bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactivity toward oxygen radicals and antioxidant action of thiol compounds
Authors: Takashima Mizuki , Shichiri Mototada , Hagihara Yoshihisa , Yoshida Yasukazu , Niki Etsuo 
Published: April 2012

AbstractThiol compounds exert diverse functions in the defense network against oxidative stress in vivo. Above all, the role of glutathione in the enzymatic removal of hydrogen peroxide and lipid hydroperoxides has been well established. The scavenging of reactive free radicals is one of the many functions. In this study, the reactivities of several thiol compounds toward oxygen‐ and nitrogen‐centered radicals were measured from their reaction with galvinoxyl and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radicals and also from their sparing effects on the decay of fluorescein, pyrogallol red, and BODIPY induced by peroxyl radicals. Furthermore, the antioxidant capacity against lipid peroxidation was assessed in the oxidation of methyl linoleate induced by free radicals in micelle systems. Cysteine, homocysteine, and glutathione exhibited considerable reactivity toward galvinoxyl, DPPH, and peroxyl radicals in this order but methionine did not. Bovine serum albumin (BSA) was less reactive toward these radicals than cysteine on molar base. Cysteine, homocysteine, and glutathione suppressed the oxidation of methyl linoleate in micelle systems, but methionine did not. The reactivity toward free radicals and antioxidant capacity of these thiol compounds were less than that of ascorbic acid, but higher than that of uric acid.
Lipid rafts generate digital‐like signal transduction in cell plasma membranes
Authors: Suzuki Kenichi G. N. 
Published: April 2012

AbstractLipid rafts are meso‐scale (5–200 nm) cell membrane domains where signaling molecules assemble and function. However, due to their dynamic nature, it has been difficult to unravel the mechanism of signal transduction in lipid rafts. Recent advanced imaging techniques have revealed that signaling molecules are frequently, but transiently, recruited to rafts with the aid of protein‐protein, protein‐lipid, and/or lipid‐lipid interactions. Individual signaling molecules within the raft are activated only for a short period of time. Immobilization of signaling molecules by cytoskeletal actin filaments and scaffold proteins may facilitate more efficient signal transmission from rafts. In this review, current opinions of how the transient nature of molecular interactions in rafts generates digital‐like signal transduction in cell membranes, and the benefits this phenomenon provides, are discussed.
ChemInform Abstract: The System Ta—V—Si: Crystal Structure and Phase Equilibria.
Authors: Khan A. U. , Broz P. , Niu H. Y. , Bursik J. , Grytsiv A. , Chen X.‐Q. , Giester G. , Rogl P. 
Published: April 2012

AbstractPhase relations in the title system are evaluated for the isothermal sections at 1500 and 1200 °C.
ChemInform Abstract: Two New Noncentrosymmetric (NCS) Polar Oxides: Syntheses, Characterization, and Structure—Property Relationships in BaMTe2O7 (M: Mg2+ or Zn2+).
Authors: Yeon Jeongho , Kim Sang‐Hwan , Nguyen Sau Doan , Lee Hana , Halasyamani P. Shiv 
Published: April 2012

AbstractThe new title compounds are prepared by solid state reaction of stoichiometric mixtures of BaCO3, MgCO3 or ZnO, TeO2, and H2TeO4·2H2O (alumina crucible, 650 °C, 3 d).
ChemInform Abstract: Two‐Stage Optimization of a Supramolecular Catalyst for Catalytic Asymmetric Hydroboration.
Authors: Moteki Shin A. , Toyama Kazuya , Liu Zeyu , Ma Jing , Holmes Andrea E. , Takacs James M. 
Published: April 2012

AbstractA series of self‐assembled ligand Zn‐catalysts [cf.
ChemInform Abstract: [3 + 2] Cycloaddition of Seleno‐ and Thioaldehydes with Cyclic Azomethine Imines.
Authors: Maeda Hajime , Takamizawa Yusuke , Segi Masahito 
Published: April 2012

