bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collagenase produced from Aspergillus sp. (UCP 1276) using chicken feather industrial residue
Authors: Ferreira Catarina Michelle Oliveira , Correia Patyanne Carvalho , Brandão‐Costa Romero Marcos Pedrosa , Albuquerque Wendell Wagner Campos , Lin Liu Tatiana Pereira Shin , Campos‐Takaki Galba Maria , Porto Ana Lúcia Figueiredo 
Published: November 2016

AbstractAn extracellular collagenolytic serine protease was purified from Aspergillus sp., isolated from the Caatinga biome in northeast Brazil by a two‐step chromatographic procedure, using an anion‐exchanger and gel filtration. The enzyme was produced by submerged fermentation of feather residue as a substrate. The purified collagenase showed a 2.09‐fold increase in specific activity and 22.85% yield. The enzyme was a monomeric protein with a molecular mass of 28.7 kDa, estimated by an SDS–PAGE and AKTA system. The optimum temperature and pH for enzyme activity were around 40°C and pH 8.0, respectively. The enzyme was strongly inhibited by phenyl‐methylsulfonyl fluoride, a serine protease inhibitor, and was thermostable until 65°C for 1 h. We then evaluated the enzyme's potential for degradation of Type I and Type V collagens for producing peptides with antifungal activity. Our results revealed that the cleavage of Type V collagen yielded more effective peptides than Type I, inhibiting growth of Aspergillus terreus, Aspergillus japonicus and Aspergillus parasiticus. Both groups of peptides (Type I and Type V) were identified by SDS–PAGE. To conclude, the thermostable collagenase we purified in this study has various potentially useful applications in the fields of biochemistry, biotechnology and biomedical sciences.
Bioequivalence study between a fixed‐dose single‐pill formulation of nebivolol plus hydrochlorothiazide and separate formulations in healthy subjects using high‐performance liquid chromatography coupled to tandem mass spectrometry
Authors: Vespasiano Celso Francisco Pimentel , Laurito Tiago Luders , Iwamoto Renan Donomae , Moreno Ronilson Agnaldo , Mendes Gustavo D. , De Nucci Gilberto 
Published: November 2016

AbstractSystemic arterial hypertension is a major risk factor for cerebrovascular disease. Therefore, adequate control of blood pressure is of enormous importance. One of the many fixed‐dose single‐pill antihypertensive formulations available on the market is the combination of nebivolol and hydrochlorothiazide. The objective of this study was to develop two distinct high‐performance liquid chromatography coupled to tandem mass spectrometry methods to simultaneously quantify nebivolol and hydrochlorothiazide in human plasma. The methods were employed in a bioequivalence study, the first assay involving a nebivolol fixed‐dose single‐pill formulation based on healthy Brazilian volunteers. Nebilet HCT™ (nebivolol 5 mg + hydrochlorothiazide 12.5 mg tablet, manufactured by Menarini) was the test formulation. The reference formulations were Nebilet™ (nebivolol 5 mg tablet, manufactured by Menarini) and Clorana™ (hydrochlorothiazide 25 mg tablet, manufactured by Sanofi). For both analytes, liquid–liquid extraction was employed for sample preparation and the chromatographic run time was 3.5 min. The limits of quantification validated were 0.02 ng/mL for nebivolol and 1 ng/mL for hydrochlorothiazide. Since the 90% CI for Cmax, AUC(0–last) and AUC(0–inf) individual test/reference ratios were within the 80–125% interval indicative of bioequivalence, it was concluded that Nebilet HCT™ is bioequivalent to Nebilet™ and Clorana™.
Synthesis and Electron Paramagnetic Resonance Studies of Oligodeoxynucleotides Containing 2‐N‐tert‐Butylaminoxyl‐2′‐deoxyadenosines
Authors: Kurita Manami , Higuchi Yoshitaka , Mirc JW , Matsumoto Shintaro , Usui Kazuteru , Suemune Hiroshi , Aso Mariko 
Published: November 2016

