bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical Synthesis of RNA with Base‐Labile 2′‐O‐(Pivaloyloxymethyl)‐Protected Ribonucleoside Phosphoramidites
Authors: Lavergne Thomas , Janin Michaël , Dupouy Christelle , Vasseur Jean‐Jacques , Debart Françoise 
Published: December 2010

AbstractThe efficiency of chemical RNA synthesis has been radically improved by the use of pivaloyloxymethyl (PivOM) groups as 2′‐protection, containing an acetal spacer that minimizes the steric effect of the ester group on the neighboring amidite during the coupling. However, the major benefit of the base‐labile PivOM groups is their simple removal upon standard basic conditions applied to deprotect the RNA and release it from solid supports. Combined with standard acyl groups for nucleobases, cyanoethyl groups for phosphates, and base‐cleavable linkers, PivOM groups make RNA deprotection as simple as DNA deprotection. Thus, no additional deprotection step with tedious desalting workup procedures is required, and RNA synthesis becomes as convenient and efficient as DNA synthesis. Curr. Protoc. Nucleic Acid Chem. 43:3.19.1‐3.19.27. © 2010 by John Wiley & Sons, Inc.
Time‐Dependent Thermocontrol of the Hydrophilic and Lipophilic Properties of DNA Oligonucleotide Prodrugs
Authors: Ausín Cristina , Grajkowski Andrzej , Cieślak Jacek , Gapeev Alexei , Beaucage Serge L. 
Published: December 2010

AbstractThis unit describes the preparation of alkylthioalkylated and formamidoalkylated alcohols, an amidoalkylated alcohol, a hydroxylalkylated phosphoramidate, and their phosphoramidothioate derivatives, all of which have been identified as heat‐sensitive thiophosphate‐protecting groups in the development of thermolytic immunostimulatory DNA prodrugs. The alcohols are converted to their deoxyribonucleoside phosphoramidite derivatives, which are then used in the preparation of thermosensitive dinucleoside phosphorothioates. The thiophosphate‐protecting groups of these dinucleoside phosphorothioates presumably undergo thermolytic cyclodeesterification at elevated temperature under essentially neutral conditions to release the desired phosphorothioate diester function. On the basis of their thermolytic deprotection kinetics, one can identify those thiophosphate‐protecting groups that (i) may be useful for thiophosphate protection of CpG motifs of immunostimulatory DNA oligonucleotides (CpG ODNs); (ii) are suitable for protection of phosphodiester functions flanking the CpG motifs; and (iii) offer adequate protection of terminal phosphodiester functions against ubiquitous extracellular and intracellular exonucleases that may be found in biological environments. Curr. Protoc. Nucleic Acid Chem. 43:4.42.1‐4.42.31. © 2010 by John Wiley & Sons, Inc.
Determination of Nucleic Acid Hydration Using Osmotic Stress
Authors: Rozners Eriks 
Published: December 2010

AbstractWater plays an important role in structure and molecular recognition of biopolymers. Understanding hydration of biopolymers is a significant problem in structural chemistry and biology. However, hydration is a dynamic process that is difficult to study. While X‐ray crystallography, NMR, and molecular modeling have provided structural detail on nucleic acid hydration and valuable insights into water dynamics, the thermodynamic contribution of water molecules to conformational equilibria and recognition of nucleic acids remains poorly understood. This unit describes a thermodynamic analysis of nucleic acid hydration using osmotic stress. Osmotic stress monitors the depression of melting temperature upon decreasing water activity, and calculates the number of thermodynamically unique water molecules associated with the double helix and released from single strands upon melting. Comparison of the number of water molecules released upon melting of nucleic acids with different sequences and chemical modifications provides insights that complement and enhance information obtained by other methods. Curr. Protoc. Nucleic Acid Chem. 43:7.14.1‐7.14.13. © 2010 by John Wiley & Sons, Inc.
Pyridine‐Directed Organolithium Addition to an Enol Ether
Authors: Yang Jingyue , Dudley Gregory B. 
Published: December 2010

