Готові списки джерел за темами / Ethylphenol

Добірка наукової літератури з теми "Ethylphenol"

Автор: Grafiati
Опубліковано: 10 грудня 2022
Оновлено: 29 січня 2023

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Статті в журналах з теми "Ethylphenol"

1

Betz, Richard, Peter Klüfers, and Peter Mayer. "4-Ethylphenol." Acta Crystallographica Section E Structure Reports Online 65, no. 3 (February 18, 2009): o544. http://dx.doi.org/10.1107/s1600536809005108.

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2

Wöhlbrand, Lars, Heinz Wilkes, Thomas Halder, and Ralf Rabus. "Anaerobic Degradation of p-Ethylphenol by “Aromatoleum aromaticum” Strain EbN1: Pathway, Regulation, and Involved Proteins." Journal of Bacteriology 190, no. 16 (June 6, 2008): 5699–709. http://dx.doi.org/10.1128/jb.00409-08.

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ABSTRACT The denitrifying “Aromatoleum aromaticum” strain EbN1 was demonstrated to utilize p-ethylphenol under anoxic conditions and was suggested to employ a degradation pathway which is reminiscent of known anaerobic ethylbenzene degradation in the same bacterium: initial hydroxylation of p-ethylphenol to 1-(4-hydroxyphenyl)-ethanol followed by dehydrogenation to p-hydroxyacetophenone. Possibly, subsequent carboxylation and thiolytic cleavage yield p-hydroxybenzoyl-coenzyme A (CoA), which is channeled into the central benzoyl-CoA pathway. Substrate-specific formation of three of the four proposed intermediates was confirmed by gas chromatographic-mass spectrometric analysis and also by applying deuterated p-ethylphenol. Proteins suggested to be involved in this degradation pathway are encoded in a single large operon-like structure (∼15 kb). Among them are a p-cresol methylhydroxylase-like protein (PchCF), two predicted alcohol dehydrogenases (ChnA and EbA309), a biotin-dependent carboxylase (XccABC), and a thiolase (TioL). Proteomic analysis (two-dimensional difference gel electrophoresis) revealed their specific and coordinated upregulation in cells adapted to anaerobic growth with p-ethylphenol and p-hydroxyacetophenone (e.g., PchF up to 29-fold). Coregulated proteins of currently unknown function (e.g., EbA329) are possibly involved in p-ethylphenol- and p-hydroxyacetophenone-specific solvent stress responses and related to other aromatic solvent-induced proteins of strain EbN1.
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3

Majer, Sean H., and Joseph M. Tanski. "4-Chloro-3-ethylphenol." Acta Crystallographica Section E Structure Reports Online 70, no. 7 (June 21, 2014): o801. http://dx.doi.org/10.1107/s1600536814013919.

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The title compound, C8H9ClO, packs with two independent molecules in the asymmetric unit, without significant differences in corresponding bond lengths and angles, with the ethyl group in each oriented nearly perpendicular to the aromatic ring having ring-to-side chain torsion angles of 81.14 (18) and −81.06 (19)°. In the crystal, molecules form an O—H...O hydrogen-bonded chain extending along theb-axis direction, through the phenol groups in which the H atoms are disordered. These chains pack together in the solid state, giving a sheet lying parallel to (001),viaan offset face-to-face π-stacking interaction characterized by a centroid–centroid distance of 3.580 (1) Å, together with a short intermolecular Cl...Cl contact [3.412 (1) Å].
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4

Zhou, Peizheng, and Billy L. Crynes. "Thermolytic reactions of o-ethylphenol." Industrial & Engineering Chemistry Process Design and Development 25, no. 4 (October 1986): 898–907. http://dx.doi.org/10.1021/i200035a011.

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5

Reeve, C. D., M. A. Carver, and D. J. Hopper. "Stereochemical aspects of the oxidation of 4-ethylphenol by the bacterial enzyme 4-ethylphenol methylenehydroxylase." Biochemical Journal 269, no. 3 (August 1, 1990): 815–19. http://dx.doi.org/10.1042/bj2690815.

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The O2-independent hydroxylase 4-ethylphenol methylenehydroxylase (4EPMH) from Pseudomonas putida JD1 catalysed the complete conversion of 4-ethylphenol into 1-(4-hydroxyphenyl)ethanol together with a small amount of 4-hydroxyacetophenone, but with no formation of the side product 4-vinylphenol reported to be formed when the similar enzyme p-cresol methylhydroxylase (PCMH) catalyses this reaction. The enantiomer of 1-(4-hydroxyphenyl)ethanol produced by 4EPMH was R(+) when horse heart cytochrome c or azurin was used as electron acceptor for the enzyme. PCMHs from various bacterial strains produced the S(-)-alcohol. Both enantiomers of 1-(4-hydroxyphenyl)ethanol were substrates for conversion into 4-hydroxyacetophenone by 4EPMH, but the S(-)-isomer was preferred. The Km and kcat. were 1.2 mM and 41 s-1 respectively for the S(-)-alcohol and 4.7 mM and 22 s-1 for the R(+)-alcohol. In addition to the 1-(4-hydroxyphenyl)ethanol dehydrogenase activity of 4-EPMH, NAD(+)-linked dehydrogenase activity for both enantiomers of the alcohol was found in extracts of Ps. putida JD1.
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6

BAŠA ČESNIK, Helena, and Klemen LISJAK. "Volatile phenolics in Teran PTP red wine." Acta agriculturae Slovenica 107, no. 1 (April 6, 2016): 5. http://dx.doi.org/10.14720/aas.2016.107.1.01.

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The volatile phenolics, 4-ethylphenol, 4-vinylphenol, 4-ethylguaiacol and 4-vinylguaiacol were quantified in Teran PTP wines that were produced in the Kras winegrowing district. The compounds were determined by using gas chromatography coupled with mass spectrometry after extraction with diethylether. Three years monitoring (2011, 2012, 2013 vintages) showed that all four undesirable compounds were identified in Teran PTP wines, however their content did not influence significantly the sensory characteristics of the wine. The average contents gained over the three-year period (2011-2013; n=82) were 153±193 µg L<sup>-1</sup> for 4-ethylphenol, 1265±682 µg L<sup>-1</sup> for 4-vinylphenol, 69±94 µg L<sup>-1</sup> for 4-ethylguaiacol and 128±106 µg L<sup>-1</sup> for 4-vinylguaiacol. 7.3 % of samples showed contents of 4-ethylphenol above the odour threshold values. For 4-vinylphenol, 4-ethylguaiacol and 4-vinylguaiacol that percentage was 98.8 %, 25.6 % and 91.5 %, respectively.
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Jones, K. H., P. W. Trudgill, and D. J. Hopper. "4-Ethylphenol metabolism by Aspergillus fumigatus." Applied and Environmental Microbiology 60, no. 6 (1994): 1978–83. http://dx.doi.org/10.1128/aem.60.6.1978-1983.1994.

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8

Takahashi, Mika, Mutsuko Hirata-Koizumi, Nobuo Nishimura, Yoshihiko Ito, Masao Sunaga, Sakiko Fujii, Eiichi Kamata, Ryuichi Hasegawa, and Makoto Ema. "Susceptibility of newborn rats to 3-ethylphenol and 4-ethylphenol compared with that of young rats." Congenital Anomalies 46, no. 1 (March 2006): 26–33. http://dx.doi.org/10.1111/j.1741-4520.2006.00098.x.

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9

Qiu, Zegang, Ying Wang, Yali Di, Xiaoxiong Ren, Weiwei Liu, Zhiqin Li, and Guangyu Li. "One-step conversion of lignin-derived alkylphenols to light arenes by co-breaking of C–O and C–C bonds." New Journal of Chemistry 46, no. 6 (2022): 2710–21. http://dx.doi.org/10.1039/d1nj05793f.

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10

Renaud, Alexis, Yoann Paint, Alex Lanzutti, Leïla Bonnaud, Lorenzo Fedrizzi, Philippe Dubois, Marc Poorteman, and Marie-Georges Olivier. "Sealing porous anodic layers on AA2024-T3 with a low viscosity benzoxazine resin for corrosion protection in aeronautical applications." RSC Advances 9, no. 29 (2019): 16819–30. http://dx.doi.org/10.1039/c9ra01970g.

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Дисертації з теми "Ethylphenol"

1

Fernandes, Miguel Tiago Nunes. "Studies on the wine spoilage yeast Brettanomyces bruxellensis: 4-ethylphenol production and improved detection." Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10986.

