bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbonyl and thiocarbonyl compounds. XI. Synthesis of halogenated benzodioxoles by the action of tetrahalo‐o‐benzoquinones on benzophenone hydrazones and their cleavage by nucleophilic reagents
Authors: Latif N. , Zeid I. , Haggag B. 
Published: April 2009

Abstractp,p′‐Dichloro‐, p,p′‐dimethyl‐ and p,p′‐dimethoxybenzophenone hydrazones react with tetrachloro‐ and tetrabromo‐o‐benzoquinone to give directly the halogenated benzodioxoles (IIIa‐IIIf), respectively, together with the corresponding tetrahalocatechol. Cleavage of the dioxole ring by nucleophilic reagents depends markedly on the nature of the substituents. The dimethoxyderivatives (IIIc) and (IIIf) proved to be unusually reactive toward cleavage by dilute mineral acids, lithium aluminum hydride, hydrazines and malonitrile, whereas the dichloro analog behaves normally and is not cleaved under the same conditions.
A new synthesis of 4‐thiouracils
Authors: Lamon Robert W. 
Published: April 2009

AbstractEthoxycarbonyl isothiocyanate has been found to form adducts with enamines which, on treatment with primary amines or ammonia, undergo apparent “amine exchange” and cyclization to 4‐thiouracil derivatives. Evidence for the 4‐thiouracil structure includes both spectral data and chemical transformations.
The synthesis of pyrimido[4,5‐d] pyridazines
Authors: Kinoshita Toshio , Castle Raymond N. 
Published: April 2009

AbstractThe synthesis of pyrimido[4,5‐d]pyridazin‐2‐one‐4‐thione (II), pyrimido[4,5‐d]pyridazine‐2,4‐dithione (VI), 4‐aminopyrimido[4,5‐d]pyridazine‐2‐thione (III), 2‐aminopyrimido[4,5‐d]‐pyridazin‐4‐one (X), 2‐methylpyrimido[4,5‐d]pyridazin‐4‐one (XII), and pyrimido[4,5‐d]‐pyridazin‐4‐one (XIII) are reported together with several new pyridazine intermediates.
A facile synthesis of 5‐substituted 1‐methyluracils and cytosine
Authors: Sakai Ted. T. , Pogolotti Alfonso L. , Santi Daniel V. 
Published: April 2009

AbstractA facile, general synthesis for a number of 5‐substituted‐1‐methyluracils and cytosine which is suitable for the preparation of micro‐quantities is reported. In contrast to other methods, the 5‐substituent plays no role in determining the position of alkylation. 1‐Methyl‐5‐hydroxymethyluracil and 1‐methyl‐5‐formyluracil have also been synthesized by an alternate route.
Synthesis of thia‐ellipticine, 5,11‐dimethylbenzothieno[2,3‐g]isoquinoline
Authors: Fujiwara Allan N. , Acton Edward M. , Goodman Leon 
Published: April 2009

Abstract1,4‐Dimethyldibenzothiophene (VII) was synthesized and was converted with butyl dichloromethyl ether to the 2‐aldehyde (VIII). The structure was confirmed by an independent synthesis of the 2‐ester (XI) derived from it. The 2‐aldehyde (VIII) with aminoacetaldehyde diethylacetal formed the Schiff′s base (IX), and Pomeranz‐Fritsch cyclization with 105% superphosphoric acid then formed thia‐ellipticine (II), an isostere of the antitumor alkaloid, ellipticine.
1‐Methyl‐3‐phenyl‐3‐thiocyanato‐1H,3H‐quinoline‐2,4‐dione: A novel thiocyanating agent
Authors: Klásek Antonín , Mrkvička Vladimír 
Published: April 2009

AbstractUnder mild reaction conditions, the thiocyanato group is selectively transferred from 1‐methyl‐3‐phenyl‐3‐thiocyanato‐1H,3H‐quinoline‐2,4‐dione (3) to some nucleophiles. Aliphatic primary and secondary amines are converted to S‐cyanothiohydroxylamines, anilines afford p‐thiocyanatoanilines, Wittig reagent is thiocyanated in α‐position, and thiols are oxidized to disulfides.
Synthesis of 10‐Aryl‐10H‐naphtho[1,8a,8‐fg]indazol‐7‐ones
Authors: Stadlbauer Wolfgang , Hojas Gerhard 
Published: April 2009

