Showing papers on "Styrene oxide published in 1989"

Metabolism of Styrene Oxide and 2-Phenylethanol in the Styrene-Degrading Xanthobacter Strain 124X.

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.

Inhibition of human liver microsomal epoxide hydrolase by valproate and valpromide: in vitro/in vivo correlation

Abstract: On the basis of drug interactions with carbamazepine epoxide, it has been hypothesized that valproic acid and valpromide are inhibitors of epoxide hydrolase, but the role of epoxide hydrolase in these interactions has not been clearly established. In this study, therapeutic concentrations of valproic acid (less than 1 mmol/L) and valpromide (less than 10 mumol/L) inhibited hydrolysis of carbamazepine epoxide and styrene oxide in human liver microsomes and in preparations of purified human liver microsomal epoxide hydrolase. Valpromide (KI = 5 mumol/L) was 100 times more potent than valproic acid (KI = 550 mumol/L) as an inhibitor of carbamazepine epoxide hydrolysis in microsomes. After administration of carbamazepine epoxide to volunteers, the transdihydrodiol formation clearance was decreased 20% by valproic acid (blood concentration approximately 113 mumol/L) and 67% by valpromide (blood concentration less than 10 mumol/L). For both valproic acid and valpromide, a striking similarity exists between in vitro and in vivo inhibitory potencies. Valproic acid and valpromide are the first drugs known to inhibit microsomal epoxide hydrolase, an important detoxification enzyme, at therapeutic concentrations.

Sub-chronic effects of styrene and styrene oxide on lipid peroxidation and the metabolism of glutathione in rat liver and brain.

Abstract: Sub-chronic effects of styrene and styrene oxide on lipid peroxidation, glutathione contents and glutathione reductase activities in the liver and brain were examined after intraperitoneal administration to rats 3 times a week for 7 weeks. Styrene (300, 400 and 500 mg/kg) and styrene oxide (200 and 300 mg/kg) increased lipid peroxidation in the liver after 7 weeks of treatment. Hepatic lipid peroxidation in the rats treated with a higher dose of styrene oxide (400 mg/kg) was significantly enhanced even after 2 weeks of treatment. On the other hand, no change in lipid peroxidation was observed in the brain under the above conditions. Neither glutathione contents nor glutathione reductase activities in the liver and brain were altered at 40 h after the last of these sub-chronic treatments. To elucidate the cause of lipid peroxidation, the time courses of glutathione content after treatment with either styrene or styrene oxide (300 mg/kg) were studied in more detail. Significant decreases in both the GSH and GSSG contents were detected shortly after these treatments and the levels recovered to the control values at 40 h in these organs, although the changes were less significant in the brain of rats treated with styrene. These results suggest that enhancement of lipid peroxidation in the liver after treatment with styrene or styrene oxide was a consequence of repeated depletions of glutathione to certain critical levels and delayed recovery of lipid peroxides.

O6-substituted-2'-deoxyguanosine-3'-phosphate adducts detected by 32P post-labeling of styrene oxide treated DNA.

Abstract: 32P post-labeling of DNA reacted with styrene oxide resulted in the detection of six adducts. In order to determine which of these corresponded to modification at the O6 position of guanine, O6-substituted styrene oxide-deoxyguanosine-3'-monophosphate derivatives were synthesized. The two synthetic isomers were purified by HPLC and the structures were confirmed by mass spectrometry and 1H NMR. 32P post-labeling and co-chromatography with the DNA-styrene-7,8-oxide reaction products resulted in the assignment of adduct number 4 as O6-(2-hydroxy-2-phenylethyl)-2'--deoxyguanosine-3',5'-bisphosphate and adduct number 5 as O6-(2-hydroxy-1-phenylethyl)-2'-deoxyguanosine-3',5'-bisphosphate.

A novel insertion reaction of epoxy compounds into phenyl ester linkages in polymer chains

Abstract: The insertion reaction of various epoxy compounds such as phenyl glycidyl ether (PGE), methyl glycidyl ether, butyl glycidyl ether (BGE), and styrene oxide into the phenyl ester linkage in the polymer chain was investigated using quaternary ammonium salts as catalysts in diglyme, anisole, sulfolane, o-dichlorobenzene, or DMSO at 100–150°C. The reaction of PGE with poly[4-(4-nitrobenzoyloxy)styrene] (polymer 1a) proceeded almost quantitatively to give the corresponding polymer using tetrabutylammonium bromide (TBAB) as catalyst in diglyme at 100°C for 24 h. The reactions of BGE with poly(4-nitrophenyl methacrylate), and copolyarylate derived from 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane and iso- and terephthaloyl chlorides also produced the corresponding polymers with 86 and 89 mol% new structural units, respectively, using TBAB in sulfolane at 150°C for 24 h. Furthermore, it was found that the degree of insertion of the epoxy compound into the ester linkage in the polymer chain was affected by the kind of epoxy compound, reaction solvent, catalyst concentration, substituent group on the phenyl ester, and structure of the polymer. Chiral polymers were also synthesized with high degrees of insertion by the reaction of chiral epoxides such as (R)-1,2-epoxyhexane, (R)-1,2-epoxyheptane, and (R)-1,2-epoxydecane with polymer 1a and poly(2,4-dichlorophenyl methacrylate) using TBAB in diglyme at 120°C for 24 h.

Grafting of Polyesters from Carbon Fiber. Anionic Ring-Opening Copolymerization of Epoxides with Cyclic Acid Anhydrides Initiated by COOK Groups on the Surface of Carbon Fiber

Abstract: To modify the surface of carbon fiber, the anionic grafting of polyesters from potassium carboxylate (COOK) groups on the surface was investigated. The COOK groups were introduced onto the surface of carbon fiber by the reaction of carboxyl groups (introduced by the oxidation of the surface with nitric acid) with potassium hydroxide. Untreated carbon fiber has no ability to initiate the anionic ring-opening copolymerization of epoxides with cyclic acid anhydrides. On the contrary, the anionic ring-opening copolymerization of epoxides—such as styrene oxide (SO), chloromethyloxirane (ECH), and glycidyl phenyl ether (GPE)—with cyclic acid anhydrides—such as maleic anhydride (MAn), succinic anhydride (SAn), and phthalic anhydride (PAn)—was found to be initiated by the COOK groups on the surface. In the polymerizations, alternating copolymers (i.e., polyesters) were effectively grafted from the carbon fiber surfaces depending on the propagation of the polymer from the surface COOK groups: for example,...

Cationic aqueous bituminous emulsion-aggregate slurries with improved curing rates

Abstract: Slurries are formed with cationic emulsions prepared by emulsifying bitumen, such as an asphalt, in water with a cation-active emulsifier which is the product of the reaction of polyamine with certain polycarboxylic acids, which product is subsequently modified by reaction with from 10-30% of a member of the group consisting of acetic anhydride, phthalic anhydride, propylene carbonate, and styrene oxide.

The Role of the External Surface in Reactions with Zeolite Catalysts

Abstract: The role of the external surface of the zeolite catalysts is examined by comparing our results in styrene oxide isomerization and toluene alkylation with those reported in other published works. As a conclusion the external surface of zeolite crystals must be regarded as catalytically active and its role can be useful to explain the catalytic behaviour of the zeolites. Nevertheless the effect of the external active sites is not sufficiently depicted and further investigations appear to be necessary.

Selective Synthesis of Carbonyl Compounds Using Zeolites

Abstract: Various typical acid-catalyzed reactions leading to carbonyl compounds were studied using zeolites taking into account their acidic and shape selective properties. Acylation of aromatic compounds by carboxylic acids over Y zeolites leads to quantitative conversion in acylated derivatives with very high para selectivity. On the other hand, the Fries rearrangement of phenylbenzoate gives mainly ortho hydroxybenzophenone. Zeolites are also efficient catalysts in hydration of various aromatic and aliphatic alkynes leading to the corresponding ketones. The epoxide rearrangement of styrene oxide yields phenylacetaldehyde with high conversion. In this latter case, the use of surface-modified zeolites shows that both external and internal acid sites of the zeolite are involved in liquid phase epoxide conversion.

Addition products of styrene oxide

Abstract: Products of the addition reaction of styrene oxide with polyalkylene glycol ether of the formula in which R is an aliphatic radical having at least 4 carbon atoms, "alkylene" is an alkylene radical having 2 or 3 carbon atoms, and m is a number from 1 to 100, and their acidic esters and salts represent a novel class of nonionogenic or anionic surfactants which are used as textile finishers, in particular as emulsifiers, wetting agents, antifoam agents or dyeing assistants.

Propylene oxide polymerization using the diphenylzinc-acetone system in benzene at 60°C

Abstract: The diphenylzinc-acetone system was used as catalyst for propylene oxide polymerization in benzene solution at 60°C. This system as well as the diphenylzinc-water system is greatly influenced by the molar ratio of acetone to diphenylzinc and the maximum catalyst activity was found for a ratio of unity. GPC results strongly suggest the presence of more than one active species for the system.13CNMR analysis indicates that the resulting poly(propylene oxide) has a head-to-tail arrangement. This system was not an effective catalyst for the styrene oxide polymerization.