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Dissertação para obtenção do Grau de Mestre em Biotecnologia
Brettanomyces bruxellensis is a major threat to wine industry due to its spoilage ability characterized by high production of volatile phenols, mainly 4-ethylphenol. The horse sweat odor, characteristic of this phenol, causes large economic losses to wineries. A better understanding of the behavior of this yeast and better detection methods may lead to a decrease in 4-ethylphenol incidence in red wines worldwide. In the present work, we studied: (i) the ability of B. bruxellensis to enter the viable but nonculturable state by using both vital staining and plate counts to distinguish between viable and culturable cells; (ii) the production of 4-ethylphenol at different growth phases; (iii) the improvement of selective culture media; (iv) the application of a Real-Time PCR protocol for the rapid detection of B. bruxellensis. The existence of a viable but nonculturable state was evidenced during growth in synthetic medium ranging from 2% in strain ISA 2211 to 71% in strain ISA 1791 of the viable cells. The production rate of 4-ethylphenol was maximum when the precursor p-coumaric acid was added during exponential growth and decreased in stationary phase with incubation time. The developed selective medium presented recovery rates higher than the general purpose medium GYP and selectivity similar to DBDM. Response time lasted from 3 to 5 days while DBDM colonies appeared only after 12 days or more of incubation. Real-Time PCR showed to be an easy and faster method for a highly selective detection, taking 3 hours to obtain a positive response. The detection threshold was 700 cells/mL which may be decreased using sample concentration by centrifugation. However, results were 3.7 times higher than the viable counts, probably due to the DNA of dead or lysed cells. Collectively, this work represented a step forward in understanding the spoiling behavior of this yeast species and enabled the development of better detection methods for B. bruxellensis.
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2

Reis, Marta Lopes Egídio. "Efeito do quitosano na viabilidade de Brettanomyces bruxellensis e na produção de 4-etilfenol em vinho." Master's thesis, ISA, 2014. http://hdl.handle.net/10400.5/6878.

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Анотація:
Mestrado em Engenharia Alimentar - Qualidade e Segurança Alimentar - Instituto Superior de Agronomia
The spoilage yeast, Brettanomyces bruxellensis, can cause the formation of film in storage wine, sediments, gas production and the production of unpleasant tastes and flavors to the consumer. Chitosan is presented as a potential product to control the yeast that alter the wine. Under laboratory conditions the effect of chitosan at different concentrations was tested in the growth of various B. bruxellensis strains in synthetic medium and wine. Viability was followed in plate with GYP medium, by hemocytometer counting with vital staining. Production of 4-ethylphenol was also analyzed. In synthetic medium it was possible to control the growth with 1 g/L of chitosan. In wine the necessary concentrations were lower, because it is a more stressful environment. With lower concentrations and with poorly adapted cells it was possible to control, the growth of the strains tested with 0,1 g/L and 0,05 g/L. However, when chitosan is added after the exponential phase, it is only possible to control the growth with 0,5 g/L. The production of 4-ethiphenol only reached significant values, over 800μg/L, on the wine trial with well adapted cells. The results in this trial show that the effect of chitosan is dependent of the strain, cellular concentration, growth stage of the cells and that the production of 4-ethylphenol was significant only in wine with well adapted cells. The usage of chitosan has no effect on the VBNC stage of the cells.
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3

Copp, Clinton W. "Production and Degradation of 4-Ethylphenol in LACTOBACILLUS SP. pep8 Cultures and in Blended Swine Lagoon Enrichments." TopSCHOLAR®, 2012. http://digitalcommons.wku.edu/theses/1189.

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4-Ethylphenol (4-EP) is a malodorant of swine waste and is derived from a component of lignin called p-coumaric acid (p-CA). The production of 4-EP from lignin in swine waste is untested. Additionally, the effect of Fe (III) on 4-EP levels is unknown. Four experiments were performed to determine if Lactobacillus sp. pep8 cultures, as well as enriched swine lagoon slurries, could liberate p-CA from lignin and convert p-CA to 4-EP. Furthermore, it was tested if the addition of Fe (III) influences the conversion of p- CA to 4-EP. Experiment 1 tested Lactobacillus sp. pep8 cultures to determine if the addition of 10 mM Fe (III) and 0.2% sulphite lignin to Lactobacillussp. pep8 cultures would stimulate production of 4-EP. Experiment 2 tested the effect of 0.2% sulphite lignin and 10 mM Fe (III) on 4-EP production in the presence of enriched swine lagoon slurries. On day 0 there was no detectable 4‐EP, for either 0.2% sulphite lignin addition or the 10 mmol l‐1 Fe (III) additions. Experiment 3 tested alternative forms of lignin, including 0.2% sulphite, indulin, or sigma lignin as potential source compounds for 4-EP production in enriched swine lagoon slurries. 4-EP produced in all three conditions are likely endogenous to the lagoon slurry additions. Experiment 4 was designed to measure the degradation of exogenous 4-EP with varying final concentrations of 4-EP in enriched swine lagoon slurries. Data in Figure 7 indicate immediate degradation of 4-EP by day 5, however, by day 7 synthesis of 4-EP occurred until day 14 where 4-EP levels remained in a steady state. Our results suggest that when both Lactobacillus sp. pep8 cultures and enriched swine lagoons are supplemented with p-CA, 4-EP is produced indicating that p-CA serves as a source of 4-EP. However, when supplemented with Fe (III) and/or sulphite, indulin, or sigma lignin, 4-EP production was not stimulated. This data indicates that, 4- EP production is not enhanced by the presence of Fe (III) in either Lactobacillus sp. pep8 cultures or in enriched swine lagoon slurries. Furthermore, lignin did not serve as a source of 4-EP.
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4