AbstractOligodeoxynucleotides (ODNs) containing 2‐N‐tert‐butylaminoxyl‐2′‐deoxyadenosine (A*) residues were synthesized to allow accurate monitoring of adenine motion by EPR spectroscopy through the agency of direct linkage of the acyclic aminoxyl group to the nucleobase, and EPR studies of the ODNs in single‐ and double‐stranded forms were performed. Upon duplex formation, peak broadening and decreases in peak height were observed in EPR spectra, and the synthesized ODNs were shown to be excellent monitors of hybridization. Comparison of peak height and the h1/h0 signal ratio provided information on the relative mobility of A* in duplexes with different stability. A second set of ODNs each containing two A* residues at different intervals and four dA residues were also synthesized. For these ODNs, correlations were observed between the EPR spectral shapes of the duplexes and the number of dA residues between A* residues, thus demonstrating the potential of A* residues in monitoring of the structures of nucleic acids.
Optimization of Caged Electrophiles for Improved Monitoring of Cysteine Reactivity in Living Cells
Authors: Abo Masahiro , Bak Daniel W. , Weerapana Eranthie 
Published: November 2016

AbstractCysteine residues play critical roles in protein function and are susceptible to numerous post‐translational modifications (PTMs) that serve to modulate the activity and localization of diverse proteins. Many of these PTMs are highly transient and labile, thus necessitating methods to study these modifications directly within the context of living cells. We previously reported a caged electrophilic probe, CBK1, that can be activated by UV for temporally controlled covalent modification of cysteine residues in living cells. To improve upon the number of cysteine residues identified in cellular cysteine‐profiling studies, the reactivity and uncaging efficiency of a panel of caged electrophiles were explored. We identified an optimized caged electrophilic probe, CIK4, that affords significantly improved coverage of cellular cysteine residues. The broader proteome coverage afforded by CIK4 renders it a useful tool for the biological investigation of cysteine‐reactivity changes and PTMs directly within living cells and highlights design elements that are critical to optimizing photoactivatable chemical probes for cellular labeling.
Acetic Acid Ketonization over Fe3O4/SiO2 for Pyrolysis Bio‐Oil Upgrading
Authors: Bennett James A. , Parlett Christopher M. A. , Isaacs Mark A. , Durndell Lee J. , Olivi Luca , Lee Adam F. , Wilson Karen 
Published: November 2016

AbstractA family of silica‐supported, magnetite nanoparticle catalysts was synthesised and investigated for continuous‐flow acetic acid ketonisation as a model pyrolysis bio‐oil upgrading reaction. The physico‐chemical properties of Fe3O4/SiO2 catalysts were characterised by using high‐resolution transmission electron microscopy, X‐ray absorption spectroscopy, X‐ray photo‐electron spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy, thermogravimetric analysis and porosimetry. The acid site densities were inversely proportional to the Fe3O4 particle size, although the acid strength and Lewis character were size‐invariant, and correlated with the specific activity for the vapour‐phase acetic ketonisation to acetone. A constant activation energy (∼110 kJ mol−1), turnover frequency (∼13 h−1) and selectivity to acetone of 60 % were observed for ketonisation across the catalyst series, which implies that Fe3O4 is the principal active component of Red Mud waste.
Essential Role of Electrode Materials in Electrochemiluminescence Applications
Authors: Valenti Giovanni , Fiorani Andrea , Li Haidong , Sojic Neso , Paolucci Francesco 
Published: November 2016

AbstractThe phenomenon of electrochemiluminescence (ECL) is luminescence triggered by electrochemical reactions at electrodes. Heterogeneous electron transfers are deeply dependent on electrode materials, therefore, besides the usual parameters, the right choice of the electrode is a crucial point to address properly in order to maximize the emission efficiency. Many different electrodes have been studied, from metallic platinum or gold through transparent indium‐doped tin oxide to carbon‐based electrodes, and others, such as paper‐based and boron‐doped diamond. This review summarizes results of ECL at different electrode surfaces, disclosing the relative advantages and disadvantages, with a particular attention to the reference Ru(bpy)32+/TPrA coreactant system. In other words, we offer an insight to recognize and select the optimal electrode material for the ECL systems of interest with particular emphasis on the biosensing applications.
Fine Sampling of the R→T Quaternary‐Structure Transition of a Tetrameric Hemoglobin
Authors: Vitagliano Luigi , Mazzarella Lelio , Merlino Antonello , Vergara Alessandro 
Published: November 2016

