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Styrene oxide

About: Styrene oxide is a(n) research topic. Over the lifetime, 1797 publication(s) have been published within this topic receiving 41536 citation(s). The topic is also known as: styryl oxide & styrene epoxide.
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Journal ArticleDOI
Franz Oesch1, Donald M. Jerina1, John W. Daly1Institutions (1)
TL;DR: The simplicity of the present assay permits the use of epoxide hydrase a a marker enzyme for microsomal membranes in hepatic microsomes increases during maturation of rats and following pretreatment of rats with phenobarbital or 3-methylcholanthrene.
Abstract: [7-3H]styrene oxide is converted to [7-3H]styrene glycol by a hepatic epoxide hydrase. Differential extraction of the incubation medium provides the basis for a rapid, simple method to assay epoxide hydrase activity. Unreacted substrate is first removed by extraction into petroleum ether followed by extraction of the glycol into ethyl acetate for assay by scintillation spectrometry. Enzyme activity is present in liver and kidneys and is localized exclusively in the microsomal fraction. The simplicity of the present assay permits the use of epoxide hydrase a a marker enzyme for microsomal membranes. The specific activity of this enzyme in hepatic microsomes increases during maturation of rats and following pretreatment of rats with phenobarbital or 3-methylcholanthrene.

407 citations


Journal ArticleDOI
Jinliang Song1, Zhaofu Zhang1, Suqin Hu1, Tianbin Wu1  +2 moreInstitutions (1)
06 Jul 2009-Green Chemistry
Abstract: The development of efficient heterogeneous catalysts for the cycloaddition of CO2 with epoxides to produce five-membered cyclic carbonates under mild reaction conditions is of great importance. In this work, the coupling reaction of CO2 with propylene oxide (PO) to produce propylene carbonate (PC) catalyzed by MOF-5 (metal-organic frameworks) in the presence of quaternary ammonium salts (Me4NCl, Me4NBr, Et4NBr, n-Pr4NBr, n-Bu4NBr) was studied in different conditions. It was discovered that MOF-5 and quaternary ammonium salts had excellent synergetic effect in promoting the reaction, and the MOF-5/n-Bu4NBr catalytic system was the most efficient among them. The optimal temperature for the reaction was around 50 °C. The reaction could be completed in 6 h at low CO2 pressure with very high selectivity. A decrease of the yield of PC was not noticeable after MOF-5 was reused three times, indicating that the MOF-5 was stable. The MOF-5/n-Bu4NBr catalytic system was also very active and selective for the cycloaddition of CO2 with other epoxides, such as glycidyl phenyl ether, epichlorohydrin and styrene oxide. The mechanism for the coupling reaction is also discussed.

362 citations


Journal Article
01 Jan 2009-Green Chemistry
Abstract: The development of efficient heterogeneous catalysts for the cycloaddition of CO₂ with epoxides to produce five-membered cyclic carbonates under mild reaction conditions is of great importance. In this work, the coupling reaction of CO₂ with propylene oxide (PO) to produce propylene carbonate (PC) catalyzed by MOF-5 (metal-organic frameworks) in the presence of quaternary ammonium salts (Me₄NCl, Me₄NBr, Et₄NBr, n-Pr₄NBr, n-Bu₄NBr) was studied in different conditions. It was discovered that MOF-5 and quaternary ammonium salts had excellent synergetic effect in promoting the reaction, and the MOF-5/n-Bu₄NBr catalytic system was the most efficient among them. The optimal temperature for the reaction was around 50 °C. The reaction could be completed in 6 h at low CO₂ pressure with very high selectivity. A decrease of the yield of PC was not noticeable after MOF-5 was reused three times, indicating that the MOF-5 was stable. The MOF-5/n-Bu₄NBr catalytic system was also very active and selective for the cycloaddition of CO₂ with other epoxides, such as glycidyl phenyl ether, epichlorohydrin and styrene oxide. The mechanism for the coupling reaction is also discussed.

345 citations


Journal ArticleDOI
Abstract: This paper gives a comprehensive report on a two-step synthesis of dimethyl carbonate (DMC) from epoxides, carbon dioxide and methanol using various basic metal oxide catalysts. The first step is the reaction of ethylene oxide or propylene oxide with CO 2 to form the corresponding cyclic carbonates, and the second step is the transesterification reaction of the cyclic carbonates with methanol to DMC and glycols. Among the catalysts examined, MgO is the most active and selective for both these reactions. Other alcohols can be used for the second step, but the activity decreases as the carbon number of the alcohol increases. Although a one-pot synthesis of DMC, i.e. the sequential reaction of the epoxide, CO 2 and methanol, is also possible with MgO, the selectivity is low because of the alcoholysis of the epoxide. In contrast with the reactions of ethylene oxide and propylene oxide, when styrene oxide is used for the first reaction and for the one-pot synthesis, mandelic acid is produced. Basic properties of the metal oxide catalysts were measured by temperature programmed desorption of CO 2 . The relationship between the catalytic performance and the basic property is discussed.

336 citations


Journal ArticleDOI
TL;DR: Styrene oxide and 2-phenylethanol metabolism in the styrene-degrading Xanthobacter sp.
Abstract: Styrene oxide and 2-phenylethanol metabolism in the styrene-degrading Xanthobacter sp. strain 124X was shown to proceed via phenylacetaldehyde and phenylacetic acid. In cell extracts 2-phenylethanol was oxidized by a phenazine methosulfate-dependent enzyme, probably a pyrroloquinoline quinone enzyme. Xanthobacter sp. strain 124X also contains a novel enzymatic activity designated as styrene oxide isomerase. Styrene oxide isomerase catalyzes the isomerization of styrene oxide to phenylacetaldehyde. The enzyme was partially purified and shown to have a very high substrate specificity. Of the epoxides tested, styrene oxide was the only substrate transformed. The initial step in styrene metabolism in Xanthobacter sp. strain 124X is oxygen dependent and probably involves oxidation of the aromatic nucleus.

322 citations


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Metrics
No. of papers in the topic in previous years
YearPapers
20221
202149
202042
201957
201861
201763

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Topic's top 5 most impactful authors

Kari Hemminki

26 papers, 819 citations

Gary P. Carlson

20 papers, 551 citations

Franz Oesch

18 papers, 615 citations

Harri Vainio

14 papers, 316 citations

Mannar R. Maurya

10 papers, 379 citations