bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transition metal free reductive dimerization of nitrogen containing barbituric acid benzylidenes
Authors: Jursic Branko S. , Stevens Edwin D. 
Published: March 2009

AbstractThrough the NMR monitoring of the reactive intermediates in the condensation of barbituric acid with nitrogen containing heterocyclic 2‐carboxaldehydes, a synthetic procedure was developed for the preparation of each of the intermediates. The simple high yield procedure for the preparation of the reductive dimer from corresponding barbituric acid benzylidenes was developed, although we were not able to elucidate the source of the reduction. The structure of the dimer was confirmed by X‐ray analysis.
2‐Arylhydrazono‐3‐oxopropanals in heterocyclic synthesis: Synthesis of arylazopyrazole, arylazoisoxazole and dialkylpyridazine‐5,6‐dicarboxylate derivatives. New one‐step synthesis of arylazopyrimidines
Authors: Al‐Shiekh Mariam A. , Salah El‐Din Abdellatif M. , Hafez Ebtisam A. , Elnagdi Mohamed H. 
Published: March 2009

AbstractA novel synthesis of arylpyrazole, isoxazole, dialkyl 1,6‐dihydropyridazine 5,6‐dicarboxylate derivatives and a new one‐step synthesis of azolopyrimidines under microwave‐assisted conditions are reported.
Use of some aryl and heteroaryl nitrilimines and nitrones in the synthesis of spiroheterocycles
Authors: Jedlovská Eva , Fišera Lubor 
Published: March 2009

Abstract1,3‐Dipolar cycloadditions of C‐(5‐nitro‐2‐furyl)‐N‐methyl nitrilimine (2a), C‐(5‐nitro‐2‐furyl)‐N‐phenyl nitrilimine (2b), C‐4‐nitrophenyl‐N‐methyl nitrilimine (2c) and C,N‐diphenyl nitrilimine (2d) with 1‐R‐substituted 3,3‐methylene‐5,5‐dimethylpyrrolidin‐2‐ones (1a‐d) where R is H, acetyl, 1,1‐dimethylethoxycarbonyl and 1‐methylethenyl proceed with complete regioselectivity in good yields to afford 1,3,7‐trisubstituted‐6‐oxo‐8,8‐dimethyl‐1,2,7‐triazaspiro[4,4]non‐2‐enes (5a‐g) exclusively. Cycloaddition of C‐(5‐nitro‐2‐furyl)‐N‐phenylnitrone (3b) to the exocyclic double bond of the dipolarophile 1a proceeds to 2‐phenyl‐3‐(5‐nitro‐2‐furyl)‐6‐oxo‐8,8‐dimethyl‐1‐oxa‐2,7‐diazaspiro[4,4]nonane (7) with complete regio‐ and stereoselectivity.
Ring transformations of heterocyclic compounds. XXIV. 1′,2′,5′,6′‐Tetrahydro‐4′H‐spiro[cyclohexa‐2,4‐diene‐1,2′‐pyrrolo[3,2,1‐ij]quinoline] and 1,2,4,5,6,7‐hexahydrospiro[azepino[3,2,1‐hi]indole‐2,1′‐cyclohexa[2,4]diene] – Two new spiro[cyclohexadiene‐azaheterocycles] easily accessible by pyrylium ring transformation
Authors: Zimmermann Thomas 
Published: March 2009

AbstractThe ring transformation of 2,4,6‐triarylpyrylium salts 1 with 2‐methyleneindolines of the type 3 in which the nitrogen atom is connected with the ortho‐carbon of the benzene ring by a (CH2)n chain is studied. Whereas the reaction of the pyrylium salts 1 with the 2‐methylene‐1,2,4,5‐tetrahydropyrrolo[3,2,1‐hi]indole 3a (n = 2), generated in situ from the 4‐methyl‐2,5‐dihydro‐1H‐pyrrolo[3,2,1‐hi]indolium perchlorate 2a, failed, the salts 1 react with the 2‐methylene‐1,2,5,6‐tetrahydro‐4H‐pyrrolo[3,2,1‐ij]quinolines 3b,c (n = 3) and the 2‐methylene‐1,2,4,5,6,7‐hexahydroazepino[3,2,1‐hi]indole 3d (n = 4), obtained in situ from the corresponding 2‐methyl‐1,4,5,6‐tetrahydropyrrolo[3,2,1‐if]lquinolinium perchlorates 2b,c and the 2‐methyl‐4,5,6,7‐tetrahydro‐1H‐azepmo[3,2,1‐hi]indolium perchlorate 2d, in the presence of triethylamine/acetic acid in boiling ethanol by a 2,5‐[C4+C2] transformation in high yield and diastereoselectivity to give the 1′,2′,5′,6′‐tetrahydro‐4′H‐spiro[cyclohexa‐2,4‐diene‐1,2′‐pyrrolo[3,2,1‐ij]quinolines] 5 and the 1,2,4,5,6,7‐hexahydrospiro[azepino[3,2,1‐hi]indole‐2,1′‐cyclohexa[2,4]dienes] 6, respectively. The influence of the length of the (CH2)n chain in 3 on the product formation and the diastereoselectivity can be explained by differences of the steric strain in the spiro compounds.
An exception of eschweiler‐clarke methylation: Cyclocondensation of α‐amino amides with formaldehyde and formic acid
Authors: Chen Fu‐Lin , Sung Kuangsen 
Published: March 2009

AbstractAn exception of Eschweiler‐Clarke methylation was found for α‐amino amides. The α‐amino amides on treatment with formaldehyde and formic acid produce cyclocondensation products, imidazolidin‐4‐ones, but N‐methylation process becomes important when three substituents of the α‐amino amides are very bulky. On the other hand, N‐methylation is the only product for Eschweiler‐Clarke methylation of the α‐amino amides with N,N‐disubstituted amide.
Routes to N‐vinyl‐nitroimidazoles and N‐vinyl‐deazapurines
Authors: Clayton Russell , Ramsden Christopher A. 
Published: March 2009

AbstractThe preparations of 4‐ and 5‐nitro‐1‐vinylimidazole (2 and 7) are described. Selective reduction of the nitro group using Fe/dil.HCl is achieved for the 4‐nitro derivative but this is not effective when ethoxymethylenemalononitrile is used to trap the amine. For 5‐nitroimidazole studies the N‐vinyl substituent is kept masked as a 2‐chloroethyl group, which remains unchanged during catalytic reduction of the nitro function (Pd/C), and is revealed by HCl elimination at a later stage. In this way, the 1‐deazapurine 13 and the tricyclic derivative 14 have been prepared.
Synthesis of 1‐(4‐thiazolyl)azulenes: Reactions of bromoacetyl‐substituted azulenes with thioamides, thioureas, and thiosemicarbazones
Authors: Takao Hiromi , Wang Dao‐Lin , Kikuchi Shigeru , Imafuku Kimiaki 
Published: March 2009

Abstract1‐(Bromoacetyl)‐3‐methylazulene (1a) and methyl 3‐(bromoacetyl)azulene‐1‐carboxylate (1b) reacted with thioamides 3a,b and thioureas 3c,d in boiling ethanol to give the corresponding (4‐thiazolyl)azulenes 4a‐d and 5a‐d in good yields, respectively. The reactions of dibromoacetyl‐substituted azulene (2) also gave (4‐thiazolyl) azulenes 5a‐d in lower yields and the azulene 2 was recovered. By heating compounds 5a‐d in 100% phosphoric acid, the ester group was eliminated to yield 1‐(4‐thiazolyl)azulenes 6a‐d. Compounds 1a,b reacted with thiosemicarbazones 7a‐f to afford [(2‐alkylidenehydrazino)thiazol‐4‐yl]azulenes 8a‐f and 9a‐f in moderate to high yields via their hydromides.
Facile cleavage of Narylsulfonyl bond of N‐arylsulfonylimidazolidinone with magnesium in methanol
Authors: Nadir Upender K. , Vijaya Krishna R. 
Published: March 2009

AbstractCleavage of Narylsulfonyl bond in N‐arylsulfonylimidazolidinones is best carried out selectively with magnesium in methanol.
Isolation and characterization of a novel tetrahydro‐[2,2′]bipyrrolyl dimer as an impurity from a knorr reaction
Authors: Thompson Alison , Alattar Yousef , Beshara Cory S. , Burley Rodney K. , Stanley Cameron T. , Robertson Katherine N. 
Published: March 2009

AbstractA novel dimer, tetraethyl 2,2′,3,3′‐tetramethyl‐1,1′,2,2′‐tetrahydro‐4H,4′H‐2,2′‐bipyrrolyl‐5,5,5′,5′‐tetracarboxylate, has been isolated as an impurity (0.4% yield) from a Knorr reaction for the synthesis of ethyl 3,5‐dimethylpyrrole‐2‐carboxylate from 2,4‐pentanedione and diethyl oximinomalonate in a dissolving zinc reduction. The solid‐state structure of this novel dimer was determined by X‐ray crystallography. Knorr reactions typically rely upon the requisite pyrrole being the only water‐insoluble crystalline material present in the reaction mixture, and so work‐up and purification procedures for Knorr reactions should be monitored carefully given the water‐insolubility of this dimer. Investigations regarding mechanistic implications and reductive dimerization are underway.
A new synthesis of 1,2,3,5‐tetrahydroimidazo[2,3‐b]‐[1,3]benzodiazocines
Authors: In Cho Hyun , Lee Seung Won , Lee Kee‐Jung 
Published: March 2009

AbstractA new synthesis of 6‐carbomethoxy‐1,2,3,5‐tetrahydroirnidazo[2,3‐b][1,3]benzodiazocines 13 by the intramolecular cycloaddition reaction of methyl 2‐(1‐aziridinylmethyl)‐3‐(2‐ureidophenyl)propenoates 10 under Appel's dehydration conditions is described. The latter were readily obtained from 2‐nitrobenzalde‐hyde with methyl acrylate through the Baylis‐Hillman reaction.
Diels‐alder reaction of 1‐methyl‐3,6,8‐trinitro‐2‐quinolone
Authors: Asahara Motoki , Nagamatsu Moriaki , Tohda Yasuo , Nishiwaki Nagatoshi , Ariga Masahiro 
Published: March 2009

Abstract1‐Methyl‐3,6,8‐trinitro‐2‐quinolone (1) behaved as the dienophile in Diels‐Alder reactions with dienes. When cyclopentadiene was used, cycloadduct 4 was obtained, which was then aromatized on treatment with triethylamine. In the reaction of 1 with hydrazone of 2‐butenal, phenanthridine derivative 7 was produced.
Hydrogen/deuterium exchange mass spectrometry identifies two highly protected regions in recombinant full‐length prion protein amyloid fibrils
Authors: Nazabal Alexis , Hornemann Simone , Aguzzi Adriano , Zenobi Renato 
Published: March 2009

AbstractUnderstanding the structural basis that distinguishes the amyloid form of the prion protein from its monomeric homologue is of crucial importance to elucidate the mechanism of the lethal diseases related to this protein. Recently, an in vitro conversion system was established which reproduces the transition of recombinant prion protein PrP(23–230) from its native α‐helical rich form into an aggregated amyloid β‐sheet rich form with physicochemical properties reminiscent to those of the disease‐related isoform of the prion protein, PrPSc. To study the tertiary and quaternary structural organization within recombinant amyloid fibrils from mouse, mPrP(23–231)βf; bovine, bPrP(23–230)βf; and elk, ePrP(23–230)βf; we utilized hydrogen/deuterium (H/D) exchange analyzed by matrix‐assisted laser desorption/ionization (MALDI) and nano‐electrospray (nano‐ESI) mass spectrometry. No significant differences were found by measuring the deuterium exchange kinetics of the aggregated fibrillar forms for mPrP(23–231)βf, bPrP(23–230)βf and ePrP(23–230)βf, indicating a similar overall structural organization of the fibrils from all three species. Next, we characterized the solvent accessibility for the soluble and fibrillar forms of the mouse prion protein by hydrogen exchange, pepsin proteolysis and nano‐ESI ion trap mass spectrometry analysis. In its amyloid form, two highly protected regions of mPrP(23–231) comprising residues [24–98] and [182–212] were identified. The residues between the two highly protected stretches were found to be more solvent exposed, but less than in the soluble protein, and might therefore rather form part of a fibrillar interface. Copyright © 2009 John Wiley & Sons, Ltd.
Simplified method for determining cadmium concentrations in rice foliage and soil by using a biosensor kit with immunochromatography
Authors: Abe Kaoru , Sakurai Yasuhiro , Okuyama Akira , Sasaki Kazuhiro , Tawarada Kei 
Published: March 2009

AbstractBACKGROUND: The behavior of cadmium in ecosystems needs to be monitored because of the human toxicity of this heavy metal. The need recently arose for a simple and quick on‐site test for trace levels of Cd in food and environmental samples. In response, an immunochromatographic assay kit for detecting Cd was manufactured by Kansai Electric Power Co. of Japan. This kit uses the antigen–antibody complex reaction between the Cd–EDTA complex and an anti‐Cd–EDTA antibody and shows the results in terms of the degree of color developed on a test paper. We previously reported the successful use of this kit to determine Cd concentrations in brown rice. Here, we applied the kit to the determination of Cd concentrations in rice foliage and soil.RESULTS: Cadmium in rice foliage was not extracted successfully by the method used for brown rice. However, it was successfully extracted by 0.1 mol L−1 HCl solution at a rice foliage:HCl ratio of 1:20, and coexisting metals were removed sufficiently by the column treatment. The Cd concentrations determined by immunochromatographic assay were well correlated with the values obtained by acid decomposition and inductively coupled plasma mass spectrometry. The 0.1 mol L−1 HCl‐extractable Cd concentration in soil was also determined successfully with the kit.CONCLUSION: Approximate Cd concentrations in rice plants and 0.1 mol L−1 HCl‐extractable Cd concentrations in soil can be monitored easily and quickly by this method at locations where facilities for acid digestion and precision analysis are not available. Copyright © 2009 Society of Chemical Industry
Novel alcoholic beverages: production of spirits and liqueurs using maceration of melon fruits in melon distillates
Authors: Hernández Gómez Luis Fernando , Úbeda Juan , Arévalo‐Villena María , Briones Ana 
Published: March 2009

AbstractBACKGROUND:The object of this study was to macerate melon fruit (Cucumis melo, L.) in melon distillate to produce a liqueur that would possess the sensory attributes of the fruit. Chemical and sensory analysis was performed on the different spirits.RESULTS:Spirits macerated with melon pieces, seeds and placenta showed double the sugar concentration compared to spirits macerated with seeds and placenta only. Concentrations of esters and higher alcohols were also higher in the first macerated. Neithern‐butanol nor ethyl butyrate were detected in any of the batches. The sensory analysis results (rank‐order tests) did not disclose any significant differences among the spirit batches although maceration with seeds and placenta conferred a golden colour to the spirit that is popular in commercial products. All the batches can be grouped close together in the greenish yellow quadrant, though in the region closer to yellow. Liqueurs contained higher quantities of ethyl acetate than the macerated spirits.CONCLUSIONS:Macerated spirit with seeds and placenta was the most adequate for production on account of its deeper colour, its suitability for filtration, and its typical melon aroma, as well as its lower production costs. The acceptability of melon liqueur was similar to other spirits tasted. Copyright © 2009 Society of Chemical Industry
Acceptability of scab‐resistant versus conventional apple cultivars by Polish adult and young consumers
Authors: Tomala Kazimierz , Baryłko‐Pikielna Nina , Jankowski Paweł , Jeziorek Kamil , Wasiak‐Zys Grażyna 
Published: March 2009

