bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regio‐ and Stereospecific O‐Glycosylation of Phenolic Compounds Catalyzed by a Fungal Glycosyltransferase from Mucor hiemalis
Authors: Feng Jin , Zhang Peng , Cui Yinglu , Li Kai , Qiao Xue , Zhang Ying‐Tao , Li Shu‐Ming , Cox Russell J. , Wu Bian , Ye Min , Yin Wen‐Bing 
Published: February 2017

AbstractGlycosylated small molecules are often bioactive and obtained mainly via microbial biotransformation especially by fungi. However, no responsible glycosylation gene/enzyme has yet been uncovered in a filamentous fungus. We report here the first identification of a phenolic glycosyltransferase MhGT1 from Mucor hiemalis. The substrate promiscuity of the new phenolic O‐glycosyltransferase was explored by using phenols from Traditional Chinese Medicinal herbs as substrates. MhGT1 exhibited robust capabilities for the regio‐ and stereospecific O‐glycosylation of 72 structurally diverse drug‐like scaffolds and sterols with uridine diphosphate (UDP) glucose as a sugar donor. Unprecedentedly, MhGT1 showed higher regiospecificities and activities for prenylated phenols than for their non‐prenylated analogues. Computational modelling of MhGT1 uncovered a truncated N‐terminal domain of the enzyme consisting of hydrophobic and charged amino acid residues which contributed to the broad substrate scope and regiospecificity towards prenylated compounds. Our findings expand the ways to obtain new glycosyltransferases and also effectively apply the enzymatic approach to obtain glycosylated compounds in drug discovery.magnified image
Ferrocenylindium Reagents in Palladium‐Catalyzed Cross‐Coupling Reactions: Asymmetric Synthesis of Planar Chiral 2‐Aryl Oxazolyl and Sulfinyl Ferrocenes
Authors: Mato Mauro , Pérez‐Caaveiro Cristina , Sarandeses Luis A. , Pérez Sestelo José 
Published: February 2017

AbstractThe preparation of ferrocenylindium species and palladium‐catalyzed cross‐coupling reactions for the synthesis of monosubstituted and planar chiral 1,2‐disubstituted ferrocenes is described. Triferrocenylindium reagents (Fc3In) are efficiently prepared in a one‐pot procedure from ferrocenes by lithiation and transmetallation to indium using InCl3. The palladium‐catalyzed cross‐coupling reactions of Fc3In (40 mol%) with a variety of organic electrophiles (aryl, heteroaryl, benzyl, alkenyl and acyl halides) in THF at 80 °C overnight provided a wide variety of monosubstituted ferrocenes in good to excellent yields. This methodology allowed the stereoselective synthesis of planar chiral 2‐aryl‐1‐oxazolylferrocenes and 2‐aryl‐1‐sulfinylferrocenes, which are of interest in asymmetric catalysis.magnified image
Heteroring‐Annulated Pyrrolino‐Tetrahydroberberine Analogues
Authors: Mari Giacomo , Crescentini Lucia De , Favi Gianfranco , Lombardi Paolo , Fiorillo Gaetano , Giorgi Gianluca , Mantellini Fabio 
Published: February 2017

AbstractA facile method for the synthesis of pyrrolino‐tetrahydroberberine derivatives starting from 1,2‐diaza‐1,3‐dienes and dihydroberberines is reported. The synthesis is a cascade reaction involving a Michael‐type addition of the enamine moiety of dihydroberberine to an azo‐ene system, followed by nitrogen cyclization on the resulting iminium ion.
Template‐Assisted meta‐C−H Alkylation and Alkenylation of Arenes
Authors: Bag Sukdev , Jayarajan Ramasamy , Mondal Rahul , Maiti Debabrata 
Published: February 2017