Abstract3‐Hydroxy‐2‐[1‐(arylhydrazono)ethyl]‐1H‐phenalen‐1‐ones 3, obtained from 2‐acetyl‐3‐hydroxy‐1H‐phenalen‐1‐one (1) and arylhydrazines 2, cyclize under acidic conditions to 8‐methyl‐10‐aryl‐10H‐naphtho‐[1,8a,8‐fg]indazol‐7‐ones 4. Indazoles 4 are also obtained from 2‐acetyl‐3‐hydroxy‐1H‐phenalen‐1‐one (1) and arylhydrazines 2 in a one‐pot reaction. 2‐Acetyl‐3‐azido‐1H‐phenalen‐1‐one (6) does not give 8‐methyl‐9‐arylamino‐9H‐naphtho[1,8a,8‐fg]indazol‐7‐ones via azide decomposition but gives again by nucleophilic replacement of the azide moiety in 6 the indazole 4.
The chemistry of 1,6‐dioxapyrenes part 3 : Scope and limitations of an acid catalyzed ring‐closing reaction
Authors: Christensen Jørn B. , Bechgaard Klaus 
Published: April 2009

AbstractOne of the few methods for synthesis of 1,6‐dioxapyrenes is the acid catalyzed cyclization of 2,6‐disubstituted 1,5‐bis(2‐oxoalkoxy)naphthalenes. The scope and limitations of this reaction has been investigated and 11 new 2,7‐disubstituted 1,6‐dioxapyrenes have been prepared and characterized. Most of the compounds undergo two reversible oxidations to give the corresponding radical as well as di‐ cations.
8‐Fluoro‐4‐hydroxy‐1H‐[1,2,4]triazino[4,5‐a]quinoline‐1,6(2H)‐dione: Synthesis and reactivity
Authors: Edmont Doloràs , Chenault Jacques 
Published: April 2009

AbstractA simple and versatile methodology to synthesise 4‐hydroxy‐1H‐[1,2,4]triazino[4,5‐a]quinoline‐1,6(2H)‐dione from methyl 6‐fluoro‐4‐oxo‐1,4‐dihydro‐2‐quinolinecarboxylate has been developed. It involves car‐bohydrazide formation followed by a condensation with triphosgene to form the fused [1,2,4]triazino ring. In addition, the reactivity of the [1,2,4]triazino ring has been studied.
Utilization of cleavage of the [1]benzofuro[2,3‐e][1,2,4]triazine ring for the synthesis of oxygen, nitrogen and sulfur derivatives of [1,2,4]triazine
Authors: Stýskala Jakub , Slouka Jan , Wiedermannová Iveta , Bednář Petr 
Published: April 2009

AbstractA series of 6‐azacytosines 4a‐4k and 5a‐5c were prepared by nucleophilic cleavage of furan ring of [1]benzofuro[2,3‐e][1,2,4]triazine derivative 1. Some of them were used for the preparation of derivatives of [1,2,4]triazolo[4,3‐d][1,2,4]triazine (6a‐6d) and tetrazolo[1,5‐d][1,2,4]triazine (7). The reaction of 1 with hydrogen sulfide afforded the corresponding 6‐(2‐hydroxyphenyl)‐2‐phenyl‐5‐thioxo‐4,5‐dihydro‐1,2,4‐tri‐azin‐3(2H)‐one (8), while with hydrogen selenide 6‐(2‐hydroxyphenyl)‐2‐phenyl‐4,5‐dihydro‐1,2,4‐triazin‐3(2H)‐one (9) was formed. The prepared compounds were tested for biological activity.
On triazoles XLVIII. Synthesis of isomeric amino‐thiazolo‐[1,2,4]triazole, amino‐[1,2,4]triazolo‐[1,3]thiazine and ‐[1,3]thiazepine derivatives
Authors: Prauda Ibolya , Reiter József 
Published: April 2009

