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1.
Abstract

Nucleophilic substitution reactions of 4-azolyl-1 β-P-D-ribofuranosylpyrimidin-2(1H)-one and 6-azolyl-9-β-D-ribofuranosyl-9H-purine derivatives, which were converted from uridine and inosine, with [15N]phthalimide in the presence of triethylamine or DBU gave N 4-phthaloyl[4-15N]cytidine and N 6-phthaloyl[6-15N]- adenosine derivatives, respectively, in high yields. Similar reactions of those azolyl derivatives with succinimide afforded N 4-succinylcytidine and N 6-succinyladenosine derivatives in high yields. The corresponding 2′-deoxyribonucleosides were also synthesized efficiently through the same procedure.

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2.
The nucleophilic addition–elimination reaction of 2′,3′,5′-tri-O-acetyl-2-fluoro-O 6-[2-(4-nitrophenyl)ethyl]inosine (8) with [15N]benzylamine in the presence of triethylamine afforded the N 2-benzyl[2-15N]guanosine derivative (13) in a high yield, which was further converted into the N 2-benzoyl[2-15N] guanosine derivative by treatment with ruthenium trichloride and tetrabutyl-ammonium periodate. A similar sequence of reactions of 2′,3′,5′-tri-O-acetyl-2-fluoro-O 6-[2-(methylthio)ethyl]inosine (9) and the 6-chloro-2-fluoro-9-(β-D-ribofuranosyl)-9H-purine derivative (11), which were respectively prepared from guanosine, with potassium [15N]phthalimide afforded the N 2-phthaloyl [2-15N]guanosine derivative (15; 62%) and 9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-6-chloro-2-[15N]phthalimido-9H-purine (17; 64%), respectively. Compounds 15 and 17 were then efficiently converted into 2′,3′,5′-tri-O-acetyl[2-15N]guanosine. The corresponding 2′-deoxy derivatives (16 and 18) were also synthesized through similar procedures.  相似文献   

3.
In an effort to develop a specific radiodiagnostic agent for articular cartilage imaging, we have investigated the biodistribution of bis[β-(N,N,N-trimethylamino)ethyl]selenide-75Se diiodide (75Se BISTAES) in rabbits. At an intravenous dose of 5 mg/kg, the greatest localization of the compound occurred in articular cartilage 15 min after injection. The compound was excreted rapidly in the urine. The results suggest that 75Se BISTAES has potential clinical use as an articular cartilage imaging agent.  相似文献   

4.

Nucleophilic aromatic substitution of 9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-6-chloro-2-fluoro-9 H-purine with N-(tert-butyldimethylsilyl)[ 15 N]phthalimide in the presence of a catalytic amount of CsF at room temperature in DMF efficiently afforded the 6-chloro-2-[ 15 N]phthalimidopurine derivative, which was subsequently converted to the [2-15N]guanosine derivative was also efficiently synthesized through a similar procedure.  相似文献   

5.
Intravenous injection of the gallium chelating agents, N,N′-ethylene bis[2-hydroxy-5-carboxyphenylglycine], (COOH-EHPG), or desferrioxamine (DFO) after gallium-67 (67Ga) injection, improved tumour/non-tumour tissue uptake ratios in mice bearing the EMT-6 sarcoma. Six hours post injection of gallium and 2 h post chelator, COOH-EHPG enhanced the tumour/blood ratios by an order of magnitude compared to untreated controls, whereas DFO increased the ratios three-fold. Twenty two hours post gallium and 2 h post chelator, the increases in ratios compared to controls were seven-fold for COOH-EHPG and two-fold for DFO. The study thus demonstrated the superior ability of COOH-EHPG for the enhancement of 67Ga tumour/blood ratios compared with DFO.  相似文献   

6.
Homocysteine plays a key role in several pathophysiological conditions. To assess the methionine–homocysteine kinetics by stable isotope methodology, we developed a simultaneous quantification method of [2H7]methionine, [2H4]methionine, methionine, [2H4]homocysteine and homocysteine in rat plasma by gas chromatography–mass spectrometry (GC–MS). [13C]Methionine and [13C]homocysteine were used as analytical internal standards to account for losses associated with the extraction, derivatization and chromatography. For labeled and non-labeled homocysteine measurements, disulfide bonds between homocysteine and other thiols or proteins were reduced by dithiothreitol. The reduced homocysteine and methionine species were purified by cation-exchange chromatography and derivatized with isobutyl chlorocarbonate in water–ethanol–pyridine. Quantification was carried out by selected ion monitoring of the molecular-related ions of N(O,S)-isobutyloxycarbonyl ethyl ester derivatives on the chemical ionization mode. The intra- and inter-day precision of the assay was less than 6% for all labeled and non-labeled methionine and homocysteine species. The method is sensitive enough to determine pharmacokinetics of labeled methionine and homocysteine.  相似文献   

