Showing papers in "Journal of Labelled Compounds and Radiopharmaceuticals in 1976"
17 citations
14 citations
TL;DR: In this paper, the 5-astatouracil was prepared via the decomposition of the 5diazonium salt of uracil in the presence of 211At− with overall yields ranging from 20 to 30%.
Abstract: 5-astatouracil was prepared via the decomposition of the 5-diazonium salt of uracil in the presence of 211At− with overall yields ranging from 20 to 30%. Identification and separation was carried out on four different high pressure liquid chromatography columns. Under identical conditions, astatination is more effective than iodination, and complex formation of halide with the diazonium compound seems to be the product forming mechanism.
13 citations
TL;DR: The positions and extent of tritium labeling in carcinogenic polycyclic hydrocarbons are rapidly and conveniently revealed by 3H n.m.r. spectroscopy as mentioned in this paper.
Abstract: The positions and extent of tritium labelling in carcinogenic polycyclic hydrocarbons are rapidly and conveniently revealed by 3H n.m.r. spectroscopy.
13 citations
TL;DR: By using a precursor peptide, containing 3,5-di-bromotyrosine in position 2 ([Dbt2]-α-melanotropin, the tedious work with highly active labelled intermediates, and the storage of the tritiated compound can be avoided.
Abstract: A novel synthesis of α-melanotropin labelled with tritium on the tyrosine residue ([Tyr-3, 5-3H2] -α-melanotropin) is described. First, a precursor peptide, containing 3,5-di-bromotyrosine in position 2 ([Dbt2]-α-melanotropin) is prepared, which can be converted into the labelled hormone by catalytic tritiation in the last step of the synthesis. By this procedure the tedious work with highly active labelled intermediates, and the storage of the tritiated compound. usually accompanied by significant autoradiolysis, can be avoided.
12 citations
TL;DR: The usefulness of 3H n.m.r. spectroscopy as an analytical tool for the determination of tritium distribution in both generally and specifically labelled compounds is illustrated by reference to the results for phenylalanine and several other amino acids.
Abstract: The usefulness of 3H n.m.r. spectroscopy as an analytical tool for the determination of tritium distribution in both generally and specifically labelled compounds is illustrated by reference to the results for phenylalanine and several other amino acids.
10 citations
TL;DR: Sodium formate-13C, prepared by hydrolysis of isopropyl formate, was allowed to react with N-methylaniline hydrochloride to prepare the formylating agent N-methylformanilide-1-13c as mentioned in this paper.
Abstract: Sodium formate-13C, prepared by hydrolysis of isopropyl formate, was allowed to react with N-methylaniline hydrochloride to prepare the formylating agent N-methylformanilide-1-13C Formylation of benzo(a)pyrene with N-methylformanilide-1-13C gave the 6-13CHO derivative which was reduced to 6-13CH3 and 6-13CH2OH benzo(a)pyrenes 6-13CH2C1 benzo(a)pyrene was prepared from the 6-13CH2OH derivative
9 citations
TL;DR: A group of radioactive 1,4-benzodiazepine derivatives have been synthesized from glycine-1-14C as discussed by the authors, and the subject compounds are labeled with carbon-14 in the 2-position of the 1, 4-bensodiazepines ring system.
Abstract: A group of radioactive 1,4-benzodiazepine derivatives have been synthesized from glycine-1-14C. The subject compounds are labeled with carbon-14 in the 2-position of the 1,4-benzodiazepine ring system.
8 citations
TL;DR: Rhodium-catalyzed carbonylation of methanol at mild temperature and pressure has been developed for small and large scale preparations of the carbon isotope isomers of acetic acid.
Abstract: Rhodium-catalyzed carbonylation of methanol at mild temperature and pressure has been developed for small- and large-scale preparations of the carbon isotope isomers of acetic acid.
8 citations
TL;DR: Subsequent equilibration of 4b with carrier free tritium oxide followed by sodium cyanoborohydride reduction yielded naloxone-15,16-3H2 having a specific activity of 4 Ci/mmole.
Abstract: Mercury(II) oxide oxidation of naltrexone (1a) and naloxone (1b) gave 15,16-didehydronaltrexone (4a) and 15,16 didehydronaloxone (4b). Subsequent reduction of 4a with tritium gas afforded naltrexone-15,16-3H2 having a-specific activity of 15.3 Ci/mmole. Subsequent equilibration of 4b with carrier free tritium oxide followed by sodium cyanoborohydride reduction yielded naloxone-15-3H having a specific activity of 4 Ci/mmole.
8 citations
TL;DR: 3H-Ochratoxins A, B, and C were obtained by tritiation of the toxins with tritiated water in acetic acid and platinum at 80° C overnight and purified by solvent partition and thin layer chromatography with the recovery yield being 80% and the specific activity being 2.6 – 3.0 Ci/mmol.
Abstract: 3H-Ochratoxins A, B, and C were obtained by tritiation of the toxins with tritiated water in acetic acid and platinum at 80° C overnight. The toxins were purified by solvent partition and thin layer chromatography with the recovery yield being 80% and the specific activity being 2.6 – 3.0 Ci/mmol. Hydrolysis of 3H-ochratoxin A with carboxypeptidase A revealed that 80.9% of the tritium in ochratoxin A molecule distributed on the phenylalanine residue with only 19.1% in ochratoxin a moiety.
TL;DR: Four deuterium-labelled compounds were prepared for use as internal standards in the quantification of methamphetamine, DOM, PCP, and methaqualone at low levels in body fluids by selected ion monitoring.
Abstract: Four deuterium-labelled compounds were prepared for use as internal standards in the quantification of methamphetamine, DOM, PCP, and methaqualone at low levels in body fluids by selected ion monitoring. The need for standards containing more than three deuterium atoms per molecule and having high isotopic purity is discussed.
TL;DR: Pentachloronitrobenzene-14C6 was synthesized in 81.7% yield by exhaustive chlorination of nitrobenzinene 14C6 as mentioned in this paper.
Abstract: Pentachloronitrobenzene-14C6 was synthesized in 81.7% yield by exhaustive chlorination of nitrobenzene-14C6. Hexachlorobenzene-14C6 was produced in 11% yield as a byproduct of the reaction.
TL;DR: In this article, a convenient method for the preparation of tritiated arene oxides was developed for the K-region and non-K-region oxides, benzo[a]pyrene 7,8- and 9,10-oxide.
Abstract: Convenient methods have been developed for the preparation of specifically tritiated arene oxides. K-Region arene oxides of phenanthene, benzo[a]anthracene and benzo[a]pyrene were prepared from triatiated cis dihydrodiols via the methoxydioxolane route and the non-K-region arene oxides, benzo[a]pyrene 7,8- and 9,10-oxide, were prepared via triated halphydrin esters.
TL;DR: In this paper, an effective antimicrobial agent has been labelled with carbon-14, which was incorporated into the C-4 position of the molecule to give XIV in 10.0% overall radiochemical yield based on barium carbonate-14C.
Abstract: 1-Ethyl-6,7-methylenedioxy-4(1H)-oxocinnoline-3-carboxylic acid (cinoxacin) (1), an effective antimicrobial agent has been labelled with carbon-14. The carbon-14 was incorporated into the C-4 position of the molecule to give XIV in 10.0% overall radiochemical yield based on barium carbonate-14C. The 13C-, 15N-, and d-labelled compounds (XV, XVII, and XVIII) have also been synthesized for absorption and metabolism studies.
TL;DR: The distribution of tritium atoms among component aminoacids has been determined, after acid hydrolysis of the labelled protein, and the specific radioactivity of purified samples is in the Curie/mmole range.
Abstract: When lyophilized samples of bovine pancreatic ribonuclease are exposed to tritium gas, the exchange process can be markedly improved by applying high frequency electric discharges.
Labelling has been carried out for 5, 15 or 30 minutes periods. Labile radioactivity, was then removed by means of molecular sieving and repeated lyophilizations, the tritiated protein being submitted to further purification by ion-exchange chromatography.
The specific radioactivity of such purified samples is in the Curie/mmole range, and the biological activity of the enzyme remains well preserved. The distribution of tritium atoms among component aminoacids has been determined, after acid hydrolysis of the labelled protein.
TL;DR: (−)-Cocaine and nor-(−)-cocaine both were labelled on the methyl ester group with tritium and the synthesis was performed by partial hydrolysis of the parent compounds and reesterification of them usingtritium-labelled methanol.
