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https://www.readbyqxmd.com/read/28526448/the-catechol-o-methyltransferase-inhibitors-tolcapone-and-entacapone-uncouple-and-inhibit-the-mitochondrial-respiratory-chain-in-heparg-cells
#1
David Grünig, Andrea Felser, Jamal Bouitbir, Stephan Krähenbühl
The catechol-O-methyltransferase inhibitor tolcapone causes hepatotoxicity and mitochondrial damage in animal models. We studied the interaction of tolcapone with mitochondrial respiration in comparison to entacapone in different experimental models. In HepaRG cells (human cell-line), tolcapone decreased the ATP content (estimated IC50 100±15μM) and was cytotoxic (estimated IC50 333±45μM), whereas entacapone caused no cytotoxicity and no ATP depletion up to 200μM. Cytochrome P450 induction did not increase the toxicity of the compounds...
May 16, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/28523234/the-effect-of-comt-val158met-and-drd2-c957t-polymorphisms-on-executive-function-and-the-impact-of-early-life-stress
#2
Kristel Klaus, Kevin Butler, Simon J Durrant, Manir Ali, Chris F Inglehearn, Timothy L Hodgson, Humberto Gutierrez, Kyla Pennington
INTRODUCTION: Previous research has indicated that variation in genes encoding catechol-O-methyltransferase (COMT) and dopamine receptor D2 (DRD2) may influence cognitive function and that this may confer vulnerability to the development of mental health disorders such as schizophrenia. However, increasing evidence suggests environmental factors such as early life stress may interact with genetic variants in affecting these cognitive outcomes. This study investigated the effect of COMT Val158Met and DRD2 C957T polymorphisms on executive function and the impact of early life stress in healthy adults...
May 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28522796/effects-of-%C3%AE-adrenoceptor-and-catechol-o-methyl-transferase-comt-polymorphism-on-postoperative-outcome-in-cardiac-surgery-patients
#3
Stefan Dhein, Pascal M Dohmen, Matthias Sauer, Julia Tews, Johannes Weickmann, Anne-Kathrin Funkat, Martin Misfeld, Michael A Borger, Friedrich W Mohr
BACKGROUND There is a long-standing debate about the role of beta-adrenoceptor polymorphisms in the cardiovascular system. We wanted to elucidate whether β1-adrenoceptor-polymorphisms affects the postoperative catecholamine consumption and the length of intermediate care unit stay in patients undergoing cardiac surgery, and whether this might be enhanced or attenuated by catechol-O-methyl-transferase (COMT) polymorphism. MATERIAL AND METHODS We included 116 patients (63±1.2 years; 34% females; 81±1 kg) undergoing cardiac surgery...
May 19, 2017: Medical Science Monitor Basic Research
https://www.readbyqxmd.com/read/28512752/an-optimized-two-photon-fluorescent-probe-for-biological-sensing-and-imaging-of-catechol-o-methyltransferase
#4
Ping Wang, Yang-Liu Xia, Li-Wei Zou, Xing-Kai Qian, Dong-Yi Dou, Qiang Jin, Shi-Yang Li, Yang Yu, Dan-Dan Wang, Qun Luo, Guangbo Ge, Ling Yang
This study aimed to develop a practical two-photon fluorescent probe for highly sensitive and selective sensing the activities of COMT in complex biological samples. To this end, a series of 3-substituted 7,8-dihydroxycoumarins were designed and synthesized. Among them, 3-BTD displayed the best combina-tion of selectivity, sensitivity, reactivity and fluorescence re-sponse following COMT-catalyzed 8-O-metylation. The newly developed two-photon fluorescent probe 3-BTD can be used for determining the activities of COMT in complex biological samples and bio-imaging of endogenous COMT in living cells and tissue slices with good cell permeability, low cytotoxicity and high imaging resolution...
May 16, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28512090/the-vibrio-cholerae-vexgh-rnd-efflux-system-maintains-cellular-homeostasis-by-effluxing-vibriobactin
#5
Dillon E Kunkle, X Renee Bina, James E Bina
Resistance-nodulation-division (RND) superfamily efflux systems have been widely studied for their role in antibiotic resistance, but their native biological functions remain poorly understood. We previously showed that loss of RND-mediated efflux in Vibrio cholerae resulted in activation of the Cpx two-component regulatory system, which mediates adaptation to stress resulting from misfolded membrane proteins. Here, we investigated the mechanism linking RND-mediated efflux to the Cpx response. We performed transposon mutagenesis screening of RND-deficient V...
May 16, 2017: MBio
https://www.readbyqxmd.com/read/28511459/a-comparison-of-2-methoxyestradiol-value-in-women-with-severe-preeclampsia-versus-normotensive-pregnancy
#6
John Wantania, Ahsanuddin Attamimi, Rukmono Siswishanto
INTRODUCTION: Preeclampsia is a pregnancy complication characterized by high blood pressure and proteinuria. Endothelial dysfunction is a major theory suggested as its aetiology. It is caused by anti-angiogenic condition characterized by low Vascular Endothelial Growth Factor (VEGF). An estradiol metabolite, called 2-Methoxy Estradiol (2-ME), is produced with the help of Catechol-O-Methyltransferase (COMT). This substance has an important role in VEGF expression. A 2-ME is suppressed in women with preeclampsia...
March 2017: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/28511130/design-synthesis-and-biological-evaluation-of-uncharged-catechol-derivatives-as-selective-inhibitors-of-ptp1b
#7
Xiang-Qian Li, Qi Xu, Jiao Luo, Li-Jun Wang, Bo Jiang, Ren-Shuai Zhang, Da-Yong Shi
Protein tyrosine phosphatases 1B (PTP1B) is a promising and validated therapeutic target to effectively treat T2DM and obesity. However, the development of charged PTP1B inhibitors was restricted due to their low cell permeability and poor bioavailability. Based on active natural products, two series of uncharged catechol derivatives were identified as PTP1B inhibitors by targeting a secondary aryl phosphate-binding site as well as the catalytic site. The most potent inhibitor 22 showed an IC50 of 0.487 μM against PTP1B and strong selectivity (27-fold) over TCPTP...
May 3, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28510533/coordination-polymer-nanocapsules-prepared-using-metal-organic-framework-templates-for-ph-responsive-drug-delivery
#8
Tang Lei, Jiafu Shi, Xiaoli Wang, Shaohua Zhang, Hong Wu, Hongfan Sun, Zhongyi Jiang
A facile, efficient and versatile approach is presented to synthesize pH-responsive nanocapsules (~120 nm) by combining the advantages of metal-organic frameworks (MOFs) and metal-organic thin films. The ZIF-8 nanoparticles are used as templates on which a thin film coating of Iron(III)-catechol complexes is derived from the coordination between dopamine-modified alginate (AlgDA) and Iron(III) ions. After the templates removal, nanocapsules with a pH-responsive wall are obtained. Doxorubicin (Dox), a typical anticancer drug, is first immobilized in ZIF-8 frameworks through coprecipitation and then encapsulated in nanocapsules after the removal of ZIF-8...
May 16, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28509370/use-of-mushroom-tyrosinase-to-introduce-michaelis-menten-enzyme-kinetics-to-biochemistry-students
#9
William H Flurkey, Jennifer K Inlow
An inexpensive enzyme kinetics laboratory exercise for undergraduate biochemistry students is described utilizing tyrosinase from white button mushrooms. The exercise can be completed in one or two three-hour lab sessions. The optimal amounts of enzyme, substrate (catechol), and inhibitor (kojic acid) are first determined, and then kinetic data is collected in the absence and presence of the inhibitor. A Microsoft Excel template is used to plot the data and to fit the Michaelis-Menten equation to the data to determine the kinetic parameters Vmax and Km ...
May 2017: Biochemistry and Molecular Biology Education
https://www.readbyqxmd.com/read/28508082/a-chlorine-free-protocol-for-processing-germanium
#10
Martin Glavinović, Michael Krause, Linju Yang, John A McLeod, Lijia Liu, Kim M Baines, Tomislav Friščić, Jean-Philip Lumb
Replacing molecular chlorine and hydrochloric acid with less energy- and risk-intensive reagents would markedly improve the environmental impact of metal manufacturing at a time when demand for metals is rapidly increasing. We describe a recyclable quinone/catechol redox platform that provides an innovative replacement for elemental chlorine and hydrochloric acid in the conversion of either germanium metal or germanium dioxide to a germanium tetrachloride substitute. Germanium is classified as a "critical" element based on its high dispersion in the environment, growing demand, and lack of suitable substitutes...