AbstractAlthough the end points of the functional transitions of tetrameric hemoglobins (Hbs) have been well characterized, atomic‐resolution data on R–T intermediate states are extremely limited. Herein, the X‐ray structures of two independent tetramers of the fully ligated carbomonoxy form of Trematomus newnesi hemoglobin (Hb1Tn) within the same crystal are described. These structures show peculiar features in the heme pocket, EF corner, and tertiary/quaternary structure. Distal histidine side chains have a propensity to swing out of the heme pocket and thus allow compression of the EF corner. In this rotameric state, the distal His group does not interact with the CO ligand, consistent with FTIR spectra recorded in solution. At the quaternary‐structure level, one tetramer is an intermediate R–T state, whereas the other assumes a T‐like structure. Altogether, the structures of these tetramers provide the best available atomic‐level picture of the R→T transition of vertebrate Hbs.
The Stability of α‐Hydroperoxyalkyl Radicals
Authors: Anglada Josep M. , Crehuet Ramon , Francisco Joseph S. 
Published: November 2016

AbstractHigh‐level ab initio and Born–Oppenheimer molecular dynamic calculations have been carried out on a series of hydroperoxyalkyl (α‐QOOH) radicals with the aim of investigating the stability and unimolecular decomposition mechanism into QO+OH of these species. Dissociation was shown to take place through rotation of the C−O(OH) bond rather than through elongation of the CO−OH bond. Through the C−O(OH) rotation, the unpaired electron of the radical overlaps with the electron density on the O−OH bond, and from this overlap the C=O π bond forms and the O−OH bond breaks spontaneously. The CH2OOH, CH(CH3)OOH, CH(OH)OOH, and α‐hydroperoxycycloheptadienyl radical were found to decompose spontaneously, but the CH(CHO)OOH has a decomposition energy barrier of 5.95 kcal mol−1owing to its steric and electronic features. The systems studied in this work provide the first insights into how structural and electronic effects govern the stabilizing influence on elusive α‐QOOH radicals.
Direct Catalytic Hydrogenation of Simple Amides: A Highly Efficient Approach from Amides to Amines and Alcohols
Authors: Shi Liyang , Tan Xuefeng , Long Jiao , Xiong Xiong , Yang Song , Xue Peng , Lv Hui , Zhang Xumu 
Published: November 2016

AbstractA highly chemoselective and reactive direct catalytic reduction of various amides to amines and alcohols was developed by using a tetradentate ruthenium complex. The catalytic system showed excellent activity (turnover numbers up to 19 600) and great functional group tolerance under mild reaction conditions, compared to several bidentate and tridentate ruthenium‐catalyzed systems.
ChemInform Abstract: NdBaScO4: Aristotype of a New Family of Geometric Ferroelectrics?
Authors: Cochrane Amber K. , Telfer Michael , Dixon Charlotte A. L. , Zhang Weiguo , Halasyamani P. Shiv , Bousquet Eric , Lightfoot Philip 
Published: November 2016

AbstractThe compounds LnBaScO4 (Ln: Nd, Eu, Y, Yb) are prepared by solid state reactions of stoichiometric mixtures of Ln2O3 and BaCO3 (1.
ChemInform Abstract: Synthesis and Crystal Structure of Calcium Dizinc Iron(III) Tris(orthophosphate), CaZn2Fe(PO4)3.
Authors: Khmiyas Jamal , Assani Abderrazzak , Saadi Mohamed , El Ammari Lahcen 
Published: November 2016

