Xn:Harmful;107-22-2Relevant articles and documents
Glycolaldehyde Production from Ethylene Glycol with Immobilized Alcohol Oxidase and Catalase
Ukeda, Hiroyuki,Ishii, Tohru,Sawamura, Masayoshi,Isobe, Kimiyasu
, p. 1589 - 1591 (1998)
An enzymatic method for glycolaldehyde production from ethylene glycol was investigated using immobilized alcohol oxidase and catalase. Those enzymes were immobilized onto Chitopearl BCW 3501. When only alcohol oxidase was immobilized onto it, the apparent activity was 190 units/g in wet gel using methanol as the substrate. Tris-HCl buffer (1.5 M; pH 9.0) was selected based on a high stability of glycolaldehyde and a low production of glyoxal as a by-product. Under the optimum conditions, 0.97 M glycolaldehyde was formed from 1.0 M ethylene glycol and the ratio of glyoxal to glycolaldehyde was less than 1%.
Products of the OH radical-initiated reactions of furan, 2- and 3-methylfuran, and 2,3- and 2,5-dimethylfuran in the presence of NO
Aschmann, Sara M.,Nishino, Noriko,Arey, Janet,Atkinson, Roger
, p. 457 - 466 (2014)
Products of the gas-phase reactions of OH radicals with furan, furan-d 4, 2- and 3-methylfuran, and 2,3- and 2,5-dimethylfuran have been investigated in the presence of NO using direct air sampling atmospheric pressure ionization tandem mass spectrometry (API-MS and API-MS/MS), and gas chromatography with flame ionization and mass spectrometric detectors (GC-FID and GC-MS) to analyze samples collected onto annular denuders coated with XAD solid adsorbent and further coated with O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine for derivatization of carbonyl-containing compounds to their oximes. The products observed were unsaturated 1,4-dicarbonyls, unsaturated carbonyl-acids and/or hydroxy-furanones, and from 2,5-dimethylfuran, an unsaturated carbonyl-ester. Quantification of the unsaturated 1,4-dicarbonyls was carried out by GC-FID using 2,5-hexanedione as an internal standard, and the measured molar formation yields were: HC(O)CH=CHCHO (dominantly the E-isomer) from OH + furan, 75 ± 5%; CH3C(O)CH=CHCHO (dominantly the E-isomer) from OH + 2-methylfuran, 31 ± 5%; HC(O)C(CH3)=CHCHO (a E-/Z-mixture) from OH + 3-methylfuran, 38 ± 2%; and CH 3C(O)C(CH3)=CHCHO from OH + 2,3-dimethylfuran, 8 ± 2%. In addition, a formation yield of 3-hexene-2,5-dione from OH + 2,5-dimethylfuran of 27% was obtained from a single experiment, in good agreement with a previous value of 24 ± 3% from GC-FID analyses of samples collected onto Tenax solid adsorbent without derivatization.
Glucose oxidation to formic acid and methyl formate in perfect selectivity
Albert, Jakob,Bukowski, Anna,Kumpidet, Chiraphat,Maerten, Stephanie,Vo?, Dorothea,Wasserscheid, Peter
, p. 4311 - 4320 (2020)
We report the highly remarkable discovery that glucose oxidation catalysed by polyoxometalates (POMs) in methanolic solution enables formation of formic acid and methyl formate in close to 100percent combined selectivity, thus with only negligible sugar oxidation to CO2. In detail, we report oxidation of a methanolic glucose solution using H8[PV5Mo7O40] (HPA-5) as catalyst at 90 °C and 20 bar O2 pressure. Experiments with 13C-labelled glucose confirm unambiguously that glucose is the only source of the observed formic acid and methyl formate formation under the applied oxidation conditions. Our results demonstrate a very astonishing solvent effect for the POM-catalysed glucose oxidation. In comparison to earlier work, a step-change in product yield and selectivity is achieved by applying an alcoholic reaction medium. The extremely high combined yields of formic acid and methyl formate greatly facilitate product isolation as low-boiling methyl formate (bp = 32 °C) can simply be isolated from the reaction mixture by distillation.
