Search results for "Activity"
showing 10 items of 7178 documents
Deprotonation of Fluoro Aromatics Using Lithium Magnesates.
2004
Abstract 3-Fluoropyridine was deprotonated on treatment with 1/3 equiv of Bu 3 MgLi in THF at −10 °C. The lithium arylmagnesate formed was either trapped with electrophiles or involved in a palladium-catalyzed cross-coupling reaction with 2-bromopyridine. The use of a less nucleophilic lithium-magnesium-dialkylamide, (TMP) 3 MgLi, allowed the reaction of 3-fluoroquinoline, giving the 2,2′-dimeric derivative. 2-Fluoropyridine and 2,6-difluoropyridine were deprotonated using 1/3 equiv of the highly coordinated magnesate Bu 4 MgLi 2 in THF at −10 °C in the presence of a substoichiometric amount of 2,2,6,6-tetramethylpiperidine. 1,3-Difluorobenzene reacted similarly when treated with Bu 3 MgLi;…
Group 13 complexes of dipyridylmethane, a forgotten ligand in coordination chemistry.
2015
The reactions of dipyridylmethane (dpma) with group 13 trichlorides were investigated in 1 : 1 and 1 : 2 molar ratios using NMR spectroscopy and X-ray crystallography. With 1 : 1 stoichiometry and Et2O as solvent, reactions employing AlCl3 or GaCl3 gave mixtures of products with the salt [(dpma)2MCl2](+)[MCl4](-) (M = Al, Ga) as the main species. The corresponding reactions in 1 : 2 molar ratio gave similar mixtures but with [(dpma)MCl2](+)[MCl4](-) as the primary product. Pure salts [(dpma)AlCl2](+)[Cl](-) and [(dpma)AlCl2](+)[AlCl4](-) could be obtained by performing the reactions in CH3CN. In the case of InCl3, a neutral monoadduct (dpma)InCl3 formed regardless of the stoichiometry emplo…
Peroxisomes and Hepatotoxicity
1995
Peroxisomes are ubiquitous organelles of eukaryotic cells and are present in significant amounts in hepatic liver cells. Peroxisomal enzymes contribute to several metabolic pathways including fatty acid, purine and amino acid catabolism or bile acid synthesis. The peroxisomal oxidative reactions produce hydrogen peroxide, mostly degraded by catalase which prevents oxidative stress. Moreover, peroxisomes are involved in arylderivative drug detoxification through its epoxide hydrolase activity.
Epoxide Hydrolases: Structure, Function, Mechanism, and Assay
2005
Epoxide hydrolases are a class of enzymes important in the detoxification of genotoxic compounds, as well as in the control of physiological signaling molecules. This chapter gives an overview on the function, structure, and enzymatic mechanism of structurally characterized epoxide hydrolases and describes selected assays for the quantification of epoxide hydrolase activity.
Brain Nucleotides and Excitatory Processes
1971
The trivial analogy in the structure of barbiturates and pyrimidines has suggested a series of studies, which were undertaken in our Laboratory since 1961 (Bonavita et al., 1960 to investigate on the role of some free nucleotides in cerebral activity.
Two-step polymerization of propylene over MgCl2-supported titanium catalyst
1998
The prepolymerization effect on propylene polymerization in the presence of a MgCl 2 -supported titanium catalyst was studied. The catalyst was pre-activated by polymerizing a small amount of propylene in the presence of Et 3 Al and cyclohexylmethyldimethoxysilane under mild conditions, and then it was used in a second step of propylene polymerization. Comparative studies of the polymerization process involving the investigated catalyst and its unmodified counterpart showed the rate-enhancement effect of prepolymerization and the same molecular weights, MWD's and isotacticities of the polymers obtained. Concentrations of active sites and propagation rate as well as transfer rate constants w…
Crystal structure of the chalcone (E)-3-(furan-2-yl)-1-phenylprop-2-en-1-one
2015
The crystal packing of the compound is described by an intermolecular arrangement with the molecules as interlaced layers in a zigzag fashion, denoting interacting self-complementary dimers mainly by the localization of weak hydrogen bonds in a head-to-tail arrangement.
Isolation, identification and toxicological characterization of TSS 1, a new mycotoxin of the rosenane class.
1990
11-β-hydroxy-7-deoxy-rosenonolactone (TSS1), a product of the pathogenic fungusTrichothecium roseum (Moniliaceae) was isolated from culture medium extracts and completely described in its structure by spectroscopical methods.TSS 1 was classified as a representative of the lactone series of the rosenane class and as a structural isomer to Rosenololactone (1) and Rosololactone (2, 3).TSS1 showed toxic effects in the growth inhibition test toE coli (EC 50: lOμg/mL) andB subtil is (EC 50: 17μg/mL), inhibited fermentation of yeast (EC 50: 2.8μg/mL) and suppressed motility ofAnemia satina larvae (EC 50: 45/μg/mL).Rosenonolactone, the best known representative of that mycotoxin class, showed only …
2-Aryl-substituted 4H-3,1-benzoxazin-4-ones as novel active substances for the cardiovascular system
1991
4H-3,1-Benzoxazin-4-ones of the structural types 3 and 4 are accessible by cyclization reactions. The introduction of the phosphonate group was achieved by way of Wohl-Ziegler bromination and subsequent Michaelis-Arbuzow reaction with a trialkyl phosphite. Pharmacological investigations on isolated left atria, ileum specimens, and Langendorff hearts as well as in vivo circulatory studies on anesthetized rats revealed that the phosphonates 4 exert calcium antagonistic effects. Whereas 2-(arylvinyl)benzoxazinones gave rise to pronounced negative inotropic effects, compound 3e exhibited relaxing effects on smooth musculature in particular and markedly increased the coronary flow through Langen…
Thioredoxin-related protein of 14 kDa may directly reduce protein cysteinylation motifs
2018
Disulfide stress has been associated with inflammation and characterized by an increase in cystine levels and protein cysteinylation. Furthermore, it was recently discovered that thioredoxin-related protein of 14 kDa (TRP14, encoded by TXNDC17) exhibits efficient cystine reductase activity. The aim of our research was to elucidate if TRP14 is also able to reduce cysteinylated proteins in mammalian cells. Thus, protein cysteinylation was assessed in control and TRP14 knockdown cells in vitro through their pre-treatment with 25 µg/ml cycloheximide for 30 min and incubation with 250 µM biotinylated cysteine for 1 h. Moreover, such TRP14 knockdown cell lysates were tested as cysteinylated subst…