AbstractSingle crystals of the new title compound are prepared by melting a dried solution of appropriate amounts of the metal nitrates in 85 wt.% H3PO4 (Pt crucible, 1283 K; cooling at a rate of 5 K/h).
ChemInform Abstract: Chiral Nanoparticles/Lewis Acids as Cooperative Catalysts for Asymmetric 1,4‐Addition of Arylboronic Acids to α,β‐Unsaturated Amides.
Authors: Yasukawa Tomohiro , Saito Yuuki , Miyamura Hiroyuki , Kobayashi Shu 
Published: November 2016

AbstractCooperative catalysts consisting of chiral Rh/Ag nanoparticles and Sc(OTf)3 are developed to catalyze asymmetric 1,4‐addition reactions of arylboronic acids to α,β‐unsaturated amides.The reaction is considered to be one of the most challenging reactions because of the low reactivity of the amide substrates.
ChemInform Abstract: A Novel Thiourea Type Organocatalyst Possessing a Single NH Functionality.
Authors: Jovanovic Predrag , Petkovic Milos , Simic Milena , Ivkovic Branka , Savic Vladimir 
Published: November 2016

AbstractThe novel catalyst is designed by altering a typical H‐bonding pattern of thiourea derivatives and utilizing the potential of the bis(trifluoromethyl)phenyl motif to participate in the H‐bond formation.
ChemInform Abstract: Visible‐Light‐Induced Arylthiofluoroalkylations of Unactivated Heteroaromatics and Alkenes.
Authors: Choi Yeojin , Yu Chunghyeon , Kim Jun Soo , Cho Eun Jin 
Published: November 2016

AbstractSome products are isolated as ketone derivatives due to hydrolysis of the introduced fluoroalkyl moiety.
ChemInform Abstract: Rhodium‐Catalyzed N‐tert‐Butoxycarbonyl (Boc) Amination by Directed C—H Bond Activation.
Authors: Wippich Julian , Truchan Nadina , Bach Thorsten 
Published: November 2016

AbstractA protocol is developed which allows a directed introduction of an ‐NH‐Boc group into a thiophene or benzene nucleus, attached to a pyridine or quinoline system.
ChemInform Abstract: A Series of Novel β‐Hydroxyamide Based Catalysts for Borane‐Mediated Enantioselective Reductions of Prochiral Ketones.
Authors: Azizoglu Murat , Erdogan Asli , Arslan Nevin , Turgut Yilmaz , Hosgoren Halil , Pirinccioglu Necmettin 
Published: November 2016

AbstractSeven catalysts are prepared and tested in the title process.
ChemInform Abstract: Copper‐Catalyzed Intermolecular Aminooxygenation of Styrenes Using N‐Fluorobenzenesulfonimide and Simple Alcohols.
Authors: Herrera‐Leyton Camilo , Madrid‐Rojas Matias , Lopez Jhon J. , Canete Alvaro , Hermosilla‐Ibanez Patricio , Perez Edwin G. 
Published: November 2016

AbstractThe utility of the method is demonstrated by its application in the synthesis of an analogue [cf.(XIa)] of the commercial antidepressant fluoxetine [cf.(XIb)]
ChemInform Abstract: Regio‐ and Stereoselective Synthesis of 1,2,3‐Trisubstituted Indanes from Diarylmethanols and Allylamides Through Iron(III) Chloride Hexahydrate.
Authors: Li Huanrong , et al.  
Published: November 2016

AbstractA broad spectrum of indan derivatives, which are of high interest in natural product and pharmaceutical chemistry, is available as single diastereomers and various functional groups are tolerated.
ChemInform Abstract: Synthesis of Functionalized Amino Epoxides by a Three‐Component Coupling Involving Aziridines, Arynes and Aldehydes.
Authors: Roy Tony , Thangaraj Manikandan , Gonnade Rajesh G. , Biju Akkattu T. 
Published: November 2016

