摘要:

AbstractThe transcarboxylation reaction mechanisms of aromatic carboxylic acid salts in an atmosphere of14CO2was studied 2,6‐Naphthalenedicarboxylic, 2,5‐pyridine‐dicarboxylic and 2,5‐furanedicarboxylic acids, labelled with14C in the carboxylic groups were p

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050302

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractFarnesylacetic acid and its geraniol ester (gefarnate) labelled with14C at the carbon‐chain were prepared via methyl cyclopropyl ketone‐14C. The intermediate, ketone‐14C was obtained in 63 % radiochemical yield from barium carbonate‐14C and from this ketone‐14C, farnesylacetic acid‐14C and gefarnate‐14C having a specific radioactivity of 1.0 mCi/mmole were prepared in 48.4 % and 37.2 % yield,

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050303

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractCassaidin‐7α‐T und Cassaidinsäure‐7α‐ T (spezifische Aktivität jeweils 20 mC/mMol) werden dargestellt durch Reduktion der Ketogruppe an C‐7 von Cassain mit Natriumborhydrid‐T (spezifische Aktivität 80 mC/mMol), gegebenenfalls gefolgt von saurer Hydrolyse des Alkaloids. Die Reduktion der teilweise gehinderten Ketogruppe liefert ausschließlich den äquatorialen Alkohol. Wie gezeigt wird, geht die unerwartete Abwesenheit des axialen Alkohols auf den sterischen Ausschluß seiner Bildung durch die benachbarte cis‐ständige Methylgruppe an C‐14 zurück. Die markierten Verbindungen sind geeignet zur Erforschung des Vorkommens von primären Redoxreaktionen an C‐7 im tierischen Organismus und, wenn dies ausgeschlossen ist, zur Abklärung des allgemeinen Stoffwechsel‐Schicks

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050304

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

Abstract5‐Halogeno derivatives of deoxyuridine labelled in the base with14C were prepared by a single‐step enzymatic synthesis. When using the dicyclohexylammonium salt of 2‐deoxy‐α‐D‐ribose‐1‐phosphate, an enzyme preparation isolated from Escherichia coli B and 5‐halogenouracil‐2‐14C the corresponding deoxyribonucleosides were obtained in a fine yield. The time course of enzymatic reactions and the dependence of yield on concentration of the enzyme preparation and of 2‐deoxy‐α‐D‐ribose‐1‐phosphate were examined. Likewise, the transfer of the deoxyribosyl group between thymidine and 5‐halogenouracil was investigated and it was found that with the reactions studied the reaction equillibrium is approximately independent on type of halogen. For isolating the 5‐halogeno derivatives of deoxyuridine‐2‐14C from the reaction mixture we used preparative paper chromatography and obtained compo

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050305

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractNoxiptilin ist ein neues Antidepressivum mit geringen Nebenwirkungen. Für die Untersuchung des Stoffwechsels und der Kinetik dieser Substanz im Organismus der Ratte wurde ein Kohlenstoff‐14C‐markiertes Noxiptilin benötigt. Die Synthese ging aus vom Bariumcarbonat‐14C (10 mMol; 387 mCi) und führte über die Stufen der o‐ Toluylsäure‐[carboxyl‐14C], Phthalsäure‐[carboxyl‐14C], Benzalphthalid‐ [14C2] zu 2‐ Phenyl‐acetyl‐[carbonyl‐14c]‐benzoe‐säure‐[carboxyl‐14C], die zu 2‐ Phenyl‐äthyl‐[1‐14‐C]‐benzoesäure‐[carboxyl‐14C] hydriert wurde. Hieraus konnte 5H‐Dibenzo [a, d]cyclohepta‐1,4‐dien‐5‐on‐[5,10‐14C2] hergestellt werden, dessen Kondensation mit O‐(β‐Dimethylaminoäthyl)‐hydroxylamin zu 5‐(2‐Dimethylaminoäthyl‐oxyimino) ‐5 H‐dibenzo[a,d]cyclohepta‐1, 4‐dien [5,10‐14C2] führte. Die radiochemische Ausbeute an dem Hydrochlorid dieser Verbindung (Noxiptilin‐14C) betrug 31,5 %. Bei der Aufbewahrung der Substanz, deren spez. Aktivität 117 μCi/mg betru

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050306

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractThe new compound N‐methyl‐4‐nitrosoacetanilide was coupled with aniline‐3H (ring‐G) in ethanol‐acetic acid and the resulting azoamide was hydrolyzed in alkali to give a high yield of N‐methyl‐4‐aminoazobenzene labelled

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050307

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractThe synthesis of14C‐labeled menthol was accomplished by preparation of14C‐labeled (±) pulegone. Catalytic hydrogenation and chemical reduction converted (±) pulegone to the isomeric menthols possessing 1.10 mCi total activity. Gas chromatographic separation of this material gave the relative abundance of each i

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050308

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

Abstracto‐Hydroxy‐DL‐phenylalanine‐2‐14C was prepared by the condensation of o‐methoxybenzyl chloride and ethyl acetamidocyanoacetate‐2‐14C and subsequent hydrolysis. The racemate was resolved by the stereospecific action of chymotrypsin on the amino acid ethyl ester at p H 5.0 to give the two isomers

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050309

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractGlutamic acid specifically labelled with isotopic hydrogen in the 2 position was produced by exchange equilibration with labelled protons during the reaction of acetylglutamic acid with acetic acid and acetic anhydride. The position of label was established by n.m.r. and mass spectrometry of the deuterium‐labelled compound, and by transaminase‐catalyzed exchange with protons in the case of tritium‐labelled compound. The specific and complete exchange obtained in our experiments contrasts with the previously reported virtual nonlabelling under somewhat different conditions in which the presumed azlactone enolized and hydrolysed in an aqueous m

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050310

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractMethyl α‐D‐[gluco‐14C(U)] pyranoside was synthesized from D‐glucose‐14C(U) and methanol using a cation exchange resin catalyst, but was found to contain 10 % of the β‐anomer as a radiochemical impurity. This was conveniently removed by treatment with a β‐glucosidase — almond emulsin — to yield the pure α‐anomer whose anal

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050311

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY