摘要:

AbstractThe201T1C1 solution is used in Nuclear Medicine for myocardial visualization.201T1 is a cyclotron‐produced radioisotope, obtained indirectly from the decay of201Pb or directly by irradiating mercury with protons. In this work,201T1 was obtained by irradiating a natural mercury target with protons in the energy range of 24 to 19 MeV, using the IPEN's CV‐28 cyclotron. Range calculations of protons in the targets and in the materials used to degrade the proton beam energy were made. At the end of the bombardment of a 329 μm thickness (6 MeV thickness) target of natural metallic mercury with 19 MeV protons provided a yield of 10 MBq201T1/

ISSN:0362-4803    

DOI:10.1002/jlcr.2580311202

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

Abstract3‐L‐Pyroglutamyl‐L‐thiazolidine‐4‐carboxylic acid (Pidotimod), a new immunostimulating agent, has been prepared labelled with14C and35isotopes starting from L‐[U‐14C]‐glutamic acid5and L‐[35S]‐cysteine hydrochloride6, respectively. In the first synthesis, L‐[U‐14C]‐5is converted into L‐[U‐14C]‐pyroglutamic acid2, which was reacted with ethyl L‐thiazolidine‐4‐carboxylate3to afford the ester4, in turn hydrolyzed to [14C]‐Pidotimod1. In the second synthesis, L‐[35S]‐6reacted with formaldehyde to give L‐[35S]‐thiazolidine‐4‐carboxylic acid7, which was coupled with the activated ester of pyroglutamic acid, compound8, to afford [35S]‐Pidotimod1. The total activity of [14C]‐Pidotimod was 1.2 mCi (specific activity 5.52 mCi/mmol) and that of [35S

ISSN:0362-4803    

DOI:10.1002/jlcr.2580311203

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractA simple and effective synthesis of D‐[3,4‐13C2]Glucose (60 atom %13C2)via13C enriched α,α' trehalose (1) produced from sodium [1‐13C]acetate by sporulating yeast is de

ISSN:0362-4803    

DOI:10.1002/jlcr.2580311204

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe new radiolabelled [3H]‐VUF 4576 has been prepared by an easy procedure using commercially available C3H3I. The new radiolabelled ligand [3H]‐VUF 4576 belongs to a subclass of prenylamine analogues which interfere with calcium regulated pathways. The compound has been synthesized in order to study the interaction of other compounds with these mechanisms and in particular the site of action of this subclass of calcium entry blockers and calmodulin antagoni

ISSN:0362-4803    

DOI:10.1002/jlcr.2580311205

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe synthesis of the high specific activity (39 Ci/mmole) tritium labelled steroid norgestrel is described. A practical synthesis of the required substrate for tritium incorporation, 18‐methyl‐Δ9(11)‐estradiol‐3‐methyl ether (6), was developedfrom norgestrel itself.Following reduction with carrier‐free tritium gas, microscale conditions were employed for the conversion of the resulting labelled intermediate (7) back to norgestrel‐[9,11‐3H], including a selectivein situprotection of the A‐ring ketone of 19‐norandrost

ISSN:0362-4803    

DOI:10.1002/jlcr.2580311206

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe mechanisms‐based glycosidase inhibitor 2‐deoxy‐2‐[18F]‐fluoro‐β‐mannosyl [18F]‐fluoride was synthesized and its covalent binding toAgrobacteriumβ‐glucosidase was d

ISSN:0362-4803    

DOI:10.1002/jlcr.2580311207

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractXenalipin1(4′‐trifluoromethyl‐2‐biphenylcarboxylic acid) was synthesized in the [14C]‐labelled form with specific activity 21.0 mCi/mmol suitable for metabolism and distribution studies in animals. The synthetic sequence involved conversion of [14C]‐ benzoic acid to the 4,4‐dimethyl‐2‐oxazoline derivative, formation of an organozinc compound, palladium‐catalyzed coupling of the arylzinc‐oxazoline with 4‐trifluoromethyliodobenzene, and acid hydrolysis. The radioch

ISSN:0362-4803    

DOI:10.1002/jlcr.2580311208

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractWe present an improved method to easily prepare gram quantities of α‐13C glycine beginning from K13CN. The four step synthesis involves the production of an N, N‐diphenyl‐cyanoformamidine intermediate through the coupling of cyanide to N, N‐diphenylcarbodiimide. Subsequent reduction by LiAlH4and hydrolysis of the resulting amidine produces fully enriched α‐13C labelled glycine with a 45‐50% yield. This relatively fast and simple synthesis uses only commonly available compounds and requires no special equipment, making the process easy to perform in any well equipped biochemistry laboratory. We further demonstrate that the product may be used, without extensive purification, to specifically label bacterially expressed proteins (E. colithioredoxin) through standard biosynthetic procedures. We also show that the13C glycine‐labelled protein may be readily analyzed using commonly available heteronuclear NMR techniques. Complete assignments for all 9 glycines of nativeE. colithioredoxi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580311209

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe radiochemical synthesis of N‐[11C‐methyl]‐L‐DOPA was accomplished by N‐methylation of the methyl and ethyl esters of L‐N‐tert‐butyl‐oxycarbonyl‐[β‐(3,4‐dimethoxyphenyl)]alaninate with [11C]iodomethane using sodium hydride in tetrahydrofuran and deprotection of the N‐methyl intermediate with hydriodic acid. A catalytic influence of Kryptofix on the methylation reaction was observed. Using the ethyl ester precursor, the average specific activity at the end‐of‐synthesis was 972 mCi/μmole. The synthesis was completed in an average of 45 minutes f

ISSN:0362-4803    

DOI:10.1002/jlcr.2580311210

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe preparation of the unsymmetrically isotope‐labelled title compounds was achieved in pure form for the first time. While mono‐15N‐cyanogen is available in a two‐step‐synthesis, the preparation of mono‐13C‐cyanogen requires five steps, the last step in both cases being the dehydration of mono‐15N‐e.g. mono‐13C‐oxamide with

ISSN:0362-4803    

DOI:10.1002/jlcr.2580311211

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY