Chemiluminescence parameters of peroxynitrous acid in the presence of short-chain alcohols and Ru(bpy)32+

2011 ◽  
Vol 65 (6) ◽  
Author(s):  
Lijun Wei ◽  
Huifen Xia ◽  
Zhaopin Wang ◽  
Ping Yuan ◽  
Tong Zhou ◽  
...  
Keyword(s):  
Excited State ◽  
Carbon Chain ◽  
Chain Structure ◽  
Short Chain ◽  
Peroxynitrous Acid ◽  
Optimum Conditions ◽  
Chemiluminescence Intensity ◽  
Branched Chain

AbstractThe chemiluminescence behaviour and mechanism of peroxynitrous acid and Ru(bpy)32+ were studied in the presence of short-chain alcohols (methanol, ethanol, propan-1-ol, propan-2-ol, butanol, 2-methylpropan-1-ol, pentanol). It was found that the chemiluminescence intensity of peroxynitrous acid and Ru(bpy)32+ system could be significantly enhanced by these seven short-chain alcohols. The maximum chemiluminescence wavelength of 608 nm of [Ru(bpy)32+]* in the excited state was attributed to the reaction between Ru(bpy)32+ and dihydroxyalkyl radicals which were generated during the redox course of peroxynitrous acid and alcohols. In addition, the chemiluminescence signals of the system presented depended largely on the solubility and branched-chain structure as well as the length of carbon chain. The analytical characteristics and parameters of the peroxynitrous acid/Ru(bpy)32+/alcohols chemiluminescence system were investigated under optimum conditions.

scholarly journals Effect of Surfactant Molecular Structure on Emulsion Stability Investigated by Interfacial Dilatational Rheology

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1127
Author(s):  
Yuejie Jin ◽  
Dingrong Liu ◽  
Jinhua Hu
Keyword(s):  
Emulsion Stability ◽  
Chain Structure ◽  
Interfacial Film ◽  
Future Design ◽  
Rheological Method ◽  
Viscoelastic Modulus ◽  
Hydrophobic Chain ◽  
Branched Chain ◽  
The Stability ◽  
Branched Structure

Polyglycerol polyricinolate (PGPR) and polyglycerol-2 dioleate were selected as model surfactants to construct water-in-oil (W/O) emulsions, and the effect of interfacial rheological properties of surfactant film on the stability of emulsions were investigated based on the interfacial dilatational rheological method. The hydrophobicity chain of PGPR is polyricinic acid condensed from ricinic acid, and that of polyglycerol-2 dioleate is oleic acid. Their dynamic interfacial tensions in 15 cycles of interfacial compression-expansion were determined. The interfacial dilatational viscoelasticity was analyzed by amplitude scanning in the range of 1–28% amplitude and frequency sweep in the range of 5–45 mHz under 2% amplitude. It was found that PGPR could quickly reach adsorption equilibrium and form interfacial film with higher interfacial dilatational viscoelastic modulus to resist the deformation of interfacial film caused by emulsion coalescence, due to its branched chain structure and longer hydrophobic chain, and the emulsion thus presented good stability. However, polyglycerol-2 dioleate with a straight chain structure had lower interfacial tension, and it failed to resist the interfacial disturbance caused by coalescence because of its lower interfacial dilatational viscoelastic modulus, and thus the emulsion was unstable. This study reveals profound understanding of the influence of branched structure of PGPR hydrophobic chain on the interfacial film properties and the emulsion stability, providing experimental reference and theoretical guidance for future design or improvement of surfactant.

scholarly journals Chicken-eaters and pork-eaters have different gut microbiota and tryptophan metabolites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jie Shi ◽  
Di Zhao ◽  
Fan Zhao ◽  
Chong Wang ◽  
Galia Zamaratskaia ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Gut Microbiota ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Branched Chain Fatty Acids ◽  
Tryptophan Metabolites ◽  
Branched Chain ◽  
Spearman’S Correlation ◽  
Gut Microbiota Composition ◽  
Chain Fatty Acids