AbstractThe reaction of seleno‐ and thioaldehydes generated in situ from (I) with cyclic azomethine imines (II) in toluene gives [3 + 2] cycloadducts (III) in high yields.
ChemInform Abstract: Amination of Benzoxazoles and 1,3,4‐Oxadiazoles Using 2,2,6,6‐Tetramethylpiperidine‐N‐oxoammonium Tetrafluoroborate as an Organic Oxidant.
Authors: Wertz Sebastian , Kodama Shintaro , Studer Armido 
Published: April 2012

AbstractDirect amination of non‐activated benzoxazoles and 1,3,4‐oxadiazoles is achieved by treatment with tetramethylpiperidine‐N‐oxoammonium tetrafluoroborate as an oxidant in the presence of catalytic amounts of triflic acid or scandium triflate.
ChemInform Abstract: Nitrile Alkylations Through Sulfinyl—Metal Exchange.
Authors: Nath Dinesh , Fleming Fraser F. 
Published: April 2012

AbstractSulfinylnitriles, e.g. (I), (XII), (XV) or (XVII), smoothly undergo sulfinyl—metal exchange with Grignard reagents, organolithium or lithium zincate reagents to generate the corresponding α‐metallated nitriles, which are trapped with various electrophiles.
ChemInform Abstract: An Efficient Protocol for the Amidation of Carboxylic Acids Promoted by Trimethyl Phosphite and Iodine.
Authors: Luo Qun‐Li , Lv Lina , Li Yu , Tan Jian‐Ping , Nan Wenhui , Hui Qun 
Published: April 2012

AbstractA mild and efficient method for the direct N‐acylation of amines with carboxylic acids is presented to afford a wide variety of aromatic and aliphatic amides.
ChemInform Abstract: Palladium‐Catalyzed Decarboxylation of Allenyl 3‐Oxoalkanoates: An Efficient Synthesis of 3,4‐Allenyl Ketones.
Authors: Wan Baoqiang , Jia Guochen , Ma Shengming 
Published: April 2012

AbstractThe versatile synthons are readily available under conditions A) in either tBuOH or THF.
ChemInform Abstract: Enantioselective Intermolecular Carbon—Carbon Bond Formation of Glyoxylate Imines with Allylstannanes Catalyzed by tropos BIPHEP—Gold(I) Complexes with Au—Au Interactions.
Authors: Kojima Masafumi , Mikami Koichi 
Published: April 2012

AbstractThe present study reveals the advantage of tropos BIPHEP—gold(I) complexes with intramolecular Au—Au interactions compared to the structurally similar atropos BINAP—gold complexes without the Au—Au interaction.
ChemInform Abstract: Asymmetric Synthesis of Trisubstituted Allenes: Copper‐Catalyzed Alkylation and Arylation of Propargylic Phosphates.
Authors: Uehling Mycah R. , Marionni Samuel T. , Lalic Gojko 
Published: April 2012

AbstractIn contrast to previous reports, the reaction of a propargylic phosphate with a bulky substituent at the γ‐position [cf.(VII)] succeeds with good yields and high enantioselectivity.
ChemInform Abstract: Hydrosilylation of Ketones Catalyzed with Mg—Al—O‐tBu Hydrotalcite.
Authors: Chen Yaoyun , Bai Ying , Peng Jiajian , Li Jiayun , Lai Guoqiao 
Published: April 2012

AbstractThe efficacy of tBu‐O‐AlMg‐hydrotalcite as heterogeneous catalyst for the hydrosylilation of ketones is studied.
ChemInform Abstract: Enantio‐ and Diastereoselective Addition of Cyclohexyl Meldrum′s Acid to β‐ and α,β‐Disubstituted Nitroalkenes via N‐Sulfinyl Urea Catalysis.
Authors: Kimmel Kyle L. , Weaver Jimmie D. , Ellman Jonathan A. 
Published: April 2012

AbstractA practical method for the construction of biologically important chiral γ‐amino acids is based on the title reaction in the presence of a sulfinyl urea catalyst.
ChemInform Abstract: An Efficient and Practical Synthesis of Aryl and Hetaryl α‐Keto Esters.
Authors: Raghunadh Akula , Meruva Suresh Babu , Kumar Nuka Anil , Kumar Gudla Santosh , Rao L. Vaikunta , Kumar U. K. Syam 
Published: April 2012

