p hr to 20 p hr. Ionizing radiation, namely ,gamma rays were applied for inducing vulcanization of prepared and loaded rubber blends, in the range from 5 kGy to 250 kGy. Different properties of prepared composites were followed up as a function of degree of loading with the waste material and dose of irradiation. The mechanical properties, namely tensile strength and elongation at break percent of the composites slightly decreased as the filler loading increased over the whole range of irradiation .Tensile modulus and hardness, on the other hand, showed an opposite trend, i.e. the increased. Other properties, namely physical, thermal and morphological confirmed the mechanical ones. Obtained results were affiliated with lack of interface adhesion between the waste materials and the rubber matrix elastomers. The lack of interface adhesion was improved by filling the composite with a limited content, up to 7 p hr, of the compatibilizer, namely, maleic anhydride (MAH). Measurements of different properties was carried out for composite loaded with 10 p hr of waste material. It has been found that the tensile properties were significantly improved with addition of the compatibilizing agent Further and significant improvement was attained in properties of prepared later composite by its loading with 40 p hr of either HAF- carbon black or Hisil as reinforcing fillers that participates in chemical as well as physical bonding. Similarly and lastly 8 p hr of N, N- methylene di acrylamide (MDA) were loaded

Synthesis and characterization of PTP/[Fe(CN)_3(dien)]·H_2O nanocomposite; study of electrical, thermal and photocatalytic properties

International Nuclear Information System (INIS)

Moosvi, Syed Kazim; Majid, Kowsar; Ara, Tabassum

2016-01-01

Highlights: • Synthesis of PTP nanocomposite with photoadduct via in-situ chemical polymerisation. • Photoadduct and its nanocomposite are characterized by UV–Vis, FTIR, XRD, and SEM characterisation techniques. • Enhanced thermal stability of nanocomposite as compared to pure PTP. • Nanocomposite exhibit non-linear I–V behaviour. • Improved electrical properties and photocatalytic activity of nanocomposite as compared to pure PTP. - Abstract: Polythiophene/[Fe(CN)_3(dien)]·H_2O nanocomposite was synthesised by oxidative chemical polymerisation method. Photoadduct was synthesised by irradiating an equimolar mixture of potassium ferricyanide and diethylenetriamine which was then reduced to nanosize by high energy ball mill. The reduction of photoadduct to nanosize was confirmed from XRD. Nanocomposite of PTP with photoadduct was then prepared by oxidative chemical polymerisation using FeCl_3 as oxidant. The successful synthesis of nanocomposite was confirmed from FTIR, XRD and SEM. TGA revealed higher thermal stability of nanocomposite as compared to pure PTP. I–V characteristics plotted on a log–log scale showed two distinct power law regions in case of nanocomposite. At lower voltages, the transport mechanism follows Ohm’s law. At higher voltages, the mechanism is consistent with space charge-limited emission. Furthermore, nanocomposite shows enhanced conductivity as compared to pure PTP. From dielectric studies, an appreciable high value of dielectric constant (4.4 × 10"6 at 100 Hz) and ac conductivity (2.1 × 10"9 S/m at 300 kHz) of nanocomposite was obtained. This indicates the possible application of this nanocomposite in charge storage devices. The photocatalytic activity of the materials was studied against the methyl orange (MO) dye under UV–Vis light and 76% degradation of MO dye was achieved in presence of nanocomposite in just 2 h, hence indicating its better photocatalytic efficiency. Results thus obtained indicate the

The antidiabetic compound 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione, isolated from Averrhoa carambola L., demonstrates significant antitumor potential against human breast cancer cells.

Science.gov (United States)

Gao, Ying; Huang, Renbin; Gong, Yixuan; Park, Hyo Sim; Wen, Qingwei; Almosnid, Nadin Marwan; Chippada-Venkata, Uma D; Hosain, Najlaa Abdulrhman; Vick, Eric; Farone, Anthony; Altman, Elliot

2015-09-15

2-Dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) is a cyclohexanedione found in the roots of Averrhoa carambola L., commonly known as starfruit. Researchers have shown that DMDD has significant therapeutic potential for the treatment of diabetes; however, the effects of DMDD on human cancers have never been reported. We investigated the cytotoxic effects of DMDD against human breast, lung and bone cancer cells in vitro and further examined the molecular mechanisms of DMDD-induced apoptosis in human breast cancer cells. DMDD suppressed the growth of breast carcinoma cells, but not normal mammary epithelial cells, via induction of G1 phase cell cycle arrest, oxidative stress and apoptosis. DMDD increased the level of intracellular reactive oxygen species (ROS) and DMDD-induced ROS generation was found to be associated with the mitochondrial activity. The cytotoxicity that was induced by DMDD was attenuated by co-treatment with the antioxidant N-acetyl-L-cysteine (NAC). DMDD-induced cell apoptosis involved the activation of both the intrinsic mitochondrial pathway and the extrinsic receptor pathway. In addition, DMDD inhibited the canonical NF-κB signaling pathway at all steps, including TNF-α production, phosphorylation of NF-κB p65 and IκBα, as well as TNF-α activated NF-κB p65 nuclear translocation.Collectively, our studies indicate that DMDD has significant potential as a safe and efficient therapeutic agent for the treatment of breast cancer.

Chemical constituents from the stem of Brosimum potabile (Moraceae Constituintes químicos do cerne de Brosimum potabile (Moraceae

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Viviane Gomes da Costa Abreu

2010-12-01

Full Text Available Three coumarins, 5-methoxypsoralene, xanthyletin, and (--marmesin, have been isolated from the ethanolic extract of the stem of the Amazonian plant Brosimum potabile. The structures were determined on the basis of NMR analyses and by comparison with spectroscopic data in the literature. The analysis of the hexane fractions by GC-MS in EIMS mode suggested the presence of (1-methylpentyl-benzene; α,α-dimethyl-4-(1-methylethyl-benzenemethanol; 1-methyl-3,5-bis(1-methylethyl-benzene; urs-12-ene; chola-5,22-dien-3β-ol; cholesta-4,6-dien-3β-ol; sitosteryl 9(Z-octadecenoate; cholesta-5,22-dien-3β-ol; cholesta-4,6,22-trien-3-one; and cholesta-4,22-dien-3-one. NMR data of other hexane fractions indicated the presence of 3β-acetoxy-lup-12,20(29-diene; 3β-acetoxy-olean-12-ene; 3β-acetoxy-urs-12-ene; and adian-5-ene. All these compounds are first described in B. potabile.Três cumarinas, 5-metoxipsoraleno, xantiletina e (--marmesina, foram isoladas no extrato etanólico do cerne da planta amazônica Brosimum potabile. Suas estruturas foram determinadas a partir das análises por RMN e por comparação com dados espectroscópicos da literatura. As análises das frações hexânicas por CG/EM sugeriram a presença de (1-metilpentil-benzeno; α,α-dimetil-4-(1-metiletil-benzenometanol; 1-metil-3,5-bis(1-metiletil-benzeno; urs-12-eno; cola-5,22-dien-3β-ol; colesta-4,6-dien-3β-ol; (9Z-octadecenoato de sitosterila; colesta-5,22-dien-3β-ol; colesta-4,6,22-trien-3-ona e colesta-4,22-dien-3-ona. Dados de RMN de outras frações hexânicas indicaram a presença de 3β-acetóxi-lup-12,20(29-dieno; 3β-acetóxi-olean-12-eno; 3β-acetóxi-urs-12-eno e adian-5-eno. Todos esses compostos foram identificados pela primeira vez em B. potabile.

Protection of HepG2 cells against acrolein toxicity by 2-cyano-3,12-dioxooleana-1,9-dien-28-imidazolide via glutathione-mediated mechanism.

Science.gov (United States)

Shah, Halley; Speen, Adam M; Saunders, Christina; Brooke, Elizabeth A S; Nallasamy, Palanisamy; Zhu, Hong; Li, Y Robert; Jia, Zhenquan

2015-10-01

Acrolein is an environmental toxicant, mainly found in smoke released from incomplete combustion of organic matter. Several studies showed that exposure to acrolein can lead to liver damage. The mechanisms involved in acrolein-induced hepatocellular toxicity, however, are not completely understood. This study examined the cytotoxic mechanisms of acrolein on HepG2 cells. Acrolein at pathophysiological concentrations was shown to cause apoptotic cell death and an increase in levels of protein carbonyl and thiobarbituric acid reactive acid substances. Acrolein also rapidly depleted intracellular glutathione (GSH), GSH-linked glutathione-S-transferases, and aldose reductase, three critical cellular defenses that detoxify reactive aldehydes. Results further showed that depletion of cellular GSH by acrolein preceded the loss of cell viability. To further determine the role of cellular GSH in acrolein-mediated cytotoxicity, buthionine sulfoximine (BSO) was used to inhibit cellular GSH biosynthesis. It was observed that depletion of cellular GSH by BSO led to a marked potentiation of acrolein-mediated cytotoxicity in HepG2 cells. To further assess the contribution of these events to acrolein-induced cytotoxicity, triterpenoid compound 2-cyano-3,12-dioxooleana-1,9-dien-28-imidazolide (CDDO-Im) was used for induction of GSH. Induction of GSH by CDDO-Im afforded cytoprotection against acrolein toxicity in HepG2 cells. Furthermore, BSO significantly inhibited CDDO-Im-mediated induction in cellular GSH levels and also reversed cytoprotective effects of CDDO-Im in HepG2 cells. These results suggest that GSH is a predominant mechanism underlying acrolein-induced cytotoxicity as well as CDDO-Im-mediated cytoprotection. This study may provide understanding on the molecular action of acrolein which may be important to develop novel strategies for the prevention of acrolein-mediated toxicity. © 2014 by the Society for Experimental Biology and Medicine.

Crystal Structure and Magnetic Behavior of Two New Dinuclear Carbonato-Bridged Copper(II) Compounds. Superexchange Pathway for the Different Coordination Modes of the Carbonato Bridge in Polynuclear Copper(II) Compounds.

Science.gov (United States)

Escuer, Albert; Mautner, Franz A.; Peñalba, Evaristo; Vicente, Ramon

1998-08-24

Four new &mgr;-CO(3)(2-) copper(II) complexes with different coordination modes for the carbonato bridge have been obtained by fixation of atmospheric CO(2): {(&mgr;(3)-CO(3))[Cu(3)(ClO(4))(3)(Et(3)dien)(3)]}(ClO(4)) (1), Et(3)dien = N,N',N"-triethylbis(2-aminoethane)amine; {(&mgr;-CO(3))[Cu(2)(H(2)O)(Et(4)dien)(2)]}(ClO(4))(2).H(2)O (2), Et(4)dien = N,N,N",N"-tetraethyl-bis(2-aminoethane)amine; {(&mgr;-CO(3))[Cu(2)(H(2)O)(2)(EtMe(4)dien)(2)]} (ClO(4))(2).2H(2)O (3), EtMe(4)dien = N'-ethyl-N,N,N",N"-tetramethylbis(2-aminoethane)amine; and {(&mgr;-CO(3))[Cu(2)(H(2)O)(Me(5)dien)(2)]}(ClO(4))(2).H(2)O (4), Me(5)dien = N,N,N',N",N"-pentamethylbis(2-aminoethane)amine. The crystal structures have been solved for 2, monoclinic system, space group P2(1)/n, formula [C(25)H(62)Cl(2)Cu(2)N(6)O(13)] with a = 12.763(6) Å, b = 25.125(8) Å, c = 13.261(4) Å, beta = 111.85(3) degrees, Z = 4, and for 3, triclinic system, space group P&onemacr;, formula [C(21)H(58)Cl(2)Cu(2)N(6)O(15)] with a = 8.412(3) Å, b = 14.667(4) Å, c = 16.555(5) Å, alpha = 99.66(2) degrees, beta = 102.14(2) degrees, gamma = 104.72(2) degrees, Z = 2. Susceptibility measurements show ferromagnetic behavior (J = +6.7(6) cm(-)(1)) for the trinuclear compound 1 whereas 2-4 are antiferromagnetically coupled with J = -17.8(8), -125.5(9), and -21.2(3) cm(-)(1) respectively. Certain synthetic aspects that may be related to the nuclearity of the copper(II) &mgr;-CO(3)(2-) compounds and the superexchange pathway for the different coordination modes of the carbonato bridge are discussed.

(1R,6R,13R,18R-(Z,Z-1,18-Bis[(4R-2,2-dimethyl-1,3-dioxolan-4-yl]-3,16-dimethylene-8,20-diazadispiro[5.6.5.6]tetracosa-7,19-diene

Directory of Open Access Journals (Sweden)

Stéphanie M. Guéret

2010-07-01

Full Text Available The crystal structure of the title compound, C34H54N2O4, has been solved in order to prove the relative and absolute chirality of the newly-formed stereocentres which were established using an asymmetric Diels–Alder reaction at an earlier stage in the synthesis. This unprecedented stable dialdimine contains a 14-membered ring and was obtained as the minor diastereoisomer in the Diels–Alder reaction. The absolute stereochemistry of the stereocentres of the acetal functionality was known to be R based on the use of a chiral (R-trisubstituted dienophile derived from enantiopure (S-glyceraldehyde. The assignment of the configuration in the dienophile and the title di-aldimine differs from (S-glyceraldehyde due to a change in the priority order of the substituents. The crystal structure establishes the presence of six stereocentres all attributed to be R. The 14-membered ring contains two aldimine bonds [C—N = 1.258 (2 and 1.259 (2 Å]. It adopts a similar conformation to that proposed for trans–trans-cyclotetradeca-1,8-dienes.

Cucurbitane-type triterpenoids from the fruit pulp of Momordica charantia.

Science.gov (United States)

Liao, Yun-Wen; Chen, Chiy-Rong; Kuo, Yueh-Hsiung; Hsu, Jue-Liang; Shih, Wen-Ling; Cheng, Hsueh-Ling; Huang, Tzou-Chi; Chang, Chi-I

2012-12-01

Three new cucurbitane-type triterpenoids, 5beta,19-epoxy-23(R)-methoxycucurbita-6,24-dien-3beta-ol (1), 5beta,19-epoxy-23(S)-methoxycucurbita-6,24-dien-3beta-ol (2), and 3beta-hydroxy-23(R)-methoxycucurbita-6,24-dien-5beta,19-olide (3), were isolated from the fruit pulp of Momordica charantia. Their structures were established on the basis of extensive NMR (1H, 13C, COSY, HMQC, HMBC, and NOESY) and EI-MS studies. Compound 1 exhibited cytotoxic activity against the SK-Hep 1 cell line.

Caraterização composicional do AES - um copolímero de enxertia de poli(estireno-co-acrilonitrila em poli(etileno-co-propileno-co-dieno Compositional characterization of AES a graft copolymer based on poly(styrene-co-acrylonitrile and poly(etyhlene-co-propylene-co-diene

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Renato Turchet

2006-06-01

Full Text Available O objetivo deste trabalho é a caracterização do AES, um copolímero de enxertia de poli(estireno-co-acrilonitrila, SAN, em poli(etileno-co-propileno-co-dieno, EPDM. Para tanto, o AES foi submetido à extração seletiva de seus componentes: o SAN livre, o EDPM livre, e o copolímero de enxertia EPDM-g-SAN. O AES e suas frações foram caracterizados por espectroscopia de infravermelho, análise elementar, calorimetria diferencial de varredura e ressonância magnética nuclear, RMN¹H e RMN13C. O AES analisado apresenta a seguinte composição em massa: 65% de EPDM-g-SAN, 13% de EPDM livre e 22% de SAN livre. O EPDM apresenta 69,8% em massa de etileno, 26,5% em massa de propileno e 4,6% em massa do dieno, 2-etilideno-5-norboneno, ENB. O SAN apresenta razão em massa acrilonitrila/estireno de 28/72 e distribuição randômica de comonômeros de estireno e acrilonitrila. Estes resultados são concordantes com a composição do AES fornecida pelo fabricante, indicando que a metodologia proposta é adequada.This work aims the characterization of AES, a graft copolymer based on poly(styrene-co-acrylonitrile, SAN, and poly(etyhlene-co-propylene-co-diene, EPDM. AES was submitted to selective extraction of its components: free SAN, EPDM chains and the graft copolymer EPDM-g-SAN. AES and its fractions were characterized by infrared spectroscopy, elemental analysis, differential scanning calorimetry, 13C and ¹H nuclear magnetic resonance. The AES has 65 wt % of EPDM-g-SAN, 13 wt % of free EPDM and 22 wt % of free SAN. EPDM has 69.8 wt % of ethylene, 26.5 wt % of propylene and 4.6 wt % of diene, 2-ethylidene-5-norbonene ENB. SAN presents acrylonitrile/styrene mass ratio of 28/72 and a random distribution of acrylonitrile and styrene comonomers. These results are in agreement with the composition reported by the AES supplier, indicating that the proposed methodology is adequate.

Synthesis and characterization of PTP/[Fe(CN){sub 3}(dien)]·H{sub 2}O nanocomposite; study of electrical, thermal and photocatalytic properties

Energy Technology Data Exchange (ETDEWEB)

Moosvi, Syed Kazim; Majid, Kowsar, E-mail: kowsarmajid@rediffmail.com; Ara, Tabassum

2016-10-20

Highlights: • Synthesis of PTP nanocomposite with photoadduct via in-situ chemical polymerisation. • Photoadduct and its nanocomposite are characterized by UV–Vis, FTIR, XRD, and SEM characterisation techniques. • Enhanced thermal stability of nanocomposite as compared to pure PTP. • Nanocomposite exhibit non-linear I–V behaviour. • Improved electrical properties and photocatalytic activity of nanocomposite as compared to pure PTP. - Abstract: Polythiophene/[Fe(CN){sub 3}(dien)]·H{sub 2}O nanocomposite was synthesised by oxidative chemical polymerisation method. Photoadduct was synthesised by irradiating an equimolar mixture of potassium ferricyanide and diethylenetriamine which was then reduced to nanosize by high energy ball mill. The reduction of photoadduct to nanosize was confirmed from XRD. Nanocomposite of PTP with photoadduct was then prepared by oxidative chemical polymerisation using FeCl{sub 3} as oxidant. The successful synthesis of nanocomposite was confirmed from FTIR, XRD and SEM. TGA revealed higher thermal stability of nanocomposite as compared to pure PTP. I–V characteristics plotted on a log–log scale showed two distinct power law regions in case of nanocomposite. At lower voltages, the transport mechanism follows Ohm’s law. At higher voltages, the mechanism is consistent with space charge-limited emission. Furthermore, nanocomposite shows enhanced conductivity as compared to pure PTP. From dielectric studies, an appreciable high value of dielectric constant (4.4 × 10{sup 6} at 100 Hz) and ac conductivity (2.1 × 10{sup 9} S/m at 300 kHz) of nanocomposite was obtained. This indicates the possible application of this nanocomposite in charge storage devices. The photocatalytic activity of the materials was studied against the methyl orange (MO) dye under UV–Vis light and 76% degradation of MO dye was achieved in presence of nanocomposite in just 2 h, hence indicating its better photocatalytic efficiency. Results thus

Zinc mediated domino elimination-alkylation of methyl 5-iodopentofuranosides

DEFF Research Database (Denmark)

Hyldtoft, Lene; Poulsen, Carina Storm; Madsen, Robert

1999-01-01

5-Iodopentofuranosides are converted with zinc and allyl/propargyl bromide into dienes/enynes which are further used in carbohydrate annulation reactions.......5-Iodopentofuranosides are converted with zinc and allyl/propargyl bromide into dienes/enynes which are further used in carbohydrate annulation reactions....

Sequential Diels–Alder/[3,3]-sigmatropic rearrangement reactions of β-nitrostyrene with 3-methyl-1,3-pentadiene

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Peter A. Wade

2013-10-01

Full Text Available The tin(IV-catalyzed reaction of β-nitrostyrene with (E-3-methyl-1,3-pentadiene in toluene afforded two major nitronic ester cycloadducts in 27% and 29% yield that arise from the reaction at the less substituted diene double bond. Also present were four cycloadducts from the reaction at the higher substituted diene double bond, two of which were the formal cycloadducts of (Z-3-methyl-1,3-pentadiene. A Friedel–Crafts alkylation product from the reaction of the diene, β-nitrostyrene, and toluene was also obtained in 10% yield. The tin(IV-catalyzed reaction of β-nitrostyrene with (Z-3-methyl-1,3-pentadiene in dichloromethane afforded four nitronic ester cycloadducts all derived from the reaction at the higher substituted double bond. One cycloadduct was isolated in 45% yield and two others are formal adducts of the E-isomer of the diene. The product formation in these reactions is consistent with a stepwise mechanism involving a zwitterionic intermediate. The initially isolated nitronic ester cycloadducts underwent tin(IV-catalyzed interconversion, presumably via zwitterion intermediates. Cycloadducts derived from the reaction at the less substituted double bond of (E-3-methyl-1,3-pentadiene underwent a [3,3]-sigmatropic rearrangement on heating to afford 4-nitrocyclohexenes. Cycloadducts derived from the reaction at the higher substituted diene double bond of either diene failed to undergo a thermal rearrangement. Rates and success of the rearrangement are consistent with a concerted mechanism possessing a dipolar transition state. An initial assessment of substituent effects on the rearrangement process is presented.

Synthetic Strategies for Converting Carbohydrates into Carbocycles by the Use of Olefin Metathesis

DEFF Research Database (Denmark)

Madsen, Robert

2007-01-01

This microreview covers recent advances in the use of ring-closing metathesis for the synthesis of carbocycles from carbohydrates. Various strategies for the synthesis of a,w-dienes from carbohydrates are presented, which give rise to a large variety of dienes with different stereochemistry, prot...

Sterol composition from inflorescences of Hieracium pilosella L.

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Tadeusz Krzaczek

2011-01-01

Full Text Available The fraction of sterol acetates from the inflorescences of Hieracium pilosella has been isolated in the typical way from petroleum ether extract. By means of the weight method the total amount of sterols was determined (0.2659%. The mixtures of sterol acetates and free sterols were investigated using GC-MS techniques. The occurrence of about 18 sterols has been observed. Cholesterol, cholest-8(14-en-3b-ol, cholesta-5.7-dien-3b-ol, cholest-7-en-3b-ol, ergosta-5.24-dien-3b-ol, campesterol, stigmasterol, b-sitosterol, fucosterol, 5a-stigmast-7-en-3a-ol were identified. The probable structures of lophenol, isofucosterol, 5a-stigmasta-7.24-dien-3b-ol, lanosta-9(11.24-dien-3b-ol and 24-ethylidene lophenol were stated on the basis of literature data. The last 4 sterols occur in a vestigial quantity, which made its identification impossible. Sitos erol and cholesterol are remarkably dominating sterols in the fraction.

Sterols from the Lakshadweep sponge, Ircinia ramosa (Killer)

Digital Repository Service at National Institute of Oceanography (India)

Parameswaran, P.S.; Naik, C.G.; Das, B.; Kamat, S.Y.

Four monohydroxy sterols, viz, (22E,24S)-24-methylcholest-5,22-dien-3(beta)-ol (3), cholesterol (4), 24(Xi)-ethylcholesterol (8) and the corresponding Delta super(4)-3 ketones, viz. (22E,24S)-24-methylcholest-4,22-dien-3-one (1), cholest-4-en-3-one...

Labdane diterpenoids from Curcuma amada rhizomes collected in Myanmar and their antiproliferative activities.

Science.gov (United States)

Win, Nwet Nwet; Ito, Takuya; Ngwe, Hla; Win, Yi Yi; Prema; Okamoto, Yasuko; Tanaka, Masami; Asakawa, Yoshinori; Abe, Ikuro; Morita, Hiroyuki

2017-10-01

Four new labdane diterpenoids, 12β-hydroxy-15-norlabda-8(17),13(14)-dien-16-oic acid (1), (E)-15-ethoxy-15-methoxylabda-8(17),12-dien-16-al (2), (E)-15α-ethoxy-14α-hydroxylabda-8(17),12-dien-16-olide (3), and 15-ethoxy-12β-hydroxylabda-8(17),13(14)-dien-16,15-olide (4) were isolated from the methanol extract of Curcuma amada rhizomes collected in Myanmar, together with 13 known analogs. Their structures were elucidated by extensive spectroscopic techniques. All of the isolates were evaluated for their antiproliferative activities against a small panel of five different human cancer cell lines (A549, human lung cancer; HeLa, human cervical cancer; MCF7, human breast cancer; PANC-1 and PSN-1, human pancreatic cancer). Among the isolates, compounds 2-4, 7, 8, 12, and 17 showed mild antiproliferative activities with IC 50 values ranging from 19.7 to 96.1μM. (E)-14-Hydroxy-15-norlabda-8(17),12-dien-16-al (11) exhibited strong antiproliferative activities selectively against HeLa, PANC-1, and PSN-1 cells, with IC 50 values of 5.88, 1.00, and 3.98μM, respectively. These potencies were comparable to those of the positive control, 5-fluorouracil. Copyright © 2017 Elsevier B.V. All rights reserved.

New α-Glucosidase Inhibitory Triterpenic Acid from Marine Macro Green Alga Codium dwarkense Boergs

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Liaqat Ali

2015-07-01

Full Text Available The marine ecosystem has been a key resource for secondary metabolites with promising biological roles. In the current study, bioassay-guided phytochemical investigations were carried out to assess the presence of enzyme inhibitory chemical constituents from the methanolic extract of marine green alga—Codium dwarkense. The bioactive fractions were further subjected to chromatographic separations, which resulted in the isolation of a new triterpenic acid; dwarkenoic acid (1 and the known sterols; androst-5-en-3β-ol (2, stigmasta-5,25-dien-3β,7α-diol (3, ergosta-5,25-dien-3β-ol (4, 7-hydroxystigmasta-4,25-dien-3-one-7-O-β-d-fucopyranoside (5, 7-hydroxystigmasta-4,25-dien-3-one (6, and stigmasta-5,25-dien-3β-ol (7. The structure elucidation of the new compound was carried out by combined mass spectrometry and 1D (1H and 13C and 2D (HSQC, HMBC, COSY, and NOESY NMR spectroscopic data. The sub-fractions and pure constituents were assayed for enzymatic inhibition of alpha-glucosidase. Compound 1 showed significant inhibition at all concentrations. Compounds 2, 3, 5, and 7 exhibited a dose-dependent response, whereas compounds 4–6 showed moderate inhibition. Utilizing such marine-derived biological resources could lead to drug discoveries related to anti-diabetics.

Triterpene Esters: Natural Products from Dorstenia arifolia (Moraceae

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Maria Auxiliadora C. Kaplan

2013-04-01

Full Text Available The phytochemical study of Dorstenia arifolia Lam. (Moraceae has led to the identification of 18 triterpenes esterified by fatty acids, five triterpenes without esterification, 12 triterpenes esterified by acetic acid, together with a known furanocoumarin: α-amyrin (1, β-amyrin (2 α-amyrin acetate (3 β-amyrin acetate (4, α-amyrin octanoate (5, β-amyrin octanoate (6, α-amyrin decanoate (7, β-amyrin decanoate (8, α-amyrin dodecanoate (9, β-amyrin dodecanoate (10, α-amyrin tetradecanoate (11, β-amyrin tetradecanoate (12, α-amyrin hexadecanoate (13, β-amyrin hexadecanoate (14, glutinol (15, glutinyl acetate (16, 11-oxo-α-amyrin (17, 11-oxo-β-amyrin (18, 11-oxo-α-amyrin acetate (19, 11-oxo-β-amyrin acetate (20 11-oxo-α-amyrin octanoate (21 11-oxo-β-amyrin octanoate (22, 11-oxo-α-amyrin decanoate (23, 11-oxo-β-amyrin decanoate (24 11-oxo-α-amyrin dodecanoate (25 11-oxo-β-amyrin dodecanoate (26, ursa-9(11,12-dien-3-yl acetate (27, oleana-9(11,12-dien-3-yl acetate (28, ursa-9(11,12-dien-3-yl decanoate (29, oleana-9(11,12-dien-3-yl decanoate (30, 12,13-epoxyolean-3-yl acetate (31, 12,13-epoxyolean-9(11en-3-yl acetate (32, taraxeryl acetate (33, lupenyl acetate (34, lanosta-8,24-dien-3-yl acetate (35 and psoralen (36. The identification of the triterpene compounds isolated as isomeric mixtures obtained from the hexane extract was based mainly in mass spectra and 13C-NMR data. The long-chain alkanoic acid esters of the triterpenes α- and β-amyrin; 11-oxo-α- and 11-oxo-β-amyrin; ursa- and olean-9(11,12-dien-3-yl; have not been reported before in the literature as constituents of the Dorstenia genus.

Tandem radical reactions and ring-closing metathesis. Application in the synthesis of cyclooctenes.

Science.gov (United States)

Sibi, Mukund P; Aasmul, Mona; Hasegawa, Hikaru; Subramanian, Thangaiah

2003-08-07

[reaction: see text] Fumarate- and acrylate-substituted oxazolidinones undergo tandem radical reaction to form dienes in moderate to good yields. The resulting dienes provide cyclooctenes in moderate to good yields after ring-closing metathesis (RCM). The role of the carbon backbone substituents and other variables in the efficiency of the eight-membered ring formation is discussed.

Triterpenoids from Arctium lappa.

Science.gov (United States)

Jeelani, S; Khuroo, M A

2012-01-01

Phytochemical investigation of the leaves of Arctium lappa led to the isolation of two triterpenoids, characterised by NMR, IR and MS as 3α-hydroxylanosta-5,15-diene and 3α-acetoxy-hop-22(29)-ene. 3α-hydroxylanosta-5,15-diene is a new triterpenoid and is isolated for the first time from this genus.

Effect of 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione, isolated from Averrhoa carambola L. (Oxalidaceae) roots, on advanced glycation end-product-mediated renal injury in type 2 diabetic KKAy mice.

Science.gov (United States)

Zheng, Ni; Lin, Xing; Wen, Qingwei; Kintoko; Zhang, Shijun; Huang, Jianchun; Xu, Xiaohui; Huang, Renbin

2013-05-10

The roots of Averrhoa carambola L. (Oxalidaceae) have a long history of medical use in traditional Chinese medicine for treating diabetes and diabetic nephropathy. 2-Dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) was isolated from the tuberous roots of A. carambola L. The purpose of this study was to investigate the beneficial effect of DMDD on the advanced glycation end-product-mediated renal injury in type 2 diabetic KKAy mice with regard to prove its efficacy by local traditional practitioners in the treatment of kidney frailties in diabetics. KKAy mice were orally administrated DMDD (12.5, 25, 50mg/kg body weight/d) or aminoguanidine (200mg/kg body weight/d) for 8 weeks. Hyperglycemia, renal AGE formation, and the expression of related proteins, such as the AGE receptor, nuclear factor-κB, transforming growth factor-β1, and N(ε)-(carboxymethyl)lysine, were markedly decreased by DMDD. Diabetes-dependent alterations in proteinuria, serum creatinine, creatinine clearance, and serum urea-N and glomerular mesangial matrix expansion were attenuated after treatment with DMDD for 8 weeks. The activities of superoxide dismutase and glutathione peroxidase, which are reduced in the kidneys of KKAy mice, were enhanced by DMDD. These findings suggest that DMDD may inhibit the progression of diabetic nephropathy and may be a therapeutic agent for regulating several pharmacological targets to treat or prevent of diabetic nephropathy. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

In diens van die Kompanjie

African Journals Online (AJOL)

was ook siektes WQl Jit onvoldoende of ondoel- treffende voeding, eentonige kos en ontoerei- kende geneesmiddels voortgespruit het, terwyl behoorlike versorging dikwels ontbreek he!. Doodsoorsake tydens die seereis het voartge- vloei uit ongelukke aan boord, beperkte ruimte vir die bemanning en geringe vars lug, ...

A comparison between the effects of gamma radiation and sulfur cure system on the microstructure and crosslink network of (styrene butadiene rubber/ethylene propylene diene monomer) blends in presence of nanoclay

International Nuclear Information System (INIS)

Shoushtari Zadeh Naseri, Aida; Jalali-Arani, Azam

2015-01-01

Rubber blends based on (styrene–butadiene rubber (SBR)/ethylene–propylene-diene monomer (EPDM)) with and without organoclay (OC) were prepared through a melt mixing process. The concentration ratio of the rubber phases (EPDM/SBR; 50/50 wt%) and the amount of the OC were kept constant. The samples were then vulcanized by means of gamma radiation using a Co-60 gamma source as well as sulfur cure system. The effect of absorbed dose on the formation of the crosslinks was confirmed by the Fourier transform infrared spectroscopy (FTIR). The effects of absorbed dose, sulfur cure system and OC on the gel content, and crosslink density were evaluated by the chemical tests. Applying the Charlesby–Pinner equation to estimate the radiation chemical yield, revealed that the use of OC in the blend caused 20% reduction in the degradation/crosslinking ratio. Employing the swelling test data, some thermodynamic parameters were determined. Using field emission scanning electron microscopy (FE-SEM) to investigate microstructure of the samples revealed a more homogeneous structure and also an increase in compatibility of the blend components in the sample cured by the irradiation in comparison to that cured by the sulfur curing system. - Highlights: • SBR/EPDM and SBR/EPDM/OC samples were prepared and irradiated by gamma radiation. • Increasing the absorbed dose and using OC enhanced gel content and crosslink density. • The increase in the absorbed dose resulted in an increase in ΔS and decrease in ΔG. • The use of OC in the blend caused 20% reduction in the degradation/crosslinking ratio. • In compare to sulfur cure sample the irradiated one showed more homogeneous structure

Free Sterols of the red alga Chondria armata (Kutz.) Okamura

Digital Repository Service at National Institute of Oceanography (India)

Govenkar, M.B.; Wahidullah, S.

. Results and Discussion The analysis of the sterol fraction by 1 H and 13 C NMR indicated it to be a mixture of four major D 5 3b-hydroxy sterols 2 cholest 5-en-3b-ol (choles- terol), 24j-methyl cholest-5,22-diene-3b-ol, 24j-ethyl cholest-5,22-diene-3b-ol....388 9 % 400 23j-Methyl 5a-cholestan-3b-ol C 28 H 50 O 30.759 6.7 % 402 24b-Ethyl cholest-5,22-diene-3b-ol C 29 H 48 O 31.21 4 % 412 24b-Ethyl cholest-5-en-3b-ol C 29 H 50 O 31.790 18.02 % 414 Table II. Mass spectroscopic characteristic of sterol acetates...

Hydrazones as substrates for cycloaddition reactions

International Nuclear Information System (INIS)

Belskaya, N P; Eliseeva, A I; Bakulev, V A

2015-01-01

The [2+2]-, [4+2]- and [3+2]-cycloaddition reactions of hydrazones and 1,2-diazabuta-1,3-dienes, azomethine imines, nitrile imines and azomethine ylides formed upon hydrazone transformations with dienophiles, dipolarophiles and dienes are considered. The principal issues of structure and reactivity of active substrates and the influence of the reaction conditions and catalysts on the reaction regioselectivity and efficiency are discussed. The bibliography includes 288 references

Kyste arachnoidien intra et supra sellaire: apport de l'IRM | Badaoui ...

African Journals Online (AJOL)

Les kystes arachnoïdiens intrasellaires sont rares et souvent étendus en suprasellaire. Leur diagnostic doit être évoqué devant toute formation de nature kystique dont le signal est identique à celui du liquide cérébro-spinal. Nous rapportons le cas d'un kyste arachnoïdien de siège intra et suprasellaire révélé par une ...

Zinc Mediated Tandem Fragmentation-Allylation of Methyl 5-Iodopentofuranosides

DEFF Research Database (Denmark)

Hyldtoft, Lene; Madsen, Robert

1999-01-01

In the presence of zinc and allyl bromide methyl 5-iodopentofuranosides undergo a tandem fragmentation alkylation to give functionalized dienes. These can undergo ring-closing olefin metathesis to produce cyclohexenes which on dihydroxylation give quercitols.......In the presence of zinc and allyl bromide methyl 5-iodopentofuranosides undergo a tandem fragmentation alkylation to give functionalized dienes. These can undergo ring-closing olefin metathesis to produce cyclohexenes which on dihydroxylation give quercitols....

Thermoplastic vulcanizate nanocomposites based on polypropylene/ethylene propylene diene terpolymer (PP/EPDM) prepared by reactive extrusion

Science.gov (United States)

Mirzadeh, Amin

using the solvent extraction and gravimetry technique. Additionally, the effect of continuity on rheological behaviour of TPE nanocomposites was investigated. The ultimate goal in this field is to maximize the rubber like behaviour by controlling the blend morphology and the level of crosslinking. Therefore, this study also covers the effects of nanoclay presence and its dispersion level on the crosslinking reaction of thermoplastic vulcanizate nanocomposites prepared by reactive extrusion. Here, the rubber phase was dynamically vulcanized using dimethylol phenolic resin or octylphenol-formaldehyde resin along with stannous chloride dihydrate as the catalyst. In the present study, the dynamic vulcanization of the prepared TPVs and corresponding nanocomposites are characterized using different criteria, such as gel content, viscosity and normalized storage modulus in the time sweep tests, nuclear magnetic resonance (NMR) signal line width, bound curative content and residual diene concentration. The combination of the above parameters appears to be sufficient to provide a clear description of the systems. The last part of the present study is devoted to find how the dispersion level of nanoclay and consequently the extent of crosslinking change the rubber like behaviour and the morphology of the prepared TPVs. Therefore, recently developed method named temperature scanning stress relaxation (TSSR) was used to estimate the rubber indices of TPVs and TPV nanocomposites. The mentioned method also successfully provided information about the extent of crosslinking reaction. It is shown that the rubber like behaviour of the blends containing 50wt% and 60wt% of EPDM in which morphological studies suggest the presence of the rubber droplets in vicinity of irregular shape rubber particles with a low level of interconnectivity, correlates with the rubber droplet size. Therefore, the nanoclay presence affects the rubber index values mainly through its effect on the size of the

SYNTHESIS AND PHARMACOLOGICAL EFFECTS OF BUTADIENE AND CYCLOPENTADIENE ADDUCTS OF METHANDROSTENOLONE IN RATS

Directory of Open Access Journals (Sweden)

FAZEL SHAMSA

2006-06-01

Full Text Available In this study the reactivity of methandrostenolone or [(17b-17-hydroxy-17-methylandrosta-1, 4-diene-3-one], as a dienophil in a Diels-Alder type cycloaddition reaction was investigated. The purpose of this approach was to investigate whether the 1-dehydro position of methandrostenolone 1 undergoes a cycloaddition reaction with dienes, such as 1, 3 butadiene or cyclopentadiene, and to investigate the biological behavior of the reaction adducts, i.e, compound 3 {(17b-17-hydroxy-17-methyl androsta [1a, 2a] cyclohex 3’, 4-diene-3-one} and compound 4 {(17b-17-hydroxy-17-methyl androsta [1a, 2a] cyclohex (2’,5’ methylene 3’, 4-diene-3-one}, relative to compound 1. The results indicated that thedDiels-Alder reactionddid notpproceed under the usual circumstances of high pressure and temperature, but could proceed in the presence of a Lewis acid (AlCl3. The structures of compounds 3 and 4 were confirmed by spectroscopic methods. The androgenic behavior of compounds 3 and 4 in comparison to compound 1 in the apomorphine test indicated that both compounds were almost devoid of androgenic activity, but prevented apomorphine mediated penile erection in male rats in a similar manner as cyproterone acetate.

Growth-arresting Activity of Acmella Essential Oil and its Isolated Component D-Limonene (1, 8 P-Mentha Diene) against Trichophyton rubrum (Microbial Type Culture Collection 296).

Science.gov (United States)

Padhan, Diptikanta; Pattnaik, Smaranika; Behera, Ajaya Kumar

2017-10-01

Spilanthes acmella is used as a remedy in toothache complaints by the tribal people of Western part of Odisha, India. The objective of this study was to study the growth-arresting activity of an indigenous Acmella essential oil (EO) ( S. acmella Murr, Asteraceae ) and its isolated component, d-limonene against Trichophyton rubrum (microbial type culture collection 296). The EO was extracted from flowers of indigenous S. acmella using Clevenger's apparatus and analyzed by gas chromatography-mass spectrometry (GC-MS). High pressure liquid chromatography (HPLC) was carried out to isolate the major constituent. The isolated fraction was subjected to fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The antidermatophytic activity was screened for using "disc diffusion" and "slant dilution" method followed by optical, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies. The molecular dockings were made between d-limonene with cell wall synthesis-related key enzymes (14 methyl deaminase and monooxygenase). The GC-MS analysis EO had inferred the presence of 7 number of major (≥2%) components. The component with highest peak area (%) was found to be 41.02. The HPLC-isolated fraction was identified as d-limonene (1,8 p-Mentha-diene) by FTIR and NMR. Qualitative and quantitative assays had suggested the growth inhibitory activity of Acmella EO and its component. Shrinkage, evacuation, cell wall puncture, and leakage of cellular constituents by the activity of Acmella oil and d-limonene were evidenced from optical, SEM, and TEM studies. The computer simulation had predicted the binding strengths of d-limonene and fluconazole with dermatophyte cell wall enzymes. There could have been synergistic action of all or some of compounds present in indigenous Acmella EO. There was presence of seven number of (d-limonene, ocimene, β-myrcene, cyclohexene, 3-(1, 5-dimethyl-4-hexenyl)-6-methylene, �

Two new triterpenoid saponins from Dianthus superbus L.

Science.gov (United States)

Chen, Xia; Luo, Jian-Guang; Kong, Ling-Yi

2010-06-01

Two new triterpenoid saponins (1 and 2) were isolated from the dried aerial parts of Dianthus superbus L. (Caryophyllaceae). Their structures were elucidated on the basis of spectral data to be 3-O-beta-D-glucopyranosyl olean-9(11),12-diene-23,28-dioic acid 28-O-beta-D-glucopyranoside (1) and 3-O-beta-D-glucopyranosyl olean-11,13(18)-diene-23,28-dioic acid 28-O-beta-D-glucopyranoside (2).

Structure elucidation of female-specific volatiles released by the parasitoid wasp Trichogramma turkestanica (Hymenoptera: Trichogrammatidae

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Armin Tröger

2014-04-01

Full Text Available Females of the parasitoid wasp Trichogramma turkestanica produce the putative polydeoxypropionates (2E,4E,6S,8S,10S-4,6,8,10-tetramethyltrideca-2,4-diene and (2E,4E,6S,8S,10S-4,6,8,10-tetramethyltrideca-2,4-dien-1-ol or their enantiomers as sex specific volatiles. The structures were assigned on the basis of GC–MS investigations using synthetic reference compounds.

Risky Business: Reducing Moral Hazard in Airlift Operations

Science.gov (United States)

2015-01-01

compared to USAF standards.43 McCarty was con- cerned about airlift transporting unnecessary items like champagne and ice that would normally move by...ice and champagne to Dien Bien Phu.44 Further con- firmation exists in the fact that upon his promotion to brigadier general, de Castries’ new rank...and congratulatory bottle of champagne were airdropped to him but fell instead into Viet Minh hands.45 Certainly not all airlifts into Dien Bien Phu

Experimental and Computational Studies of the Macrocyclic Effect of an Auxiliary Ligand on Electron and Proton Transfers Within Ternary Copper(II)-Histidine Complexes

International Nuclear Information System (INIS)

Song, Tao; Lam, Corey; Ng, Dominic C.; Orlova, G.; Laskin, Julia; Fang, De-Cai; Chu, Ivan K.

2009-01-01

The dissociation of [Cu II (L)His] -2+ complexes [L = diethylenetriamine (dien) or 1,4,7-triazacyclononane (9-aneN 3 )] bears a strong resemblance to the previously reported behavior of [Cu II (L)GGH] -2+ complexes. We have used low energy collision-induced dissociation experiments and density functional theory (DFT) calculations at the B3LYP/6-31+G(d) level to study the macrocyclic effect of the auxiliary ligands on the formation of His -+ from prototypical [Cu II (L)His] -2+ systems. DFT revealed that the relative energy barriers of the same electron transfer (ET) dissociation pathways of [Cu II (9-aneN 3 )His] -2+ and [Cu II (dien)His] -2+ are very similar, with the ET reactions of [Cu II (9-aneN 3 )His] -2+ leading to the generation of two distinct His -+ species; in contrast, the proton transfer (PT) dissociation pathways of [Cu II (9-aneN 3 )His] -2+ and [Cu II (dien)His] -2+ differ considerably. The PT reactions of [Cu II (9-aneN 3 )His] -2+ are associated with substantially higher barriers (>13 kcal/mol) than those of [Cu II (dien)His] -2+ . Thus, the sterically encumbered auxiliary 9-aneN3 ligand facilitates ET reactions while moderating PT reactions, allowing the formation of hitherto non-observable histidine radical cations.

Cytoprotection of human endothelial cells against oxidative stress by 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im): application of systems biology to understand the mechanism of action.

Science.gov (United States)

Wang, Xinyu; Bynum, James A; Stavchansky, Solomon; Bowman, Phillip D

2014-07-05

Cellular damage from oxidative stress, in particular following ischemic injury, occurs during heart attack, stroke, or traumatic injury, and is potentially reducible with appropriate drug treatment. We previously reported that caffeic acid phenethyl ester (CAPE), a plant-derived polyphenolic compound, protected human umbilical vein endothelial cells (HUVEC) from menadione-induced oxidative stress and that this cytoprotective effect was correlated with the capacity to induce heme oxygenase-1 (HMOX1) and its protein product, a phase II cytoprotective enzyme. To further improve this cytoprotective effect, we studied a synthetic triterpenoid, 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im), which is known as a potent phase II enzyme inducer with antitumor and anti-inflammatory activities, and compared it to CAPE. CDDO-Im at 200nM provided more protection to HUVEC against oxidative stress than 20μM CAPE. We explored the mechanism of CDDO-Im cytoprotection with gene expression profiling and pathway analysis and compared to that of CAPE. In addition to potent up-regulation of HMOX1, heat shock proteins (HSP) were also found to be highly induced by CDDO-Im in HUVEC. Pathway analysis results showed that transcription factor Nrf2-mediated oxidative stress response was among the top canonical pathways commonly activated by both CDDO-Im and CAPE. Compared to CAPE, CDDO-Im up-regulated more HSP and some of them to a much higher extent. In addition, CDDO-Im treatment affected Nrf2 pathway more significantly. These findings may provide an explanation why CDDO-Im is a more potent cytoprotectant than CAPE against oxidative stress in HUVEC. Copyright © 2014 Elsevier B.V. All rights reserved.

INHIBITION OF HUMAN LOW-DENSITY LIPOPROTEINS OXIDATION BY Hibiscus radiatus CUV. CALYCES EXTRACT

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Hernawan Hernawan

2010-06-01

Full Text Available Hibiscus radiatus Cuv calyces extracts rich in polyphenols was screened for their potential to inhibit oxidation of human low-density lipoproteins-cholesterol (LDL-C in vitro. The inhibition of LDL-C oxidation (antioxidant activity was determined by measuring the formation of conjugated dienes and thiobarbituric acid reagent substances (TBARS. LDL-C oxidation was carried out in the presence of H. radiatus Cuv calyces extract (20 and 50 μM. CuSO4 (10 μM was used as the oxidation initiator and  butylated hydroxytoluene (BHT at 50 μM was used as standard antioxidant. The protective effect of H. radiatus Cuv. calyces extract toward human low-density lipoproteins, complex lipid system was  demonstrated by significant increase lag time (> 103 min, diminished of the propagation rate (44 %, and diminution of conjugated dienes formation 59.42 % (50 μM compared to control.   Keywords: antioxidant, conjugated dienes, Hibiscus radiatus Cuv, low-density lipoproteins-cholesterol

Characterization and synthesis of volatile compounds from the defensive secretions of some "daddy longlets" (Arachnida: Opiliones: Leiobunum spp.).

Science.gov (United States)

Jones, T H; Meinwald, J; Hicks, K; Eisner, T

1977-02-01

Analyses of the chief volatile constituents of the defensive secretions of three oplionids were carried out. Leiobunum nigripalpi produces three closely related C7 compounds: E-4-methyl-4-hexen-3-one(I), 4-methylhexan-3-one(II), and 4-methylhexan-3-ol(III), along with E-4-methyl-4-hepten-3-one(IV), E,E-2,4-dimethylhexa-2,4-dienal(IX), and a minor, unidentified component. L. leiopenis secretion contains E-4-methyl-4-hepten-3-one(IV), 4-methylheptan-3-one(V), E,E-2,4-dimethylhexa-2,4-dien-1-ol(VII), and E,E-2,4-dimethylhepta-2,4-dien-1-ol(VIII). L. calcar yields chiefly E-4,6-dimethyl-6-octen-3-one(VI) and E,E-2,4-dimethylhexa-2,4-dien-1-ol(VII). Six of these compounds are new natural products. The structures of these compounds, which can be regarded either as polyketide-derived or as modified isoprenoids, raise interesting biosynthetic questions.

Study of the Deformation/Interaction Model: How Interactions Increase the Reaction Barrier

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Zhiling Liang

2018-01-01

Full Text Available The interactions (including weak interactions between dienophiles and dienes play an important role in the Diels-Alder reaction. To elucidate the influence of these interactions on the reactivity, a popular DFT functional and a variational DFT functional corrected with dispersion terms are used to investigate different substituent groups incorporated on the dienophiles and dienes. The bond order is used to track the trajectory of the cycloaddition reaction. The deformation/interaction model is used to obtain the interaction energy from the reactant complex to the inflection point until reaching the saddle point. The interaction energy initially increases with a decrease in the interatomic distance, reaching a maximum value, but then decreases when the dienophiles and dienes come closer. Reduced density gradient and chemical energy component analysis are used to analyse the interaction. Traditional transition state theory and variational transition state theory are used to obtain the reaction rates. The influence of tunneling on the reaction rate is also discussed.

Diazo Esters as Dienophiles in Intramolecular (4 + 2) Cycloadditions: Computational Explorations of Mechanism.

Science.gov (United States)

Duan, Abing; Yu, Peiyuan; Liu, Fang; Qiu, Huang; Gu, Feng Long; Doyle, Michael P; Houk, K N

2017-02-22

The first experimental examples of Diels-Alder (DA) reactions of diazo compounds as heterodienophiles with dienes have been studied with density functional theory (DFT) using the M06-2X functional. For comparison, the reactivities of diazo esters as dienophiles or 1,3-dipoles with 1,3-dienes in intermolecular model systems have been analyzed by the distortion/interaction model. The 1,3-dipolar cycloaddition is strongly favored for the intermolecular system. The intramolecular example is unique because the tether strongly favors the (4 + 2) cycloaddition.

Nuts as raw material for confectionary industry

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L. Eliseeva

2017-03-01

Full Text Available The aim of this paper was to explore chemical and sensory stability of walnuts during their storage. We determined fatty acids composition, as well as chemical indicators of lipid oxidative stability (peroxide and thiobarbituric values and conjugated dienes during accelerated storage of walnuts. Besides this, a thorough descriptive analysis was performed. The accelerated storage of walnuts was shown to cause the significant changes in sensory characteristics of walnuts, as well as the significant increase of peroxide and thiobarbituric values and contents of conjugated dienes.

Analysis of the chemical composition of essential oil from Algerian Inula viscosa (L. Aiton

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Imad Eddine Haoui

2015-07-01

Full Text Available The chemical composition of the essential oil of Inula viscosa (L. leaves, obtained by both hydrodistillation and steam distillation, was investigated by GC–MS. The major components for hydrodistillation were: 12-carboxyeudesma-3,11 (13 diene (28.88%; linolenic acid (7.80%; palmitic acid (5.38%; butyl hydroxy toluene (4.11% and fokienol (3.37%, while for steam distillation were: 12-carboxyeudesma-3,11 (13 diene (56.81%; 2,3-didehydrocostic acid (3.25%; butyl hydroxy toluene (2.63% and pentacosane (2.31%.

Wild Bitter Melon Leaf Extract Inhibits Porphyromonas gingivalis-Induced Inflammation: Identification of Active Compounds through Bioassay-Guided Isolation

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Tzung-Hsun Tsai

2016-04-01

Full Text Available Porphyromonas gingivalis has been identified as one of the major periodontal pathogens. Activity-directed fractionation and purification processes were employed to identify the anti-inflammatory active compounds using heat-killed P. gingivalis-stimulated human monocytic THP-1 cells in vitro. Five major fractions were collected from the ethanol/ethyl acetate extract of wild bitter melon (Momordica charantia Linn. var. abbreviata Ser. leaves and evaluated for their anti-inflammatory activity against P. gingivalis. Among the test fractions, Fraction 5 effectively decreased heat-killed P. gingivalis-induced interleukin (IL-8 and was subjected to separation and purification by using chromatographic techniques. Two cucurbitane triterpenoids were isolated from the active fraction and identified as 5β,19-epoxycucurbita-6,23-diene-3β,19,25-triol (1 and 3β,7β,25-trihydroxycucurbita-5,23-dien-19-al (2 by comparing spectral data. Treatments of both compounds in vitro potently suppressed P. gingivalis-induced IL-8, IL-6, and IL-1β levels and the activation of mitogen-activated protein kinase (MAPK in THP-1 cells. Both compounds effectively inhibited the mRNA levels of IL-6, tumor necrosis factor (TNF-α, and cyclooxygenase (COX-2 in P. gingivalis-stimulated gingival tissue of mice. These findings imply that 5β,19-epoxycucurbita-6,23-diene-3β,19,25-triol and 3β,7β,25-trihydroxycucurbita-5,23-dien-19-al could be used for the development of novel therapeutic approaches against P. gingivalis infections.

The enthalpies of formation of two dibenzocyclooctadienones

Energy Technology Data Exchange (ETDEWEB)

Perisanu, St.; Contineanu, Iulia; Banciu, M.D.; Liebman, Joel F.; Farivar, Behzad S.; Mullan, Melissa A.; Chickos, James S.; Rath, Nigam; Hillesheim, Dorothea M

2003-04-17

The standard molar enthalpies of formation ({delta}{sub f}H{sub m}{sup 0}(s)/kJ mol{sup -1}) for 2,3:6,7-dibenzocycloocta-2,6-dien-1-one and 2,3:7,8-dibenzocycloocta-2,7-dien-1-one [6H-11,12-dihydro-dibenzo[a,e]cycloocten-5-one (ketone 1) and 10H-11,12-dihydrodibenzo[a,d]-cycloocten-5-one (ketone 2), respectively] were derived from enthalpies of combustion, measured by means of a microbomb calorimeter. The fusion and vaporization enthalpies of these compounds were obtained from DSC and correlation gas chromatography measurements. The standard molar enthalpies of formation in the gas phase were calculated by combining the condensed phase standard molar enthalpies of formation with the fusion and vaporization enthalpies adjusted to 298.15 K. Values for {delta}{sub f}H{sub m}{sup 0}(g) of (-39.9{+-}5.5) and (-14.8{+-}5.3) kJ mol{sup -1} were obtained for 2,3:6,7-dibenzocycloocta-2,6-dien-1-one and 2,3:7,8-dibenzocycloocta-2,7-dien-1-one, respectively. Quantum chemical calculations are reported for the compounds investigated experimentally and an additional four isomers. Isomerization enthalpies are derived from computed energies. The enthalpies of formation are also calculated by group additivity, compared with the experimental values and then correlated with the structure of the molecules investigated. The X-ray analysis of ketone 1 is also reported.

The enthalpies of formation of two dibenzocyclooctadienones

International Nuclear Information System (INIS)

Perisanu, St.; Contineanu, Iulia; Banciu, M.D.; Liebman, Joel F.; Farivar, Behzad S.; Mullan, Melissa A.; Chickos, James S.; Rath, Nigam; Hillesheim, Dorothea M.

2003-01-01

The standard molar enthalpies of formation (Δ f H m 0 (s)/kJ mol -1 ) for 2,3:6,7-dibenzocycloocta-2,6-dien-1-one and 2,3:7,8-dibenzocycloocta-2,7-dien-1-one [6H-11,12-dihydro-dibenzo[a,e]cycloocten-5-one (ketone 1) and 10H-11,12-dihydrodibenzo[a,d]-cycloocten-5-one (ketone 2), respectively] were derived from enthalpies of combustion, measured by means of a microbomb calorimeter. The fusion and vaporization enthalpies of these compounds were obtained from DSC and correlation gas chromatography measurements. The standard molar enthalpies of formation in the gas phase were calculated by combining the condensed phase standard molar enthalpies of formation with the fusion and vaporization enthalpies adjusted to 298.15 K. Values for Δ f H m 0 (g) of (-39.9±5.5) and (-14.8±5.3) kJ mol -1 were obtained for 2,3:6,7-dibenzocycloocta-2,6-dien-1-one and 2,3:7,8-dibenzocycloocta-2,7-dien-1-one, respectively. Quantum chemical calculations are reported for the compounds investigated experimentally and an additional four isomers. Isomerization enthalpies are derived from computed energies. The enthalpies of formation are also calculated by group additivity, compared with the experimental values and then correlated with the structure of the molecules investigated. The X-ray analysis of ketone 1 is also reported

Solvent Effects in Asymmetric Hetero Diels-Alder and Ene Reactions

DEFF Research Database (Denmark)

Johannsen, Mogens; Jørgensen, Karl Anker

1996-01-01

The use of polar solvents such as nitromethane or 2-nitropropane leads to a significant improvement of the catalytic properties of a cationic copper-Lewis acid in the hetero Diels-Alder reaction of alkyl glyoxylates with dienes; The scope of a newly developed copper(II)-bisoxazoline catalyst...... for the hetero Diels-Alder reaction is demonstrated by the reaction of different dienes with alkyl glyoxylates in nitroalkane solvents with the formation of the hetero Diels-Alder adduct in high enantiomeric excess as the major product. The synthetic application of the reaction is exemplified by an improved...

Synthesis of a Phlorin from a Meso-Fused Anthriporphyrin by a Diels-Alder Strategy.

Science.gov (United States)

Aslam, Adil S; Hong, Jung-Ho; Shin, June-Ho; Cho, Dong-Gyu

2017-12-18

An anthracene-containing meso-fused carbaporphyrin, which has extended π-conjugation pathways as compared to the corresponding naphthalene-containing carbaporphyrin, has been synthesized. The weak global aromaticity of the anthriporphyrin also allowed its use as the diene for a Diels-Alder reaction with dimethyl acetylenedicarboxylate (DMAD). The resulting phlorin contains an interesting bicyclic structure. Moreover, to the best of our knowledge, this phlorin is the first Diels-Alder adduct of a diene forming part of the global π-conjugation pathway of an aromatic porphyrinoid. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reversible Thermoset Adhesives

Science.gov (United States)

Mac Murray, Benjamin C. (Inventor); Tong, Tat H. (Inventor); Hreha, Richard D. (Inventor)

2016-01-01

Embodiments of a reversible thermoset adhesive formed by incorporating thermally-reversible cross-linking units and a method for making the reversible thermoset adhesive are provided. One approach to formulating reversible thermoset adhesives includes incorporating dienes, such as furans, and dienophiles, such as maleimides, into a polymer network as reversible covalent cross-links using Diels Alder cross-link formation between the diene and dienophile. The chemical components may be selected based on their compatibility with adhesive chemistry as well as their ability to undergo controlled, reversible cross-linking chemistry.

Cucurbitane-type triterpenes from Citrullus lanatus (watermelon) seeds.

Science.gov (United States)

Kikuchi, Takashi; Okada, Rina; Harada, Yu; Ikushima, Kenji; Yamakawa, Takahiro; Yamada, Takeshi; Tanaka, Reiko

2013-10-01

Two new cucurbitane-type triterpenes, 24-hydroperoxycucurbita-5,25-dien-3beta-ol (1) and 25-hydroperoxycucurbita-5,23-dien-3beta-ol (2), were isolated from a MeOH extract of Citrullus lanatus seeds. Compounds 1 and 2 exhibited moderate cytotoxic activities with IC50 values of 33.4-52.4 microM against HL-60 (human leukemia), P388 (murine leukemia), and L1210 (murine leukemia) cells. Compound 1 showed melanogenesis inhibitory activity (melanin content 80.0 %) with low cytotoxicity (cell viability 97.6%) at a low concentration (10 microM).

An Imide-Based Pentacyclic Building Block for n-Type Organic Semiconductors

Energy Technology Data Exchange (ETDEWEB)

Wu, Fu-Peng [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM); Un, Hio-Ieng [Peking Univ., Beijing (China). Beijing National Lab. for Molecular Sciences, Key Lab. of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Key Lab. of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering; Li, Yongxi [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM); Hu, Hailiang [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM); Yuan, Yi [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM); Yang, Bin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS); Xiao, Kai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS); Chen, Wei [Argonne National Lab. (ANL), Lemont, IL (United States). Science Div.; Wang, Jie-Yu [Peking Univ., Beijing (China). Beijing National Lab. for Molecular Sciences, Key Lab. of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Key Lab. of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering; Jiang, Zuo-Quan [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM); Pei, Jian [Peking Univ., Beijing (China). Beijing National Lab. for Molecular Sciences, Key Lab. of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Key Lab. of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering; Liao, Liang-Sheng [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM)

2017-10-09

A new electron-deficient unit with fused 5-heterocyclic ring was developed by replacing a cyclopenta-1,3-diene from electron-rich donor indacenodithiophene (IDT) with cyclohepta- 4,6-diene-1,3-diimde unit. The imide bridging endows BBI with fixed planar configuration and both low the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbit (LUMO) energy levels. Organic field-effect transistors (OFETs) based on BBI polymers exhibit electron mobility up to 0.34 cm2 V-1 s-1, which indicates that the BBI is a promising ntype semiconductor for optoelectronics.

Les carcinomes de la thyroïde: profils épidémiologique, clinique et thérapeutique, à propos de 102 cas

Science.gov (United States)

Touati, Mohamed Mliha; Aljalil, Abdelfettah; Darouassi, Youssef; Chihani, Mehdi; Lahkim, Mohammed; Fihri, Jawad Al Fassi; Bouaity, Brahim; Ammar, Haddou

2015-01-01

Les carcinomes thyroïdiens sont des tumeurs malignes assez rares, représentant 1% des cancers. Ils sont généralement de bon pronostic, et présentent des aspects cliniques et évolutifs variés selon leur origine histologique. Notre travail est une étude rétrospective portant sur 102 cas de carcinomes de la thyroïde, colligés sur un nombre total de 811 gestes chirurgicaux thyroïdiens, au service d'oto-rhino-laryngologie et de chirurgie cervico-faciale de l'hôpital militaire Avicenne de Marrakech, sur une période de 8 ans, allant de janvier 2006 à décembre 2013. Les carcinomes thyroïdiens atteignent le sujet jeune avant l’âge de 50 ans, en particulier le sexe féminin. La tendance dans les pays en voie de développement, comme dans le monde entier est en croissance continue, ceci peut être expliqué par l'amélioration des outils d'imagerie et des moyens diagnostiques cytologiques et anatomo-pathologiques. PMID:26405495

Desvulcanização do resíduo de terpolímero de etileno-propileno-dieno (EPDM-r por micro-ondas Devulcanization of ethylene-propylene-diene polymer residues (EPDM-r by microwaves

Directory of Open Access Journals (Sweden)

Vinicius Pistor

2010-09-01

Full Text Available Elastômeros vulcanizados são materiais comumente empregados em diversas aplicações, como nas indústrias automotiva e calçadista. Neste trabalho, aparas do terpolímero de etileno-propileno-dieno (EPDM-r provenientes da indústria automotiva foram submetidas a micro-ondas durante diferentes tempos de exposição (2-5 min. Após a desvulcanização, as amostras foram caracterizadas por teor de gel, calorimetria exploratória diferencial (DSC e energias de ativação de degradação (Ea determinadas por análise termogravimétrica (TGA. O comportamento de degradação apresentou composição do EPDM-r condizente com a literatura. A análise de teor de gel demonstrou que o EPDM-r foi desvulcanizado quando exposto às micro-ondas por 5 minutos. As análises de DSC não indicaram modificações significativas nas amostras estudadas, e o estudo de Ea mostrou que os aditivos encontrados na composição do EPDM-r influenciam na eficiência do método de regeneração por micro-ondas.Vulcanized elastomers are materials commonly used in several applications, such as automotive and footwear industries. In this study, scraps of ethylene-propylene-diene terpolymer (EPDM-r from the automotive industry were exposed to microwaves during different periods (2-5 min. After devulcanization, the samples were characterized by gel content, differential scanning calorimetry (DSC and activation energy of degradation (Ea determined by thermogravimetric analysis (TGA. The degradation behavior of EPDM-r was consistent with the literature. The gel content analysis showed that the EPDM-r was devulcanized only at 5 minutes of exposure to the microwaves. DSC analysis demonstrated no significant changes in the samples, and the Ea results confirmed that the additives found in the composition of the EPDM-r affect the efficiency of the regeneration method.

Isolation of cytotoxic diterpenoids from the Chilean medicinal plant Azorella compacta Phil from the Atacama Desert by high-speed counter-current chromatography.

Science.gov (United States)

Bórquez, Jorge; Bartolucci, Nandy López; Echiburú-Chau, Carlos; Winterhalter, Peter; Vallejos, Javier; Jerz, Gerold; Simirgiotis, Mario J

2016-06-01

Azorella compacta (Apiaceae) is a native Chilean cushion shrub which produces a resin containing mulinane and azorellane diterpenoids. This plant has been used since pre-Colombian times to treat inflammation and dental neuralgias. In this work the first preparative fractionation of diterpenoids present in this plant by means of high-speed counter-current chromatography (HSCCC) was applied, and cytotoxic effects of the isolated compounds were evaluated for the first time against a panel of MCF7 cells. The major compounds isolated were identified by means of spectroscopy as azorellanol, 13α, 14α-dihydroxymulin-11-en-20-oic acid, mulinolic acid, mulin-11,13-dien-20-oic acid, 17-acetoxy-mulin-11,13-dien-20 oic acid, and 17-acetoxy-mulinic acid (compounds 7, 9-11 and 13, respectively), and four minor diterpenoids [7-deacetyl-azorellanol (6), 13-epi-azorellanol, 7-acetoxy-mulin-9,12-diene, and 17-acetoxy-mulin-11,13-dien-20-oic acid (compounds 4, 8 and 12)], together with three new minor diterpenoids: 13β,14β-dihydroxymulin-11-en-20-oic acid (1), 13-epiazorellanone (2) and 13-epi-7-deacetyl-azorellanol (3) were identified. Besides, compounds 4, 6, 7, 8 and 11 displayed good cytotoxic activity (less than 50% cell viability at 100 µM). Among them, compound 7, an acetylated azorellane, was the most active. HSCCC allowed the isolation of 13 diterpenoids present in A. compacta. Three compounds are reported for the first time. Isolated azorellanes are more potent cytotoxic agents than are mulinanes. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Bis[N-(2-aminoethylethane-1,2-diamine-κ3N,N′,N′′]copper(II tris[diamminetetrakis(thiocyanato-κNchromate(III] thiocyanate dimethyl sulfoxide tetradecasolvate monohydrate

Directory of Open Access Journals (Sweden)

Vitalina M. Nikitina

2011-08-01

Full Text Available The ionic title complex, [Cu(C4H13N32]2[Cr(NCS4(NH32]3(NCS·14C2H6OS·H2O, consists of complex [Cu(dien2]2+ cations [dien is N-(2-aminoethylethane-1,2-diamine], complex [Cr(NCS4(NH32]− anions, an NCS− counter-anion and uncoordinated dimethyl sulfoxide (DMSO and water solvent molecules. One of the Cr atoms lies on an inversion center, while the second Cr atom and the Cu atom lie in general positions. The thiocyanate counter-anion and water molecule are disordered over two positions close to an inversion center. There are several types of hydrogen-bond interactions present in the title compound, which connect the complex cations and anions into bulky [Cu2Cr3] polynuclear species. The four NH3 groups of the complex anions and six bridging DMSO O atoms link the three complex anions via hydrogen bonding into the anionic polynuclear species [Cr(NCS4(NH32]3·6DMSO. The last one is connected by four bridging DMSO O atoms with the two complex copper cations through N—H... O hydrogen bonds between the terminal NH3 groups of the anionic polynuclear species and the NH and NH2 groups of the dien ligand. One additional DMSO molecule is connected via hydrogen bonding to one of the terminal NH3 groups of the anionic polynuclear species. Another DMSO molecule is connected via hydrogen bonding to each Cu(dien2]2+ cation.

DFT studies for the substituent effect on the diels-alder reaction of 1,4-diaza-1,3-butadienes

International Nuclear Information System (INIS)

Lee, Gab Yong

2001-01-01

DFT calculations have been performed on several substituted 1,4-diaza-1,3-butadienes (1,4-DABs) with electron donating and withdrawing groups at the terminal two nitrogens to investigate the reactivity of Diels-Alder reaction with acrolein. The calculated FMO (Frontier Molecular orbital) energies for the optimized 1,4-disubstituted-1,4DABs have been used to explain both normal and inverse electron demand Diels-Alder reactions. It is shown that the electron donating and withdrawing substituents lead to the normal(HOMO diene controlled) and inverse electron demand (LUMO diene controlled) Diels-Alder reactions, respectively

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.

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.

Dammarane triterpenes from the leaves of Panax ginseng enhance cellular immunity

DEFF Research Database (Denmark)

Tran, Tien-Lam; Kim, Young-Ran; Yang, Jun-Li

2014-01-01

In our search for immune stimulating materials from natural source, bioassay-guided fractionation of a methanol extract of Panax ginseng leaves led to the isolation of three dammarane triterpenes (1-3), including two previously unknown compounds 27-demethyl-(E,E)-20(22),23-dien-3β,6α,12β-trihydro......In our search for immune stimulating materials from natural source, bioassay-guided fractionation of a methanol extract of Panax ginseng leaves led to the isolation of three dammarane triterpenes (1-3), including two previously unknown compounds 27-demethyl-(E,E)-20(22),23-dien-3β,6α,12β...

Antiprotozoal compounds from Asparagus africanus

DEFF Research Database (Denmark)

Oketch-Rabah, H A; Dossaji, S F; Christensen, S B

1997-01-01

Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl)-bisphenol.......Two antiprotozoal compounds have been isolated from the roots of Asparagus africanus Lam. (Liliaceae), a new sapogenin, 2 beta, 12 alpha-dihydroxy-(25R)-spirosta-4,7-dien-3-one (1), which was named muzanzagenin, and the lignan (+)-nyasol (2), (Z)-(+)-4,4'-(3-ethenyl-1-propene-1,3-diyl...

X-ray Absorption Spectroscopy Combined with Time-Dependent Density Functional Theory Elucidates Differential Substitution Pathways of Au(I) and Au(III) with Zinc Fingers.

Science.gov (United States)

Abbehausen, Camilla; de Paiva, Raphael Enoque Ferraz; Bjornsson, Ragnar; Gomes, Saulo Quintana; Du, Zhifeng; Corbi, Pedro Paulo; Lima, Frederico Alves; Farrell, Nicholas

2018-01-02

A combination of two elements' (Au, Zn) X-ray absorption spectroscopy (XAS) and time-dependent density functional theory (TD-DFT) allowed the elucidation of differential substitution pathways of Au(I) and Au(III) compounds reacting with biologically relevant zinc fingers (ZnFs). Gold L 3 -edge XAS probed the interaction of gold and the C-terminal Cys 2 HisCys finger of the HIV-1 nucleocapsid protein NCp7, and the Cys 2 His 2 human transcription factor Sp1. The use of model compounds helped assign oxidation states and the identity of the gold-bound ligands. The computational studies accurately reproduced the experimental XAS spectra and allowed the proposition of structural models for the interaction products at early time points. The direct electrophilic attack on the ZnF by the highly thiophilic Au(I) resulted in a linear P-Au-Cys coordination sphere after zinc ejection whereas for the Sp1, loss of PEt 3 results in linear Cys-Au-Cys or Cys-Au-His arrangements. Reactions with Au(III) compounds, on the other hand, showed multiple binding modes. Prompt reaction between [AuCl(dien)] 2+ and [Au(dien)(DMAP)] 3+ with Sp1 showed a partially reduced Au center and a final linear His-Au-His coordination. Differently, in the presence of NCp7, [AuCl(dien)] 2+ readily reduces to Au(I) and changes from square-planar to linear geometry with Cys-Au-His coordination, while [Au(dien)(DMAP)] 3+ initially maintains its Au(III) oxidation state and square-planar geometry and the same first coordination sphere. The latter is the first observation of a "noncovalent" interaction of a Au(III) complex with a zinc finger and confirms early hypotheses that stabilization of Au(III) occurs with N-donor ligands. Modification of the zinc coordination sphere, suggesting full or partial zinc ejection, is observed in all cases, and for [Au(dien)(DMAP)] 3+ this represents a novel mechanism for nucleocapsid inactivation. The combination of XAS and TD-DFT presents the first direct experimental

Azirinium ylides from α-diazoketones and 2H-azirines on the route to 2H-1,4-oxazines: three-membered ring opening vs 1,5-cyclization

Directory of Open Access Journals (Sweden)

Nikolai V. Rostovskii

2015-03-01

Full Text Available Strained azirinium ylides derived from 2H-azirines and α-diazoketones under Rh(II-catalysis can undergo either irreversible ring opening across the N–C2 bond to 2-azabuta-1,3-dienes that further cyclize to 2H-1,4-oxazines or reversibly undergo a 1,5-cyclization to dihydroazireno[2,1-b]oxazoles. Dihydroazireno[2,1-b]oxazoles derived from 3-aryl-2H-azirines and 3-diazoacetylacetone or ethyl diazoacetoacetate are able to cycloadd to acetyl(methylketene generated from 3-diazoacetylacetone under Rh(II catalysis to give 4,6-dioxa-1-azabicyclo[3.2.1]oct-2-ene and/or 5,7-dioxa-1-azabicyclo[4.3.1]deca-3,8-diene-2-one derivatives. According to DFT calculations (B3LYP/6-31+G(d,p, the cycloaddition can involve two modes of nucleophilic attack of the dihydroazireno[2,1-b]oxazole intermediate on acetyl(methylketene followed by aziridine ring opening into atropoisomeric oxazolium betaines and cyclization. Azirinium ylides generated from 2,3-di- and 2,2,3-triaryl-substituted azirines give rise to only 2-azabuta-1,3-dienes and/or 2H-1,4-oxazines.

Niobium Pentachloride Activation of Enone Derivatives: Diels-Alder and Conjugate Addition Products

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Gil Valdo José da Silva

2002-05-01

Full Text Available Niobium pentachloride has proven to be a powerful activating agent for Diels-Alder or conjugate addition reactions of cycloenones. The Diels-Alder product was obtained only with an unsubstituted enone (cyclohexenone and the highly reactive diene cyclopentadiene; substituents in the b-position of enones seem to prevent Diels-Alder reaction: oxygenated substituents favor the formation of vinyl chlorides (ethyl ether or dichloromethane as solvents or enol ethers (ethyl acetate as solvent, while a methyl substituent prevents any kind of transformation with NbCl5. Less reactive dienes, furan and 2-methylfuran gave the conjugate addition products of the furan ring to the enone system.

Bioinspired intramolecular Diels-Alder reaction: a rapid access to the highly-strained cyclopropane-fused polycyclic skeleton.

Science.gov (United States)

Zhu, Shifa; Guo, Zhengjiang; Huang, Zhipeng; Jiang, Huanfeng

2014-02-24

A bioinsipred gold-catalyzed tandem Diels-Alder/Diels-Alder reaction of an enynal and a 1,3-diene, forming the highly-strained benzotricyclo[3.2.1.0(2,7) ]octane skeleton, was reported. In contrast, a Diels-Alder/Friedel-Crafts tandem reaction occurred instead when silver salts were used as the catalyst. Although both reactions experienced the similar Diels-Alder reaction of a pyrylium intermediate with a 1,3-diene, they have different reaction mechanisms. The former proceeded with a stepwise Diels-Alder reaction, while the latter one with a concerted one. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isogermacrene A, a proposed intermediate in sesquiterpene biosynthesis.

Science.gov (United States)

Hackl, Thomas; König, Wilfried A; Muhle, Hermann

2004-08-01

In the essential oil of the liverwort Saccogyna viticulosa, collected on the island of Madeira, the new sesquiterpene hydrocarbons isogermacrene A (5) and its Cope rearrangement product iso-beta-elemene (6) were identified. 5 is proposed to act as the biogenetic precursor of several new sesquiterpenes identified in the volatiles of S. viticulosa. These include iso-alpha-humulene, alpha-gorgonene, gorgona-1,4(15), 11-triene and gorgon- 11-en-4-ol. In addition, the Cope product of zierene, isozierene, allo-aromadendra-4(15),10(14)-diene, aromadendra-4(15),10(14)-dien-1-ol and a prenylguaiane diterpene alcohol, named viticulol, were identified as new natural products.

Na+/K+-ATPase: Activity and inhibition

Science.gov (United States)

Čolović, M.; Krstić, D.; Krinulović, K.; Momić, T.; Savić, J.; Vujačić, A.; Vasić, V.

2009-09-01

The aim of the study was to give an overview of the mechanism of inhibition of Na+/K+-ATPase activity induced by some specific and non specific inhibitors. For this purpose, the effects of some ouabain like compounds (digoxin, gitoxin), noble metals complexes ([PtCl2DMSO2], [AuCl4]-, [PdCl4]2-, [PdCl(dien)]+, [PdCl(Me4dien)]+), transition metal ions (Cu2+, Zn2+, Fe2+, Co2+), and heavy metal ions (Hg2+, Pb2+, Cd2+) on the activity of Na+/K+-ATPase from rat synaptic plasma membranes (SPM), porcine cerebral cortex and human erythrocytes were discussed.

EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2015. Scientific Opinion on Flavouring Group Evaluation 208 Revision 1 (FGE.208Rev1): Consideration of genotoxicity data on representatives for 10 alicyclic aldehydes with the a,b-unsaturation in ring / side-chain and precursors from chemical subgroup 2.2 of FGE.19

DEFF Research Database (Denmark)

Beltoft, Vibe Meister; Nørby, Karin Kristiane

genotoxicity studies on p-mentha-1,8-dien-7-al [FL-no: 05.117], the representative substance for FGE.19 subgroup 2.2. This substance was tested in vivo in a combined micronucleus assay in bone marrow and Comet assay in liver and duodenum. It did not induce any increase in micronucleated polychromatic...... erythrocytes of the bone marrow of male rats in the micronucleus test and it did not induce DNA damage in duodenum of the same animals as analysed by the Comet assay. The Comet assay performed in liver shows a positive result and therefore the Panel concluded that p-mentha-1,8-dien-7-al [FL-no: 05...

Les dysthyroïdies chez l’hémodialysé chronique

Directory of Open Access Journals (Sweden)

Najoua Zbiti

2010-10-01

Full Text Available INTRODUCTION: Les dysthyroïdies chez l’hémodialysé chronique sont représentées par une hypothyroïdie: dite le syndrome de basse T3, actuellement nommée "le syndrome de la maladie euthyroïdienne". L’objectif de notre travail est de déterminer le profil thyroïdien de nos HDC afin de préciser la prévalence des différents troubles thyroïdiens dans notre population et de dégager les facteurs prédictifs, aussi on a précisé l’évolution sur une période de 3 ans. METHODES: Il s’agit d’une étude rétrospective réalisée en Mars 2007 concernant 68 patients adultes en hémodialyse périodique. Nous avons analysé les paramètres anthropométriques, cliniques et biologiques. Le dosage des hormones thyroïdiennes ((triiodothyronine libre FT3, (thyroxine libre FT4 et (thyréostimuline ultra-sensible TSHus s’est effectué selon la méthode radio-immunologique. Nous avons comparé 2 groupes de patients avec et sans dysthyroïdie (définie par un taux anormal de FT3 et/ou de FT4 et/ou de TSH afin de dégager les facteurs de risque. On a réalisé une surveillance biologique des hormones thyroïdiennes pendant 3 ans afin de préciser l’incidence des différents troubles thyroïdiens dans la même population. RESULTATS: Tous les patients sont en euthyroïdie clinique. On n’a noté aucun cas de goitre. Le profil thyroïdien est caractérisé par une hypothyroïdie biologique, la prévalence était de 28%. Nous n'avons pas trouvé des cas d'hyperthyroïdie. L'étude comparative des deux groupes de malades biologiquement euthyroïdiens et hypothyroïdiens a révèle le syndrome inflammatoire (p=0.001, l’âge avancé (p=0.003, et la durée prolongée en hémodialyse (p=0.04 comme des facteurs de risque liés à l’hypothyroïdie biologique. Deux HDC ont nécessité un traitement hormonal substitutif vu le contexte du diabète dans un cas et de la grossesse dans l’autre cas. Le suivi biologique pendant trois ans n’a r

Organic chemistry of graphene: the Diels-Alder reaction.

Science.gov (United States)

Denis, Pablo A

2013-11-11

Herein, by using dispersion-corrected density functional theory, we investigated the Diels-Alder chemistry of pristine and defective graphene. Three dienes were considered, namely 2,3-dimethoxy-1,3-butadiene (DMBD), 9-methylanthracene (9MA), and 9,10-dimethylanthracene (910DMA). The dienophiles that were assayed were tetracyanoethylene (TCNE) and maleic anhydride (MA). When pristine graphene acted as the dienophile, we found that the cycloaddition products were 47-63 kcal mol(-1) less stable than the reactants, thus making the reaction very difficult. The presence of Stone-Wales translocations, 585 double vacancies, or 555-777 reconstructed double vacancies did not significantly improve the reactivity because the cycloaddition products were still located at higher energy than the reactants. However, for the addition of 910DMA to single vacancies, the product showed comparable stability to the separated reactants, whereas for unsaturated armchair edges the reaction was extremely favorable. With regards the reactions with dienophiles, for TCNE, the cycloaddition product was metastable. In the case of MA, we observed a reaction product that was less stable than the reactants by 50 kcal mol(-1) . For the reactions between graphene as a diene and the dienophiles, we found that the most-promising defects were single vacancies and unsaturated armchair edges, because the other three defects were much-less reactive. Thus, we conclude that the reactions with these above-mentioned dienes may proceed on pristine or defective sheets with heating, despite being endergonic. The same statement also applies to the dienophile maleic anhydride. However, for TCNE, the reaction is only likely to occur onto single vacancies or unsaturated armchair edges. We conclude that the dienophile character of graphene is slightly stronger than its behavior as a diene. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

(4+2) Cycloaddition reactions with inverse electron demand of nitrogen bearing, heteroaromatic cations

International Nuclear Information System (INIS)

Ritzberger-Baumgartner, W.

1996-06-01

Three cationic, heteroaromatic diene-systems (1, 2, 3, 4-tetramethoxycarbonyl-quinolizinium-tetrafluoroborate (M), 8, 9, 10, 11-tetrarnethoxycarbonylpyrido[2,1-a]-isoquinolinium-TFB and triazolo[1,5-b]isoquinolinium-TFBs) and a cationic, non-aromatic diene (2,5,5-trimethyl-3-oxo-1, 2, 4-triazolium-TFB) were synthesized. The dienes were employed successfully in cycloaddition reactions with a number ofconjugated dienophiles (including norbornene). The mechanism underlying these cycloaddition reactions was discussed in the theoretical section. At first quantumchemical calculations of the frontier orbital energies provided the proof, that the reactions followed the pattern of reactions with inverse electron demand. Calculation of the charge distribution and of the orbital coefficients led to the conclusion, that these reactions are mainly orbital controlled. Two mechanistic variants were in discussion. Either the reactions proceed in a concerted manner resembling the Diels-Alder reaction with inverse electron demand or in two distinct steps with the formation of a cationic intermediate following the attack of the heterodienes acting as weak electrophiles at the dienophiles being weak nucleophiles. Calculations of a possible transition state of these cycloaddition reactions revealed a pronounced preference for the formation of the bond between the logical reaction centers in the first step of a two-step reaction. However, experimental and theoretical findings led to the conviction, that cationic polar cycloaddition reactions proceed exactly along the crossroad between a concerted and a two-step mechanism and depending on the electrophilic strength of the diene and the nucleophilic strength of the dienophile these reactions show more characteristics of one of the two mechanistic possibilities. The high regioselectivity as well as the high stereoselectivity could be explained satisfactory with the help of the calculated orbital coefficients. (author)

A mechanistic study on the reaction pathways leading to benzene and naphthalene in cellulose vapor phase cracking

International Nuclear Information System (INIS)

Norinaga, Koyo; Yang, Huamei; Tanaka, Ryota; Appari, Srinivas; Iwanaga, Keita; Takashima, Yuka; Kudo, Shinji; Shoji, Tetsuya; Hayashi, Jun-ichiro

2014-01-01

The reaction pathways leading to aromatic hydrocarbons such as benzene and naphthalene in gas-phase reactions of multi-component mixtures derived from cellulose fast pyrolysis were studied both experimentally and numerically. A two-stage tubular reactor was used for evaluating the reaction kinetics of secondary vapor phase cracking of the nascent pyrolysates at temperature ranging from 400 to 900 °C, residence time from 0.2 to 4.3 s, and at 241 kPa. The products of alkyne and diene were identified from the primary pyrolysis of cellulose even at low temperature range 500–600 °C. These products include acetylene, propyne, propadiene, vinylacetylene, and cyclopentadiene. Experiments were also numerically validated by a detailed chemical kinetic model consisting of more than 8000 elementary step-like reactions with over 500 chemical species. Acceptable capabilities of the kinetic model in predicting concentration profiles of the products enabled us to assess reaction pathways leading to benzene and naphthalene via the alkyne and diene from primary pyrolysates of cellulose. C 3 alkyne and diene are primary precursors of benzene at 650 °C, while combination of ethylene and vinylacetylene produces benzene dominantly at 850 °C. Cyclopentadiene is a prominent precursor of naphthalene. Combination of acetylene with propyne or allyl radical leads to the formation of cyclopentadiene. Furan and acrolein are likely important alkyne precursors in cellulose pyrolysis at low temperature, whereas dehydrogenations of olefins are major route to alkyne at high temperatures. - Highlights: • Analytical pyrolysis experiments provided data for kinetic modeling. • Detailed chemical kinetic model was used and evaluated. • Alkyne and diene were important intermediates for aromatic hydrocarbon formation. • Reaction pathways leading to aromatic hydrocarbons were proposed

Liquid crystalline networks for electroluminescent displays

International Nuclear Information System (INIS)

Contoret, A.E.A.

2001-09-01

This work presents the first low molar mass organic electroluminescent (EL) material to form a nematic glass and then emit plane-polarised light from the vitrified state on application of an electric field. Photocrosslinkable molecules are also discussed which form insoluble films on illumination with ultra-violet light. This approach combines the ease of deposition of small molecules with the robustness and stability of polymers, allowing simple fabrication of multi-layer EL devices and photo-patterning. A range of conjugated low molar-mass molecules are considered, containing the anthracene, perylene and fluorene cores, with the aims of producing a general recipe for efficient EL, based on ordered, stable nematics at room temperature. Many physical properties are compared and molecular mechanics modeling is used to represent molecular geometries. An acrylate and several diene photo-polymerisable derivatives of the fluorenes undergo photo-crosslinking. Infrared and photoluminescence spectroscopy is used to examine crosslinking in detail and to optimise exposure conditions. The diene shows no significant degradation for an optimal exposure, but requires a high fluence of 100 Jcm -2 to form an insoluble film. A doped photo-alignment layer is used for the first time to obtain polarised El with ratio 11:1 and 80 cdm -2 brightness from the crosslinked diene. The insoluble crosslinked network allows spin coating of an electron transporting over-layer, resulting in increased brightness. Complex impedance spectroscopy and time of flight measurements confirm good material properties with complete depletion of the crosslinkable diene molecule and non-dispersive conduction. Finally, a novel deposition technique, pulsed laser deposition (PLD), is presented, as an alternative to spin coating or vapour deposition. Minimal degradation is observed for optimised deposition conditions and a PLD film is successfully demonstrated in an EL device. (author)

Two new hydrogen bond-supported supramolecular compounds assembly from polyoxovanadate and organoamines

International Nuclear Information System (INIS)

Duan Weijie; Cui Xiaobing; Xu Yan; Xu Jiqing; Yu Haihui; Yi Zhihui; Cui Jiwen; Wang Tiegang

2007-01-01

Two novel organic-inorganic hybrid compounds based on organoamines and polyoxovanadates formulated as (H 2 dien) 4 [H 10 V 18 O 42 (PO 4 )](PO 4 ).2H 2 O (1) (dien=diethylenetriamine) and (Him) 8 [HV 18 O 42 (PO 4 )] (2) (im=imidazole) have been prepared under hydrothermal conditions by using different starting materials, and characterized by elemental analyses, IR, ESR, XPS, TGA and single-crystal X-ray diffraction analyses. Crystal data for compound 1: C 16 H 74 N 12 O 52 V 18 P 2 , Monoclinic, space group C2/c, a=23.9593(4) A, b=13.0098(2) A, c=20.1703(4) A, β=105.566(3) o , V=6056.6(19) A 3 , Z=4; for compound 2, C 24 H 41 N 16 O 46 V 18 P, Tetragonal, space group I4/mmm, a=13.5154(8) A, b=13.5154(8) A, c=19.1136 A, β=90 o , V=3491.4(3) A 3 , Z=2. Compound 1 consists of protonated diens together with polyoxovanadates [H 10 V 18 O 42 (PO 4 )] 5- . Compound 2 is composed of protonated ims and polyoxovanadates [HV 18 O 42 (PO 4 )] 8- . There are hydrogen-bonding interactions between polyoxovanadates and different organoamines in 1 and 2. Polyoxovanadates are linked through H 2 dien into a three-dimensional network via hydrogen bonds in 1, while polyoxovanadates are linked by Him into a two-dimensional layer network via hydrogen bonds in 2. The crystal packing patterns of the two compounds reveal various supramolecular frameworks. - Graphical abstract: Two new organic-inorganic hybrid compounds based on [V 18 O 42 (PO 4 )] building blocks have been hydrothermally synthesized. 1 is the first 3-D supramolecular network structure consisting of [V 18 O 42 (PO 4 )] unit, while 2 possesses 2-D layered supramolecular structure

Free-volume micro-structure of the amorphous polymers at Tg

International Nuclear Information System (INIS)

Bartos, J.

1995-01-01

The positron annihilation spectroscopy was used to the study of the free-volume microstructure of the amorphous polymers [diene-elastomers, vinyl-elastomers and thermoplastics, aromatic thermoplastics

Chemical constituents of Gustavia Augusta L. (Lecythidaceae); Constituintes quimicos de Gustavia Augusta L. (Lecythidaceae)

Energy Technology Data Exchange (ETDEWEB)

Souza, Afonso Duarte Leao de; Rocha, Arnaldo F. Imbiriba da; Pinheiro, Maria Lucia Belem; Andrade, Carlos Humberto de S.; Galotta, Ana Lucia de A. Queiroz; Santos, Maria do Perpetuo Socorro S. dos [Amazonas Univ., Manaus, AM (Brazil). Dept. de Quimica]. E-mail: afonsodlsouza@yahoo.com.br

2001-08-01

The Gustavia augusta is used in the folk medicine against leishmaniasis and showed anti-inflammatory action. The phyto chemical studies of the plant stem bark have led to the isolation of (22E)-stigmasta-7,22-dien-3{beta}-ol, 24{alpha}(S)-ethyl-5{alpha}-colesta-7, trans-22-dien-3-one, D-friedoolean-14-en-3{beta}-ol, D-friedoolean-14-en-3-one and D-friedoolean-14-en-3{alpha}-ol along with stigmasterol, {alpha}-amyrin, {beta}-amyrin, lupeol, 3{alpha}-hydroxy-lupeol and betulinic acid. The structures of these compounds were identified by IR, GC/M S, {sup 1} H and {sup 1} {sup 3} C NMR spectral analysis and comparison with literature data. (author)

[Chemical study on fruiting bodies of Boletus vioaceo-fuscus].

Science.gov (United States)

Ma, Bing-ji; Ruan, Yuan; Liu, Ji-kai

2007-09-01

To investigate the chemical constituents of Boletus vioaceo-fuscus. The compounds were isolated with column chromatography. The structures were determined by spectroscopic techniques. Six compounds were isolated from the fruiting bodies of Boletus vioaceo-fiuscus. They were identified as ergosta-5, 7, 22-triene-3beta-ol (1), dihydrofuran-2, 5-dione (2), (22E, 24R)-5alpha, 6alpha-epoxyergosta-8, 22-diene-3beta, 7alpha-diol (3), (22E, 24R)-5alpha, 6alpha-epoxyergosta-8 (14), 22-diene-3beta, 7alphadiol (4), cerebroside B (5) and adenosine (6), respectively. All the Compounds were obtained from the fruiting bodies of Boletus vioaceo-fiscus for the first time.

Chemical constituents of Gustavia Augusta L. (Lecythidaceae)

International Nuclear Information System (INIS)

Souza, Afonso Duarte Leao de; Rocha, Arnaldo F. Imbiriba da; Pinheiro, Maria Lucia Belem; Andrade, Carlos Humberto de S.; Galotta, Ana Lucia de A. Queiroz; Santos, Maria do Perpetuo Socorro S. dos

2001-01-01

The Gustavia augusta is used in the folk medicine against leishmaniasis and showed anti-inflammatory action. The phyto chemical studies of the plant stem bark have led to the isolation of (22E)-stigmasta-7,22-dien-3β-ol, 24(α(S)-ethyl-5α-colesta-7, trans-22-dien-3-one, D-friedoolean-14-en-3β-ol, D-friedoolean-14-en-3-one and D-friedoolean-14-en-3α-ol along with stigmasterol, α-amyrin, β-amyrin, lupeol, 3α-hydroxy-lupeol and betulinic acid. The structures of these compounds were identified by IR, GC/M S, 1 H and 1 3 C NMR spectral analysis and comparison with literature data. (author)

Unconventional exo selectivity in thermal normal-electron-demand Diels-Alder reactions

Science.gov (United States)

Ho, Guo-Ming; Huang, Ci-Jhang; Li, Elise Yu-Tzu; Hsu, Sheng-Kai; Wu, Ti; Zulueta, Medel Manuel L.; Wu, Kevin Binchia; Hung, Shang-Cheng

2016-10-01

The Diels-Alder reaction is a useful tool for generating functionalized chiral molecules through the concerted cycloaddition of dienes and dienophiles leading to six-membered rings. Traditionally, the selective predictions of the products rely heavily on consideration of the secondary orbital interactions that stabilize the endo pathway. However, there remain some basic examples defying this notion and produce the exo-isomer as major product. Here we systematically evaluated of the structural features driving exo selectivity in thermal normal-electron-demand Diels-Alder reactions. Substitution at the Cβ position and the size and electronegativity of the electron-withdrawing group of the dienophile are contributing factors. Experimental and computational studies both point toward the steric and electrostatic forces between the substituents in both the diene and the dienophile that increase the likelihood of the exo pathway. For these substrates, the dominance of the endo pathway is reduced by transition state distortions and poor structural alignments of the reacting partners. We also noted the tilt of the dienophile with respect to the diene causing steric strain on the functionalities at the more advanced bond forming carbon-carbon position of the endo transition state. Insights into such factors may benefit synthetic planning and asserting control over this important named reaction.

The Essential Oils of Rhaponticum carthamoides Hairy Roots and Roots of Soil-Grown Plants: Chemical Composition and Antimicrobial, Anti-Inflammatory, and Antioxidant Activities

Science.gov (United States)

Rijo, Patrícia; Garcia, Catarina; Kalemba, Danuta; Toma, Monika; Szemraj, Janusz; Pytel, Dariusz; Śliwiński, Tomasz

2016-01-01

The essential oils were isolated by hydrodistillation from the hairy roots (HR) and roots of soil-grown plants (SGR) of Rhaponticum carthamoides and were analyzed by GC-MS method. In the both essential oils 62 compounds were identified. The root essential oils showed the differences in the qualitative and quantitative composition. The sesquiterpene hydrocarbons (55–62%) dominated in both essential oils. The major compounds of HR essential oil were cyperene, 13-norcypera-1(5),11(12)-diene, and cadalene while aplotaxene, nardosina-1(10),11-diene, and dauca-4(11),8-diene dominated in SGR essential oil. Both essential oils showed antibacterial activity especially against Enterococcus faecalis (ATCC 29212) and Pseudomonas aeruginosa (ATCC 27853) (MIC value = 125 µg/mL). HR and SGR essential oils also decreased the expression of IL-1β, IL-6, and TNF-α and the ROS level in LPS-treatment astrocytes. This is the first report to describe the chemical composition of R. carthamoides essential oil from hairy roots, its protective effect against LPS-induced inflammation and ROS production in astrocytes, and its antimicrobial potential. The results show that R. carthamoides hairy roots may be a valuable source of the essential oil and may be an alternative to the roots of soil-grown plants. PMID:28074117

Imino Diels-Alder-Based Construction of a Piperidine A-Ring Unit for Total Synthesis of the Marine Hepatotoxin Cylindrospermopsin.

Science.gov (United States)

Heintzelman, Geoffrey R.; Weinreb, Steven M.; Parvez, Masood

1996-07-12

The synthesis of a piperidine A-ring precursor to the alkaloid cylindrospermopsin (1) is described. The initial approach to the A-ring precursor focused on the imino Diels-Alder reaction of diene 8 with ethyl (N-tosylimino)acetate (9) to form the cycloadduct 10 as a single stereoisomer. However, all attempts to convert ester 10 to a requisite diene such as 5 were unsuccessful. An alternative strategy involved the Diels-Alder cycloaddition of N-tosylimine 9 with oxygenated diene 19 under either thermal or Lewis acid-catalyzed conditions to produce a mixture of cis and trans enones 20 and 21. Although the undesired cis-enone 20 was the major product under all reaction conditions, it could be converted to the desired trans enone 21 by acid-catalyzed isomerization. Copper-mediated conjugate addition of vinylmagnesium bromide to cis-enone 20 followed by stereoselective ketone reduction with L-Selectride produced alcohol 23, whose structure was confirmed by X-ray crystallography. Similarly, trans-enone 21 was converted to alcohol 25 whose structure and stereochemistry were also established by X-ray analysis. Alcohol 25 was then protected as the silyl ether 26, which was hydroborated at the terminal olefin to produce primary alcohol ester 28having the stereochemistry and functionality needed for cylindrospermopsin.

The Essential Oils of Rhaponticum carthamoides Hairy Roots and Roots of Soil-Grown Plants: Chemical Composition and Antimicrobial, Anti-Inflammatory, and Antioxidant Activities.

Science.gov (United States)

Skała, Ewa; Rijo, Patrícia; Garcia, Catarina; Sitarek, Przemysław; Kalemba, Danuta; Toma, Monika; Szemraj, Janusz; Pytel, Dariusz; Wysokińska, Halina; Śliwiński, Tomasz

2016-01-01

The essential oils were isolated by hydrodistillation from the hairy roots (HR) and roots of soil-grown plants (SGR) of Rhaponticum carthamoides and were analyzed by GC-MS method. In the both essential oils 62 compounds were identified. The root essential oils showed the differences in the qualitative and quantitative composition. The sesquiterpene hydrocarbons (55-62%) dominated in both essential oils. The major compounds of HR essential oil were cyperene, 13-norcypera-1(5),11(12)-diene, and cadalene while aplotaxene, nardosina-1(10),11-diene, and dauca-4(11),8-diene dominated in SGR essential oil. Both essential oils showed antibacterial activity especially against Enterococcus faecalis (ATCC 29212) and Pseudomonas aeruginosa (ATCC 27853) (MIC value = 125  µ g/mL). HR and SGR essential oils also decreased the expression of IL-1 β , IL-6, and TNF- α and the ROS level in LPS-treatment astrocytes. This is the first report to describe the chemical composition of R. carthamoides essential oil from hairy roots, its protective effect against LPS-induced inflammation and ROS production in astrocytes, and its antimicrobial potential. The results show that R. carthamoides hairy roots may be a valuable source of the essential oil and may be an alternative to the roots of soil-grown plants.

Diens en diensbaarheid tot opbou van die kerk

Directory of Open Access Journals (Sweden)

A. C. Barnard

1988-08-01

Full Text Available Service and Servitude in View of the Edification of the Church The most important change Christ brings about is that people who, in the past, desired to be served, are now willing to serve. The believer is a person who serves and the church is a service community. The service is comprehensive: we serve God, we serve our fellow believers, we serve in the church, we serve in the world, we serve people when they are in need, wherever they are, and we serve God in our services of worship.

Synthesis and properties of dioxo Tc(V) cationic complexes with nitrogen containing ligands

International Nuclear Information System (INIS)

Gambino, D.; Kremer, C.; Savio, E.; Leon, A.; Kremer, E.

1990-01-01

A series of Tc(V) cationic complexes was synthesized by electrochemical reduction of TcO 4 - . The electrolysis was performed in aqueous media containing amines as ligands: ethylenediamine (en), diethylenetriamine (dien), triethylenetetramine (trien) and 1,3-diaminopropane (1,3-dap). The combination of different techniques allows to propose the general formula [TcO 2 (amine) 2 ] + for these compounds. Electrodeposition of TcO 2 was a competitive reaction. The UV spectra were compared with those for other Tc(V) amine complexes. The presence of two peaks could be verified. Preliminary studies showed that kinetic stability decreased in the sequence en, 1,3-dap, trien, dien. The decomposition rate increased when the pH was lowered. (author) 16 refs.; 2 figs.; 3 tabs

Biotransformation of a cage-like diels-alder adduct and derivatives by Mucor ramosissimus samutsevitsch Biotransformação de um aduto de diels-alder cage-like e derivados por Mucor ramosissimus samutsevitsch

Directory of Open Access Journals (Sweden)

Felicia Megumi Ito

2009-09-01

Full Text Available The present study aimed to evaluate the ability for biotransformation of the Diels-Alder adduct tricyclo[6.2.1.0(2,7]undeca-4,9-dien-3,6-dione (1 and two synthetic derivatives by the saprobe fungus Mucor ramosissimus Samutsevitsch. Products from oxidation, isomerization and, regioselective and enantioselective reduction were achieved.Neste trabalho avaliou-se a capacidade de biotransformação do aduto de Diels-Alder triciclo[6.2.1.0(2-7]undeca-4,9-dien-3,6-diona (1 e dois derivados sintéticos pelo fungo sapróbio Mucor ramosissimus Samutsevitsch. Produtos de oxidação, isomerização e redução regiosseletiva e enantiosseletiva foram obtidos.

About the activity and selectivity of less well-known metathesis catalysts during ADMET polymerizations

Directory of Open Access Journals (Sweden)

Hatice Mutlu

2010-12-01

Full Text Available We report on the catalytic activity of commercially available Ru-indenylidene and “boomerang” complexes C1, C2 and C3 in acyclic diene metathesis (ADMET polymerization of a fully renewable α,ω-diene. A high activity of these catalysts was observed for the synthesis of the desired renewable polyesters with molecular weights of up to 17000 Da, which is considerably higher than molecular weights obtained using the same monomer with previously studied catalysts. Moreover, olefin isomerization side reactions that occur during the ADMET polymerizations were studied in detail. The isomerization reactions were investigated by degradation of the prepared polyesters via transesterification with methanol, yielding diesters. These diesters, representing the repeat units of the polyesters, were then quantified by GC-MS.

Effects of irradiation on color and lipid oxidation of prosciutto

International Nuclear Information System (INIS)

Kong Qiulian; Qi Wenyuan; Yue Ling; Chen Zhijun; Bao Yingzi; Dai Xudong; Xu Yun

2011-01-01

This study dealt with the effect of irradiation on the color, ordor and lipid oxidation of prosciutto crudo. The hams were irradiated by γ-ray and electronic beam (EB). Changes of color, ordor, TBA value (TBARS), peroxide value (POV), carbonyl value and conjugated diene value were analyzed and compared with nonirradiated hams. Results showed that color index (a * ) of control, γ-ray irradiated and EB irradiated were 14.39, 9.45 and 11.71 respectively. γ-ray irradiation had been shown to have apparently detrimental effect on the color and ordor of hams, while EB irradiation had little detrimental effect. Irradiation increased POV and conjugated diene value, but the amounts of lipid oxidation products (TBARS, carbonyl value) were less than nonirradiated hams. (authors)

Biodegradation of 2,4-dichlorophenol using Mycoplana dimorpha ...

African Journals Online (AJOL)

STORAGESEVER

2008-06-17

Jun 17, 2008 ... dation kinetic models have been developed, proposed and used in ... kinetic models. ..... Dihydroxycyclohexa-3, 5-Diene (Nicotinamide Adenine Dinucleotide) .... (KMUP-3) in rat trachea: The involvement of soluble guanylate.

Computational assessment of the electronic structures of cyclohexa-1,2,4-triene, 1-oxacyclohexa-2,3,5-triene (3delta(2)-pyran), their benzo derivatives, and cyclohexa-1,2-diene. An experimental approach to 3delta(2)-pyran.

Science.gov (United States)

Engels, Bernd; Schöneboom, Jan C; Münster, Arno F; Groetsch, Stefan; Christl, Manfred

2002-01-16

The six-membered cyclic allenes given in the title have been studied theoretically by means of an MR-CI approach. For all compounds, the allene structures were found to be the ground states in the gas phase. In the cases of cyclohexa-1,2-diene (1), the isobenzene 2, and the isonaphthalene 7, the most stable structures having a planar allene moiety are the diradicals 1b, 2b, and 7b, representing the transition states for the racemization of 1a, 2a, and 7a and being less stable than the latter by 14.1, 8.9, and 11.2 kcal/mol, respectively. At variance with this order, the 3delta(2)-pyran 4 and the chromene 5 have the zwitterions 4c and 5c as the most stable planar structures, which lie only 1.0 and 5.4 kcal/mol above 4a and 5a, respectively. According to the simulation of the solvent effect, 4c even becomes the ground state of 4 in THF solution. The frontier orbitals of the respective states of 2 and 4 suggest different rates and sites for the reaction with nucleophiles. For the first time, the pyran 4 has been generated and trapped. As a precursor for 4, 3-bromo-4H-pyran (9) was chosen, the synthesis of which was achieved on two routes from 4H-pyran. The treatment of 9 with potassium tert-butoxide (KOt-Bu)/18-crown-6 gave 4-tert-butoxy-4H-pyran as the only discernible product, whether styrene or furan was present, indicating the interception of 4 by KOt-Bu. Finally, the disagreement between the experiment and the theory concerning the heat of formation and the electronic nature of the isobenzene 2 is resolved by demonstrating that the experimental data can provide only an upper limit of the DeltaH(f) degrees value.

Protective Effect of 2-Dodecyl-6-Methoxycyclohexa-2, 5-Diene-1, 4-Dione, Isolated from Averrhoa Carambola L., Against Palmitic Acid-Induced Inflammation and Apoptosis in Min6 Cells by Inhibiting the TLR4-MyD88-NF-κB Signaling Pathway

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Qiuqiao Xie

2016-09-01

Full Text Available Background/Aims: Studies have demonstrated that 2-dodecyl-6-methoxycyclohexa-2, 5-diene-1, 4-dione (DMDD, isolated from the roots of Averrhoa carambola L., has significant therapeutic potential for the treatment of diabetes. However, the protective effect of DMDD against pancreatic beta cell dysfunction has never been reported. We investigated whether DMDD protected against palmitic acid-induced dysfunction in pancreatic β-cell line Min6 cells by attenuating the inflammatory response and apoptosis and to shed light on its possible mechanism. Methods: Cell viability was assessed by CCK-8. Glucose-stimulated insulin secretion levels and inflammatory cytokines levels were examined by ELISA. Apoptosis was assessed by Annexin V-FITC/PI Flow cytometry assay, Hoechst 33342/PI double-staining assay, and Transmission electron microscopy assay. Relative quantitative real-time PCR and western blot were used to determine the expressions of genes and proteins. Results: Cell viability and glucose-stimulated insulin secretion levels were increased in DMDD-pretreated Min6 cells. DMDD inhibited inflammatory cytokines IL-6, TNF-α and MCP-1 generations in palmitic acid (PA-induced Min6 cells. Moreover, DMDD protected against PA-induced Min6 cells apoptosis and the expression of Cleaved-Caspase-3, -8 and -9 were down-regulated and the Bcl-2/Bax ratio was increased in DMDD-pretreated Min6 cells. In addition, the expression of TLR4, MyD88 and NF-κB were down-regulated in DMDD-pretreated Min6 cells and TAK-242-pretreated group cells. Conclusions: DMDD protected Min6 cells against PA-induced dysfunction by attenuating the inflammatory response and apoptosis, and its mechanism of this protection was associated with inhibiting the TLR4-MyD88-NF-κB signaling pathway.

Protective Effect of 2-Dodecyl-6-Methoxycyclohexa-2, 5-Diene-1, 4-Dione, Isolated from Averrhoa Carambola L., Against Palmitic Acid-Induced Inflammation and Apoptosis in Min6 Cells by Inhibiting the TLR4-MyD88-NF-κB Signaling Pathway.

Science.gov (United States)

Xie, Qiuqiao; Zhang, Shijun; Chen, Chunxia; Li, Juman; Wei, Xiaojie; Xu, Xiaohui; Xuan, Feifei; Chen, Ning; Pham, Thithaihoa; Qin, Ni; He, Junhui; Ye, Fangxing; Huang, Wansu; Huang, Renbin; Wen, Qingwei

2016-01-01

Studies have demonstrated that 2-dodecyl-6-methoxycyclohexa-2, 5-diene-1, 4-dione (DMDD), isolated from the roots of Averrhoa carambola L., has significant therapeutic potential for the treatment of diabetes. However, the protective effect of DMDD against pancreatic beta cell dysfunction has never been reported. We investigated whether DMDD protected against palmitic acid-induced dysfunction in pancreatic β-cell line Min6 cells by attenuating the inflammatory response and apoptosis and to shed light on its possible mechanism. Cell viability was assessed by CCK-8. Glucose-stimulated insulin secretion levels and inflammatory cytokines levels were examined by ELISA. Apoptosis was assessed by Annexin V-FITC/PI Flow cytometry assay, Hoechst 33342/PI double-staining assay, and Transmission electron microscopy assay. Relative quantitative real-time PCR and western blot were used to determine the expressions of genes and proteins. Cell viability and glucose-stimulated insulin secretion levels were increased in DMDD-pretreated Min6 cells. DMDD inhibited inflammatory cytokines IL-6, TNF-α and MCP-1 generations in palmitic acid (PA)-induced Min6 cells. Moreover, DMDD protected against PA-induced Min6 cells apoptosis and the expression of Cleaved-Caspase-3, -8 and -9 were down-regulated and the Bcl-2/Bax ratio was increased in DMDD-pretreated Min6 cells. In addition, the expression of TLR4, MyD88 and NF-κB were down-regulated in DMDD-pretreated Min6 cells and TAK-242-pretreated group cells. DMDD protected Min6 cells against PA-induced dysfunction by attenuating the inflammatory response and apoptosis, and its mechanism of this protection was associated with inhibiting the TLR4-MyD88-NF-κB signaling pathway. © 2016 The Author(s) Published by S. Karger AG, Basel.

Non-phenolic antioxidant compounds from Buddleja asiatica.

Science.gov (United States)

el-Sayed, Mortada M; Abdel-Hameed, El-Sayed S; Ahmed, Wafaa S; el-Wakil, Eman A

2008-01-01

The methanol extract of the leaves of Buddleja asiatica Lour. (Loganiaceae) showed antioxidant activity toward the well known in vitro antioxidant tests such as total antioxidant capacity by the phosphomolybdenum method, free radical scavenging activity by the 1,1-diphenyl-2-picrylhydrazyl scavenging assay (DPPH assay) and hydrogen peroxide scavenging methods. Due to the high scavenging activity of the n-butanol successive fraction toward DPPH and H2O2 (SC50 = 11.99 and 18.54 microg/ml, respectively), this extract was subjected to chromatographic separation and isolation. Four non-phenolic compounds were isolated and identified on the basis of spectroscopic and chemical analyses: 1-O-beta-D-glucopyranosyl-2-methoxy-3-(2-hydroxy-triaconta-3,12-dienoate)-glycerol (1), 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->2)]-beta-D-fucopyranosyl-olean-11,13(18)-diene-3 beta,23,28-triol (2), 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-beta-D-fucopyranosyl-olean-11,13(18)-diene-3,23,28-triol (3), and 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)]-[beta-D-xylopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl-acid-olean-11,13(18)-diene-3 beta,23,28-triol (4). The four compounds were evaluated as antioxidant agents using the three antioxidant bioassay tests.

The metabolism of carbohydrates and lipid peroxidation in lead-exposed workers.

Science.gov (United States)

Kasperczyk, Aleksandra; Dobrakowski, Michal; Ostałowska, Alina; Zalejska-Fiolka, Jolanta; Birkner, Ewa

2015-12-01

The present study was undertaken to estimate the effect of occupational exposure to lead on the blood concentration of glucose and several enzymes involved in glycolysis, the citric acid cycle, and the pentose phosphate pathway. To estimate the degree of lipid peroxidation, the concentrations of conjugated dienes were determined. The examined group included 145 healthy male employees of lead-zinc works. Taking into account the mean blood lead levels, the examined group was divided into two subgroups. The control group was composed of 36 healthy male administrative workers. The markers of lead exposure were significantly elevated in both subgroups when compared with the controls. There were no significant changes in fasting glucose concentration and fructose-1,6-bisphosphate aldolase activity in the study population. The concentration of conjugated dienes was significantly higher in both subgroups, whereas the activity of malate dehydrogenase was significantly higher only in the group with higher exposure. The activities of lactate dehydrogenase and sorbitol dehydrogenase were significantly decreased in the examined subgroups. The activity of glucose-6-phosphate dehydrogenase decreased significantly in the group with higher exposure and could be the cause of the elevated concentrations of conjugated dienes. It is possible to conclude that lead interferes with carbohydrate metabolism, but compensatory mechanisms seem to be efficient, as glucose homeostasis in lead-exposed workers was not disturbed. © The Author(s) 2013.

Triterpenos aislados de corteza de Bursera graveolens (Burseraceae y su actividad biologica

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Jorge Robles

Full Text Available Bursera graveolens (Burseraceae, known in Colombia as "sasafrás", is useful for its medicinal properties and is rich in secondary metabolites. In our research, we carried out antimicrobial tests of several fractions and ethanolic extracts from aerial parts against Bacillus subtilis and Staphylococcus aureus, that showed growth inhibitory activity when applied at 250 mg/mL for extracts and 150 mg/mL for fractions. We carried out an antiinflamatory assay also, that showed 71% of inhibition by extracts (81% of Indomethacin and 70% of inhibition by fractions (78% of Indomethacin. Phytochemical investigation of the bark of Bursera graveolens (Burseraceae yielded three tetracyclic triterpene acids that have oxygenation in C-3, carboxylic acid in C-21 and unsaturation in C-24 and have been identified as 3-oxotirucalla-8,24-dien-21-oic acid (b-elemonic acid, 3a-hydroxytirucalla-8,24-dien-21-oic acid (a-elemolic acid and 3a-hydroxytirucalla-7,24-dien-21-oic acid. The isolated compounds were identified using spectroscopic methods including one and two-dimensional Nuclear Magnetic Resonance (COSY, HMQC, HMBC, NOESY experiments and comparison with published data. This is the first report of the isolated compounds in Bursera graveolens and they have a very important chemotaxonomic significance within the Burseraceae family and related families from the order Rutales.

Aspergillus fumigatus CY018, an endophytic fungus in Cynodon dactylon as a versatile producer of new and bioactive metabolites.

Science.gov (United States)

Liu, J Y; Song, Y C; Zhang, Z; Wang, L; Guo, Z J; Zou, W X; Tan, R X

2004-11-09

Aspergillus fumigatus CY018 was recognized as an endophytic fungus for the first time in the leaf of Cynodon dactylon. By bioassay-guided fractionation, the EtOAc extract of a solid-matrix steady culture of this fungus afforded two new metabolites, named asperfumoid (1) and asperfumin (2), together with six known bioactive compounds including monomethylsulochrin, fumigaclavine C, fumitremorgin C, physcion, helvolic acid and 5alpha,8alpha-epidioxy-ergosta-6,22-diene-3beta-ol as well as other four known compounds ergosta-4,22-diene-3beta-ol, ergosterol, cyclo(Ala-Leu) and cyclo(Ala-Ile). Through detailed spectroscopic analyses including HRESI-MS, homo- and hetero-nuclear correlation NMR experiments (HMQC, COSY, NOESY and HMBC), the structures of asperfumoid and asperfumin were established to be spiro-(3-hydroxyl-2,6-dimethoxyl-2,5-diene-4-cyclohexone-(1,3')-5'-methoxyl-7'-methyl-(1'H, 2'H, 4'H)-quinoline-2',4'-dione) and 5-hydroxyl-2-(6-hydroxyl-2-methoxyl-4-methylbenzoyl)-3,6-dimethoxyl-benzoic methyl ester, respectively. All of the 12 isolates were subjected to in vitro bioactive assays against three human pathogenic fungi Candida albicans, Tricophyton rubrum and Aspergillus niger. As a result, asperfumoid, fumigaclavine C, fumitremorgin C, physcion and helvolic acid were shown to inhibit C. albicans with MICs of 75.0, 31.5, 62.5, 125.0 and 31.5 microg/mL, respectively.

Exploitation of rare earth catalysts in polymer syntheses

Institute of Scientific and Technical Information of China (English)

Shen Zhiquan

2006-01-01

The studies over forty years on rare earth catalysts in polymer syntheses of diene,alkyne,alkylene oxide,thiirane, carbon dioxide copolymerization, lactide,caprolactone,cyclic carbonate and so forth in China have been reviewed.

Catalytic hydrogenation of alkyne and alkadiene impurities from alkenes. Practical and theoretical aspects

International Nuclear Information System (INIS)

Nikolaev, S A; Smirnov, V V; Zanaveskin, Leonid N; Zanaveskin, K L; Averyanov, Vyacheslav A

2009-01-01

The review is devoted to heterogeneous catalysts for selective hydrogenation of highly unsaturated impurities (dienes and acetylenes) in hydrocarbonic streams. The most promising systems are nanocomposites on the basis of palladium or gold.

Hydrogen atom transfer reactions in thiophenol: photogeneration of two new thione isomers.

Science.gov (United States)

Reva, Igor; Nowak, Maciej J; Lapinski, Leszek; Fausto, Rui

2015-02-21

Photoisomerization reactions of monomeric thiophenol have been investigated for the compound isolated in low-temperature argon matrices. The initial thiophenol population consists exclusively of the thermodynamically most stable thiol form. Phototransformations were induced by irradiation of the matrices with narrowband tunable UV light. Irradiation at λ > 290 nm did not induce any changes in isolated thiophenol molecules. Upon irradiation at 290-285 nm, the initial thiol form of thiophenol converted into its thione isomer, cyclohexa-2,4-diene-1-thione. This conversion occurs by transfer of an H atom from the SH group to a carbon atom at the ortho position of the ring. Subsequent irradiation at longer wavelengths (300-427 nm) demonstrated that this UV-induced hydrogen-atom transfer is photoreversible. Moreover, upon irradiation at 400-425 nm, the cyclohexa-2,4-diene-1-thione product converts, by transfer of a hydrogen atom from the ortho to para position, into another thione isomer, cyclohexa-2,5-diene-1-thione. The latter thione isomer is also photoreactive and is consumed if irradiated at λ atom-transfer isomerization reactions dominate the unimolecular photochemistry of thiophenol confined in a solid argon matrix. A set of low-intensity infrared bands, observed in the spectra of UV irradiated thiophenol, indicates the presence of a phenylthiyl radical with an H- atom detached from the SH group. Alongside the H-atom-transfer and H-atom-detachment processes, the ring-opening photoreaction occurred in cyclohexa-2,4-diene-1-thione by the cleavage of the C-C bond at the alpha position with respect to the thiocarbonyl C[double bond, length as m-dash]S group. The resulting open-ring conjugated thioketene adopts several isomeric forms, differing by orientations around single and double bonds. The species photogenerated upon UV irradiation of thiophenol were identified by comparison of their experimental infrared spectra with the spectra theoretically calculated for

New labdane diterpenes from Solidago canadensis.

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Wangensteen, Helle; Phan, Thi T; Rise, Frode; Halvorsen, Trine G; Malterud, Karl E

2012-01-01

The ethanol extract of roots of Solidago canadensis yielded eight labdane-type diterpenes. Five of those were new natural compounds (9,13,15,16-bisepoxy-labdane-7-ene-6,15-dione (3a), 13-epi-9,13,15,16-bisepoxy-labdane-7-ene-6,15-dione (3b), 15,16-epoxy-labdane-7,13-diene-6,16-dione (5), 15-ethoxy-9,13,15,16-bisepoxy-labdane-7-ene-6-one (6a) and 13-epi-15-ethoxy-9,13,15,16-bisepoxy-labdane-7-ene-6-one (6b). The known labdane diterpenes deoxysolidagenone (1), solidagenone (2) and 15,16-epoxy-labdane-7,13-diene-6,15-dione (4) were also isolated. Chemical structures were determined using 1D and 2D NMR techniques and MS analysis.

Dehalogenation Activity of Selected Fungi Toward δ-Iodo-γ-Lactone Derived from trans,trans-Farnesol.

Science.gov (United States)

Gliszczyńska, Anna; Gładkowski, Witold; Świtalska, Marta; Wietrzyk, Joanna; Szumny, Antoni; Gębarowska, Elżbieta; Wawrzeńczyk, Czesław

2016-04-01

Time-course of biotransformation of racemic trans-4-((E)-4',8'-dimethylnona-3',7'-dien-1-yl)-5-iodomethyl-4-methyldihydrofuran-2-one (1) in fungal and yeast cultures was investigated. In these conditions, the substrate 1 was enantioselectively dehalogenated yielding 4-((E)-4',8'-dimethylnona-3',7'-dien-1-yl)-4-methyl-5-methylenedihydrofuran-2-one (2) and its structure was established based on the spectroscopic data. The most effective biocatalyst used was Didymosphaeria igniaria, which catalyzed the process with highest rate and enantioselectivity (ee of product = 76%). The antiproliferative activity of δ-iodo-γ-lactone 1, product of its biotransformation 2, and starting substrate (farnesol) were evaluated toward two cancer cell lines: A549 (human lung adenocarcinoma) and HL-60 (human promyelocytic leukemia). © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

Factors Affecting The Retention Of Knowledge Workers

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Margie Sutherland

2004-11-01

Een van die eienskappe van kenniswerkers is hulle hoë vlak van mobiliteit. Die koste van arbeidsomset van hierdie sleutelbronne is hoog in beide finansiële en nie-finansiële terme. Daar bestaan dus ’n behoefte om die faktore wat onderliggend is aan die retensiekognisies van kenniswerkers te verstaan. Data is ingesamel van 306 kenniswerkers in voltydse diens wat ’n wye reeks demografiese groeperings verteenwoordig. Die resultate dui daarop dat werktevredenheid en organisasieverbondenheid nie die kenniswerkers se verwagte lengte van diens voorspel nie. Faktorontleding het sewe onderliggende dimensies van retensiekognisies blootgelê. ’n Bondelontleding het nege duidelike bondels van kenniswerkers ten opsigte van hulle retensiekognisies onderskei. Hoë vlakke van individualisme, behoefte aan uitdaging en fokus op persoonlike ontwikkeling is aangedui. Die implikasies van hierdie bevindinge word bespreek.

Oxidative stability of Liposomes composed of docosahexaenoic acid-containing phospholipids

DEFF Research Database (Denmark)

Vikbjerg, Anders Falk; Andresen, Thomas Lars; Jørgensen, Kent

2007-01-01

Oxidative stability of liposomes made of (Docosahexaenoic acid) DHA-containing phosphatidylcholine (PC) was examined during preparation and storage. After preparation of the liposomes, the concentration of primary (conjugated dienes) and secondary oxidation products (Thiobarbituric acid...

Reactions of aromatic diazonium salts with unsaturated compounds in the presence of nucleophiles

Science.gov (United States)

Grishchuk, B. D.; Gorbovoi, P. M.; Ganushchak, N. I.; Dombrovskii, A. V.

1994-03-01

The review surveys the reactions of aromatic diazonium salts with diene and monounsaturated compounds in the presence of nucleophiles. Certain further reactions of the reaction products and their application are considered. The bibliography includes 63 references.

A three-component synthesis of functionalized ketenimines by the reaction of alkyl isocyanides and dialkyl acetylenedicarboxylates in the presence of 2-quinolinol

OpenAIRE

BITA MOHTAT; HOORIEH DJAHANIANI; ISSA YAVARI; KOBRA NADERI

2011-01-01

The 1:1 reactive intermediates generated by the addition of alkyl isocyanides to dialkyl acetylenedicarboxylates were trapped by 2-quinolinol to yield highly functionalized ketenimines and, in some cases, minor amounts of 1-azabuta-1,3-dienes.

Kinetics and mechanism of the oxidation of alkenes and silanes by hydrogen peroxide catalyzed by methylrhenium trioxide (MTO) and a novel application of electrospray mass spectrometry to study the hydrolysis of MTO

Energy Technology Data Exchange (ETDEWEB)

Tan, Haisong [Iowa State Univ., Ames, IA (United States)

1999-11-08

Conjugated dienes were oxidized by hydrogen peroxide with methylrhenium trioxide (MTO) as catalyst. Methylrhenium bis-peroxide was the major reactive catalyst present. Hydroxyalkenes and trisubstituted silane were also tested. Mechanisms for each of these reactions are presented.

Highly Regio- and Stereoselective Diels-Alder Cycloadditions via Two-Step and Multicomponent Reactions Promoted by Infrared Irradiation under Solvent-Free Conditions

Science.gov (United States)

Flores-Conde, Maria Ines; Reyes, Leonor; Herrera, Rafael; Rios, Hulme; Vazquez, Miguel A.; Miranda, Rene; Tamariz, Joaquin; Delgado, Francisco

2012-01-01

Infrared irradiation promoted the Diels-Alder cycloadditions of exo-2-oxazolidinone dienes 1–3 with the Knoevenagel adducts 4–6, as dienophiles, leading to the synthesis of new 3,5-diphenyltetrahydrobenzo[d]oxazol-2-one derivatives (7, 9, 11 and 13–17), under solvent-free conditions. These cycloadditions were performed with good regio- and stereoselectivity, favoring the para-endo cycloadducts. We also evaluated the one-pot three-component reaction of active methylene compounds 20, benzaldehydes 21 and exo-2-oxazolidinone diene 2 under the same reaction conditions. A cascade Knoevenagel condensation/Diels-Alder cycloaddition reaction was observed, resulting in the final adducts 13–16 in similar yields. These procedures are environmentally benign, because no solvent and no catalyst were employed in these processes. The regioselectivity of these reactions was rationalized by Frontier Molecular Orbital (FMO) calculations. PMID:22489113

Highly Regio- and Stereoselective Diels-Alder Cycloadditions via Two-Step and Multicomponent Reactions Promoted by Infrared Irradiation under Solvent-Free Conditions

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Francisco Delgado

2012-02-01

Full Text Available Infrared irradiation promoted the Diels-Alder cycloadditions of exo-2-oxazolidinone dienes 1–3 with the Knoevenagel adducts 4–6, as dienophiles, leading to the synthesis of new 3,5-diphenyltetrahydrobenzo[d]oxazol-2-one derivatives (7, 9, 11 and 13–17, under solvent-free conditions. These cycloadditions were performed with good regio- and stereoselectivity, favoring the para-endo cycloadducts. We also evaluated the one-pot three-component reaction of active methylene compounds 20, benzaldehydes 21 and exo-2-oxazolidinone diene 2 under the same reaction conditions. A cascade Knoevenagel condensation/Diels-Alder cycloaddition reaction was observed, resulting in the final adducts 13–16 in similar yields. These procedures are environmentally benign, because no solvent and no catalyst were employed in these processes. The regioselectivity of these reactions was rationalized by Frontier Molecular Orbital (FMO calculations.

A kinetic model for the first stage of pygas upgrading

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J. L. de Medeiros

2007-03-01

Full Text Available Pyrolysis gasoline - PYGAS - is an intermediate boiling product of naphtha steam cracking with a high octane number and high aromatic/unsaturated contents. Due to stabilization concerns, PYGAS must be hydrotreated in two stages. The first stage uses a mild trickle-bed conversion for removing extremely reactive species (styrene, dienes and olefins prior to the more severe second stage where sulfured and remaining olefins are hydrogenated in gas phase. This work addresses the reaction network and two-phase kinetic model for the first stage of PYGAS upgrading. Nonlinear estimation was used for model tuning with kinetic data obtained in bench-scale trickle-bed hydrogenation with a commercial Pd/Al2O3 catalyst. On-line sampling experiments were designed to study the influence of variables - temperature and spatial velocity - on the conversion of styrene, dienes and olefins.

Safety Evaluation of Oil Samples Collected from Different Food Points of Multan City of Pakistan

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Saeed Akhtar

2018-05-01

Full Text Available Cooking oil has become a part and parcel of modern food system and therefore its safety is of prime significance for health agencies around the globe to ensure good health among the community. Current study was designed to investigate the physicochemical properties including free fatty acids, peroxide value and conjugated dienes; minerals (nickel & cobalt and heavy metals (lead and cadmium in oil samples collected from different areas of Multan city of Pakistan. The findings of this study revealed that free fatty acid percentages, conjugated dienes, cobalt and nickel concentrations were in normal ranges while the peroxide values, lead and cadmium concentrations were recorded above the norms. Strict regulatory measures need to be adopted to ensure good quality oil supply and to protect the people from health implications of physicochemical and metallic hazards prevailing in fried oils and fried foods.

Flavonóides, norisoprenóides e outros terpenos das folhas de Tapirira guianensis Flavonoids, norisoprenoids and other terpenes from leaves of Tapirira guianensis

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Suzimone de J. Correia

2008-01-01

Full Text Available From hexane fraction of methanol extract of leaves of Tapirira guianensis (Anacardiaceae were obtained lupeol, 24-methylenecycloartan-3-ol, phytol, α-amyrin, β-amyrin, sitosterol, sitostenone, glycosyl sitosterol, as well as sitosterol esterified with palmitic and stearic acids. Phytol, α-amyrin and β-amyrin esterified with fatty acids were also identified from same extract. The EtOAc extract besides the norisoprenoids (6S,7E,9S-6,9-dihydroxy-megastigma-4,7-dien -3-one 9-O-β-glucopyranoside and (6S,7E,9R-6,9-dihydroxy-megastigma-4,7-dien-3-one 9-O-β-glucopyranoside also afforded kaempferol 3-O-rhamnoside, kaempferol 3-O-arabinofuranoside, quercetin 3-O-rhamnoside, and kaempferol. The structural elucidation of isolated compounds were based on UV, IR, MS, ¹H and 13C NMR data analysis.

Flavonoids, norisoprenoids and other terpenes from leaves of Tapirira guianensis; Flavonoides, norisoprenoides e outros terpenos das folhas de Tapirira guianensis

Energy Technology Data Exchange (ETDEWEB)

Correia, Suzimone de J. [Universidade Estadual do Sudoeste da Bahia, Jequie, BA (Brazil). Dept. de Quimica e Exatas; David, Jorge M.; Silva, Eliezer P. da [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica]. E-mail: jmdavid@ufba.br; David, Juceni P. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Faculdade de Farmacia; Lopes, Lucia M.X. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica; Guedes, Maria Lenise S. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Biologia

2008-07-01

From hexane fraction of methanol extract of leaves of Tapirira guianensis (Anacardiaceae) were obtained lupeol, 24-methylenecycloartan-3-ol, phytol, {alpha}-amyrin, {beta}-amyrin, sitosterol, sitostenone, glycosyl sitosterol, as well as sitosterol esterified with palmitic and stearic acids. Phytol, {alpha}-amyrin and {beta}-amyrin esterified with fatty acids were also identified from same extract. The EtOAc extract besides the norisoprenoids (6S,7E,9S)-6,9-dihydroxy-megastigma-4,7-dien-3-one 9-O-{beta}-glucopyranoside and (6S,7E,9R)-6,9-dihydroxy-megastigma-4,7-dien-3-one 9-O-{beta}-glucopyranoside also afforded kaempferol 3-O-rhamnoside, kaempferol 3-O-arabinofuranoside, quercetin 3-O-rhamnoside, and kaempferol. The structural elucidation of isolated compounds were based on UV, IR, MS, {sup 1}H and {sup 13}C NMR data analysis. (author)

Flavonoids, norisoprenoids and other terpenes from leaves of Tapirira guianensis

International Nuclear Information System (INIS)

Correia, Suzimone de J.; David, Jorge M.; Silva, Eliezer P. da; David, Juceni P.; Lopes, Lucia M.X.; Guedes, Maria Lenise S.

2008-01-01

From hexane fraction of methanol extract of leaves of Tapirira guianensis (Anacardiaceae) were obtained lupeol, 24-methylenecycloartan-3-ol, phytol, α-amyrin, β-amyrin, sitosterol, sitostenone, glycosyl sitosterol, as well as sitosterol esterified with palmitic and stearic acids. Phytol, α-amyrin and β-amyrin esterified with fatty acids were also identified from same extract. The EtOAc extract besides the norisoprenoids (6S,7E,9S)-6,9-dihydroxy-megastigma-4,7-dien-3-one 9-O-β-glucopyranoside and (6S,7E,9R)-6,9-dihydroxy-megastigma-4,7-dien-3-one 9-O-β-glucopyranoside also afforded kaempferol 3-O-rhamnoside, kaempferol 3-O-arabinofuranoside, quercetin 3-O-rhamnoside, and kaempferol. The structural elucidation of isolated compounds were based on UV, IR, MS, 1 H and 13 C NMR data analysis. (author)

Investigation of oxidative degradation and non‐enzymatic browning reactions in krill and fish oils

DEFF Research Database (Denmark)

Thomsen, Birgitte Raagaard; Haugsgjerd, Bjørn Ole; Griinari, Mikko

2013-01-01

conditions using the Oxipres™ at 90°C. The results from analysis of PV, AV, TBARS, conjugated dienes and trienes, and the antioxidant content suggested that krill oil was more oxidatively stable than fish oil. However, the color or other constituents of the krill oil might affect the result......The aim of this research was to investigate the oxidation progress and pathways of krill and fish oil during 21 days of incubation at 40°C. The oxidative stability of the oils was investigated through: (i) classical methods such as peroxide value (PV), anisidine value (AV), thiobarbituric reactive...... substance (TBARS), conjugated dienes and trienes, and antioxidant content, and (ii) advanced methods such as determination of volatiles content by dynamic headspace (DHS)‐GC/MS, lipid classes, and pyrrole content. In addition, the oxidative stability of the oils was evaluated under accelerated oxidation...

Terpenoids, flavonoids and other constituents of Eupatorium betonicaeforme (Asteraceae)

Energy Technology Data Exchange (ETDEWEB)

Albuquerque, Maria Rose Jane R.; Pires, Andreza Maria L.; Pessoa, Otilia Deusdenia L.; Silveira, Edilberto R. [Ceara Univ., Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica. Curso de Pos-Graduacao em Quimica Organica]. E-mail: opessoa@ufc.br

2006-01-15

A new acylated kaurene diterpene, characterized as 15{alpha}-decanoyloxy-kaur-16-en-19-oic acid, along with nine known compounds: pentacosanoic acid, 24{alpha}-ethyl-5{alpha}-cholesta-7,22E-dien-3{beta}-ol, 15{alpha}-hydroxy-kaur-16-en-19-oic acid, 8{beta}-angeloyloxy-9{beta},10{beta}-dihydroxy-1-oxogermacra-4E,11(13)dien-12,6{alpha}-olide, 3{beta}-hydroxyeicosan-1,5{beta}-olide, taraxasteryl acetate, 7-Omethylkaempferol, kaempferol, and nepetin were isolated from the flowers of Eupatorium betonicaeforme (Asteraceae). In addition, from the aerial parts were isolated taraxasteryl acetate and {alpha}- and {beta}-amyrin, while the mixture of {beta}-sitosterol and stigmasterol, and 6-acetyl-2,2-dimethylchroman-4-one were isolated from the roots. The structure elucidation of all compounds was performed by spectroscopic analysis and comparison with published data from literature. (author)

Terpenoids, flavonoids and other constituents of Eupatorium betonicaeforme (Asteraceae)

International Nuclear Information System (INIS)

Albuquerque, Maria Rose Jane R.; Pires, Andreza Maria L.; Pessoa, Otilia Deusdenia L.; Silveira, Edilberto R.