AbstractTo expand the scope of meta‐functionalization, a pyrimidine‐based template effective for the formation of β‐aryl aldehydes and ketones, using allyl alcohols, by meta‐C−H activation of benzylsulfonyl esters is described. In addition, α,β‐unsaturated aldehydes were generated by in situ olefination and deprotection of allyl benzyl ethers. These new functionalizations at the meta‐position of an arene have also been successfully implemented in benzylphosphonate, phenethyl carbonyl, and phenethylsulfonyl ester scaffolds. Key to these successful new functionalizations is the creation of an electropositive palladium center by accepting the electron cloud from the metal to the energetically low‐lying π‐orbitals of pyrimidine ring, and it favors coordination of allyl alcohol to the metal center.
Determining the Origin of Rate‐Independent Chemoselectivity in CuAAC Reactions: An Alkyne‐Specific Shift in Rate‐Determining Step
Authors: Seath Ciaran P. , Burley Glenn A. , Watson Allan J. B. 
Published: February 2017

AbstractWe report a kinetic and spectroscopic analysis of alkyne‐dependent chemoselectivity in the copper‐catalyzed azide–alkyne click (CuAAC) reaction. Studies of six alkyne subtypes reveal that the rate‐determining step (RDS) of an aromatic ynamine class is shifted from acetylide formation to the azide ligation/migratory insertion event allowing chemoselectivity independent of overall rate.
Polyurethane adhesives containing Diels–Alder‐based thermoreversible bonds
Authors: Turkenburg Daniël Hendrik , van Bracht Henk , Funke Björn , Schmider Martin , Janke Doreen , Fischer Hartmut Rudolf 
Published: February 2017

ABSTRACTA facile two‐step process is developed to obtain polyester urethanes that contain various concentrations of thermoreversible Diels–Alder adduct–based bonds for the development of adhesives. Besides linear systems thermoreversible networks have been included in the study. The reactions are verified using IR‐spectroscopy and gel permeation chromatography analysis. The material properties are characterized with solvent exposure tests, dynamic scanning calorimetry, microindentation and rheology and the potential for application as adhesives is tested with an elcometer. Material properties have been found highly tunable for the system, and high adhesive strengths (off‐scale) are found for polyester urethanes that are doped with an intermediate level Diels–Alder functional groups. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44972.
Localization patterns of dopamine active transporter synthesizing cells during development of brine shrimp
Authors: Kim Bo Yong , Shin Gyeong Hee , Lee In Soo , Kim Suhng Wook , Kim Ho Seung , Kim Jin Kwan , Lee Seung Gwan 
Published: February 2017

AbstractThere have been many studies on dopamine active transporter (DAT) in humans and laboratory animals; however, there is a lack of information on DAT in brine shrimp. In this study, we demonstrated the neuronal and nonneuronal characteristics of DAT‐synthesizing (DAT+ cells) during development of brine shrimp. In neuronal cells, the DAT+ neurons in the central body and lobes of a protocerebrum (PC) controlled the deutocerebrum. The sensory cells of nauplius eyes projected their decussated axons to the PC, and the DAT+ cells at the posterior region were associated with migration and control of the 10 posterior neurons during the early nauplius stage. In nonneuronal cells, the five types of glands, that is, the salt, antennal, mandible, and accessory glands and posterior gland1 and gland2 synthesized DAT protein. In addition, the gut and rectum dilator muscles and renal cells expressed DAT protein. Thus, DAT protein acts in the development of several types of cells during development of brine shrimp.
Tetrabutylammonium Salts of Aluminum(III) and Gallium(III) Phthalocyanine Radical Anions Bonded with Fluoren‐9‐olato− Anions and Indium(III) Phthalocyanine Bromide Radical Anions
Authors: Konarev Dmitri V. , Khasanov Salavat S. , Ishikawa Manabu , Nakano Yoshiaki , Otsuka Akihiro , Yamochi Hideki , Saito Gunzi , Lyubovskaya Rimma N. 
Published: February 2017

AbstractReduction of aluminum(III), gallium(III), and indium(III) phthalocyanine chlorides by sodium fluorenone ketyl in the presence of tetrabutylammonium cations yielded crystalline salts of the type (Bu4N+)2[MIII(HFl−O−)(Pc.3−)].−(Br−)⋅1.5 C6H4Cl2 [M=Al (1), Ga (2); HFl−O−=fluoren‐9‐olato− anion; Pc=phthalocyanine] and (Bu4N+) [InIIIBr(Pc.3−)].−⋅0.875 C6H4Cl2⋅0.125 C6H14 (3). The salts were found to contain Pc.3− radical anions with negatively charged phthalocyanine macrocycles, as evidenced by the presence of intense bands of Pc.3− in the near‐IR region and a noticeable blueshift in both the Q and Soret bands of phthalocyanine. The metal(III) atoms coordinate HFl−O− anions in 1 and 2 with short Al−O and Ga−O bond lengths of 1.749(2) and 1.836(6) Å, respectively. The C−O bonds [1.402(3) and 1.391(11) Å in 1 and 2, respectively] in the HFl−O− anions are longer than the same bond in the fluorenone ketyl (1.27–1.31 Å). Salts 1–3 show effective magnetic moments of 1.72, 1.66, and 1.79 μB at 300 K, respectively, owing to the presence of unpaired S=1/2 spins on Pc.3−. These spins are coupled antiferromagnetically with Weiss temperatures of −22, −14, and −30 K for 1–3, respectively. Coupling can occur in the corrugated two‐dimensional phthalocyanine layers of 1 and 2 with an exchange interaction of J/kB=−0.9 and −1.1 K, respectively, and in the π‐stacking {[InIIIBr(Pc.3−)].−}2 dimers of 3 with an exchange interaction of J/kB=−10.8 K. The salts show intense electron paramagnetic resonance (EPR) signals attributed to Pc.3−. It was found that increasing the size of the central metal atom strongly broadened these EPR signals.
Pharmacokinetic interactions in mice between irinotecan and MBL‐II‐141, an ABCG2 inhibitor
Authors: Hénin Emilie , Honorat Mylène , Guitton Jérôme , Di Pietro Attilio , Payen Léa , Tod Michel 
Published: February 2017

AbstractPurpose. The chromone derivative MBL‐II‐141, specifically designed to inhibit ABCG2, was previously demonstrated to combine strong inhibition potency, low toxicity and good efficiency in reversing resistance to irinotecan in a xenografted mouse model. Here, the pharmacokinetic interactions in mice between irinotecan, its active metabolite SN‐38 and MBL‐II‐141 were characterized quantitatively in the blood and in the brain. Methods. Compartmental models were used to fit the data. Goodness‐of‐fit was assessed by simulation‐based diagnostic tools. Results. Irinotecan increased the MBL‐II‐141 apparent clearance and Vss 1.5‐fold, probably by increasing the MBL‐II‐141 unbound fraction. MBL‐II‐141 decreased the total apparent clearance of irinotecan by 23%, by decreasing its biliary clearance. MBL‐II‐141 increased 3‐fold the brain accumulation of irinotecan, as a result of the rise of systemic exposure combined with the inhibition of ABCG2‐mediated efflux at the blood–brain barrier. Finally, SN‐38 exposure was increased by 1.16‐fold under treatment with MBL‐II‐141, owing to the higher irinotecan exposure with increased metabolism towards the formation of SN‐38. Conclusions. These results may help to anticipate the pharmacokinetic interactions between MBL‐II‐141 and other ABCG2 substrates. The irinotecan‐MBL‐II‐141 interaction is also expected to occur in humans. Copyright © 2017 John Wiley & Sons, Ltd.
Optimization of intestinal microsomal preparation in the rat: A systematic approach to assess the influence of various methodologies on metabolic activity and scaling factors
Authors: Hatley Oliver J.D. , Jones Christopher R. , Galetin Aleksandra , Rostami‐Hodjegan Amin 
Published: February 2017

