bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaction of 1‐benzoselenopyrylium salts with grignard reagents: Formation of 2,4‐disubstituted selenochromenes and their conversion into the corresponding 1‐benzoselenopyrylium salts
Authors: Sashida Haruki , Yoshida Masahiro , Minamida Hiroshi , Teranishi Masanori
Published: March 2009

Treatment of 2‐tert‐butyl‐1‐benzoselenopyrylium salts 1A and 2‐phenyl‐1‐benzoselenopyrylium salts 1B with an alkyl(phenyl)magnesium halide resulted in nucleophilic addition at the C‐4 position to give the corresponding 2,4‐disubstituted 4H‐selenochromenes 2A and 2B in good yields, respectively. The obtained selenochromenes 2 were then easily converted into the 4‐substituted 2‐tert‐butyl‐1‐benzoselenopyrylium salts 6A by treatment with triphenylcarbenium tetrafluoroborate in high yields. The 4‐substituted 2‐phenyl derivatives 6B were also obtained in a similar manner. The reaction of the unsubstituted 1‐benzoselenopy‐rylium salt 1C with an alkylmagnesium halide is also described.
Carbocyclic galanthamine analogs: Incorporating the phenethylamine motif
Authors: Treu Matthias , Hametner Christian , Fröhlich Johannes , Jordis Ulrich , Mereiter Kurt
Published: March 2009

An unnatural analog of the anti‐Alzheimer drug galanthamine bearing a phenethylamine moiety has been prepared as a racemic mixture using K3[Fe(CN)6] induced tandem cyclization techniques in the key step to form derivatives of a novel heterocyclic ring system.
New optically active pyrazoles: Syntheses and the structural characterization of menthopyrazole analogues
Authors: Kashima Choji , Miwa Yohei , Shibata Saori , Nakazono Hiroyuki
Published: March 2009

New chiral pyrazoles, (4R,7R)‐4‐methyl‐7‐isopropyl‐3‐phenyl‐ (3‐phenyliso menthopyrazole cis‐1), (4R,7S)‐4‐methyl‐7‐isopropyl‐ (1‐menthopyrazole; trans‐2), (4R,7R)‐4‐isopropyl‐7‐methyl‐ (iso carvomen‐thopyrazole, cis‐3) and (4R,7S)‐4‐isopropyl‐7‐methyl‐4,5,6,7‐tetrahydro‐1H‐indazole (carvomenthopyra‐zole, trans‐3) were prepared. The diastereomeric pairs of these 1–3 were structurally characterized by NMR spectroscopy. The subtle differences of structures of 1–3 should induce the useful effects for a chiral auxiliary or a chiral catalyst.
Difference in photochemical behavior in 3,6‐ and 2,5‐di‐tert‐butyl‐3H‐azepine: The first photochemical bond formation between 2‐ and 6‐position of 3H‐azepine ring
Authors: Satake Kyosuke , Tawada Yuko , Takami Shizuka , Kimura Masaru
Published: March 2009

Different photochemical behavior between 3,6‐ and 2,5‐di‐t‐butyl‐3H‐azepine was observed. The former gave wavelength dependent products 3,5‐di‐t‐butylpyridine on irradiation through Pyrex filter via photolysis and 4,7‐di‐t‐butyl‐2‐azabicyclo[3.2.0]hepta‐2,6‐diene on irradiation through quartz filter via photo‐isomerization. Meanwhile, 2,5‐di‐t‐butyl derivative gave exclusively a labile 2,5‐di‐t‐butyl‐6‐azabicyclo‐[3.2.0]hepta‐2,6‐diene on irradiation through Pyrex filter via hitherto unknown photoisomerization mode of the bond formation between 2‐ and 6‐position of the ring.
Studies on pyrrolidinones. Synthesis of new α‐pyridones derivatives
Authors: Malecki Natacha , Houssin Raymond , Héanichart Jean‐Pierre , Couturier Daniel , Petra Ferdinand , Legentil Laurent , Rigo Benoîct
Published: March 2009

Dimethyl 7‐methoxycarbonylmethyl‐5‐oxo‐1,2,3,5‐tetrahydro‐indolizine‐3,8‐dicarboxylate was synthesized starting from methyl pyroglutamate. A study was made of the reactions of this highly functionalized pyridone with ethyl iodide, selenium oxide, isoamyl nitrite and formaldehyde. Literature reports that reaction of 4‐(1‐carbomethoxypropyl)‐5‐carbomethoxy‐1,6‐cyclopentano‐2‐pyridone with formaldehyde lead to a 95% yield of a monolactone (26) precursor of camptothecin. Our experiments resulted in 15 % of this monolactone and 40% of a new dilactone (27).
Synthesis and crystal structure characterization of two new antibacterial agents: 5‐[1‐(2,3‐ and 2,4‐dichlorophenyl)‐2‐phenylethyl]‐2,4,6‐trichloropyrimidines
Authors: Allouchi H. , Fellahi Y. , Héabert C. , Frangin Y. , Courseille C.
Published: March 2009

The synthesis of 5‐[1‐(2,3‐dichlorophenyl)‐2‐phenylethyl]‐2,4,6‐trichloropyrimidine (4a) and 5‐[1‐(2,4‐dichlorophenyl)‐2‐phenylethyl]‐2,4,6‐trichloropyrimidine (4b) is described. These compounds were prepared by chlorination of the corresponding 5‐substituted barbituric acids obtained by treatment of the 5‐ben‐zylidenebarbituric acids with benzylzinc bromide in the preceding step. These new trichloropyrimidines belong to a series of pyrimidine derivatives which show in vitro antibacterial activity against the undesirable human bacterial flora of the axilla and foot. The characterization of these compounds were performed by spectroscopy and X‐ray structure determination. Compounds 4a and 4b crystallize in the monoclinic system. In the crystal of 4a there are two conformers A and B both of which are the same type of conformation, and are different from that found in the structure of 4b. The crystal cohesion results from numerous very week Van der Waals interactions.
2‐(4‐methylpyridin‐2‐yl)‐1H‐benzimidazole derivatives. Part I. X‐Ray structural analysis
Authors: Gervasio Giuliana , Marabello Domenica , Barolo Claudia , Quagliotto Pierluigi , Viscardi Guido
Published: March 2009

