摘要:

AbstractImproved reliable methods for the partial chemical synthesis of phosphatidylcholines and phosphatidylethanolamines are described. Glycerophosphorylcholine (GPC) as its cadmium chloride complex was acylated rapidly (3 hr) with deuterated acyl anhydrides in dimethylformamide (DMF) to give phosphatidylcholines in>90% yields. The products were free ofsn‐1 andsn‐2 isomers. 2‐Lysophosphatidylcholines were rapidly acylated with acyl anhydrides, used in nearly stoichiometric amounts, in chloroform affording mixed‐chain phosphatidylcholines in>85% yield. Pure phosphatidylethanolamines are prepared routinely in>70% yield by an improved procedure from the corresponding phospatidylcholines using phosphol

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210102

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractTyrosine derivatives were introduced onto the N‐terminal deprotected Pentagastrin to yield precursors of labelling. The tritiated derivative Boc‐3,5‐3H2‐Tyr‐Pentagastrin of high specific radioactivity (45 Ci/mmol) was obtained by catalytic dehalogenation of the corresponding di‐iodo‐derivative in the presence of tritium gas. Iodination of Boc‐Tyr‐Pentagastrin by NaI and chloramine T led to the formation of several compounds separated by HPLC. Conditions to obtain the mono‐iodinated non‐oxidized peptide, the only biologically active derivative, were investigated. Analytical chromatographic behaviour as well as biological activity of the tritiated and of the various iodinated p

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210103

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractWe report here the synthesis of tritiated cromolyn diethyl ester of high specific activity and acceptable stability for use inin vitroandin vivomodels of experimental asthma in the guinea pig. Preparation of an aryl brominated precursor, 1,3‐bis‐(2‐acetyl‐3‐hydroxy −6‐bromophenoxy)‐2‐propanol, followed by catalytic debromination with tritium gas and two subsequent synthetic steps atforded tritiated cromolyn diethyl ester with a specific activity of 135 mC

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210104

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractOrtho‐deuterated arylcarboxylic acids and their sodium salts may be prepared with high regioselectivity by isotopic exchange with deuterium oxide in the presence of a range of commercially available group VIII metal complexes. When rhodium trichloride trihydrate is employed a range of arylcarboxamides and arylmethanamines are also selectively labelled at theortho‐positi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210105

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe incorporation of18O into the 3‐hydroxyl of bile acids has been accomplished by hydrolysis of the acetal corresponding to the 3‐oxo bile acid with H2O, followed by hydride reduction of the ketone to the labeled hydroxyl funct

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210106

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe incorporation of13C, and/or2H2, into methyl 3β‐hydroxychol‐5‐en‐24‐oate to give products with an abundance of the isotopic label at a specific position, useful for metabolism studies, has been ac

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210107

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe Lindlar‐catalysed deuteration of methyl stearolate was studied to determine the effect of various poisons on the rate of reaction and on the isotopic purity of the methyl oleate‐9, 10‐d2produced. Poisons containing both exchangable and nonexchangable α protons on the heterocyclic ring [quinoline, quinaldine, γ‐collidine, acridine, and pyridine] were used. All poisons yielded methyl oleate‐9, 10‐d2having 94–97% isotopic purity. Very little over‐reduction of oleate to stearate occurred. Lindlar‐catalysed H‐D exchange involving the poison

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210108

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe micro‐scale synthesis of14C‐labelled methylazoxymethanol acetate (14C‐MAM‐acetate) having a specific activity of 110 mCi/mmol was accomplished in 25% yield from N,N′‐[methyl‐14C] ‐dimethylhydrazine with a specific activity o

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210109

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractTwo potential lipophilic myelin imaging agents (1,1,2,2‐tetrafluoro‐1,2‐diphenylethane and 1‐fluoroadamantane) were tritium labeled. The most effective method employed the microwave discharge activation of tritium gas technique and resulted in specific activities of 177 mCi/mmol for 1,1,2,2‐tetrafluoro‐1,2‐diphenylethane and 593 mCi/mmol for 1‐fluoroadamantane. Using this tritiation method significant amounts of tritium‐for‐fluorine substitution was also observed in the labeling of 1‐fluoroadamatane, resulting in nearly equivalent amounts of tritiated adamantane

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210110

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

Abstract(S)‐Histidine methyl ester was converted on a 20 g scale to its Nα, Nπ‐cyclic urea by treatment with carbonyl diimidazole. The Nτposition was alkylated with [D3]‐methyl iodide and the product was hydrolyzed to give isomerically and isotopically pure Nτ‐[D3] methylhistidine, without significant loss of optic

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210111

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY