摘要:

AbstractTritiated equilin of specific activity 6.85 × 108dpm/mg has been prepared by catalytic exchange with tritium oxide. It was found after a series of chemical reactions, that at least 90 % of the radioactivity remained in the B‐ring of the molecule. Of this, 75 % was found to be present at C

ISSN:0022-2135    

DOI:10.1002/jlcr.2590040202

出版商:John Wiley&Sons, Ltd.    

年代:1968

数据来源: WILEY

摘要:

AbstractThe radiation energy absorbed in solutions of phosphorus‐32, iodine‐125 and ‐131, mercury‐197 and ‐203 was calculated and tabulated for various time of storage. The influence of geometrical shape of solutions was also evaluated. An experimental verification of calculations was carried out for solutions of iodine‐131, the good agreement was obtained. The possibilities and limitations of the use of external gamma irradiation for estimating the self‐radiation effect w

ISSN:0022-2135    

DOI:10.1002/jlcr.2590040203

出版商:John Wiley&Sons, Ltd.    

年代:1968

数据来源: WILEY

摘要:

AbstractDie Synthese lief uber folgende Zwischenstufen : Umsetzung von Cyclopentanon mit KCN, Reduktion des gebildeten Cyanhydrins mil LiAlH4zum Aminol, Demjanov‐Ringerweiterung zu 2‐markiertem Cyclohexanon, Reaktion desselben mit 2‐Diphenylyl‐magnesiumjodid, Dehydratisierung und Dehydrierung des gebildeten Carbinols zu o‐Terphenyl‐13C. Ausbeute 16 % bez. auf KCN. Die Reinigung erfolgte mit präparativer DC auf Kieselgel. Die wichtigsten Nebenprodukte des letzten Schrittes sind o‐Xneyl‐cyclohexan, das unbekannte Hexahydrotriphenylen, p‐Terphenyl, o‐Quatervh

ISSN:0022-2135    

DOI:10.1002/jlcr.2590040204

出版商:John Wiley&Sons, Ltd.    

年代:1968

数据来源: WILEY

摘要:

AbstractTritium labelled substrates are commonly used in enzyme assays on account of their high specific activity, cheapness and availability. Because of certain special effects occurring with tritium labelled compounds, isotope effects may erroneously be inferred from rate measurements using these compounds. These special effects, and recommended methods of detecting and eliminating them, are discussed.

ISSN:0022-2135    

DOI:10.1002/jlcr.2590040205

出版商:John Wiley&Sons, Ltd.    

年代:1968

数据来源: WILEY

摘要:

AbstractMevalonic‐3′, 4‐D acid and –3′, 4‐T acid were synthesized by using deuterated and tritiated Ivater and the total yield of the labelled MV A was 6.5 %. The specific activity of the tritiated MV A, which was derived from 2.3 g. of tritiated water (250 mCi), was 1

ISSN:0022-2135    

DOI:10.1002/jlcr.2590040206

出版商:John Wiley&Sons, Ltd.    

年代:1968

数据来源: WILEY

摘要:

Uniformly14C‐labelled quinic acid has been biosynthesized by exposing young Quercus pedunculata Ehrh leaves to a source of light in a14CO2atmosphere. A preliminary study of the change in specific radioactivity of the labelled acid with time has led to a determination of the optimum metabolisation time. After extraction, separation over ion‐exchange resins and purification by preparative chromatography have allowed to obtain from 10 mCi of Ba14CO30,26 mCi of quinic acid, the radiochemical purity of which was proved by autoradiography.L'acide quinique14C uniformément marqué a été synthétisé en exposant à la lumière, en présence de14CO2, des jeunes feuilles de Quercus pedunculata Ehrh. L'étude de l'évolution, en fonction du temps, de la radioactivité spécifique de l'acide marqué a conduit à déterminer un temps de métabolisation optimum. Aprés extraction, la séparation sur résines échangeuses d'ions et la chromarographie préparative ont permis d'obtenir à partir de 10 mCi de Ba14CO3, 0,26 mCi d'acide quinique radi

ISSN:0022-2135    

DOI:10.1002/jlcr.2590040207

出版商:John Wiley&Sons, Ltd.    

年代:1968

数据来源: WILEY

摘要:

AbstractThe self‐radiolysis of a tritiated organic compound has been studied with particular attention to the determination of its percent decomposition, its G(‐M)value, as well as yields of the radiolysis products.Reliable figures have been obtained with the use of accurate experimental techniques, in particular the reverse isotopic dilution method coupled to preparative gas‐chromatog

ISSN:0022-2135    

DOI:10.1002/jlcr.2590040208

出版商:John Wiley&Sons, Ltd.    

年代:1968

数据来源: WILEY

摘要:

AbstractA rapid and simple procedure is described for synthesizing a wide range of tritium and14C‐labelled tertiary amines in millimolar quantities with good yields by melting together alkylhalides and secondary amine

ISSN:0022-2135    

DOI:10.1002/jlcr.2590040209

出版商:John Wiley&Sons, Ltd.    

年代:1968

数据来源: WILEY

摘要:

AbstractThe synthesis of14C and3H labelled methylazoxymethylacetate, ( MAM‐ O Ac), a hepatotoxic and carcinogenic compound, was accomplished by the incorporation of a radioisotope labelled methyl group into N,N′ ‐dimethylhydrazine with methyl iodide instead of dimethyl sulfate. Monosodium dibenzoylhydrazine was methylated with labelled methyl iodide and the second methyl group was subsequently added with unlabelled dimethyl sulfate to produce N,N′ ‐dimethylhydrazine. This modification made it possible to prepare labelled N,N′ ‐dimethylhydrazine with a small amount of total radioactivity and avoid an excessive waste of the methyl label. The labelled compound was then used in the synthesis of MAM‐OAc by a previously published procedure. The incorporation of radioactivity into N,N′‐dimethylhydrazine was in the range of 75‐95 %. Better yields were obtained for3

ISSN:0022-2135    

DOI:10.1002/jlcr.2590040210

出版商:John Wiley&Sons, Ltd.    

年代:1968

数据来源: WILEY

摘要:

AbstractS‐Ribosyl‐L‐homocysteine radioisotopically labelled in specific moieties has been prepared by enzymatic hydrolysis of the glycosyl bond of sulfur‐35 or tritium‐labelled S‐adenosyl‐L‐homocysteine. Procedures for chromatographic purification and analys

ISSN:0022-2135    

DOI:10.1002/jlcr.2590040211

出版商:John Wiley&Sons, Ltd.    

年代:1968

数据来源: WILEY