Search results for "OXIDATION"
showing 10 items of 1913 documents
Effect of sublethal concentrations of copper sulphate on seabreamSparus auratafingerlings
2007
The gilthead seabream is the most important Mediterranean aquacultured fish species. The main objective of this study was to investigate whether copper sulphate bath treatments used routinely in aquaculture have effects on important physiological functions of early life stages of the gilthead seabream (Sparus aurata). Fingerlings (80-90 days, 0.27 ± 0.06 g) were exposed to copper sulphate baths at 0, 0.25, 0.5 and 1.5 mg L −1 during 24 h. Effects on the central nervous function were evaluated analysing brain acetylcholinesterase activity (AChE). Oxidative stress was assessed by the quantification of lipid peroxidation (LP). Heat shock proteins (HSP70) were used as a general response to chem…
Effects of dichlorvos aquaculture treatments on selected biomarkers of gilthead sea bream (Sparus aurata L.) fingerlings
2007
Abstract The gilthead sea bream ( Sparus aurata ) is the most important marine cultured species in the Mediterranean. Dichlorvos is one of the main chemical agents used in bath treatments against ectoparasites of marine farmed fish. The main objective of this study was to investigate the effects of 24 h dichlorvos baths on selected biomarkers that are involved in important physiological functions or indicative of gilthead sea bream fingerlings growth. To attain this objective, the in vivo effects of dichlorvos on cholinesterases' activity (ChE), lipid peroxidation (TBARS), RNA/DNA ratio, glutathione S -transferases activity (GST) and heat shock proteins HSP70 were studied. The characterizat…
Charged Tags for the Identification of Oxidative Drug Metabolites Based on Electrochemistry and Mass Spectrometry
2020
Abstract Most of the active pharmaceutical ingredients like Metoprolol are oxidatively metabolized by liver enzymes, such as Cytochrome P450 monooxygenases into oxygenates and therefore hydrophilic products. It is of utmost importance to identify the metabolites and to gain knowledge on their toxic impacts. By using electrochemistry, it is possible to mimic enzymatic transformations and to identify metabolic hot spots. By introducing charged‐tags into the intermediate, it is possible to detect and isolate metabolic products. The identification and synthesis of initially oxidized metabolites are important to understand possible toxic activities. The gained knowledge about the metabolism will…
Series of Near-IR-Absorbing Transition Metal Complexes with Redox Active Ligands
2020
New soluble and intensely near-IR-absorbing transition metal (Ti, Zr, V, Ni) complexes were synthesized using a redox non-innocent N,N&rsquo
Guarana seed extracts as a useful strategy to extend the shelf life of pork patties: UHPLC-ESI/QTOF phenolic profile and impact on microbial inactiva…
2018
Abstract The antioxidant and antimicrobial effects of guarana seed extracts (GSE) added to pork patties were evaluated for 18 days storage at 2 ± 1 °C. Five treatments were prepared: i) without natural antioxidant [control (negative control)], ii) with BHT at 200 mg/kg (positive control), and iii) with three different concentrations: 250 mg/kg (guarana seed low dose-GSL), 500 mg/kg (guarana seed medium dose-GSM) and 1000 mg/kg (guarana seed high dose-GSH) of guarana extracts, respectively. The pH, instrumental colour (CIE L*, a*, b*), total viable counts (TVC), Pseudomonas spp. counts and lactic acid bacteria (LAB) counts, 2-thiobarbituric acid reactive substances (TBARS) and carbonyl co…
Syntheses, X-ray structures, and physicochemical properties of phenoxo-bridged dinuclear nickel(II) complexes: kinetics of transesterification of 2-h…
2009