AbstractThis study was aimed to evaluate the differences in the composition of gut microbiota, tryptophan metabolites and short-chain fatty acids in feces between volunteers who frequently ate chicken and who frequently ate pork. Twenty male chicken-eaters and 20 male pork-eaters of 18 and 30 years old were recruited to collect feces samples for analyses of gut microbiota composition, short-chain fatty acids and tryptophan metabolites. Chicken-eaters had more diverse gut microbiota and higher abundance of Prevotella 9, Dialister, Faecalibacterium, Megamonas, and Prevotella 2. However, pork-eaters had higher relative abundance of Bacteroides, Faecalibacterium, Roseburia, Dialister, and Ruminococcus 2. In addition, chicken-eaters had high contents of skatole and indole in feces than pork-eaters, as well as higher contents of total short chain fatty acids, in particular for acetic acid, propionic acid, and branched chain fatty acids. The Spearman’s correlation analysis revealed that the abundance of Prevotella 2 and Prevotella 9 was positively correlated with levels of fecal skatole, indole and short-chain fatty acids. Thus, intake of chicken diet may increase the risk of skatole- and indole-induced diseases by altering gut microbiota.

scholarly journals Activation of short-chain ketones and isopropanol in sulfate-reducing bacteria

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jasmin Frey ◽  
Sophie Kaßner ◽  
Dieter Spiteller ◽  
Mario Mergelsberg ◽  
Matthias Boll ◽  
...  
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Short Chain ◽  
Enzyme Assays ◽  
Protein Patterns ◽  
Sulfate Reducing ◽  
Protein Gel ◽  
Branched Chain ◽  
Reducing Bacteria ◽  
Coenzyme B ◽  
Nitrate Reducing Bacteria

Abstract Background Degradation of acetone by aerobic and nitrate-reducing bacteria can proceed via carboxylation to acetoacetate and subsequent thiolytic cleavage to two acetyl residues. A different strategy was identified in the sulfate-reducing bacterium Desulfococcus biacutus that involves formylation of acetone to 2-hydroxyisobutyryl-CoA. Results Utilization of short-chain ketones (acetone, butanone, 2-pentanone and 3-pentanone) and isopropanol by the sulfate reducer Desulfosarcina cetonica was investigated by differential proteome analyses and enzyme assays. Two-dimensional protein gel electrophoresis indicated that D. cetonica during growth with acetone expresses enzymes homologous to those described for Desulfococcus biacutus: a thiamine diphosphate (TDP)-requiring enzyme, two subunits of a B12-dependent mutase, and a NAD+-dependent dehydrogenase. Total proteomics of cell-free extracts confirmed these results and identified several additional ketone-inducible proteins. Acetone is activated, most likely mediated by the TDP-dependent enzyme, to a branched-chain CoA-ester, 2-hydroxyisobutyryl-CoA. This compound is linearized to 3-hydroxybutyryl-CoA by a coenzyme B12-dependent mutase followed by oxidation to acetoacetyl-CoA by a dehydrogenase. Proteomic analysis of isopropanol- and butanone-grown cells revealed the expression of a set of enzymes identical to that expressed during growth with acetone. Enzyme assays with cell-free extract of isopropanol- and butanone-grown cells support a B12-dependent isomerization. After growth with 2-pentanone or 3-pentanone, similar protein patterns were observed in cell-free extracts as those found after growth with acetone. Conclusions According to these results, butanone and isopropanol, as well as the two pentanone isomers, are degraded by the same enzymes that are used also in acetone degradation. Our results indicate that the degradation of several short-chain ketones appears to be initiated by TDP-dependent formylation in sulfate-reducing bacteria.

STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES: LXI. PROPERTIES OF THE FRACTIONATED NITRATES OF TWO FRACTIONS OF CORN STARCH

1946 ◽  
Vol 24b (5) ◽  
pp. 246-253 ◽  
Author(s):  
W. R. Ashford ◽  
T. H. Evans ◽  
Harold Hibbert
Keyword(s):  
Relative Stability ◽  
Corn Starch ◽  
Chain Structure ◽  
Linear Type ◽  
Relative Stabilities ◽  
Preferential Adsorption ◽  
Chain Fraction ◽  
Branched Chain ◽  
Nitrogen Contents

Corn starch has been separated into two individual components, arbitrarily designated as amylose (linear fraction) and amylopectin (branched-chain fraction) by means of preferential adsorption on cellulose (Tanret–Pacsu method). These components have been nitrated and their nitrates fractionated by dissolution in ethanol. The relative stabilities and nitrogen contents of the nitrated fractions have been studied.Unfractionated amylose nitrate has greater stability than unfractionated amylopectin nitrate as judged by the Bergmann–Junk test. Dissolution methods of fractionation showed a much higher solubility of the amylopectin nitrate, the greater relative stability of the amylose fractions, and the somewhat greater stabilizing action of ethanol in the case of the latter.The widely different solubilities of amylose and amylopectin nitrates in conjunction with the lower ethanol solubility of whole starch nitrate are in accordance with the theory of a branched-chain structure for amylopectin and the linear type for amylose.