AbstractBACKGROUND: One of the problems in marketing fruit is to increase the share of fruits produced in sustainable agriculture to meet the expectation of ecology‐oriented consumers. Acceptability of such fruits by the consumers is of paramount importance. The objective of this study was to explore the acceptability of three scab‐resistant apple cultivars as compared with three popular conventional cultivars by Polish consumers of various age groups (adults, youngsters and children). Acceptability was tested on apples harvested in two consecutive years (2004 and 2005) after 2 months cold storage. Apple samples were chosen among 22 conventional and scab‐resistant cultivars for their distinctive differences in sensory profiles. Consumers evaluated separately the degree of external (appearance) and internal (flavour and texture) liking of an apple using a 9‐point hedonic scale (children used a 5‐point scale) and completed a questionnaire detailing socio‐demographic and apple‐concerning behavioural questions.RESULTS: The results based on internal liking data have shown that in all age groups, consumers were similarly segmented into three clusters: cluster 1, which liked all cultivars a great deal and equally; cluster 2, which preferred firm, juicy and rather acidic fruits; and cluster 3, which liked sweeter apples with intensive ripe apple flavour and moderate firmness.CONCLUSION: It is concluded that scab‐resistant cultivars with the above sensory characteristics might be accepted by quite a large segment of consumers, in each of the age groups tested. Copyright © 2009 Society of Chemical Industry
Analysis of pomegranate seed oil for the presence of jacaric acid
Authors: Sassano Gary , Sanderson Paul , Franx Johan , Groot Pascal , van Straalen Jeroen , Bassaganya‐Riera Josep 
Published: March 2009

AbstractBACKGROUND: Pomegranate seed oil is predominantly composed of triglycerides containing unsaturated fatty acids, including high levels of conjugated linolenic acids (CLnAs). The major CLnA component, punicic acid, is known to possess biological activity. Consequently, it is desirable to obtain a detailed characterisation of pomegranate seed oil fatty acid profiles, including molecules potentially co‐eluting with punicic acid, such as jacaric acid.RESULTS: Conjugated fatty acid profiles of a commercial sample of cold pressed pomegranate seed oil were characterised in detail by both gas chromatography of methyl esters and by 13C NMR spectroscopy. The methylation procedures were found to be critical for determination of accurate fatty acid profiles. GC analysis was unable to resolve jacaric acid from punicic acid, the major fatty acid present in pomegranate seed oil. To establish the presence or absence of jacaric acid, 13C NMR was employed.CONCLUSION: This is the first study to investigate pomegranate seed oil for the presence of jacaric acid. Punicic acid, eleostearic acid, and catalpic acid were confirmed by 13C NMR, but jacaric acid was not found. Thus, we have shown that punicic acid levels may be accurately measured by gas chromatography alone in pomegranate seed oil. Copyright © 2009 Society of Chemical Industry
Expression analysis of endo‐1,4‐β‐glucanase genes during aril breakdown of harvested longan fruit
Authors: Xiao Ruo , Chen Jian‐ye , Chen Jian‐wen , Ou Min , Jiang Yue‐ming , Lin He‐tong , Lu Wang‐jin 
Published: March 2009