Abstractas important substructures of biologically active substances
ChemInform Abstract: A Reactivity Switch in the Gold‐Catalyzed Coupling of Allyl Sulfides with Propargylic Carboxylates.
Authors: Davies Paul W. , Albrecht Sebastien J.‐C. 
Published: April 2012

AbstractDepending on the non‐migrating substituent on the sulfur and the aromatic group at the propargylic position of the alkyne, the reaction follows different reaction pathways.
ChemInform Abstract: Phosphine‐Free Conversion of Alcohols into Alkyl Thiocyanates Using Trichloroisocyanuric Acid/NH4SCN.
Authors: Azadi Roya , Mokhtari Babak , Makaremi Mohamad‐Ali 
Published: April 2012

AbstractThe combination is successfully employed for the conversion of alcohols into thiocyanates and isothiocyanates, respectively.
ChemInform Abstract: Retropinacol Rearrangement in the Synthesis of 3,3,4‐Trimethyl‐2‐azaspiro[4.5]deca‐1,6,9‐trien‐8‐one Derivatives.
Authors: Shklyaev Yu. V. , Stryapunina O. G. , Maiorova O. A. 
Published: April 2012

AbstractWith the object to obtaining biologically active substances, the three‐component reaction of anisole (I), pivalaldehyde (II) and nitriles (III) is performed.
ChemInform Abstract: Efficient Synthesis of Bis(heterocyclyl)methanes.
Authors: Singh Kamaljit , Sharma Shivali , Sharma Amit 
Published: April 2012

AbstractAn efficient synthesis of a number of meso‐elaborated bis(heterocyclyl)methanes such as (IV) and (VII), which are otherwise difficult to obtain through a direct aldehyde condensation route, is developed.
ChemInform Abstract: Effective Synthesis of 1,5‐Disubstituted 2,1‐Benzisothiazol‐3(1H)‐ones.
Authors: Kharul Rajendra K. , Prajapati Pinkal N. , Thorave Amol A. , Shah Hardik A. , Dhar Arghya , Joshi Darshan A. , Jain Mukul R. , Patel Pankaj R. , Pancholi S. S. 
Published: April 2012

AbstractAn improved procedure is used for the preparation of 1,5‐disubstituted benzoisothiazoles, e.g. (VI).
ChemInform Abstract: Synthesis of New Sulfinyl Derivatives of 4,5‐Diphenyl‐4H‐1,2,4‐triazoles.
Authors: Rodygin K. S. , Rubtsova S. A. , Kuchin A. V. 
Published: April 2012

AbstractSulfides (I) are oxidized to the corresponding sulfoxides (II) using Kagan′s reagent and cumene hydroperoxide as an oxidant.
ChemInform Abstract: Nickel‐Catalyzed Dehydrogenative [4 + 2] Cycloaddition of 1,3‐Dienes with Nitriles.
Authors: Ohashi Masato , Takeda Ippei , Ikawa Masashi , Ogoshi Sensuke 
Published: April 2012

AbstractThe title reaction allows an efficient and regioselective access to a wide range of pyridines.
ChemInform Abstract: New Ylidene Derivatives of Pyrrolo[2,1‐a]isoquinoline‐2,3‐dione in the Synthesis of Dispiropyrrolidines.
Authors: Shvets A. A. , Mikhailovskii A. G. , Zimakov D. V. , Kurbatov S. V. , Surikova O. V. 
Published: April 2012

AbstractCondensation of dione (I) with rhodanine (II) affords the thiazolidin‐5‐ylidene (III) in moderate yield.
ChemInform Abstract: Construction of a Six‐Membered Fused N‐Heterocyclic Ring via a New 3‐Component Reaction: Synthesis of (Pyrazolo)pyrimidines/pyridines.
Authors: Kumar P. Mahesh , Kumar K. Siva , Mohakhud Pradeep Kumar , Mukkanti K. , Kapavarapu R. , Parsa Kishore V. L. , Pal Manojit 
Published: April 2012

AbstractA one‐pot TfOH‐catalyzed cascade affords title series (IV) and (VI).
ChemInform Abstract: One‐Pot Synthesis of 4‐Aminoquinazolines by Hexamethyldisilazane‐Mediated Reaction of Quinazolin‐4(3H)‐ones with Amines.
Authors: Shen Zhen‐Lu , He Xiao‐Fei , Hong Yi‐Ming , Hu Xin‐Quan , Mo Wei‐Min , Hu Bao‐Xian , Sun Nan 
Published: April 2012

