Oxidation Of Glycolaldehyde Research Articles

In‐Situ Investigations of Polyoxometalate‐Catalysed Biomass Oxidation to Formic Acid by Using Multinuclear High Resolution Flow NMR Spectroscopy

AbstractBiomass valorisation over polyoxometalate‐based (POM) catalysts is a promising strategy for green and sustainable chemistry. In order to further improve such processes e. g. by using different additives, a better understanding of the chemical influence of various additives on the catalyst is paramount. The main objective of this study is to gain a deeper understanding of the effects caused by various additives on the catalytically active vanadium species in the selective aerobic oxidation of carbohydrates to formic acid (esters). After carefully choosing a suitable model system, the oxidation of glycolaldehyde using the heteropolyacid H5PV2Mo10O40 (HPA‐2) as a catalyst was studied in situ by Flow Nuclear magnetic resonance (FlowNMR) spectroscopy. These measurements allowed to identify the catalytically active isomer of the HPA‐2‐catalyst and to observe the influence of additives on the reaction kinetics in situ. These findings provide a good basis for further improving POM‐based catalytic aerobic oxidation of biomass.

Glycolaldehyde is an endogenous source of lysine N-pyrrolation

Lysine N-pyrrolation converts lysine residues to Nϵ-pyrrole-l-lysine (pyrK) in a covalent modification reaction that significantly affects the chemical properties of proteins, causing them to mimic DNA. pyrK in proteins has been detected in vivo, indicating that pyrrolation occurs as an endogenous reaction. However, the source of pyrK remains unknown. In this study, on the basis of our observation in vitro that pyrK is present in oxidized low-density lipoprotein and in modified proteins with oxidized polyunsaturated fatty acids, we used LC-electrospray ionization-MS/MS coupled with a stable isotope dilution method to perform activity-guided separation of active molecules in oxidized lipids and identified glycolaldehyde (GA) as a pyrK source. The results from mechanistic experiments to study GA-mediated lysine N-pyrrolation suggested that the reactions might include GA oxidation, generating the dialdehyde glyoxal, followed by condensation reactions of lysine amino groups with GA and glyoxal. We also studied the functional significance of GA-mediated lysine N-pyrrolation in proteins and found that GA-modified proteins are recognized by apolipoprotein E, a binding target of pyrrolated proteins. Moreover, GA-modified proteins triggered an immune response to pyrrolated proteins, and monoclonal antibodies generated from mice immunized with GA-modified proteins specifically recognized pyrrolated proteins. These findings reveal that GA is an endogenous source of DNA-mimicking pyrrolated proteins and may provide mechanistic insights relevant for innate and autoimmune responses associated with glucose metabolism and oxidative stress.

Volatility and Yield of Glycolaldehyde SOA Formed through Aqueous Photochemistry and Droplet Evaporation

Aqueous hydroxyl radical (∼10−12 M) oxidation of glycolaldehyde (1 mM), followed by droplet evaporation, forms secondary organic aerosol (SOA) that exhibits an effective liquid vapor pressure and enthalpy of vaporization of ∼10−7 atm and ∼70 kJ/mol, respectively, similar to the mix of organic acids identified in reaction samples. Salts of these acids have vapor pressures about three orders of magnitude lower (e.g., ammonium succinate ∼10−11 atm), suggesting that the gas–particle partitioning behavior of glycolaldehyde SOA depends strongly on whether products are present in the atmosphere as acids or salts. Several reaction samples were used to simulate cloud droplet evaporation using a vibrating orifice aerosol generator. Samples were also analyzed by ion chromatography (IC), electrospray ionization mass spectrometry (ESI-MS), IC-ESI-MS, and for total carbon. Glycolaldehyde SOA mass yields were 50–120%, somewhat higher than yields reported previously (40–60%). Possible reasons are discussed: (1) formation of oligomers from droplet evaporation, (2) inclusion of unquantified products formed by aqueous photooxidation, (3) differences in gas–particle partitioning, and (4) water retention in dried particles. These and similar results help to explain the enrichment of organic acids in particulate organic matter above clouds compared with those found below clouds, as observed previously in aircraft campaigns. Copyright 2012 American Association for Aerosol Research