Abstract: (−)-Cocaine and nor-(−)-cocaine both were labelled on the methyl ester group with tritium. The synthesis was performed by partial hydrolysis of the parent compounds and reesterification of them using tritium-labelled methanol.
TL;DR: In this article, Levulinic-4-14C acid was synthesized in 57% yield by condensation of ethyl acetoacetate-3-14c with ethyl bromoacetates and subsequent decarboxylation with hydrochloric acid, which was labelled with carbon-14 at C-2 position of indole nucleus for the use of metabolic studies.
Abstract: 5-Methoxy-2-methyl-1-(3,4-methylenedioxybenzoyl)indole-3-acetic acid (ID-955)(I), a new anti-inflammatory agent, was labelled with carbon-14 at C-2 position of indole nucleus for the use of metabolic studies. The procedure used is shown in Fig. 1 and 2. Levulinic-4-14C acid was synthesized in 57% yield by condensation of ethyl acetoacetate-3-14C with ethyl bromoacetate and subsequent decarboxylation with hydrochloric acid. Reaction of III with N1-(3,4-methylenedioxybenzoyl)-4-methoxyphenylhydrazine (II) gave ID-955-2-14C (I) in 58% yield. A total of 10.6 mCi of pure ID-955-2-14c (I) was obtained, representing 25% radiochemical yield from sodium acetate-1-14C.
TL;DR: The synthesis of two peptides, L-cystinyl-bis-L-valine and bis-6-(L-2-aminoadipyl)-L-cysteine-3,3′-T, is described.
Abstract: The synthesis of two peptides, L-cystinyl-bis-L-valine and bis-6-(L-2-aminoadipyl)-L-cystinyl-bis-L-valine, labeled with L-valine-14C(U) or L-cystine-3,3′-T, is described.
TL;DR: The potent carcinogen benzo[a]pyrene specifically tritiated in the 6-position was synthesized through hydrogenation of 6-bromobenzo[b] pyrene with tritium gas as discussed by the authors.
Abstract: The potent carcinogen benzo[a]pyrene specifically tritiated in the 6-position was synthesized through hydrogenation of 6-bromobenzo[a]pyrene with tritium gas. The benzo[a]pyrene-6-t was then employed in the synthesis of benzo[a]pyrene-6-t 4,5-oxide of high specific activity via. the corresponding cis-diol, quinone and trans-diol. Also, BaP-6-d and BaP-G-t were employed in the synthesis of the corresponding K-region oxidized derivatives (cis- and trans-diols, quinones, and oxides). Loss of the isotopic label was generally minimal except in the transformations involving the high specific activity BaP-6-t compounds.
TL;DR: N-Phenyl-2-naphthylamine has been synthesized with 14C in positions 1, 4, 5 and 8, with 13C in position 8 (small amounts of [1-13C] naphthalene and 2-[8-13c]naphethylamine are formed as by-products), and with the N-phenyl nucleus uniformly labelled with 14c.
Abstract: N-Phenyl-2-naphthylamine has been synthesized (1) with 14C in positions 1, 4, 5 and 8, (2) with 13C in position 8 (small amounts of [1-13C] naphthalene and 2-[8-13C]naphthylamine are formed as by-products), and (3) with the N-phenyl nucleus uniformly labelled with 14C.
TL;DR: In this paper, the effects of alterations in reaction time, metal ion, solvent and catalyst were investigated, and the effect of alteration in reaction times, metal ions, solvent, and catalyst was investigated.
Abstract: Labeled silver carbonate was prepared from barium carbonate-13C or -14C and aqueous silver nitrate in 95 to 100% yield. Diethyl carbonate-13C or -14C was generated in 60 to 85% overall yield by treatment of labeled silver carbonate with ethyl iodide and tetraethylammonium iodide in dimethylformamide. The effects of alterations in reaction time, metal ion, solvent and catalyst were investigated.
TL;DR: In this article, 2-Thenoic acid (14C = 0) is prepared in 75 % radioactive yield by carbonation with 14CO2 of 2-thienyL-magnesium bromide under FrieLdeL-Grafts conditions.
