Oxidative Esterification of Aldehydes with Urea Hydrogen Peroxide Catalyzed by Aluminum Chloride Hexahydrate

Energy Technology Data Exchange (ETDEWEB)

Lee, Sin-Ae; Kim, Yoon Mi; Lee, Jong Chan [Chung-Ang University, Seoul (Korea, Republic of)

2016-08-15

We have developed a new, environmentally benign and highly efficient oxidative preparation of methyl esters by the reaction of various aldehydes with UHP in methanol catalyzed by readily accessible aluminum(III) chloride hexahydrate. This new greener and cost effective direct esterification method can serve as a useful alternative to existing protocols. Esters are some of the most important functional groups in organic chemistry and have been found in the sub-structure of a variety of natural products, industrial chemicals, and pharmaceuticals. Numerous methods have been reported for the preparation of various esters. In particular, this method gives low yields for both aldehydes containing electron donating substituents in aromatic rings and heterocyclic aldehydes. Therefore, development of a more general, efficient, and greener protocol for the esterification of aldehydes with readily available catalyst is still desirable.

Efficient and Highly Selective Solvent-Free Oxidation of Primary Alcohols to Aldehydes Using Bucky Nanodiamond.

Science.gov (United States)

Lin, Yangming; Wu, Kuang-Hsu Tim; Yu, Linhui; Heumann, Saskia; Su, Dang Sheng

2017-09-11

Selective oxidation of alcohols to aldehydes is widely applicable to the synthesis of various green chemicals. The poor chemoselectivity for complicated primary aldehydes over state-of-the-art metal-free or metal-based catalysts represents a major obstacle for industrial application. Bucky nanodiamond is a potential green catalyst that exhibits excellent chemoselectivity and cycling stability for the selective oxidation of primary alcohols in diverse structures (22 examples, including aromatic, substituted aromatic, unsaturated, heterocyclic, and linear chain alcohols) to their corresponding aldehydes. The results are comparable to reported transition-metal catalysts including conventional Pt/C and Ru/C catalysts for certain substrates under solvent-free conditions. The possible activation process of the oxidant and substrates by the surface oxygen groups and defect species are revealed with model catalysts, ex situ electrochemical measurements, and ex situ attenuated total reflectance. The zigzag edges of sp 2 carbon planes are shown to play a key role in these reactions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Copper(I)/TEMPO Catalyzed Aerobic Oxidation of Primary Alcohols to Aldehydes with Ambient Air

Science.gov (United States)

Hoover, Jessica M.; Steves, Janelle E.; Stahl, Shannon S.

2012-01-01

This protocol describes a practical laboratory-scale method for aerobic oxidation of primary alcohols to aldehydes, using a chemoselective CuI/TEMPO catalyst system. The catalyst is prepared in situ from commercially available reagents, and the reactions are performed in a common organic solvent (acetonitrile) with ambient air as the oxidant. Three different reaction conditions and three procedures for the isolation and purification of the aldehyde product are presented. The oxidations of eight different alcohols, described here, include representative examples of each reaction condition and purification method. Reaction times vary from 20 min to 24 h, depending on the alcohol, while the purification methods each take about 2 h. The total time necessary for the complete protocol ranges from 3 – 26 h. PMID:22635108

Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

Energy Technology Data Exchange (ETDEWEB)

Li, Yan; Chang, Jie; Ouyang, Yong; Zheng, Xianwei [South China Univ. of Technology, Guangzhou (China)

2014-06-15

High value-added aromatic aldehydes (e. g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide (H{sub 2}O{sub 2}) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin (Co(TPPS{sub 4})) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without Co(TPPS{sub 4}). Moreover, a possible mechanism of HFBO oxidation using Co(TPPS{sub 4})/H{sub 2}O{sub 2} was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under Co(TPPS{sub 4})/H{sub 2}O{sub 2} system.

Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

International Nuclear Information System (INIS)

Li, Yan; Chang, Jie; Ouyang, Yong; Zheng, Xianwei

2014-01-01

High value-added aromatic aldehydes (e. g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide (H 2 O 2 ) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin (Co(TPPS 4 )) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without Co(TPPS 4 ). Moreover, a possible mechanism of HFBO oxidation using Co(TPPS 4 )/H 2 O 2 was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under Co(TPPS 4 )/H 2 O 2 system

Catalytic wet-air oxidation of lignin in a three-phase reactor with aromatic aldehyde production

Directory of Open Access Journals (Sweden)

Sales F.G.

2004-01-01

Full Text Available In the present work a process of catalytic wet air oxidation of lignin obtained from sugar-cane bagasse is developed with the objective of producing vanillin, syringaldehyde and p-hydroxybenzaldehyde in a continuous regime. Palladium supported on g-alumina was used as the catalyst. The reactions in the lignin degradation and aldehyde production were described by a kinetic model as a system of complex parallel and series reactions, in which pseudo-first-order steps are found. For the purpose of producing aromatic aldehydes in continuous regime, a three-phase fluidized reactor was built, and it was operated using atmospheric air as the oxidizer. The best yield in aromatic aldehydes was of 12%. The experimental results were compatible with those values obtained by the pseudo-heterogeneous axial dispersion model (PHADM applied to the liquid phase.

Oxidation of Group 8 transition-Metal Hydrides and Ionic Hydrogenation of Ketones and Aldehydes

Energy Technology Data Exchange (ETDEWEB)

Smith, Kjell-Tore

1996-08-01

Transition-metal hydrides have received considerable attention during the last decades because of their unusual reactivity and their potential as homogeneous catalysts for hydrogenation and other reactions of organic substrates. An important class of catalytic processes where transition-metal hydrides are involved is the homogeneous hydrogenation of alkenes, alkynes, ketones, aldehydes, arenes and nitro compounds. This thesis studies the oxidation of Group 8 transition-metal hydrides and the ionic hydrogenation of ketones and aldehydes.

Assessment and predictor determination of indoor aldehyde levels in Paris newborn babies' homes.

Science.gov (United States)

Dassonville, C; Demattei, C; Laurent, A-M; Le Moullec, Y; Seta, N; Momas, I

2009-08-01

Exposure to indoor chemical air pollutants expected to be potentially involved in allergic respiratory diseases in infants is poorly documented. A specific environmental investigation included in a birth cohort study was carried out to first assess indoor airborne aldehyde levels, using passive devices and their variability within 1 year (1, 6, 9 and 12 months) in the bedroom of 196 Paris infants, and second, to identify predictors for aldehyde concentrations using interviewer administered questionnaires about housing factors. Comfort parameters and carbon dioxide levels were measured simultaneously. Aldehydes were detected in almost all dwellings and geometric mean levels (geometric standard deviation) at the first visit were respectively for formaldehyde, acetaldehyde, hexanal, and pentanal 19.4 (1.7) microg/m(3), 8.9 (1.8) microg/m(3), 25.3 (3.1) microg/m(3), 3.7 (2.3) microg/m(3), consistent with earlier published results. Generalized Estimating Equation multivariate analyses showed that, apart from comfort parameters, aeration and season, the main indoor aldehyde sources were either continuous (building materials and coverings especially when they were new) or discontinuous (smoking, use of air fresheners and cleaning products, DIY etc...). Finally, the data collected by questionnaires should be sufficient to enable us to classify each infant in our cohort study according to his/her degree of exposure to the main aldehydes. This analysis contributed to document indoor aldehyde levels in Parisian homes and to identify factors determining these levels. In the major part of newborn babies' homes, indoor formaldehyde levels were above the guideline value of 10 microg/m(3) proposed by the French Agency for Environmental and Occupational Health Safety for long-term exposure. Given this result, it is essential to study the health impact of exposure to aldehydes especially formaldehyde on the incidence of respiratory and allergic symptoms, particularly during the

Indoor aldehydes: measurement of contamination levels and identification of their determinants in Paris dwellings

International Nuclear Information System (INIS)

Clarisse, B.; Laurent, A.M.; Seta, N.; Le Moullec, Y.; El Hasnaoui, A.; Momas, I.

2003-01-01

The recent increased prevalence of childhood asthma and atopy has brought into question the impact of outdoor pollutants and indoor air quality. The contributory role of aldehydes to this problem and the fact that they are mainly derived from the domestic environment make them of particular interest. This study therefore measures six different aldehyde levels in Paris dwellings from potentially different sources and identifies their indoor determinants. The study was carried out in the three principal rooms of 61 flats with no previous history of complaint for olfactory nuisance or specific symptoms, two-thirds of the flats having been recently refurbished. Aldehydes were sampled in these rooms using passive samplers, and a questionnaire on potential aldehyde sources was filled out at the same time. A multiple linear regression model was used to investigate indoor aldehyde determinants. Our study revealed that propionaldehyde and benzaldehyde were of minor importance compared to formaldehyde, acetaldehyde, pentanal, and hexanal. We found that levels of these last four compounds depended on the age of wall or floor coverings (renovations less than 1 year old), smoking, and ambient parameters (carbon dioxide levels, temperature). These results could help in the assessment of indoor aldehyde emissions

Palladium-Catalyzed Anti-Markovnikov Oxidation of Allylic Amides to Protected beta-Amino Aldehydes

NARCIS (Netherlands)

Dong, Jiajia; Harvey, Emma C.; Fananas-Mastral, Martin; Browne, Wesley R.; Feringa, Bernard

2014-01-01

A general method for the preparation of N-protected beta-amino aldehydes from allylic amines or linear allylic alcohols is described. Here the Pd(II)-catalyzed oxidation of N-protected allylic amines with benzoquinone is achieved in tBuOH under ambient conditions with excellent selectivity toward

Aldehyde Selective Wacker Oxidations of Phthalimide Protected Allylic Amines : A New Catalytic Route to beta(3)-Amino Acids

NARCIS (Netherlands)

Weiner, Barbara; Baeza Garcia, Alejandro; Jerphagnon, Thomas; Feringa, Ben L.

2009-01-01

A new method for the synthesis of B-3-amino acids is presented. Phthalimide protected allylic amines are oxidized under Wacker conditions selectively to aldehydes using PdCl2 and CuCl or Pd(MeCN)(2)Cl(NO2) and CuCl2 as complementary catalyst systems. The aldehydes are produced in excellent yields

Mechanistic investigation of the gold-catalyzed aerobic oxidation of aldehydes: added insight from Hammett studies and isotopic labelling experiments

DEFF Research Database (Denmark)

Fristrup, Peter; Johansen, Louise Bahn; Christensen, Claus Hviid

2008-01-01

The gold-catalyzed aerobic oxidation of aldehydes proceeds through development of a partial negative charge and has a significant kinetic isotope effect (k(H)/k(D) = 2.8-2.9), which illustrates that activation of the C-H bond takes place in the rate-determining step.......The gold-catalyzed aerobic oxidation of aldehydes proceeds through development of a partial negative charge and has a significant kinetic isotope effect (k(H)/k(D) = 2.8-2.9), which illustrates that activation of the C-H bond takes place in the rate-determining step....

Efficient Method for Aromatic-Aldehyde Oxidation by Cleavage of Their Hydrazones Catalysed by Trimethylsilanolate

Czech Academy of Sciences Publication Activity Database

Bürglová, K.; Okorochenkov, S.; Buděšínský, Miloš; Hlaváč, J.

2017-01-01

Roč. 2017, č. 2 (2017), s. 389-396 ISSN 1434-193X R&D Projects: GA MŠk(CZ) LO1304 Institutional support: RVO:61388963 Keywords : aldehydes * oxidation * hydrazones * solid-phase synthesis * reaction mechanisms Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 2.834, year: 2016

One-pot synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines using supported gold and base as catalysts

DEFF Research Database (Denmark)

Kegnæs, Søren; Mielby, Jerrik Jørgen; Mentzel, Uffe Vie

2012-01-01

Synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines via intermediate formation of methyl esters is highly efficient and selective when using a catalytic system comprised of supported gold nanoparticles and added base in methanol.......Synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines via intermediate formation of methyl esters is highly efficient and selective when using a catalytic system comprised of supported gold nanoparticles and added base in methanol....

Oxidation of N-alkyl and N-aryl azaheterocycles by free and immobilized rabbit liver aldehyde oxidase

NARCIS (Netherlands)

Angelino, S.A.G.F.

1984-01-01

Aldehyde oxidase isolated from rabbit liver is studied in this thesis with regard to its application in organic synthesis. The enzyme has a broad substrate specificity towards azaheterocycles and therefore offers great potential for profitable use.

The oxidation of

Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus.

Science.gov (United States)

Mansourian, Arash; Shanbehzadeh, Najmeh; Kia, Seyed Javad; Moosavi, Mahdieh-Sadat

2017-01-01

Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further studies are needed for introducing aldehyde dehydrogenase as a prognostic

Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus*

Science.gov (United States)

Mansourian, Arash; Shanbehzadeh, Najmeh; Kia, Seyed Javad; Moosavi, Mahdieh-Sadat

2017-01-01

Background Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. Objective This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Method Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. Results The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. Limitations of the study This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. Conclusions The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further

Ni-Catalyzed Dehydrogenative Cross-Coupling: Direct Transformation of Aldehydes to Esters and Amides

Science.gov (United States)

Whittaker, Aaron M.; Dong, Vy M.

2015-01-01

By exploring a new mode of Ni-catalyzed cross-coupling, we have developed a protocol to transform both aromatic and aliphatic aldehydes into either esters or amides directly. The success of this oxidative coupling depends on the appropriate choice of catalyst and organic oxidant, including the use of either α,α,α-trifluoroacetophenone or excess aldehyde. We present mechanistic data that supports a catalytic cycle involving oxidative addition into the aldehyde C–H bond. PMID:25424967

Five Fatty Aldehyde Dehydrogenase Enzymes from Marinobacter and Acinetobacter spp. and Structural Insights into the Aldehyde Binding Pocket

Energy Technology Data Exchange (ETDEWEB)

Bertram, Jonathan H.; Mulliner, Kalene M.; Shi, Ke; Plunkett, Mary H.; Nixon, Peter; Serratore, Nicholas A.; Douglas, Christopher J.; Aihara, Hideki; Barney, Brett M.; Parales, Rebecca E.

2017-04-07

Enzymes involved in lipid biosynthesis and metabolism play an important role in energy conversion and storage and in the function of structural components such as cell membranes. The fatty aldehyde dehydrogenase (FAldDH) plays a central function in the metabolism of lipid intermediates, oxidizing fatty aldehydes to the corresponding fatty acid and competing with pathways that would further reduce the fatty aldehydes to fatty alcohols or require the fatty aldehydes to produce alkanes. In this report, the genes for four putative FAldDH enzymes fromMarinobacter aquaeoleiVT8 and an additional enzyme fromAcinetobacter baylyiwere heterologously expressed inEscherichia coliand shown to display FAldDH activity. Five enzymes (Maqu_0438, Maqu_3316, Maqu_3410, Maqu_3572, and the enzyme reported under RefSeq accession no.WP_004927398) were found to act on aldehydes ranging from acetaldehyde to hexadecanal and also acted on the unsaturated long-chain palmitoleyl and oleyl aldehydes. A comparison of the specificities of these enzymes with various aldehydes is presented. Crystallization trials yielded diffraction-quality crystals of one particular FAldDH (Maqu_3316) fromM. aquaeoleiVT8. Crystals were independently treated with both the NAD⁺cofactor and the aldehyde substrate decanal, revealing specific details of the likely substrate binding pocket for this class of enzymes. A likely model for how catalysis by the enzyme is accomplished is also provided.

IMPORTANCEThis study provides a comparison of multiple enzymes with the ability

Quantification of the 2-deoxyribonolactone and nucleoside 5'-aldehyde products of 2-deoxyribose oxidation in DNA and cells by isotope-dilution gas chromatography mass spectrometry: differential effects of gamma-radiation and Fe2+-EDTA.

Science.gov (United States)

Chan, Wan; Chen, Bingzi; Wang, Lianrong; Taghizadeh, Koli; Demott, Michael S; Dedon, Peter C

2010-05-05

The oxidation of 2-deoxyribose in DNA has emerged as a critical determinant of the cellular toxicity of oxidative damage to DNA, with oxidation of each carbon producing a unique spectrum of electrophilic products. We have developed and validated an isotope-dilution gas chromatography-coupled mass spectrometry (GC-MS) method for the rigorous quantification of two major 2-deoxyribose oxidation products: the 2-deoxyribonolactone abasic site of 1'-oxidation and the nucleoside 5'-aldehyde of 5'-oxidation chemistry. The method entails elimination of these products as 5-methylene-2(5H)-furanone (5MF) and furfural, respectively, followed by derivatization with pentafluorophenylhydrazine (PFPH), addition of isotopically labeled PFPH derivatives as internal standards, extraction of the derivatives, and quantification by GC-MS analysis. The precision and accuracy of the method were validated with oligodeoxynucleotides containing the 2-deoxyribonolactone and nucleoside 5'-aldehyde lesions. Further, the well-defined 2-deoxyribose oxidation chemistry of the enediyne antibiotics, neocarzinostatin and calicheamicin gamma(1)(I), was exploited in control studies, with neocarzinostatin producing 10 2-deoxyribonolactone and 300 nucleoside 5'-aldehyde per 10(6) nt per microM in accord with its established minor 1'- and major 5'-oxidation chemistry. Calicheamicin unexpectedly caused 1'-oxidation at a low level of 10 2-deoxyribonolactone per 10(6) nt per microM in addition to the expected predominance of 5'-oxidation at 560 nucleoside 5'-aldehyde per 10(6) nt per microM. The two hydroxyl radical-mediated DNA oxidants, gamma-radiation and Fe(2+)-EDTA, produced nucleoside 5'-aldehyde at a frequency of 57 per 10(6) nt per Gy (G-value 74 nmol/J) and 3.5 per 10(6) nt per microM, respectively, which amounted to 40% and 35%, respectively, of total 2-deoxyribose oxidation as measured by a plasmid nicking assay. However, gamma-radiation and Fe(2+)-EDTA produced different proportions of 2

Cyclodextrin Aldehydes are Oxidase Mimics

DEFF Research Database (Denmark)

Fenger, Thomas Hauch; Bjerre, Jeannette; Bols, Mikael

2009-01-01

Cyclodextrins containing 6-aldehyde groups were found to catalyse oxidation of aminophenols in the presence of hydrogen peroxide. The catalysis followed Michaelis-Menten kinetics and is related to the catalysis previously observed with cyclodextrin ketones. A range of different cyclodextrin aldeh...

Association of air pollution sources and aldehydes with biomarkers of blood coagulation, pulmonary inflammation, and systemic oxidative stress.

Science.gov (United States)

Altemose, Brent; Robson, Mark G; Kipen, Howard M; Ohman Strickland, Pamela; Meng, Qingyu; Gong, Jicheng; Huang, Wei; Wang, Guangfa; Rich, David Q; Zhu, Tong; Zhang, Junfeng

2017-05-01

Using data collected before, during, and after the 2008 Summer Olympic Games in Beijing, this study examines associations between biomarkers of blood coagulation (vWF, sCD62P and sCD40L), pulmonary inflammation (EBC pH, EBC nitrite, and eNO), and systemic oxidative stress (urinary 8-OHdG) with sources of air pollution identified utilizing principal component analysis and with concentrations of three aldehydes of health concern. Associations between the biomarkers and the air pollution source types and aldehydes were examined using a linear mixed effects model, regressing through seven lag days and controlling for ambient temperature, relative humidity, gender, and day of week for the biomarker measurements. The biomarkers for pulmonary inflammation, particularly EBC pH and eNO, were most consistently associated with vehicle and industrial combustion, oil combustion, and vegetative burning. The biomarkers for blood coagulation, particularly vWF and sCD62p, were most consistently associated with oil combustion. Systemic oxidative stress biomarker (8-OHdG) was most consistently associated with vehicle and industrial combustion. The associations of the biomarkers were generally not significant or consistent with secondary formation of pollutants and with the aldehydes. The findings support policies to control anthropogenic pollution sources rather than natural soil or road dust from a cardio-respiratory health standpoint.

Urban and rural ambient air aldehyde levels in Schenectady, New York and on Whiteface Mountain, New York

Energy Technology Data Exchange (ETDEWEB)

Schulam, P; Newbold, R; Hull, L A

1985-01-01

The air in the city of Schenectady, NY was sampled daily and analyzed for the presence of low molecular weight aldehydes during the months of June-August 1983. The diurnal variation of the aldehyde concentrations was also determined over a two day period during August. The dominant aldehyde was formaldehyde and its concentration varied from about 1-31 ppb. There was also observed a significant daily variation that appeared to correlate with traffic conditions. The technique was also used to monitor the aldehyde levels on the summit of Whiteface Mountain in Wilmington, NY at the SUNYA Atmospheric Sciences Research Center. The monitoring was done on a daily basis during the week of 14-20 August and, during that week, every 3 h for a 3-day period. The two dominant aldehydes were formaldehyde and acetaldehyde and they varied in concentration from about 0.8-2.6 and 0.2-0.8 ppb, respectively.

Identification and characterization of aldehyde oxidases (AOXs) in the cotton bollworm

Science.gov (United States)

Xu, Wei; Liao, Yalin

2017-12-01

Aldehyde oxidases (AOXs) are a family of metabolic enzymes that oxidize aldehydes into carboxylic acids; therefore, they play critical roles in detoxification and degradation of chemicals. By using transcriptomic and genomic approaches, we successfully identified six putative AOX genes (HarmAOX1-6) from cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae). In silico expression profile, reverse transcription (RT)-PCR, and quantitative PCR (qPCR) analyses showed that HarmAOX1 is highly expressed in adult antennae, tarsi, and larval mouthparts, so they may play an important role in degrading plant-derived compounds. HarmAOX2 is highly and specifically expressed in adult antennae, suggesting a candidate pheromone-degrading enzyme (PDE) to inactivate the sex pheromone components (Z)-11-hexadecenal and (Z)-9-hexadecenal. RNA sequencing data further demonstrated that a number of host plants they feed on could significantly upregulate the expression levels of HarmAOX1 in larvae. This study improves our understanding of insect aldehyde oxidases and insect-plant interactions.

Aldehyde Dehydrogenases in Arabidopsis thaliana: Biochemical Requirements, Metabolic Pathways, and Functional Analysis.

Science.gov (United States)

Stiti, Naim; Missihoun, Tagnon D; Kotchoni, Simeon O; Kirch, Hans-Hubert; Bartels, Dorothea

2011-01-01

Aldehyde dehydrogenases (ALDHs) are a family of enzymes which catalyze the oxidation of reactive aldehydes to their corresponding carboxylic acids. Here we summarize molecular genetic and biochemical analyses of selected ArabidopsisALDH genes. Aldehyde molecules are very reactive and are involved in many metabolic processes but when they accumulate in excess they become toxic. Thus activity of aldehyde dehydrogenases is important in regulating the homeostasis of aldehydes. Overexpression of some ALDH genes demonstrated an improved abiotic stress tolerance. Despite the fact that several reports are available describing a role for specific ALDHs, their precise physiological roles are often still unclear. Therefore a number of genetic and biochemical tools have been generated to address the function with an emphasis on stress-related ALDHs. ALDHs exert their functions in different cellular compartments and often in a developmental and tissue specific manner. To investigate substrate specificity, catalytic efficiencies have been determined using a range of substrates varying in carbon chain length and degree of carbon oxidation. Mutational approaches identified amino acid residues critical for coenzyme usage and enzyme activities.

CuO and Ag2O/CuO Catalyzed Oxidation of Aldehydes to the Corresponding Carboxylic Acids by Molecular Oxygen

Directory of Open Access Journals (Sweden)

Yaowu Sha

2008-04-01

Full Text Available Furfural was oxidized to furoic acid by molecular oxygen under catalysis by 150nm-sized Ag2O/CuO (92% or simply CuO (86.6%. When 30 nm-size catalyst was used,the main product was a furfural Diels-Alder adduct. Detailed reaction conditions andregeneration of catalysts were investigated. Under optimal conditions, a series of aromaticand aliphatic aldehydes were oxidized to the corresponding acids in good yields.

Identification of aldehyde oxidase 1 and aldehyde oxidase homologue 1 as dioxin-inducible genes

International Nuclear Information System (INIS)

Rivera, Steven P.; Choi, Hyun Ho; Chapman, Brett; Whitekus, Michael J.; Terao, Mineko; Garattini, Enrico; Hankinson, Oliver

2005-01-01

Aldehyde oxidases are a family of highly related molybdo-flavoenzymes acting upon a variety of compounds of industrial and medical importance. We have identified aldehyde oxidase 1 (AOX1) as a 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin) inducible gene in the mouse hepatoma cell line Hepa-1. AOX1 mRNA levels were not increased by dioxin in mutant derivatives of the Hepa-1 cell line lacking either functional aryl hydrocarbon receptor (AHR) or aryl hydrocarbon receptor nuclear translocator (ARNT) proteins, thus demonstrating that transcriptional induction of AOX1 in response to dioxin occurs through the AHR pathway. Dioxin induction of AOX1 mRNA was also observed in mouse liver. In addition, levels of AOX1 protein as well as those of aldehyde oxidase homologue 1 (AOH1), a recently identified homolog of AOX1, were elevated in mouse liver in response to dioxin. Employing an aldehyde oxidase specific substrate, AOX1/AOH1 activity was shown to be induced by dioxin in mouse liver. This activity was inhibited by a known inhibitor of aldehyde oxidases, and eliminated by including tungstate in the mouse diet, which is known to lead to inactivation of molybdoflavoenzymes, thus confirming that the enzymatic activity was attributable to AOX1/AOH1. Our observations thus identify two additional xenobiotic metabolizing enzymes induced by dioxin

α,β-Unsaturated aldehyde pollutant acrolein suppresses cardiomyocyte contractile function: Role of TRPV1 and oxidative stress.

Science.gov (United States)

Wu, Zhenbiao; He, Emily Y; Scott, Glenda I; Ren, Jun

2015-01-01

Air pollution is associated with an increased prevalence of heart disease and is known to trigger a proinflammatory response via stimulation of transient receptor potential vanilloid cation channels (TRPV1, also known as the capsaicin receptor). This study was designed to examine the effect of acrolein, an essential α,β-unsaturated aldehyde pollutant, on myocardial contractile function and the underlying mechanism involved with a focus on TRPV1 and oxidative stress. Cardiomyocyte mechanical and intracellular Ca(2+) properties were evaluated using an IonOptix MyoCam® system including peak shortening (PS), maximal velocity of shortening/relengthening (± dL/dt), time-to-PS (TPS), time-to-90% relengthening (TR90 ), fura-2 fluorescence intensity (FFI) and intracellular Ca(2+) decay. Changes in apoptosis and TRPV1 were evaluated using Western blot analysis. The degree of oxidative stress was assessed using the ratio between reduced and oxidized glutathione. Results obtained revealed that exposure of cardiomyocytes to acrolein acutely compromised contractile and intracellular Ca(2+) properties including depressed PS, ± dL/dt and ΔFFI, as well as prolonged TR90 and intracellular Ca(2+) decay. In addition, acrolein exposure upregulated TRPV1 associated with an increase in both apoptosis and oxidative stress. However, the acrolein-induced cardiomyocyte contractile and intracellular Ca(2+) anomalies, as well as apoptosis (as evidenced by Bcl-2, Bax, FasL, Caspase-3 and -8), were negated by the reactive oxygen species (ROS) scavenger glutathione or the TRPV1 antagonist capsazepine. Collectively these data suggest that the α,β-unsaturated aldehyde pollutant acrolein may play a role in the pathogenesis and sequelae of air pollution-induced heart disease via a TRPV1- and oxidative stress-dependent mechanism. © 2013 Wiley Periodicals, Inc.

Alcohol, Aldehydes, Adducts and Airways

Directory of Open Access Journals (Sweden)

Muna Sapkota

2015-11-01

Full Text Available Drinking alcohol and smoking cigarettes results in the formation of reactive aldehydes in the lung, which are capable of forming adducts with several proteins and DNA. Acetaldehyde and malondialdehyde are the major aldehydes generated in high levels in the lung of subjects with alcohol use disorder who smoke cigarettes. In addition to the above aldehydes, several other aldehydes like 4-hydroxynonenal, formaldehyde and acrolein are also detected in the lung due to exposure to toxic gases, vapors and chemicals. These aldehydes react with nucleophilic targets in cells such as DNA, lipids and proteins to form both stable and unstable adducts. This adduction may disturb cellular functions as well as damage proteins, nucleic acids and lipids. Among several adducts formed in the lung, malondialdehyde DNA (MDA-DNA adduct and hybrid malondialdehyde-acetaldehyde (MAA protein adducts have been shown to initiate several pathological conditions in the lung. MDA-DNA adducts are pre-mutagenic in mammalian cells and induce frame shift and base-pair substitution mutations, whereas MAA protein adducts have been shown to induce inflammation and inhibit wound healing. This review provides an insight into different reactive aldehyde adducts and their role in the pathogenesis of lung disease.

The Oxidative Fermentation of Ethanol in Gluconacetobacter diazotrophicus Is a Two-Step Pathway Catalyzed by a Single Enzyme: Alcohol-Aldehyde Dehydrogenase (ADHa

Directory of Open Access Journals (Sweden)

Saúl Gómez-Manzo

2015-01-01

Full Text Available Gluconacetobacter diazotrophicus is a N2-fixing bacterium endophyte from sugar cane. The oxidation of ethanol to acetic acid of this organism takes place in the periplasmic space, and this reaction is catalyzed by two membrane-bound enzymes complexes: the alcohol dehydrogenase (ADH and the aldehyde dehydrogenase (ALDH. We present strong evidence showing that the well-known membrane-bound Alcohol dehydrogenase (ADHa of Ga. diazotrophicus is indeed a double function enzyme, which is able to use primary alcohols (C2–C6 and its respective aldehydes as alternate substrates. Moreover, the enzyme utilizes ethanol as a substrate in a reaction mechanism where this is subjected to a two-step oxidation process to produce acetic acid without releasing the acetaldehyde intermediary to the media. Moreover, we propose a mechanism that, under physiological conditions, might permit a massive conversion of ethanol to acetic acid, as usually occurs in the acetic acid bacteria, but without the transient accumulation of the highly toxic acetaldehyde.

Atmospheric measurements of hydroperoxides and aldehydes during field campaigns : new results due to improvement of measurements techniques

Science.gov (United States)

François, S.; Sowka, I.; Poulain, L.; Monod, A.; Wortham, H.

2003-04-01

Hydroperoxides and aldehydes are considered as atmospheric reservoirs of OH, HO_2 and RO_2 radicals and can reflect the oxidizing levels of the atmosphere. They are considered as important gas phase photo-oxidants present in the atmosphere. However, the atmospheric role of these compounds can vary from one species to another, therefore it is essential to investigate their measurement and speciation in the atmosphere. Atmospheric measurements were realized during two different field campaigns in the Marseilles area (France). Hydroperoxides were trapped in aqueous phase, with a glass coil and analyzed by HPLC/fluorescence detector with post column derivatization. Aldehydes were trapped in a liquid phase containing 2-4 DNPH, with a mist chamber and analyzed by HPLC/UV. The analytical techniques provided individual separation and quantification of seven hydroperoxides (hydrogen peroxide, hydroxymethyl hydroperoxide, bis(hydroxymethyl) peroxide, 1-hydroxyethyl hydroperoxide, methyl hydroperoxide, ethyl hydroperoxide and peroxyacetic acid) and eleven volatile aldehydes (formaldehyde, acetaldehyde, acrolein, acetone, propionaldehyde, crotonaldehyde, butyraldehyde, benzaldehyde, glyoxal, valeraldehyde and methylglyoxal). The first field campaign was part of the ESCOMPTE project (June 4th to July 16th 2001). During this campaign five different sampling sites, at low altitudes (<= 285 m), were investigated (maritime, urban, sub-industrial, biogenic and rural sites) and atmospheric measurements were realized during photochemical air pollution events. The second field campaign was part of the BOND project (July 2nd to July 14th 2002). Atmospheric measurements of hydroperoxides were carried out on one biogenic site, at altitude 690 m. The measurement system was improved allowing online sampling and analysis. During these field campaigns collection efficiencies were better than 96% for hydroperoxides, and from 78% to 96% for aldehydes. Detection limits were between 7,3× 10-3 �

Partial Reduction of Esters to Aldehydes Using a Novel Modified Red-Al Reducing Agent

Energy Technology Data Exchange (ETDEWEB)

Shin, Won Kyu; Kang, Daehoon; An, Duk Keun [Kangwon National Univ., Chunchon (Korea, Republic of)

2014-07-15

We have developed a convenient alternative method for the synthesis of aldehydes from both aromatic and aliphatic esters in very good to excellent yields in the absence of any additives using a modified Red-Al that was easily prepared by reacting commercially available Red-Al with cis-2,6-dimethyl morpholine. The advantages of the present methodology are as follows: simple preparation procedure of the reducing agent, improved product yields, convenient reaction temperature, and short reaction times. Therefore, the new reagent has great potential to be a useful alternative partial reducing agent for the synthesis of aldehydes from esters in organic synthesis. Aldehydes are valuable building blocks and reactive intermediates in organic synthesis. The general and classical syntheses of aldehydes from esters involve reduction-oxidation and partial reduction using efficient partial reducing agents. Obviously, one-step partial reduction methods are more useful than two-step reduction-oxidation methods owing to their simplicity, and generality in organic synthesis.

Direct Vinylation of Alcohols or Aldehydes Employing Alkynes as Vinyl Donors: A Ruthenium Catalyzed C-C Bond Forming Transfer Hydrogenation

Science.gov (United States)

Patman, Ryan L.; Chaulagain, Mani Raj; Williams, Vanessa M.; Krische, Michael J.

2011-01-01

Under the conditions of ruthenium catalyzed transfer hydrogenation, 2-butyne couples to benzylic and aliphatic alcohols 1a–1i to furnish allylic alcohols 2a–2i, constituting a direct C-H vinylation of alcohols employing alkynes as vinyl donors. Under related transfer hydrogenation conditions employing formic acid as terminal reductant, 2-butyne couples to aldehydes 4a, 4b, and 4e to furnish identical products of carbonyl vinylation 2a, 2b, and 2e. Thus, carbonyl vinylation is achieved from the alcohol or the aldehyde oxidation level in the absence of any stoichiometric metallic reagents. Nonsymmetric alkynes 6a–6c couple efficiently to aldehyde 4b to provide allylic alcohols 2m–2o as single regioisomers. Acetylenic aldehyde 7a engages in efficient intramolecular coupling to deliver cyclic allylic alcohol 8a. PMID:19173651

Aldehydic acids in frying oils: formation, toxicological significance and analysis

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Kamal-Eldin, Afaf

1996-10-01

Full Text Available Aldehydic acids are generated in oxidized lipids as a result of decomposition of hydroperoxides by (β-scission reactions. Aldehydes are known to interact with proteins and DNA and to impair enzymatic functions. Aldehydic esters from oxidized lipids were reabsorbed to a significant extent in rats. This paper reviews the mechanism of formation of esterified aldehydic acids in frying oils and their physiological/toxicological effects. The paper also gives an overview of relevant basic analytical techniques that needs to be improved to establish reliable quantitative method (s.

Ácidos aldehídicos son producidos en lípidos oxidados como resultado de la descomposición de hidroperóxidos por reacciones de (β-escición. Es conocido que los aldehídos interaccionan con las proteínas y el ADN y debilitan las funciones enzimáticas. Los esteres aldehídicos de lípidos oxidados fueron reabsorbidos en una cantidad significativa en ratas. Este artículo revisa los mecanismos de formación de ácidos aldehídicos esterificados en aceites de fritura y sus efectos fisiológicos/toxicológicos. El artículo también ofrece una visión de conjunto de las técnicas analíticas básicas que necesitan ser mejoradas para establecer métodos cuantitativos fiables.

The Arabidopsis aldehyde oxidase 3 (AA03) gene product catalyzes the final step in abscisic acid biosynthesis in leaves

NARCIS (Netherlands)

Seo, M.; Peeters, A.J.M.; Koiwai, H.; Oritani, T.; Marion-Poll, A.; Zeevaart, J.A.D.; Koornneef, M.; Kamiya, Y.; Koshiba, T.

2000-01-01

Abscisic acid (ABA) is a plant hormone involved in seed development and germination and in responses to various environmental stresses. The last step of ABA biosynthesis involves oxidation of abscisic aldehyde, and aldehyde oxidase (EC 1.2.3.1) is thought to catalyze this reaction. An aldehyde

The use of tomato aminoaldehyde dehydrogenase 1 for the detection of aldehydes in fruit distillates.

Science.gov (United States)

Frömmel, Jan; Tarkowski, Petr; Kopečný, David; Šebela, Marek

2016-09-25

Plant NAD(+)-dependent aminoaldehyde dehydrogenases (AMADHs, EC 1.2.1.19) belong to the family 10 of aldehyde dehydrogenases. They participate in the metabolism of polyamines or osmoprotectants. The enzymes are characterized by their broad substrate specificity covering ω-aminoaldehydes, aliphatic and aromatic aldehydes as well as nitrogen-containing heterocyclic aldehydes. The isoenzyme 1 from tomato (Solanum lycopersicum; SlAMADH1) oxidizes aliphatic aldehydes very efficiently and converts also furfural, its derivatives or benzaldehyde, which are present at low concentrations in alcoholic distillates such as fruit brandy. In this work, SlAMADH1 was examined as a bioanalytical tool for their detection. These aldehydes arise from fermentation processes or thermal degradation of sugars and their presence is related to health complications after consumption including nausea, emesis, sweating, decrease in blood pressure, hangover headache, among others. Sixteen samples of slivovitz (plum brandy) from local producers in Moravia, Czech Republic, were analyzed for their aldehyde content using a spectrophotometric activity assay with SlAMADH1. In all cases, there were oxidative responses observed when monitoring NADH production in the enzymatic reaction. Aldehydes in the distillate samples were also subjected to a standard determination using reversed-phase HPLC with spectrophotometric and tandem mass spectrometric detection after a derivatization with 2,4-dinitrophenylhydrazine. Results obtained by both methods were found to correlate well for a majority of the analyzed samples. The possible applicability of SlAMADH1 for the evaluation of aldehyde content in food and beverages has now been demonstrated. Copyright © 2015 Elsevier B.V. All rights reserved.

Organic acids and aldehydes in rainwater in a northwest region of Spain

Energy Technology Data Exchange (ETDEWEB)

Pena, R.M.; Garcia, S.; Herrero, C. [Universidad de Santiago de Compostela, Lugo (Spain). Departamento de Quimica Analitica, Nutricion y Bromatologia

2002-11-01

During a 1 year period, measurements of carboxylic acids and aldehydes were carried out in rainwater samples collected at nine different sites in NW Spain surrounding a thermal power plant in order to determine concentration levels and sources. In addition, certain major ions (Cl{sup -}, NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, Na{sup +}, NH{sub 4}{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}) were also determined. Aldehyde and carboxylic acid concentration patterns and their effects on rainwater composition concerning temporal, seasonal and spatial variations were evaluated. Among carboxylic acids, formic and acetic were predominant (VWA 7.0 and 8.3 {mu}M), while formaldehyde and acroleine were the dominant aldehydes (VWA 0.42 and 1.25 {mu}M). Carboxylic acids were estimated to account for 27.5% of the total free acidity (TFA), whereas sulphuric and nitric acid accounted for 46.2% and 26.2%, respectively. Oxalic acid was demonstrated to be an important contributing compound to the acidification in rainwater representing 7.1% of the TFA. The concentration of aldehydes and carboxylic acids, which originated mainly from biogenic emissions in the area studied, was strongly dependent on the season of the year (growing and non-growing). The ratios of formic to acetic acids are considerably different in the two seasons suggesting that there exist distinct sources in both growing and non-growing seasons. Principal component analysis was applied in order to elucidate the sources of aldehydes and organic acids in rainwater. The prevalence of natural vegetative origins for both of these compounds versus anthropogenic emissions was demonstrated and the importance of the oxidation of aldehydes as a relevant source of organic acids was also established. (author)

The ORF slr0091 of Synechocystis sp. PCC6803 encodes a high-light induced aldehyde dehydrogenase converting apocarotenals and alkanals

KAUST Repository

Trautmann, Danika

2013-07-05

Oxidative cleavage of carotenoids and peroxidation of lipids lead to apocarotenals and aliphatic aldehydes called alkanals, which react with vitally important compounds, promoting cytotoxicity. Although many enzymes have been reported to deactivate alkanals by converting them into fatty acids, little is known about the mechanisms used to detoxify apocarotenals or the enzymes acting on them. Cyanobacteria and other photosynthetic organisms must cope with both classes of aldehydes. Here we report that the Synechocystis enzyme SynAlh1, encoded by the ORF slr0091, is an aldehyde dehydrogenase that mediates oxidation of both apocarotenals and alkanals into the corresponding acids. Using a crude lysate of SynAlh1-expressing Escherichia coli cells, we show that SynAlh1 converts a wide range of apocarotenals and alkanals, with a preference for apocarotenals with defined chain lengths. As suggested by in vitro incubations and using engineered retinal-forming E. coli cells, we found that retinal is not a substrate for SynAlh1, making involvement in Synechocystis retinoid metabolism unlikely. The transcript level of SynAlh1 is induced by high light and cold treatment, indicating a role in the stress response, and the corresponding gene is a constituent of a stress-related operon. The assumptions regarding the function of SynAlh are further supported by the surprisingly high homology to human and plant aldehyde dehydrogenase that have been assigned to aldehyde detoxification. SynAlh1 is the first aldehyde dehydrogenase that has been shown to form both apocarotenoic and fatty acids. This dual function suggests that its eukaryotic homologs may also be involved in apocarotenal metabolism, a function that has not been considered so far. Aldehyde dehydrogenases play an important role in detoxification of reactive aldehydes. Here, we report on a cyanbacterial enzyme capable in converting two classes of lipid-derived aldehydes, apocaotenals and alkanals. The corresponding gene is a

Glycation and glycoxidation of low-density lipoproteins by glucose and low-molecular mass aldehydes. Formation of modified and oxidized particles

DEFF Research Database (Denmark)

Knott, Heather M; Brown, Bronwyn E; Davies, Michael Jonathan

2003-01-01

by the adduction of glucose or species derived from glucose, such as low-molecular mass aldehydes, to proteins. These reactions can be nonoxidative (glycation) or oxidative (glycoxidation) and result in the conversion of low-density lipoproteins (LDL) to a form that is recognized by the scavenger receptors...... with glucose. These processes are rapid and unaffected by low concentrations of copper ions. In contrast, lipid and protein oxidation are slow processes and occur to a limited extent in the absence of added copper ions. No evidence was obtained for the stimulation of lipid or protein oxidation by glucose...... or methylglyoxal in the presence of copper ions, whereas glycolaldehyde stimulated such reactions to a modest extent. These results suggest that the earliest significant events in this system are metal ion-independent glycation (modification) of the protein component of LDL, whilst oxidative events (glycoxidation...

Role of Lipid Peroxidation-Derived α, β-Unsaturated Aldehydes in Vascular Dysfunction

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Seung Eun Lee

2013-01-01

Full Text Available Vascular diseases are the most prominent cause of death, and inflammation and vascular dysfunction are key initiators of the pathophysiology of vascular disease. Lipid peroxidation products, such as acrolein and other α, β-unsaturated aldehydes, have been implicated as mediators of inflammation and vascular dysfunction. α, β-Unsaturated aldehydes are toxic because of their high reactivity with nucleophiles and their ability to form protein and DNA adducts without prior metabolic activation. This strong reactivity leads to electrophilic stress that disrupts normal cellular function. Furthermore, α, β-unsaturated aldehydes are reported to cause endothelial dysfunction by induction of oxidative stress, redox-sensitive mechanisms, and inflammatory changes such as induction of cyclooxygenase-2 and cytokines. This review provides an overview of the effects of lipid peroxidation products, α, β-unsaturated aldehydes, on inflammation and vascular dysfunction.

Different specificities of two aldehyde dehydrogenases from Saccharomyces cerevisiae var. boulardii.

Science.gov (United States)

Datta, Suprama; Annapure, Uday S; Timson, David J

2017-04-30

Aldehyde dehydrogenases play crucial roles in the detoxification of exogenous and endogenous aldehydes by catalysing their oxidation to carboxylic acid counterparts. The present study reports characterization of two such isoenzymes from the yeast Saccharomyces cerevisiae var. boulardii (NCYC 3264), one mitochondrial (Ald4p) and one cytosolic (Ald6p). Both Ald4p and Ald6p were oligomeric in solution and demonstrated positive kinetic cooperativity towards aldehyde substrates. Wild-type Ald6p showed activity only with aliphatic aldehydes. Ald4p, on the contrary, showed activity with benzaldehyde along with a limited range of aliphatic aldehydes. Inspection of modelled structure of Ald6p revealed that a bulky amino acid residue (Met 177 , compared with the equivalent residue Leu 196 in Ald4p) might cause steric hindrance of cyclic substrates. Therefore, we hypothesized that specificities of the two isoenzymes towards aldehyde substrates were partly driven by steric hindrance in the active site. A variant of wild-type Ald6p with the Met 177 residue replaced by a valine was also characterized to address to the hypothesis. It showed an increased specificity range and a gain of activity towards cyclohexanecarboxaldehyde. It also demonstrated an increased thermal stability when compared with both the wild-types. These data suggest that steric bulk in the active site of yeast aldehyde dehydrogenases is partially responsible for controlling specificity. © 2017 The Author(s).

Protocatechuic aldehyde attenuates cisplatin-induced acute kidney injury by suppressing Nox-mediated oxidative stress and renal inflammation

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Li Gao

2016-12-01

Full Text Available Cisplatin is a classic chemotherapeutic agent widely used to treat different types of cancers including ovarian, head and neck, testicular and uterine cervical carcinomas. However, cisplatin induces acute kidney injury by directly triggering an excessive inflammatory response, oxidative stress and programmed cell death of renal tubular epithelial cells. All of which lead to higher mortality rates in patients. In this study we examined the protective effect of protocatechuic aldehyde (PA in vitro in cisplatin-treated tubular epithelial cells and in vivo in cisplatin nephropathy. PA is a monomer of Traditional Chinese Medicine isolated from the root of S. miltiorrhiza. Results show that PA prevented cisplatin-induced decline of renal function and histological damage, which was confirmed by attenuation of KIM1 in both mRNA and protein levels. Moreover, PA reduced renal inflammation by suppressing oxidative stress and programmed cell death in response to cisplatin, which was further evidenced by in vitro data. Of note, PA suppressed NAPDH oxidases, including Nox2 and Nox4, in a dosage-dependent manner. Moreover, silencing Nox4, but not Nox2, removed the inhibitory effect of PA on cisplatin-induced renal injury, indicating that Nox4 may play a pivotal role in mediating the protective effect of PA in cisplatin-induced acute kidney injury. Collectively, our data indicate that PA largely blocked cisplatin-induced acute kidney injury by suppressing Nox-mediated oxidative stress and renal inflammation without compromising anti-tumor activity of cisplatin. These findings suggest that PA and its derivatives may serve as potential protective agents for cancer patients with cisplatin treatment.

In vitro assessment of human airway toxicity from major aldehydes in automotive emissions

Energy Technology Data Exchange (ETDEWEB)

Grafstroem, R.C. [Karolinska Inst., Stockholm (Sweden). Inst. of Environmental Medicine

1997-09-01

Automotive exhausts can significantly contribute to the levels of reactive aldehydes, including formaldehyde, acetaldehyde and acrolein, in urban air. The use of alcohols as an alternative fuel for gasoline or diesel may further increase these emissions. Since it is unclear if aldehyde inhalation may induce pathological states, including cancer, in human airways, the toxic properties of the above-mentioned aldehydes were studied in cultured target cell types. Each aldehyde modified vital cellular functions in a dose-dependent manner, and invariably inhibited growth and induced abnormal terminal differentiation. Decreases of cellular thiols and increases of intracellular Ca{sup 2+} were observed, and moreover, variable types and amounts of short-lived or persistent genetic damage were induced. The concentrations required for specified levels of a particular type of injury varied up to 10000-fold among the aldehydes. Overall, distinctive patterns of cytopathological activity were observed, which differed both qualitatively and quantitatively among the aldehydes. Finally, aldehydes inhibited DNA repair processes and increased cytotoxicity and mutagenesis in synergy with other known toxicants, indicating that aldehydes may also enhance damage by other constituents in automotive exhausts. In summary, the aldehydes, notably {sup m}u{sup M}-mM formaldehyde, caused pathological effects and induced mechanisms that relate to acute toxicity and cancer development in airway epithelial cells. Since `no-effect` levels may not exist for carcinogenic agents, the overall results support a need for elimination of aldehydes in automotive exhausts. 41 refs

Distinct roles of jasmonates and aldehydes in plant-defense responses.

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E Wassim Chehab

Full Text Available BACKGROUND: Many inducible plant-defense responses are activated by jasmonates (JAs, C(6-aldehydes, and their corresponding derivatives, produced by the two main competing branches of the oxylipin pathway, the allene oxide synthase (AOS and hydroperoxide lyase (HPL branches, respectively. In addition to competition for substrates, these branch-pathway-derived metabolites have substantial overlap in regulation of gene expression. Past experiments to define the role of C(6-aldehydes in plant defense responses were biased towards the exogenous application of the synthetic metabolites or the use of genetic manipulation of HPL expression levels in plant genotypes with intact ability to produce the competing AOS-derived metabolites. To uncouple the roles of the C(6-aldehydes and jasmonates in mediating direct and indirect plant-defense responses, we generated Arabidopsis genotypes lacking either one or both of these metabolites. These genotypes were subsequently challenged with a phloem-feeding insect (aphids: Myzus persicae, an insect herbivore (leafminers: Liriomyza trifolii, and two different necrotrophic fungal pathogens (Botrytis cinerea and Alternaria brassicicola. We also characterized the volatiles emitted by these plants upon aphid infestation or mechanical wounding and identified hexenyl acetate as the predominant compound in these volatile blends. Subsequently, we examined the signaling role of this compound in attracting the parasitoid wasp (Aphidius colemani, a natural enemy of aphids. PRINCIPAL FINDINGS: This study conclusively establishes that jasmonates and C(6-aldehydes play distinct roles in plant defense responses. The jasmonates are indispensable metabolites in mediating the activation of direct plant-defense responses, whereas the C(6-aldehyes are not. On the other hand, hexenyl acetate, an acetylated C(6-aldehyde, is the predominant wound-inducible volatile signal that mediates indirect defense responses by directing tritrophic

Headspace solid-phase microextraction coupled to gas chromatography for the analysis of aldehydes in edible oils.

Science.gov (United States)

Ma, Chunhua; Ji, Jiaojiao; Tan, Connieal; Chen, Dongmei; Luo, Feng; Wang, Yiru; Chen, Xi

2014-03-01

Oxidation has important effects on the quality of edible oils. In particular, the generation of aldehydes produced by the oxidation of oils is one of the deteriorative factors to their quality. The aim of this study was to develop a method to determine the aldehydes as lipid oxidation markers in edible oils. Seven aldehydes generated from lipid oxidation were studied using headspace solid-phase microextraction coupled to gas chromatography with a flame ionization detector. The extraction efficiency of five commercial fibers was investigated and the influence of extraction temperature, extraction time, desorption temperature, and desorption time were optimized. The best result was obtained with 85 μm carboxen/polydimethylsiloxane, extraction at 50 °C for 15 min and desorption in the gas chromatography injector at 250 °C for 2 min. Under the optimized conditions, the content of hexanal was the highest of the seven aldehydes in all edible oils. The limits of detection for hexanal in the three oils were found to range from 4.6 to 10.2 ng L(-1). The reproducibility of the method was evaluated and the relative standard deviations were less than 8.9%. This developed approach was successfully applied to analyze hexanal in peanut oil, soy oil, and olive oil samples, and these results were compared with those obtained using the thiobarbituric acid-reactive substances (TBARs) method. © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Do flavouring compounds contribute to aldehyde emissions in e-cigarettes?

Science.gov (United States)

Farsalinos, Konstantinos E; Voudris, Vassilis

2018-05-01

A recent study identified up to 10,000-fold higher aldehyde emissions from flavoured compared to unflavoured e-cigarette liquids. We set to replicate this study and also test similar flavourings with a new-generation e-cigarette device. Three liquids with the highest levels of aldehyde emissions in the previous study were tested (in standard and sweetened versions) using the same e-cigarette device and puffing patterns. Additionally, similar flavourings from a different manufacturer were tested using a new-generation e-cigarette device. Unflavoured samples were also tested. Low levels of formaldehyde (8.3-62 μg/g), acetaldehyde (12.1-26.0 μg/g) and acrolein (5.4-19.4 μg/g) were detected, lower by up to 589-fold compared to the previous report. Unflavoured liquid emitted 16.1 μg/g formaldehyde, 5.6 μg/g acetaldehyde and 2.4 μg/g acrolein, significantly lower compared to 2 liquids for formaldehyde and 1 for acrolein. Emissions from the new-generation device were even lower. Aldehyde emissions from all flavoured liquids were 79-99.8% lower than smoking and lower than commonly measured indoor levels and occupational and indoor safety limits. The e-cigarettes tested herein emit very low levels of aldehydes. Some flavourings may contribute to aldehyde emissions, but the absolute levels were minimal. Validated methods should be used when analysing e-cigarette emissions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Role of aldehyde chemistry and NOx concentrations in secondary organic aerosol formation

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P. O. Wennberg

2010-08-01

Full Text Available Aldehydes are an important class of products from atmospheric oxidation of hydrocarbons. Isoprene (2-methyl-1,3-butadiene, the most abundantly emitted atmospheric non-methane hydrocarbon, produces a significant amount of secondary organic aerosol (SOA via methacrolein (a C4-unsaturated aldehyde under urban high-NOx conditions. Previously, we have identified peroxy methacryloyl nitrate (MPAN as the important intermediate to isoprene and methacrolein SOA in this NOx regime. Here we show that as a result of this chemistry, NO2 enhances SOA formation from methacrolein and two other α, β-unsaturated aldehydes, specifically acrolein and crotonaldehyde, a NOx effect on SOA formation previously unrecognized. Oligoesters of dihydroxycarboxylic acids and hydroxynitrooxycarboxylic acids are observed to increase with increasing NO2/NO ratio, and previous characterizations are confirmed by both online and offline high-resolution mass spectrometry techniques. Molecular structure also determines the amount of SOA formation, as the SOA mass yields are the highest for aldehydes that are α, β-unsaturated and contain an additional methyl group on the α-carbon. Aerosol formation from 2-methyl-3-buten-2-ol (MBO232 is insignificant, even under high-NO2 conditions, as PAN (peroxy acyl nitrate, RC(OOONO2 formation is structurally unfavorable. At atmospherically relevant NO2/NO ratios (3–8, the SOA yields from isoprene high-NOx photooxidation are 3 times greater than previously measured at lower NO2/NO ratios. At sufficiently high NO2 concentrations, in systems of α, β-unsaturated aldehydes, SOA formation from subsequent oxidation of products from acyl peroxyl radicals+NO2 can exceed that from RO2+HO2 reactions under the same inorganic seed conditions, making RO2+NO2 an important channel for SOA formation.

Role of aldehyde chemistry and NOx concentrations in secondary organic aerosol formation

Science.gov (United States)

Chan, A. W. H.; Chan, M. N.; Surratt, J. D.; Chhabra, P. S.; Loza, C. L.; Crounse, J. D.; Yee, L. D.; Flagan, R. C.; Wennberg, P. O.; Seinfeld, J. H.

2010-08-01

Aldehydes are an important class of products from atmospheric oxidation of hydrocarbons. Isoprene (2-methyl-1,3-butadiene), the most abundantly emitted atmospheric non-methane hydrocarbon, produces a significant amount of secondary organic aerosol (SOA) via methacrolein (a C4-unsaturated aldehyde) under urban high-NOx conditions. Previously, we have identified peroxy methacryloyl nitrate (MPAN) as the important intermediate to isoprene and methacrolein SOA in this NOx regime. Here we show that as a result of this chemistry, NO2 enhances SOA formation from methacrolein and two other α, β-unsaturated aldehydes, specifically acrolein and crotonaldehyde, a NOx effect on SOA formation previously unrecognized. Oligoesters of dihydroxycarboxylic acids and hydroxynitrooxycarboxylic acids are observed to increase with increasing NO2/NO ratio, and previous characterizations are confirmed by both online and offline high-resolution mass spectrometry techniques. Molecular structure also determines the amount of SOA formation, as the SOA mass yields are the highest for aldehydes that are α, β-unsaturated and contain an additional methyl group on the α-carbon. Aerosol formation from 2-methyl-3-buten-2-ol (MBO232) is insignificant, even under high-NO2 conditions, as PAN (peroxy acyl nitrate, RC(O)OONO2) formation is structurally unfavorable. At atmospherically relevant NO2/NO ratios (3-8), the SOA yields from isoprene high-NOx photooxidation are 3 times greater than previously measured at lower NO2/NO ratios. At sufficiently high NO2 concentrations, in systems of α, β-unsaturated aldehydes, SOA formation from subsequent oxidation of products from acyl peroxyl radicals+NO2 can exceed that from RO2+HO2 reactions under the same inorganic seed conditions, making RO2+NO2 an important channel for SOA formation.

Cardiac-specific overexpression of aldehyde dehydrogenase 2 exacerbates cardiac remodeling in response to pressure overload

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Sujith Dassanayaka

2018-07-01

Full Text Available Pathological cardiac remodeling during heart failure is associated with higher levels of lipid peroxidation products and lower abundance of several aldehyde detoxification enzymes, including aldehyde dehydrogenase 2 (ALDH2. An emerging idea that could explain these findings concerns the role of electrophilic species in redox signaling, which may be important for adaptive responses to stress or injury. The purpose of this study was to determine whether genetically increasing ALDH2 activity affects pressure overload-induced cardiac dysfunction. Mice subjected to transverse aortic constriction (TAC for 12 weeks developed myocardial hypertrophy and cardiac dysfunction, which were associated with diminished ALDH2 expression and activity. Cardiac-specific expression of the human ALDH2 gene in mice augmented myocardial ALDH2 activity but did not improve cardiac function in response to pressure overload. After 12 weeks of TAC, ALDH2 transgenic mice had larger hearts than their wild-type littermates and lower capillary density. These findings show that overexpression of ALDH2 augments the hypertrophic response to pressure overload and imply that downregulation of ALDH2 may be an adaptive response to certain forms of cardiac pathology. Keywords: Heart failure, Hypertrophy, Oxidative stress, Aldehydes, Cardiac remodeling, Hormesis

Aldehyde levels in e-cigarette aerosol: Findings from a replication study and from use of a new-generation device.

Science.gov (United States)

Farsalinos, Konstantinos E; Kistler, Kurt A; Pennington, Alexander; Spyrou, Alketa; Kouretas, Dimitris; Gillman, Gene

2018-01-01

A recent study identified high aldehyde emissions from e-cigarettes (ECs), that when converted to reasonable daily human EC liquid consumption, 5 g/day, gave formaldehyde exposure equivalent to 604-3257 tobacco cigarettes. We replicated this study and also tested a new-generation atomizer under verified realistic (no dry puff) conditions. CE4v2 atomizers were tested at 3.8 V and 4.8 V, and a Nautilus Mini atomizer was tested at 9.0 W and 13.5 W. All measurements were performed in a laboratory ISO-accredited for EC aerosol collection and aldehyde measurements. CE4v2 generated dry puffs at both voltage settings. Formaldehyde levels were >10-fold lower, acetaldehyde 6-9-fold lower and acrolein 16-26-fold lower than reported in the previous study. Nautilus Mini did not generate dry puffs, and minimal aldehydes were emitted despite >100% higher aerosol production per puff compared to CE4v2 (formaldehyde: 16.7 and 16.5 μg/g; acetaldehyde: 9.6 and 10.3 μg/g; acrolein: 8.6 and 11.7 μg/g at 9.0 W and 13.5 W, respectively). EC liquid consumption of 5 g/day reduces aldehyde exposure by 94.4-99.8% compared to smoking 20 tobacco cigarettes. Checking for dry puffs is essential for EC emission testing. Under realistic conditions, new-generation ECs emit minimal aldehydes/g liquid at both low and high power. Validated methods should be used when analyzing EC aerosol. Copyright © 2017 Elsevier Ltd. All rights reserved.

INTERACTION OF ALDEHYDES DERIVED FROM LIPID PEROXIDATION AND MEMBRANE PROTEINS.

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Stefania ePizzimenti

2013-09-01

Full Text Available A great variety of compounds are formed during lipid peroxidation of polyunsaturated fatty acids of membrane phospholipids. Among them, bioactive aldehydes, such as 4-hydroxyalkenals, malondialdehyde (MDA and acrolein, have received particular attention since they have been considered as toxic messengers that can propagate and amplify oxidative injury. In the 4-hydroxyalkenal class, 4-hydroxy-2-nonenal (HNE is the most intensively studied aldehyde, in relation not only to its toxic function, but also to its physiological role. Indeed, HNE can be found at low concentrations in human tissues and plasma and participates in the control of biological processes, such as signal transduction, cell proliferation and differentiation. Moreover, at low doses, HNE exerts an anti-cancer effect, by inhibiting cell proliferation, angiogenesis, cell adhesion and by inducing differentiation and/or apoptosis in various tumor cell lines. It is very likely that a substantial fraction of the effects observed in cellular responses, induced by HNE and related aldehydes, be mediated by their interaction with proteins, resulting in the formation of covalent adducts or in the modulation of their expression and/or activity. In this review we focus on membrane proteins affected by lipid peroxidation-derived aldehydes, under physiological and pathological conditions.

Identification and characterisation of Aedes aegypti aldehyde dehydrogenases involved in pyrethroid metabolism.

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Nongkran Lumjuan

Full Text Available Pyrethroid insecticides, especially permethrin and deltamethrin, have been used extensively worldwide for mosquito control. However, insecticide resistance can spread through a population very rapidly under strong selection pressure from insecticide use. The upregulation of aldehyde dehydrogenase (ALDH has been reported upon pyrethroid treatment. In Aedes aegypti, the increase in ALDH activity against the hydrolytic product of pyrethroid has been observed in DDT/permethrin-resistant strains. The objective of this study was to identify the role of individual ALDHs involved in pyrethroid metabolism.Three ALDHs were identified; two of these, ALDH9948 and ALDH14080, were upregulated in terms of both mRNA and protein levels in a DDT/pyrethroid-resistant strain of Ae. aegypti. Recombinant ALDH9948 and ALDH14080 exhibited oxidase activities to catalyse the oxidation of a permethrin intermediate, phenoxybenzyl aldehyde (PBald, to phenoxybenzoic acid (PBacid.ALDHs have been identified in association with permethrin resistance in Ae. aegypti. Characterisation of recombinant ALDHs confirmed the role of this protein in pyrethroid metabolism. Understanding the biochemical and molecular mechanisms of pyrethroid resistance provides information for improving vector control strategies.

Study on physico-chemical properties of dialdehyde yam starch with different aldehyde group contents

International Nuclear Information System (INIS)

Zhang, Liming; Liu, Peng; Wang, Yugao; Gao, Wenyuan

2011-01-01

Dialdehyde yam starches (DASs) are prepared and characterized. Compared with native starch, viscosity average molecular weight of DASs decreases, and the extent of degradation depends on content of the aldehyde groups. Fourier transform infrared (FT-IR) spectra confirm that the characteristic peak for C=O group at 1732 cm -1 is enhanced with the increasing of content of the aldehyde groups. Scanning electron microscopy (SEM) micrographs show that the surface of starch granules becomes wrinkled. X-ray diffraction (XRD) patterns clearly indicate that their crystallinity decreases with the increasing content of the aldehyde groups before they become amorphous at higher oxidation states. The experimental results of thermogravimetric analysis (TGA) show that DASs have poor stability as compared to native starch. With the increase in content of the aldehyde groups, the thermal stability of DAS declines gradually. According to the results of differential scanning calorimetry (DSC), gelatinization temperature (T o and T p ) of DASs are increased, whereas the gelatinization enthalpy decreased.