AbstractAn efficient method for the synthesis of 4‐aminoquinazolines (II) is developed.
ChemInform Abstract: N‐Alkylation of Unsymmetrical 1,6‐Dihydro‐1,2,4,5‐tetrazine under Alkali Condition.
Authors: Xu Feng , Yang Zhen‐Zhen , Zhang Shi‐Jie , Hu Wei‐Xiao 
Published: April 2012

AbstractThe products (III) decompose gradually at room temperature and should be stored at ‐20 °C.
ChemInform Abstract: Polyethylene Glycol Promoted Dialkyl, Aryl/Heteroaryl Phosphonates
Authors: Naidu K. Reddi Mohan , Dadapeer E. , Reddy C. Bhupendra , Rao A. Janardhan , Reddy C. Suresh , Raju C. Naga 
Published: April 2012

AbstractAn efficient, ecofriendly synthesis of novel phosphonates (III) (12 examples) in polyethylene glycol, which serves as reaction medium and catalyst, is achieved.
ChemInform Abstract: One‐Pot, Three‐Component Synthesis of 5‐(Alkylimino)‐2‐ (diethoxyphosphoryl)‐2,5‐dihydrofuran‐3,4‐dicarboxylates.
Authors: Azizian Javad , Ramazani Ali , Haji Mohammad , Azizkhani Vahid 
Published: April 2012

AbstractA facile one‐pot, multicomponent method for the synthesis of 2‐phosphono‐substituted furans (V) is described and a reasonable reaction mechanism is proposed.
ChemInform Abstract: New Luminescent Dyes from the Series of 1,3,7‐Substituted Dibenzothiophene‐5,5‐diones.
Authors: Ol'khovik V. K. , Petushok V. G. , Kalechits G. V. , Baranovskii A. V. 
Published: April 2012

AbstractThe new linear polyconjugated compounds (I) and (II) show strong luminescence in solutions as well as in the solid state and exhibit electroluminescent properties.
ChemInform Abstract: Synthetic Approach to 4a‐Methyltetrahydrofluorene‐Type Diterpenoids via an Aromatic Oxidation of Phenol Derivatives.
Authors: Chen Wuhong , Kobayashi Koichi , Takahashi Kazunori , Honda Toshio 
Published: April 2012

AbstractAn aromatic oxidation with a hypervalent iodine reagent is used as a strategy for the preparation of the title compounds.
Visible‐Light Photooxidation of Water to Oxygen at Hybrid TiO2–Polyheptazine Photoanodes with Photodeposited Co‐Pi (CoOx) Cocatalyst
Authors: Bledowski Michal , Wang Lidong , Ramakrishnan Ayyappan , Bétard Angélique , Khavryuchenko Oleksiy V. , Beranek Radim 
Published: April 2012

AbstractA cobalt oxide‐based oxygen‐evolving cocatalyst (Co‐Pi) is photodeposited by visible‐light irradiation onto nanocrystalline TiO2–polyheptazine (TiO2–PH) hybrid photoelectrodes in a phosphate buffer. The Co‐Pi cocatalyst couples effectively to photoholes generated in the surface polyheptazine layer of the TiO2–PH photoanode, as evidenced by complete photooxidation of water to oxygen under visible‐light (λ>420 nm) irradiation at moderate bias potentials. In addition, the presence of the cocatalyst also reduces significantly the recombination of photogenerated charges, particularly at low bias potentials, which is ascribed to better photooxidation kinetics resulting in lower accumulation of holes. This suggests that further improvements of photoconversion efficiency can be achieved if more effective catalytic sites for water oxidation are introduced to the surface structure of the hybrid photoanodes.
Interdependent binary choices under social influence: Phase diagram for homogeneous unbiased populations
Authors: Fernández del Río Ana , Korutcheva Elka , de la Rubia Javier 
Published: April 2012

AbstractCoupled Ising models are studied in a discrete choice theory framework, where they can be understood to represent interdependent choice making processes for homogeneous populations under social influence. Two different coupling schemes are considered: the nonlocal or group interdependence model is used to study two interrelated groups making the same binary choice and the local or individual interdependence model represents a single group, where agents make two binary choices that depend on each other. For both models, phase diagrams and their implications in socioeconomic contexts are described and compared in the absence of private deterministic utilities (zero opinion fields). © 2012 Wiley Periodicals, Inc. Complexity, 2012
Stem cell maintenance in the adult mammalian hippocampus: A matter of signal integration?
Authors: Schwarz Tobias J. , Ebert Birgit , Lie D. Chichung 
Published: April 2012

AbstractThe continuous generation of new neurons from stem cells in the hippocampal dentate gyrus is considered an important contributor to hippocampal plasticity. A prerequisite for the life‐long generation of new dentate granule neurons is the maintenance of the neural stem cell pool. A number of essential molecular regulators and signals for hippocampal neural stem cell maintenance have been identified, but how these pathways interact to prevent precocious differentiation or exhaustion of the stem cell pool is currently unknown. Here, we summarize the current knowledge on the molecular regulation of the hippocampal stem cell pool and discuss the possibility that signal integration through Notch signaling controls stem cell maintenance in the adult hippocampus. © 2012 Wiley Periodicals, Inc. Develop Neurobiol 72: 1006–1015, 2012
Aliphatic Dicarboxylate Ligands Assemble Weakly Coupled Molecular Pairs of [MnIII]2 Units
Authors: Gómez Verónica , Corbella Montserrat , Fernández Gema , Roubeau Olivier , Teat Simon J. , Maestro Miguel A. 
Published: April 2012

AbstractSeven new tetranuclear MnIII compounds have been obtained by assembling two dinuclear units, [{Mn(L)(NN)}2(μ‐O)]4+, with aliphatic dicarboxylate ligands COO(CH2)nCOO2–: succinato (n = 2, C42–), glutarato (n = 3, C52–) and adipato (n = 4, C62–), and NN = 2,2′‐bipyridine (bpy) or 1,10‐phenanthroline (phen). The general formula for these compounds is [{Mn(L)(NN)}4(μ‐Cm)2(μ‐O)2]X4 [X = ClO4, NN = bpy and Cm = C4 (1), C5 (2) and C6 (3); X = ClO4, NN = phen and Cm = C4 (4), C5 (5) and C6 (6); X = NO3, NN = bpy and Cm = C5 (7)]. Compounds 1, 2 and 4 were characterized by X‐ray diffraction, which confirmed the assembly of two dinuclear entities. The magnetic properties of the seven compounds were studied and the results indicate that the main interaction takes place within the dinuclear units. Compound 4 shows a dominant ferromagnetic coupling with J = 4.0 cm–1, while the rest of compounds display antiferromagnetic couplings with J values of –2.8 (1), –1.9 (2), –3.3 (3), –0.3 (5), –0.4 (6) and –9.3 cm–1 (7), which are all in agreement with magneto‐structural correlations. In the case of compound 4, a weak but significant antiferromagnetic coupling of the S = 4 [MnIII]2 subunits with an interaction constant of –0.9 cm–1 was observed.
When Cyclodextrins Meet Click Chemistry
Authors: Faugeras Pierre‐Antoine , Boëns Benjamin , Elchinger Pierre‐Henri , Brouillette François , Montplaisir Daniel , Zerrouki Rachida , Lucas Romain 
Published: April 2012

AbstractCyclodextrins are important building blocks in organic chemistry. This review deals with the role of click chemistry in this family of cyclic oligosaccharides, focusing on the different areas of chemistry, including chromatography, biological applications, the elaboration of superstructures, and metal detection, that benefit from this reaction. In this paper, attention is given to organic modifications by using functionalizations such as azidation and propargylation and to click chemistry grafting onto the two faces of cyclodextrins. Research papers where cyclodextrins are not directly involved in a click chemistry reaction are not considered.
Tuning Wavefunction Mixing in Push–Pull Molecules: From Neutral to Zwitterionic Compounds
Authors: Capobianco Amedeo , Esposito Antonio , Caruso Tonino , Borbone Fabio , Carella Antonio , Centore Roberto , Peluso Andrea 
Published: April 2012

AbstractA new push–pull molecule, containing an (alkylamino)thiophene as electron donor and 1,3‐bis(dicyanomethylidene)‐2‐indenylindene as electron acceptor, has been synthesized and characterized in the solid state by X‐ray crystallography, in solution by UV/Vis and NMR spectroscopy and by theoretical calculations. The quinoidal zwitterionic form of this compound was underscored both in the solid state and in moderately polar solvents. Experimental and theoretical analyses were also performed on two similar push–pull molecules, selectively chosen to vary basic chemical features such as the resonance energy of the aromatic group and the steric hindrance of the attractor. Comparative analysis of the three compounds has shown that steric hindrance, resonance energy and the polarity of the environment play a significant role in stabilizing one limiting resonance form over the other. By varying these chemical variables, fine tuning of the electronic ground state of a push–pull molecule, from the neutral aromatic form to the charge‐separated zwitterion, passing through a form in which the two limiting forms contribute almost equally (the cyanine limit), can be achieved.
Plasma carotenoid levels are not directly related to heavy metal exposure or reproductive success in three insectivorous passerines
Authors: Eeva Tapio , Rainio Miia , Kanerva Mirella , Salminen Juha-Pekka 
Published: April 2012

Abstract
The authors measured plasma carotenoid levels in three insectivorous bird species, the pied flycatcher (Ficedula hypoleuca), the blue tit (Cyanistes caeruleus), and the great tit (Parus major) in metal-polluted and unpolluted sites around a copper smelter. Their aim was to determine whether there was interspecific, age-related, or yearly variation in carotenoid levels and their responses to the ambient pollution level. The three bird species showed qualitatively and quantitatively similar carotenoid profiles, with lutein being always the predominant plasma carotenoid. Ficedula hypoleuca nestlings showed higher plasma carotenoid levels in the unpolluted than in the polluted area, whereas no significant differences were found in F. hypoleuca females or in nestlings or females of the Parids. Yearly comparison of plasma concentrations (only for P. major nestlings) showed, however, that levels varied nonsynchronously between polluted and unpolluted sites among the breeding seasons, with the yearly variation being higher in the polluted area. The survival of nestlings did not depend on their plasma carotenoid concentrations. The two Parid species showed lower nestling survival at sites with high metal exposure levels. The authors conclude that plasma carotenoid levels showed a marked spatial, temporal, and age-related variation, but were not directly related to heavy metal exposure or the reproductive success of birds. Environ. Toxicol. Chem. 2012;31:1363–1369. © 2012 SETAC
Accumulation kinetics of arsenic in Daphnia magna under different phosphorus and food density regimes
Authors: Miao Ai-Jun , Wang Ning-Xin , Yang Liu-Yan , Wang Wen-Xiong 
Published: April 2012

Abstract
In the present study, the dissolved uptake, dietary assimilation, and elimination of arsenic (initially added as arsenate) in the freshwater cladoceran Daphnia magna were examined. A biphasic correlation between the arsenic uptake rate and its ambient concentration, as well as a two–saturation-site arsenic uptake competition with phosphate was observed. The calculated uptake rate constant, as influenced by the ambient phosphorus concentration, ranged from 0.035 to 0.35 L/g/d. Food concentration substantially decreased (by 23.2–64.4%) the arsenic assimilation efficiency with the incipient limiting algal food concentration of 3.86 mg/L dry weight. Arsenic assimilation by the daphnids was independent of their own phosphorus status, but was lower when their algal diet was phosphorus-limited and thus contained a higher proportion of arsenite due to the enhanced biotransformation. Arsenic efflux rate constant ranged from 0.34 to 0.44 d−1 with increased food concentration slightly facilitating its loss. Excretion, accounting for 51.3 to 60.6% of total loss, was the dominant pathway for arsenic elimination with a remarkable contribution from offspring production (24.7–29.8%), whereas molting (3.64–4.05%) and egestion (7.9–11.9%) had minor roles only. According to the well-established biokinetic model, dietary assimilation was predicted to be the main pathway for arsenic bioaccumulation in the daphnids, and arsenic has a great potential to be biodiminished along the food chain. Environ. Toxicol. Chem. 2012;31:1283–1291. © 2012 SETAC