bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclizations of Silyl Enol Ether Radical Cations − The Cause of the Stereoselectivity
Authors: Bunte Jens O. , Heilmann Eike K. , Hein Birka , Mattay Jochen
Published: August 2004

We have used photoinduced electron transfer (PET) activation of silyl enol ethers for the synthesis of tricyclic hydrocarbons. The mechanism of this reaction was investigated by conducting independent radical‐induced cyclizations of corresponding iodo ketones and performing density functional theory (DFT) calculations on the possible intermediates. Our aim was to explain the nature of the reactive intermediate of the cyclization step and to find the causes of the various types of selectivity observed in this process. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Double Cyclization of Bis(α‐hetarylmethyl)amino Esters to Optically Active Bridged N‐Heterocycles of HIV‐Inhibiting Activity
Authors: Faltz Heike , Bender Christoph , Wöhrl Birgitta M. , Vogel‐Bachmayr Karin , Hübscher Ullrich , Ramadan Kristijan , Liebscher Jürgen
Published: August 2004

Anellated 1‐azabicyclo[3.3.1]nonanes 6 were synthesized by several routes starting from natural α‐amino esters 2 and o‐haloaryl‐ or o‐bromohetarylmethyl bromides 1. N‐Alkylation of the starting amino esters to 5 and 3 was followed by halogen/lithium exchange and double cyclization. The cyclization products 6 exhibit interesting inhibition of RNase H and DNA‐polymerase activity of reverse transcriptase (RT) of HIV‐1 at concentrations where human cellular DNA polymerases are not affected. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of Substituted Se‐Phenyl Selenocarboxylates from Terminal Alkynes
Authors: Tiecco Marcello , Testaferri Lorenzo , Temperini Andrea , Bagnoli Luana , Marini Francesca , Santi Claudio , Terlizzi Raffaella
Published: August 2004

Se‐Phenyl selenocarboxylates have been conveniently prepared from (phenylseleno)acetylenes by treatment with p‐toluenesulfonic acid monohydrate in dichloromethane. This easy conversion is compatible with a broad range of oxygen‐ and nitrogen‐containing functional groups. The Se‐phenyl selenocarboxylates were easily converted into the corresponding esters and amides. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
From N‐Substituted Thioamides to Symmetrical and Unsymmetrical 3,4,5‐Trisubstituted 4H‐1,2,4‐Triazoles: Synthesis and Characterisation of New Chelating Ligands
Authors: Klingele Marco H. , Brooker Sally
Published: August 2004

An improved protocol for the synthesis of N‐substituted pyridine‐2‐thiocarboxamides under the conditions of the Willgerodt−Kindler reaction, employing a catalytic amount of sodium sulfide nonahydrate, has been developed. Following this protocol, eight thioamides carrying aromatic or aliphatic N‐substituents have been prepared in good to excellent yields. Condensation of these thioamides or their S‐alkylated congeners with hydrazides in refluxing 1‐butanol has afforded eight unfused 3,4,5‐trisubstituted 4H‐1,2,4‐triazoles in good yields, including four examples of the otherwise not easily obtainable 4‐alkyl‐3,5‐diaryl‐4H‐1,2,4‐triazoles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Mechanistic Aspects of the Bismuth‐Catalysed Oxidation of Epoxides to α‐Diketones
Authors: Antoniotti Sylvain , Duñach Elisabet
Published: August 2004

The mechanism of the direct oxidation of 1,2‐disubstituted epoxides to α‐diketones catalysed by BiIII derivatives was examined. The oxidation was carried out in DMSO under dioxygen. Experimental evidence for the various steps of the reaction was obtained from spectroscopic data, isolation of intermediate species, reactions with Bi0, reaction under dinitrogen rather than under dioxygen, measurement of the oxygen consumption, cyclic voltammetry, and oxidations performed in the presence of methyl phenyl sulfoxide. The direct epoxide‐to‐diketone oxidation involves two main reaction steps: a first DMSO‐mediated oxidative ring‐opening of the oxirane ring, and a second Bi‐catalysed oxidation to the α‐diketone by dioxygen. A catalytic cycle is proposed combining the different results. A new alternative preparation of Bi(OTf)3 by oxidative dissolution of Bi0 is also described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
4,5‐Didehydro‐9‐demethyl‐9‐halo‐5,6‐dihydroretinals and Their 9‐Cyclopropyl and 9‐Isopropyl Derivatives − Simple Preparation of α‐Ionone Derivatives and Pure (all‐E)‐, (9Z)‐ and (11Z)‐α‐Retinals
Authors: Wang Yajie , Lugtenburg Johan
Published: August 2004