Melt viscosity depressant for polyester resin

Abstract: PURPOSE: To lower the melt viscosity of a polyester resin without lowering its degree of polymerization by using a specified compound. CONSTITUTION: An aromatic glycol of the formula: HO-X-OH (wherein X is an aromatic residue) is reacted by an addition reaction with an alkylene oxide such as ethylene oxide, propylene oxide or styrene oxide, and the product is acylated with a 2-22C fatty acid to obtain a melt viscosity depressant for polyester resins comprising a compound of the formula (wherein A is a 2-22C acyl; R is a 1-4C alkylene or a styrene residue; and m and n are positive integers to give a sum of m+n of 1-4). 0.1-10 pts.wt. this depressant is added to 100 pts.wt. polyester resin. COPYRIGHT: (C)1990,JPO&Japio

Selective inhibition of cytosolic epoxide hydrolase activity in vitro by compounds that inhibit catalase

Abstract: The ability of a number of known inhibitors of catalase activity to affect cytosolic and microsomal epoxide hydrolase activities in vitro, measured as enzymatic trans-stilbene oxide hydrolysis and styrene oxide hydrolysis, respectively, was investigated. Catalase and cytosolic epoxide hydrolase activities are inhibited by hydroxylated metabolites of 2-amino-4,5-diphenylthiazole (DPT). The metabolite hydroxylated on the 4-phenyl ring (4OH-DPT) and the metabolite hydroxylated on both phenyl rings (4,5-DIOH-DPT) are potent inhibitors of both enzymes; the metabolite hydroxylated on the 5-phenyl ring (5OH-DPT) is less potent. Unmetabolized DPT has no effect on either enzyme. 4OH-DPT inhibits, but 5OH-DPT enhances, microsomal epoxide hydrolase activity. 4,5-DIOH-DPT and DPT have no effect on this enzyme. Other compounds that inhibit both catalase and cytosolic epoxide hydrolase activities, but do not inhibit microsomal epoxide hydrolase activity, are nordihydroguaiaretic acid and 2-aminothiazole. Microsomal epoxide hydrolase activity is enhanced by 2-aminothiazole and levamisole in vitro. Thus these inhibitors of catalase are selective epoxide hydrolase inhibitors in that they inhibit cytosolic epoxide hydrolase activity in vitro, but have either no effect on, or increase the activity of, microsomal epoxide hydrolase in vitro. Conversely, the selective cytosolic epoxide hydrolase inhibitors 4-phenylchalcone oxide and 4'-phenylchalcone oxide do not inhibit catalase activity, nor does trichloropropene oxide, a selective microsomal epoxide hydrolase inhibitor.

Iodation of epoxy compound and production of iodohydrin

Abstract: PURPOSE:To obtain the title compound useful as a synthetic raw material for allylic alcohols, etc., useful as synthetic intermediates for drugs and agricultural chemicals, solvents, etc., in high selectivity and directly, by iodating an epoxy group-containing compound with GeI2. CONSTITUTION:An epoxy group-containing compound as a raw material is reacted with GeI2 which is dissolved in a solvent such as dimethylformamide or diethylformamide to give the aimed compound. The reaction temperature is room temperature when the epoxide compound of the raw material is cyclohexene oxide, -20 deg.C when the raw material is butylene oxide and -40 deg.C when the raw material is styrene oxide or butadiene monoepoxide. The amount of GeI2 used is preferably 0.5-1 equivalent based on 1 equivalent epoxy group. As another method wherein the raw material, GeI2 and water are used, preferably the raw material is iodated and hydrolyzed with water to give the aimed compound.

Styrene oxide products

Abstract: Styrene oxide products of the formula in which R is an aliphatic radical having 1 to 24 carbon atoms, "Alkylene" is an alkylene radical having 2 or 3 carbon atoms, one of Y1 and Y2 is phenyl and the other is hydrogen, m is a number from 1 to 100, and one of Y3 and Y4 is phenyl and the other is hydrogen, and the acid esters and salts thereof are a novel class of nonionogenic or anionic surfactants which are used as textile finishes, in particular as emulsifiers, dyeing assistants, wetting agents, deaerating agents or padding assistants.

Determination of epoxide hydrolase activity by high performance liquid chromatography

Abstract: A new highly sensitive method of microsomal epoxide hydrolase activity has been worked out. The product of styrene oxide enzyme hydrolysis--phenylethyleneglycol (PEG) was extracted by n-butanol, and its aliquot was analysed by high-performance liquid-chromatography on Silica Gel using hexane-isopropanol-water (80:28:2) mobile phase. PEG was detected at 210 nm. The detection limit of PEG was 5 pmol per injection. The coefficient of variation of the method was 3.7%.

Reaction of Styrene Oxide in the Presence of Ion-exchange Resins

Abstract: The reactions of styrene oxide (1) with acetone, the isomerization of oxides, and reactions of (1) with alcohols in the presence of H-form ion-exchange resins (Dowex 50W-X8, Dowex 50 W-X4, Diaion PK 216, Amberlyst 15 and Nafion NR 50) were studied. The following results were obtained : 2, 2-Dimethyl-4-phenyl-1, 3-dioxolane was synthesized in a high yield (isolated yield 93%) by a simple reaction of (1) with acetone catalyzed by Amberlyst 15 or Nafion NR 50. Phenylacetaldehyde was obtained (isolated yield 91%) by the isomerization of (1) catalyzed by Amberlyst 15 or Nafion NR 50. 2-Phenyl-2-methoxyethanol was obtained in a high yield by the reaction of (1) with methanol catalyzed by ion-exchange resins.