Read by QxMD icon Read

w hydroxylation

Hunter W Schroer, Kathryn L Langenfeld, Xueshu Li, Hans-Joachim Lehmler, Craig L Just
Insensitive munitions explosives are new formulations that are less prone to unintended detonation compared to traditional explosives. While these formulations have safety benefits, the individual constituents, such as 2,4-dinitroanisole (DNAN), have an unknown ecosystem fate with potentially toxic impacts to flora and fauna exposed to DNAN and/or its metabolites. Fungi may be useful in remediation and have been shown to degrade traditional nitroaromatic explosives, such as 2,4,6-trinitrotoluene and 2,4-dinitrotoluene, that are structurally similar to DNAN...
December 2, 2016: Biodegradation
Ying-Yuan Lu, Hai-Xu Cheng, Xin Wang, Xiao-Wei Wang, Jun-Yi Liu, Pu Li, Ya-Qing Lou, Jun Li, Chuang Lu, Guo-Liang Zhang
1. The aim of this study was to identify the hepatic metabolic enzymes, which involved in the biotransformation of 6-benzyl-1-benzyloxymethyl-5-iodouracil (W-1), a novel non-nucleoside reverse transcriptase inhibitor (NNRTIs) in rat and human in vitro. 2. The parent drug of W-1 was incubated with RLMs or recombinant CYPs (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5, respectively) in the presence or absence of NADPH regenerating system. The metabolites of W-1 were analyzed with liquid chromatography-ion trap-time of flight-mass spectrometry (LC-IT-TOF-MS)...
December 2, 2016: Xenobiotica; the Fate of Foreign Compounds in Biological Systems
Ling-Li Deng, Maierhaba Taxipalati, Fei Que, Hui Zhang
Attempts were made to solubilize thymol in Tween 80 micelle to study the solubilization mechanism of thymol and the effect of solubilization on its antioxidant activity. The maximum solubilized concentration of thymol in a 2.0% (w/v) Tween 80 micelle solution is 0.2 wt%. There was no significant difference in Z-average diameter between the empty micelles and thymol solubilized micelles. (1)H NMR spectra indicated that 3-H and 4-H on the benzene ring of thymol interacted with the ester group between the hydrophilic head group and the hydrophobic tail group of Tween 80 by Van der Waals' force...
December 1, 2016: Scientific Reports
Nina Beyer, Justyna K Kulig, Anette Bartsch, Martin A Hayes, Dick B Janssen, Marco W Fraaije
To facilitate the wider application of the NADPH-dependent P450BM3, we fused the monooxygenase with a phosphite dehydrogenase (PTDH). The resulting monooxygenase-dehydrogenase fusion enzyme acts as a self-sufficient bifunctional catalyst, accepting phosphite as a cheap electron donor for the regeneration of NADPH.The well-expressed fusion enzyme was purified and analyzed in comparison to the parent enzymes. Using lauric acid as substrate for P450BM3, it was found that the fusion enzyme had similar substrate affinity and hydroxylation selectivity while it displayed a significantly higher activity than the non-fused monooxygenase...
November 29, 2016: Applied Microbiology and Biotechnology
H Schweikl, M Godula, C Petzel, C Bolay, K A Hiller, W Buchalla
OBJECTIVE: Resin monomers such as 2-hydroxyethyl methacrylate (HEMA) induce apoptosis because of the excess formation of reactive oxygen species (ROS). The portion of ROS including superoxide anions, hydrogen peroxide or hydroxyl radicals in monomer-induced apoptosis is unknown. Here, the effectiveness of superoxide anions or hydroxyl radicals was analyzed using tempol or sodium formate as radical scavengers. METHODS: RAW264.7 mouse macrophages were exposed to HEMA (0-6-8mM) in the presence of tempol (0-0...
