摘要:

AbstractIsotopic exchange of hydrogen in a system of solvent‐water‐3H was used to prepare 5‐fluoroorotic acid‐3H(G) which was decarboxylated and the hydrogen‐3H removed from labile bonds to yield 5′‐fluorouracil‐6‐3H. It was found in tracer experiments that a suitable solvent for the isotopic exchange of hydrogen was anhydrous dimethylformamide of dioxane. Water‐3H of high specific activity was prepared in these solvents by reduction of PtO2to Pt using carrierfree tritium. The specific activity of 5‐fluorouracil‐6‐3H was of the order of Ci/mmole, the radiochemical pu

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050402

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractRecent developments particularly in the field of nuclear magnetic resonance spectrometry suggest that there is a growing demand for compounds labelled with stable isotopes. In particular the isotopes H2, C13, N15and O17offer in some circumstances several advantages over the comparable radioactive isotopes and in this article we show how some workers have grasped the opportunities afforded. The availability of such compounds together with the problems associated with labelling and detection are discussed.

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050403

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractEs wird die Synthese eines14C und3H markierten 17β‐Heptanoyloxy‐17α‐äthinyl‐4‐östren‐3‐on beschrieben.Die14C Markierung erfolgte in der Position 4 des Steroidmoleküls (VIIa) sowie in der Position ľ der Oenanthsäure (XII) und die3H Markierung in Position 7 des Steroidmoleküls (VIIb).Wir benutzten Ba14CO3als Ausgangsmaterial und erreichten Ausbeuten über alle Stufen von 6% (VIIa) und 35% (XII); ausgehend vom Tritiumgas betrug die Ausbeute 6% (VIIb). Die Endprodukte wurden sorgfältigst gereinigt und der chemische und radiochemische Reinheitsgrad in mindestens zwei Dünnschichtsystemen und einer Verdünnungsanalyse geprüft. Die

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050404

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractPossibilities of enzymic synthesis of nucleoside‐5′‐triphosphates‐14C(U) of adenine, guanine, cytosine and uracil of high specific activity and radiochemical purity by means of a purified enzyme isolated from Escherichia coli B were studied. The effect of enzyme concentration in the reaction mixture in dependence on the time of the enzyme reaction is decisive for an optimal production of radioactive nucleoside‐5′‐triphosphates. A simple and rapid method of preparation of radioactive nucleoside‐5′‐triphosphates, including preparative paper chromatography as the single isolation step, is described and information on the radiolysis of the isolated nucle

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050405

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractDie Synthese von zwei mit14C unterschiedlich markierten Pyrokohlensäurediäthylestern wird beschrieben. Der einfach darzustellende Pyrokohlensäurediäthylester ist ein ausgezeichnetes Mittel zur Synthese auch von sonst schwierig zugänglichen markierten Estern und Carbäthoxyverbindungen. Während Pyrokohlensäure‐diäthylester‐(Carbonyl‐14C) nur zur Synthese14C‐markierter N‐, S‐, und O‐Carbäthoxyverbindungen brauchbar ist, liefert Pyrokohlensäurediäthylester‐(Äthyl‐14C) sowohl14C‐markierte Äthylester als auch14C

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050406

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractThe biosynthesis by and the isolation of 1‐menthol‐14C from Mentha arvensis grown in14CO2are described. Crystals (18 mg; 3.2 mCi/g) were obtained after column chromatographic purification of the steam distillate of the leaves. Purity of greater than 99.5 % was established by gas‐liquid radiochromatog

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050407

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractThe synthesis of 3‐(o‐chlorophenyl)‐2‐methyl‐4[3H]‐quinazolinone labeled with14C in both the 2 and 4 positions of the quinazolinone ring i

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050408

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractO‐Ethyl‐S‐phenyl‐ethylphosphonodithioate(1)a broad spectrum soil insecticide(2)was uniformly labeled in the benzene ring with Carbon‐14 to expand the residue and metabolism information(3)gained from previous labelings of this co

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050409

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractTritioammonia, 10 Ci/g, tritiated piperidine, 5‐hydroxytryptophan, glutamine, and asparagine by refluxing at −35 °C. Within 1.5 to 6 hours the specific activities reached 0.02, 0.775, 1.24 and 2.48 mCi/mmole, purified. Cyclooctatetraene was not exchangelabeled under these conditions. For liquid‐scintillation counting of tritioammonia, ortho‐bromobenzoic acid in toluene‐dioxan served well. Autoradiolysis was

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050410

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractUniformly labeled riboflavin‐14C was synthesized by the organism, Ashbya gossypii. Riboflavin with a specific activity of 79.0 mCi/mmole was obtained after extensive purification. Degradation of riboflavin with light and NaOH indicated that the14C label was present in both the isoalloxazine ring and in the side chain. Radioautographs of the chromatographed vitamin showed that a single radioactive band was found that coincided with authentic riboflavi

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050411

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY