Search results for "Reactive"
showing 10 items of 1469 documents
Venous Thrombosis Associated with HMG-CoA Reductase Inhibitors
2013
Abstract Among the various hypolipidemic drugs, 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors (also known as "statins") belong to a heterogeneous class of compounds, sharing an identical hypocholesterolemic effect that develops through direct inhibition of a rate-limiting step in endogenous cholesterol synthesis. Their mechanism of action entails competitive inhibition of HMG-CoA reductase. Several lines of evidence suggest that the pleiotropic effects of statins may also play a role in prevention of venous thrombosis, wherein hypercholesterolemic patients are characterized by enhanced thrombin generation, increased susceptibility to endothelial dysfunction and plate…
11H‑Pyrido[3′,2′:4,5]pyrrolo[3,2‑c]cinnoline and Pyrido[3′,2′:4,5]pyrrolo[1,2‑c][1,2,3]benzotriazine: Two New Ring Systems with Antitumor Activity
2014
Derivatives of new ring systems 11H-pyrido[3',2':4,5]pyrrolo[3,2-c]cinnoline and pyrido[3',2':4,5]pyrrolo[1,2-c][1,2,3]benzotriazine have been prepared from the key intermediates 2-(1H-pyrrolo[2,3-b]pyridin-2-yl)anilines in excellent yields (94-99%) and screened by the National Cancer Institute (Bethesda, MD) on about 60 human tumor cell lines derived from nine cancer cell types. The tested compounds exhibited antiproliferative activity against all the human cell lines, showing comparable MG_MID (mean graph midpoint) values in the range of 0.74-1.15 μM. A particular efficacy was observed against the leukemia subpanel (GI50 = 0.73-0.0090 μM). Flow cytometric analysis of the cell cycle demons…
Orthometalation reactions in trifluoroacetate dirhodium(II) compounds. Molecular structure of Rh2(O2CCF3)2[(C6H4)PPh2]2·(PPh3)2·2(C7H8)
1994
Abstract Rh 2 (O 2 CCF 3 ) 3 [(C 6 H 4 )PPh 2 ]·(HO 2 CCF 3 ) 2 reacts with PPh 3 yielding the doubly metalated compound Rh 2 (O 2 CCH 3 ) 2− [(C 6 H 4 )PPh 2 ] 2 ·(HO 2 CCF 3 ) 2 . The reaction proceeds via a reactive intermediate with an equatorial phosphine, Rh 2 (η 2 -O 2 CCF 3 )(μ-O 2 CCF 3 ) 2 [(C 6 H 4 )PPh 2 ](PPh 3 )·(HO 2 CCF 3 ), which can also be generated in moderate yield under photochemical conditions. The structure of the PPh 3 bis-adduct Rh 2 (O 2 CCF 3 ) 2 [(C 6 H 4 )PPh 2 ] 2 ·(PPh 3 ) 2 ·2(C 7 H 8 ) has been determined by X-ray diffraction. M r =1663.27, orthorhombic, space group Fdd 2, a =41.748(9), b =21.620(5), c =17.375(5) A, V =15683(6) A 3 , Z =8, D x =1.41 g cm −3…
Ferrocenyl-Coupled N-Heterocyclic Carbene Complexes of Gold(I)
2016
Four gold(I) carbene complexes featuring 4-ferro-cenyl-substituted imidazol-2-ylidene ligands were investigated for antiproliferative and antivascular properties. They were active against a panel of seven cancer cell lines, including multidrug-resistant ones, with low micromolar or nanomolar IC50 (72 h) values, according to their lipophilicity and cellular uptake. The delocalized lipophilic cationic complexes 8 and 10 acted by increasing the reactive oxygen species in two ways: through a genuine ferrocene effect and by inhibiting the thioredoxin reductase. Both complexes gave rise to a reorganization of the F-actin cytoskeleton in endothelial and melanoma cells, associated with a G1 phase c…
Synthesis and biological evaluation of 4-nitro-substituted 1, 3-diaryltriazenes as a novel class of potent antitumor agents
2011
Abstract We describe the synthesis and biological activity of a new class of 1,3-diaryltriazenes, namely 4-nitro-substituted 1,3-diaryltriazenes. Structure–activity relationship analysis reveals that 1,3-diaryltriazenes can be modified from inactive to highly cytotoxic compounds by the introduction of two nitro groups at the para positions of benzene rings and two additional electron-withdrawing groups (bromo, chloro, trifluoromethyl or fluoro substituents) at their ortho position. In order to increase the solubility of the modified compounds, we introduced various acyl groups to their triazene nitrogen. The results of LC-MS/MS analysis showed that N -acyltriazenes can be considered as prod…