AbstractThe metabolic capacity of the intestine and its importance as the initial barrier to systemic exposure can lead to underestimation of first‐pass, and thus overestimation of oral bioavailability. However, the in vitro tools informing estimates of in vivo intestinal metabolism are limited by the complexity of the in vitro matrix preparation and uncertainty with the scaling factors for in vitro to in vivo extrapolation. A number of methods currently exist in the literature for the preparation of intestinal microsomes; however, the impact of key steps in the preparation procedure has not been critically assessed. In the current study, changes in enterocyte isolation, the impact of buffer constituents heparin and glycerol, as well as sonication as a direct method of homogenization were assessed systematically. Furthermore, fresh vs. frozen tissue samples and the impact of microsome freeze thawing was assessed. The rat intestinal microsomes were characterized for CYP content as well as metabolic activity using testosterone and 4‐nitropheonol as probes for CYP and UGT activity, respectively. Comparisons in metabolic activity and scaled unbound intestinal intrinsic clearance (CLintu,gut) were made to commercially available microsomes using 25 drugs with a diverse range of metabolic pathways and intestinal metabolic stabilities. An optimal, robust and reproducible microsomal preparation method for investigation of intestinal metabolism is proposed. The importance of characterization of the in vitro matrix and the potential impact of intestinal scaling factors on the in vitro–in vivo extrapolation of FG needs to be investigated further. © 2017 The Authors Biopharmaceutics & Drug Disposition Published by John Wiley & Sons Ltd.
Stability studies of potent opioid analgesic, morphine‐6‐O‐sulfate in various buffers and biological matrices by HPLC‐DAD analysis
Authors: Yadlapalli Jai Shankar K. , Albayati Zaineb A.F. , Penthala Narasimha R. , Hendrickson Howard P. , Crooks Peter A. 
Published: February 2017

AbstractThe 6‐O‐sulfate ester of morphine (M6S) has previously been shown to be an analgesic with greater potency and fewer side effects than morphine. However, being a sulfate ester derivative of morphine, the question exists as to whether this compound is stable in biological fluids and tissues with regard to pH‐ and esterase‐mediated degradation. To date, no studies have focused on the stability profile of M6S across the physiologically relevant pH range of 1.2–7.4. In addition, the stability of M6S is not known in rat plasma and rat brain homogenate, or in simulated rat gastric and intestinal fluids. This study determines the stability profile of M6S (utilized as the sodium salt) and demonstrates that M6S is highly stable and resilient to either enzymatic‐ or pH‐dependent hydrolysis in vitro.
Development and qualification of an LC–MS/MS method for investigating the biological implications of micelle entrapped paclitaxel in cell culture and rats
Authors: Kaddoumi Amal , Gill Kanwaldeep K. , Elfakhri Khaled , Nazzal Sami 
Published: February 2017

AbstractPaclitaxel is a front‐line antineoplastic drug used in chemotherapeutic modalities for treatment of various types of malignancies. However, its efficacy is limited by dose‐related toxicities. In this study, we have explored two important biological aspects of entrapping paclitaxel in PEG2000‐DSPE micelles. First, we evaluated the impact of this micellar delivery system on P‐glycoprotein (P‐gp)–paclitaxel interaction, and we investigated differences in plasma pharmacokinetics of free and micelle‐entrapped paclitaxel. For quantification of paclitaxel, an LC–MS/MS method was developed. Paclitaxel was extracted from samples using a simple one‐step protein precipitation. Chromatographic conditions included a C18 column with a mobile phase consisting of 0.1% formic acid in acetonitrile–water (60:40, v/v) pumped at 1 mL/min. The lower limit of quantitation in both plasma and cell lysate was 1.0 ng/mL. The quantitative linear range was 1–1000 ng/mL. In addition, P‐gp efflux studies on free and micellar paclitaxel showed the proficiency of PEG2000‐DSPE micelles in evading P‐gp‐mediated efflux, thus increasing paclitaxel uptake. Furthermore, the micellar paclitaxel levels were maintained in the body for longer time as compared with taxol, which is desirable for increasing the efficacy of paclitaxel in cancer treatment.
Simultaneous determination of the bioactive components in rat plasma by UPLC‐MS/MS and application in pharmacokinetic studies after oral administration of radix Scutellariae extract
Authors: Tao Jin‐Hua , Xu Jun , Jiang Shu , Ling Yong , Wang Dong‐Geng 
Published: February 2017