AbstractIsomeric type 1 and 2 amino‐1,2,4‐triazoles condensed with thiazole, thiazine and thiazepine rings were synthesised from 5‐amino‐2,3‐dihydro‐1H‐1,2,4‐triazol‐3‐thione and α,ω‐dihaloalkanes through the 5‐amino‐3‐(ω‐haloalkylthio)‐1H‐1,2,4‐triazole intermediates. The reaction conditions leading to derivatives 1 and 2, respectively, were determined. A general and safe method for the unambiguous differentiation between structures 1 and 2 was offered by their cmr spectra.
Synthesis, lipophilicity and structure of 2,5‐disubstituted 1, 3, 5‐dithiazine derivatives
Authors: Winfield Leyte , Zhang Chunming , Reid Christy A. , Stevens Edwin D. , Trudell Mark L. , Izenwasser Sari , Wade Dean 
Published: April 2009

AbstractA series of 2,5‐disubstituted 1,3,5‐dithiazine derivatives were synthesized as potential analogues of the potent dopamine uptake inhibitor GBR 12909. The lipophilic character of the 1,3,5‐dithiazine derivatives were experimentally (log P) and computationally (clog P) determined. The in vitro binding affinities of the 2,5‐disubstituted 1,3,5‐dithiazine derivatives at the dopamine transporter were determined to be much less potent than the binding affinity of GBR 12909 due to steric and electronic effects inherent to the 1,3,5‐dithiazine ring system. The X‐ray crystal structure of 2‐(2‐[bis(4‐fluorophenyl)methoxy]ethyl)‐5‐(3‐phenylpropyl)‐1,3,5‐dithiazine (7) revealed that the 5‐(3‐phenylpropyl) group is in a pseudo‐axial orientation and syn to the 2‐ethoxybenzhydryl moiety.
Synthesis of N1‐substituted coumarino[4,3‐c] pyrazoles
Authors: Čačič Milan , Trkovnik Mladen , Has‐Schön Elizabeta 
Published: April 2009

Abstract3‐Acyl‐4‐hydroxy‐2‐oxo‐2H‐chromen derivatives 1a‐d were condensed with (7‐hydroxy‐2‐oxo‐2H‐chromen‐4‐yl)‐acetic acid hydrazide 2, (4‐methyl‐2‐oxo‐2H‐chromen‐7‐yloxy)‐acetic acid hydrazide 3, and (7‐hydrazinocarbonylmethoxy‐2‐oxo‐2H‐chromen‐4‐yl)‐acetic acid hydrazide 4, to give corresponding 3‐alkyl‐1‐[2‐(7‐hydroxy‐2‐oxo‐2H‐chromeno‐4‐yl)‐acetyl]‐1H‐chromeno[4,3‐c]pyrazole‐4‐one 5a‐d, 3‐alkyl‐1‐[2‐(4‐methyl‐2‐oxo‐2H‐chromeno‐7‐yloxy)‐acetyl]‐1H‐chromeno[4,3‐c]pyrazole‐4‐one 6a‐d, and 1‐{4‐[(3‐alkyl‐1H‐chromeno[4,3‐c]pyrazole‐4‐one‐1‐yl)‐carbonylmethyl]‐2‐oxo‐2H‐chromen‐7‐yloxy‐acetyl}‐3‐alkyl‐1H‐chromeno[4,3‐c]pyrazole‐4‐one 7a‐d.
Synthesis of tricyclic pyrido[2,3‐b][1,4]‐thiazines via nucleophilic substitution of activated precursors
Authors: Weber Manuela , Jäger Walter , Erker Thomas 
Published: April 2009

AbstractPyrido‐anellated compounds analogous to tricyclic 1,4‐benzothiazine derivatives were synthesized. Thus, under mild reaction conditiones substitution of thiolactim 3 with different N‐nucleophiles yielded the precursors for compounds, which were cyclized in a further step to the corresponding tricyclic derivatives.
Direct synthesis of γ‐substituted phthalides via ortho‐aryl benzoic acid mediated benzyl radical cyclization
Authors: Mahmoodi N. O. , Salehpour M. 
Published: April 2009