α‐Ionone and several of its chemically modified derivatives have been prepared in high yield in full isomeric purity by a Wadsworth−Emmons procedure using imino‐phosphonate anion reagents. Starting from α‐ionone, 5‐(2′,6′,6′‐trimethylcyclo‐2′‐hexen‐1′‐yl)‐4‐penten‐2‐yn‐1‐al could be prepared in a high yielding one‐pot procedure. The corresponding (9‐Cl‐, 9‐Br‐ and 9‐I‐α‐ionylidene)acetaldehyde system could be obtained in one step in a quantitative mixture of (9Z) and (all‐E) isomers by 1,4‐nucleophilic addition reactions. The pure (all‐E) and (9Z) isomers could be separated by simple column chromatography. The corresponding [(9Z)‐ and (all‐E)‐9‐demethyl‐9‐fluoro‐α‐ionylidene]acetaldehydes could also be obtained in pure form by simple column chromatography. These α‐ionylidene systems could be easily converted either into the (all‐E)‐4,5‐didehydro‐9‐demethyl‐9‐halo‐5,6‐dihydroretinals or the corresponding (9Z) isomers in two steps. Similar mixtures of the corresponding (9Z,11Z)‐ and (9Z)‐nitriles could be obtained by normal chemistry. The (9Z,11Z) isomer is the main component of this mixture, and could be obtained in pure form. Subsequent reduction with DIBAL‐H and careful workup gave the pure (9Z,11Z)‐9‐haloretinals. These (9Z,11Z) isomers show a similar extreme acid sensitivity to the corresponding 9‐halo‐β‐retinals. α‐Retinal and its 9‐demethyl, 19,19‐ethano and 19,19‐dimethyl derivatives have been prepared in the (all‐E), (9Z), and (11Z) isomeric forms in a similar manner. The corresponding β‐retinal and its 9‐demethyl derivative in the various isomeric forms are known. In this paper the 19,19‐ethano‐ and 19,19‐dimethyl‐β‐retinals in the (all‐E), (9Z), and (11Z) isomeric forms are also reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
4,5‐Dihydro‐3H‐benzo[c]azepines from 1,7‐Electrocyclization Reactions of 2‐Aza‐4,5‐benzoheptatrienyllithium Compounds
Authors: Gerdes Klaus , Sagar Pramod , Fröhlich Roland , Wibbeling Birgit , Würthwein Ernst‐Ulrich
Published: August 2004

Various differently substituted (2‐alkenylbenzylidene)amines 4b−d gave, upon deprotonation with amide bases and addition of an electrophile, the respective 4,5‐dihydro‐3H‐benzo[c]azepines 6a−k in moderate to good yields. The imines 4 are easily accessible from 2‐bromobenzaldehyde (1) by Wittig olefination, formylation with DMF, and subsequent condensation with benzylamine. The ring‐closure reaction is interpreted as an anionic 1,7‐electrocyclization reaction involving benzo‐annulated 2‐azaheptatrienyllithium compounds. This reaction, and the subsequent addition of the electrophiles, proceed with excellent diastereoselectivity, determined by the (E) or (Z) configuration of the imines 4b−d. The corresponding allylimines 4e,f do not give ninemembered heterocycles 7, but rather the corresponding 3‐vinyl‐4,5‐dihydro‐3H‐benzo[c]azepines 6l,m. Molecular structures of several compounds 6 in the solid state were determined by X‐ray crystallography, including the structure of a 14‐membered ring dimer 8. High‐level quantum chemical calculations on model anions concerning structures and relative energies of possible intermediates and transition states support the pericyclic mechanism suggested for the ring‐closure reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Modular Approach to a New Class of Monodentate Chiral Phosphorus Ligands and Their Application in Enantioselective Copper‐Catalysed Conjugate Additions of Diethylzinc to Cyclohexenone
Authors: Monti Chiara , Gennari Cesare , Steele Rebecca M. , Piarulli Umberto
Published: August 2004

A new family of chiral phosphorus ligands (5) for use in enantioselective catalysis have been synthesised. The ligands contain the electron‐poor bis(sulfonyl)diazaphospholidine moiety and possess a highly modular structure which is well suited to the synthesis of a library. A small library (23 members) of ligands 5 was prepared and tested in the enantioselective copper‐catalysed conjugate addition of diethylzinc to cyclohexenone. Complete conversions were obtained with enantiomeric excesses (ee) of up to 75%. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
First Stable O‐Amidinylhydroxylamines and Their Transformations into Sulfenamides by Intramolecular 1,5‐O→S Amine Migration
Authors: Sączewski Franciszek , Kornicka Anita , Gdaniec Maria , Hałasa Rafal , Werel Władyslaw
Published: August 2004

The reaction of 2‐chloro‐4,5‐dihydroimidazole (1) with aliphatic hydroxylamines 2−4 gives O‐amidinylhydroxylamines 5−7 in contrast to the analogous reaction of 1 with N‐arylhydroxylamines in which N‐substitution occurs. A number of thiocarbamoylsulfenamides 8−10 have been prepared by the reaction of 5−7 with carbon disulfide under basic and mild conditions. The key step in the 1,5‐O→S amine migration involves the tandem nucleophilic addition‐electrophilic amination reaction. The intermolecular version of this process using preformed triethylammonium dithiocarbamates gives the corresponding sulfenamides 14−16. Functionalized ethylenediamines 17−19 are obtained by treatment of 8 and 9 with amines. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Stabilised 2,3‐Pyridyne Reactive Intermediates of Exceptional Dienophilicity
Authors: Connon Stephen J. , Hegarty Anthony F.
Published: August 2004

The enhanced dienophilicity of 4‐methoxy, 4‐aryloxy and 4‐thiophenoxy analogues 6−9 of 2,3‐pyridyne (2) relative to 2 itself is reported. The regioselective lithiation of 4‐alkoxy‐ (22, 23 and 25) and 4‐thiophenoxy‐2‐chloropyridine (24) at low temperatures, followed by elimination of lithium chloride affords 4‐alkoxy‐ and 4‐thiophenoxypyridynes, which can be trapped in situ in a [4+2] cycloaddition reaction with furan to give endoxides 28−31 in moderate to good yields (25−58%). In contrast, precursors with a hydrogen (18) or methyl (12) substituent at C‐4 give no evidence for pyridyne formation under these conditions. Attempts to generate 6‐isopropoxy‐2,3‐pyridyne (10) from the low‐temperature lithiation of 2‐chloro‐6‐isopropoxypyridine were unsuccessful due to the instability of the 2‐chloro‐6‐isopropoxy‐5‐lithiopyridine. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Pd/C‐Catalyzed Transfer Reduction of Aryl Chlorides with Sodium Formate in Water
Authors: Arcadi Antonio , Cerichelli Giorgio , Chiarini Marco , Vico Raquel , Zorzan Daniel
Published: August 2004

Sodium formate catalytic transfer reduction, in the presence of palladium on carbon, accomplishes not only the rapid dehalogenation of aromatic chlorocarbons in water at room temperature, but also the reduction of the aromatic moieties to alicyclic rings at 100 °C. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
The Reaction of 3,4‐Dinitrothiophene with Grignard Reagents: Formation of 2‐(3‐Amino‐4‐nitrothiophen‐2‐yl)phenols
Authors: Bianchi Lara , Dell'Erba Carlo , Maccagno Massimo , Mugnoli Angelo , Novi Marino , Petrillo Giovanni , Severi Elda , Tavani Cinzia
Published: August 2004

The treatment of 3,4‐dinitrothiophene with an aryl Grignard reagent results in the reduction of one nitro group accompanied by the ipso‐substitution of a hydrogen atom by an ortho‐phenolic group on the ring carbon adjacent to the reduced nitro group. A Claisen‐type intramolecular rearrangement is proposed as the pivotal step of a rather complex mechanism, followed by proton‐transfer aromatizing steps. This work shows yet another facet of the variegated reactivity of 3,4‐dinitrothiophene towards nucleophiles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis and Characterization of a New Fluorescent Zwitterionic Spirocyclic Meisenheimer Complex of 1,3,5‐Trinitrobenzene
Authors: Al‐Kaysi Rabih O. , Guirado Gonzalo , Valente Edward J.
Published: August 2004

In this communication we present the first stable zwitterionic spirocyclic Meisenheimer compound based on an N→N rearrangement in the reaction between picric acid and diisopropylcarbodiimide. The structure was confirmed by single‐crystal X‐ray diffraction. Furthermore, this compound exhibits interesting fluorescence properties (φf = 0.4−0.5), not shared with a typical Meisenheimer complex, and a fluorescence lifetime (τ = 9.1 ns) in dichloromethane. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A New Route for the Thermal Isomerization of a Highly Substituted Hexadienyne Derivative
Authors: Berger Harald , Hopf Henning , Dix Ina , Jones Peter G.
Published: August 2004

Whereas the thermal isomerization of perphenylbutenyne (11) at 290 °C in toluene leads to the benzannelated semibullvalene derivative 13, pyrolysis at 360 °C furnishes the triphenylnaphthalene 12. The mechanisms of both cycloisomerizations, which presumably proceed via the isobenzene intermediate 14, are discussed. The structure of the rearrangement product 13 was proven by single‐crystal X‐ray analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
The Formal [3+2+1] Cyclisation of Cyclopropylamines with Carboxylic Anhydrides: A Quick Access to Polysubstituted 2,3,3a,4‐Tetrahydro6(5H)‐indolone Ring Systems
Authors: Larquetoux Laurent , Kowalska Justyna A. , Six Yvan
Published: August 2004

Several 2‐azabicyclo[3.1.0]hexanes were synthesised using the intramolecular version of the Kulinkovich−de Meijere cyclopropanation reaction. Upon heating in the presence of a carboxylic anhydride, the cyclopropane rings of these systems open up to afford vinylogous amides. Depending on the reaction conditions used, the monoacylated compounds may be the major products, or subsequent acylation may take place to afford cyclic diketones. The method is flexible, and it is possible to incorporate different acyl groups in a two‐step sequence. The diketones are easily converted into 2,3,3a,4‐tetrahydro‐6(5H)‐indolone derivatives by intramolecular aldolisation. The products, which are highly functionalised alcohols, are obtained as single diastereoisomers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A New Neighbouring‐Group Reaction to Form Pyridopyrrolobenzoxazinediones
Authors: Hamprecht Gerhard , Zimmermann Norbert , Weiß Thomas D.
Published: August 2004

The azaphthalimide 2a is the first phthalimide oxygen found to undergo a neighboring‐group participation reaction with a vicinal N‐phenyl carboxylic acid chloride upon nucleophilic addition with alcohols. Owing to the free rotation of the N‐phenyl moiety, hetero‐anellated benzoxazinedione isomers 3 and 4 are accessible, whereby 3 is preferred to 4 as the pyridine nitrogen in 2a preferentially activates the o‐carbonyl group. Yields of up to 92% were obtained when bases such as HCl acceptors were avoided by heating 2a with alcohols. The reaction is restricted to primary and secondary alcohols, as 2a is nonplanar in respect of the heterocyclic and benzene moiety, which prevents tertiary alcohols attacking the pyrrolidinedione carbonyl group. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Cover Picture: Synthesis and Biological Evaluation of Phorbol‐Resiniferatoxin (RTX) Hybrids (Eur. J. Org. Chem. 16/2004)
Authors: Appendino Giovanni , Bertolino Andrea , Minassi Alberto , Annunziata Rita , Szallasi Arpad , de Petrocellis Luciano , Di Marzo Vincenzo
Published: August 2004

The cover picture shows Euphorbia resinifera Berg and its constituent resiniferatoxin (RTX), a phorboid that acts as an ultrapotent biological analogue of capsaicin, the hot principle of chili pepper and the archetypal vanilloid. Ever since its isolation, interest within the organic community for phorbol has been high on account of its challenging structure, puzzling reactivity, and remarkable bioactivity. Diacyl derivatives of phorbol can act as ultrapotent analogues of the endolipid sn‐1,2‐diacylglycerol (DAG) and show powerful tumour‐promoting properties. The more recent discovery that certain non‐tumour‐promoting phorbol derivatives and phorbol‐related compounds can activate vanilloid receptors of the TRPV1 and TRPV4 type has made phorbol very interesting also for neurosciences. The article by G. Appendino et al. on p. 3413 ff. describes the synthesis of hybrid phorbol‐resiniferatoxin of interest for the study of vanilloid receptors, which discloses some new and unpredictable aspects of the chemistry of phorbol. (Photo courtesy by Prof. Mauro Ballero, University of Cagliari)
Electrochemistry of Nucleic Acids at Solid Electrodes and Its Applications
Authors: de‐los‐Santos‐Álvarez Patricia , Lobo‐Castañón M. Jesús , Miranda‐Ordieres Arturo J. , Tuñón‐Blanco Paulino
Published: August 2004

The knowledge of the redox chemistry of nucleic acids (NA) is of paramount importance in cancer and aging research. Charge migration through DNA is also involved in biologically relevant functions such as DNA damage and repair. In the first part of this article the main aspects of the electrochemistry of nucleic acids at solid electrodes are revised, including redox processes, photoelectroactivity and electrical conductivity. In the second part, an overview of its applications is presented. Methods for electrochemical detection of NA, NA‐based biosensors for detection of nonnucleic acid molecules, studies on the nature and dynamics of interactions and structural conformations of NA, are some applications that take advantage of NA electrochemistry at solid electrodes.
Usefulness of visible dyes for the staining of protein or DNA in electrophoresis
Authors: Jin Li‐Tai , Choi Jung‐Kap
Published: August 2004

Since 1993, we have studied visible organic dye stains for protein or DNA to improve methodologies and developed the counterion dye staining method. The method employs two oppositely charged dyes that form an ion‐pair complex in the staining solution. The selective binding of free dye to protein or DNA in the staining solution improves detection sensitivity and speed. It is a rapid and sensitive procedure, involving fixing/staining or staining/quick destaining steps that are completed in 1–1.5 h. The lowest detection limits achieved are 4–8 ng of protein on polyacrylamide gels and ∼10 ng of DNA on agarose gels. The focus of this review is to chronicle the development and current status of the counterion dye staining method for detection of protein or DNA. As an extended application of visible dyes, we also discuss the visible dye staining method for detecting protein on blotting membranes developed in our laboratory.
Detection of tetracysteine‐tagged proteins using a biarsenical fluorescein derivative through dry microplate array gel electrophoresis
Authors: Feldman Galia , Bogoev Roumen , Shevirov Julia , Sartiel Adam , Margalit Ilana
Published: August 2004

The design of an extended‐run 96‐well sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) system and the development of protein detection technology based upon fluorescein derivatives that bind to peptide epitope tags, allows the creation of a truly high‐throughput analysis of protein expression, where less than 20 min are needed to separate proteins and analyze results. We demonstrate the overall capabilities of such a method combination in a complex cell lysate background, while comparing the specific results obtained using a biarsenical fluorescein‐derivative and tetracysteine epitope‐tagged proteins with total protein staining using a fluorescent gel stain and with Western blotting where an anti‐oligohistidine (His) tag antibody has been employed. When applied on purified target proteins without extraneous protein background, the demonstrated sensitivity of the assay on the extended‐run 96‐array precast SDS‐PAGE system allows detection of quantities of tagged protein as low as 1 pmol per band.
Speciation of protein‐bound trace elements by gel electrophoresis and atomic spectrometry
Authors: Ma Renli , McLeod Cameron W. , Tomlinson Kerry , Poole Robert K.
Published: August 2004

The metabolism of trace elements, in particular their binding to proteins in biological systems is of great importance in biochemical, toxicological, and pharmacological studies. As a result there has been a sustained interest over the last two decades in the speciation of protein‐bound metals. Various analytical approaches have been employed, combining efficient separation of metalloproteins by liquid chromatography or electrophoresis with high‐sensitivity elemental detection. Slab‐gel electrophoresis (GE) is a key platform for high‐resolution protein separation, and has been combined with autoradiography and various atomic spectrometric techniques for in‐gel determination of protein‐bound metals. Recently, the combination of GE with state‐of‐the‐art inductively coupled plasma‐mass spectrometry (ICP‐MS), particularly when linked to laser ablation (LA) for direct gel interrogation, has opened up new opportunities for rapid characterization of metalloproteins. The use of GE and atomic spectrometry for the speciation of protein‐bound trace elements is reviewed in this paper. Technical requirements for gel electrophoresis/atomic spectrometric measurement are considered in terms of method compatibilities, detection capability and potential usefulness. The literature is also surveyed to illustrate current status and future trends.
A rapid solid‐phase fluorescence‐based protein assay for quantitation of protein electrophoresis samples containing detergents, chaotropes, dyes, and reducing agents
Authors: Agnew Brian J. , Murray Dustin , Patton Wayne F.
Published: August 2004

A new solid‐phase, fluorescence‐based protein assay was developed that quantifies proteins in the presence of detergents, urea and reducing agents (one‐dimensional sodium dodecyl sulfate (1‐D SDS) lysis buffers and urea isoelectric focusing (IEF) buffers). A specially designed 96‐well microplate facilitates application of protein samples to the assay paper and allows easy quantitation of samples using fluorescence microplate readers (top or bottom reading format). Alternatively, stained membranes may be directly scanned using a variety of different laser or charge‐coupled device (CCD)‐based imaging devices with UV or visible imaging capabilities. Since protein is specifically bound to the membrane, contaminants are readily washed away, avoiding interference with the protein measurement. The protein assay has a dynamic range extending from 10 ng to 5 μg of protein per microliter and requires only 1 μL of sample, which is ideal for samples destined for electrophoresis. The protein‐to‐protein variability of staining of ten different proteins was determined to be comparable with that of the bicinchoninic acid (BCA) and Lowry assays (16%). Additionally, the quality of the assay according to Z‐factor analyses is excellent.
Detection of phosphoproteins on electroblot membranes using a small‐molecule organic fluorophore
Authors: Goodman Teresa , Schulenberg Birte , Steinberg Thomas H. , Patton Wayne F.
Published: August 2004

A new formulation of the small‐molecule organic fluorophore, Pro‐Q® Diamond dye, has been developed that permits rapid and simple detection of phosphoproteins directly on polyvinylidene difluoride (PVDF) or nitrocellulose membranes (electroblots). Protein samples are first separated by electrophoresis and then electroblotted to membranes, stained and destained, in an analogous manner as typically performed with Amido Black or Ponceau S dye staining of total protein profiles. After staining, blots are imaged using any of a variety of laser‐based gel scanners, xenon‐arc lamp‐based gel scanners or charge‐coupled device (CCD) camera‐based imaging devices equipped with UV trans‐ or epi‐illumination. The uncomplicated and reliable staining protocol delivers results in as little as 1 h and the limit of detection for the stain is typically 2–4 ng of phosphoprotein with a linear dynamic range of approximately 15‐fold. Compared with traditional radiolabeling and antibody‐based approaches, the new method offers significant advantages, including avoidance of radioactivity, no need for expensive antibodies, no requirement for blocking unoccupied sites on the membrane with protein or detergent solutions, no sequence context‐specific binding to phosphorylated amino acid residues and the ability to analyze the native, steady‐state phosphorylation of proteins obtained directly from tissue specimens or body fluids. Pro‐Q Diamond dye binds directly and exclusively to the phosphate moiety, allowing it to detect the broadest spectrum of phosphorylated proteins possible. The stain binds noncovalently to phosphoproteins and is thus fully compatible with matrix‐assisted laser desorption/ionization‐time of flight‐mass spectrometry (MALDI‐TOF‐MS) or Edman sequencing. The blot stain is also compatible with standard colorimetric, fluorogenic, and chemiluminescent detection techniques employed in immunoblotting.
Effects of External Mass Transfer and Product Inhibition on a Simulated Immobilized Enzyme‐Catalyzed Reactor for Lactose Hydrolysis
Authors: AL‐Muftah A. E. , Abu‐Reesh I. M.
Published: August 2004

A mathematical model has been developed for predicting the performance and simulation of a packed bed immobilized enzyme reactor performing lactose hydrolysis, which follows Michaelis‐Menten kinetics with competitive product (galactose) inhibition. The performance characteristics of a packed bed immobilized enzyme reactor have been analyzed taking into account the effects of various diffusional phenomena like axial dispersion and external mass transfer limitations. The model design equations are then solved by Galerkin's method and orthogonal collocation on finite elements. The effects of external mass transfer and axial dispersion have been studied and their effects were shown to reduce the external effectiveness factor. The effects of product inhibition have been investigated at different operating conditions correlated at different regimes using dimensionless moduli (St, γ, θ, Da)1). The product inhibition was shown to reduce the substrate conversion, and, additionally, to decrease the effectiveness factor when Da > Daxo, however, it increases the effectiveness factor when Da < Daxo. The effectiveness factor is found to be independent of the product inhibition at a crossover point at which Daxo is defined. Effects of St and Pe have been investigated at different kinetic regimes and the results show that their effects have a strong dependency on the kinetic parameters θ, γ (i.e., Km/Kp), and Daxo.
Production of Liquid, Water‐Dispersible, Phytosterol Formulations for Increased Dose Response in Food Systems
Authors: Engel R. , Knorr D.
Published: August 2004

Vital to the stability of plant cell membranes, phytosterols are present in all foods of plant origin. Over forty different known phytosterols, of which β‐sitosterol, stigmasterol and campesterol are prevalent in natural products, can be distinguished from cholesterol as well as from each other. The development of formulations of chemically unbound, non‐crystalline phytosterols is desirable in order to decrease the required daily dose, at constant health promoting effect.
Selection and Application of Microorganisms to Improve Oil Recovery
Authors: Almeida P. F. , Moreira R. S. , Almeida R.C.C. , Guimarães A. K. , Carvalho A. S. , Quintella C. , Esperidiã M. C. A. , Taft C. A.
Published: August 2004

Microbial enhanced oil recovery (Meor) is an incontestably efficient alternative to improve oil recovery, especially in mature fields and in oil reservoirs with high paraffinic content. This is the case for most oil fields in the Recôncavo basin of Bahia, Brazil. Given the diverse conditions of most oil fields, an approach to apply Meor technology should consider primarily: (i) microbiological studies to select the appropriate microorganisms and (ii) mobilization of oil in laboratory experiments before oil field application. A total of 163 bacterial strains, selectively isolated from various sources, were studied to determine their potential to be used in Meor. A laboratory microbial screening based on physiological and metabolic profiles and growth rates under conditions representative for oil fields and reservoirs revealed that 10 bacterial strains identified as Pseudomonas aeruginosa (2), Bacillus licheniformis (2), Bacillus brevis (1), Bacillus polymyxa (1), Micrococcus varians (1), Micrococcus sp. (1), and two Vibrio species demonstrated potential to be used in oil recovery. Strains of B. licheniformis and B. polymyxa produced the most active surfactants and proved to be the most anaerobic and thermotolerant among the selected bacteria. Micrococcus and B. brevis were the most salt‐tolerant and polymer producing bacteria, respectively, whereas Vibrio sp. and B. polymyxa strains were the most gas‐producing bacteria. Three bacterial consortia were prepared with a mixture of bacteria that showed metabolic and technological complementarity and the ability to grow at a wide range of temperatures and salinity characteristics for the oil fields in Bahia, Brazil. Oil mobilization rates in laboratory column experiments using the three consortia of bacteria varied from 11.2 to 18.3 % [v/v] of the total oil under static conditions. Consortia of B. brevis, B. icheniformis and B. polymyxa exhibited the best oil mobilization rates. Using these consortia under anaerobic conditions could be an interesting alternative for Meor technology because their growth could be easily controlled through the administration of phosphate and inorganic electron acceptors. Bacterial strains selected in this work could be valuable for further application in oil recovery at productive and mature oil well sites as well as for the prevention and control of paraffin deposits.
Search of Microorganisms that Degrade PAHs under Alkaline Conditions
Authors: Gerbeth A. , Krausse S. , Gemende B. , Müller R.H.
Published: August 2004