7.
A series of N,N-disubstituted-N′-[1-aryl-1H-pyrazol-5-yl]-methnimidamides was synthesized by a newly developed microwave reaction and their antiproliferative activities were evaluated. Microwave irradiation of 5-amino-1,3-disubstituted pyrazoles with various amide solvents in the presence of POCl3 provided the corresponding 2a2k, 3a3c, and 4a4f in good to excellent yields. The obtained methnimidamides were tested against NCI-H661, NPC-TW01, and Jurkat cancer cell lines and the results indicated that compounds 2d and 2e were the most potent with IC50 values in low micromolar range.  相似文献   

8.
应用微细胞检测基因产物的方法由于质粒和噬菌体等的DAN分子能在细胞内进行自我复制,以及DNA重组技术的普及,质粒DNA做为异源性DNA分子的载体,在基因工程中目前已被广泛应用。在克隆或分析真核生物或原核生物的多种不同基因时,常用检测基因表达来确定其存在。把含有某一目的基因的DNA片段和载体质粒的DNA进行重组,再通过重组DNA在受体细胞中的转录、翻译、  相似文献   

9.
M. Fischer 《BioControl》1971,16(1):101-109
Zusammenfassung Doryctes molorchi wird neu beschrieben,Doryctes petrovskii Kokujew wird redeskribiert. Ersterer ist ausMolorchus umbellatarum Schreber, letzterer ausPogonochaerus hispidus L. (Col., Cerambycidae) gezogen. Beide Arten sind neu für ?sterreich. Der Bestimmungsschlüssel für die pal?arktischenDoryctes-Arten nachTelenga wird erweitert.
Summary Doryctes molorchi is described as new andD. petrovskii Kokujew is redrescribed. The former is reared fromMolorchus umbellatarum Schreber, the latter fromPogonochaerus hispidus L. (Col., Cerambycidae). The species are new to the fauna of Austria. A key for identification of the palearcticDoryctes species afterTelenga (1941) is given.


Die Untersuchungen wurden mit Unterstützung des Fonds zur F?rderung der wissenschaftlichen Forschung durchgeführt.  相似文献   

10.
答:这里的[H]并不是指氢离子(H+),而是指辅酶中的氢(还原性氢),[H]的产生与利用即NADH、FADH。和NADPH的产生与利用。光合作用与呼吸作用中产生和利用的[H]不同,光合作用产生及利用NADPH.而呼吸作用产生与利用的[H]主要是NADH与FADH2。  相似文献   

11.
P. Cochereau 《BioControl》1970,15(3):281-285
Résumé La TachinaireMicrophthalma europaea Egg., parasite de larves deScarabaeidae en Afrique du Nord [Hurpin & Fresneau, 1964] a été multipliée à Nouméa (Nouvelle-Calédonie) sur un nouvel h?te de substitutionProtaetia fusca Hrbt. (Cetoniinae). Cet h?te nouveau permet maińtenant un élevage massif du parasite en Nouvelle-Calédonie, avant sa libération éventuelle à l'?le Wallis contre les larves d'Oryctes rhinoceros L., unDynastinae ravageur du cocotier.
Summary The Tachinid fly,Microphthalma europaea Egg., parasite onScarabaeidae larvae in North Africa (Hurpin & Fresneau, 1964) was multiplied in Noumea (New Caledonia) on a new alternative hostProtaetia fusca Hrbt. (Cetoniinae). The contingent introduction of this parasite fly to Wallis island against larvae ofOryctes rhinoceros L. (Dynastinae), the coconut rhinoceros beetle, so could be now more easy from New Caledonia.


Nous remercions le DrP. Jourdeuhil, Directeur de la Station de Lutte Biologique d'Antibes (France), d'avoir bien voulu lire notre manuscrit et nous apporter ses conseils les plus judicieux.  相似文献   

12.
记述云南高黎贡山[虫脩]目异[虫脩]科和[虫脩]科5个新种,即刺胸阿异[虫脩]Aruanoidea notata,sp.nov.,高山短肛[虫脩]Baculum altissimum,sp.nov.,光亮拟短肛[虫脩]Parabaculum laevigatum,sp.nov.,双角刺[虫脩]Cnipsomorpha biangulatus,sp.nov.,黑缘介[虫脩]Interphasma marginatum,sp.nov.,并且首次记述了污色无翅刺蟾Cnipsomorpha colorantis(Chen et He)的雄性。模式标本分别存放于北京林业大学与中国林业科学研究院昆虫标本馆。  相似文献   