AbstractThe transition‐metal‐free procedure for the three‐component coupling of aziridines, arynes and aldehydes affords N‐aryl α‐amino epoxides in moderate to good yields and diastereoselectivities.
ChemInform Abstract: Straightforward Synthesis and Antioxidant Studies of Chalcogenoaziridines.
Authors: Borges Rodrigo , Andrade Floyd C. D. , Schwab Ricardo S. , Sousa Fernanda S. S. , de Souza Maurice Neto , Savegnago Lucielli , Schneider Paulo H. 
Published: November 2016

AbstractCompound (IIIb) shows potential as an antioxidative agent.
ChemInform Abstract: Alkene Dioxygenation with Malonoyl Peroxides: Synthesis of γ‐Lactones, Isobenzofuranones, and Tetrahydrofurans.
Authors: Alamillo‐Ferrer Carla , Karabourniotis‐Sotti Marianna , Kennedy Alan R. , Campbell Matthew , Tomkinson Nicholas C. O. 
Published: November 2016

AbstractThe reaction between homoallylic alcohols or carboxylic acids and malonoyl peroxide provides the title products in moderate to high yields.
ChemInform Abstract: Stereoselective Synthesis of Cyclopentanone‐Fused Benzosultams Through Tomita Zipper Cyclization.
Authors: Ramachary Dhevalapally B. , Krishna Patoju M. , Reddy T. Prabhakar 
Published: November 2016

AbstractThe products are isolated in high yields, with excellent diastereoselectivity as a mixture of E/Z isomers.
ChemInform Abstract: A Novel and Facile Synthesis of 3,4‐Diacyl‐2H‐pyran‐2‐ones. New C—C Bond Formation.
Authors: Kotali Antigoni , Nasiopoulou Despina A. , Harris Philip A. 
Published: November 2016

AbstractApplying the ′transformation of a hydroxy into an acyl group′ (TROHIA) concept, 3‐acetyl‐4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one (i.e., dehydroacetic acid) has been converted into the 3‐acetyl‐4‐aryloyl‐6‐methyl‐2H‐pyran‐2‐ones in 2 steps with excellent yields for the first step but modest yields for the second step only.
ChemInform Abstract: Boronic Acid/Broensted Acid Co‐Catalyst Systems for the Synthesis of 2H‐Chromenes from Phenols and α,β‐Unsaturated Carbonyls.
Authors: Dimakos Victoria , Singh Tishaan , Taylor Mark S. 
Published: November 2016

AbstractVariations of arylboronic and Broensted acid components lead to combinations which show optimal catalytic activity for chromene and napthopyran synthesis via condensation of phenols, naphthols, and enones.
ChemInform Abstract: One‐Step Synthesis of Xanthones and Thio‐Xanthones by Using Magnetically Separable Copper Ferrite Nanoparticles as a Catalyst under Ligand Free Conditions.
Authors: Venkanna Avudoddi , Goud Palle Vinod Kumar , Prasad Pulaganti Vijaya , Shanker Medi , Rao Pallapothula Venkateswar 
Published: November 2016

AbstractA broad spectrum of substituted phenols and thiophenol (IVb) can be used in the title reaction with o‐substituted benzaldehydes.
ChemInform Abstract: Borane‐Catalyzed Metal‐Free Hydrogenation of 2,7‐Disubstituted 1,8‐Naphthyridines.
Authors: Wang Wei , Feng Xiangqing , Du Haifeng 
Published: November 2016

AbstractThe metal‐free hydrogenation of disubstituted naphthyridines is realized for the first time by using borane catalysts, generated in situ by hydroboration of pentafluorostyrene with Piers′ borane.
ChemInform Abstract: Catalytic Oxidation of Alcohols: Recent Advances
Authors: Kopylovich Maximilian N. , Ribeiro Ana P. C. , Alegria Elisabete C. B. A. , Martins Nuno M. R. , Martins Luisa M. D. R. S. , Pombeiro Armando J. L. 
Published: November 2016

AbstractReview: 330 refs.
ChemInform Abstract: Icosahedral Boron Clusters: A Perfect Tool for the Enhancement of Polymer Features
Authors: Nunez R. , Romero I. , Teixidor F. , Vinas C. 
Published: November 2016