Effects of sh-reagents on rat hepatic aldehyde dehydrogenase activity

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Konoplitskaya, K.L.; Kuz' mina, G.I.; Grigor' yeva, M.V.; Poznyakova, T.N.

The liver serves as the primary organ for the oxidation of ingested ethanol via a pathway involving alcohol- and aldehyde dehydrogenase. In view of the problem of alcoholism, three enzymes are of particular interest in understanding the biochemical mechanism that may be involved in alcohol addiction and in the formulation of therapeutic approaches. While alcohol dehydrogenase has been studied in considerable detail, current attention is centered on aldehyde dehydrogenase. A comparative analysis of the effects of a series of SH-active reagents - tetraethylthiuram disulfide (TETD), 5,5-dithiobisnitrobenzoic acid (DTNB), p-chloromercurybenzoate (PCMB), and N-ethylmaleimide (NEM) - were tested for their effects on the activity of aldehyde dehydrogenase of the hepatic mitochondrial (isozymes I and II) and microsomal (isozyme II) fractions of outbred albino rats. DTNB was found to be inhibited by 100 and 50% mitochondrial isozymes I and II, respectively, and by 20%, the microsomal enzyme under the conditions employed. DTNB and NEM inhibited by 30 and 50% isozymes I and II of the mitochondria, but had no effect on the microsomal isozyme. 24 references, 3 figures.

First general methods toward aldehyde enolphosphates.

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Barthes, Nicolas; Grison, Claude

2012-02-01

We herein report two innovative methods toward aldehyde enolphosphates and the first saccharidic aldehyde enolphosphates. Aldehyde enolphosphate function is worthwhile to be considered as a good phosphoenolpyruvate analogue. Copyright © 2011 Elsevier Inc. All rights reserved.

A Catalase-related Hemoprotein in Coral Is Specialized for Synthesis of Short-chain Aldehydes

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Teder, Tarvi; Lõhelaid, Helike; Boeglin, William E.; Calcutt, Wade M.; Brash, Alan R.; Samel, Nigulas

2015-01-01

In corals a catalase-lipoxygenase fusion protein transforms arachidonic acid to the allene oxide 8R,9-epoxy-5,9,11,14-eicosatetraenoic acid from which arise cyclopentenones such as the prostanoid-related clavulones. Recently we cloned two catalase-lipoxygenase fusion protein genes (a and b) from the coral Capnella imbricata, form a being an allene oxide synthase and form b giving uncharacterized polar products (Lõhelaid, H., Teder, T., Tõldsepp, K., Ekins, M., and Samel, N. (2014) PloS ONE 9, e89215). Here, using HPLC-UV, LC-MS, and NMR methods, we identify a novel activity of fusion protein b, establishing its role in cleaving the lipoxygenase product 8R-hydroperoxy-eicosatetraenoic acid into the short-chain aldehydes (5Z)-8-oxo-octenoic acid and (3Z,6Z)-dodecadienal; these primary products readily isomerize in an aqueous medium to the corresponding 6E- and 2E,6Z derivatives. This type of enzymatic cleavage, splitting the carbon chain within the conjugated diene of the hydroperoxide substrate, is known only in plant cytochrome P450 hydroperoxide lyases. In mechanistic studies using 18O-labeled substrate and incubations in H218O, we established synthesis of the C8-oxo acid and C12 aldehyde with the retention of the hydroperoxy oxygens, consistent with synthesis of a short-lived hemiacetal intermediate that breaks down spontaneously into the two aldehydes. Taken together with our initial studies indicating differing gene regulation of the allene oxide synthase and the newly identified catalase-related hydroperoxide lyase and given the role of aldehydes in plant defense, this work uncovers a potential pathway in coral stress signaling and a novel enzymatic activity in the animal kingdom. PMID:26100625

Nitrite promotes protein carbonylation and Strecker aldehyde formation in experimental fermented sausages: are both events connected?

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Villaverde, A; Ventanas, J; Estévez, M

2014-12-01

The role played by curing agents (nitrite, ascorbate) on protein oxidation and Strecker aldehyde formation is studied. To fulfill this objective, increasing concentrations of nitrite (0, 75 and 150ppm) and ascorbate (0, 250 and 500ppm) were added to sausages subjected to a 54day drying process. The concurrence of intense proteolysis, protein carbonylation and formation of Strecker aldehydes during processing of sausages suggests that α-aminoadipic semialdehyde (AAS) and γ-glutamic semialdehyde (GGS) may be implicated in the formation of Strecker aldehydes. The fact that nitrite (150ppm, ingoing amount) significantly promoted the formation of protein carbonyls at early stages of processing and the subsequent formation of Strecker aldehydes provides strength to this hypothesis. Ascorbate (125 and 250ppm) controlled the overall extent of protein carbonylation in sausages without declining the formation of Strecker aldehydes. These results may contribute to understanding the chemistry fundamentals of the positive influence of nitrite on the flavor and overall acceptability of cured muscle foods. Copyright © 2014 Elsevier Ltd. All rights reserved.

Role and structural characterization of plant aldehyde dehydrogenases from family 2 and family 7.

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Končitíková, Radka; Vigouroux, Armelle; Kopečná, Martina; Andree, Tomáš; Bartoš, Jan; Šebela, Marek; Moréra, Solange; Kopečný, David

2015-05-15

Aldehyde dehydrogenases (ALDHs) are responsible for oxidation of biogenic aldehyde intermediates as well as for cell detoxification of aldehydes generated during lipid peroxidation. So far, 13 ALDH families have been described in plants. In the present study, we provide a detailed biochemical characterization of plant ALDH2 and ALDH7 families by analysing maize and pea ALDH7 (ZmALDH7 and PsALDH7) and four maize cytosolic ALDH(cALDH)2 isoforms RF2C, RF2D, RF2E and RF2F [the first maize ALDH2 was discovered as a fertility restorer (RF2A)]. We report the crystal structures of ZmALDH7, RF2C and RF2F at high resolution. The ZmALDH7 structure shows that the three conserved residues Glu(120), Arg(300) and Thr(302) in the ALDH7 family are located in the substrate-binding site and are specific to this family. Our kinetic analysis demonstrates that α-aminoadipic semialdehyde, a lysine catabolism intermediate, is the preferred substrate for plant ALDH7. In contrast, aromatic aldehydes including benzaldehyde, anisaldehyde, cinnamaldehyde, coniferaldehyde and sinapaldehyde are the best substrates for cALDH2. In line with these results, the crystal structures of RF2C and RF2F reveal that their substrate-binding sites are similar and are formed by an aromatic cluster mainly composed of phenylalanine residues and several nonpolar residues. Gene expression studies indicate that the RF2C gene, which is strongly expressed in all organs, appears essential, suggesting that the crucial role of the enzyme would certainly be linked to the cell wall formation using aldehydes from phenylpropanoid pathway as substrates. Finally, plant ALDH7 may significantly contribute to osmoprotection because it oxidizes several aminoaldehydes leading to products known as osmolytes.

Recycling Monoethylene Glycol (MEG from the Recirculating Waste of an Ethylene Oxide Unit

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Moayed Mohsen

2017-06-01

Full Text Available In the ethylene glycol generation unit of petrochemical plants, first a reaction of ethylene oxide takes place which is then followed by other side reactions. These reactions include water absorption with ethylene oxide, which leads to the generation of formaldehyde and acetaldehyde. Over the lifetime of the alpha-alumina-based silver catalyst there is an increase in side reactions, increasing the amount of the formaldehyde and acetaldehyde generated by the ethylene oxide reactor which leads to reduced MEG product purity. Given the need of a petrochemical complex to further strip the aldehyde (formaldehyde and acetaldehyde to increase the quality of the MEG and increase the lifetime of the alpha-alumina-based silver catalyst, resin beds are designed and their surface absorption capacity is investigated to optimize aldehyde (formaldehyde and acetaldehyde removal in the recirculating water flow of the ethylene oxide unit. Experiments show that the ion exchange system based on strong anionic resin pre-treated with a sodium bisulfite solution can reduce the aldehyde level from about 300ppm to less than 5ppm. After the resin is saturated with aldehyde, the resin can be recycled using the sodium bisulfite solution which is a cheap chemical substance.

Influences of cinnamic aldehydes on H⁺ extrusion activity and ultrastructure of Candida.

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Shreaz, Sheikh; Bhatia, Rimple; Khan, Neelofar; Muralidhar, Sumathi; Manzoor, Nikhat; Khan, Luqman Ahmad

2013-02-01

The antifungal effects of cinnamaldehyde, 4-hydroxy-3-methoxycinnamaldehyde (coniferyl aldehyde) and 3,5-dimethoxy-4-hydroxycinnamaldehyde (sinapaldehyde) were investigated against 65 strains of Candida (six standard, 39 fluconazole-sensitive and 20 fluconazole-resistant). MICs of cinnamaldehyde, coniferyl aldehyde and sinapaldehyde ranged from 100 to 500 µg ml(-1), 100 to 300 µg ml(-1) and 100 to 200 µg ml(-1), respectively. All tested isolates showed a marked sensitivity towards these aldehydes in spot and time-kill assays. Sinapaldehyde was found to be the most effective, followed by coniferyl aldehyde and cinnamaldehyde. At their respective MIC(90) values, the three compounds caused mean inhibition levels of glucose-stimulated H(+)-efflux of 36, 34 and 41 % (cinnamaldehyde), 41, 42 and 47 % (coniferyl aldehyde) and 43, 45 and 51 % (sinapaldehyde) for standard-sensitive, clinical-sensitive and clinical-resistant isolates, respectively. Inhibition levels of H(+)-efflux caused by plasma membrane ATPase inhibitors N,N'-dicyclohexylcarbodiimide (100 µM) and diethylstilbestrol (10 µM) were 34, 45 and 44 %, and 57, 39 and 35 %, for standard-sensitive, clinical-sensitive and clinical-resistant isolates, respectively. Intracellular pH (pHi) was found to decrease by 0.34, 0.42 and 0.50 units following incubation with three tested aldehydes from the control pHi of 6.70. Scanning electron microscopy and transmission electron microscopy analysis was performed on a representative strain, C. albicans 10261, showing alterations in morphology, cell wall, plasma membrane damage and lysis. Haemolytic activity of the three compounds varied from 10 to 15 % at their highest MIC compared to an activity level of 20 % shown by fluconazole at 30 µg ml(-1). In conclusion, this study shows significant activity of cinnamic aldehydes against Candida, including azole-resistant strains, suggesting that these molecules can be developed as antifungals.

Ubiquitin-aldehyde: a general inhibitor of ubiquitin-recycling processes

International Nuclear Information System (INIS)

Hershko, A.; Rose, I.A.

1987-01-01

The generation and characterization of ubiquitin (Ub)-aldehyde, a potent inhibitor of Ub-C-terminal hydrolase, has previously been reported. The authors examine the action of this compound on the Ub-mediated proteolytic pathway using the system derived from rabbit reticulocytes. Addition of Ub-aldehyde was found to strongly inhibit breakdown of added 125 I-labeled lysozyme, but inhibition was overcome by increasing concentrations of Ub. The following evidence shows the effect of Ub-aldehyde on protein breakdown to be indirectly caused by its interference with the recycling of Ub, leading to exhaustion of the supply of free Ub: (i) Ub-aldehyde markedly increased the accumulation of Ub-protein conjugates coincident with a much decreased rate of conjugate breakdown; (ii) release of Ub from isolated Ub-protein conjugates in the absence of ATP (and therefore not coupled to protein degradation) is markedly inhibited by Ub-aldehyde. On the other hand, the ATP-dependent degradation of the protein moiety of Ub conjugates, which is an integral part of the proteolytic process, is not inhibited by this agent; (iii) direct measurement of levels of free Ub showed a rapid disappearance caused by the inhibitor. The Ub is found to be distributed in derivatives of a wide range of molecular weight classes. It thus seems that Ub-aldehyde, previously demonstrated to inhibit the hydrolysis of Ub conjugates of small molecules, also inhibits the activity of a series of enzymes that regenerate free Ub from adducts with proteins and intermediates in protein breakdown

Myoglobin-Catalyzed Olefination of Aldehydes.

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Tyagi, Vikas; Fasan, Rudi

2016-02-12

The olefination of aldehydes constitutes a most valuable and widely adopted strategy for constructing carbon-carbon double bonds in organic chemistry. While various synthetic methods have been made available for this purpose, no biocatalysts are known to mediate this transformation. Reported herein is that engineered myoglobin variants can catalyze the olefination of aldehydes in the presence of α-diazoesters with high catalytic efficiency (up to 4,900 turnovers) and excellent E diastereoselectivity (92-99.9 % de). This transformation could be applied to the olefination of a variety of substituted benzaldehydes and heteroaromatic aldehydes, also in combination with different alkyl α-diazoacetate reagents. This work provides a first example of biocatalytic aldehyde olefination and extends the spectrum of synthetically valuable chemical transformations accessible using metalloprotein-based catalysts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Protein conjugated with aldehydes derived from lipid peroxidation as an independent parameter of the carbonyl stress in the kidney damage

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Medina-Navarro Rafael

2011-11-01

Full Text Available Abstract Background One of the well-defined and characterized protein modifications usually produced by oxidation is carbonylation, an irreversible non-enzymatic modification of proteins. However, carbonyl groups can be introduced into proteins by non-oxidative mechanisms. Reactive carbonyl compounds have been observed to have increased in patients with renal failure. In the present work we have described a procedure designed as aldehyde capture to calculate the protein carbonyl stress derived solely from lipid peroxidation. Methods Acrolein-albumin adduct was prepared as standard at alkaline pH. Rat liver microsomal membranes and serum samples from patients with diabetic nephropathy were subjected to the aldehyde capture procedure and aldol-protein formation. Before alkalinization and incubation, samples were precipitated and redisolved in 6M guanidine. The absorbances of the samples were read with a spectrophotometer at 266 nm against a blank of guanidine. Results Evidence showed abundance of unsaturated aldehydes derived from lipid peroxidation in rat liver microsomal membranes and in the serum of diabetic patients with advanced chronic kidney disease. Carbonyl protein and aldol-proteins resulted higher in the diabetic nephropathy patients (p Conclusion The aldehyde-protein adduct represents a non oxidative component of carbonyl stress, independent of the direct amino acid oxidation and could constitute a practical and novelty strategy to measure the carbonyl stress derived solely from lipid peroxidation and particularly in diabetic nephropathy patients. In addition, we are in a position to propose an alternative explanation of why alkalinization of urine attenuates rhabdomyolysis-induced renal dysfunction.

Aldehyde-sequestering drugs: tools for studying protein damage by lipid peroxidation products.

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Burcham, Philip C; Kaminskas, Lisa M; Fontaine, Frank R; Petersen, Dennis R; Pyke, Simon M

2002-12-27

Elevated levels of reactive alpha,beta-unsaturated aldehydes (e.g. malondialdehyde, 4-hydroxynonenal and acrolein) in the affected tissues of various degenerative conditions suggest these substances are active propagators of the disease process. One experimental approach to attenuating damage by these intermediates employs 'aldehyde-sequestering drugs' as sacrificial nucleophiles, thereby sparing cell macromolecules and perhaps slowing disease progression. Drugs with demonstrated trapping activity toward lipid-derived aldehydes include various amine compounds such as aminoguanidine, carnosine and pyridoxamine. We have focused on identifying scavengers of acrolein, perhaps the most toxic aldehyde formed during lipid peroxidation cascades. Various phthalazine compounds (hydralazine and dihydralazine) were found to trap acrolein readily, forming hydrazone derivatives in a rapid Schiff-type reaction. These compounds strongly protect against acrolein-mediated toxicity in isolated hepatocytes.

Flavoring Compounds Dominate Toxic Aldehyde Production during E-Cigarette Vaping.

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Khlystov, Andrey; Samburova, Vera

2016-12-06

The growing popularity of electronic cigarettes (e-cigarettes) raises concerns about the possibility of adverse health effects to primary users and people exposed to e-cigarette vapors. E-Cigarettes offer a very wide variety of flavors, which is one of the main factors that attract new, especially young, users. How flavoring compounds in e-cigarette liquids affect the chemical composition and toxicity of e-cigarette vapors is practically unknown. Although e-cigarettes are marketed as safer alternatives to traditional cigarettes, several studies have demonstrated formation of toxic aldehydes in e-cigarette vapors during vaping. So far, aldehyde formation has been attributed to thermal decomposition of the main components of e-cigarette e-liquids (propylene glycol and glycerol), while the role of flavoring compounds has been ignored. In this study, we have measured several toxic aldehydes produced by three popular brands of e-cigarettes with flavored and unflavored e-liquids. We show that, within the tested e-cigarette brands, thermal decomposition of flavoring compounds dominates formation of aldehydes during vaping, producing levels that exceed occupational safety standards. Production of aldehydes was found to be exponentially dependent on concentration of flavoring compounds. These findings stress the need for a further, thorough investigation of the effect of flavoring compounds on the toxicity of e-cigarettes.

Deodorants: An experimental provocation study with cinnamic aldehyde

DEFF Research Database (Denmark)

Bruze, M.; Johansen, J. D.; Andersen, K. E.

2003-01-01

BACKGROUND: Axillary dermatitis is common and overrepresented in individuals with contact allergy to fragrances. Many individuals suspect their deodorants to be the incriminating products. OBJECTIVE: Our aim was to investigate the significance of cinnamic aldehyde in deodorants for the development...... of axillary dermatitis when used by individuals with and without contact allergy to cinnamic aldehyde. METHODS: Patch tests with deodorants and ethanol solutions with cinnamic aldehyde, and repeated open application tests with roll-on deodorants without and with cinnamic aldehyde at different concentrations......, were performed in 37 patients with dermatitis, 20 without and 17 with contact allergy to cinnamic aldehyde. RESULTS: A repeated open application test with positive findings was noted only in patients hypersensitive to cinnamic aldehyde (P deodorants containing...

Preparation of riboflavin specifically labeled in the 5'-hydroxymethyl terminus using a vitamin B2-aldehyde-forming enzyme from Schizophyllum commune

International Nuclear Information System (INIS)

Kekelidze, T.N.; Edmondson, D.E.; McCormick, D.B.

1995-01-01

A method is described for synthesis of riboflavin selectively labeled in the hydrogens at the 5'-hydroxymethyl position. In this method, a vitamin B 2 -aldehyde-forming enzyme from Schizophyllum commune is used to specifically and completely oxidize the 5'-hydroxymethyl of riboflavin to the 5'-aldehyde. This reaction is monitored spectrophotometrically by the reduction of 2,6-dichlorophenolindophenol at 600 nm. Appearance of aldehyde product was directly quantitated by reverse-phase high-performance liquid chromatography. Product is extracted from the incubation mixture by phenol after saturation with (NH 4 ) 2 SO 4 and then further purified by benzyl alcohol extraction. The 5'-aldehyde is reduced with appropriately labeled sodium borohydride to yield the vitamin specifically labeled in the 5'-hydroxymethyl group. (author)

Exposure to mutagenic aldehydes and particulate matter during panfrying of beefsteak with margarine, rapeseed oil, olive oil or soybean oil.

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Sjaastad, Ann Kristin; Svendsen, Kristin

2008-11-01

The aim of the study was to see if a cook could be exposed to mutagenic aldehydes in fumes from frying of beefsteak using margarine, rapeseed oil, soybean oil or virgin olive oil as frying fat. In addition, levels of particle exposure were measured to make the results comparable to other studies. The levels of higher aldehydes and total particles were measured in the breathing zone of the cook during the panfrying of beefsteak with the four different frying fats. In addition, the number of particles in the size intervals 0.3-0.5, 0.5-0.7 and 0.7-1.0 microm in the kitchen was registered. Measured levels of mutagenic aldehydes were between non-detectable and 25.33 microg m(-3) air. The exposure level of total aerosol was between 1.0 and 11.6 mg m(-3). Higher aldehydes were detected in all samples from this study, and mutagenic aldehydes were detected in most of the samples. Frying with margarine gave statistically significantly higher levels of mutagenic aldehydes and particles in all three size fractions than frying with the three different kinds of oil.

[Pollution Characteristics of Aldehydes and Ketones Compounds in the Exhaust of Beijing Typical Restaurants].

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Cheng, Jing-chen; Cui, Tong; He, Wan-qing; Nie, Lei; Wang, Jun-ling; Pan, Tao

2015-08-01

Aldehydes and ketones compounds, as one of the components in the exhaust of restaurants, are a class of volatile organic compounds (VOCs) with strong chemical reactivity. However, there is no systematic study on aldehydes and ketones compounds in the exhaust of restaurants. To further clarify the food source emission levels of aldehydes and ketones compounds and controlling measures, to access city group catering VOCs emissions control decision-making basis, this study selected 8 Beijing restaurants with different types. The aldehydes and ketones compounds were sampled using DNPH-silica tube, and then ultra performance liquid chromatography was used for quantitative measurement. The aldehydes and ketones concentrations of reference volume condition from 8 restaurants in descending order were Roasted Duck restaurant, Chinese Style Barbecue, Home Dishes, Western Fast-food, School Canteen, Chinese Style Fast-food, Sichuan Cuisine, Huaiyang Cuisine. The results showed that the range of aldehydes and ketones compounds (C1-C9) concentrations of reference volume condition in the exhaust of restaurants was 115.47-1035.99 microg x m(-3). The composition of aldehydes and ketones compounds in the exhaust of sampled restaurants was obviously different. The percentages of C1-C3 were above 40% in the exhaust from Chinese style restaurants. Fast food might emit more C4-C9 aldehydes and ketones compounds. From the current situation of existing aldehydes and ketones compounds control, the removal efficiency of high voltage electrostatic purifiers widely used in Beijing is limited.

Chemoenzymatic synthesis of chiral 2,2'-bipyridine ligands and their N-oxide derivatives: applications in the asymmetric aminolysis of epoxides and asymmetric allylation of aldehydes.

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Boyd, D R; Sharma, N D; Sbircea, L; Murphy, D; Malone, J F; James, S L; Allen, C C R; Hamilton, J T G

2010-03-07

A series of enantiopure 2,2'-bipyridines have been synthesised from the corresponding cis-dihydrodiol metabolites of 2-chloroquinolines. Several of the resulting hydroxylated 2,2'-bipyridines were found to be useful chiral ligands for the asymmetric aminolysis of meso-epoxides leading to the formation of enantioenriched amino alcohols (-->84% ee). N-oxide and N,N'-dioxide derivatives of these 2,2'-bipyridines, including separable atropisomers, have been synthesised and used as enantioselective organocatalysts in the asymmetric allylation of aldehydes to give allylic alcohols (-->86% ee).

Genotoxic consequences of endogenous aldehydes on mouse haematopoietic stem cell function.

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Garaycoechea, Juan I; Crossan, Gerry P; Langevin, Frederic; Daly, Maria; Arends, Mark J; Patel, Ketan J

2012-09-27

Haematopoietic stem cells (HSCs) regenerate blood cells throughout the lifespan of an organism. With age, the functional quality of HSCs declines, partly owing to the accumulation of damaged DNA. However, the factors that damage DNA and the protective mechanisms that operate in these cells are poorly understood. We have recently shown that the Fanconi anaemia DNA-repair pathway counteracts the genotoxic effects of reactive aldehydes. Mice with combined inactivation of aldehyde catabolism (through Aldh2 knockout) and the Fanconi anaemia DNA-repair pathway (Fancd2 knockout) display developmental defects, a predisposition to leukaemia, and are susceptible to the toxic effects of ethanol-an exogenous source of acetaldehyde. Here we report that aged Aldh2(-/-) Fancd2(-/-) mutant mice that do not develop leukaemia spontaneously develop aplastic anaemia, with the concomitant accumulation of damaged DNA within the haematopoietic stem and progenitor cell (HSPC) pool. Unexpectedly, we find that only HSPCs, and not more mature blood precursors, require Aldh2 for protection against acetaldehyde toxicity. Additionally, the aldehyde-oxidizing activity of HSPCs, as measured by Aldefluor stain, is due to Aldh2 and correlates with this protection. Finally, there is more than a 600-fold reduction in the HSC pool of mice deficient in both Fanconi anaemia pathway-mediated DNA repair and acetaldehyde detoxification. Therefore, the emergence of bone marrow failure in Fanconi anaemia is probably due to aldehyde-mediated genotoxicity restricted to the HSPC pool. These findings identify a new link between endogenous reactive metabolites and DNA damage in HSCs, and define the protective mechanisms that counteract this threat.

The Effect of Polyunsaturated Aldehydes on Skeletonema marinoi (Bacillariophyceae: The Involvement of Reactive Oxygen Species and Nitric Oxide

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Alessandra A. Gallina

2014-07-01

Full Text Available Nitric oxide (NO and reactive oxygen species (ROS production was investigated in the marine diatom, Skeletonema marinoi (SM, exposed to 2E,4E/Z-decadienal (DECA, 2E,4E/Z-octadienal (OCTA, 2E,4E/Z-heptadienal (HEPTA and a mix of these last two (MIX. When exposed to polyunsaturated aldehydes (PUA, a decrease of NO was observed, proportional to the PUA concentration (85% of the initial level after 180 min with 66 µM DECA. Only OCTA, HEPTA and MIX induced a parallel increase of ROS, the highest (2.9-times the control with OCTA concentrations twice the EC50 for growth at 24 h (20 μM. The synthesis of carotenoids belonging to the xanthophyll cycle (XC was enhanced during exposure, suggesting their antioxidant activity. Our data provide evidence that specific pathways exist as a reaction to PUA and that they depend upon the PUA used and/or the diatom species. In fact, Phaeodactylum tricornutum (PT produces NO in response to DECA, but not to OCTA. We advance the hypothesis that SM perceives OCTA and HEPTA as intra-population infochemicals (as it produces PUA, while PT (non-PUA producing species perceives them as allelochemicals. The ability to produce and to use PUA as infochemicals may underlie ecological traits of different diatom species and modulate ecological success in natural communities.

Site directed mutagenesis of amino acid residues at the active site of mouse aldehyde oxidase AOX1.

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Silvia Schumann

Full Text Available Mouse aldehyde oxidase (mAOX1 forms a homodimer and belongs to the xanthine oxidase family of molybdoenzymes which are characterized by an essential equatorial sulfur ligand coordinated to the molybdenum atom. In general, mammalian AOs are characterized by broad substrate specificity and an yet obscure physiological function. To define the physiological substrates and the enzymatic characteristics of mAOX1, we established a system for the heterologous expression of the enzyme in Escherichia coli. The recombinant protein showed spectral features and a range of substrate specificity similar to the native protein purified from mouse liver. The EPR data of recombinant mAOX1 were similar to those of AO from rabbit liver, but differed from the homologous xanthine oxidoreductase enzymes. Site-directed mutagenesis of amino acids Val806, Met884 and Glu1265 at the active site resulted in a drastic decrease in the oxidation of aldehydes with no increase in the oxidation of purine substrates. The double mutant V806E/M884R and the single mutant E1265Q were catalytically inactive enzymes regardless of the aldehyde or purine substrates tested. Our results show that only Glu1265 is essential for the catalytic activity by initiating the base-catalyzed mechanism of substrate oxidation. In addition, it is concluded that the substrate specificity of molybdo-flavoenzymes is more complex and not only defined by the three characterized amino acids in the active site.

Self-Standing Nanocellulose Janus-Type Films with Aldehyde and Carboxyl Functionalities.

Science.gov (United States)

Nypelö, Tiina; Amer, Hassan; Konnerth, Johannes; Potthast, Antje; Rosenau, Thomas

2018-03-12

Nanocellulose-based self-standing films are becoming a substrate for flexible electronics, diagnostics, and sensors. Strength and surface chemistry are vital variables for these film-based endeavors, the former is one of the assets of nanocellulose. To contribute to the latter, nanocellulose films are tuned with a side-specific functionalization, having an aldehyde and a carboxyl side. The functionalities were obtained combining premodification of the film components by periodate oxidation with ozone post-treatment. Periodate oxidation of cellulose nanocrystals results in film components that interact through intra- and intermolecular hemiacetals and lead to films with an elastic modulus of 11 GPa. The ozone treatment of one film side induces conversion of the aldehyde into carboxyl functionalities. The ozone treatment on individual crystals was largely destructive. Remarkably, such degradation is not observed for the self-standing film, and the film strength at break is preserved. Preserving a physically intact film despite ozone treatment is a credit to using the dry film structure held together by interparticle covalent linkages. Additionally, gas-phase post-treatment avoids disintegration that could result from immersion into solvents. The crystalline cellulose "Janus" film is suggested as an interfacial component in biomaterial engineering, separation technology, or in layered composite materials for tunable affinity between the layers.

Volatile molecular markers of VOO Thermo-oxidation: Effect of heating processes, macronutrients composition, and olive ripeness on the new emitted aldehydic compounds.

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Oueslati, Imen; Manaï, Hédia; Madrigal-Martínez, Mónica; Martínez-Cañas, Manuel A; Sánchez-Casas, Jacinto; Zarrouk, Mokhtar; Flamini, Guido

2018-04-01

Heating operation has been applied to Chétoui extra-virgin olive oils (EVOOs) extracted from fruits with several ripening stages (RS). The studied samples, were subjected to microwave and conventional heating. Results showed that heated VOOs after 2.5 h and 7 min of conventional and microwave heating, respectively, gave rise to a drastically decrease of LOX products and allowed the detection of toxic new formed aldehydic volatiles (alkanal: nonanal, alkenals: (Z)-2-heptenal and (E)-2-decenal, and alkadienals: (E.E)-2.4-decadienal), which can be used as markers of VOO degradation. Their abundance in the VOO headspaces depends on their boiling points, the rate of their possible degradation to yield other compounds, on the heating processes and on the rate of macronutrients. The emission rate of the new synthesized volatiles during heating processes was mainly attributed to enzymatic oxidation of some fatty acids. Hexanal, (Z)-2-heptenal, (E)-2-octenal, (E)-2-nonenal, (E,E) and (E,Z)-2,4-decadienal, and (E,E)-2,4-nonadienal, derived from linoleic acid, and heptanol, octanal, nonanal, decanal, (E) and (Z)-2-decenal, (E)-2-undecenal, and (E,E)-2,4-nonadienal, are emitted after degradation of oleic acid. During thermo-oxidation, the ECN 44 (LLO, and OLnO), and the ECN 46 (OLO, and PLO + SLL) compounds decreased, whereas, the ECN 48 (OOO, and PPO), and the ECN 50 (SOO) compounds increased when temperature and heating time increased. The several variations of the studied biochemical compounds depend to the heating processes. Ripening stage of olive fruits can be used as a tool to monitor the emission rate of the aldehydic volatiles, but cannot be used for a chemometric discrimination. Copyright © 2018 Elsevier Ltd. All rights reserved.

Process for producing furan from furfural aldehyde

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Diebold, J.P.; Evans, R.J.

1987-04-06

A process of producing furan and derivatives thereof as disclosed. The process includes generating furfural aldehyde vapors and then passing those vapors over a zeolite catalyst at a temperature and for a residence time effective to decarbonylate the furfural aldehydes to form furans and derivatives thereof. The resultant furan vapors and derivatives are then separated. In a preferred form, the furfural aldehyde vapors are generated during the process of converting biomass materials to liquid and gaseous fuels.

Process for producing furan from furfural aldehyde

Science.gov (United States)

Diebold, James P.; Evans, Robert J.

1988-01-01

A process of producing furan and derivatives thereof is disclosed. The process includes generating furfural aldehyde vapors and then passing those vapors over a zeolite catalyst at a temperature and for a residence time effective to decarbonylate the furfural aldehydes to form furans and derivatives thereof. The resultant furan vapors and derivatives are then separated. In a preferred form, the furfural aldehyde vapors are generated during the process of converting biomass materials to liquid and gaseous fuels.

Significance of Lipid-Derived Reactive Aldehyde-Specific Immune Complexes in Systemic Lupus Erythematosus.

Directory of Open Access Journals (Sweden)

Gangduo Wang

Full Text Available Even though systemic lupus erythematosus (SLE is associated with high morbidity and mortality rates among young and middle-aged women, the molecular mechanisms of disease pathogenesis are not fully understood. Previous studies from our laboratory suggested an association between oxidative stress and SLE disease activity (SLEDAI. To further assess the role of reactive oxygen species (ROS in SLE, we examined the contribution of lipid-derived reactive aldehydes (LDRAs-specific immune complexes in SLE. Sera from 60 SLE patients with varying SLEDAI and 32 age- and gender- matched healthy controls were analyzed for oxidative stress and related markers. Patients were divided into two groups based on their SLEDAI scores (<6 and ≥ 6. Both SLEDAI groups showed higher serum 4-hydroxynonenal (HNE-/malondialdehyde (MDA-protein adducts and their specific immune complexes (HNE-/MDA-specific ICs together with IL-17 than the controls, but the levels were significantly greater in the high SLEDAI (≥ 6 group. Moreover, the serum levels of anti-oxidant enzymes Cu/Zn superoxide dismutase (SOD and catalase (CAT were significantly reduced in both patient groups compared to controls. Remarkably, for the first time, our data show that increased HNE-/MDA-specific ICs are positively associated with SLEDAI and elevated circulating immune complexes (CICs, suggesting a possible causal relationship among oxidative stress, LDRA-specific ICs and the development of SLE. Our findings, apart from providing firm support to an association between oxidative stress and SLE, also suggest that these oxidative stress markers, especially the HNE-/MDA-specific ICs, may be useful in evaluating the prognosis of SLE as well as in elucidating the mechanisms of disease pathogenesis.

Aldehyde-functionalized porous nanocellulose for effective removal of heavy metal ions from aqueous solutions

Science.gov (United States)

C. Yao; F. Wang; Z. Cai; X. Wang

2016-01-01

Nanoscale sorption is a promising strategy for catalyst and purification system design. In this paper, cellulose nanofibrils (CNFs) were densely attached with aldehyde functional groups on the surface via a mild periodate oxidation process, and then applied as mesoporous sorbents to remove Cu(II) and Pb(II) from aqueous solutions. In the studied concentration range (0....

Tropospheric chemistry of natural hydrocarbons, aldehydes, and peroxy radicals: Their connections to sulfuric acid production and climate effects

International Nuclear Information System (INIS)

Gaffney, J.S.; Marley, N.A.

1993-05-01

Recent work has shown that natural hydrocarbon emissions can significantly affect the levels of urban and regional tropospheric ozone. We report on the reactivities of these biogenic trace gases, particularly isoprene, focusing on their importance in the production of aldehydes and peroxy radicals, leading to increased levels of hydrogen over regional forests. Hydrogen peroxide can lead to the wet oxidation of sulfur dioxide to acidic sulfate in aerosols, fogs, and clouds. In turn, acidic sulfate can act to as a light scattering aerosol and a source of cloud condensation nuclei (CCN), potentially leading to global cooling. Aerosol sulfate and other dissolved organic and inorganic compounds can also play important roles as a greenhouse species in the lower troposphere

Cellular fatty acids and aldehydes of oral Eubacterium.

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Itoh, U; Sato, M; Tsuchiya, H; Namikawa, I

1995-02-01

The cellular fatty acids and aldehydes of oral Eubacterium species were determined by gas chromatography-mass spectrometry. E. brachy and E. lentum contained mainly branched-chain fatty acids, whereas the others contained straight-chain acids. E. brachy, E. lentum, E. yurii ssp. yurii, E. yurii spp. margaretiae, E. limosum, E. plauti and E. aerofaciens also contained aldehydes with even carbon numbers. In addition to species-specific components, the compositional ratios of fatty acids and aldehydes characterized each individual species. The 10 species tested were divided into 5 groups by the principal component analysis. Cellular fatty acids and aldehydes would be chemical markers for interspecies differentiation of oral Eubacterium.

Expressional studies of the aldehyde oxidase (AOX1) gene during myogenic differentiation in C2C12 cells

Energy Technology Data Exchange (ETDEWEB)

Kamli, Majid Rasool; Kim, Jihoe; Pokharel, Smritee; Jan, Arif Tasleem [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Lee, Eun Ju [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Bovine Genome Resources Bank, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Choi, Inho, E-mail: inhochoi@ynu.ac.kr [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Bovine Genome Resources Bank, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of)

2014-08-08

Highlights: • AOX1 contributes to the formation of myotube. • Silencing of AOX1 reduces myotube formation. • AOX1 regulates MyoG gene expression. • AOX1 contributes to myogenesis via H{sub 2}O{sub 2}. - Abstract: Aldehyde oxidases (AOXs), which catalyze the hydroxylation of heterocycles and oxidation of a wide variety of aldehydic compounds, have been present throughout evolution from bacteria to humans. While humans have only a single functional aldehyde oxidase (AOX1) gene, rodents are endowed with four AOXs; AOX1 and three aldehyde oxidase homologs (AOH1, AOH2 and AOH3). In continuation of our previous study conducted to identify genes differentially expressed during myogenesis using a microarray approach, we investigated AOX1 with respect to its role in myogenesis to conceptualize how it is regulated in C2C12 cells. The results obtained were validated by silencing of the AOX1 gene. Analysis of their fusion index revealed that formation of myotubes showed a marked reduction of up to 40% in AOX1{sub kd} cells. Expression of myogenin (MYOG), one of the marker genes used to study myogenesis, was also found to be reduced in AOX1{sub kd} cells. AOX1 is an enzyme of pharmacological and toxicological importance that metabolizes numerous xenobiotics to their respective carboxylic acids. Hydrogen peroxide (H{sub 2}O{sub 2}) produced as a by-product in this reaction is considered to be involved as a part of the signaling mechanism during differentiation. An observed reduction in the level of H{sub 2}O{sub 2} among AOX1{sub kd} cells confirmed production of H{sub 2}O{sub 2} in the reaction catalyzed by AOX1. Taken together, these findings suggest that AOX1 acts as a contributor to the process of myogenesis by influencing the level of H{sub 2}O{sub 2}.

40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for the...

Comparison of aldehyde emissions simulation with FTIR measurements in the exhaust of a spark ignition engine fueled by ethanol

Science.gov (United States)

Zarante, Paola Helena Barros; Sodré, José Ricardo

2018-02-01

This work presents a numerical simulation model for aldehyde formation and exhaust emissions from ethanol-fueled spark ignition engines. The aldehyde simulation model was developed using FORTRAN software, with the input data obtained from the dedicated engine cycle simulation software AVL BOOST. The model calculates formaldehyde and acetaldehyde concentrations from post-flame partial oxidation of methane, ethane and unburned ethanol. The calculated values were compared with experimental data obtained from a mid-size sedan powered by a 1.4-l spark ignition engine, tested on a chassis dynamometer. Exhaust aldehyde concentrations were determined using a Fourier Transform Infrared (FTIR) Spectroscopy analyzer. In general, the results demonstrate that the concentrations of aldehydes and the source elements increased with engine speed and exhaust gas temperature. The measured acetaldehyde concentrations showed values from 3 to 6 times higher than formaldehyde in the range studied. The model could predict reasonably well the qualitative experimental trends, with the quantitative results showing a maximum discrepancy of 39% for acetaldehyde concentration and 21 ppm for exhaust formaldehyde.

The Arabidopsis thaliana REDUCED EPIDERMAL FLUORESCENCE1 gene encodes an aldehyde dehydrogenase involved in ferulic acid and sinapic acid biosynthesis.

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Nair, Ramesh B; Bastress, Kristen L; Ruegger, Max O; Denault, Jeff W; Chapple, Clint

2004-02-01

Recent research has significantly advanced our understanding of the phenylpropanoid pathway but has left in doubt the pathway by which sinapic acid is synthesized in plants. The reduced epidermal fluorescence1 (ref1) mutant of Arabidopsis thaliana accumulates only 10 to 30% of the sinapate esters found in wild-type plants. Positional cloning of the REF1 gene revealed that it encodes an aldehyde dehydrogenase, a member of a large class of NADP(+)-dependent enzymes that catalyze the oxidation of aldehydes to their corresponding carboxylic acids. Consistent with this finding, extracts of ref1 leaves exhibit low sinapaldehyde dehydrogenase activity. These data indicate that REF1 encodes a sinapaldehyde dehydrogenase required for sinapic acid and sinapate ester biosynthesis. When expressed in Escherichia coli, REF1 was found to exhibit both sinapaldehyde and coniferaldehyde dehydrogenase activity, and further phenotypic analysis of ref1 mutant plants showed that they contain less cell wall-esterified ferulic acid. These findings suggest that both ferulic acid and sinapic acid are derived, at least in part, through oxidation of coniferaldehyde and sinapaldehyde. This route is directly opposite to the traditional representation of phenylpropanoid metabolism in which hydroxycinnamic acids are instead precursors of their corresponding aldehydes.

Determination of unsymmetrical dimethylhydrazine in water and soil by derivatization with aromatic aldehydes using GC/MS

Energy Technology Data Exchange (ETDEWEB)

Atamaniouk, V [Ukrainian Academy of Science (Ukraine); Ananieva, L [Ukrainian Ministry of Defence (Ukraine); Ladanowski, C [Environment Canada, Ottawa, ON (Canada). Emergencies Engineering Div.; Cathum, S; Whittaker, H

1996-09-01

An analytical technique for the detection of hydrazine in environmental samples was described. Unsymmetrical dimethyl hydrazine (UDMH) is used in rocket fuel as a high-energy propellant. It is highly toxic and has been banned in Canada and the United States since 1989. However, in 1995 traces of UDMH were found in apples and the dangerous carcinogenic NDMA (a major byproduct of UDMH oxidation) was detected in drinking water in Ontario. The analysis of UDMH by derivation of seven aldehydes was investigated. A gas chromatography and a mass spectroscopy method of determining the presence of UDMH in water by reacting it with various aldehydes in dichromethane, was developed. 43 refs., 8 tabs., 15 figs.

Threshold responses in cinnamic-aldehyde-sensitive subjects

DEFF Research Database (Denmark)

Johansen, J D; Andersen, K E; Rastogi, Suresh Chandra

1996-01-01

Cinnamic aldehyde is an important fragrance material and contact allergen. The present study was performed to provide quantitative data on the eliciting capacity of cinnamic aldehyde, to be considered in assessment of clinical relevance and health hazard. The skin response to serial dilution patch...

Application of ultraviolet, ozone, and advanced oxidation treatments to washwaters to destroy nitrosamines, nitramines, amines, and aldehydes formed during amine-based carbon capture.

Science.gov (United States)

Shah, Amisha D; Dai, Ning; Mitch, William A

2013-03-19

Although amine-based CO(2) absorption is a leading contender for full-scale postcombustion CO(2) capture at power plants, concerns have been raised about the potential release of carcinogenic N-nitrosamines and N-nitramines formed by reaction of exhaust gas NO(x) with the amines. Experiments with a laboratory-scale pilot unit suggested that washwater units meant to scrub contaminants from absorber unit exhaust could potentially serve as a source of N-nitrosamines via reactions of residual NO(x) with amines accumulating in the washwater. Dosage requirements for the continuous treatment of the washwater recycle line with ultraviolet (UV) light for destruction of N-nitrosamines and N-nitramines, and with ozone or hydroxyl radical-based advanced oxidation processes (AOPs) for destruction of amines and aldehydes, were evaluated. Although amine destruction. Ozone achieved 90% amine removal in washwaters at 5-12 molar excess of ozone, indicating transferred dosage levels of ∼100 mg/L for 90% removal in a first-stage washwater unit, but likely only ∼10 mg/L if applied to a second-stage washwater. Accurate dosage and cost estimates would require pilot testing to capture synergies between UV and ozone treatments.

Determination of Aldehyde Dehydrogenase (ALDH Isozymes in Human Cancer Samples - Comparison of Kinetic and Immunochemical Assays

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Dorota Borecka

2002-12-01

Full Text Available A fluorimetric assay of aldehyde dehydrogenase isozymes, based on naphthaldehyde oxidation, is compared with Western Blotting analysis on several clinical samples obtained from surgery. The comparison reveals qualitatively good correlation of ALDH1A1 isozyme detection with two methods and somewhat worse on ALDH3A1 assay.

Ultraviolet Radiation: Cellular Antioxidant Response and the Role of Ocular Aldehyde Dehydrogenase Enzymes

Science.gov (United States)

Marchitti, Satori A.; Chen, Ying; Thompson, David C.; Vasiliou, Vasilis

2011-01-01

Solar ultraviolet radiation (UVR) exposes the human eye to near constant oxidative stress. Evidence suggests that UVR is the most important environmental insult leading to the development of a variety of ophthalmoheliosis disorders. UVR-induced reactive oxygen species are highly reactive with DNA, proteins and cellular membranes, resulting in cellular and tissue damage. Antioxidant defense systems present in ocular tissues function to combat reactive oxygen species and protect the eye from oxidative damage. Important enzymatic antioxidants are the superoxide dismutases, catalase, glutathione peroxidases, glutathione reductase and members of the aldehyde dehydrogenase (ALDH) superfamily. Glutathione, ascorbic and uric acids, α-tocopherol, NADPH and ferritin serve as small molecule, nonenzymatic antioxidants. Ocular tissues have high levels of these antioxidants which are essential for the maintenance of redox homeostasis in the eye and protection against oxidative damage. ALDH1A1 and ALDH3A1, present abundantly in the cornea and lens, have been shown to have unique roles in the defense against UVR and the downstream effects of oxidative stress. This review presents the properties and functions of ocular antioxidants that play critical roles in the cellular response to UVR exposure, including a focused discussion of the unique roles that the ALDH1A1 and ALDH3A1 enzymes have as multi-functional ocular antioxidants. PMID:21670692

A soft tissue adhesive based on aldehyde-sodium alginate and amino-carboxymethyl chitosan preparation through the Schiff reaction

Science.gov (United States)

Wu, Yu; Yuan, Liu; Sheng, Nai-an; Gu, Zi-qi; Feng, Wen-hao; Yin, Hai-yue; Morsi, Yosry; Mo, Xiu-mei

2017-09-01

Sodium alginate and carboxymethyl chitosan have been extensively applied in tissue engineering and other relative fields due to their low price and excellent biocompatibility. In this paper, we oxidized sodium alginate with sodium periodate to convert 1,2-hydroxyl groups into aldehyde groups to get aldehyde-sodium alginate (ASA). Carboxymethyl chitosan was modified with ethylenediamine (ED) in the presence of water-soluble N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) to introduce additional amino groups to get amino-carboxymethyl chitosan (A-CS). Upon mixing the A-SA and A-CS aqueous solutions together, a gel rapidly formed based on the Schiff's base reaction between aldehyde groups in A-SA and amino groups in A-CS. FTIR analysis confirmed the characteristic peak of Schiff's base group in the hydrogel. It was confirmed that the gelation time be dependent on the aldehyde group content in A-SA and amino group content in A-CS. The fasted hydrogel formation takes place within 10 min. The data of bonding strength and cytotoxicity measurement also showed that the hydrogel had good adhesion and biocompatibility. All these results support that this gel has the potential as soft tissue adhesive.

Acrolein—an α,ß-Unsaturated Aldehyde: A Review of Oral Cavity Exposure and Oral Pathology Effects

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Dror Aizenbud

2016-07-01

Full Text Available Acrolein is a highly reactive unsaturated aldehyde widely present in the environment, particularly as a product of tobacco smoke. Our previous studies indicated the adverse consequences of even short-term acrolein exposure and proposed a molecular mechanism of its potential harmful effect on oral cavity keratinocytic cells. In this paper we chose to review the broad spectrum of acrolein sources such as pollution, food, and smoking. Consequently, in this paper we consider a high level of oral exposure to acrolein through these sources and discuss the noxious effects it has on the oral cavity including on salivary quality and contents, oral resistance to oxidative stress, and stress mechanism activation in a variety of oral cells.

Colorimetric Recognition of Aldehydes and Ketones.

Science.gov (United States)

Li, Zheng; Fang, Ming; LaGasse, Maria K; Askim, Jon R; Suslick, Kenneth S

2017-08-07

A colorimetric sensor array has been designed for the identification of and discrimination among aldehydes and ketones in vapor phase. Due to rapid chemical reactions between the solid-state sensor elements and gaseous analytes, distinct color difference patterns were produced and digitally imaged for chemometric analysis. The sensor array was developed from classical spot tests using aniline and phenylhydrazine dyes that enable molecular recognition of a wide variety of aliphatic or aromatic aldehydes and ketones, as demonstrated by hierarchical cluster, principal component, and support vector machine analyses. The aldehyde/ketone-specific sensors were further employed for differentiation among and identification of ten liquor samples (whiskies, brandy, vodka) and ethanol controls, showing its potential applications in the beverage industry. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Unsaturated aldehydes as alkene equivalents in the Diels-Alder reaction

DEFF Research Database (Denmark)

Taarning, Esben; Madsen, Robert

2008-01-01

A one-pot procedure is described for using alpha,beta-unsaturated aldehydes as olefin equivalents in the Diels-Alder reaction. The method combines the normal electron demand cycloaddition with aldehyde dienophiles and the rhodium-catalyzed decarbonylation of aldehydes to afford cyclohexenes...

Characterization of TEMPO-oxidized bacterial cellulose scaffolds for tissue engineering applications

International Nuclear Information System (INIS)

Luo, Honglin; Xiong, Guangyao; Hu, Da; Ren, Kaijing; Yao, Fanglian; Zhu, Yong; Gao, Chuan; Wan, Yizao

2013-01-01

Introduction of active groups on the surface of bacterial cellulose (BC) nanofibers is one of the promising routes of tailoring the performance of BC scaffolds for tissue engineering. This paper reported the introduction of aldehyde groups to BC nanofibers by 2,2,6,6-tetramethylpyperidine-1-oxy radical (TEMPO)-mediated oxidation and evaluation of the potential of the TEMPO-oxidized BC as tissue engineering scaffolds. Periodate oxidation was also conducted for comparison. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses were carried out to determine the existence of aldehyde groups on BC nanofibers and the crystallinity. In addition, properties relevant to scaffold applications such as morphology, fiber diameter, mechanical properties, and in vitro degradation were characterized. The results indicated that periodate oxidation could introduce free aldehyde to BC nanofibers and the free aldehyde groups on the TEMPO-oxidized BC tended to transfer to acetal groups. It was also found that the advantageous 3D structure of BC scaffolds remained unchanged and that no significant changes in morphology, fiber diameter, tensile structure and in vitro degradation were found after TEMPO-mediated oxidation while significant differences were observed upon periodate oxidation. The present study revealed that TEMPO-oxidation could impart BC scaffolds with new functions while did not degrade their intrinsic advantages. - Highlights: • TEMPO-mediated oxidation on BC scaffold for tissue engineering use was conducted. • TEMPO-mediated oxidation did not degrade the intrinsic advantages of BC scaffold. • TEMPO-mediated oxidation could impart BC scaffold with new functional groups. • Feasibility of TEMPO-oxidized BC as tissue engineering scaffold was confirmed

Background Atmospheric Levels of Aldehydes, BTEX and PM10 Pollutants in a Medium-Sized City of Southern Italy

International Nuclear Information System (INIS)

Iovino, P.; Salvestrini, S.; Capasso, S.

2007-01-01

Background atmospheric levels of aldehydes, BTEX and PM10 pollutants were measured in the suburb of Caserta (Italy), 75 thousands inhabitants, 41 0 04' N, on rainless weekdays and weekends during 2005. On weekdays the average daily concentrations (μg m -3 ) were 41.6 PM10, 8.6 benzene, 25.2 toluene, 6.3 ethylbenzene, 14.0 (m+p)-xylene, 11.7 o-xylene, 6.5 formaldehyde, 3.3 acetaldehyde. All the pollutant concentrations were strictly correlated (mean correlation coefficients = 0.90). At weekends the concentrations were lower by about 1.6 times. Both on weekdays and at weekends the PM10 and benzene levels exceeded the limits set by the EU Directive 30/1999 and 69/2000, respectively

Heterologous Expression of Aldehyde Dehydrogenase in Lactococcus lactis for Acetaldehyde Detoxification at Low pH.

Science.gov (United States)

Lyu, Yunbin; LaPointe, Gisèle; Zhong, Lei; Lu, Jing; Zhang, Chong; Lu, Zhaoxin

2018-02-01

Aldehyde dehydrogenase (E.C. 1.2.1.x) can catalyze detoxification of acetaldehydes. A novel acetaldehyde dehydrogenase (istALDH) from the non-Saccharomyces yeast Issatchenkia terricola strain XJ-2 has been previously characterized. In this work, Lactococcus lactis with the NIsin Controlled Expression (NICE) System was applied to express the aldehyde dehydrogenase gene (istALDH) in order to catalyze oxidation of acetaldehyde at low pH. A recombinant L. lactis NZ3900 was obtained and applied for the detoxification of acetaldehyde as whole-cell biocatalysts. The activity of IstALDH in L. lactis NZ3900 (pNZ8148-istALDH) reached 36.4 U mL -1 when the recombinant cells were induced with 50 ng mL -1 nisin at 20 °C for 2 h. The IstALDH activity of recombinant L. lactis cells showed higher stability at 37 °C and pH 4.0 compared with the crude enzyme. L. lactis NZ3900 (pNZ8148-istALDH) could convert acetaldehyde at pH 2.0 while the crude enzyme could not. Moreover, the resting cells of L. lactis NZ3900 (pNZ8148-istALDH) showed a 2.5-fold higher activity and better stability in catalyzing oxidation of acetaldehyde at pH 2.0 compared with that of Escherichia coli expressing the IstALDH. Taken together, the L. lactis cells expressing recombinant IstALDH are potential whole-cell biocatalysts that can be applied in the detoxification of aldehydes.

Preparation, characterization and antibacterial activity of oxidized κ-carrageenan.

Science.gov (United States)

Zhu, Mingjin; Ge, Liming; Lyu, Yongbo; Zi, Yaxin; Li, Xinying; Li, Defu; Mu, Changdao

2017-10-15

The oxidized κ-carrageenans with different oxidation levels were prepared through the hydrogen peroxide and copper sulfate redox system. The oxidation level of oxidized κ-carrageenan was successfully controlled by adjusting the dosage of hydrogen peroxide. The results showed that the microtopography of oxidized κ-carrageenan changed from rough granules to smooth flakes, mainly resulting from the easily melting property of oxidized κ-carrageenan induced by introduced carboxyl and aldehyde groups. Especially, the antibacterial activity of oxidized κ-carrageenans against Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) was systematically investigated. The results showed that the oxidized κ-carrageenan could damage the bacterial cell wall and cytoplasmic membrane and suppress the growth of both Gram-positive and Gram-negative bacteria. The oxidized κ-carrageenan possessed broad-spectrum antibacterial activity, which may be used as a new antibacterial agent. Copyright © 2017 Elsevier Ltd. All rights reserved.

Toxic Diatom Aldehydes Affect Defence Gene Networks in Sea Urchins.

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Stefano Varrella

Full Text Available Marine organisms possess a series of cellular strategies to counteract the negative effects of toxic compounds, including the massive reorganization of gene expression networks. Here we report the modulated dose-dependent response of activated genes by diatom polyunsaturated aldehydes (PUAs in the sea urchin Paracentrotus lividus. PUAs are secondary metabolites deriving from the oxidation of fatty acids, inducing deleterious effects on the reproduction and development of planktonic and benthic organisms that feed on these unicellular algae and with anti-cancer activity. Our previous results showed that PUAs target several genes, implicated in different functional processes in this sea urchin. Using interactomic Ingenuity Pathway Analysis we now show that the genes targeted by PUAs are correlated with four HUB genes, NF-κB, p53, δ-2-catenin and HIF1A, which have not been previously reported for P. lividus. We propose a working model describing hypothetical pathways potentially involved in toxic aldehyde stress response in sea urchins. This represents the first report on gene networks affected by PUAs, opening new perspectives in understanding the cellular mechanisms underlying the response of benthic organisms to diatom exposure.

An integrated QSAR-PBK/D modelling approach for predicting detoxification and DNA adduct formation of 18 acyclic food-borne α,β-unsaturated aldehydes

Energy Technology Data Exchange (ETDEWEB)

Kiwamoto, R., E-mail: reiko.kiwamoto@wur.nl; Spenkelink, A.; Rietjens, I.M.C.M.; Punt, A.

2015-01-01

Acyclic α,β-unsaturated aldehydes present in food raise a concern because the α,β-unsaturated aldehyde moiety is considered a structural alert for genotoxicity. However, controversy remains on whether in vivo at realistic dietary exposure DNA adduct formation is significant. The aim of the present study was to develop physiologically based kinetic/dynamic (PBK/D) models to examine dose-dependent detoxification and DNA adduct formation of a group of 18 food-borne acyclic α,β-unsaturated aldehydes without 2- or 3-alkylation, and with no more than one conjugated double bond. Parameters for the PBK/D models were obtained using quantitative structure–activity relationships (QSARs) defined with a training set of six selected aldehydes. Using the QSARs, PBK/D models for the other 12 aldehydes were defined. Results revealed that DNA adduct formation in the liver increases with decreasing bulkiness of the molecule especially due to less efficient detoxification. 2-Propenal (acrolein) was identified to induce the highest DNA adduct levels. At realistic dietary intake, the predicted DNA adduct levels for all aldehydes were two orders of magnitude lower than endogenous background levels observed in disease free human liver, suggesting that for all 18 aldehydes DNA adduct formation is negligible at the relevant levels of dietary intake. The present study provides a proof of principle for the use of QSAR-based PBK/D modelling to facilitate group evaluations and read-across in risk assessment. - Highlights: • Physiologically based in silico models were made for 18 α,β-unsaturated aldehydes. • Kinetic parameters were determined by in vitro incubations and a QSAR approach. • DNA adduct formation was negligible at levels relevant for dietary intake. • The use of QSAR-based PBK/D modelling facilitates group evaluations and read-across.

Cu-catalyzed C(sp³)-H bond activation reaction for direct preparation of cycloallyl esters from cycloalkanes and aromatic aldehydes.

Science.gov (United States)

Zhao, Jincan; Fang, Hong; Han, Jianlin; Pan, Yi

2014-05-02

Cu-catalyzed dehydrogenation-olefination and esterification of C(sp(3))-H bonds of cycloalkanes with TBHP as an oxidant has been developed. The reaction involves four C-H bond activations and gives cycloallyl ester products directly from cycloalkanes and aromatic aldehydes.

Study of a specific lignin model: γ-oxidation and how it influences the hydrolysis efficiency of alcohol-aldehyde dehydrogenation copolymers.

Science.gov (United States)

Bouxin, Florent; Baumberger, Stéphanie; Renault, Jean-Hugues; Dole, Patrice

2011-05-01

Six coniferyl alcohol-coniferaldehyde dehydrogenation copolymers (DHcoPs) were synthesized in order to determine the influence of an increased number of aldehyde functions on hydrolysis. After heterogeneous hydrolysis using acidic Montmorillonite K10 clay, the DHcoPs were thioacidolyzed and analyzed by gel permeation chromatography (GPC). Comparison of the thioacidolyzed products, with and without the hydrolysis step, showed that there was a greater proportion of condensation reaction in the absence of aldehyde. When the coniferaldehyde content in the initial synthetic mixture was more than 30% (w/w), only a low fraction of condensed products was generated during the K10 clay hydrolysis step. This suggests that condensation pathways are mainly due to the alcohol present in the γ-position in the DHcoPs. Investigation of the reactivity and the potential condensation of aldehyde and alcohol monomers under hydrolysis conditions showed the important conversion of coniferyl alcohol and conversely the stability of coniferaldehyde. Copyright © 2011 Elsevier Ltd. All rights reserved.

Catalytic oxidation using nitrous oxide

Directory of Open Access Journals (Sweden)

Juan Carlos Beltran-Prieto

2017-01-01

Full Text Available Nitrous oxide is a very inert gas used generally as oxidant as it offers some advantage compared with other oxidants such as O2 but a considerably higher temperature (> 526 °C is often required. For particular cases such as the oxidation of sugar alcohols, especially for the oxidation of primary alcohols to aldehydes, N2O has the advantage over O2 of a higher reaction selectivity. In the present paper we present the modelling of oxidation reaction of sugar alcohols using an oxidizing agent in low concentrations, which is important to suppress subsequent oxidation reactions due to the very low residual concentrations of the oxidizing agent. For orientation experiments we chose nitrous oxide generated by thermal decomposition of ammonium nitrate. Kinetic modeling of the reaction was performed after determination of the differential equations that describe the system under study.

Evaluation of alcohol dehydrogenase and aldehyde dehydrogenase enzymes as bi-enzymatic anodes in a membraneless ethanol microfluidic fuel cell

Science.gov (United States)

Galindo-de-la-Rosa, J.; Arjona, N.; Arriaga, L. G.; Ledesma-García, J.; Guerra-Balcázar, M.

2015-12-01

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AldH) enzymes were immobilized by covalent binding and used as the anode in a bi-enzymatic membraneless ethanol hybrid microfluidic fuel cell. The purpose of using both enzymes was to optimize the ethanol electro-oxidation reaction (EOR) by using ADH toward its direct oxidation and AldH for the oxidation of aldehydes as by-products of the EOR. For this reason, three enzymatic bioanode configurations were evaluated according with the location of enzymes: combined, vertical and horizontally separated. In the combined configuration, a current density of 16.3 mA cm-2, a voltage of 1.14 V and a power density of 7.02 mW cm-2 were obtained. When enzymes were separately placed in a horizontal and vertical position the ocp drops to 0.94 V and to 0.68 V, respectively. The current density also falls to values of 13.63 and 5.05 mA cm-2. The decrease of cell performance of bioanodes with separated enzymes compared with the combined bioanode was of 31.7% and 86.87% for the horizontal and the vertical array.

Nitroxide-catalyzed selective oxidation of alcohols and polysaccharides

International Nuclear Information System (INIS)

Ponedel'kina, I Yu; Khaibrakhmanova, E A; Odinokov, Viktor N

2010-01-01

The use of nitroxide radicals in the selective oxidation of alcohols is considered. Attention is focused on the oxidation of polysaccharides as a method of preparation of polyuronic acids, aldehydes and hemiacetals.

Periodate oxidation of nanoscaled magnetic dextran composites

International Nuclear Information System (INIS)

Hong Xia; Guo Wei; Yuan Hang; Li Jun; Liu Yanmei; Ma Lan; Bai Yubai; Li Tiejin

2004-01-01

Highly hydrophilic, uniform and nontoxic magnetic fluids consisting of magnetite (Fe 3 O 4 ) and dextran were prepared. A periodate oxidation method was used to further activate the magnetic dextran, forming magnetic polyaldehyde-dextran, which could be conjugated to biomolecules such as proteins or antibodies. Oxidated Magnetic dextran composites were characterized by TEM, XRD and SQUID magnetometry. Moreover, a flexible, rapid and simple method to detect aldehydes was introduced to the magnetic composite system by utilizing 2,4-dinitrophenylhydrazine reagent. The result of the quantitative analysis of aldehyde was given by thermogravimetric analysis and elemental analysis

Enzymatic oxidation of 2-phenylethylamine to phenylacetic acid and 2-phenylethanol with special reference to the metabolism of its intermediate phenylacetaldehyde.

Science.gov (United States)

Panoutsopoulos, Georgios I; Kouretas, Demetrios; Gounaris, Elias G; Beedham, Christine

2004-12-01

2-phenylethylamine is an endogenous constituent of the human brain and is implicated in cerebral transmission. This bioactive amine is also present in certain foodstuffs such as chocolate, cheese and wine and may cause undesirable side effects in susceptible individuals. Metabolism of 2-phenylethylamine to phenylacetaldehyde is catalysed by monoamine oxidase B but the oxidation to its acid is usually ascribed to aldehyde dehydrogenase and the contribution of aldehyde oxidase and xanthine oxidase, if any, is ignored. The objective of this study was to elucidate the role of the molybdenum hydroxylases, aldehyde oxidase and xanthine oxidase, in the metabolism of phenylacetaldehyde derived from its parent biogenic amine. Treatments of 2-phenylethylamine with monoamine oxidase were carried out for the production of phenylacetaldehyde, as well as treatments of synthetic or enzymatic-generated phenylacetaldehyde with aldehyde oxidase, xanthine oxidase and aldehyde dehydrogenase. The results indicated that phenylacetaldehyde is metabolised mainly to phenylacetic acid with lower concentrations of 2-phenylethanol by all three oxidising enzymes. Aldehyde dehydrogenase was the predominant enzyme involved in phenylacetaldehyde oxidation and thus it has a major role in 2-phenylethylamine metabolism with aldehyde oxidase playing a less prominent role. Xanthine oxidase does not contribute to the oxidation of phenylacetaldehyde due to low amounts being present in guinea pig. Thus aldehyde dehydrogenase is not the only enzyme oxidising xenobiotic and endobiotic aldehydes and the role of aldehyde oxidase in such reactions should not be ignored.