AbstractDirect synthesis of γ‐substituted phthalids from related ortho‐aryl benzoic acids with 48–85% yield are covered. The direct oxidation in the presence of peroxydisulphate‐copper (II) chloride in aqueous medium was applied. The reaction is highly regioselective and leads exclusively to γ‐butyrolactone, through very stable benzylic radical intermediate.
Reactions of isocyanates with methyl N‐(cyanothioformyl)anthranilate
Authors: Deck L. M. , Papadopoulos E. P. , Smith K. A. 
Published: April 2009

AbstractThe triethylamine‐catalyzed reactions of methyl N‐(cyanothioformyl)anthranilate (1) with isocyanates result in cyclization involving the cyano group to form methyl 2‐(4‐imino‐2‐oxo‐3‐substituted‐5‐thioxoimi‐dazolidin‐1‐yl)benzoates (4). Ring closure at the ester carbonyl to form 3‐aryl‐3,4‐dihydro‐4‐oxoquinazo‐line‐2‐carbonitriles (8) is observed when the S‐methyl derivative of 1 is allowed to react with aromatic amines.
A facile one‐pot synthesis of novel substituted 1,2,3,4‐tetrahydropyrimidines
Authors: Karim Enamul , Kishore Kaushal , Vishwakarma Jai N. 
Published: April 2009

AbstractA facile one‐pot synthesis of 5‐benzoyl‐6‐methylthio‐1,2,3,4‐tetrahydropyrimidines in good yields is reported.
Synthesis, X‐ray crystal structure and biological activities of α‐phenoxyl‐1,2,3‐thiadiazoleacetamide
Authors: Zhao Wei Guang , Li Zheng Ming , Yang Zhao 
Published: April 2009

AbstractThe annelation of 1,2,3‐thiadiazole rings was accomplished by the reaction of N‐acylhydrazone 2a bearing an adjacent α‐methyl with thionyl chloride to give α‐chloro‐N‐methyl‐1,2,3‐thiadiazole‐4‐acetamide 4 and was demonstrated by the X‐ray crystal structure of its derivative 5a. A novel series of α‐substituted phenoxy‐N‐methyl‐1,2,3‐thiadiazole‐4‐acetamide 5 were synthesized through the reaction of the compound 4 and phenols. The results of bioassays show that the title compounds exhibit good anti‐HBV activities. The crystal of compound 5a, N‐methyl‐α‐2‐bromophenyl‐1,2,3‐thiadiazole‐4‐acetamide, has been prepared and determined by X‐ray diffraction.
Application of baylis‐hillman methodology in a new synthesis of 3‐oxo‐2,3‐dihydro‐1H‐isoindoles
Authors: Song Young Seok , Lee Chang Hoon , Lee Kee‐Jung 
Published: April 2009

AbstractThe Baylis‐Hillman reaction of 2‐cyanobenzaldehyde with some activated alkenes leading to the formation of 3‐oxo‐2,3‐dihydro‐1H‐isoindoles has been described.
Synthesis of sydnonimine derivatives as potential trypanocidal agents
Authors: Soulère Laurent , Hoffmanna Pascal , Bringaud Frédéric 
Published: April 2009

AbstractN‐(p‐Nitrophenoxy)carbonyl‐3‐morpholino‐sydnonimine (NCMS) has been prepared from 3‐morpholinosydnonimine hydrochloride. Using the Griess assay and the superoxide‐mediated reduction of ferricytochrome c, the nitric oxide (NO•) and superoxide anion (O2•‐) ‐ releasing properties in phosphate buffer pH 7.4 of this novel peroxynitrite donor was studied and compared with the known 3‐morpholino‐sydnonimine (SIN‐1). From compound NCMS, a series of N‐substituted sydnonimine derivatives were easily prepared that contain purine or melaminophenyl groups which specify a recognition by a trypanosomal purine transporter. The ability of these new sydnonimines to inhibit the uptake of [23H]adenosine on Trypanosoma equiperdum was studied.
Liquid‐phase synthesis of mixture‐based bicyclic β‐lactam libraries
Authors: Gedey Szilvia , Fülöp Ferenc , Vainiotalo Pirjo , De Witte Peter A. M. , Zupkó Istvían 
Published: April 2009