The X‐ray analyses of some neutral and cationic derivatives of 2‐(4‐methylpyridin‐2‐yl)‐1H‐benzimida‐zole are reported and the structural data tentatively correlated to relative UV‐visible properties. A rotation of the γ‐picoline ring with respect to the benzimidazole moiety may be responsible of the spectral behavior.
Preparative route to 2‐ethoxycarbonylimidazole‐4‐phosphonate and diethylimidazole‐2,4‐dicarboxylate
Authors: Vuilhorgne Marc , Malpart Joëul , Mutti Stéaphane , Mignani Serge
Published: March 2009

Practical synthesis of 2‐ethoxycarbonylimidazole‐4‐phosphonate (1a) and diethyl imidazole‐2,4‐dicar‐boxylate (1b) are described.
Synthesis of substituted 3‐phenyl‐6h‐pyrazolo[4,3‐d]isoxazoles from corresponding 4‐benzoyl‐5‐hydroxypyrazoles
Authors: Holzer Wolfgang , Hahn Katharina
Published: March 2009

Treatment of 1,(3)‐(di)substituted 4‐benzoyl‐5‐hydroxypyrazoles with phosphorus oxychloride affords the corresponding 4‐benzoyl‐5‐chloropyrazoles. Reaction of the latter with hydroxylamine leads to oximes, which can be cyclized to novel 3‐phenyl‐6H‐pyrazolo[4,3‐d]isoxazoles by treatment with sodium hydride in dimethyl formamide. Detailed nmr spectroscopic studies (1H, 13C) with all obtained compounds are presented.
New approach to l'C‐modified riboside scaffold via stereoselective functionalization of D‐(+)‐ribonic‐y‐lactone
Authors: Alzérreca Arnaldo
Published: March 2009

We describe the preparation and spectroscopic properties of a novel class of nucleoside analogues in which a phenyl sulfonyl methylene group is attached to the 1′‐carbon atom of P‐D‐ribofuranose. The glyco‐sylation of 5‐O‐(tert‐butyldiphenylsilyl)‐2,3‐O‐isopropylidene‐D‐ribofuranolactone lb with phenyl methyl‐lithium sulfone in THF at −60° C afforded 5‐O‐(tert‐butyldiphenylsilyl)‐1′‐(benzenesulfonylmethylene)‐2′,3′‐O‐isopropylidene‐α‐D‐ribofuranose 2b. When subjected to deoxydative reaction conditions with boron trifluoride etherate in the presence of triethylsilane at −45° C, lactol 2b was converted into 2′,3′‐O‐isopro‐pylidene‐1′‐deoxy‐1′‐(benzenesulfonylmethylene)‐β‐D‐ribofuranose 4b with excellent stereocontrol over the anomeric carbon in moderate yield. This method has the potential for the development of a wider array of useful probes derived from 1′‐deoxy‐β‐D‐ribofuranose for nucleic acid research and for antisense therapeutic agents through further functionalization of the coupled sulfonyl group.
Facile syntheses and antimicrobial studies of 6‐(aryloxy/arylthio/chloroethoxy)‐2,10‐dichloro‐4,8‐dinitro‐12‐trichloromemyl‐12H‐dibenzo[d,g][13,2]dioxaphosphocin 6‐oxides
Authors: Kumar K. Ananda , Kasthuraiah M. , Reddy C. Suresh , Berlin K. D.
Published: March 2009

Synthesis of several novel 6‐aryloxy/arylmio/chloroethoxy‐2,10‐dichloro‐4,8‐dinitro‐12‐trichloro‐memyl‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐oxides (4a‐k) was accomplished by reacting 2,2‐bis (2‐hydroxy‐5‐chloro‐3‐nitrophenyl)‐1,1,1‐trichloroethane 2 with different aryl phosphorodichloridates (3a‐g) and O‐2‐chloroethyl phosphoryldichloride (3h) in the presence of triethylamine in dry toluene at 60–65 °C. Actually some of these compounds were prepared by reacting monochloride 5 resulting from the condensation of phosphorus oxychloride with 2 in situ, with different phenols and thiophenols. The chemical structures were confirmed by elemental, ir and 1H, 13C, 31P nmr and mass spectral data analyses. These compounds were screened for antifungal activity against Aspergillus flavus, Alternaria alternata, Fusarium solani, Curvularia lunata and Pyricularia oryzae and antibacterial activity on Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas syringae and Klebsiella pneumoniae. Some of them possessed significant activity.
Synthesis and isolation of chloro‐β‐carbolines obtained by chlorination of β‐carboline alkaloids in solution and in solid state
Authors: Ponce Maria A. , Tarzi Olga I. , Erra‐Balsells Rosa
Published: March 2009

β‐Carbolines (1‐5) undergo electrophilic aromatic substitution with N‐chlorosuccinimide and N‐chlorobenzotriazole under different experimental conditions. Although 6‐chloro and 8‐chloro‐nor‐har‐mane (1a and 1b) and 6‐chloro and 8‐chloro‐harmane (2a and 2b) obtained by chlorination with sodium hypochlorite of nor‐harmane (1) and harmane (2) were isolated and fully characterized recently, other chloroderivatives of nor‐harmane and harmane have never been described. The preparation and subsequent isolation, purification and full characterization of the dichloroderivatives 1c and 2c are reported (mp, Rf, 1H nmr, 13C nmr and ms) together with the preparation, isolation and charaterization, for the first time, of the chloroderivatives obtained from harmine (3a‐3c), harmol (4a‐4b) and 7‐acetylharmol (5a‐5c). As chlorinating reagent N‐chlorosuccinimide and N‐chlorobenzotriazole in solution as well as the β‐carboline ‐N‐chlorosuccinimide solid mixture have been used and their uses have been compared. Gc (tR) and gc‐ms (m/z) data for other monochloro derivative of nor‐harmane (1d) and monochloro‐ and dichloroderivatives of harmane (2d and 2e‐2f), obtained in trace amounts, are also included (Scheme 1 and Table I). Semiempirical AM1 and PM3 calculations have been performed in order to predict reactivity in terms of the energies of HOMO‐LUMO difference and in terms of the charge density of β‐carbolines (1‐5) and chloro‐β‐carbolines (1a‐1c, 2a‐2c, 3a‐3c, 4a‐4b, and 5a‐5c) (Scheme 1). Theoretical and experimental results are discussed briefly.
Synthesis of macrocyclic polyethers with partially fluorinated side arms
Authors: Elshani Sadik , Wai Chien M. , Shreeve Jean'ne M. , Hwang Hong‐Sik , Bartsch Richard A.
Published: March 2009

Different types of macrocyclic polyethers with partially fluorinated side arms are prepared. These new macrocyclic ligands are based on sym‐dibenzo‐16‐crown‐5 and sym‐dicyclohexano‐16‐crown‐5 scaffolds.
Reactions of an indolinonic nitroxide with superoxide radical anion in the presence of alkylhalides. Unexpected formation of a reduced transposed product
Authors: Carloni Patricia , Vianelli Roberto , Greci Lucedio
Published: March 2009

This study concerns the reactions of 2‐methyl‐2‐phenyl‐3‐phenylimino‐2,3‐dihydroindol‐l‐oxyl and 2,2,6,6‐tetramethylpiperidine‐1‐oxyl with alkylperoxyls, generated from potassium superoxide and a series of alkylhalides, in order to evaluate possible differences in reactivity with primary, secondary and tertiary alkylperoxyls. To better understand the reactivity of the studied indolinonic aminoxyl in alkaline medium, the investigation was extended to its reactions with potassium hydroxide and potassium tert‐butoxide in different solvents.
3H‐indolium salts efficiently prepared from N‐substituted anilines and α‐branched ketones by an one‐pot synthesis
Authors: Zimmermann Thomas , Brede Ortwin
Published: March 2009

Starting with the N‐substituted anilines 4/12 and the α‐branched ketones 3 the 3H‐indolium salts 1 and their fused derivatives 13 are prepared by combining a sodium nitrite nitrosation, a zinc dust reduction, a hydrazone formation and a Fischer indolization to a reaction sequence in which the isolation and purification of intermediates is not necessary. The scope and limitations of this effective one‐pot synthesis are discussed.
Synthesis α‐aminonitrile through anodic cyanation of N‐benzylpiperidine
Authors: Zhao Ping , Yin Ying‐Wu
Published: March 2009

Six‐membered cyclic α‐aminonitrile has been prepared from anodic cyanation of N‐benzylpiperidine. Good yields of α‐aminonitriles could be obtained through potentiostatic electrolysis under different conditions. The results also explain why high yield α‐aminonitriles could not be obtained under constant current electrolysis.
Syntheses of 5‐alkylthio‐1,3‐diaryl‐1,2,4‐triazoles
Authors: Navidpour Latifeh , Karimi Leila , Amini Mohsen , Vosooghi Mohssen , Shafiee Abbas
Published: March 2009

Arylation of the readily available 3‐alkythio‐5‐aryl‐1,2,4‐triazoles gave 5‐alkylthio‐1,3‐diaryl‐1,2,4‐triazoles in moderate yield. The structures of the latter were confirmed by NOE and 13C‐NMR.
Investigation on the condensation of α and β ketoaldehydes with hydroxyaromatic compounds
Authors: Talinli Naciye , Karliga Bekir
Published: March 2009

Mechanism of the condensation reactions of methylglyoxal, phenylglyoxal and benzoylacetaldehyde with phenolic compounds have been discussed. It was observed that the reaction mechanisms changed depending on the type of the phenolic and also dicarbonyl compounds. While, methylglyoxal gave the angular methyl derivative of naphthofuraranonaphthofuran with 2‐naphthol, phenylglyoxal and its p‐chloro and p‐methoxy derivatives formed benzo[b]naphtho[2,1‐f]oxepine‐13‐ones. However, resorcinol behaved different and gave 2‐phenyl‐3‐(2,4‐dihydroxy)‐6‐hydroxy‐benzo[b]furans with phenylglyoxal derivatives. 2‐Phenyl‐4‐(2‐hydroxynaphmyl)‐4H‐naphtho[b]pyran was produced from the reaction of benzoylacetaldehyde and 2‐naphthol, but the reaction product was 3,9‐dihydroxy‐6‐phenyl‐6,12‐methano‐12H‐dibenzo[1,3]dioxocin when the same carbonyl compound reacted with resorcinol.
Synthesis and structure of cycloalkane‐ and norbornane‐condensed 6‐aryl‐1,2,4,5‐tetrahydropyridazinones
Authors: Csende Ferenc , Hetényi Anasztárzia , Stájer Géza , Fülöp Ferenc
Published: March 2009

The C=N double bond of certain cis‐ or trans‐cycloalkane and diexo‐ or diendo‐norbornane‐condensed pyridazinones was reduced with NaBH3CN. The cis‐ or trans nature of the starting cycloalkane derivatives was always retained in the saturated products, with a high degree of diastereoselectivity: the hydrogen on the new stereocenter and the annelational hydrogen next to the carbonyl always exhibited the same steric orientation. The stereostructures were determined by means of nmr measurements and confirmed by molecular modelling.
Efficient synthesis in three steps and spectral determination of methyl‐5‐[(o‐, m‐, and p‐substituted‐phenylthio]‐2‐benzimidazolecarbamates
Authors: Cortés Eduardo Cortés , Mendoza Rafael Sosa , Gutiérrez Maximiliano Santibáñez , De Cortés Olivia Garcéa‐Mellado
Published: March 2009

The preparation and spectral properties often novel methyl 5‐[(o‐, m‐, and p‐substituted)‐phenylthio]‐2‐benzimidazolecarbamates with possible pharmacological activity as antihelmintics is described; by condensation and cyclization between 5‐methylthioures sulfate chloroformic acid methyl ester and 3,4‐diaminophenyl‐substituted‐phenylthio ether dissolved in ethanol. The structures of all final products were corroborated by ir; 1H‐nmr, 13C‐nmr and ms.
Diazoniapentaphenes. Synthesis from pyridine‐2‐carboxaldehyde and structural verifications
Authors: Krapcho A. Paul , Cadamuro Sergio A.
Published: March 2009

Reactions of pyridine‐2‐carboxaldehyde (9) with α,α′‐dibromo‐o‐ and p‐xylenes led to the corresponding bis‐pyridinium aldehydes 10 and 14. These aldehydes were quite reactive and the respective hydrates 11 and 15 were also formed. Cyclization of 10 or 11 with 48% HBr led to 12 while cyclization with PPA followed by conversion to the bis tribromide and loss of bromine led to 1. Cyclization of 14 or 15 with 48% HBr led to 3. Attempts to react α,α′‐dibromo‐m‐xylene with pyridine‐2‐carboxaldehyde (9) were not successful for the preparation of the bis‐pyridinium aldehyde 13. The bis‐pyridinium acetals 4, 5 and 6 were prepared and cyclized to afford 1, 2 and 3, respectively, by the previously reported procedures. The structures of 1 and 2 were verified by 1H‐NMR and 13C‐NMR spectroscopy while that of 3 was confirmed by X‐ray analysis.
The preparation of 3‐substituted 1,2‐benzisothiazole 1,1‐dioxides from lithiated intermediates or grignard reagents and methyl 2‐(aminosulfonyl)benzoate
Authors: Dunn S. Patrick , Hajiaghamohseni Laela M. , Lioi Sara B. , Meierhoefer Michelle A. , Walters Matthew J. , Beam Charles F.
Published: March 2009

A polylithiated β‐ketoester, β‐diketone, or β‐ketoamide was condensed‐cyclized with lithiated methyl 2‐(aminosulfonyl)benzoate, to afford new 3‐substituted 1,2‐benzisothiazole 1,1‐dioxides. Some Grignard or organolithium reagents were also condensed‐cyclized with methyl 2‐(aminosulfonyl)benzoate to give 3‐substituted 1,2‐benzisothiazole 1,1‐dioxides.
Synthesis of polyfunctionally substituted heteroaromatic compounds via benzotriazolyl chalcones with antimicrobial and antifungal activities
Authors: Al‐Omran Fatima , El‐Khair Adel Abou
Published: March 2009

The utility of both 3‐(1‐benzotriazolyl) chalcone derivatives 3a‐c and 2‐(1‐benzotriazolyl)‐1,4‐pentadien‐3‐one (18) in the synthesis of some new 2‐(1H)‐pyridone, pyridine, pyrazole and isoxazole derivatives is reported. Antimicrobial and antifungal screening of some selected examples from the synthesized products were carried out. The structure of the newly synthesized compounds was elucidated by elemental analysis, ir, 1H and 13C nmr investigations.
A new regioselective synthesis and bioactivity of 1H‐pyrazolo[3,4‐d]pyrimidin‐4(5H)‐one derivatives
Authors: Wang Hong‐Qing , Liu Zhao‐Jie , Yang Li‐Min , Ding Ming‐Wu
Published: March 2009

A series of new 1H‐pyrazolo[3,4‐d]pyrimidin‐4(5H)‐one Derivatives 5 has been designed and regio‐selectively synthesized via a tandem aza‐Wittig reaction. The structures of all compounds prepared have been confirmed by 1H NMR, IR, EI‐MS spectroscopy and elemental analyses. The results of preliminary bioassay indicate that most compounds 5 possess an inhibition effect against Botrytis cinereapers and Pyricularia oryzae at the concentration of 50 mg/L.
Oxazepines and thiazepines. 41 . Synthesis of 4‐aryl‐2,3‐dihydro‐2‐styryl‐1,5‐benzothiazepines by the reaction of (E,E)‐cinnamylideneacetophenones with 2‐aminothiophenol and their conversion into 2,2‐disubstituted 3‐acetyl‐2,3‐dihydrobezothiazoles
Authors: Lévai Albert
Published: March 2009

New 4‐aryl‐2,3‐dihydro‐2‐styryl‐1,5‐benzothiazepines 8–13 have been synthesized by an acid catalyzed reaction of 2‐arninothiophenol (1) and (E,E)‐cinnamylideneacetophenones 2–7. Ring contraction of 1,5‐benzothiazepines 8–13 provided 2,2‐disubstituted 3‐acetyl‐2,3‐dihydrobenzothiazoles 14–19 under acetylating conditions.
An efficient synthesis of 1‐H‐pyrazole‐4‐carboxylic acid esters with vilsmeier reagent under neat conditions
Authors: Sridhar R. , Sivaprasad G. , Perumal P. T.
Published: March 2009

A convenient, solvent‐free Vilsmeier reagent is experimented under neat condition (both thermal and microwave conditions). An efficient method for the synthesis of various substituted 1H‐pyrazole‐4‐carboxylic acid esters is reported.
Consecutive isomerization and cyclization of 3‐(2‐aminophenyl)‐1‐arylprop‐2‐yn‐1‐ols leading to 2‐arylquinolines in the presence of potassium hydroxide
Authors: Cho Chan Sik , Lee Na Young , Kim Tae‐Jeong , Shim Sang Chul
Published: March 2009

3‐(2‐Aminophenyl)‐1‐arylprop‐2‐yn‐1‐ols are readily converted to 2‐arylquinolines in good yields in ethanol at 80° in the presence of potassium hydroxide via domino isomerization and cyclization.
New one step synthesis of crown compounds containing a 1,3,4‐thiadiazole moiety
Authors: Bentiss Fouad , Lebrini Mounim , Lagrenée Michel
Published: March 2009

New macrocyclic polyether compounds containing a 2,5‐bis(2‐hydroxyphenyl)‐1,3,4‐thiadiazole moiety have been prepared by a nucleophilic substitution reaction involving ethylene or polyethylene glycol ditosylate and a bisphenol, the 2,5‐bis(2‐hydroxyphenyl)‐1,3,4‐thiadiazole, with solid anhydrous carbonate as a base. The structures of the macrocycles obtained were firmly established by 1H and 13C nmr spectroscopy and their mass spectra.
Regioselective epoxidation of 3‐(3‐Oxo‐3‐arylpropenyl)chromen‐4‐ones by dimethyldioxirane
Authors: Lévai Albert , Jekő József
Published: March 2009

Regioselective epoxidation of 3‐(3‐oxo‐3‐arylpropenyl)chromen‐4‐ones 1a‐h by isolated dimethyldioxirane provided epoxides 2a‐h as sole detectable and isolable products in good (75–86%) yields.
An expedient synthesis of an isofervenulin analogue
Authors: Bach Andrew , Jiang Xinglong , Mckenna Joseph , Prasad Kapa , Repic Oljan , Shieh Wen‐Chung
Published: March 2009