ARA-aldehyde and ABA-trans-diol in apple fruits

International Nuclear Information System (INIS)

Rock, C.D.; Zeevaart, J.A.D.

1989-01-01

We have isolated ABA-aldehyde and ABA-t-diol from postharvest apple fruits, cv. Granny Smith and confirmed their structure by GC-MS. These putative ABA biosynthetic precursors incorporate 18 O to a similar degree as ABA during 48 hours under 18 O 2 atmospheres. The presence of significant amounts of ABA-aldehyde can explain the unique 18 O labeling pattern of ABA in this tissue, where a majority of ABA molecules containing 18 O is labeled in the 1'-hydroxyl group and not in the side chain carboxyl group, the primary site of incorporation for stressed leaves. Exchange of the carbonyl oxygen of ABA-aldehyde with water would decrease 18 O enrichment in the side chain. Results of 18 O 2 experiments and feeding studies using hexadeutero-ABA-aldehyde will be presented and the biosynthetic relationship of these compounds discussed

Application of heterocyclic aldehydes as components in Ugi–Smiles couplings

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Katelynn M. Mason

2016-09-01

Full Text Available Efficient one-pot Ugi–Smiles couplings are reported for the use of furyl-substituted aldehyde components. In the presence of these heterocyclic aldehydes, reactions tolerated variations in amine components and led to either isolated N-arylamide Ugi–Smiles adducts or N-arylepoxyisoindolines, products of tandem Ugi–Smiles Diels–Alder cyclizations, in moderate yields. A thienyl-substituted aldehyde was also a competent component for Ugi–Smiles adduct formation.

Reduction of Aldehydes and Ketones by Sodium Dithionite

NARCIS (Netherlands)

Vries, Johannes G. de; Kellogg, Richard M.

1980-01-01

Conditions have been developed for the effective reduction of aldehydes and ketones by sodium dithionite, Na2S2O4. Complete reduction of simple aldehydes and ketones can be achieved with excess Na2S2O4 in H2O/dioxane mixtures at reflux temperature. Some aliphatic ketones, for example, pentanone and

Monitoring of fatty aldehyde dehydrogenase by formation of pyrenedecanoic acid from pyrenedecanal

NARCIS (Netherlands)

Keller, Markus A.; Watschinger, Katrin; Golderer, Georg; Maglione, Manuel; Sarg, Bettina; Lindner, Herbert H.; Werner-Felmayer, Gabriele; Terrinoni, Alessandro; Wanders, Ronald J. A.; Werner, Ernst R.

2010-01-01

Fatty aldehyde dehydrogenase (EC 1.2.1.48) converts long-chain fatty aldehydes to the corresponding acids. Deficiency in this enzyme causes the Sjogren Larsson Syndrome, a rare inherited disorder characterized by ichthyosis, spasticity, and mental retardation. Using a fluorescent aldehyde,

Substrate specificity and subcellular localization of the aldehyde-alcohol redox-coupling reaction in carp cones.

Science.gov (United States)

Sato, Shinya; Fukagawa, Takashi; Tachibanaki, Shuji; Yamano, Yumiko; Wada, Akimori; Kawamura, Satoru

2013-12-20

Our previous study suggested the presence of a novel cone-specific redox reaction that generates 11-cis-retinal from 11-cis-retinol in the carp retina. This reaction is unique in that 1) both 11-cis-retinol and all-trans-retinal were required to produce 11-cis-retinal; 2) together with 11-cis-retinal, all-trans-retinol was produced at a 1:1 ratio; and 3) the addition of enzyme cofactors such as NADP(H) was not necessary. This reaction is probably part of the reactions in a cone-specific retinoid cycle required for cone visual pigment regeneration with the use of 11-cis-retinol supplied from Müller cells. In this study, using purified carp cone membrane preparations, we first confirmed that the reaction is a redox-coupling reaction between retinals and retinols. We further examined the substrate specificity, reaction mechanism, and subcellular localization of this reaction. Oxidation was specific for 11-cis-retinol and 9-cis-retinol. In contrast, reduction showed low specificity: many aldehydes, including all-trans-, 9-cis-, 11-cis-, and 13-cis-retinals and even benzaldehyde, supported the reaction. On the basis of kinetic studies of this reaction (aldehyde-alcohol redox-coupling reaction), we found that formation of a ternary complex of a retinol, an aldehyde, and a postulated enzyme seemed to be necessary, which suggested the presence of both the retinol- and aldehyde-binding sites in this enzyme. A subcellular fractionation study showed that the activity is present almost exclusively in the cone inner segment. These results suggest the presence of an effective production mechanism of 11-cis-retinal in the cone inner segment to regenerate visual pigment.

A Catalase-related Hemoprotein in Coral Is Specialized for Synthesis of Short-chain Aldehydes: DISCOVERY OF P450-TYPE HYDROPEROXIDE LYASE ACTIVITY IN A CATALASE.

Science.gov (United States)

Teder, Tarvi; Lõhelaid, Helike; Boeglin, William E; Calcutt, Wade M; Brash, Alan R; Samel, Nigulas

2015-08-07

In corals a catalase-lipoxygenase fusion protein transforms arachidonic acid to the allene oxide 8R,9-epoxy-5,9,11,14-eicosatetraenoic acid from which arise cyclopentenones such as the prostanoid-related clavulones. Recently we cloned two catalase-lipoxygenase fusion protein genes (a and b) from the coral Capnella imbricata, form a being an allene oxide synthase and form b giving uncharacterized polar products (Lõhelaid, H., Teder, T., Tõldsepp, K., Ekins, M., and Samel, N. (2014) PloS ONE 9, e89215). Here, using HPLC-UV, LC-MS, and NMR methods, we identify a novel activity of fusion protein b, establishing its role in cleaving the lipoxygenase product 8R-hydroperoxy-eicosatetraenoic acid into the short-chain aldehydes (5Z)-8-oxo-octenoic acid and (3Z,6Z)-dodecadienal; these primary products readily isomerize in an aqueous medium to the corresponding 6E- and 2E,6Z derivatives. This type of enzymatic cleavage, splitting the carbon chain within the conjugated diene of the hydroperoxide substrate, is known only in plant cytochrome P450 hydroperoxide lyases. In mechanistic studies using (18)O-labeled substrate and incubations in H2(18)O, we established synthesis of the C8-oxo acid and C12 aldehyde with the retention of the hydroperoxy oxygens, consistent with synthesis of a short-lived hemiacetal intermediate that breaks down spontaneously into the two aldehydes. Taken together with our initial studies indicating differing gene regulation of the allene oxide synthase and the newly identified catalase-related hydroperoxide lyase and given the role of aldehydes in plant defense, this work uncovers a potential pathway in coral stress signaling and a novel enzymatic activity in the animal kingdom. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Direct, enantioselective α-alkylation of aldehydes using simple olefins.

Science.gov (United States)

Capacci, Andrew G; Malinowski, Justin T; McAlpine, Neil J; Kuhne, Jerome; MacMillan, David W C

2017-11-01

Although the α-alkylation of ketones has already been established, the analogous reaction using aldehyde substrates has proven surprisingly elusive. Despite the structural similarities between the two classes of compounds, the sensitivity and unique reactivity of the aldehyde functionality has typically required activated substrates or specialized additives. Here, we show that the synergistic merger of three catalytic processes-photoredox, enamine and hydrogen-atom transfer (HAT) catalysis-enables an enantioselective α-aldehyde alkylation reaction that employs simple olefins as coupling partners. Chiral imidazolidinones or prolinols, in combination with a thiophenol, iridium photoredox catalyst and visible light, have been successfully used in a triple catalytic process that is temporally sequenced to deliver a new hydrogen and electron-borrowing mechanism. This multicatalytic process enables both intra- and intermolecular aldehyde α-methylene coupling with olefins to construct both cyclic and acyclic products, respectively. With respect to atom and step-economy ideals, this stereoselective process allows the production of high-value molecules from feedstock chemicals in one step while consuming only photons.

Physiologically based in silico modelling to examine DNA adduct formation by different food-borne a,ß-unsaturated aldehydes at realistic low dietary exposure levels

NARCIS (Netherlands)

Kiwamoto, R.

2015-01-01

Abstract (R.Kiwamoto ISBN 978-94-6257-284-3)

Various α,β-unsaturated aldehydes are present in fruits, vegetables, spices, or processed products containing these items as natural constituents or as added food flavouring agents. Because of the α,β-unsaturated aldehyde moiety the β carbon in

27 CFR 24.183 - Use of distillates containing aldehydes.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Use of distillates... distillates containing aldehydes. Distillates containing aldehydes may be received on wine premises for use in the fermentation of wine and then returned to the distilled spirits plant from which distillates were...

Universal electrode interface for electrocatalytic oxidation of liquid fuels.

Science.gov (United States)

Liao, Hualing; Qiu, Zhipeng; Wan, Qijin; Wang, Zhijie; Liu, Yi; Yang, Nianjun

2014-10-22

Electrocatalytic oxidations of liquid fuels from alcohols, carboxylic acids, and aldehydes were realized on a universal electrode interface. Such an interface was fabricated using carbon nanotubes (CNTs) as the catalyst support and palladium nanoparticles (Pd NPs) as the electrocatalysts. The Pd NPs/CNTs nanocomposite was synthesized using the ethylene glycol reduction method. It was characterized using transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, voltammetry, and impedance. On the Pd NPs/CNTs nanocomposite coated electrode, the oxidations of those liquid fuels occur similarly in two steps: the oxidations of freshly chemisorbed species in the forward (positive-potential) scan and then, in the reverse scan (negative-potential), the oxidations of the incompletely oxidized carbonaceous species formed during the forward scan. The oxidation charges were adopted to study their oxidation mechanisms and oxidation efficiencies. The oxidation efficiency follows the order of aldehyde (formaldehyde) > carboxylic acid (formic acid) > alcohols (ethanol > methanol > glycol > propanol). Such a Pd NPs/CNTs nanocomposite coated electrode is thus promising to be applied as the anode for the facilitation of direct fuel cells.

SHORT COMMUNICATION MICROWAVE-ASSISTED OXIDATION ...

African Journals Online (AJOL)

a

2Department of Chemistry, Faculty of Science, Imam Khomeini International ... Although the oxidation of organic compounds under non-aqueous conditions ... primary alcohols to aldehydes and secondary alcohols to ketones (Scheme 1). CH3.

Insight into Coenzyme A cofactor binding and the mechanism of acyl-transfer in an acylating aldehyde dehydrogenase from Clostridium phytofermentans.

Science.gov (United States)

Tuck, Laura R; Altenbach, Kirsten; Ang, Thiau Fu; Crawshaw, Adam D; Campopiano, Dominic J; Clarke, David J; Marles-Wright, Jon

2016-02-22

The breakdown of fucose and rhamnose released from plant cell walls by the cellulolytic soil bacterium Clostridium phytofermentans produces toxic aldehyde intermediates. To enable growth on these carbon sources, the pathway for the breakdown of fucose and rhamnose is encapsulated within a bacterial microcompartment (BMC). These proteinaceous organelles sequester the toxic aldehyde intermediates and allow the efficient action of acylating aldehyde dehydrogenase enzymes to produce an acyl-CoA that is ultimately used in substrate-level phosphorylation to produce ATP. Here we analyse the kinetics of the aldehyde dehydrogenase enzyme from the fucose/rhamnose utilisation BMC with different short-chain fatty aldehydes and show that it has activity against substrates with up to six carbon atoms, with optimal activity against propionaldehyde. We have also determined the X-ray crystal structure of this enzyme in complex with CoA and show that the adenine nucleotide of this cofactor is bound in a distinct pocket to the same group in NAD(+). This work is the first report of the structure of CoA bound to an aldehyde dehydrogenase enzyme and our crystallographic model provides important insight into the differences within the active site that distinguish the acylating from non-acylating aldehyde dehydrogenase enzymes.

Establishment of evaluation system for oxidation/anti-oxidation in living organisms using radiation irradiation and its practical application

International Nuclear Information System (INIS)

Umegaki, Keizo

2000-01-01

Basic study on the degree of oxidation damages after X-ray irradiation and changes in the anti-oxidative defense action was made using the rat. In addition, amplification of trace DNA damages by X-ray irradiation was investigated with human lymphocytes. Wistar rats were exposed to X-ray at 3 Gy under no anesthetization and killed after various time after the irradiation. The content of vitamin C, an anti-oxidant vitamin C in the bone marrow was markedly reduced by X-ray irradiation and the content after 24 hours from the irradiation was about 2% of that of the unexposed group. The content of vitamin E in the bone marrow was ca. 43% of that of the unexposed group. However, the contents of these anti-oxidant vitamins gradually recovered from 3-4 days after the irradiation. On the other hand, the content of 4-hydroxynonenal among the aldehydes that were tested as the indicator for oxidation damage of lipid was significantly increased one day after the irradiation and the contents of hexanal and TBARS reached the maximum level 3 days after. However, daily administration of about 100-fold larger amount of vitamin E (α-tocopherol at 460 mg/kg) for 3 days before the irradiation resulted in an increase in its content in the bone marrow, but significant decreases in the vitamin E and C levels in the bone marrow 24 hours after X-ray irradiation and aldehyde contents were increased, suggesting that pre-irradiation administration of vitamin E has no effects on the damages of bone marrow cells. As an indicator of DNA damages, the rate of appearance for lymphocytes having micronuclei was determined. The number of such lymphocytes was not significantly changed by exercise, but the number after irradiation at 1.5 Gy was dose dependently increased. These results suggested that trace DNA oxidation damages produced by severe exercise were markedly amplified by X-ray irradiation in not-trained subjects. (M.N.)

Analysis of aldehydes in human exhaled breath condensates by in-tube SPME-HPLC.

Science.gov (United States)

Wang, ShuLing; Hu, Sheng; Xu, Hui

2015-11-05

In this paper, polypyrrole/graphene (PPy/G) composite coating was prepared by a facile electrochemical polymerization strategy on the inner surface of a stainless steel (SS) tube. Based on the coating tube, a novel online in-tube solid-phase microextraction -high performance liquid chromatography (IT-SPME-HPLC) was developed and applied for the extraction of aldehydes in the human exhaled breath condensates (EBC). The hybrid PPy/G nanocomposite exhibits remarkable chemical and mechanical stability, high selectivity, and satisfactory extraction performance toward aldehyde compounds. Moreover, the proposed online IT-SPME-HPLC method possesses numerous superiorities, such as time and cost saving, process simplicity, high precision and sensitivity. Some parameters related to extraction efficiency were optimized systematically. Under the optimal conditions, the recoveries of the aldehyde compounds at three spiked concentration levels varied in the range of 85%-117%. Good linearity was obtained with excellent correlation coefficients (R(2)) being larger than 0.994. The relative standard deviations (n = 5) of the method ranged from 1.8% to 11.3% and the limits of detection were between 2.3 and 3.3 nmol L(-1). The successful application of the proposed method in human EBC indicated that it is a promising approach for the determination of trace aldehyde metabolites in complex EBC samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Airborne aldehydes in cabin-air of commercial aircraft: Measurement by HPLC with UV absorbance detection of 2,4-dinitrophenylhydrazones.

Science.gov (United States)

Rosenberger, Wolfgang; Beckmann, Bibiana; Wrbitzky, Renate

2016-04-15

This paper presents the strategy and results of in-flight measurements of airborne aldehydes during normal operation and reported "smell events" on commercial aircraft. The aldehyde-measurement is a part of a large-scale study on cabin-air quality. The aims of this study were to describe cabin-air quality in general and to detect chemical abnormalities during the so-called "smell-events". Adsorption and derivatization of airborne aldehydes on 2,4-dinitrophenylhydrazine coated silica gel (DNPH-cartridge) was applied using tailor-made sampling kits. Samples were collected with battery supplied personal air sampling pumps during different flight phases. Furthermore, the influence of ozone was investigated by simultaneous sampling with and without ozone absorption unit (ozone converter) assembled to the DNPH-cartridges and found to be negligible. The method was validated for 14 aldehydes and found to be precise (RSD, 5.5-10.6%) and accurate (recovery, 98-103 %), with LOD levels being 0.3-0.6 μg/m(3). According to occupational exposure limits (OEL) or indoor air guidelines no unusual or noticeable aldehyde pollution was observed. In total, 353 aldehyde samples were taken from two types of aircraft. Formaldehyde (overall average 5.7 μg/m(3), overall median 4.9 μg/m(3), range 0.4-44 μg/m(3)), acetaldehyde (overall average 6.5 μg/m(3), overall median 4.6, range 0.3-90 μg/m(3)) and mostly very low concentrations of other aldehydes were measured on 108 flights. Simultaneous adsorption and derivatization of airborne aldehydes on DNPH-cartridges to the Schiff bases and their HPLC analysis with UV absorbance detection is a useful method to measure aldehydes in cabin-air of commercial aircraft. Copyright © 2015 Elsevier B.V. All rights reserved.

Molecularly Imprinted Sol-Gel-Based QCM Sensor Arrays for the Detection and Recognition of Volatile Aldehydes

Directory of Open Access Journals (Sweden)

Chuanjun Liu

2017-02-01

Full Text Available The detection and recognition of metabolically derived aldehydes, which have been identified as important products of oxidative stress and biomarkers of cancers; are considered as an effective approach for early cancer detection as well as health status monitoring. Quartz crystal microbalance (QCM sensor arrays based on molecularly imprinted sol-gel (MISG materials were developed in this work for highly sensitive detection and highly selective recognition of typical aldehyde vapors including hexanal (HAL; nonanal (NAL and bezaldehyde (BAL. The MISGs were prepared by a sol-gel procedure using two matrix precursors: tetraethyl orthosilicate (TEOS and tetrabutoxytitanium (TBOT. Aminopropyltriethoxysilane (APT; diethylaminopropyltrimethoxysilane (EAP and trimethoxy-phenylsilane (TMP were added as functional monomers to adjust the imprinting effect of the matrix. Hexanoic acid (HA; nonanoic acid (NA and benzoic acid (BA were used as psuedotemplates in view of their analogous structure to the target molecules as well as the strong hydrogen-bonding interaction with the matrix. Totally 13 types of MISGs with different components were prepared and coated on QCM electrodes by spin coating. Their sensing characters towards the three aldehyde vapors with different concentrations were investigated qualitatively. The results demonstrated that the response of individual sensors to each target strongly depended on the matrix precursors; functional monomers and template molecules. An optimization of the 13 MISG materials was carried out based on statistical analysis such as principle component analysis (PCA; multivariate analysis of covariance (MANCOVA and hierarchical cluster analysis (HCA. The optimized sensor array consisting of five channels showed a high discrimination ability on the aldehyde vapors; which was confirmed by quantitative comparison with a randomly selected array. It was suggested that both the molecularly imprinting (MIP effect and the matrix

Self-degradation of tissue adhesive based on oxidized dextran and poly-L-lysine.

Science.gov (United States)

Matsumura, Kazuaki; Nakajima, Naoki; Sugai, Hajime; Hyon, Suong-Hyu

2014-11-26

We have developed a low-toxicity bioadhesive based on oxidized dextran and poly-L-lysine. Here, we report that the mechanical properties and degradation of this novel hydrogel bioadhesive can be controlled by changing the extent of oxidation of the dextran and the type or concentration of the anhydride species in the acylated poly-L-lysine. The dynamic moduli of the hydrogels can be controlled from 120 Pa to 20 kPa, suggesting that they would have mechanical compatibility with various tissues, and could have applications as tissue adhesives. Development of the hydrogel color from clear to brown indicates that the reaction between the dextran aldehyde groups and the poly-L-lysine amino groups may be induced by a Maillard reaction via Schiff base formation. Degradation of the aldehyde dextran may begin by reaction of the amino groups in the poly-L-lysine. The gel degradation can be ascribed to degradation of the aldehyde dextran in the hydrogel, although the aldehyde dextran itself is relatively stable in water. The oxidized dextran and poly-L-lysine, and the degraded hydrogel showed low cytotoxicities. These findings indicate that a hydrogel consisting of oxidized dextran and poly-L-lysine has low toxicity and a well-controlled degradation rate, and has potential clinical applications as a bioadhesive. Copyright © 2014 Elsevier Ltd. All rights reserved.

Scientific Opinion on the safety and efficacy of straight-chain primary aliphatic alcohols/aldehydes/acids, acetals and esters with esters containing saturated alcohols and acetals containing saturated aldehydes (chemical group 1) when used as flavourings for all animal species

OpenAIRE

EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP)

2013-01-01

Chemical group 1 (CG 1) consists of straight-chain primary aliphatic alcohols/aldehydes/acids, acetals and esters with esters containing saturated alcohols and acetals containing saturated aldehydes of which 86 are currently authorised for use as flavours in food. The FEEDAP Panel was unable to perform an assessment of ethyl oleate because of its insufficient purity. The following compounds are considered to be safe for all animal species at the use level proposed for feed flavourings: formic...

Thermal, Catalytic Conversion of Alkanes to Linear Aldehydes and Linear Amines.

Science.gov (United States)

Tang, Xinxin; Jia, Xiangqing; Huang, Zheng

2018-03-21

Alkanes, the main constituents of petroleum, are attractive feedstocks for producing value-added chemicals. Linear aldehydes and amines are two of the most important building blocks in the chemical industry. To date, there have been no effective methods for directly converting n-alkanes to linear aldehydes and linear amines. Here, we report a molecular dual-catalyst system for production of linear aldehydes via regioselective carbonylation of n-alkanes. The system is comprised of a pincer iridium catalyst for transfer-dehydrogenation of the alkane using t-butylethylene or ethylene as a hydrogen acceptor working sequentially with a rhodium catalyst for olefin isomerization-hydroformylation with syngas. The system exhibits high regioselectivity for linear aldehydes and gives high catalytic turnover numbers when using ethylene as the acceptor. In addition, the direct conversion of light alkanes, n-pentane and n-hexane, to siloxy-terminated alkyl aldehydes through a sequence of Ir/Fe-catalyzed alkane silylation and Ir/Rh-catalyzed alkane carbonylation, is described. Finally, the Ir/Rh dual-catalyst strategy has been successfully applied to regioselective alkane aminomethylation to form linear alkyl amines.

Ambient concentrations of aldehydes in relation to Beijing Olympic air pollution control measures

Science.gov (United States)

Gong, J. C.; Zhu, T.; Hu, M.; Zhang, L. W.; Cheng, H.; Zhang, L.; Tong, J.; Zhang, J.

2010-08-01

Aldehydes are ubiquitous constituents of the atmosphere. Their concentrations are elevated in polluted urban atmospheres. The present study was carried out to characterize three aldehydes of most health concern (formaldehyde, acetaldehyde, and acrolein) in a central Beijing site in the summer and early fall of 2008 (from June to October). Measurements were made before, during, and after the Beijing Olympics to examine whether the air pollution control measures implemented to improve Beijing's air quality during the Olympics had any impact on concentrations of the three aldehydes. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.34 ± 15.12 μg/m3, 27.09 ± 15.74 μg/m3 and 2.32 ± 0.95 μg/m3, respectively, for the entire period of measurements, all being the highest among the levels measured in cities around the world in photochemical smog seasons. Among the three measured aldehydes, only acetaldehyde had a substantially reduced mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Formaldehyde and acrolein followed the changing pattern of temperature and were each significantly correlated with ozone (a secondary product of photochemical reactions). In contrast, acetaldehyde was significantly correlated with several pollutants emitted mainly from local emission sources (e.g., NO2, CO, and PM2.5). These findings suggest that local direct emissions had a larger impact on acetaldehyde than formaldehyde and acrolein.

Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

Energy Technology Data Exchange (ETDEWEB)

Taylor, Rebecca L. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)]. E-mail: r.l.taylor@ncl.ac.uk; Caldwell, Gary S. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom); Bentley, Matthew G. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)

2005-08-15

The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD{sub 50} values of 7 and 20 {mu}M for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 {mu}M of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD{sub 50} of decadienal by approximately a third for both species. 1 {mu}M of copper chloride in solutions of decadienal reduced the 24 h LD{sub 50} of decadienal to A. salina nauplii by approximately 11% and 1 {mu}M zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 {mu}M copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed.

Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

International Nuclear Information System (INIS)

Taylor, Rebecca L.; Caldwell, Gary S.; Bentley, Matthew G.

2005-01-01

The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD 50 values of 7 and 20 μM for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 μM of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD 50 of decadienal by approximately a third for both species. 1 μM of copper chloride in solutions of decadienal reduced the 24 h LD 50 of decadienal to A. salina nauplii by approximately 11% and 1 μM zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 μM copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed

Synthesis, spectroscopic characterization and catalytic oxidation ...

Indian Academy of Sciences (India)

were characterized by infrared, electronic, electron paramagnetic resonance ... The catalytic oxidation property of ruthenium(III) complexes were also ... cies at room temperature. ..... aldehyde part of Schiff base ligands, catalytic activ- ity of new ...

Silver-Catalyzed Aldehyde Olefination Using Siloxy Alkynes.

Science.gov (United States)

Sun, Jianwei; Keller, Valerie A; Meyer, S Todd; Kozmin, Sergey A

2010-03-20

We describe the development of a silver-catalyzed carbonyl olefination employing electron rich siloxy alkynes. This process constitutes an efficient synthesis of trisubstituted unsaturated esters, and represents an alternative to the widely utilized Horner-Wadsworth-Emmons reaction. Excellent diastereoselectivities are observed for a range of aldehydes using either 1-siloxy-1-propyne or 1-siloxy-1-hexyne. This mild catalytic process also enables chemoselective olefination of aldehydes in the presence of either ester or ketone functionality. Furthermore, since no by-products are generated, this catalytic process is perfectly suited for development of sequential reactions that can be carried out in a single flask.

1H NMR and SPME-GC/MS study of hydrolysis, oxidation and other reactions occurring during in vitro digestion of non-oxidized and oxidized sunflower oil. Formation of hydroxy-octadecadienoates.

Science.gov (United States)

Nieva-Echevarría, Bárbara; Goicoechea, Encarnación; Manzanos, María J; Guillén, María D

2017-01-01

Both fresh and slightly oxidized sunflower oils, as models of omega-6 rich lipids, were submitted to in vitro gastrointestinal digestion and studied by 1 H NMR and SPME-GC/MS. Changes in lipolysis degree, lipid composition and oxidative level were studied by 1 H NMR. Three quantitative approaches were used and several equations were newly developed. In oxidized oil digestates slightly lower hydrolysis and a higher advance of oxidation took place during digestion. This latter was evidenced by a greater decrease of lipid unsaturation degree and enhanced generation of oxidation products (cis,trans-hydroperoxy-octadecadienoates, cis,trans- and trans,trans-hydroxy-octadecadienoates). For the first time, the generation of hydroxy-octadecadienoates during in vitro digestion is reported. Furthermore, SPME-GC/MS study of non-digested and digested samples headspaces confirmed that lipid oxidation occurred: abundances of volatile markers increased (including potentially toxic alpha,beta-unsaturated aldehydes), especially in oxidized oils digestates. Markers of Maillard-type and esterification reactions were also detected in the digestates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radon and aldehyde concentrations in the indoor environment. Final report

International Nuclear Information System (INIS)

Moschandreas, D.J.; Rector, H.E.

1981-04-01

Findings regarding indoor air contaminants in the energy-efficient residence (EER) in Mt. Airy, Maryland are reported. The objectives of the study were to collect and analyze relevant air quality samples (specifically radon and aldehydes), characterize the indoor air quality with respect to radon and aldehydes, and develop relationships between air infiltration rates and contaminant levels. One-fifth of the measured formaldehyde concentrations were in the range that may cause health concerns. Although indoor temperature and relative humidity affect indoor HCHO concentration, the elevated formaldehyde concentrations were measured under very low air infiltration rates. The data show that ventilation of the indoor air space is somewhat effective in reducing high HCHO concentrations. The operation of the heat exchanger led to an increase of the air infiltration rate which in turn resulted in substantial reduction of formaldehyde concentrations. A considerable number of the collected samples of indoor air displayed radon concentrations at levels higher than 1.0 to 4.0 nCim -3 (assuming an equilibrium factor of 0.5, these radon levels would correspond to working levels above the health guidelines suggested by the US EPA for homes in Florida built on land reclaimed from phosphate mining). As in the case of indoor formaldehyde concentrations, elevated indoor concentrations are substantially reduced when the infiltration rate is increased. The data base shows that the use of the air to air heat exchanger leads to reduction of indoor radon concentration by increasing the residential ventilation rate

Enantioselective ProPhenol-catalyzed addition of 1,3-diynes to aldehydes to generate synthetically versatile building blocks and diyne natural products.

Science.gov (United States)

Trost, Barry M; Chan, Vincent S; Yamamoto, Daisuke

2010-04-14

A highly enantioselective method for the catalytic addition of terminal 1,3-diynes to aldehydes was developed using our dinuclear zinc ProPhenol (1) system. Furthermore, triphenylphosphine oxide was found to interact synergistically with the catalyst to substantially enhance the chiral recognition. The generality of this catalytic transformation was demonstrated with aryl, alpha,beta-unsaturated and saturated aldehydes, of which the latter were previously limited in alkynyl zinc additions. The chiral diynol products are also versatile building blocks that can be readily elaborated; this was illustrated through highly selective trans-hydrosilylations, which enabled the synthesis of a beta-hydroxyketone and enyne. Additionally, the development of this method allowed for the rapid total syntheses of several biologically important diynol-containing natural products.

Abscisic (ABA)-aldehyde is a precursor to, and 1',4'-trans-ABA-diol a catabolite of, ABA in apple

International Nuclear Information System (INIS)

Rock, C.D.; Zeevaart, J.A.D.

1990-01-01

Previous 18 O labeling studies of abscisic acid (ABA) have shown that apple (Malus domestica Borkh. cv Granny Smith) fruits synthesize a majority of [ 18 O]ABA with the label incorporated in the 1'-hydroxyl position and unlabeled in the carboxyl group (JAD Zeevaart, TG Heath, DA Gage [1989] Plant Physiol 91: 1594-1601). It was proposed that exchange of 18 O in the side chain with the medium occurred at an aldehyde intermediate stage of ABA biosynthesis. We have isolated ABA-aldehyde and 1'-4'-trans-ABA-diol (ABA-trans-diol) from 18 O-labeled apple fruit tissue and measured the extent and position of 18 O incorporation by tandem mass spectrometry. 18 O-Labeling patterns of ABA-aldehyde, ABA-trans-diol, and ABA indicate that ABA-aldehyde is a precursor to, and ABA-trans-diol a catabolite of, ABA. Exchange of 18 O in the carbonyl of ABA-aldehyde can be the cause of loss of 18 O from the side chain of [ 18 O]ABA. Results of feeding experiments with deuterated substrates provide further support for the precursor-product relationship of ABA-aldehyde → ABA → ABA-trans-diol. The ABA-aldehyde and ABA-trans-diol contents of fruits and leaves were low, approximately 1 and 0.02 nanograms per gram fresh weight for ABA-aldehyde and ABA-trans-diol, respectively, while ABA levels in fruits ranged from 10 to 200 nanograms per gram fresh weight. ABA biosynthesis was about 10-fold lower in fruits than in leaves. In fruits, the majority of ABA was conjugated to β-D-glucopyranosyl abscisate, whereas in leaves ABA was mainly hydroxylated to phaseic acid. Parallel pathways for ABA and trans-ABA biosynthesis and conjugation in fruits and leaves are proposed

Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

Science.gov (United States)

Tian, Feng-Xia; Zang, Jian-Lei; Wang, Tan; Xie, Yu-Li; Zhang, Jin; Hu, Jian-Jun

2015-01-01

Aldehyde dehydrogenases (ALDHs) constitute a superfamily of NAD(P)+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

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Feng-Xia Tian

Full Text Available Aldehyde dehydrogenases (ALDHs constitute a superfamily of NAD(P+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

Glu504Lys Single Nucleotide Polymorphism of Aldehyde Dehydrogenase 2 Gene and the Risk of Human Diseases

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Yan Zhao

2015-01-01

Full Text Available Aldehyde dehydrogenase (ALDH 2 is a mitochondrial enzyme that is known for its important role in oxidation and detoxification of ethanol metabolite acetaldehyde. ALDH2 also metabolizes other reactive aldehydes such as 4-hydroxy-2-nonenal and acrolein. The Glu504Lys single nucleotide polymorphism (SNP of ALDH2 gene, which is found in approximately 40% of the East Asian populations, causes defect in the enzyme activity of ALDH2, leading to alterations in acetaldehyde metabolism and alcohol-induced “flushing” syndrome. Evidence suggests that ALDH2 Glu504Lys SNP is a potential candidate genetic risk factor for a variety of chronic diseases such as cardiovascular disease, cancer, and late-onset Alzheimer’s disease. In addition, the association between ALDH2 Glu504Lys SNP and the development of these chronic diseases appears to be affected by the interaction between the SNP and lifestyle factors such as alcohol consumption as well as by the presence of other genetic variations.

RDH13L, an enzyme responsible for the aldehyde-alcohol redox coupling reaction (AL-OL coupling reaction) to supply 11-cis retinal in the carp cone retinoid cycle.

Science.gov (United States)

Sato, Shinya; Miyazono, Sadaharu; Tachibanaki, Shuji; Kawamura, Satoru

2015-01-30

Cone photoreceptors require effective pigment regeneration mechanisms to maintain their sensitivity in the light. Our previous studies in carp cones suggested the presence of an unconventional and very effective mechanism to produce 11-cis retinal, the necessary component in pigment regeneration. In this reaction (aldehyde-alcohol redox coupling reaction, AL-OL coupling reaction), formation of 11-cis retinal, i.e. oxidation of 11-cis retinol is coupled to reduction of an aldehyde at a 1:1 molar ratio without exogenous NADP(H) which is usually required in this kind of reaction. Here, we identified carp retinol dehydrogenase 13-like (RDH13L) as an enzyme catalyzing the AL-OL coupling reaction. RDH13L was partially purified from purified carp cones, identified as a candidate protein, and its AL-OL coupling activity was confirmed using recombinant RDH13L. We further examined the substrate specificity, subcellular localization, and expression level of RDH13L. Based on these results, we concluded that RDH13L contributes to a significant part, but not all, of the AL-OL coupling activity in carp cones. RDH13L contained tightly bound NADP(+) which presumably functions as a cofactor in the reaction. Mouse RDH14, a mouse homolog of carp RDH13L, also showed the AL-OL coupling activity. Interestingly, although carp cone membranes, carp RDH13L and mouse RDH14 all showed the coupling activity at 15-37 °C, they also showed a conventional NADP(+)-dependent 11-cis retinol oxidation activity above 25 °C without addition of aldehydes. This dual mechanism of 11-cis retinal synthesis attained by carp RDH13L and mouse RDH14 probably contribute to effective pigment regeneration in cones that function in the light. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Elastin aging and lipid oxidation products in human aorta

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Kamelija Zarkovic

2015-04-01

Full Text Available Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA, (4-hydroxynonenal, malondialdehyde, acrolein, form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development.

Oxidative Stability of Dispersions Prepared from Purified Marine Phospholipid and the Role of α-Tocopherol

DEFF Research Database (Denmark)

Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

2012-01-01

, respectively, during 32 days of storage at 2 °C. Nonenzymatic browning was investigated through measurement of Strecker aldehydes, color changes, and pyrrole content. Dispersions containing α-tocopherol or higher levels of purified marine PL showed a lower increment of volatiles after 32 days storage......The objective of this study was to investigate the oxidative stability of dispersions prepared from different levels of purified marine phospholipid (PL) obtained by acetone precipitation, with particular focus on the interaction between α-tocopherol and PL in dispersions. This also included...... the investigation of nonenzymatic browning in purified marine PL dispersions. Dispersions were prepared by high-pressure homogenizer. The oxidative and hydrolytic stabilities of dispersions were investigated by determination of hydroperoxides, secondary volatile oxidation products, and free fatty acids...

The correlation between aldehyde dehydrogenase-1A1 level and tumor shrinkage after preoperative chemoradiation in locally advanced rectal cancer

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Rhandyka Rafli

2015-12-01

Full Text Available This study was performed to determine the correlation between aldehyde dehydrogenase-1A1 (ALDH1A1 level and tumor shrinkage after chemoradiation in locally advanced rectal cancer. This is a retrospective study of 14 locally advanced rectal cancer patients with long course neoadjuvant chemoradiation. ALDH1A1 level was measured using ELISA from paraffin embedded tissue. Tumor shrinkage was measured from computed tomography (CT scan or magnetic resonance imaging (MRI based on Response Evaluation Criteria in Solid Tumor v1.1 (RECIST v1.1. The mean of ALDH1A1 level was 9.014 ± 3.3 pg/mL and the mean of tumor shrinkage was 7.89 ± 35.7%. Partial response proportion was 28.6%, stable disease proportion was 50% and progressive disease proportion was 21.4%. There was a significant strong negative correlation (r = –0.890, plt; 0.001 between ALDH1A1 and tumor shrinkage. In conclusion, tumor shrinkage in locally advanced rectal cancer after preoperative chemoradiation was influenced by ALDH1A1 level. Higher level of ALDH1A1 suggests decreased tumor shrinkage after preoperative chemoradiation.

Interference of aldehyde metabolizing enzyme with diamine oxidase/histaminase/activity as determined by 14C putrescine method

International Nuclear Information System (INIS)

Fogel, W.A.; Bieganski, T.; Wozniak, J.; Maslinski, C.

1978-01-01

The Δ 1 pyrroline formation, as an indicator of diamine oxidase activity according to Okuyama and Kobayashi 14 C putrescine test (1961, Archs Biochem. Biophys., vol.95, 242), has been investigated in several tissue homogenates. When guinea pig liver homogenate was used as a source of enzyme in the presence of aldehyde dehydrogenase inhibitors chlorate hydrate and acetaldehyde the level of formation Δ 1 pyrroline was strongly increased in a dose-dependent manner. Also inhibition of aldehyde reductase by phenobarbital enhanced Δ 1 pyrroline formation, but to a lesser degree. In other tissues, with very high initial diamine oxidase activity (rat intestine, dog kidney) or with very low diamine oxidase activity (guinea pig skin, dog liver) the influence of these inhibitors was only slight. Pyrazole, an inhibitor of alcohol dehydrogenase exerted only a small effect on Δ 1 pyrroline formation. All aldehyde-metabolizing enzymes inhibitors, except pyrazole, were without effect on purified pea seddling and hog kidney diamine oxidases. The use of aldehyde-metabolizing enzymes inhibitors may help to reveal the real values of diamine oxidase activity, when tissues homogenates are used as a source of enzyme. (author)

Direct enzyme assay evidence confirms aldehyde reductase function of Ydr541cp and Ygl039wp from Saccharomyces cerevisiae.

Science.gov (United States)

Moon, Jaewoong; Liu, Z Lewis

2015-04-01

The aldehyde reductase gene ARI1 is a recently characterized member of an intermediate subfamily within the short-chain dehydrogenase/reductase (SDR) superfamily that clarified mechanisms of in situ detoxification of 2-furaldehyde and 5-hydroxymethyl-2-furaldehyde by Saccharomyces cerevisiae. Uncharacterized open reading frames (ORFs) are common among tolerant candidate genes identified for lignocellulose-to-advanced biofuels conversion. This study presents partially purified proteins of two ORFs, YDR541C and YGL039W, and direct enzyme assay evidence against aldehyde-inhibitory compounds commonly encountered during lignocellulosic biomass fermentation processes. Each of the partially purified proteins encoded by these ORFs showed a molecular mass of approximately 38 kDa, similar to Ari1p, a protein encoded by aldehyde reductase gene. Both proteins demonstrated strong aldehyde reduction activities toward 14 aldehyde substrates, with high levels of reduction activity for Ydr541cp toward both aromatic and aliphatic aldehydes. While Ydr541cp was observed to have a significantly higher specific enzyme activity at 20 U/mg using co-factor NADPH, Ygl039wp displayed a NADH preference at 25 U/mg in reduction of butylaldehyde. Amino acid sequence analysis identified a characteristic catalytic triad, Ser, Tyr and Lys; a conserved catalytic motif of Tyr-X-X-X-Lys; and a cofactor-binding sequence motif, Gly-X-X-Gly-X-X-Ala, near the N-terminus that are shared by Ydr541cp, Ygl039wp, Yol151wp/GRE2 and Ari1p. Findings of aldehyde reductase genes contribute to the yeast gene annotation and aids development of the next-generation biocatalyst for advanced biofuels production. Copyright © 2015 John Wiley & Sons, Ltd.

Threshold responses in cinnamic-aldehyde-sensitive subjects: results and methodological aspects

DEFF Research Database (Denmark)

Johansen, J D; Andersen, Klaus Ejner; Rastogi, S C

1996-01-01

Cinnamic aldehyde is an important fragrance material and contact allergen. The present study was performed to provide quantitative data on the eliciting capacity of cinnamic aldehyde, to be considered in assessment of clinical relevance and health hazard. The skin response to serial dilution patch...

Oxidized Xanthan Gum and Chitosan as Natural Adhesives for Cork

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Diana Paiva

2016-07-01

Full Text Available Natural cork stopper manufacturing produces a significant amount of cork waste, which is granulated and combined with synthetic glues for use in a wide range of applications. There is a high demand for using biosourced polymers in these composite materials. In this study, xanthan gum (XG and chitosan (CS were investigated as possible natural binders for cork. Xanthan gum was oxidized at two different aldehyde contents as a strategy to improve its water resistance. This modification was studied in detail by 1H and 13C nuclear magnetic resonance (NMR, and the degree of oxidation was determined by the hydroxylamine hydrochloride titration method. The performance of the adhesives was studied by tensile tests and total soluble matter (TSM determinations. Xanthan gum showed no water resistance, contrary to oxidized xanthan gum and chitosan. It is hypothesized that the good performance of oxidized xanthan gum is due to the reaction of aldehyde groups—formed in the oxidation process—with hydroxyl groups on the cork surface during the high temperature drying. Combining oxidized xanthan gum with chitosan did not yield significant improvements.

Studying fatty aldehyde metabolism in living cells with pyrene-labeled compounds

NARCIS (Netherlands)

Keller, Markus A.; Watschinger, Katrin; Lange, Karsten; Golderer, Georg; Werner-Felmayer, Gabriele; Hermetter, Albin; Wanders, Ronald J. A.; Werner, Ernst R.

2012-01-01

The lack of fatty aldehyde dehydrogenase function in Sjogren Larsson Syndrome (SLS) patient cells not only impairs the conversion of fatty aldehydes into their corresponding fatty acid but also has an effect on connected pathways. Alteration of the lipid profile in these cells is thought to be

Identification and characterization of an antennae-specific aldehyde oxidase from the navel orangeworm.

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Young-Moo Choo

Full Text Available Antennae-specific odorant-degrading enzymes (ODEs are postulated to inactivate odorant molecules after they convey their signal. Different classes of insect ODEs are specific to esters, alcohols, and aldehydes--the major functional groups of female-produced, hydrophobic sex pheromones from moth species. Esterases that rapidly inactive acetate and other esters have been well-studied, but less is known about aldehyde oxidases (AOXs. Here we report cloning of an aldehyde oxidase, AtraAOX2, from the antennae of the navel orangeworm (NOW, Amyelois transitella, and the first activity characterization of a recombinant insect AOX. AtraAOX2 gene spans 3,813 bp and encodes a protein with 1,270 amino acid residues. AtraAOX2 cDNA was expressed in baculovirus-infected insect Sf21 cells as a ≈280 kDa homodimer with 140 kDa subunits. Recombinant AtraAOX2 degraded Z11Z13-16Ald and plant volatile aldehydes as substrates. However, as expected for aldehyde oxidases, recombinant AtraAOX2 did not show specificity for Z11Z13-16Ald, the main constituent of the sex pheromone, but showed high activity for plant volatile aldehydes. Our data suggest AtraAOX2 might be involved in degradation of a diversity of aldehydes including sex pheromones, plant-derived semiochemicals, and chemical cues for oviposition sites. Additionally, AtraAOX2 could protect the insect's olfactory system from xenobiotics, including pesticides that might reach the sensillar lymph surrounding the olfactory receptor neurons.

Toxicity of polyunsaturated aldehydes of diatoms to Indo-Pacific bioindicator organism Echinometra mathaei.

Science.gov (United States)

Sartori, Davide; Gaion, Andrea

2016-01-01

Although it is well known suitability of early developmental stages of sea urchin as recommended model for pollutant toxicity testing, little is known about the sensitivity of Indo-Pacific species Echinometra mathaei to polyunsaturated aldehydes. In this study, the effect of three short chain aldehydes, 2,4-decadienal (DD), 2,4-octadienal (OD) and 2,4-heptadienal (HD), normally found in many diatoms, such as Skeletonema costatum, Skeletonema marinoi and Thalassiosira rotula, was evaluated on larval development of E. mathaei embryos. Aldehydes affected larval development in a dose-dependent manner, in particular HD>OD>DD; the results of this study highlighted the higher sensitivity of this species toward aldehydes compared with data registered for other sea urchin species. In comparison with studies reported in the literature, contrasting results were observed during our tests; therefore, an increasing toxic effect was registered with decreasing the chain length of aldehydes. This work could provide new insights in the development of new toxicological assays toward most sensitive species.

Effect of whey protein on the In Vivo Release of Aldehydes.

NARCIS (Netherlands)

Weel, K.G.C.; Boelrijk, A.E.M.; Burger, J.J.; Claassen, N.E.; Gruppen, H.; Voragen, A.G.J.

2003-01-01

Retention of aldehydes by whey proteins in solutions buffered at a range of pH values was studied under static and dynamic headspace conditions and in vivo in exhaled air. Static headspace measurements showed a clear increase in retention in the presence of whey proteins for aldehydes with longer

HPLC analysis of aldehydes in automobile exhaust gas: Comparison of exhaust odor and irritation in different types of gasoline and diesel engines

International Nuclear Information System (INIS)

Roy, Murari Mohon

2008-01-01

This study investigated high performance liquid chromatography (HPLC) to identify and measure aldehydes from automobile exhaust gas. Four aldehydes: formaldehyde (HCHO), acetaldehyde (CH 3 CHO), acrolein (H 2 C=CHCHO) and propionaldehyde (CH 3 CH 2 CHO) and one ketone, acetone (CH 3 ) 2 CO are separated. The other higher aldehydes in exhaust gas are very small and cannot be separated. A new method of gas sampling, hereafter called bag sampling in HPLC is introduced instead of the trapping gas sampling method. The superiority of the bag sampling method is its transient gas checking capability. In the second part of this study, HPLC results are applied to compare exhaust odor and irritation of exhaust gases in different types of gasoline and diesel engines. Exhaust odor, irritation and aldehydes are found worst in direct injection (DI) diesel engines and best in some good multi-point injection (MPI) gasoline and direct injection gasoline (DIG) engines. Indirect injection (IDI) diesel engines showed odor, irritation and aldehydes in between the levels of MPI gasoline, DIG and DI diesel engines

Effect of selected aldehydes on the growth and fermentation of ethanologenic Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Zaldivar, J.; Ingram, L.O. [Univ. of Florida, Gainesville (United States). Dept. of Microbiology and Cell Science; Martinez, A. [Univ. of Florida, Gainesville (United States). Dept. of Microbiology and Cell Science]|[Univ. Nacional Autonoma de Mexico (Mexico). Inst. de Biotecnologia

1999-10-05

Bioethanol production from lignocellulosic raw-materials requires the hydrolysis of carbohydrate polymers into a fermentable syrup. During the hydrolysis of hemicellulose with dilute acid, a variety of toxic compounds are produced such as soluble aromatic aldehydes from lignin and furfural from pentose destruction. In this study, the authors have investigated the toxicity of representative aldehydes (furfural, 5-hydroxymethlyfurfural, 4-hydroxybenzaldehyde, syringaldehyde, and vanillin) as inhibitors of growth and ethanol production by ethanologenic derivatives of Escherichia coli B (strains K011 and LY01). Aromatic aldyhydes were at least twice as toxic as furfural of 5-hydroxymethylfurfural on a weight basis. The toxicities of all aldehydes (and ethanol) except furfural were additive when tested in binary combinations. In all cases, combinations with furfural were unexpectedly toxic. Although the potency of these aldehydes was directly related to hydrophobicity indicating a hydrophobic site of action, none caused sufficient membrane damage to allow the leakage of intracellular magnesium even when present at sixfold the concentrations required for growth inhibition. Of the aldehydes tested, only furfural strongly inhibited ethanol production in vitro. A comparison with published results for other microorganisms indicates that LY01 is equivalent or more resistant than other biocatalysts to the aldehydes examined in this study.

Atmospheric levels of aldehydes and BTEX and their relationship with vehicular fleet changes in Rio de Janeiro urban area.

Science.gov (United States)

Martins, Eduardo Monteiro; Arbilla, Graciela; Bauerfeldt, Glauco Favilla; de Paula, Murilo

2007-05-01

A comprehensive monitoring campaign to assess aldehydes and BTEX concentrations was performed during 12 months, in the Tijuca district (Rio de Janeiro), an area with commercial activities and a high flux of vehicles. The mean concentrations of formaldehyde and acetaldehyde were 151 and 30 ppb, respectively. The high formaldehyde/acetaldehyde ratio was attributed to extensive use of compressed natural gas (CNG). The number of CNG vehicles in the metropolitan Region of Rio de Janeiro increased from 23000 in January 2001 to 161000 in January 2005. Monitoring data show that, for the same period, methane and formaldehyde concentrations increased while NO(x) and CO levels diminished. Mean concentrations for benzene, toluene, ethylbenzene, m,p-xylene and o-xylene, were 1.1, 4.8, 3.6, 10.4 and 3.0 micro gm(-3), respectively. Benzene and toluene concentrations were lower than the values determined in 1996, for the same location. The levels of ethylbenzene and xylenes determined in this work are similar to values obtained in 1996. This fact may be explained as a consequence of changes in the gasoline composition.

Interference of aldehyde metabolizing enzyme with diamine oxidase/histaminase/activity as determined by /sup 14/C putrescine method

Energy Technology Data Exchange (ETDEWEB)

Fogel, W A [Polish Academy of Sciences, Cracow (Poland). Inst. of Pharmacology; Bieganski, T; Wozniak, J; Maslinski, C

1978-01-01

The ..delta../sup 1/ pyrroline formation, as an indicator of diamine oxidase activity according to Okuyama and Kobayashi /sup 14/C putrescine test (1961, Archs Biochem. Biophys., vol.95, 242), has been investigated in several tissue homogenates. When guinea pig liver homogenate was used as a source of enzyme in the presence of aldehyde dehydrogenase inhibitors chlorate hydrate and acetaldehyde the level of formation ..delta../sup 1/ pyrroline was strongly increased in a dose-dependent manner. Also inhibition of aldehyde reductase by phenobarbital enhanced ..delta../sup 1/ pyrroline formation, but to a lesser degree. In other tissues, with very high initial diamine oxidase activity (rat intestine, dog kidney) or with very low diamine oxidase activity (guinea pig skin, dog liver) the influence of these inhibitors was only slight. Pyrazole, an inhibitor of alcohol dehydrogenase exerted only a small effect on ..delta../sup 1/ pyrroline formation. All aldehyde-metabolizing enzymes inhibitors, except pyrazole, were without effect on purified pea seddling and hog kidney diamine oxidases. The use of aldehyde-metabolizing enzymes inhibitors may help to reveal the real values of diamine oxidase activity, when tissues homogenates are used as a source of enzyme.

Maternal Aldehyde Elimination during Pregnancy Preserves the Fetal Genome

Science.gov (United States)

Oberbeck, Nina; Langevin, Frédéric; King, Gareth; de Wind, Niels; Crossan, Gerry P.; Patel, Ketan J.

2014-01-01

Summary Maternal metabolism provides essential nutrients to enable embryonic development. However, both mother and embryo produce reactive metabolites that can damage DNA. Here we discover how the embryo is protected from these genotoxins. Pregnant mice lacking Aldh2, a key enzyme that detoxifies reactive aldehydes, cannot support the development of embryos lacking the Fanconi anemia DNA repair pathway gene Fanca. Remarkably, transferring Aldh2−/−Fanca−/− embryos into wild-type mothers suppresses developmental defects and rescues embryonic lethality. These rescued neonates have severely depleted hematopoietic stem and progenitor cells, indicating that despite intact maternal aldehyde catabolism, fetal Aldh2 is essential for hematopoiesis. Hence, maternal and fetal aldehyde detoxification protects the developing embryo from DNA damage. Failure of this genome preservation mechanism might explain why birth defects and bone marrow failure occur in Fanconi anemia, and may have implications for fetal well-being in the many women in Southeast Asia that are genetically deficient in ALDH2. PMID:25155611

Maternal aldehyde elimination during pregnancy preserves the fetal genome.

Science.gov (United States)

Oberbeck, Nina; Langevin, Frédéric; King, Gareth; de Wind, Niels; Crossan, Gerry P; Patel, Ketan J

2014-09-18

Maternal metabolism provides essential nutrients to enable embryonic development. However, both mother and embryo produce reactive metabolites that can damage DNA. Here we discover how the embryo is protected from these genotoxins. Pregnant mice lacking Aldh2, a key enzyme that detoxifies reactive aldehydes, cannot support the development of embryos lacking the Fanconi anemia DNA repair pathway gene Fanca. Remarkably, transferring Aldh2(-/-)Fanca(-/-) embryos into wild-type mothers suppresses developmental defects and rescues embryonic lethality. These rescued neonates have severely depleted hematopoietic stem and progenitor cells, indicating that despite intact maternal aldehyde catabolism, fetal Aldh2 is essential for hematopoiesis. Hence, maternal and fetal aldehyde detoxification protects the developing embryo from DNA damage. Failure of this genome preservation mechanism might explain why birth defects and bone marrow failure occur in Fanconi anemia, and may have implications for fetal well-being in the many women in Southeast Asia that are genetically deficient in ALDH2. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Low cytotoxic tissue adhesive based on oxidized dextran and epsilon-poly-L-lysine.

Science.gov (United States)

Hyon, Suong-Hyu; Nakajima, Naoki; Sugai, Hajime; Matsumura, Kazuaki

2014-08-01

A novel adhesive hydrogel consisting of dextran and epsilon-poly(L-lysine) (dextran-PL) with multiple biomedical applications was developed. Periodate oxidation in aqueous media almost stoichiometrically introduces aldehyde groups in dextran molecules, and aldehyde dextran can react with the primary amino groups in epsilon-PL (ɛ-PL) at neutral pH to form a hydrogel. The gelation time of the hydrogel can be easily controlled by the extent of oxidation in dextran and of the acylation in ɛ-PL by anhydrides. The shear adhesion strength of dextran-PL was 10 times higher than that of fibrin glue, when wet collagen sheets were selected as test specimens. The cytotoxicity of aldehyde dextran and ɛ-PL were 1000 times lower than that of glutaraldehyde and poly(allylamine). The considerably low cytotoxicity of aldehyde dextran could be ascribed to its low reactivity with amine species when compared with glutaraldehyde. In contrast, a high reactivity of amino groups in ɛ-PL was observed when compared with glycine, L-lysine, and gelatin, which could be explained by their poor dissociation at neutral pH, thus leading to low cytotoxicity. © 2013 Wiley Periodicals, Inc.

Chronic oral exposure to the aldehyde pollutant acrolein induces dilated cardiomyopathy

Science.gov (United States)

Ismahil, Mohamed Ameen; Hamid, Tariq; Haberzettl, Petra; Gu, Yan; Chandrasekar, Bysani; Srivastava, Sanjay; Bhatnagar, Aruni

2011-01-01

Environmental triggers of dilated cardiomyopathy are poorly understood. Acute exposure to acrolein, a ubiquitous aldehyde pollutant, impairs cardiac function and cardioprotective responses in mice. Here, we tested the hypothesis that chronic oral exposure to acrolein induces inflammation and cardiomyopathy. C57BL/6 mice were gavage-fed acrolein (1 mg/kg) or water (vehicle) daily for 48 days. The dose was chosen based on estimates of human daily unsaturated aldehyde consumption. Compared with vehicle-fed mice, acrolein-fed mice exhibited significant (P acrolein adduct formation indicative of physical translocation of ingested acrolein to the heart. Acrolein also induced myocyte hypertrophy (∼2.2-fold increased myocyte area, P acrolein-exposed hearts, along with upregulated gene expression of proinflammatory cytokines tumor necrosis factor-α and interleukin-1β. Long-term oral exposure to acrolein, at an amount within the range of human unsaturated aldehyde intake, induces a phenotype of dilated cardiomyopathy in the mouse. Human exposure to acrolein may have analogous effects and raise consideration of an environmental, aldehyde-mediated basis for heart failure. PMID:21908791

Elastin aging and lipid oxidation products in human aorta.

Science.gov (United States)

Zarkovic, Kamelija; Larroque-Cardoso, Pauline; Pucelle, Mélanie; Salvayre, Robert; Waeg, Georg; Nègre-Salvayre, Anne; Zarkovic, Neven

2015-01-01

Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM) components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs) are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA), (4-hydroxynonenal, malondialdehyde, acrolein), form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Effects of cooking method, cooking oil, and food type on aldehyde emissions in cooking oil fumes.

Science.gov (United States)

Peng, Chiung-Yu; Lan, Cheng-Hang; Lin, Pei-Chen; Kuo, Yi-Chun

2017-02-15

Cooking oil fumes (COFs) contain a mixture of chemicals. Of all chemicals, aldehydes draw a great attention since several of them are considered carcinogenic and formation of long-chain aldehydes is related to fatty acids in cooking oils. The objectives of this research were to compare aldehyde compositions and concentrations in COFs produced by different cooking oils, cooking methods, and food types and to suggest better cooking practices. This study compared aldehydes in COFs produced using four cooking oils (palm oil, rapeseed oil, sunflower oil, and soybean oil), three cooking methods (stir frying, pan frying, and deep frying), and two foods (potato and pork loin) in a typical kitchen. Results showed the highest total aldehyde emissions in cooking methods were produced by deep frying, followed by pan frying then by stir frying. Sunflower oil had the highest emissions of total aldehydes, regardless of cooking method and food type whereas rapeseed oil and palm oil had relatively lower emissions. This study suggests that using gentle cooking methods (e.g., stir frying) and using oils low in unsaturated fatty acids (e.g., palm oil or rapeseed oil) can reduce the production of aldehydes in COFs, especially long-chain aldehydes such as hexanal and t,t-2,4-DDE. Copyright © 2016 Elsevier B.V. All rights reserved.

Methyltrioxorhenium as catalyst of a novel aldehyde olefination

Energy Technology Data Exchange (ETDEWEB)

Herrmann, W.A. (Technische Univ. Muenchen, Garching (Germany). Anorganisch-Chemisches Inst.); Wang Mei (Academia Sinica, Dalian Inst. of Chemical Physics (China))

1991-12-01

From aldehydes or cyclic ketones, diazoalkanes, and teritiary phosphanes, olefins may be prepared with MTO as catalyst. In particular, diazoacetates and -malonates (R{sup 2}, R{sup 3} = H, CO{sub 2}Et, or 2 x CO{sub 2}Me) can be transformed into olefins with aliphatic and aromatic aldehydes (R{sup 1} = iPr, trans-PhCH=CH, Ph, 4-NO{sub 2}C{sub 6}H{sub 4}, etc.). Readily accessible starting materials, easy handling, mild reaction conditions, and good yields characterize the new synthesis method. (R' = Ph, 3-C{sub 6}H{sub 4}SO{sub 3}Na, nBu.) (orig.).

The chemical oxidation of lignin found in Sappi Saiccor dissolving ...

African Journals Online (AJOL)

2011-01-11

Jan 11, 2011 ... Oxygen oxidation has previously been shown to produce aldehyde-type compounds, and in this work has produced good yields of both vanillin and syringaldehyde compared to previous oxygen oxidation reac- tions. Hydrogen peroxide is a strong oxidising agent that tends to over-oxidise the lignin during ...

Liquid chromatography-dopant-assisted atmospheric pressure photoionization-mass spectrometry: Application to the analysis of aldehydes in atmospheric aerosol particles.

Science.gov (United States)

Ruiz-Jiménez, José; Hautala, Sanna; Parshintsev, Jevgeni; Laitinen, Totti; Hartonen, Kari; Petäjä, Tuukka; Kulmala, Markku; Riekkola, Marja-Liisa

2013-01-01

A complete methodology based on LC-anisole-toluene dopant-assisted atmospheric pressure photoionization-IT-MS was developed for the determination of aldehydes in atmospheric aerosol particles. For the derivatization, ultrasound was used to accelerate the reaction between the target analytes and 2,4-dinitrophenylhydrazine. The developed methodology was validated for three different samples, gas phase, ultrafine (Dp = 30 ± 4 nm; where Dp stands for particle diameter) and all-sized particles, collected on Teflon filters. The method quantitation limits ranged from 5 to 227 pg. The accuracy and the potential matrix effects were evaluated using standard addition methodology. Recoveries ranged between 91.7 and 109.9%, and the repeatability and the reproducibility of the method developed between 0.5 and 8.0% and between 2.9 and 11.1%, respectively. The results obtained by the developed methodology compared to those provided by the previously validated method revealed no statistical differences. The method developed was applied to the determination of aldehydes in 16 atmospheric aerosol samples (30 nm and all-sized samples) collected at the Station for Measuring Forest Ecosystem-Atmosphere Relations II during spring 2011. The mean concentrations of aldehydes, and oxidation products of terpenes were between 0.05 and 82.70 ng/m(3). © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

On the nature of the olefination reaction involving ditungsten hexaalkoxides and aldehydes or ketones

Energy Technology Data Exchange (ETDEWEB)

Chisholm, M.H.; Huffman, J.C.; Lucas, E.A.; Sousa, A.; Streib, W.E. [Indiana Univ., Bloomington, IN (United States)

1992-03-25

Reductive coupling of aldehydes and ketones to olefins under the action of ditungsten hexaalkoxides was investigated. In these reactions, reductive cleavage of the aldehyde or ketone carbonyl is followed by formation of the olefinic C-C bond and breaking of the carbonyl C-O bond of the second aldehyde or ketone. Observations concerning the initial C-O bond cleavage and subsequent C-C bond formation are presented. 10 refs., 4 figs.

Reductive detoxification of acrolein as a potential role for aldehyde reductase (AKR1A) in mammals.

Science.gov (United States)

Kurahashi, Toshihiro; Kwon, Myoungsu; Homma, Takujiro; Saito, Yuka; Lee, Jaeyong; Takahashi, Motoko; Yamada, Ken-Ichi; Miyata, Satoshi; Fujii, Junichi

2014-09-12

Aldehyde reductase (AKR1A), a member of the aldo-keto reductase superfamily, suppresses diabetic complications via a reduction in metabolic intermediates; it also plays a role in ascorbic acid biosynthesis in mice. Because primates cannot synthesize ascorbic acid, a principle role of AKR1A appears to be the reductive detoxification of aldehydes. In this study, we isolated and immortalized mouse embryonic fibroblasts (MEFs) from wild-type (WT) and human Akr1a-transgenic (Tg) mice and used them to investigate the potential roles of AKR1A under culture conditions. Tg MEFs showed higher methylglyoxal- and acrolein-reducing activities than WT MEFs and also were more resistant to cytotoxicity. Enzymatic analyses of purified rat AKR1A showed that the efficiency of the acrolein reduction was about 20% that of glyceraldehyde. Ascorbic acid levels were quite low in the MEFs, and while the administration of ascorbic acid to the cells increased the intracellular levels of ascorbic acid, it had no affect on the resistance to acrolein. Endoplasmic reticulum stress and protein carbonylation induced by acrolein treatment were less evident in Tg MEFs than in WT MEFs. These data collectively indicate that one of the principle roles of AKR1A in primates is the reductive detoxification of aldehydes, notably acrolein, and protection from its detrimental effects. Copyright © 2014 Elsevier Inc. All rights reserved.