Four dinuclear nickel(II) complexes [Ni(II)(2)(L(1))(O(2)CMe)(2)(H(2)O)(2)][PF(6)].MeOH.3H(2)O (1), [Ni(II)(2)(L(1))(O(2)CMe)(2)(NCS)] (2), [Ni(II)(2)(L(2))(O(2)CMe)(2)(MeOH)(H(2)O)][ClO(4)] (3), and [Ni(II)(2)(L(2))(O(2)CMe)(2)(MeOH)(H(2)O)][BPh(4)].3MeOH.H(2)O (4) have been synthesized [HL(1): 2,6-bis[N-methyl-N-(2-pyridylethyl)amino]-4-methylphenol; HL(2): 2,6-bis[3-(pyridin-2-yl)pyrazol-1-ylmethyl]-4-methylphenol]. Complexes 1, 3, and 4 are new while complex 2 was reported previously by Fenton and co-workers (the structure of 2 was presented but no physicochemical properties of this complex were reported; in this work such studies have been completed). X-ray crystallographic analyses of…
Effects of 2-month ozone exposure in spinach leaves on photosynthesis, antioxidant systems and lipid peroxidation
2003
The photosynthesis response, antioxidant systems and lipid peroxidation were studied in leaves from spinach plants (Spinacia oleracea L.) in response to ozone fumigation, ambient air and charcoal filtered air treatments. The photosynthetic activity was tested through gas exchange and chlorophyll a fluorescence measurements. Ambient air and ozone fumigation caused a decrease in the photosynthetic rate (25% and 63%, respectively) mainly due to a reduced mesophyll activity, as evidenced by the increased intercellular CO, concentration. These data agree with a large reduction in the non-cyclic electron flow (7% and 16%), a lower capacity to reduce the quinone pool and a higher development of no…
Response of Spinach Leaves (Spinacia oleracea L.) to Ozone Measured by Gas Exchange, Chlorophyll a Fluorescence, Antioxidant Systems, and Lipid Perox…
2004
Spinach (Spinacia oleracea L. cv. Clermont) leaves grown in open-top chambers and exposed to three different concentrations of ozone were measured for gas exchange, chlorophyll a fluorescence, antioxidant systems, and lipid peroxidation at the end of growing season. High O-3 concentration reduced F-v/F-m, indicating that the efficiency in the energy conversion of photosystem 2 (PS2) was altered. The rate of non-cyclic electron transport rate and the capacity to reduce the quinone pool were also affected. The development of non-photochemical quenching was not high enough to decrease the photon excess in the PS2. The limitation of photosynthetic activity was probably correlated with stomata c…
Bacterial 2,3-butanediol dehydrogenases
1978
Enterobacter aerogenes, Aeromonas hydrophila, Serratia marcescens and Staphylococcus aureus possessing L(+)-butanediol dehydrogenase produced mainly meso-butanediol and small amounts of optically active butanediol; Acetobacter suboxydans, Bacillus polymyxa and Erwinia carotovora containing D(-)-butanediol dehydrogenase produced more optically active butanediol than meso-butanediol. Resting and growing cells of these organisms oxidezed only one enantiomer of racemic butanediol. The D(-)-butanediol dehydrogenase from Bacillus polymyxa was partially purified (30-fold) with a specific activity of 24.5. Except NAD and NADH no other cofactors were required. Optimum pH-values for oxidation and red…
Preferential azido bridging regulating the structural aspects in cobalt(III) and copper(II)–Schiff base complexes: Syntheses, magnetostructural corre…
2011
International audience; A tridentate NNO donor Schiff base ligand [(1Z,3E)-3-((pyridin-2-yl)methylimino)-1-phenylbut-1-en-1-ol = LH] in presence of azide ions coordinates with cobalt(II) and copper(II) ions giving rise to three new coordination complexes [Co2(L)2(μ1,1-N3)2(N3)2] (1), [Cu2(L)2(μ1,3-N3)]·ClO4 (2) and [(μ1,1-N3)2Cu5(μ-OL)2(μ1,1-N3)4(μ1,1,1-N3)2]n (3). The complexes have been characterized by elemental analysis, FT-IR, UV–Vis spectral studies, and single crystal X-ray diffraction studies. These complexes demonstrate that under different synthetic conditions the azide ions and the Schiff base ligand (LH) show different coordination modes with cobalt(II) and copper(II) ions, givi…