2006-01-01

A new acylated kaurene diterpene, characterized as 15α-decanoyloxy-kaur-16-en-19-oic acid, along with nine known compounds: pentacosanoic acid, 24α-ethyl-5α-cholesta-7,22E-dien-3β-ol, 15α-hydroxy-kaur-16-en-19-oic acid, 8β-angeloyloxy-9β,10β-dihydroxy-1-oxogermacra-4E,11(13)dien-12,6α-olide, 3β-hydroxyeicosan-1,5β-olide, taraxasteryl acetate, 7-Omethylkaempferol, kaempferol, and nepetin were isolated from the flowers of Eupatorium betonicaeforme (Asteraceae). In addition, from the aerial parts were isolated taraxasteryl acetate and α- and β-amyrin, while the mixture of β-sitosterol and stigmasterol, and 6-acetyl-2,2-dimethylchroman-4-one were isolated from the roots. The structure elucidation of all compounds was performed by spectroscopic analysis and comparison with published data from literature. (author)

Acrobat Distiller, Job 15

African Journals Online (AJOL)

lynette

tative study was to explore the meaning making process involved in transformative ... daaraan toe te ken, kan die ervaring as stimulus vir “gewone” leer dien. 'n Ervaring ..... (habits of mind or general frame of reference) and meaning schemes.

Burgers in Britse Diens (1902) | Ploeger | Scientia Militaria: South ...

African Journals Online (AJOL)

The article deals with ex-Burghers serving under the British in South Africa during 1902 and their reasons for supporting British Military authorities. The antagonism between the joiners and the burghers is discussed as well as the joiners' eventual disillusionment with the British government and the contempt with which their ...

A three-component synthesis of functionalized ketenimines by the reaction of alkyl isocyanides and dialkyl acetylenedicarboxylates in the presence of 2-quinolinol

Directory of Open Access Journals (Sweden)

BITA MOHTAT

2011-01-01

Full Text Available The 1:1 reactive intermediates generated by the addition of alkyl isocyanides to dialkyl acetylenedicarboxylates were trapped by 2-quinolinol to yield highly functionalized ketenimines and, in some cases, minor amounts of 1-azabuta-1,3-dienes.

Synthesis of Precursors of the Agalacto (Exo) Fragment of the Quartromicins via an Auxiliary-Controlled Exo-Selective Diels-Alder Reaction

Science.gov (United States)

Qi, Jun; Roush, William R.

2008-01-01

A direct synthesis of the α-hydroxyaldehyde exo-5, a precursor of the exo-spirotetronate subunit o f the quartromicins, was achieved through an exo-selective Lewis acid-catalyzed Diels-Alder reaction of dienophile 12a and diene 1. PMID:16774259

Role of CD5-negative CD8 T Cells in Adaptation to Antigenic ...

African Journals Online (AJOL)

Purpose: To investigate the effect of 3-oxotirucalla-7, 24-dien-21-oic acid on CD8+ T cell recovery in human immunodeficiency ..... enhances the probability of immune system recovery. ... PE: Fine tuning of TCR signaling by CD5. J Immunol.

'De 'lijmwaarde' van merken

NARCIS (Netherlands)

Mossinkoff, Marco

2013-01-01

Marketingwetenschap en -praktijk lijken in een crisis te verkeren: de consument en haar koopgedrag lijken steeds minder voorspelbaar, met alle nadelige gevolgen van dien voor het aanzien van marketing als vakgebied. Bij nadere beschouwing blijkt die onvoorspelbaarheid echter vooral betrekking te

Exploring betapapillomavirus infections and their association with cutaneous squamous-cell carcinoma

NARCIS (Netherlands)

Plasmeijer, Elsemieke Iebeliene

2010-01-01

In dit proefschrift staat het onderzoek beschreven naar de relatie tussen betapapillomavirussen (betaPV) en het cutane plaveiselcelcarcinoom (PCC) en diens voorloper actinische keratose (AK). BetaPV maken deel uit van de papillomavirusfamilie, die meer dan 100 humane papillomavirussen (HPV) omvat

Antiparasitic, Nematicidal and Antifouling Constituents from Juniperus Berries

Science.gov (United States)

A bioassay-guided fractionation of Juniperus procera berries yielded antiparasitic, nematicidal and antifouling constituents, including a wide range of known abietane, pimarane and labdane diterpenes. Among these, abieta-7,13-diene (1) demonstrated in vitro antimalarial activity against Plasmodium f...

Impact behaviour of polystyene/EPDM-rubber blends : influence of electron beam irradiation

NARCIS (Netherlands)

Gisbergen, van J.G.M.; Borgmans, C.P.J.H.; Sanden, van der M.C.M.; Lemstra, P.J.

1990-01-01

Electron beam irradiation of polystyrene/ethylene propylene diene monomer (PS/EPDM) blends, using polystyrene/polybutadiene block copolymers as compatibilizers, resulted in a two to three fold increase in Izod impact value. This greatly increased impact resistance is probably related to

Chemical Composition and Insecticidal Activity of the Essential Oil of Illicium pachyphyllum Fruits against Two Grain Storage Insects

Directory of Open Access Journals (Sweden)

Hui-Wen Dong

2012-12-01

Full Text Available The aim of this research was to determine chemical composition and insecticidal activity of the essential oil of Illicium pachyphyllum fruits against two grain storage insects, Sitophilus zeamais and Tribolium castaneum, and to isolate any insecticidal constituents from the essential oil. The essential oil of I. pachyphyllum fruits was obtained by hydrodistillation and analyzed by GC-MS. A total of 36 components of the essential oil were identified, with the principal compounds in the essential oil being trans-ρ-mentha-1(7,8-dien-2-ol (24.56%, D-limonene (9.79%, caryophyllene oxide (9.32%, and cis-carveol (5.26% followed by β-caryophyllene (4.63% and bornyl acetate. Based on bioactivity-guided fractionation, the three active constituents were isolated and identified as trans-ρ-mentha-1(7,8-dien-2-ol, D-limonene and caryophyllene oxide. The essential oil of I. pachyphyllum fruits exhibited contact toxicity against S. zeamais and T. castaneum adults, with LD50 values of 17.33 μg/adult and 28.94 μg/adult, respectively. trans-p-Mentha-1(7,8-dien-2-ol (LD50 = 8.66 μg/adult and 13.66 μg/adult, respectively exhibited stronger acute toxicity against S. zeamais and T. castaneum adults than either caryophyllene oxide (LD50 = 34.09 μg/adult and 45.56 μg/adult and D-limonene (LD50 = 29.86 μg/adult and 20.14 μg/adult. The essential oil of I. pachyphyllum possessed fumigant toxicity against S. zeamais and T. castaneum adults with LC50 values of 11.49 mg/L and 15.08 mg/L, respectively. trans-p-Mentha-1(7,8-dien-2-ol exhibited stronger fumigant toxicity against S. zeamais and T. castaneum adults, respectively, with LC50 values of 6.01 mg/L and 8.14 mg/L, than caryophyllene oxide (LC50 = 17.02 mg/L and 15.98 mg/L and D-limonene (LC50 = 33.71 mg/L and 21.24 mg/L. The results indicate that the essential oil of I. pachyphyllum fruits and its constituent compounds have potential for development into natural insecticides or fumigants for the control of

Cymbopogon citratus and Cymbopogon giganteus essential oils have cytotoxic effects on tumor cell cultures. Identification of citral as a new putative anti-proliferative molecule.

Science.gov (United States)

Bayala, Bagora; Bassole, Imaël H N; Maqdasy, Salwan; Baron, Silvère; Simpore, Jacques; Lobaccaro, Jean-Marc A

2018-03-06

Cymbopogon species are used as traditional remedies in Burkina Faso for treating several diseases. We aimed to study the effects of their essential oils on cancer cell lines. For that purpose, Cymbopogon citratus (DC.) Stapf. and Cymbopogon giganteus Chiov. were studied for their essential oils after various chemical extractions. Antioxidant, potential anti-inflammatory action (inhibition of lipoxygenase) and cytotoxic activities were also tested on various prostate cancer and glioblastoma cell lines. Thirty-three compounds were identified in the essential oil of C. giganteus: Limonene (19.33%), Mentha-1(7),8-dien-2-ol cis (17.34%), Mentha-1(7),8-dien-2-ol trans (13.95%), trans-Mentha-2,8-diene-para-ol 1 (13.91%) and Mentha-2,8-diene-1-ol, cis-para (8.10%) were the most abundant. C. citratus essential oil contained 15 compounds and the major ones were geranial/citral A (48.18%) and neral/citral B (34.37%). Essential oil of C. citratus showed the highest ability to scavenge DPPH + radicals (approximately 68% at 8 mg/mL) while C. giganteus exhibited the highest capability to reduce ABTS + (0.59μmolET/g). The essential oil of C. citratus was the most effective on prostate cell lines LNCaP (IC 50  = 6.36 μg/ml) and PC-3 (IC 50  = 32.1 μg/ml), and on glioblastoma cell lines (SF-767 (IC 50  = 45.13 μg/ml) and SF-763 (IC 50  = 172.05 μg/ml). Interestingly, the activity of essential oil of C. citratus was statistically equal to that of its major component, citral. Combination of both oils showed antagonist, additive, indifferent and synergistic effects on LNCaP, PC-3, SF-767 and SF-763 cell lines, respectively. In conclusion, plants from the traditional medicine in Burkina Faso could be of interest for identifying new compounds, such as citral, for the treatment of prostate cancer and glioblastoma. Copyright © 2018 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

The impact of politics on heritage and cultural tourism in South Africa ...

African Journals Online (AJOL)

Die impak van politiek op erfenis- en kultuurtoerisme in Suid-Afrika: Hierdie artikel handel oor die verpolitisering van gedenktekens, monumente, museums en historiese terreine wat as toeristebesienswaardighede dien. Dit bevat eerstens 'n uiteensetting van die wisselwerking tussen kultuur, erfenis, toerisme en politiek en

Variabele prestatiebeloning

NARCIS (Netherlands)

Cortebeek, Veerle; Van Ruysseveldt, Joris

2010-01-01

Dit rapport vormt een overzicht aan informatie in verband met variabele presta-tiebeloning. Om alle misverstanden te vermijden, starten we met een afbakening van varia-bele prestatiebeloning. “Prestatiebeloning betekent dat noch de functie, noch de kenmerken van de functiehouder, maar wel diens

Norsesquiterpene hydrocarbon, chemical composition and antimicrobial activity of Rhaponticum carthamoides root essential oil

Czech Academy of Sciences Publication Activity Database

Havlík, J.; Buděšínský, Miloš; Klouček, P.; Kokoška, L.; Valterová, Irena; Vašíčková, Soňa; Zelený, V.

2009-01-01

Roč. 70, č. 3 (2009), s. 414-418 ISSN 0031-9422 Institutional research plan: CEZ:AV0Z40550506 Keywords : 13-norcypera-1(5),11(12)-diene * cyperene * antimicrobial activity Subject RIV: CC - Organic Chemistry Impact factor: 3.104, year: 2009

Influence of electron beam irradiation on the impact properties of polystyrene/EPDM rubber blends

NARCIS (Netherlands)

Gisbergen, van J.G.M.; Sanden, van der M.C.M.; Haan, de J.W.; Ven, van de L.J.M.; Lemstra, P.J.

1991-01-01

The influence of electron beam (EB) irradiation on the impact properties of compatibilized polystyrene/ethylene-propylene-diene-monomer (PSIEPDM) blends was studied. The change in impact value upon irradiation proved to be strongly dependent on the type of compatibilizer used. Using a

Efficient synthesis of enantiopure conduritols by ring-closing metathesis

DEFF Research Database (Denmark)

Jørgensen, Morten; Iversen, Erik Høgh; Paulsen, Andreas Lundtang

2001-01-01

Two short synthetic approaches to enantiopure conduritols are described starting from the chiral pool. In both cases, the cyclohexene ring is assembled via ring-closing olefin metathesis. The terminal diene precursers for the metathesis reaction are prepared either from octitols or from tartaric...

Autoxidation of polyunsaturated fatty acids. Part I. Effect of ozone on the autoxidation of neat methyl linoleate and methyl linolenate

Energy Technology Data Exchange (ETDEWEB)

Pryor, W.A.; Stanley, J.P.; Blair, E.; Cullen, G.B.

Neat samples of polyunsaturated fatty acids were exposed to ozone in air in a flow system, and the formation of peroxides, conjugated dienes and thiobarbituric acid (TBA)-reactive material was followed as a function of time. The effect of ozone is to shorten the induction period normally observed in autoxidation studies, but the ozone, at the concentrations used here (0-1.5 ppm), appears to have no effect on the rates of product formation after the induction period. During the induction period, increasing ozone concentrations gives rise to substantially increased rates of peroxide (or materials which titrate like peroxide) formation, a slightly increased rate of conjugated diene formation, and no significant increase in the rate of production of TBA-reactive material. Vitamin E lengthens the induction period but appears to have no other effect. Some of these data are in conflict with earlier reports of Menzel et al.

Transformation of ergosterol peroxide to cytotoxic substances by rat intestinal bacteria.

Science.gov (United States)

Lee, Joo-Sang; Ma, Chao-Mei; Park, Dong-Ki; Yoshimi, Yasuharu; Hatanaka, Minoru; Hattori, Masao

2008-05-01

Ergosterol peroxide (EPO, 1) is a major antitumor sterol produced by edible or medicinal mushrooms. Following oral administration of 1 to rats or anaerobic in vitro incubation of 1 with rat fecal bacteria, three metabolites were detected and their structures were identified to be 5alpha,6alpha-epoxyergosta-8(14),22-diene-3beta,7alpha-diol (M1, 2), 5alpha,6alpha-epoxyergosta-8,22-diene-3beta,7alpha-diol (M2, 3), and 5alpha,6alpha-epoxy-3beta-hydroxyergosta-22-ene-7-one (M3, 4) by spectroscopic analysis. Of these, M2 and M3 showed more potent inhibitory activity than the original compound 1 against proliferation of CACO-2, WiDr, DLD-1 and Colo320 human colorectal adenocarcinoma cells. These findings suggest that bacterial metabolites of EPO play a significant role in its cytotoxic activity against human colorectal cancer cells.

A chicory cytochrome P450 mono-oxygenase CYP71AV8 for the oxidation of (+)-valencene.

Science.gov (United States)

Cankar, Katarina; van Houwelingen, Adèle; Bosch, Dirk; Sonke, Theo; Bouwmeester, Harro; Beekwilder, Jules

2011-01-03

Chicory (Cichorium intybus L.), which is known to have a variety of terpene-hydroxylating activities, was screened for a P450 mono-oxygenase to convert (+)-valencene to (+)-nootkatone. A novel P450 cDNA was identified in a chicory root EST library. Co-expression of the enzyme with a valencene synthase in yeast, led to formation of trans-nootkatol, cis-nootkatol and (+)-nootkatone. The novel enzyme was also found to catalyse a three step conversion of germacrene A to germacra-1(10),4,11(13)-trien-12-oic acid, indicating its involvement in chicory sesquiterpene lactone biosynthesis. Likewise, amorpha-4,11-diene was converted to artemisinic acid. Surprisingly, the chicory P450 has a different regio-specificity on (+)-valencene compared to germacrene A and amorpha-4,11-diene. Copyright © 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

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.

Glutathione depletion by valproic acid in sandwich-cultured rat hepatocytes: Role of biotransformation and temporal relationship with onset of toxicity

International Nuclear Information System (INIS)

Kiang, Tony K.L.; Teng Xiaowei; Surendradoss, Jayakumar; Karagiozov, Stoyan; Abbott, Frank S.; Chang, Thomas K.H.

2011-01-01

The present study was conducted in sandwich-cultured rat hepatocytes to investigate the chemical basis of glutathione (GSH) depletion by valproic acid (VPA) and evaluate the role of GSH depletion in VPA toxicity. Among the synthetic metabolites of VPA investigated, 4-ene-VPA and (E)-2,4-diene-VPA decreased cellular levels of total GSH, but only (E)-2,4-diene-VPA was more effective and more potent than the parent drug. The in situ generated, cytochrome P450-dependent 4-ene-VPA did not contribute to GSH depletion by VPA, as suggested by the experiment with a cytochrome P450 inhibitor, 1-aminobenzotriazole, to decrease the formation of this metabolite. In support of a role for metabolites, alpha-F-VPA and octanoic acid, which do not undergo biotransformation to form a 2,4-diene metabolite, CoA ester, or glucuronide, did not deplete GSH. A time course experiment showed that GSH depletion did not occur prior to the increase in 2',7'-dichlorofluorescein (a marker of oxidative stress), the decrease in [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium] (WST-1) product formation (a marker of cell viability), or the increase in lactate dehydrogenase (LDH) release (a marker of necrosis) in VPA-treated hepatocytes. In conclusion, the cytochrome P450-mediated 4-ene-VPA pathway does not play a role in the in situ depletion of GSH by VPA, and GSH depletion is not an initiating event in VPA toxicity in sandwich-cultured rat hepatocytes.

Selective electrochemical determination of homocysteine in the presence of cysteine and glutathione

International Nuclear Information System (INIS)

Salehzadeh, Hamid; Mokhtari, Banafsheh; Nematollahi, Davood

2014-01-01

Graphical abstract: 3,5-Di-tert-buthylcatechol was used for the selective electrochemical determination of homocysteine in the presence of cysteine and glutathione at the glassy carbon and carbon nanotube modified glassy carbon electrode. - Highlights: • Selective electrochemical determination of homocysteine. • Catalytic electron transfer of 3,5-di-tert-buthylcatechol in the presence of homocysteine. • Michael type addition reaction of electrochemically generated 3,5-di-tert-buthyl-o-benzoquinone with glutathione. - Abstract: The electrochemical oxidation of 3,5-di-tert-buthylcatechol in the presence of homocysteine was used for the selective electrochemical determination of homocysteine in the presence of cysteine and glutathione at a glassy carbon and a glassy carbon electrode modified with carbon nanotube. The results revealed that the electrochemically generated 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione exhibits high catalytic activity toward homocysteine oxidation at reduced over-potential and low catalytic activity for oxidation of cysteine. The catalytic activity 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione toward cysteine was suppressed in the presence of 4-N,N-dimethylaminocinnamaldehyde. Contrary to homocysteine and cysteine, the reaction of glutathione with 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione is a substituation reaction. This method exhibits three dynamic linear ranges of 2.5 to 10 μmol L −1 , 10 to 100 μmol L −1 and 100 to 1000 μmol L −1 , and a lower detection limit (3σ) of 0.89 ± 3.53% μmol L −1 for homocysteine

First catalytic hetero-Diels-Alder reaction of imidazole-2-thiones and in silico biological evaluation of the cycloadducts

NARCIS (Netherlands)

Eleftheriadis, Nikolaos; Samatidou, Evanthia; Neochoritis, Constantinos G.

The Lewis acid-catalyzed Diels-Alder reactions of suitably substituted imidazole-2-thiones with dienes were studied. It was found that the electron density of the imidazole core influenced the reaction, since electron withdrawing groups led to the novel spiro-derivatives 2 whereas electron donating

Effect of Multiwalled Carbon Nanotubes on the Properties of EPDM/NBR Dissimilar Elastomer Blends

NARCIS (Netherlands)

Hoikkanen, M.; Poikelispää, M.; Das, A.; Honkanen, M.; Dierkes, Wilma K.; Vuorinen, J.

2015-01-01

In the presence of multiwalled carbon nanotubes (MWCNT), polar nitrile-butadiene rubber (NBR) and nonpolar ethylene propylene diene rubber (EPDM) blends were prepared following a melt mixing method. For the preparation of MWCNT filled EPDM/NBR blends, two mixing methods were used: direct mixing and

A catalytic and stoichiometric approach to the synthesis of the steroid B-ring en route to estratrienes

Czech Academy of Sciences Publication Activity Database

Herrmann, Pavel; Kotora, Martin

2007-01-01

Roč. 48, č. 18 (2007), s. 3209-3212 ISSN 0040-4039 R&D Projects: GA MŠk(CZ) LC06070 Institutional research plan: CEZ:AV0Z40550506 Keywords : zirconocene * dienes * cyclization * catalysis Subject RIV: CC - Organic Chemistry Impact factor: 2.615, year: 2007

Die sosiaal-wetenskaplike kritiese eksegese van Nuwe ...

African Journals Online (AJOL)

p1243322

tot die sosiaal-wetenskaplike kritiek van die Nuwe Testament te dien. Hierdie kritiese benadering tot eksegese wil die wyse van kommunikasie van Nuwe-. Testamentiese tekste ondersoek deur die ...... theory or set of hypotheses which attempts to explain the connections and interrelationships between social phenomena.

Convergent Synthesis of Pancratistatin from Piperonal and Xylose

DEFF Research Database (Denmark)

Dam, Johan Hygum; Madsen, Robert

2009-01-01

to afford a highly functionalised 1,7-diene, which is then converted into the corresponding cyclohexene by ring-closing olefin metathesis. Subsequent Overman rearrangement, dihydroxylation and deprotection afford the natural product in a total of 25 steps from the two starting materials. The longest linear...

Role of CD5-negative CD8 + T Cells in Adaptation to Antigenic ...

African Journals Online (AJOL)

+ T cell recovery in human immunodeficiency virus type 1 (HIV-1) disease. Methods: The increase in the rates of CD8+ T cells over 48 weeks following treatment with 3- oxotirucalla-7, 24-dien-21-oic acid was investigated. Plasma HIV-1 load ...

Modeling on the kinetics of an EPDM devulcanization in an internal batch mixer using an amine as the devulcanizing agent

NARCIS (Netherlands)

Sutanto, P.; Laksmana, F. L.; Picchioni, E.; Janssen, L. P. B. M.; Picchioni, F.

2006-01-01

The use of amines and the application of mechanical force (shear) in rubber devulcanization have been reported in the literatures. In this paper, the devulcanization of ethylene propylene diene rubber (EPDM) is conducted in a Brabender batch mixer using hexadecylarnine (HDA) as the devulcanizing

South African seed oils are safe for human consumption | Opperman ...

African Journals Online (AJOL)

Reported parameters included the fatty acid profile, TFA content, peroxide level and conjugated diene (CD) content. Design: Samples were purchased from local retail stores. Two independent researchers de-identified the oils, and stored them in numbered containers under nitrogen until commencement of the analysis.

Highly selective cobalt-catalyzed hydrovinylation of styrene

NARCIS (Netherlands)

Grutters, M.M.P.; Müller, C.; Vogt, D.

2006-01-01

The hydrovinylation reaction is a codimerization of a 1,3-diene or vinyl arene and ethene with great potential for fine chemicals and pharmaceuticals. For the first time, enantioselective cobalt-catalyzed hydrovinylations of styrene were achieved with a cobalt-based system bearing a chiral

Role of β-h elimination in rhodium-mediated carbene insertion polymerization

NARCIS (Netherlands)

Finger, M.; Reek, J.N.H.; de Bruin, B.

2011-01-01

The importance of β-H elimination as a possible mechanism to induce chain termination/transfer and/or the formation of stereodefects in the Rh(diene)-mediated oligomerization and polymerization of carbenes has been studied by means of different approaches. As a remarkable feature, this reaction is

Lipid constituents of marine sponge Suberites carnosus

Digital Repository Service at National Institute of Oceanography (India)

Mishra, P.D.; Wahidullah, S.; DeSouza, L.; Kamat, S.Y.

Sterols (22E) - 24- methyl-cholest - 4, 8(9), 22(23) - triene - 3, 7 - diol (1) and (22E)-24-methyl-ergost-6, 22(23)-diene-5, 8-epidioxy-3-ol (2), a fatty acid nonadecanoic acid and a fatty ester methyl nonadecanoate have been isolated from...

Enyne Metathesis Catalyzed by Ruthenium Carbene Complexes

DEFF Research Database (Denmark)

Poulsen, Carina Storm; Madsen, Robert

2003-01-01

Enyne metathesis combines an alkene and an alkyne into a 1,3-diene. The first enyne metathesis reaction catalyzed by a ruthenium carbene complex was reported in 1994. This review covers the advances in this transformation during the last eight years with particular emphasis on methodology...

(II) complexes containing isocyanide and labile nitrile ligands

African Journals Online (AJOL)

A new ruthenium(II) complex containing both acetonitrile and propionitrile moieties as coordinating ligands has been prepared. The treatment of the polymer [{RuCl2(COD)}x], (COD = cycloocta-1,5-diene) (1) with a mixture of acetonitrile and propionitrile under reflux produced a new precursor ...

A novel stereoselective synthesis of N-heterocycles by intramolecular hydrovinylation

DEFF Research Database (Denmark)

Bothe, Ulrich; Rudbeck, H. C.; Tanner, David Ackland

2001-01-01

A novel method for the synthesis of bicyclic amines has been developed. Cyclisation of 1,6-dienes by intramolecular hydrovinylation in the presence of catalytic amounts of allylpalladium chloride dimer afforded bicyclic amines in one step. Added phosphines, silver salts, as well as the nature of ...

Crystal structures and photoelectron spectra of some trimethanoanthracenes, tetramethanonaphthacenes, and pentamethanopentacenes. Experimental evidence for laticyclic hyperconjugation

DEFF Research Database (Denmark)

Paddon-Row, Michael N.; Englehardt, Lutz M.; Skelton, Brian W.

1987-01-01

Photoelectron (p.e.) spectra of the series of dienes (), (), ()-(), and crystal structures for the dodecachlorodienes()-() are reported. The spectra revealed large [small pi]-splitting energies of 0.32 and 0.52 eV for () and () respectively. The value of () is attributed to the presence of orbita...

Synthesis of the carbocyclic core of the cornexistins by ring-closing metathesis.

Science.gov (United States)

Clark, J Stephen; Marlin, Frederic; Nay, Bastien; Wilson, Claire

2003-01-09

An advanced intermediate in the synthesis of the phytotoxins cornexistin and hydroxycornexistin has been synthesized. Sequential palladium-mediated sp(2)-sp(3) fragment coupling and ring-closing diene metathesis have been used to construct the nine-membered carbocyclic core found in the natural products. [reaction--see text

Remendable Polymeric Materials Using Reversible Covalent Bonds

Science.gov (United States)

2008-12-01

response in poly(ethylene-co-methacrylic acid ) copolymers. Journal of The Royal Society Interface, 4, 405-411. Kavitha, A. A., and N. K. Singha...2007: A tailor-made polymethacrylate bearing a reactive diene in reversible diels-alder reaction. J. Polym. Sci. A Polym. Chem., 45, 4441-4449

'N perd van 'n ander kleur sas somerset (1942-1986) | Wessels ...

African Journals Online (AJOL)

Naas die bekende vlootvaartuie soos byvoorbeeld duikbote, vliegdekskepe en missieldraende aanvalsvaartuie, is daar in die meeste vlote ter werêld ander vaartuigtipes wat soms 'n groot deel van hul leeftyd hawegebonde is, maar nogtans waardevolle diens ten behoewe van ander skepe of ter beskerming van hawens ...

'N PERD VAN 'N ANDER KLEUR SAS SOMERSET (1942-1986)

African Journals Online (AJOL)

Naas die bekende vlootvaartuie soos byvoorbeeld duikbote, vliegdekskepe en missieldraende aanvalsvaartuie, is daar in die meeste vlote ter wereld ander vaartuigtipes wat soms 'n groot deel van hul leeftyd hawegebonde is, maar nogtans waardevolle diens ten behoewe van ander skepe of ter beskerming van hawens ...

Implicit versus explicit : An ACT-R learning perspective

NARCIS (Netherlands)

Taatgen, N.A.

1999-01-01

Dienes & Perner propose a theory of implicit and explicit knowledge that is not entirely complete. It does not address many of the empirical issues, nor does it explain the difference between implicit and explicit learning. It does, however, provide a possible unified explanation, as opposed to the

Shape of deconstruction

International Nuclear Information System (INIS)

Shiraishi, Kiyoshi; Sakamoto, Kenji; Kan, Nahomi

2003-01-01

We construct a six-dimensional Maxwell theory using a latticized extra space, the continuum limit of which is a shifted torus recently discussed by Dienes. This toy model exhibits a correspondence between continuum theory and discrete theory, and gives a geometrical insight into theory-space model building

Iodine, a Mild Reagent for the Aromatization of Terpenoids.

Science.gov (United States)

Domingo, Victoriano; Prieto, Consuelo; Silva, Lucia; Rodilla, Jesús M L; Quílez del Moral, José F; Barrero, Alejandro F

2016-04-22

Efficient procedures based on the use of iodine for the aromatization of a series of terpenoids possessing diene and homoallylic or allylic alcohol functionalities are described. Different examples are reported as a proof-of-concept study. Furthermore, iodine also proved to mediate the dehydrogenation of testosterone.

Radiation enhanced conduction in insulators: computer modelling

International Nuclear Information System (INIS)

Fisher, A.J.

1986-10-01

The report describes the implementation of the Klaffky-Rose-Goland-Dienes [Phys. Rev. B.21 3610,1980] model of radiation-enhanced conduction and describes the codes used. The approach is demonstrated for the data for alumina of Pells, Buckley, Hill and Murphy [AERE R.11715, 1985]. (author)

Synthesis of Gabosine A and N from Ribose by the Use of Ring-Closing Metathesis

DEFF Research Database (Denmark)

Monrad, Rune Nygaard; Fanefjord, Mette; Hansen, Flemming Gundorph

2009-01-01

-methylallyl bromide. The functionalized octa-1,7-diene, thus obtained, is converted into the six-membered gabosine skeleton by ring-closing olefin metathesis. Subsequent protective group manipulations and oxidation gives rise to gabosine N in a total of 8 steps from ribose while the synthesis of gabosine...

Essential oils of Zingiber cassumunar Roxb. from Northeast India

NARCIS (Netherlands)

Bordoloi, A.K.; Sperkova, J.; Leclercq, P.A.

1999-01-01

The essential oils of Zingiber cassumunar, Zingiberaceae, were isolated from its rhizomes and leaves by hydrodistillation. Analysis of the oils by GC and GC/MS revealed that the rhizome oil contained terpinen-4-ol (50.5%), (E)-1-(3,4-dimethoxyphenyl)buta-1,3-diene 09.1%),

Intramolecular anionic diels-alder reactions of 1-aryl-4-oxahepta-1,6-diyne systems in DMSO.

Science.gov (United States)

Kudoh, Takayuki; Mori, Tomoko; Shirahama, Mitsuhito; Yamada, Masashi; Ishikawa, Teruhiko; Saito, Seiki; Kobayashi, Hisayoshi

2007-04-25

Base-promoted cycloaddition reactions of 1-aryl- or 1-aryl-7-substituted-4-oxahepta-1,6-diyne systems in DMSO have proven to involve an anionic intramolecular Diels-Alder process taking place even at room temperature in spite of the reaction suffering from temporary disruption of aromaticity. Although initially formed alpha-arylallenide anion can be protonated by DMSO, it can be back to the allenide anion probably because of a small acidity difference between alpha-arylallene and DMSO. The alpha-arylallenide anion in combination with the alpha-aryl substituent can constitute an anionic diene structure that undergoes the intramolecular Diels-Alder reaction involving the C(6)-yne part, a very fast process probably because of the increased HOMO-1 level of the anionic diene, as shown by DFT calculations. Diversified substituted naphthalenes, benzofurans, phenanthrenes, and quinolines, including biaryl architectures, are available from 4-oxahepta-1,6-diynes in a highly expeditious way.

Effects of irradiation on color and lipid oxidation of prosciutto

International Nuclear Information System (INIS)

Kong Qiulian; Qi Wenyuan; Yue Ling; Chen Zhijun; Bao Yingzi; Dai Xudong; Xu Yun

2012-01-01

This study dealt with the effect of irradiation on the color, irradiation odor and lipid oxidation of prosciutto crudo. The hams were irradiated by γ-ray and electronic beam (EB). Changes of color, irradiation odor, TBA value (TBARS), peroxide value (POV), carbonyl value and conjugated diene value were analyzed and compared with non-irradiated hams. Results showed that color index (a * ) of control, γ-ray irradiated and EB irradiated were 14.39, 9.45 and 11.71 respectively. The ratios of a * /b * were different with the type of rays. The ratio of a * /b * of EB irradiation was same with control, while that of γ-ray irradiation was decreased apparently. γ-ray irradiation had been shown to have apparently detrimental effect on the color and odor of hams, while EB irradiation had little detrimental effect. Irradiation increased POV and conjugated diene value, but the amounts of lipid oxidation products (TBARS, carbonyl value) were less than nonirradiated hams. (authors)

Antioxidant and antifungal activities of Camellia sinensis (L. Kuntze leaves obtained by different forms of production

Directory of Open Access Journals (Sweden)

L. E. A. Camargo

Full Text Available Abstract The antioxidant and anticandidal activities of leaves obtained from Camellia sinensis by non-fermentation (green and white teas, semi-fermentation (red tea and fermentation method (black tea were investigated. It was evaluated the total phenolic content by Folin-Ciocalteau assay; antioxidant capacities were evaluated in vitro using DPPH and ABTS radicals, hypochlorous acid and superoxide anion scavenger assays, induced hemolysis, lipid peroxidation by conjugated diene formation and myeloperoxidase activity. Anticandidal activity was performed on three strains of Candida spp. The results showed that non-fermented teas have a higher concentration of phenolic compounds, and then presented the best inhibitory activity of AAPH-induced hemolysis, the best inhibition of conjugated diene formation and more pronounced antioxidant activity in all tests. The highest anticandidal activity was obtained from fermented tea, followed by non-fermented tea. These results indicate that the antioxidant activity demonstrated has no direct relation with the anticandidal activity.

Two new triterpene saponins from the anti-inflammatory saponin fraction of Ilex pubescens root.

Science.gov (United States)

Wang, Jing-Rong; Zhou, Hua; Jiang, Zhi-Hong; Liu, Liang

2008-07-01

The saponin fraction from the ethanolic extracts of the root of Ilex pubescens Hook. et Arn. (Ilexaceae) was found to exhibit potent anti-inflammatory effects on carrageenan-induced paw edema in rats. Two novel triterpene saponins, pubescenosides C and D (1 and 2, resp.), together with five known saponins were isolated from this saponin fraction. The structures of 1 and 2 were elucidated as (20beta)-3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-xylopyranosyl]ursa-12,18-dien-28-oic acid 28-O-beta-D-glucopyranosyl ester, and (20beta)-3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->2)-beta-D-xylopyranosyl]ursa- 12,18-dien-28-oic acid 28-O-beta-D-glucopyranosyl ester, respectively, on the basis of chemical and spectroscopic data. Five known saponins isolated from the saponin fraction were identified as ilexsaponin B(1), B(2), B(3), A(1), and chikusetsusaponin IV(a).

Obtusifoliol related steroids from Euphorbia sogdiana with cell growth inhibitory activity and apoptotic effects on breast cancer cells (MCF-7 and MDA-MB231).

Science.gov (United States)

Aghaei, Mahmoud; Yazdiniapour, Zeinab; Ghanadian, Mustafa; Zolfaghari, Behzad; Lanzotti, Virginia; Mirsafaee, Vahid

2016-11-01

From the aerial parts of Euphorbia sogdiana Popov, obtusifoliol (1) and two related steroids (2-3) have been isolated and characterized along with a known cycloartane derivative (4). The chemical structure of the obtusifoliol-related compounds, obtained by 1D and 2D NMR, and MS measurements, have been determined as: 3β,7α-dihydroxy-4α,14α-dimethyl-5α-ergosta-8,24(28)-diene-11-one (2) and 3β-hydroxy-4α,14α-dimethyl-5α-ergosta-8,24(28)-diene-1-one (3). Compound 2 has been previously isolated from Euphorbia chamaesyce while compound 3 was never reported before. The isolated compounds 1-4 were subjected to cytotoxic tests on the breast cancer cells, MCF-7 and MDA-MB231. Further pharmacological tests on the more active compounds 2 and 3 indicated their action to be related to cell growth inhibitory activity and apoptotic effects on the tested cells. Copyright © 2016 Elsevier Inc. All rights reserved.

[The activity of glutathione antioxidant system at melaksen and valdoxan action under experimental hyperthyroidism in rats].

Science.gov (United States)

Gorbenko, M V; Popova, T N; Shul'gin, K K; Popov, S S

2013-01-01

Investigation of glutathione antioxidant system activity and diene conjugates content in rats liver and blood serum at the influence of melaksen and valdoxan under experimental hyperthyroidism (EG) has been revealed. It has been established that the activities of glutathione reductase (GR), glutathione peroxidase (GP) and glutathione transferase (GT), growing at pathological conditions, change to the side of control value at these substunces introduction. Reduced glutathione content (GSH) at melaxen and valdoxan action increased compared with values under the pathology, that, obviously, could be associated with a reduction of its spending on the detoxication of free radical oxidation (FRO) toxic products. Diene conjugates level in rats liver and blood serum, increasing at experimental hyperthyroidism conditions, under introduction of melatonin level correcting drugs, also approached to the control meaning. Results of the study indicate on positive effect of melaxen and valdoxan on free radical homeostasis, that appears to be accompanied by decrease of load on the glutathione antioxidant system in comparison with the pathology.

Oxidative demethylation of lanosterol in cholesterol biosynthesis: accumulation of sterol intermediates

International Nuclear Information System (INIS)

Shafiee, A.; Trzaskos, J.M.; Paik, Y.K.; Gaylor, J.L.

1986-01-01

With [ 3 H-24,25]-dihydrolanosterol as substrate, large-scale metabolic formation of intermediates of lanosterol demethylation was carried out to identify all compounds in the metabolic process. Utilizing knowledge of electron transport of lanosterol demethylation, we interrupted the demethylation reaction allowing accumulation and confirmation of the structure of the oxygenated intermediates lanost-8-en-3 beta,32-diol and 3 beta-hydroxylanost-8-en-32-al, as well as the demethylation product 4,4-dimethyl-cholesta-8,14-dien-3 beta-ol. Further metabolism of the delta 8.14-diene intermediate to a single product 4,4-dimethyl-cholest-8-en-3 beta-ol occurs under interruption conditions in the presence of 0.5 mM CN-1. With authentic compounds, each intermediate has been rigorously characterized by high performance liquid chromatography and gas-liquid chromatography plus mass spectral analysis of isolated and derivatized sterols. Intermediates that accumulated in greater abundance were further characterized by ultraviolet, 1 H-NMR, and infrared spectroscopy of the isolated sterols

Olefin metathesis and metathesis polymerization

CERN Document Server

Ivin, K J

1997-01-01

This book is a follow-up to Ivins Olefin Metathesis, (Academic Press, 1983). Bringing the standard text in the field up to date, this Second Edition is a result of rapid growth in the field, sparked by the discovery of numerous well-defined metal carbene complexes that can act as very efficient initiators of all types of olefin metathesis reaction, including ring-closing metathesis of acyclic dienes, enynes, and dienynes; ring-opening metathesis polymerizationof cycloalkenes, acyclic diene metathesis polymerization; and polymerization of alkynes, as well as simple olefin metathesis. Olefin Metathesis and Metathesis Polymerization provides a broad, up-to-date account of the subject from its beginnings in 1957 to the latest applications in organic synthesis. The book follows the same format as the original, making it useful toteachers and to researchers, and will be of particular interest to those working in the fields of organic chemistry, polymer chemistry, organometallic chemistry, catalysis, materials scien...

Studies on the experimental variables effects on rhodium catalyzed hydroformylation of unsaturated fatty esters and comparison of [RhH(CO)(PPh3)3] and [RhCl3.3H2O] as starting catalytic precursors

International Nuclear Information System (INIS)

Mendes, Ana N.F.; Gregorio, Jose R.; Rosa, Ricardo G. da

2005-01-01

Hydroformylation experiments were performed with technical-grade methyl oleate (MO) and soybean oil (SO) using [RhH(CO)(PPh 3 ) 3 ] and [RhCl 3 .3H 2 O] (double bond/Rh = 745) as catalyst precursors modified or not by triphenylphosphine. [RhH(CO)(PPh 3 ) 3 ] shows 100% conversion and 80-91% selectivity to aldehydes in only 4h for both substrates under mild conditions (100 deg C, 40 bar, CO/H 2 = 2:1, ligand/Rh = 10:1). Despite the rapid isomerization of the soybean oil, producing trans isomers and conjugated dienes, no effects were observed on its further conversion to aldehydes. The reaction of soybean oil conducted with pure [RhCl 3 .3H 2 O] produced only conjugated dienes, and when this precursor was modified with triphenylphosphine (ligand/Rh = 10:1) no reaction was observed at all. Curiously, yellow crystals corresponding to the complex [Rh(Cl)(CO)(PPh 3 ) 2 ] were quantitatively isolated at the end of the reaction. (author)

The adhesive properties of chlorinated ultra-high molecular weight polyethylene

NARCIS (Netherlands)

Menting, H.N.A.M.; Voets, P.E.L.; Lemstra, P.J.

1995-01-01

Ultra-high molecular weight polyethylene (UHMW-PE) is well known for its abrasion and chemical resistance. Recently we developed a new application for UHMW-PE as a liner in elastomeric hoses. It was found that the adhesion between UHMW-PE and elastomers such as ethylene-propylene-diene monomer

die ontstaan en die ontwikkeling van die skoolkadette-stelsel in die rsa

African Journals Online (AJOL)

toe algemene diensplig ingestel is. Die diens- plig het intussen sy volle beslag gekry en in. Weermagkringe het die gedagte posgevat dat skoolkadette. 'n deeglike ondersoek vereis ten einde die skoolgaande seun vir sy komende nasionale diensplig te orienteer. Tydens kadetopleldlng leer die seuns al die fynere kunsles ...

Effects of the Hydrophobicity of the Reactants on Diels-Alder Reactions in Water

NARCIS (Netherlands)

Meijer, Ale; Otto, Sijbren; Engberts, Jan B.F.N.

1998-01-01

To assess the importance of the hydrophobicity of different parts of diene and dienophile on the aqueous acceleration of Diels-Alder reactions, second-order rate constants have been determined for the reactions of cyclopentadiene (1), 2,3-dimethyl-1,3-butadiene (4), and 1,3-cyclohexadiene (6) with

Multistep Synthesis of a Terphenyl Derivative Showcasing the Diels-Alder Reaction

Science.gov (United States)

Davie, Elizabeth A. Colby

2015-01-01

An adaptable multistep synthesis project designed for the culmination of a second-year organic chemistry laboratory course is described. The target compound is a terphenyl derivative that is an intermediate in the synthesis of compounds used in organic light-emitting devices. Students react a conjugated diene with dimethylacetylene dicarboxylate…

Continuous gradient temperature Raman spectroscopy of n-6 DPA and DHA from -100 C to 20°C

Science.gov (United States)

One of the great unanswered questions with respect to biological science in general is the absolute necessity of DHA in fast signal processing tissues. N-6 DPA, with just one less diene, group, is fairly abundant in terrestrial food chains yet cannot substitute for DHA. Gradient Temperature Raman sp...

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. Uma Maheswar Rao. Articles written in Bulletin of Materials Science. Volume 24 Issue 6 December 2001 pp 587-593 Surface Studies. Investigation of surface modifications in ethylene propylene diene monomer (EPDM) rubber due to tracking under a.c. and d.c. voltages.

Lithium-Assisted Copolymerization of CO 2 /Cyclohexene Oxide: A Novel and Straightforward Route to Polycarbonates and Related Block Copolymers

KAUST Repository

Zhang, Dongyue; Zhang, Hefeng; Hadjichristidis, Nikolaos; Gnanou, Yves; Feng, Xiaoshuang

2016-01-01

of this initiating system also resides in the easy access to PSt-b-PCHC (PSt: polystyrene) and PI-b-PCHC (PI: polyisoprene) block copolymers which can be derived by mere one-pot sequential addition of styrene or dienes first and then of CO2 and CHO under the same

ent-Pimarane and ent-Kaurane Diterpenes from Aldama discolor (Asteraceae and Their Antiprotozoal Activity

Directory of Open Access Journals (Sweden)

Mauro S. Nogueira

2016-09-01

Full Text Available Aldama discolor (syn.Viguiera discolor is an endemic Asteraceae from the Brazilian “Cerrado”, which has not previously been investigated for its chemical constituents and biological activity. Diterpenes are common secondary metabolites found in Aldama species, some of which have been reported to present potential antiprotozoal and antimicrobial activities. In this study, the known ent-3-α-hydroxy-kaur-16-en-18-ol (1, as well as three new diterpenes, namely, ent-7-oxo-pimara-8,15-diene-18-ol (2, ent-2S,4S-2-19-epoxy-pimara-8(3,15-diene-7β-ol (3 and ent-7-oxo-pimara-8,15-diene-3β-ol (4, were isolated from the dichloromethane extract of A. discolor leaves and identified by means of MS and NMR. The compounds were assayed in vitro against Trypanosoma brucei rhodesiense, T. cruzi and Leishmania donovani, Plasmodium falciparum and also tested for cytotoxicity against mammalian cells (L6 cell line. The ent-kaurane 1 showed significant in vitro activity against both P. falciparum (IC 50 = 3.5 μ M and L. donovani (IC 50 = 2.5 μ M and ent-pimarane 2 against P. falciparum (IC 50 = 3.8 μ M. Both compounds returned high selectivity indices (SI >10 in comparison with L6 cells, which makes them interesting candidates for in vivo tests. In addition to the diterpenes, the sesquiterpene lactone budlein A (5, which has been reported to possess a strong anti-T. b. rhodesiense activity, was identified as major compound in the A. discolor extract and explains its high activity against this parasite (100% growth inhibition at 2 μ g/mL.

ent-Pimarane and ent-Kaurane Diterpenes from Aldama discolor (Asteraceae) and Their Antiprotozoal Activity.