Bacterial strains were enriched from building rubble contaminated with polycyclic aromatic hydrocarbons (PAHs). These strains were studied as an inoculum in bioremediation processes with contaminated building rubble. The selection criteria for the bacteria were broad profiles in PAH degradation, stable expression of the traits and tolerance to alkaline conditions. Various strains of Micrococcus sp., Dietzia sp., Rhodococcus sp. and Pseudomonas sp. met the selection criteria. In general, degradative activity was limited at higher pH values. Strains of Micrococcus were suitable for practical use as complete degradation of various PAHs was observed at pH values exceeding 10. Strains of Dietzia sp. showed broad PAH degradation profile, but in some cases degradation came to a halt leaving some of the PAHs unutilized. With Dietzia sp. this could be due to inhibitory effects from the accumulation of toxic PAH metabolic products and/or growth‐limiting media conditions.
Monitoring Microbial Attachment in Seawater
Authors: Li X. , Wang J. , Liu X. , Wang W. , Yan L.
Published: August 2004

The attachment activity of microorganisms in seawater was studied by electrochemical and microscopic techniques. It was frequently observed that in natural seawater, the open circuit potential (Eocp) of stainless steel was ennobled due to biofilm formation on the metal surface. Microscope observation revealed that the ennoblement of the Eocp value of stainless steel changed linearly with the number of bacteria attached to the metal surface. Considering the fact that Eocp of copper is almost a constant for a longer time in seawater, a compound electrode was made up of a stainless steel electrode and copper electrode for assessing the attachment of microbes in different seawater media according to the change in the potential difference between the two metals. The results demonstrated a good performance of the compound electrode for this purpose.
Effects of Cadmium Exposure on Phytochelatin and the Synthesis of Abscisic Acid in Funalia trogii
Authors: Yürekli F. , Ünyayar A. , Porgali Z.B. , Mazmanci M.A.
Published: August 2004

Heavy metal toxicity poses major environmental and health problems as heavy metals are more difficult to remediate than chemical contaminants, which can be degraded by microorganisms. Phytochelatins are formed in plants and some fungi upon exposure to a range of different heavy metals. Fungi show sensitivity to many environmental factors, including nutrient limitation, changes in carbon sources and heavy metal exposure.
Phosphate‐Assisted Phytoextraction in As‐Contaminated Soil
Authors: Tassi E. , Pedron F. , Barbafieri M. , Petruzzelli G.
Published: August 2004

In this paper, the effect of phosphate on As phytoextraction was examined. The effect of phosphate on As dissolution, the As uptake of plants, the internal plant translocation, and phytotoxic effect were investigated. Lupine plants were grown on As‐contaminated soil collected from an industrial site containing 670 mg/kg As and were treated with biammonium phosphate (BAP). Two different BAP application procedures were tested: single‐dose and multiple split additions. BAP was found to be effective in increasing the water‐soluble As concentration in the test soil. As the concentration of water‐soluble As increased, the Lupine plants responded accordingly with an increased As uptake. The As content in the shoots and the translocation factor were the highest when BAP was added in multiple split additions. On the contrary, a single application caused the highest As content in the roots and consequently the lowest translocation factor. In addition, it was established that the single‐application method significantly reduced the plant biomass by twofold, this reduction being an evident phytotoxic symptom. Measurements of the combined biomass production and As content values revealed that the highest As phytoextraction is obtained with BAP applied in multiple doses which is about 14‐fold higher than in the control plants, whereas a single‐dose BAP application increased the phytoextraction rate only 1.6 times. These results demonstrate that significant improvements in the current phosphate‐assisted phytoextraction of As could be achieved.
Production of α‐Amylase and Glucoamylase by a New Isolate of Trichoderma sp. Using Sorghum Starch as a Carbon Source
Authors: Pacheco‐Chávez R.A. , Carvalho J.C.M. , Tavares L.C. , Vessoni Penna T.C. , Converti A. , Sato S.
Published: August 2004

The performance of a new Trichoderma sp. isolate to produce extracellular α‐amylase and glucoamylase from raw sorghum starch was evalutated. To reduce the costs of starch saccharification and the consumption of amylolytic enzymes, this microorganism has been used for the first time in cultivations using such a carbon source without any prior gelatinization.
Biotreatment of Industrial Wastewater by Selected Algal‐Bacterial Consortia
Authors: Safonova E. , Kvitko K.V. , Iankevitch M.I. , Surgko L.F. , Afti I.A. , Reisser W.
Published: August 2004