Ocular biocompatibility of gelatin microcarriers functionalized with oxidized hyaluronic acid

Energy Technology Data Exchange (ETDEWEB)

Lai, Jui-Yang, E-mail: jylai@mail.cgu.edu.tw [Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan (China); Biomedical Engineering Research Center, Chang Gung University, Taoyuan 33302, Taiwan (China); Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan (China); Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan (China); Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan (China); Ma, David Hui-Kang [Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan (China); Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan (China); Department of Chinese Medicine, Chang Gung University, Taoyuan 33302, Taiwan (China)

2017-03-01

Given that the presence of aldehyde groups on the oxidized sugar residues may pose toxicity concerns, it is necessary to examine the safety of gelatin microcarriers (GMC) functionalized with oxidized hyaluronic acid (oHA) for potential ophthalmic applications. In this study, the ocular biocompatibility of biopolymer microcarriers was investigated in vitro using primary rabbit corneal cell cultures and in vivo using the anterior chamber of the rabbit eye model. Our results showed that different types of corneal cells including epithelial, stromal, and endothelial cells remain viable and actively proliferate following 2 and 4 days of exposure to test materials. In addition, similar interleukin-6 gene expression levels and comet tail lengths were seen in the presence and absence of biopolymer microcarriers, suggesting no cellular inflammation and genotoxicity. After 7 and 14 days of intracameral injection in the rabbit eyes, both the GMC samples and their counterparts functionalized with oHA were well tolerated in the ocular anterior chamber as demonstrated by slit-lamp biomicroscopy. Clinical observations including specular microscopic examinations, corneal topography, and corneal thickness measurements also showed that the rabbits bearing biopolymer microcarriers exhibit no signs of corneal edema and astigmatism as well as endothelial damage, indicating the absence of tissue response. It is concluded that the GMC materials functionalized with oHA (oxidation level: 10.4 ± 0.9%) are compatible toward corneal cells and ocular anterior segment tissues at a concentration of 10 mg/ml. The information about the effect of coupling of aldehyde-functionalized HA to gelatin on in vitro and in vivo biocompatibility of biopolymer composites can be used as further development of corneal stromal cell microcarriers for tissue engineering applications. - Highlights: • We examine in vitro and in vivo ocular biocompatibility of biopolymer microcarrier. • Gelatin-oxidized HA

Ocular biocompatibility of gelatin microcarriers functionalized with oxidized hyaluronic acid

International Nuclear Information System (INIS)

Lai, Jui-Yang; Ma, David Hui-Kang

2017-01-01

Given that the presence of aldehyde groups on the oxidized sugar residues may pose toxicity concerns, it is necessary to examine the safety of gelatin microcarriers (GMC) functionalized with oxidized hyaluronic acid (oHA) for potential ophthalmic applications. In this study, the ocular biocompatibility of biopolymer microcarriers was investigated in vitro using primary rabbit corneal cell cultures and in vivo using the anterior chamber of the rabbit eye model. Our results showed that different types of corneal cells including epithelial, stromal, and endothelial cells remain viable and actively proliferate following 2 and 4 days of exposure to test materials. In addition, similar interleukin-6 gene expression levels and comet tail lengths were seen in the presence and absence of biopolymer microcarriers, suggesting no cellular inflammation and genotoxicity. After 7 and 14 days of intracameral injection in the rabbit eyes, both the GMC samples and their counterparts functionalized with oHA were well tolerated in the ocular anterior chamber as demonstrated by slit-lamp biomicroscopy. Clinical observations including specular microscopic examinations, corneal topography, and corneal thickness measurements also showed that the rabbits bearing biopolymer microcarriers exhibit no signs of corneal edema and astigmatism as well as endothelial damage, indicating the absence of tissue response. It is concluded that the GMC materials functionalized with oHA (oxidation level: 10.4 ± 0.9%) are compatible toward corneal cells and ocular anterior segment tissues at a concentration of 10 mg/ml. The information about the effect of coupling of aldehyde-functionalized HA to gelatin on in vitro and in vivo biocompatibility of biopolymer composites can be used as further development of corneal stromal cell microcarriers for tissue engineering applications. - Highlights: • We examine in vitro and in vivo ocular biocompatibility of biopolymer microcarrier. • Gelatin-oxidized HA

Application of two analytic techniques of sampling for the determination of aldehydes in air and in rain water in three areas of Costa Rica

International Nuclear Information System (INIS)

Vega Montero, D. I

2001-01-01

The aldehydes are of supreme interest in the quality of the air of Costa Rica; reason why it is very important to determine them qualitative and quantitatively. This study has as objectives the identification and quantification of aldehydes in samples of air and of rain water in three areas of Costa Rica, to compare two methods of taking of samples of air and to correlate the concentration of the aldehydes in the different points of taking of samples. The sampling one carries out in three located stations, in the Hill of the Piroclasticos (3 km. To the Northeast of the active crater of the Volcano Irazu), Escazu (it plants potabilizadora of water) and in Turrucares (facilities of the Rural Watch). The used sampling devices, denuders and cartridges, they were recovered with a breakup of 2,4-dinitrofenilhidrazina o'clock like absorbent reagent, which I form the corresponding hidrazonas in presence of the aldehydes. The identification and quantification of the aldehydes, one carries out by means of chromatography it liquidates of high resolution. The comparison among the concentrations of the aldehydes in air gathered by the two used sampling methods indicates that a significant difference exists among them, at a level of trust of 95% [es

Occupational exposure of aldehydes resulting from the storage of wood pellets.

Science.gov (United States)

Rahman, Mohammad Arifur; Rossner, Alan; Hopke, Philip K

2017-06-01

An exposure assessment was conducted to investigate the potential for harmful concentrations of airborne short chain aldehydes emitted from recently stored wood pellets. Wood pellets can emit a number of airborne aldehydes include acetaldehyde, formaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and hexanal. Exposure limits have been set for these compounds since they can result in significant irritation of the upper respiratory system at elevated concentrations. Formaldehyde is a recognized human carcinogen and acetaldehyde is an animal carcinogen. Thus, air sampling was performed in a wood pellet warehouse at a pellet mill, two residential homes with bulk wood pellet storage bins, and in controlled laboratory experiments to evaluate the risk to occupants. Using NIOSH method 2539, sampling was conducted in five locations in the warehouse from April-June 2016 when it contained varying quantities of bagged pellets as well as two homes with ten ton bulk storage bins. The aldehyde concentrations were found to increase with the amount of stored pellets. Airborne concentrations of formaldehyde were as high as 0.45 ppm in the warehouse exceeding the NIOSH REL-C, and ACGIH TLV-C occupational exposure limits (OELs). The concentrations of aldehydes measured in the residential bins were also elevated indicating emissions may raise indoor air quality concerns for occupants. While individual exposures are of concern the combined irritant effect of all the aldehydes is a further raise the concerns for building occupants. To minimize exposure and the risk of adverse health effects to a building's occupants in storage areas with large quantities of pellets, adequate ventilation must be designed into storage areas.

Gold nanoparticle catalyzed oxidation of alcohols - From biomass to commodity chemicals

DEFF Research Database (Denmark)

Taarning, Esben; Christensen, Claus H.

2007-01-01

and glycerol are rich in alcohol functionalities. Thus, a key step in utilizing these resources lies in the conversion of this functional group. Benign oxidations involving oxygen as the stoichiometric oxidant are important from both an environmental and economical perspective. Recently, it has become clear...... that supported gold nanoparticles are highly active catalysts for oxidizing alcohols and aldehydes using oxygen as the oxidant. This perspective will focus on the use of gold nanoparticles in the oxidation of renewables....

Lewis acid catalysis and Green oxidations: sequential tandem oxidation processes induced by Mn-hyperaccumulating plants.

Science.gov (United States)

Escande, Vincent; Renard, Brice-Loïc; Grison, Claude

2015-04-01

Among the phytotechnologies used for the reclamation of degraded mining sites, phytoextraction aims to diminish the concentration of polluting elements in contaminated soils. However, the biomass resulting from the phytoextraction processes (highly enriched in polluting elements) is too often considered as a problematic waste. The manganese-enriched biomass derived from native Mn-hyperaccumulating plants of New Caledonia was presented here as a valuable source of metallic elements of high interest in chemical catalysis. The preparation of the catalyst Eco-Mn1 and reagent Eco-Mn2 derived from Grevillea exul exul and Grevillea exul rubiginosa was investigated. Their unusual polymetallic compositions allowed to explore new reactivity of low oxidative state of manganese-Mn(II) for Eco-Mn1 and Mn(IV) for Eco-Mn2. Eco-Mn1 was used as a Lewis acid to catalyze the acetalization/elimination of aldehydes into enol ethers with high yields; a new green and stereoselective synthesis of (-)-isopulegol via the carbonyl-ene cyclization of (+)-citronellal was also performed with Eco-Mn1. Eco-Mn2 was used as a mild oxidative reagent and controlled the oxidation of aliphatic alcohols into aldehydes with quantitative yields. Oxidative cleavage was interestingly noticed when Eco-Mn2 was used in the presence of a polyol. Eco-Mn2 allowed direct oxidative iodination of ketones without using iodine, which is strongly discouraged by new environmental legislations. Finally, the combination of the properties in the Eco-Mn catalysts and reagents gave them an unprecedented potential to perform sequential tandem oxidation processes through new green syntheses of p-cymene from (-)-isopulegol and (+)-citronellal; and a new green synthesis of functionalized pyridines by in situ oxidation of 1,4-dihydropyridines.

Heat-stable, FE-dependent alcohol dehydrogenase for aldehyde detoxification

Science.gov (United States)

Elkins, James G.; Clarkson, Sonya

2018-04-24

The present invention relates to microorganisms and polypeptides for detoxifying aldehydes associated with industrial fermentations. In particular, a heat-stable, NADPH- and iron-dependent alcohol dehydrogenase was cloned from Thermoanaerobacter pseudethanolicus 39E and displayed activity against a number of aldehydes including inhibitory compounds that are produced during the dilute-acid pretreatment process of lignocellulosic biomass before fermentation to biofuels. Methods to use the microorganisms and polypeptides of the invention for improved conversion of bio mass to biofuel are provided as well as use of the enzyme in metabolic engineering strategies for producing longer-chain alcohols from sugars using thermophilic, fermentative microorganisms.

SELECTIVE OXIDATION OF ALCOHOLS - COMPARING DIFFERENT CATALYTIC PROCESSES

Science.gov (United States)

Oxidation of alcohols to aldehydes, ketones or carboxylic acids is one of the most desirable chemical transformations in organic synthesis as these products are important precursors and intermediates for many drugs, vitamins and fragrances. Numerous methods are available for alc...

Effects of the biodiesel blend fuel on aldehyde emissions from diesel engine exhaust

Science.gov (United States)

Peng, Chiung-Yu; Yang, Hsi-Hsien; Lan, Cheng-Hang; Chien, Shu-Mei

Interest in use of biodiesel fuels derived from vegetable oils or animal fats as alternative fuels for petroleum-based diesels has increased due to biodiesels having similar properties of those of diesels, and characteristics of renewability, biodegradability and potential beneficial effects on exhaust emissions. Generally, exhaust emissions of regulated pollutants are widely studied and the results favor biodiesels on CO, HC and particulate emissions; however, limited and inconsistent data are showed for unregulated pollutants, such as carbonyl compounds, which are also important indicators for evaluating available vehicle fuels. For better understanding biodiesel, this study examines the effects of the biodiesel blend fuel on aldehyde chemical emissions from diesel engine exhausts in comparison with those from the diesel fuel. Test engines (Mitsubishi 4M40-2AT1) with four cylinders, a total displacement of 2.84 L, maximum horsepower of 80.9 kW at 3700 rpm, and maximum torque of 217.6 N m at 2000 rpm, were mounted and operated on a Schenck DyNAS 335 dynamometer. Exhaust emission tests were performed several times for each fuel under the US transient cycle protocol from mileages of 0-80,000 km with an interval of 20,000 km, and two additional measurements were carried out at 40,000 and 80,000 km after maintenance, respectively. Aldehyde samples were collected from diluted exhaust by using a constant volume sampling system. Samples were extracted and analyzed by the HPLC/UV system. Dominant aldehydes of both fuels' exhausts are formaldehyde and acetaldehyde. These compounds together account for over 75% of total aldehyde emissions. Total aldehyde emissions for B20 (20% waste cooking oil biodiesel and 80% diesel) and diesel fuels are in the ranges of 15.4-26.9 mg bhp-h -1 and 21.3-28.6 mg bhp-h -1, respectively. The effects of increasing mileages and maintenance practice on aldehyde emissions are insignificant for both fuels. B20 generates slightly less emission than

Effect of low levels of lipid oxidation on the curvature, dynamics, and permeability of lipid bilayers and their interactions with cationic nanoparticles

Science.gov (United States)

Lee, Hwankyu; Malmstadt, Noah

2018-04-01

Lipid bilayers composed of saturated and unsaturated lipids, oxidized lipids, and cholesterol at concentrations of 0–18 mol% oxidized lipid were simulated, showing that the presence of oxidized lipid increases bilayer disorder, curvature, and lateral dynamics at low oxidized-lipid concentrations of 18 mol% or less. The aldehyde terminal of a shortened oxidized-lipid tail tends to interact with water and thus bends toward the bilayer-water interface, in agreement with previous experiments and simulations. In particular, water molecules pass through the oxidized bilayer without pore formation, implying passive permeability. A single nanoparticle, which consists of 300 polystyrene (PS) chains with cationic terminals, added to this bilayer simulation induces negative bilayer curvature and inserts to the bilayer, regardless of the oxidized-lipid concentration. Hydrophobic monomers and cationic terminals of the PS particle interact respectively with lipid tails and headgroups, leading to the wrapping of either lipid monolayer or bilayer along the particle surface. These results indicate that lipid oxidation increases membrane curvature and permeability even at such a low concentration of oxidized lipid, which supports the experimental observations regarding the passive permeability of oxidized bilayer, and also that oxidized lipids of low concentration do not significantly influence the insertion of a cationic PS particle to the bilayer.

Reactions of the radical cations of aliphatic aldehydes in freon matrices

International Nuclear Information System (INIS)

Belevskij, V.N.; Belopushkin, S.I.; Feldman, V.I.

1985-01-01

ESR spectra of γ-irradiated solutions of acetic and propionic aldehydes in freon-11 and freon-113 affected by aldehyde concentration, temperature, and the action of light were studied. It is shown that the radical cations are converted into neutral radicals, and the cations CHsub(3)CHsub(2)CHOsup(+). are converted to RCO and CHsub(3)CHCHO due to ion-molecular reactions of proton transfer of hydrogen atom transfer. (author)

Oxidative desulfurization of dibenzothiophene with molecular oxygen using emulsion catalysis.

Science.gov (United States)

Lü, Hongying; Gao, Jinbo; Jiang, Zongxuan; Yang, Yongxing; Song, Bo; Li, Can

2007-01-14

Dibenzothiophene (DBT) is oxidized to the corresponding sulfoxide and sulfone in an emulsion system (W/O) composed of polyoxometalate anion [C(18)H(37)N(CH(3))3](5)[PV(2)Mo(10)O(40)] as both the surfactant and catalyst, using molecular oxygen as the oxidant and aldehyde as the sacrificial agent under mild conditions.

Direct chemoselective synthesis of glyconanoparticles from unprotected reducing glycans and glycopeptide aldehydes

DEFF Research Database (Denmark)

Thygesen, Mikkel Boas; Sørensen, Kasper Kildegaard; Cló, Emiliano

2009-01-01

Chemoselective oxime coupling was used for facile conjugation of unprotected, reducing glycans and glycopeptide aldehydes with core-shell gold nanoparticles carrying reactive aminooxy groups on the organic shell.......Chemoselective oxime coupling was used for facile conjugation of unprotected, reducing glycans and glycopeptide aldehydes with core-shell gold nanoparticles carrying reactive aminooxy groups on the organic shell....

Exposure to polycyclic aromatic hydrocarbons (PAHs), mutagenic aldehydes and particulate matter during pan frying of beefsteak.

Science.gov (United States)

Sjaastad, Ann Kristin; Jørgensen, Rikke Bramming; Svendsen, Kristin

2010-04-01

Cooking with gas or electric stoves produces fumes, especially during frying, that contain a range of harmful and potentially mutagenic compounds as well as high levels of fine and ultrafine particles. The aim of this study was to see if polycyclic aromatic hydrocarbons (PAHs) and higher mutagenic aldehydes which were collected in the breathing zone of the cook, could be detected in fumes from the frying of beefsteak. The frying was performed in a model kitchen in conditions similar to those in a Western European restaurant kitchen. The levels of PAHs (16 EPA standard) and higher aldehydes (trans,trans-2,4-decadienal, 2,4-decadienal, trans-trans-2,4-nonadienal, trans-2-decenal, cis-2-decenal, trans-2-undecenal, 2-undecenal) were measured during frying on an electric or gas stove with margarine or soya bean oil as the frying fat. The number concentration of particles electric stove causes increased occupational exposure to some of the components in cooking fumes which may cause adverse health effects.

Mild and Efficient Oxidation of Aromatic Alcohols and Other Substrates Using NiO2/CH3COOH System

Directory of Open Access Journals (Sweden)

Mohammad Kooti

2008-01-01

Full Text Available A variety of aromatic alcohols were efficiently oxidized to their corresponding aldehydes and ketones in good to excellent yields using nickel peroxide activated by acetic acid. Some thiols and amines were also readily oxidized by this oxidant under mild conditions.

Oxidative versus Non-oxidative Decarboxylation of Amino Acids: Conditions for the Preferential Formation of Either Strecker Aldehydes or Amines in Amino Acid/Lipid-Derived Reactive Carbonyl Model Systems.

Science.gov (United States)

Zamora, Rosario; León, M Mercedes; Hidalgo, Francisco J

2015-09-16

Comparative formation of both 2-phenylethylamine and phenylacetaldehyde as a consequence of phenylalanine degradation by carbonyl compounds was studied in an attempt to understand if the amine/aldehyde ratio can be changed as a function of reaction conditions. The assayed carbonyl compounds were selected because of the presence in the chain of both electron-donating and electron-withdrawing groups and included alkenals, alkadienals, epoxyalkenals, oxoalkenals, and hydroxyalkenals as well as lipid hydroperoxides. The obtained results showed that the 2-phenylethylamine/phenylacetaldehyde ratio depended upon both the carbonyls and the reaction conditions. Thus, it can be increased using electron-donating groups in the chain of the carbonyl compound, small amounts of carbonyl compound, low oxygen content, increasing the pH, or increasing the temperature at pH 6. Opposed conditions (use of electron-withdrawing groups in the chain of the carbonyl compound, large amounts of carbonyl compound, high oxygen contents, low pH values, and increasing temperatures at low pH values) would decrease the 2-phenylethylamine/phenylacetaldehyde ratio, and the formation of aldehydes over amines in amino acid degradations would be favored.

Identification of glutathione adducts of α-chlorofatty aldehydes produced in activated neutrophils

Science.gov (United States)

Duerr, Mark A.; Aurora, Rajeev; Ford, David A.

2015-01-01

α-Chlorofatty aldehydes (α-ClFALDs) are produced by hypochlorous acid targeting plasmalogens during neutrophil activation. This study investigated the reaction of the α-chlorinated carbon of α-ClFALD with the nucleophile, GSH. Utilizing ESI/MS/MS, the reaction product of GSH and the 16-carbon α-ClFALD, 2-chlorohexadecanal (2-ClHDA), was characterized. The resulting conjugate of 2-ClHDA and GSH (HDA-GSH) has an intact free aldehyde, and the chlorine at the α-carbon is ejected. Stable isotope-labeled [d4]HDA-GSH was synthesized, which further confirmed the structure, and was used to quantify natural α-ClFALD conjugates of GSH (FALD-GSH) using reverse-phase LC with detection by ESI/MS/MS using selected reaction monitoring. HDA-GSH is elevated in RAW 264.7 cells treated with physiologically relevant concentrations of exogenous 2-ClHDA. Furthermore, PMA-treated primary human neutrophils have elevated levels of HDA-GSH and the conjugate of 2-chlorooctadecanal (2-ClODA) and GSH (ODA-GSH), as well as elevated levels of 2-ClHDA and 2-ClODA. Production of both conjugates in PMA-stimulated neutrophils was reduced by 3-aminotriazole pretreatment, which also blocks endogenous α-ClFALD production. Additionally, plasma FALD-GSH levels were elevated in the K/BxN mouse arthritis model. Taken together, these studies demonstrate novel peptidoaldehydes derived from GSH and α-ClFALD in activated human neutrophils and in vivo in K/BxN mice. PMID:25814023

Microenvironmental characteristics important for personal exposures to aldehydes in Sacramento, CA, and Milwaukee, WI

Science.gov (United States)

Raymer, J. H.; Akland, G.; Johnson, T. R.; Long, T.; Michael, L.; Cauble, L.; McCombs, M.

Oxygenated additives in gasoline are designed to decrease the ozone-forming hydrocarbons and total air toxics, yet they can increase the emissions of aldehydes and thus increase human exposure to these toxic compounds. This paper describes a study conducted to characterize targeted aldehydes in microenvironments in Sacramento, CA, and Milwaukee, WI, and to improve our understanding of the impact of the urban environment on human exposure to air toxics. Data were obtained from microenvironmental concentration measurements, integrated, 24-h personal measurements, indoor and outdoor pollutant monitors at the participants' residences, from ambient pollutant monitors at fixed-site locations in each city, and from real-time diaries and questionnaires completed by the technicians and participants. As part of this study, a model to predict personal exposures based on individual time/activity data was developed for comparison to measured concentrations. Predicted concentrations were generally within 25% of the measured concentrations. The microenvironments that people encounter daily provide for widely varying exposures to aldehydes. The activities that occur in those microenvironments can modulate the aldehyde concentrations dramatically, especially for environments such as "indoor at home." By considering personal activity, location (microenvironment), duration in the microenvironment, and a knowledge of the general concentrations of aldehydes in the various microenvironments, a simple model can do a reasonably good job of predicting the time-averaged personal exposures to aldehydes, even in the absence of monitoring data. Although concentrations of aldehydes measured indoors at the participants' homes tracked well with personal exposure, there were instances where personal exposures and indoor concentrations differed significantly. Key to the ability to predict exposure based on time/activity data is the quality and completeness of the microenvironmental

Quantitative analysis of aldehydes in canned vegetables using static headspace-gas chromatography-mass spectrometry.

Science.gov (United States)

Serrano, María; Gallego, Mercedes; Silva, Manuel

2017-11-17

Volatile aldehydes appear in canned vegetables as constituents and some of them can also be present as disinfection by-products (DBPs) because of the contact between vegetables and treated water. This paper describes two static headspace-gas chromatography-mass spectrometry (SHS-GC-MS) methods to determine 15 aldehydes in both the solid and the liquid phases of canned vegetables. The treatment for both phases of samples was carried out simultaneously into an SHS unit, including the leaching of the aldehydes (from the vegetable), their derivatization and volatilization of the oximes formed. Detection limits were obtained within the range of 15-400μg/kg and 3-40μg/L for aldehydes in the solid and the liquid phases of the food, respectively. The relative standard deviation was lower than 7% -for the whole array of the target analytes-, the trueness evaluated by recovery experiments provided %recoveries between 89 and 99% and short- and long-term stability studies indicated there was no significant variation in relative peak areas of all aldehydes in both phases of canned vegetables after their storing at 4°C for two weeks. The study of the origin of the 15 aldehydes detected between both phases of canned vegetables showed that: i) the presence of 13 aldehydes -at average concentrations of 2.2-39μg/kg and 0.25-71μg/L for the solid and the liquid phases, respectively- is because they are natural constituents of vegetables; and ii) the presence of glyoxal and methylglyoxal -which are mainly found in the liquid phase (average values, 1.4-4.1μg/L)- is ascribed to the use of treated water, thereby being DBPs. Copyright © 2017 Elsevier B.V. All rights reserved.

Defensome against toxic diatom aldehydes in the sea urchin Paracentrotus lividus.

Directory of Open Access Journals (Sweden)

Vincenzo Marrone

Full Text Available Many diatom species produce polyunsaturated aldehydes, such as decadienal, which compromise embryonic and larval development in benthic organisms. Here newly fertilized Paracentrotus lividus sea urchins were exposed to low concentration of decadienal and the expression levels of sixteen genes, implicated in a broad range of functional responses, were followed by Real Time qPCR in order to identify potential decadienal targets. We show that at low decadienal concentrations the sea urchin Paracentrotus lividus places in motion different classes of genes to defend itself against this toxic aldehyde, activating hsp60 and two proteases, hat and BP10, at the blastula stage and hsp56 and several other genes (14-3-3ε, p38 MAPK, MTase, and GS at the prism stage. At this latter stage all genes involved in skeletogenesis (Nec, uni, SM50 and SM30 were also down-expressed, following developmental abnormalities that mainly affected skeleton morphogenesis. Moreover, sea urchin embryos treated with increasing concentrations of decadienal revealed a dose-dependent response of activated target genes. Finally, we suggest that this orchestrated defense system against decadienal represents part of the chemical defensome of P. lividus affording protection from environmental toxicants.

Mechanistic study of ruthenium (III) catalysed oxidation of L-lysine by ...

Indian Academy of Sciences (India)

Administrator

MS received 15 April 2008; revised 2 July 2008. Abstract. The kinetics of Ru(III) catalysed oxidation of L-lysine by diperiodatoargentate (III) (DPA) in alkaline medium at 298 K and a constant ionic strength of 0⋅50 mol dm. –3 was studied spectrophotometri- cally. The oxidation products are aldehyde (5-aminopentanal) and ...

NADP-Dependent Aldehyde Dehydrogenase from Archaeon Pyrobaculum sp.1860: Structural and Functional Features

Directory of Open Access Journals (Sweden)

Ekaterina Yu. Bezsudnova

2016-01-01

Full Text Available We present the functional and structural characterization of the first archaeal thermostable NADP-dependent aldehyde dehydrogenase AlDHPyr1147. In vitro, AlDHPyr1147 catalyzes the irreversible oxidation of short aliphatic aldehydes at 60–85°С, and the affinity of AlDHPyr1147 to the NADP+ at 60°С is comparable to that for mesophilic analogues at 25°С. We determined the structures of the apo form of AlDHPyr1147 (3.04 Å resolution, three binary complexes with the coenzyme (1.90, 2.06, and 2.19 Å, and the ternary complex with the coenzyme and isobutyraldehyde as a substrate (2.66 Å. The nicotinamide moiety of the coenzyme is disordered in two binary complexes, while it is ordered in the ternary complex, as well as in the binary complex obtained after additional soaking with the substrate. AlDHPyr1147 structures demonstrate the strengthening of the dimeric contact (as compared with the analogues and the concerted conformational flexibility of catalytic Cys287 and Glu253, as well as Leu254 and the nicotinamide moiety of the coenzyme. A comparison of the active sites of AlDHPyr1147 and dehydrogenases characterized earlier suggests that proton relay systems, which were previously proposed for dehydrogenases of this family, are blocked in AlDHPyr1147, and the proton release in the latter can occur through the substrate channel.

Fe-Catalyzed Oxidative Cleavage of Unsaturated Fatty Acids

NARCIS (Netherlands)

Spannring, P.

2013-01-01

The oxidative cleavage of unsaturated fatty acids into aldehydes or carboxylic acids gives access to valuable products. The products can be used as chemical building blocks, as emulsifiers or in the paint or polymer industry. Ozonolysis is applied industrially to cleave the fatty acid oleic acid

An Efficient Synthesis of 2-Substituted Benzimidazoles via Photocatalytic Condensation of o-Phenylenediamines and Aldehydes.

Science.gov (United States)

Kovvuri, Jeshma; Nagaraju, Burri; Kamal, Ahmed; Srivastava, Ajay K

2016-10-10

A photocatalytic method has been developed for the efficient synthesis of functionalized benzimidazoles. This protocol involves photocatalytic condensation of o-phenylenediamines with various aldehydes using the Rose Bengal as photocatalyst. The method was found to be general and was successfully employed for accessing pharmaceutically important benzimidazoles by the condensation of aromatic, heteroaromatic and aliphatic aldehydes with o-phenylenediamines, in good-to-excellent yields. Notably, the method was found to be effective for the condensation of less reactive heterocyclic aldehydes with o-phenylenediamines.

Aerobic, catalytic oxidation of alcohols in ionic liquids

Directory of Open Access Journals (Sweden)

Souza Roberto F. de

2006-01-01

Full Text Available An efficient and simple catalytic system based on RuCl3 dissolved in ionic liquids has been developed for the oxidation of alcohols into aldehydes and ketones under mild conditions. A new fluorinated ionic liquid, 1-n-butyl-3-methylimidazolium pentadecafluorooctanoate, was synthesized and demonstrated better performance that the other ionic liquids employed. Moreover this catalytic system utilizes molecular oxygen as an oxidizing agent, producing water as the only by-product.

Preparation of 3,5-disubstituted pyrazoles and isoxazoles from terminal alkynes, aldehydes, hydrazines, and hydroxylamine.

Science.gov (United States)

Harigae, Ryo; Moriyama, Katsuhiko; Togo, Hideo

2014-03-07

The reaction of terminal alkynes with n-BuLi, and then with aldehydes, followed by the treatment with molecular iodine, and subsequently hydrazines or hydroxylamine provided the corresponding 3,5-disubstituted pyrazoles or isoxazoles in good yields with high regioselectivity, through the formations of propargyl secondary alkoxides and α-alkynyl ketones. The present reactions are one-pot preparation of 3,5-disubstituted pyrazoles from terminal alkynes, aldehydes, molecular iodine, and hydrazines, and 3,5-disubstituted isoxazoles from terminal alkynes, aldehydes, molecular iodine, and hydroxylamine.

Identification of glutathione adducts of α-chlorofatty aldehydes produced in activated neutrophils.

Science.gov (United States)

Duerr, Mark A; Aurora, Rajeev; Ford, David A

2015-05-01

α-Chlorofatty aldehydes (α-ClFALDs) are produced by hypochlorous acid targeting plasmalogens during neutrophil activation. This study investigated the reaction of the α-chlorinated carbon of α-ClFALD with the nucleophile, GSH. Utilizing ESI/MS/MS, the reaction product of GSH and the 16-carbon α-ClFALD, 2-chlorohexadecanal (2-ClHDA), was characterized. The resulting conjugate of 2-ClHDA and GSH (HDA-GSH) has an intact free aldehyde, and the chlorine at the α-carbon is ejected. Stable isotope-labeled [d4]HDA-GSH was synthesized, which further confirmed the structure, and was used to quantify natural α-ClFALD conjugates of GSH (FALD-GSH) using reverse-phase LC with detection by ESI/MS/MS using selected reaction monitoring. HDA-GSH is elevated in RAW 264.7 cells treated with physiologically relevant concentrations of exogenous 2-ClHDA. Furthermore, PMA-treated primary human neutrophils have elevated levels of HDA-GSH and the conjugate of 2-chlorooctadecanal (2-ClODA) and GSH (ODA-GSH), as well as elevated levels of 2-ClHDA and 2-ClODA. Production of both conjugates in PMA-stimulated neutrophils was reduced by 3-aminotriazole pretreatment, which also blocks endogenous α-ClFALD production. Additionally, plasma FALD-GSH levels were elevated in the K/BxN mouse arthritis model. Taken together, these studies demonstrate novel peptidoaldehydes derived from GSH and α-ClFALD in activated human neutrophils and in vivo in K/BxN mice. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

Control of lipid oxidation at the mitochondrial level

DEFF Research Database (Denmark)

Sahlin, Kent

2009-01-01

, but the mechanisms regulating fuel preferences remain unclear. During intense exercise, oxidation of long-chain fatty acids (LCFAs) decreases, and the major control is likely to be at the mitochondrial level. Potential mitochondrial sites for control of lipid oxidation include transport of LCFAs into mitochondrial......-oxidation by redox state is thought to be an important mechanism for the slowing of lipid oxidation during intensive exercise....

Selective Oxidation of Alcohols Using Photoactive VO@g‑C3N4

Data.gov (United States)

U.S. Environmental Protection Agency — A photoactive VO@g-C3N4 catalyst has been developed for the selective oxidation of alcohols to the corresponding aldehydes and ketones. The visible light mediated...

Toxicity and detoxification of lipid-derived aldehydes in cultured retinal pigmented epithelial cells

International Nuclear Information System (INIS)

Choudhary, S.; Xiao, T.; Srivastava, S.; Zhang, W.; Chan, L.L.; Vergara, L.A.; Van Kuijk, F.J.G.M.; Ansari, N.H.

2005-01-01

Age-related macular degeneration (ARMD) is the leading cause of blindness in the developed world and yet its pathogenesis remains poorly understood. Retina has high levels of polyunsaturated fatty acids (PUFAs) and functions under conditions of oxidative stress. To investigate whether peroxidative products of PUFAs induce apoptosis in retinal pigmented epithelial (RPE) cells and possibly contribute to ARMD, human retinal pigmented epithelial cells (ARPE-19) were exposed to micromolar concentrations of H 2 O 2 , 4-hydroxynonenal (HNE) and 4-hydroxyhexenal (HHE). A concentration- and time-dependent increase in H 2 O 2 -, HNE-, and HHE-induced apoptosis was observed when monitored by quantifying DNA fragmentation as determined by ELISA, flow cytometry, and Hoechst staining. The broad-spectrum inhibitor of apoptosis Z-VAD inhibited apoptosis. Treatment of RPE cells with a thionein peptide prior to exposure to H 2 O 2 or HNE reduced the formation of protein-HNE adducts as well as alteration in mitochondrial membrane potential and apoptosis. Using 3 H-HNE, various metabolic pathways to detoxify HNE by ARPE-19 cells were studied. The metabolites were separated by HPLC and characterized by ElectroSpray Ionization-Mass Spectrometry (ESI-MS) and gas chromatography-MS. Three main metabolic routes of HNE detoxification were detected: (1) conjugation with glutathione (GSH) to form GS-HNE, catalyzed by glutathione-S-transferase (GST) (2) reduction of GS-HNE catalyzed by aldose reductase, and (3) oxidation of HNE catalyzed by aldehyde dehydrogenase (ALDH). Preventing HNE formation by a combined strategy of antioxidants, scavenging HNE by thionein peptide, and inhibiting apoptosis by caspase inhibitors may offer a potential therapy to limit retinal degeneration in ARMD

Chemical linkage to injected tissues is a distinctive property of oxidized avidin.

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Rita De Santis

Full Text Available We recently reported that the oxidized avidin, named AvidinOX®, resides for weeks within injected tissues as a consequence of the formation of Schiff's bases between its aldehyde groups and tissue protein amino groups. We also showed, in a mouse pre-clinical model, the usefulness of AvidinOX for the delivery of radiolabeled biotin to inoperable tumors. Taking into account that AvidinOX is the first oxidized glycoprotein known to chemically link to injected tissues, we tested in the mouse a panel of additional oxidized glycoproteins, with the aim of investigating the phenomenon. We produced oxidized ovalbumin and mannosylated streptavidin which share with avidin glycosylation pattern and tetrameric structure, respectively and found that neither of them linked significantly to cells in vitro nor to injected tissues in vivo, despite the presence of functional aldehyde groups. The study, extended to additional oxidized glycoproteins, showed that the in vivo chemical conjugation is a distinctive property of the oxidized avidin. Relevance of the high cationic charge of avidin into the stable linkage of AvidinOX to tissues is demonstrated as the oxidized acetylated avidin lost the property. Plasmon resonance on matrix proteins and cellular impedance analyses showed in vitro that avidin exhibits a peculiar interaction with proteins and cells that allows the formation of highly stable Schiff's bases, after oxidation.

Semi-catalytic reduction of secondary amides to imines and aldehydes.

Science.gov (United States)

Lee, Sun-Hwa; Nikonov, Georgii I

2014-06-21

Secondary amides can be reduced by silane HSiMe2Ph into imines and aldehydes by a two-stage process involving prior conversion of amides into iminoyl chlorides followed by catalytic reduction mediated by the ruthenium complex [Cp(i-Pr3P)Ru(NCCH3)2]PF6 (1). Alkyl and aryl amides bearing halogen, ketone, and ester groups were converted with moderate to good yields under mild reaction conditions to the corresponding imines and aldehydes. This procedure does not work for substrates bearing the nitro-group and fails for heteroaromatic amides. In the case of cyano substituted amides, the cyano group is reduced to imine.

Oxidized low density lipoprotein increases RANKL level in human vascular cells. Involvement of oxidative stress

Energy Technology Data Exchange (ETDEWEB)

Mazière, Cécile, E-mail: maziere.cecile@chu-amiens.fr [Biochemistry Laboratory, South Hospital University, René Laennec Avenue, Amiens 80000 (France); Salle, Valéry [Internal Medicine, North Hospital University, Place Victor Pauchet, Amiens 80000 (France); INSERM U1088 (EA 4292), SFR CAP-Santé (FED 4231), University of Picardie – Jules Verne (France); Gomila, Cathy; Mazière, Jean-Claude [Biochemistry Laboratory, South Hospital University, René Laennec Avenue, Amiens 80000 (France)

2013-10-18

Highlights: •Oxidized LDL enhances RANKL level in human smooth muscle cells. •The effect of OxLDL is mediated by the transcription factor NFAT. •UVA, H{sub 2}O{sub 2} and buthionine sulfoximine also increase RANKL level. •All these effects are observed in human fibroblasts and endothelial cells. -- Abstract: Receptor Activator of NFκB Ligand (RANKL) and its decoy receptor osteoprotegerin (OPG) have been shown to play a role not only in bone remodeling but also in inflammation, arterial calcification and atherosclerotic plaque rupture. In human smooth muscle cells, Cu{sup 2+}-oxidized LDL (CuLDL) 10–50 μg/ml increased reactive oxygen species (ROS) and RANKL level in a dose-dependent manner, whereas OPG level was not affected. The lipid extract of CuLDL reproduced the effects of the whole particle. Vivit, an inhibitor of the transcription factor NFAT, reduced the CuLDL-induced increase in RANKL, whereas PKA and NFκB inhibitors were ineffective. LDL oxidized by myeloperoxidase (MPO-LDL), or other pro-oxidant conditions such as ultraviolet A (UVA) irradiation, incubation with H{sub 2}O{sub 2} or with buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis{sub ,} also induced an oxidative stress and enhanced RANKL level. The increase in RANKL in pro-oxidant conditions was also observed in fibroblasts and endothelial cells. Since RANKL is involved in myocardial inflammation, vascular calcification and plaque rupture, this study highlights a new mechanism whereby OxLDL might, by generation of an oxidative stress, exert a deleterious effect on different cell types of the arterial wall.

Aerobic and Electrochemical Oxidations with N-Oxyl Reagents

Science.gov (United States)

Miles, Kelsey C.

Selective oxidation of organic compounds represents a significant challenge for chemical transformations. Oxidation methods that utilize nitroxyl catalysts have become increasingly attractive and include Cu/nitroxyl and nitroxyl/NO x co-catalyst systems. Electrochemical activation of nitroxyls is also well known and offers an appealing alternative to the use of chemical co-oxidants. However, academic and industrial organic synthetic communities have not widely adopted electrochemical methods. Nitroxyl catalysts facilitate effective and selective oxidation of alcohols and aldehydes to ketones and carboxylic acids. Selective benzylic, allylic, and alpha-heteroatom C-H abstraction can also be achieved with nitroxyls and provides access to oxygenated products when used in combination with molecular oxygen as a radical trap. This thesis reports various chemical and electrochemical oxidation methods that were developed using nitroxyl mediators. Chapter 1 provides a short review on practical aerobic alcohol oxidation with Cu/nitroxyl and nitroxyl/NO x systems and emphasizes the utility of bicyclic nitroxyls as co-catalysts. In Chapter 2, the combination of these bicyclic nitroxyls with NOx is explored for development of a mild oxidation of alpha-chiral aryl aldehydes and showcases a sequential asymmetric hydroformylation/oxidation method. Chapter 3 reports the synthesis and characterization of two novel Cu/bicyclic nitroxyl complexes and the electronic structure analysis of these complexes. Chapter 4 highlights the electrochemical activation of various nitroxyls and reports an in-depth study on electrochemical alcohol oxidation and compares the reactivity of nitroxyls under electrochemical or chemical activation. N-oxyls can also participate in selective C-H abstraction, and Chapter 5 reports the chemical and electrochemical activation of N-oxyls for radical-mediated C-H oxygenation of (hetero)arylmethanes. For these electrochemical transformations, the development of

Nephelauxetic and hypersensitive nature of neodymium(III) complexes with α-pyridyl-thiosemicarbazide and its furfural-2-aldehyde and thiophene-2-aldehyde derivatives

International Nuclear Information System (INIS)

Jain, C.L.; Mundley, P.N.; Khandelwal, B.E.

1986-01-01

A new series of octahedral Nd(III) complexes with recently synthesised α-pyridylthiosemicarbazide (C 6 H 8 N 4 S or 'PT'), N-(α-pyridyl)furfural-2-aldehyde-thiosemicarbazone (C 11 H 10 N 4 SO or 'PFT') and N-(α-pyridyl)thiophene-2-aldehyde-thiosemicarbazone (C 11 H 10 N 4 S 2 or 'PTT'), have been isolated and characterised on the basis of their elemental analysis, magnetic and reflectance and ir spectral data revealing 'PT' as bidentate (pyridinic-N and thioketo-S) and 'PFT' and 'PTT' as tetradentate with pyridinic-N, thioketo-S, imine-N and furfuryl-O/thiophenyl-S as donor sites. Isolation and characterisation of Nd(III) complexes with 'PT', 'PFT' and 'PTT' and their nephelauxetic and hypersensitive nature are studied in order to evaluate the stereochemistry of the ligands around Nd(III) ion. (author). 12 refs., 2 tables

Role and structural characterization of plant aldehyde dehydrogenases from family 2 and family 7

Czech Academy of Sciences Publication Activity Database

Končitíková, R.; Vigouroux, A.; Kopečná, M.; Andree, T.; Bartoš, Jan; Šebela, M.; Moréra, S.; Kopečný, D.

2015-01-01

Roč. 468, Part: 1 (2015), s. 109-123 ISSN 0264-6021 R&D Projects: GA ČR GA15-22322S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : aldehyde dehydrogenase 2 (ALDH2) * aldehyde dehydrogenase 7 (ALDH7) * benzaldehyde Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.562, year: 2015

Myeloperoxidase enzyme levels and oxidative stress in bipolar ...

African Journals Online (AJOL)

USER

2010-05-31

May 31, 2010 ... Patients with BD had significantly higher mean hsCRP levels than healthy controls. However .... MPO is a critical component of the oxidative activity of ..... nervous system vulnerability to oxidative stres (Sorce and. Krause ...

Applicability of the theory of thermodynamic similarity to predict the enthalpies of vaporization of aliphatic aldehydes

Science.gov (United States)

Esina, Z. N.; Korchuganova, M. R.

2015-06-01

The theory of thermodynamic similarity is used to predict the enthalpies of vaporization of aliphatic aldehydes. The predicted data allow us to calculate the phase diagrams of liquid-vapor equilibrium in a binary water-aliphatic aldehyde system.

Generalized Anxiety Disorder (GAD) and Comorbid Major Depression with GAD Are Characterized by Enhanced Nitro-oxidative Stress, Increased Lipid Peroxidation, and Lowered Lipid-Associated Antioxidant Defenses.

Science.gov (United States)

Maes, Michael; Bonifacio, Kamila Landucci; Morelli, Nayara Rampazzo; Vargas, Heber Odebrecht; Moreira, Estefânia Gastaldello; St Stoyanov, Drozdstoy; Barbosa, Décio Sabbatini; Carvalho, André F; Nunes, Sandra Odebrecht Vargas

2018-05-07

Accumulating evidence shows that nitro-oxidative pathways play an important role in the pathophysiology of major depressive disorder (MDD) and bipolar disorder (BD) and maybe anxiety disorders. The current study aims to examine superoxide dismutase (SOD1), catalase, lipid hydroperoxides (LOOH), nitric oxide metabolites (NOx), advanced oxidation protein products (AOPP), malondialdehyde (MDA), glutathione (GSH), paraoxonase 1 (PON1), high-density lipoprotein cholesterol (HDL), and uric acid (UA) in participants with and without generalized anxiety disorder (GAD) co-occurring or not with BD, MDD, or tobacco use disorder. Z unit-weighted composite scores were computed as indices of nitro-oxidative stress driving lipid and protein oxidation. SOD1, LOOH, NOx, and uric acid were significantly higher and HDL and PON1 significantly lower in participants with GAD than in those without GAD. GAD was more adequately predicted by increased SOD + LOOH + NOx and lowered HDL + PON1 composite scores. Composite scores of nitro-oxidative stress coupled with aldehyde and AOPP production were significantly increased in participants with comorbid GAD + MDD as compared with all other study groups, namely MDD, GAD + BD, BD, GAD, and healthy controls. In conclusion, GAD is characterized by increased nitro-oxidative stress and lipid peroxidation and lowered lipid-associated antioxidant defenses, while increased uric acid levels in GAD may protect against aldehyde production and protein oxidation. This study suggests that increased nitro-oxidative stress and especially increased SOD1 activity, NO production, and lipid peroxidation as well as lowered HDL-cholesterol and PON1 activity could be novel drug targets for GAD especially when comorbid with MDD.

Origin of low-molecular mass aldehydes as disinfection by-products in beverages.

Science.gov (United States)

Serrano, María; Gallego, Mercedes; Silva, Manuel

2017-09-01

A novel, simple and automatic method based on static headspace-gas chromatography-mass spectrometry has been developed to determine 10 low-molecular mass aldehydes that can be found in beverages, coming from the treated water used in their production. These aldehydes are the most frequently found in treated water as water disinfection by-products, so they can be used as indicators of the addition of treated water to beverages. The study covered a large number of fruit juices and soft drinks. The presence of the whole array of analytes is related to the contact with treated water during beverage production, mainly by the addition of treated water as ingredient. In particular, propionaldehyde, valeraldehyde and benzaldehyde can be used as indicators of the addition of treated water in these kinds of beverages. Among the ten aldehydes, only formaldehyde and acetaldehyde are naturally present in all kinds of fruit, and their concentrations are related to stage of the ripening of the fruit.

A catalytic reactor for the organocatalyzed enantioselective continuous flow alkylation of aldehydes.

Science.gov (United States)

Porta, Riccardo; Benaglia, Maurizio; Puglisi, Alessandra; Mandoli, Alessandro; Gualandi, Andrea; Cozzi, Pier Giorgio

2014-12-01

The use of immobilized metal-free catalysts offers the unique possibility to develop sustainable processes in flow mode. The challenging intermolecular organocatalyzed enantioselective alkylation of aldehydes was performed for the first time under continuous flow conditions. By using a packed-bed reactor filled with readily available supported enantiopure imidazolidinone, different aldehydes were treated with three distinct cationic electrophiles. In the organocatalyzed α-alkylation of aldehydes with 1,3-benzodithiolylium tetrafluoroborate, excellent enantioselectivities, in some cases even better than those obtained in the flask process (up to 95% ee at 25 °C), and high productivity (more than 3800 h(-1) ) were obtained, which thus shows that a catalytic reactor may continuously produce enantiomerically enriched compounds. Treatment of the alkylated products with Raney-nickel furnished enantiomerically enriched α-methyl derivatives, key intermediates for active pharmaceutical ingredients and natural products. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Poly(ethylene oxide) surfactant polymers

OpenAIRE

VACHEETHASANEE, KATANCHALEE; WANG, SHUWU; QIU, YONGXING; MARCHANT, ROGER E.

2004-01-01

We report on a series of structurally well-defined surfactant polymers that undergo surface-induced self-assembly on hydrophobic biomaterial surfaces. The surfactant polymers consist of a poly(vinyl amine) backbone with poly(ethylene oxide) and hexanal pendant groups. The poly(vinyl amine) (PVAm) was synthesized by hydrolysis of poly(N-vinyl formamide) following free radical polymerization of N-vinyl formamide. Hexanal and aldehyde-terminated poly (ethyleneoxide) (PEO) were simultaneously att...

Olfactory sensitivity for sperm-attractant aromatic aldehydes: a comparative study in human subjects and spider monkeys.

Science.gov (United States)

Kjeldmand, Luna; Salazar, Laura Teresa Hernandez; Laska, Matthias

2011-01-01

Using a three-alternative forced-choice ascending staircase procedure, we determined olfactory detection thresholds in 20 human subjects for seven aromatic aldehydes and compared them to those of four spider monkeys tested in parallel using an operant conditioning paradigm. With all seven odorants, both species detected concentrations lyral, and 3-phenylpropanal. No significant correlation between presence/absence of an oxygen-containing moiety attached to the benzene ring or presence/absence of an additional alkyl group next to the functional aldehyde group, and olfactory sensitivity was found in any of the species. However, the presence of a tertiary butyl group in para position (relative to the functional aldehyde group) combined with a lack of an additional alkyl group next to the functional aldehyde group may be responsible for the finding that both species were most sensitive to bourgeonal.

Identification of glutathione adducts of α-chlorofatty aldehydes produced in activated neutrophils

OpenAIRE

Duerr, Mark A.; Aurora, Rajeev; Ford, David A.

2015-01-01

α-Chlorofatty aldehydes (α-ClFALDs) are produced by hypochlorous acid targeting plasmalogens during neutrophil activation. This study investigated the reaction of the α-chlorinated carbon of α-ClFALD with the nucleophile, GSH. Utilizing ESI/MS/MS, the reaction product of GSH and the 16-carbon α-ClFALD, 2-chlorohexadecanal (2-ClHDA), was characterized. The resulting conjugate of 2-ClHDA and GSH (HDA-GSH) has an intact free aldehyde, and the chlorine at the α-carbon is ejected. Stable isotope-l...

Kinetics and mechanism of the oxidation of substituted ...

Indian Academy of Sciences (India)

Unknown

Oxidation of meta- and para-substituted benzylamines by cetyltrimethyl- ... method.12 As per this method, the aldimine is hydrolysed to the aldehyde and then ... reactions were studied at constant temperature (± 0⋅1 K) and were followed by .... electronic interaction between the substituent and the reaction centre, (σ+–σ0) is ...

Selective oxidation of alcohols using photoactive VO@g-C3N4.

Science.gov (United States)

A photoactive VO@g-C3N4 catalyst has been developed for the selective oxidation of alcohols to the corresponding aldehydes and ketones. The visible light mediated activity of the catalyst could be attributed to photoactive graphitic carbon nitrides surface.

Graphene oxide decorated electrospun gelatin nanofibers: Fabrication, properties and applications

Energy Technology Data Exchange (ETDEWEB)

Jalaja, K. [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram, Kerala 695 547 (India); Sreehari, V.S. [Indian Institute of Science Education and Research Bhopal, Bhauri, Madhya Pradesh 462066 (India); Kumar, P.R. Anil [Tissue culture laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Thiruvananthapuram, Kerala 695 012 (India); Nirmala, R. James, E-mail: nirmala@iist.ac.in [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram, Kerala 695 547 (India)

2016-07-01

Gelatin nanofiber fabricated by electrospinning process is found to mimic the complex structural and functional properties of natural extracellular matrix for tissue regeneration. In order to improve the physico-chemical and biological properties of the nanofibers, graphene oxide is incorporated in the gelatin to form graphene oxide decorated gelatin nanofibers. The current research effort is focussed on the fabrication and evaluation of physico-chemical and biological properties of graphene oxide-gelatin composite nanofibers. The presence of graphene oxide in the nanofibers was established by transmission electron microscopy (TEM). We report the effect of incorporation of graphene oxide on the mechanical, thermal and biological performance of the gelatin nanofibers. The tensile strength of gelatin nanofibers was increased from 8.29 ± 0.53 MPa to 21 ± 2.03 MPa after the incorporation of GO. In order to improve the water resistance of nanofibers, natural based cross-linking agent, namely, dextran aldehyde was employed. The cross-linked composite nanofibers showed further increase in the tensile strength up to 56.4 ± 2.03 MPa. Graphene oxide incorporated gelatin nanofibers are evaluated for bacterial activity against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria and cyto compatibility using mouse fibroblast cells (L-929 cells). The results indicate that the graphene oxide incorporated gelatin nanofibers do not prevent bacterial growth, nevertheless support the L-929 cell adhesion and proliferation. - Highlights: • Graphene oxide nano reinforced gelatin nanofibers are fabricated by electrospinning. • Graphene oxide (0.5%) loading resulted in increased tensile strength. • GO/gelatin nanofibers are cross-linked with dextran aldehyde. • Composite nanofibers favoured adhesion of L-929 cells. • GO/gelatin mats do not prevent bacterial growth.

Silver-catalyzed synthesis of amides from amines and aldehydes

Science.gov (United States)

Madix, Robert J; Zhou, Ling; Xu, Bingjun; Friend, Cynthia M; Freyschlag, Cassandra G

2014-11-18

The invention provides a method for producing amides via the reaction of aldehydes and amines with oxygen adsorbed on a metallic silver or silver alloy catalyst. An exemplary reaction is shown in Scheme 1: (I), (II), (III). ##STR00001##

Quantitative analysis by GC-MS/MS of 18 aroma compounds related to oxidative off-flavor in wines.

Science.gov (United States)

Mayr, Christine M; Capone, Dimitra L; Pardon, Kevin H; Black, Cory A; Pomeroy, Damian; Francis, I Leigh

2015-04-08

A quantitation method for 18 aroma compounds reported to contribute to "oxidative" flavor in wines was developed. The method allows quantitation of the (E)-2-alkenals ((E)-2-hexenal, (E)-2-heptenal, (E)-2-octenal, and (E)-2-nonenal), various Strecker aldehydes (methional, 2-phenylacetaldehyde, 3-methylbutanal, and 2-methylpropanal), aldehydes (furfural, 5-methylfurfural, hexanal, and benzaldehyde), furans (sotolon, furaneol, and homofuraneol), as well as alcohols (methionol, eugenol, and maltol) in the same analysis. The aldehydes were determined after derivatization directly in the wine with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride; the formed oximes along with the underivatized aroma compounds were isolated by solid-phase extraction and analyzed by means of GC-MS/MS. The method was used to investigate the effect of different closures (synthetic closures, natural corks, and screw cap) on the formation of oxidation-related compounds in 14 year old white wine. Results showed a significant increase in the concentration of some of the monitored compounds in the wine, particularly methional, 2-phenylacetaldehyde, and 3-methylbutanal.

Aldehyde-functionalized chitosan-montmorillonite films as dynamically-assembled, switchable-chemical release bioplastics.

Science.gov (United States)

Chabbi, Jamal; Jennah, Oumayma; Katir, Nadia; Lahcini, Mohamed; Bousmina, Mosto; El Kadib, Abdelkrim

2018-03-01

Temporal release of synergistic and/or complementary chemicals (e.g.: drugs) is recognized as extremely challenging because of their frequently intertwined kinetic delivery and presently, straightforward concepts enabling to circumvent this bottleneck are missing in the open literature. In this framework, we report herein on aldehyde-functionalized, transparent and flexible chitosan-montmorillonite hybrid films that act as a new generation of eco-friendly, controlled-chemical release bioplastics. These dynamically-assembled nanomaterials are designed by a ternary assembly from biowaste derived chitin biopolymer, aromatic aldehydes and layered clay nanoparticles. On the basis of their geometrical and conformational properties, the oxygenated groups on the grafted aromatics interact preferentially with either the base Schiff belonging to the carbohydrate (via intramolecular CNHO-Ar known as "imine clip") or with the hydroxyl groups belonging to the clay surface (via intermolecular Si-OHO-Ar). The exfoliated clay nanoparticles within the carbohydrate polymer enables either accelerating or slowing down of the imine (CN) hydrolysis depending on the interaction of the conjugated aromatics. This provides the driving force for fine tuning host-guest interactions at the molecular level and constitutes an entry toward subtle discrimination of different chemicals (e.g. complementary fertilizers, synergistic drugs) during their sequential release. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ytterbia doped nickel–manganese mixed oxide catalysts for liquid phase oxidation of benzyl alcohol

Directory of Open Access Journals (Sweden)

S.S.P. Sultana

2017-11-01

Full Text Available Nickel–manganese mixed oxides doped with 1, 3, 5 mol% ytterbia have been prepared by co-precipitation method and used in the catalytic oxidation of benzyl alcohol. Catalytic activity of these oxides calcined at 400 °C and 500 °C was studied for selective oxidation of benzyl alcohol to the corresponding aldehyde using molecular oxygen as an oxidizing agent. The results showed that thermally stable 5 mol% ytterbia doped nickel–manganese oxide [Yb2O3-(5%-Ni6MnO8] exhibited highest catalytic performance when it was calcined at 400 °C. A 100% conversion of the benzyl alcohol was achieved with >99% selectivity to benzaldehyde within a reaction period of 5 h at 100 °C. The mixed oxide prepared has been characterized by scanning election microscopy (SEM and energy dispersive X-ray analysis (EDXA, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR, thermogravimetric analysis (TGA, Brunauer–Emmett–Teller (BET and temperature programed reduction (H2-TPR.

Cytochrome P450BM-3 reduces aldehydes to alcohols through a direct hydride transfer

International Nuclear Information System (INIS)

Kaspera, Rüdiger; Sahele, Tariku; Lakatos, Kyle; Totah, Rheem A.

2012-01-01

Highlights: ► Cytochrome P450BM-3 reduced aldehydes to alcohols efficiently (k cat ∼ 25 min −1 ). ► Reduction is a direct hydride transfer from R-NADP 2 H to the carbonyl moiety. ► P450 domain variants enhance reduction through potential allosteric/redox interactions. ► Novel reaction will have implications for metabolism of xenobiotics. -- Abstract: Cytochrome P450BM-3 catalyzed the reduction of lipophilic aldehydes to alcohols efficiently. A k cat of ∼25 min −1 was obtained for the reduction of methoxy benzaldehyde with wild type P450BM-3 protein which was higher than in the isolated reductase domain (BMR) alone and increased in specific P450-domain variants. The reduction was caused by a direct hydride transfer from preferentially R-NADP 2 H to the carbonyl moiety of the substrate. Weak substrate-P450-binding of the aldehyde, turnover with the reductase domain alone, a deuterium incorporation in the product from NADP 2 H but not D 2 O, and no inhibition by imidazole suggests the reductase domain of P450BM-3 as the potential catalytic site. However, increased aldehyde reduction by P450 domain variants (P450BM-3 F87A T268A) may involve allosteric or redox mechanistic interactions between heme and reductase domains. This is a novel reduction of aldehydes by P450BM-3 involving a direct hydride transfer and could have implications for the metabolism of endogenous substrates or xenobiotics.

Flavour release of aldehydes and diacetyl in oil/water systems

DEFF Research Database (Denmark)

Haahr, Anne-Mette; Bredie, W. L. P.; Stahnke, Louise Heller

2000-01-01

from the pure oil. The release over time for diacetyl and (E,E)-2,4-hexadienal showed a linear relationship in all systems. The other compounds followed an exponential relationship between the time and the fraction released in the aqueous systems. It was demonstrated that the release of the volatile...... compounds was dependent on the chain length, the degree of unsaturation as well as the characteristics of the model system. (C) 2000 Elsevier Science Ltd. All rights reserved.......The concentration- and time-dependent release of three C-6-aldehydes, six C-9-aldehydes and diacetyl was studied in model systems. The systems were water, rapeseed oil and oil-in-water emulsions. Dynamic headspace sampling was used to collect the volatile compounds. In the concentration...

An Improved Protocol for the Aldehyde Olefination Reaction Using (bmim ( as Reaction Medium

Directory of Open Access Journals (Sweden)

Vivek Srivastava

2013-01-01

Full Text Available [Ru(CODCl2]/CuCl2·2H2O/LiCl catalytic system works efficiently in ionic liquid media for aldehyde olefination reaction. It offers good yield and selectivity with the added advantage of 5 times recyclability for [Ru(CODCl2] /CuCl2·2H2O/LiCl catalytic system. We also successfully reduced the reaction time from 12 hours to 9 hours for the aldehyde olefination reaction.

Aldehyde Dehydrogenase 1 and Raf Kinase Inhibitor Protein ...

African Journals Online (AJOL)

Aldehyde Dehydrogenase 1 and Raf Kinase Inhibitor Protein Expression Defines the Proliferative Nature of Cervical Cancer Stem Cells. ... of cervical cancer stem cells and also to validate them in initial and advanced stages of cervical cancer. Keywords: Cervical cancer, ALDH1, BALB/c-nu/nu, HeLa cells, RKIP, Sox2 ...

Effect of variable power levels on the yield of total aerosol mass and formation of aldehydes in e-cigarette aerosols.

Science.gov (United States)

Gillman, I G; Kistler, K A; Stewart, E W; Paolantonio, A R

2016-03-01

The study objective was to determine the effect of variable power applied to the atomizer of refillable tank based e-cigarette (EC) devices. Five different devices were evaluated, each at four power levels. Aerosol yield results are reported for each set of 25 EC puffs, as mass/puff, and normalized for the power applied to the coil, in mass/watt. The range of aerosol produced on a per puff basis ranged from 1.5 to 28 mg, and, normalized for power applied to the coil, ranged from 0.27 to 1.1 mg/watt. Aerosol samples were also analyzed for the production of formaldehyde, acetaldehyde, and acrolein, as DNPH derivatives, at each power level. When reported on mass basis, three of the devices showed an increase in total aldehyde yield with increasing power applied to the coil, while two of the devices showed the opposite trend. The mass of formaldehyde, acetaldehyde, and acrolein produced per gram of total aerosol produced ranged from 0.01 to 7.3 mg/g, 0.006 to 5.8 mg/g, and acrolein from EC aerosols from specific devices, and were compared to estimated exposure from consumption of cigarettes, to occupational and workplace limits, and to previously reported results from other researchers. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Aldehydes react with scribed silicon to form alkyl monolayers Characterization by ToF-SIMS suggests an even-odd effect

International Nuclear Information System (INIS)

Lua, Y.-Y.; Fillmore, W. Jonathan J.; Linford, Matthew R.

2004-01-01

Alkyl monolayers are formed when silicon is chemomechanically scribed in the presence of aldehydes (from butanal to nonanal). X-ray photoelectron spectroscopy (XPS), wetting, and time-of-flight secondary ion mass spectrometry (ToF-SIMS) suggest increasingly thick and hydrophobic monolayers with increasing aldehyde chain length. Superimposed on the general trend of stronger ToF-SIMS signals for hydrocarbon fragments from longer aldehyde precursors is an even-odd effect. This effect is most pronounced for smaller (one- and two-carbon) hydrocarbon fragments and for monolayers prepared with shorter aldehyde precursors. This is the first time than an even-odd effect has been demonstrated for monolayers on scribed silicon

Aldehydes react with scribed silicon to form alkyl monolayers Characterization by ToF-SIMS suggests an even-odd effect

Energy Technology Data Exchange (ETDEWEB)

Lua, Y.-Y.; Fillmore, W. Jonathan J.; Linford, Matthew R

2004-06-15

Alkyl monolayers are formed when silicon is chemomechanically scribed in the presence of aldehydes (from butanal to nonanal). X-ray photoelectron spectroscopy (XPS), wetting, and time-of-flight secondary ion mass spectrometry (ToF-SIMS) suggest increasingly thick and hydrophobic monolayers with increasing aldehyde chain length. Superimposed on the general trend of stronger ToF-SIMS signals for hydrocarbon fragments from longer aldehyde precursors is an even-odd effect. This effect is most pronounced for smaller (one- and two-carbon) hydrocarbon fragments and for monolayers prepared with shorter aldehyde precursors. This is the first time than an even-odd effect has been demonstrated for monolayers on scribed silicon.

A new method for the chemoselective reduction of aldehydes and ...

Indian Academy of Sciences (India)

Department of Chemistry, Akdeniz University, 07058, Antalya, Turkey e-mail: ... Kinetics of reduction of aldehydes and ketones to corresponding alcohols were also examined and .... hol and unreducted ketone remain in organic phase. The.

The Intramolecular Diels–Alder Reaction of Tryptamine-Derived Zincke Aldehydes Is a Stepwise Process

OpenAIRE

Pham, Hung V.; Martin, David B. C.; Vanderwal, Christopher D.; Houk, K. N.

2012-01-01

Computational studies show that the base-mediated intramolecular Diels–Alder of tryptamine-derived Zincke aldehydes, used as a key step in the synthesis of the Strychnos alkaloids norfluorocurarine and strychnine, proceeds via a stepwise pathway. The experimentally determined importance of a potassium counterion in the base is explained by its ability to preorganize the Zincke aldehyde diene in an s-cis conformation suitable to bicyclization. Computation also supports the thermodynamic import...

Cytochrome P450BM-3 reduces aldehydes to alcohols through a direct hydride transfer

Energy Technology Data Exchange (ETDEWEB)

Kaspera, Ruediger; Sahele, Tariku; Lakatos, Kyle [Department of Medicinal Chemistry, University of Washington, Box 357610, Seattle, WA 98195-7610 (United States); Totah, Rheem A., E-mail: rtotah@u.washington.edu [Department of Medicinal Chemistry, University of Washington, Box 357610, Seattle, WA 98195-7610 (United States)

2012-02-17

Highlights: Black-Right-Pointing-Pointer Cytochrome P450BM-3 reduced aldehydes to alcohols efficiently (k{sub cat} {approx} 25 min{sup -1}). Black-Right-Pointing-Pointer Reduction is a direct hydride transfer from R-NADP{sup 2}H to the carbonyl moiety. Black-Right-Pointing-Pointer P450 domain variants enhance reduction through potential allosteric/redox interactions. Black-Right-Pointing-Pointer Novel reaction will have implications for metabolism of xenobiotics. -- Abstract: Cytochrome P450BM-3 catalyzed the reduction of lipophilic aldehydes to alcohols efficiently. A k{sub cat} of {approx}25 min{sup -1} was obtained for the reduction of methoxy benzaldehyde with wild type P450BM-3 protein which was higher than in the isolated reductase domain (BMR) alone and increased in specific P450-domain variants. The reduction was caused by a direct hydride transfer from preferentially R-NADP{sup 2}H to the carbonyl moiety of the substrate. Weak substrate-P450-binding of the aldehyde, turnover with the reductase domain alone, a deuterium incorporation in the product from NADP{sup 2}H but not D{sub 2}O, and no inhibition by imidazole suggests the reductase domain of P450BM-3 as the potential catalytic site. However, increased aldehyde reduction by P450 domain variants (P450BM-3 F87A T268A) may involve allosteric or redox mechanistic interactions between heme and reductase domains. This is a novel reduction of aldehydes by P450BM-3 involving a direct hydride transfer and could have implications for the metabolism of endogenous substrates or xenobiotics.

The Reduction of Nitriles to Aldehydes: Applications of Raney Nickel ...

African Journals Online (AJOL)

NJD

The selective reduction of a nitrile to an aldehyde, especially when the substrate ..... prelude to reductive amination chemistry was thwarted by a rapid aldol ... and allowed the direct incorporation of the α-methylbenzylamine chiral auxiliary.

OXYGEN 18 EXCHANGE REACTIONS OF ALDEHYDES AND KETONES

Energy Technology Data Exchange (ETDEWEB)

Byrn, Marianne; Calvin, Melvin

1965-12-01

Using infra-red spectroscopy, the equilibrium exchange times have been determined for a series of ketones, aromatic aldehydes, and {beta}-ketoesters reacting with oxygen 18 enriched water. These exchange times have been evaluated in terms of steric and electronic considerations, and applied to a discussion of the exchange times of chlorophylls a and b and chlorophyll derivatives.

Thimerosal-Derived Ethylmercury Is a Mitochondrial Toxin in Human Astrocytes: Possible Role of Fenton Chemistry in the Oxidation and Breakage of mtDNA

Directory of Open Access Journals (Sweden)

Martyn A. Sharpe

2012-01-01

Full Text Available Thimerosal generates ethylmercury in aqueous solution and is widely used as preservative. We have investigated the toxicology of Thimerosal in normal human astrocytes, paying particular attention to mitochondrial function and the generation of specific oxidants. We find that ethylmercury not only inhibits mitochondrial respiration leading to a drop in the steady state membrane potential, but also concurrent with these phenomena increases the formation of superoxide, hydrogen peroxide, and Fenton/Haber-Weiss generated hydroxyl radical. These oxidants increase the levels of cellular aldehyde/ketones. Additionally, we find a five-fold increase in the levels of oxidant damaged mitochondrial DNA bases and increases in the levels of mtDNA nicks and blunt-ended breaks. Highly damaged mitochondria are characterized by having very low membrane potentials, increased superoxide/hydrogen peroxide production, and extensively damaged mtDNA and proteins. These mitochondria appear to have undergone a permeability transition, an observation supported by the five-fold increase in Caspase-3 activity observed after Thimerosal treatment.

Kinetic mechanism of an aldehyde reductase of Saccharomyces cerevisiae that relieves toxicity of furfural and 5-hydroxymethylfurfural

Science.gov (United States)

An effective means of relieving the toxicity of furan aldehydes, furfural (FFA) and 5-hydroxymethylfurfural (HMF), on fermenting organisms is essential for achieving efficient fermentation of lignocellulosic biomass to ethanol and other products. Ari1p, an aldehyde reductase from Saccharomyces cerev...

Peptide aldehyde inhibitors of bacterial peptide deformylases.

Science.gov (United States)

Durand, D J; Gordon Green, B; O'Connell, J F; Grant, S K

1999-07-15

Bacterial peptide deformylases (PDF, EC 3.5.1.27) are metalloenzymes that cleave the N-formyl groups from N-blocked methionine polypeptides. Peptide aldehydes containing a methional or norleucinal inhibited recombinant peptide deformylase from gram-negative Escherichia coli and gram-positive Bacillus subtilis. The most potent inhibitor was calpeptin, N-CBZ-Leu-norleucinal, which was a competitive inhibitor of the zinc-containing metalloenzymes, E. coli and B. subtilis PDF with Ki values of 26.0 and 55.6 microM, respectively. Cobalt-substituted E. coli and B. subtilis deformylases were also inhibited by these aldehydes with Ki values for calpeptin of 9.5 and 12.4 microM, respectively. Distinct spectral changes were observed upon binding of calpeptin to the Co(II)-deformylases, consistent with the noncovalent binding of the inhibitor rather than the formation of a covalent complex. In contrast, the chelator 1,10-phenanthroline caused the time-dependent inhibition of B. subtilis Co(II)-PDF activity with the loss of the active site metal. The fact that calpeptin was nearly equipotent against deformylases from both gram-negative and gram-positive bacterial sources lends further support to the idea that a single deformylase inhibitor might have broad-spectrum antibacterial activity. Copyright 1999 Academic Press.

Anaerobic ammonium oxidation mediated by Mn-oxides: from sediment to strain level.

Science.gov (United States)

Javanaud, Cedric; Michotey, Valerie; Guasco, Sophie; Garcia, Nicole; Anschutz, Pierre; Canton, Mathieu; Bonin, Patricia

2011-11-01

Nitrite and (29)N(2) productions in slurry incubations of anaerobically sediment after (15)NO(3) or (15)NH(4) labelling in the presence of Mn-oxides suggested that anaerobic Mn-oxides mediated nitrification coupled with denitrification in muddy intertidal sediments of Arcachon Bay (SW Atlantic French coast). From this sediment, bacterial strains were isolated and physiologically characterized in terms of Mn-oxides and nitrate reduction as well as potential anaerobic nitrification. One of the isolated strain, identified as Marinobacter daepoensis strain M4AY14, was a denitrifier. Nitrous oxide production by this strain was demonstrated in the absence of nitrate and with Mn-oxides and NH(4) amendment, giving indirect proof of anaerobic nitrate or nitrite production. Anaerobic Mn-oxide-mediated nitrification was confirmed by (29)N(2) production in the presence of (15)NO(3) and (14)NH(4) under denitrifying conditions. Anaerobic nitrification by M4AY14 seemed to occur only in the absence of nitrate, or at nitrate levels lower than that of Mn-oxides. Most of the other isolates were affiliated with the Shewanella genus and were able to use both nitrate and Mn-oxides as electron acceptors. When both electron acceptors were present, whatever their concentrations, nitrate and Mn-oxide reduction co-occurred. These data indicate that bacterial Mn-oxide reduction could be an important process in marine sediments with low oxygen concentrations, and demonstrate for the first time the role of bacteria in anaerobic Mn-mediated nitrification. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

The relationship between leptin level and oxidative status parameters in hemodialysis patients.

Science.gov (United States)

Horoz, Mehmet; Aslan, Mehmet; Koylu, Ahmet O; Bolukbas, Cengiz; Bolukbas, Filiz F; Selek, Sahbettin; Erel, Ozcan

2009-01-01

Both serum leptin level and oxidative stress are increased in hemodialysis (HD) patients. In the present study, we aimed to investigate whether there is association between oxidative status and leptin level in HD patients. Thirty-five HD patients and 25 healthy controls were enrolled in the present study. Serum leptin level, total peroxide (TP) level, total antioxidant capacity (TAC), and oxidative stress index (OSI) were determined. Serum leptin level, TP level, and OSI were significantly higher in HD patients than controls (all P < 0.001) while TAC was lower (P < 0.001). In HD patients, serum leptin level was significantly correlated with TP level and OSI (r = 0.372, P < 0.001 and r = 0.409, P < 0.001, respectively). The correlation of serum leptin level with TP level and OSI remained statistically significant after adjusting for age, gender, and body-fat percentage (r = 0.446, P < 0.001 and r = 0.463, P < 0.001, respectively). Hyperleptinemia seems to be associated with increased oxidative stress in HD patients, and this association may provide better understanding about the disorders related to either elevated serum leptin levels and/or increased oxidative stress in HD patients.

Cloning and heterologous expression of two aryl-aldehyde dehydrogenases from the white-rot basidiomycete Phanerochaete chrysosporium

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Tomofumi [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Fukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu-shi, Fukuoka 818-0135 (Japan); Ichinose, Hirofumi [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Wariishi, Hiroyuki, E-mail: hirowari@agr.kyushu-u.ac.jp [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Bio-Architecture Center, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Innovation Center for Medical Redox Navigation, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)

2010-04-09

We identified two aryl-aldehyde dehydrogenase proteins (PcALDH1 and PcALDH2) from the white-rot basidiomycete Phanerochaete chrysosporium. Both PcALDHs were translationally up-regulated in response to exogenous addition of vanillin, one of the key aromatic compounds in the pathway of lignin degradation by basidiomycetes. To clarify the catalytic functions of PcALDHs, we isolated full-length cDNAs encoding these proteins and heterologously expressed the recombinant enzymes using a pET/Escherichia coli system. The open reading frames of both PcALDH1 and PcALDH2 consisted of 1503 nucleotides. The deduced amino acid sequences of both proteins showed high homologies with aryl-aldehyde dehydrogenases from other organisms and contained ten conserved domains of ALDHs. Moreover, a novel glycine-rich motif 'GxGxxxG' was located at the NAD{sup +}-binding site. The recombinant PcALDHs catalyzed dehydrogenation reactions of several aryl-aldehyde compounds, including vanillin, to their corresponding aromatic acids. These results strongly suggested that PcALDHs metabolize aryl-aldehyde compounds generated during fungal degradation of lignin and various aromatic xenobiotics.

Cloning and heterologous expression of two aryl-aldehyde dehydrogenases from the white-rot basidiomycete Phanerochaete chrysosporium

International Nuclear Information System (INIS)

Nakamura, Tomofumi; Ichinose, Hirofumi; Wariishi, Hiroyuki

2010-01-01

We identified two aryl-aldehyde dehydrogenase proteins (PcALDH1 and PcALDH2) from the white-rot basidiomycete Phanerochaete chrysosporium. Both PcALDHs were translationally up-regulated in response to exogenous addition of vanillin, one of the key aromatic compounds in the pathway of lignin degradation by basidiomycetes. To clarify the catalytic functions of PcALDHs, we isolated full-length cDNAs encoding these proteins and heterologously expressed the recombinant enzymes using a pET/Escherichia coli system. The open reading frames of both PcALDH1 and PcALDH2 consisted of 1503 nucleotides. The deduced amino acid sequences of both proteins showed high homologies with aryl-aldehyde dehydrogenases from other organisms and contained ten conserved domains of ALDHs. Moreover, a novel glycine-rich motif 'GxGxxxG' was located at the NAD + -binding site. The recombinant PcALDHs catalyzed dehydrogenation reactions of several aryl-aldehyde compounds, including vanillin, to their corresponding aromatic acids. These results strongly suggested that PcALDHs metabolize aryl-aldehyde compounds generated during fungal degradation of lignin and various aromatic xenobiotics.

Homogeneous catalytic hydrogenation of bio-oil and related model aldehydes with RuCl{sub 2}(PPh{sub 3}){sub 3}

Energy Technology Data Exchange (ETDEWEB)

Huang, F.; Li, W.; Lu, Q.; Zhu, X. [Anhui Province Key Laboratory of Biomass Clean Energy, University of Science and Technology of China, Hefei (China)

2010-12-15

A homogeneous RuCl{sub 2}(PPh{sub 3}){sub 3} catalyst was prepared for the hydrogenation of bio-oil to improve its stability and fuel quality. Experiments were first performed on three model aldehydes of acetaldehyde, furfural and vanillin selected to represent the linear aldehydes, oxygen heterocyclic aldehydes and aromatic aldehydes in bio-oil. The results demonstrated the high hydrogenation capability of this homogeneous catalyst under mild conditions (55-90 C, 1.3-3.3 MPa). The highest conversion of the three model aldehydes was over 90 %. Furfural and acetaldehyde were singly converted to furfuryl alcohol and ethanol after hydrogenation, while vanillin was mainly converted to vanillin alcohol, together with a small amount of 2-methoxy-4-methylphenol and 2-methoxyphenol. Further experiments were conducted on a bio-oil fraction extracted by ethyl acetate and on the whole bio-oil at 70 C and 3.3 MPa. Most of the aldehydes were transformed to the corresponding alcohols, and some ketones and compounds with C-C double bond were converted to more stable compounds. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Plant volatile aldehydes as natural insecticides against stored-product beetles.

Science.gov (United States)

Hubert, Jan; Münzbergová, Zuzana; Santino, Angelo

2008-01-01

Infestation by stored-product pests causes serious losses in food and feed commodities. Among possible strategies against these pests, which aim to reduce the use of synthetic insecticides, including fumigants, natural insecticides produced by plants represent one of the most promising approaches for their ecochemical control. Three six-carbon and nine-carbon aldehydes, natural plant volatiles produced by the plant lipoxygenase pathway, were tested for their insecticidal activity against five species of stored-product beetles in feeding, fumigation and combined bioassays. The compounds (2E,6Z)-nonadienal, (2E)-nonenal and (2E)-hexenal were incorporated into feeding discs in feeding bioassays or evaporated from filter paper in closed glass chambers in fumigation tests. Beetle sensitivity to aldehydes differed according to the different treatments. The highest activity was obtained by (2E)-hexenal in fumigation tests, with the LC(50) ranging from 4 to 26 mg L(-1), while (2E, 6Z)-nonadienal was the most effective in feeding tests, giving LD(50)s ranging from 0.44 to 2.76 mg g(-1) when applied to feeding discs. Fumigation tests in the presence of wheat grains confirmed that (2E)-hexenal was the most effective compound, with a calculated LC(99) ranging from 33 to 166 mg L(-1). The results of both feeding and fumigation tests indicated that natural plant aldehydes are potential candidates to control stored-product beetles.

Copper(II)/amine synergistically catalyzed enantioselective alkylation of cyclic N-acyl hemiaminals with aldehydes.

Science.gov (United States)

Sun, Shutao; Mao, Ying; Lou, Hongxiang; Liu, Lei

2015-07-07

The first catalytic asymmetric alkylation of N-acyl quinoliniums with aldehydes has been described. A copper/amine synergistic catalytic system has been developed, allowing the addition of functionalized aldehydes to a wide range of electronically varied N-acyl quinoliniums in good yields with excellent enantiocontrol. The synergistic catalytic system was also effective for N-acyl dihydroisoquinoliniums and β-caboliniums, demonstrating the general applicability of the protocol in the enantioselective alkylation of diverse cyclic N-acyl hemiaminals.

Impact of aerobic exercise on cognitive impairment and oxidative stress markers in methamphetamine-dependent patients.

Science.gov (United States)

Zhang, Kai; Zhang, Qiaoyang; Jiang, Haifeng; Du, Jiang; Zhou, Chenglin; Yu, Shunying; Hashimoto, Kenji; Zhao, Min

2018-03-17

This study aimed to investigate whether 12-week moderate-intensity aerobic exercise has beneficial effects on oxidative stress markers in blood and on cognitive functions in patients who have methamphetamine dependence. Serum levels of oxidative stress markers, including total anti-oxidation capability, super oxide dismutase (SOD), catalase (CAT), and methane dicarboxylic aldehyde (MDA), were measured at baseline (all participants) and the 12-week follow-up (methamphetamine-dependent patients). Serum levels of CAT and MDA in methamphetamine-dependent patients (n = 68) were higher than those in healthy controls (n = 35) at baseline. Furthermore, the international shopping list (ISL) task scores of methamphetamine-dependent patients were significantly lower than those of the controls, indicating verbal memory deficits in methamphetamine-dependent patients. Although there were no significant interactions for all cognitive function scores, aerobic exercise improved the processing speed in methamphetamine-dependent patients. Of interest, aerobic exercise significantly attenuated a spontaneous increase in serum MDA levels in methamphetamine-dependent patients after 12-weeks of abstinence. In conclusion, this study showed that methamphetamine-dependent patients with verbal learning and memory deficits have higher serum levels of MDA, and that a 12-week aerobic exercise program may have beneficial effects on the processing speed as well as blood lipid peroxidation in methamphetamine-dependent patients. Copyright © 2018. Published by Elsevier B.V.

Changes in nonpolar aldehydes in bean cotyledons during ageing

Czech Academy of Sciences Publication Activity Database

Wilhelmová, Naděžda; Domingues, P.; Srbová, M.; Fuksová, H.; Wilhelm, J.

2006-01-01

Roč. 50, č. 4 (2006), s. 559-564 ISSN 0006-3134 R&D Projects: GA ČR GA522/03/0312 Institutional research plan: CEZ:AV0Z50380511 Keywords : Ageing * aldehydes * lipid peroxidation * lipofuscin-like pigments (LFP) Subject RIV: CE - Biochemistry Impact factor: 1.198, year: 2006

Effects of light and copper ions on volatile aldehydes of milk and milk fractions

Energy Technology Data Exchange (ETDEWEB)

Jeno, W.; Bassette, R.; Crang, R.E.

1988-09-01

Raw, laboratory-pasteurized and plant-pasteurized homogenized milks were exposed to copper ions (5 ppm), to sunlight or fluorescent light and the effects determined on the composition of volatile aldehydes. The greatest change due to copper treatment was an increase in n-hexanal; acetaldehyde showed the least response in each of the sources of milk. The responses were similar from all three sources of milk with laboratory-pasteurized milk samples showing the greatest responses for each aldehyde analyzed. Similar milk samples exposed to sunlight also showed an increase in volatile aldehydes from all milk sources but with the greatest response being acetaldehyde and n-pentanal components. The milk fraction most susceptible to changes in the presence of light was neutralized whey, whereas resuspended cream was most susceptible to copper exposure. Overall, dialyzed whey appeared to be influenced more than other milk fractions by both light and copper ions.

Nitrous oxide levels in operating and recovery rooms of Iranian hospitals.

Science.gov (United States)

Maroufi, Sh Sadigh; Gharavi, Mj; Behnam, M; Samadikuchaksaraei, A

2011-01-01

Nitrous oxide (N(2)O) is the oldest anesthetic in routine clinical use and its occupational exposure is under regulation by many countries. As studies are lacking to demonstrate the status of nitrous oxide levels in operating and recovery rooms of Iranian hospitals, we aimed to study its level in teaching hospitals of Tehran University of Medical Sciences. During a 6-month period, we have measured the shift-long time weighted average concentration of N(2)O in 43 operating and 12 recovery rooms of teaching hospitals of Tehran University of Medical Sciences. The results show that the level of nitrous oxide in all hospitals is higher than the limits set by different countries and anesthetists are at higher risk of exposure. In addition, it was shown that installation of air ventilation could reduce not only the overall exposure level, but also the level of exposure of anesthetists in comparison with other personnel. The high nitrous oxide level in Iranian hospitals necessitates improvement of waste gas evacuation systems and regular monitoring to bring the concentration of this gas into the safe level.

Strecker Aldehyde Formation in Wine: New Insights into the Role of Gallic Acid, Glucose, and Metals in Phenylacetaldehyde Formation.

Science.gov (United States)

Monforte, Ana Rita; Martins, Sara I F S; Silva Ferreira, Antonio C

2018-03-14

Strecker degradation (SD) leading to the formation of phenylacetaldehyde (PA) was studied in wine systems. New insights were gained by using two full factorial designs focusing on the effects of (1) pH and (2) temperature. In each design of experiments (DoE) three factors, glucose, gallic acid, and metals at two levels (present or absence), were varied while phenylalanine was kept constant. The obtained results gave a clear indication, with statistical significance, that in wine conditions, the SD occurs in the presence of metals preferentially via the phenolic oxidation independent of the temperature (40 or 80 °C). The reaction of the amino acid with the o-quinone formed by the oxidation of the gallic acid seems to be favored when compared with the SD promoted by the reaction with α-dicarbonyls formed by MR between glucose and phenylalanine. In fact, kinetics results showed that the presence of glucose had an inhibitory effect on PA rate of formation. PA formation was 4 times higher in the control wine when compared to the same wine with 10 g/L glucose added. By gallic acid quinone quantitation it is shown that glucose affects directly the concentration of the quinone. decreasing the rate of quinone formation. This highlights the role of sugar in o-quinone concentration and consequently in the impact on Strecker aldehyde formation, a promising new perspective regarding wine shelf-life understanding.

Straightforward synthesis of 3´-deoxy-3´,4´-didehydronucleoside-5´-aldehydes via 2´,3´-O-orthoester group elimination: a simple route 3´,4´-didehydronucleosides

Czech Academy of Sciences Publication Activity Database

Petrová, Magdalena; Buděšínský, Miloš; Rosenberg, Ivan

2010-01-01

Roč. 51, č. 52 (2010), s. 6874-6876 ISSN 0040-4039 R&D Projects: GA ČR GA203/09/0820; GA MŠk(CZ) LC06077; GA AV ČR KAN200520801 Institutional research plan: CEZ:AV0Z40550506 Keywords : Moffat oxidation * beta-elimination * nucleoside-5'-aldehydes * 3',4'-didehydronucleosides Subject RIV: CC - Organic Chemistry Impact factor: 2.618, year: 2010

Amphiphilic hollow porous shell encapsulated Au@Pd bimetal nanoparticles for aerobic oxidation of alcohols in water

KAUST Repository

Zou, Houbing

2015-01-01

© The Royal Society of Chemistry 2015. This work describes the design, synthesis and analysis of an amphiphilic hollow mesoporous shell encapsulating catalytically active Au@Pd bimetal nanoparticles. The particles exhibited excellent catalytic activity and stability in the aerobic oxidation of primary and secondary alcohols to their corresponding aldehydes or ketones in water when using air as an oxidizing agent under atmospheric pressure.

Inhibiting mitochondrial β-oxidation selectively reduces levels of nonenzymatic oxidative polyunsaturated fatty acid metabolites in the brain.

Science.gov (United States)

Chen, Chuck T; Trépanier, Marc-Olivier; Hopperton, Kathryn E; Domenichiello, Anthony F; Masoodi, Mojgan; Bazinet, Richard P

2014-03-01

Schönfeld and Reiser recently hypothesized that fatty acid β-oxidation is a source of oxidative stress in the brain. To test this hypothesis, we inhibited brain mitochondrial β-oxidation with methyl palmoxirate (MEP) and measured oxidative polyunsaturated fatty acid (PUFA) metabolites in the rat brain. Upon MEP treatment, levels of several nonenzymatic auto-oxidative PUFA metabolites were reduced with few effects on enzymatically derived metabolites. Our finding confirms the hypothesis that reduced fatty acid β-oxidation decreases oxidative stress in the brain and β-oxidation inhibitors may be a novel therapeutic approach for brain disorders associated with oxidative stress.

Contribution to the study of carbohydrate radiolysis: study of the formation of malonic aldehyde during gamma irradiation of glucose

International Nuclear Information System (INIS)

Enrico, Gerard.

1974-01-01

It was shown that malonic aldehyde can be formed directly by radiation of dry glucose or through the radicals of water when the latter is present. The direct effect leads to a malonic aldehyde production proportional to the dose and independent of dose rate, temperature over a wide range, presence of oxygen and crystalline state of the glucose, but strongly dependent on the water content and anomeric form of the glucose. Isotopic labelling showed that both ends of the glucose molecule participate in the malonic aldehyde formation. Extrapolation to linear polymers (maltose, maltotriose) reveals the independence of the radiolysis yield with regard to the α 1-4 bond and suggests that it tends towards that of glucose in amylose. The indirect effect is linked with the action of the OH radicals of water and appears when glucose is irradiated in a sufficiently hydrated state or in solution. In the latter case the malonic aldehyde concentration is largely independent of the glucose concentration and is not proportional to the dose. Oxygen has little effect but a strong activation is observed at high pH. The use of 14 C showed that the aldehyde end of glucose is responsible for most of the malonic aldehyde. Polymerisation of the glucose by α 1-4 binding reduces the radiolytic yield. The indirect effect would thus be negligible in amylose [fr

Volatile aldehydes are promising broad-spectrum postharvest insecticides.

Science.gov (United States)

Hammond, D G; Rangel, S; Kubo, I

2000-09-01

A variety of naturally occurring aldehydes common in plants have been evaluated for their insecticidal activity and for phytotoxicity to postharvest fruits, vegetables, and grains. Twenty-nine compounds were initially screened for their activity against aphids on fava bean leaf disks. Application under reduced pressure (partial vacuum) for the first quarter of fumigation increased insecticidal activity severalfold. The 11 best aldehydes were assayed against aphids placed under the third leaf of whole heads of iceberg lettuce using the same two-tier reduced-pressure regime, which caused no additional detriment to the commodity over fumigation at atmospheric pressure. Phytotoxicity to naked and wrapped iceburg lettuce, green and red table grapes, lemon, grapefruit, orange, broccoli, avocado, cabbage, pinto bean, and rice at doses that killed 100% of aphids was recorded for three promising fumigants: propanal, (E)-2-pentenal, and 2-methyl-(E)-2-butenal. These three compounds have excellent potential as affordable postharvest insect control agents, killing 100% of the aphids with little or no detectable harm to a majority of the commodities tested. Preliminary assays indicate that similar doses are also effective against mealybugs, thrips, and whitefly.

Elucidating the contributions of multiple aldehyde/alcohol dehydrogenases to butanol and ethanol production in Clostridium acetobutylicum

OpenAIRE

Dai, Zongjie; Dong, Hongjun; Zhang, Yanping; Li, Yin

2016-01-01

Ethanol and butanol biosynthesis in Clostridium acetobutylicum share common aldehyde/alcohol dehydrogenases. However, little is known about the relative contributions of these multiple dehydrogenases to ethanol and butanol production respectively. The contributions of six aldehyde/alcohol dehydrogenases of C. acetobutylicum on butanol and ethanol production were evaluated through inactivation of the corresponding genes respectively. For butanol production, the relative contributions from thes...

Enhanced detection of aldehydes in Extra-Virgin Olive Oil by means of band selective NMR spectroscopy

Science.gov (United States)

Dugo, Giacomo; Rotondo, Archimede; Mallamace, Domenico; Cicero, Nicola; Salvo, Andrea; Rotondo, Enrico; Corsaro, Carmelo

2015-02-01

High resolution Nuclear Magnetic Resonance (NMR) spectroscopy is a very powerful tool for comprehensive food analyses and especially for Extra-Virgin Olive Oils (EVOOs). We use the NMR technique to study the spectral region of aldehydes (8-10 ppm) for EVOOs coming from the south part of Italy. We perform novel experiments by using mono and bidimensional band selective spin-echo pulse sequences and identify four structural classes of aldehydes in EVOOs. For the first time such species are identified in EVOOs without any chemical treatment; only dilution with CDCl3 is employed. This would allow the discrimination of different EVOOs for the aldehydes content increasing the potentiality of the NMR technique in the screening of metabolites for geographical characterization of EVOOs.

Copepod reproduction is unaffected by diatom aldehydes or lipid composition

DEFF Research Database (Denmark)

Dutz, Jörg; Koski, Marja; Jonasdottir, Sigrun

2008-01-01

We investigated whether reduced reproductive success of copepods fed with diatoms was related to nutritional imbalances with regard to essential lipids or to the production of inhibitory aldehydes. In 10-d laboratory experiments, feeding, egg production, egg hatching success, and fecal pellet...

Anaerobic Nitroxide-Catalyzed Oxidation of Alcohols Using the NO+/NO center dot Redox Pair

Czech Academy of Sciences Publication Activity Database

Holan, Martin; Jahn, Ullrich

2014-01-01

Roč. 16, č. 1 (2014), s. 58-61 ISSN 1523-7060 R&D Projects: GA ČR GA13-40188S Institutional support: RVO:61388963 Keywords : oxidation * nitroxides * aldehydes * alcohols * ketones * alkyl nitrites Subject RIV: CC - Organic Chemistry Impact factor: 6.364, year: 2014

Possible involvement of membrane lipids peroxidation and oxidation of catalytically essential thiols of the cerebral transmembrane sodium pump as component mechanisms of iron-mediated oxidative stress-linked dysfunction of the pump's activity

Directory of Open Access Journals (Sweden)

T.I. Omotayo

2015-04-01

Full Text Available The precise molecular events defining the complex role of oxidative stress in the inactivation of the cerebral sodium pump in radical-induced neurodegenerative diseases is yet to be fully clarified and thus still open. Herein we investigated the modulation of the activity of the cerebral transmembrane electrogenic enzyme in Fe2+-mediated in vitro oxidative stress model. The results show that Fe2+ inhibited the transmembrane enzyme in a concentration dependent manner and this effect was accompanied by a biphasic generation of aldehydic product of lipid peroxidation. While dithiothreitol prevented both Fe2+ inhibitory effect on the pump and lipid peroxidation, vitamin E prevented only lipid peroxidation but not inhibition of the pump. Besides, malondialdehyde (MDA inhibited the pump by a mechanism not related to oxidation of its critical thiols. Apparently, the low activity of the pump in degenerative diseases mediated by Fe2+ may involve complex multi-component mechanisms which may partly involve an initial oxidation of the critical thiols of the enzyme directly mediated by Fe2+ and during severe progression of such diseases; aldehydic products of lipid peroxidation such as MDA may further exacerbate this inhibitory effect by a mechanism that is likely not related to the oxidation of the catalytically essential thiols of the ouabain-sensitive cerebral electrogenic pump.

Magnetic gold nanocatalyst (nanocat-Fe–Au): catalytic applications for the oxidative esterification and hydrogen transfer reactions

Science.gov (United States)

An efficient and sustainable protocol is described for the oxidative esterification of aldehydes and the reduction of aromatic nitro compounds that uses magnetically separable and reusable maghemite-supported gold nanocatalyst (nanocat-Fe-Au) under mild conditions. The complex ch...

MOLECULAR MODELLING OF HUMAN ALDEHYDE OXIDASE AND IDENTIFICATION OF THE KEY INTERACTIONS IN THE ENZYME-SUBSTRATE COMPLEX

Directory of Open Access Journals (Sweden)

Siavoush Dastmalchi

2005-05-01

Full Text Available Aldehyde oxidase (EC 1.2.3.1, a cytosolic enzyme containing FAD, molybdenum and iron-sulphur cluster, is a member of non-cytochrome P-450 enzymes called molybdenum hydroxylases which is involved in the metabolism of a wide range of endogenous compounds and many drug substances. Drug metabolism is one of the important characteristics which influences many aspects of a therapeutic agent such as routes of administration, drug interaction and toxicity and therefore, characterisation of the key interactions between enzymes and substrates is very important from drug development point of view. The aim of this study was to generate a three-dimensional model of human aldehyde oxidase (AO in order to assist us to identify the mode of interaction between enzyme and a set of phethalazine/quinazoline derivatives. Both sequence-based (BLAST and inverse protein fold recognition methods (THREADER were used to identify the crystal structure of bovine xanthine dehydrogenase (pdb code of 1FO4 as the suitable template for comparative modelling of human AO. Model structure was generated by aligning and then threading the sequence of human AO onto the template structure, incorporating the associated cofactors, and molecular dynamics simulations and energy minimization using GROMACS program. Different criteria which were measured by the PROCHECK, QPACK, VERIFY-3D were indicative of a proper fold for the predicted structural model of human AO. For example, 97.9 percentages of phi and psi angles were in the favoured and most favoured regions in the ramachandran plot, and all residues in the model are assigned environmentally positive compatibility scores. Further evaluation on the model quality was performed by investigation of AO-mediated oxidation of a set of phthalazine/quinazoline derivatives to develop QSAR model capable of describing the extent of the oxidation. Substrates were aligned by docking onto the active site of the enzyme using GOLD technology and then

Aldehyde dehydrogenase 2 in aplastic anemia, Fanconi anemia and hematopoietic stem cells.

Science.gov (United States)

Van Wassenhove, Lauren D; Mochly-Rosen, Daria; Weinberg, Kenneth I

2016-09-01

Maintenance of the hematopoietic stem cell (HSC) compartment depends on the ability to metabolize exogenously and endogenously generated toxins, and to repair cellular damage caused by such toxins. Reactive aldehydes have been demonstrated to cause specific genotoxic injury, namely DNA interstrand cross-links. Aldehyde dehydrogenase 2 (ALDH2) is a member of a 19 isoenzyme ALDH family with different substrate specificities, subcellular localization, and patterns of expression. ALDH2 is localized in mitochondria and is essential for the metabolism of acetaldehyde, thereby placing it directly downstream of ethanol metabolism. Deficiency in ALDH2 expression and function are caused by a single nucleotide substitution and resulting amino acid change, called ALDH2*2. This genetic polymorphism affects 35-45% of East Asians (about ~560 million people), and causes the well-known Asian flushing syndrome, which results in disulfiram-like reactions after ethanol consumption. Recently, the ALDH2*2 genotype has been found to be associated with marrow failure, with both an increased risk of sporadic aplastic anemia and more rapid progression of Fanconi anemia. This review discusses the unexpected interrelationship between aldehydes, ALDH2 and hematopoietic stem cell biology, and in particular its relationship to Fanconi anemia. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Decreased total antioxidant levels and increased oxidative stress in ...

African Journals Online (AJOL)

Background: Chronic hyperglycaemia in diabetes mellitus leads to increased lipid peroxidation in the body, followed by the development of chronic complications due to oxidative stress. Objective: The aim of this study was to compare total antioxidant (TAO) levels and oxidative stress in type 2 diabetes mellitus (T2DM) ...

Silica-Supported Catalyst for Enantioselective Arylation of Aldehydes under Batch and Continuous-Flow Conditions.

Science.gov (United States)

Watanabe, Satoshi; Nakaya, Naoyuki; Akai, Junichiro; Kanaori, Kenji; Harada, Toshiro

2018-05-04

A silica-supported 3-aryl H 8 -BINOL-derived titanium catalyst exhibited high performance in the enantioselective arylation of aromatic aldehydes using Grignard and organolithium reagents not only under batch conditions but also under continuous-flow conditions. Even with a simple pipet reactor packed with the heterogeneous catalyst, the enantioselective production of chiral diarylmethanols could be achieved through a continuous introduction of aldehydes and mixed titanium reagents generated from the organometallic precursors. The pipet reactor could be used repeatedly in different reactions without appreciable deterioration of the activity.

A HIGHLY STEREOSELECTIVE, NOVEL COUPLING REACTION BETWEEN ALKYNES WITH ALDEHYDES. (R828129)

Science.gov (United States)

In the presence of indium triflate or gallium chloride, a novel coupling between internal alkynes and aldehydes occurred to give unsaturated ketones and [4+1] annulation products. Graphical Abstrac...

Organocatalyzed Asymmetric α-Oxidation, α-Aminoxylation and α-Amination of Carbonyl Compounds

Directory of Open Access Journals (Sweden)

Worawan Bhanthumnavin

2010-02-01

Full Text Available Organocatalytic asymmetric α-oxidation and amination reactions of carbonyl compounds are highly useful synthetic methodologies, especially in generating chiral building blocks that previously have not been easily accessible by traditional methods. The concept is relatively new and therefore the list of new catalysts, oxidizing and aminating reagents, as well as new substrates, are expanding at an amazing rate. The scope of this review includes new reactions and catalysts, mechanistic aspects and synthetic applications of α-oxidation, hydroxylation, aminoxylation, amination, hydrazination, hydroxyamination and related α-heteroatom functionalization of aldehydes, ketones and related active methylene compounds published during 2005–2009.

Pharmacological activation of aldehyde dehydrogenase 2 promotes osteoblast differentiation via bone morphogenetic protein-2 and induces bone anabolic effect

Energy Technology Data Exchange (ETDEWEB)

Mittal, Monika; Pal, Subhashis; China, Shyamsundar Pal; Porwal, Konica [Division of Endocrinology and Centre for Research in Anabolic Skeletal Targets in Health and Illness (ASTHI), CSIR-Central Drug Research Institute, Lucknow 226031 (India); Dev, Kapil [Division of Medicinal and Process Chemistry, CSIR-Central Drug Research Institute, Lucknow 226031 (India); Shrivastava, Richa [Division of Toxicology, CSIR-Central Drug Research Institute, Lucknow 226031 (India); Raju, Kanumuri Siva Rama; Rashid, Mamunur [Pharmaceutics Division, CSIR-Central Drug Research Institute, Lucknow 226031 (India); Trivedi, Arun Kumar; Sanyal, Sabyasachi [Biochemistry Division, CSIR-Central Drug Research Institute, Lucknow 226031 (India); Wahajuddin, Muhammad [Pharmaceutics Division, CSIR-Central Drug Research Institute, Lucknow 226031 (India); Bhaduria, Smrati [Division of Toxicology, CSIR-Central Drug Research Institute, Lucknow 226031 (India); Maurya, Rakesh [Division of Medicinal and Process Chemistry, CSIR-Central Drug Research Institute, Lucknow 226031 (India); Chattopadhyay, Naibedya, E-mail: n_chattopadhyay@cdri.res.in [Division of Endocrinology and Centre for Research in Anabolic Skeletal Targets in Health and Illness (ASTHI), CSIR-Central Drug Research Institute, Lucknow 226031 (India)

2017-02-01

Aldehyde dehydrogenases (ALDHs) are a family of enzymes involved in detoxifying aldehydes. Previously, we reported that an ALDH inhibitor, disulfiram caused bone loss in rats and among ALDHs, osteoblast expressed only ALDH2. Loss-of-function mutation in ALDH2 gene is reported to cause bone loss in humans which suggested its importance in skeletal homeostasis. We thus studied whether activating ALDH2 by N-(1, 3-benzodioxol-5-ylmethyl)-2, 6-dichlorobenzamide (alda-1) had osteogenic effect. We found that alda-1 increased and acetaldehyde decreased the differentiation of rat primary osteoblasts and expressions of ALDH2 and bone morphogenetic protein-2 (BMP-2). Silencing ALDH2 in osteoblasts abolished the alda-1 effects. Further, alda-1 attenuated the acetaldehyde-induced lipid-peroxidation and oxidative stress. BMP-2 is essential for bone regeneration and alda-1 increased its expression in osteoblasts. We then showed that alda-1 (40 mg/kg dose) augmented bone regeneration at the fracture site with concomitant increase in BMP-2 protein compared with control. The osteogenic dose (40 mg/kg) of alda-1 attained a bone marrow concentration that was stimulatory for osteoblast differentiation, suggesting that the tissue concentration of alda-1 matched its pharmacologic effect. In addition, alda-1 promoted modeling-directed bone growth and peak bone mass achievement, and increased bone mass in adult rats which reiterated its osteogenic effect. In osteopenic ovariectomized (OVX) rats, alda-1 reversed trabecular osteopenia with attendant increase in serum osteogenic marker (procollagen type I N-terminal peptide) and decrease in oxidative stress. Alda-1 has no effect on liver and kidney function. We conclude that activating ALDH2 by alda-1 had an osteoanabolic effect involving increased osteoblastic BMP-2 production and decreased OVX-induced oxidative stress. - Highlights: • Alda-1 induced osteoblast differentiation that involved upregulation of ALDH2 and BMP-2 • Alda-1

Effect of phenolic aldehydes and flavonoids on growth and inactivation of Oenococcus oeni and Lactobacillus hilgardii

OpenAIRE

Figueiredo, Ana Rita; Campos, Francisco; Freitas, Víctor de; Hogg, Tim; Couto, José António

2008-01-01

The aim of this work was to investigate the effect of wine phenolic aldehydes, flavonoids and tannins on growth and viability of strains of Oenococcus oeni and Lactobacillus hilgardii. Cultures were grown in ethanol-containing MRS/TJ medium supplemented with different concentrations of phenolic aldehydes or flavonoids and monitored spectrophotometrically. The effect of tannins was evaluated by monitoring the progressive inactivation of cells in ethanol-containing phosphate buffer supplemented...

Base-catalyzed efficient tandem [3 + 3] and [3 + 2 + 1] annulation-aerobic oxidative benzannulations.

Science.gov (United States)

Diallo, Aboubacar; Zhao, Yu-Long; Wang, He; Li, Sha-Sha; Ren, Chuan-Qing; Liu, Qun

2012-11-16

An efficient synthesis of substituted benzenes via a base-catalyzed [3 + 3] aerobic oxidative aromatization of α,β-unsaturated carbonyl compounds with dimethyl glutaconate was reported. All the reactions were carried out under mild, metal-free conditions to afford the products in high to excellent yields with molecular oxygen as the sole oxidant and water as the sole byproduct. Furthermore, a more convenient tandem [3 + 2 + 1] aerobic oxidative aromatization reaction was developed through the in situ generation of the α,β-unsaturated carbonyl compounds from aldehydes and ketones.

RAGE polymorphisms and oxidative stress levels in Hashimoto's thyroiditis.

Science.gov (United States)

Giannakou, Maria; Saltiki, Katerina; Mantzou, Emily; Loukari, Eleni; Philippou, Georgios; Terzidis, Konstantinos; Lili, Kiriaki; Stavrianos, Charalampos; Kyprianou, Miltiades; Alevizaki, Maria

2017-05-01

Polymorphisms of the receptor for advanced glycation end products (RAGE) gene have been studied in various autoimmune disorders, but not in Hashimoto's thyroiditis. Also, increased oxidative stress has been described in patients with Hashimoto's thyroiditis. The aim of this study was to investigate the possible role of two common RAGE polymorphisms (-429T>C, -374T>A) in Hashimoto's thyroiditis; in parallel, we studied oxidative stress levels. A total of 300 consecutive euthyroid women were examined and classified into three groups: Hashimoto's thyroiditis with treatment (n = 96), Hashimoto's thyroiditis without treatment (n = 109) and controls (n = 95). For a rough evaluation of oxidative stress, total lipid peroxide levels in serum were measured. The -429T>C AluI and -374T>A MfeI polymorphisms of RAGE were studied in genomic DNA. Significant association of the RAGE system with Hashimoto's thyroiditis was found only with regard to the prevalence of the -429T>C, but not with -374T>A polymorphism. The levels of oxidative stress were significantly elevated in Hashimoto's thyroiditis patients under treatment. Further analysis demonstrated that an oxidative stress cut-off value of 590 μmol/L is associated with an increased risk of progression of Hashimoto's thyroiditis from euthyroidism to hypothyroidism; this risk is further increased in carriers of the RAGE -429T>C polymorphism. Our findings indicate that both examined risk factors may be implicated in the occurrence of Hashimoto's thyroiditis, but this covers only a fraction of the pathophysiology of the disease. © 2017 Stichting European Society for Clinical Investigation Journal Foundation.

A mild, efficient method for the oxidation of α-diazo-β-hydroxyesters to α-diazo-β-ketoesters

OpenAIRE

Li, Puhui; Majireck, Max M.; Korboukh, Ilia; Weinreb, Steven M.

2008-01-01

A wide variety of α-diazo-β-ketoesters can be prepared in good overall yields via a two-step sequence involving addition of ethyl lithiodiazoacetate to aliphatic, aromatic and conjugated aldehydes followed by mild oxidation with the Dess-Martin periodinane.

Enantioselective Direct α-Amination of Aldehydes via a Photoredox Mechanism: A Strategy for Asymmetric Amine Fragment Coupling

OpenAIRE

Cecere, Giuseppe; Koenig, Christian M.; Alleva, Jennifer L.; MacMillan, David W. C.

2013-01-01

The direct, asymmetric α-amination of aldehydes has been accomplished via a combination of photoredox and organocatalysis. Photon-generated, nitrogen-centered radicals undergo enantioselective α-addition to catalytically formed chiral enamines to directly produce stable α-amino aldehyde adducts bearing synthetically useful amine substitution patterns. Incorporation of a photolabile group on the amine precursor obviates the need to employ a photoredox catalyst in this transformation. Important...

Analysis of Endogenous Alkanes and Aldehydes in the Exhaled Breath of Workers Exposed to Silica Containing Dust

Directory of Open Access Journals (Sweden)

Mahdi Jalali

2015-03-01

Full Text Available Background & Objectives : Silica is one of the most air pollutant in workplaces which long-term occupational exposure to silica is associated with an increased risk for respiratory diseases such as silicosis. Silicosis is an oxidative stress related disease and can lead to the development of lung cancer. This study aims to analysis of endogenous alkanes and aldehydes in the exhaled breath of workers exposed to silica containing dusts. Methods: In this study, the exhaled breath of 20 workers exposed to silica containing dust (case group, 20 healthy non-smokers and 25 healthy smokers (control group were analyzed. The breath samples using 3-liter Tedlar bags were collected. The volatile organic compounds (VOCs were extracted with solid phase micro-extraction (SPME and analyzed using gas chromatography-mass spectrometry (GC- MS. Result: Totally, thirty nine VOCs were found in all breath samples (at least once. Aldehydes and alkanes such as acetaldehyde, hexanal, nonanal, decane, pentadecane, 2-methle propane, 3-methyle pentane and octane were detected in the exhaled breath subjects. Among the these compounds, mean peak area of acetaldehyde, hexanal, nonanal, decane and pentadecane were higher in the exhaled breath of an case group than control groups (Pvalue<0.05 . Conclusions : The use of exhaled breath analysis as well as new media in the occupational toxicology and exposure biomarker assessment studies. It seems that acetaldehyde, hexanal, nonanal, decane and pentadecane can be considered as useful breath biomarkers for exposure assessment of silica containing dust. However, additional studies are needed to confirm thes results.

NANOSIZED MAGNESIUM OXIDE AS CATALYST FOR THE RAPID AND GREEN SYNTHESIS OF SUBSTITUTED 2-AMINO-2-CHROMENES

Science.gov (United States)

A nanosized magnesium oxide catalyzed three-component condensation reaction of aldehyde, malononitrile and ¿-naphthol proceeded rapidly in water/PEG to afford corresponding 2-amino-2-chromenes in high yields at room temperature. The greener protocol was found to be fairly general...

A mild, efficient method for the oxidation of α-diazo-β-hydroxyesters to α-diazo-β-ketoesters

Science.gov (United States)

Li, Puhui; Majireck, Max M.; Korboukh, Ilia; Weinreb, Steven M.

2008-01-01

A wide variety of α-diazo-β-ketoesters can be prepared in good overall yields via a two-step sequence involving addition of ethyl lithiodiazoacetate to aliphatic, aromatic and conjugated aldehydes followed by mild oxidation with the Dess-Martin periodinane. PMID:19421308

Nickel exposure and plasma levels of biomarkers for assessing oxidative stress in nickel electroplating workers.

Science.gov (United States)

Tsao, Yu-Chung; Gu, Po-Wen; Liu, Su-Hsun; Tzeng, I-Shiang; Chen, Jau-Yuan; Luo, Jiin-Chyuan John

2017-07-01

The mechanism of nickel-induced pathogenesis remains elusive. To examine effects of nickel exposure on plasma oxidative and anti-oxidative biomarkers. Biomarker data were collected from 154 workers with various levels of nickel exposure and from 73 controls. Correlations between nickel exposure and oxidative and anti-oxidative biomarkers were determined using linear regression models. Workers with a exposure to high nickel levels had significantly lower levels of anti-oxidants (glutathione and catalase) than those with a lower exposure to nickel; however, only glutathione showed an independent association after multivariable adjustment. Exposure to high levels of nickel may reduce serum anti-oxidative capacity.

Effect of water content on thermal oxidation of oleic acid investigated by combination of EPR spectroscopy and SPME-GC-MS/MS.

Science.gov (United States)

Chen, Hongjian; Cao, Peirang; Li, Bo; Sun, Dewei; Wang, Yong; Li, Jinwei; Liu, Yuanfa

2017-04-15

Promotion of water to the thermal oxidation of oleic acid was detected by the combination of EPR, SPME-GC-MS/MS and GC. Spin-trapping technique was used to identify and quantify the radical species formed during thermal oxidation of oleic acid by using DMPO as electron spin trap. The most abundant radical species were identified as DMPO-alkyl radical adducts. EPR intensity plateau of the samples with 5% water content was 140% higher than the samples without water. It implies oleic acid samples with high water content had high level of oxidation rates. The proportion of aldehydes of the samples with 2% water content was the maximum about 59.97%. Among the formed products, (E,E)-2,4-decadienal has genotoxic and cytotoxic effects, whose percentage was nearly twice comparing with that of 5-0% water content. This study demonstrated that higher water content in frying systems would contribute to seriously oxidation and degradation of oleic acids. Copyright © 2016 Elsevier Ltd. All rights reserved.

Critical role of aldehydes in cigarette smoke-induced acute airway inflammation

NARCIS (Netherlands)

van der Toorn, Marco; Slebos, Dirk-Jan; de Bruin, Harold G.; Gras, Renee; Rezayat, Delaram; Jorge, Lucie; Sandra, Koen; van Oosterhout, Antoon J. M.

2013-01-01

Background: Cigarette smoking (CS) is the most important risk factor for COPD, which is associated with neutrophilic airway inflammation. We hypothesize, that highly reactive aldehydes are critical for CS-induced neutrophilic airway inflammation. Methods: BALB/c mice were exposed to CS, water

Oxidative coupling of methane over alkali-promoted simple molybdate catalysts

International Nuclear Information System (INIS)

Discoll, S.A.; Zhang, L.; Ozkan, U.S.

1992-01-01

The study of various metal oxides and alkali promoted metal oxide catalysts has received much interest in recent years after the earlier reports of ethylene synthesis through oxidative coupling of methane, and of achieving high selectivities over a Li/MgO catalyst under methane and oxygen cofeed conditions. The addition of promoter ions to several oxide catalysts has been studied to determine the effect of the promoter ion on catalytic activity and selectivity. The authors' work has focused on the use of alkali promoters for a simple molybdate catalyst. MnMoO 4 . A study of Na, Li, K, Mg, Ba, Mn, Co, Fe, Cu, Zn, and Ni molybdates by Kiwi et al showed that with the exception of NiMoO 4 , the molybdates were stable for long periods of time under reaction conditions for oxidative coupling. At a conversion level of about 60%, selectivities ranged from 9.8% to 16.6%. The MnMoO 4 and K 2 MnMoO 4 molybdates were the least selective catalysts. Another molybdate, PbMoO 4 , was studied by Baerns et al., with 19% selectivity to C 2 hydrocarbons at 1% conversion. An 11.4% conversion to form aldehyde was also reported. In this paper the authors report the characterization and catalytic behavior of MnMoO 4 catalysts promoted with either Li, Na, or K in oxidative coupling of methane

An Efficient Amide-Aldehyde-Alkene Condensation: Synthesis for the N-Allyl Amides.

Science.gov (United States)

Quan, Zheng-Jun; Wang, Xi-Cun

2016-02-01

The allylamine skeleton represents a significant class of biologically active nitrogen compounds that are found in various natural products and drugs with well-recognized pharmacological properties. In this personal account, we will briefly discuss the synthesis of allylamine skeletons. We will focus on showing a general protocol for Lewis acid-catalyzed N-allylation of electron-poor N-heterocyclic amides and sulfonamide via an amide-aldehyde-alkene condensation reaction. The substrate scope with respect to N-heterocyclic amides, aldehydes, and alkenes will be discussed. This method is also capable of preparing the Naftifine motif from N-methyl-1-naphthamide or methyl (naphthalene-1-ylmethyl)carbamate, with paraformaldehyde and styrene in a one-pot manner. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed-bed microreactor

Directory of Open Access Journals (Sweden)

Andrew Bogdan

2009-04-01

Full Text Available We demonstrate the preparation and characterization of a simplified packed-bed microreactor using an immobilized TEMPO catalyst shown to oxidize primary and secondary alcohols via the biphasic Anelli-Montanari protocol. Oxidations occurred in high yields with great stability over time. We observed that plugs of aqueous oxidant and organic alcohol entered the reactor as plugs but merged into an emulsion on the packed-bed. The emulsion coalesced into larger plugs upon exiting the reactor, leaving the organic product separate from the aqueous by-products. Furthermore, the microreactor oxidized a wide range of alcohols and remained active in excess of 100 trials without showing any loss of catalytic activity.

Synthesis of a Fluorescent Acridone Using a Grignard Addition, Oxidation, and Nucleophilic Aromatic Substitution Reaction Sequence

Science.gov (United States)

Goodrich, Samuel; Patel, Miloni; Woydziak, Zachary R.

2015-01-01

A three-pot synthesis oriented for an undergraduate organic chemistry laboratory was developed to construct a fluorescent acridone molecule. This laboratory experiment utilizes Grignard addition to an aldehyde, alcohol oxidation, and iterative nucleophilic aromatic substitution steps to produce the final product. Each of the intermediates and the…

AAV Gene Therapy for Alcoholism: Inhibition of Mitochondrial Aldehyde Dehydrogenase Enzyme Expression in Hepatoma Cells.

Science.gov (United States)

Sanchez, Anamaria C; Li, Chengwen; Andrews, Barbara; Asenjo, Juan A; Samulski, R Jude

2017-09-01

Most ethanol is broken down in the liver in two steps by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH2) enzymes, which metabolize down ethanol into acetaldehyde and then acetate. Some individuals from the Asian population who carry a mutation in the aldehyde dehydrogenase gene (ALDH2*2) cannot metabolize acetaldehyde as efficiently, producing strong effects, including facial flushing, dizziness, hypotension, and palpitations. This results in an aversion to alcohol intake and protection against alcoholism. The large prevalence of this mutation in the human population strongly suggests that modulation of ALDH2 expression by genetic technologies could result in a similar phenotype. scAAV2 vectors encoding ALDH2 small hairpin RNA (shRNA) were utilized to validate this hypothesis by silencing ALDH2 gene expression in human cell lines. Human cell lines HEK-293 and HepG2 were transduced with scAAV2/shRNA, showing a reduction in ALDH2 RNA and protein expression with the two viral concentration assayed (1 × 10 4 and 1 × 10 5 vg/cell) at two different time points. In both cell lines, ALDH2 RNA levels were reduced by 90% and protein expression was inhibited by 90% and 52%, respectively, 5 days post infection. Transduced HepG2 VL17A cells (ADH+) exposed to ethanol resulted in a 50% increase in acetaldehyde levels. These results suggest that gene therapy could be a useful tool for the treatment of alcoholism by knocking down ALDH2 expression using shRNA technology delivered by AAV vectors.

Proteomic based approach for characterizing 4-hydroxy-2-nonenal induced oxidation of buffalo (Bubalus bubalis) and goat (Capra hircus) meat myoglobins

OpenAIRE

Maheswarappa, Naveena B.; Rani, K. Usha; Kumar, Y. Praveen; Kulkarni, Vinayak V.; Rapole, Srikanth

2016-01-01

Background Myoglobin (Mb) is a sarcoplasmic heme protein primarily responsible for meat color and its chemistry is species specific. 4-hydroxy-2-nonenal (HNE) is a cytotoxic lipid derived aldehyde detected in meat and was reported to covalently adduct with nucleophilic histidine residues of Mb and predispose it to greater oxidation. However, no literature is available on characterization of lipid oxidation induced oxidation of Indian water buffalo (Bubalus bubalis) and goat (Capra hircus) myo...

Acrolein produces nitric oxide through the elevation of intracellular calcium levels to induce apoptosis in human umbilical vein endothelial cells: implications for smoke angiopathy.

Science.gov (United States)

Misonou, Yoshiko; Asahi, Michio; Yokoe, Shunichi; Miyoshi, Eiji; Taniguchi, Naoyuki

2006-03-01

Acrolein is a highly electrophilic alpha, beta-unsaturated aldehyde, the levels of which are increased in the blood of smokers. To determine if acrolein is involved in the pathology of smoke angiopathy, the effect of acrolein on human umbilical vein endothelial cells (HUVEC) was examined. Intracellular nitric oxide (NO) levels, determined using diaminofluorescein-2 diacetate (DAF-2 DA), an NO sensitive fluorescent dye, were found to be increased after treatment in HUVEC with 10 microM acrolein. The measurement of nitrite with 2,3-diaminonaphthalene and a Western blot analysis revealed that nitrite and S-nitroso-cysteine levels were increased in a dose-dependent manner, confirming that NO production is increased by acrolein. The increase was not reduced by treatment with 10mM N-acetyl-l-cysteine (NAC), an anti-oxidant, but was reduced with 10 microM of the intracellular calcium chelator, 1,2-bis (o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid tetra (acetoxymethyl) ester. Acrolein-stimulated NO production was significantly reduced by pretreatment with 1mM N(G)-nitro-l-arginine-methyl ester (L-NAME), an NO synthase inhibitor. The cytotoxicity of acrolein was reduced by pretreatment with 10 microM 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (carboxy-PTIO), an intracellular NO scavenger, or 1mM L-NAME, whereas it was not reduced by 10mM NAC, 20 microM Curcumin, another peroxide scavenger, or 100 microM Mn(III)TMPyP, a superoxide dismutase mimic. Nuclear staining and a Western blot analysis using an anti-cleaved caspase 3 antibody revealed that the reduced viability of HUVEC by acrolein was due to apoptosis, which was reversed after pretreatment with 0.1mM carboxy-PTIO or 1mM L-NAME. Thus, acrolein increases intracellular calcium production to induce intracellular NO production by a calcium-dependent NO synthase, possibly eNOS, and the excess and rapid increase in NO might lead to the apoptosis of HUVEC. These data suggest that acrolein might be

Untersuchungen zum atmosphärenchemischen Abbau langkettiger Aldehyde

OpenAIRE

Plagens, Heike

2001-01-01

In dieser Arbeit wurden die bimolekularen Geschwindigkeitskonstanten für die Reaktionen von Hexanal, Heptanal, Oktanal und Nonanal mit OH and Cl Radikalen bei (298 ± 2) K und (1000 ± 20) mbar experimentell bestimmt. Ebenso wurde die Chlorgeschwindigkeitskonstante für Butanal gemessen. Die Werte sind (in Einheiten von cm3 Molekül-1 s-1) in Tabelle 1 zusammengefaßt. Tabelle 1: Aldehyde kOH kCl Butanal - (2,21 ± 0,16) · 10-10 Hexan...

Oxidative stress reduces levels of dysbindin-1A via its PEST domain.

Science.gov (United States)

Yap, Mei-Yi Alicia; Lo, Yew-Long; Talbot, Konrad; Ong, Wei-Yi

2014-12-01

Oxidative stress resulting from the generation of reactive oxygen species has been proposed as an etiological factor in schizophrenia. The present study tests the hypothesis that oxidative stress can affect levels of dysbindin-1A, encoded by Dtnbp1, a genetic risk factor for schizophrenia, via its PEST domain. In vitro studies on SH-SY5Y cells indicate that oxidative stress triggers proteasomal degradation of dysbindin-1A, and that this requires interactions with its PEST domain, which may be a TRIM32 target. We specifically found (a) that oxidative stress induced in SH-SY5Y cells by 500 µM hydrogen peroxide reduced levels of full-length dysbindin-1, but did not reduce levels of that protein lacking its PEST domain and (b) that levels of full-length dysbindin-1, but not dysbindin-1 lacking its PEST domain, were higher in cells treated with the proteasome inhibitor MG132. Oxidative stress thus emerges as the first known cellular factor regulating dysbindin-1 isoforms with PEST domains. These findings are consistent with the previously noted fact that phosphorylation of PEST domains often marks proteins for proteasomal degradation, and raises the possibility that treatments reducing oxidative stress in the brain, especially during development, may lower schizophrenia risk. Copyright © 2014 Elsevier Ltd. All rights reserved.

YqhD. A broad-substrate range aldehyde reductase with various applications in production of biorenewable fuels and chemicals

Energy Technology Data Exchange (ETDEWEB)

Jarboe, Laura R. [Iowa State Univ., Ames, IA (United States). Dept. of Chemical and Biological Engineering

2011-01-15

The Escherichia coli NADPH-dependent aldehyde reductase YqhD has contributed to a variety of metabolic engineering projects for production of biorenewable fuels and chemicals. As a scavenger of toxic aldehydes produced by lipid peroxidation, YqhD has reductase activity for a broad range of short-chain aldehydes, including butyraldehyde, glyceraldehyde, malondialdehyde, isobutyraldehyde, methylglyoxal, propanealdehyde, acrolein, furfural, glyoxal, 3-hydroxypropionaldehyde, glycolaldehyde, acetaldehyde, and acetol. This reductase activity has proven useful for the production of biorenewable fuels and chemicals, such as isobutanol and 1,3- and 1,2-propanediol; additional capability exists for production of 1-butanol, 1-propanol, and allyl alcohol. A drawback of this reductase activity is the diversion of valuable NADPH away from biosynthesis. This YqhD-mediated NADPH depletion provides sufficient burden to contribute to growth inhibition by furfural and 5-hydroxymethyl furfural, inhibitory contaminants of biomass hydrolysate. The structure of YqhD has been characterized, with identification of a Zn atom in the active site. Directed engineering efforts have improved utilization of 3-hydroxypropionaldehyde and NADPH. Most recently, two independent projects have demonstrated regulation of yqhD by YqhC, where YqhC appears to function as an aldehyde sensor. (orig.)

Titanocene(III)-Catalyzed Three-Component Reaction of Secondary Amides, Aldehydes, and Electrophilic Alkenes.

Science.gov (United States)

Zheng, Xiao; He, Jiang; Li, Heng-Hui; Wang, Ao; Dai, Xi-Jie; Wang, Ai-E; Huang, Pei-Qiang

2015-11-09

An umpolung Mannich-type reaction of secondary amides, aliphatic aldehydes, and electrophilic alkenes has been disclosed. This reaction features the one-pot formation of C-N and C-C bonds by a titanocene-catalyzed radical coupling of the condensation products, from secondary amides and aldehydes, with electrophilic alkenes. N-substituted γ-amido-acid derivatives and γ-amido ketones can be efficiently prepared by the current method. Extension to the reaction between ketoamides and electrophilic alkenes allows rapid assembly of piperidine skeletons with α-amino quaternary carbon centers. Its synthetic utility has been demonstrated by a facile construction of the tricyclic core of marine alkaloids such as cylindricine C and polycitorol A. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Simultaneous analysis of aromatic aldehydes and coumarins with high pressure liquid chromatography. Application to wines and brandies stored in oak barrels].

