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w hydroxylation

Natela Dushukyan, Diana M Dunn, Rebecca A Sager, Mark R Woodford, David R Loiselle, Michael Daneshvar, Alexander J Baker-Williams, John D Chisholm, Andrew W Truman, Cara K Vaughan, Timothy A Haystead, Gennady Bratslavsky, Dimitra Bourboulia, Mehdi Mollapour
The serine/threonine protein phosphatase 5 (PP5) regulates multiple cellular signaling networks. A number of cellular factors, including heat shock protein 90 (Hsp90), promote the activation of PP5. However, it is unclear whether post-translational modifications also influence PP5 phosphatase activity. Here, we show an "on/off switch" mechanism for PP5 regulation. The casein kinase 1δ (CK1δ) phosphorylates T362 in the catalytic domain of PP5, which activates and enhances phosphatase activity independent of Hsp90...
November 14, 2017: Cell Reports
Jitrayut Jitonnom, Joni Mujika, Marc W van der Kamp, Adrian J Mulholland
Creatininase catalyzes the conversion of creatinine (a biosensor for kidney function) to creatine via a two-step mechanism: water-addition followed by ring-opening. Water-addition is common to other known cyclic amidohydrolases, but the precise mechanism for ring-opening is still under debate. The proton donor in this step is either His178, or a water molecule bound to one of metal ions, and the roles of His178 and Glu122 are unclear. Here, the two possible reaction pathways have been fully examined by means of combined quantum mechanics/molecular mechanics simulations at the SCC-DFTB/CHARMM22 level of theory...
November 15, 2017: Biochemistry
Zineb Boutamine, Oualid Hamdaoui, Slimane Merouani
Sonochemical degradation at 600 kHz of 2-phenoxyethanol (PhE), an endocrine disrupting compound, was performed in the presence of several organic additives, namely: 2-propanol, Triton X-100 and sucrose, of different volatilities to obtain detailed information on the reaction zone and the oxidation pathway of this priority emerging water contaminate. It was found that sonication at 600 kHz and 120 W completely remove PhE (10 mg L(-1)) from aerated solutions within 100 min of irradiation. Very little removal of PhE (∼7%) and low accumulation of H2O2 took place in the presence of adequate amount of 2-propanol, indicating that reaction with OH radical outside the bubble is the major degradation pathway of PhE...
March 2018: Ultrasonics Sonochemistry
Bin Ma, Adam T Zarth, Erik S Carlson, Peter W Villalta, Pramod Upadhyaya, Irina Stepanov, Stephen S Hecht
The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a powerful lung carcinogen in animal models and is considered a causative factor for lung cancer in tobacco users. NNK is stereoselectively and reversibly metabolized to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), which is also a lung carcinogen. Both NNK and NNAL undergo metabolic activation by α-hydroxylation on their methyl groups to form pyridyloxobutyl and pyridylhydroxybutyl DNA base and phosphate adducts, respectively...
November 13, 2017: Chemical Research in Toxicology
Hui Chen, Ricky Y K Man, Susan W S Leung
Hypertension is associated with endothelial dysfunction, which favors the release of endothelium-derived contracting factors, including vasoconstrictor prostanoids and reactive oxygen species. Peroxisome proliferator-activated receptor α (PPARα) agonists, clinically used as lipid lowering drugs, possess antioxidant properties and exert beneficial effects in the vascular system. The present study aimed to identify the mechanism(s) underlying the acute effects of the PPARα agonists, Wy14643 and fenofibate, on endothelium-dependent contractions, in particular, those related to oxidative stress, in the aorta of the spontaneously hypertensive rat (SHR)...
