Search Within
Applied Filters:
Keyword:'409758'
Showing 1-28 of 28 results for "

409758

" within Papers
Kraiwan Punyain et al.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 83(1), 368-378 (2011-09-20)
Organic radical cations form dicationic dimers in solution, observed experimentally as diamagnetic species in temperature-dependent EPR and low temperature UV/Vis spectroscopy. Dimerization of paraphenylenediamine, N,N-dimethyl-paraphenylenediamine and 2,3,5,6-tetramethyl-paraphenylenediamine radical cation in ethanol/diethylether mixture was investigated theoretically according to geometry, energetics and...
Hedi Ben Mansour et al.
Environmental science and pollution research international, 18(9), 1527-1535 (2011-05-11)
Acid orange 52 (AO52), extensively used in textile industries, was decolorized by Pseudomonas putida mt-2. AO52 azoreduction products such as N,N'-dimethyl-p-phenylenediamine (DMPD) and 4-aminobenzenesulfonic acid (4-ABS), were identified in the static degradation mixture. These amines were identified only in media...
V Fogliano et al.
Journal of agricultural and food chemistry, 47(3), 1035-1040 (1999-12-20)
A novel method for measuring the antioxidant activity using N, N-dimethyl-p-phenylenediamine (DMPD) was developed. The radical cation of this compound gives a stable colored solution and a linear inhibition of color formation can be observed in the presence of 0....
Jean-François Lesgards et al.
International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition, 75(1), 11-18 (2005-04-16)
Assessment of the antioxidant activity of vitamins and other compounds is of interest in the understanding of their in vivo effects. In this study, we have investigated the activity of several lipid and water-soluble vitamins in human whole blood. Measurements...
F Tessier et al.
International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition, 66(2), 166-170 (1996-01-01)
An HPLC micro-method with fluorescence detection has been developed to determine total vitamin C (vit C) and dehydroascorbic acid (DHA) concentrations in human plasma samples. This method is based on the rapid, specific reaction of DHA with dimethyl-o-phenylenediamine (DMPD) to...
P de Macédo et al.
Analytical biochemistry, 285(1), 16-20 (2000-09-22)
Herein we report the development of a direct and continuous spectrophotometric method for determining transglutaminase (TGase) activity by using N,N-dimethyl-1,4-phenylenediamine (DMPDA) as a gamma-glutamyl acceptor substrate and carbobenzyloxy-l-glutamylglycine (Z-Gln-Gly) as a typical peptide gamma-glutamyl donor substrate. The transamidation activity of...
Joseph B Issa et al.
The journal of physical chemistry. B, 111(24), 6878-6886 (2007-06-02)
Photoinduced intramolecular charge separation across proline-bridged donor-acceptor complexes of the type Pyr-(Pro)n-DMPD (where Pyr=pyrene-1-sulfonyl and DMPD=N,N-dimethyl-1,4-phenylenediamine) was studied. The steady-state emission spectrum for n=0, 1, 2, 3 showed an increase in emission intensity with the number of proline residues. Time-dependent...
J Khosla et al.
American journal of respiratory cell and molecular biology, 10(4), 462-469 (1994-04-01)
The purpose of this study was to determine whether the cytochemically defined distribution of sulfated macromolecules is significantly different in microdomains of basement membranes (BMs) associated with different levels of pulmonary airways. The high iron diamine-thiocarbohydrazide-silver proteinate (HID-TCH-SP) technique, which...
Yeqing Lan et al.
Environmental science & technology, 39(7), 2087-2094 (2005-05-06)
Chromate (CrVI) reduction by sulfide was conducted in anaerobic batch experimental systems. The molar ratio of the reduced CrVI to the oxidized S(-II) was 1:1.5 during the reaction, suggesting that the product of sulfide oxidation was elemental sulfur. Under the...
K Wimalasena et al.
The Journal of biological chemistry, 271(42), 26032-26043 (1996-10-18)
The interactions of reductants with dopamine beta-monooxygenase (DbetaM) were examined using two novel classes of reductants. The steady-state kinetics of the previously characterized DbetaM reductant, N,N-dimethyl-1,4-p-phenylenediamine (DMPD), were parallel to the ascorbic acid-supported reaction with respect to pH dependence and...
Xiang-yuan Huang et al.
Guang pu xue yu guang pu fen xi = Guang pu, 22(4), 627-630 (2003-08-27)
A new catalytic spectrophotometic method for the determination of trace chromium (VI) is reported in this paper. The method is based on the catalytic action of chromium (VI) on the oxidative coupling of p-Amino-N,N-dimethylaniline dihydrochloride and 1-Amino-8-naphthol-3,6-disulfonic acid to form...
Francisco J Morales et al.
Journal of agricultural and food chemistry, 50(16), 4657-4661 (2002-07-26)
The Maillard reaction has a dramatic impact on the overall acceptance and nutritional quality of most of the foods consumed daily in European countries. Melanoidins are polymeric structures formed in the last stage of the Maillard reaction with nearly unknown...
Veronica Verde et al.
Free radical research, 36(8), 869-873 (2002-11-08)
Oxidative stress has been clearly implicated in human disease by a growing body of scientific evidences. There is no ideal method for the measurement of this parameter. A possible strategy would be to measure simultaneously several biomarkers representing damage to...
S Marroquí et al.
Journal of bacteriology, 183(3), 854-864 (2001-02-24)
We isolated a Tn5-induced Rhizobium tropici mutant that has enhanced capacity to oxidize N,N-dimethyl-p-phenylendiamine (DMPD) and therefore has enhanced respiration via cytochrome oxidase. The mutant had increased levels of the cytochromes c(1) and CycM and a small increase in the...