Science.gov (United States)

Nogueira, Mauro S; Da Costa, Fernando B; Brun, Reto; Kaiser, Marcel; Schmidt, Thomas J

2016-09-15

Aldama discolor (syn.Viguiera discolor) is an endemic Asteraceae from the Brazilian "Cerrado", which has not previously been investigated for its chemical constituents and biological activity. Diterpenes are common secondary metabolites found in Aldama species, some of which have been reported to present potential antiprotozoal and antimicrobial activities. In this study, the known ent-3-α-hydroxy-kaur-16-en-18-ol (1), as well as three new diterpenes, namely, ent-7-oxo-pimara-8,15-diene-18-ol (2), ent-2S,4S-2-19-epoxy-pimara-8(3),15-diene-7β-ol (3) and ent-7-oxo-pimara-8,15-diene-3β-ol (4), were isolated from the dichloromethane extract of A. discolor leaves and identified by means of MS and NMR. The compounds were assayed in vitro against Trypanosoma brucei rhodesiense, T. cruzi and Leishmania donovani, Plasmodium falciparum and also tested for cytotoxicity against mammalian cells (L6 cell line). The ent-kaurane 1 showed significant in vitro activity against both P. falciparum (IC 50 = 3.5 μ M) and L. donovani (IC 50 = 2.5 μ M) and ent-pimarane 2 against P. falciparum (IC 50 = 3.8 μ M). Both compounds returned high selectivity indices (SI >10) in comparison with L6 cells, which makes them interesting candidates for in vivo tests. In addition to the diterpenes, the sesquiterpene lactone budlein A (5), which has been reported to possess a strong anti-T. b. rhodesiense activity, was identified as major compound in the A. discolor extract and explains its high activity against this parasite (100% growth inhibition at 2 μ g/mL).

Kyste arachnoïdien extradural rachidien | Naama | African Journal of ...

African Journals Online (AJOL)

African Journal of Neurological Sciences. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 28, No 1 (2009) >. Log in or Register to get access to full text downloads.

5. Die Britse militere diens: Plaaslike Burger- korpse Gidse en ...

African Journals Online (AJOL)

Columbia University, City of New York. The editors are both connected with this university. The publication comprises of a foreword by the editors, eight chapters by different authors, an afterward about the authors and an index. The photographs which are extremely realistic and clarifying to the theme, deserve special ...

Can a pentamethylcyclopentadienyl ligand act as a proton-relay in f-element chemistry? Insights from a joint experimental/theoretical study.

Science.gov (United States)

Kefalidis, Christos E; Perrin, Lionel; Burns, Carol J; Berg, David J; Maron, Laurent; Andersen, Richard A

2015-02-14

Isomerisation of buta-1,2-diene to but-2-yne by (Me(5)C(5))(2)Yb is a thermodynamically favourable reaction, with the Δ(r)G° estimated from experimental data at 298 K to be -3.0 kcal mol(-1). It proceeds in hydrocarbon solvents with a pseudo first-order rate constant of 6.4 × 10(-6) s(-1) and 7.4 × 10(-5) s(-1) in C(6)D(12) and C(6)D(6), respectively, at 20 °C. This 1,3-hydrogen shift is formally forbidden by symmetry and has to occur by an alternative pathway. The proposed mechanism for buta-1,2-diene to but-2-yne isomerisation by (Me(5)C(5))(2)Yb involves coordination of methylallene (buta-1,2-diene) to (Me(5)C(5))(2)Yb, and deprotonation of methylallene by one of the Me(5)C(5) ligands followed by protonation of the terminal methylallenyl carbon to yield the known coordination compound (Me(5)C(5))(2)Yb(η(2)-MeC[triple bond, length as m-dash]CMe). Computationally, this mechanism is not initiated by a single electron transfer step, and the ytterbium retains its oxidation state (II) throughout the reactivity. Experimentally, the influence of the metal centre is discussed by comparison with the reaction of (Me(5)C(5))(2)Ca towards buta-1,2-diene, and (Me(5)C(5))(2)Yb with ethylene. The mechanism by which the Me(5)C(5) acts as a proton-relay within the coordination sphere of a metal also rationalises the reactivity of (i) (Me(5)C(5))(2)Eu(OEt(2)) with phenylacetylene, (ii) (Me(5)C(5))(2)Yb(OEt(2)) with phenylphosphine and (iii) (Me(5)C(5))(2)U(NPh)(2) with H(2) to yield (Me(5)C(5))(2)U(HNPh)(2). In the latter case, the computed mechanism is the heterolytic activation of H(2) by (Me(5)C(5))(2)U(NPh)(2) to yield (Me(5)C(5))(2)U(H)(HNPh)(NPh), followed by a hydrogen transfer from uranium back to the imido nitrogen atom using one Me(5)C(5) ligand as a proton-relay. The overall mechanism by which hydrogen shifts using a pentamethylcyclopentadienyl ligand as a proton-relay is named Carambole in reference to carom billiards.

Research Paper ISSN 0189-6016©2008

African Journals Online (AJOL)

AJTCAM

identified as (ent)-kaur-16-en-19-oic acid (KA) and (ent)-pimara-8, 15-dien-19-oic acid (PA). Both compounds were significantly effective regarding analgesics, hypothermia, duration of pentobarbital-induced anesthesia, and depression of locomotor activity enhanced by methamphetamine at doses of 300 mg/kg (KA) and ...

GE[)URE~[)E

African Journals Online (AJOL)

liter te orienteer. n. Direktoraat. Openbare. Betrekkinge is onder beheer van die Oorlogskantoor gestig en 'n aantal offisiere is aangestel. Hulle werk was om die Leer te beskrywe en soveel as moontlik in die openbare pers te laat verskyn. Hierdie organisasie het goeie vredestydse diens gelewer, maar sou die oorlogstyd ...

Effect of intermittent frying on fatty acids, vitamin E, lipid oxidation ...

African Journals Online (AJOL)

Quality parameters determined in this study were: fatty acid composition of the oils, ... quality were analyzed by High Performance Liquid Chromatography in isocratic mode. ... Conjugated dienes, Anisidine value and viscosity as markers of lipid ... In soybean oils, about 57% and 62.5% of linoleic and linolenic acids were lost ...

Nasionale beplanning en kodrdinering van veekundige

African Journals Online (AJOL)

en riglyne aanvaa.r word, is dit duidelik dat diereproduksie in die toekoms nog aansienlik sal moet ontwikkel as .... die Streek dus prim€r'n gemeenskap dien en 'n bepaalde gebied ontwikkel, bedien die Instituut 'n bedryf of 'n vak en .... :Projek. Entiteit+Studieveld+Plan. :Subprojek. Entiteit + Studieveld + Plon + Aksie : Faset.

Een oude vondst op Java van de Groote Aalscholver (Phalacrocorax sulcirostris territori (Math.) in het museum te Buitenzorg

NARCIS (Netherlands)

Hoogerwerf, A.

1947-01-01

In De Tropische Natuur (jrg. 24, Juni 1935, p. 90/91) maakten wij, bij een goede foto der levende volgels, melding van een groote aalscholver door ons in 1935 waargenomen in de Brantas-delta, die later bleek Phalacrocorax sulcirostris territori te zijn en door ons onder dien naam werd gepubliceerd

In vitro and in vivo metabolism of the progestagen Org 30659 in several species

NARCIS (Netherlands)

Verhoeven, CHJ; Krebbers, SFM; Wagenaars, GN; Bogy, CJ; Groothuis, GMM; Olinga, P; Vos, RME

The metabolism of Org 30659 [(17 alpha)-17-hydroxy-11-methylene-19-norpregna-4,15-dien-20-yn-3-one], a new potent progestagen currently under clinical development by NV Organon for use in oral contraceptive and hormone replacement therapy, was studied in vivo after oral administration to rats and

Irritant potential of some constituents from oleo-gum-resin of Commiphora myrrha.

Science.gov (United States)

Saeed, M Asif; Sabir, A W

2004-01-01

The irritant potentials of essential oil and seven sesquiterpenoids compounds newly isolated from the oleo-gum-resin of Commiphora myrrha were investigated by open mouse ear assay. The essential oil, curzerenone, furanodiene-6-one and furanoeudesma-1,3-diene showed potent and persistent irritant effects while others possess least irritant potentials.

Minor sterols from the sponge Ircinia ramosa (Killer)

Digital Repository Service at National Institute of Oceanography (India)

Parameswaran, P.S.; Naik, C.G.; Das, B.; Kamat, S.Y.

Three sterols, isolated from the lipid fraction of the sponge Ircinia ramosa were characterised as cholest-5-en-3 beta-ol-7-one (7-oxo cholesterol, 1), cholest 5-23-dien-b beta ol-7-one (7-oxo demosterol, 2) and 24E-ethyl cholest-5-en-3 beta -ol-7...

Functional properties of milk drinks flavored with mangaba pulp and ...

African Journals Online (AJOL)

Lígia Campos de Moura, Marco Antônio Pereira da Silva, Geovana Rocha Plácido, Márcio Caliari, Diene Gonçalves Souza, Jéssica Leal Freitas e Souza, Juliana Aparecida Célia, Kênia Borges de Oliveira, Karen Martins Leão, Luiz Eduardo Costa do Nascimento ...

Oxidizability of unsaturated fatty acids and of a non-phenolic lignin structure in the manganese peroxidase-dependent lipid peroxidation system

Science.gov (United States)

Alexander N. Kapich; Tatyana V. Korneichik; Annele Hatakka; Kenneth E. Hammel

2010-01-01

Unsaturated fatty acids have been proposed to mediate the oxidation of recalcitrant, non-phenolic lignin structures by fungal manganese peroxidases (MnP), but their precise role remains unknown. We investigated the oxidizability of three fatty acids with varying degrees of polyunsaturation (linoleic, linolenic, and arachidonic acids) by measuring conjugated dienes...

(+)-Geodin from Aspergillus terreus

DEFF Research Database (Denmark)

Rønnest, Mads Holger; Nielsen, Morten Thrane; Leber, Blanka

2011-01-01

The fungal metabolite (+)-geodin [systematic name: (2R)-methyl 5,7-dichloro-4-hydroxy-6'-methoxy-6-methyl-3,4'-dioxospiro[benzofuran-2,1'-cyclohexa-2',5'-diene]-2'-carboxylate], C(17)H(12)Cl(2)O(7), was isolated from Aspergillus terreus. The crystal structure contains two independent molecules...

Carbohydrate carbocyclization by a zinc-mediated tandem reaction and ring-closing enyne metathesis

DEFF Research Database (Denmark)

Poulsen, Carina Storm; Madsen, Robert

2002-01-01

reaction, an amino group can be introduced in the 1,7-enyne products. Addition of 2-TMS-ethynylcerium(III) chloride after the reductive ring-opening produces the corresponding 1,6-enynes. Further annulation of the product 1,3-dienes can be achieved through a Diels-Alder reaction with good control of stereo...

The framework convention on tobacco control measures: does ...

African Journals Online (AJOL)

Die globale afmetings van hierdie probleem het die Verenigde Nasies, deur middel van die WGO, aangespoor om nasies in hulle stryd teen die tabakspandemie te help. Die Raamwerkkonvensie oor Tabakbeheermaatreels is met die spesifieke doelstelling om as 'n gids vir nasies te dien, wat hulle in staat sal stel om sowel ...

40 CFR Table 6 to Subpart Jjj of... - Known Organic HAP Emitted From the Production of Thermoplastic Products

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Known Organic HAP Emitted From the... HAP Emitted From the Production of Thermoplastic Products Thermoplastic product/Subcategory Organic HAP/chemical name(CAS No.) Acet-aldehyde (75-07-0) Acrylo-nitrile (107-13-1) 1,3 Buta-diene (106-99-0...

Composition of the oil of Eupatorium stoechadosmum Hance from Vietnam

NARCIS (Netherlands)

Dung, N.X.; Tam, Nguyen T.; Kruk, C.; Leclercq, P.A.

1991-01-01

The essential oil of Eupatorium stoechadosmum Hance from Vietnam was analyzed by GC/MS. The main constituents were found to be thymohydroquinone dimethyl ether (confirmed by 1H-NMR, 73.6%), and B-caryophyllene (8.9%), accounting e for more than 82% of the oil. Selina-4,11-diene (11.0%) was also

Family Fathers Lost in Theatre Paradox

DEFF Research Database (Denmark)

Kuhlmann, Annelis

2008-01-01

Diderot's influence on theatre is well known through The Paradox of Acting (Paradoxe sur le comédien). However, Diderot also wrote a few drames bourgeois, among which is The Family Father (Le Père de famille), which still in Diderot's days was edited in Copenhagen in French, and which in Danish...

prosesseringsmetodes op die voedingswaarde van

African Journals Online (AJOL)

gebring is, kon geen betekenisvolle verskille tussen die drie monsters gevind word nie. Volgens Opstvedt (1976) kan ME waardes ook dien as 'n kriteria van proteien- kwaliteit, hoofsaaklik a.g.v. die verhoogde stikstofuit- skeiding in die urine wat sal plaasvind a.g.v. beskadiging van aminosure. De Groote (1968) het gevind ...

13 Febr. 1955. B. GD r . B. G emser , Hebreeuse Spraakkuns, JL van ...

African Journals Online (AJOL)

Test

onder die paradigma is dit korrek gegee). Die herhalingsoefening na die werkwoord met laryngale en beginalef sal goeie diens doen om die student homself nogeens goed rekenskap te laat gee van die reëls betreffende die keelklanke. By die behandeling van die pe-nun verba mis ons die dikwels voorkomende emfatiese ...

Toward improved construction health, safety, and ergonomics in ...

African Journals Online (AJOL)

Hierdie dien as plaaslike insig en 'n lyn van gestruktureerde vrae vir gebruik in die hoofstudie, wat geposisioneer is in die aksie-navorsing (AN) paradigma en gebruik die fokusgroep (FG) metode om groot kwalitatiewe data in te samel van SARAP-geregistreerde deelnemers. Sintese van die FG data met die literatuur asook ...

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Abstract. In the present work, tracking phenomena has been studied with the ethylene propylene diene monomer (EPDM) material under the a.c. and d.c. voltages, with ammonium chloride/acid rain solution as the contaminant. It is noticed that the tracking time depends on the conductivity and flow rate of the contaminant.

Novel route to 5-position vinyl derivatives of thiolactomycin: Olefination vs. deformylation

Science.gov (United States)

Kim, Pilho; Barry, Clifton E.; Dowd*, Cynthia S.

2006-01-01

Vinyl and diene derivatives of thiolactomycin have been prepared via Horner-Wadsworth-Emmons olefination from protected 5-formyl-3,5-dimethylthiotetronic acid. Several 4-position protecting groups and a variety of phosphonates were evaluated, with MOM protection and β-ketophosphonates yielding the highest ratio of desired product to deformylated product. PMID:16699591

INSECTICIDAL ACTIVITIES OF ESSENTIAL OILS EXTRACTED FROM THREE SPECIES OF POACEAE ON ANOPHELES GAMBIAE SPP, MAJOR VECTOR OF MALARIA

Directory of Open Access Journals (Sweden)

Dominique C. K. Sohounhloué

2010-12-01

Full Text Available In this paper, the insecticidal activities on Anopheles gambiae spp of the essential oils (EO extracted from the dry leaves of some species collected in Benin were studied. The essential oil yields are 2.8, 1.7 and 1.4�0respectively for Cymbopogon schoanenthus (L. Spreng (CS, Cymbopogon citratus Stapf. (CC and Cymbopogon giganteus (Hochst. Chiov (CG. The GC/MS analysis showed that the EO of CS had a larger proportion in oxygenated monoterpenes (86.3�20whereas those of the sheets of CC and CG are relatively close proportions (85.5�0and 82.7�0respectively with. The piperitone (68.5�  2-carene (11.5� and -eudesmol (4.6�20are the major components of the EO of CS while trans para-mentha-1(7,8-dien-2-ol (31.9� trans para-mentha-2,8-dien-1-ol (19.6� cis para-mentha-2,8-dien-1-ol (7.2� trans piperitol (6.3�20and limonene (6.3�20prevailed in the EO of CG. The EO of CC revealed a rich composition in geranial (41.3� neral (33� myrcene (10.4� and geraniol (6.6� The biological tests have shown that these three EO induced 100�0mortality of Anopheles gambiae to 1.1, 586.58 and 1549 µg•cm-2 respectively for CC, CS and CG. These effects are also illustrated by weak lethal concentration for 50�0anopheles population (CC: 0.306; CS: 152.453 and CG: 568.327 µg•cm-2 in the same order of reactivity. The EO of CC appeared most active on two stocks (sensitive and resistant of Anopheles gambiae.

Chemical Diversity and Biological Activity of the Volatiles of Five Artemisia Species from Far East Russia

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Gulmira Özek

2014-05-01

Full Text Available Artemisia argyi , A. feddei, A. gmelinii, A. manshurica, and A. olgensis (Asteraceae were collected in Far East Russia. Oils were hydrodistilled and simultaneously analyzed by GC-FID and GC/MS. Main constituents were found as follows in Artemisia oils: selin-11-en-4 a -ol (18.0%, 1,8-cineole (14.2.0%, artemisia alcohol (12.9%, borneol (9.7% in A. argyi; camphor (31.2%, 1,8-cineole (17.6%, a -thujone (5.7% in A. feddei; longiverbenone (12.0%, isopinocamphone (8.9%, 1,8-cineole (6.7%, camphor (5.8%, trans-p-menth-2-en-1-ol (5.3% in A. gmelinii; germacrene D (11.2%, rosifoliol (10.1%, caryophyllene oxide (6.8%, eudesma-4(15,7-dien-1 b -ol (5.6% in A. manshurica; eudesma-4(15,7-dien-1 b -ol (6.9%, caryophyllene oxide (5.6%, guaia-6,10(14-dien-4 b -ol (5.1% and hexadecanoic acid (5.0% in A. olgensis. Oils were subsequently submitted for antifungal and antimosquito evaluations. Artemisia species oils showed biting deterrent effects in Aedes aegypti and Artemisia gmelinii oil with the most active biting deterrence index values of 0.82 ± 0.1 at 10 m g/mL. Larval bioassay of A. gmelinii and A. olgensis oils showed higher larvicidal activity against Ae. aegypti larvae with LD50 values of 83.8 (72.6 – 95.7 ppm and 91.0 (73.8 – 114.5 ppm, respectively. Antifungal activity was evaluated against the strawberry anthracnose-causing fungal plant pathogens Colletotrichum acutatum, C. fragariae and C. gloeosporioides using direct overlay bioautography assay and all showed non-selective weak antifungal activity. Antioxidant evaluations of the oils were performed by using b -carotene bleaching, Trolox equivalent and DPPH tests. The tested Artemisia oils demonstrated moderate antioxidant activity.

The Protective Effect of Hippophae Rhamnoides Carotenoid Extract Against Lipid Peroxidation in Crude Vegetable Oils

Directory of Open Access Journals (Sweden)

Sanda Andrei

2014-11-01

Full Text Available Vegetable oils are important elements of the human diet because they contain essential nutritional factors. Due to the manufacturing processes or inadequate conditions of storage, they may also contain lipid oxidation products that are toxic to the body. The purpose of this paper is to test the protective effect of carotenoid-rich extracts obtained from the fruits of Hippophae rhamnoides on crude sunflower, pumpkin and olive oils oxidative processes. In order to evaluate the effect of antioxidant carotenoids, three stages were followed: thermal induction of lipid peroxidation in the presence of AAPH (2,2'-Azobis(2-amidinopropane dihydrochloride; determination of the level of lipid peroxidation in oxidized oils in the presence and absence of antioxidants, by quantifying the concentration of conjugated dienes and malonyl dialdehyde (MDA; determination of the level of lipid peroxidation by evaluating the profile of the fatty acids and the ratio between the saturated and unsaturated fatty acids (UFA / SFA, using an GC-MS method. In the case of sunflower oil, it was observed that sea buckthorn fruit extract significantly decreased MDA concentration but does not significantly reduce the concentration of conjugated dienes. The protective effect of carotenoids is more evident in the case of oil from pumpkin seeds. In the olive oil, unlike the first two types of oils, the carotenoids extract inhibits both the MDA and the conjugated dienes formation to a lesser extent, statistically insignificant. Overall, the ratio UFA / SFA decreases in crude oxidized oils. In the oils in which carotenoids were added was observed an increase in the UFA / SFA ratio. Carotenoids fraction from sea buckthorn fruits, rich in xanthophylls’ esters, possess a good antioxidant effect, protecting vegetable oils against peroxidation processes induced in the presence of AAPH

Antioxidant activity of banana flavonoids.

Science.gov (United States)

Vijayakumar, S; Presannakumar, G; Vijayalakshmi, N R

2008-06-01

The antioxidant activity of flavonoids from banana (Musa paradisiaca) was studied in rats fed normal as well as high fat diets. Concentrations of peroxidation products namely malondialdehyde, hydroperoxides and conjugated diens were significantly decreased whereas the activities of catalase and superoxide dismutase were enhanced significantly. Concentrations of glutathione were also elevated in the treated animals.

CHEMISRTY OF NOVEL SPIRO OXAZOLO-THIADIAZOLES DERIVATIVES – SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION CHEMISRTY NEUARTIGER SPIRO oxazolo-Thiadiazole DERIVATE - Synthese, Charakterisierung und biologische Bewertung

OpenAIRE

Vijay V. Dabholkar, Abhishek Karekar, Prem Naik & N. B. Shinde

2012-01-01

A series of novel 2-N-acetyl hydrazino,4-acetyl,7-phenyl,9-(substitutedbenzylidine),1-thia, 3,4,8,triaza,6-oxa Spiro[4.4] nona-2,7-diene (4) were synthesized and screened for their antibacterial activity. The structures of the products were confirmed by IR, 1H,13C NMR and elemental analysis.

Asymmetric total synthesis of a putative sex pheromone component from the parasitoid wasp Trichogramma turkestanica

NARCIS (Netherlands)

Geerdink, Danny; Buter, Jeffrey; van Beek, Teris A.; Minnaard, Adriaan J.

2014-01-01

Virgin females of the parasitoid wasp Trichogramma turkestanica produce minute amounts of a sex pheromone, the identity of which has not been fully established. The enantioselective synthesis of a putative component of this pheromone, (6S,8S,10S)-4,6,8,10-tetramethyltrideca-2E,4E-dien-1-ol (2), is

facteurs predictifs d'atteinte ganglionnaire centrale dans les cancers

African Journals Online (AJOL)

9 mai 2013 ... laire, l'envahissement ganglionnaire latéral, la bilatéralité et l'envahissement ganglionnaire central. un évidemment gan- glionnaire central prophylactique doit donc être particulièrement considéré chez ces patients. Mots clés : carcinome thyroïdien, évidement ganglionnaire, métastase ganglionnaire.

KI~I)ERS I~ ~ILITERE VERI3A~1)

African Journals Online (AJOL)

dat hy te oud vir trompetblaser geword het. Hy kwalifiseer as Gesondheidsinspekteur en attesteer op 2 Junie 1944 weer by die Suid-. Afrikaanse Weermag om as Vrywilliger in. Wereldoorlog 1/ diens te doen. Hy word op. 17 Mei 1946 met die rang van sersant gede- mobiliseer. Op 70-jarige leeftyd tree Fray as Hoofgesond-.

Dogmatiek en Christelike Etiek binne die Fakulteit Teologie (Afd A ...

African Journals Online (AJOL)

their influence on the study of Dogmatics and Ethics in the Department. The article concludes with a vision for ... heid door systematische ordening' (Berkhof 1982:14) aan die een kant en om diens aan die kerklike verkondiging aan die ander kant gaan, sal bogenoemde twee sake beslis nie uit die cog verloor kan word nie.

General Allylic C–H Alkylation with Tertiary Nucleophiles

Science.gov (United States)

2015-01-01

A general method for intermolecular allylic C–H alkylation of terminal olefins with tertiary nucleophiles has been accomplished employing palladium(II)/bis(sulfoxide) catalysis. Allylic C–H alkylation furnishes products in good yields (avg. 64%) with excellent regio- and stereoselectivity (>20:1 linear:branched, >20:1 E:Z). For the first time, the olefin scope encompasses unactivated aliphatic olefins as well as activated aromatic/heteroaromatic olefins and 1,4-dienes. The ease of appending allyl moieties onto complex scaffolds is leveraged to enable this mild and selective allylic C–H alkylation to rapidly diversify phenolic natural products. The tertiary nucleophile scope is broad and includes latent functionality for further elaboration (e.g., aliphatic alcohols, α,β-unsaturated esters). The opportunities to effect synthetic streamlining with such general C–H reactivity are illustrated in an allylic C–H alkylation/Diels–Alder reaction cascade: a reactive diene is generated via intermolecular allylic C–H alkylation and approximated to a dienophile contained within the tertiary nucleophile to furnish a common tricyclic core found in the class I galbulimima alkaloids. PMID:24641574

General allylic C-H alkylation with tertiary nucleophiles.

Science.gov (United States)

Howell, Jennifer M; Liu, Wei; Young, Andrew J; White, M Christina

2014-04-16

A general method for intermolecular allylic C-H alkylation of terminal olefins with tertiary nucleophiles has been accomplished employing palladium(II)/bis(sulfoxide) catalysis. Allylic C-H alkylation furnishes products in good yields (avg. 64%) with excellent regio- and stereoselectivity (>20:1 linear:branched, >20:1 E:Z). For the first time, the olefin scope encompasses unactivated aliphatic olefins as well as activated aromatic/heteroaromatic olefins and 1,4-dienes. The ease of appending allyl moieties onto complex scaffolds is leveraged to enable this mild and selective allylic C-H alkylation to rapidly diversify phenolic natural products. The tertiary nucleophile scope is broad and includes latent functionality for further elaboration (e.g., aliphatic alcohols, α,β-unsaturated esters). The opportunities to effect synthetic streamlining with such general C-H reactivity are illustrated in an allylic C-H alkylation/Diels-Alder reaction cascade: a reactive diene is generated via intermolecular allylic C-H alkylation and approximated to a dienophile contained within the tertiary nucleophile to furnish a common tricyclic core found in the class I galbulimima alkaloids.

New Insights into the Diels-Alder Reaction of Graphene Oxide.

Science.gov (United States)

Brisebois, Patrick P; Kuss, Christian; Schougaard, Steen B; Izquierdo, Ricardo; Siaj, Mohamed

2016-04-18

Graphene oxide is regarded as a major precursor for graphene-based materials. The development of graphene oxide based derivatives with new functionalities requires a thorough understanding of its chemical reactivity, especially for canonical synthetic methods such as the Diels-Alder cycloaddition. The Diels-Alder reaction has been successfully extended with graphene oxide as a source of diene by using maleic anhydride as a dienophile, thereby outlining the presence of the cis diene present in the graphene oxide framework. This reaction provides fundamental information for understanding the exact structure and chemical nature of graphene oxide. On the basis of high-resolution (13) C-SS NMR spectra, we show evidence for the formation of new sp(3) carbon centers covalently bonded to graphene oxide following hydrolysis of the reaction product. DFT calculations are also used to show that the presence of a cis dihydroxyl and C vacancy on the surface of graphene oxide are promoting the reaction with significant negative reaction enthalpies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of electron beam irradiation on quality of fresh chilled pork

International Nuclear Information System (INIS)

Shang Yibin; Gao Meixu; Li Shurong; Pei Ying; Wang Zhidong

2013-01-01

The effects of electron beam irradiation on nutrient quality, lipid oxidation and sensory quality of fresh chilled pork were investigated. Fresh chilled pork whose fat to muscle ratio was 1 : 6 was grounded and packaged, and then irradiated at doses of 0, 2.0, 3.8, 6.2, 8.3 and 10.5 kGy. The contents of fat andprotein, chromaticity, sensory characteristics, lipid oxidation index of TBARS value, POV, diene value of irradiated and unirradiated samples were measured. The results showed that there were no significant differences (5% level) in content of proteinand fat between irradiated and control samples, but irradiation could significantly increase TBARS value and POV. EB irradiation enhanced the increase of total diene value. The samples treated with 3.8 and 6.2 kGy showed good color during storage. There were no significant differences in sensory characteristics among different EB doses. It is concluded that 4-6 kGy EB irradiation, which is effective for decontamination, shows no significant effect on qualities of fresh chilled pork. (authors)

IDENTIFICACIÓN DE ALGUNOS METABOLITOS SECUNDARIOS DEL EXTRACTO EN ACETATO DE ETILO DE Muricea sp.I IDENTIFICATION OF SOME SECONDARY METABOLITES FROM THE ETHYL- ACETATE-EXTRACT OF THE OCTOCORAL, Muricea sp.

Directory of Open Access Journals (Sweden)

Ángel Camacho

2018-04-01

Full Text Available Some chromatographic fractions obtained from the ethyl-acetate-extract of the unidentified octocoral species of the genus, Muricea , showed antibacterial activity against Escherichia coli , Salmonella enteritidis , Citrobacter freundii , Staphylococcus aureus , and Bacillus subtlis , which indicates the presence of bioactive compounds in it. The GC/MS analysis of some fractions obtained by continuous chromatographic separation, allowed identification of metabolites, such that: ( Z -9-octadecenoic acid methyl ester, octadecenoic acid methyl ester, 1-methyl-4-ethoxy-δ(3-pyrrolin-2-one, endo-1-bourbonanol, dibutylphtalate, 4,5-epoxy-1-isopropyl-4-methyl- 1-cyclohexene, 1,3,3-trimethyl-7-oxabcyclo[2.2.1]heptane-2-carboxylic acid ethyl ester, 2,6-dimethyl-2-trans- 6-octadiene, farnesol, 3β-cholesta-5,22-dien-3-ol, cholesterol, (3β,22 E ,24S-ergosta-5,22-dien-3-ol, (3β,5α-2- methylenecholestan-3-ol, 3-hidroxylongifolol, by comparison with the WILEY and NIST databases and the study of the fragmentation patterns of their mass spectra.

Effect of conventional cooking methods on lipid oxidation indices in lamb meat

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A Pourkhalili

2012-05-01

Full Text Available Lipid oxidation is one of the most deteriorative reactions occurred in foodstuff which has harmful impacts on the both food quality and consumer's health. This study was designed to speculate the influence of three conventional cooking methods including boiling, frying and grilling on lipid oxidation parameters in cooked lamb meat. Sections of lamb meat from longissimus dorsi muscle, taken from native Lori-Bakhtiary sheep species were cut into uniform pieces and cooked using boiling, frying and roasting methods according to the cooking routine and tradition in Iranian society, in terms of temperature and time. Proximate compositions (moisture, lipid, ash and protein in the raw and cooked meat were determined using the standard methods of analysis. Moreover, weight loss was measured after each treatment. Lipid oxidation parameters such as peroxide value, conjugated diene and TBARS indices were measured in the raw and cooked samples. Evaluation of lipid oxidation parameters showed that peroxide value was significantly decreased in all cooked samples. In contrast, conjugated diene value was significantly increased in the fried and grilled samples (p

Cytotoxic sesquiterpene lactones from the aerial parts of Inula aucheriana.

Directory of Open Access Journals (Sweden)

Ahmad Reza Gohari

2015-06-01

Full Text Available Inula aucheriana DC is a member of the family Asteraceae which is known to produce cytotoxic secondary metabolites noted as sesquiterpene lactones. In the present study, sesquiterpene lactones inuchinenolide B, 6-deoxychamissonolide (stevin and 14-acetoxy-1β,5α,7αH-4β-hydroxy-guai-9(10,11(13-dien-12,8α-olide were isolated from I. aucheriana. Inuchinenolide B and 14-acetoxy-1β,5α,7αH-4β-hydroxy-guai-9(10,11(13-dien-12,8α-olide were further evaluated by the MTT (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide assay to demonstrate cytotoxic activity with IC50 values of (56.6, 19.0, (39.0, 11.8, and (55.7, 15.3 μg/mL against HepG-2, MCF-7 and A-549 cells, respectively. The cytotoxic activity of the two evaluated sesquiterpene lactones partly explains the cytotoxic activity that was previously observed for the extracts of Inula aucheriana. The isolated compounds could be further investigated in cancer research studies.

EFEK KONSUMSI MINUMAN BUBUK KAKAO LINDAK BEBAS LEMAK TERHADAP AKTIVITAS ANTIOKSIDAN FLAVONOID PADA PLASMA MANUSIA

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Welli Yuliatmoko

2008-09-01

Full Text Available Fat free cocoa powder is a rich source of flavonoid antioxidants including epicatechin, catechin, and procyanidins, which have attracted interest regarding cardiovascular health. The aim of this research was to evaluate the effect of Indonesian fat free cocoa powder drink consumption on antioxidants activity. Healthy woman subjects were divided into cocoa group (n=9 and control group (n=9. Cocoa powder drink containing skim milk and sugar was given to the cocoa group. The control group received only water containing skim milk and sugar. The criteria of the respondents were according to health medical diagnosis and informed consent signature. Their peripheral blood was withdrawn for the analysis of antioxidants capacity. Antioxidants capacity consisted of antiradical by DPPH method, malonaldehyde (MDA content, vitamin C, and diene conjugation. The data of cocoa group showed that there were significant increased in antiradical, vitamin C and decreased in MDA content (p<0.05. Cocoa consumption increased diene conjugation however was not significantly (p<0.05. In conclusion, the Indonesian fat free cocoa powder has increased plasma antioxidant system, which manifest good health function.

Synthesis and field evaluation of synthetic blends of the sex pheromone of Crocidosema aporema (Lepidoptera: Tortricidae) in soybean

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, Andres; Altesor, Paula; Liberati, Paola; Rossini, Carmen [Laboratorio de Ecologia Quimica, Facultad de Quimica, Universidad de la Republica, Montevideo (Uruguay); Alves, Leticia; Ramos, Juan; Carrera, Ignacio; Gonzalez, David; Seoane, Gustavo; Gamenara, Daniela [Departamento de Quimica Organica, Facultad de Quimica, Universidad de la Republica, Montevideo (Uruguay); Silva, Horacio; Castiglioni, Enrique [Departamento de Proteccion Vegetal, Facultad de Agronomia, EEMAC, Universidad de la Republica, Paysandu (Uruguay)

2012-11-15

Crocidosema (= Epinotia) aporema (Walsingham) (Lepidoptera: Tortricidae) is a bud borer that feeds on soybean and forage legumes. Its economic importance is restricted to South America, where it can alternate throughout the year between forage and grain legumes. The sex pheromone of C. aporema females is composed of a 15:1 mixture of (7Z,9Z)-dodeca-7,9-dien-1-ol and (7Z,9Z)- dodeca-7,9-dienyl acetate. Aiming at the development of a monitoring tool, it was synthesized both components of the pheromone and evaluated male captures in pheromone traps baited with different blends of synthetic pheromone, in an experimental soybean field in Uruguay. The conjugated dienes were obtained from 2-pentyn-1-ol and 1,7-heptanediol, by oxidation of the former, Wittig coupling and Zn-catalyzed reduction of the triple bond. The 1:1 mixture was the most efficient in capturing males. The pheromone traps were attractive for up to 40 days, even with small septum loads (0.1 mg) and low population levels. (author)

Synthesis and 5α-Reductase Inhibitory Activity of C21 Steroids Having 1,4-diene or 4,6-diene 20-ones and 4-Azasteroid 20-Oximes

Directory of Open Access Journals (Sweden)

Eunsook Ma

2011-12-01

Full Text Available The synthesis and evaluation of 5α-reductase inhibitory activity of some 4-azasteroid-20-ones and 20-oximes and 3β-hydroxy-, 3β-acetoxy-, or epoxy-substituted C21 steroidal 20-ones and 20-oximes having double bonds in the A and/or B ring are described. Inhibitory activity of synthesized compounds was assessed using 5α-reductase enzyme and [1,2,6,7-3H]testosterone as substrate. All synthesized compounds were less active than finasteride (IC50: 1.2 nM. Three 4-azasteroid-2-oximes (compounds 4, 6 and 8 showed good inhibitory activity (IC50: 26, 10 and 11 nM and were more active than corresponding 4-azasteroid 20-ones (compounds 3, 5 and 7. 3β-Hydroxy-, 3β-acetoxy- and 1α,2α-, 5α,6α- or 6α,7α-epoxysteroid-20-one and -20-oxime derivatives having double bonds in the A and/or B ring showed no inhibition of 5α-reductase enzyme.

New Synthesis of Perhydrotriazolotriazoles Catalyzed by TiCl{sub 4} under Ambient Conditions

Energy Technology Data Exchange (ETDEWEB)

Safari, J.; Gandomiravandi, S.; Ghotbinejad, M. [Univ. of Kashan, Kashan (Iran, Islamic Republic of)

2012-02-15

Aromatic 2,3-diazabuta-1,3-dienes in glacial acetic acid with isothiocyanate in the presence of catalyst TiCl{sub 4} at room temperature produced via criss-cross cycloaddition reactions the corresponding perhydro[1,2,4]triazolo[1,2-a][1,2,4] triazole-1,5-dithiones in relatively high yields and short reaction time.

Metal complex catalysis in the synthesis of organoaluminium compounds

International Nuclear Information System (INIS)

Dzhemilev, Usein M; Ibragimov, Askhat G

2000-01-01

The published data on the synthesis of organoaluminium compounds involving metal complex catalysts are generalised and systematised. Hydro-, carbo- and cycloalumination reactions of alkenes, conjugated dienes and alkynes catalysed by Ti and Zr complexes are considered in detail. The use of organoaluminium reagents in organic synthesis and novel reactions involving these compounds are discussed. The bibliography includes 240 references.

Sterols isolated from Tubifex tubifex.

Science.gov (United States)

Perez Gutierrez, Rosa Martha; Reyes, Ivan Cordova

2006-11-01

Four 3beta-hydroxysterols isolated from chloroform extract from Tubifex tubifex were shown to have the structures stigmast-23-en-3-ol, stigmast-7,14-dien-3-ol, 22-dehydrocholesterol, and 24 methylenecholesterol based on spectroscopic methods. Stigmasterol and beta-sitosterol were also investigated on the basis of mass spectral analyses and compared with known compounds.

Diterpenoids and phenolics from pseudopanax simplex

Directory of Open Access Journals (Sweden)

JOHN W. VAN KLINK

2006-02-01

Full Text Available An ethanolic extract of Pseudopanax simplex yielded kaempferol-3,7-di-O-rhamnopyranoside, chlorogenic acid, maltol glucoside, ent-kaur-16-en-18-acid, and 4R,5S,9R,10S,13S-ent-pimara-7,15-dien-19-oic acid. Full NMR data for the last compound are reported for the first time.

Enantioselective Synthesis of Aminodiols by Sequential Rhodium-Catalysed Oxyamination/Kinetic Resolution: Expanding the Substrate Scope of Amidine-Based Catalysis.

Science.gov (United States)

Guasch, Joan; Giménez-Nueno, Irene; Funes-Ardoiz, Ignacio; Bernús, Miguel; Matheu, M Isabel; Maseras, Feliu; Castillón, Sergio; Díaz, Yolanda

2018-03-26

Regio- and stereoselective oxyamination of dienes through a tandem rhodium-catalysed aziridination-nucleophilic opening affords racemic oxazolidinone derivatives, which undergo a kinetic resolution acylation process with amidine-based catalysts (ABCs) to achieve s values of up to 117. This protocol was applied to the enantioselective synthesis of sphingosine. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The isomerization of allylrhodium intermediates in the rhodium-catalyzed nucleophilic allylation of cyclic imines.

Science.gov (United States)

Hepburn, Hamish B; Lam, Hon Wai

2014-10-20

Allylrhodium species generated from potassium allyltrifluoroborates can undergo isomerization by 1,4-rhodium(I) migration to give more complex isomers, which then react with cyclic imines to provide products with up to three new stereochemical elements. High enantioselectivities are obtained using chiral diene-rhodium complexes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

die geskiedenis van die saw gedenkteken te fort klapperkop militere ...

African Journals Online (AJOL)

As gevolg van enige optrede, op enige plek, te enige tyd, deur enige vyand van die RSA of deur enige terroris(te), insurgent(e) of ander persoon of persone wat die RSA en sy volkere kwaadgesind is. h. Binne twee jaar (vyfhondred-en-dertig dae) nadat hy/sy met 'n ongeskiktheids- pensioen uit diens getree het agv siekte,.

DIE SUID-AFRIKAANSE JEUG IN VOORTREKKERTYDPERK

African Journals Online (AJOL)

dien. Die planke en velie moes keer dat die assegaaie die mense tref. Voor die geveg het die vrouens en groter dogters koeels gegiet. Tydens die geveg het die seuns gehelp skiet terwyl die vrouens en dogters die gewere vir die mans gelaai het. Van die dogters soos Nellie. Botha (11 jaar oud) en haar sussie Fya (15 jaar.

Synthesis and Characterization of High Energy Polymers.

Science.gov (United States)

1981-03-31

and characterization of new high energy elastomers. IV. References 1. J.C.W. Chien, T. Kohara , C. P. Lillya, T. Sarubbi, B.-H. Su and R. S. Miller, J...Catalyzed Nitromercuration of Diene Polymers, J.C.W. Chien, T. Kohara , C. P. Lillya, T. Sarubbi, B.-H. Su, and R. S. Miller, J. Polm.. Sci. Polym. Chem. Ed

African Journal of Neurological Sciences - 2009 Vol. 28 No 1

African Journals Online (AJOL)

RESUME. Le kyste arachnoïdien extra-dural spinal est une affection rare. Sa pathogénie reste méconnue. Nous rapportons le cas d'une jeune fille de 12 ans, sans antécédents pathologiques, admise au service de neurochirurgie, hôpital militaire Avicenne, Marrakech, pour un syndrome de compression médullaire à.

Cyclopentadiene-mediated hydride transfer from rhodium complexes.

Science.gov (United States)

Pitman, C L; Finster, O N L; Miller, A J M

2016-07-12

Attempts to generate a proposed rhodium hydride catalytic intermediate instead resulted in isolation of (Cp*H)Rh(bpy)Cl (1), a pentamethylcyclopentadiene complex, formed by C-H bond-forming reductive elimination from the fleeting rhodium hydride. The hydride transfer ability of diene 1 was explored through thermochemistry and hydride transfer reactions, including the reduction of NAD(+).

New phenolic esters from the resinous exudate of Haplopappus taeda.

Science.gov (United States)

Faini, Francesca; Labbé, Cecilia; Torres, René; Rodilla, Jesús M; Silva, Lucía; Delle Monache, Franco

2007-12-01

Two new phenolic esters 9-trans-p-coumaroyloxy-alpha-terpineol (1) and 7-trans-p-coumaroyloxy-taedol (2), both endowed with free radical scavenger activity and cleroda-3,13 (E)-dien-15,18-diol (3) for which a cis stereochemistry at the decalin junction was found, were isolated from the resinous exudate from Haplopappus taeda upper parts.

Between ethylene and polyenes--the non-adiabatic dynamics of cis-dienes

DEFF Research Database (Denmark)

Kuhlman, Thomas Scheby; Glover, William J; Mori, Toshifumi

2012-01-01

Using Ab Initio Multiple Spawning (AIMS) with a Multi-State Multi-Reference Perturbation theory (MS-MR-CASPT2) treatment of the electronic structure, we have simulated the non-adiabatic excited state dynamics of cyclopentadiene (CPD) and 1,2,3,4-tetramethyl-cyclopentadiene (Me4-CPD) following exc...

Irradiation of isotactic polypropylene and polypropylene/ethylene-propylene (diene-monomer) blends

NARCIS (Netherlands)

Gisbergen, van J.G.M.; Meijerink, J.I.; Overbergh, N.; Kleintjes, L.; Lemstra, P.J.

1989-01-01

The influence of electron beam irradiation on rheological properties and morphology of polypropylene and polypropylene/ethylene-propylene rubber blends was studied. Electron beam irradiation of isotactic PP causes pronounced chain scission (degradation) at dosis = 100 kGy. Melt viscosity can be

Hydrogen-Bonding Catalysis of Tetraalkylammonium Salts in an Aza-Diels-Alder Reaction.

Science.gov (United States)

Kumatabara, Yusuke; Kaneko, Shiho; Nakata, Satoshi; Shirakawa, Seiji; Maruoka, Keiji

2016-08-05

A piperidine-derived tetraalkylammonium salt with a non-coordinating counteranion worked as an effective hydrogen-bonding catalyst in an aza-Diels-Alder reaction of imines and a Danishefsky diene. The hydrogen-bonding interaction between the ammonium salt and an imine was observed as part of a (1) H NMR titration study. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

D IE M IST IEK — 'N B E SK O U IN G V O L G E N S D IE ST A N D ...

African Journals Online (AJOL)

Test

tariaat ge!d, die absolute waarheid moet wees. ,Dié waarheid is vir. Berdjajew onafhank!ik, dit word gedien, is abso!uut en dien nie. Hy het 'n vaste ge!oof in die persona!istiese aristokrasie van die gees. Vanuit Rus!and is hy na Duitsland. Met die fascisme en Nazi- isme kon Berdjajew egter ook nie volkome tereg kom nie.

Synthetic studies with Pinus elliottiis rosin derivatives. Oxidation of maleopimaric anhydride methyl ester and trimethyl fumaropimarate

Directory of Open Access Journals (Sweden)

Hess Sonia C.