Microbial oxidases catalyzing conversion of glycolaldehyde into glyoxal

The present paper reviews oxidases catalyzing conversion of glycolaldehyde into glyoxal. The enzymatic oxidation of glycolaldehyde into glyoxal was first reported in alcohol oxidases (AODs) from methylotrophic yeasts such as Candida and Pichia, and glycerol oxidase (GLOD) from Aspergillus japonicus, although it had been reported that these enzymes are specific to short-chain linear aliphatic alcohols and glycerol, respectively. These enzymes continuously oxidized ethylene glycol into glyoxal via glycolaldehyde. The AODs produced by Aspergillus ochraceus and Penicillium purpurescens also oxidized glycolaldehyde. A new enzyme exhibiting oxidase activity for glycolaldehyde was reported from a newly isolated bacterium, Paenibacillus sp. AIU 311. The Paenibacillus enzyme exhibited high activity for aldehyde alcohols such as glycolaldehyde and glyceraldehyde, but not for methanol, ethanol, ethylene glycol or glycerol. The deduced amino acid sequence of the Paenibacillus AOD was similar to that of superoxide dismutases (SODs), but not to that of methylotrophic yeast AODs. Then, it was demonstrated that SODs had oxidase activity for aldehyde alcohols including glycolaldehyde. The present paper describes characteristics of glycolaldehyde oxidation by those enzymes produced by different microorganisms.

Purification and characterization of a novel alcohol oxidase from Paenibacillus sp. AIU 311

An oxidase catalyzing the conversion of glycolaldehyde to glyoxal was purified to the homogeneous state from Paenibacillus sp. AIU 311, and its properties were revealed. This enzyme was specific to glycolaldehyde and glyceraldehyde, and the reaction rates to other alcohols and aldehydes were less than 6% of that of glycolaldehyde. The Km values for glycolaldehyde and glyceraldehyde were estimated to be 13.2 and 7.5 mM, respectively. The glycolaldehyde oxidation was optimum at pH 6.5 and 50 degrees C. The molecular mass of this enzyme was 49 kDa, and it consisted of two identical subunits of 24 kDa. The NH2-terminal sequence was not homologous to those of alcohol oxidases. This is the first report of an oxidase exhibiting high specificity to a hydroxy group of aldehyde alcohols.

Investigation of the mechanism of dissociation of glycolaldehyde dimer (2,5-dihydroxy-1,4-dioxane) by FTIR spectroscopy

Glycolaldehyde represents the simplest α-hydroxycarbonyl moiety–a common structural feature of reducing sugars. It exists in solid state, only in crystalline dimeric form as 2,5-dihydroxy-1,4-dioxane. However, in solution phase or during heating, it dissociates into different dimeric and monomeric forms. FTIR spectroscopy was used to study the effect of temperature, pH and solvent on the dissociation and chemical transformations of glycolaldehyde. The infrared spectra were recorded in different solvents as a function of time and temperature (both during heating and cooling cycles) between 30 and 85 °C. During heating, glycolaldehyde cyclic dimer generated two bands in the carbonyl region, one at 1744 cm −1 and the other at 1728 cm −1. These bands increased during the heating cycle and decreased during the cooling cycle. The data indicated that the glycolaldehyde cyclic dimer (2,5-dihydroxy-1,4-dioxane) undergoes a ring opening to form the acyclic dimer (1728 cm −1) that can recyclize into the 2-hydroxymethyl-4-hydroxy-1,3-dioxolane structure. The acyclic dimer can also dissociate into monomeric glycoladehyde (1744 cm −1) in equilibrium with the enediol form (1703 cm −1). There is evidence to indicate oxidation of glycolaldehyde into glycolic acid during heating, in either neutral or basic aqueous solutions.

Kinetics and mechanism of the oxidation of glycolaldehyde by tetrachloroaurate(III)

Kinetics and mechanism of the oxidation of glycolaldehyde by tetrachloroaurate(III)

Electrochemical and Infrared Spectroscopic Quantitative Determination of the Platinum-Catalyzed Ethylene Glycol Oxidation Mechanism at CO Adsorption Potentials

The electrochemical mechanism for ethylene glycol oxidation by polycrystalline platinum at 0.30 V/SCE in 0.10 M HClO4 is investigated by reflection infrared spectroscopic, coulometric, and voltammetric measurements of 0.10 M ethylene glycol, glycolaldehyde, glyoxal, glycolic acid, glyoxylic acid, and oxalic acid. CO2, glycolic acid, and adsorbed CO are identified as reaction products for ethylene glycol and glycolaldehyde oxidation. A two-path mechanism is proposed for 0.30 V oxidation of ethylene glycol and glycolaldehyde: either the reacting molecule undergoes direct oxidation to desorbing glycolic acid or it undergoes direct dissociation of the carbon−carbon bond to form various amounts of aqueous CO2 and adsorbed CO. Calculations are performed, assuming the quantities of CO and CO2 depend statistically upon the identities of the two functional groups comprising the two-carbon reactant molecule and upon oxidation conditions. Calculation results for dissociation at 0.30 V show that nearly 100% of the c...