AbstractBACKGROUND: The aim of the present study was to investigate the expression profiles of three endo‐1,4‐β‐glucanase (EGase, EC 3.2.1.4) genes during aril breakdown of longan fruit stored at room temperature (25 °C), low temperature (10 °C) or on transferring fruit stored at 10 °C for 20 days to 25 °C.RESULTS: Three longan full‐length cDNAs, designated Dl‐EGase1, Dl‐EGase2 and Dl‐EGase3, were isolated and characterized. EGase activity in aril tissues of longan fruit increased with the appearance of aril breakdown symptoms, while RNA gel blot analysis revealed that the accumulations of three Dl‐EGase genes exhibited differential characteristics with the occurrence of aril breakdown. Dl‐EGase2 may be involved in the aril breakdown in longan fruit at the later stage of storage at room temperature. Conversely, expression of Dl‐EGase3 could be mainly involved in aril breakdown of fruit stored at 10 °C. In addition, Dl‐EGase3 and Dl‐Egase2 were related to the aril breakdown of fruit transferred from low temperature to room temperature.CONCLUSION: The results obtained in this study indicate that Dl‐EGase genes are involved in the aril breakdown of longan fruit and that considerable variation exists between expression patterns of individual members of the EGase gene family. Copyright © 2009 Society of Chemical Industry
Pelvic floor stimulation: What are the good vibrations?
Authors: Lauper Monika , Kuhn Annette , Gerber Regina , Luginbühl Helena , Radlinger Lorenz 
Published: March 2009

AbstractObjectiveThe aim of this study was to determine if two different whole body vibration, sinusoidal vibration (SV) and stochastic resonance vibration (SRV), using various intensities lead to a reactive activation of pelvic floor muscles.Study DesignWe compared the pelvic floor muscle response of a healthy control group with that of a post partum group with weakened pelvic floor contraction. Activation effects of stochastic resonance vibration and sinusoidal vibration with six increasing vibration intensities were investigated using pelvic floor EMG and compared to activity during rest and maximum voluntary contraction.ResultsBoth whole body vibration systems were able to activate pelvic floor muscles significantly depending on vibration intensity. Generally, the SRV achieved a significantly higher activation than maximum voluntary contraction, especially in women post partum and using a frequency of 6–12 Hz.ConclusionSRV, compared to SV, leads to higher pelvic floor muscle activation in subjects with weakened pelvic floor muscles and achieves higher pelvic floor activation than maximum voluntary contraction alone. Neurourol. Urodynam. 28:405–410, 2009. © 2009 Wiley‐Liss, Inc.
Rigid body dynamics in terms of quaternions: Hamiltonian formulation and conserving numerical integration
Authors: Betsch Peter , Siebert Ralf 
Published: March 2009

AbstractIn the present paper unit quaternions are used to describe the rotational motion of a rigid body. The unit‐length constraint is enforced explicitly by means of an algebraic constraint. Correspondingly, the equations of motion assume the form of differential‐algebraic equations (DAEs). A new route to the derivation of the mass matrix associated with the quaternion formulation is presented. In contrast to previous works, the newly proposed approach yields a non‐singular mass matrix. Consequently, the passage to the Hamiltonian framework is made possible without the need to introduce undetermined inertia terms. The Hamiltonian form of the DAEs along with the notion of a discrete derivative make possible the design of a new quaternion‐based energy–momentum scheme. Two numerical examples demonstrate the performance of the newly developed method. In this connection, comparison is made with a quaternion‐based variational integrator, a director‐based energy–momentum scheme, and a momentum conserving scheme relying on the discretization of the classical Euler's equations. Copyright © 2009 John Wiley & Sons, Ltd.
Individual and family adaptation in Taiwanese families of individuals with severe and persistent mental illness (SPMI)
Authors: Hsiao Chiu‐Yueh , Riper Marcia Van 
Published: March 2009

AbstractThe purpose of this study was to examine individual and family adaptation in Taiwanese families of persons with severe and persistent mental illness. Mediating effects of social support and meaning of family caregiving on the relationship between pile‐up of demands and family adaptation were also assessed. Data were collected from 84 families using mailed questionnaires and analyzed using principal component analysis and mixed linear modeling. Adaptation was associated with lower pile‐up of demands, greater social support, and more positive interpretation of family caregiving. Partially mediating effects of social support and meaning of family caregiving were supported. The results imply a need for developing culturally sensitive interventions to decrease family demands and amplify individual, family, and community strengths and resources. © 2009 Wiley Periodicals, Inc. Res Nurs Health 32:307–320, 2009