Keskin, Mehmet Yigit. "Studies on the incidence of Dekkera bruxellensis in Turkish wines and effect of low temperatures on 4-ethylphenol production." Master's thesis, ISA/UL, 2012. http://hdl.handle.net/10400.5/8596.

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Анотація:
Mestrado Vinifera EuroMaster - Instituto Superior de Agronomia
Brettanomyces/Dekkera bruxellensis has the ability to produce significant amounts of 4-ethylphenol (4-EP) and cause important organoleptic defects in affected wines. In this work we investigated the incidence of B. bruxellensis and of 4-ethylphenol in Turkish red wines randomly collected at winery facilities. Among 40 samples, this species was only recovered from one sample aged in oak barrels. In 4 samples, culturable population was not found but the 4-EP concentration indicated previous Dekkera bruxellensis activity. Thus, following potential Brettanomyces-sourced aroma impacts in wine using 4-Ethylphenol and 4-Ethylguaiacol concentrations as proxies should only be considered reliable at analyte levels >100 μg/l (Rayne and Eggers, 2007). Furthermore, we studied the influence of storage temperature on the production of 4-EP by wild of D. bruxellensis in 3 different Portuguese red wines. Temperatures of 10 ºC and 15ºC were not effective in preventive the increase of 4-EP over 600 μg/l during 90 days. At 3 ºC one sample showed similar 4-EP increase while in two other samples its concentration was kept unchanged. Production of 4-EP at 3ºC and 10ºC was confirmed when the strain TR 26 was incubated in red wine for 49 days. However, the total amount of 4-EP produced was below 150 μg/l while at 15ºC and 20ºC the values reached 1600 μg/l. Therefore, the effect of low temperatures acts by delaying microbial growth which results in lower concentrations of 4-EP but once temperature increases 4-EP production is readily stimulated
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5

Oro, Inês Correia Horta Lazo. "Avaliação do crescimento de leveduras de alteração em vinhos utilizando a metodologia de superficies de resposta." Master's thesis, ISA, 2014. http://hdl.handle.net/10400.5/7068.

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Анотація:
Mestrado em Viticultura e Enologia - Instituto Superior de Agronomia / Universidade do Porto. Faculdade de Ciências
This study aimed to understand the effects of different factors on the growth of spoilage yeasts in red wine and consequent production of metabolites using response surface methodology. The combination of the effects of glucose, ethanol and free sulfur dioxide on the growth of various species of yeast change (Zygosaccharomyces bailii, Schizosaccharomyces pombe, Dekkera / Brettanomyces bruxellensis, Saccharomycodes ludwigii , Saccharomyces cerevisiae) was studied using the method of response surfaces for 60 days at 25 ° C. The initial composition of red wine used in the experiments ranged 2-10 g/L glucose, 10 - 15% (v/v) ethanol and 0 - 40 mg/L of free sulphur dioxide. The results showed that the strain Saccharomyces ludwigii tested is the most resistant to ethanol and free sulfur dioxide in constrast to the most susceptible, Dekkera bruxellensis. The influence of glucose on the growth was not statistically significant, and there was no direct relationship between the production of 4- ethylphenol and glucose consumption. Furthermore, when the cells were inactivated, specially Dekkera bruxllensis, by sulphur dionxide and ethanol, glucose didn’t increase the wine susceptibility.
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6

Pradelles, Rémi. "Etude des capacités de biosorption des levures vis-à-vis du 4-ethylphenol et de la (-)geosmine : deux molécules d'altération du vin." Dijon, 2009. http://www.theses.fr/2009DIJOS028.