An efficient approach has been developed for the synthesis of an isofervenulin analogue 1 employing a one‐pot condensation‐substitution reaction of a chlorocarboethoxytriazine (electrophile) with a urea (nucleophile). The resulting cyclization reaction resulted in the synthesis of a pyrimido‐heterocycle in good yield in either acidic or basic media. The former was assisted by utilizing trimethylsilyl chloride.
A facile synthesis of cytogenin (8‐hydroxy‐3‐hydroxymethyl‐6‐methoxyisocoumarin)
Authors: Saeed Aamer
Published: March 2009

A facile and straightforward synthesis of cytogenin 1 (8‐hydroxy‐3‐hydroxymethyl‐6‐methoxyisocoumarin) metabolite of Streptoverticillium eurocidicum and Certocystis fimbriata has been achieved. Condensation of chloroacetyl chloride with 3,5‐dimethoxyhomophthalic acid 2 directly furnished 3‐chloromethyl‐6,8‐dimethoxyisocoumarin 3 which was hydrolyzed to 6,8‐dimethoxy‐3‐hydroxymethylisocoumarin 4 using 0.05% aqueous sodium hydroxide in THF. Regioselective demethylation of 4 yielded cytogenin 1. In model experiments, 3‐chloromethylisocoumarin was prepared and converted into 3‐hydroxymethyl isocoumarin.
Transformation of schiff bases derived from alpha‐naphthaldehyde. Synthesis, spectral data and biological activity of new‐3‐aryl‐2‐(α‐naphtyl)‐4‐thiazolidinones and N‐aryl‐N‐[1‐(α‐naphthyl)but‐3‐enyl]amines
Authors: Kouznetsov Vladimir , Rodríguez William , Stashenko Elena , Ochoa Carmen , Vega Celeste , Rolón Miriam , Pereira David Montero , Escario José A. , Barrio Alicia Gémez
Published: March 2009

New N‐aryl substituted 2‐(α‐naphthyl)‐4‐thiazolidinones were prepared by the cyclocondensation of α‐mercaptoacetic acid and corresponding N‐(α‐naphthyliden)anilines. The same starting materials were utilized to obtain a new series of N‐aryl‐N‐[1‐(α‐naphthyl)but‐3‐enyl]amines, which was synthesized through an addition of the Grignard reagent (allylmagnesium bromide) to the double bond CN of the aldimines. The antichagasic and trichomonacidal in vitro activity, as well as, the antifungal and cytotoxic properties of some of these compounds were evaluated.
Random poly(fluorenylene‐vinylene)s containing 3,7‐Dibenzothiophene‐5,5‐dioxide units: Synthesis, photophysical, and electroluminescence properties
Authors: Grisorio Roberto , Piliego Claudia , Cosma Pinalysa , Fini Paola , Mastrorilli Piero , Gigli Giuseppe , Suranna Gian Paolo , Nobile Cosimo Francesco
Published: March 2009

The synthesis of new random poly(arylene‐vinylene)s containing the electron withdrawing 3,7‐dibenzothiophene‐5,5‐dioxide unit was achieved by the Suzuki–Heck cascade polymerization reaction. The properties of poly[9,9‐bis(2‐ethylhexyl)‐2,7‐fluorenylene‐vinylene‐co‐3,7‐dibenzothiophene‐5,5‐dioxide‐vinylene] (50/50 mol/mol, P1) and poly[1,4‐bis(2‐ethylhexyloxy)‐2,5‐phenylene‐vinylene‐co‐3,7‐dibenzothiophene‐5,5‐dioxide‐vinylene] (50/50 mol/mol, P2) were compared with those of terpolymers obtained by combining the fluorene, dibenzothiophene, and 1,4‐bis(2‐ethylexyloxy)benzene in 20/40/40 (P3), 50/25/25 (P4), and 80/10/10 (P5) molar ratios. The polymers were characterized by 1H NMR and IR, whereas their thermal properties were investigated by TGA and DSC. Polymers P1–5 are blue–green emitters in solution (λem between 481 and 521 nm) whereas a profound red shift observed in the solid state is emission (λem from 578 to 608 nm) that can be attributed both to the charge transfer stabilization exerted by the polar medium and to intermolecular interactions occurring in the solid state. Cyclic voltammetry permitted the evaluation of the ionization potentials and also revealed a quasi‐reversible behavior in the reduction scans for the polymers (P1–4) containing the higher amounts of 3,7‐dibenzothiophene‐5,5‐dioxide units. Electroluminescent devices with both ITO/PEDOT‐PSS/P1–5/Ca/Al (Type I) and ITO/PEDOT‐PSS/P1–5/Alq3/Ca/Al (Type II) configuration were fabricated showing a yellow to yellow–green emission. In the case of P4, a luminance of 1835 cd/m2 and an efficiency of 0.25 cd/A at 14 V were obtained for the Type II devices. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2093–2104, 2009
Polyelectrolyte complex nanoparticles from N‐carboxyethylchitosan and polycationic double hydrophilic diblock copolymers
Authors: Mincheva Rosica , Bougard François , Paneva Dilyana , Vachaudez Magali , Fustin Charles‐André , Gohy Jean‐François , Manolova Nevena , Rashkov Iliya , Dubois Philippe
Published: March 2009

For the first time, the polyelectrolyte complex (PEC) formation tool was used for preparation of core‐shell nanoparticles form the natural polyampholyte N‐carboxyethylchitosan (CECh) and weak polycationic (protonated) polyoxyethylene‐b‐poly[2‐(dimethyl‐amino)ethyl methacrylate] (POE‐b‐PDMAEMA) diblock copolymers. The performed dynamic light scattering analyses revealed that nanoparticles with a PEC core and a POE shell could be formed at mixing ratio between the oppositely charged groups equal to 1/1 depending on CECh molar mass, polymerization degree of PDMAEMA block and ionic strength. The results were confirmed by the performed AFM and cryo‐TEM analyses. When high molar mass CECh was used, core‐shell nanoparticles were obtained with the diblock copolymer of the shortest PDMAEMA block at ionic strength (I) of 0.01. At ionic strength value close to the physiological one (I = 0.1) secondary aggregation occurred. Spherical nanoparticles at I = 0.1 were obtained upon lowering the CECh molar mass. Depending on the polymer partners and medium parameters the size of the obtained particles varied from 60 to 600 nm. The X‐ray photoelectron spectra evidenced the hydrophilic POE‐block shell—coacervate CECh/PDMAEMA‐block core structure. The nanoparticles are stable in a rather narrow pH range around 7.0, thus revealing the high pH‐sensitivity of the obtained core‐shell particles. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2105–2117, 2009
Removal of Model Proteins Using Beams of Argon Ions, Oxygen Atoms and Molecules: Mimicking the Action of Low‐Pressure Ar/O2 ICP Discharges
Authors: Kylián Ondřej , Benedikt Jan , Sirghi Lucel , Reuter Rüdiger , Rauscher Hubert , von Keudell Achim , Rossi François
Published: March 2009

