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w hydroxylation

Christopher W Pugh, Peter J Ratcliffe
Investigation into the regulation of the erythropoietin gene by oxygen led to the discovery of a process of direct oxygen sensing that transduces many cellular and systemic responses to hypoxia. The oxygen-sensitive signal is generated through the catalytic action of a series of 2-oxoglutarate-dependent oxygenases that regulate the transcription factor hypoxia-inducible factor (HIF) by the post-translational hydroxylation of specific amino acid residues. Here we review the implications of the unforeseen complexity of the HIF transcriptional cascade for the physiology and pathophysiology of hypoxia, and consider the origins of post-translational hydroxylation as a signaling process...
March 14, 2017: Experimental Cell Research
Laura M Woods, Joseph W Arico, Jeffrey D Frein, Dan L Sackett, Richard E Taylor
The synthesis of two deoxygenated analogues of potent epothilones is reported in an effort to analyze the relative importance of molecular conformation and ligand-target interactions to biological activity. 7-deoxy-epothilone D and 7-deoxy-(S)-14-methoxy-epothilone D were prepared through total synthesis and shown to maintain the conformational preferences of their biologically active parent congeners through computer modeling and nuclear magnetic resonance (NMR) studies. The significant decrease in observed potency for each compound suggests that a hydrogen bond between the C7-hydroxyl group and the tubulin binding site plays a critical role in the energetics of binding in the epothilone class of polyketides...
March 17, 2017: International Journal of Molecular Sciences
Thu M Tran, Carissa S Hampton, Tom W Brossard, Michael Harmata, J David Robertson, Silvia S Jurisson, David M Braun
Sucrose transporter (SUT) proteins translocate sucrose across cell membranes; however, mechanistic aspects of sucrose binding by SUTs are not well resolved. Specific hydroxyl groups in sucrose participate in hydrogen bonding with SUT proteins. We previously reported that substituting a radioactive fluorine-18 [(18)F] at the C-6' position within the fructosyl moiety of sucrose did not affect sucrose transport by the maize (Zea mays) ZmSUT1 protein. To determine how (18)F substitution of hydroxyl groups at two other positions within sucrose, the C-1' in the fructosyl moiety or the C-6 in the glucosyl moiety, impact sucrose transport, we synthesized 1'-[F(18)]fluoro-1'-deoxysucrose and 6-[F(18)]fluoro-6-deoxysucrose ([(18)F]FDS) analogs...
March 8, 2017: Plant Physiology and Biochemistry: PPB
Apurva Koul, Suresh K Abraham
Saffron (SAF), the dried stigmas of Crocus sativus is commonly used for flavouring and coloring food. Studies on bioactivity of SAF have demonstrated its in vivo antioxidant activity. The aim of our study was to assess the impact of SAF intake on γ-radiation (RAD) induced: (a) chromosomal damage, (b) oxidative stress in liver and brain and (c) histopathological effects in the intestinal cells and male germ cells in mice. Freeze-dried aqueous extract of SAF was used for the experiments. Our preliminary cell-free DNA nicking assay using pBR322 DNA revealed protective effects of freeze-dried SAF extract against hydroxyl radical induced DNA damage...
March 15, 2017: Toxicology Mechanisms and Methods
S Ryu, S Park, J H Lee, Y R Kim, H S Na, H S Lim, H Y Choi, I Y Hwang, J G Lee, Z W Park, W Y Oh, J M Kim, S E Choi
We performed a double-blinded, genotype-based stratification study to explore the pharmacokinetics and pharmacodynamics of amitriptyline according to CYP2C19 and CYP2D6 genotype in Korean subjects. Twenty-four healthy adults were grouped by genotype of CYP2C19 and CYP2D6. After a single dose of 25 mg of amitriptyline, blood samples were collected and anticholinergic effects were measured. The extent of N-demethylation of amitriptyline significantly decreased in subjects carrying two nonfunctional alleles of CYP2C19...