May 2017: Science Advances
https://www.readbyqxmd.com/read/28500325/catechol-functional-chitosan-silver-nanoparticle-composite-as-a-highly-effective-antibacterial-agent-with-species-specific-mechanisms
#11
Xiaofei Huang, Xiaojiong Bao, Yalan Liu, Zhengke Wang, Qiaoling Hu
In this study, silver nanoparticles (Ag NPs) coated with catechol-conjugated chitosan (CSS) were prepared using green methods. Interestingly, we uncovered that CSS-coated Ag NPs (CSS-Ag NPs) exhibited a higher toxicity against gram-negative Escherichia coli (E. coli) bacteria than against gram-positive Staphylococcus aureus (S. aureus) bacteria. The differences revealed that the CSS-Ag NPs killed gram bacteria with distinct, species-specific mechanisms. The aim of this study is to further investigate these underlying mechanisms through a series of analyses...
May 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28495231/descriptive-study-of-the-parkinsonian-population-in-the-north-of-france-epidemiological-analysis-and-healthcare-consumption
#12
N Carriere, D Verloop, C Dupont, V Fontaine, M Tir, P Krystkowiak, A Blanchard, L Defebvre, M-M Defebvre
BACKGROUND: The "neurodegenerative diseases plan" under elaboration for the Hauts-de-France region requires better knowledge of the patient population and care pathways. In France, the prevalence of Parkinson's disease (PD) has been estimated from cohorts to be about 1-3 per 1000 inhabitants, but exhaustive data are scarce for the general population. The purpose of this study was to evaluate the prevalence of PD in the Hauts-de-France region and to assess PD-related healthcare consumption...
May 8, 2017: Revue Neurologique
https://www.readbyqxmd.com/read/28494719/levodopa-in-parkinson-s-disease-current-status-and-future-developments
#13
N Tambasco, M Romoli, P Calabresi
Ever since the pioneering reports in the 60s, L-3,4-Dioxyphenylalanine (levodopa) has represented the gold standard for the treatment of Parkinson's Disease (PD). However, long-term levodopa (LD) treatment is frequently associated with fluctuations in motor response, often challenging to resolve, with serious impact on patients quality of life. The pharmacokinetic and pharmacodynamics properties of LD are pivotal to such motor fluctuations: discontinuous drug delivery, short half-life, poor bioavailability, and narrow therapeutic window are all crucial for such fluctuations...
May 10, 2017: Current Neuropharmacology
https://www.readbyqxmd.com/read/28494613/new-natural-product-an-efficient-antimicrobial-applications-of-new-newly-synthesized-pyrimidine-derivatives-by-the-electrochemical-oxidation-of-hydroxyl-phenol-in-the-presence-of-2-mercapto-6-trifluoromethyl-pyrimidine-4-ol-as-nucleophile
#14
Zia Ul Haq Khan, Amjad Khan, Pingyu Wan, Arif Ullah Khan, Kamran Tahir, Nawshad Muhammad, Faheem Ullah Khan, Hidayat Ullah Shah, Zia Ullah Khan
Some new pyrimidine derivatives have been synthesised by electrochemical oxidation of catechol (1a) in the existence of 2-mercapto-6-(trifluoromethyl) pyrimidine-4-ol (3) as a nucleophile in aqueous solution using Cyclic Voltammetric and Controlled Potential Coulometry. The catechol has been oxidised to o-quinone through electrochemical method and participative in Michael addition reaction, leading to the development of some new pyrimidine derivatives. The products were achieved in good yield with high pureness...
May 11, 2017: Natural Product Research
https://www.readbyqxmd.com/read/28493469/nature-inspired-synthesis-of-nanostructured-electrocatalysts-through-mineralization-of-calcium-carbonate
#15
Jong Wan Ko, Eun Jin Son, Chan Beum Park
Biomineralization is a biogenic process that produces elaborate inorganic and organic hybrid materials in nature. Inspired by the natural process, this study explores novel mineralization approach to create nanostructured CaCO3 films composed of amorphous CaCO3 hemispheres using catechol-rich polydopamine (PDA) as a biomimetic mediator. We successfully transformed thus-synthesized biomimetic CaCO3 to nanostructured films of metal oxide minerals, such as FeOOH, CoCO3, NiCO3, and MnOOH, via a simple procedure...