A new approach for remediation processes in highly polluted environments is presented. The efficiency of algal‐bacterial associations for the remediation of industrial wastewater of a pond in Samara, Russia, was investigated. After screening of algae and bacteria for the resistance to the wastewater the following strains were selected: the algal strains Chlorella sp. ES‐13, Chlorella sp. ES‐30, Scenedesmus obliquus ES‐55, several Stichococcus strains (ES‐19, ES‐85, ES‐86, ES‐87, ES‐88), and Phormidium sp. ES‐90 and the bacterial strains Rhodococcus sp. Ac‐1267, Kibdelosporangium aridum 754 as well as two unidentified bacterial strains (St‐1, St‐2) isolated from the collector pond. All the strains listed above were immobilized onto various solid carriers (capron fibers for algae; ceramics, capron and wood for bacteria) and used for biotreatment in a pilot installation. The results showed that the selected algae and bacteria formed stable consortia during the degradation of the waste, which was demonstrated for the first time for the green alga Stichococcus. Stichococcus and Phormidium cells attached to capron fibers with the help of slime and formed a matrix. This matrix fixed the bacteria and eukaryotic algae and prevented them from being washed off. A significant decrease in the content of the pollutants was observed: phenols were removed up to 85 %, anionic surface active substances (anionic SAS) up to 73 %, oil spills up to 96 %, copper up to 62 %, nickel up to 62 %, zinc up to 90 %, manganese up to 70 %, and iron up to 64 %. The reduction of the biological oxygen demand (BOD25) and the chemical oxygen demand COD amounted to 97 % and 51 %, respectively.
Rapid Purification of High Quality DNA from Large Whole Blood Samples Using a New Rapid Protocol
Authors: Long J.‐R. , Zhang Y.‐Y. , Hofer E. , Seemann C. , Schatz M. , O'Brien D. , Deng H.‐W.
Published: August 2004

The efficiency and quality of DNA purification from blood samples is one of the important issues for genetic studies on human diseases. Several protocols for the isolation of genomic DNA from blood have been described. In order to improve the efficiency of the purification without affecting DNA quality and quantity, a new protocol, called Puregene EP (Enhanced Productivity) is described for this kit.
An Integrated System for the Bioremediation of Wastewater Containing Xenobiotics and Toxcic Metals
Authors: Chuichulcherm S.
Published: August 2004

An integrated system for the biotreatment of acidic wastewaters containing both toxic metals and organics is presented. It consists of two bioprocess stages (i) an anaerobic, SRB stage (containing alkaline‐tolerant sulfate‐reducing bacteria) that at pH 8 (chosen to acclimatize the bacteria in the biomedium) produces high concentrations of total sulfide ions (more than 400 mg/L) which are added to the wastewater to precipitate the heavy metals out at pH 2 as metal sulfides, and (ii) an aerobic, acidophilic stage containing heterotrophic bacteria (WJB3) that degrade organic xenobiotics.

The anaerobic system was comprised of a 4‐L fluidized bed bioreactor with immobilized SRB, a mixing tank, and a precipitation tank. The effluent from the bioreactor with a high concentration of sulfide ions was fed into a mixing tank where model wastewaters containing toxic metals and phenol at pH 2 were also fed at increasing loading rates until free metal ions could be detected in the precipitation tank outlet. Then the effluent from the precipitation tank outlet was fed into a 2.5‐L aerobic bioreactor in which phenol was degraded. In this research, 100 % removal efficiencies were obtained with wastewaters containing more than 400 mg/L metal ions and 900 mg/L phenol at a 6‐h HRT of the mixing tank.
Cultivation of the Dible Mushroom Lentinula edodes (Shiitake) in Pasteurized Wheat Straw – Alternative Use of Georthermal Energy in Mexico
Authors: Mata G. , Gaitán‐Hernández R.
Published: August 2004

Five edible Lentinula edodes strains were evaluated. The mushrooms were cultivated on a wheat straw substrate that was previously pasteurized by immersion in water heated by residual geothermal vapor, which was also used to warm incubation and production rooms. Finely chopped wheat straw (Triticum aestivum L.) was pasteurized and then spawned with supplemented spawn capable of supplying nutrients and enriching the substrate, with the expectation of yield improvement. The samples were incubated for 60 days before the production started and thus, the mushrooms produced had pileus diameters ranging from 5 to 20 cm. The yields fluctuated from 6.2 to 13.9 % (fresh weight of mushrooms/fresh weight of substrate). Biological efficiency ranged from 24.8 to 55.6 % (fresh weight of mushrooms/dry weight of substrate), while the production rate reached varied from 0.19 to 0.55 % (biological efficiency/production time starting from inoculation).

The cultivation system evaluated here offers the possibility of lowering production costs by cultivating the mushroom on easily obtainable substrate and shortening the culture cycle. The efficiency of this use of geothermal energy and supplemented spawn for shiitake mushroom cultivation on non‐sterilized substrates was proven.
Profit‐based unit commitment for GenCos in a deregulated power market
Authors: Yamin H. Y.
Published: August 2004

This paper presents a new formulation and solution methodology for the profit‐based unit commitment problem in C++ for a price‐taker GenCo in a day‐ahead deregulated power market. This model can be used by the price‐taker GenCo in order to maximize its own profit through committing and scheduling its units. The demand, spinning reserve and non‐spinning reserve as well as the probability that reserves are called and generated are considered in the proposed model. The mixed integer programming problem is solved using Lagrangian Relaxation (LR) and the multipliers are updated using Evolutionary Programming (EP). The proposed method uses the advantage of EP which can provide a near‐global solution combined with the advantage of LR which can find a solution within a short time. Once the unit commitment is determined, the generation scheduling problem is solved using the interior point method. The tests of the proposed model are performed on an IEEE 118‐bus network and a GenCo with 36 units. Copyright © 2004 John Wiley & Sons, Ltd.
Aroma compounds and volatile chemical composition of Ruellia menthoides (Nees) Hiern
Authors: Facundo Valdir A. , Pinto Angelo C. , Rezende Claudia M.
Published: August 2004