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La présence de 4-éthylphénol et de ( )géosmine au sein d’un vin imposent des déviations organoleptiques qualifiées respectivement de « sueur de cheval » et de « moisi-terreux ». Leur origine microbiologique ainsi que leurs faibles seuils de perceptions posent d’importants problèmes en terme de gestion de la qualité des vins. Les levures oenologiques assurant la fermentation alcoolique sont de potentiels matériaux sorbants, notamment mis en évidence suite aux études portant sur l’élevage sur lie des vins. Ce travail se propose d’étudier leur potentiel biosorbant vis-à-vis du 4-éthylphénol et de la ( )géosmine dans un vin modèle synthétique. Les études sur l’influence de la souche de levure, du milieu de culture et des procédés post-récolte appliqués à la biomasse (autolyse, séchage par atomisation, par lyophilisation, par solution saturée en sels, réhydratation) ont permis de démontrer que ces paramètres déterminent grandement la capacité de sorption via des modifications de structure et/ou de composition de la surface levurienne. La caractérisation des capacités de sorption de souches de mutant délétées de gènes codant pour des protéines clés de la paroi a confirmé l’importance de la nature de la structure pariétale dans ces phénomènes de sorption. De plus, les mesures en parallèle des propriétés physico-chimiques de surface des levures (hydrophobie, caractère électron-donneur, potentiel zéta) ainsi que leur caractérisation par IRTF-ATR avant et après sorption, démontrent que les éléments pariétaux mais aussi membranaires sont impliqués dans la sorption et diffèrent selon la molécule sorbée
Presence of 4-ethylphenol and (-)geosmin in a wine impose organoleptic deviations that are described as “horse sweat” and “earthy” or “mouldy”. Their microbiological origin and their very low perception threshold cause important problems in winemaking quality management. Enological yeasts that are responsible for alcoholic fermentation are potential sorbant materials. This property was discovered during works about wine aging on lees. In this work we have studied yeast biosorption capacities for 4-ethylphenol and (-)geosmin in a synthetic model wine. Studies on the influence of yeast strain, culture medium and post-harvest processes applied to biomass (autolysis, atomisation drying, spray-drying, salt-drying and rehydration) lead to show that these parameters are determinant for sorption capacities because of the changes in structure and/or composition of yeast surface. The caracterisation of sorption properties of mutant strains that were deleted of genes coding for key wall proteins, confirmed that wall structure is of major importance in sorption phenomenon. Moreover measurements of physico-chemical properties of yeast wall (hydrophobicity, electron-donnor caracter, zeta potential) and their caracterisation by ATR-FTIR before and after sorption, show that wall components and membrane are implied in sorption and that they differ according to the sorbed molecule
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7

Heuchel, Moritz [Verfasser], and Yvonne [Akademischer Betreuer] Traa. "Co-catalytic cracking of n-decane and 2-ethylphenol as model hydrocarbons for fossil- and bio-based feeds in FCC over zeolite catalysts / Moritz Heuchel ; Betreuer: Yvonne Traa." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2018. http://d-nb.info/1156902037/34.

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8

Kheir, Joyce. "Evaluation du risque Brettanomyces dans le vignoble libanais et étude cinétique de la bioconversion de l'acide p-coumarique en 4-éthylphénol." Phd thesis, Toulouse, INPT, 2012. http://oatao.univ-toulouse.fr/8929/1/kheir.pdf.

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Les altérations sensorielles des vins dues à la présence des levures du genre Brettanomyces se caractérisent par une augmentation de la teneur en phénols volatils tel que le 4-éthylphénol. Le premier objectif de ce travail était de faire un état des lieux sur le risque « éthylphénol » au Liban en s'intéressant à la présence d'un précurseur (acide p-coumarique), du microorganisme responsable (Brettanomyces) et du produit final (4-éthylphénol) dans les vins élaborés dans ce pays. Une forte hétérogénéité de concentrations en acide p-coumarique a été observée avec des valeurs variant de 0 à 31,4 mg.L-1. Des niveaux importants de 4-éthylphénols de l'ordre de 1,367 mg.L-1 ont été détectés sur certains vins. Un dépistage du contaminant microbien a permis de confirmer pour la première fois la présence de Brettanomyces au Liban, les proportions restant toutefois assez faibles (3 % des échantillons testés). Une étude génétique a caractérisé les souches retenues qui se sont montrées diverses au sein de l'espèce. Le travail a porté ensuite sur l'analyse cinétique des étapes réactionnelles constituant le processus enzymatique de la bioconversion des substrats acide p-coumarique et 4-vinlphénol en 4-éthylphénol pour 5 souches de Brettanomyces bruxellensis d'origines libanaises et françaises. La variabilité entre les souches s'est exprimée aux niveaux génétique et cinétique. Des profils hétérogènes de bioréaction ont été mis en évidence en fonction de la nature des souches. L'analyse du bilan-matière a révélé l'existence probable de phénomènes d'adsorption sur les parois des Brettanomyces qui sont souche-dépendants. La dernière partie a été consacrée à l'évaluation du lien entre quantité de biomasse et production de 4-éthylphénol ainsi qu'à l'influence de quelques paramètres environnementaux (pH, source d'ammonium et milieu de culture) sur la cinétique réactionnelle.
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9

Hixson, Josh L. "Chemistry of hydroxycinnamate esters and their role as precursors to Dekkera produced off-flavour in wine." Thesis, 2012. http://hdl.handle.net/2440/76099.