2000-01-01

Full Text Available Ozonolysis of maleopimaric anhydride methyl ester in the presence of tetracyanoethylene led to an epoxide and an ozonide. Ozonolysis of the trimethyl fumaropimarate, followed by treatment with Me2S, led to an epoxide, a diene, a keto-acid and an allylic oxidation product. Some of the compounds obtained were active against Staphylococcus aureus, Bacillus subtilis and Micrococcus luteus.

Effects of 5-nitro-2-furaldehyde on the radiation damage of liposomes

International Nuclear Information System (INIS)

Kuropteva, Z.V.; Sprinz, H.; Schaefer, H.; Winkler, E.

1986-01-01

By means of 1 H-NMR spectroscopy the influence of 5-nitro-2-furaldehyde (NF) on the permeation of Eu 3+ ions into irradiated liposomes of egg yolk lecithin was examined. In the presence of NF there was an increase in the permeability of irradiated liposomes. The damage of the liposomes was quantified spectrophotometrically in terms of diene conjugation. (author)

Case series

African Journals Online (AJOL)

abp

15 mars 2016 ... cancer in Belarus after Chernobyl. Int Congr Ser. 2007;1299(1):27-31. PubMed | Google Scholar. 6. Wémeau JL, Caron P, Helal B et al.Thyroïde et Chernoby l. Ann. Endocrinol. 2001;62(5):435-6. PubMed| Google Scholar. 7. Damak H. Nodules thyroïdiens?: Facteurs prédictifs de malignité. 2002 Sfax.

Nonadecadienone, a New Termite Trail-Following Pheromone Identified in Glossotermes oculatus (Serritermitidae)

Czech Academy of Sciences Publication Activity Database

Hanus, Robert; Šobotník, Jan; Krasulová, Jana; Jiroš, Pavel; Žáček, Petr; Kalinová, Blanka; Dolejšová, Klára; Cvačka, Josef; Bourguignon, T.; Roisin, Y.; Lacey, M. J.; Sillam-Dusses, David

2012-01-01

Roč. 37, č. 1 (2012), s. 55-63 ISSN 0379-864X R&D Projects: GA ČR GAP506/10/1570 Institutional research plan: CEZ:AV0Z40550506 Keywords : Glossotermes * Serritermitidae * sternal gland * termites * trail-following pheromone * (10Z,13Z)-nonadeca-10,13-dien-2-one Subject RIV: CC - Organic Chemistry Impact factor: 3.222, year: 2012

Synthesis of a natural product-inspired eight-membered ring lactam library via ring-closing metathesis.

Science.gov (United States)

Brown, Neil; Xie, Baohan; Markina, Nataliya; Vandervelde, David; Perchellet, Jean-Pierre H; Perchellet, Elisabeth M; Crow, Kyle R; Buszek, Keith R

2008-09-01

We have prepared a novel speculative eight-membered lactam demonstration library based on the skeletal structure of the potent antitumor marine natural product octalactin A. The basic scaffold was readily constructed in a convergent fashion via ring-closing metathesis chemistry from the corresponding diene amides. A cursory examination of the biological properties of the library validates the relevance and significance of these structures.

Dithioacetals as C{sup 2+} cation synthons

Energy Technology Data Exchange (ETDEWEB)

Tien-Yau Luh [National Taiwan Univ., Taipei (China)

1995-12-31

The nickel-catalyzed cross coupling reactions of the benzylic and allylic dithioacetal group with Grignard reagents group giving olefins will be presented. The reaction provides a convenient procedure for the synthesis of various vinylsilanes and silyl-substituted conjugated dienes. Allylic dithioacetals undergo geminal dimethylation reactions when bidentate phosphine ligands are used. Treatment of dithioacetals with geminal dimetallic species affords the corresponding olefination products.

Crystallinity and the effect of ionizing radiation in polyethylene. V. Distribution of trans-vinylene and trans, trans conjugated double bonds in linear polyethylene

International Nuclear Information System (INIS)

Patel, G.N.

1975-01-01

Freeze-dried chain folded single crystals and the single crystals without amorphous surface layers (crystalline cores) of different thicknesses of linear polyethylene were irradiated with 60 Co γ-rays up to 600 Mrad. Concentration of trans-vinylene double bonds and conjugated diene produced during irradiation of the crystals was measured by infrared. Concentrations of trans-vinylene and of the conjugated diene were independent of thickness of crystalline core which suggest that the double bonds were randomly distributed in the crystalline parts of the crystals. Concentrations of trans-vinylene and of conjugated double bonds were lower in chain-folded crystals than in the crystalline cores and this suggests that the folds (amorphous surface layers) are less preferential sites for formation of the double bonds. The zero-order growth and first-order decay kinetics of trans-vinylene double bonds was studied by the equation derived by Dole et al. The equation is strictly obeyed up to 300 Mrad and the results then deviate. Since there is the decay of trans-vinylene double bonds and though there are no crosslinks in the crystalline cores, it has been suggested that the decay of the double bond does not result in the crosslinks

Reactive chemically modified piezoelectric crystal detectors: A new class of high-selectivity sensors

International Nuclear Information System (INIS)

Fadeev, A.Yu.; Filatov, A.L.; Lisichkin, G.V.

1994-01-01

A great number of works have focused on the study of properties of modified piezoelectric quartz crystal detectors (PQCDs) coated with sorbing substrates and on applying sensors based on them for the analysis of diluted gas mixtures and solutions. This work offers a new class of gravemetric sensors characterized by a reversible chemical reaction that occurs on their surface. Silica films are proposed as a sorbing coating of quartz detectors, and a chemical modification of a surface is suggested for covalent fixation of the necessary compounds. PQCDs were chemically modified with reactive diene derivatives that can also act as dienophiles. Hexachlorocyclopentadiene (HCCPD, resonater I) and cyclopentadiene (CPD, resonator II) were fixed on a PQCD surface in several stages. After treatment with the resonaters, the PQCD in a CPD gas phase exhibited time dependent frequency shifts from 20-100 Hz. The results suggest that there is a reversible chemical reaction on the electrode surface of resonators I and II when they interact with CPD vapors. Therefore, PQCDs modified with reactive dienes were prepared for the first time and may be employed as selective sensors for CPD

Influence of folic acid, pyridoxal phosphate and cobalamin on plasma homocyst(e)ine levels and the susceptibility of low-density lipoprotein to ex-vivo oxidation.

Science.gov (United States)

Weiss, N; Feussner, A; Hailer, S; Spengel, F A; Keller, C; Wolfram, G

1999-10-15

Mild hyperhomocyst(e)inaemia is a risk factor for atherosclerotic vascular disease. In-vitro studies have shown that autooxidation of homocyst(e)ine is accompanied by the generation of oxygen radicals. This may lead to oxidative modification of low-density lipoproteins (LDL) and promote atherosclerotic vascular lesions. In male patients with peripheral arterial occlusive disease we determined fasting and post methionine load homocyst(e)ine levels by high performance liquid chromatography and the susceptibility of their LDL particles to ex-vivo oxidation by continously measuring the conjugated diene production induced by incubation with copper ions. Oxidation resistance (expressed as lag time), maximal oxidation rate, and extent of oxidation (expressed of total diene production) of LDL from patients with normal or mildly elevated homocyst(e)ine levels did not differ significantly. Folic acid, pyridoxal phosphate and cobalamin supplementation significantly decreased plasma homocyst(e)ine levels in hyperhomocyst(e)inaemic patients. This went along with a significant decrease in the extent of LDL oxidation and additionally increased HDL-cholesterol levels. The clinical relevance of these findings for the long-term course of atherosclerotic vascular disorders has to be determined by intervention studies.

The Inhibition Effect of Cell DNA Oxidative Damage and LDL Oxidation by Bovine Colostrums

Directory of Open Access Journals (Sweden)

Chih-Wei Chen

2016-10-01

Full Text Available In the present study, we investigated the effect of bovine colostrums on inhibition of DNA oxidative damage and low density lipoprotein (LDL oxidation in vitro. Results showed that whey and skimmed milk exhibited not only higher inhibitory activities of oxidative damage of deoxyribose but also an inhibitory effect on the breakdown of supercoiled DNA into open circular DNA and linear DNA. The quantities of 8-OH-2′-dG formed under whey, caseins and skimmed milk treatment were 0.24, 0.24 and 1.24 μg/mL, respectively. The quantity of malondialdehyde formed through LDL oxidation induced by copprous ion was significantly decreased as colostrums protein solutions were added, in which whey and caseins led to a more significant decrease than skimmed milk. The formation of conjugated dienes could be inhibited by treatment with colostrums protein solutions. Whey exhibited the longest lag time of conjugated dienes formation among the colostrums proteins. The lag time of the whey was 2.33 times that of the control. From the results of foregoing, the bovine colostrums protein has potential value in the inhibition of DNA oxidation damage and LDL oxidation.

Verticillarone: a new seco-fusicoccane diterpenoid ketonepoxide from Hypoestes verticillaris.

Science.gov (United States)

Al-Rehaily, Adnan J; Al-Yahya, M A; Mirza, Humayun H; Ahmed, Bahar

2002-06-01

The aerial parts of Hypoestes verticillaris (L.F.) Sol. (Acanthaceae) has afforded a new seco-fusicoccane diterpenoid ketonepoxide, which was characterized as 1(10) seco-fusicocc-3 (4)-ene-5, 11, 14-trione-8 (9), 1 (7)-diepoxide (1) on the basis of spectral analysis and named as verticillarone, along with earlier reported diterpenoid, i.e. 13-hydroxy-7-oxo-labda-8, 14-diene (2).

Origin of Exo/Endo Selectivity in the Intramolecular Diels-Alder Reaction

International Nuclear Information System (INIS)

Yan, Shihai; Ryu, Do Hyun; Lee, Jin Yong

2010-01-01

The stereoselectivity of the intramolecular Diels-Alder reactions of 1 and its derivatives were investigated by ab initio calculations. The stereoselectivity mainly originates from the steric repulsion and the orbital interactions. The additional s-cis and s-trans conformations by introducing the carbonyl group at the neighbor of diene or dienophile may change the stereoselectivity, hence this kind of substitution can be utilized for stereoselective asymmetric synthesis

Dehydrogenative Diels-Alder reaction.

Science.gov (United States)

Ozawa, Takuya; Kurahashi, Takuya; Matsubara, Seijiro

2011-10-07

The dehydrogenative cycloaddition of dieneynes, which possess a diene in the form of a styrene moiety and a dienophile in the form of an alkyne moiety, produces naphthalene derivatives when heated. It was found that a key requirement of this process is the presence of a silyl group attached to the alkyne moiety, which forces a dehydrogenation reaction to occur. © 2011 American Chemical Society

Structure determination of cyclo pentane terpene derivatives by crossed NMR and MS techniques

Energy Technology Data Exchange (ETDEWEB)

Pianet, I.; Bourgeois, G. [Bordeaux-1 Univ., 33 - Talence (France); Dolatkhani, M.; Cramail, H.; Deffieux, A. [Centre National de la Recherche Scientifique (CNRS), 33 - Talence (France)

1995-10-01

3 of the 4 stereoisomers of the 1-isopropenyl 2,3-dimethylcyclopentane, obtained from the cracking of 3,7-dimethylocta-1,6-diene, were purified and characterized. Dihedral angles, between the protons of the substituted carbons, have been determined by molecular modelling. Analysis of the NMR and mass spectra allowed us to access to the structure of the different isomers. (authors). 6 refs., 2 tabs.

LES GOITRES BÉNINS EN ORL

African Journals Online (AJOL)

18 juin 2007 ... Montury S., de Clermont H, Gatina J.H. Prévalence des cancers thyroïdiennes à la Réunion à partir des données scinti- graphiques. Bull Patho Exot, 1997. 9. Moumen M, Touhami M, Elaoui M.E, Fares F.El. Les micro-carcinomes thyroïdiens. Médecine du Maghreb, 1992, 31 :25-28. 10. Ntyonga-Pono M.P.

Antibacterial activity and composition of the essential oils of two ...

African Journals Online (AJOL)

STORAGESEVER

2010-04-12

Apr 12, 2010 ... Methyl eugenol. -. 0.1. 2037. Salvial-4(14)-en-1-one. -. 0.1. 2045. Humulene epoxide-I. -. 0.2. 2050 (E)-Nerolidol. -. 1.5. 2057 Ledol. -. 0.1. 2071 Humulene epoxide-II. -. 0.8. 2073 p-Mentha-1,4-dien-7-ol. 0.1. -. 2080 Cubenol. 0.1. 0.2. 2088 1-epi-Cubenol. -. 0.2. 2104 Viridiflorol. -. 11.5. 2113 Cumin alcohol.

Palladium-Catalyzed Decarboxylative γ-Olefination of 2,5-Cyclohexadiene-1-carboxylic Acid Derivatives with Vinyl Halides.

Science.gov (United States)

Chang, Chi-Hao; Chou, Chih-Ming

2018-04-06

This study explores a Pd-catalyzed decarboxylative Heck-type Csp 3 -Csp 2 coupling reaction of 2,5-cyclohexadiene-1-carboxylic acid derivatives with vinyl halides to provide γ-olefination products. The olefinated 1,3-cyclohexadienes can be further oxidized to produce meta-alkylated stilbene derivatives. Additionally, the conjugated diene products can also undergo a Diels-Alder reaction to produce a bicyclo[2.2.2]octadiene framework.

Willem II of Floris de Voogd? Vragen rond een grafmonument en een skelet in de Koorkerk te Middelburg

Directory of Open Access Journals (Sweden)

Peter Henderikx

2015-12-01

Full Text Available William II or Florence the Guardian?: Questions about a Tomb and a Skeleton in the Abbey Church at MiddelburgBoth William II, Count of Holland and Zeeland and King of the Holy Roman Empire (†1256, re-interred 1282 and his brother Florence the Guardian (†1258 are buried in the Norbertine abbey church in Middelburg. In 1817 a skeleton was found in a bricked up niche, along with the remains of a tombstone on which was carved a knightly figure whose shield bears the coat of arms of Holland. Based on the results of an examination of the bones by George J.R. Maat and his team (Leiden University Medical Centre, Henderikx takes it that the skeleton could be either that of the King of the Holy Roman Empire or of Florence the Guardian. Considering that the skeleton, burial space and tombstone formed a coherent whole, and the high-relief on the tombstone almost certainly does not refer to the King of Rome but to his brother, Henderikx concludes that the skeleton must be the  earthly remains of Florence the Guardian.Roomskoning Willem II, graaf van Holland en Zeeland (†1256, herbegraven 1282 en diens broer Floris de Voogd (†1258 zijn beiden in de norbertijner abdijkerk in Middelburg begraven. In 1817 werd daar in een dichtgemetselde nis een skelet aangetroffen samen met de resten van een zerk met daarop een gebeeldhouwde ridderfiguur met op diens wapenschild het wapen van Holland. Uitgaande van de resultaten van het onderzoek van het botmateriaal door George J.R. Maat cum suis (Leids Universitair Medisch Centrum stelt Henderikx vast dat het skelet afkomstig kan zijn van zowel de Roomskoning als van Floris de Voogd. Aangezien skelet, grafruimte en zerk steeds één samenhangend geheel hebben gevormd en het beeldhouwwerk op de zerk zo goed als zeker niet naar de Roomskoning maar naar diens broer verwijst, komt Henderikx tot de conclusie dat het skelet het stoffelijk overschot moet zijn van Floris de Voogd.

Nurses' perceptions about Botswana patients' anti-retroviral therapy adherence

Directory of Open Access Journals (Sweden)

Esther Kip

2009-09-01

Opsomming Anti-retrovirale middels (ARMs word gratis verskaf in Botswana. Lewenslange getroue nakoming van ARM voorskrifte is noodsaaklik om die pasiënt se algehele staat van welsyn te verbeter en om die ontwikkeling te voorkom van stamme van die menslike immuun-gebrek virus (MIV wat weerstand bied teen anti-retrovirale behandeling (ARB. Persone met ARB-weerstandbiedende MIV stamme kan dit versprei na ander mense toe, wat duurder ARB vereis met swakker gesondheidsuitkomste. Die doel van hierdie verkennende, beskrywende, kwalitatiewe studie was om te bepaal wat verpleegkundiges se sienings is oor pasiënte in Botswana se nakoming van ARB, en om faktore te identifiseer wat die ARB-nakoming kan bevorder of benadeel. Vier ARB terreine was ewekansig gekies en al 16 verpleegkundiges wat ARB dienste by die terreine verskaf, het deelgeneem aan semi-gestruktureerde onderhoude. Hierdie verleegkundiges het aangedui dat pasiënte se ARB handhawing beïnvloed word deur diens-verwante en pasiënt-verwante faktore. Diens-verwante faktore behels die ontoeganklikheid van ARB klinieke, beperkte kliniekure, gesondheidswerkers se onvermoë om in pasiënte se plaaslike tale te kommunikeer, lang wagtye by klinieke en vertragings om ingelig te word oor uitslae van CD4 en virale tellings. Verpleegkundiges kan nie pasiënte opvolg of telefonies kontak wat versuim om op te daag vir behandeling nie. Verpleegkundiges moet nagskofte werk wat pasiënt-verpleegkundige verhoudings onderbreek. Pasiënt-verwante faktore behels pasiënte se gebrekkige opvoeding, hulle onvermoë om die belangrikheid van uitslae van CD4 en virale tellings te verstaan, finansiële ontberinge, nie-openbaarmaking en nie-aanvaarding van hulle MIV positiewe status, alkohol misbruik, die gebruik van tradisionele medisynes en die newe-effekte van ARB. Die uitdagings van lewenslange ARB handhawing is veelsydig en behels beide pasiënt-verwante en diens-verwante faktore. Die verskaffing van gratis ARMs verseker nie ARB

Effect of natural β-carotene supplementation in children exposed to radiation from the Chernobyl accident

International Nuclear Information System (INIS)

Ben-Amotz, A.; Yatziv, S.; Sela, M.; Greenberg, S.; Rachmilevich, B.; Shwarzman, M.; Weshler, Z.

1998-01-01

Attempts were made to evaluate 709 children (324 boys and 385 girls) who had been exposed long-term to different doses of radiation during and after the Chernobyl accident and had moved to Israel between 1990 and 1994. Upon arrival, all of them underwent a check-up for most common clinical disorders and were then divided into three groups according to their residences (distance from the reactor) and the level of irradiation exposure: no radiation, 2 , and >5 Ci/m 2 , respectively. Blood serum analyses for total carotenoids, retinol, α-tocopherol and oxidized conjugated dienes in 262 of the children showed increased HPLC levels of conjugated dienes, indicating increased levels of oxidation of in vivo blood lipids in children from the contaminated areas. The levels were higher in girls than in boys. Some 57 boys and 42 girls were given a basal diet with a diurnal supplementation of 40 mg natural 9-cis and all-trans equal isomer mixture β-carotene in a capsulated powder form of the alga Dunaliella bardawil, for a period of 3 months. Blood serum analyses were regularly conducted before supplementation to determine the baseline effect of radiation exposure to the children, after 1 and 3 months of natural β-carotene supplementation. After supplementation, the levels of the oxidized conjugated dienes decreased in the children's sera without any significant changes in the level of total carotenoids, retinol or α-tocopherol. Other common blood biochemicals were within the normal range for all tests and no statistical differences before or after supplementation of β-carotene were noted. High pressure liquid chromatography (HPLC) analyses for carotenoids in the blood detected mainly oxycarotenoids, and to a lesser extent, all-trans β-carotene, α-carotene, but not 9-cis β-carotene. The results suggest that irradiation increases the susceptibility of lipids to oxidation in the Chernobyl children and that natural β-carotene may act as an in vivo lipophilic antioxidant

Effect of I125 on oxidation behavior of lipoprotein subpopulations

International Nuclear Information System (INIS)

Majtenyi, S.

2002-07-01

Lipoproteins play a central role in lipid metabolism. They serve as a transport vehicle for cholesterol and triglycerides keeping them in plasma in solution. Lipoproteins are characterized by the content of specific apoproteins and differences in the hydrated density ranges. Moreover, they are distinguished by electrophoretic mobility and other characteristics as high and low-density lipoproteins, respectively lipoprotein (a). More specifically, HDL is classified into HDL 2 and HDL 3 . In atherogenesis, lipoproteins are considered to play a key-role. Oxidatively modified LDL is selectively taken up via scavenger receptors of the macrophage-monocyte system. These cells are transformed into foam cells promoting atherogenesis in vessels in the subendothelial space. Oxidized HDL essentially appears to loose its protective effects on LDL and its beneficial function in reverse cholesterol transport. Thus, it turns proatherogenic. The effects various species of free radicals exert on lipoproteins are the reason for this oxidative modification. Thyroid function also influences lipoproteins in a complex manner. Based on their hydrated density ranges, lipoprotein subpopulations were fractionated and isolated via isopycnic density gradient ultracentrifugation. After investigation of the general oxidation behavior, initiated by addition of CuSO 4 to the isolated samples of HDL 3 , HDL 2 , LDL and Lp(a), the influence of different activities of radioiodine-125 on the kinetics of the formation of conjugated dienes was assessed. This was achieved by coincubation of plasma with I 125 . The spectrophotometrical measurement of the concentration of conjugated dienes in the course of CuSO 4 -induced lipid peroxidation leads to measurable changes in absorption at 234 nm. These changes in absorption over time result in a characteristically shaped curve graphically plotted. The shape of these curves mirrors different indicators of lipid peroxidation. Therefrom lag time, maximal

Images in medicine

African Journals Online (AJOL)

abp

12 nov. 2015 ... exerçant un scalopping sur le mur postérieur de. L3; (B) IRM médullaire (coupe sagittale en T1) intracanalaire à l'étage L3-L4 qui élargit le foramen intervertébral sans signe de compression du fourreau dural en rapport avec un kyste arachnoïdien; (C) IRM médullaire (coupe sagittale en T2) intracanalaire ...

Diels-Alder reactions of anthracenes with C-sulfonyldithioformates

DEFF Research Database (Denmark)

El-Sayed, I.; Ali, O.M.; Fischer, A.

2003-01-01

C-Sulfonyldithioformates (2) (R-1 = ArSO2, R 2 = ArS) readily add to anthracene and 9-methylanthracene (1) in a Diels-Alder fashion with formation of 9,10-dihydro-10,9-(epithiomethano)anthracenes (3) which in turn may suffer thermally induced elimination of arenesulfinic acid to yield the 9......-anthracenedithiocarboxylic esters (4). The reactions with the unsymmetrical diene 9-methylanthracene take place in a highly stereoselective fashion....

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

B3LYP/6-31G() calculations were performed to obtain all the transition states and products for the 128 distinct reaction channels of Diels-Alder reactions by taking all possible combinations from a series of dienes (1N-a, 1N-b, 2N, 1P-a, 1P-b, 2P, 1O, 1S) and dienophiles (NE, PE, OE, SE, AE, OHE, MeE, CNE).

Fe(II)/Fe(III)-Catalyzed Intramolecular Didehydro-Diels-Alder Reaction of Styrene-ynes.

Science.gov (United States)

Mun, Hyeon Jin; Seong, Eun Young; Ahn, Kwang-Hyun; Kang, Eun Joo

2018-02-02

The intramolecular didehydro-Diels-Alder reaction of styrene-ynes was catalyzed by Fe(II) and Fe(III) to produce various naphthalene derivatives under microwave heating conditions. Mechanistic calculations found that the Fe(II) catalyst activates the styrenyl diene in an inverse-electron-demand Diels-Alder reaction, and the consecutive dehydrogenation reaction can be promoted by either Fe(II)-catalyzed direct dehydrogenation or an Fe(III)-catalyzed rearomatization/dehydrogenation pathway.

Diels-Alder Reactions of 12-Hydroxy-9(10®20-5aH-abeo-abieta-1(10,8(9,12(13-triene-11,14-dione

Directory of Open Access Journals (Sweden)

Shougang Hu

2013-06-01

Full Text Available 12-Hydroxy-9(10®20-5aH-abeo-abieta-1(10,8(9,12(13-triene-11,14-dione (quinone 2 served as the dienophile in numerous intermolecular Diels-Alder reactions. These cycloadditions were conducted either thermally (including microwave heating or with Lewis acid activation. While most dienes reacted with quinone 2 in good chemical yield, others were incompatible under the experimental conditions used.

Physics-Based Modeling of Permeation: Simulation of Low-Volatility Agent Permeation and Aerosol Vapor Liquid Assessment Group Experiments

Science.gov (United States)

2015-06-01

methylphosphonothiolate (VX) through natural latex rubber and neoprene resulting from LVAP tests. 2. The permeation model is used to study the sensitivity of...Styrene–Butadiene– Rubber , Ethylene–Propylene–Diene Terpolymer, and Natural Rubber Versus Hydrocarbons (C8–C16). Macromolecules 1991, 24 (9), 2598–2605...22 14. Harogoppad, S.B.; Aminabhavi, T.M. Diffusion and Sorption of Organic Liquids through Polymer Membranes 2. Neoprene, SBR, EPDM, NBR , and

Synthesis of 2,5-Disubstituted Octahydroquinolin-4-ones via anIntramolecular Hetero Diels-Alder Reaction

Directory of Open Access Journals (Sweden)

J. Antonio Palenzuela

2007-02-01

Full Text Available A route for the preparation of 2,5-disubstituted octahydroquinolin-4-ones, synthetic precursors of the decahydroquinoline-type toxins, is presented. The key steps are an asymmetric epoxidation and an intramolecular hetero Diels-Alder reaction between an activated diene and an imine. The presence of an allylic stereogenic center induces some selectivity and thus only two cycloadducts are obtained in 70:30 ratio and good yield.

Thymoquinone, the Nigella sativa Bioactive Compound, Prevents Circulatory Oxidative Stress Caused by 1,2-Dimethylhydrazine in Erythrocyte during Colon Postinitiation Carcinogenesis

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Hanene Jrah Harzallah

2012-01-01

Rats exposed to DMH showed an increase of malondialdehyde and conjugated diene levels, and an augmentation of enzyme activities like catalase, glutathione peroxidase, and superoxide dismutase activities was also noted. The TQ pretreatment restored the parameters cited above to near-normal values. However, the posttreatment shows an activity similar as that presented by DMH. Therefore, our investigation revealed that TQ was a useful compound preventing DMH-induced erythrocyte damages.

Neuro chemical characteristic of structures of nociceptive system athyperthyroid function of the thyroid gland

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O. M. Demchenko

2015-06-01

Full Text Available The papercomprises the study of the conditionofpro-antioxidantprocesses in the formationso fnociceptivesystem (cerebral cortex, hippocampus, stem and thalamus in the presence of the experiment al induced hyperthyroidism. It was found that nociceptive irritation (laparotomy on the background of hyper thyroidism had not pronounced effect on the content of diene conjugates (DC and malondialdehyde. The level of enzymes of antioxidant system of superoxidedismutase (SOD and glutathioneperoxidase (GPO decreased.

Näitleja paradoks / Denis Diderot ; tõlkinud Mirjam Lepikult

Index Scriptorium Estoniae

Diderot, Denis

2006-01-01

Järg: nr. 12, lk. 2649-2684, sisaldab katkendit Moliere' i näidendist "Armutusk" (lk. 2654-2657) ; 2007, nr. 1, lk. 121-145. Orig.: Diderot, Denis. Paradoxe sur le comédien suivi de Lettres sur le théatre a Madame Riccoboni et a Mademoiselle Jodin. ⁹dition présentée, établie et annotée par Robert Abirached. Paris : Gallimard, 1994. [Esitrükk 1830

ONR Far East Scientific Information Bulletin

Science.gov (United States)

1990-09-01

Sendai tion of raw materials, homogeneous energy sources, gases that permeate the in October 1990. The Science andI Tech- shaping, sintering with control...or gain a larger sector of the aero- Claude Bathias space market. Both nations have excellent Department Materiaux Industriales directed research and...yielding The reactants may be gases , liquids, vinyl- and diene-based polymers are of grow- and solids, such as reactive fillers. While ing interest

Association hyperthyroïdie et cancers différenciés de la thyroïde ...

African Journals Online (AJOL)

Association hyperthyroïdie et cancers différenciés de la thyroïde. Nassim Essabah Haraj, Hayat Ahandar, Siham El Aziz, Asma Chadli. Abstract. La présence d'une hyperthyroïdie n'est plus une assurance contre la survenue d'un cancer thyroïdien. L'association des deux n'est pas rare. Il s'agit d'une étude rétrospective de ...

Case series

African Journals Online (AJOL)

abp

26 mai 2015 ... cervico-faciale de l'hôpital militaire Avicenne de Marrakech, sur une période de 8 ans, allant de janvier 2006 à décembre 2013.Les carcinomes thyroïdiens atteignent le sujet jeune avant l'âge de 50 ans, en particulier le sexe féminin. La tendance dans les pays en voie de développement, comme dans le ...

Measuring strategic control in implicit learning: how and why?

OpenAIRE

Norman, Elisabeth

2015-01-01

Several methods have been developed for measuring the extent to which implicitly learned knowledge can be applied in a strategic, flexible manner. Examples include generation exclusion tasks in Serial Reaction Time (SRT) learning (Goschke, 1998; Destrebecqz and Cleeremans, 2001) and 2-grammar classification tasks in Artificial Grammar Learning (AGL; Dienes et al., 1995; Norman et al., 2011). Strategic control has traditionally been used as a criterion for determining whether acquired knowledg...

The effects of multiply ionizing gamma irradiations on the xenobiotic metabolizing system in the liver of rats

International Nuclear Information System (INIS)

Zavodnik, L.B.; Buko, V.U.

2009-01-01

The aim of the work was the studying the effect of multiply low doses of gamma-irradiation in a total doze 1 and 2 Gy on processes lipid peroxidation and xenobiotics metabolizing in rat liver. It was shown the multiply irradiation causes the expressed activation of lipid peroxidation, by increase of TBARS level and dien conjugates. The system of microsomal oxidations was broken at the same time. (authors)

The Intramolecular Diels–Alder Reaction of Tryptamine-Derived Zincke Aldehydes Is a Stepwise Process

OpenAIRE

Pham, Hung V.; Martin, David B. C.; Vanderwal, Christopher D.; Houk, K. N.

2012-01-01

Computational studies show that the base-mediated intramolecular Diels–Alder of tryptamine-derived Zincke aldehydes, used as a key step in the synthesis of the Strychnos alkaloids norfluorocurarine and strychnine, proceeds via a stepwise pathway. The experimentally determined importance of a potassium counterion in the base is explained by its ability to preorganize the Zincke aldehyde diene in an s-cis conformation suitable to bicyclization. Computation also supports the thermodynamic import...

'n Evaluering van die 6M-Simulasie opleidingkursus vir oningewyde swart werkers

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R. van Niekerk

1984-11-01

'n Evaluering van die 6M-Simulasie Opleidingskursus word bespreek met verwysing na die bemeestering van kursusinhoud, die invloed van opleiding op werkprestasie en reaksie van kursusgangers. Resultate dui op 'n beduidende toename in kennis ongeag tussenkomende veranderlikes soos ouderdom, opvoedkundige kwalifikasies, jare diens, huistaal, geboorteplek en werkkategorie. 'n Positiewe reaksie op 34 vrae wat verband hou met die werksituasie, en op die kursusinhoud en opleidingstegnieke word ook gerapporteer.

Synthesis of nitrogen-containing dispiroheterocycles using nitrilimines (II

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Dalloul Hany M.

2010-01-01

Full Text Available A series of 1,2,4,9,10,12-hexaazadispiro[4.2.4.2]tetradeca-2,10-dienes (5a-j was synthesized by the reaction of 1,4-cyclohexanedione oxime 3 with appropriate nitrilimines 2. The microanalysis and spectral data of the synthesized compounds are in full agreement with their molecular structure. The microbial features of some of the synthesized compounds were studied by a known method.

Phytochemicals from Kaempferia angustifolia Rosc. and Their Cytotoxic and Antimicrobial Activities

Directory of Open Access Journals (Sweden)

Sook Wah Tang

2014-01-01

Full Text Available Phytochemical investigation on rhizomes of Kaempferia angustifolia has afforded a new abietene diterpene, kaempfolienol (1 along with crotepoxide (2, boesenboxide (3, 2′-hydroxy-4,4′,6′-trimethoxychalcone (4, zeylenol (5, 6-methylzeylenol (6, (24S-24-methyl-5α-lanosta-9(11, 25-dien-3β-ol (7, sucrose, β-sitosterol, and its glycoside (8. The structures of the compounds were elucidated on the basis of spectroscopic methods (IR, MS, and NMR. Isolation of 6-methylzeylenol (6, (24S-24-methyl-5α-lanosta-9(11, 25-dien-3β-ol (7, and β-sitosterol-3-O-β-D-glucopyranoside (8 from this plant species has never been reported previously. The spectroscopic data of (7 is firstly described in this paper. Cytotoxic screening indicated that most of the pure compounds tested showed significant activity with (4 showing the most potent activity against HL-60 (human promyelocytic leukemia and MCF-7 (human breast cancer cell lines. However, all extracts and most of the pure compounds tested were found to be inactive against HT-29 (human colon cancer and HeLa (human cervical cancer cell lines. Similarly, none of the extracts or compounds showed activity in the antimicrobial testing.

Isoxazolium N-ylides and 1-oxa-5-azahexa-1,3,5-trienes on the way from isoxazoles to 2H-1,3-oxazines

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Alexander F. Khlebnikov

2014-08-01

Full Text Available Theoretical and experimental studies of the reaction of isoxazoles with diazo compounds show that the formation of 2H-1,3-oxazines proceeds via the formation of (3Z-1-oxa-5-azahexa-1,3,5-trienes which undergo a 6π-cyclization. The stationary points corresponding to the probable reaction intermediates, isoxazolium N-ylides, were located by DFT calculations at the B3LYP/6-31G(d level only for derivatives without a substituent in position 3 of the isoxazole ring. These isoxazolium N-ylides are thermodynamically and kinetically very unstable. According to the calculations and experimental results 2H-1,3-oxazines are usually more thermodynamically stable than the corresponding open-chain isomers, (3Z-1-oxa-5-azahexa-1,3,5-trienes. The exception are oxaazahexatrienes derived from 5-alkoxyisoxazoles, which are thermodynamically more stable than the corresponding 2H-1,3-oxazines. Therefore, the reaction of diazo esters with 5-alkoxyisoxazoles is a good approach to 1,4-di(alkoxycarbonyl-2-azabuta-1,3-dienes. The reaction conditions for the preparation of aryl- and halogen-substituted 2H-1,3-oxazines and 1,4-di(alkoxycarbonyl-2-azabuta-1,3-dienes from isoxazoles were investigated.

Prognostic implications of ischemia modified albumin in known cases of86 elderly hypertensive South Asian aged 56-64 years - a hospital based study

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Arun Kumar

2014-02-01

Full Text Available Objective: To study associated ischemia modified albumin in hypertensive participants and to compare the results with normotensive healthy controls. Methods: A total of 86 hypertensive patients and 86 age-sex matched normotensive healthy volunteers were selected for this study. The study was conducted for a period of 3 years from September 2007 to August 2010. Biochemical parameters and other parameters such as smoking habits, systolic and diastolic blood pressure and family history were recorded. Lipid profile, ischemia modified albumin, malondialdehyde and conjugated diene were measured by standard methods and results were compared between patients and controls. Results: Total cholesterol, triglycerides, low density lipoprotein cholesterol were significantly higher (P<0.001 in hypertensive subjects when compared to normotensive control. Also, significant differences were seen in high density lipoprotein cholesterol levels between both groups (P<0.001 . The index of lipid per oxidation comprising both malondialdehyde and conjugated dienes were significantly higher in hypertensive compared to normotensive controls. Ischemia modified albumin levels were significantly increased among hypertensive compared to normotensive controls (P<0.001. Conclusions: Hypertensive patients have increased oxidative stress and are accompanied with rise in ischemia modified albumin. Ischemia modified albumin could be incorporated as a diagnostic test parameter in hypertensive to avoid the future acute coronary complications.

Transport of sterols to the plasma membrane of leek seedlings

International Nuclear Information System (INIS)

Moreau, P.; Hartmann, M.A.; Perret, A.M.; Sturbois-Balcerazak, B.; Cassagne, C.

1998-01-01

To investigate the intracellular transport of sterols in etiolated leek (Allium porrum L.) seedlings, in vivo pulse-chase experiments with [1-14C]acetate were performed. Then, endoplasmic reticulum-, Golgi-, and plasma membrane (PM)-enriched fractions were prepared and analyzed for the radioactivity incorporated into free sterols. In leek seedlings sterols are present as a mixture in which (24R)-24-ethylcholest-5-en-3beta-ol is by far the major compound (around 60%). The other sterols are represented by cholest-5-en-3beta-ol, 24-methyl-cholest-5-en-3beta-ol, (24S)-24-ethylcholesta-5,22E-dien-3beta-ol, and stigmasta-5,24(24(1))Z-dien-3Beta-ol. These compounds are shown to reside mainly in the PM. Our results clearly indicate that free sterols are actively transported from the endoplasmic reticulum to the PM during the first 60 min of chase, with kinetics very similar to that of phosphatidylserine. Such a transport was found to be decreased at low temperature (12 degrees C) and following treatment with monensin and brefeldin A. These data are consistent with a membrane-mediated process for the intracellular transport of sterols to the PM, which likely involves the Golgi apparatus

Sterol patterns of cultured zooxanthellae isolated from marine invertebrates: Synthesis of gorgosterol and 23-desmethylgorgosterol by aposymbiotic algae.

Science.gov (United States)

Withers, N W; Kokke, W C; Fenical, W; Djerassi, C

1982-06-01

QUANTITATIVE STEROL COMPOSITIONS OF CULTURED ZOOXANTHELLAE ISOLATED FROM VARIOUS PACIFIC AND ATLANTIC INVERTEBRATE HOSTS: Zoanthus sociatus (a zoanthid), Oculina diffusa (a scleractian coral), Tridacna gigas (a giant clam), Melibe pilosa (a nudibranch), and Aiptasia pulchella (a sea anemone) are reported. The results clearly demonstrate large differences in sterol patterns of zooxanthellae and that there is no obvious relationship between the taxonomic affiliation of the host and the sterol pattern of its isolated symbiont. The sterols of the zooxanthellae of O. diffusa (Cnidaria) and T. gigas (Mollusca) are qualitatively equivalent. Based on the structures of the two major free sterols synthesized by each alga, the zooxanthellae from different hosts were separated into three distinct groups. It was also found that an aposymbiotic alga can synthesize the unique marine sterols gorgosterol and 23-desmethylgorgosterol. Most of the sterols were identified by using mass spectroscopy and 360-MHz proton magnetic resonance. Spectroscopic data are reported for four novel sterols-(23,24R)-dimethyl-5alpha-cholest-(22E)-en-3beta-o l, 23-methyl-5alpha-cholest-22E-en-3beta-ol, cholesta-5,14-dien-3beta-ol, and 4alpha-methyl-5alpha-cholesta-8(14)-24-dien-3beta-ol.

Saponins from the traditional medicinal plant Momordica charantia stimulate insulin secretion in vitro

Science.gov (United States)

Keller, Amy C.; Ma, Jun; Kavalier, Adam; He, Kan; Brillantes, Anne-Marie B.; Kennelly, Edward J.

2012-01-01

The antidiabetic activity of Momordica charantia (L.), Cucurbitaceae, a widely-used treatment for diabetes in a number of traditional medicine systems, was investigated in vitro. Antidiabetic activity has been reported for certain saponins isolated from M. charantia. In this study insulin secretion was measured in MIN6 β-cells incubated with an ethanol extract, saponin-rich fraction, and five purified saponins and cucurbitane triterpenoids from M. charantia, 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al (1), momordicine I (2), momordicine II (3), 3-hydroxycucurbita-5,24-dien-19-al-7,23-di-O-β-glucopyranoside (4), and kuguaglycoside G (5). Treatments were compared to incubation with high glucose (27 mM) and the insulin secretagogue, glipizide (50 μM). At 125 μg/ml, an LC-ToF-MS characterized saponin-rich fraction stimulated insulin secretion significantly more than the DMSO vehicle, p=0.02. At concentrations 10 and 25 μg/ml, compounds 3 and 5 also significantly stimulated insulin secretion as compared to the vehicle, p≤0.007, and p= 0.002, respectively. This is the first report of a saponin-rich fraction, and isolated compounds from M. charantia, stimulating insulin secretion in an in vitro, static incubation assay. PMID:22133295

Effect of gamma irradiation on some minor classes of chicken lipids

International Nuclear Information System (INIS)

Rady, A.H.; Schwartz, D.P.

1991-01-01

Chicken skin and subcutaneous fat from 12 fresh chickens were ground frozen and samples then irradiated in air and vacuum at 2-5 degree C using Cs 137 . Doses of 0,1,3,6 and 10 kGy were used at a dose rate of 100 Gy/min. Extracted lipid was analyzed for individual un esterified fatty acids (UFA), total carotenoids and chlosta-3,5-dien-7-one was determined in the unsaponifiable matter (USM). Results of the study indicated that all individual USF increased markedly at 1 kGy, decreased somewhat at 3 kGy and then increased gradually or leveled off. Total carotenoids in air packed samples decreased sharply at 1 kGy then decreased gradually with higher doses. In vacuum packed samples, only a slight decrease in total carotenoids occurred at 1 kGy followed by a sharp decrease at 3 kGy and then a more gradual decrease paralleling the air packed decrease. Cholesta-3,5-dien-7-one compound was identified in minute amount(10 lipid) in USM of non-irradiated samples, while it showed a dramatic gradual increase in both media with increasing irradiation dose and reached 420-458 μg/g lipid in USM of samples irradiated at 10 kGy

Les dysthyroïdies chez l'hémodialysé chronique | Zbiti | Pan African ...

African Journals Online (AJOL)

Introduction: Les dysthyroïdies chez l'hémodialysé chronique sont représentées par une hypothyroïdie: dite le syndrome de basse T3, actuellement nommée "le syndrome de la maladie euthyroïdienne". L'objectif de notre travail est de déterminer le profil thyroïdien de nos HDC afin de préciser la prévalence des différents ...

Pregnane glycosides from Sansevieria trifasciata.

Science.gov (United States)

Mimaki, Y; Inoue, T; Kuroda, M; Sashida, Y

1997-01-01

Phytochemical analysis of the whole plant of Sansevieria trifasciata, one of the most common Agavaceae plants, has resulted in the isolation of four new pregnane glycosides. Their structures have been determined by spectroscopic analysis and acid- and alkaline-catalysed hydrolysis to be 1 beta,3 beta-dihydroxypregna-5,16-dien-20-one glycosides. This is believed to be the first report of the isolation of the pregnane glycosides from a plant of the family Agavaceae.

Novel quinazoline ring synthesis by cycloaddition of N-arylketenimines with N,N-disubstituted cyanamides.

Science.gov (United States)

Shimizu, Masao; Oishi, Akihiro; Taguchi, Yoichi; Gama, Yasuo; Shibuya, Isao

2002-03-01

The reaction of N-aryl-substituted ketenimines with N,N-disubstituted cyanamides or (MeS)2C=N-CN under high pressure afforded 4-(N,N-disubstituted amino) or 4-(MeS)2C=N-substituted quinazoline derivatives, respectively. These products were formed by [4+2] cycloaddition between the aza-diene moieties of the N-arylsubstituted ketenimines and cyano groups. A 4-(unsubstituted amino)quinazoline derivative was synthesized by hydrolysis of the latter product.

Civil-Military Relations in the French Fourth Republic during the First Indochina War

Science.gov (United States)

2015-05-21

occupation from 1941 to 1945. His life was marked by tragedy as his father and wife, both ardent Communists, died in French prisons in Indochina...the latter half of 1949, the Soviets detonated their first atomic weapon and Mao Zedong’s Communist forces triumphed in the Chinese Civil War, leading...Gaulle’s Greatest General. Havertown, PA: Casemate Publishers, 2011. Morgan, Ted. Valley of Death: The Tragedy at Dien Bien Phu that Led America into

The Brown Water Navy in the Mekong Delta: COIN in the Littorals and Inland Waters

Science.gov (United States)

2008-01-01

frrmly under the control of the communist insurgency known as the Viet Cong (VC). The absence of major cities and physical infrastructure south of...control the physical environment, win popular support, ~\\l) address needs of the people, and legitimacy of the local government.3 In South Vietnam...the region. The Genesis of the Viet COllg Subsequent to the French defeat at Dien Bien Phu, the Geneva Accords divided Vietnam into the Democratic

Measurement and Ranking of Permeation Specimen Thickness Profiles: High-Density Polyethylene Swatches

Science.gov (United States)

2016-05-01

SP-034; U.S. Army Chemical Research, Development and Engineering Center: Aberdeen Proving Ground, MD, 1992; UNCLASSIFIED Report. 5. McHugh , V.M...Seitzinger, A.T.; Shuely, W.J.; McHugh , V.M. Compatibility Study of Butyl Rubber and Ethylene-Propylene-Diene Rubber with the Components of U.S. Army...Research, Development and Engineering Center: Aberdeen Proving Ground, MD, 1990; UNCLASSIFIED Report. 41 18. McHugh , V. M.; Shuely, W. J.; Brletich

1-Cyclohexyl-6,7-dimethoxy-1,4-dihydronaphthalene

Directory of Open Access Journals (Sweden)

Shao-Yuan Chen

2014-06-01

Full Text Available The title compound, C18H24O2, was isolated from the leaves extract of Ficus carica L. The cyclohexane ring displays a chair conformation whereas the cyclohexa-1,4-diene ring adopts a flattened boat conformation with methyl C atoms at the prow and stern. In the crystal, molecules are linked by weak C—H...O hydrogen bonds into supramolecular chains propagated along the b-axis direction.