AbstractFive sets of 27‐membered combinatorial libraries of alicyclic β‐lactams were prepared via liquid‐phase Ugi 4‐center 3‐component reactions (U‐4C‐3CR) utilizing 3 different cis β‐amino acids, 3 different isonitriles and 5×3 sets of aldehydes. Through combinations of the building blocks of one of these libraries, all of the possible sublibraries were also generated. A few azetidinone derivatives were synthesized individually by parallel synthesis.
Synthesis of 1,2,5,6‐/1,2,3,6‐tetrahydropyridinyl‐tetrahydro‐cyclopentaisoxazole derivatives
Authors: Ahn Mija , Park Jung Mee , Lee Ihl‐Young Choi , Jung Myung Hee 
Published: April 2009

AbstractFused tetrahydrocyclopenta‐isoxazoles were synthesized by 1,3‐dipolar cycloaddition reactions with pyridinealdoxime or tetrahydropyridinealdoxime and cycloalkenes.
Metallation reactions. XXXIV. Synthesis of 2‐(1‐hydroxy‐1‐arylethyl)‐1,3‐benzoxathiol‐3‐oxide derivatives
Authors: Cabiddu Salvatore , Cadoni Enzo , Melis Stefana , Ianni Alen , Bernard Angela M. , Cabiddu Maria G. , De Montis Stefania , Fattuoni Claudia , Ianelli Sandra 
Published: April 2009

AbstractThe reaction of benzoxathiole‐3‐oxide with lithiumdiisopropylamide in tetrahydrofuran gave an anion, which was reacted with various aryl‐methyl‐ketones to give 2‐(1‐hydroxy‐1‐arylethyl)‐1,3‐benzoxathiol‐3‐oxide derivatives. The reaction was carried out in different temperature conditions: at ‐88 °C the trans addition stereoisomers to the sulfoxide oxygen atom were the main products.
A novel synthetic approach for the synthesis of pyridocarbazole alkaloids
Authors: Ergün Yavuz , Okaya Gürol , Patir Süleyman 
Published: April 2009

AbstractThe synthesis of 11‐methyl‐6H‐pyrido[4,3‐b]carbazole‐1(2H)‐one (5), which can be important for the synthesis of other pyridocarbazole alkaloids and especially 1‐substituted ellipticines, is described. Construction of the tetracyclic structure was achieved by a new route and two important precursor compounds (4a and 4b) for the synthesis of pyridocarbazole alkaloids and also many new tetrahydrocar‐bazole derivatives (7, 8, 9, 10, 11, 12, 13) were synthesized.
On triazoles XLIX. Synthesis of 5,6‐dihydrothiazolo[3,2‐b]‐[1,2,4]triazol‐2‐yl‐, 6,7‐dihydro‐5H‐[1,2,4]triazolo[5,1‐b][1,3]thiazin‐2‐yl‐, and 5,6,7,8‐tetrahydro[1,2,4]triazolo[5,1‐b] [1,3]thiazepin‐2‐yl‐isoquinolinium salts
Authors: Prauda Ibolya , Reiter József 
Published: April 2009

Abstract5′‐Mercapto‐1′H‐1,2,4‐triazol‐3′‐yl‐isoquinolinium salts (6) were synthesised by the reaction of ortho‐acyl phenylacetones (2) or the corresponding pyrylium salts (3) and 5‐amino‐2,3‐dihydro‐1H‐1,2,4‐triazole‐3‐thione (5). Treatment of thioles 6 withα,ω‐dibromoalkanes led to type 15, 16 and 17 isoquinolinium salts condensed with thiazole, thiazine and thiazepine rings. When 6 are reacted with dibromomethane (10) 11 type dimeric structures are obtained.
A new intramolecular recyclization in water‐base cleavage reaction of 2,2‐dialkyl‐4‐hydroxymethylbenz[f]iso indolinium bromides and chlorides
Authors: Chukhajian Emma O. , Gevorkyan Hasmik R. , Chukhajian Eliza O. , Shahkhatuni Knarik G. , Panosyan Henrik A. , Tamazyan Rafael A. 
Published: April 2009