The action of Ar/O2 plasmas with proteins is mimicked by employing a particle beam experiment with individually controllable and absolutely calibrated sources of O atoms/O2 molecules and of argon ions. It is demonstrated that beams of thermal O atoms and of O2 molecules with fluences up to jO = 8.6 × 1018 cm−2 and jO2 = 5.4 × 1020 cm−2 have no measurable effect on the proteins at room temperature, whereas the combination of an O/O2 beam and of an 100 eV Ar+ ion beam induces very efficient protein removal, which is accompanied by a significant increase of their surface roughness. These observations are attributed to the process of chemical sputtering caused by the simultaneous impact of incident radicals and energetic ions.

magnified image
Overexpression of cyclin E messenger ribonucleic acid in nasopharyngeal carcinoma correlates with poor prognosis
Authors: Ko M-T , Su C-Y , Huang S-C , Chen C-H , Hwang C-F
Published: March 2009

Aims:

S-phase kinase-associated protein 2 is required for the degradation of p27 protein, which is a negative regulator of cyclin E/cyclin-dependent kinase 2 complex. The present study examined the expression of cyclin E, S-phase kinase-associated protein 2 and p27 protein in nasopharyngeal carcinoma.

Methods:

Tissue from 35 cases of nasopharyngeal carcinoma and 10 normal nasopharyngeal tissue samples underwent reverse polymerase chain reaction to detect messenger ribonucleic acid. Immunohistochemical analysis was performed on 29 nasopharyngeal tissue samples in order to detect protein expression.

Results:

Messenger ribonucleic acid expression in the nasopharyngeal carcinoma tissue samples analysed indicated a 1.75-fold change in the amount of S-phase kinase-associated protein 2, a 0.34-fold change in the amount of cyclin E and a 0.31-fold change in the amount of p27 protein, compared with positive controls. High levels of cyclin E significantly correlated with late-stage nasopharyngeal carcinoma (p = 0.009) and a poor overall survival (p = 0.010). Immunohistochemical analysis indicated positive expression of S-phase kinase-associated protein 2 in 16/29 nasopharyngeal tissue samples (55 per cent), of cyclin E in 13/29 samples (45 per cent) and of p27 protein in 17/29 (59 per cent) samples.

Conclusions:

Overexpression of cyclin E messenger ribonucleic acid showed an adverse prognostic significance, correlating with an advanced stage of nasopharyngeal carcinoma and a low overall survival rate.
A Notice
Authors: Arié Rachael
Published: March 2009

The history of Arabic science has produced, during these last decades, some interesting studies from European scholars, such as those of D. A. King, O. Kurz and Juan Vernet, to name only these.
‘Insolence and pride’: problems with the representation of the South-East Asian Portuguese communities in Alexander Hamilton's ‘A New Account of the East Indies’ (1727)
Authors: HALIKOWSKI-SMITH STEFAN
Published: March 2009

One of the most influential European printed sources on South-East Asia at the turn of the eighteenth century was the Scottish sea-captain Alexander Hamilton's memoirs. The picture he paints of the Portuguese communities that had existed since the period of Portuguese ascendancy in the sixteenth century is overwhelmingly negative. But a close textual and empirical analysis of his text shows that not only was he frequently misinformed in terms of the historical developments relating to that community, but that he merely conforms to a set of standard rhetorical tropes we can associate with the Black Legend, which had grown up in Protestant countries of northern Europe since the 16th century to denigrate Portugal and her achievements. This article urges that this key text consequently be used with far greater circumspection than has hitherto been the case.
Hidden Costs of the Welfare State: Employers' Compliance Costs and the Working Tax Credit
Authors: Godwin Michael , Lawson Colin
Published: March 2009

This paper explores the impact of the decision to make the Working Tax Credit (WTC) payable via the employer, until March 2006. A unique survey shows the unequal distribution of compliance costs across firms and industries. It also suggests that the arrangement had some unanticipated results, and may have damaged the effectiveness of the WTC. Some employers' compliance costs may have been shifted to employees. So from a social policy perspective administration is policy – the delivery system affects outcomes. However the switch to payments through HMRC from April 2006 does not remove all compliance costs from employers.
Heme–Hemopexin Complex Attenuates Neuronal Cell Death and Stroke Damage
Authors: Li Rung-chi , Saleem Sofiyan , Zhen Gehua , Cao Wangsen , Zhuang Hean , Lee Jongseok , Smith Ann , Altruda Fiorella , Tolosano Emanuela , Doré Sylvain
Published: March 2009

Hemoproteins undergo degradation during hypoxic/ischemic conditions, but the prooxidant free heme that is released cannot be recycled and must be degraded. The extracellular heme associates with its high-affinity binding protein, hemopexin (HPX). Hemopexin is shown here to be expressed by cortical neurons and it is present in mouse cerebellum, cortex, hippocampus, and striatum. Using the transient ischemia model (90-min middle cerebral artery occlusion followed by 96-h survival), we provide evidence that HPX is protective in the brain, as neurologic deficits and infarct volumes were significantly greater in HPX−/− than in wild-type mice. Addressing the potential protective HPX cellular pathway, we observed that exogenous free heme decreased cell survival in primary mouse cortical neuron cultures, whereas the heme bound to HPX was not toxic. Heme-HPX complexes induce HO1 and, consequently, protect primary neurons against the toxicity of both heme and prooxidant tert-butyl hydroperoxide; such protection was decreased in HO1−/− neuronal cultures. Taken together, these data show that HPX protects against heme-induced toxicity and oxidative stress and that HO1 is required. We propose that the heme-HPX system protects against stroke-related damage by maintaining a tight balance between free and bound heme. Thus, regulating extracellular free heme levels, such as with HPX, could be neuroprotective.
Phyllometric parameters and artificial neural networks for the identification of Banksia accessions
Authors: Messina Giuseppe , Pandolfi Camilla , Mugnai Sergio , Azzarello Elisa , Dixon Kingsley , Mancuso Stefano
Published: March 2009

Taxonomic identification is traditionally carried out with dichotomous keys, or at least computer-based identification keys, often on the basis of subjective visual assessment and frequently unable to detect small differences at subspecies and varietal ranks. The aims of the present work were to (1) clearly discriminate a wide group of accessions (species, subspecies and varieties) belonging to the genus Banksia on the basis of 14 phyllometric parameters determined by image analysis of the leaves, and (2) unequivocally identify the accessions with a relatively simple back-propagation neural-network (BPNN) architecture (single hidden layer) in order to develop a complementary method for fast botanical identification. The results indicate that this kind of network could be effectively and successfully used to discriminate among Banksia accessions, as the BPNN enabled a 93% unequivocal and correct simultaneous identification. Our BPNN had the advantage of being able to resolve subtle associations between characters, and of making incomplete data (i.e. absence of Banksia flower parameters such as the colour or size of styles) useful in species diagnostics. This method is relatively useful; it is easy to execute as no particular competences are necessary, equipment is low cost (scanner connected to a PC and software available as freeware) and data acquisition is fast and effective.
Generation of a nicking enzyme that stimulates site-specific gene conversion from the I-AniI LAGLIDADG homing endonuclease
Authors: McConnell Smith Audrey , Takeuchi Ryo , Pellenz Stefan , Davis Luther , Maizels Nancy , Monnat Raymond J. , Stoddard Barry L.
Published: March 2009

Homing endonucleases stimulate gene conversion by generating site-specific DNA double-strand breaks that are repaired by homologous recombination. These enzymes are potentially valuable tools for targeted gene correction and genome engineering. We have engineered a variant of the I-AniI homing endonuclease that nicks its cognate target site. This variant contains a mutation of a basic residue essential for proton transfer and solvent activation in one active site. The cleavage mechanism, DNA-binding affinity, and substrate specificity profile of the nickase are similar to the wild-type enzyme. I-AniI nickase stimulates targeted gene correction in human cells,
in cis
and
in trans
, at ≈1/4 the efficiency of the wild-type enzyme. The development of sequence-specific nicking enzymes like the I-AniI nickase will facilitate comparative analyses of DNA repair and mutagenesis induced by single- or double-strand breaks.
Doubly hybrid density functional for accurate descriptions of nonbond interactions, thermochemistry, and thermochemical kinetics
Authors: Zhang Ying , Xu Xin , Goddard William A.
Published: March 2009

We develop and validate a density functional, XYG3, based on the adiabatic connection formalism and the Görling–Levy coupling-constant perturbation expansion to the second order (PT2). XYG3 is a doubly hybrid functional, containing 3 mixing parameters. It has a nonlocal orbital-dependent component in the exchange term (exact exchange) plus information about the unoccupied Kohn–Sham orbitals in the correlation part (PT2 double excitation). XYG3 is remarkably accurate for thermochemistry, reaction barrier heights, and nonbond interactions of main group molecules. In addition, the accuracy remains nearly constant with system size.
Receptor expression modulates the specificity of transforming growth factor‐β signaling pathways
Authors: Murakami Masaru , Kawachi Hiroyuki , Ogawa Kenji , Nishino Yoshii , Funaba Masayuki
Published: March 2009

In current models of transforming growth factor‐β (TGF‐β) family signaling, type II receptors activate specific activin receptor‐like kinase (ALK) type I receptors. These serine/threonine kinases activate ligand‐dependent receptor regulated (R)‐Smad by phosphorylating carboxy‐terminal serines. We found that the receptor expression levels affected the phosphorylation and activation of the two R‐Smad subclasses, activin/TGF‐β‐specific (AR‐Smad) and bone morphogenetic protein (BMP)‐specific (BR‐Smad). Co‐expressing constitutively active type I and type II receptors in COS7 cells resulted in the phosphorylation of both R‐Smad subclasses in a ligand‐independent manner. This was verified using in vitro kinase assays. In untransfected B16 melanoma cells, TGF‐β1 and BMP‐2 induced phosphorylation of both R‐Smad subclasses, and TGF‐β1 up‐regulated the inhibitor of differentiation (Id) gene, which is usually regulated by BMP. By contrast, BMP‐2 up‐regulated plasminogen activator inhibitor‐1 (PAI‐1), which is an AR‐Smad‐regulated gene. Except for ALK4 and ALK6, levels of type I and type II receptor mRNAs were higher in B16 cells than in HeLa and HepG2 cells, in which TGF‐β1 and BMP‐2 induced phosphorylation of only the expected R‐Smad. These results help to explain the diverse effects of this ligand family.
Rab11 and its effector Rip11 participate in regulation of insulin granule exocytosis
Authors: Sugawara Kenji , Shibasaki Tadao , Mizoguchi Akira , Saito Tetsuya , Seino Susumu
Published: March 2009

Rab GTPases and their effectors play important roles in membrane trafficking between cellular compartments in eukaryotic cells. In the present study, we examined the roles of Rab11B and its effectors in insulin secretion in pancreatic β‐cells. In the mouse insulin‐secreting cell line MIN6, Rab11 was co‐localized with insulin‐containing granules, and over‐expression of the GTP‐ or the GDP‐bound form of Rab11B significantly inhibited regulated secretion, indicating involvement of Rab11B in regulated insulin secretion. To determine the downstream signal of Rab11‐mediated insulin secretion, we examined the effects of various Rab11‐interacting proteins on insulin secretion, and found that Rip11 is involved in cAMP‐potentiated insulin secretion but not in glucose‐induced insulin secretion. Analyses by immunocytochemistry and subcellular fractionation revealed Rip11 to be co‐localized with insulin granules. The inhibitory effect of the Rip11 mutant was not altered in MIN6 cells lacking Epac2, which mediates protein kinase A (PKA)‐independent potentiation of insulin secretion, compared with wild‐type MIN6 cells. In addition, Rip11 was found to be phosphorylated by PKA in MIN6 cells. The present study shows that both Rab11 and its effector Rip11 participate in insulin granule exocytosis and that Rip11, as a substrate of PKA, regulates the potentiation of exocytosis by cAMP in pancreatic β‐cells.
Participation and risk‐taking behaviour in sports in children with haemophilia
Authors: KÖITER J. , VAN GENDEREN F. R. , BRONS P. P. T. , NIJHUIS‐VAN DER SANDEN M. W. G.
Published: March 2009