Science.gov (United States)

Salagoity-Auguste, M H; Tricard, C; Sudraud, P

1987-04-17

Aromatic aldehydes (vanillin, syringaldehyde, coniferaldehyde and sinapaldehyde) and coumarins (esculetin, umbelliferone, scopoletin and methylumbelliferone) are natural wood compounds. Storage of wines and brandies in oak barrels increases notably aldehydes and coumarins (particularly scopoletin) concentrations. These compounds were separated by high-performance liquid chromatography, on hydrocarbon bonded reversed-phase packings, with a water-acetonitrile elution gradient. They were first extracted from wines and brandies by diethyl ether and then injected on chromatographic column. A double detection was used to determine simultaneously aromatic aldehydes and coumarins by UV absorption and fluorescence respectively.

Enzymatic oxidations of alcohols in biosynthesis of bumblebee pheromones

OpenAIRE

Bártová, Adéla

2016-01-01

Secretion of cephalic labial gland of Buff-tailed bumblebee males (Bombus terrestris) contains a mixture of terpene alcohols, aliphatic alcohols, esters and alkanes with small amount of aldehydes potentially biosynthetized of (S)-2,3-dihydrofarnesol and geranylcitronellol (major alcoholic compounds). This secretion acts as a marking and luring pheromone during patrolling. This study is focused on oxidation of terpene alcohols using enzymes of cephalic labial gland of a bumblebee. In vitro inc...

2,3,7,8-Tetrachlorodibenzo-p-dioxin modulates estradiol-induced aldehydic DNA lesions in human breast cancer cells through alteration of CYP1A1 and CYP1B1 expression.

Science.gov (United States)

Chen, Shou-Tung; Chen, Dar-Ren; Fang, Ju-Pin; Lin, Po-Hsiung

2015-05-01

Many genes responsible for the bioactivation of endogenous estrogen to reactive quinonoid metabolites, including cytochrome P450 (CYP) 1A1, 1A2, and 1B1, are well-known target genes of the aryl hydrocarbon receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The purpose of this research was to investigate the roles of TCDD-mediated altered gene expression in the induction of aldehydic DNA lesions (ADLs) by 17β-estradiol (E2) in human MDA-MB-231 and MCF-7 breast cancer cells. We demonstrated that increases in the number of oxidant-mediated ADLs, including abasic sites and aldehydic base/sugar lesions, were detected in MDA-MB-231 cells exposed to E2. The DNA-damaging effects of E2 in MDA-MB-231 cells were prevented by pretreatment of cells with TCDD. In contrast, we did not observe statistically significant increases in the number of ADLs in MCF-7 cells exposed to E2. However, with TCDD pretreatment, an approximately twofold increase in the number of ADLs was detected in MCF-7 cells exposed to E2. TCDD pretreatment induces disparity in the disposition of E2 to reactive quinonoid metabolites and the subsequent formation of oxidative DNA lesions through alteration of CYP1A1 and CYP1B1 expression in human breast cancer cells.

S-Nitrosomycothiol Reductase and Mycothiol Are Required for Survival Under Aldehyde Stress and Biofilm Formation in Mycobacterium smegmatis

Science.gov (United States)

Vargas, Derek; Hageman, Samantha; Gulati, Megha; Nobile, Clarissa J.; Rawat, Mamta

2017-01-01

We show that Mycobacterium smegmatis mutants disrupted in mscR, coding for a dual function S-nitrosomycothiol reductase and formaldehyde dehydrogenase, and mshC, coding for a mycothiol ligase and lacking mycothiol (MSH), are more susceptible to S-nitrosoglutathione (GSNO) and aldehydes than wild type. MSH is a cofactor for MscR, and both mshC and mscR are induced by GSNO and aldehydes. We also show that a mutant disrupted in egtA, coding for a γ-glutamyl cysteine synthetase and lacking in ergothioneine, is sensitive to nitrosative stress but not to aldehydes. In addition, we find that MSH and S-nitrosomycothiol reductase are required for normal biofilm formation in M. smegmatis, suggesting potential new therapeutic pathways to target to inhibit or disrupt biofilm formation. PMID:27321674

Evaluation of oxidant, antioxidant, and S100B levels in patients with conversion disorder.

Science.gov (United States)

Büyükaslan, Hasan; Kandemir, Sultan Basmacı; Asoğlu, Mehmet; Kaya, Halil; Gökdemir, Mehmet Tahir; Karababa, İbrahim Fatih; Güngörmez, Fatih; Kılıçaslan, Fethiye; Şavik, Emin

2016-01-01

Various psychodynamic, neurobiological, genetic, and sociocultural factors are believed to be involved in the etiology of conversion disorder (CD). Oxidative metabolism has been shown to deteriorate in association with many health problems and psychiatric disorders. We evaluated oxidative metabolism and S100B levels in the context of this multifactorial disease. Thirty-seven patients with CD (25 females and 12 males) and 42 healthy volunteers (21 females and 21 males), all matched for age and sex, were included in this study. The total oxidant status, total antioxidant status, oxidative stress index, and S100B levels were compared between the two groups. The total oxidant status, oxidative stress index, and S100B levels were significantly higher in patients with CD than in the control group, whereas the total antioxidant status was significantly lower. CD is associated with deterioration of oxidative metabolism and increased neuronal damage.

Effect of phenolic aldehydes and flavonoids on growth and inactivation of Oenococcus oeni and Lactobacillus hilgardii.

Science.gov (United States)

Figueiredo, Ana Rita; Campos, Francisco; de Freitas, Víctor; Hogg, Tim; Couto, José António

2008-02-01

The aim of this work was to investigate the effect of wine phenolic aldehydes, flavonoids and tannins on growth and viability of strains of Oenococcus oeni and Lactobacillus hilgardii. Cultures were grown in ethanol-containing MRS/TJ medium supplemented with different concentrations of phenolic aldehydes or flavonoids and monitored spectrophotometrically. The effect of tannins was evaluated by monitoring the progressive inactivation of cells in ethanol-containing phosphate buffer supplemented with grape seed extracts with different molecular weight tannins. Of the phenolic aldehydes tested, sinapaldehyde, coniferaldehyde, p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde and 3,4,5-trihydroxybenzaldehyde significantly inhibited the growth of O. oeni VF, while vanillin and syringaldehyde had no effect at the concentrations tested. Lact. hilgardii 5 was only inhibited by sinapaldehyde and coniferaldehyde. Among the flavonoids, quercetin and kaempferol exerted an inhibitory effect especially on O. oeni VF. Myricetin and the flavan-3-ols studied (catechin and epicatechin) did not affect considerably the growth of both strains. Condensed tannins (particularly tetramers and pentamers) were found to strongly affect cell viability, especially in the case of O. oeni VF. In general, this strain was found to be more sensitive than Lact. hilgardii 5 to the phenolic compounds studied. This work contributes to the knowledge of the effect of different phenolic compounds on the activity of wine lactic acid bacteria, which, especially in the case of aldehydes and of different molecular weight fractions of tannins, is very scarce.

Development of an azanoradamantane-type nitroxyl radical catalyst for class-selective oxidation of alcohols.

Science.gov (United States)

Doi, Ryusuke; Shibuya, Masatoshi; Murayama, Tsukasa; Yamamoto, Yoshihiko; Iwabuchi, Yoshiharu

2015-01-02

The development of 1,5-dimethyl-9-azanoradamantane N-oxyl (DMN-AZADO; 1,5-dimethyl-Nor-AZADO, 2) as an efficient catalyst for the selective oxidation of primary alcohols in the presence of secondary alcohols is described. The compact and rigid structure of the azanoradamantane nucleus confers potent catalytic ability to DMN-AZADO (2). A variety of hindered primary alcohols such as neopentyl primary alcohols were efficiently oxidized by DMN-AZADO (2) to the corresponding aldehydes, whereas secondary alcohols remained intact. DMN-AZADO (2) also has high catalytic efficiency for one-pot oxidation from primary alcohols to the corresponding carboxylic acids in the presence of secondary alcohols and for oxidative lactonization from diols.

Direct Aldehyde C-H Arylation and Alkylation via the Combination of Nickel, Hydrogen Atom Transfer, and Photoredox Catalysis.

Science.gov (United States)

Zhang, Xiaheng; MacMillan, David W C

2017-08-23

A mechanism that enables direct aldehyde C-H functionalization has been achieved via the synergistic merger of photoredox, nickel, and hydrogen atom transfer catalysis. This mild, operationally simple protocol transforms a wide variety of commercially available aldehydes, along with aryl or alkyl bromides, into the corresponding ketones in excellent yield. This C-H abstraction coupling technology has been successfully applied to the expedient synthesis of the medicinal agent haloperidol.

A unified approach for the synthesis of symmetrical and unsymmetrical dibenzyl ethers from aryl aldehydes through reductive etherification

Directory of Open Access Journals (Sweden)

J. Sembian Ruso

2016-05-01

Full Text Available In this paper, we describe a simple and convenient conversion of aryl aldehydes to symmetrical dibenzyl ethers through reductive etherification. Similarly, unsymmetrical dibenzyl ether was obtained from aryl aldehyde and TES-protected benzyl alcohol. Triethyl silane with catalytic amount of InCl3 was found to be an efficient condition for the reductive etherification. Moreover, it exhibits remarkable functional group compatibility with yield ranging from good to excellent.

Supported Rh-phosphine complex catalysts for continuous gas-phase decarbonylation of aldehydes

DEFF Research Database (Denmark)

Malcho, Phillip; Garcia-Suarez, Eduardo J.; Mentzel, Uffe Vie

2014-01-01

Heterogeneous silica supported rhodium-phosphine complex catalysts are employed for the first time in the catalytic decarbonylation of aldehydes in continuous gas-phase. The reaction protocol is exemplified for the decarbonylation of p-tolualdehyde to toluene and further extended to other aromatic...

Substituent effect of phenolic aldehyde inhibition on alcoholic fermentation by Saccharomyces cerevisiae

Science.gov (United States)

Rui Xie; Maobing Tu; Thomas Elder

2016-01-01

Phenolic compounds significantly inhibit microbial fermentation of biomass hydrolysates. To understand thequantitative structure-inhibition relationship of phenolic aldehydes on alcoholic fermentation, the effect of 11 differentsubstituted benzaldehydes on the final ethanol yield was examined. The results showed that the degree of phenolic...

Lipids and Oxidative Stress Associated with Ethanol-Induced Neurological Damage

Directory of Open Access Journals (Sweden)

José A. Hernández

2016-01-01

Full Text Available The excessive intake of alcohol is a serious public health problem, especially given the severe damage provoked by chronic or prenatal exposure to alcohol that affects many physiological processes, such as memory, motor function, and cognitive abilities. This damage is related to the ethanol oxidation in the brain. The metabolism of ethanol to acetaldehyde and then to acetate is associated with the production of reactive oxygen species that accentuate the oxidative state of cells. This metabolism of ethanol can induce the oxidation of the fatty acids in phospholipids, and the bioactive aldehydes produced are known to be associated with neurotoxicity and neurodegeneration. As such, here we will review the role of lipids in the neuronal damage induced by ethanol-related oxidative stress and the role that lipids play in the related compensatory or defense mechanisms.

Pharmacological inhibition of arachidonate 15-lipoxygenase (ALOX15) protects human spermatozoa against oxidative stress.

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Walters, Jessica L H; De Iuliis, Geoffry N; Dun, Matthew D; Aitken, Robert John; McLaughlin, Eileen A; Nixon, Brett; Bromfield, Elizabeth G

2018-03-13

One of the leading causes of male infertility is defective sperm function, a pathology that commonly arises from oxidative stress in the germline. Lipid peroxidation events in the sperm plasma membrane result in the generation of cytotoxic aldehydes such as 4-hydroxynonenal (4HNE), which accentuate the production of reactive oxygen species (ROS) and cause cellular damage. One of the key enzymes involved in the metabolism of polyunsaturated fatty acids to 4HNE in somatic cells is arachidonate 15-lipoxygenase (ALOX15). Although ALOX15 has yet to be characterized in human spermatozoa, our previous studies have revealed a strong link between ALOX15 activity and the levels of oxidative stress and 4HNE in mouse germ cell models. In view of these data, we sought to assess the function of ALOX15 in mature human spermatozoa and determine whether the pharmacological inhibition of this enzyme could influence the level of oxidative stress experienced by these cells. By driving oxidative stress in vitro with exogenous H2O2, our data reveal that 6,11-dihydro[1]benzothiopyrano[4,3-b]indole (PD146176; a selective ALOX15 inhibitor), was able to significantly reduce several deleterious, oxidative insults in spermatozoa. Indeed, PD146176 attenuated the production of ROS, as well as membrane lipid peroxidation and 4HNE production in human spermatozoa. Accordingly, ALOX15 inhibition also protected the functional competence of these cells to acrosome react and bind homologous human zonae pellucidae. Together, these results implicate ALOX15 in the propagation of an oxidative stress cascade within human spermatozoa and offer insight into potential therapeutic avenues to address male fertility that arises from oxidative stress.

An Efficient Glycoblotting-Based Analysis of Oxidized Lipids in Liposomes and a Lipoprotein.

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Furukawa, Takayuki; Hinou, Hiroshi; Takeda, Seiji; Chiba, Hitoshi; Nishimura, Shin-Ichiro; Hui, Shu-Ping

2017-10-05

Although widely occurring lipid oxidation, which is triggered by reactive oxygen species (ROS), produces a variety of oxidized lipids, practical methods to efficiently analyze oxidized lipids remain elusive. Herein, it is shown that the glycoblotting platform can be used to analyze oxidized lipids. Analysis is based on the principle that lipid aldehydes, one of the oxidized lipid species, can be captured selectively, enriched, and detected. Moreover, 3-methyl-1-p-tolyltriazene (MTT) methylates phosphoric and carboxylic acids, and this MTT-mediated methylation is, in combination with conventional tandem mass spectrometry (MS/MS) analysis, an effective method for the structural analysis of oxidized lipids. By using three classes of standards, liposomes, and a lipoprotein, it is demonstrated that glycoblotting represents a powerful approach for focused lipidomics, even in complex macromolecules. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxidized trilinoleate and tridocosahexaenoate induce pica behavior and change locomotor activity.

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Kitamura, Fuki; Watanabe, Hiroyuki; Umeno, Aya; Yoshida, Yasukazu; Kurata, Kenji; Gotoh, Naohiro

2013-01-01

Pica behavior, a behavior that is characterized by eating a nonfood material such as kaolin and relates to the degree of discomfort in animals, and the variations of locomotor activity of rats after eating deteriorated fat and oil extracted from instant noodles were examined in our previous study. The result shows that oxidized fat and oil with at least 100 meq/kg in peroxide value (PV) increase pica behavior and decrease locomotor activity. In the present study, the same two behaviors were measured using autoxidized trilinoleate (tri-LA) and tridocosahexaenoate (tri-DHA) as a model of vegetable and fish oil, respectively, to compare fatty acid differences against the induction of two behaviors. The oxidized levels of tri-LA and tri-DHA were analyzed with PV and p-anisidine value (AnV), the method to analyze secondary oxidized products. The oxidation levels of respective triacylglycerol (TAG) samples were carefully adjusted to make them having almost the same PV and AnV. As the results, 600 or more meq/kg in PV of both TAGs significantly increased the consumption of kaolin pellets compared to the control group. Furthermore, 300 or more meq/kg in PV of tri-LA and 200 or more meq/kg in PV of tri-DHA demonstrated significant decrease in locomotor activity compared to control group. These results would indicate that the oxidized TAG having the same PV and/or AnV would induce the same type of pica behavior and locomotor activity. Furthermore, that the structure of oxidized products might not be important and the amount of hydroperoxide group and/or aldehyde group in deteriorated fats and oils might affect the pica behavior and locomotor activity were thought.

Compostos carbonílicos atmosféricos: fontes, reatividade, níveis de concentração e efeitos toxicológicos Atmospheric carbonyl compounds: sources, reactivity, concentration levels and toxicologic effects

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Marta Valéria Almeida Santana de Andrade

2002-12-01

Full Text Available In the last three decades carbonyl compounds, aldehydes and ketones, have received a great deal of attention due to their strong influence on photochemical smog formation and their recognized adverse human health effects. Carbonyl compounds are directly emitted into the atmosphere by combustion sources and also produced from photochemical oxidation of hydrocarbons and other organic compounds. In this paper it is presented a general overview about the carbonyl compounds sources, reactivity, concentration levels and toxicological effects.

Formation of high-molecular-weight compounds via the heterogeneous reactions of gaseous C8-C10 n-aldehydes in the presence of atmospheric aerosol components

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Han, Yuemei; Kawamura, Kimitaka; Chen, Qingcai; Mochida, Michihiro

2016-02-01

A laboratory study on the heterogeneous reactions of straight-chain aldehydes was performed by exposing n-octanal, nonanal, and decanal vapors to ambient aerosol particles. The aerosol and blank filters were extracted using methanol. The extracts were nebulized and the resulting compositions were examined using a high-resolution time-of-flight aerosol mass spectrometer. The mass spectral analysis showed that the exposures of the aldehydes to aerosol samples increased the peak intensities in the high mass range. The peaks in the mass spectra of the aerosol samples after exposure to different aldehydes were characterized by a homologous series of peak shifts due to the addition of multiple CH2 units. This result is explained by the formation of high-molecular-weight (HMW) compounds that contain single or multiple aldehyde moieties. The HMW fragment peaks for the blank filters exposed to n-aldehydes were relatively weak, indicating an important contribution from the ambient aerosol components to the formation of the HMW compounds. Among the factors affecting the overall interaction of aldehydes with atmospheric aerosol components, gas phase diffusion possibly limited the reactions under the studied conditions; therefore, their occurrence to a similar degree in the atmosphere is not ruled out, at least for the reactions involving n-nonanal and decanal. The major formation pathways for the observed HMW products may be the self-reactions of n-aldehydes mediated by atmospheric aerosol components and the reactions of n-aldehydes with organic aerosol components. The observed formation of HMW compounds encourages further investigations into their effects on the aerosol properties as well as the organic aerosol mass in the atmosphere.

Ionic Liquids in Selective Oxidation: Catalysts and Solvents.

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Dai, Chengna; Zhang, Jie; Huang, Chongpin; Lei, Zhigang

2017-05-24

Selective oxidation has an important role in environmental and green chemistry (e.g., oxidative desulfurization of fuels and oxidative removal of mercury) as well as chemicals and intermediates chemistry to obtain high-value-added special products (e.g., organic sulfoxides and sulfones, aldehydes, ketones, carboxylic acids, epoxides, esters, and lactones). Due to their unique physical properties such as the nonvolatility, thermal stability, nonexplosion, high polarity, and temperature-dependent miscibility with water, ionic liquids (ILs) have attracted considerable attention as reaction solvents and media for selective oxidations and are considered as green alternatives to volatile organic solvents. Moreover, for easy separation and recyclable utilization, IL catalysts have attracted unprecedented attention as "biphasic catalyst" or "immobilized catalyst" by immobilizing metal- or nonmetal-containing ILs onto mineral or polymer supports to combine the unique properties of ILs (chemical and thermal stability, capacity for extraction of polar substrates and reaction products) with the extended surface of the supports. This review highlights the most recent outcomes on ILs in several important typical oxidation reactions. The contents are arranged in the series of oxidation of sulfides, oxidation of alcohols, epoxidation of alkenes, Baeyer-Villiger oxidation reaction, oxidation of alkanes, and oxidation of other compounds step by step involving ILs as solvents, catalysts, reagents, or their combinations.

Polyamine modification by acrolein exclusively produces 1,5-diazacyclooctanes: a previously unrecognized mechanism for acrolein-mediated oxidative stress.

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Tsutsui, Ayumi; Imamaki, Rie; Kitazume, Shinobu; Hanashima, Shinya; Yamaguchi, Yoshiki; Kaneda, Masato; Oishi, Shinya; Fujii, Nobutaka; Kurbangalieva, Almira; Taniguchi, Naoyuki; Tanaka, Katsunori

2014-07-28

Acrolein, a toxic unsaturated aldehyde generated as a result of oxidative stress, readily reacts with a variety of nucleophilic biomolecules. Polyamines, which produced acrolein in the presence of amine oxidase, were then found to react with acrolein to produce 1,5-diazacyclooctane, a previously unrecognized but significant downstream product of oxidative stress. Although diazacyclooctane formation effectively neutralized acrolein toxicity, the diazacyclooctane hydrogel produced through a sequential diazacyclooctane polymerization reaction was highly cytotoxic. This study suggests that diazacyclooctane formation is involved in the mechanism underlying acrolein-mediated oxidative stress.

Association between oxidative stress index and serum lipid levels in healthy young adults

International Nuclear Information System (INIS)

Turkdogan, K.E.

2014-01-01

Objectives: To investigate the relationship between lipid levels and oxidative stress index in healthy young adults. Methods: The study was camed out at the Department of Emergency Service, Faculty of Medicine, Cumhuriyet University, Sivas, Turkey, between January 2011 and July 2012. A total of 100 healthy adult volunteers were enrolled in the study. Venous blood samples (10 ml) were collected from all individuals, and serum lipid parameters, total antioxidant capacity and total oxidative levels were studied. SPSS 15 was used for statistical analysis. Results: Overall, there were 84 (84%) males and 16 (16%) females. The mean age of the male population was 30+-3 years, while that of the females was 31+-3 years. Overall age ranged from 25 to 35 years. A statistically significant correlation was found between the oxidative stress index and serum cholesterol (p<0.001; r=0.596), triglyceride (p<0.001; r=0.476) and low-density lipoprotein levels (p<0.001; r=0.318). However, no significant correlation was found between oxidative stress index and serum high-density lipoprotein levels (p=0.564; r=0.058). Conclusion: The results showed that even at an early age, there is a direct linear correlation between oxidative stress and serum lipid levels. (author)

Effect of L-Carnitine on Skeletal Muscle Lipids and Oxidative Stress in Rats Fed High-Fructose Diet

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Panchamoorthy Rajasekar

2007-01-01

Full Text Available There is evidence that high-fructose diet induces insulin resistance, alterations in lipid metabolism, and oxidative stress in rat tissues. The purpose of this study was to evaluate the effect of L-carnitine (CAR on lipid accumulation and peroxidative damage in skeletal muscle of rats fed high-fructose diet. Fructose-fed animals (60 g/100 g diet displayed decreased glucose/insulin (G/I ratio and insulin sensitivity index (ISI0,120 indicating the development of insulin resistance. Rats showed alterations in the levels of triglycerides, free fatty acids, cholesterol, and phospholipids in skeletal muscle. The condition was associated with oxidative stress as evidenced by the accumulation of lipid peroxidation products, protein carbonyls, and aldehydes along with depletion of both enzymic and nonenzymic antioxidants. Simultaneous intraperitoneal administration of CAR (300 mg/kg/day to fructose-fed rats alleviated the effects of fructose. These rats showed near-normal levels of the parameters studied. The effects of CAR in this model suggest that CAR supplementation may have some benefits in patients suffering from insulin resistance.

A Highly Practical Copper(I)/TEMPO Catalyst System for Chemoselective Aerobic Oxidation of Primary Alcohols

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Hoover, Jessica M.; Stahl, Shannon S.

2011-01-01

Aerobic oxidation reactions have been the focus of considerable attention, but their use in mainstream organic chemistry has been constrained by limitations in their synthetic scope and by practical factors, such as the use of pure O2 as the oxidant or complex catalyst synthesis. Here, we report a new (bpy)CuI/TEMPO catalyst system that enables efficient and selective aerobic oxidation of a broad range of primary alcohols, including allylic, benzylic and aliphatic derivatives, to the corresponding aldehydes using readily available reagents, at room temperature with ambient air as the oxidant. The catalyst system is compatible with a wide range of functional groups and the high selectivity for 1° alcohols enables selective oxidation of diols that lack protecting groups. PMID:21861488

A Highly Efficient Solvent-Free Acetalization of Aldehydes to 1,1 ...

African Journals Online (AJOL)

1,1-Diacetates are prepared in excellent yields from aldehydes and acetic anhydride under solvent-free conditions at room temperature in short reaction times using catalytic amount of sulfonic acid functionalized silica (SiO2-Pr-SO3H) which could be easily handled and removed from the mixture of reaction. Keywords: 1 ...

A stress surveillance system based on calcium and nitric oxide in marine diatoms.

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Assaf Vardi

2006-03-01

Full Text Available Diatoms are an important group of eukaryotic phytoplankton, responsible for about 20% of global primary productivity. Study of the functional role of chemical signaling within phytoplankton assemblages is still in its infancy although recent reports in diatoms suggest the existence of chemical-based defense strategies. Here, we demonstrate how the accurate perception of diatom-derived reactive aldehydes can determine cell fate in diatoms. In particular, the aldehyde (2E,4E/Z-decadienal (DD can trigger intracellular calcium transients and the generation of nitric oxide (NO by a calcium-dependent NO synthase-like activity, which results in cell death. However, pretreatment of cells with sublethal doses of aldehyde can induce resistance to subsequent lethal doses, which is reflected in an altered calcium signature and kinetics of NO production. We also present evidence for a DD-derived NO-based intercellular signaling system for the perception of stressed bystander cells. Based on these findings, we propose the existence of a sophisticated stress surveillance system in diatoms, which has important implications for understanding the cellular mechanisms responsible for acclimation versus death during phytoplankton bloom successions.

β-oxidation and rapid metabolism, but not uptake regulate brain eicosapentaenoic acid levels.

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Chen, Chuck T; Bazinet, Richard P

2015-01-01

The brain has a unique polyunsaturated fatty acid composition, with high levels of arachidonic and docosahexaenoic acids (DHA) while levels of eicosapentaenoic acid (EPA) are several orders of magnitude lower. As evidence accumulated that fatty acid entry into the brain was not selective and, in fact, that DHA and EPA enter the brain at similar rates, new mechanisms were required to explain their large concentration differences in the brain. Here we summarize recent research demonstrating that EPA is rapidly and extensively β-oxidized upon entry into the brain. Although the ATP generated from the β-oxidation of EPA is low compared to the use of glucose, fatty acid β-oxidation may serve to regulate brain fatty acid levels in the absence of selective transportation. Furthermore, when β-oxidation of EPA is blocked, desaturation of EPA increases and Land׳s recycling decreases to maintain low EPA levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radical cations in radiation chemistry of aldehydes. ESR study and quantum chemical analysis

International Nuclear Information System (INIS)

Belevskii, V.N.; Tyurin, D.A.; Chuvilkin, N.D.

1998-01-01

Quantum-chemical (MNDO-UHF) calculations of electronic, spin and energy characteristics of radical cations (RC) of ethanal, propanal, butanal, and pentanal and their distonic isomers were performed. The calculations both with 'frozen' (vertical ionization) and completely optimize geometry (adiabatic approximation) were made. It was been shown that the most positive charge and spin population are localized at O atoms and adjacent C atom as well as at aldehyde protons. The C-H bonds corresponding to those protons as well as neighboring C-O and C-C bonds are considerable weaker (longer) in radical cations as compared to their neutral precursors. That is why such reaction centers are apt to deprotonation with the formation of acyl radical as well as to α- and β-splitting (scission) which are well-known from aldehydes mass-spectra. Our calculations shown that distonic RC (products of intramolecular H-atom transfer) are more stable as compare to their classical isomers: e.g. the difference in energy ΔE = -0.95 eV, -1.2 eV, and -1.5 eV for tree distonic isomers of butanal RC as compare to classical isomer, ΔE -1.2 eV for distonic RC of ethanal. The results of calculations are effectively correlated with ESR data obtained in freonic solutions, X- and gamma-irradiated at 77 K and in liquid aldehydes, X-irradiated by using 2,4,6-tri-tert-burylnitrosobenzene (BNB) and t-BuNO (NtB) as a spin traps. (author)

Yeast aquaporin regulation by 4-hydroxynonenal is implicated in oxidative stress response.

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Rodrigues, Claudia; Tartaro Bujak, Ivana; Mihaljević, Branka; Soveral, Graça; Cipak Gasparovic, Ana

2017-05-01

Reactive oxygen species, especially hydrogen peroxide (H 2 O 2 ), contribute to functional molecular impairment and cellular damage, but also are necessary in normal cellular metabolism, and in low doses play stimulatory role in cell proliferation and stress resistance. In parallel, reactive aldehydes such as 4-hydroxynonenal (HNE), are lipid peroxidation breakdown products which also contribute to regulation of numerous cellular processes. Recently, channeling of H 2 O 2 by some mammalian aquaporin isoforms has been reported and suggested to contribute to aquaporin involvement in cancer malignancies, although the mechanism by which these membrane water channels are implicated in oxidative stress is not clear. In this study, two yeast models with increased levels of membrane polyunsaturated fatty acids (PUFAs) and aquaporin AQY1 overexpression, respectively, were used to evaluate their interplay in cell's oxidative status. In particular, the aim of the study was to investigate if HNE accumulation could affect aquaporin function with an outcome in oxidative stress response. The data showed that induction of aquaporin expression by PUFAs results in increased water permeability in yeast membranes and that AQY1 activity is impaired by HNE. Moreover, AQY1 expression increases cellular sensitivity to oxidative stress by facilitating H 2 O 2 influx. On the other hand, AQY1 expression has no influence on the cellular antioxidant GSH levels and catalase activity. These results strongly suggest that aquaporins are important players in oxidative stress response and could contribute to regulation of cellular processes by regulation of H 2 O 2 influx. © 2017 IUBMB Life, 69(5):355-362, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

Genome-wide identification and analysis of the aldehyde dehydrogenase (ALDH) gene superfamily in apple (Malus × domestica Borkh.).

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Li, Xiaoqin; Guo, Rongrong; Li, Jun; Singer, Stacy D; Zhang, Yucheng; Yin, Xiangjing; Zheng, Yi; Fan, Chonghui; Wang, Xiping

2013-10-01

Aldehyde dehydrogenases (ALDHs) represent a protein superfamily encoding NAD(P)(+)-dependent enzymes that oxidize a wide range of endogenous and exogenous aliphatic and aromatic aldehydes. In plants, they are involved in many biological processes and play a role in the response to environmental stress. In this study, a total of 39 ALDH genes from ten families were identified in the apple (Malus × domestica Borkh.) genome. Synteny analysis of the apple ALDH (MdALDH) genes indicated that segmental and tandem duplications, as well as whole genome duplications, have likely contributed to the expansion and evolution of these gene families in apple. Moreover, synteny analysis between apple and Arabidopsis demonstrated that several MdALDH genes were found in the corresponding syntenic blocks of Arabidopsis, suggesting that these genes appeared before the divergence of lineages that led to apple and Arabidopsis. In addition, phylogenetic analysis, as well as comparisons of exon-intron and protein structures, provided further insight into both their evolutionary relationships and their putative functions. Tissue-specific expression analysis of the MdALDH genes demonstrated diverse spatiotemporal expression patterns, while their expression profiles under abiotic stress and various hormone treatments indicated that many MdALDH genes were responsive to high salinity and drought, as well as different plant hormones. This genome-wide identification, as well as characterization of evolutionary relationships and expression profiles, of the apple MdALDH genes will not only be useful for the further analysis of ALDH genes and their roles in stress response, but may also aid in the future improvement of apple stress tolerance. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Chemoselective Preparation of 1,1-Diacetates from Aldehydes, Mediated by a Keggin Heteropolyacid Under Solvent Free Conditions at Room Temperature

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G. Romanelli

2007-01-01

Full Text Available A simple, general and efficient method has been developed for the conversion of aldehydes to 1,1-diacetates using acetic anhydride, a catalytic amount of non commercial Keggin heteropolyacid (H6 PalMo11O40 (1% mol in solvent free conditions at room temperature. Aromatic and aliphatic, simple and conjugated aldehydes were protected with excellent yields.

Visible-light-promoted and one-pot synthesis of phenanthridines and quinolines from aldehydes and O-acyl hydroxylamine.

Science.gov (United States)

An, Xiao-De; Yu, Shouyun

2015-06-05

A one-pot synthesis of phenanthridines and quinolines from commercially available or easily prepared aldehydes has been reported. O-(4-Cyanobenzoyl)hydroxylamine was utilized as the nitrogen source to generate O-acyl oximes in situ with aldehydes catalyzed by Brønsted acid. O-Acyl oximes were then subjected to visible light photoredox catalyzed cyclization via iminyl radicals to furnish aza-arenes. A variety of phenanthridines and quinolines have been prepared assisted by Brønsted acid and photocatalyst under visible light at room temperature with satisfactory yields.

Threshold photoelectron spectroscopy and photoionization total ion yield spectroscopy of simple organic acids, aldehydes, ketones and amines

International Nuclear Information System (INIS)

Yencha, Andrew J; Malins, Andrew E R; Siggel-King, Michele R F; Eypper, Marie; King, George C

2009-01-01

We have initiated a research program to investigate the ionization behavior of some simple organic molecules containing the carboxyl group (R 2 C=O), where R could be H, OH, NH 2 , or CH 3 or other aliphatic or aromatic carbon groups, using threshold photoelectron spectroscopy and photoionization total ion yield spectroscopy. We report here on the simplest organic acid, formic acid, and two simple aldehydes: acetaldehyde and the simplest unsaturated aldehyde, 2-propenal (acrolein). The objective of this study was to characterize the valence cationic states of these molecules with vibrational structural resolution.

QSTR with extended topochemical atom (ETA) indices. 14. QSAR modeling of toxicity of aromatic aldehydes to Tetrahymena pyriformis

Energy Technology Data Exchange (ETDEWEB)

Roy, Kunal, E-mail: kunalroy_in@yahoo.com [Drug Theoretics and Cheminformatics Laboratory, Division of Medicinal and Pharmaceutical Chemistry, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700 032 (India); Das, Rudra Narayan [Drug Theoretics and Cheminformatics Laboratory, Division of Medicinal and Pharmaceutical Chemistry, Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700 032 (India)

2010-11-15

Aldehydes are a toxic class of chemicals causing severe health hazards. In this background, quantitative structure-toxicity relationship (QSTR) models have been developed in the present study using Extended Topochemical Atom (ETA) indices for a large group of 77 aromatic aldehydes for their acute toxicity against the protozoan ciliate Tetrahymena pyriformis. The ETA models have been compared with those developed using various non-ETA topological indices. Attempt was also made to include the n-octanol/water partition coefficient (log K{sub o/w}) as an additional descriptor considering the importance of hydrophobicity in toxicity prediction. Thirty different models were developed using different chemometric tools. All the models have been validated using internal validation and external validation techniques. The statistical quality of the ETA models was found to be comparable to that of the non-ETA models. The ETA models have shown the important effects of steric bulk, lipophilicity, presence of electronegative atom containing substituents and functionality of the aldehydic oxygen to the toxicity of the aldehydes. The best ETA model (without using log K{sub o/w}) shows encouraging statistical quality (Q{sub int}{sup 2}=0.709,Q{sub ext}{sup 2}=0.744). It is interesting to note that some of the topological models reported here are better in statistical quality than previously reported models using quantum chemical descriptors.

Exploring Cooperative Effects in Oxidative NHC Catalysis: Regioselective Acylation of Carbohydrates.

Science.gov (United States)

Cramer, David L; Bera, Srikrishna; Studer, Armido

2016-05-23

The utility of oxidative NHC catalysis for both the regioselective and chemoselective functionalization of carbohydrates is explored. Chiral NHCs allow for the highly regioselective oxidative esterification of various carbohydrates using aldehydes as acylation precursors. The transformation was also shown to be amenable to both cis/trans diol isomers, free amino groups, and selective for specific sugar epimers in competition experiments. Efficiency and regioselectivity of the acylation can be improved upon using two different NHC catalysts that act cooperatively. The potential of the method is documented by the regioselective acylation of an amino-linked neodisaccharide. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxidation of aromatic alcohols on zeolite-encapsulated copper amino acid complexes

Energy Technology Data Exchange (ETDEWEB)

Ernst, S.; Teixeira Florencio, J.M. [Kaiserslautern Univ. (Germany). Dept. of Chemistry, Chemical Technology

1998-12-31

Copper complexes of the amino acids histidine, arginine and lysine have been introduced into the supercages of zeolite Y and, for the first time, into the large intracrystalline cavities of zeolites EMT and MCM-22. The resulting host/guest compounds are characterized by X-ray powder diffraction, UV/VIS-spectroscopy in the diffuse reflectance mode and by catalytic tests in the liquid-phase oxidation of aromatic alcohols (viz. benzyl alcohol, 2- and 3-methylbenzyl alcohol and 2,5-dimethylbenzyl alcohol) with tertiary-butylhydroperoxide as oxidant. It was observed that intracrystalline copper-amino acid complexes possess remarkable catalytic activity, yielding the corresponding aromatic aldehydes and acids. (orig.)

Volatile profile, lipid oxidation and protein oxidation of irradiated ready-to-eat cured turkey meat products

International Nuclear Information System (INIS)

Feng, Xi; Ahn, Dong Uk

2016-01-01

Irradiation had little effects on the thiobarbituric acid reactive substances (TBARS) values in ready-to-eat (RTE) turkey meat products, while it increased protein oxidation at 4.5 kGy. The volatile profile analyses indicated that the amount of sulfur compounds increased linearly as doses increased in RTE turkey meat products. By correlation analysis, a positive correlation was found between benzene/ benzene derivatives and alcohols with lipid oxidation, while aldehydes, ketones and alkane, alkenes and alkynes were positively correlated with protein oxidation. Principle component analysis showed that irradiated meat samples can be discriminated by two categories of volatile compounds: Strecker degradation products and radiolytic degradation products. The cluster analysis of volatile data demonstrated that low-dose irradiation had minor effects on the volatile profile of turkey sausages (<1.5 kGy). However, as the doses increased, the differences between the irradiated and non-irradiated cured turkey products became significant. - Highlights: • Irradiation had little effects on lipid oxidation of ready-to-eat cured turkey. • 4.5 kGy irradiation increased protein oxidation. • Irradiated samples were isolated due to Strecker/radiolytic degradation products. • 1.5 kGy irradiation had limited effects on the volatile profile of turkey sausages. • Dimethyl disulfide can be used as a potential marker for irradiated meat products.

Decreased total antioxidant levels and increased oxidative stress in ...

African Journals Online (AJOL)

21–25 ... Decreased total antioxidant levels and increased oxidative stress in South ... antioxidant-rich diet and lifestyle changes in T2DM patients would help to avert the .... glycation of proteins and the formation of advanced glycosylation.

Organocatalytic asymmetric michael addition of aldehydes to beta-nitroacroleine dimethyl acetal.

Science.gov (United States)

Reyes, Efraim; Vicario, Jose L; Badía, Dolores; Carrillo, Luisa

2006-12-21

[Structure: see text] The organocatalytic asymmetric Michael addition of aldehydes to beta-nitroacroleine dimethyl acetal has been studied in detail. The reaction took place with excellent yields and high stereoselectivities when a chiral beta-amino alcohol such as L-prolinol was employed as the catalyst, leaving a formation of highly functionalized enantioenriched compounds containing two differentiated formyl groups together with a nitro moiety.

Comparative genomics of aldehyde dehydrogenase 5a1 (succinate semialdehyde dehydrogenase and accumulation of gamma-hydroxybutyrate associated with its deficiency

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Malaspina Patrizia

2009-01-01

Full Text Available Abstract Succinic semialdehyde dehydrogenase (SSADH; aldehyde dehydrogenase 5A1 [ALDH5A1]; locus 6p22 occupies a central position in central nervous system (CNS neurotransmitter metabolism as one of two enzymes necessary for γ-aminobutyric acid (GABA recycling from the synaptic cleft. Its importance is highlighted by the neurometabolic disease associated with its inherited deficiency in humans, as well as the severe epileptic phenotype observed in Aldh5a1-/- knockout mice. Expanding evidence now suggests, however, that even subtle decreases in human SSADH activity, associated with rare and common single nucleotide polymorphisms, may produce subclinical pathological effects. SSADH, in conjunction with aldo-keto reductase 7A2 (AKR7A2, represent two neural enzymes responsible for further catabolism of succinic semialdehyde, producing either succinate (SSADH or γ-hydroxybutyrate (GHB; AKR7A2. A GABA analogue, GHB is a short-chain fatty alcohol with unusual properties in the CNS and a long pharmacological history. Moreover, SSADH occupies a further role in the CNS as the enzyme responsible for further metabolism of the lipid peroxidation aldehyde 4-hydroxy-2-nonenal (4-HNE, an intermediate known to induce oxidant stress. Accordingly, subtle decreases in SSADH activity may have the capacity to lead to regional accumulation of neurotoxic intermediates (GHB, 4-HNE. Polymorphisms in SSADH gene structure may also associate with quantitative traits, including intelligence quotient and life expectancy. Further population-based studies of human SSADH activity promise to reveal additional properties of its function and additional roles in CNS tissue.

The effect of peroxynitrite decomposition catalyst MnTBAP on aldehyde dehydrogenase-2 nitration by organic nitrates: role in nitrate tolerance.

Science.gov (United States)

Mollace, Vincenzo; Muscoli, Carolina; Dagostino, Concetta; Giancotti, Luigino Antonio; Gliozzi, Micaela; Sacco, Iolanda; Visalli, Valeria; Gratteri, Santo; Palma, Ernesto; Malara, Natalia; Musolino, Vincenzo; Carresi, Cristina; Muscoli, Saverio; Vitale, Cristiana; Salvemini, Daniela; Romeo, Francesco

2014-11-01

Bioconversion of glyceryl trinitrate (GTN) into nitric oxide (NO) by aldehyde dehydrogenase-2 (ALDH-2) is a crucial mechanism which drives vasodilatory and antiplatelet effect of organic nitrates in vitro and in vivo. Oxidative stress generated by overproduction of free radical species, mostly superoxide anions and NO-derived peroxynitrite, has been suggested to play a pivotal role in the development of nitrate tolerance, though the mechanism still remains unclear. Here we studied the free radical-dependent impairment of ALDH-2 in platelets as well as vascular tissues undergoing organic nitrate ester tolerance and potential benefit when using the selective peroxynitrite decomposition catalyst Mn(III) tetrakis (4-Benzoic acid) porphyrin (MnTBAP). Washed human platelets were made tolerant to nitrates via incubation with GTN for 4h. This was expressed by attenuation of platelet aggregation induced by thrombin (40U/mL), an effect accompanied by GTN-related induction of cGMP levels in platelets undergoing thrombin-induced aggregation. Both effects were associated to attenuated GTN-induced nitrite formation in platelets supernatants and to prominent nitration of ALDH-2, the GTN to NO metabolizing enzyme, suggesting that GTN tolerance was associated to reduced NO formation via impairment of ALDH-2. These effects were all antagonized by co-incubation of platelets with MnTBAP, which restored GTN-induced responses in tolerant platelets. Comparable effect was found under in in vivo settings. Indeed, MnTBAP (10mg/kg, i.p.) significantly restored the hypotensive effect of bolus injection of GTN in rats made tolerants to organic nitrates via chronic administration of isosorbide-5-mononitrate (IS-5-MN), thus confirming the role of peroxynitrite overproduction in the development of tolerance to vascular responses induced by organic nitrates. In conclusion, oxidative stress subsequent to prolonged use of organic nitrates, which occurs via nitration of ALDH-2, represents a key event

Vapor pressures and enthalpies of vaporization of a series of the linear aliphatic aldehydes

Czech Academy of Sciences Publication Activity Database

Verevkin, S. P.; Krasnykh, E. L.; Vasiltsova, T. V.; Koutek, Bohumír; Doubský, Jan; Heintz, A.

2003-01-01

Roč. 206, - (2003), s. 331-339 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z4055905 Keywords : aldehydes * vapor pressure * enthalpy of vaporization Subject RIV: CC - Organic Chemistry Impact factor: 1.165, year: 2003

Dual Enantioselective Control using D-phenylglycine-L-proline-derived Catalysts for the Enantioselective Addition of Diethylzinc to Aldehyde

International Nuclear Information System (INIS)

Kang, Seock Yong; Park, Yong Sun

2016-01-01

Dipeptide-derived catalysts are of great interest in various asymmetric transformations because of their short and simple preparation and easy modification of their modular structure by using different α-amino acids. We recently reported the first example of dipeptide-catalyzed enantioselective addition of dialkylzinc to aldehydes. We have developed a novel D-Phg-L-Pro dipeptide-derived catalyst for the addition of diethylzinc to aromatic aldehydes. We also disclosed an effective chiral switching by simply modifying nonchiral part of D-Phg-L-Pro dipeptide.

Oxidative stress and neurological disorders in relation to blood lead levels in children.

Science.gov (United States)

Ahamed, M; Fareed, Mohd; Kumar, A; Siddiqui, W A; Siddiqui, M K J

2008-01-01

Oxidative stress plays a pivotal role in the pathogenesis of neurological disorders. Free radical generation appears to be the mode of lead toxicity. We evaluated the effects of blood lead levels on oxidative stress parameters in children suffering from neurological disorders. Thirty children (aged 3-12 years) with neurological disorders (cerebral palsy [n = 12], seizures [n = 11], and encephalopathy [n = 7]) were recruited in the study group. Sixty healthy children (aged 3-12 years) from similar socio-economic environments and not suffering from any chronic disease were taken as the controls. Blood lead levels and oxidant/antioxidant status were determined. Mean blood lead level was significantly higher while delta-aminolevulinic acid dehydratase (delta-ALAD) activity, a biomarker for lead exposure, was significantly lower in the study group as compared to the control group (P children with neurological disorders. Lead-induced oxidative stress as an underlying mechanism for neurological diseases in children warranted further investigation.

Molecular characterization of the fatty alcohol oxidation pathway for wax-ester mobilization in germinated jojoba seeds.

Science.gov (United States)

Rajangam, Alex S; Gidda, Satinder K; Craddock, Christian; Mullen, Robert T; Dyer, John M; Eastmond, Peter J

2013-01-01

Jojoba (Simmondsia chinensis) is the only plant species known to use liquid wax esters (WEs) as a primary seed storage reserve. Upon germination, WE hydrolysis releases very-long-chain fatty alcohols, which must be oxidized to fatty acids by the sequential action of a fatty alcohol oxidase (FAO) and a fatty aldehyde dehydrogenase (FADH) before they can be β-oxidized. Here, we describe the cloning and characterization of genes for each of these two activities. Jojoba FAO and FADH are 52% and 68% identical to Arabidopsis (Arabidopsis thaliana) FAO3 and ALDH3H1, respectively. The genes are expressed most strongly in the cotyledons of jojoba seedlings following germination, but transcripts can also be detected in vegetative tissues. Proteomic analysis indicated that the FAO and FADH proteins can be detected on wax bodies, but they localized to the endoplasmic reticulum when they were expressed as amino-terminal green fluorescent protein fusions in tobacco (Nicotiana tabacum) leaves. Recombinant jojoba FAO and FADH proteins are active on very-long-chain fatty alcohol and fatty aldehyde substrates, respectively, and have biochemical properties consistent with those previously reported in jojoba cotyledons. Coexpression of jojoba FAO and FADH in Arabidopsis enhanced the in vivo rate of fatty alcohol oxidation more than 4-fold. Taken together, our data suggest that jojoba FAO and FADH constitute the very-long-chain fatty alcohol oxidation pathway that is likely to be necessary for efficient WE mobilization following seed germination.

Allene oxide synthase, allene oxide cyclase and jasmonic acid levels in Lotus japonicus nodules.

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Anna Zdyb

Full Text Available Jasmonic acid (JA, its derivatives and its precursor cis-12-oxo phytodienoic acid (OPDA form a group of phytohormones, the jasmonates, representing signal molecules involved in plant stress responses, in the defense against pathogens as well as in development. Elevated levels of JA have been shown to play a role in arbuscular mycorrhiza and in the induction of nitrogen-fixing root nodules. In this study, the gene families of two committed enzymes of the JA biosynthetic pathway, allene oxide synthase (AOS and allene oxide cyclase (AOC, were characterized in the determinate nodule-forming model legume Lotus japonicus JA levels were to be analysed in the course of nodulation. Since in all L. japonicus organs examined, JA levels increased upon mechanical disturbance and wounding, an aeroponic culture system was established to allow for a quick harvest, followed by the analysis of JA levels in whole root and shoot systems. Nodulated plants were compared with non-nodulated plants grown on nitrate or ammonium as N source, respectively, over a five week-period. JA levels turned out to be more or less stable independently of the growth conditions. However, L. japonicus nodules formed on aeroponically grown plants often showed patches of cells with reduced bacteroid density, presumably a stress symptom. Immunolocalization using a heterologous antibody showed that the vascular systems of these nodules also seemed to contain less AOC protein than those of nodules of plants grown in perlite/vermiculite. Hence, aeroponically grown L. japonicus plants are likely to be habituated to stress which could have affected JA levels.

Product Analysis of the {OH} Oxidation of Acrolein and Methacrolein in the Presence of {NO}

Science.gov (United States)

Dransfield, T. J.; Sprengnether, M. M.; Huang, Y.; Donahue, N. M.; Demerjian, K. L.; Anderson, J. G.

2002-12-01

The oxidation of acrolein and methacrolein by OH in the presence of high NO was studied under "wall-less" conditions in Harvard's High Pressure Flow System. The experiment was conducted at 450 torr with a reaction time of several seconds. In the present work, first stage products are formed at 1013 molecules/cm3 levels and analyzed in-situ by FTIR spectroscopy. The use of Reaction Modulation Spectroscopy allows for accurate measurement of the very small(~1%) change in unsaturated aldehyde and NO reactants, in addition to product concentrations. Observed products from the acrolein oxidation include: formaldehyde(CH2O), glyoxal(CHOCHO), glycolaldehyde(CH2OHCHO), ketene(CH2CO), nitrogen dioxide, carbon dioxide and carbon monoxide. The methacrolein oxidation produces: formaldehyde, methylgyloxal(CH3COCHO), hydroxyacetone(CH2OHC(O)CH3), ketene, nitrogen dioxide, carbon dioxide and carbon monoxide. Both reactions also produce peroxynitrates and alkylnitrates that have proven difficult to spectrally resolve. We observe elevated yields of ketene relative to previously published experiments conducted on longer timescales. We interpret this as evidence of rapid ketene removal in these systems. The mechanisms for ketene formation are discussed.

Quantification of Dissolved and Particulate Polyunsaturated Aldehydes in the Adriatic Sea

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Raffaella Casotti

2011-03-01

Full Text Available Polyunsaturated aldehydes (PUA are supposed to play critical roles in chemically-mediated plankton interactions. Laboratory studies suggest that they act as mediators of chemical defense and chemical communication. PUA are oxylipins containing an α,β,γ,δ-unsaturated aldehyde structure element and are mainly found in diatoms. We present here a detailed surface mapping of PUA during a spring bloom of the diatom Skeletonema marinoi in the Adriatic Sea. We monitored dissolved PUA, as well as particulate PUA, which are produced by phytoplankton after cell disintegration. Our survey revealed a patchy distribution of PUA and shows that at most stations S. marinoi is the major contributor to the overall PUA. Our data also suggest that lysis of a diatom bloom can contribute significantly to the dissolved PUA concentrations and that other producers, which are smaller in cell size compared to diatoms, have to be taken into account as well if the total PUA content of marine samples is considered. The analyses of samples collected in deeper water suggests that diatom contribution to PUA decreases with depth, while smaller-sized unidentified organisms take place as dominant contributors to the PUA concentrations.

Metformin induces oxidative stress in white adipocytes and raises uncoupling protein 2 levels.

Science.gov (United States)

Anedda, Andrea; Rial, Eduardo; González-Barroso, M Mar

2008-10-01

Metformin is a drug widely used to treat type 2 diabetes. It enhances insulin sensitivity by improving glucose utilization in tissues like liver or muscle. Metformin inhibits respiration, and the decrease in cellular energy activates the AMP-activated protein kinase that in turn switches on catabolic pathways. Moreover, metformin increases lipolysis and beta-oxidation in white adipose tissue, thereby reducing the triglyceride stores. The uncoupling proteins (UCPs) are transporters that lower the efficiency of mitochondrial oxidative phosphorylation. UCP2 is thought to protect against oxidative stress although, alternatively, it could play an energy dissipation role. The aim of this work was to analyse the involvement of UCP2 on the effects of metformin in white adipocytes. We studied the effect of this drug in differentiating 3T3-L1 adipocytes and found that metformin causes oxidative stress since it increases the levels of reactive oxygen species (ROS) and lowers the aconitase activity. Variations in UCP2 protein levels parallel those of ROS. Metformin also increases lipolysis in these cells although only when the levels of ROS and UCP2 have decreased. Hence, UCP2 does not appear to be needed to facilitate fatty acid oxidation. Furthermore, treatment of C57BL/6 mice with metformin also augmented the levels of UCP2 in epididymal white adipose tissue. We conclude that metformin treatment leads to the overexpression of UCP2 in adipocytes to minimize the oxidative stress that is probably due to the inhibition of respiration caused by the drug.

A Green Approach for Allylations of Aldehydes and Ketones: Combining Allylborate, Mechanochemistry and Lanthanide Catalyst

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Viviane P. de Souza

2016-11-01

Full Text Available Secondary and tertiary alcohols synthesized via allylation of aldehydes and ketones are important compounds in bioactive natural products and industry, including pharmaceuticals. Development of a mechanochemical method using potassium allyltrifluoroborate salt and water, to successfully perform the allylation of aromatic and aliphatic carbonyl compounds is reported for the first time. By controlling the grinding parameters, the methodology can be selective, namely, very efficient for aldehydes and ineffective for ketones, but by employing lanthanide catalysts, the reactions with ketones can become practically quantitative. The catalyzed reactions can also be performed under mild aqueous stirring conditions. Considering the allylation agent and its by-products, aqueous media, energy efficiency and use of catalyst, the methodology meets most of the green chemistry principles.

A General and Convenient Method for the Rhodium-Catalyzed Decarbonylation of Aldehydes

DEFF Research Database (Denmark)

Kreis, Michael; Palmelund, Anders; Bunch, Lennart

2006-01-01

A practical protocol for the decarbonylation of a wide range of aldehydes has been developed by using commercially available RhCl3x3H2O and dppp in a diglyme solution. This method gives rise to decarbonylated products in good to high yield and is particularly useful because of its experimental si...

Mild and Efficient One Pot Synthesis of Imidazolinesand Benzimidazoles from Aldehydes

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Rajesh Kumar

2007-01-01

Full Text Available A series of some imidazolines and benzimidazoles were synthesizedfrom various aldehydes and 1,2-diamines in the presence of ceric(IVammonium nitrate (CAN. The title compounds were prepared via one stepsynthesis method. The simplicity of the reaction conditions with shorterreaction time and with out use of column chromatography to get the pureproducts in high yields makes this method more attractive for organic chemists.

Are PTH levels related to oxidative stress and inflammation in chronic kidney disease patients on hemodialysis?

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Marcel Jaqueto

Full Text Available Abstract Introduction: Patients at end stage renal disease have higher levels of inflammation and oxidative stress than the general population. Many factors contribute to these issues, and the parathyroid hormone (PTH is also implicated. Objective: The study was conducted in order to assess the relationship between PTH levels and inflammation and oxidative stress in hemodialysis patients. Methods: Cross-sectional study with patients of two hemodialysis facilities in Londrina, Brazil. Patients with other conditions known to generate oxidative stress and inflammation were excluded. Blood levels of PTH and biochemical parameters of inflammation (interleukins 1 and 6, tumor necrosis factor-alpha and oxidative stress (total plasma antioxidant capacity, malonic dialdehyde, lipid hydroperoxidation, advanced oxidation protein products, quantification of nitric oxide metabolites, and 8-isoprostane were measured before a dialysis session. Then, we made correlation analyses between PTH levels - either as the continuous variable or categorized into tertiles-, and inflammatory and oxidative stress biomarkers. Results: PTH did not show any correlation with the tested inflammation and oxidative stress parameters, nor as continuous variable neither as categorical variable. Conclusion: In this descriptive study, the results suggest that the inflammation and oxidative stress of hemodialysis patients probably arise from mechanisms other than secondary hyperparathyroidism.

Secondary amine-initiated three-component synthesis of 3,4-dihydropyrimidinones and thiones involving alkynes, aldehydes and thiourea/urea

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Jie-Ping Wan

2014-01-01

Full Text Available The three-component reactions of aldehydes, electron deficient alkynes and ureas/thioureas have been smoothly performed to yield a class of unprecedented 3,4-dihydropyrimidinones and thiones (DHPMs. The reactions are initiated by the key transformation of an enamine-type activation involving the addition of a secondary amine to an alkyne, which enables the subsequent incorporation of aldehydes and ureas/thioureas. This protocol tolerates a broad range of aryl- or alkylaldehydes, N-substituted and unsubstituted ureas/thioureas and alkynes to yield the corresponding DHPMs with specific regioselectivity.

Classifying oxidative stress by F2-isoprostane levels across human diseases: A meta-analysis.

Science.gov (United States)

van 't Erve, Thomas J; Kadiiska, Maria B; London, Stephanie J; Mason, Ronald P

2017-08-01

The notion that oxidative stress plays a role in virtually every human disease and environmental exposure has become ingrained in everyday knowledge. However, mounting evidence regarding the lack of specificity of biomarkers traditionally used as indicators of oxidative stress in human disease and exposures now necessitates re-evaluation. To prioritize these re-evaluations, published literature was comprehensively analyzed in a meta-analysis to quantitatively classify the levels of systemic oxidative damage across human disease and in response to environmental exposures. In this meta-analysis, the F 2 -isoprostane, 8-iso-PGF 2α , was specifically chosen as the representative marker of oxidative damage. To combine published values across measurement methods and specimens, the standardized mean differences (Hedges' g) in 8-iso-PGF 2α levels between affected and control populations were calculated. The meta-analysis resulted in a classification of oxidative damage levels as measured by 8-iso-PGF 2α across 50 human health outcomes and exposures from 242 distinct publications. Relatively small increases in 8-iso-PGF 2α levels (ganalysis of published data. This analysis provides knowledge on the true involvement of oxidative damage across human health outcomes as well as utilizes past research to prioritize those conditions requiring further scrutiny on the mechanisms of biomarker generation. Copyright © 2017. Published by Elsevier B.V.

A Comparative study on VOCs and aldehyde-ketone emissions from a spark Ignition vehicle fuelled on compressed natural gas and gasoline

International Nuclear Information System (INIS)

Shah, A.N.

2012-01-01

In this work, an experimental study was conducted on a spark ignition (SI) vehicle fuelled on compressed natural gas (CNG), and gasoline to compare the unregulated emissions such as volatile organic compounds (VOCs) and aldehyde-ketones or carbonyls. In the meantime, ozone forming potential (OFP) of pollutants was also calculated on the basis of their specific reactivity (SR). The vehicle was run on a chassis dynamometer following the Chinese National Standards test scheduled for light duty vehicle (LDV) emissions. According to the results, total aldehyde-ketones were increased by 39.4% due to the substantial increase in formaldehyde and acrolein + acetone emissions, while VOCs and BTEX (benzene, toluene, ethyl benzene, and xylene) reduced by 85.2 and 86% respectively, in case of CNG fuelled vehicle as compared to gasoline vehicle. Although total aldehyde-ketones were higher with CNG relative to gasoline, their SR was lower due decrease in acetaldehyde, propionaldehyde, crotonaldehyde, and methacrolein species having higher maximum incremental reactivity (MIR) values. The SR of VOCs and aldehyde-ketones emitted from CNG fuelled vehicle was decreased by above 10% and 32% respectively, owing to better physicochemical properties and more complete burning of CNG as compared to gasoline. (author)

Electro-oxidation of methanol and formic acid on platinum nanoparticles with different oxidation levels

International Nuclear Information System (INIS)

Hsieh, Chien-Te; Hsiao, Han-Tsung; Tzou, Dong-Ying; Yu, Po-Yuan; Chen, Po-Yen; Jang, Bi-Sheng

2015-01-01

Herein reported is an atomic layer deposition (ALD) process of platinum (Pt) from (methylcyclopentadienyl) trimethylplatinum (MeCpPtMe 3 ) and oxygen (O 2 ) for synthesizing the Pt electrocatalysts toward methanol and formic acid oxidation. The as-synthesized Pt catalysts are thermally reduced in 5 vol% H 2 within temperature window of 150–450 °C. The reduction treatment induces a decrease in amount of Pt oxide (Pt–O) species, e.g., PtO and PtO 2 . The presence of Pt–O species not only enhances catalytic activity but also improves anti-poisoning ability toward the oxidation of methanol and formic acid. The improved activity originates from the fact that the Pt–O species, formed by the ALD route, creates a large number of active sites (e.g., Pt–O ads and Pt–(OH) ads ) to strip the CO-adsorbed sites, leading to a high-level of CO tolerance. This work also proposes a stepwise reaction steps to shed some lights on how the Pt–O species promote the catalytic activity. - Highlights: • This study adopts atomic layer deposition (ALD) to grow metallic Pt nanoparticles. • The Pt catalysts show catalytic activity toward methanol and formic acid oxidation. • The reduction treatment induces a decrease in amount of Pt oxide (Pt–O) species. • The Pt–O species creates a number of active sites to strip the CO-adsorbed sites. • A stepwise reaction step concerning the promoted catalytic activity is proposed

Re-evaluation of peroxide value as an indicator of the quality of edible oils.

Science.gov (United States)

Shiozawa, Satoshi; Tanaka, Masaharu; Ohno, Katsutoshi; Nagao, Yasuhiro; Yamada, Toshihiro

2007-06-01

The oxidation of oils has important effects on the quality of oily foods, such as instant noodles. In particular, the generation of aldehydes, which accompanies the oxidation of oils, is one of the first factors to reduce food quality. We examined various indicators of oil quality during temperature-accelerated storage and found that peroxide value (POV) was highly correlated with the total concentration of major odorants. Moreover, the correlation of POV with the total concentration of five unsaturated aldehydes (t-2-heptenal, t-2-octenal, t-2-decenal, t-2-undecenal and t,t-2,4-decadienal) that show strong cytotoxicity was greater than the correlation of POV with the total concentration of major odorants. The maximum allowable concentration of the five aldehydes was calculated based on the 'no observed adverse-effect level' of the aldehyde that showed the highest cytotoxicity, t,t-2,4-decadienal, along with the human daily oil intake. We showed that it is useful to utilize POV as an indicator to control food quality and safety.

Antioxidant factors, nitric oxide levels, and cellular damage in leprosy patients

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Taysa Ribeiro Schalcher

2013-09-01

Full Text Available Introduction The immune response caused by Mycobacterium leprae is a risk factor for the development of oxidative stress (OS in leprosy patients. This study aimed to assess OS in leprosy patients before the use of a multidrug therapy. Methods We evaluated the nitric oxide (NO concentration; antioxidant capacity; levels of malondialdehyde, methemoglobin and reduced glutathione; and the activity of catalase and superoxide dismutase (SOD in leprosy patients. Results We observed lower SOD activity in these leprosy patients; however, the NO levels and antioxidant capacity were increased. Conclusions The infectious process in response to M. leprae could primarily be responsible for the OS observed in these patients.

The oxidation of alcohols and aldehydes by potassium chlorate in te presence of a ruthenium heteropolycomplex

International Nuclear Information System (INIS)

Kuznetsova, L.I.; Likholobov, V.A.; Detusheva, L.G.

1993-01-01

At interaction of K 2 RuOHCl 5 with Na 2 PW 11 O 39 catalyst for oxidation of primary alcohols and adlehydes up to proper carboxylic acid (yield ∼ 100%) was formed in aqueous solution, pH 2; 25-75 deg C. Acroleinwas demonstrated to be oxidized in acrylic acid with high selectivity

Long-term vegetarians have low oxidative stress, body fat, and cholesterol levels.