Ring-cleavage Reactions of Aromatic Hydrocarbons Studied by FT-IR Spectroscopy. III. Photooxidation of 1,2,3-, 1,2,4-, and 1,3,5-Trimethylbenzenes in the NOx-Air System
Bandow, Hiroshi,Washida, Nobuaki
, p. 2549 - 2555 (1985)
Photooxidation of 1,2,3-, 1,2,4-, and 1,3,5-trimethylbenzenes was carried out in the NOx-air system.Formation of glyoxal, methylglyoxal and biacetyl was observed in the case of 1,2,3- and 1,2,4-trimethylbenzenes, and only methylglyoxal was observed from 1,3,5-trimethylbenzene.Yield of glyoxal, methylglyoxal and biacetyl were 7, 18, and 45percent and 8, 37, and 11percent of trimethylbenzene consumed in cases of 1,2,3- and 1,2,4-trimethylbenzenes, respectively.The reaction mechanism which was used to explain the yields of α-dicarbonyl compounds from toluene and o-, m-, p-xylenes in the preceding paper (part II) has been applied to explain these yields, and has been found to reproduce these yields well.Formation of 3-hexene-2,5-dione was observed only from 1,2,4-trimethylbenzene.The fractions of the ring-cleavage process in the total reaction were 70, 56, and 64percent in cases of 1,2,3-, 1,2,4-, and 1,3,5-trimethylbenzenes, respectively.The yields of the ring-cleavage process are discussed.
Study of the atmospheric chemistry of 2-formylcinnamaldehyde
Aschmann, Sara M.,Arey, Janet,Atkinson, Roger
, p. 7876 - 7886 (2013)
2-Formylcinnamaldehyde is a significant product of the reaction of naphthalene with OH radicals, and its photolysis and gas-phase reactions with O3, NO3 radicals, and OH radicals have been investigated in this work. 2-Formylcinnamaldehyde was observed to undergo photolysis by black lamps, with a photolysis rate of 0.14 × J(NO2), where J(NO2) is the NO2 photolysis rate. The measured rate constants for the reactions of 2-formylcinnamaldehyde with O3, NO3 radicals, and OH radicals (in units of cm3 molecule-1 s-1) were 1.8 × 10-18, 4.3 × 10-14, and 2.1 × 10-11, respectively, with those for the O3 and NO3 reactions being for the E-isomer. 2-Formylcinnamaldehyde was observed to undergo significant adsorption and desorption from the reaction chamber Teflon film walls, and the photolysis rate and rate constants are subject to significant uncertainties. In the atmosphere, the dominant chemical loss processes for 2-formylcinnamaldehyde will be photolysis during daylight hours and reaction with NO3 radicals during nighttime. Phthaldialdehyde and glyoxal were observed as products of the OH radical and O3 reactions, and photolysis of E-2- formylcinnamaldehyde led to formation of Z-2-formylcinnamaldehyde plus two other molecular weight 160 isomers. The present results are compared with previous literature data, and reaction mechanisms are discussed.
Oxidation of aminodinitrotoluenes with ozone: Products and pathways
Spanggord, Ronald J.,Yao, C. David,Mill, Theodore
, p. 497 - 504 (2000)
An investigation of the products from the reaction of ozone with aminodinitrotoluenes (ADNTs) provides information about the oxidation pathway. Studies conducted at low conversions of 2- and 4-ADNT show 2:1 ozone/ADNT stoichiometries, prompt formation of glyoxylic and pyruvic acids, and NO2- and NO3- (NOx) ions. Reaction schemes to account for these results involve a 1,3-dipolar cycloaddition of ozone to selected double bonds of the aromatic ring, leading to ring cleavage. 15N-Labeling experiments indicate that the amino function is not involved in the initial ozone oxidation and eventually is incorporated into pyruvamide (2-ADNT) and oxamic acid (4-ADNT) before being oxidized to nitrate.
Aqueous Photochemistry of Glyoxylic Acid
Eugene, Alexis J.,Xia, Sha-Sha,Guzman, Marcelo I.
, p. 3817 - 3826 (2016)
Aerosols affect climate change, the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. While the formation of secondary organic aerosols (SOA) from gas phase precursors is relatively well understood, studying aqueous chemical reactions contributing to the total SOA budget is the current focus of major attention. Field measurements have revealed that mono-, di-, and oxo-carboxylic acids are abundant species present in SOA and atmospheric waters. This work explores the fate of one of these 2-oxocarboxylic acids, glyoxylic acid, which can photogenerate reactive species under solar irradiation. Additionally, the dark thermal aging of photoproducts is studied by UV-visible and fluorescence spectroscopies to reveal that the optical properties are altered by the glyoxal produced. The optical properties display periodicity in the time domain of the UV-visible spectrum of chromophores with absorption enhancement (thermochromism) or loss (photobleaching) during nighttime and daytime cycles, respectively. During irradiation, excited state glyoxylic acid can undergo α-cleavage or participate in hydrogen abstractions. The use of 13C nuclear magnetic resonance spectroscopy (NMR) analysis shows that glyoxal is an important intermediate produced during direct photolysis. Glyoxal quickly reaches a quasi-steady state as confirmed by UHPLC-MS analysis of its corresponding (E) and (Z) 2,4-dinitrophenylhydrazones. The homolytic cleavage of glyoxylic acid is proposed as a fundamental step for the production of glyoxal. Both carbon oxides, CO2(g) and CO(g) evolving to the gas-phase, are quantified by FTIR spectroscopy. Finally, formic acid, oxalic acid, and tartaric acid photoproducts are identified by ion chromatography (IC) with conductivity and electrospray (ESI) mass spectrometry (MS) detection and 1H NMR spectroscopy. A reaction mechanism is proposed based on all experimental observations.