Summary.  The aim of this study was to investigate participation in sports activities and risk‐taking behaviour in children with haemophilia and the relationship to personal and health related factors. Ninety‐nine children (mean age 12.6 years) completed questionnaires regarding participation in sports and physical education, medication, health related quality of life, and perceived motor competence. Furthermore, weight, height, active range of motion, pain, and muscle strength were assessed. Based on a risk exposure factor (REF) we defined subgroups with low, medium, and high risk when participating in sport. Most children participate in sport five times a week (mean 140 min per week), and little absence during school sports was reported. In general, prophylaxis was not tailored to sport activities. Boys with haemophilia preferred other sports than their Dutch contemporaries. The top‐5 being soccer, swimming, tennis, gymnastics, and cardio‐fitness for the former; soccer, gymnastics, tennis, hockey, and swimming for the latter. Significant differences between the low risk group and both other groups were found for sport intensity, total energy expenditure (EE) and average risk factor (ARF), however the medium and high‐risk groups did not differ in ARF. REF and sport participation increased associated with increasing interest in athletic and motor activities. No significant differences were found between REF groups regarding age, Z‐BMI, Z‐AROM, Z‐Muscle force, and the presence of painful joints. As in normal peers motivation to participate in sport depends upon the enthusiasm and interest, in children with haemophilia choice of sports differs, probably related to sport advice.
Retiform uterine tumours resembling ovarian sex cord tumours. A comparative immunohistochemical study with retiform structures of the female genital tract
Authors: Nogales Francisco F , Stolnicu Simona , Harilal Kadappayil R , Mooney Eoghan , García‐Galvis Olga F
Published: March 2009

Aims:  To analyse both the clinicopathological and immunohistochemical findings in six cases of uterine tumours resembling ovarian sex cord tumours with a predominant epithelial retiform component resembling the rete ovarii (RUTROSCT) and to compare their immunophenotype with tissues containing retiform structures such as the normal rete ovarii, retiform Wolffian adnexal tumour (RWAT) and ovarian retiform areas of Sertoli‐Leydig cell tumours (ORSLCT).

Methods and results:  Six RUTROSCTs were analysed. The average age of patients was 65 years, and all tumours behaved in a benign fashion. Four were intracavitary and two intramural. Two cases were misdiagnosed as malignant in endometrial biopsy specimens and one in the hysterectomy specimen. Histologically they had a tubulopapillary or glomeruloid formation; a sex‐cord‐like or endometrial stromal component was absent or comprised at most 30% of the tumour. RUTROCST showed consistent positivity for CAM5.2, cytokeratin (CK) 7, vimentin, calretinin, progesterone receptor and apical CD10. CD56 and α‐inhibin were positive in half of the cases. Epithelial membrane antigen, desmin, smooth muscle actin and calponin were negative. Comparatively, rete ovarii and RWAT had a similar positivity for CK7, CD56, CD10 and calretinin. ORSLCT differed in its conspicuous positivity to CD56, CD10, α‐inhibin and calretinin, but absent CK7 expression.

Conclusions:  RUTROSCTs have benign behaviour but may be confused with various uterine adenocarcinomas or metastases. Correct diagnosis should avoid overtreatment. The immunophenotype of retiform areas is similar to that of adult rete ovarii and RWAT with minor divergence from ORSLCT.
Sex‐specific adult dispersal and its selective consequences in the brown anole,Anolis sagrei
Authors: Calsbeek Ryan
Published: March 2009

Dispersal behaviour is a potentially risky life‐history strategy that can impact habitat use as well as competition over territories and mates.

I studied natural selection on dispersal behaviour over the course of four breeding seasons in a Bahamian population of brown anoles (Anolis sagrei).

Both males and females showed extremely high site fidelity over the course of each reproductive season. Movement distance in males was negatively correlated with body size at first capture in spring (small males dispersed further). Moreover, differences in body size between dispersing males and the body size of the male territory residents that they replaced were correlated with the distance that males dispersed. Relatively larger males dispersed shorter distances compared with relatively smaller males. There was no relationship between dispersal distance and body size in females. However, females were more likely to disperse away from areas of low female density and into areas of higher female density, and female dispersal distances were negatively correlated with the number of female neighbours at the site of capture in spring (before dispersal).

These data suggest that, whereas male dispersal is driven by inter‐male competition, female dispersal is more likely related to variation in territory quality.

Natural selection acted on dispersal distance in conjunction with male, but not female body size. Although smaller males were the more likely to disperse, these males paid a high cost in terms of viability indicating that dispersal is a potentially risky strategy.
Anonymous non‐response analysis in the ABCD cohort study enabled by probabilistic record linkage
Authors: Tromp M. , Van Eijsden M. , Ravelli A. C. J. , Bonsel G. J.
Published: March 2009

Selective non‐response is an important threat to study validity as it can lead to selection bias. The Amsterdam Born Children and their Development study (ABCD‐study) is a large cohort study addressing the relationship between life style, psychological conditions, nutrition and sociodemographic background of pregnant women and their children's health. Possible selective non‐response and selection bias in the ABCD‐study were analysed using national perinatal registry data. ABCD‐study data were linked with national perinatal registry data by probabilistic medical record linkage techniques. Differences in the prevalence of relevant risk factors (sociodemographic and care‐related factors) and birth outcomes between respondents and non‐respondents were tested using Pearson chi‐squared tests. Selection bias (i.e. bias in the association between risk factors and specific outcomes) was analysed by regression analysis with and without adjustment for participation status.

The ABCD non‐respondents were significantly younger, more often non‐western, and more often multiparae. Non‐respondents entered antenatal care later, were more often under supervision of an obstetrician and had a spontaneous delivery more often. Non‐response however, was not significantly associated with preterm birth (odds ratio 1.10; 95% CI 0.93, 1.29) or low birthweight (odds ratio 1.16; 95% CI 0.98, 1.37) after adjustment for sociodemographic risk factors. The associations found between risk factors and adverse pregnancy outcomes were similar for respondents and non‐respondents. Anonymised record linkage of cohort study data with national registry data indicated that selective non‐response was present in the ABCD‐study, but selection bias was acceptably low and did not influence the main study questions.