November 10, 2017: American Journal of Physiology. Heart and Circulatory Physiology
M W P Tsang-A-Sjoe, I E M Bultink, L A Korswagen, A van der Horst, I Rensink, M de Boer, D Hamann, A E Voskuyl, D Wouters
Genetic variation of the genes encoding complement component C4 is strongly associated with systemic lupus erythematosus (SLE), a chronic multi-organ auto-immune disease. This study examined C4 and its isotypes on a genetic, protein, and functional level in 140 SLE patients and 104 healthy controls. Gene copy number (GCN) variation, silencing CT-insertion, and the retroviral HERV-K(C4) insertion) were analyzed with multiplex ligation-dependent probe amplification. Increased susceptibility to SLE was found for low GCN (≪2) of C4A...
October 25, 2017: Molecular Immunology
Núria Miralles, José Enrique Gómez, Arjan W Kleij, Elena Fernández
A method for the copper-catalyzed borylmethylation and borylation of vinyl cyclic carbonates through an SN2' mechanism is reported. These singular reactions involve selective SN2' allylic substitutions with concomitant ring opening of the cyclic carbonate and with extrusion of CO2 and formation of a useful hydroxyl functionality in a single step. The stereoselectivity of the homoallylic borylation and allylic borylation processes can be controlled, and synthetically useful unsaturated (E)-pent-2-ene-1,5-diols and (E)-but-2-ene-1,4-diols are accessed...
October 27, 2017: Organic Letters
J W Han, B G Ng, J K Sohng, Y J Yoon, G J Choi, B S Kim
AIMS: To identify the roles of the two O-methyltransferase homologous genes pdmF and pdmT in the pradimicin biosynthetic gene cluster of Actinomadura hibisca P157-2. METHODS AND RESULTS: Pradimicins are pentangular polyphenol antibiotics synthesized by bacterial type II polyketide synthases (PKSs) and tailoring enzymes. Pradimicins are naturally derivatized by combinatorial O-methylation at two positions (i.e., 7-OH and 11-OH) of the benzo[α]naphthacenequinone structure...
October 26, 2017: Journal of Applied Microbiology
Sina Dobaradaran, Ramin Nabizadeh Nodehi, Kamyar Yaghmaeian, Jalil Jaafari, Maryam Hazrati Niari, Arvind Kumar Bharti, Shilpi Agarwal, Vinod Kumar Gupta, Ali Azari, Nabi Shariatifar
As a reusable sonocatalyst, magnetically separable Fe3O4-TiO2@MWCNT (FMT) was synthesized by an ultrasound-assisted wet impregnation method and was evaluated in the removal of 2-chlorophenol (2CP). Physical and chemical properties of the catalyst composite materials were investigated by all catalysts were systematically characterized using Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray Analysis (EDX), Dynamic light scattering (DLS), and N2-physisorption...
October 12, 2017: Journal of Colloid and Interface Science
Lucas W Hernandez, Jola Pospech, Ulrich Klöckner, Tanner W Bingham, David Sarlah
A concise synthesis of (+)-pancratistatin and (+)-7-deoxypancratistatin from benzene using an enantioselective, dearomative carboamination strategy has been achieved. This approach, in combination with the judicious choice of subsequent olefin-type difunctionalization reactions, permits rapid and controlled access to a hexasubstituted core. Finally, minimal use of intermediary steps as well as direct, late stage C-7 hydroxylation provides both natural products in six and seven operations.
November 8, 2017: Journal of the American Chemical Society
Corinna Gressl, Michael Brunsteiner, Adrian Davis, Margaret Landis, Klimentina Pencheva, Garry Scrivens, Gregory W Sluggett, Geoffrey P F Wood, Heidrun Gruber-Woelfler, Johannes G Khinast, Amrit Paudel
Understanding properties and mechanisms that govern drug degradation in the solid state is of high importance to ensure drug stability and safety of solid dosage forms. In this study, we attempt to understand drug-excipient interactions in the solid state using both theoretical and experimental approaches. The model active pharmaceutical ingredients (APIs) under study are carvedilol (CAR) and codeine phosphate (COP), which are known to undergo esterification with citric acid (CA) in the solid state. Starting from the crystal structures of two different polymorphs of each compound, we calculated the exposure and accessibility of reactive hydroxyl groups for a number of relevant crystal surfaces, as well as descriptors that could be associated with surface stabilities using molecular simulations...