AbstractThe water‐base cleavage reaction of 2,2‐dialkyl‐4‐hydroxymethylbenz[f]isoindolinium bromides and chlorides (2b‐g) and (4a‐g) was investigated. It was established that the above‐mentioned salts in water‐base cleavage reaction undergo intramolecular recyclization. As a result 1,3‐dihydro‐4‐dialkylaminomethyl‐naphto[1,2‐c]furans (5a‐g) are obtained in 62‐72% yields. The same products in 65‐70% yields may be obtained by step cyclization cleavage reaction of dialkyl‐4‐hydroxybutyn‐2‐yl‐(3‐phenylpropargyl) ammonium salts (1b‐g) and (3a‐g), as well. The structure of the resulting amines 5a‐g are determined and approved by X‐ray diffraction, nmr and ir spectroscopic methods.
Synthesis of pyridazine derivatives through the unexpected intermediate 5‐amino‐ 4‐cyano ‐2,3‐dihydro‐furan‐2,3‐disulfonic acid disodium salt
Authors: Cacciari Barbara , Spalluto Giampiero , Ferretti Valeria 
Published: April 2009

AbstractAn unexpected compound (5‐amino‐4‐cyano‐2,3‐dihydrofuran‐2,3‐disulfonic acid disodium salt, 4) was isolated from the reaction of glyoxale bis hydrogen sulfite disodium salt with malononitrile. Its structure was undoubtly identified through crystal structure analysis. Compound 4 was highly stable and it was isolated easily and in a very high yield. Its reactivity was studied in the reactions with some hydrazine derivatives in order to obtain different pyridazine analogs.
1,3‐dipolar cycloaddition reactions of nitrile oxides to prop‐1‐ene‐1,3‐sultone
Authors: Tian Li , Xu Guo‐Yan , Ye Yong , Liu Lun‐Zu 
Published: April 2009

AbstractThe reaction of prop‐1‐ene‐1,3‐sultone 1 with a variety of nitrile oxides 3 afforded novel [3+2] cycloaddition products 4 in good yield. The cycloaddition reaction achieved excellent regioselectivity.
Synthesis of heterocycle‐substituted pyropheophorbide derivatives
Authors: Wang Jin‐Jun , Shim Young Key , Jiang Gui‐Ji , Imafuku Kimiaki 
Published: April 2009

AbstractMethyl pyropheophorbide‐a (MPPa) (1) was converted to two aldehydes, methyl 2‐formylmethyl‐2‐devinylpyropheophorbide‐a (2) and methyl 2‐formyl‐2‐devinylpyropheophorbide‐a (3). The former 2 reacted with active methylene compounds having a cyano function in the presence of sulfur to afford thiophene‐substituted chlorins 5a‐c and reacted with arylhydrazines to yield indole‐substituted chlorins 6a‐d. From the latter 3, a α‐diketo chlorin 7 was obtained via Wittig reaction and oxidation. Compound 7 reacted with o‐phenylenediamine to afford 2‐quinoxalyl‐substituted pyropheophorbide‐a 8. The reaction of MPPa (1) with anthranilamide to give a spiro‐substituted compound 9.
Synthesis of some trifluoromethyl substituted 1‐methylpyrazoles
Authors: Pavlik James W. , Ayudhya Theppawut Israsena Na , Tantayanon Supawan 
Published: April 2009

AbstractThe major products from the reaction of β‐alkoxyvinyl trifluoromethyl ketones 1a‐c with methylhydrazine (2) in absolute ethanol are the 3‐(trifluoromethyl)‐substituted‐1‐methylpyrazoles 3a‐3c with lesser amounts of the 5‐(trifluoromethyl)‐substituted products 4a‐4c and 5a‐5c. Carrying out the reaction in non‐polar, aprotic solvents can further enhance the regioselectivity favoring the 3‐ (trifluoromethyl) ‐substituted isomers.
10‐Thia‐mesobilirubin‐xiiiα
Authors: Ghosh Brahmananda , Lightner David A. 
Published: April 2009