AbstractA highly sensitive and rapid ultraperformance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method has been developed and validated for simultaneous quantification of the four main bioactive compounds, i.e. baicalin, baicalein, wogonoside and wogonin, in rat plasma after oral administration of Radix Scutellariae extract. Clarithromycin was used as an internal standard (IS). Plasma samples were processed by protein precipitation with methanol. The separation was performed on an Acquity BEH C18 column (100 × 2.1 mm, 1.7 μm) at a flow rate of 0.4 mL/min, using 0.1% formic acid–acetonitrile as mobile phase. The MS/MS ion transit ions monitored were 447.5 → 270.1 for baicalin, 270.1 → 168.1 for baicalein, 461.2 → 284.0 for wogonoside, 284.2 → 168.1 for wogonin and 748.5 → 158.1 for IS. Method validation was performed according to US Food and Drug Administration guidelines and the results met the acceptance criteria. The lower limit of quantification (LLOQ) achieved was 1.13 ng/mL for baicalin, 1.23 ng/mL for baicalein, 0.82 ng/mL for wogonoside and 0.36 ng/mL for wogonin. The calibration curves obtained were linear (r > 0.99) over the concentration range ~ 1–1000 ng/mL. The intra‐ and inter‐day precision was <15% and the accuracy was within ±14.7%. After validation, this method was successfully applied to a pharmacokinetic study of Radix Scutellariae extract.
A method for independent component graph analysis of resting‐state fMRI
Authors: Ribeiro de Paula Demetrius , Ziegler Erik , Abeyasinghe Pubuditha M. , Das Tushar K. , Cavaliere Carlo , Aiello Marco , Heine Lizette , di Perri Carol , Demertzi Athena , Noirhomme Quentin , Charland‐Verville Vanessa , Vanhaudenhuyse Audrey , Stender Johan , Gomez Francisco , Tshibanda Jean‐Flory L. , Laureys Steven , Owen Adrian M. , Soddu Andrea 
Published: February 2017

AbstractIntroductionIndependent component analysis (ICA) has been extensively used for reducing task‐free BOLD fMRI recordings into spatial maps and their associated time‐courses. The spatially identified independent components can be considered as intrinsic connectivity networks (ICNs) of non‐contiguous regions. To date, the spatial patterns of the networks have been analyzed with techniques developed for volumetric data.ObjectiveHere, we detail a graph building technique that allows these ICNs to be analyzed with graph theory.MethodsFirst, ICA was performed at the single‐subject level in 15 healthy volunteers using a 3T MRI scanner. The identification of nine networks was performed by a multiple‐template matching procedure and a subsequent component classification based on the network “neuronal” properties. Second, for each of the identified networks, the nodes were defined as 1,015 anatomically parcellated regions. Third, between‐node functional connectivity was established by building edge weights for each networks. Group‐level graph analysis was finally performed for each network and compared to the classical network.ResultsNetwork graph comparison between the classically constructed network and the nine networks showed significant differences in the auditory and visual medial networks with regard to the average degree and the number of edges, while the visual lateral network showed a significant difference in the small‐worldness.ConclusionsThis novel approach permits us to take advantage of the well‐recognized power of ICA in BOLD signal decomposition and, at the same time, to make use of well‐established graph measures to evaluate connectivity differences. Moreover, by providing a graph for each separate network, it can offer the possibility to extract graph measures in a specific way for each network. This increased specificity could be relevant for studying pathological brain activity or altered states of consciousness as induced by anesthesia or sleep, where specific networks are known to be altered in different strength.
Motor unit potentials of the erector spinae muscle by concentric needle electromyography
Authors: Posa Andreas , Niśkiewicz Izabela , Emmer Alexander , Kluge Yorck , Kornhuber Malte E. 
Published: February 2017