Atmospheric chemistry of unsaturated carbonyls: butenedial, 4-oxo-2- pentenal, 3-hexene-2,5-dione, maleic anhydride, 3H-furan-2-one, and 5-methyl-3H-furan-2-one
Bierbach,Barnes,Becker,Wiesen
, p. 715 - 729 (1994)
As part of a study on the oxidation mechanisms of aromatics some aspects of the atmospheric chemistry of several possible products, unsaturated 1,4-dicarbonyl compounds and two furanones, have been investigated in a 1080-L reaction chamber by 296 ± 2 K in 1000 mbar of synthetic air. The results indicate that reaction with OH radicals will be an important atmospheric sink for all of the unsaturated carbonyls studied here. However, for butenedial, 4-oxo-2-pentenal, and hexene-2,5-dione the results suggest that photolysis will probably be an even stronger sink. -from Authors
Formation of glyoxal by oxidative dehydrogenation of ethylene glycol
Ai, Mamoru
, p. 375 - 381 (2002)
Iron(III) phosphates doped with a very small amount of molybdenum(VI) were found to be effective as catalysts for a vapor-phase oxidative dehydrogenation of ethylene glycol to glyoxal. The effects of the molybdenum(VI) content and of the reaction variable
Microsome-mediated oxidation of N-nitrosodiethanolamine (NDELA), a bident carcinogen
Loeppky, Richard N.,Goelzer, Petra
, p. 457 - 469 (2002)
N-Nitrosodiethanolamine (NDELA), an environmentally prevalent, potent carcinogen, undergoes competitive rat liver microsome-mediated oxidation at both the α (adjacent to N)-and β-positions of the 2-hydroxyethyl chains. The former process, α-hydroxylation, is detected by the formation of glycolaldehyde (determined as its 2,4-dinitrophenylhydrazone DNP) that is assumed to arise from the decomposition of the corresponding α-hydroxynitrosamine, which is also the progenitor of the 2-hydroxyethyldiazonium ion. This finding refutes prior published work that states that the α-hydroxylation of NDELA does not occur. Competitive microsomal oxidation at the β-position gives the hemiacetal N-nitroso-2-hydroxymorpholine (NHMOR) at a rate 1.5 times α-hydroxylation. Glycolaldehyde is oxidized in this system to glyoxal at a rate 39 times the conversion of NDELA to glycolaldehyde. The α-hydroxylation of NHMOR at either C-3 or C-5 to give glyoxal or glycolaldehyde, respectively, occurs at respective rates 3-6 times that of the α-hydroxylation of NDELA. Ethylene glycol, a hydrolysis product of the 2-hydroxyethyldiazonium ion is shown to undergo microsome mediate oxidation to glyoxal. Ethyl-2-hydroxyethylnitrosamine (NEELA) undergoes a similar set of microsome-mediated oxidations at α-position of the ethyl (fastest) and 2-hydroxyethyl groups, as well as β-oxidation of the 2-hydroxyethyl group, a process which is slightly more rapid than α-hydroxylation of the same chain. Comparisons of oxidations rates of these substrates, as manipulated by preinducers, isoniazid, streptozocin, and phenobarbital, and enzyme inhibitors diethyldithiocarbamate and 4-methylpyrazole, with that of dimethylnitrosamine, a substrate for cytochrome P450 2E1, strongly suggest that this isozyme is also responsible for the oxidations reported here. α-Deuteration of NDELA practically eliminates its α-hydroxylation by microsomes from isoniazid induced rats, but doubles β-oxidation, while β-deuteration of this substrate significantly reduces β-oxidation and enhances α-hydroxylation. Since both glyoxal-guanine and 2-hydroxyethyl-DNA base adducts are known to arise from the in vivo administration of NDELA and because this work demonstrates that these two fragments can come from the microsomal oxidation of a single nitrosamine molecule containing the 2-hydroxyethyl group, NDELA and related nitrosamines are bident (two-toothed) carcinogens, a process which is likely to enhance their carcinogenic potency.