Exploring endoperoxides as a new entry for the synthesis of branched azasugars

DEFF Research Database (Denmark)

Domeyer, Svenja; Bjerregaard, Mark; Johansson, Henrik

2017-01-01

A new class of nitrogen-containing endoperoxides were synthesised by a photochemical [4 + 2]-cycloaddition between a diene and singlet oxygen. The endoperoxides were dihydroxylated and protected to provide a series of endoperoxide building blocks for organic synthesis, with potential use as precu...... as precursors for the synthesis of branched azasugars. Preliminary exploration of the chemistry of these building blocks provided access to a variety of derivatives including tetrahydrofurans, epoxides and protected amino-tetraols....

Highly enantio- and diastereoselective allylic alkylation of Morita-Baylis-Hillman carbonates with allyl ketones

KAUST Repository

Tong, Guanghu

2013-05-17

The asymmetric allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates with allyl ketones has been developed. The α-regioselective alkylation adducts, containing a hexa-1,5-diene framework with important synthetic value, were achieved in up to 83% yield, >99% ee, and 50:1 dr by using a commercially available Cinchona alkaloid as the catalyst. From the allylic alkylation adduct, a cyclohexene bearing two adjacent chiral centers was readily prepared. © 2013 American Chemical Society.

Determination of the Mechanical Properties of Rubber by FT-NIR

OpenAIRE

Pornprasit, Rattapol; Pornprasit, Philaiwan; Boonma, Pruet; Natwichai, Juggapong

2016-01-01

Mechanical tests, for example, tensile and hardness tests, are usually used to evaluate the properties of rubber materials. In this work, mechanical properties of selected rubber materials, that is, natural rubber (NR), styrene butadiene rubber (SBR), nitrile butadiene rubber (NBR), and ethylene propylene diene monomer (EPDM), were evaluated using a near infrared (NIR) spectroscopy technique. Here, NR/NBR and NR/EPDM blends were first prepared. All of the samples were then scanned using a FT-...

The DISAM Journal of International Security Assistance Management. Volume 30, Number 1, March 2008

Science.gov (United States)

2008-03-01

annexation of a little patch of ground called Sudetenland? Or a French defeat at a place called Dien Bien Phu? Or the return of an obscure cleric to...chats on personal, non-work related subjects – including politics and religion. Family (children), sports, travel, and cuisine are safe...lieu of 2 standard forms can be approved on a case-by- forms or translated versions (Spanish, case basis. The request and forms French , etc.) need

Three new drimane sesquiterpenoids from cultures of the fungus Penicillium sp.

Science.gov (United States)

Ding, Jian-Hai; Ding, Zhang-Gui; Chunyu, Wei-Xun; Zhao, Jiang-Yuan; Wang, Hai-Bin; Liu, Shi-Wei; Wang, Fei

2017-08-01

Three new drimane sesquiterpenoids, 12-hydroxyalbrassitriol (1), drim-8(12)-en-6β,7α, 9α,11-tetraol (2), and drim-68(12)-dien-9α,11-diol (3), along with one known analog albrassitriol (4), were isolated from cultures of the tin mine tailings-associated fungus Penicillium sp. The new structures were determined on the basis of extensive spectroscopic analyses. All compounds were tested for their cytotoxicities against five human cancer cell lines.

Highly enantio- and diastereoselective allylic alkylation of Morita-Baylis-Hillman carbonates with allyl ketones

KAUST Repository

Tong, Guanghu; Zhu, Bo; Lee, Richmond; Yang, Wenguo; Tan, Davin; Yang, Caiyun; Han, Zhiqiang; Yan, Lin; Huang, Kuo-Wei; Jiang, Zhiyong

2013-01-01

The asymmetric allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates with allyl ketones has been developed. The α-regioselective alkylation adducts, containing a hexa-1,5-diene framework with important synthetic value, were achieved in up to 83% yield, >99% ee, and 50:1 dr by using a commercially available Cinchona alkaloid as the catalyst. From the allylic alkylation adduct, a cyclohexene bearing two adjacent chiral centers was readily prepared. © 2013 American Chemical Society.

Mariann Lewinsky (Hg.): Cento Anni Fa. Attrici Comiche E Suffragette 1910–1914/Comic Actresses And Suffragettes 1910–1914. Bologna: Edizioni Cinemateca di Bologna 2010.

OpenAIRE

Sarah Dellmann

2011-01-01

Diese DVD stellt 19 kurze Komödien aus den Jahren 1910 bis 1914 zusammen. Das noch junge Genre der Komödie, so die Kuratorin Mariann Lewinsky, war innerhalb der Filmproduktion das entscheidende Terrain der Auseinandersetzungen um Geschlechterrollen. In den Filmen werden Komikerinnen gezeigt, die mit traditionellen Geschlechterrollen brechen und den Handlungsraum von Frauen erweitern. Ein Kapitel ist den Suffragetten gewidmet, hier findet sich auch dokumentarisches Filmmaterial der Zeit. Im be...

Silymarin and vitamin E reduce amiodarone-induced lysosomal phospholipidosis in rats

International Nuclear Information System (INIS)

Agoston, Marta; Oersi, Ferenc; Feher, Erzsebet; Hagymasi, Krisztina; Orosz, Zsuzsa; Blazovics, Anna; Feher, Janos; Vereckei, Andras

2003-01-01

Several antioxidants have been shown to reduce lysosomal phospholipidosis, which is a potential mechanism of amiodarone toxicity, and prevent amiodarone toxicity by antioxidant and/or non-antioxidant mechanisms. The aim of this study was to test whether the co-administration of two structurally different antioxidants vitamin E and silymarin with amiodarone can reduce amiodarone-induced lysosomal phospholipidosis, and if yes, by reducing the tissue concentration of amiodarone and desethylamiodarone or by their antioxidant action. To this end, male Fischer 344 rats were treated by gavage once a day for 3 weeks and randomly assigned to the following four experimental groups: 1, control; 2, amiodarone (150 mg/(kg per day)); 3, amiodarone (150 mg/(kg per day)) plus vitamin E (100 mg/(kg per day)); 4, amiodarone (150 mg/(kg per day)) plus silymarin (60 mg/(kg per day)) treated groups. Total plasma phospholipid (PL), liver-conjugated diene, thiobarbituric acid reactive substances (TBARSs), amiodarone and desethylamiodarone concentrations were determined and the extent of lysosomal phospholipidosis in the liver was estimated by a semi-quantitative electron microscopic method. Amiodarone treatment increased significantly the liver-conjugated diene (P<0.001), TBARS (P=0.012), plasma total PL (P<0.001) concentrations compared with control. Antioxidants combined with amiodarone significantly decreased the liver-conjugated diene (P<0.001 for both), TBARS (P=0.016 for vitamin E, P=0.053 borderline for silymarin) and plasma total PL (P=0.058 borderline for vitamin E, P<0.01 for silymarin) concentrations compared with amiodarone treatment alone. Silymarin significantly (P=0.021) reduced liver amiodarone, but only tended to decrease desethylamiodarone concentration; however, vitamin E failed to do so. Amiodarone treatment increased lysosomal phospholipidosis (P<0.001) estimated by semi-quantitative electron microscopic method and both antioxidants combined with amiodarone reduced

SYNTHESIS OF STYRENE-BUTADIENE STATISTIC COPOLYMERS CONTAINING MAGNESIUM INITIATOR

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A. V. Firsova

2015-01-01

Full Text Available The article discusses the use of organomagnesium initiators in the synthesis of styrene-butadiene random copolymer (SBR obtained solution polymerization and their influence on the properties of rubber. Selected organic magnesium dialkyl initiator is combined with a modifier, which is a mixed alkoxide of an alkali and alkaline earth metals, which allows to control the micr ostructure of the diene polymer and its molecular weight characteristics. Alcohol derivatives selected high-boiling alcohols tetra (hydroxypropyl ethylenediamine (lapromol 294 and tetrahydrofurfuryl alcohol (TGFS. Selection of high-boiling alcohols due to the fact that the destruction of alkoxide with aqueous polymer degassing they do not fall into the return solvent and almost fall into the exact water. The metal components of alkoxides are lithium, sodium, potassium, magnesium and calcium. The resulting solutions are stable when stored modifier t hroughout the year even at -40 °C. The scheme of obtaining the new catalyst systems based organomagnesium and alcoxide of alkali and alkaline earth metals, which yields as functionalized SBR with a statistical and a distribution block of butadiene and styrene was developed. The process of copolymerization with styrene to butadiene organomagnesium initiators as using an organolithium compound (n-butyllithium was carried out, and without it. Found that the addition of n-butyllithium in the reaction mixture leads to a sharp increase in the rate of reaction. The results of studies of the effect of composition of the initiator system on the structure of diene polymers. It was revealed that a mixed initiator system affords a high conversion of monomers (to 90 % in 1 hour 1,2-polybutadiene content increased to 60 %. The process of polymerization of only a mixture of organomagnesium initiators and alcoxide of alkali and alkaline earth metals are not actively proceeds, conversion of the monomers reaches to 90 % in 4 hours, the microstructure

Protection capacity against low-density lipoprotein oxidation and antioxidant potential of some organic and non-organic wines.

Science.gov (United States)

Kalkan Yildirim, Hatice; Delen Akçay, Yasemin; Güvenç, Ulgar; Yildirim Sözmen, Eser

2004-08-01

Current research suggests that phenolics from wine may play a positive role against oxidation of low-density lipoprotein (LDL), which is a key step in the development of atherosclerosis. Considering the effects of different wine-making techniques on phenols and the wine consumption preference influencing the benefical effects of the product, organically and non-organically produced wines were obtained from the grapes of Vitis vinifera origin var: Carignan, Cabernet Sauvignon, Merlot, Grenache, Columbard and Semillon. Levels of total phenols [mg/l gallic acid equivalents (GAE)], antioxidant activity (%) and inhibition of LDL oxidation [%, inhibition of diene and malondialdehyde (MDA) formation] were determined. Some phenolic acids (gallic acid, p-hydroxybenzoic acid, syringic acid, 2,3-dihydroxybenzoic acid, ferulic acid, p-coumaric acid and vanillic acid) were quantified by high-performance liquid chromatography equipped with an electrochemical detection carried at +0.65 V (versus Ag/AgCl, 0.5 microA full scale). The highest concentrations of gallic, syringic and ferulic acids were found in organic Cabernet Sauvignon; 2,3-dihydroxybenzoic acid in organic Carignan and p-coumaric and vanillic acids in non-organic Merlot wine. High levels of antioxidant activity (AOA), inhibition of LDL oxidation and total phenol levels were found in non-organic Merlot (101.950% AOA; 88.570% LDL-diene; 41.000% LDL-MDA; 4700.000 mg/l GAE total phenol) and non-organic Cabernet Sauvignon (92.420% AOA; 91.430% LDL-diene; 67.000% LDL-MDA; 3500.000 mg/l GAE total phenol) grape varieties. Concentrations of some individual phenolic constituents (ferulic, p-coumaric, vanillic) are correlated with high antioxidant activity and inhibition of LDL oxidation. The best r value for all examined characteristics was determined for gallic acid, followed by 2,3-dihydroxybenzoic, syringic, ferulic and p-coumaric acids. Negative correlation of vanillic with MDA and p-hydroxybenzoic acid with LDL were

Effect of electron beam irradiation on the properties of crosslinked rubbers

Science.gov (United States)

Banik, Indranil; Bhowmick, Anil K.

2000-05-01

Influence of electron beam (EB) irradiation on the mechanical and dynamic mechanical properties of crosslinked fluorocarbon (FKM) rubber, natural rubber (NR), ethylene propylene diene monomer (EPDM) rubber and nitrile rubber (NBR) has been investigated. The modulus, gel fraction, glass transition temperature ( Tg) and storage modulus increased, while the elongation at the break and the loss tangent (tan δ) Tg decreased. FKM and NBR vulcanizates have been shown to have EB radiation resistance up to 1500 kGy.

Case report

African Journals Online (AJOL)

abp

5 juin 2017 ... carcinome parathyroïdien après chirurgie. Dans une étude récente, les auteurs ont recommandé une radiothérapie postopératoire de. 40-50 Gy chez les patients à haut risque de récidive locale [16]. L'efficacité de la chimiothérapie dans le cancer de la parathyroïde n'a pas été démontrée dans la littérature ...

metastase de la voûte crânienne revelant un carcinome differencie ...

African Journals Online (AJOL)

Mots clés: métastase, voûte crânienne, cancer de la thyroïde. Thyroid carcinoma ... Les métastases à distance des cancers différenciés thyroï- diens (CDT) sont rares et surviennent chez 10 à 15 % des patients (3). Leurs localisations préférentielles sont le pou- ... péricarde, la plèvre, les surrénales, la peau, les reins, l'hy-.

Polyketones as alternating copolymers of carbon monoxide

International Nuclear Information System (INIS)

Belov, Gennady P; Novikova, Elena V

2004-01-01

Characteristic features of the catalytic synthesis of alternating copolymers of carbon monoxide with various olefins, dienes, styrene and its derivatives are considered. The diversity of catalyst systems used for the copolymerisation of carbon monoxide is demonstrated and their influence on the structure and the molecular mass of the resulting copolymers is analysed. The data on the structure and physicochemical and mechanical properties of this new generation of functional copolymers are generalised and described systematically for the first time.

Synthesis of Hydroxynaphtharines; Sintesis de naftazarinas hidroxiladas

Energy Technology Data Exchange (ETDEWEB)

Farina, F.; Fernandez, E.; Gimeno, V.; Valderrama, J.A. [Instituto de Quimica Organica General, CSIC, Madrid (Spain)

1995-12-01

A variety of naththazarines type 4 and 8 were prepared through Diels-Alder reactions of substituted 1,4-benzoquinones with 1,3-dienes. Thiele-Winter reaction of 5 afforded 6 which by chromic oxidation yielded naththazarines 7 and/or naphthoquinones 9. Hydroxynaphthazarines of type 8 were synthesized from 5 through 2,3-epoxides of the type 14. The structural study of the products, by H-NMR, showed the typical tautomerism of the naphthazarine system. 23 refs.

Military Review, January 1992. Volume 72, Number 1

Science.gov (United States)

1992-01-01

tinuing theme for Vietcong propagandists who COMBAT CUISINE The cooks of the French Expeditionary Corps bottles, along with ammunition and medical sup...Vuono’s goal for the 1990s: an French Brigade in Stuttgart, Germany, offers a Army that is deployable, lethal, agile and versa- suitable model of such an...author offers several valid insights into the faulty planning and execution of the French stand at Dien Bien Phu in 1954 in Indochina, T 2400 ON 7 MAY

An ylide transformation of rhodium(I) carbene: enantioselective three-component reaction through trapping of rhodium(I)-associated ammonium ylides by β-nitroacrylates.

Science.gov (United States)

Ma, Xiaochu; Jiang, Jun; Lv, Siying; Yao, Wenfeng; Yang, Yang; Liu, Shunying; Xia, Fei; Hu, Wenhao

2014-11-24

The chiral Rh(I)-diene-catalyzed asymmetric three-component reaction of aryldiazoacetates, aromatic amines, and β-nitroacrylates was achieved to obtain γ-nitro-α-amino-succinates in good yields and with high diastereo- and enantioselectivity. This reaction is proposed to proceed through the enantioselective trapping of Rh(I)-associated ammonium ylides by nitroacrylates. This new transformation represents the first example of Rh(I)-carbene-induced ylide transformation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Response of a lichen and two epiphytic vascular species as indicators of air pollution

Energy Technology Data Exchange (ETDEWEB)

Coria, G.; Gonzalez, C.M.; Gudino, G.L.; Wannaz, E.D. [Univ. Nacional de Cordoba, Cordoba (Argentina). Facultad de Ciencias Exactas, Fisicas y Naturales; Carreras, H.A.; Pignata, M.L. [Univ. Nacional de Cordoba, Cordoba (Argentina). Facultad de Ciencias Exactas, Fisicas y Naturales]|[Instituto Multidisciplinario de Biologia Vegetal (IMBIV-UNC), Cordoba (Argentina)

2002-07-01

Plant material from Ramalina celastri (Spreng.) Krog and Swinsc., Tillandsia capillaris Ruiz and Pav. f. capillaris and Tillandsia tricholepis Baker were transplanted to eleven monitoring sites, categorized as urban, farming and farming/cattle-raising. The concentrations of pigments, hydroperoxy conjugated dienes, malondialdehyde and sulfur were determined. Chlorophyll b / chlorophyll a, phaeophytin a / chlorophyll a ratios were also calculated, and a Pollution Index (PI) and a Foliar Damage Index (FDI) were calculated from some physiological parameters. (orig.)

Preparation and isolation of isobenzofuran

Directory of Open Access Journals (Sweden)

Morten K. Peters

2017-12-01

Full Text Available The synthesis, isolation and characterization of isobenzofuran are described in this publication. Isobenzofuran is of general interest in synthetic and physical organic chemistry because it is one of the most reactive dienes known. A number of synthetic pathways have been published which all suffer from disadvantages such as low yields and difficult purification. We present a synthetic pathway to prepare isobenzofuran in laboratory scale with high yields, from affordable, commercially available starting materials.

Synthesis of Substituted α-Trifluoromethyl Piperidinic Derivatives

Directory of Open Access Journals (Sweden)

Sarah Rioton

2017-03-01

Full Text Available A comprehensive survey of pathways leading to the generation of α-trifluoromethyl monocyclic piperidinic derivatives is provided (65 references. These compounds have been synthesized either from 6-membered rings e.g., pipecolic acid or lactam derivatives by introduction a trifluoromethyl group, from pyridine or pyridinone derivatives by reduction, and from 5-membered rings e.g., prolinol derivatives by ring expansion, from linear amines by cyclization or from dienes/dienophiles by [4 + 2]-cycloaddition.

Major International R and D Ranges and Test Facilities. Summary of Capabilities

Science.gov (United States)

1990-01-01

Fabrications De Telecommunications (SEFT) 51 Centre D’Etudes De Gramat (CEG) 53 Direction Des Constructions Navales (DCN) 56 Centre D’Essais Et D’Evaluations...MAS (DAT)ICAEPE (DIEN) * MA (OCA*) 0 GRAMAT CEO (DRET) CAZAUX CEB (DCA&) BISCARROSSEO CELDEN TUOSE ITE AABE E(DAT)CA TARES CAP (DA) ATS (DAT) CEAT (DC...at Arcucil, Cazaux. and Gramat . The five Hydrodynamic Testing centers are: Le Centre D’Analyse de Defense (CAD) at (CMCM) at Arcueil. Conducts

Magnetic field effect on indole exciplexes: an anomalous dielectric dependence

International Nuclear Information System (INIS)

Sengupta, Tamal; Basu, Samita

2004-01-01

Individual exciplex formation between various aromatic hydrocarbons, anthracene, pyrene, all-s-trans-1,4-diphenylbuta-1,3-diene and a heteroaromatic amine, 1,2-dimethylindole, was investigated by steady-state fluorescence and magnetic field effect (MFE). A comparative study was carried out with two other exciplex systems 9-cyanophenanthrene-1,2-dimethylindole and 9-cyanophenanthrene-N-methylindole. The extent of charge transfer and dielectric dependence of MFE reveals the potential role of specific interactions related to exciplex geometry

Rapid Access to Ortho-Alkylated Vinylarenes from Aromatic Acids by Dearomatization and Tandem Decarboxylative C-H Olefination/Rearomatization.

Science.gov (United States)

Tsai, Hung-Chang; Huang, Yen-Hsiang; Chou, Chih-Ming

2018-03-02

A two-step straightforward method for the preparation of ortho-alkylated vinylarenes from readily available benzoic acids is described. The synthetic route involves the dearomatization of benzoic acids by Birch reduction providing alkylated cyclohexa-2,5-dienyl-1-carboxylic acids. The diene subsequently undergoes a decarboxylative C-H olefination followed by rearomatization to deliver ortho-alkylated vinylarene. Mechanistic studies suggest that a Pd/Ag bimetallic catalytic system is important in the tandem decarboxylative C-H olefination/rearomatization step.

Mass-fragmentographic determination of 25-hydroxy-vitamin D3 using deuterium labeled internal standard

International Nuclear Information System (INIS)

Bjorkhem, I.; Holmberg, I.

1975-01-01

25-[26- 2 H 3 ] Hydroxy-vitamin D 3 has been synthesized according to the following route: 3β-acetoxy-27-nor-cholest-5-en-25-one → 3β-acetoxy-27-nor-cholesta-5,7-dien-25-one → [26- 2 H 3 ] cholesta-5,7-diene-3β,25-diol → 25-[26- 2 H 3 ] hydroxy-vitamin D 3 . A fixed amount of 25-[26- 2 H 3 ] hydroxy-vitamin D 3 , usually 250 ng, is added to a fixed amount of serum, usually 2.5 ml, and the mixture is extracted with a chloroform-methanol mixture. The extract is chromatographed on a Sephadex LH-20 column together with a trace amount of 25-[26- 3 H] hydroxy-vitamin D 3 . The chromatographic fraction corresponding to 25-hydroxy-vitamin D 3 is collected and the amount of unlabeled 25-hydroxy-vitamin D 3 is determined from the ratio between the mass fragmentographic recording of m/e 131 (base peak of unlabeled 25-hydroxy-vitamin D 3 ) and m/e 134 (base peak of 25-[26- 2 H 3 ] hydroxy-vitamin D 3 ). The relative standard deviation of the method was about 5%. The mean value for 25-hydroxy-vitamin D 3 obtained from 23 different serum samples from healthy Swedish men and women was 27 ng/ml with a standard deviation of 10 ng/ml

Insect molting hormone and sterol biosynthesis in spinach

International Nuclear Information System (INIS)

Grebenok, R.J.; Adler, J.H.

1990-01-01

Insect molting hormones, which are produced by plants and are effective molecules in the control of insect crop pests, are biosynthesized in developing spinach leaves (Spinacia oleracea L.). The major sterols biosynthesized by spinach are avenasterol (24α-ethyl-5α-cholesta-7,24(28)-dien-3β-ol), spinasterol (24α-ethyl-5α-cholesta-7,22-dien-3β-ol), and 22-dihydrospinasterol (24α-ethyl-5α-cholest-7-en-3β-ol). The major ecdysteroids biosynthesized are ecdysterone (2β,3β,14α,20R,22R,25-hexahydroxy-5β-cholest-7-en-6-one) and polypodine B (2β,3β,5β,14α,20R,22R,25-heptahycroxycholest-7-en-6-one) and polypodine B (2β,3β,5β,14α,20R,22R,25-heptahydroxycholest-7-en-6-one). When labeled 2- 14 C-mevalonic acid was incorporated into young leaves isolated squalene, sterols and ecdysteroids contained the label. During a short (16 h) incorporation period in intact young leaves of 100 day old plants, the avenasterol has the highest specific activity in counts per minute per μg of sterol followed by 22-dihydrospinasterol which is more highly labeled than spinasterol. The ecdysteroids synthesized, on an entire plant basis, account for 20% of the total steroid (sterol and ecdysteroid) isolated from the plant

Photoaffinity labeling of the oxysterol binding protein

International Nuclear Information System (INIS)

Taylor, F.R.; Kandutsch, A.A.; Anzalone, L.; Spencer, T.A.

1986-01-01

A cytosolic receptor protein for oxygenated sterols, that is thought to be involved in the regulation of HMG-CoA reductase and cholesterol biosynthesis, can be labeled covalently by the photoactivated affinity compound [5,6- 3 H]-7,7'-azocholestane-3β,25-diol (I). Several other compounds were tested including 25-hydroxycholesta-4,6-dien-3-one, 25-azido-27-norcholest-5-en-3β-ol,3β,25-dihydroxycholest-5-en-7-one and 3β-hydroxycholesta-8(14),9(11)-dien-15-one. However, these sterols either did not bind to the receptor with adequate affinity or did not react covalently with the receptor during photolysis. Compound I binds to the receptor with very high affinity (K/sub d/ = 30 nM). After activation with long wavelength UV, two tritium labeled proteins, M/sub r/ approximately 95K and 65K daltons, are found upon SDS gel electrophoresis. No labeling occurs when the binding reaction is carried out in the presence of a large excess of 25-hydroxycholesterol. It is possible that the smaller polypeptide is a degradation product. Under the reaction conditions investigated so far labeling is relatively inefficient (< 1% of bound sterol). These results are generally consistent with previous information suggesting that the M/sub r/ of the receptor subunit is 97,000. Covalent labeling of the receptor should greatly facilitate its further purification and characterization

Cholinesterase inhibitory activity and structure elucidation of a new phytol derivative and a new cinnamic acid ester from Pycnanthus angolensis

Directory of Open Access Journals (Sweden)

Taiwo O. Elufioye

Full Text Available ABSTRACT The leaves of Pycnanthus angolensis (Welw. Warb., Myristicaceae, are used as memory enhancer and anti-ageing in Nigerian ethnomedicine. This study aimed at evaluating the cholinesterase inhibitory property as well as isolates the bioactive compounds from the plant. The acetylcholinesterase and butyrylcholinesterase inhibitory potentials of extracts, fractions, and isolated compounds were evaluated by colorimetric and TLC bioautographic assay techniques. The extract inhibited both enzymes with activity increasing with purification, ethyl acetate fraction being most active fraction at 65.66 ± 1.06% and 49.38 ± 1.66% against acetylcholinesterase and butyrylcholinesterase, respectively while the supernatant had 77.44 ± 1.18 inhibition against acetylcholinesterase. Two new bioactive compounds, (2E, 18E-3,7,11,15,18-pentamethylhenicosa-2,18-dien-1-ol (named eluptol and [12-(4-hydroxy-3-methyl-oxo-cyclopenta-1,3-dien-1yl-11-methyl-dodecyl](E-3-(3,4-dimethylphenylprop-2-enoate (named omifoate A were isolated from the plant with IC50 of 22.26 µg/ml (AChE, 34.61 µg/ml (BuChE and 6.51 µg/ml (AChE, 9.07 µg/ml (BuChE respectively. The results showed that the plant has cholinesterase inhibitory activity which might be responsible for its memory enhancing action, thus justifying its inclusion in traditional memory enhancing preparations

Curcumin prevents the oxidation and lipid modification of LDL and its inhibition of prostacyclin generation by endothelial cells in culture.

Science.gov (United States)

Mahfouz, Mohamedain M; Zhou, Sherry Q; Kummerow, Fred A

2009-11-01

Low-density lipoprotein (LDL) was isolated from human plasma and oxidized by 5microM copper sulfate for 4h at 37 degrees C in the absence and presence of 1, 3, 5, 10, or 20microM of curcumin. LDL oxidized in the absence of curcumin (oxLDL) showed an increased levels of conjugated dienes, lipid peroxides (TBARS) and lysolecithin (lysoPC) and a significant loss of polyunsaturated fatty acids (PUFA). LDL oxidized with 5microM copper sulfate in the presence of curcumin caused a significant decrease of conjugated diene, lipid peroxides, lysoPC and significant increase of PUFA compared to oxLDL. These changes were dose dependent and reached a maximum at 5microM curcumin. Incubation of human endothelial cells (EC) with 200microg protein/ml of oxLDL caused a significant decrease of prostacyclin (PGI(2)) generation. LDL oxidized in presence of 5microM curcumin did not show any inhibition of PGI(2) generation compared to the control cells. These results indicate that curcumin is an effective chain-breaking antioxidant which prevents oxidation and lipid modification of LDL. The inhibition of oxLDL on PGI(2) is considered a contributing factor in the pathogenesis of thrombosis and atherosclerosis. Curcumin supplementation could be an effective strategy in preventing LDL oxidation and its impact on atherosclerosis and lesion formation.

ENDURANCE TRAINING AND GLUTATHIONE-DEPENDENT ANTIOXIDANT DEFENSE MECHANISM IN HEART OF THE DIABETIC RATS

Directory of Open Access Journals (Sweden)

Mustafa Atalay

2003-06-01

Full Text Available Regular physical exercise beneficially influences cardiac antioxidant defenses in normal rats. The aim of this study was to test whether endurance training can strengthen glutathione-dependent antioxidant defense mechanism and decrease lipid peroxidation in heart of the streptozotocin-induced diabetic rats. Redox status of glutathione in blood of diabetic rats in response to training and acute exercise was also examined. Eight weeks of treadmill training increased the endurance in streptozotocin-induced diabetic rats. It did not affect glutathione level in heart tissue at rest and also after exercise. On the other hand, endurance training decreased glutathione peroxidase activity in heart, while glutathione reductase and glutathione S-transferase activities were not affected either by acute exhaustive exercise or endurance training. Reduced and oxidized glutathione levels in blood were not affected by either training or acute exercise. Conjugated dienes levels in heart tissue were increased by acute exhaustive exercise and also 8 weeks treadmill training. Longer duration of exhaustion in trained group may have contributed to the increased conjugated dienes levels in heart after acute exercise. Our results suggest that endurance type exercise may make heart more susceptible to oxidative stress. Therefore it may be wise to combine aerobic exercise with insulin treatment to prevent its adverse effects on antioxidant defense in heart in patients with diabetes mellitus

Chemical Composition of Essential Oils of Xanthium spinosum L., an Invasive Species of Corsica.

Science.gov (United States)

Andreani, Stéphane; Paolini, Julien; Costa, Jean; Muselli, Alain

2017-01-01

Xanthium spinosum L. is a highly invasive plant originated from South America throughout the world as well as in Corsica Island. The chemical composition of X. spinosum essential oils from 25 Corsican locations was investigated using GC-FID and GC/MS. Seventy-four components, which accounted for 96.2% of the total amount, were reported for the first time in the essential oil from aerial parts. The main compounds were eudesma-4(14),7-dien-1β-ol (61; 21.3%), germacrene D (36; 8.8%) and cadalene (60; 8.7%). Comparison with the literature highlighted the originality of the Corsican essential oil and eudesma-4(14),7-dien-1β-ol could be used as taxonomical marker to the systematics of the Xanthium genus. The essential oils obtained from separate organs and during the plant vegetative cycle were also studied to gain more knowledge about the correlations between the volatile production and the phenological states of this weed. The production of oxygenated sesquiterpenes was predominant during the plant-flowering process. The study focuses on direct correlation between the chemical composition of individual 25 oil samples and the morphological differences of the plant. Our results have gained more knowledge about the secondary metabolite production that occurs during the plant life, they could be interesting in order to manage the dispersal of X. spinosum. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

DIELS-ALDER REACTIONS IN AQUEOUS-SOLUTIONS - ENFORCED HYDROPHOBIC INTERACTIONS BETWEEN DIENE AND DIENOPHILE

NARCIS (Netherlands)

BLOKZIJL, W; BLANDAMER, MJ; ENGBERTS, JBFN

1991-01-01

Second-order rate constants and isobaric activation parameters for the intermolecular Diels-Alder reactions of cyclopentadiene with alkyl vinyl ketones (2a,b) and 5-substituted-1,4-naphthoquinones (3a-c) as well as for the intramolecular Diels-Alder reaction of N-furfuryl-N-methylmaleamic acid (4)

Palladium Hydride Promoted Stereoselective Isomerization of Unactivated Di(exo)methylenes to Endocyclic Dienes

OpenAIRE

Jung, Michael E.; Lee, Gloria S.; Pham, Hung V.; Houk, K. N.

2014-01-01

The exomethylenes of 2,6-disubstituted bicyclo[3.3.1]nonan-9-ones 2 are readily isomerized over a palladium catalyst under an atmosphere of hydrogen to predominantly form the isomer 3 with C 2 symmetry with very little formation of the analogous product with C s symmetry. A hydrogen source is essential to effect the rearrangement.

les facteurs prédictifs de malignité des nodules thyroïdiens

African Journals Online (AJOL)

19 déc. 2007 ... Le but de notre travail est de rassembler les critères épi- démiologiques, cliniques et paracliniques ..... L'aspect visible des nodules à l'inspection. Nodules malins Nodules bénins. %. Nbre. % .... Schlumberger M, De Vathaire F. Iode 131 : utilisation médicale. Effets can- cérigènes et génétiques. Annales ...

Thermosetting materials from the radiation-modified polymer compositions, 2. Development of adhesion-active and thermostable thermosetting materials

International Nuclear Information System (INIS)

Kalkis, V.; Maksimovs, R.D.; Zicans, J.; Bocoka, T.; Revjakins, O.

1999-01-01

Methods that improve the adhesion and thermal stability of the thermosetting materials are considered. Experimental studies of the blends composed of polyethylene, ethylene-propylene-diene copolymer (with characteristic specific for rubbers) and mesomorphic copolyesters, using rheological, spectrometric, and thermomechanical methods, have shown that radiation modification improves the adhesion and deformation properties as well as thermal stability of these blends. Therefore, materials of such system can be successfully used, e.g., as elastic and adhesion-active thermosetting materials at temperature above 473 K. (author)

Stigmastadiene and specific extitntion (270 nm) to evaluate the presence of refined oils in virgin olive oil commercialized in Brazil

OpenAIRE

Aued-Pimentel,Sabria; Silva,Simone Alves Da; Takemoto,Emy; Cano,Cristiane Bonaldi

2013-01-01

The increased marketing of olive oil in Brazil has intensified legal requirements to ensure regulation of this product. The measurement of the specific extinction at 270 nm (E 270) and content of stigmastadiene can be used to assess the presence of refined oils in virgin olive oil. During the vegetable oil refining process, compounds with conjugated double bonds are generated from unsaturated fatty acids that absorb at 270 nm and sterols, such as stigmasta-3,5-diene. To compare these paramete...

Effect of electron beam irradiation on the properties of crosslinked rubbers

Energy Technology Data Exchange (ETDEWEB)

Banik, Indranil; Bhowmick, Anil K. E-mail: anilkb@rtc.iitkgp.ernet.in

2000-05-01

Influence of electron beam (EB) irradiation on the mechanical and dynamic mechanical properties of crosslinked fluorocarbon (FKM) rubber, natural rubber (NR), ethylene propylene diene monomer (EPDM) rubber and nitrile rubber (NBR) has been investigated. The modulus, gel fraction, glass transition temperature (T{sub g}) and storage modulus increased, while the elongation at the break and the loss tangent (tan {delta}){sub T{sub g}} decreased. FKM and NBR vulcanizates have been shown to have EB radiation resistance up to 1500 kGy. (author)

Effect of electron beam irradiation on the properties of crosslinked rubbers

International Nuclear Information System (INIS)

Banik, Indranil; Bhowmick, Anil K.

2000-01-01

Influence of electron beam (EB) irradiation on the mechanical and dynamic mechanical properties of crosslinked fluorocarbon (FKM) rubber, natural rubber (NR), ethylene propylene diene monomer (EPDM) rubber and nitrile rubber (NBR) has been investigated. The modulus, gel fraction, glass transition temperature (T g ) and storage modulus increased, while the elongation at the break and the loss tangent (tan δ) T g decreased. FKM and NBR vulcanizates have been shown to have EB radiation resistance up to 1500 kGy. (author)

Hydrogen transfer reduction of polyketones catalyzed by iridium complexes: a novel route towards more biocompatible materials.

Science.gov (United States)

Milani, Barbara; Crottib, Corrado; Farnetti, Erica

2008-09-14

Transfer hydrogenation from 2-propanol to CO/4-methylstyrene and CO/styrene polyketones was catalyzed by [Ir(diene)(N-N)X] (N-N = nitrogen chelating ligand; X = halogen) in the presence of a basic cocatalyst. The reactions were performed using dioxane as cosolvent, in order to overcome problems due to low polyketone solubility. The polyalcohols were obtained in yields up to 95%, the conversions being markedly dependent on the nature of the ligands coordinated to iridium as well as on the experimental conditions.

Corncobs as a Potential Source of Functional Chemicals

Directory of Open Access Journals (Sweden)

Amani Marzouk

2013-11-01

Full Text Available Phytochemical examination of corncob extracts led to the isolation of a new lignan identified as 7,7'-dihydroxy-3'-O-demethyl-4-methoxymatairesinol, together with seven known compounds, identified as β-sitosterol, β-sitosteryl-β-D-glucoside, 6β-hydroxy-campest-4-en-3-one, 5α,8α-epidioxyergosta-6,22-dien-3β-ol, tricin, kaempferol and p-coumaric acid. The isolated compounds were identified by one and two-dimensional NMR spectroscopies and mass spectrometry.

Purification and properties of a 3 alpha-hydroxysteroid dehydrogenase of rat liver cytosol and its inhibition by anti-inflammatory drugs.

OpenAIRE

Penning, T M; Mukharji, I; Barrows, S; Talalay, P

1984-01-01

An NAD(P)-dependent 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) was purified to homogeneity from rat liver cytosol, where it is responsible for most if not all of the capacity for the oxidation of androsterone, 1-acenaphthenol and benzenedihydrodiol (trans-1,2-dihydroxycyclohexa-3,5-diene). The dehydrogenase has many properties (substrate specificity, pI, Mr, amino acid composition) in common with the dihydrodiol dehydrogenase (EC 1.3.1.20) purified from the same source [Vogel, Bentley...

Molybdenum(5) template action in acetone with ethylenediamine condensation reaction

International Nuclear Information System (INIS)

Ashurova, N.Kh.; Yakubov, K.G.; Tsivadze, A.Yu.; AN SSSR, Moscow

1994-01-01

Ability of molybdenum(5) oxopentahalides [MoOX 5 ] 2- (X = Cl - , Br - ) to show their template action in acetone with ethylenediamine condensation reaction is identified. Macrocyclic metallic complexes [MoO(Td)X]X 2 , where Td is 5,7,7,12,14,14 hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11 dien, are separated and identified. Perchlorate salt of Td·2HClO 4 macrocycle is obtained through action of concentrated perchloric acid on synthesized complexes. 13 refs.; 3 figs

New Stethoscope With Extensible Diaphragm.

Science.gov (United States)

Takashina, Tsunekazu; Shimizu, Masashi; Muratake, Torakazu; Mayuzumi, Syuichi

2016-08-25

This study compared the diagnostic efficacy of the common suspended diaphragm stethoscope (SDS) with a new extensible diaphragm stethoscope (EDS) for low-frequency heart sounds. The EDS was developed by using an ethylene propylene diene monomer diaphragm. The results showed that the EDS enhanced both the volume and quality of low-frequency heart sounds, and improved the ability of examiners to auscultate such heart sounds. Based on the results of the sound analysis, the EDS is more efficient than the SDS. (Circ J 2016; 80: 2047-2049).

Chiral Pyridinium Phosphoramide as a Dual Brønsted Acid Catalyst for Enantioselective Diels-Alder Reaction.

Science.gov (United States)

Nishikawa, Yasuhiro; Nakano, Saki; Tahira, Yuu; Terazawa, Kanako; Yamazaki, Ken; Kitamura, Chitoshi; Hara, Osamu

2016-05-06

Chiral pyridinium phosphoramide 1·HX was designed to be a new class of chiral Brønsted acid catalyst in which both the pyridinium proton and the adjacent imide-like proton activated by the electron-withdrawing pyridinium moiety could work cooperatively as strong dual proton donors. The potential of 1·HX was shown in the enantioselective Diels-Alder reactions of 1-amino dienes with various dienophiles including N-unsubstituted maleimide, which has yet to be successfully used in an asymmetric Diels-Alder reaction.

Physical chemistry research for engineering and applied sciences, v.2 polymeric materials and processing

CERN Document Server

Pearce, Eli M; Pethrick, Richard A

2015-01-01

PrefaceInvestigation on the Influence of a Strong Electric Field on the Electrical, Transport and Diffusion Properties of Carbon Nanostructures; S. A. Sudorgin and N. G. LebedevA Study Thermal Stability of Polyurethane Elastomers; I. A. Novakov, M. A. Vaniev, D. V. Medvedev, N. V. Sidorenko, G. V. Medvedev, and D. O. GusevTrends in Aromatic Polyesters; Z. S. Khasbulatova and G. E. ZaikovMicroheterogeneous Titanium Ziegler-Natta Catalysts: 1,3-Diene Polymerization Under Ultrasound Irradiations; V. P. Zakharov, V. Z. Mingaleev, I. D. Zakirov

Synthesis of Dihydrobenzofurans via Palladium-Catalyzed Heteroannulations

Energy Technology Data Exchange (ETDEWEB)

Rozhkov, Roman Vladimirovich [Iowa State Univ., Ames, IA (United States)

2004-01-01

Palladium-catalyzed heteroannulation of 1,3-dienes with 3-iodo-2-alkenols, and 2-iodo-2-alkenols, as well as their amino analogs, affords the corresponding cyclic ethers and amines respectively. The presence of a β-hydrogen in the vinylic halide results in β-hydride elimination giving the corresponding alkyne. The presence of a bulky group in the α-position of the vinylic halide results in failure or reduced amounts of annulation products. A chloride source, pyridine base and electron-rich phosphine are essential for this reaction.

Easy Impossibility Proofs for Distributed Concensus Problems.

Science.gov (United States)

1985-07-01

device F such that in any system t which u rums F, dhe behavor of each outedge (4.9) b Er In this case, we write FA(E.Ed for F. This axiom expmees a pom...node ad edO bebaiorn SylLSimilarly. Iflbasysm dien A is dwsystcmobtained byscwafteswaydock In 1y h. Intuitively, a scled dock or behavor is in the...Agency Branch Office, Pasadena ATTN: Program MonagemeIIIIIIntIMIS 1030 gast Green Street 1400 Wilson Boulevard Pasadena, CA 91106 Arlington, VA 22209 (1

Stable 7,14-disubstituted-5,12-dithiapentacenes with quinoidal conjugation

KAUST Repository

Ye, Qun

2014-08-01

Two 7,14-disubstituted-5,12-dithiapentacenes (1 and 2) with quinoidal conjugation were synthesized. Their ground-state quinoidal structures were proven by X-ray crystallographic analysis. They showed very different electronic and optical properties from those of the corresponding pentacene derivatives with diene conjugation, and their stability was significantly improved. Organic field effect transistors based on solution processed thin films of 1 and 2 exhibited a hole mobility of up to 0.032 cm-2 V-1 s -1. © 2014 American Chemical Society.

Three New Lanostanoids from the Mushroom Ganoderma tropicum

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Shuang-Shuang Zhang

2015-02-01

Full Text Available Three new lanostanoid triterpenes—ganotropic acid (1, 3β,7β,15α,24-tetra- hydroxy-11,23-dioxo-lanost-8-en-26-oic acid (2 and 3β,7β,15α,28-tetrahydroxy-11,23- dioxo-lanost-8,16-dien-26-oic acid (3—were isolated from the n-BuOH extract of the fruiting bodies of the mushroom Ganoderma tropicum. Their structures were elucidated by 1D and 2D NMR spectroscopy, as well as HR-EI-MS data.

Transformations of the radical cations of 1,3-dienes, 1,4-dienes, and cyclopentene as studied by ESR technique in irradiated frozen freon matrices and by spin trapping technique in liquid phase

International Nuclear Information System (INIS)

Shchapin, I.Yu.; Belevskij, V.N.

1996-01-01

Transformations of cation-radicals of 1,3- and 1,4-pentadienes, 2,3-dimethylbutadienes and cyclopentene, formed by X-ray irradiation at 77 K, are studied in the freon-11 and 113 matrices. It is shown that cation-radicals of 1,3-pentadienes in the CFCl 3 matrix at 77 K are regrouped in cyclopentene cation-radicals. There is no such a regrouping in the freon-113 matrix. The 1,4-pentadiene radicals have plane structure in the CFCl 3 matrix and are transformed into pentadienyl radicals in the freon-113 matrix. The cation radicals of dimethylbutadiene in the freon-113 matrix are transformed into end allyl radicals. The cation-radicals of cyclopentene in the freon-113 matrix are transformed at 110 K in cyclic allyl radicals. The radicals formation mechanism is in good agreement with the data, obtained during studies on liquid hydrocarbons, X-irradiated at 293 K in the presence of spin trap of 2.4.6-tri-tert-butylnitrosobenzene

Identification and Functional Characterization of Sesquiterpene Synthases from Xanthium strumarium.

Science.gov (United States)

Li, Yuanjun; Chen, Fangfang; Li, Zhenqiu; Li, Changfu; Zhang, Yansheng

2016-03-01

Xanthium strumarium synthesizes various pharmacologically active sesquiterpenes. The molecular characterization of sesquiterpene biosynthesis in X. strumarium has not been reported so far. In this study, the cDNAs coding for three sesquiterpene synthases (designated as XsTPS1, XsTPS2 and XsTPS3) were isolated using the X. strumarium transcriptome that we recently constructed. XsTPS1, XsTPS2 and XsTPS3 were revealed to have primary activities forming germacrene D, guaia-4,6-diene and germacrene A, respectively, by either ectopic expression in yeast cells or purified recombinant protein-based in vitro assays. Quantitative real-time PCRs and metabolite analysis for the different plant parts showed that the transcript abundance of XsTPS1-XsTPS3 is consistent with the accumulation pattern of their enzymatic products, supporting their biochemical functions in vivo. In particular, we discovered that none of the XsTPS2 product, guaia-4,6-diene, can be detected in one of the X. strumarium cultivars used in this study (it was named the Hubei-cultivar), in which a natural deletion of two A bases in the XsTPS2 cDNA disrupts its activity, which further confirmed the proposed biochemical role of XsTPS2 in X. strumarium in vivo. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Development of Colletotrichum gloeosporioides Restriction Enzyme-Mediated Integration Mutants as Biocontrol Agents Against Anthracnose Disease in Avocado Fruits.