AbstractIntroductionThe needle electromyography (EMG) serves to supply additional information in patients with suspected neuromuscular disorders. We aimed to provide motor unit potential (MUP) data by concentric needle EMG in the erector spinae (ES) in comparison with biceps brachii (BB) and lateral vastus (LV).MethodsElectromyography MUP data (n) were obtained in ES (517), BB (539), and LV (627) in 32 healthy volunteers (16f).ResultsMotor unit potential data: amplitude (μV) 393 ± 174 (ES), 375 ± 162 (BB), and 577 ± 304 (LV); duration (ms) 10.4 ± 2.4 (ES), 10.1 ± 2.1 (BB), and 11.1 ± 2.3 (LV), area (μV × ms) 585 ± 327 (ES), 538 ± 267 (BB), and 881 ± 492 (LV); phase number 3.23 ± 0.94 (ES), 2.98 ± 0.76 (BB), and 3.19 ± 0.81 (LV); size index 0.60 ± 0.56 (ES), 0.51 ± 0.53 (BB), and 0.96 ± 0.55 (LV). LV displayed higher values (p at least <.001) for MUP amplitude, duration, area, and size index as compared to both, BB and ES.ConclusionConcentric needle EMG investigations in healthy adult human subjects revealed similar MUP parameters in the ES and BB muscles, while in the LV muscle MUP amplitude, duration, area, and size index were significantly larger. Different neuromuscular disorders display a predominant involvement of proximally located muscles such as truncal muscles. The present results given here may facilitate the diagnosis of neuromuscular disorders.
The Lababidi Procedure
Authors: Hagler Donald J. 
Published: February 2017

Key Points

Long‐term risk of mortality, aortic insufficiency, and aortic valve replacement (AVR) reintervention are the objectives of the report.
They discuss how this may impact our congenital interventional practice questioning which risk factors may be modifiable.
Should the interventionalist be satisfied with a residual gradient of 30–35mm Hg and mild AR in the neonate?
Xylitol Hydrogenolysis over Ruthenium‐Based Catalysts: Effect of Alkaline Promoters and Basic Oxide‐Modified Catalysts
Authors: Rivière Maxime , Perret Noémie , Cabiac Amandine , Delcroix Damien , Pinel Catherine , Besson Michèle 
Published: February 2017

AbstractThe aqueous‐phase hydrogenolysis of xylitol into glycols over Ru/C was performed in the presence and absence of a wide range of concentrations of Ca(OH)2 to investigate the reaction pathway. Without base, epimerization and cascade decarbonylation were the predominant reactions with high selectivities to C5 and C4 alditols and light alkanes at full conversion. Glycol production was obtained by the addition of Ca(OH)2 to promote the retro‐aldol reaction. It competed with reactions without base and became the main reaction for a OH−/ xylitol molar ratio Rmol(OH/xylitol) of 0.13, and high selectivities to glycols (56 %) and glycerol (16 %) were observed. However, lactate was a byproduct at up to 27 % with a high base amount (Rmol(OH/xylitol)=0.68). Bifunctional Ru/metal oxide/C catalysts (metal: Zn, Sn, Mn, Sr, W) were synthesized and were able to cleave the C−C bond into glycols without a base promoter. The 3.1 wt %Ru/MnO(4.5 %)/C catalyst was the most active (220 h−1) with reasonable selectivity to glycols (22 %) and glycerol (10 %) and a low production of lactate (<1 %). Nevertheless, metal oxide leaching of the catalyst was observed likely because of the production of traces of lactate.
Sol‐Gel Synthesis of Carbon‐Coated LaCoO3 for Effective Electrocatalytic Oxidation of Salicylic Acid
Authors: Sivakumar Mani , Sakthivel Mani , Chen Shen‐Ming , Veerakumar Pitchaimani , Liu Shang‐Bin 
Published: February 2017

AbstractThe electrooxidative activity of a carbon‐coated LaCoO3 (C@LaCoO3) composite material, prepared by using a facile sol‐gel method with citric acid as the carbon precursor, was investigated. The as‐prepared C@LaCoO3 material was characterized by using a variety of different physicochemical techniques, including XRD, SEM, EDX, EIS, and FTIR spectroscopy, which revealed effective coating of carbon on the surfaces of the metal oxide with a well‐defined structure, high crystallinity, and low‐transfer resistance. Based on the results obtained from cyclic voltammetry and amperometric techniques, the C@LaCoO3‐modified electrode was found to exhibit extraordinary electrocatalytic activity for oxidation of salicylic acid with a desirable linear range, sensitivity, and detection limit of 0.0005–2.44 mM, 250.59 μA μM− cm−2, and 0.05 μM, respectively, rendering practical applications for real samples analysis.