AbstractA previously reported anionic rearrangement of benzyl 2‐pyridyl ethers can now be accessed by a distinct and unusual mechanism: addition of alkyllithium reagents to α‐(2‐pyridyloxy)‐styrene triggers an anionic rearrangement to afford tertiary pyridyl carbinols. The process is explained by invoking a contra‐electronic, pyridine‐directed carbolithiation of the enol ether π‐system.
Chemoselective Cascade Synthesis of N‐Fused Heterocycles via Silver(I) Triflate‐Catalyzed Friedel–Crafts/N‐C Bond Formation Sequence
Authors: Hao Lu , Pan Yingming , Wang Tao , Lin Min , Chen Li , Zhan Zhuang‐ping 
Published: December 2010

AbstractAn efficient cascade methodology toward chemoselective synthesis of N‐fused heterocycles including 9H‐pyrrolo[1,2‐a]indole, 3H‐pyrrolo[1,2‐a]indole and 1H‐pyrrolo[1,2‐a]indole derivatives has been developed. This transformation proceeds via a silver(I) triflate‐catalyzed consecutive Friedel–Crafts reaction/NC bond formation sequence between readily available propargyl alcohols and 3‐substituted 1H‐indoles. Not only is excellent chemoselectivity observed according to the substitution patterns of propargyl alcohols, but also the Lewis acid‐catalyzed NC bond formation process can be carried out under base‐ and ligand‐free conditions.
Iridium‐Catalyzed Asymmetric Allylic Amination with Polar Amines: Access to Building Blocks with Lead‐Like Molecular Properties
Authors: Tosatti Paolo , Horn Joachim , Campbell Amanda J. , House David , Nelson Adam , Marsden Stephen P. 
Published: December 2010

AbstractThe combination of an air‐stable iridium catalyst and the dipolar aprotic solvent dimethyl sulfoxide (DMSO) allowed, for the first time, the systematic exploitation of highly polar, functionalized amines in asymmetric allylic substitutions: low molecular weight, sp3‐rich chiral building blocks were obtained with physicochemical properties that will be valuable in the synthesis of lead‐like small molecules.
Zinc(II)‐Dipicolylamine‐Functionalized Polydiacetylene–Liposome Microarray: A Selective and Sensitive Sensing Platform for Pyrophosphate Ions
Authors: Kim Kyung Mi , Oh Dong Ju , Ahn Kyo Han 
Published: December 2010

AbstractA microarray‐chip assay system for the fluorescence detection of phosphate‐containing analytes in aqueous media has been constructed from stimuli‐responsive polymerized poly(diacetylene)‐liposomes for the first time. Proper combination of the liposome components (ZnII‐dipicolylamine for phosphate binding and an amine‐terminated component for anchoring the liposome onto an aldehyde‐derivatized glass plate), has led to a microarray chip that selectively detects pyrophosphate, an important biomarker, over competing anions, such as phosphate and adenosine triphosphate, with nanomolar sensitivity. The chip‐based assay shows advantages, such as high specificity and sensitivity, over solution‐based assays that use the same liposomes, and over known homogeneous molecular sensing systems.
Die Milch macht's – auch bei Pflanzen. Milchröhren und Milchsaft
Authors: Schnepf Eberhard 
Published: December 2010

AbstractViele verschiedene Pflanzen haben Milchröhren und produzieren Milchsaft. Dieser fließt aus, wenn die Pflanze verletzt wird, koaguliert dann schnell und schützt die Wunde. Milchsaft ist eine Mischung aus Vakuolen und Cytoplasma und enthält viele verschiedenartige sekundäre Pflanzenstoffe, besonders Polyterpene (meistens in der Form von Latex‐Partikeln) und oft Giftstoffe. Ungegliederte Milchröhren bestehen aus einer einzigen Zelle, gegliederte entstehen durch die Fusion von Einzelzellen. Beide Typen können verzweigt sein. Berühmt/berüchtigt ist der Milchsaft des Schlafrnohns, Papaver somniferum; er enthält Opium. Technisch sehr wichtig geworden ist der Milchsaft von Hevea brasiliensis, nachdem die Vulkanisierung erfunden worden war.
Nord‐ und Südpolarmeer im Klimawandel. Ein biologischer Vergleich
Authors: Hempel Gotthilf , Piepenburg Dieter 
Published: December 2010