AbstractThe 10‐thia analog of mesobilirubin‐XIIIα, with the central C(10) CH2group replaced by sulfur (1a) was synthesized by condensation of neoxanthobilirubic acid (3) with sulfur dichloride. Thia‐rubin1ais a brilliant yellow solid, forming bright yellow solutions with uv‐visible absorption maximum from 425–440 nm.
Relationship between kernel size and shape and lipase activity of naked oat before and after pearling treatment
Authors: Hu XinZhong , Wei Yimin , Ren Changzhong , Zhao Jing 
Published: April 2009

AbstractBACKGROUND: In China, some oat‐processing companies use pearling treatment to remove part of kernel lipase activity before further deactivation such as infrared roasting. Kernel size and shape are important physical properties of oat kernels. However, there are no reports concerning the change of oat kernel size and shape and lipase activity during pearling treatment.RESULTS: In this research, we tested lipase activity in the kernels of four different oat varieties and we studied the relationship between kernel size and shape and lipase activity. The effect of pearling treatment on oat lipase activity was also examined. A TM‐05C Satake mill was employed to pearl oat samples, with different pearling times ranging from 0 to 45 s at 5 s intervals. The oat lipase activity, lipid content and kernel shape and size after the pearling treatment were tested. Results showed that not only oat variety but also kernel size and shape had marked effects on lipase activity. Pearling treatment could significantly reduce lipase activity. During pearling treatment, small changes in kernel size and shape could cause a dramatic decline in lipase activity.CONCLUSIONS: Pearling treatment could be an effective pretreatment for further deactivation treatment of oats. Copyright © 2009 Society of Chemical Industry
Directed self‐assembly of single quantum dots for telecommunication wavelength optical devices
Authors: Dalacu D. , Reimer M.E. , Fréderick S. , Kim D. , Lapointe J. , Poole P.J. , Aers G.C. , Williams R.L. , Ross McKinnon W. , Korkusinski M. , Hawrylak P. 
Published: April 2009

AbstractThe ability to control the nucleation site of a single quantum dot will have a profound effect on the development of quantum dot‐based photonic devices. The deterministic approach will provide a truly scalable technology that can take full advantage of conventional semiconductor processing for device fabrication. In this review, we discuss the progress towards the integration of deterministically nucleated single quantum dots with top‐down quantum optical devices targeting telecommunication wavelengths. Advances in site‐controlled quantum dot nucleation using selective‐area epitaxy now makes it possible to position quantum dots at predetermined positions on a substrate in registry with alignment markers. This, in turn, has allowed for devices fabricated in subsequent processing steps to be aligned to individual quantum dots. The specific devices being targeted are gated‐single dots and coupled dot‐cavity systems which are key components of efficient sources of single photons and entangled photon pairs.
Radical cations of amino acids and peptides: Structures and stabilities
Authors: Hopkinson A.C. 
Published: April 2009

AbstractAmino acid and peptide radical cations, M.+, are formed by oxidative dissociations of [Cu(auxiliary ligand)(M)].2+ and [MetalIII(salen)(M)]+ complexes. The most easily formed radicals contain either an aromatic or basic amino acid residue. Aromatic amino acids have low ionization energies, are easily oxidized and delocalize the charge and spin over the ring systems; basic amino acids facilitate formation of α‐radicals that have captodative structures in which the charge and spin are formally separated, although feeding back some of the charge onto the amide or carboxyl group adjacent to the radical center through hydrogen bonding enriches the electron‐withdrawing properties and is highly stabilizing. DFT calculations located five isomers of His.+ with an α‐radical with a captodative structure at the global minimum in a deep potential well. An IRMPD spectrum confirmed that this isomer is the experimentally observed “long‐lived” isomer. When both charge and spin are on the peptide backbone, as in [GGG].+, captodative structures have the lowest energies; the barriers to interconversion between the three isomeric α‐radicals of [GGG].+ are high as the charge impedes migration of a hydrogen atom. Dissociation of [GGG].+ is charge‐driven. In peptide radical cations containing a basic amino acid residue the charge is sequestered on the side chain and the radical center, either on the backbone or on another side chain, initiates the fragmentation. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 28:655–671, 2009