March 2017: Clinical and Translational Science
Xiao Meng, Ni Zeng, Jin Zhang, Long Jiang, Yi Dan
Herein, we report a new approach to fabricate polyvinyl alcohol (PVA) based hydrophilic monoliths by alcoholysis of porous emulsion-templated polyvinyl acetate (PVAc). The precursory PVAc-based monolith is obtained by polymerization of a W/O high internal phase emulsion (HIPE) containing vinyl acetate as the external phase while water as the internal phase. As an alcoholysis-stable tri-functional commonomer, triallyl isocyanurate is chosen as the crosslinking agent to prevent possible collapse of the polymeric skeleton and the consequent losses in mechanical properties during the alcoholysis step...
July 1, 2017: Journal of Colloid and Interface Science
Beverly H K Po, Ka-Lok Ho, Michael H W Lam, John P Giesy, Jill M Y Chiu
Hydroxylated- and methoxylated- polybrominated diphenyl ethers (OH-PBDEs and MeO-PBDEs) are more toxic than PBDEs and occur widely in the marine environment, and yet their origins remain controversial. In this study, four species of microalgae (Isochrysis galbana, Prorocentrum minimum, Skeletonema grethae and Thalassiosira pseudonana) were exposed to BDE-47, which is synthetic and is the predominant congener of PBDEs in the environment. By chemical analysis after incubation of 2 to 6 days, the efficiency of uptake of BDE-47 and, more importantly, the potential of undergoing biotransformation to form OH-PBDEs and MeO-PBDEs by the microalgae were investigated...
March 13, 2017: Scientific Reports
Tao Ji, Ze Cui, Wenlong Zhang, Yunjiu Cao, Yongfang Zhang, Shu-Ang He, Mingdong Xu, Yangang Sun, Rujia Zou, Junqing Hu
Herein, we report a photocatalytic heterojunction device of rutile TiO2 nanorod arrays based on a p-n silicon junction (TiO2@PN) and its full absorption of ultraviolet and visible light for synergistic photodegradation. The fabricated TiO2@PN had excellent photocatalytic degradation of methyl orange (MO) under irradiation of a 300 W Xe lamp, and its pseudo-first-order rate constant k was 0.221 h(-1), which was greatly higher than that for TiO2 nanorod arrays based on an n-p silicon junction (TiO2@NP, 0.078 h(-1)) and glass (TiO2@G, 0...
March 27, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
L Muthulakshmi, H Nellaiah, T Kathiresan, N Rajini, Fenila Christopher
In this work, two bioflocculants, namely, EB-EPS and B1-EPS were derived from Enterobacter sp. and Bacillus sp., respectively and analyzed with regard to their production and characterization. About 0.9 g and 0.16 g of purified EB and B1 were obtained from I L of fermentation broth. Chemical analysis showed the contents of purified EB and B1 mainly as 88.7% and 92.8% (w/w) of carbohydrate, and 11.3% and 21.8% (w/w) protein, respectively. Fourier-transform infrared (FTIR) spectrometry analysis revealed the presence of hydroxyl, amide and carboxyl groups in the identified bioflocculant...
February 16, 2017: Preparative Biochemistry & Biotechnology
Kai Li, Zhenyu Huang, Xiaoqiao Zeng, Baibiao Huang, Shanmin Gao, Jun Lu
To improve the utilization of visible light and reduce photogenerated electron/hole recombination, Ti(3+) self-doped TiO2/oxygen-doped graphitic carbon nitride (Ti(3+)-TiO2/O-g-C3N4) heterojunctions were prepared via hydrothermal treatment of a mixture of g-C3N4 and titanium oxohydride sol obtained from the reaction of TiH2 with H2O2. In this way, exfoliated O-g-C3N4 and Ti(3+)-TiO2 nanoparticles were obtained. Simultaneously, strong bonding was formed between Ti(3+)-TiO2 nanoparticles and exfoliated O-g-C3N4 during the hydrothermal process...