AbstractDie Polarmeere der Arktis und Antarktis sind geprägt durch das Vorkommen von Meereis, das einen eigenen Lebensraum darstellt und das auch die Ökosysteme des Freiwassers und des Meeresbodens stark beeinflusst. Die Lebensbedingungen im Nord‐ und Südpolarmeer unterscheiden sich deutlich als Folge der Unterschiede ihrer geographischen Lage, des jeweiligen Lichtregimes und der Meereisbedeckung. Aufgrund ihrer unterschiedlichen Vereisungs‐ und Besiedlungsgeschichte steht der jungen, artenarmen arktischen Fauna eine alte, artenreiche antarktische Fauna gegenüber. Der Klimawandel ist im Nordpolarmeer und auch an der Antarktischen Halbinsel besonders deutlich. Hier schrumpft die sommerliche Eisbedeckung dramatisch und auch das mehrjährige Dauereis schwindet. Dies beeinträchtigt die Meereislebensgemeinschaften und ihre assoziierte Fauna und hat weitreichende Konsequenzen für das polare Plankton und Benthos.
Berufschancen für Bachelor und Master in der Biologie: Mehr als Praktikum oder Pharmaberater?
Authors: Klöck Gerd 
Published: December 2010

AbstractDie Berufsaussichten für Biologen werden traditionell als schwierig bezeichnet. Zwar wird allgemein angenommen, dass bestimmte Spezialisierungen während des Studiums den Berufseinstieg erleichtern. Die große Zahl von arbeitsuchenden Studierenden und Absolventen zeigt aber, dass selbst im Bereich der boomenden Life Science‐Branche die Trauben für Berufseinsteiger relativ hoch zu hängen scheinen. Wie ist die Arbeitsmarktlage für Biologen wirklich? Was macht Absolventen für Firmen interessant? Welche Rolle spielen dabei die neuen Abschlüsse, Bachelor und Master, und hat man als Bachelor‐Absolvent der Biologie überhaupt eine Chance auf dem Arbeitsmarkt?
Click Chemistry for Rapid Labeling and Ligation of RNA
Authors: Paredes Eduardo , Das Subha R. 
Published: December 2010

AbstractThe copper(I)‐promoted azide–alkyne cycloaddition reaction (click chemistry) is shown to be compatible with RNA (with free 2′‐hydroxyl groups) in spite of the intrinsic lability of RNA. RNA degradation is minimized through stabilization of the CuI in aqueous buffer with acetonitrile as cosolvent and no other ligand; this suggests the general possibility of “ligandless” click chemistry. With the viability of click chemistry validated on synthetic RNA bearing “click”‐reactive alkynes, the scope of the reaction is extended to in‐vitro‐transcribed or, indeed, any RNA, as a click‐reactive azide is incorporated enzymatically. Once clickable groups are installed on RNA, they can be rapidly click labeled or conjugated together in click ligations, which may be either templated or nontemplated. In click ligations the resultant unnatural triazole‐linked RNA backbone is not detrimental to RNA function, thus suggesting a broad applicability of click chemistry in RNA biological studies.
ChemInform Abstract: Phase Separation and Suppression of the Structural and Magnetic Transitions in Superconducting Doped Iron Tellurides, Fe1+xTe1‐ySy.
Authors: Zajdel Pawel , Hsieh Ping‐Yen , Rodriguez Efrain E. , Butch Nicholas P. , Magill Jeff D. , Paglione Johnpierre , Zavalij Peter , Suchomel Matthew R. , Green Mark A. 
Published: December 2010

AbstractSamples of Fe1+xTe1‐ySy (0 < y < 0.15) are prepared by direct reaction of the elements (775 °C, 2 d) and characterized by single crystal XRD and powder neutron diffraction.
ChemInform Abstract: Microstructure and Magnetoresistance of Heterogeneous Gold‐Rich Ag3Au1.1Te2.
Authors: Kienle L. , Duppel V. , Lembke G. , Mogwitz B. , Janek J. , von Kreutzbruck M. , Simon A. 
Published: December 2010

