bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regiospecific ortho‐Aromatic Hydroxylation via Cyclonickelation Using Hydrogen Peroxide and Other Oxygen Donors: Synthesis of Metalloazosalophens (Eur. J. Inorg. Chem. 27/2007)
Authors: Pattanayak Poulami , Lal Pratihar Jahar , Patra Debprasad , Burrows Andrew , Mohan Mary , Chattopadhyay Surajit 
Published: September 2007

AbstractThe cover picture shows the reaction sequence of an NiII‐assisted regiospecific ortho‐aromatic hydroxylation. Sequential events of orthonickelation, oxygen insertion into the Ni–C bond induced by H2O2 and demetallation have been demonstrated to be involved in the aromatic hydroxylation in 2‐(arylazo)aniline. The H2O2‐induced O insertion into the Ni–C bond led to the formation of metalloazosalophen analogues of metallosalophens for the first time. Details are discussed in the article by S. Chattopadhyay et al. on p. 4263 ff.
Dietary sphingolipids lower plasma cholesterol and triacylglycerol and prevent liver steatosis
Authors: Nieuwenhuizen Willem F. , Duivenvoorden Ilse , Voshol Peter J. , Rensen Patrick C. N. , van Duyvenvoorde Wim , Romijn Johannes A. , Emeis Jef J. , Havekes Louis M. 
Published: September 2007

AbstractThe prevalence of dyslipidemia and obesity resulting from excess energy intake and physical inactivity is increasing. The liver plays a pivotal role in the systemic lipid homeostasis. Effective, natural dietary interventions that lower plasma lipids and promote liver health are needed. APOE*3Leiden mice were fed a Western‐type diet, supplemented with different sphingolipids, to determine their effect on plasma lipids and liver steatosis. Hepatic lipid levels and lipid‐related gene expression were also determined. Dietary sphingolipids dose‐dependently lowered both plasma cholesterol (C) and triglycerides (TG) in APOE*3Leiden mice. 1% Phytosphingosine (PS) reduced C and TG by 57 and 58%, respectively. PS (a) decreased the absorption of dietary C and free fatty acid but did not affect the intestinal TG lipolysis, (b) increased hepatic VLDL‐TG production whereas plasma lipolysis was not affected; and (c) increased the hepatic uptake of VLDL remnants. Hepatic mRNA levels indicated enhanced hepatic lipid synthesis and VLDL and LDL uptake. Livers of PS (1%) fed mice were lighter (−22%), less pale, and contained less cholesteryl ester (−61%) and TG (−56%). Furthermore, markers for liver inflammation (SAA) and liver damage (ALAT) were decreased by 74% and 79%, respectively in PS‐fed mice. Sphingolipids lower plasma C and TG and protect the liver from fat‐ and cholesterol‐induced steatosis. In a preliminary small double‐blind cross‐over study with six middle‐aged slightly overweight male volunteers the daily supplementation of one gram of PS to the diet resulted in a −9.8% (p = 0.0074) and – 13.2% (p = 0.0002) reduction of total C and LDL‐C, respectively. The C/HDL‐C ratio was not significantly affected (p = 0.0571). Due to the relatively low pre‐study levels of TG in the human volunteers, and the individual variability of TG levels, the TG lowering in humans was not significant in this first small study, but per individual there was a clear trend in TG lowering.
A novel method for the determination of acid value of vegetable oils
Authors: Li Shu‐Guo , Zhang Hui , Xue Wen‐Tong 
Published: September 2007

AbstractThe voltammetric behavior of naphthoquinone in the presence of free fatty acids (FFA) at the polypyrrole (PPy)‐modified electrode was investigated in an ethanol/1,2‐dichloroethane (3 : 1) solution containing 0.1 M LiClO4. A well‐defined new reduction peak appeared at a more positive potential and was higher than that obtained at the bare Pt electrode. Based on the fact that the new reduction peak current showed a good correlation with the concentration of fatty acids, an electroanalytical method for the acid value (AV) of vegetable oils was developed using the PPy‐modified electrode in linear potential sweep voltammetry. The experimental parameters were optimized to obtain a sensitive voltammetric response in this work. A linear calibration graph was obtained in the concentration range of 5.0×10–6–6×10–3 M for FFA (R = 0.993), with a sensitivity of 2.41×10–2 A L/mol and a detection limit of 1.2×10–6 M (S/N = 3). Each assay of vegetable oil sample took about 80 s. The developed method is applied to the AV determination of six commercial vegetable oils. The results well agreed with those obtained by the titration method. Compared to the conventional titration method, the proposed method is superior in sensitivity and accuracy and requires a small amount of vegetable oil sample, with no pretreatment.
Preliminary chemical characterization of Tunisian monovarietal virgin olive oils and comparison with Sicilian ones
Authors: Baccouri Olfa , Cerretani Lorenzo , Bendini Alessandra , Caboni Maria Fiorenza , Zarrouk Mokhtar , Pirrone Luigi , Miled Douja Daoud Ben 
Published: September 2007