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Анотація:
The potential for malodour in wine caused by the accumulation of ethylphenols has been widely studied with respect to the breakdown of the hydroxycinnamic acids, p-coumaric and ferulic acid, by D. bruxellensis. The presence of esterified hydroxycinnamate conjugates in grapes and wine is well established and they account for a large proportion of the hydroxycinnamate content. There exists the possibility that these conjugates could also provide the potential for spoilage, though they have never been linked to the direct formation of ethylphenols. The research highlighted within this thesis examines the potential role of a number of esterified conjugates in the production of ethylphenols by D. bruxellensis. Two classes of berry derived esters, the tartaric acid and glucose bound hydroxycinnamates, as well as the vinification formed ethyl esters, were synthesised and used for model fermentation experiments. Chapter 2 describes the preparation of a number of protected hydroxycinnamic acid derivatives that were used in the synthesis of the hydroxycinnamoyl tartrate esters (7 and 8) for the first time. Coupling 1-O-chloroacetyl protected p-coumaric and ferulic acids (21 and 22) with di-tert-butyl-L-tartrate (34) followed by selective hydrolysis of the tert-butyl esters yielded p-coumaroyl tartrate (7) and feruloyl tartrate (8). Hydroxycinnamoyl glucose esters (9 and 10) were prepared using the same hydroxycinnamates (21 and 22), esterifying with a prepared trichloroacetimidate glucosyl donor sequence, though purification of the glucose esters resulted in undesired chemical transformations. It was found that photoisomerisation of the glucose esters could be prevented via synthesis under red light, which gave trans-9 and 10, however migration of the hydroxycinnamoyl moiety around the glucose ring, which yielded mainly the 2-O-α- and 6-O-α-esters, was a product of submitting the esters to non-aqueous solvents and could not be avoided. The acyl migration of the glucose esters that was observed in Chapter 2 has been researched at a DFT B3LYP 6-31G* theoretical level in Chapter 3 with respect to both the thermodynamics and kinetics of the transformations. The desired 1-O-β-esters were thermodynamically favoured only in water, while in any other solvent studied the 2-O-α- and 6-O-α-esters would prevail. Kinetically, migration to the 3-O-position involved lower energy barriers which can be equated to a more rapid process, although the ring-flipped conformation needed to achieve the migration would promote subsequent migration to the 6-O-position. Step-wise migration, from the 1-O- to the 2-O-position, was found to be thermodynamically less favoured than other migrations investigated. This effect can be rationalised by the formation of a 5-membered cyclic intermediate in comparison to the 6- membered intermediate produced during 1-O- to 3-O-migration. However, the energy barriers involved in 1-O-β- to 2-O-β-migration better explain the comparative extent of migration observed between the p-coumaroyl and feruloyl glucose esters. The possibility of multiple glucose esters existing in wine was the focus of a brief study, finding two separate p-coumaroyl glucose esters in red and white wine, while a lesser extent of migration in feruloyl glucose limited observation to concentrated wine alone. However, due to co-elution of feruloyl glucose (10) with suspected p-coumaroyl anthocyanin derivatives in red wine, HPLC-MRM was required to detect it, which is the first report of this compound in red wine. Theoretical studies into observed photoisomerisations and the synthesis of cis-hydroxycinnamates are described in Chapter 4. The cis-ethyl hydroxycinnamates were isolated and hydrolysed to give a mixture of cis/trans-hydroxycinnamic acids (3 and 4), which could be separated by flash chromatography, though the pure cis-isomers isomerised rapidly under ambient conditions and slowly under red light back to the trans-isomers. Stable isomeric mixtures were achieved by irradiation with ultra-violet light giving mixtures of 40-50% of the cis-isomer which could be used further in fermentation studies. Computational evidence suggested that isomerisation of the hydroxycinnamic acids was favoured with greater resonance throughout the molecule. Those with deprotonated phenolic moieties possessed the most intramolecular electron movement, decreasing the HOMO-LUMO gap and promoting photoisomerisation. Smaller solvent and substrate effects were also noted, though the nature of the phenol and carboxyl clearly played the most important role in determining stability of each isomer. Fermentation in the presence of the synthesised trans-hydroxycinnamoyl esters (7-12) and investigation into the stereospecificity of D. bruxellensis enzyme activities was performed as detailed in Chapter 5. In Australia, three genetic groups of D. bruxellensis account for 98% of isolates, with the largest of these groups making up 85%. AWRI 1499 is a representative of the largest genetic group, with AWRI 1608 and AWRI 1613 belonging to the two remaining significant genetic groups. In the presence of AWRI 1499, the transethyl- esters (11 and 12) were metabolised to varying extents with the preference for breakdown of ethyl coumarate (11) over ethyl ferulate (12). This selectivity was investigated further and found to be common for both AWRI 1499 and AWRI 1608, while AWRI 1613 was unable to breakdown either ester. The preference for formation of 4- ethylphenol (1) over 4-ethylguaiacol (2) from the ethyl esters could accentuate the ratio of these compounds as seen in wine, initially thought to be brought about by the relative concentration of the precursor acids. Of the berry derived esters, the tartrate esters (7 and 8) were not metabolised by AWRI 1499, and subsequent fermentations with AWRI 1608 and 1613 yielded the same result. This confirmed that the tartrate esters cannot contribute directly to the formation of ethylphenols during exposure to D. bruxellensis. The glucose esters were metabolised by AWRI 1499 to a moderate extent (35% conversion), providing information that these can contribute to the accumulation of ethylphenols during barrel ageing. Furthermore, the isomerisation of the glucose esters lead to studies into the stereoselectivity of D. bruxellensis enzyme activities, whereby the decarboxylase as well as the ethyl esterase showed selectivity for the trans-isomers and that the cis-hydroxycinnamate content of grapes and wine are not important in the accumulation of ethylphenols. The experimental procedures employed throughout Chapters 2-5 are outlined in Chapter 6.
Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2012
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10