Abstract: 2-Thenoic acid (14C = 0) 1 is prepared in 75 % radioactive yield by carbonation with 14CO2 of 2-thienyL-magnesium bromide. Boiling of 1 with oxalyl chloride gives rise to 2-thenoylchloride (14CO) which is not isolated and is condensed with 2,3 dichLoroanisoLe under FrieLdeL-Grafts conditions. Ketone 3 is demeth Lated with AlCl3 in benzene to give rise to 4- 2-thenoyl (14C = O)-2,3-dichloro phenol 4. The sodium derivative of 4 is condensed in D.M.F. with sodium chloracetate to Lead to the title compound with an overall yield of 16 % based on 14CO2 – TieniLic acid-14c, specific activity: 50 mCi/mMole, has been found to be sensitive to self-irra-diation decomposition in the dry state at - 25%° C. Radiation decomposition is minimized at 24 mCi/mMole in methanol solution.
TL;DR: The tritium labeling of papaverine by catalytic deshalogenation of monobromopapaverine gives a compound whereof the specific radioactivity is 43 Ci/mM as discussed by the authors.
Abstract: Le marquage au tritium de la papaverine par deshalogenation catalytique de la monobromopapaverine conduit a un produit dont la radioactivite specifique est de 43 Ci/mM. Nos resultats ont montre que seulement 49 % de cette radioactivite resultent de la substitution du brome par le tritium; 46 % sont localises dans le groupe methylene tandis que les 5 % restants sont repartis sur les autres positions.
The tritium labelling of papaverine by catalytic deshalogenation of monobromopapaverine gives a compound whereof the specific radioactivity is 43 Ci/mM. Our results have shown that only 49 % of this radioactivity came from the substitution of bromine by tritium; 46 % are located in the methylen group while the remaining 5 % are distributed over the other positions.
TL;DR: In this paper, a new antitumor agent, Hexamethylmelamine (14C-HMM), has been prepared from 14C-urea by a 2-step synthesis.
Abstract: L'hexamethylmelamine (noyau) 14C-2-4-6 (HMM 14C), un nouvel agent antitumoral, a ete synthetisee a partir de l'uree 14C en 2 stades. L'uree 14C est cyclisee dans l'o-dichlorobenzene en acide cyanurique 14C-2-4-6, purifie par chromatographie sur colonne d'echangeur d'ions Sephadex SP C-25. L'amination directe de l'acide en presence de HMPT et de dimethylamine donne l'HMM 14C. Apres purification par chromatographie sur colonne de gel de silice d'adsorption, on obtient. l'HMM 14C avec un rendement radioactif global de 18 % par rapport a l'uree 14C, activite specifique : 32 mCi/mMole.
(Ring-2,4,6-14C) Hexamethylmelamine (14C-HMM), a new antitumor agent, has been prepared from 14C-urea by a 2 step synthesis. 14C-Urea is cyclized in o-dichlorobenzene to (2,4,6-14C) cyanuric acid, purified by chromatography on an ion exchange resin column Sephadex SP C-25. Direct amination of acid in presence of HMPT and dimethylamine gives 14C-HMM. After purification by silicageladsorption column chromatography 14C-HMM is obtained with a radioactive overall yield of 18 % based on 14C-urea, specific activity = 32 mCi/mMol.
TL;DR: In this paper, the tris(trimethylsilyl) 1-lithio-1,1,2 propane tricarboxylate was used to give a 66% yield of 2-methyl-3-(benzoyl-7-14C) propionic acid after cyclisation with hydrazine, followed by treatment with bromine in acetic acid.
Abstract: Benzoyl chloride-714C is condensed with tris(trimethylsilyl) 1-lithio-1,1,2 propane tricarboxylate, which after hydrolysis gives rise to a 66% yield of 2-methyl-3-(benzoyl-7-14C) propionic acid. After cyclisation with hydrazine, followed by treatment with bromine in acetic acid, 3-hydroxy-4-methyl-6-phenyl pyndazine 6-14C is secured in a 77% yield. This hydroxypyridazine treated with POCl3 gave a 90% yield of 90 % pure 4-methyl-6-phenyl-3-chloropyndazine 6-14C; The latter treated with 2-morpholino-1-aminoethane in presence of sodium iodide has given 3-morpholinoethylamino 4-methyl 6-phenylpyndazine 6-14C. The overall yield based on barium carbonate 14C is 16.7 % (specific activity 18.5 mCi/mMole).