November 2, 2017: Molecular Pharmaceutics
Yang Liu, Yahui Yang, Qiong Liu, Yaomin Li, Jie Lin, Wenzhang Li, Jie Li
H2O, as a product of reduced reaction by H2, may affect the chemical equilibrium according to the changing of the pressure ratio of H2O/H2 in the system. Meanwhile, the performance may also be influenced by adsorption of H2O on the surface of the material. In this work, the effect of H2O is studied by reducing plate-like array WO3 films under different pressure ratio of H2O/H2. It is controlled by changing the water temperature in the washing bottle through which the Ar/H2 (80:20) gas flows. The higher water vapor pressure not only decreases the content of W(5+) but also increases the content of surface hydroxyl groups in the WO3 films...
October 12, 2017: Journal of Colloid and Interface Science
Robert B Balow, Jeffrey G Lundin, Grant C Daniels, Wesley O Gordon, Monica McEntee, Gregory W Peterson, James H Wynne, Pehr E Pehrsson
Zirconium hydroxide (Zr(OH)4) has excellent sorption properties and wide-ranging reactivity toward numerous types of chemical warfare agents (CWAs) and toxic industrial chemicals. Under pristine laboratory conditions, the effectiveness of Zr(OH)4 has been attributed to a combination of diverse surface hydroxyl species and defects; however, atmospheric components (e.g., CO2, H2O, etc.) and trace contaminants can form adsorbates with potentially detrimental impact to the chemical reactivity of Zr(OH)4. Here, we report the hydrolysis of a CWA simulant, dimethyl methylphosphonate (DMMP) on Zr(OH)4 determined by gas chromatography-mass spectrometry and in situ attenuated total reflectance Fourier transform infrared spectroscopy under ambient conditions...
October 31, 2017: ACS Applied Materials & Interfaces
Peng Wang, Xue Jiang, Jun Hu, Jijun Zhao
Continuous miniaturization of magnetic units in spintronics devices inspires efforts to search for novel 2D magnetic materials with giant magnetic anisotropy energy (MAE). Through systematic first-principles calculations, large MAE of 24 meV in W or Re embedded 2D polyporphyrin frameworks is found. Interestingly, the MAE can be enhanced up to 60 meV, through replacing the hydrogen atoms on the edges of the Re based 2D polyporphyrin framework by hydroxyl and amino radicals. Analysis of the electronic structures reveals that the enhancement of MAE is mainly attributed to charge redistributions and energy shifts of Re 5d orbitals induced by the functional radicals...
October 2017: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Emanuel Y C Ron, Merichel Plaza, Thordis Kristjansdottir, Roya R R Sardari, Snaedis H Bjornsdottir, Steinn Gudmundsson, Gudmundur Oli Hreggvidsson, Charlotta Turner, Ed W J van Niel, Eva Nordberg-Karlsson
Rhodothermus marinus, a marine aerobic thermophile, was first isolated from an intertidal hot spring in Iceland. In recent years, the R. marinus strain PRI 493 has been genetically modified, which opens up possibilities for targeted metabolic engineering of the species, such as of the carotenoid biosynthetic pathway. In this study, the carotenoids of the R. marinus type-strain DSM 4252(T) , strain DSM 4253, and strain PRI 493 were characterized. Bioreactor cultivations were used for pressurized liquid extraction and analyzed by ultra-high performance supercritical fluid chromatography with diode array and quadropole time-of-flight mass spectrometry detection (UHPSFC-DAD-QTOF/MS)...