H2O2 Recycling during Oxidation of the Arylglycerol .beta.-Aryl Ether Lignin Structure by Lignin Peroxidase and Glyoxal Oxidase

Oxidative C alpha-C beta cleavage of the arylglycerol beta-aryl ether lignin model 1-(3,4-dimethoxy-phenyl)-2-phenoxypropane-1,3-diol (I) by Phanerochaete chrysosporium lignin peroxidase in the presence of limiting H2O2 was enhanced 4-5-fold by glyoxal oxidase from the same fungus. Further investigation showed that each C alpha-C beta cleavage reaction released 0.8-0.9 equiv of glycolaldehyde, a glyoxal oxidase substrate. The identification of glycolaldehyde was based on 13C NMR spectrometry of reaction product obtained from beta-, gamma-, and beta,gamma-13C-substituted I, and quantitation was based on an enzymatic NADH-linked assay. The oxidation of glycolaldehyde by glyoxal oxidase yielded 0.9 oxalate and 2.8 H2O2 per reaction, as shown by quantitation of oxalate as 2,3-dihydroxyquinoxaline after derivatization with 1,2-diaminobenzene and by quantitation of H2O2 in coupled spectrophotometric assays with veratryl alcohol and lignin peroxidase. These results suggest that the C alpha-C beta cleavage of I by lignin peroxidase in the presence of glyoxal oxidase should regenerate as many as 3 H2O2. Calculations based on the observed enhancement of LiP-catalyzed C alpha-C beta cleavage by glyoxal oxidase showed that approximately 2 H2O2 were actually regenerated per cleavage of I when both enzymes were present. The cleavage of arylglycerol beta-aryl ether structures by ligninolytic enzymes thus recycles H2O2 to support subsequent cleavage reactions.

Fourier transform infrared study of the kinetics and mechanisms for the chlorine-atom- and hydroxyl-radical-initiated oxidation of glycolaldehyde

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFourier transform infrared study of the kinetics and mechanisms for the chlorine-atom- and hydroxyl-radical-initiated oxidation of glycolaldehydeH. Niki, P. D. Maker, C. M. Savage, and M. D. HurleyCite this: J. Phys. Chem. 1987, 91, 8, 2174–2178Publication Date (Print):April 1, 1987Publication History Published online1 May 2002Published inissue 1 April 1987https://doi.org/10.1021/j100292a038RIGHTS & PERMISSIONSArticle Views223Altmetric-Citations45LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (572 KB) Get e-Alerts

Vitamin B6 biosynthesis and glycolate reductase in Flavobacterium sp. 238-7.

An enzyme which reduces glycolate to glycolaldehyde as the first step of the biosynthesis of vitamin B6 was studied using the particulate fraction of Flavobacterium sp. 238-7, a vitamin B6 producer. The enzyme catalyzes the reduction of glycolate in the presence of NADPH, but not the oxidation of glycolaldehyde, and is designated as glycolate reductase. There is a positive correlation between the activity of the enzyme and vitamin B6 biosynthesis. The activity and the formation of the enzyme were not affected by vitamin B6. This enzyme probably plays a role in the extraordinary accumulation of vitamin B6 by the bacterium.

The oxidation of organic substances with compounds of trivalent manganese: XXI. The oxidation of glycoaldehyde with hexaquomanganese(III) ions in a noncomplexing perchloric acid medium

The oxidation of glycolaldehyde with hexaquomanganese(III) ions in a noncomplexing perchloric acid medium was studied. The optimum conditions have been found for analytical use of the reaction. The recommended procedure is based on the oxidation of the test substance with the oxidant in the absence of atmospheric oxygen and back-titration of the unconsumed reagent with ferrous sulfate. 2 Accuracy and Reproducibility of the Determination of Glycolaldehyde with Hexaquomanganese(III) Ions in a Noncomplexing Perchloric Acid Medium Taken (μg) Found (μg) a Standard deviation (μg) 751 748 12 1501 1485 15 2252 2192 7 a The values are the average of seven determinations, from which the standard deviation value was calculated.

Oxidation of glycolaldehyde by manganese(III) sulphate

Glycolaldehyde was found to be oxidized by manganese(III) sulphate with exchange of two electrons to give formaldehyde and formic acid. The kinetics of the reaction was studied and the reaction mechanism deduced. A convenient procedure is suggested for an indirect determination of glycolaldehyde based on its oxidation with excess manganese(III) sulphate and subsequent retitration of the unreacted reagent with ferrous sulphate.