Accessibility of the Carbon Black Particle Surface to Elastomers

1970 ◽  
Vol 43 (2) ◽  
pp. 464-469 ◽  
Author(s):  
P. Aboytes ◽  
A. Voet
Keyword(s):  
Carbon Black ◽  
Particle Surface ◽  
Carbon Black Particle ◽  
Carbon Chain ◽  
Chain Structure ◽  
Inert Atmosphere ◽  
Chemical Surface ◽  
Molecular Weights ◽  
Surface Areas ◽  
Black Surface

Abstract Experimental carbon blacks were prepared with the generally encountered slit-shaped pores of discrete dimensions of 9,12.5, and 16 A˚ width in greatly differing size distribution. Equilibrium adsorption in the saturation range was determined in n-hexane for butadiene—styrene elastomers of the SBR type of average molecular weights of 1500; 2000; 15,000; and 300,000. In attempting to correlate the saturation adsorption values with carbon black surface areas, it was found that a simple linear relation in the range investigated could only be obtained by assuming that pores of 9 A˚ width were inaccessible to SBR of 1500 and 2000 MW; that pores of 9 and 12.5 A˚ width were inaccessible to SBR of 15,000 MW; and that all pores smaller than 20 A˚ width were inaccessible to SBR of 300,000 MW. The data indicated that there are no differences between high, regular and low structure blacks in saturation elastomer adsorption under conditions of equivalent dispersion. Equally, upon breaking the persistent carbon chain structure by dry ball milling in an inert atmosphere and equalizing the chemical surface properties by removal of surface oxides, no difference in elastomer adsorption from solution was observed. It must be concluded that commonly used high molecular elastomers do not have any access to smaller carbon black pores. Since access to the surface is a prerequisite for reinforcement, it is obvious that the surface in the pores of carbon black generally does not participate in reinforcing elastomers. The elastomer adsorbed per unit external black surface area appears to be independent of the carbon chain structure, indicating that the so called surface activity of the carbon black is independent of the chain length.

scholarly journals Free Radical Mediated Oxidative Degradation of Carotenes and Xanthophylls

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1038 ◽  
Author(s):  
Raphael C. Mordi ◽  
Olabisi T. Ademosun ◽  
Christiana O. Ajanaku ◽  
Ifedolapo O. Olanrewaju ◽  
John C. Walton
Keyword(s):  
Excited State ◽  
Free Radical ◽  
Vitamin A ◽  
Molecular Oxygen ◽  
Oxidative Degradation ◽  
Chain Structure ◽  
Ring Structure ◽  
Peroxyl Radicals ◽  
Chemical Structures ◽  
Excited State Quenching

This article reviews the excited-state quenching, pro-vitamin A activity and anticarcinogenicity of carotenes and xanthophylls in relation to their chemical structures. Excited-state quenching improved with the length of the conjugated chain structure. Pro-vitamin A activity was dependent on the presence of at least one beta-ionyl ring structure. The effectiveness of carotenoids as antioxidants depended on their ability to trap peroxyl radicals with production of resonance-stabilized carotenyl radicals. The products identified from oxidations of carotenes and xanthophylls with molecular oxygen and other oxidizing agents are presented. The free radical-mediated mechanisms that have been proposed to account for the different classes of products are reviewed.

scholarly journals Identification of Elongase Genes Mediating Branched Chain Fatty Acid Elongation (P08-108-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Sesha Durga Kumar Kothapalli ◽  
Zhen Wang ◽  
Dong Hao Wang ◽  
Hui Gyu Park ◽  
Yuanyuan Yan ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Methyl Esters ◽  
Saturated Fatty Acids ◽  
Carbon Chain ◽  
Ionization Mass ◽  
Moderate Activity ◽  
Mcf7 Cells ◽  
Functional Studies ◽  
Branched Chain