AbstractAg3Au1.1Te2 is synthesized from the elements in evacuated quartz ampules at 700 °C and characterized by HRTEM, SEM, and magnetoresistance measurements.
ChemInform Abstract: A New Pseudo‐polymorph in Mineral Sphenicidite Family (NH4) [Fe2(OH)(H2O)(PO4)2] ·1.5H2O Exhibiting Spontaneous Magnetization Below 25 K.
Authors: Zhou Hong , Duan Hai‐bao , Zhang Hui , Ren Xiao‐Ming 
Published: December 2010

AbstractGreen block‐shaped single crystals of the title compound are hydrothermally synthesized from a mixture of FeSO4, (NH4)2HPO4, H3BO3, NH4OH, C2H4O4, and H2O (autoclave, 180 °C, 3 d, 45% yield).
ChemInform Abstract: Isocyanide Based Multicomponent Reactions of Oxazolidines and Related Systems.
Authors: Waller Robert W. , Diorazio Louis J. , Taylor Brian A. , Motherwell William B. , Sheppard Tom D. 
Published: December 2010

AbstractOxazolidines constitute a powerful and flexible scaffold for a set of multicomponent reactions leading to potentially useful structural diversity in a single reaction step.
ChemInform Abstract: A Convergent, Modular Access to Complex Amines.
Authors: Quiclet‐Sire Beatrice , Revol Guillaume , Zard Samir Z. 
Published: December 2010

AbstractVarious xanthates can be added to N‐vinyl phthalimide (II) with little formation of oligomers, if the xanthate is used in excess and the medium slightly diluted.
ChemInform Abstract: Asymmetric Suzuki Cross‐Couplings of Activated Secondary Alkyl Electrophiles: Arylations of Racemic α‐Chloroamides.
Authors: Lundin Pamela M. , Fu Gregory C. 
Published: December 2010

AbstractVarious α‐chloroamides are arylated with good yields and good to excellent enantioselectivity in the presence of chiral ligand DAL.
ChemInform Abstract: KHSO4 Assisted Michael Addition‐Elimination Reactions of Formylated Acetophenones in Water: A Facile General Green Synthetic Route to 3‐(Alkyl/aralkyl/aryl)amino‐1‐arylprop‐2‐en‐1‐ones
Authors: Devi A. S. , Dutta M. C. , Nongkhlaw R. , Vishwakarma J. N. 
Published: December 2010

Abstract19 examples
ChemInform Abstract: Palladacycle Containing Nitrogen and Selenium: Highly Active Pre‐Catalyst for the Suzuki—Miyaura Coupling Reaction and Unprecedented Conversion into Nanosized Pd17Se15.
Authors: Rao Gyandshwar Kumar , Kumar Arun , Ahmed Jahangeer , Singh Ajai Kumar 
Published: December 2010

AbstractA new air‐ and moisture‐insensitive palladacycle shows high catalytic activity for the Suzuki—Miyaura coupling reaction of phenyl boronic acid (II) with functionalized aryl/hetaryl halides (I).
ChemInform Abstract: Three‐Component Reaction of Methyl 2,4‐Dioxo‐4‐phenylbutanoate and Methyl 2,4‐Dioxopentanoate with Aromatic Aldehydes and Propane‐1,2‐diamine and Chemical Properties of the Products.
Authors: Gein V. L. , Kasimova N. N. , Aliev Z. G. , Vakhrin M. I. 
Published: December 2010

AbstractDepending on the molar ratio, reaction of compounds (I), (II) and (III) leads to 2,5‐dihydro‐1H‐pyrrol‐2‐one derivatives (IV) or (XV), resp., possessing 2 (or 4) reactive carbonyl groups.
ChemInform Abstract: One‐Pot Synthesis of New Spiro[cyclopropane‐1,3′‐[3H]indol]‐2′(1′H)‐ones from 3‐Phenacylideneoxindoles.
Authors: Shaabanzadeh Masoud , Khabari Faranak 
Published: December 2010

AbstractHydrazine addition to α,β‐enones (I) affords a spiroindolepyrazolone as intermediate which is not separated but reacted in situ with lead tetraacetate (II) to form a mixture of diastereoisomeric spirocyclopropaneindolones (III) and (IV).
ChemInform Abstract: 2‐Methyltetrahydrofuran as a Suitable Green Solvent for Phthalimide Functionalization Promoted by Supported KF.
Authors: Pace Vittorio , Hoyos Pilar , Fernandez Maria , Sinisterra Jose V. , Alcantara Andres R. 
Published: December 2010