AbstractWork was carried out on the characterization of monovarietal virgin olive oils (VOO) from Tunisia and Sicily (Italy). The two main Tunisian VOO (cvv. Chétoui of the North and cv. Chemlali grown in the Center and some regions of the South) and three principal Sicilian VOO (cvv. Nocellara del Belice, Biancolilla and Cerasuola) were studied. Moreover, the Chétoui oils were tested in a rain‐fed control and an irrigation regime. All olive samples were picked at three different stages of ripeness. Analyses of major components (fatty acids and triacylglycerols) and minor ones (squalene, tocopherols and phenolic compounds) were carried out. Chétoui oils had a higher level of phenolic compounds followed by Chemlali. Generally, in the Sicilian oils these natural antioxidant contents were lower. These preliminary results indicate that it was possible to classify the Tunisian and Sicilian oils tested in their original growing area based on their chemical composition.
Lipid production by oleaginous Mucorales cultivated on renewable carbon sources
Authors: Papanikolaou Seraphim , Galiotou‐Panayotou Maria , Fakas Stylianos , Komaitis Michael , Aggelis George 
Published: September 2007

AbstractMortierella isabellina and Cunninghamella echinulata were cultivated on glucose‐, pectin‐, starch‐ and lactose‐based media. Culture on glucose at two initial C/N ratios favored lipid synthesis in the media with increased C/N. Starch was an adequate substrate for both molds, but lipid (in g/g of biomass) was produced in lower quantities compared with the glucose trial. Pectin was inadequate for C. echinulata whereas growth of M. isabellina was satisfactory (8.4 g/L), followed by moderate lipid production. Growth of C. echinulata on lactose was negligible, while that of M. isabellina was notable (9.5 g/L) although lipid in biomass was only 0.36 g/g. Hydrolytic enzymes (α‐amylase, polygalacturonase and β‐galactosidase) activities of both strains seemed to be low enough to saturate their metabolic capabilities. This seemed a major cause for the lower amount of lipid accumulated during growth on complex media compared with that on glucose. Cellular fatty acids of M. isabellina were oleic, linoleic and palmitic acid, while γ‐linolenic acid (GLA) was produced in low quantities. In C. echinulata grown on glucose, lactose or starch, GLA concentration was notable at the beginning and end of culture. Growth on pectin at the first growth steps was accompanied by the production of saturated fatty acids, the amount of which decreased thereafter.
Synthesis of Spirocyclic Pyridoazepines as Analogues of Galanthamine by Nucleophilic Aromatic Substitution of 3‐Substituted 2‐Chloropyridines
Authors: Vanlaer Sofie , De Borggraeve Wim M. , Compernolle Frans 
Published: September 2007

AbstractIn this report we describe the synthesis of spirocyclic pyridoazepines starting from easily available precursors. The key step of our synthesis is an intramolecular nucleophilic aromatic substitution of the appropriate 3‐substituted 2‐chloropyridines. The final compounds, designed as simplified analogues of the alkaloid galanthamine, showed significant acetylcholinesterase inhibition activity.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Electrochemical Oxidation of ds‐DNA on Polypyrrole Nanofiber Modified Pencil Graphite Electrode
Authors: Özcan Ali , Şahin Yücel , Özsöz Mehmet , Turan Servet 
Published: September 2007