Sarawut Lunvongsa et al.
Analytical sciences : the international journal of the Japan Society for Analytical Chemistry, 22(1), 169-172 (2006-01-25)
A simple flow injection analysis (FIA) method is described for the sequential determination of iron and copper. The detection method for iron and copper is based on their catalytic activities in the oxidation reaction of N,N-dimethyl-p-phenylenediamine (DPD) with hydrogen peroxide....
Simple colorimetric method for determination of peroxide.
A S Yalçin et al.
Clinical chemistry, 39(12), 2534-2535 (1993-12-01)
M Scherer et al.
Archives of microbiology, 170(2), 78-84 (1998-07-31)
Sexual development in Aspergillus nidulans is a morphogenetic differentiation process triggered by internal and environmental signals. As a first step in analyzing the developmental pathway at the molecular level, laccase II (EC 1.10.3.2), which is specifically expressed in early stages...
Jed Costanza et al.
Environmental science & technology, 43(3), 909-914 (2009-02-28)
This study explores the transformation of trichloroethene (TCE) caused by heating contaminated soil and groundwater samples obtained from the East Gate Disposal Yard (EGDY) located in Fort Lewis, WA. After field samples transferring into glass ampules and introducing 1.5 micromol...
C Li et al.
The Biochemical journal, 300 ( Pt 1), 31-36 (1994-05-15)
C-terminal alpha-amidation is a structural feature essential to the biological activity of many peptide hormones. Peptidylglycine alpha-amidating mono-oxygenase (PAM; EC 1.14.17.3) catalyses conversion of glycine-extended peptide hormone precursors into their corresponding alpha-hydroxyglycine derivatives. This reaction is the first step in...
F J Alcaín et al.
Redox report : communications in free radical research, 3(5-6), 287-293 (1998-12-16)
Swiss 3T3 fibroblasts can be weakly stimulated to grow by bombesin, epidermal growth factor or ceruloplasmin when cells are maintained in Dulbecco's Modified Essential Medium (DMEM), the pH of which is 7.75. Addition of insulin synergizes with the other mitogens....
P K Wong et al.
Journal of applied microbiology, 85(1), 79-87 (1998-08-29)
Klebsiella pneumoniae RS-13 and Acetobacter liquefaciens S-1, both methyl red (MR)-degrading bacterial strains, degraded N,N'-dimethyl-p-phenylenediamine (DMPD) under aerobic conditions. DMPD, a toxic and mutagenic aromatic amine, is formed during the reductive cleavage of azo dyes such as MR. The effects...
V Leskovac et al.
The Italian journal of biochemistry, 45(1), 9-18 (1996-03-01)
The steady-state kinetics, product identification, stoichiometries, and solvent isotope effects of yeast alcohol dehydrogenase catalyzed reduction of p-nitroso-N,N-dimethylaniline (NDMA) by NADH, are reported. NDMA is enzymatically reduced to p-hydroxylamine-N,N-dimethylaniline, which is further enzymatically dehydrated to corresponding quinonediimine cation (QDI+). QDI+...
On-line electrochemical-mass spectrometry study of the mechanism of oxidation of N, N-dimethyl-p-phenylenediamine in aqueous electrolytes.
Modestov AD, et al.
Journal of Electroanalytical Chemistry, 565(1), 7-19 (2004)
Guo-Ting Tian et al.
Acta biochimica Polonica, 59(3), 407-412 (2012-09-05)
A novel laccase with a molecular mass of 64 kDa and the N-terminal sequence AIGPDDTINF was isolated from fresh fruiting bodies of the mushroom Pleurotus nebrodensis. The purification protocol comprised ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose, and gel...
K Wimalasena et al.
Analytical biochemistry, 197(2), 353-361 (1991-09-02)
Based on the novel chromophoric electron donors, N,N-dimethyl-1,4-phenylenediamine (DMPD) and 2-amino-2-deoxy-L-ascorbic acid (2-aminoascorbic acid), two sensitive, convenient, and continuous spectrophotometric assays for dopamine beta-monooxygenase (EC 1.14.17.1) are described. Both, DMPD and 2-aminoascorbic acid are kinetically and stoichiometrically well-behaved electron donors...
Claudineia R Silva et al.
Talanta, 85(3), 1703-1705 (2011-08-03)
A spectrophotometric flow injection procedure involving N,N-dimethyl-p-phenylenediamine (DMPD) is applied to the sulfide monitoring of a sugar fermentation by Saccharomyces cerevisiae under laboratory conditions. The gaseous chemical species evolving from the fermentative process, mainly CO(2), are trapped allowing a cleaned...
Francisco J Morales et al.
Journal of agricultural and food chemistry, 50(10), 2788-2792 (2002-05-02)
The Maillard reaction (MR) has a clear impact in food science, nutrition, and medical research. Free radical scavenging capacities of several MR mixtures made from single combinations of glucose or lactose and amino acids (gly, his, lys, trp, met, and...
C Störle et al.
Chemico-biological interactions, 83(3), 271-291 (1992-08-28)
N,N-Dimethyl-p-phenylenediamine (DMPD) reacted directly with oxyhemoglobin under formation of ferrihemoglobin and, presumably, the N,N-dimethyl-p-phenylenediamine radical cation (DMPP.+). The apparent second-order rate constant of this reaction was 1 M-1 s-1 (pH 7.4, 37 degrees C). The reaction rate was diminished by...