AbstractA chemoselective nitrogen functionalization of phthalimides (I) by using KF‐alumina in 2‐methyltetrahydrofuran, a solvent obtained from renewal sources, is described.
ChemInform Abstract: Simple Synthesized Mannich Bases as Ligands in Cu‐Catalyzed N‐Arylation of Imidazoles in Water.
Authors: Zhu Yefeng , Shi Yixing , Wei Yunyang 
Published: December 2010

AbstractA simple, environmentally friendly and efficient protocol for the N‐arylation of imidazoles and related N‐heterocycles is developed.
ChemInform Abstract: The First Synthesis of 3‐Hydroxy‐2‐(polyfluoroalkyl)chromones and Their Ammonium Salts. 3‐Hydroxychromone in the Mannich Reaction.
Authors: Irgashev Roman A. , Sosnovskikh Vyacheslav Ya. , Sokovnina Anna A. , Roeschenthaler Gerd‐Volker 
Published: December 2010

AbstractNitrozation of (polyfluoroalkyl)chromanones (I) gives rise to the formation of previously unknown 3‐hydroxy‐2‐(polyfluoroalkyl)chromones (II).
ChemInform Abstract: Asymmetric Metal‐Free Synthesis of Fluoroquinolones by Organocatalytic Hydrogenation.
Authors: Rueping Magnus , Stoeckel Mirjam , Sugiono Erli , Theissmann Thomas 
Published: December 2010

AbstractHighly enantioselective organocatalytic transfer hydrogenations allow the syntheses of the title compounds (II) and (V), which are known precursors of the antibiotics flumequine (III) and levofloxacine (VI).
ChemInform Abstract: 2‐Amino‐6‐(3,4‐ethylenedioxythiophen‐2‐yl)‐4‐(2‐thienyl)pyrimidine: Synthesis and Properties.
Authors: Shklyaeva E. V. , Bushueva A. Yu. , Romanova V. A. , Abashev G. G. 
Published: December 2010

AbstractTitle compound (VI) containing an electron‐deficient pyrimidine ring linked to two electron‐donating moieties is synthesized starting from thiophene (I).
ChemInform Abstract: Design, Synthesis and Antiviral Activity of 5‐Hydroxymethyl‐3‐phosphonyl‐4,5‐dihydrofuran Analogues of Nucleotides.
Authors: Lee Hee‐Yoon , Lee Kiho , Hah Jung Hwan , Moon Deuk Kyu , Lee Chong‐Kyo 
Published: December 2010

AbstractSix 5‐hydroxymethyl‐3‐phosphonyl‐4,5‐dihydrofuran analogues of nucleotides of type (III), (V) and (VI) are prepared and tested for their antiviral effects.
ChemInform Abstract: Novel Imidazobenzazepine Derivatives as Dual H1/5‐HT2A Antagonists for the Treatment of Sleep Disorders.
Authors: Gianotti Massimo , Corti Corrado , Delle Fratte Sonia , Di Fabio Romano , Leslie Colin P. , Pavone Francesca , Piccoli Laura , Stasi Luigi , Wigglesworth Mark J. 
Published: December 2010

AbstractThe derivatives (I) are shown to possess potent and balanced H1/5‐HT2A receptor antagonist activities.
ChemInform Abstract: Synthesis and SAR of Novel, 4‐(Phenylsulfamoyl)phenylacetamide mGlu4 Positive Allosteric Modulators (PAMs) Identified by Functional High‐Throughput Screening (HTS).
Authors: Engers Darren W. , Gentry Patrick R. , Williams Richard , Bolinger Julie D. , Weaver C. David , Menon Usha N. , Conn P. Jeffrey , Lindsley Craig W. , Niswender Colleen M. , Hopkins Corey R. 
Published: December 2010