March 22, 2017: ACS Applied Materials & Interfaces
Lisa Emhofer, Markus Himmelsbach, Wolfgang Buchberger, Christian W Klampfl
In this paper the metabolism of four non-steroidal anti-inflammatory drugs, (ketoprofen, mefenamic acid, naproxen, and diclofenac) by cress (Lepidium sativum) is described. Cress was cultivated hydroponically in water spiked with the parent drugs at levels ranging from 0.01mgL(-1) to 1mgL(-1). Employing an approach based on the analysis of the plant extracts by HPLC coupled either with quadrupole-time-of-flight mass spectrometry, or Orbitrap MS or triple quadrupole (QqQ) MS allowed the identification of twenty substances (sixteen metabolites and four parent drugs)...
March 31, 2017: Journal of Chromatography. A
Andrew W Gardner, Polly S Montgomery, Yan D Zhao, Federico Silva-Palacios, Zoltan Ungvari, Anna Csiszar, William E Sonntag
OBJECTIVE: The primary aim of the study was to assess whether both the amount and pace of daily walking were associated with circulating antioxidant capacity in symptomatic patients with peripheral artery disease (PAD). METHODS: Community-based walking was measured in 244 men and women who were limited by symptomatic PAD during a 1-week period in which they wore an ankle-mounted step activity monitor. Patients were further characterized by circulating antioxidant capacity with the OxiSelect (Cell Biolabs Inc, San Diego, Calif) hydroxyl radical antioxidant capacity (HORAC) activity assay...
March 1, 2017: Journal of Vascular Surgery
Enxiang Shang, Junfeng Niu, Yang Li, Yijing Zhou, John Charles Crittenden
In this study, the phototoxicity of cadmium sulfide (CdS), molybdenum disulfide (MoS2), and tungsten disulfide (WS2) nanoparticles (NPs) toward Escherichia coli (E. coli) under UV irradiation (365 nm) was investigated. At the same mass concentration of NPs, the toxicity of three NPs decreased in the order of CdS > MoS2 > WS2. For example, the death rates of E. coli exposed to 50 mg/L CdS, MoS2, and WS2 were 96.7%, 38.5%, and 31.2%, respectively. Transmission electron microscope and laser scanning confocal microscope images of E...
February 28, 2017: Environmental Pollution
Nahuel A Paolini, Martin Attwood, Samuel B Sondalle, Carolina Marques Dos Santos Vieira, Anita M van Adrichem, Franca M di Summa, Marie-Françoise O'Donohue, Pierre-Emmanuel Gleizes, Swaksha Rachuri, Joseph W Briggs, Roman Fischer, Peter J Ratcliffe, Marcin W Wlodarski, Riekelt H Houtkooper, Marieke von Lindern, Taco W Kuijpers, Jonathan D Dinman, Susan J Baserga, Matthew E Cockman, Alyson W MacInnes
Ribosomal protein (RP) gene mutations, mostly associated with inherited or acquired bone marrow failure, are believed to drive disease by slowing the rate of protein synthesis. Here de novo missense mutations in the RPS23 gene, which codes for uS12, are reported in two unrelated individuals with microcephaly, hearing loss, and overlapping dysmorphic features. One individual additionally presents with intellectual disability and autism spectrum disorder. The amino acid substitutions lie in two highly conserved loop regions of uS12 with known roles in maintaining the accuracy of mRNA codon translation...
March 2, 2017: American Journal of Human Genetics
Corrine A Kumar, Arjun Saha, Krishnan Raghavachari
Transition metal sulfides (TMS) are being investigated with increased frequency because of their ability to efficiently catalyze the hydrogen evolution reaction. We have studied the trimetallic TMS cluster ions, Mo3S4(-), W3S4(-), and W3S3(-), and probed their efficiency for bond activation and hydrogen evolution from water. These clusters have geometries that are related to the edge sites on bulk MoS2 surfaces that are known to play a role in hydrogen evolution. Using density functional theory, the electronic structures of these clusters and their chemical reactivity with water have been investigated...