November 22, 2016: Dental Materials: Official Publication of the Academy of Dental Materials
Carla Luzia Borges Reis, Lorena Mara Alexandre E Silva, Tigressa Helena Soares Rodrigues, Anne Kamilly Nogueira Félix, Rílvia Saraiva de Santiago-Aguiar, Kirley Marques Canuto, Maria Valderez Ponte Rocha
To enhance the enzymatic digestibility of cashew apple bagasse (CAB) feedstock in order to produce sugar fermentation-derived bioproducts, the CAB was subjected to three different pretreatments with the ionic liquid 2-hydroxyl-ethylammonium acetate (2-HEAA) and characterized by FTIR, NMR and chemical methods. All conditions were able to delignify CAB, however the best lignin removal (95.8%) was achieved through the method performed with 8.7% w/w of CAB/2-HEAA ratio at 130°C for 24h. Although the cellulose crystallinity has been increased in CAB treated with the ionic liquid, but this fact did not influence its digestibility...
November 8, 2016: Bioresource Technology
Amin Bornadel, Mohamed Ismail, Mahmoud Sayed, Rajni Hatti-Kaul, Sang-Hyun Pyo
Six-membered cyclic carbonates with hydroxyl and methoxycarbonyloxy functional groups were prepared by transesterification of trimethylolpropane (TMP) with dimethylcarbonate (DMC) by solvent-free lipase-mediated flow reaction followed by thermal cyclization. The flow reaction efficiency was evaluated using different configurations of reactor consisting of packed beds of Novozym®435 (immobilized Candida antarctica lipase B-CalB-a.k.a. N435) and molecular sieves, flowrate, and biocatalyst loads. The mixed column of the biocatalyst and molecular sieves, allowing rapid and efficient removal of the by-product-methanol-was the most efficient setup...
November 14, 2016: Biotechnology Progress
Yasaman Heidari, Graeme W Howe, Ronald Kluger
It has previously been established that the deprotonated amino substituent of the pyrimidine of thiamin diphosphate (ThDP) acts as an internal base to accept the C2H of the thiazolium in ThDP-dependent enzymes. The amino group has also been implicated in assisting the departure of the aldehydic product formed after loss of CO2 from ketoacid substrates. However, the potential role for the pyrimidine amino group in the key decarboxylation step has not been assessed. Oxythiamin contains a hydroxyl group in place of the pyrimidine amino group in thiamin, providing a basis for comparison of reactivity...
October 31, 2016: Bioorganic Chemistry
Fabian A Grimm, Hans-Joachim Lehmler, Wen Xin Koh, Jeanne DeWall, Lynn M Teesch, Keri C Hornbuckle, Peter S Thorne, Larry W Robertson, Michael W Duffel
Despite increasing evidence for a major role for sulfation in the metabolism of lower-chlorinated polychlorinated biphenyls in vitro and in vivo, and initial evidence for potential bioactivities of the resulting sulfate ester metabolites, the formation of PCB sulfates in PCB exposed human populations had not been explored. The primary goal of this study was to determine if PCB sulfates, and potentially other conjugated PCB derivatives, are relevant classes of PCB metabolites in the serum of humans with known exposures to PCBs...
January 2017: Environment International
Romel Dator, Andrea Carrà, Laura Maertens, Valeria Guidolin, Peter W Villalta, Silvia Balbo
Reactive carbonyl compounds (RCCs) are ubiquitous in the environment and are generated endogenously as a result of various physiological and pathological processes. These compounds can react with biological molecules inducing deleterious processes believed to be at the basis of their toxic effects. Several of these compounds are implicated in neurotoxic processes, aging disorders, and cancer. Therefore, a method characterizing exposures to these chemicals will provide insights into how they may influence overall health and contribute to disease pathogenesis...
October 26, 2016: Journal of the American Society for Mass Spectrometry
Athanasios Athanasiadis, Clare Fitzgerald, Nicholas M Davidson, Chiara Giorio, Stanley W Botchway, Andrew D Ward, Markus Kalberer, Francis D Pope, Marina K Kuimova
Organic aerosols (OAs) play important roles in multiple atmospheric processes, including climate change, and can impact human health. The physico-chemical properties of OAs are important for all these processes and can evolve through reactions with various atmospheric components, including oxidants. The dynamic nature of these reactions makes it challenging to obtain a true representation of their composition and surface chemistry. Here we investigate the microscopic viscosity of the model OA composed of squalene, undergoing chemical aging...
October 26, 2016: Physical Chemistry Chemical Physics: PCCP
R Rohaizu, W D Wanrosli
Highly stable and dispersible nanocrystalline cellulose (NCC) was successfully isolated from oil palm empty fruit bunch microcrystalline cellulose (OPEFB-MCC), with yields of 93% via a sono-assisted TEMPO-oxidation and a subsequent sonication process. The sono-assisted treatment has a remarkable effect, resulting in an increase of more than 100% in the carboxylate content and a significant increase of approximately 39% in yield compared with the non-assisted process. TEM images reveal the OPEFB-NCC to have rod-like crystalline morphology with an average length and width of 122 and 6nm, respectively...
January 2017: Ultrasonics Sonochemistry
Shima N N S Hashim, Lachlan J Schwarz, Basil Danylec, Mahesh K Potdar, Reinhard I Boysen, Milton T W Hearn
This investigation describes a general procedure for the selectivity mapping of molecularly imprinted polymers, using (E)-resveratrol-imprinted polymers as the exemplar, and polyphenolic compounds present in Pinot noir grape skin extracts as the test compounds. The procedure is based on the analysis of samples generated before and after solid-phase extraction of (E)-resveratrol and other polyphenols contained within the Pinot noir grape skins using (E)-resveratrol-imprinted polymers. Capillary reversed-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionisation tandem mass spectrometry (ESI MS/MS) was then employed for compound analysis and identification...
December 1, 2016: Talanta
Kyungtae Lee, Woojin Lee, Hyo Sug Lee, Jaikwang Shin, Jieun Park, Seongsuk Lee, Samjong Choi, Sueryeon Kim, Jinseong Kim, Youngseon Shim
The decomposition reactions of the Si precursor, diisopropylaminosilane (DIPAS), on W(110) and hydroxylated WO3(001) surfaces are investigated to elucidate the initial reaction mechanism of the atomic layer deposition (ALD) process using density functional theory (DFT) calculations combined with ab initio molecular dynamics (AIMD) simulations. The decomposition reaction of DIPAS on WO3(001) consists of two steps: Si-N dissociative chemisorption and decomposition of SiH3*. It is found that the Si-N bond cleavage of DIPAS is facile on WO3(001) due to hydrogen bonding between the surface OH group and the N atom of DIPAS...
October 12, 2016: Physical Chemistry Chemical Physics: PCCP
A Rugor, M Tataruch, J Staroń, A Dudzik, E Niedzialkowska, P Nowak, A Hogendorf, A Michalik-Zym, D B Napruszewska, A Jarzębski, K Szymańska, W Białas, M Szaleniec
Steroid C25 dehydrogenase (S25DH) from Sterolibacterium denitrificans Chol-1S is a molybdenum oxidoreductase belonging to the so-called ethylbenzene dehydrogenase (EBDH)-like subclass of DMSO reductases capable of the regioselective hydroxylation of cholesterol or cholecalciferol to 25-hydroxy products. Both products are important biologically active molecules: 25-hydroxycholesterol is responsible for a complex regulatory function in the immunological system, while 25-hydroxycholecalciferol (calcifediol) is the activated form of vitamin D3 used in the treatment of rickets and other calcium disorders...
October 11, 2016: Applied Microbiology and Biotechnology
Annewieke J W Verloop, Jean-Paul Vincken, Harry Gruppen
Formation of black tea thearubigins involves at least two of the following oxidation steps: (i) oligomerization, (ii) rearrangement, (iii) hydroxylation. The first two are mainly catalysed by polyphenol oxidase(PPO), whereas the enzyme responsible for hydroxylation has not yet been identified. Two main oxidative activities, peroxidase(POD) and PPO, occur in tea leaves. POD was hypothesized to be responsible for hydroxylation. Model systems with horseradish POD and mushroom tyrosinase were used investigating hydroxylation of theaflavins(TF)...
October 10, 2016: Journal of Agricultural and Food Chemistry
Ayan Pal, Rajat S Das, Weicheng Zhang, Megan Lang, Larry W McLaughlin, Jack W Szostak
The significance of the precise position of the hydroxyl at the 3'-end of an RNA primer for nonenzymatic template-directed primer extension is not well understood. We show that an RNA primer terminating in 3'-hydroxymethyl-2',3'-dideoxy-guanosine has greatly diminished activity, suggesting that the spatial preorganization of the terminal sugar contributes significantly to the efficiency of primer extension.
September 29, 2016: Chemical Communications: Chem Comm
Charles W Schindler, Eric B Thorndike, Masaki Suzuki, Kenner C Rice, Michael H Baumann
BACKGROUND AND PURPOSE: 3,4-Methylenedioxypyrovalerone (MDPV) is a synthetic cathinone with stimulatory cardiovascular effects that can lead to serious medical complications. Here, we examined the pharmacological mechanisms underlying these cardiovascular actions of MDPV in conscious rats. EXPERIMENTAL APPROACH: Male Sprague-Dawley rats had telemetry transmitters surgically implanted for the measurement of BP and heart rate (HR). On test days, rats were placed individually in standard isolation cubicles...
December 2016: British Journal of Pharmacology
Mingxing Qian, Elizabeth B Engler-Chiurazzi, Sara E Lewis, Nigam P Rath, James W Simpkins, Douglas F Covey
Estrone and 17β-estradiol are phenolic steroids that are known to be neuroprotective in multiple models of neuronal injury. Previous studies have identified the importance of their phenolic steroid A-ring for neuroprotection and have identified ortho substituents at the C-2 and C-4 positions on the phenol ring that enhance this activity. To investigate the importance of the steroid ring system for neuroprotective activity, phenolic compounds having the cyclopent[b]anthracene, cyclopenta[b]phenanthrene, benz[f]indene, benz[e]indene, indenes linked to a phenol, and a phenolic spiro ring system were prepared...
October 18, 2016: Organic & Biomolecular Chemistry
Tom H Wright, Ben J Bower, Justin M Chalker, Gonçalo J L Bernardes, Rafal Wiewiora, Wai-Lung Ng, Ritu Raj, Sarah Faulkner, M Robert J Vallée, Anuchit Phanumartwiwath, Oliver D Coleman, Marie-Laëtitia Thézénas, Maola Khan, Sébastien R G Galan, Lukas Lercher, Matthew W Schombs, Stefanie Gerstberger, Maria E Palm-Espling, Andrew J Baldwin, Benedikt M Kessler, Timothy D W Claridge, Shabaz Mohammed, Benjamin G Davis
Posttranslational modification of proteins expands their structural and functional capabilities beyond those directly specified by the genetic code. However, the vast diversity of chemically-plausible (including unnatural but functionally relevant) side-chains is not readily accessible. We describe C (sp(3))-C (sp(3)) bond-forming reactions on proteins under biocompatible conditions, which exploit unusual carbon free radical chemistry, and use them to form Cβ-Cγ bonds with altered side chains. We demonstrate how these transformations enable a wide-diversity of natural, unnatural, posttranslationally-modified (methylated, glycosylated, phosphorylated, hydroxylated) and labeled (fluorinated, isotopically-labeled) side-chains to be added to a common, readily-accessible dehydroalanine precursor in a range of representative protein types and scaffolds...
September 22, 2016: Science
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"