May 10, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28485972/nanocomposite-deposited-membrane-for-oil-in-water-emulsion-separation-with-in-situ-removal-of-anionic-dyes-and-surfactants
#16
Na Liu, Qingdong Zhang, Ruixiang Qu, Weifeng Zhang, Haifang Li, Yen Wei, Lin Feng
The decontamination of various pollutants including oils, organic dyes and surfactants from water is an unprecedented issue throughout the world. A facile filtration process for in situ multifunctional water purification by employing a low-cost and easy-made catechol-PEI nanocomposite deposited membrane has been designed. In combination with the intrinsic hydrophilicity of amino-rich groups, the resultant membrane possesses superhydrophilicity and underwater superoleophobicity, which is simultaneously advantageous for capturing anionic pollutants due to the electrostatic interaction...
May 9, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28481078/simple-fabrication-of-titanium-dioxide-n-doped-carbon-hybrid-material-as-non-precious-metal-electrocatalyst-for-the-oxygen-reduction-reaction
#17
Shangbin Jin, Cuiling Li, Lok Kumar Shrestha, Yusuke Yamauchi, Katsuhiko Ariga, Jonathan P Hill
We report a new approach for the fabrication of hybrid titanium dioxide/carbon materials derived from a porous titanium coordination polymer composed of a catechol-substituted porphyrin and Ti(4+). Titanium dioxide nanocrystals were formed distributed in a nitrogen-doped carboniferous matrix after the thermolysis of the coordination polymer. The identity of the titanium dioxide phase, i.e., anatase or rutile, could be controlled by varying the thermolysis temperature. Electrochemical performances of the composites were explored with results demonstrating that the hybrid materials are promising cathodic materials for the oxygen reduction reaction...
May 16, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28481013/silylene-nickel-promoted-cleavage-of-b-o-bonds-from-catechol-borane-to-the-hydroborylene-ligand
#18
Terrance J Hadlington, Tibor Szilvási, Matthias Driess
The first 16 valence electron [bis(NHC)](silylene)Ni(0) complex 1, [((TMS) L)ClSi:→Ni(NHC)2 ], bearing the acyclic amido-chlorosilylene ((TMS) L)ClSi: ((TMS) L=N(SiMe3 )Dipp; Dipp=2,6-Pr(i)2 C6 H4 ) and two NHC ligands (N-heterocyclic carbene=:C[(Pr(i) )NC(Me)]2 ) was synthesized in high yield and structurally characterized. Compound 1 is capable of facile dihydrogen activation under ambient conditions to give the corresponding HSi-NiH complex 2. Most notably, 1 reacts with catechol borane to afford the unprecedented hydroborylene-coordinated (chloro)(silyl)nickel(II) complex 3, {[cat((TMS) L)Si](Cl)Ni←:BH(NHC)2 }, via the cleavage of two B-O bonds and simultaneous formation of two Si-O bonds...
May 8, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28480927/antiradical-activity-of-catecholamines-and-metabolites-of-dopamine-theoretical-and-experimental-study
#19
D Dimić, D Milenković, J Dimitrić Marković, Z Marković
The importance of molecules with antiradical potency that are produced in the human body has significantly increased. Among others, neurotransmitters and their metabolites act as the first line of defense against oxidative stress in the peripheral endocrine and the central nervous systems. Dopamine (DO), epinephrine (EP), norepinephrine (NE), l-DOPA, catechol, and three metabolites of dopamine (3-methoxytyramine (3-MT), homovanillic acid (HO), and 3,4-dihydrophenylacetic acid (DOPAC)) were investigated for their antiradical potency via computational methods and DPPH assay...
May 8, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28473993/salvia-miltiorrhiza-roots-against-cardiovascular-disease-consideration-of-herb-drug-interactions
#20
REVIEW
Feng Chen, Li Li, Dan-Dan Tian
Salvia miltiorrhiza root (Danshen) is widely used in Asia for its cardiovascular benefits and contains both hydrophilic phenolic acids and lipophilic tanshinones, which are believed to be responsible for its therapeutic efficacy. This review summarized the effects of these bioactive components from S. miltiorrhiza roots on pharmacokinetics of comedicated drugs with mechanic insights regarding alterations of protein binding, enzyme activity, and transporter activity based on the published data stemming from both in vitro and in vivo human studies...
2017: BioMed Research International
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