AbstractThe title compounds are evaluated as mGlu4 positive allosteric modulators (PAMs).
ChemInform Abstract: Combined Coinage Metal Catalysis for the Synthesis of Bioactive Molecules
Authors: Krause Norbert , Aksin‐Artok Oezge , Breker Viola , Deutsch Carl , Gockel Birgit , Poonoth Manojkumar , Sawama Yoshinari , Sawama Yuka , Sun Tao , Winter Christian 
Published: December 2010

AbstractReview: 37 refs.
ChemInform Abstract: Cycloadditions of Allylsilanes. Part 22. Stereoselective Synthesis of Cyclopentanes and Cyclobutanes by Lewis Acid Promoted [3 + 2] and [2 + 2] Cycloadditions of Allylsilanes
Authors: Schmidt Arndt W. , Knoelker Hans‐Joachim 
Published: December 2010

AbstractReview: about 150 refs.
ChemInform Abstract: Recent Synthesis of Marine Natural Products with Antihypertensive Activity
Authors: Dighe Nachiket S. , Pattan Shashikant R. , Musmade Deepak S. , Chavan Prerana A. , Tambe Snehalata K. , Sanap Manjusha S. , Gaware Vinayak M. 
Published: December 2010

AbstractReview: 10 refs.
Study of stereoselective interactions of carbamoylated quinine and quinidine with 3,5‐dinitrobenzoyl α‐amino acids using VCD spectroscopy in the region of CH stretching vibrations
Authors: Julínek Ondřej , Lindner Wolfgang , Urbanová Marie 
Published: December 2010

AbstractThe stereoselective complexation of tert‐butylcarbamoyl quinine and tert‐butylcarbamoyl quinidine selectors (SOs) with 3,5‐dinitrobenzoyl (DNB) derivatives of D‐ and L‐alpha amino acids (DNB‐Ala, DNB‐Val, DNB‐Leu, and DNB‐Ile) as well as achiral DNB‐Gly has been studied by vibrational circular dichroism (VCD) spectroscopy in the spectral region of CH stretching vibrations. All the complexes of SOs and sterically compatible enantiomers of derivatized amino acid selectands (SAs) showed induced circular dichroism (ICD) bands in the region of aromatic CH stretching vibrations, indicating the occurrence of a π–π interaction between the aromatic moieties of SA and SO. To our knowledge, this is the first report in which a π–π interaction was observed by VCD spectroscopy in this spectral region. No ICD bands were disclosed in the spectra of the sterically incompatible SA and SO complexes. The spectral pattern in the region of aliphatic CH stretching vibrations showed interaction‐induced conformational adaptations in sterically favorable SA and SO complexes. No such spectral changes were observed for any of the sterically incompatible complexes. The DNB‐Gly complexes exhibited spectral patterns similar to those observed for sterically favorable pairs of SOs and chiral SAs. Chirality, 2011. © 2010 Wiley‐Liss, Inc.
Exchangeable Characteristics of Potassium in Five Important Soils of Taiwan
Authors: Lin Yong‐Hong 
Published: December 2010

AbstractThe application of potassium fertilizer by farmers is often not appropriate and causing environmental pollution. By understanding the adsorptive characteristics of potassium (K) on different soils, we can prevent excessive application of K‐fertilizer that can cause environmental impact. The Gapon exchange coefficient (KG), for exchange between K and Ca, was considered as an important factor influencing the adsorption of K. This study was conducted to compare the constantKGof five important farm soils in Taiwan. TheKGand CEC were then used to predict K buffering capacity (PBC). Finally, the relationship between exchangeable K ratio (EP) and K adsorption ratio (PAR) was examined. The results show that five soils have same trends, indicating thatKGdecreases with increase in K saturation. The CEC andKGof Liuying (Ly) soil are both high, so that their K buffering capacity is high. TheKGand CEC of Chanjing (Cj) and Sanhua (Sh) soil show moderate values. The CEC of Erling (El) soil is high, but itsKGis low, so that its K buffering capacity is moderate. On the other hand, theKGof Newniaokang (Nnk) soil is high but its CEC is low, so its K buffering capacity is also moderate. The correlations betweenEPand PAR of five soil show linear relationship at three treatments of CaCl2concentration. This study may provide an important clue to the fertilization management of K‐fertilizer on the different soil properties in Taiwan.