AbstractReview: development of hybrid organic‐inorganic π conjugated, silane, siloxane and coordination polymers containing boron clusters, which have received considerable academic and technological interest due to the combination of the electronic, optical and thermal properties of traditional inorganic materials with desirable properties of organic plastics, including mechanical flexibility and low production costs; 55 refs.
Polymerchemie mit Kosmetika – Einfache Versuche mit Haarshampoo und Wimperntusche
Authors: Hoßfeld Viviane , Lühken Arnim 
Published: November 2016

AbstractSilicone finden immer wieder neue Verwendungen als moderne Werkstoffe und sind dabei Grenzgänger zwischen der anorganischen und der organischen Chemie. Als Bestandteile von Alltagsprodukten treten sie zunehmend häufiger in das Bewusstsein der Verbraucher. Beispielsweise in Fugendichtmassen und Backformen sind sie der offensichtliche Hauptbestandteil, in Kosmetika jedoch auf den ersten Blick nicht als Inhaltsstoff erkennbar. In diesem Beitrag werden fünf einfache Schulversuche zur Untersuchung alltäglicher Kosmetikprodukte vorgestellt, die phänomenologisch Stoff‐Eigenschafts‐Beziehungen der Silicone in Kosmetika aufzeigen sollen.
Hermite‐Padé Approximants for a Pair of Cauchy Transforms with Overlapping Symmetric Supports
Authors: Aptekarev Alexander I. , Van Assche Walter , Yattselev Maxim L. 
Published: November 2016

AbstractHermite‐Padé approximants of type II are vectors of rational functions with a common denominator that interpolate a given vector of power series at infinity with maximal order. We are interested in the situation when the approximated vector is given by a pair of Cauchy transforms of smooth complex measures supported on the real line. The convergence properties of the approximants are rather well understood when the supports consist of two disjoint intervals (Angelesco systems) or two intervals that coincide under the condition that the ratio of the measures is a restriction of the Cauchy transform of a third measure (Nikishin systems). In this work we consider the case where the supports form two overlapping intervals (in a symmetric way) and the ratio of the measures extends to a holomorphic function in a region that depends on the size of the overlap. We derive Szegő‐type formulae for the asymptotics of the approximants, identify the convergence and divergence domains (the divergence domains appear for Angelesco systems but are not present for Nikishin systems), and show the presence of overinterpolation (a feature peculiar for Nikishin systems but not for Angelesco systems). Our analysis is based on a Riemann‐Hilbert problem for multiple orthogonal polynomials (the common denominator).© 2016 Wiley Periodicals, Inc.
Cobalt Nanoparticle‐Embedded Porous Carbon Nanofibers with Inherent N‐ and F‐Doping as Binder‐Free Bifunctional Catalysts for Oxygen Reduction and Evolution Reactions
Authors: Singhal Richa , Kalra Vibha 
Published: November 2016

AbstractEfficient, low‐cost, non‐precious metal‐based, and stable bifunctional electrocatalysts are key to various energy storage and conversion devices such as regenerative fuel cells and metal‐air batteries. In this work, we report cobalt nanoparticle‐embedded porous carbon nanofibers with inherent N‐ and F‐doping as binder‐free bifunctional electrocatalysts with excellent activity for both the oxygen reduction and oxygen evolution reaction (ORR/OER) in an alkaline medium. Single‐step electrospinning of a solution of the polymer mixture (carbon precursor) and the cobalt precursor followed by controlled pyrolysis with an intermediate reduction step in H2 (to reduce cobalt oxides to cobalt) was utilized to synthesize an integrated freestanding catalyst. The fabricated catalyst with effective structural and electronic interaction between the cobalt metal nanoparticles and the N‐ and F‐doped carbon defect sites showed enhanced catalytic properties compared to the benchmark catalysts for ORR and OER (Pt, Ir, and Ru). The ORR potential at the current density of −3 mA cm−2 was 0.81 VRHE and the OER potential at a current density of 10 mA cm−2 was 1.595 VRHE, resulting in a ΔE of only 0.785 V.