13.
该文介绍了绿藻[FeFe]氢化酶的研究现状,包括酶的结构、催化中心、金属簇的性质,以及对氧的敏感性和可能的解决办法。并且对已报道的绿藻[FeFe]氢化酶基因及其调控等问题作了介绍。  相似文献   

14.
P. Delattre 《BioControl》1974,19(1):13-31
Résumé Les potentialités d'un prédateur et son aptitude á réaliser la régulation des populations de sa proie sont les premiers éléments qui doivent être examinés avant la mise en œuvre d'une méthode de lutte biologique. Plusieurs critéres écologiques ont permis d'aborder l'étude de l'évaluation de l'efficacité prédatrice d'un acarien,Zetzellia mali Ewing., dans des conditions naturelles de milieu. Quelques observations au laboratoire, concernant notamment les préférences alimentaires et les capacités de survie du prédateur, ont complété cette premiére étude.
Summary This predatory effect was assessed by observing natural populations of mites, according to several ecological criteria. The results of this study outlines the fairly important effect of the predatory miteZetzellia mali on the prey populations, thus proving the interest of maintaining some sedentary useful animals of this type in the orchards. Some data have been collected in order to help the predatory activity of this mite in commercial orchards.
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15.
L2[o,r2]上的人口算子   总被引:3,自引:1,他引:2  
用LZ〔0,:。〕表示通常意义下的Hilbert空间.在空间L“〔0,1。〕中,人口发展算子A“2’定义如下:定义域。‘A,={。‘·,卜‘·,dP(了) dr一“(r)p(,)〔LZ〔o,:,〕;p(o)_。f犷,,_,.,、:,_、*,_、J_1、*‘_、二。,,、‘,*、‘_、__dp(:)=夕l无(r)h(了)户(,)d了卜对p(1)〔D(A),(AP)(7)=一丝书井三 rJ九一’一“一’J‘一‘一’dT一“(r)P(犷),其中,1。为社会中人能活到的最大年龄,〔;,,12〕为妇女育龄区间,h(1)表示生育模式,k(下)表示女性比例函数,那(犷)表示相对死亡率,口>o为妇女总和生育率.拼(r),k(了),h(了)满足下面条件(I).召(,),…  相似文献   

16.
为进一步深入研究我国人群中轮状病毒主要流行的P[4]、P[6]和P[8]型毒株的受体结合特点及结构基础,本研究将P[4]、P[6]和P[8]型毒株VP8*核心区(VP8*core)基因分别构建到原核表达载体pGEX4T-1和pET30a中,利用大肠杆菌表达获得轮状病毒P[4]、P[6]和P[8]型毒株VP8*核心区蛋白,并通过亲和层析分别纯化得到VP8*core-GST融合蛋白和VP8*-his标签蛋白,SDS-PAGE显示蛋白大小分别为46kDa和20kDa。综上,本研究成功构建了pGEX4T-1-VP8*core和pET30a-VP8*core重组质粒,利用原核表达系统得到VP8*coreGST融合蛋白和VP8*core-his蛋白,为VP8*蛋白的功能和结构研究提供基础。  相似文献   

17.
18.
19.
李森 《生物学通报》2011,46(5):23-24
光合作用与呼吸作用所涉及的[H]指NADH、FADH2与NADPH中的还原性氢。光合作用与呼吸作用中产生和利用的[H]不同,光合作用产生及利用NADPH,而呼吸作用产生与利用的[H]主要是NADH与FADH2。  相似文献   

20.
La localisation des ?ufs et des larves dePsyllaephagus euphyllurae SILV. endoparasite du psylle de l'olivier (Euphyllura olivina COSTA) ainsi que le régime alimentaire de la phase post-embryonnaire sont identifiés par examen microscopique des coupes histologiques de larves de 5c stade parasitèes. L'entomophage dépose les 2/3 de ses ?ufs dans le thorax et son régime alimentaire comprend 2 phases bien distinctes:
  • - une première phase stéatophage de 7 à 7,5 jours pendant laquelle la larve ingère le tissu adipeux de l'hôte,
  • - une deuxième phase sarcophage de 1 à 1,5 jours au cours de laquelle la larve dePsyllaephagus euphyllurae fortement mandibulée consomme tous les organes de l'hôte à l'exception des téguments qui sont alors momifiés.
  • Pendant la 1ère période, la digestion commence à être visible chez une larve âgée de 3 jours, et durant la 2ème période, elle suit l'ingestion des organes de l'hôte qui sont sous forme de fragments non reconnaissables dans le tube digestif moyen.  相似文献   

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