The aerial parts of Ruellia menthoides (Acanthaceae) were submitted to steam distillation from which an intense spicy and camphoraceous aroma was obtained. Gas chromatography–mass spectrometry analysis associated to co‐injection of standards suggested mono and sesquiterpenes as the main compounds. Aroma extract dilution analysis indicated 1,8‐cineole and S‐(−)‐camphor as the most intense compounds of the extract using chiral gas chromatography. Odor threshold for both compounds was determined by gas chromatography–olfactometry. Copyright © 2004 John Wiley & Sons, Ltd.
Investigation of the aroma compounds from headspace and aqueous solution from the cambará (Gochnatia Velutina) honey
Authors: Moreira R. F. A. , De Maria C. A. B.
Published: August 2004

An investigation was carried out to identify the compounds responsible for the cambará honey aroma. Volatiles were isolated from the headspace or aqueous extract by adsorptive column chromatography, eluted with acetone and analysed by GC–FID, GC–O and GC–MS. Volatiles were separated on polar and non‐polar phase columns. Phenylacetic acid, diethylene glycol and benzaldehyde were by far the most abundant volatile compounds in the aqueous extract, while benzaldehyde and benzonitrile predominated in the headspace fraction. Based on AEDA, benzaldehyde, 2,3‐methybutanoic acid and benzonitrile were found to be the most potent odorants in both headspace and aqueous extract aromas. 2‐Phenylethanol was only found in the headspace aroma. Phenyl‐1,2‐propanedione, benzoic and phenylacetic acid were odour‐active compounds found only in the aqueous extract. Copyright © 2004 John Wiley & Sons, Ltd.
Increased power for case‐control studies of single nucleotide polymorphisms through incorporation of family history and genetic constraints
Authors: Thompson Deborah , Witte John S. , Slattery Martha , Goldgar David
Published: August 2004

Association studies assessing the relationship between a common polymorphism and disease generally compare allele frequencies in cases and controls. In such studies, a limited amount of information is often available about disease incidence in relatives. We hypothesised that more power could be obtained by incorporating the constraints imposed by the properties of a genetic polymorphism, and that power could be further increased by using family history (FH) information. We have developed a simple method for incorporating basic FH information from cases and controls into a genetic association study, assuming Hardy‐Weinberg equilibrium (HWE) in the general population. We model the likelihood of the data in terms of the allele frequency and its relative risk (RR) of disease and perform likelihood ratio tests. Using simulations, we compared the power to detect an association using this approach with that of a 2 × 2 chi‐squared test, for a range of disease models. The sample size required to detect an association is consistently lower for tests including the HWE constraint, with the largest reduction for more common alleles. The required sample size is reduced further by stratifying by FH. Stratifying by FH also improves the precision of the RR estimates. In situations where basic FH data are already available, this study shows that efficiency can be improved by the inclusion of even this small amount of extra information. © 2004 Wiley‐Liss, Inc.
Linkage disequilibrium mapping in trisomic populations: Analytical approaches and an application to congenital heart defects in Down syndrome
Authors: Kerstann Kimberly F. , Feingold Eleanor , Freeman Sallie B. , Bean Lora J. H. , Pyatt Robert , Tinker Stuart , Jewel Amy H. , Capone George , Sherman Stephanie L.
Published: August 2004

Many of the birth defects associated with trisomy exhibit both variable expressivity and incomplete penetrance. This variability suggests that it is allelic variation and not simply the presence of an additional chromosome that leads to the development of certain trisomy‐associated birth defects. With the proper tools, one may use trisomic populations to identify genes involved in the development of specific birth defects. A trisomic population may be advantageous over a normal population if the defect is over‐represented in the trisomic population. Alternatively, one can view the trisomic populations as a “model system” to offer insight into aspects of both normal and abnormal embryonic development. Standard disomic linkage disequilibrium mapping approaches need to be adjusted to account for the presence of the additional genetic material in the trisomic individuals. We present an approach for linkage disequilibrium mapping of variable phenotypes in a trisomic population that adequately accounts for the additional alleles and the pattern of non‐independent inheritance. We establish the laboratory methods and statistical tools necessary to conduct an association study in a trisomic population. As an example, we have applied these tools to a pilot study of Down syndrome–associated congenital heart defects. © 2004 Wiley‐Liss, Inc.
Reconstruction of the hard palate using the radial forearm free flap: Indications and outcomes
Authors: Genden Eric M. , Wallace Derrick I. , Okay Devin , Urken Mark L.
Published: August 2004

Background.

Although prosthetic obturation is the “gold standard” for restoration of hard‐palate defects, obturators can be problematic. We present 10 cases of palatal reconstruction with the radial forearm free flap and compare patient satisfaction with defect‐matched patients rehabilitated with prosthetic obturation.

Methods.

Twelve patients who underwent radial forearm free flap (RFFF) reconstruction of a hard‐palate defect and eight patients, with similar‐sized defects who were rehabilitated with a prosthetic obturator, were evaluated for donor site and recipient site complications, diet, and patient satisfaction.

Results.

All the patients in both groups were able to resume an unrestricted diet with normal mastication and articulation. Both groups achieved equivalent satisfaction scores with regard to appearance, chewing, and taste; however, the patients reconstructed with an RFFF reported higher satisfaction scores in speech, comfort, convenience, and social interaction.

Conclusions.

RFFF reconstruction of hard‐palate defects provides a functional alternative to conventional prosthetic obturators. © 2004 Wiley Periodicals, Inc. Head Neck 26: 808–814, 2004