Search results for "Cyclic compound"
showing 10 items of 819 documents
PCDEs, PCBs, PCDDs AND PCDFs in black guillemots and white-tailed sea eagles from the Baltic Sea
1995
Abstract Concentrations and patterns of several chloro compounds including polychlorinated dibenzo p-dioxins (PCDD), dibenzofurans (PCDF), biphenyls (PCB) and diphenyl ethers (PCDE) were determined in black guillemots ( Cepphus grylle L.) and white-tailed sea-eagles ( Hallaeetus albicilla L.) from the Baltic Sea environment. Three breast muscles of eagles were analyzed and had different concentrations and patterns of the studied compounds, whereas the three guillemot eggs were found to have more similar levels and patterns. The concentrations of individual PCDE congeners varied from
Chlorinated phenolic compounds in coniferous needles. Effects of metal and paper industry and incineration
1997
Abstract Pine needles were analyzed for their contents of chlorinated phenolic compounds. Altogether about 30 samples from surroundings of a metal scrap plant, a pulp and paper mill, a hazardous waste incinerator and reference samples outside of the immediate influence of these were analyzed by GC/ECD and GC/MS. Most phenolic compounds in the needles were found to be bound to the plant material and were not extractable as such by organic solvents. The concentrations of some bound chlorinated phenolic compounds were on level of 1–300 ng/g in dried needle. For many compounds the concentrations were remarkably higher in the three years old needles compared to the concentrations in the one and …
Epoxides derived from various polycyclic hydrocarbons as substrates of homogeneous and microsome-bound epoxide hydratase. A general assay and kinetic…
1976
A general assay for epoxide hydratase using epoxides derived from polycyclic aromatic hydrocarbons as substrates is described. Addition of dimethylsulphoxide to the incubation mixture after incubation allowed unreacted epoxide and its phenolic by-product to be extracted into light petroleum whilst the product dihydrodiol remained in the aqueous phase. The product was then extracted into ethyl acetate and estimated radiochemically. This assay gave low extraction blanks (0.8-3.8%) when six K-region epoxides of polycyclic hydrocarbons were used, with high recoveries of the corresponding dihydrodiol in the ethyl acetate phase (65-89%). Radiochromatograms demonstrated that all the radioactivity …
Isolierung und Identifizierung von Sterinen im Metabolismus des Pilzes Botrytis cinerea / Isolation and identification of sterols in the metabolism o…
1983
The fungus Botrytis cinerea, which belongs to the class of ascomycetes, has been analysed for its sterol composition. It is able to produce ergosterol, cerevisterol, lanosterol/dihydrolanosterol and cholesterol besides β-sitosterol. The identification of the sterols is carried out with different analytical methods including mass spectrometry. In the extracts of the mycelium also squalene has been identified
Über die Bildung von Cholesterin durch Botrytis cinerea nach Lanosterinzugabe / The Production of Cholesterol by Botrytis cinerea after Addition of L…
1980
Abstract The fungus Botrytis cinerea, which is found on the grapes, is able to produce cholesterol after addition of lanosterol to the culture medium. The identification of cholesterol is carried out with different analytical methods including mass spectrometry. Under the same conditions ergosterol arises from squalene and not cholesterol.
Oxysterol mixture in hypercholesterolemia-relevant proportion causes oxidative stress-dependent eryptosis.
2014
Background/Aims: Oxysterol activity on the erythrocyte (RBC) programmed cell death (eryptosis) had not been studied yet. Effects of an oxysterol mixture in hyper-cholesterolemic-relevant proportion, and of individual compounds, were investigated on RBCs from healthy humans. Methods: Membrane phosphatidylserine (PS) externalization, calcium entry, ROS production, amino-phospholipid translocase (APLT) activity were evaluated by cytofluorimetric assays, cell volume from forward scatter. Prostaglandin PGE2 was measured by ELISA; GSH-adducts and lipoperoxides by spectrophotometry. Involvement of protein kinase C and caspase was investigated by inhibitors staurosporin, calphostin C, and Z-DEVD-FM…
An evidence based therapeutic approach to hereditary and acquired angioedema
2014
Purpose of review Hereditary angioedema (HAE) due to C1 esterase inhibitor (C1-INH) deficiency (HAE-C1-INH), HAE with normal C1-INH, and acquired angioedema due to C1-INH deficiency are rare but important diseases that can be associated with significant morbidity and mortality. Research into the pathogenesis of angioedema has expanded greatly and has led to new clinical trials with novel therapeutic agents and strategies. Recent findings Strategies for managing HAE-C1-INH are aimed at treating acute attacks or preventing attacks through the use of prophylactic treatment. Agents available in Europe for treating acute attacks include plasma-derived C1-INH concentrates, a bradykinin B2 recepto…
Towards the fluorogenic detection of peroxide explosives through host-guest chemistry
2018
[EN] Two dansyl-modified beta-cyclodextrin derivatives (1 and 2) have been synthesized as host-guest sensory systems for the direct fluorescent detection of the peroxide explosives diacetone diperoxide (DADP) and triacetone triperoxide (TATP) in aqueous media. The sensing is based on the displacement of the dansyl moiety from the cavity of the cyclodextrin by the peroxide guest resulting in a decrease of the intensity of the fluorescence of the dye. Both systems showed similar fluorescent responses and were more sensitive towards TATP than DADP.
Isolation and Characterization of a New Less-Toxic Derivative of the Fusarium Mycotoxin Diacetoxyscirpenol after Thermal Treatment
2011
Trichothecenes are an important class of mycotoxins that act as potent protein synthesis inhibitors in eukaryotic organisms. The compound 4,15-diacetoxyscirpenol is highly toxic for plants and animals. Potatoes are especially prone to be contaminated with 4,15-diacetoxyscirpenol after infection with Fusarium sambucinum. In the current study, the reduction of 4,15-diacetoxyscirpenol during thermal treatment in aqueous solution was monitored. A new derivative was detected and named DAS-M1. After isolation, DAS-M1 was characterized with LC-HR-MS and LC-MS/MS and structurally elucidated with (1)H, (13)C, and 2D NMR. Potatoes were inoculated with F. sambucinum, and the infected potatoes were coo…
How Proximal Nucleobases Regulate the Catalytic Activity of G-Quadruplex/Hemin DNAzymes
2018
International audience; G-quadruplexes (G4s) are versatile catalytic DNAs when combined with hemin. Despite the repertoire of catalytically competent G4/hemin complexes studied so far, little is known about the detailed catalytic mechanism of these biocatalysts. Herein, we have carried out an in-depth analysis of the hemin binding site within the G4/hemin catalysts, providing the porphyrinic cofactor with a controlled nucleotidic environment. We intensively assessed the position-dependent catalytic enhancement in model reactions and found that proximal nucleobases enhance the catalytic ability of the G4/hemin complexes. Our results allow for revisiting the mechanism of the G4/hemin-based ca…