Wang, Yong-Siang, and 王詠翔. "Synthesis, Physical and Optoelectronic Behaviors of Ethylphenyl Fulleropyrrolidines." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/389588.

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碩士
國立臺北科技大學
有機高分子研究所
101
Fullerenes have been widely utilized as the electron acceptor material in polymer solar cells because they possess good electron affinity ability and high electron mobility. To resolve the poor solubility problem of our previously synthesized fullerene derivatives NMPC, in this study, we further design a new series of fulleropyrrolidine derivatives, including NMPEC, NPPEC, NiPPPEC, NHPEC, NEHPEC, NiPTPEC, and NCHPEC, with excellent solubility in common organic solvent. The molecular structure of these fullerene derivatives was characterized by 1H NMR, 13C NMR, MALDI-TOF MS and elemental analysis (EA). UV-Vis was employed to determine their optical band gap and solubility. CV was applied to resolve the LUMO of C60 derivatives. However, as this series of fullerene derivatives was used as electron acceptor to fabricate conventional poly(3-hexylthiophene-based bulk-heterojunction solar cells, abnormal S-shaped current-voltage (I-V) curves were observed due to the formation of fullerene-rich layer between hole transport and photoactive blend. Consequently, the inverted cell structure gives nice I-V curves for all fulleropyrrolidines synthesized herein with a power conversion efficiency of ~3%, demonstrating they can be utilized as effective acceptor material in inverted polymer solar cells.
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Частини книг з теми "Ethylphenol"

1

Wohlfarth, Ch. "Dielectric constant of 4-ethylphenol." In Supplement to IV/6, 430. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-75506-7_257.

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2

Wohlfarth, Ch. "Dielectric constant of the mixture (1) methanol; (2) 4-ethylphenol." In Supplement to IV/6, 788–89. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-75506-7_462.

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3

Mclntire, William S., and Craig Bohmont. "The chemical and stereochemical course of oxidation of 4- ethylphenol and other 4-alkylphenols by ^-cresol methylhydroxylase." In Flavins and Flavoproteins 1987, edited by D. E. Edmondson and D. B. McCormick, 677–86. Berlin, Boston: De Gruyter, 1987. http://dx.doi.org/10.1515/9783110884715-113.

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4

Wohlfarth, Ch. "Second virial coefficient of poly[(4-ethylphenoxy)(phenoxy)phosphazene]." In Polymer Solutions, 861–62. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-02890-8_535.