Science.gov (United States)

Kim, Mi Kyung; Cho, Sang Woon; Park, Yoo Kyoung

2012-04-01

Excessive oxidative stress and abnormal blood lipids may cause chronic diseases. This risk can be reduced by consuming an antioxidant- and fiber-rich vegetarian diet. We compared biomarkers of oxidative stress, antioxidant capacity, and lipid profiles of sex- and age-matched long-term vegetarians and omnivores in Korea. Forty-five vegetarians (23 men and 22 women; mean age, 49.5 ± 5.3 years), who had maintained a vegetarian diet for a minimum of 15 years, and 30 omnivores (15 men and 15 women; mean age, 48.9 ± 3.6 years) participated in this study. Their 1-day, 24-h recall, and 2-day dietary records were analyzed. Oxidative stress was measured by the levels of diacron reactive oxygen metabolites (d-ROM). Antioxidant status was determined by the biological antioxidant potential (BAP) and levels of endogenous antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. We observed that vegetarians had a significantly lower body fat percentage (21.6 ± 6.4%) than that of omnivores (25.4 ± 4.6%; P vegetarians than those in omnivores (331.82 ± 77.96 and 375.80 ± 67.26 Carratelli units; P vegetarians and omnivores were 173.73 ± 31.42 mg/dL and 193.17 ± 37.89 mg/dL, respectively (P vegetarians and omnivores, respectively, indicating that vegetarians had significantly lower lipid levels. Thus, oxidative stress, body fat, and cholesterol levels were lower in long-term vegetarians than those in omnivores.

Characterisation of recombinant human fatty aldehyde dehydrogenase: implications for Sjögren-Larsson syndrome

NARCIS (Netherlands)

Lloyd, Matthew D.; Boardman, Kieren D. E.; Smith, Andrew; van den Brink, Daan M.; Wanders, Ronald J. A.; Threadgill, Michael D.

2007-01-01

Fatty aldehyde dehydrogenase (FALDH) is an NAD+-dependent oxidoreductase involved in the metabolism of fatty alcohols. Enzyme activity has been implicated in the pathology of diabetes and cancer. Mutations in the human gene inactivate the enzyme and cause accumulation of fatty alcohols in

Inhibition of palm oil oxidation by zeolite nanocrystals.

Science.gov (United States)

Tan, Kok-Hou; Awala, Hussein; Mukti, Rino R; Wong, Ka-Lun; Rigaud, Baptiste; Ling, Tau Chuan; Aleksandrov, Hristiyan A; Koleva, Iskra Z; Vayssilov, Georgi N; Mintova, Svetlana; Ng, Eng-Poh

2015-05-13

The efficiency of zeolite X nanocrystals (FAU-type framework structure) containing different extra-framework cations (Li(+), Na(+), K(+), and Ca(2+)) in slowing the thermal oxidation of palm oil is reported. The oxidation study of palm oil is conducted in the presence of zeolite nanocrystals (0.5 wt %) at 150 °C. Several characterization techniques such as visual analysis, colorimetry, rheometry, total acid number (TAN), FT-IR spectroscopy, (1)H NMR spectroscopy, and Karl Fischer analyses are applied to follow the oxidative evolution of the oil. It was found that zeolite nanocrystals decelerate the oxidation of palm oil through stabilization of hydroperoxides, which are the primary oxidation product, and concurrently via adsorption of the secondary oxidation products (alcohols, aldehydes, ketones, carboxylic acids, and esters). In addition to the experimental results, periodic density functional theory (DFT) calculations are performed to elucidate further the oxidation process of the palm oil in the presence of zeolite nanocrystals. The DFT calculations show that the metal complexes formed with peroxides are more stable than the complexes with alkenes with the same ions. The peroxides captured in the zeolite X nanocrystals consequently decelerate further oxidation toward formation of acids. Unlike the monovalent alkali metal cations in the zeolite X nanocrystals (K(+), Na(+), and Li(+)), Ca(2+) reduced the acidity of the oil by neutralizing the acidic carboxylate compounds to COO(-)(Ca(2+))1/2 species.

Lignocellulose pretreatment technologies affect the level of enzymatic cellulose oxidation by LPMO

DEFF Research Database (Denmark)

Rodríguez-Zúñiga, Ursula Fabiola; Cannella, David; de Campos Giordano, Roberto

2015-01-01

of the cellulose oxidizing enzyme lytic polysaccharide monooxygenase (LPMO). The highest activity of LPMO was observed for the hydrothermally pretreated biomasses, which also contained the highest level of lignin. All hydrolysis were done at high dry matter levels, using a commercial enzyme preparation containing......Sugarcane bagasse, corn stover, and wheat straw are among the most available resources for production of cellulosic ethanol. For these biomasses we study the influence of pre-treatment methods on the chemical composition, as well as on the subsequent reactions of enzymatic hydrolysis and oxidation...

Kinetics and mechanism of the selective oxidation of primary aliphatic alcohols under phase transfer catalysis

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K. Bijudas

2014-03-01

Full Text Available Kinetics of the oxidation of primary aliphatic alcohols has been carried out using phase transferred monochromate in benzene. Tetrabutylammonium bromide (TBAB and tetrabutylphosphonium bromide (TBPB are used as phase transfer catalysts (PT catalyst. The reaction shows first order dependence on both [alcohol] and [monochromate ion]. The oxidation leads to the formation of corresponding aldehyde and no traces of carboxylic acid has been detected. The reaction mixture failed to induce the polymerization of added acrylonitrile which rules out the presence radical intermediates in the reaction. Various thermodynamic parameters have been evaluated and a suitable mechanism has been proposed.

Kinetics of Oxidation of Some Amino Acids by N-Chlorosaccharin in Aqueous Acetic Acid Medium

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N. A. Mohamed Farook

2004-01-01

Full Text Available The kinetics of oxidation of some amino acids namely, glycine, alanine, aspartic acid, arginine, and histidine, (AA by N-chlorosaccharin (NCSA in aqueous acetic acid medium in the presence of perchloric acid have been investigated. The observed rate of oxidation is first order in [AA], [NCSA] and of inverse fractional order in [H+]. The main product of the oxidation is the corresponding aldehyde. The ionic strength on the reaction rate has no significant effect. The effect of changing the dielectric constant of the medium on the rate indicates the reaction to be of dipole-dipole type. Hypochlorous acid has been postulated as the reactive oxidizing species. The reaction constants involved in the mechanism are derived. The activation parameters are computed with respect to slow step of the mechanism.

Functional analysis of aldehyde oxidase using expressed chimeric enzyme between monkey and rat.

Science.gov (United States)

Itoh, Kunio; Asakawa, Tasuku; Hoshino, Kouichi; Adachi, Mayuko; Fukiya, Kensuke; Watanabe, Nobuaki; Tanaka, Yorihisa

2009-01-01

Aldehyde oxidase (AO) is a homodimer with a subunit molecular mass of approximately 150 kDa. Each subunit consists of about 20 kDa 2Fe-2S cluster domain storing reducing equivalents, about 40 kDa flavine adenine dinucleotide (FAD) domain and about 85 kDa molybdenum cofactor (MoCo) domain containing a substrate binding site. In order to clarify the properties of each domain, especially substrate binding domain, chimeric cDNAs were constructed by mutual exchange of 2Fe-2S/FAD and MoCo domains between monkey and rat. Chimeric monkey/rat AO was referred to one with monkey type 2Fe-2S/FAD domains and a rat type MoCo domain. Rat/monkey AO was vice versa. AO-catalyzed 2-oxidation activities of (S)-RS-8359 were measured using the expressed enzyme in Escherichia coli. Substrate inhibition was seen in rat AO and chimeric monkey/rat AO, but not in monkey AO and chimeric rat/monkey AO, suggesting that the phenomenon might be dependent on the natures of MoCo domain of rat. A biphasic Eadie-Hofstee profile was observed in monkey AO and chimeric rat/monkey AO, but not rat AO and chimeric monkey/rat AO, indicating that the biphasic profile might be related to the properties of MoCo domain of monkey. Two-fold greater V(max) values were observed in monkey AO than in chimeric rat/monkey AO, and in chimeric monkey/rat AO than in rat AO, suggesting that monkey has the more effective electron transfer system than rat. Thus, the use of chimeric enzymes revealed that 2Fe-2S/FAD and MoCo domains affect the velocity and the quantitative profiles of AO-catalyzed (S)-RS-8359 2-oxidation, respectively.

Electro-oxidation of methanol and formic acid on platinum nanoparticles with different oxidation levels

Energy Technology Data Exchange (ETDEWEB)

Hsieh, Chien-Te, E-mail: cthsieh@saturn.yzu.edu.tw [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan (China); Hsiao, Han-Tsung; Tzou, Dong-Ying; Yu, Po-Yuan [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan (China); Chen, Po-Yen; Jang, Bi-Sheng [Materials and Electro-Optics Research Division, National Chung-Shan Institute of Science and Technology, Taoyuan 325, Taiwan (China)

2015-01-15

Herein reported is an atomic layer deposition (ALD) process of platinum (Pt) from (methylcyclopentadienyl) trimethylplatinum (MeCpPtMe{sub 3}) and oxygen (O{sub 2}) for synthesizing the Pt electrocatalysts toward methanol and formic acid oxidation. The as-synthesized Pt catalysts are thermally reduced in 5 vol% H{sub 2} within temperature window of 150–450 °C. The reduction treatment induces a decrease in amount of Pt oxide (Pt–O) species, e.g., PtO and PtO{sub 2}. The presence of Pt–O species not only enhances catalytic activity but also improves anti-poisoning ability toward the oxidation of methanol and formic acid. The improved activity originates from the fact that the Pt–O species, formed by the ALD route, creates a large number of active sites (e.g., Pt–O{sub ads} and Pt–(OH){sub ads}) to strip the CO-adsorbed sites, leading to a high-level of CO tolerance. This work also proposes a stepwise reaction steps to shed some lights on how the Pt–O species promote the catalytic activity. - Highlights: • This study adopts atomic layer deposition (ALD) to grow metallic Pt nanoparticles. • The Pt catalysts show catalytic activity toward methanol and formic acid oxidation. • The reduction treatment induces a decrease in amount of Pt oxide (Pt–O) species. • The Pt–O species creates a number of active sites to strip the CO-adsorbed sites. • A stepwise reaction step concerning the promoted catalytic activity is proposed.

Local and systemic oxidative stress and glucocorticoid receptor levels in chronic obstructive pulmonary disease patients

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Zeng, Mian; Li, Yue; Jiang, Yujie; Lu, Guifang; Huang, Xiaomei; Guan, Kaipan

2013-01-01

BACKGROUND: Previous studies have indicated that oxidative stress plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). OBJECTIVES: To study local and systemic oxidative stress status in COPD patients, and to clarify the relationship between local and systemic oxidative stress. METHODS: Lipid peroxide malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) and GSH peroxidase (GSH-PX) levels in induced sputum and plasma, as well as glucocorticoid receptor (GR) levels in peripheral blood leukocytes were examined in 43 acute exacerbation of COPD patients (group A), 35 patients with stable COPD (group B) and 28 healthy controls (14 smokers [group C]; 14 nonsmokers [group D]). RESULTS: MDA levels in induced sputum and plasma decreased progressively in groups A to D, with significant differences between any two groups (P<0.001). GSH, SOD and GSH-PX levels in both induced sputum and plasma increased progressively in groups A to D, with significant differences between any two groups (P<0.001). GR levels in peripheral blood leukocytes decreased progressively in groups D to A (all comparisons P<0.001). Pearson analysis revealed strong correlations between MDA, GSH, SOD and GSH-PX levels in plasma and induced sputum. The activity of SOD in plasma and sputum were both positively correlated with GR levels (partial correlation coefficients 0.522 and 0.574, respectively [P<0.001]). CONCLUSIONS: Oxidative stress levels were elevated in COPD patients. There was a correlation between local and systemic oxidative status in COPD, and between decreased SOD activity and decreased GR levels in COPD patients. PMID:23457673

Molecular Characterization of the Fatty Alcohol Oxidation Pathway for Wax-Ester Mobilization in Germinated Jojoba Seeds1[W

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Rajangam, Alex S.; Gidda, Satinder K.; Craddock, Christian; Mullen, Robert T.; Dyer, John M.; Eastmond, Peter J.

2013-01-01

Jojoba (Simmondsia chinensis) is the only plant species known to use liquid wax esters (WEs) as a primary seed storage reserve. Upon germination, WE hydrolysis releases very-long-chain fatty alcohols, which must be oxidized to fatty acids by the sequential action of a fatty alcohol oxidase (FAO) and a fatty aldehyde dehydrogenase (FADH) before they can be β-oxidized. Here, we describe the cloning and characterization of genes for each of these two activities. Jojoba FAO and FADH are 52% and 68% identical to Arabidopsis (Arabidopsis thaliana) FAO3 and ALDH3H1, respectively. The genes are expressed most strongly in the cotyledons of jojoba seedlings following germination, but transcripts can also be detected in vegetative tissues. Proteomic analysis indicated that the FAO and FADH proteins can be detected on wax bodies, but they localized to the endoplasmic reticulum when they were expressed as amino-terminal green fluorescent protein fusions in tobacco (Nicotiana tabacum) leaves. Recombinant jojoba FAO and FADH proteins are active on very-long-chain fatty alcohol and fatty aldehyde substrates, respectively, and have biochemical properties consistent with those previously reported in jojoba cotyledons. Coexpression of jojoba FAO and FADH in Arabidopsis enhanced the in vivo rate of fatty alcohol oxidation more than 4-fold. Taken together, our data suggest that jojoba FAO and FADH constitute the very-long-chain fatty alcohol oxidation pathway that is likely to be necessary for efficient WE mobilization following seed germination. PMID:23166353

Antisickling activity evaluation of 4 aromatic aldehydes using proton magnetic relaxation

International Nuclear Information System (INIS)

Falcon Dieguez, J.E.; Grisel del Toro Garcia; Yamirka Alonso Geli; Lores Guevara, M.A.

2006-12-01

The formation of a Shiff base aduct hemoglobin-aromatic aldehyde, has been reported as inhibitor of the hemoglobin S polymerization. Using the Proton Magnetic Resonance methodology, the polymerization kinetics can be studied and the delay time can be determined. Our studies in vitro show the inhibitor effect of the isovanillin, o-vanillin, m-hydroxybenzaldehyde and the p-hydroxybenzaldehyde, using molar ratio (hemoglobin S/compound) 1:1, 1:4 and 1:8. The td increment (expressed in percents) obtained for each one of the molar ratio was the following: isovanillin: 34±6% (1:1), 68±16% (1:4), ovanillin: 26±10% (1:1), 63±20% (1:4), m-hydroxybelzaldehyde: 16±4% (1:1), 44±12% (1:4) and the phydroxybenzaldehyde: 10±3% (1:1), 32±8% (1:4). In the case of 1:8, the characteristic kinetics curve was not obtained. At the used concentrations, hemolytic activity was not found on the red blood cell. These results confirm the antisickling activity of these aromatic aldehydes, for a technique different to that reported in literature that also allows the quantification of concentration effect. The same ones will facilitate the study of the therapeutic usefulness of these compounds in the sickle cell anemia treatment. (author)

Camphor-10-sulfonic acid catalyzed condensation of 2-naphthol with aromatic/aliphatic aldehydes to 14-aryl/alkyl-14H-dibenzo[a,j]xanthenes

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Kundu Kshama

2014-01-01

Full Text Available (±-Camphor-10-sulfonic acid (CSA catalyzed condensation of 2-naphthol with both aliphatic/aromatic aldehydes at 80°C yielded 14-alkyl/aryl-dibenzoxanthenes as the sole product in high yields. However, the same condensation with benzaldehyde at 25°C afforded a mixture of intermediate 1,1-bis-(2-hydroxynaphthylphenylmethane and 14-phenyl-dibenzoxanthene while the condensation with aliphatic aldehydes at 25°C furnished the corresponding 14-alkyl-dibenzoxanthenes as the sole product. Moreover, condensation of 2-naphthol with aromatic/aliphatic aldehydes with low catalyst loading (2 mol% was greatly accelerated under microwave irradiation to afford the corresponding 14-aryl/alkyl-dibenzoxanthenes as the sole product in high yields.

[Increased oxidized LDL cholesterol levels in peritoneal fluid of women with advanced-stage endometriosis].

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Polak, Grzegorz; Mazurek, Diana; Rogala, Ewelina; Nowicka, Aldona; Derewianka-Polak, Magdalena; Kotarski, Jan

2011-03-01

Proinflammatory and prooxidative environment in the peritoneal cavity may be involved in the pathogenesis of endometriosis. Imbalance between reactive oxygen species levels and the antioxidant capacity leads to oxidation of low-density lipoproteins (LDL). The importance of oxidized LDL (Ox-LDL) in the development of atherosclerosis is well recognized. The aim of our study was to evaluate for the presence of ox-LDL in the peritoneal fluid (PF) of women with and without endometriosis. A total of 60 women who underwent laparoscopy were divided into groups: endometriosis sufferers with minimal to mild (n 20) and moderate to severe (n 20) stages, and the reference group (n 20) with functional follicle ovarian cysts. Oxidized LDL levels were determined in the PF using enzyme immunoassay Oxidized LDL levels were detectable in all peritoneal fluid samples. Significantly increased levels of ox-LDL were observed in PF of women with stage III/IV endometriosis compared to the reference group (p = 0.03). However peritoneal fluid ox-LDL concentrations did not differ significantly between patients with minimal/mild and women with moderate/severe stage of the disease (p = 0.2). No significant difference in the PF ox-LDL concentrations was also found between women with stage I/II endometriosis and patients with follicle cysts (p = 0.3). Increased peritoneal fluid ox-LDL levels observed in women with advanced-stage endometriosis suggest the important role of oxidative stress in the pathogenesis of the disease.

Microwave Assisted Solvent Free Synthesis of Azomethines from Aryl Aldehydes on Melamin Formaldehyde as Solid Support

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Ramin Rezaei

2011-01-01

Full Text Available Various aryl aldehydes underwent prompt one pot conversion into the corresponding azomethines in high yields by reacting with hydroxylamine hydrochloride supported on melamine formaldehyde under microwave irradiation.

Melamine Trisulfonic Acid as a New, Efficient and Reusable Catalyst for the Chemoselective Oxathioacetalyzation of Aldehydes

International Nuclear Information System (INIS)

Shirini, F.; Albadi, J.

2010-01-01

We developed an efficient and high yielding method for the chemoselective oxathioacetalyzation of aldehydes. Relatively short reaction times, high efficiency, heterogeneous reaction conditions, availability and recyclability of the reagent and easy work-up are among the other advantages of this method, which make this procedure a useful and attractive addition to the available methods. We are exploring further applications of MTSA for the other types of functional group transformations in our laboratory. 1,3-Oxathiolanes are synthetically important protecting groups for aldehydes due to their considerable stability under a variety of reaction conditions, ease of formation and removal, equality to acyl carbanions in C-C bond forming reactions, and use in enantioselective synthesis of tertiary α-hydroxy acids and glycols

Preparation and characterization of dialdehyde starch by one-step acid hydrolysis and oxidation.

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Zuo, Yingfeng; Liu, Wenjie; Xiao, Junhua; Zhao, Xing; Zhu, Ying; Wu, Yiqiang

2017-10-01

Dialdehyde starch was prepared by one-step synthesis of acid hydrolysis and oxidation, using corn starch as the raw material, sodium periodate (NaIO 4 ) as the oxidant, and hydrochloric acid (HCl) as the acid solution. The prepared dialdehyde starch was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and gel permeation chromatography (GPC). The results confirmed that oxidation occurred between the starch and NaIO 4 . The acid hydrolysis reaction reduced the molecular weight of starch and effectively improved the aldehyde group contents (92.7%). Scanning electron microscope (SEM) analysis indicated that the average particle size decreased after acid hydrolysis and oxidation reaction. X-ray diffraction (XRD) and thermal gravimetric analyzer (TGA) analysis demonstrated that the crystallinity of the obtained dialdehyde starch showed a downward trend and a decelerated thermal decomposition rate. The starch after acid hydrolysis and oxidation exhibited lower hot paste viscosity and higher reactivity. Copyright © 2017. Published by Elsevier B.V.

Monolayer structures of alkyl aldehydes: Odd-membered homologues

International Nuclear Information System (INIS)

Phillips, T.K.; Clarke, S.M.; Bhinde, T.; Castro, M.A.; Millan, C.; Medina, S.

2011-01-01

Crystalline monolayers of three aldehydes with an odd number of carbon atoms in the alkyl chain (C 7 , C 9 and C 11 ) at low coverages are observed by a combination of X-ray and neutron diffraction. Analysis of the diffraction data is discussed and possible monolayer crystal structures are proposed; although unique structures could not be ascertained for all molecules. We conclude that the structures are flat on the surface, with the molecules lying in the plane of the layer. The C 11 homologue is determined to have a plane group of either p2, pgb or pgg, and for the C 7 homologue the p2 plane group is preferred.

Degradation product emission from historic and modern books by headspace SPME/GC-MS: evaluation of lipid oxidation and cellulose hydrolysis.

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Clark, Andrew J; Calvillo, Jesse L; Roosa, Mark S; Green, David B; Ganske, Jane A

2011-04-01

Volatile organic compounds emitted from a several decade series of bound periodicals (1859-1939) printed on ground wood paper, as well as historical books dating from the 1500s to early 1800s made from cotton/linen rag, were studied using an improved headspace SPME/GC-MS method. The headspace over the naturally aging books, stored upright in glass chambers, was monitored over a 24-h period, enabling the identification of a wide range of organic compounds emanating from the whole of the book. The detection of particular straight chain aldehydes, as well as characteristic alcohols, alkenes and ketones is correlated with oxidative degradation of the C(18) fatty acid constituency of paper. The relative importance of hydrolytic and oxidative chemistry involved in paper aging in books published between 1560 and 1939 was examined by comparing the relative abundances of furfural (FUR) a known cellulose hydrolysis product, and straight chain aldehydes (SCA) produced from the oxidation of fatty acids in paper. The relative abundance of furfural is shown to increase across the 379-year publication time span. A comparison of relative SCA peak areas across the series of books examined reveals that SCA emission is more important in the cotton/linen rag books than in the ground wood books.

Does dietary fat intake influence oocyte competence and embryo quality by inducing oxidative stress in follicular fluid?

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Kazemi, Ashraf; Ramezanzadeh, Fatemeh; Nasr-Esfahani, Mohammad Hosein; Saboor Yaraghi, Ali Akbar; Ahmadi, Mehdi

2013-12-01

Fat-rich diet may alter oocyte development and maturation and embryonic development by inducing oxidative stress (OS) in follicular environment. To investigate the relationship between fat intake and oxidative stress with oocyte competence and embryo quality. In observational study follicular fluid was collected from 236 women undergoing assisted reproduction program. Malon-di-aldehyde (MDA) levels and total antioxidant capacity (TAC) levels of follicular fluid were assessed as oxidative stress biomarkers. In assisted reproduction treatment cycle fat consumption and its component were assessed. A percentage of metaphase ΙΙ stage oocytes, fertilization rate were considered as markers of oocyte competence and non-fragmented embryo rate, mean of blastomer and good cleavage (embryos with more than 5 cells on 3 days post insemination) rate were considered as markers of embryo quality. The MDA level in follicular fluid was positively related to polyunsaturated fatty acids intake level (p=0.02) and negatively associated with good cleavage rate (p=0.045). Also good cleavage rate (p=0.005) and mean of blastomer (p=0.006) was negatively associated with polyunsaturated fatty acids intake levels. The percentage of metaphase ΙΙ stage oocyte was positively related to the TAC levels in follicular fluid (p=0.046). The relationship between the OS biomarkers in FF and the fertilization rate was not significant. These findings revealed that fat rich diet may induce the OS in oocyte environment and negatively influence embryonic development. This effect can partially be accounted by polyunsaturated fatty acids uptake while oocyte maturation is related to TAC and oocytes with low total antioxidant capacity have lower chance for fertilization and further development.

Does dietary fat intake influence oocyte competence and embryo quality by inducing oxidative stress in follicular fluid?

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Kazemi, Ashraf; Ramezanzadeh, Fatemeh; Nasr-Esfahani, Mohammad Hosein; Saboor Yaraghi, Ali Akbar; Ahmadi, Mehdi

2013-01-01

Background: Fat-rich diet may alter oocyte development and maturation and embryonic development by inducing oxidative stress (OS) in follicular environment. Objective: To investigate the relationship between fat intake and oxidative stress with oocyte competence and embryo quality. Materials and Methods: In observational study follicular fluid was collected from 236 women undergoing assisted reproduction program. Malon-di-aldehyde (MDA) levels and total antioxidant capacity (TAC) levels of follicular fluid were assessed as oxidative stress biomarkers. In assisted reproduction treatment cycle fat consumption and its component were assessed. A percentage of metaphase ΙΙ stage oocytes, fertilization rate were considered as markers of oocyte competence and non-fragmented embryo rate, mean of blastomer and good cleavage (embryos with more than 5 cells on 3 days post insemination) rate were considered as markers of embryo quality. Results: The MDA level in follicular fluid was positively related to polyunsaturated fatty acids intake level (p=0.02) and negatively associated with good cleavage rate (p=0.045). Also good cleavage rate (p=0.005) and mean of blastomer (p=0.006) was negatively associated with polyunsaturated fatty acids intake levels. The percentage of metaphase ΙΙ stage oocyte was positively related to the TAC levels in follicular fluid (p=0.046). The relationship between the OS biomarkers in FF and the fertilization rate was not significant. Conclusion: These findings revealed that fat rich diet may induce the OS in oocyte environment and negatively influence embryonic development. This effect can partially be accounted by polyunsaturated fatty acids uptake while oocyte maturation is related to TAC and oocytes with low total antioxidant capacity have lower chance for fertilization and further development. PMID:24639727

Total oxidant status, total antioxidant capacity and ischemia modified albumin levels in children with celiac disease.

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Sayar, Ersin; Özdem, Sebahat; Uzun, Gülbahar; İşlek, Ali; Yılmaz, Aygen; Artan, Reha

2015-01-01

In our study, we aimed to investigate ischemia modified albumin (IMA) as an oxidative stress marker, as well as other oxidant and antioxidant markers that have not been evaluated in children with celiac disease. A total of 37 pediatric patients who were diagnosed with celiac disease (CD) and 29 healthy children were enrolled in this prospective study. We evaluated the IMA, total oxidant status, total antioxidant capacity, sulfhydryl, and advanced oxidation protein products in all of the subjects. We also compared the levels at the time of the diagnosis, and following a gluten-free diet (GFD) in the children with CD. While the IMA and the other oxidant marker levels were significantly higher in the patient group compared to the control group, the antioxidant marker levels were found to be significantly lower in the patient group, compared to the control group. We also determined that the tissue transglutaminase IgA showed a highly positive correlation, and that the IMA showed a moderately positive correlation with the Marsh-Oberhuber histopathological stage. Additionally, the IMA and other oxidant marker levels were significantly lower, while the antioxidant marker levels were significantly higher after the GFD, compared to the pre-diet period. We detected that oxidative stress played a role in the pathogenesis of CD, and that this could be evaluated using oxidative stress markers, which would regress after the GFD. We also detected that IMA is a marker that shows a correlation with the histopathological stage, and may be used in the diagnosis.

Reductive amination of aldehyde 2,4-dinitorophenylhydrazones using 2-picoline borane and high-performance liquid chromatographic analysis.

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Uchiyama, Shigehisa; Inaba, Yohei; Matsumoto, Mariko; Suzuki, Gen

2009-01-01

A new method for the determination of carbonyls in air using 2,4-dinitrophenylhydrazine (DNPH) has been developed. The traditional method for the measurement of carbonyl compounds, using DNPH to form the corresponding 2,4-dinitrophenylhydrazone (DNPhydrazone) derivatives, is subject to analytical errors because DNPhydrazones form both E- and Z-geometrical isomers as a result of the C=N double bond. To overcome this issue, a method for transforming the C=N double bond into a C-N single bond, using reductive amination of DNPhydrazone derivatives, has been developed. Reductive amination of aldehyde DNPhydrazones was carried out by adding 2-picoline borane acetonitrile solution in eluate through the DNPH-cartridge. The amination reactions of C(1)-C(10) aldehyde DNPhydrazones were completely converted into the reduced forms within 40 min in the presence of 1 mmol/L 2-picoline borane and 20 mmol/L of phosphoric acid. These reduced forms were very stable and did not change when stored for 2 weeks at room temperature. The absorption maximum wavelengths of the reduced forms from C(1)-C(10) aldehyde DNPhydrazones were 351-352 nm and shifted 6-7 nm toward shorter wavelengths when compared to the corresponding DNPhydrazones, and the molar absorption coefficients were 1.5 x 10(4) (C(1)) to 2.2 x 10(4) L/mol/cm (C(10)). Complete separation between C(1)-C(10) aldehyde DNPhydrazones and the corresponding reduced forms can be achieved by operating the HPLC in gradient mode using an Ascentis RP-Amide column (150 mm x 4.6 mm i.d.). The RSDs of DNPhydrazone (Z + E) peak areas ranged from 0.40-0.66 and those of the corresponding reduced forms ranged from 0.26-0.41. It was shown that the reductive amination method gave improved HPLC analytical precision because of the absence of isomers.

Effects of Tannic Acid on Lipid and Protein Oxidation, Color, and Volatiles of Raw and Cooked Chicken Breast Meat during Storage

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Marwan Al-Hijazeen

2016-06-01

Full Text Available The objective of this study was to determine the effect of tannic acid (TA on the oxidative stability and the quality characteristics of ground chicken breast meat. Five treatments including (1 control (none added, (2 2.5 ppm TA, (3 5 ppm TA, (4 10 ppm TA, and (5 5 ppm butylated hydroxyanisole (BHA were added to boneless, skinless ground chicken breast meat, and used for both raw and cooked meat studies. For the raw meat study, the ground chicken breast meat was packaged in oxygen-permeable bags and stored at 4 °C for 7 days. For the cooked study, raw ground meat samples were vacuum-packaged in oxygen-impermeable vacuum bags, cooked in-bag to the internal temperature of 75 °C, re-packaged in oxygen-permeable bags, and then stored. Both raw and cooked meats were analyzed for lipid and protein oxidation, color, and volatiles (cooked meat only at 0, 3, and 7 days of storage. Raw meats with 10 ppm of TA added had significantly (p ≤ 0.05 lower lipid and protein oxidation than other treatments during storage. In addition, TA at 10 ppm level maintained the highest color a*- and L*-values during storage. Cooked chicken breast meat with 5 and 10 ppm TA added produced significantly (p ≤ 0.05 lower amounts of off-odor volatiles than other treatments. Among the volatile compounds, the amount of hexanal increased rapidly during storage for cooked meat. However, meats with 5 and 10 ppm TA added showed the lowest amount of hexanal and other aldehydes related to lipid oxidation, indicating a strong antioxidant effect of TA in cooked chicken breast meat. Furthermore, the differences in aldehydes among the treatments were bigger in cooked than in raw meat, indicating that the antioxidant effect of TA in cooked meat was greater than that in raw meat. Therefore, TA at >5 ppm can be used as a good natural preservative in cooked chicken meat to maintain its quality during storage.

Correlation analysis of reactivity in the oxidation of some organic diols by tripropylammonium fluorochromate in non-aqueous media

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S. Sheik Mansoor

2016-09-01

Full Text Available The kinetics of oxidation of some organic diols by tripropylammonium fluorochromate (TriPAFC have been studied in dimethylsulfoxide (DMSO. The main product of oxidation is the corresponding hydroxy aldehydes. The reaction is first order with respect to TriPAFC and exhibited Michaelis-Menten type kinetics with respect to organic diols. The reaction is catalyzed by hydrogen ions. The hydrogen ion dependence has the form: kobs = a + b[H+]. Various thermodynamic parameters for the oxidation have been reported and discussed along with the validity of isokinetic relationship. Oxidation of diols was studied in 18 different organic solvents. The rate data are showing satisfactory correlation with Kamlet–Taft solvotochromic parameters (α, β and π∗. A suitable mechanism of oxidation has been proposed.

Oxidative stress and decreased thiol level in patients with migraine: cross-sectional study.

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Eren, Yasemin; Dirik, Ebru; Neşelioğlu, Salim; Erel, Özcan

2015-12-01

Although migraine is a neurological disorder known since long, its physiopathology remains unclear. Recent studies suggest that migraine is associated with oxidative stress; however, they report divergent results. The aim of the present study was to evaluate total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and serum thiol level in migraine patients with or without aura. The study group consisted of 141 migraine patients. The control group included 70 healthy subjects. TAS, TOS, OSI were evaluated using a method developed by Erel. Serum thiol level was measured using the Hu method. No difference was found in TAS, TOS, OSI between the patients and controls. The level of thiol was significantly lower in patients than in controls. Negative correlations were detected between thiol level and Migraine Disability Assessment score in patients. Although TAS, TOS, and OSI were similar to those of the control group, serum thiol level, an important marker of antioxidant capacity, was significantly lower in migraines compared with controls, and caused more serious disability. Novel treatment approaches may be developed based on these data, and compounds containing thiol, such as alpha lipoic acid and N-acetyl cysteine, may be used in prophylaxis.

ENVIRONMENTAL TECHNOLOGY PROTOCOL VERIFICATION REPORT, EMISSIONS OF VOCS AND ALDEHYDES FROM COMMERCIAL FURNITURE (WITH APPENDICES)

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As part of a U.S. Environmental Protection Agency Environmental Technology Verification program, the Research Triangle Institute (RTI) developed a test protocol for measuring volatile organic compounds and aldehydes in a large chamber. RTI convened stakeholders for the commercial...

Indoor air quality in Portuguese schools: levels and sources of pollutants.

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Madureira, J; Paciência, I; Pereira, C; Teixeira, J P; Fernandes, E de O

2016-08-01

Indoor air quality (IAQ) parameters in 73 primary classrooms in Porto were examined for the purpose of assessing levels of volatile organic compounds (VOCs), aldehydes, particulate matter, ventilation rates and bioaerosols within and between schools, and potential sources. Levels of VOCs, aldehydes, PM2.5 , PM10 , bacteria and fungi, carbon dioxide (CO2 ), carbon monoxide, temperature and relative humidity were measured indoors and outdoors and a walkthrough survey was performed concurrently. Ventilation rates were derived from CO2 and occupancy data. Concentrations of CO2 exceeding 1000 ppm were often encountered, indicating poor ventilation. Most VOCs had low concentrations (median of individual species <5 μg/m(3) ) and were below the respective WHO guidelines. Concentrations of particulate matter and culturable bacteria were frequently higher than guidelines/reference values. The variability of VOCs, aldehydes, bioaerosol concentrations, and CO2 levels between schools exceeded the variability within schools. These findings indicate that IAQ problems may persist in classrooms where pollutant sources exist and classrooms are poorly ventilated; source control strategies (related to building location, occupant behavior, maintenance/cleaning activities) are deemed to be the most reliable for the prevention of adverse health consequences in children in schools. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Characterization of aldehyde dehydrogenase isozymes in ovarian cancer tissues and sphere cultures

International Nuclear Information System (INIS)

Saw, Yu-Ting; Thompson, David; Vasiliou, Vasilis; Berkowitz, Ross S; Ng, Shu-Wing; Yang, Junzheng; Ng, Shu-Kay; Liu, Shubai; Singh, Surendra; Singh, Margit; Welch, William R; Tsuda, Hiroshi; Fong, Wing-Ping

2012-01-01

Aldehyde dehydrogenases belong to a superfamily of detoxifying enzymes that protect cells from carcinogenic aldehydes. Of the superfamily, ALDH1A1 has gained most attention because current studies have shown that its expression is associated with human cancer stem cells. However, ALDH1A1 is only one of the 19 human ALDH subfamilies currently known. The purpose of the present study was to determine if the expression and activities of other major ALDH isozymes are associated with human ovarian cancer and ovarian cancer sphere cultures. Immunohistochemistry was used to delineate ALDH isozyme localization in clinical ovarian tissues. Western Blot analyses were performed on lysates prepared from cancer cell lines and ovarian cancer spheres to confirm the immunohistochemistry findings. Quantitative reverse transcription-polymerase chain reactions were used to measure the mRNA expression levels. The Aldefluor® assay was used to measure ALDH activity in cancer cells from the four tumor subtypes. Immunohistochemical staining showed significant overexpression of ALDH1A3, ALDH3A2, and ALDH7A1 isozymes in ovarian tumors relative to normal ovarian tissues. The expression and activity of ALDH1A1 is tumor type-dependent, as seen from immunohistochemisty, Western blot analysis, and the Aldefluor® assay. The expression was elevated in the mucinous and endometrioid ovarian epithelial tumors than in serous and clear cell tumors. In some serous and most clear cell tumors, ALDH1A1 expression was found in the stromal fibroblasts. RNA expression of all studied ALDH isozymes also showed higher expression in endometrioid and mucinous tumors than in the serous and clear cell subtypes. The expression of ALDH enzymes showed tumor type-dependent induction in ovarian cancer cells growing as sphere suspensions in serum-free medium. The results of our study indicate that ALDH enzyme expression and activity may be associated with specific cell types in ovarian tumor tissues and vary according to

Evaluation of oxidant, antioxidant, and S100B levels in patients with conversion disorder

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Büyükaslan H

2016-07-01

Full Text Available Hasan Büyükaslan,1 Sultan Basmacı Kandemir,2 Mehmet Asoğlu,3 Halil Kaya,4 Mehmet Tahir Gökdemir,1 İbrahim Fatih Karababa,3 Fatih Güngörmez,5 Fethiye Kılıçaslan,6 Emin Şavik7 1Department of Emergency Medicine, Faculty of Medicine, Harran University, 2Department of Psychiatry, Balıklıgöl State Hospital, 3Department of Psychiatry, Faculty of Medicine, Harran University, Sanliurfa, 4Bursa Yüksek Ihtisas Training and Research Hospital, Bursa, 5Department of Emergency Medicine, Mehmet Akif İnan Research Hospital, 6Department of Child and Adolescent Psychiatry, 7Department of Biochemistry, Faculty of Medicine, Harran University, Sanliurfa, Turkey Introduction: Various psychodynamic, neurobiological, genetic, and sociocultural factors are believed to be involved in the etiology of conversion disorder (CD. Oxidative metabolism has been shown to deteriorate in association with many health problems and psychiatric disorders. We evaluated oxidative metabolism and S100B levels in the context of this multifactorial disease.Methods: Thirty-seven patients with CD (25 females and 12 males and 42 healthy volunteers (21 females and 21 males, all matched for age and sex, were included in this study. The total oxidant status, total antioxidant status, oxidative stress index, and S100B levels were compared between the two groups.Results: The total oxidant status, oxidative stress index, and S100B levels were significantly higher in patients with CD than in the control group, whereas the total antioxidant status was significantly lower.Conclusion: CD is associated with deterioration of oxidative metabolism and increased neuronal damage. Keywords: conversion disorder, oxidative stress, S100B

Aldehyde dehydrogenase polymorphism in North American, South American, and Mexican Indian populations.

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Goedde, H W; Agarwal, D P; Harada, S; Rothhammer, F; Whittaker, J O; Lisker, R

1986-01-01

While about 40% of the South American Indian populations (Atacameños, Mapuche, Shuara) were found to be deficient in aldehyde dehydrogenase isozyme I (ALDH2 or E2), preliminary investigations showed very low incidence of isozyme deficiency among North American natives (Sioux, Navajo) and Mexican Indians (mestizo). Possible implications of such trait differences on cross-cultural behavioral response to alcohol drinking are discussed. PMID:3953578

Copolymerization of poly (ethylene oxide) and poly (methyl methacrylate) initiated by ceric ammonium nitrate

International Nuclear Information System (INIS)

Gomes, A.S.; Ferreira, A.A.; Coutinho, F.M.B.; Marinho, J.R.D.

1984-01-01

Cerium (IV) salts such as the ceric ammonium nitrate and ceric ammonium sulfate in aqueous acid solution with reducing agents such as alcohols, thiols, glycols, aldehydes and amines are well known initiators of vinyl polymerization. In this work, the polymerization of methyl methacrylate initiated by ceric ammonium nitrate/HNO 3 -poly(ethylene oxide) with hydroxyl end group system was studied in aqueous solution at 25 0 C to obtain block copolymers. (Author) [pt

MICROWAVE-ASSISTED CU (I) CATALYZED SOLVENT-FREE THREE COMPONENT COUPLING OF ALDEHYDE, ALKYNE AND AMINE

Science.gov (United States)

Direct Grignard type addition of terminal alkynes to in situ generated imines, from aldehydes and amines, occurs under microwave irradiation using CuBr alone in a one-pot operation. This solventless approach provides ready access to propargylamines and is applicable both...

Variation of nitric oxide levels in imported Plasmodium falciparum ...

African Journals Online (AJOL)

SERVER

2008-03-18

Mar 18, 2008 ... ISSN 1684–5315 © 2008 Academic Journals. Full Length Research Paper. Variation of nitric oxide levels in imported Plasmodium falciparum malaria episodes. De Sousa, Karina*, Silva, Marcelo S. and Tavira, Luís T. Instituto de Higiene e Medicina Tropical, Centro de Malária e outras Doenças Tropicais, ...

Selective oxidation of propene on bismuth molybdate and mixed oxides of tin and antimony and of uranium and antimony

International Nuclear Information System (INIS)

Pendleton, P.; Taylor, D.

1976-01-01

Propene + 18 0 2 reactions have been studied in a static reaction system on bismuth molybdate and mixed oxides of tin and antimony and of uranium and antimony. The [ 16 0] acrolein content of the total acrolein formed and the proportion of 16 0 in the oxygen of the carbon dioxide by-product have been determined. The results indicate that for each catalyst the lattice is the only direct source of the oxygen in the aldehyde, and that lattice and/or gas phase oxygen is used in carbon dioxide formation. Oxygen anion mobility appears to be greater in the molybdate catalyst than in the other two. (author)

Radiation-Induced Polymerization of Aldehydes and Ketones; Polymerisation radiochimique des aldehydes et des cetones; Radiatsionnaya polimerizatsiya al'degidov i ketonov; Polimerizacion radioinducida de aldehidos y cetonas

Energy Technology Data Exchange (ETDEWEB)

Hayashi, K.; Yamaoka, H.; Fujiwara, K.; Sakamoto, M.; Mori, S.; Natori, T.; Yoshida, H.; Okamura, S. [Japanese Association for Radiation Research on Polymers, Neyagawa Osaka (Japan); Kyoto University, Kyoto (Japan)

1963-11-15

Several kinds of aldehydes and ketones are polymerized by irradiation. Formaldehyde can be polymerized into high molecular weight polyoxymethylene by radiation-induced polymerization in the liquid phase at low temperatures. The polymerization mechanism is considered to be a cationic chain reaction both in the case of bulk and of solution in methylenechloride and toluene, but to be anionic in ethylether. Acetaldehyde and propionaldehyde are recognized as being hardly polymerized in the pure liquid phase, but easily polymerized in the presence of {gamma}-alumina. In the solid state polymerization, crystalline polymers are obtained as the stable- for- heat-treatment form under suitableconditions. Glyoxal can be polymerized into a three-dimensional network polymer. With formaldehyde it can be copolymerized into some cross-linked polyoxymethylene. Acetones such as chloroor bromoacetone and methylethylketone or diacetyl can be polymerized in the solid state into polymers which are unstable. Ketene can be polymerized into a polyester-type polymer with liquid phase polymerization; polyketone is obtained additionally when polymerization is carried out in the solid state. The copolymer with formaldehyde is slightly more stable. Dimethylketene can be easily polymerized both in the liquid and solid states into polyacetal. All these polymerizations are special examples of radiation-induced reactions and the reaction kinetics are interesting. Some details of this are discussed here. (author) [French] Plusieurs sortes d'aldehydes et de cetones se polymerisent sous l'effet des rayons gamma. L'aldehyde formique peut se transformer en polyoxymethylene de poids moleculaire eleve par polymerisation radiochimique en phase liquide a basses temperatures. On pense que la polymerisation est une reaction cationique en chaine lorsqu'il s'agit de masses ou de solutions dans du chlorure de methylene et du toluene, mais une reaction anionique en chaule dans une solution d'ether ethylique. L'aldehyde

Serum oxidized low-density lipoprotein level as a marker of oxidative stress in patients undergoing hyperbaric oxygen therapy.

Science.gov (United States)

Keskin, Kudret; Kilci, Hakan; Aksan, Gökhan; Çetinkal, Gökhan; Yıldız, Süleyman Sezai; Kocaman Türk, Füsun; Bingöl, Gülsüm

2017-09-01

Oxidative stress (OS) is involved in the pathogenesis of atherosclerosis. Hyperbaric oxygen therapy (HBOT), in which 100% oxygen is inhaled under hyperbaric pressure, may create OS. Therefore, the aim of this research was to measure the serum oxidized low-density lipoprotein (oxLDL) level in patients undergoing HBOT. Twenty-nine patients who underwent HBOT to treat various diseases were enrolled in this study. The serum oxLDL level was measured at the beginning of the first and after the 10th therapy session. There was no significant difference between the oxLDL level of patients before and after HBOT (4.96±0.1 vs. 4.94±0.1 U/mL; p=0.36). HBOT seems to be safe in terms of oxLDL production up to 10 sessions. However, further large-scale studies investigating longer duration of HBOT treatment are required to understand the role of OS.

Hypoxia and oxidation levels of DNA and lipids in humans and animal experimental models

DEFF Research Database (Denmark)

Møller, Peter; Risom, Lotte; Lundby, Carsten

2008-01-01

The objective of this review was to evaluate the association between hypoxia and oxidative damage to DNA and lipids. Evaluation criteria encompassed specificity and validation status of the biomarkers, study design, strength of the association, dose-response relationship, biological plausibility......, analogous exposures, and effect modification by intervention. The collective interpretation indicates persuasive evidence from the studies in humans for an association between hypoxia and elevated levels of oxidative damage to DNA and lipids. The levels of oxidatively generated DNA lesions and lipid...... in subjects at high altitude. Most of the animal experimental models should be interpreted with caution because the assays for assessment of lipid peroxidation products have suboptimal validity....

A quick responding quartz crystal microbalance sensor array based on molecular imprinted polyacrylic acids coating for selective identification of aldehydes in body odor.

Science.gov (United States)

Jha, Sunil K; Hayashi, Kenshi

2015-03-01

In present work, a novel quartz crystal microbalance (QCM) sensor array has been developed for prompt identification of primary aldehydes in human body odor. Molecularly imprinted polymers (MIP) are prepared using the polyacrylic acid (PAA) polymer matrix and three organic acids (propenoic acid, hexanoic acid and octanoic acid) as template molecules, and utilized as QCM surface coating layer. The performance of MIP films is characterized by 4-element QCM sensor array (three coated with MIP layers and one with pure PAA for reference) dynamic and static responses to target aldehydes: hexanal, heptanal, and nonanal in single, binary, and tertiary mixtures at distinct concentrations. The target aldehydes were selected subsequent to characterization of body odor samples with solid phase-micro extraction gas chromatography mass spectrometer (SPME-GC-MS). The hexanoic acid and octanoic acid imprinted PAA exhibit fast response, and better sensitivity, selectivity and reproducibility than the propenoic acid, and non-imprinted PAA in array. The response time and recovery time for hexanoic acid imprinted PAA are obtained as 5 s and 12 s respectively to typical concentrations of binary and tertiary mixtures of aldehydes using the static response. Dynamic sensor array response matrix has been processed with principal component analysis (PCA) for visual, and support vector machine (SVM) classifier for quantitative identification of target odors. Aldehyde odors were identified successfully in principal component (PC) space. SVM classifier results maximum recognition rate 79% for three classes of binary odors and 83% including single, binary, and tertiary odor classes in 3-fold cross validation. Copyright © 2014 Elsevier B.V. All rights reserved.

Protocatechuic aldehyde inhibits migration and proliferation of vascular smooth muscle cells and intravascular thrombosis

Energy Technology Data Exchange (ETDEWEB)

Moon, Chang Yoon [The Hotchkiss School, Lakeville, CT (United States); Endocrinology, Brain Korea 21 Project for Medical Science, Institute of Endocrine Research, and Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University College of Medicine, Seoul (Korea, Republic of); Ku, Cheol Ryong [Endocrinology, Brain Korea 21 Project for Medical Science, Institute of Endocrine Research, and Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University College of Medicine, Seoul (Korea, Republic of); Cho, Yoon Hee, E-mail: wooriminji@gmail.com [Endocrinology, Brain Korea 21 Project for Medical Science, Institute of Endocrine Research, and Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, Eun Jig, E-mail: ejlee423@yuhs.ac [Endocrinology, Brain Korea 21 Project for Medical Science, Institute of Endocrine Research, and Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University College of Medicine, Seoul (Korea, Republic of); Endocrinology, Northwestern University Feinberg School of Medicine, Chicago, IL (United States)

2012-06-22

Highlights: Black-Right-Pointing-Pointer Protocatechuic aldehyde (PCA) inhibits ROS production in VSMCs. Black-Right-Pointing-Pointer PCA inhibits proliferation and migration in PDGF-induced VSMCs. Black-Right-Pointing-Pointer PCA has anti-platelet effects in ex vivo rat whole blood. Black-Right-Pointing-Pointer We report the potential therapeutic role of PCA in atherosclerosis. -- Abstract: The migration and proliferation of vascular smooth muscle cells (VSMCs) and formation of intravascular thrombosis play crucial roles in the development of atherosclerotic lesions. This study examined the effects of protocatechuic aldehyde (PCA), a compound isolated from the aqueous extract of the root of Salvia miltiorrhiza, an herb used in traditional Chinese medicine to treat a variety of vascular diseases, on the migration and proliferation of VSMCs and platelets due to platelet-derived growth factor (PDGF). DNA 5-bromo-2 Prime -deoxy-uridine (BrdU) incorporation and wound-healing assays indicated that PCA significantly attenuated PDGF-induced proliferation and migration of VSMCs at a pharmacologically relevant concentration (100 {mu}M). On a molecular level, we observed down-regulation of the phosphatidylinositol 3-kinase (PI3K)/Akt and the mitogen-activated protein kinase (MAPK) pathways, both of which regulate key enzymes associated with migration and proliferation. We also found that PCA induced S-phase arrest of the VSMC cell cycle and suppressed cyclin D2 expression. In addition, PCA inhibited PDGF-BB-stimulated reactive oxygen species production in VSMCs, indicating that PCA's antioxidant properties may contribute to its suppression of PDGF-induced migration and proliferation in VSMCs. Finally, PCA exhibited an anti-thrombotic effect related to its inhibition of platelet aggregation, confirmed with an aggregometer. Together, these findings suggest a potential therapeutic role of PCA in the treatment of atherosclerosis and angioplasty-induced vascular restenosis.

Electron impact ionization of cycloalkanes, aldehydes, and ketones

Energy Technology Data Exchange (ETDEWEB)

Gupta, Dhanoj; Antony, Bobby, E-mail: bka.ism@gmail.com [Department of Applied Physics, Indian School of Mines, Dhanbad, JH 826 004 (India)

2014-08-07

The theoretical calculations of electron impact total ionization cross section for cycloalkane, aldehyde, and ketone group molecules are undertaken from ionization threshold to 2 keV. The present calculations are based on the spherical complex optical potential formalism and complex scattering potential ionization contribution method. The results of most of the targets studied compare fairly well with the recent measurements, wherever available and the cross sections for many targets are predicted for the first time. The correlation between the peak of ionization cross sections with number of target electrons and target parameters is also reported. It was found that the cross sections at their maximum depend linearly with the number of target electrons and with other target parameters, confirming the consistency of the values reported here.

Green Tea Polyphenols Decrease Strecker Aldehydes and Bind to Proteins in Lactose-Hydrolyzed UHT Milk.

Science.gov (United States)

Jansson, Therese; Rauh, Valentin; Danielsen, Bente P; Poojary, Mahesha M; Waehrens, Sandra S; Bredie, Wender L P; Sørensen, John; Petersen, Mikael A; Ray, Colin A; Lund, Marianne N

2017-12-06

The effect of epigallocatechin gallate enriched green tea extract (GTE) on flavor, Maillard reactions and protein modifications in lactose-hydrolyzed (LH) ultrahigh temperature (UHT) processed milk was examined during storage at 40 °C for up to 42 days. Addition of GTE inhibited the formation of Strecker aldehydes by up to 95% compared to control milk, and the effect was similar when GTE was added either before or after UHT treatment. Release of free amino acids, caused by proteolysis, during storage was also decreased in GTE-added milk either before or after UHT treatment compared to control milk. Binding of polyphenols to milk proteins was observed in both fresh and stored milk samples. The inhibition of Strecker aldehyde formation by GTE may be explained by two different mechanisms; inhibition of proteolysis during storage by GTE or binding of amino acids and proteins to the GTE polyphenols.

Homogeneous-oxide stack in IGZO thin-film transistors for multi-level-cell NAND memory application

Science.gov (United States)

Ji, Hao; Wei, Yehui; Zhang, Xinlei; Jiang, Ran

2017-11-01

A nonvolatile charge-trap-flash memory that is based on amorphous indium-gallium-zinc-oxide thin film transistors was fabricated with a homogeneous-oxide structure for a multi-level-cell application. All oxide layers, i.e., tunneling layer, charge trapping layer, and blocking layer, were fabricated with Al2O3 films. The fabrication condition (including temperature and deposition method) of the charge trapping layer was different from those of the other oxide layers. This device demonstrated a considerable large memory window of 4 V between the states fully erased and programmed with the operation voltage less than 14 V. This kind of device shows a good prospect for multi-level-cell memory applications.

Histochemical detection of the in vivo produced cellular aldehydes by means of direct Schiff's reaction in CCl/sub 4/ intoxicated rat liver

Energy Technology Data Exchange (ETDEWEB)

Taper, H.S.; Somer, M.P.; Lans, M.; Gerlache, J. de; Roberfroid, M.

1988-04-01

A histochemical technique for detection of the in vivo induced cellular aldehydes based on the direct Schiff's reaction is reported in this paper. CCl/sub 4/-intoxicated rat liver was used as an experimental model. Fresh and non-pretreated rat liver cryostat sections fixed in 10% formol calcium solution and washed in distilled water were exposed to Schiff's reagent. The sections were then immersed in two baths of sodium bisulphite solution, then in water, dehydrated in ethanol, cleared in xylene and mounted in a synthetic anhydrous mounting medium. As Schiff positive areas presented well circumscribed foci which increased with time following intoxication, semiquantitative planimetric measurements were feasible. The direct Schiff's reaction detects cellular aldehydes in a sensitive, rapid histologically and topographically estimable way. The appearance of these aldehydes precedes distinctly morphological alterations detectable by other histochemical of histological techniques. No positive results were obtained in control, non-intocicated rat livers. Inhibitons of this direct Schiff's was obtained in positive control rat liver sections preincubated in solutions of aldehyde blockers. Histochemical detection of aldehydes may give useful information on different aspects of tissue and organ intoxication such as their topography, appearance, evolution, extension, consequences and effects of treatment. The direct Schiff's reaction can be considered as a valuable tool in fundamental and applied reasearch dealing with various toxicological, environmental, pathological, cancer-related and therapeutic problems.

Regio- and Stereoselective Conjugate Addition of Aldehydes to β-Tosyl Enones under the Catalysis of a Binaphthyl-Modified Chiral Amine.

Science.gov (United States)

Kano, Taichi; Sugimoto, Hisashi; Maruyama, Hiroki; Maruoka, Keiji

2015-07-13

A simple axially chiral amine catalyst promoted the regio-, diastereo-, and enantioselective conjugate addition of aldehydes to β-tosyl enones, which serve as ynone surrogates. The adducts were readily converted by treatment with L-selectride into less accessible enones with a γ stereogenic center. Such compounds cannot be prepared through the amine-catalyzed conjugate addition of aldehydes to ynones. The obtained enones underwent further conjugate addition of diorganozinc compounds in the presence of a copper catalyst. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quality changes in krill and krill products during their manufacturing process

DEFF Research Database (Denmark)

Lu, Henna Fung Sieng; Jacobsen, Charlotte; Bruheim, Inge

The main objective of this study is to a) investigate the effect of temperature towards the non-enzymatic browning reactions and lipid oxidation in krill products sampled at different stages during their manufacturing process. In order to further investigate this, a simple model system comprising...... amino acids (leucine, isoleucine, valine, methionine and lysine) was prepared with addition of lipid (saturated and α, β-unsaturated aldehydes) or non-enzymatic (Strecker aldehydes and pyrazine) derived volatiles. Therefore, the secondary objective is to investigate if the occurrence of non......-enzymatic browning reactions and lipid oxidation in krill products during their manufacturing process. The occurrence of these reactions could be observed in krill meal and this was ascribed to the presence of carbonyl compounds derived lipid oxidation products. The presence of a high level of non...

Poly(ethylene oxide) surfactant polymers.

Science.gov (United States)

Vacheethasanee, Katanchalee; Wang, Shuwu; Qiu, Yongxing; Marchant, Roger E

2004-01-01

We report on a series of structurally well-defined surfactant polymers that undergo surface-induced self-assembly on hydrophobic biomaterial surfaces. The surfactant polymers consist of a poly(vinyl amine) backbone with poly(ethylene oxide) and hexanal pendant groups. The poly(vinyl amine) (PVAm) was synthesized by hydrolysis of poly(N-vinyl formamide) following free radical polymerization of N-vinyl formamide. Hexanal and aldehyde-terminated poly(ethylene oxide) (PEO) were simultaneously attached to PVAm via reductive amination. Surfactant polymers with different PEO:hexanal ratios and hydrophilic/hydrophobic balances were prepared, and characterized by FT-IR, 1H-NMR and XPS spectroscopies. Surface active properties at the air/water interface were determined by surface tension measurements. Surface activity at a solid surface/water interface was demonstrated by atomic force microscopy, showing epitaxially molecular alignment for surfactant polymers adsorbed on highly oriented pyrolytic graphite. The surfactant polymers described in this report can be adapted for simple non-covalent surface modification of biomaterials and hydrophobic surfaces to provide highly hydrated interfaces.

Study of Foeniculum vulgare (Fennel Seed Extract Effects on Serum Level of Oxidative Stress

Directory of Open Access Journals (Sweden)

Sadeghpour Nahid

2015-04-01

Full Text Available Objective: The Foeniculum vulgare (FVE, known as fennel, has a long history of herbal uses as both food and medicine. The seed of this plant has been used to promote menstruation, alleviate the symptoms of female climacteric, and increase the number of ovarian follicles. The aim of this study was to evaluate the fennel extract effects on serum level of oxidative stress in female mice. Materials and Methods: Totally, 28 virgin female albino mice were divided into four groups (n = 7. Groups 1 and 2 (experimental groups were administered FVE at 100 and at a concentration of 100 and 200 mg/kg for 5 days, interaperitoneally. Group 3 (negative control received ethanol and Group 4 (positive control received normal saline. Animals were scarified at 6th day, sera were collected and the level of oxidative stress was determination of using total antioxidant status kit. Results: Data analysis revealed that there is a significant difference in the mean level of serum oxidative stress between four different groups. P value in experimental groups compared to the control group was (P < 0.0001. Conclusion: Fennel extract can decrease the serum level of oxidative factors in female mice; it can be introduced as a novel medicine for treatment of infertility

Changes in Nitric Oxide Level and Thickness Index of Synovial Fluid ...

African Journals Online (AJOL)

patients after intra-articular injection of sodium hyaluronate, while the effect is insignificant in severe patients. Thus, sodium hyaluronate can effectively improve nitric oxide levels in synovial fluid, reduce ..... Modern Med Health, 2014; 1:.

Changes in Nitric Oxide Level and Thickness Index of Synovial Fluid ...

African Journals Online (AJOL)

Changes in Nitric Oxide Level and Thickness Index of Synovial Fluid in Osteoarthritis Patients ... Tropical Journal of Pharmaceutical Research ... and moderate phase patients after intra-articular injection of sodium hyaluronate, while the effect ...

Ru/Me-BIPAM-Catalyzed Asymmetric Addition of Arylboronic Acids to Aliphatic Aldehydes and α-Ketoesters

Directory of Open Access Journals (Sweden)

Momoko Watanabe

2011-06-01

Full Text Available A ruthenium-catalyzed asymmetric arylation of aliphatic aldehydes and α-ketoesters with arylboronic acids has been developed, giving chiral alkyl(arylmethanols and α-hydroxy esters in good yields. The use of a chiral bidentate phosphoramidite ligand (Me-BIPAM achieved excellent enantioselectivities.

Pu-erh Tea Reduces Nitric Oxide Levels in Rats by Inhibiting Inducible Nitric Oxide Synthase Expression through Toll-Like Receptor 4

Science.gov (United States)

Xu, Yang; Wang, Guan; Li, Chunjie; Zhang, Min; Zhao, Hang; Sheng, Jun; Shi, Wei

2012-01-01

Pu-erh tea undergoes a unique fermentation process and contains theabrownins, polysaccharides and caffeine; although it is unclear about which component is associated with the down regulation of nitric oxide levels or how this process is mediated. To address this question we examined the effects of pu-erh tea on nitric oxide synthase (NOS) genes. Cohorts of rats were separately given four-week treatments of water as control, pu-erh tea, or the tea components: theabrownins, caffeine or polysaccharides. Five experimental groups were injected with lipopolysaccharides (LPS) to induce nitric oxide (NO) production, while the corresponding five control groups were injected with saline as a negative control. The serum and liver NO concentrations were examined and the NOS expression of both mRNA and protein was measured in liver. The results showed that the rats which were fed pu-erh tea or polysaccharides had lower levels of NO which corresponded with the down-regulation of inducible nitric oxide synthase (iNOS) expression. We further demonstrate that this effect is mediated through reduction of Toll-like receptor 4 (TLR4) signaling. Thus we find that the polysaccharide components in pu-erh tea reduce NO levels in an animal model by inhibiting the iNOS expression via signaling through TLR4. PMID:22837686

Effects of ascorbic acid and antioxidants on color, lipid oxidation and volatiles of irradiated ground beef

International Nuclear Information System (INIS)

Ahn, D.U.; Nam, K.C.

2004-01-01

Beef loins with 3 different aging times after slaughter were ground, added with none, 0.1% ascorbic acid, 0.01% sesamol+0.01% α-tocopherol, or 0.1% ascorbic acid+0.01% sesamol+0.01% tocopherol. The meats were packaged in oxygen-permeable bags, irradiated at 2.5 kGy, and color, oxidation-reduction potential (ORP), lipid oxidation and volatile profiles were determined. Irradiation decreased the redness of ground beef, and visible color of beef changed from a bright red to a green/brown depending on the age of meat. Addition of ascorbic acid prevented color changes in irradiated beef, and the effect of ascorbic acid became greater as the age of meat or storage time after irradiation increased. The ground beef added with ascorbic acid had lower ORP than control, and the low ORP of meat helped maintaining the heme pigments in reduced form. During aerobic storage, S-volatiles disappeared while volatile aldehydes significantly increased in irradiated beef. Addition of ascorbic acid at 0.1% or sesamol+α-tocopherol at each 0.01% level to ground beef prior to irradiation were effective in reducing lipid oxidation and S-volatiles. As storage time increased, however, the antioxidant effect of sesamol+tocopherol in irradiated ground beef was superior to that of ascorbic acid

Effects of ascorbic acid and antioxidants on color, lipid oxidation and volatiles of irradiated ground beef

Energy Technology Data Exchange (ETDEWEB)

Ahn, D.U. E-mail: duahn@iastate.edu; Nam, K.C

2004-10-01

Beef loins with 3 different aging times after slaughter were ground, added with none, 0.1% ascorbic acid, 0.01% sesamol+0.01% {alpha}-tocopherol, or 0.1% ascorbic acid+0.01% sesamol+0.01% tocopherol. The meats were packaged in oxygen-permeable bags, irradiated at 2.5 kGy, and color, oxidation-reduction potential (ORP), lipid oxidation and volatile profiles were determined. Irradiation decreased the redness of ground beef, and visible color of beef changed from a bright red to a green/brown depending on the age of meat. Addition of ascorbic acid prevented color changes in irradiated beef, and the effect of ascorbic acid became greater as the age of meat or storage time after irradiation increased. The ground beef added with ascorbic acid had lower ORP than control, and the low ORP of meat helped maintaining the heme pigments in reduced form. During aerobic storage, S-volatiles disappeared while volatile aldehydes significantly increased in irradiated beef. Addition of ascorbic acid at 0.1% or sesamol+{alpha}-tocopherol at each 0.01% level to ground beef prior to irradiation were effective in reducing lipid oxidation and S-volatiles. As storage time increased, however, the antioxidant effect of sesamol+tocopherol in irradiated ground beef was superior to that of ascorbic acid.

