Search results for "Polycyclic compound"
showing 10 items of 391 documents
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…
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.
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…
Benzodiazepine receptor interactions may be involved in the neurotoxicity of various penicillin derivatives
1980
The interaction of seven penicillin derivatives with specific [3H]flunitrazepam binding to benzodiazepine receptors was investigated. The affinities of the penicillins for benzodiazepine receptor seemed to depend on the lipophilia of the derivatives. The concentrations of the penicillins which inhibit specific [3H]flunitrazepam binding are consistent with penicillin levels found in the central nervous system of patients developing penicillin induced convulsions. The results suggest that penicillins inhibit GABAergic transmission not only at the GABA receptor, but also at the benzodiazepine receptor, which is thought to be part of a neuronal system facilitating GABAergic transmission. Both m…
Separation and identification of petroporphyrins extracted from the oil shales of Tarfaya: geochemical study
2002
Abstract Vanadyl and nickel porphyrins were isolated from the oil shales of Tarfaya (Morocco) by extraction followed by column chromatography. The ratios and characteristics of these porphyrin complexes were essentially obtained on the basis of UV–visible and mass spectrometry data. Geochemical information could be drawn from these data. The nature and the contents of the metals coordinated and non-coordinated to porphyrin systems were also determined in this study.
Natural payload delivery of the doxorubicin anticancer drug from boron nitride oxide nanosheets
2019
International audience; We studied the behavior of doxorubicin (DOX; an anticancer drug) molecules loaded on a boron nitride oxide nanosheet (BNO-NS) using the density functional theory (DFT), time-dependent density functional theory (TDDFT), and molecular dynamic (MD) simulation methods. We found that DOX molecules in pi-pi or covalent interaction with BNO-NS preserve their optical properties in water. Moreover, the BNO-NS vector allowed stabilizing the DOX molecules on a cellular membrane contrary to isolated DOX that randomly moved in the solvent box without any interaction with the cell membrane. From these results, we conclude that hydrophilic BNO-NS represents a good candidate for DOX…
In silico identification and experimental validation of hits active against KPC-2 β-lactamase
2018
Bacterial resistance has become a worldwide concern, particularly after the emergence of resistant strains overproducing carbapenemases. Among these, the KPC-2 carbapenemase represents a significant clinical challenge, being characterized by a broad substrate spectrum that includes aminothiazoleoxime and cephalosporins such as cefotaxime. Moreover, strains harboring KPC-type β-lactamases are often reported as resistant to available β-lactamase inhibitors (clavulanic acid, tazobactam and sulbactam). Therefore, the identification of novel non β-lactam KPC-2 inhibitors is strongly necessary to maintain treatment options. This study explored novel, non-covalent inhibitors active against KPC-2, …