October 17, 2017: MicrobiologyOpen
Jaeok Park, Dmitry Rodionov, Joris W De Schutter, Yih-Shyan Lin, Youla S Tsantrizos, Albert M Berghuis
Human farnesyl pyrophosphate synthase (hFPPS) catalyzes the production of the 15-carbon isoprenoid farnesyl pyrophosphate. The enzyme is a key regulator of the mevalonate pathway and a well-established drug target. Notably, it was elucidated as the molecular target of nitrogen-containing bisphosphonates, a class of drugs that have been widely successful against bone resorption disorders. More recently, research has focused on the anticancer effects of these inhibitors. In order to achieve increased non-skeletal tissue exposure, we created phenylaminopyridine bisphosphonates (PNP-BPs) that have bulky hydrophobic side chains through a structure-based approach...
2017: PloS One
Xinran Zhang, Ivan da Silva, Harry G W Godfrey, Samantha K Callear, Sergey A Sapchenko, Yongqiang Cheng, Inigo Vitórica-Yrezábal, Mark D Frogley, Gianfelice Cinque, Chiu C Tang, Carlotta Giacobbe, Catherine Dejoie, Svemir Rudić, Anibal J Ramirez-Cuesta, Melissa A Denecke, Sihai Yang, Martin Schröder
During nuclear waste disposal process, radioactive iodine as a fission product can be released. The widespread implementation of sustainable nuclear energy thus requires the development of efficient iodine stores that have simultaneously high capacity, stability and more importantly, storage density (and hence minimized system volume). Here, we report high I2 adsorption in a series of robust porous metal-organic materials, MFM-300(M) (M = Al, Sc, Fe, In). MFM-300(Sc) exhibits fully reversible I2 uptake of 1...
November 3, 2017: Journal of the American Chemical Society
Madhuri Vaghela, Krishna Iyer, Nancy Pandita
BACKGROUND AND OBJECTIVES: Gymnema sylvestre R. Br. is a well-known Indian medicinal herb. Gymnemic acids are pentacyclic triterpenes saponins and active phytoconstituents of Gymnema sylvestre. The study aimed at evaluation of the in vitro rat liver cytochrome P450 (CYP) inhibition potential of extracts and total gymnemic acid (TA)-enriched fractions from G. sylvestre. METHODS: Standardization of G. sylvestre [ethanolic (EL), hydroethanolic (HE), total acid of ethanolic (TAE), total acid of hydroethanolic (TAHE) and total acid of aqueous (TAAQ) extract] was done with respect to deacyl gymnemic acid (DAGA), using reverse phase-high performance liquid chromatography (RP-HPLC)...
October 10, 2017: European Journal of Drug Metabolism and Pharmacokinetics
Philip W Wertz
ω-Hydroxyacids are fatty acids bearing a hydroxyl group on the terminal carbon. They are found in mammals and higher plants and are often involved in providing a permeability barrier, the primary purpose of which is to reduce water loss. Some ω-hydroxyacid derivatives may be involved in water proofing and signaling. The purpose of this review is to survey the known natural sources of ω-hydroxyacids. ω -Hydroxyacids are produced by two different P450-dependent mechanisms. The longer (30 - 34 carbons) ω-hydroxyacids are produced by chain extension from palmitic acid until the chain extends across the membrane in which the extension is taking place, and then the terminal carbon is hydroxylated...
October 10, 2017: International Journal of Cosmetic Science
Alexander V Kachur, Alejandro D Arroyo, Nikaela W Bryan, Sarah J Saylor, Anatoliy V Popov, E James Delikatny
Direct electrophilic fluorination using molecular fluorine gas is used in organic synthesis to create novel fluorine-containing compounds with potential beneficial activity that could not be obtained by nucleophilic substitution. In this paper, we report a novel electrophilic substitution of bromine by fluorine in an aromatic system. The mechanism of this type of fluorination was explored using the reaction between bromothymolsulfonphthalein (Bromothymol Blue) and dilute fluorine gas under acidic conditions...
August 2017: Journal of Fluorine Chemistry
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