Cytotoxicity and modes of action of four naturally occuring benzophenones: 2,2′,5,6′-Tetrahydroxybenzophenone, guttiferone E, isogarcinol and isoxant…
2012
Abstract Introduction The emergence of drug-resistant cancer cells drastically reduces the efficacy of many antineoplasic agents and, consequently, increases the frequency of therapeutic failure. Benzophenones are known to display many pharmacological properties including cytotoxic activities. The present study was aimed at investigating the cytotoxicity and the modes of action of four naturally occurring benzophenones 2,2′,5,6′-tetrahydroxybenzophenone ( 1 ), isogarcinol ( 2 ), isoxanthochymol ( 3 ) and guttiferone E ( 4 ) on a panel of eleven cancer cell lines including various sensitive and drug-resistant phenotypes. Methods The cytotoxicity of the compounds was determined using a resazu…
DNA interaction of new copper(II) complexes with sulfonamides as ligands
2007
New copper(II) complexes with sulfonamide ligands have been prepared and characterized. Sulfonamide ligands were prepared through a reaction between 8-aminoquinoline and either 2-mesitylene (Hqmesa), 4-tert-butylbenzene (Hqtbsa), or alpha-toluene (Halphaqtsa) sulfonyl chlorides. The structural analysis carried out for complex [Cu(alphaqtsa)(2)] indicated that the local environment of the Cu(II) cation is between a square planar and a tetrahedral geometry, with stacking of the benzene rings of the sulfonyl ligands between neighbor molecules. Powder EPR spectra at room temperature gave rhombic spectra for the [Cu(alphaqtsa)(2)] and [Cu(qmesa)(2)] complexes and an axial spectrum for the [Cu(qt…
Antineoplastic Drug-Induced Cardiotoxicity: A Redox Perspective
2018
Antineoplastic drugs can be associated with several side effects, including cardiovascular toxicity (CTX). Biochemical studies have identified multiple mechanisms of CTX. Chemoterapeutic agents can alter redox homeostasis by increasing the production of reactive oxygen species (ROS) and reactive nitrogen species RNS. Cellular sources of ROS/RNS are cardiomyocytes, endothelial cells, stromal and inflammatory cells in the heart. Mitochondria, peroxisomes and other subcellular components are central hubs that control redox homeostasis. Mitochondria are central targets for antineoplastic drug-induced CTX. Understanding the mechanisms of CTX is fundamental for effective cardioprotection, without…
Rapid chemical evolution of tropospheric volcanic emissions from Redoubt Volcano, Alaska, based on observations of ozone and halogen-containing gases
2013
Abstract We report results from an observational and modeling study of reactive chemistry in the tropospheric plume emitted by Redoubt Volcano, Alaska. Our measurements include the first observations of Br and I degassing from an Alaskan volcano, the first study of O 3 evolution in a volcanic plume, as well as the first detection of BrO in the plume of a passively degassing Alaskan volcano. This study also represents the first detailed spatially-resolved comparison of measured and modeled O 3 depletion in a volcanic plume. The composition of the plume was measured on June 20, 2010 using base-treated filter packs (for F, Cl, Br, I, and S) at the crater rim and by an instrumented fixed-wing a…
Lipid-Altering Efficacy of Ezetimibe/Simvastatin 10/20 mg Compared to Rosuvastatin 10 mg in High-Risk Patients with and without Type 2 Diabetes Melli…
2010
AIMS: This post hoc analysis compared the effects of switching to ezetimibe/simvastatin 10/20 mg (EZE/SIMVA) or rosuvastatin 10 mg (ROSUVA) in uncontrolled high-risk hypercholesterolemic patients with/without type 2 diabetes mellitus (T2DM) despite statin monotherapy. METHODS: Patients (n = 618) at high risk for coronary vascular disease with elevated LDL-C ≥100 and ≤190 mg/dL despite use of statins were randomized 1:1 to double-blind EZE/SIMVA 10/20 mg or ROSUVA 10 mg for 6 weeks. Patients were classified as having T2DM based on ≥1 of the following: diagnosis of T2DM, antidiabetic medication, or FPG ≥126 mg/dL. This analysis evaluated percent changes from baseline in lipids among patients …