Abstract Objectives Saturated branched chain fatty acids (BCFA) terminating with either an isopropyl or sec-butyl group, are common bioactive food components consumed from beef, fish, and dairy products. Little is known about their endogenous metabolism and the enzymes mediating their interconversion. Our main objective was to test the substrate specificity of the fatty acid elongases (ELOVL1–7) towards elongation of representative BCFA, anteiso-15:0 and iso-18:0. We also assessed competition between BCFA and normal saturated fatty acid (n-SFA). Methods MCF7 human breast cancer cells are used for functional studies. PcDNA3.1 expression vector was used to clone seven open reading frames of ELOVL transcripts (ELOVL1–7). MCF7 cells were transiently transfected with specific ELOVL1–7 transgene vector or empty vector (control). After 24 h incubation, the transfected MCF7 cells were treated with BSA-bound substrates. After additional 24 h incubation, cells were harvested by trypsinization, fatty acid methyl esters prepared and analyzed quantitatively by GC-FID. Fatty acid composition was characterized by gas chromatography (GC) –electron ionization mass spectrometry (EIMS) and EIMS/MS for branched carbon chain. Results Transient transfection of ELOVL1–7 into MCF7 cells show that ELOVL6 had highest activity towards elongation of anteiso-15:0→anteiso-17:0, followed by ELOVL5 which showed moderate activity. ELOVL3 was found to be most active ELOVL mediating elongation of iso-18:0→iso-20:0. Our competition results show in ELOVL6 cells anteiso-15:0 competes with n-SFA n-16:0, whereas, in ELOVL3 cells iso-18:0 competes with n-18:0. Conclusions The elongation of anteiso-15:0 and iso-18:0 BCFA is predominantly operated by the ELOVL6 and ELOVL3, respectively that are well known to operate on normal saturated fatty acids, rather than the ELOVL2 and ELOVL5 which operate on lower-melting polyunsaturated fatty acids. The competition between BCFA and n-SFA for ELOVL1–7 mediated elongation may have implications in the skin, sebaceous, and meibomian glands where both normal and BCFA are present at comparable levels. Funding Sources NIH grant R01 AT007003.

scholarly journals Proteomic and Membrane Lipid Correlates of Re-duced Host Defense Peptide Susceptibility in a snoD Mutant of Staphylococcus aureus

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 169
Author(s):  
Christian Kohler ◽  
Richard Proctor ◽  
Arnold Bayer ◽  
Michael Yeaman ◽  
Michael Lalk ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Compositional Data ◽  
Insertion Site ◽  
Growth Conditions ◽  
Membrane Lipid ◽  
Anaerobic Growth ◽  
Short Chain ◽  
Aureus Strain ◽  
Branched Chain ◽  
The Impact

We previously described a transposon mutant in Staphylococcus aureus strain SH1000 that exhibited reduced susceptibility to cationic thrombin-induced platelet microbicidal proteins (tPMPs). The transposon insertion site was mapped to the gene snoD, the staphylococcal nuo orthologue. Hence, further studies have been performed to understand how this mutation impacts susceptibility to tPMP, by comparing proteomics profiling and membrane lipid analyses of the parent vs. mutant strains. Surprisingly, the mutant showed differential regulation of only a single protein when cultivated aerobically (FadB), and only a small number of proteins under anaerobic growth conditions (AdhE, DapE, Ddh, Ald1, IlvA1, AgrA, Rot, SA2366, and SA2367). Corresponding to FadB impact on lipid remodeling, membrane fatty acid analyses showed that the snoD mutant contained more short chain anteiso-, but fewer short chain iso-branched chain fatty acids under both aerobic and anaerobic conditions vs. the parental strain. Based upon these proteomic and membrane compositional data, a hypothetical “network” model was developed to explain the impact of the snoD mutation upon tPMP susceptibility.

A Study on Gadolinium Sensitized Chemiluminescence System

2012 ◽  
Vol 535-537 ◽  
pp. 1337-1340 ◽  
Author(s):  
Chi Yang ◽  
Nai Lin Ren
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Linear Relationship ◽  
Relative Standard Deviation ◽  
Optimum Conditions ◽  
Chemiluminescence Intensity ◽  
Experimental Conditions ◽  
Relative Standard

A new chemiluminescence system was built by using gadolinium as sensitizer, and the analysis capabilities of this system was tested as below. The method is based on chemluminescence of Ce (IV)-SO32- sensitized by Gd3+-OFLX. The effects of some critical experimental conditions were discussed and the optimum conditions for chemluminescence emission were investigated. The linear relationship between the relative chemiluminescence intensity and the concentration of OFLX is in the range of 2×10-9 g/mL～5×10-7 g/mL with a detection limit of 1.0×10-9g/mL .The relative standard deviation is 2.8% (n=11) for a level of 5.0×10-7 g/mL. The method has been applied to the analysis of OFLX in tablets with satisfactory results.

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