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5

"2,4-Dichloro-6-ethylphenol." In Halogenated Benzenes, Toluenes and Phenols with Water, 240–41. Elsevier, 1985. http://dx.doi.org/10.1016/b978-0-08-023926-2.50064-7.

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6

"4-Chloro-3-methyl-5-ethylphenol." In Halogenated Benzenes, Toluenes and Phenols with Water, 250–51. Elsevier, 1985. http://dx.doi.org/10.1016/b978-0-08-023926-2.50069-6.

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7

Hixson, Josh L., Chris D. Curtin, Mark A. Sefton, and Dennis K. Taylor. "Stereospecificity of D. bruxellensis in the Production of Ethylphenol Off-Flavor in Wine." In Flavour Science, 183–87. Elsevier, 2014. http://dx.doi.org/10.1016/b978-0-12-398549-1.00035-0.

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8

"Zinc ethylphenyl dithiocarbamate." In Toxological Evaluations, 381–98. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-642-60280-1_12.

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9

"Table IV: Volatile compounds identified in the dust of swine confinement units Hydrocarbons Ketones Hexane 1) Acetone 4) «t-Pinen 1) Butanone 4) Limonen 1) Pentanone 4) 3,7,7-Trimethyl -Octanone 4) bicyclo (3,1,1)-l-0ctene-3-one 4) 2-Hepten 1) Benzene 1) Acids Toluene 1) Acetic 4)5)6) Alcohols Propionic 4)5)6) i-Butyric 1)5)6) 1-Pentanol 1) Butyric 4)5)6) 1-Heptanol 1) 1-Valeric 5)6) 4-Methylcyclo-Valeric 4)5)6) hexanol 1) Hexanoic 4)5) 2-Ethylhexanol 1) Heptanoic 4) Octanoic 4) Phenols Nonanoic 4) Decanoic 4) Phenol 1)3)6) Undecanoic 4) p-Cresol 3)4)6) Dodecanoic 4) o-Cresol 1) Laurie 3) p-Ethylphenol 3)6) Tridecanoic 4) o-Ethylphenol 4) Tetradecanoic 4) m-Ethylphenol 4) Benzoic 4) Phenyl acetic 3)4) Indoles 3-Phenyl propionic 3) Hydrocinnamic 4) Indole 2)6) Skatole 2)3)6) Miscellaneous Compounds Aldehydes 2-Pentylfuran 3) Vanillin 3) Butanal 4) 2-Butenal 4) Pentanal 4) 2-Pentenal 4) Hexanal 1)3)4) 1) = WEURMAN (13) 2-Hexenal 4) 2) = TRAVIS and ELLIOTT (31) Heptanal 1)3) 2-Heptenal 4) 3) = HAMMOND et al. (30) 2.4-Heptadienal 3)4) 4) = HAMMOND et al. (40) Nonanal 3) 2-Nonenal 3) 5) = AENGST (33) 2.4-Nonadienal 3)4) 6) = HARTUNG (34) Decanal 4) 2.4-Decadienal 3)4) Benzaldehyde 1)4)." In Odour Prevention and Control of Organic Sludge and Livestock Farming, 344. CRC Press, 1986. http://dx.doi.org/10.1201/9781482286311-138.

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Тези доповідей конференцій з теми "Ethylphenol"

1

Lopez, Juan, Susana Blanco, Alberto Macario, and Fernando Gonzalez. "TRANSIENT CHIRALITY AND MICROSOLVATION IN p-ETHYLPHENOL." In 2022 International Symposium on Molecular Spectroscopy. Urbana, Illinois: University of Illinois at Urbana-Champaign, 2022. http://dx.doi.org/10.15278/isms.2022.te02.

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2

del Valle, Manel, Anna Herrera-Chacon, and Andreu González-Calabuig. "Comparative study of two Electronic Tongues for the detection of ethylphenols by MIP-based and chemically modified voltammetric sensors." In 7th International Electronic Conference on Sensors and Applications. Basel, Switzerland: MDPI, 2020. http://dx.doi.org/10.3390/ecsa-7-08237.

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3

Singh, Jagvir, Kamelesh Kumari, Prashant Singh, Gopal K. Mehrotra, and Netra Pal Singh. "Synthesis of metal-Bis(N-(3-ethylphenyl)-pyridine-2-acetyl-hydrazine complexes and evaluation of their magnetic and antimicrobial activity." In FUNCTIONAL MATERIALS: Proceedings of the International Workshop on Functional Materials (IWFM-2011). AIP, 2012. http://dx.doi.org/10.1063/1.4736927.

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