AbstractPreparation of a polypyrrole nanofiber (PPyNF) modified pencil graphite (PG) electrode and its usage in the electrochemical DNA biosensors was investigated. The electrodes (PPyNF/PG1 and PPyNF/PG2) were prepared from a solution containing 0.1 M pyrrole, 0.1 M Na2CO3 and 0.1 M LiCIO4 by using potentiostatic and potentiodynamic methods. PPyNF/PG2 electrodes which were prepared by potentiostatic procedure showed higher responses for the oxidation of ds‐DNA than the PPyNF/PG1 electrodes prepared by potentiodynamic methods. Immobilization of the ds‐DNA on PG and PPyNF/PG surfaces was performed at a constant potential, +0.5 V, for 300 s in 0.5 M ABS (pH 4.8) containing 15 μg mL−1 ds‐DNA and 20 mM LiCIO4. The oxidation peak potentials of the ds‐DNA bases, guanine and adenine, were shifted to more cathodic values by using PPyNF/PG electrodes. The oxidation signal of the guanine base of ds‐DNA was decreased in the presence of methylene blue.
Bismuth Film Electrode as an Alternative for Mercury Electrodes: Determination of Azo Dyes and Application for Detection in Food Stuffs
Authors: Claux Benoît , Vittori Olivier 
Published: September 2007

AbstractBismuth electrodes were investigated and exhibit electrochemical properties similar to mercury electrodes but with much lower toxicity. An electrochemical application of bismuth film modified glassy carbon electrode for azo dyes determination was investigated. The plating step was optimized in order to achieve its analytical efficiency. A plating potential of −0.9 V in a solution of 200 mg/L Bi(NO3)3, 0.5 M HNO3 for 100 s yields to a suitable electrode (in terms of stability and detection). Azo dyes such as azorubine (i.e., carmoisine, E122), amaranth (E123), ponceau 4R (i.e., new coccine, E124) and allura red (E129) were determined by differential pulse voltammetry in a NaCl solution in the concentration range of few ppm to 100 ppm. The reproducibility of the signal, characterized by the relative standard deviation, was found to be less than 5%, the detection and quantification limits were few mg/L. The influence of other food components on the signal was studied and the applicability was tested on real beverages samples.
Preparation of Carbon Nanotubes/Neutral Red Composite Film Modified Electrode and Its Catalysis on Rutin
Authors: Wang Guangfeng , Hu Nianjun , Wang Wen , Li Pengcheng , Gu Haochen , Fang Bin 
Published: September 2007

AbstractNeutral red was directly electropolymerized onto the carbon nanotubes modified electrode. A polymerized neutral red/carbon nanotubes composite film was characterized by scanning electron micrograph (SEM) and cyclic voltammetry (CV). Well‐defined voltammetric responses are observed for [Fe(CN)6]4−/3− on the composite film modified glassy carbon electrode. And it's found that this modified electrode has good catalysis on the redox of rutin. Differential pulse voltammetry method was used to determinate the concentration of rutin and obtain a linear equation between the current and concentration in a certain range. The modified electrode is satisfied with us for its good sensibility and stability.
A Nanocomposite Chitosan Based on Ferrocene‐Modified Silica Nanoparticles and Carbon Nanotubes for Biosensor Application
Authors: Qiu Jian‐Ding , Guo Jin , Liang Ru‐Ping , Xiong Meng 
Published: September 2007

AbstractA novel amperometric biosensor for glucose was developed by entrapping glucose oxidase (GOD) in a chitosan composite doped with ferrocene monocarboxylic acid‐aminated silica nanoparticles conjugate (FMC‐ASNPs) and multiwall carbon nanotubes (MWNTs). The entrapped FMC‐ASNPs conjugate performed excellent redox electrochemistry and the presence of MWNTs improved the conductivity of the composite film. This matrix showed a biocompatible microenvironment for retaining the native activity of the entrapped GOD and was in favor of the accessibility of substrate to the active site of GOD, thus the affinity to substrates is improved greatly. Under optimal conditions this biosensor was able to detect glucose with a detection limit of 10 μM (S/N=3) in the linear range of 0.04 to 6.5 mM. The proximity of these three components FMC‐ASNPs, MWNTs and GOD enhanced the electron transfer between the film and electrode. This composite film can be extended to immobilize other enzymes and biomolecules, which will greatly facilitate the development of biosensors and other bioelectrochemical devices.
CE methods applied to the analysis of micronutrients in foods
Authors: Cheung Rodney Hau Fung , Marriott Philip J. , Small Darryl M. 
Published: September 2007