Science.gov (United States)

Yakoby, N; Zhou, R; Kobiler, I; Dinoor, A; Prusky, D

2001-02-01

ABSTRACT Reduced-pathogenicity mutants of the avocado fruit pathogen Colletotrichum gloeosporioides isolate Cg-14 (teleomorph: Glomerella cingulata) were generated by insertional mutagenesis by restriction enzyme-mediated integration (REMI) transformation. Following seven transformations, 3,500 hygromycin-resistant isolates were subjected to a virulence assay by inoculation on mesocarp and pericarp of cv. Fuerte avocado fruits. Fourteen isolates showed a reduced degree of virulence relative compared with wild-type Cg-14. Two isolates, Cg-M-142 and Cg-M-1150, were further characterized. Cg-M-142 produced appressoria on avocado pericarp similar to Cg-14, but caused reduced symptom development on the fruit's pericarp and mesocarp. Isolate Cg-M-1150 did not produce appressoria; it caused much reduced maceration on the mesocarp and no symptoms on the pericarp. Southern blot analysis of Cg-M-142 and Cg-M-1150 showed REMI at different XbaI sites of the fungal genome. Pre-inoculation of avocado fruit with Cg-M-142 delayed symptom development by the wild-type isolate. Induced resistance was accompanied by an increase in the levels of preformed antifungal diene, from 760 to 1,200 mug/g fresh weight 9 days after inoculation, whereas pre-inoculation with Cg-M-1150 did not affect the level of antifungal diene, nor did it delay the appearance of decay symptoms. The results presented here show that reduced-pathogenicity isolates can be used for the biological control of anthracnose caused by C. gloeosporioides attack.

Molecular Docking Studies of Marine Diterpenes as Inhibitors of Wild-Type and Mutants HIV-1 Reverse Transcriptase

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Alessandra M. T. de Souza

2013-10-01

Full Text Available AIDS is a pandemic responsible for more than 35 million deaths. The emergence of resistant mutations due to drug use is the biggest cause of treatment failure. Marine organisms are sources of different molecules, some of which offer promising HIV-1 reverse transcriptase (RT inhibitory activity, such as the diterpenes dolabelladienotriol (THD, IC50 = 16.5 µM, (6R-6-hydroxydichotoma-3,14-diene-1,17-dial (HDD, IC50 = 10 µM and (6R-6-acetoxydichotoma-3,14-diene-1,17-dial (ADD, IC50 = 35 µM, isolated from a brown algae of the genus Dictyota, showing low toxicity. In this work, we evaluated the structure-activity relationship (SAR of THD, HDD and ADD as anti HIV-1 RT, using a molecular modeling approach. The analyses of stereoelectronic parameters revealed a direct relationship between activity and HOMO (Highest Occupied Molecular Orbital-LUMO (Lowest Unoccupied Molecular Orbital gap (ELUMO–EHOMO, where antiviral profile increases with larger HOMO-LUMO gap values. We also performed molecular docking studies of THD into HIV-1 RT wild-type and 12 different mutants, which showed a seahorse conformation, hydrophobic interactions and hydrogen bonds with important residues of the binding pocket. Based on in vitro experiments and docking studies, we demonstrated that mutations have little influence in positioning and interactions of THD. Following a rational drug design, we suggest a modification of THD to improve its biological activity.

Alterations of markers of oxidative stress caused by environmental factors and their dynamics under impact of native biomodulators

International Nuclear Information System (INIS)

Stasytyte-Buneviciene, D.; Juozulynas, A.; Bunevicius, J.

2004-01-01

Intensified formation of free radicals is one of the most important harmful factors of ionizing radiation acting upon human organism. Under physiological conditions, anti oxidative system preserves from harmful influence of free radicals. To avoid a disturbing influence of oxidative stress upon the processes of human homeostasis, additional quantities of antioxidants are indispensable. Among native biomodulators, pollen are well known for their anti oxidative, antitoxic and radioprotective properties. Dynamics of alterations of markers of oxidative stress as well as possibilities of restitution of their qualitative and quantitative indices were studied using native pollen. Correction programme was performed on 50 persons, 9 males and 41 female, residing and working under impact of harmful factors of oxidative stress, who used pollen 10 g per day during a period of 30 days. Control group consisted of 57 persons, 10 males and 47 females living and working under the same conditions. Blood tests (diene conjugates, malonic dialdehyde and katalase) using standard spectrophotometric methodic were studied before and after the course of treatment. After the treatment, contents of metabolites of lipid peroxidation, diene conjugates and malonic dialdehyde in blood serum essentially reduced. Activity of catalase decreased significantly in blood serum of the males and regularly smoking females. In conclusion, data presented demonstrate anti oxidative efficiency of native pollen and suggest more often it's applying in cases with alterated processes of homeostasis under impact of harmful factors of oxidative stress including influence of ionizing radiation. (author)

Drastic nickel ion removal from aqueous solution by curcumin-capped Ag nanoparticles

Science.gov (United States)

Bettini, S.; Pagano, R.; Valli, L.; Giancane, G.

2014-08-01

A completely green synthesis protocol has been adopted to obtain silver nanoaggregates capped by the natural compound (1E, 6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-diene), also known as curcumin. The synthesis has been monitored by infrared, Raman, visible and fluorescence spectroscopies. Characterization confirms that curcumin reduces and caps the nanoparticles, and such a procedure allows its solubility in water and drastically increases curcumin stability. Silver nanoparticles (AgNPs)/curcumin complex has been dispersed in a water solution containing a known nickel ion concentration. After three days, a grey precipitate is observed and nickel concentration in the solution is reduced by about 70%.A completely green synthesis protocol has been adopted to obtain silver nanoaggregates capped by the natural compound (1E, 6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-diene), also known as curcumin. The synthesis has been monitored by infrared, Raman, visible and fluorescence spectroscopies. Characterization confirms that curcumin reduces and caps the nanoparticles, and such a procedure allows its solubility in water and drastically increases curcumin stability. Silver nanoparticles (AgNPs)/curcumin complex has been dispersed in a water solution containing a known nickel ion concentration. After three days, a grey precipitate is observed and nickel concentration in the solution is reduced by about 70%. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr02583k

α-Linalool - a marker compound of forged/synthetic sweet basil (Ocimum basilicum L.) essential oils.

Science.gov (United States)

Radulović, Niko S; Blagojević, Polina D; Miltojević, Ana B

2013-10-01

Ocimum basilicum L. (sweet basil) is known to occur as several chemotypes or cultivars that differ in their essential oil composition. The surprising discovery of 3,7-dimethylocta-1,7-dien-3-ol, the rare α isomer of the well-known monoterpene alcohol β-linalool (3,7-dimethylocta-1,6-dien-3-ol), in samples of Serbian basil oil provoked an investigation of the origin of α-linalool in these samples. Three scenarios were considered, namely (a) the existence of a new natural chemotype, (b) an artefactual formation during the isolation procedure and (c) the case of a synthetic/forged oil. Noteworthy amounts (15.1-16.9%) of pure α-linalool were isolated from a commercial sample of basil oil, and detailed spectral analyses (MS, IR, (1) H and (13) C NMR) unequivocally confirmed its identity. The analysis by GC and GC/MS of an additional 20 samples of different O. basilicum oils commercially available on the Serbian market or isolated from plant material cultivated in Serbia resulted in the identification of 149 compounds. The obtained compositional data were compared using multivariate statistical analysis to reveal the possible existence of a new basil chemotype. The results of the chemical and statistical analyses give more pro arguments for the synthetic/forged oil hypothesis and suggest that α-linalool could be used as a marker compound of such O. basilicum oils. © 2013 Society of Chemical Industry.

Monoclonal antibodies to DNA modified with cis- or trans-diamminedichloroplatinum(II)

International Nuclear Information System (INIS)

Sundquist, W.I.; Lippard, S.J.; Stollar, B.D.

1987-01-01

Murine monoclonal antibodies that bind selectively to adducts formed on DNA by the antitumor drug cis-diamminedichloroplatinum(II), cis-DDP, or to the chemothrapeutically inactive trans isomer trans-DDP were elicited by immunization with calf thymus DNA modified with either cis- or trans-DDP at ratios of bound platinum per nucleotide, (D/N)/sub b/, of 0.06-0.08. The binding of two monoclonal antibodies to cis-DDP-modified DNA was competitively inhibited in an enzyme-linked immunosorbent assay (ELISA) by 4-6 nM concentrations of cis-DDP bound to DNA. Adducts formed by cis-DDP on other synthetic DNA polymers did not inhibit antibody binding to cis-DDP-DNA. The biologically active compounds [Pt(en)Cl 2 ], [Pt(dach)Cl 2 ], and [Pt(NH 3 ) 2 (cbdca)] (carboplatin) all formed antibody-detectable adducts on DNA, whereas the inactive platinum complexes trans-DDP and [Pt(dien)Cl]Cl (dien, diethylenetriamine) did not. The monoclonal antibodies therefore recognize a bifunctional Pt-DNA adduct with cis stereochemistry in which platinum is coordinated by two adjacent guanines or, to a lesser degree, by adjacent adenine and guanine. A monoclonal antibody raised against trans-DDP-DNA was competitively inhibited in an ELISA by 40 nM trans-DDP bound to DNA. This antibody crossreacted with unmodified, denatured DNA. The recognition of cis- or trans-DDP-modified DNAs by monoclonal antibodies thus parallels the known modes of DNA binding of these compounds and may correlate with their biological activities

Bioactive 30-Noroleanane Triterpenes from the Pericarps of Akebia trifoliata

Directory of Open Access Journals (Sweden)

Jing Wang

2014-04-01

Full Text Available Two new 30-noroleanane triterpenes, 2α,3β,20α-trihydroxy-30-norolean-12-en-28-oic acid (1, 2α,3β-dihydroxy-23-oxo-30-norolean-12,20(29-dien-28-oic acid (2, were isolated from the pericarps of Akebia trifoliata, together with four known ones, 3β-akebonoic acid (3, 2α,3β-dihydroxy-30-noroleana-12,20(29-dien-28-oic acid (4, 3α-akebonoic acid (5 and quinatic acid (6. Their structures were established on the basis of detailed spectroscopic analysis, and they were all isolated from the pericarps of A. trifoliata for the first time. Compounds 3−6 showed in vitro bacteriostatic activity against four assayed Gram-positive bacterial strains. In particular 3 showed antibacterial activity toward MRSA with a MIC value 25 μg/mL, which was more potent than kanamycin (MIC 125 μg/mL. No compounds showed antibacterial activity toward the three Gram-negative bacteria tested. Compounds 4 and 5 showed interesting in vitro growth inhibitory activity against human tumor A549 and HeLa cell lines, with IC50 values ranging from 8.8 and 5.6 μM, respectively. Compounds 1, 2, 5 and 6 were further revealed to show significant in vitro α-glucosidase inhibitory activity with IC50 values from 0.035 to 0.367 mM, which were more potent than the reference compound acarbose (IC50 0.409 mM.

A New Dihydrochromone Dimer and Other Secondary Metabolites from Cultures of the Marine Sponge-Associated Fungi Neosartorya fennelliae KUFA 0811 and Neosartorya tsunodae KUFC 9213

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Decha Kumla

2017-12-01

Full Text Available A previously unreported dihydrochromone dimer, paecilin E (1, was isolated, together with eleven known compounds: β-sitostenone, ergosta-4,6,8 (14, 22-tetraen-3-one, cyathisterone, byssochlamic acid, dehydromevalonic acid lactone, chevalone B, aszonalenin, dankasterone A (2, helvolic acid, secalonic acid A and fellutanine A, from the culture filtrate extract of the marine sponge-associated fungus Neosartorya fennelliae KUFA 0811. Nine previously reported metabolites, including a chromanol derivative (3, (3β, 5α, 22E, 3,5-dihydroxyergosta-7,22-dien-6-one (4, byssochlamic acid, hopan-3β,22-diol, chevalone C, sartorypyrone B, helvolic acid, lumichrome and the alkaloid harmane were isolated from the culture of the marine-sponge associated fungus Neosartorya tsunodae KUFC 9213. Paecilin E (1, dankasterone A (2, a chromanol derivative (3, (3β, 5α, 22E-3,5-dihydroxyergosta-7,22-dien-6-one (4, hopan-3β,22-diol (5, lumichrome (6, and harmane (7 were tested for their antibacterial activity against Gram-positive and Gram-negative reference and multidrug-resistant strains isolated from the environment. While paecilin E (1 was active against S. aureus ATCC 29213 and E. faecalis ATCC 29212, dankastetrone A (2 was only effective against E. faecalis ATCC 29212 and the multidrug-resistant VRE E. faecalis A5/102. Both compounds neither inhibit biofilm mass production in any of the strains at the concentrations tested nor exhibit synergistic association with antibiotics.

Intralipid minimizes hepatocytes injury after anoxia-reoxygenation in an ex vivo rat liver model.

Science.gov (United States)

Stadler, Michaela; Nuyens, Vincent; Boogaerts, Jean G

2007-01-01

Ischemia-reperfusion injury is a determinant in liver injury occurring during surgical procedures, ischemic states, and multiple organ failure. The pre-existing nutritional status of the liver, i.e., fasting, might contribute to the extent of tissue injury. This study investigated whether Intralipid, a solution containing soybean oil, egg phospholipids, and glycerol, could protect ex vivo perfused livers of fasting rats from anoxia-reoxygenation injury. The portal vein was cannulated, and the liver was removed and perfused in a closed ex vivo system. Isolated livers were perfused with glucose 5.5 and 15 mM, and two different concentrations of Intralipid, i.e., 0.5:100 and 1:100 (v/v) Intralipid 10%:medium (n = 5 in each group). The experiment consisted of perfusion for 15 min, warm anoxia for 60 min, and reoxygenation during 60 min. Hepatic enzymes, potassium, glucose, lactate, bilirubin, dienes, trienes, and cytochrome-c were analyzed in perfusate samples. The proportion of glycogen in hepatocytes was determined in biopsies. Intralipid attenuated transaminases, lactate dehydrogenase, potassium, diene, and triene release in the perfusate (dose-dependant) during the reoxygenation phase when compared with glucose-treated groups. The concentration of cytochrome-c in the medium was the highest in the 5.5-mM glucose group. The glycogen content was low in all livers at the start of the experiment. Intralipid presents, under the present experimental conditions, a better protective effect than glucose in anoxia-reoxygenation injury of the rat liver.

Depression of membrane-bound Na+-K+-ATPase activity induced by free radicals and by ischemia of kidney

International Nuclear Information System (INIS)

Kako, K.; Kato, M.; Matsuoka, T.; Mustapha, A.

1988-01-01

A partially purified, membrane-bound Na + -K + -ATPase fraction, prepared from the outer medulla of porcine kidney, was incubated in the presence of 0.1-100 mM H 2 O 2 for either 15 or 30 min at 37 degree C. The activity of ouabain-sensitive Na + -K + -ATPase was reduced proportionally to the concentration of H 2 O 2 and the duration of incubation. There were decreases in SH contents and turnover rates of the Na + -K + -ATPase preparation, while malondialdehyde (MDA) and conjugated dienes were generated from the membrane lipids in the course of the incubation. The concentrations of ethanolamine (E) plasmalogen and of arachidonic acid in the E glycerophospholipid molecules were reduced by the free radical reaction. Similarly, a reduction in Na + K + -ATPase activity and the formation of MDA and conjugated dienes, together with a decrease in E glycerophospholipids, were observed when the membrane fraction was exposed to ultraviolet irradiation (254 nm) for 30 min at 4 degree C. Microsomal fractions, prepared from the outer medulla of canine kidney after 1 h of unilateral ischemia and 1 h of reperfusion, showed a decreased Na + -K + -ATPase activity, a reduced amount of SH groups, and an increased MDA. These changes were normalized by the infusion of N-mercaptopropionylglycine. These results support the view (1) that free radical generation affects the enzyme protein as well as membrane lipids, and (2) that free radicals may be formed in the ischemic reperfused kidney

Correlation of serum paraoxonase activities in known cases of 130 elderly hypertensive South Asian aged 56-64 years - a hospital based study

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Arun Kumar

2014-02-01

Full Text Available Objective: To evaluate paraoxonase activity, antioxidant status and lipid peroxidation in hypertensive participants and to address the hypothesis that oxidative modifications of lipids due to hypertension can cause changes in serum paraoxonase activities. Methods: The serum paraoxonase activities, antioxidants and lipid peroxidation were determined in 130 hypertensive participants and 130 age-sexes matched normotensive healthy volunteers served as control. Serum paraoxonase activities were measured by enzymatic kit. The glutathione peroxidase, superoxide dismutase and catalase activity were determined by standard methods. Malondialdehyde was measured by thiobarbituric acid reaction. Conjugated diene level was measured by Recknagel and Glende method. Serum uric acid, total bilirubin, serum albumin, serum ascorbic acid and lipid profile were analyzed by standard methods. Results: Total cholesterol, triglycerides, low-density lipoprotein cholesterol were significantly higher and high-density lipoprotein cholesterol were significantly lower in hypertensive patients when compared to normotensive healthy controls. The superoxide dismutase, glutathione peroxidase and catalase were significantly lower in hypertensive when compared with normotensive. Similar findings were observed in the levels of albumin, uric acid, bilirubin and ascorbic acid when hypertensives were compared with normotensive. The oxidative stress indicators namely malondialdehyde and conjugated diene were significantly higher and paraoxonase activity were significantly lower in hypertensive. Conclusions: Our study concludes that paraoxonase activities are bound to alter in hypertension which is caused due to interplay of several confounding factors namely oxidative stress, increased oxidized low-density lipoprotein and depletion of antioxidants.

Obelų fotosintetinės sistemos reakcija į ozono sukeltą stresą

OpenAIRE

Sakalauskaitė, Jurga; Brazaitytė, Aušra; Samuolienė, Giedrė; Urbonavičiūtė, Akvilė; Šabajevienė, Gintarė; Šikšnianienė, Jūratė Bronė; Baranauskis, Kęstutis; Gelvonauskis, Bronislovas; Duchovskis, Pavelas

2006-01-01

Darbo tikslas – modeliuojamomis sąlygomis nustatyti obelų tolerancijos sritis ozono poveikiui. Bandymai atlikti LSDI Augalų fiziologijos laboratorijos fitotroniniame komplekse. Tirtos vienametės obelaitės (Alvo P60) ir tokios ozono koncentracijos: 0 (kontroliniai augalai), 80, 160, 240 μg m-3 (7 h per dieną, 5 dienas per savaitę). Bandymo pradžioje (savaitė po ozono poveikio), pabaigoje ir praėjus mėnesiui po ozono poveikio obelų lapuose nustatyta fotosintetinių pigmentų koncentracija. Visų k...

Syntheses of the Stemona Alkaloids (±)-Stenine, (±)-Neostenine, and (±)-13-Epineostenine Using a Stereodivergent Diels-Alder/Azido-Schmidt Reaction

Science.gov (United States)

Frankowski, Kevin J.; Golden, Jennifer E.; Zeng, Yibin; Lei, Yao; Aubé, Jeffrey

2009-01-01

A tandem Diels-Alder/azido Schmidt reaction sequence provides rapid access to the core skeleton shared by several Stemona alkaloids including stenine, neostenine, tuberstemonine, and neotubererostemonine. The discovery and evolution of inter- and intramolecular variations of this process and their applications to total syntheses of (±)–stenine and (±)–neostenine is described. The stereochemical outcome of the reaction depends on both substrate type and reaction condition, enabling the preparation of both (±)–stenine and (±)–neostenine from the same diene/dienophile combination. PMID:18396881

An azafluorenone alkaloid and a megastigmane from Unonopsis lindmanii (Annonaceae)

International Nuclear Information System (INIS)

Yoshida, Nidia C.; Siqueira, Joao M. de; Rodrigues, Ricardo P.; Correia, Rodolfo P.; Garcez, Walmir S.

2013-01-01

The azafluorenone alkaloid 5,8-dimethoxy-7-hydroxy-1-methyl-4-azafluoren-9-one and the megastigman (–)-(5R*, 6S*)-megastigman-3-one-10,7-olide were isolated from aerial parts of Unonopsis lindmanii (Annonaceae), along with the known compounds (3S*,5S*,8R*)-3,5-dihydroxymegastigma-6,7-dien-9-one (grasshopper ketone), N-trans-feruloyltyramine, (–)-anonaine, (–)-asimilobine, liriodenine and (–)-syringaresinol. This is the first description of the presence of megastigmanes in Annonaceae. The structures of the compounds were elucidated based on spectroscopic data. (author)

Química de especies del genero espeletia Espeletia killipii - Espeletia tunjana

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Rubén Darío Torrenegra

2010-07-01

Full Text Available De las partes aéreas de 2 especies del género Espeletia se aislaron compuestos del tipo diterpeno Acido (-i-Kaur-9( 11, 16-dien-19-oico, el (-Kaur-16-en-19-ol, los terpenos friedeiina, sitosterol-estigmasterol, y dos sesquiterpenlactonas del tipo melampólido, Acetato de Longipilin y Polimatin B. Los últimos compuestos no reportados hasta el momento en la química del género Espeletia. Del extracto etanólico se identificaron dos flavonoides: Quercetina y 3-metoxiquercetina.

Borostannylation of Alkynes and Enynes. Scope and Limitations of the Reaction and Utility of the Adducts

Science.gov (United States)

Singidi, Ramakrishna Reddy; RajanBabu, T. V.

2010-01-01

The utility of the bis-metallating reagent 1,3-dimethyl-2-trimethylstannyl-2-bora-1,3-diazacyclopentane (1) has not been fully realized because of the hydrolytic instability of the products derived from catalyzed vicinal syn-additions to alkynes. The isolation of variety of such adducts derived from alkynes (and also from hitherto unreported additions to 1,3-enynes) as stable boron pinacolates is reported. Examples of the applications of resulting products in tandem cross-coupling reactions and as dienes in Diels-Alder reactions are illustrated. PMID:20459076

Crystal growth in EPDM by chemi-crystallisation as a function of the neutron irradiation dose and flux level

International Nuclear Information System (INIS)

Lambri, O.A.; Salvatierra, L.M.; Sanchez, F.A.; Matteo, C.L.; Sorichetti, P.A.; Celauro, C.A.

2005-01-01

Neutron irradiation at room temperature were performed on EPDM (ethylene-propylene-diene monomer) in two different nuclear reactors at different fluxes. The effect of the irradiation on the chain arrangement in the polymer, as a function of the dose is discussed. Different crystal concentrations and crystal shapes, developed by chemi-crystallisation, are obtained depending on the neutron dose. In addition the radiation damage degree in the polymer depends both on the dose and the flux level. Dynamical mechanical analysis, swelling studies, X-ray diffraction, differential thermal analysis and infrared studies were employed as experimental techniques

Nitrile-assisted oxidation over oxidative-annulation: Pd-catalyzed α,β-dehydrogenation of α-cinnamyl β-keto nitriles.

Science.gov (United States)

Nallagonda, Rajender; Reddy, Reddy Rajasekhar; Ghorai, Prasanta

2017-09-13

A palladium-catalyzed oxidation reaction is disclosed where the nitrile functionality on the substrate simply changes the course of the reaction. Our previous finding showed that using the Pd(ii)-catalyst in the presence of benzoquinone as an oxidant, 2-cinnamyl-1,3-dicarbonyls provides functionalized furans via oxidative cyclization. When a nitrile group is replaced with one of the carbonyl functionalities of the same substrate, the oxidative cyclization was completely suppressed; instead, the oxidation at the α,β-position occurred to provide α,β,γ,δ-diene containing β-keto nitriles.

Synthesis of canrenone and related steroids labelled with tritium, carbon-14, and sulfur-35

International Nuclear Information System (INIS)

Markos, C.S.; Dorn, C.R.; Zitzwitz, D.J.

1988-01-01

The syntheses of [1- 3 H]canrenone, [1- 3 H]spironolactone, [1- 3 H] potassium canrenoate, [22- 14 C]canrenone, [22- 14 C]spironolactone, [22- 14 C]potassium canrenoate, and [ 35 S]spironolactone are reported. Tritium labelled compounds were obtained by catalytic reduction of a 3-keto-1, 4-diene precursor followed by exchange of enolizable label. Carbon-14 compounds were obtained by reaction of a 17-ethynyl steroid with 14 CO 2 . Sulfur-35 spironolactone was synthesized by the in-situ generation of [ 35 S]thiolacetic acid from [ 35 S]sodium sulfide. (author)

Acquisitions de la Bibliothèque Géographie

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Bernadette Joseph

2008-03-01

Full Text Available AfriqueAngola : oil, broad-based growth, and equity, Washington, D.C., World Bank, cop. 2007, G 19-3337BATTISTINI, René, Géographie de l’Afrique orientale, Kenya, Uganda et Tanzanie, Paris, Centre de documentation universitaire, 1969, BCOURS 314BEN YAHMED, Gabon , un pari d’avenir, Paris, les Éd. du Jaguar, DL 2007, G 19-3336BEN YAHMED, HOUSTIN, NDIAYE, WADE, Atlas du Sénégal, Paris, les Éd. J.A., impr. 2007, G 19-3353CHARTON, H., L’Afrique orientale : annuaire 2005, G 19-3289IOP, NIANG DIENE...

Jaunimo užimtumas ir jų įsitraukimą į darbo rinką lengvinančios priemonės

OpenAIRE

Kvedaraitė, Nida; Repečkienė, Aušra; Glinskienė, Rasa; Žvirelienė, Renata

2012-01-01

Pastarųjų dešimtmečių vieno svarbiausių fenomeno – globalizacijos – transformacinės galimybės stipriai skverbiasi į ekonominio-socialinio gyvenimo sritis ir neišvengiamai lemia darbo rinkos pokyčius, kelia naujus reikalavimus ir iššūkius visuomenei, susidedančiai iš skirtingų socialinių grupių. Viena jautriausių socialinių grupių yra jaunimas, kurio integracija į darbo rinką tampa bene aktualiausia šių dienų ekonomine, socialine ir politine problema. Europos Komisijos komunikato „Judus jaunim...

Homoconjugation vs. Exciton Coupling in Chiral α,β-Unsaturated Bicyclo[3.3.1]nonane Dinitrile and Carboxylic Acids

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Gintautas Bagdžiūnas

2014-07-01

Full Text Available The chiroptical properties of enantiomerically pure bicyclo[3.3.1]nona-2,6-diene-2,6-dicarbonitrile and related acids were studied by circular dichroism spectroscopy and theoretical computations. A consideration of the molecular structure of the synthesized difunctional compounds revealed that chromophores are predisposed to transannular through-space interaction due to a favourable conformation of the bicyclic skeleton and a rather small interchromophoric distance. Evidence for non-exciton-type coupling between the two acrylonitrile and acrylate moieties in 3 and 4, respectively, was obtained by chiroptical spectroscopy and DFT calculations.

An azafluorenone alkaloid and a megastigmane from Unonopsis lindmanii (Annonaceae)

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Nidia C., E-mail: nidiayoshida@usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Quimica; Siqueira, Joao M. de [Universidade Federal de Sao Joao Del Rei, Divinpolis, MG (Brazil). Departamento de Farmacia; Rodrigues, Ricardo P. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas; Correia, Rodolfo P. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Ciencias Biomedicas; Garcez, Walmir S., E-mail: walmir.garcez@ufms.br [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Departamento de Quimica

2013-04-15

The azafluorenone alkaloid 5,8-dimethoxy-7-hydroxy-1-methyl-4-azafluoren-9-one and the megastigman (-)-(5R*, 6S*)-megastigman-3-one-10,7-olide were isolated from aerial parts of Unonopsis lindmanii (Annonaceae), along with the known compounds (3S*,5S*,8R*)-3,5-dihydroxymegastigma-6,7-dien-9-one (grasshopper ketone), N-trans-feruloyltyramine, (-)-anonaine, (-)-asimilobine, liriodenine and (-)-syringaresinol. This is the first description of the presence of megastigmanes in Annonaceae. The structures of the compounds were elucidated based on spectroscopic data. (author)

Phosphate Tether-Mediated Ring-Closing Metathesis for the Generation of P-Stereogenic, Z-Configured Bicyclo[7.3.1]- and Bicyclo[8.3.1]phosphates.

Science.gov (United States)

Markley, Jana L; Maitra, Soma; Hanson, Paul R

2016-02-05

A phosphate tether-mediated ring-closing metathesis (RCM) study to the synthesis of Z-configured, P-stereogenic bicyclo[7.3.1]- and bicyclo[8.3.1]phosphates is reported. Investigations suggest that C3-substitution, olefin substitution, and proximity of the forming olefin to the bridgehead carbon of the bicyclic affect the efficiency and stereochemical outcome of the RCM event. This study demonstrates the utility of phosphate tether-mediated desymmetrization of C2-symmetric, 1,3-anti-diol-containing dienes in the generation of macrocyclic phosphates with potential synthetic and biological utility.

Unification and approximation of the law of civil procedure

OpenAIRE

Juronytė, Austė

2014-01-01

Šiame darbe yra analizuojami bendrieji civilinio proceso teisės vienodinimo ir derinimo civilinėse ir komercinėse bylose teorinai ir praktiniai klausimai: tai civilinio proceso teisės samprata, istorija ir pagrindiniai šių dienų civilinio proceso teisės raidos bruožai. Taip pat pirmojoje darbo dalyje analizuojamos civilinio proceso teisės vienodinimo kliūtys bei pagrindinės civilinio proceso teisės vienodinimo priežastys arba tikslai, svarstoma kiek jos yra pagrįstos. Antroji darbo dalis yra ...

Optical and Scanning electron Microscopy as advanced analysis methods to determine the condition of synthetic geo membranes

International Nuclear Information System (INIS)

Soriano Carrillo, J.; Blanco Fernandez, M.; Garcia Calleja, M. A.; Leiro Lopez, A.; Mateo Sanz, B.; Aguilar Gonzalez, E.; Rubin de Celix, M.

2014-01-01

Microscopic techniques have been widely used for years in the study of inorganic materials however their use in organic materials and specifically, in synthetic geo membranes, is very limited. In this study, this innovative technology has been used with the different geo synthetic polymeric barriers with which this research team is experienced: plasticized polyvinyl chloride, polyethylenes, rubbers such as ethenyltriphenyl-diene monomer terpolymer and butyl, polyolefins, ethylene-vinyl acetate copolymer, chlorosulfonated polyethylene and polypropylene. the influence of the extraction area and the time since their application is tested. (Author)

Razonamiento lógico-matemático en las escuelas

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Rocío Berrocal-Mora

2002-07-01

Full Text Available Based on the results of their licenciatura thesis "Methodological strategy for the development of logical-mathematical reasoning”, presented to the Division of Rural Education, CIDE the authors explain the six phases developed by the German mathematician, Zotan Pier Dienes. They propose an alternative strategy to deepen and accomplish a better achievement in the development of factual thinking. The reader will find, in the section "EDUCARE in the classroom" that appears in this edition, a methodological proposal, founded in the theoretical postulates presented and discussed in this article.

Optical and Scanning electron Microscopy as advanced analysis methods to determine the condition of synthetic geo membranes; Las microscopias optica de reflexion y electronica de barrido como metodos avanzados de analisis para conocer el estado de las geomembranes

Energy Technology Data Exchange (ETDEWEB)

Soriano Carrillo, J.; Blanco Fernandez, M.; Garcia Calleja, M. A.; Leiro Lopez, A.; Mateo Sanz, B.; Aguilar Gonzalez, E.; Rubin de Celix, M.

2014-02-01

Microscopic techniques have been widely used for years in the study of inorganic materials however their use in organic materials and specifically, in synthetic geo membranes, is very limited. In this study, this innovative technology has been used with the different geo synthetic polymeric barriers with which this research team is experienced: plasticized polyvinyl chloride, polyethylenes, rubbers such as ethenyltriphenyl-diene monomer terpolymer and butyl, polyolefins, ethylene-vinyl acetate copolymer, chlorosulfonated polyethylene and polypropylene. the influence of the extraction area and the time since their application is tested. (Author)

Abgestaubt und eingescannt – Papyrologie goes Internet

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Nadine Quenouille

2016-08-01

Full Text Available This paper was originally presented during the Conference „Wikipedia trifft Altertum: Freies Wissen, Neue Medien, populäre Wissensvermittlung und Enzyklopädien in den Altertumswissenschaften“ on 10. / 11. June 2011 at the Georg-August-University in Göttingen. It focuses on the history and evolution of digital tools in Papyrology, which began as early as 1982 with the Duke Databank of Documentary Papyri and is currently growing and continuing with a Multilingual Online Dictionary of the Administrative Terms of Graeco-Roman-Byzantine Egypt.

Antiproliferative Compounds of Cyphostemma greveana from a Madagascar Dry Forest[1

OpenAIRE

Cao, Shugeng; Hou, Yanpeng; Brodie, Peggy; Miller, James S.; Randrianaivo, Richard; Rakotobe, Etienne; Rasamison, Vincent E.; Kingston, David G. I.

2011-01-01

Bioassay-guided fractionation of the EtOH extracts obtained from a plant identified as Cyphostemma greveana Desc. (Vitaceae) led to the identification of one macrolide, lasiodiplodin (1), three sesquiterpenoids, 12-hydroxy-15-oxo-selina-4,1l-diene (2), 1β,6α-dihydroxyeudesm-4(15)-ene (3), and (7R*)-opposit-4(15)-ene-1β,7-diol (5), and the new diterpenoid, 16,18-dihydroxykolavenic acid lactone (4). All the isolates were tested against the A2780 human ovarian cancer cell line, and compound 4 an...

Reactions of 3d-series metallocenes with organic cadmium compounds

International Nuclear Information System (INIS)

Razuvaev, G.A.; Mar'in, V.P.; Vyshinskaya, L.I.; Grinval'd, I.I.; Spiridonova, N.N.

1987-01-01

Interaction of organic cadmium compounds and 3d-series metallocenes, Cp 2 M (M=V, Cr, Mn, Ni, Co) has been studied. It is shown that direction of these reactions is determined by metallocene nature. Reactions of oxidizing addition leading to σ-complexes formation are characteristic for vanadium and chromium metallocenes. When reacting cobaltocene with R 2 Cd, R group introduction to cyclopentadienyl ring and elimination of cobalt diene complexes take place. Manganocene and nickelocene interaction goes through the stage of complex formation with transition metal - cadmium bond

Le carcinome parathyroïdien: à propos d'un cas et revue de la ...

African Journals Online (AJOL)

Le traitement est basé sur la chirurgie. Femme âgée de 59 ans, aux antécédents d'hypertension artérielle, et de lithiases rénales récidivantes, consultait pour des douleurs osseuses diffuses avec asthénie. L'examen du cou a trouvé une tuméfaction basi-cervicale dure et à bord inférieur non palpable. A la biologie: ...

' n Prakties-teologiese begronding vir Gemeentebou as kommunikatiewe handeling in diens van die evangelie

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J. C. an der Merwe

1999-12-01

Full Text Available A practical theological foundation for church growth as communicative act in the service of the gospel. The aim of this article is to reflect on a pracical theological perspective on the theoretical premises of church growth. This is done within the framework of the postmodern paradigm. Church growth focuses on the analysis, description and explanation of the practical situations of congregations in order to enhance church management. The episttmological framework of this aricleis the distinction metatheory, basis theory and theory of practice. The focus is on the relationship between basis theory and the theory of the practice of church growth. The aricle departs from an approach where empirical data form the basis for the construction of a praxis for church growth. The author argues for a biblical foundation by means of which the empirical data should be evaluated in order to devise a model for praxis.

(2E,4E-1-(2-Hydroxyphenyl-5-phenylpenta-2,4-dien-1-one

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W. A. Silva

2011-09-01

Full Text Available In the structure of the title chalcone, C17H14O2, derived from cinnamaldehyde, the olefine group has a trans configuration. The molecular conformation is stabilized by an intramolecular O—H...O hydrogen-bond interaction with graph-set motif S(6.

Quantitative structure-activation barrier relationship modeling for Diels-Alder ligations utilizing quantum chemical structural descriptors.

Science.gov (United States)

Nandi, Sisir; Monesi, Alessandro; Drgan, Viktor; Merzel, Franci; Novič, Marjana

2013-10-30

In the present study, we show the correlation of quantum chemical structural descriptors with the activation barriers of the Diels-Alder ligations. A set of 72 non-catalysed Diels-Alder reactions were subjected to quantitative structure-activation barrier relationship (QSABR) under the framework of theoretical quantum chemical descriptors calculated solely from the structures of diene and dienophile reactants. Experimental activation barrier data were obtained from literature. Descriptors were computed using Hartree-Fock theory using 6-31G(d) basis set as implemented in Gaussian 09 software. Variable selection and model development were carried out by stepwise multiple linear regression methodology. Predictive performance of the quantitative structure-activation barrier relationship (QSABR) model was assessed by training and test set concept and by calculating leave-one-out cross-validated Q2 and predictive R2 values. The QSABR model can explain and predict 86.5% and 80% of the variances, respectively, in the activation energy barrier training data. Alternatively, a neural network model based on back propagation of errors was developed to assess the nonlinearity of the sought correlations between theoretical descriptors and experimental reaction barriers. A reasonable predictability for the activation barrier of the test set reactions was obtained, which enabled an exploration and interpretation of the significant variables responsible for Diels-Alder interaction between dienes and dienophiles. Thus, studies in the direction of QSABR modelling that provide efficient and fast prediction of activation barriers of the Diels-Alder reactions turn out to be a meaningful alternative to transition state theory based computation.

DETERMINACIÓN DE ÁCIDOS GRASOS Y COMPUESTOS TRITERPENOIDES DEL CUERPO FRUCTIFERO DE Suillus luteus.

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Ivonne Nieto

2009-04-01

Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Del cuerpo fructífero de Suillus luteus se extrajeron e identificaron, con base en el análisis de sus espectros de masas,  dieciséis compuestos, los cuales corresponden al ácido palmítico, oléico, linolénico y linoléico, octadecanoato de etilo, ergosta-7,22-dien-3β-ol, ergosta-7-en-3β-ol, estigmasterol, ergosta-3,5,7,9(11,22-pentaeno, ergosta-2,5,7,9(11,14,22-hexaeno, 23-metil-estigmast-3,5,7,22-tetraeno, 23-metil-estigmast-3,5,7,9(11,22-pentaeno, ergosta-4,6,15(16,22-tetraen-3-ona,  ergosta-1,5,7,9(11,22-pentaen-3-ona, ergosta-5,7,9(11,22-tetraen-3β-ol y ergosta-5,6,7-trihidroxi-7,22-dien-3β-ol. Siendo este un hongo tan poco estudiado, todos los compuestos, a excepción de los ácidos grasos, se reportan aquí por primera vez.

Anti-BACE1 and Antimicrobial Activities of Steroidal Compounds Isolated from Marine Urechis unicinctus

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Yong-Zhe Zhu

2018-03-01

Full Text Available The human β-site amyloid cleaving enzyme (BACE1 has been considered as an effective drug target for treatment of Alzheimer’s disease (AD. In this study, Urechis unicinctus (U. unicinctus, which is a Far East specialty food known as innkeeper worm, ethanol extract was studied by bioassay-directed fractionation and isolation to examine its potential β-site amyloid cleaving enzyme inhibitory and antimicrobial activity. The following compounds were characterized: hecogenin, cholest-4-en-3-one, cholesta-4,6-dien-3-ol, and hurgadacin. These compounds were identified by their mass spectrometry, 1H, and 13C NMR spectral data, comparing those data with NIST/EPA/NIH Mass spectral database (NIST11 and published values. Hecogenin and cholest-4-en-3-one showed significant inhibitory activity against BACE1 with EC50 values of 116.3 and 390.6 µM, respectively. Cholesta-4,6-dien-3-ol and hurgadacin showed broad spectrum antimicrobial activity, particularly strongly against Escherichia coli (E. coli, Salmonella enterica (S. enterica, Pasteurella multocida (P. multocida, and Physalospora piricola (P. piricola, with minimal inhibitory concentration (MIC ranging from 0.46 to 0.94 mg/mL. This is the first report regarding those four known compounds that were isolated from U. unicinctus and their anti-BACE1 and antimicrobial activity, highlighting the fact that known natural compounds may be a critical source of new medicine leads. These findings provide scientific evidence for potential application of those bioactive compounds for the development of AD drugs and antimicrobial agents.

Anti-BACE1 and Antimicrobial Activities of Steroidal Compounds Isolated from Marine Urechis unicinctus.

Science.gov (United States)

Zhu, Yong-Zhe; Liu, Jing-Wen; Wang, Xue; Jeong, In-Hong; Ahn, Young-Joon; Zhang, Chuan-Jie

2018-03-14

The human β-site amyloid cleaving enzyme (BACE1) has been considered as an effective drug target for treatment of Alzheimer's disease (AD). In this study, Urechis unicinctus (U. unicinctus) , which is a Far East specialty food known as innkeeper worm, ethanol extract was studied by bioassay-directed fractionation and isolation to examine its potential β-site amyloid cleaving enzyme inhibitory and antimicrobial activity. The following compounds were characterized: hecogenin, cholest-4- en -3-one, cholesta-4,6- dien -3-ol, and hurgadacin. These compounds were identified by their mass spectrometry, ¹H, and 13 C NMR spectral data, comparing those data with NIST/EPA/NIH Mass spectral database (NIST11) and published values. Hecogenin and cholest-4- en -3-one showed significant inhibitory activity against BACE1 with EC 50 values of 116.3 and 390.6 µM, respectively. Cholesta-4,6- dien -3-ol and hurgadacin showed broad spectrum antimicrobial activity, particularly strongly against Escherichia coli (E. coli) , Salmonella enterica (S. enterica) , Pasteurella multocida (P. multocida) , and Physalospora piricola (P. piricola) , with minimal inhibitory concentration (MIC) ranging from 0.46 to 0.94 mg/mL. This is the first report regarding those four known compounds that were isolated from U. unicinctus and their anti-BACE1 and antimicrobial activity, highlighting the fact that known natural compounds may be a critical source of new medicine leads. These findings provide scientific evidence for potential application of those bioactive compounds for the development of AD drugs and antimicrobial agents.

The Amoebicidal Effect of Ergosterol Peroxide Isolated from Pleurotus ostreatus.

Science.gov (United States)

Meza-Menchaca, Thuluz; Suárez-Medellín, Jorge; Del Ángel-Piña, Christian; Trigos, Ángel

2015-12-01

Dysentery is an inflammation of the intestine caused by the protozoan parasite Entamoeba histolytica and is a recurrent health problem affecting millions of people worldwide. Because of the magnitude of this disease, finding novel strategies for treatment that does not affect human cells is necessary. Ergosterol peroxide is a sterol particularly known as a major cytotoxic agent with a wide spectrum of biological activities produced by edible and medicinal mushrooms. The aim of this report is to evaluate the amoebicidal activity of ergosterol peroxide (5α, 8α-epidioxy-22E-ergosta-6,22-dien-3β-ol isolated from 5α, 8α-epidioxy-22E-ergosta-6,22-dien-3β-ol) (Jacq.) P. Kumm. f. sp. Florida. Our results show that ergosterol peroxide produced a strong cytotoxic effect against amoebic growth. The inhibitory concentration IC50 of ergosterol peroxide was evaluated. The interaction between E. histolytica and ergosterol peroxide in vitro resulted in strong amoebicidal activity (IC50  = 4.23 nM) that may be due to the oxidatory effect on the parasitic membrane. We also tested selective toxicity of ergosterol peroxide using a cell line CCL-241, a human epithelial cell line isolated from normal human fetal intestinal tissue. To the best of our knowledge, this is the first report on the cytotoxicity of ergosterol peroxide against E. histolytica, which uncovers a new biological property of the lipidic compound isolated from Pleurotus ostreatus (Jacq.) P. Kumm. f. sp. Florida. Copyright © 2015 John Wiley & Sons, Ltd.

Increased fluidity and oxidation of malarial lipoproteins: relation with severity and induction of endothelial expression of adhesion molecules

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Looareesuwan Sornchai

2004-06-01

Full Text Available Abstract Introduction Oxidative stress has been demonstrated in malaria. The potential oxidative modification of lipoproteins derived from malaria patients was studied. These oxidized lipids may have role in pathogenesis of malaria. Method The plasma lipid profile and existence of oxidized forms of very low density lipoprotein (VLDL, low density lipoprotein (LDL and high density lipoprotein (HDL were investigated in malaria (17 mild and 24 severe patients and 37 control subjects. Thiobarbituric acid reactive substances (TBARs, conjugated dienes, tryptophan fluorescence and fluidity of lipoproteins were determined as markers of oxidation. The biological effect of malarial lipoproteins was assessed by the expression of adhesion molecules on endothelial cells. Results Malarial lipoproteins had decreased cholesterol (except in VLDL and phospholipid. The triglyceride levels were unchanged. The cholesterol/phospholipid ratio of LDL was decreased in malaria, but increased in VLDL and HDL. TBARs and conjugate dienes were increased in malarial lipoproteins, while the tryptophan fluorescence was decreased. The fluidity of lipoproteins was increased in malaria. These indicated the presence of oxidized lipoproteins in malaria by which the degree of oxidation was correlated with severity. Of three lipoproteins from malarial patients, LDL displayed the most pronounced oxidative modification. In addition, oxidized LDL from malaria patients increased endothelial expression of adhesion molecules. Conclusion In malaria, the lipoproteins are oxidatively modified, and the degree of oxidation is related with severity. Oxidized LDL from malarial patients increases the endothelial expression of adhesion molecules. These suggest the role of oxidized lipoproteins, especially LDL, on the pathogenesis of disease.