Steric control of reactivity: formation of oximes, benzodiazepinone N-oxides and isoxazoloquinolinones

OpenAIRE

Heaney, Frances; Bourke, Sharon; Cunningham, Desmond; McArdle, Patrick

1998-01-01

Reaction of the alkenyl carbonyl compounds 1 with hydroxylamine can lead to the formation of the oximes 2, the benzodiazepinone N-oxides 3 or the isoxazoloquinolinones 5. The product(s) of reaction are shown to depend on the electronic nature of the terminal olefinic substituent R3 and the space filling capacity of the substituents R1, R2 and R4. When the olefinic centre is electron poor (R3 = CO2Et) ketocarbonyls convert exclusively to bicyclic nitrones 3 whereas aldehydes are more sensitive...

Evaluation of peroxidative stress of cancer cells in vitro by real-time quantification of volatile aldehydes in culture headspace.

Science.gov (United States)

Shestivska, Violetta; Rutter, Abigail V; Sulé-Suso, Josep; Smith, David; Španěl, Patrik

2017-08-30

Peroxidation of lipids in cellular membranes results in the release of volatile organic compounds (VOCs), including saturated aldehydes. The real-time quantification of trace VOCs produced by cancer cells during peroxidative stress presents a new challenge to non-invasive clinical diagnostics, which as described here, we have met with some success. A combination of selected ion flow tube mass spectrometry (SIFT-MS), a technique that allows rapid, reliable quantification of VOCs in humid air and liquid headspace, and electrochemistry to generate reactive oxygen species (ROS) in vitro has been used. Thus, VOCs present in the headspace of CALU-1 cancer cell line cultures exposed to ROS have been monitored and quantified in real time using SIFT-MS. The CALU-1 lung cancer cells were cultured in 3D collagen to mimic in vivo tissue. Real-time SIFT-MS analyses focused on the volatile aldehydes: propanal, butanal, pentanal, hexanal, heptanal and malondialdehyde (propanedial), that are expected to be products of cellular membrane peroxidation. All six aldehydes were identified in the culture headspace, each reaching peak concentrations during the time of exposure to ROS and eventually reducing as the reactants were depleted in the culture. Pentanal and hexanal were the most abundant, reaching concentrations of a few hundred parts-per-billion by volume, ppbv, in the culture headspace. The results of these experiments demonstrate that peroxidation of cancer cells in vitro can be monitored and evaluated by direct real-time analysis of the volatile aldehydes produced. The combination of adopted methodology potentially has value for the study of other types of VOCs that may be produced by cellular damage. Copyright © 2017 John Wiley & Sons, Ltd.

Accumulation of polyunsaturated aldehydes in the gonads of the copepod Acartia tonsa revealed by tailored fluorescent probes.

Science.gov (United States)

Wolfram, Stefanie; Nejstgaard, Jens C; Pohnert, Georg

2014-01-01

Polyunsaturated aldehydes (PUAs) are released by several diatom species during predation. Besides other attributed activities, these oxylipins can interfere with the reproduction of copepods, important predators of diatoms. While intensive research has been carried out to document the effects of PUAs on copepod reproduction, little is known about the underlying mechanistic aspects of PUA action. Especially PUA uptake and accumulation in copepods has not been addressed to date. To investigate how PUAs are taken up and interfere with the reproduction in copepods we developed a fluorescent probe containing the α,β,γ,δ-unsaturated aldehyde structure element that is essential for the activity of PUAs as well as a set of control probes. We developed incubation and monitoring procedures for adult females of the calanoid copepod Acartia tonsa and show that the PUA derived fluorescent molecular probe selectively accumulates in the gonads of this copepod. In contrast, a saturated aldehyde derived probe of an inactive parent molecule was enriched in the lipid sac. This leads to a model for PUAs' teratogenic mode of action involving accumulation and covalent interaction with nucleophilic moieties in the copepod reproductive tissue. The teratogenic effect of PUAs can therefore be explained by a selective targeting of the molecules into the reproductive tissue of the herbivores, while more lipophilic but otherwise strongly related structures end up in lipid bodies.

Accumulation of polyunsaturated aldehydes in the gonads of the copepod Acartia tonsa revealed by tailored fluorescent probes.

Directory of Open Access Journals (Sweden)

Stefanie Wolfram

Full Text Available Polyunsaturated aldehydes (PUAs are released by several diatom species during predation. Besides other attributed activities, these oxylipins can interfere with the reproduction of copepods, important predators of diatoms. While intensive research has been carried out to document the effects of PUAs on copepod reproduction, little is known about the underlying mechanistic aspects of PUA action. Especially PUA uptake and accumulation in copepods has not been addressed to date. To investigate how PUAs are taken up and interfere with the reproduction in copepods we developed a fluorescent probe containing the α,β,γ,δ-unsaturated aldehyde structure element that is essential for the activity of PUAs as well as a set of control probes. We developed incubation and monitoring procedures for adult females of the calanoid copepod Acartia tonsa and show that the PUA derived fluorescent molecular probe selectively accumulates in the gonads of this copepod. In contrast, a saturated aldehyde derived probe of an inactive parent molecule was enriched in the lipid sac. This leads to a model for PUAs' teratogenic mode of action involving accumulation and covalent interaction with nucleophilic moieties in the copepod reproductive tissue. The teratogenic effect of PUAs can therefore be explained by a selective targeting of the molecules into the reproductive tissue of the herbivores, while more lipophilic but otherwise strongly related structures end up in lipid bodies.

Markers of Lipid Oxidative Damage in the Exhaled Breath Condensate of Nano TiO2 Production Workers.

Czech Academy of Sciences Publication Activity Database

Pelclová, D.; Ždímal, Vladimír; Kačer, P.; Zíková, Naděžda; Komarc, M.; Fenclová, Z.; Vlčková, Š.; Schwarz, Jaroslav; Makeš, Otakar; Syslová, K.; Navrátil, Tomáš; Turci, F.; Corazzari, I.; Zakharov, S.; Bello, D.

2017-01-01

Roč. 11, č. 1 (2017), s. 52-63 ISSN 1743-5390 R&D Projects: GA ČR(CZ) GBP503/12/G147 Institutional support: RVO:67985858 ; RVO:61388955 Keywords : exhaled breath condensate * aldehydes * oxidative stress * occupational exposure * monitoring Subject RIV: DN - Health Impact of the Environment Quality; CF - Physical ; Theoretical Chemistry (UFCH-W) OBOR OECD: Public and environmental health; Physical chemistry (UFCH-W) Impact factor: 6.428, year: 2016

NMR analysis of aldehydes in Sicilian extra-virgin olive oils by DPFGSE techniques

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Enrico Rotondo

2011-03-01

Full Text Available The DPFGSE NMR sequences open new perspectives in the volatile compounds analysis of food matrices. Many fresh extra-virgin Sicilian olive oils, analyzed by this technique, show two main resonances in the aldehydic spectral region (9–10 ppm, at 9.18 and 9.58 ppm. The former was never reported so far, the latter was sometime highlighted as a minor aldehydic component signal of spectra showing stronger resonances at 9.45 and 9.70 ppm. Thermal treatment at 220°C of extra virgin olive oil samples lead to the complete transformation of the resonances at 9.18 and 9.58 ppm into those at 9.45 and 9.70 ppm in 50 minutes. Analogous transformation takes place place in CDCl3 at rt in several weeks. These results suggest the transformation of relatively unstable compounds into thermodynamically more stable products whose resonances are commonly reported in the literature. Even though these chemical changes involve minimal amount of product, they are of crucial importance to define: i organoleptic extra virgin olive oil properties; ii fraudulent chemical or thermal treatment detection; iii extra virgin oil ageing.

The participation of human hepatic P450 isoforms, flavin-containing monooxygenases and aldehyde oxidase in the biotransformation of the insecticide fenthion

International Nuclear Information System (INIS)

Leoni, Claudia; Buratti, Franca M.; Testai, Emanuela

2008-01-01

Although fenthion (FEN) is widely used as a broad spectrum insecticide on various crops in many countries, very scant data are available on its biotransformation in humans. In this study the in vitro human hepatic FEN biotransformation was characterized, identifying the relative contributions of cytochrome P450 (CYPs) and/or flavin-containing monooxygenase (FMOs) by using single c-DNA expressed human enzymes, human liver microsomes and cytosol and CYP/FMO-specific inhibitors. Two major metabolites, FEN-sulfoxide and FEN-oxon (FOX), are formed by some CYPs although at very different levels, depending on the relative CYP hepatic content. Formation of further oxidation products and the reduction of FEN-sulfoxide back to FEN by the cytosolic aldehyde oxidase enzyme were ruled out. Comparing intrinsic clearance values, FOX formation seemed to be favored and at low FEN concentrations CYP2B6 and 1A2 are mainly involved in its formation. At higher levels, a more widespread CYP involvement was evident, as in the case of FEN-sulfoxide, although a higher efficiency of CYP2C family was suggested. Hepatic FMOs were able to catalyze only sulfoxide formation, but at low FEN concentrations hepatic FEN sulfoxidation is predominantly P450-driven. Indeed, the contribution of the hepatic isoforms FMO 3 and FMO 5 was generally negligible, although at high FEN concentrations FMO's showed activities comparable to the active CYPs, accounting for up to 30% of total sulfoxidation. Recombinant FMO 1 showed the highest efficiency with respect to CYPs and the other FMOs, but it is not expressed in the adult human liver. This suggests that FMO 1 -catalysed sulfoxidation may represent the major extra-hepatic pathway of FEN biotransformation

Oxidative and nitrosative stress in trichloroethene-mediated autoimmune response

International Nuclear Information System (INIS)

Wang Gangduo; Cai Ping; Ansari, G.A.S.; Khan, M. Firoze

2007-01-01

Reactive oxygen and nitrogen species (RONS) are implicated in the pathogenesis of several autoimmune diseases. Also, increased lipid peroxidation and protein nitration are reported in systemic autoimmune diseases. Lipid peroxidation-derived aldehydes (LPDAs) such as malondialdehyde (MDA) and 4-hydroxynonenal (HNE) are highly reactive and bind proteins covalently, but their potential to elicit an autoimmune response and contribution to disease pathogenesis remain unclear. Similarly, nitration of protein could also contribute to disease pathogenesis. To assess the status of lipid peroxidation and/or RONS, autoimmune-prone female MRL+/+ mice (5-week old) were treated with trichloroethene (TCE), an environmental contaminant known to induce autoimmune response, for 48 weeks (0.5 mg/ml via drinking water), and formation of antibodies to LPDA-protein adducts was followed in the sera of control and TCE-treated mice. TCE treatment led to greater formation of both anti-MDA- and -HNE-protein adduct antibodies and higher serum iNOS and nitrotyrosine levels. The increase in TCE-induced oxidative stress was associated with increases in anti-nuclear-, anti-ssDNA- and anti-dsDNA-antibodies. These findings suggest that TCE exposure not only leads to oxidative/nitrosative stress, but is also associated with induction/exacerbation of autoimmune response in MRL+/+ mice. Further interventional studies are needed to establish a causal role of RONS in TCE-mediated autoimmunity

Marine phospholipids: The current understanding of their oxidation mechanisms and potential uses for food fortification

DEFF Research Database (Denmark)

Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

2017-01-01

reactions, namely, Strecker aldehydes, pyrroles, oxypolymers, and other impurities that may positively or negatively affect the oxidative stability and quality of marine PL. This review was undertaken to provide the industry and academia with an overview of the current understanding of the quality changes......There is a growing interest in using marine phospholipids (PL) as ingredient for food fortification due to their numerous health benefits. However, the use of marine PL for food fortification is a challenge due to the complex nature of the degradation products that are formed during the handling...... and storage of marine PL. For example, nonenzymatic browning reactions may occur between lipid oxidation products and primary amine group from phosphatidylethanolamine or amino acid residues that are present inmarine PL. Therefore, marine PL contain products from nonenzymatic browning and lipid oxidation...

"Juice Monsters": Sub-Ohm Vaping and Toxic Volatile Aldehyde Emissions.

Science.gov (United States)

Talih, Soha; Salman, Rola; Karaoghlanian, Nareg; El-Hellani, Ahmad; Saliba, Najat; Eissenberg, Thomas; Shihadeh, Alan

2017-10-16

An emerging category of electronic cigarettes (ECIGs) is sub-Ohm devices (SODs) that operate at ten or more times the power of conventional ECIGs. Because carcinogenic volatile aldehyde (VA) emissions increase sharply with power, SODs may expose users to greater VAs. In this study, we compared VA emissions from several SODs and found that across device, VAs and power were uncorrelated unless power was normalized by coil surface area. VA emissions and liquid consumed were correlated highly. Analyzed in light of EU regulations limiting ECIG liquid nicotine concentration, these findings suggest potential regulatory levers and pitfalls for protecting public health.

Plasma oxidative stress level of IgA nephropathy in children and the effect of early intervention with angiotensin-converting enzyme inhibitors.

Science.gov (United States)

Pei, Yuxin; Xu, Yuanyuan; Ruan, Jingwei; Rong, Liping; Jiang, Mengjie; Mo, Ying; Jiang, Xiaoyun

2016-01-01

The purpose of this study was to investigate the change of the plasma oxidative stress level in children with IgA nephropathy (IgAN) and analyze its relativity to the clinical and pathological classification. To discuss the early effects of angiotensin-converting enzyme inhibitors (ACEIs) on the plasma oxidative stress level in children with IgA nephropathy. Thirty-eight children with IgAN were divided into groups according to their clinical features, pathologic grades, and treatments. Twenty healthy children were included in the control group. The plasma level of advanced oxidation protein products (AOPPs), malonaldehyde (MDA), and superoxide dismutase (SOD) were detected. The plasma level of oxidative stress was significantly increased in the IgAN group, including a higher plasma level of AOPP and MDA and a lower plasma level of SOD. After treatment, the plasma level of oxidative stress was significantly decreased in the ACEI group. The children with IgAN had an increase in the plasma level of oxidative stress, expressed as an increased plasma level of AOPP and MDA and a decreased plasma level of SOD. Oxidative stress was associated with the progression of IgAN in children. Early treatment with ACEI therapy can significantly reduce the plasma level of oxidative stress in children with IgAN. © The Author(s) 2016.

Advanced Quadrupole Ion Trap Instrumentation for Low Level Vehicle Emissions Measurements

International Nuclear Information System (INIS)

McLuckey, S.A.

1997-01-01

Quadrupole ion trap mass spectrometry has been evaluated for its potential use in vehicle emissions measurements in vehicle test facilities as an analyzer for the top 15 compounds contributing to smog generation. A variety of ionization methods were explored including ion trap in situ chemical ionization, atmospheric sampling glow discharge ionization, and nitric oxide chemical ionization in a glow discharge ionization source coupled with anion trap mass spectrometer. Emphasis was placed on the determination of hydrocarbons and oxygenated hydrocarbons at parts per million to parts per billion levels. Ion trap in situ water chemical ionization and atmospheric sampling glow discharge ionization were both shown to be amendable to the analysis of arenes, alcohols, aldehydes and, to some degree, alkenes. Atmospheric sampling glow discharge also generated molecular ions of methy-t-butyl ether (MTBE). Neither of these ionization methods, however, were found to generate diagnostic ions for the alkanes. Nitric oxide chemical ionization, on the other hand, was found to yield diagnostic ions for alkanes, alkenes, arenes, alcohols, aldehydes, and MTBE. The ability to measure a variety of hydrocarbons present at roughly 15 parts per billion at measurement rates of 3 Hz was demonstrated. All of the ions with potential to serve as parent ions in a tandem mass spectrometry experiment were found to yield parent-to-product conversion efficiencies greater than 75%. The flexibility afforded to the ion trap by use of tailored wave-forms applied to the end-caps allows parallel monitoring schemes to be devised that provide many of the advantages of tandem mass spectrometry without major loss in measurement rate. A large loss in measurement rate would ordinarily result from the use of conventional tandem mass spectrometry experiments carried out in series for a large number of targeted components. These results have demonstrated that the ion trap has an excellent combination of

Ketosis in buffalo (Bubalus bubalis): clinical findings and the associated oxidative stress level.

Science.gov (United States)

Youssef, Mohamed A; El-Khodery, Sabry Ahmed; El-deeb, Wael M; Abou El-Amaiem, Waleed E E

2010-12-01

As little is known about the oxidant/antioxidant status in buffalo with ketosis, the present study was delineated to assess the oxidative stress level associated with clinical ketosis in water buffalo. A total of 91 parturient buffalo at smallholder farms were studied (61 suspected to be ketotic and 30 healthy). Clinical and biochemical investigations were carried out for each buffalo. Based on clinical findings and the level of beta-hydroxybutyrate (BHB), buffalo were allocated into ketotic (42), subclinical cases (19). Clinically, there was an association between clinical ketosis and anorexia (pketosis compared with subclinical and control cases, there was a significant increase (pketosis.

Enzyme-inspired functional surfactant for aerobic oxidation of activated alcohols to aldehydes in water

KAUST Repository

Chen, Batian; Bukhriakov, Konstantin; Sougrat, Rachid; Rodionov, Valentin

2015-01-01

We describe an enzyme-inspired catalytic system based on a rationally designed multifunctional amphiphile. The resulting micelles feature metal-binding sites and stable free radical moieties as well as fluorous pockets that attract and preconcentrate molecular oxygen. In the presence of copper ions, the micelles effect chemoselective aerobic alcohol oxidation under ambient conditions in water, a transformation that is challenging to achieve nonenzymatically.

Enzyme-inspired functional surfactant for aerobic oxidation of activated alcohols to aldehydes in water

KAUST Repository

Chen, Batian

2015-02-06

We describe an enzyme-inspired catalytic system based on a rationally designed multifunctional amphiphile. The resulting micelles feature metal-binding sites and stable free radical moieties as well as fluorous pockets that attract and preconcentrate molecular oxygen. In the presence of copper ions, the micelles effect chemoselective aerobic alcohol oxidation under ambient conditions in water, a transformation that is challenging to achieve nonenzymatically.

THE USE OF A NOVEL ALDEHYDE-FUNCTIONALIZED CHITOSAN HYDROGEL TO PREPARE POROUS TUBULAR SCAFFOLDS FOR VASCULAR TISSUE ENGINEERING APPLICATIONS

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Eduardo P. Azevedo

Full Text Available In this work, porous tubular scaffolds were prepared from a novel water soluble aldehyde-functionalized chitosan (ALDCHIT hydrogel, which was obtained by dissolving this chitosan derivative in water and using oxidized dextrose (OXDEXT as the crosslinking agent at different ALDCHIT:OXDEXT mole ratios (10:1, 10:2 and 10:4. By increasing the amount of OXDEXT in respect to ALDCHIT the hydrogels became more rigid and could absorb more than 200% of its weight in water. Since the ALDCHIT:OXDEXT 10:4 was the most stable hydrogel, its ability to form porous tubular scaffolds was investigated. The tubular scaffolds were prepared by the lyophilization method, where the orientation of the pores was controlled by exposing either the internal or the external surface of the frozen hydrogel during the sublimation step. When only the inner surface of the frozen hydrogel was exposed, tubular scaffolds with a highly porous lumen and a sealed outer surface were obtained, where the orientation of the pores, their sizes and interconnectivity seem to be optimum for vascular tissue engineering application.

The molecular cloning of dihydroartemisinic aldehyde reductase and its implication in artemisinin biosynthesis in Artemisia annua

NARCIS (Netherlands)

Ryden, A.M.; Ruyter-Spira, C.P.; Quax, W.J.; Hiroyuki, O.; Toshiya, M.; Kayser, O.; Bouwmeester, H.J.

2010-01-01

A key point in the biosynthesis of the antimalarial drug artemisinin is the formation of dihydroartemisinic aldehyde which represents the key difference between chemotype specific pathways. This key intermediate is the substrate for several competing enzymes, some of which increase the metabolic

Reduction of Aldehydes and Ketones to Corresponding Alcohols Using Diammonium Hydrogen Phosphite and Commercial Zinc Dust

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K. Anil Kumar

2011-01-01

Full Text Available A mild and an efficient system has been developed for the reduction of aromatic aldehydes and ketones to their corresponding alcohols in good yield using inexpensive commercial zinc dust as catalyst and diammonium hydrogen phosphite as a hydrogen donor.

Curcumin loaded gum arabic aldehyde-gelatin nanogels for breast cancer therapy

Energy Technology Data Exchange (ETDEWEB)

Sarika, P.R., E-mail: sarikapaithal@gmail.com; Nirmala, Rachel James, E-mail: nirmala@iist.ac.in

2016-08-01

Curcumin, a widely studied hydrophobic polyphenol with anticancer potential is loaded in gum arabic aldehyde-gelatin (GA Ald-Gel) nanogels to improve its bioavailability and therapeutic efficacy towards cancer cells. Physicochemical properties of the curcumin loaded GA Ald-Gel nanogels are investigated by different techniques including dynamic light scattering (DLS), NMR spectroscopy and scanning electron microscopy (SEM). These nanogels exhibit hydrodynamic diameter of 452 ± 8 nm with a zeta potential of − 27 mV. The nanogels possess an encapsulation efficiency of 65 ± 3%. Potential of the nanogels for controlled release of curcumin is illustrated by in vitro drug release studies. Hemocompatibility and cytocompatibility of the drug loaded nanogels are evaluated. In vitro cytotoxicity of the bare and curcumin loaded nanogels are analyzed by MTT assay towards MCF-7 cells. The results manifest that curcumin loaded nanogels induce toxicity in MCF-7 cells. Confocal laser scanning microscopy (CLSM) studies indicate in vitro cellular uptake of the nanogels in MCF-7 cells. All these results prove the suitability of the curcumin loaded GA Ald-Gel nanogels for cancer therapy. - Highlights: • Curcumin loaded gum arabic aldehyde-gelatin nanogels were prepared. • Nanogels maintained negative zeta potential after curcumin loading. • Curcumin release is higher at acidic pH compared to neutral pH. • Curcumin loaded GA Ald-Gel nanogels shows toxicity towards MCF-7 cells. • Green fluorescence in MCF-7 cells confirmed the intracellular uptake.

Curcumin loaded gum arabic aldehyde-gelatin nanogels for breast cancer therapy

International Nuclear Information System (INIS)

Sarika, P.R.; Nirmala, Rachel James

2016-01-01

Curcumin, a widely studied hydrophobic polyphenol with anticancer potential is loaded in gum arabic aldehyde-gelatin (GA Ald-Gel) nanogels to improve its bioavailability and therapeutic efficacy towards cancer cells. Physicochemical properties of the curcumin loaded GA Ald-Gel nanogels are investigated by different techniques including dynamic light scattering (DLS), NMR spectroscopy and scanning electron microscopy (SEM). These nanogels exhibit hydrodynamic diameter of 452 ± 8 nm with a zeta potential of − 27 mV. The nanogels possess an encapsulation efficiency of 65 ± 3%. Potential of the nanogels for controlled release of curcumin is illustrated by in vitro drug release studies. Hemocompatibility and cytocompatibility of the drug loaded nanogels are evaluated. In vitro cytotoxicity of the bare and curcumin loaded nanogels are analyzed by MTT assay towards MCF-7 cells. The results manifest that curcumin loaded nanogels induce toxicity in MCF-7 cells. Confocal laser scanning microscopy (CLSM) studies indicate in vitro cellular uptake of the nanogels in MCF-7 cells. All these results prove the suitability of the curcumin loaded GA Ald-Gel nanogels for cancer therapy. - Highlights: • Curcumin loaded gum arabic aldehyde-gelatin nanogels were prepared. • Nanogels maintained negative zeta potential after curcumin loading. • Curcumin release is higher at acidic pH compared to neutral pH. • Curcumin loaded GA Ald-Gel nanogels shows toxicity towards MCF-7 cells. • Green fluorescence in MCF-7 cells confirmed the intracellular uptake.

Bioinspired aerobic oxidation of secondary amines and nitrogen heterocycles with a bifunctional quinone catalyst.

Science.gov (United States)

Wendlandt, Alison E; Stahl, Shannon S

2014-01-08

Copper amine oxidases are a family of enzymes with quinone cofactors that oxidize primary amines to aldehydes. The native mechanism proceeds via an iminoquinone intermediate that promotes high selectivity for reactions with primary amines, thereby constraining the scope of potential biomimetic synthetic applications. Here we report a novel bioinspired quinone catalyst system consisting of 1,10-phenanthroline-5,6-dione/ZnI2 that bypasses these constraints via an abiological pathway involving a hemiaminal intermediate. Efficient aerobic dehydrogenation of non-native secondary amine substrates, including pharmaceutically relevant nitrogen heterocycles, is demonstrated. The ZnI2 cocatalyst activates the quinone toward amine oxidation and provides a source of iodide, which plays an important redox-mediator role to promote aerobic catalytic turnover. These findings provide a valuable foundation for broader development of aerobic oxidation reactions employing quinone-based catalysts.

Fractal and variability analysis of simulations in ozone level due to oxides of nitrogen and sulphur

Science.gov (United States)

Bhardwaj, Rashmi; Pruthi, Dimple

2017-10-01

Air pollution refers to the release of pollutants into the air. These pollutants are detrimental to human the planet as a whole. Apart from causing respiratory infections and pulmonary disorders, rising levels of Nitrogen Dioxide is worsening ozone pollution. Formation of Ground-level ozone involves nitrogen oxides and volatile gases in the sunlight. Volatile gases are emitted from vehicles primarily. Ozone is harmful gas and its exposure can trigger serious health effects as it damages lung tissues. In order to decrease the level of ozone, level of oxides leading to ozone formation has to be dealt with. This paper deals with the simulations in ozone due to oxides of nitrogen and sulphur. The data from Central Pollution Control Board shows positive correlation for ozone with oxides of sulphur and nitrogen for RK Puram, Delhi in India where high concentration of ozone has been found. The correlation between ozone and sulphur, nitrogen oxides is moderate during summer while weak during winters. Ozone with nitrogen and sulphur dioxide follow persistent behavior as Hurst exponent is between 0.5 and 1. The fractal dimension for Sulphur dioxide is 1.4957 indicating the Brownian motion. The behavior of ozone is unpredictable as index of predictability is close to zero.

Cyclic α-Alkoxyphosphonium Salts from (2-(Diphenylphosphino)phenyl)methanol and Aldehydes and Their Application in Synthesis of Vinyl Ethers and Ketones via Wittig Olefination.

Science.gov (United States)

Huang, Wenhua; Rong, Hong-Ying; Xu, Jie

2015-07-02

Cyclic α-alkoxyphosphonium salts have been synthesized from (2-(diphenylphosphino)phenyl)methanol and aldehydes in 36-89% yields. These phosphonium salts are bench-stable solids and undergo Wittig olefination with aldehydes under basic conditions (K2CO3 or t-BuOK) to form benzylic vinyl ethers, which are readily hydrolyzed to 1,2-disubstituted ethanones under acidic conditions. The formation mechanism of these phosphonium salts via hemiacetal is also proposed.

Serum Antioxidative Enzymes Levels and Oxidative Stress Products in Age-Related Cataract Patients

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Dong Chang

2013-01-01

Full Text Available Purpose. To investigate the activity of antioxidative enzymes and the products of oxidative stress in patients with age-related cataracts and compare the findings with those in healthy control subjects. Method. Sixty patients with age-related cataract and sixty healthy controls of matched age and gender were included in this study. Serum samples were obtained to detect the antioxidative enzymes of superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px, and oxidation degradation products of malondialdehyde (MDA, 4-hydroxynonenal (4-HNE, conjugated diene (CD, advanced oxidation protein products (AOPP, protein carbonyl (PC, and 8-hydroxydeoxyguanosine (8-OHdG. Results. Serum SOD, GSH-Px, and CAT activities in cataract group were significantly decreased as compared to the control subjects (P<0.05. The levels of MDA, 4-HNE, and CD in cataract patients were significantly higher than those in the control subjects (P<0.05, P<0.01. Cataract patients had higher levels of 8-OHdG, AOPP, and PC with respect to the comparative group of normal subjects (P<0.01. And there was no statistical significance in concentration of antioxidative enzymes and oxidative stress products in patients with different subtype cataract. Conclusions. Oxidative stress is an important risk factor in the development of age-related cataract, and augmentation of the antioxidant defence systems may be of benefit to prevent or delay cataractogenesis.

Covalent Immobilization of Bacillus licheniformis γ-Glutamyl Transpeptidase on Aldehyde-Functionalized Magnetic Nanoparticles

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Meng-Chun Chi

2013-02-01

Full Text Available This work presents the synthesis and use of surface-modified iron oxide nanoparticles for the covalent immobilization of Bacillus licheniformis γ-glutamyl transpeptidase (BlGGT. Magnetic nanoparticles were prepared by an alkaline solution of divalent and trivalent iron ions, and they were subsequently treated with 3-aminopropyltriethoxysilane (APES to obtain the aminosilane-coated nanoparticles. The functional group on the particle surface and the amino group of BlGGT was then cross-linked using glutaraldehyde as the coupling reagent. The loading capacity of the prepared nanoparticles for BlGGT was 34.2 mg/g support, corresponding to 52.4% recovery of the initial activity. Monographs of transmission electron microscopy revealed that the synthesized nanoparticles had a mean diameter of 15.1 ± 3.7 nm, and the covalent cross-linking of the enzyme did not significantly change their particle size. Fourier transform infrared spectroscopy confirmed the immobilization of BlGGT on the magnetic nanoparticles. The chemical and kinetic behaviors of immobilized BlGGT are mostly consistent with those of the free enzyme. The immobilized enzyme could be recycled ten times with 36.2% retention of the initial activity and had a comparable stability respective to free enzyme during the storage period of 30 days. Collectively, the straightforward synthesis of aldehyde-functionalized nanoparticles and the efficiency of enzyme immobilization offer wide perspectives for the practical use of surface-bound BlGGT.

Relative levels of dietary EPA and DHA impact gastric oxidation and essential fatty acid uptake.

Science.gov (United States)

Dasilva, Gabriel; Boller, Matthew; Medina, Isabel; Storch, Judith

2018-05-01

Previous research showed that increasing the proportion of docosahexaenoic acid (DHA) in marine lipid supplements significantly reduces associated health benefits compared with balanced eicosapentaenoic acid (EPA):DHA supplementation Dasilva et al., 2015 [1]. It was therefore hypothesized that the EPA and DHA molecules might have differential resistance to oxidation during gastric digestion and that the oxidation level achieved could be inversely correlated with intestinal absorption and, hence, with the resultant health benefits. Accordingly, we tested this proposed mechanism of action by investigating the degree of oxidation in the stomach, and the levels of bioaccessible lipids, of varying molar proportions of DHA and EPA (2:1, 1:1 and 1:2) using the dynamic gastrointestinal tract model TIM-1. In addition, small intestine enterocyte absorption and metabolism were simulated by Caco-2 cell monolayers that were incubated with these same varying proportions of DHA and EPA, and comparing oxidized and nonoxidized polyunsaturated fatty acids (PUFAs). The results show an inverse correlation between lipid oxidation products in the stomach and the levels of bioaccessible lipids. The balanced 1:1 EPA:DHA diet resulted in lower oxidation of PUFAs during stomach digestion relative to the other ratios tested. Finally, cell-based studies showed significantly lower assimilation of oxidized EPA and DHA substrates compared to nonoxidized PUFAs, as well as significant differences between the net uptake of EPA and DHA. Overall, the present work suggests that the correct design of diets and/or supplements containing marine lipids can strongly influence the stability and bioaccessibility of PUFAs during gastrointestinal digestion and subsequent absorption. This could modulate their health benefits related with inflammation, oxidative stress and metabolic disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

Glycation of low-density lipoproteins by methylglyoxal and glycolaldehyde gives rise to the in vitro formation of lipid-laden cells

DEFF Research Database (Denmark)

Brown, B E; Dean, R T; Davies, Michael Jonathan

2005-01-01

AIMS/HYPOTHESIS: Previous studies have implicated the glycoxidative modification of low-density lipoprotein (LDL) by glucose and aldehydes (apparently comprising both glycation and oxidation), as a causative factor in the elevated levels of atherosclerosis observed in diabetic patients. Such LDL...... or endothelial cells. The extent of lipid accumulation depends on the degree of glycation, with increasing aldehyde concentration or incubation time, giving rise to greater extents of particle modification and lipid accumulation. Modification of lysine residues appears to be a key determinant of cellular uptake...

Evaluation of the melatonin and oxidative stress markers level in serum of fertile and infertile women

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Sara Soleimani Rad

2015-07-01

Full Text Available Background: Infertility is defined as the inability to achieve the pregnancy within a year of unprotected intercourse. Infertility is a complex issue and different factors such as stress oxidative can be involved in this problem. So, any attempt to neutralize oxidative stress would be helpful in the treatment of infertility. Melatonin is a known scavenger of free radicals. Objective: The aim of our study was to evaluate the level of melatonin and its correlation with oxidative biomarkers in fertile and infertile women. Materials and Methods: The participants including fertile and infertile women were divided into two groups of 30 people. Blood sampling was performed and sera were collected. The level of Malondialdehyde (MDA, total antioxidant capacity (TAC and melatonin were detected. Data were analyzed using T-test and their correlation was assessed using Spearman test. Results: Serum melatonin from fertile women was higher than infertile women but the difference was not significant (p= 0.46. MDA level in fertile women was significantly lower than infertile women (p<0.001 and the level of TAC in fertile women was significantly higher than infertile women (p<0.001. Spearman test revealed a significant and direct correlation between melatonin and TAC in fertile and infertile women and a significant but reverse correlation between melatonin and MDA in infertile and fertile women. Conclusion: Differences in the level of oxidative stress biomarkers in fertile and infertile individuals have been reported. This study revealed a significant correlation between melatonin and oxidative stress biomarkers, concluding that melatonin level could be involved in infertility.

YKL071W from Saccharomyces cerevisiae encodes a novel aldehyde reductase for detoxification of glycolaldehyde and furfural derived from lignocellulose.

Science.gov (United States)

Wang, Hanyu; Ouyang, Yidan; Zhou, Chang; Xiao, Difan; Guo, Yaping; Wu, Lan; Li, Xi; Gu, Yunfu; Xiang, Quanju; Zhao, Ke; Yu, Xiumei; Zou, Likou; Ma, Menggen

2017-12-01

Aldehydes generated as by-products during the pretreatment of lignocellulose are the key inhibitors to Saccharomyces cerevisiae, which is considered as the most promising microorganism for industrial production of biofuel, xylitol as well as other special chemicals from lignocellulose. S. cerevisiae has the inherent ability to in situ detoxify aldehydes to corresponding alcohols by multiple aldehyde reductases. Herein, we report that an uncharacterized open reading frame YKL071W from S. cerevisiae encodes a novel "classical" short-chain dehydrogenase/reductase (SDR) protein with NADH-dependent enzymatic activities for reduction of furfural (FF), glycolaldehyde (GA), formaldehyde (FA), and benzaldehyde (BZA). This enzyme showed much better specific activities for reduction of GA and FF than FA and BZA, and displayed much higher Km and Kcat/Km but lower Vmax and Kcat for reduction of GA than FF. For this enzyme, the optimum pH was 5.5 and 6.0 for reduction of GA and FF, and the optimum temperature was 30 °C for reduction of GA and FF. Both pH and temperature affected stability of this enzyme in a similar trend for reduction of GA and FF. Cu 2+ , Zn 2+ , Ni 2+ , and Fe 3+ had severe inhibition effects on enzyme activities of Ykl071wp for reduction of GA and FF. Transcription of YKL071W in S. cerevisiae was significantly upregulated under GA and FF stress conditions, and its transcription is most probably regulated by transcription factor genes of YAP1, CAD1, PDR3, and STB5. This research provides guidelines to identify more uncharacterized genes with reductase activities for detoxification of aldehydes derived from lignocellulose in S. cerevisiae.

Characterization of aldehyde dehydrogenase isozymes in ovarian cancer tissues and sphere cultures

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Saw Yu-Ting

2012-08-01

Full Text Available Abstract Background Aldehyde dehydrogenases belong to a superfamily of detoxifying enzymes that protect cells from carcinogenic aldehydes. Of the superfamily, ALDH1A1 has gained most attention because current studies have shown that its expression is associated with human cancer stem cells. However, ALDH1A1 is only one of the 19 human ALDH subfamilies currently known. The purpose of the present study was to determine if the expression and activities of other major ALDH isozymes are associated with human ovarian cancer and ovarian cancer sphere cultures. Methods Immunohistochemistry was used to delineate ALDH isozyme localization in clinical ovarian tissues. Western Blot analyses were performed on lysates prepared from cancer cell lines and ovarian cancer spheres to confirm the immunohistochemistry findings. Quantitative reverse transcription-polymerase chain reactions were used to measure the mRNA expression levels. The Aldefluor® assay was used to measure ALDH activity in cancer cells from the four tumor subtypes. Results Immunohistochemical staining showed significant overexpression of ALDH1A3, ALDH3A2, and ALDH7A1 isozymes in ovarian tumors relative to normal ovarian tissues. The expression and activity of ALDH1A1 is tumor type-dependent, as seen from immunohistochemisty, Western blot analysis, and the Aldefluor® assay. The expression was elevated in the mucinous and endometrioid ovarian epithelial tumors than in serous and clear cell tumors. In some serous and most clear cell tumors, ALDH1A1 expression was found in the stromal fibroblasts. RNA expression of all studied ALDH isozymes also showed higher expression in endometrioid and mucinous tumors than in the serous and clear cell subtypes. The expression of ALDH enzymes showed tumor type-dependent induction in ovarian cancer cells growing as sphere suspensions in serum-free medium. Conclusions The results of our study indicate that ALDH enzyme expression and activity may be associated

Impact of Lipid Oxidization on Vertical Structures and Electrostatics of Phospholipid Monolayers Revealed by Combination of Specular X-ray Reflectivity and Grazing-Incidence X-ray Fluorescence.

Science.gov (United States)

Korytowski, Agatha; Abuillan, Wasim; Makky, Ali; Konovalov, Oleg; Tanaka, Motomu

2015-07-30

The influence of phospholipid oxidization of floating monolayers on the structure perpendicular to the global plane and on the density profiles of ions near the lipid monolayer has been investigated by a combination of grazing incidence X-ray fluorescence (GIXF) and specular X-ray reflectivity (XRR). Systematic variation of the composition of the floating monolayers unravels changes in the thickness, roughness and electron density of the lipid monolayers as a function of molar fraction of oxidized phospholipids. Simultaneous GIXF measurements enable one to qualitatively determine the element-specific density profiles of monovalent (K(+) or Cs(+)) and divalent ions (Ca(2+)) in the vicinity of the interface in the presence and absence of two types of oxidized phospholipids (PazePC and PoxnoPC) with high spatial accuracy (±5 Å). We found the condensation of Ca(2+) near carboxylated PazePC was more pronounced compared to PoxnoPC with an aldehyde group. In contrast, the condensation of monovalent ions could hardly be detected even for pure oxidized phospholipid monolayers. Moreover, pure phospholipid monolayers exhibited almost no ion specific condensation near the interface. The quantitative studies with well-defined floating monolayers revealed how the elevation of lipid oxidization level alters the structures and functions of cell membranes.

YNL134C from Saccharomyces cerevisiae encodes a novel protein with aldehyde reductase activity for detoxification of furfural derived from lignocellulosic biomass.

Science.gov (United States)

Zhao, Xianxian; Tang, Juan; Wang, Xu; Yang, Ruoheng; Zhang, Xiaoping; Gu, Yunfu; Li, Xi; Ma, Menggen

2015-05-01

Furfural and 5-hydroxymethylfurfural (HMF) are the two main aldehyde compounds derived from pentoses and hexoses, respectively, during lignocellulosic biomass pretreatment. These two compounds inhibit microbial growth and interfere with subsequent alcohol fermentation. Saccharomyces cerevisiae has the in situ ability to detoxify furfural and HMF to the less toxic 2-furanmethanol (FM) and furan-2,5-dimethanol (FDM), respectively. Herein, we report that an uncharacterized gene, YNL134C, was highly up-regulated under furfural or HMF stress and Yap1p and Msn2/4p transcription factors likely controlled its up-regulated expression. Enzyme activity assays showed that YNL134C is an NADH-dependent aldehyde reductase, which plays a role in detoxification of furfural to FM. However, no NADH- or NADPH-dependent enzyme activity was observed for detoxification of HMF to FDM. This enzyme did not catalyse the reverse reaction of FM to furfural or FDM to HMF. Further studies showed that YNL134C is a broad-substrate aldehyde reductase, which can reduce multiple aldehydes to their corresponding alcohols. Although YNL134C is grouped into the quinone oxidoreductase family, no quinone reductase activity was observed using 1,2-naphthoquinone or 9,10-phenanthrenequinone as a substrate, and phylogenetic analysis indicates that it is genetically distant to quinone reductases. Proteins similar to YNL134C in sequence from S. cerevisiae and other microorganisms were phylogenetically analysed. Copyright © 2015 John Wiley & Sons, Ltd.

Synthesis of acid-base bifunctional mesoporous materials by oxidation and thermolysis

Energy Technology Data Exchange (ETDEWEB)

Yu, Xiaofang [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Zou, Yongcun [State Key Laboratory of Inoranic Synthesis and Preparative Chemistryg, College of Chemistry, Jilin University, Changchun 130012 (China); Wu, Shujie; Liu, Heng [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Guan, Jingqi, E-mail: guanjq@jlu.edu.cn [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Kan, Qiubin, E-mail: qkan@jlu.edu.cn [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China)

2011-06-15

Graphical abstract: A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst. The obtained sample of SO{sub 3}H-MCM-41-NH{sub 2} containing amine and sulfonic acids exhibits excellent catalytic activity in aldol condensation reaction. Research highlights: {yields} Synthesize acid-base bifunctional mesoporous materials SO{sub 3}H-MCM-41-NH{sub 2}. {yields} Oxidation and then thermolysis to generate acidic site and basic site. {yields} Exhibit good catalytic performance in aldol condensation reaction between acetone and various aldehydes. -- Abstract: A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst SO{sub 3}H-MCM-41-NH{sub 2}. This method was achieved by co-condensation of tetraethylorthosilicate (TEOS), 3-mercaptopropyltrimethoxysilane (MPTMS) and (3-triethoxysilylpropyl) carbamicacid-1-methylcyclohexylester (3TAME) in the presence of cetyltrimethylammonium bromide (CTAB), followed by oxidation and then thermolysis to generate acidic site and basic site. X-ray diffraction (XRD) and transmission electron micrographs (TEM) show that the resultant materials keep mesoporous structure. Thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), back titration, solid-state {sup 13}C CP/MAS NMR and solid-state {sup 29}Si MAS NMR confirm that the organosiloxanes were condensed as a part of the silica framework. The bifunctional sample (SO{sub 3}H-MCM-41-NH{sub 2}) containing amine and sulfonic acids exhibits excellent acid-basic properties, which make it possess high activity in aldol condensation reaction between acetone and various aldehydes.

Alcohol Dehydrogenase-1B (rs1229984) and Aldehyde Dehydrogenase-2 (rs671) Genotypes Are Strong Determinants of the Serum Triglyceride and Cholesterol Levels of Japanese Alcoholic Men.

Science.gov (United States)

Yokoyama, Akira; Yokoyama, Tetsuji; Matsui, Toshifumi; Mizukami, Takeshi; Kimura, Mitsuru; Matsushita, Sachio; Higuchi, Susumu; Maruyama, Katsuya

2015-01-01

Elevated serum triglyceride (TG) and high-density-lipoprotein cholesterol (HDL-C) levels are common in drinkers. The fast-metabolizing alcohol dehydrogenase-1B encoded by the ADH1B*2 allele (vs. ADH1B*1/*1 genotype) and inactive aldehyde dehydrogenase-2 encoded by the ALDH2*2 allele (vs. ALDH2*1/*1 genotype) modify ethanol metabolism and are prevalent (≈90% and ≈40%, respectively) in East Asians. We attempted to evaluate the associations between the ADH1B and ALDH2 genotypes and lipid levels in alcoholics. The population consisted of 1806 Japanese alcoholic men (≥40 years) who had undergone ADH1B and ALDH2 genotyping and whose serum TG, total cholesterol, and HDL-C levels in the fasting state had been measured within 3 days after admission. High serum levels of TG (≥150 mg/dl), HDL-C (>80 mg/dl), and low-density-lipoprotein cholesterol (LDL-C calculated by the Friedewald formula ≥140 mg/dl) were observed in 24.3%, 16.8%, and 15.6%, respectively, of the subjects. Diabetes, cirrhosis, smoking, and body mass index (BMI) affected the serum lipid levels. Multivariate analysis revealed that the presence of the ADH1B*2 allele and the active ALDH2*1/*1 genotype increased the odds ratio (OR; 95% confidence interval) for a high TG level (2.22 [1.67-2.94] and 1.39 [0.99-1.96], respectively), and decreased the OR for a high HDL-C level (0.37 [0.28-0.49] and 0.51 [0.37-0.69], respectively). The presence of the ADH1B*2 allele decreased the OR for a high LDL-C level (0.60 [0.45-0.80]). The ADH1B*2 plus ALDH2*1/*1 combination yielded the highest ORs for high TG levels and lowest OR for a high HDL-C level. The genotype effects were more prominent in relation to the higher levels of TG (≥220 mg/dl) and HDL-C (≥100 mg/dl). The fast-metabolizing ADH1B and active ALDH2, and especially a combination of the two were strongly associated with higher serum TG levels and lower serum HDL-C levels of alcoholics. The fast-metabolizing ADH1B was associated with lower serum LDL

Alcohol Dehydrogenase-1B (rs1229984 and Aldehyde Dehydrogenase-2 (rs671 Genotypes Are Strong Determinants of the Serum Triglyceride and Cholesterol Levels of Japanese Alcoholic Men.

Directory of Open Access Journals (Sweden)

Akira Yokoyama

Full Text Available Elevated serum triglyceride (TG and high-density-lipoprotein cholesterol (HDL-C levels are common in drinkers. The fast-metabolizing alcohol dehydrogenase-1B encoded by the ADH1B*2 allele (vs. ADH1B*1/*1 genotype and inactive aldehyde dehydrogenase-2 encoded by the ALDH2*2 allele (vs. ALDH2*1/*1 genotype modify ethanol metabolism and are prevalent (≈90% and ≈40%, respectively in East Asians. We attempted to evaluate the associations between the ADH1B and ALDH2 genotypes and lipid levels in alcoholics.The population consisted of 1806 Japanese alcoholic men (≥40 years who had undergone ADH1B and ALDH2 genotyping and whose serum TG, total cholesterol, and HDL-C levels in the fasting state had been measured within 3 days after admission.High serum levels of TG (≥150 mg/dl, HDL-C (>80 mg/dl, and low-density-lipoprotein cholesterol (LDL-C calculated by the Friedewald formula ≥140 mg/dl were observed in 24.3%, 16.8%, and 15.6%, respectively, of the subjects. Diabetes, cirrhosis, smoking, and body mass index (BMI affected the serum lipid levels. Multivariate analysis revealed that the presence of the ADH1B*2 allele and the active ALDH2*1/*1 genotype increased the odds ratio (OR; 95% confidence interval for a high TG level (2.22 [1.67-2.94] and 1.39 [0.99-1.96], respectively, and decreased the OR for a high HDL-C level (0.37 [0.28-0.49] and 0.51 [0.37-0.69], respectively. The presence of the ADH1B*2 allele decreased the OR for a high LDL-C level (0.60 [0.45-0.80]. The ADH1B*2 plus ALDH2*1/*1 combination yielded the highest ORs for high TG levels and lowest OR for a high HDL-C level. The genotype effects were more prominent in relation to the higher levels of TG (≥220 mg/dl and HDL-C (≥100 mg/dl.The fast-metabolizing ADH1B and active ALDH2, and especially a combination of the two were strongly associated with higher serum TG levels and lower serum HDL-C levels of alcoholics. The fast-metabolizing ADH1B was associated with lower serum LDL

Solvent-free oxidation of secondary alcohols to carbonyl compounds by 1, 3-Dibromo-5, 5-Dimethylhydantoin (DBDMH) and 1, 3-Dichloro-5, 5-Dimethylhydantoin (DCDMH)

Energy Technology Data Exchange (ETDEWEB)

Khazaei, Ardeshir; Abbasi, Fatemeh, E-mail: Khazaei_1326@yahoo.com, E-mail: fatemehabbasi807@gmail.com [Faculty of Chemistry, Department of Organic Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Kianiborazjani, Maryam [Faculty of Science, Department of Chemistry, Bushehr Payame Noor University (PNU), Bushehr (Iran, Islamic Republic of); Saednia, Shahnaz [Young Researchers Club, Toyserkan Branch, Islamic Azad University, Toyserkan (Iran, Islamic Republic of)

2014-02-15

Aldehydes and ketones are important intermediates, especially for the construction of carbon-skeletons. The oxidation of alcohols is so important that a large number of methods and reagents have been reported for this purpose. N-halo reagents are widely used in organic synthesis and as a continuation of our interest in the application of N-halo compounds in organic synthesis, dibromo dimethylhydantoin (DBDMH) and dichloro dimethylhydantoin (DCDMH) were used for the oxidation of alcohols and our ongoing work on development of highly efficient oxidation protocols. We observed the oxidation of secondary alcohols with stoichiometric amounts of DBDMH and DCDMH under solvent-free conditions in the range of temperature 70-80 deg C. (author)

Reactions of CH-acids with α,β-unsaturated aldehydes in ionic liquids

DEFF Research Database (Denmark)

Kryshtal, G. V.; Zhdankina, G. M.; Astakhova, Irina Kira

2004-01-01

Metal carbonate-catalyzed reactions of CH-acids (diethyl malonate, ethyl acetoacetate, ethyl cyanoacetate, and ethyl 2-acetyl- and 2-ethoxycarbonyl-5,9- dimethyldeca-4,8-dienoates) with α,β-unsaturated aldehydes (acrolein, crotonaldehyde, citral) were studied in an ionic liquid, 1-butyl-3......- methylimidazolium hexafluorophosphate [bmim][PF 6], and in a 1-butyl-3-methylimidazolium bromide ([bmim][Br]) - benzene system. The reactions with acrolein and crotonaldehyde afforded Michael addition products, those with citral resulted in Knoevenagel addition products. Sonication increased the yields...

Peritoneal adhesion prevention with a biodegradable and injectable N,O-carboxymethyl chitosan-aldehyde hyaluronic acid hydrogel in a rat repeated-injury model

Science.gov (United States)

Song, Linjiang; Li, Ling; He, Tao; Wang, Ning; Yang, Suleixin; Yang, Xi; Zeng, Yan; Zhang, Wenli; Yang, Li; Wu, Qinjie; Gong, Changyang

2016-11-01

Postoperative peritoneal adhesion is one of the serious issues because it induces severe clinical disorders. In this study, we prepared biodegradable and injectable hydrogel composed of N,O-carboxymethyl chitosan (NOCC) and aldehyde hyaluronic acid (AHA), and assessed its anti-adhesion effect in a rigorous and severe recurrent adhesion model which is closer to clinical conditions. The flexible hydrogel, which gelated in 66 seconds at 37 °C, was cross-linked by the schiff base derived from the amino groups of NOCC and aldehyde groups in AHA. In vitro cytotoxicity test showed the hydrogel was non-toxic. In vitro and in vivo degradation examinations demonstrated the biodegradable and biocompatibility properties of the hydrogel. The hydrogel discs could prevent the invasion of fibroblasts, whereas fibroblasts encapsulated in the porous 3-dimensional hydrogels could grow and proliferate well. Furthermore, the hydrogel was applied to evaluate the anti-adhesion efficacy in a more rigorous recurrent adhesion model. Compared with normal saline group and commercial hyaluronic acid (HA) hydrogel, the NOCC-AHA hydrogel exhibited significant reduction of peritoneal adhesion. Compared to control group, the blood and abdominal lavage level of tPA was increased in NOCC-AHA hydrogel group. These findings suggested that NOCC-AHA hydrogel had a great potential to serve as an anti-adhesion candidate.

Synthesis of Arylthiopyrimidines by Copper-catalyzed Aerobic Oxidative C-S Cross-coupling

Energy Technology Data Exchange (ETDEWEB)

Lee, Ok Suk; Kim, Hyeji; Sohn, Jeong-Hun [Chungnam National University, Daejeon (Korea, Republic of); Lee, Hee-Seung [KAIST, Daejeon (Korea, Republic of); Shin, Hyunik [Yonsung Fine Chemicals R and D Center, Suwon (Korea, Republic of)

2016-02-15

Copper-catalyzed C–S cross-coupling reactions have been considered as powerful tools in synthetic chemistry and utilized for diverse heterocycle syntheses. In the reactions, the aspects of no need of ligands has been particular advantage over other metal catalysis. We have developed a Cu-catalyzed cascade reaction for the synthesis of fully substituted 2-arylthiopyrimidines from 3,4-dihydropyrimidine-2(1H)-thiones (DHPMs) under aerobic conditions. This cascade reaction of DHPM with aryl iodide proceeds presumably via sequential tautomerization, C–S cross-coupling, and oxidative dehydrogenation (oxidation followed by elimination). Considering that DHPM substrates were easily synthesized by Biginelli three component coupling reaction of aryl aldehyde, β-ketoester, and thiourea, the present method provides a direct access toward diverse 2-arylthiopyrimidines which have been used as a prominent substructure of drug molecules.

Kinetics and Mechanism of Oxidation of Aromatic Aldehydes by Imidazolium Dichromate in Aqueous Acetic Acid Medium

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S. Sheik Mansoor

2009-01-01

Full Text Available The kinetics of oxidation of benzaldehyde (BA and para-substituted benzaldehydes by imidazolium dichromate (IDC has been studied in aqueous acetic acid medium in the presence of perchloric acid. The reaction is first order each in [IDC], [Substrate] and [H+]. The reaction rates have been determined at different temperatures and the activation parameters calculated. Electron withdrawing substituents are found to increase the reaction and electron releasing substituents are found to retard the rate of the reaction and the rate data obey the Hammett relationship. The products of the oxidation are the corresponding acids. The rate decreases with the increase in the water content of the medium. A suitable mechanism is proposed.

aldB, an RpoS-dependent gene in Escherichia coli encoding an aldehyde dehydrogenase that is repressed by Fis and activated by Crp.

OpenAIRE

Xu, J; Johnson, R C

1995-01-01

Escherichia coli aldB was identified as a gene that is negatively regulated by Fis but positively regulated by RpoS. The complete DNA sequence determined in this study indicates that aldB encodes a 56.3-kDa protein which shares a high degree of homology with an acetaldehyde dehydrogenase encoded by acoD of Alcaligenes eutrophus and an aldehyde dehydrogenase encoded by aldA of Vibrio cholerae and significant homology with a group of other aldehyde dehydrogenases from prokaryotes and eukaryotes...

Characterization of Volatile Compounds with HS-SPME from Oxidized n-3 PUFA Rich Oils via Rancimat Tests.

Science.gov (United States)

Yang, Kai-Min; Cheng, Ming-Ching; Chen, Chih-Wei; Tseng, Chin-Yin; Lin, Li-Yun; Chiang, Po-Yuan

2017-02-01

Algae oil and fish oil are n-3 PUFA mainstream commercial products. The various sources for the stability of n-3 PUFA oxidation are influenced by the fatty acid composition, extraction and refined processing. In this study, the oil stability index (OSI) occurs within 2.3 to 7.6 hours with three different n-3 PUFA rich oil. To set the OSI in the Rancimat test as the oil stability limit and observed various degrees of oxidation (0, 25, 50, 75, 100 and 125%). The volatile oxidation compounds were analyzed via headspace-solid phase microextraction (HS-SPME) and GC/MS. We detected 51 volatile compound variations during the oxidation, which were composed of aldehydes, hydrocarbons, cyclic compounds, alcohols, benzene compounds, ketones, furans, ester and pyrrolidine. The off-flavor characteristics can be strongly influenced by the synergy effects of volatile oxidation compounds. Chemometric analysis (PCA and AHC) was applied to identify the sensitive oxidation marker compounds, which included a (E,E)-2,4-heptadienal appropriate marker, via lipid oxidation in the n-3 PUFA rich oil.

Impact of environmental tobacco smoke exposure in women on oxidative stress in the antral follicle and assisted reproduction outcomes.

Science.gov (United States)

Kazemi, Ashraf; Ramezanzadeh, Fatemeh; Esfahani, Mohammad Hosein Nasr; Saboor-Yaraghi, Ali Akbar; Nejat, Saharnaz; Rahimi-Foroshani, Abbas

2013-08-01

Cigarette smoke contains many oxidants and may alter the human reproduction by inducing oxidative stress (OS) in both active and passive smokers. This study was designed to evaluate the effect of environmental tobacco smoke (ETS) exposure on oxidative stress in the follicular fluid and the assisted reproduction outcomes. An observational prospective study was carried out on 236 infertile women, who underwent assisted reproduction cycles. The ETS exposure was assessed using self-reported ETS exposure and the cotinine level in follicular fluid. To evaluate the OS in follicular fluid (FF) malon-di-aldehyde (MDA) and total antioxidant capacity (TAC) were measured. The number of retrieved oocytes, rate of metaphase II stage oocytes, fertilization rate, good cleavage rate, and no-fragmented embryo rate were considered as the assisted reproduction outcomes. The results were adjusted for age, body mass index, duration, and etiology of infertility; P-values less than 0.05 were considered significant. The MDA and TAC levels in FF were not related to the self-report number of the weekly ETS exposure and cotinine levels in FF. Also, the number of retrieved oocytes, MII stage oocytes, fertilization rate, good cleavage rate, and no-fragmented embryo rate were not related to the cotinine level and weekly ETS exposure. However, in women whose cotinine levels in FF were lower and equal/above 3.5 ng/ml, the number of retrieved oocytes was higher (12.63 ± .71 vs. 9.28 ± 1.11, P = 0.01). The relationship between the MDA level and cleavage rate (Beta = -18.5, confidence interval-34.9 and-2.1, P assisted reproduction success by influencing the number of available oocytes. Although, the OS in a follicular environment affect the ability of oocytes to reach the specific cleavage stages at appropriate time intervals, it does not mediate poor-assisted reproduction outcomes due to ETS exposure.

Kinetics of the reactions of bromine atoms with a series of aliphatic aldehydes at 298 K

Energy Technology Data Exchange (ETDEWEB)

Szilagyi, I.; Imrik, K.; Dobe, S.; Berces, T. [Magyar Tudomanyos Akademia, Budapest (Hungary). Koezponti Kemiai Kutato Intezete

1998-01-01

The kinetics of the reactions of Br({sup 2}P{sub 3/2}) with selected aldehydes, i.e. ethanal (1), propanal (2), 2-methyl-propanal (3), 2.2-dimethyl-propanal (4) and trichloroacetaldehyde (5) were studied at 298{+-}2 K. Rate constants for overall reactions were measured using the fast flow technique with resonance fluorescence detection of Br. Complementary determinations were carried out by the laser flash photolysis method. The following rate constants were obtained in the kinetic measurements ({+-}2{sigma}): k{sub 1}=(2.1{+-}0.2) x 10{sup 12}, k{sub 2}=(4.3{+-}0.4) x 10{sup 12}, k{sub 3}=(6.3{+-}1.4) x 10{sup 12}, k{sub 4}=(8.5{+-}0.8) x 10{sup 12}, k{sub 5}{<=}1 x 10{sup 9}, all in cm{sup 3}mol{sup -1}s{sup -1} units. The probable mechanism for the reactions of bromine atoms with aliphatic aldehydes has been discussed. (orig.)

Corneal aldehyde dehydrogenase and glutathione S-transferase activity after excimer laser keratectomy in guinea pigs.

Science.gov (United States)

Bilgihan, K; Bilgihan, A; Hasanreisoğlu, B; Turkozkan, N

1998-03-01

The free radical balance of the eye may be changed by excimer laser keratectomy. Previous studies have demonstrated that excimer laser keratectomy increases the corneal temperature, decreases the superoxide dismutase activity of the aqueous, and induces lipid peroxidation in the superficial corneal stroma. Aldehyde dehydrogenase (ALDH) and glutathione S-transferase (GST) are known to play an important role in corneal metabolism, particularly in detoxification of aldehydes, which are generated from free radical reactions. In three groups of guinea pigs mechanical corneal de-epithelialisation was performed in group I, superficial corneal photoablation in group II, and deep corneal photoablation in group III, and the corneal ALDH and GST activities measured after 48 hours. The mean ALDH and GST activities of group I and II showed no differences compared with the controls (p > 0.05). The corneal ALDH activities were found to be significantly decreased (p < 0.05) and GST activities increased (p < 0.05) in group III. These results suggest that excimer laser treatment of high myopia may change the ALDH and GST activities, metabolism, and free radical balance of the cornea.

Coagulation and oxidative stress plasmatic levels in a type 2 diabetes population.

Science.gov (United States)

Barillari, Giovanni; Fabbro, Elisabetta; Pasca, Samantha; Bigotto, Enrico

2009-06-01

Type 2 diabetes mellitus (DM2) is a metabolic disorder characterized by relative insulin deficiency, insulin resistance and hyperglycemia. DM2 improperly managed can cause severe complications such as renal failure, blindness or arterial disease. In addition to serious complications due to DM2, in the past 20 years, several studies have demonstrated the association between DM2, insulin resistance and prothrombotic risk. In our study, we wanted to evaluate the correlation between coagulation factor levels, oxidative plasmatic levels and DM2. We considered 20 DM2 patients (65% women and 35% men), 40-65 years of age, who had a BMI between 25 and 40 kg/m2 and followed a diet with or without oral antidiabetic treatment and 20 controls, blood donors, 15 men (75%) and five women (25%), who had a BMI between 25 and 40 kg/m2 and their age was between 40 and 65 years. Plasmatic levels of oxidative stress markers (tumor necrosis factor-alpha, nitrotyrosine, oxidized low-density lipoprotein) and coagulation markers (factors VII, VIII, IX, XI, XII, antithrombin III and fibrinogen) of both populations were analyzed following statistic criteria. The analyzed data of this study related to oxidative stress and coagulation factors proved that the differences observed between diabetic patients and controls were not statistically significant (P statistically significant (P < 0.01). In patients with DM2, factor VIII increased from 79 to 103%, factor IX from 88 to 103%, factor XII from 87 to 105% and finally, antithrombin III from 81 to 103%. Different results between literature and our study could be due to fact that the patients considered were in the early stage of diabetes when endothelial damage is absent and vascular complications are not clinically expressed. In this study, it is still shown that DM2 is a multifactor disease and its physiopathologic mechanisms are not completely known today.

Hantzsch Reaction Starting Directly from Alcohols through a Tandem Oxidation Process

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Xiaobing Liu

2017-01-01

Full Text Available A Brønsted acidic ionic liquid, 3-(N,N-dimethyldodecylammonium propanesulfonic acid hydrogen sulphate ([DDPA][HSO4], has been successfully applied to catalyze sequential oxidation of aromatic alcohols with NaNO3 followed by their condensation with dicarbonyl compound and ammonium acetate. The corresponding pyridine analogues of Hantzsch 1,4-dihydropyridines could be obtained as a major product with high yields by the multicomponent reaction. The present work utilizing alcohols instead of aldehyde in Hantzsch reaction is a valid and green alternative to the classical synthesis of the corresponding pyridine analogues of Hantzsch 1,4-dihydropyridines.

Catalytic oxidation for treatment of ECLSS and PMMS waste streams. [Process Material Management Systems

Science.gov (United States)

Akse, James R.; Thompson, John; Scott, Bryan; Jolly, Clifford; Carter, Donald L.