AbstractThis article reviews the applications of CE that are relevant to the analysis of small molecules in foods. CE has been applied to a wide range of important areas of food analysis and is rapidly being established as an alternative technique to chromatographic methods including HPLC and GC within analytical food and research laboratories. In recent years the analysis of food by CE has become more frequent and important and as such a variety of compounds have been separated and quantified. Although many other analytes have been detected by CE, this review will highlight areas relating primarily to the rather broad chemical classes of free amino acids, carbohydrates, organic acids, vitamins and a variety of antioxidants. In addition, information relating to the analyte, sample matrix, mode of CE employed, scope of the methodology and the detection and derivatization of the small molecules are considered and discussed.
CZE for the speciation of arsenic in aqueous soil extracts
Authors: Kutschera Kristin , Schmidt Anne‐Christine , Köhler Stefan , Otto Matthias 
Published: September 2007

AbstractWe developed two separation methods using CZE with UV detection for the determination of the most common inorganic and methylated arsenic species and some phenylarsenic compounds. Based on the separation method for anions using hydrodynamic sample injection the detection limits were 0.52, 0.25, 0.27, 0.12, 0.37, 0.6, 0.6, 1.2 and 1.0 mg As/L for phenylarsine oxide (PAO), p‐aminophenylarsonic acid (p‐APAA), o‐aminophenylarsonic (o‐APAA), phenylarsonic acid (PAA), 4‐hydroxy‐3‐nitrobenzenearsonic acid (roxarsone), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenite or arsenious acid (AsIII) and arsenate (AsV), respectively. These detection limits were improved by large‐volume sample stacking with polarity switching to 32, 28, 14, 42, 22, 27, 26 and 27 μg As/L for p‐APAA, o‐APAA, PAA, roxarsone, MMA, DMA, AsIII and AsV, respectively. We have applied both methods to the analysis of the arsenic species distribution in aqueous soil extracts. The identification of the arsenic species was validated by means of both standard addition and comparison with standard UV spectra. The comparison of the arsenic species concentrations in the extracts determined by CZE with the total arsenic concentrations measured by inductively coupled plasma‐atomic emission spectroscopy (ICP‐AES) indicated that CZE is suited for the speciation of arsenic in environmental samples with a high arsenic content. The extraction yield of phenylarsenic compounds from soil was derived from the arsenic concentrations of the aqueous soil extracts and the total arsenic content of the soil determined by ICP‐AES after microwave digestion. We found that 6–32% of the total amount of arsenic in the soil was extractable by a one‐step extraction with water in dependence on the type of arsenic species.
Application of CE with novel dynamic coatings and field‐amplified sample injection to the sensitive determination of isomeric benzoic acids in atmospheric aerosols and vehicular emission
Authors: Dabek‐Zlotorzynska Ewa , Piechowski Maria 
Published: September 2007

AbstractA simple and reliable CE method with direct UV detection has been developed to separate eight isomeric benzoic acids in atmospheric aerosols and vehicular emission without complex sample pretreatment. Optimal electrophoretic conditions, with migration times under 5 min, were obtained by using a 50 mM acetate buffer (pH 4.7) containing a dynamic surface coating EOTrol™ LN (0.005% w/v). The separations were carried out in a cathode to anode direction (−30 kV) allowing the low cathodal EOF (∼1×10−9 m2V−1s−1) to extend the effective separation by slowing the movement of the studied aromatic acids. Moreover, the sensitivity of the method at 200 nm was enhanced by using a field‐amplified sample injection (FASI) with electrokinetic (EK) sample injection (−2 kV, 60 s). Prior to sample injection, a short water plug (3 s at 0.5 psi) was introduced. Under these conditions, the method was capable of detecting the analytes in deionized water with LODs (S/N = 3) as low as 0.1 μg/L for most of the studied acids. In the presence of 10 mg/L of sulphate (added to simulate a sample matrix), LODs ranged from 0.26 to 0.62 μg/L. The validation of the method has proven an excellent separation performance and accuracy for the determination of isomeric benzoic acids in the studied matrices.
CE in anticancer metallodrug research – an update
Authors: Hartinger Christian G. , Keppler Bernhard K. 
Published: September 2007