February 17, 2017: Journal of Physical Chemistry. A
Zhenzhong Lu, Harry G W Godfrey, Ivan da Silva, Yongqiang Cheng, Mathew Savage, Floriana Tuna, Eric J L McInnes, Simon J Teat, Kevin J Gagnon, Mark D Frogley, Pascal Manuel, Svemir Rudić, Anibal J Ramirez-Cuesta, Timothy L Easun, Sihai Yang, Martin Schröder
Hydrogen bonds dominate many chemical and biological processes, and chemical modification enables control and modulation of host-guest systems. Here we report a targeted modification of hydrogen bonding and its effect on guest binding in redox-active materials. MFM-300(V(III)) {[V(III)2(OH)2(L)], LH4=biphenyl-3,3',5,5'-tetracarboxylic acid} can be oxidized to isostructural MFM-300(V(IV)), [V(IV)2O2(L)], in which deprotonation of the bridging hydroxyl groups occurs. MFM-300(V(III)) shows the second highest CO2 uptake capacity in metal-organic framework materials at 298 K and 1 bar (6...
February 13, 2017: Nature Communications
Rosa María Baena-Nogueras, Eduardo González-Mazo, Pablo A Lara-Martín
There is growing concern regarding the widespread use of antibiotics and their presence in the aqueous environment. Their removal in the water column is mediated by different types of degradation processes for which the mechanisms are still unclear. This research is focused on characterizing the photodegradation kinetics and pathways of two largely employed antibiotics families: sulfonamides (9 SDs) and fluoroquinolones (6 FQs). Degradation percentages and rates were measured in pure water exposed to simulated natural sunlight at a constant irradiance value (500 W m(-2)) during all the experiments, and the main photoproducts formed were characterized through accurate mass measurement using ultraperformance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-QToF-MS)...
March 21, 2017: Environmental Science & Technology
Agata Kryczyk, Paweł Żmudzki, Urszula Hubicka
The main goal of the presented work was to investigate the effect of ZnO or/and TiO2 on the stability of bifonazole in solutions under UVA irradiation. To this end, a simple and reproducible UPLC method for the determination of bifonazole in the presence of its photocatalytic degradation products was developed. Linearity was studied in the range of 0.0046-0.15 mg mL(-1) with a determination coefficient of 0.9996. Bifonazole underwent photocatalytic degradation process under the experimental conditions used...
February 10, 2017: Biomedical Chromatography: BMC
Paul C Lemaire, Mariah King, Gregory N Parsons
Area-selective thin film deposition is expected to be important for advanced sub-10 nanometer semiconductor devices, enabling feature patterning, alignment to underlying structures, and edge definition. Several atomic layer deposition (ALD) processes show inherent propensity for substrate-dependent nucleation. This includes tungsten ALD (W-ALD) which is more energetically favorable on Si than on SiO2. However, the selectivity is often lost after several ALD cycles. We investigated the causes of tungsten nucleation on SiO2 and other "non-growth" surfaces during the WF6/SiH4 W-ALD process to determine how to expand the "selectivity window...
February 7, 2017: Journal of Chemical Physics
Susovan Jana, Mohammed H Al-Huniti, Bo Yeun Yang, Shuiyu Lu, Victor W Pike, Salvatore D Lepore
New bifunctional phase transfer agents were synthesized and investigated for their abilities to promote rapid fluorination at silicon. These agents, dubbed crown ether nucleophilic catalysts (CENCs), are 18-crown-6 derivatives containing a side-arm and a potentially nucleophilic hydroxyl group. These CENCs proved efficacious in the fluorination of hindered silicon substrates, with fluorination yields dependent on the length of linker connecting the metal chelating unit to the hydroxyl group. The efficacy of these CENCs was also demonstrated for rapid radiofluorination under mild conditions for eventual application in molecular imaging with positron emission tomography (PET)...
February 20, 2017: Journal of Organic Chemistry
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