AbstractWith the current demographic development and the knowledge that the probability to be diagnosed with cancer increases with age, the search for new treatment options in cancer chemotherapy is of utmost importance for the society. Capillary electrophoretic methods have been applied in the last few years for studying the properties of metal‐based drugs and drug candidates. Especially, the elucidation of the mode of action of such compounds could contribute significantly to design new drugs for overcoming the threat of cancer. This review article highlights the developments in metallodrug research applying CE during the last 4 years and follows a review from 2003 (Hartinger, C. G., Timerbaev, A. R., Keppler, B. K., Electrophoresis 2003, 24, 2023–2037). Most importantly the broadening of application areas of CE must be noted: especially the binding studies of metal complexes toward proteins (including the determination of association and rate constants), following redox reactions of metal complexes and their influence on the reactivity toward biotargets, etc. are important development areas of the last few years. In parallel with these new applications goes the usage of new or modified separation methods including microemulsion EKC or ACE, or the advantageous use of equipping the CE system with mass spectrometric detectors such as inductively coupled plasma (ICP) or ESI mass spectrometers (MS) for determining the degree of metallation of a protein or characterizing the adducts. Finally, upcoming requirements for expanding the method's application area are discussed including studies on new targets in the cell, analyzing real‐world samples, methodological development, and contributions to improve the design of new anticancer agents.
Determination of vigabatrin in human plasma by means of CE with LIF detection
Authors: Musenga Alessandro , Mandrioli Roberto , Comin Irene , Kenndler Ernst , Raggi Maria Augusta 
Published: September 2007

AbstractA method has been developed for the quantitation of the antiepileptic drug vigabatrin (VGB) in human plasma. It is based on CE with LIF detection. The effect of the pH of the buffer and of N‐methylglucamine (GLC) as BGE constituent was investigated. The final BGE consisted of 50 mM borate buffer, pH 9.0, with 100 mM GLC and enabled separation within 12 min at 20 kV voltage. An SPE procedure was used for the pretreatment of biological samples, based on mixed‐mode lipophilic‐cation exchange cartridges, followed by a derivatization step with 6‐carboxyfluorescein‐N‐succinimidyl ester (CFSE). Fluorescence was excited by an Ar‐ion laser (λexc = 488 nm). Linearity was observed in the 10–120 μg/mL plasma concentration range. Extraction yield was >96%, precision (expressed as RSD) <6.7% and accuracy (recovery) was between 97.0 and 101.6%. The method has been successfully applied to the analysis of VGB in plasma of epileptic patients undergoing therapy with the drug.
Fluorinated ethylenepropylene copolymer as a potential capillary material in CE
Authors: Evenhuis Christopher J. , Yang Wen‐Chu , Johns Cameron , Macka Miroslav , Haddad Paul R. 
Published: September 2007

AbstractIn this work, a new generation UV‐transparent polymer, fluorinated ethylenepropylene copolymer (FEP) exhibiting a low degree of crystallinity, extruded in dimensions similar to the most commonly used CE capillaries of ∼80 μm id and about 360 μm od was investigated for its use as a CE capillary. FEP is transparent down to the low‐UV region, and as fluorinated polymers in general are good electrical insulators and exhibit reasonable heat conductivity, it has considerable potential as a material for electrodriven analysis in capillary or microchip formats. The FEP capillary has been characterised with regard to some important aspects for its use as a CE capillary, including its profile of EOF versus pH, as well as procedures for manipulating EOF by coating the inner capillary wall with various semipermanent and dynamic layers. The FEP capillaries were tested and compared with fused‐silica capillary for the separation of inorganic and small organic ions using conditions involving direct and indirect detection in the low‐UV region. Finally, advantages of the use of the FEP capillary for simultaneous detection of a mixture containing nine inorganic cations and anions using indirect photometric detection with a movable light‐emitting diode (LED) detector and a novel electrolyte are demonstrated.
Analysis of inorganic and small organic ions by CE with amperometric detection
Authors: Chen Rongsheng , Cheng Han , Wu Wenzhan , Ai Xiaoni , Huang Weihua , Wang Zongli , Cheng Jieke 
Published: September 2007

AbstractCapillary electrophoresis has become a widely useful analytical technology. Amperometric detection is extensively employed in capillary electrophoresis for its many inherent virtues, such as rapid response, remarkable sensitivity, and low cost of both detectors and instrumentations. Analysis of inorganic and small organic ions by capillary electrophoresis is an important research field. This review focuses on the recent developments of capillary electrophoresis coupled with amperometric detection for analysis of inorganic and small organic ions. Advancements in electrophoresis separation modes, amperometric detection modes, working electrodes, and applications of inorganic ions, amino acids, phenols, and amines are discussed.