bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of biologically active radioiodinated thymopentin
Authors: Venkat Krish , Tischio John , Crowther Jonathan , Audhya Tapan , Goldstein Gideon 
Published: October 2006

AbstractThymopentin (TP5, Arg‐Lys‐Asp‐Val‐Tyr), a synthetic pentapeptide corresponding to amino acids 32–36 of the thymic hormone thymopoietin, has the biological activity of the parent compound. The tyrosyl residue was iodinated using the chloramine‐T method and the reaction mixture separated by HPLC into peaks corresponding to free TP5, mono‐iodo TP5 and di‐iodo TP5, identified by mass spectrometry. Biological activity was retained in the iodinated peptides but, surprisingly, free TP5 had lost biological activity during the separation process. The biologically active monoiodinated TP5 had a specific activity of 28 μCi/μg and will be useful in studies of receptor binding.
Synthesis of high specific activity 80mBr and 123I labeled 5‐halodeoxyuridines and other 80mBr compounds for the study of auger electron toxicity
Authors: Mease Rc , Gatley Sj , Friedman Am 
Published: October 2006

AbstractConvenient preparations of 80mBr and 123I‐labeled 5‐halodeoxyuridines, required for basic investigations of Auger electron radiotoxicity, are described. These radioactive thymidine analogs were synthesized from deoxyuridine, radiohalide and N‐chlorosuccinimide in dilute sulfuric acid. Yields were 50–60% for 80mBr and 60–70% for 123I. Apparent specific radioactivities (based on UV absorption under the radioactive HPLC peaks) were 150–550 Ci/mmol and over 2000 Ci/mmol for 80mBr and 123I, respectively. 5‐[80mBr]bromouracil was produced in 89% yield when uracil was used. [80mBr]Bromoantipyrine was produced in higher yield and specific activity using peroxyacetic acid, rather than N‐chlorosuccinimide as oxidant (90% and 4,000 Ci/mmol versus 50% and 2000 Ci/mmol).
Synthesis of carbon‐11 labelled calcium channel antagonists
Authors: Holschbach M. , Roden W. , Hamkens W. 
Published: October 2006

AbstractA useful synthetic approach to carbon‐11 labelled 1,4‐dihydropyridines is described. Carbon‐11 labelled calcium channel antagonists 11C‐Nifedipine, 11C‐Nisoldipine, 11C‐Nitrendipine and 11C‐CF3‐Nifedipine were synthesized by a modified Hantzsch method using protected carboxy functions. Deprotection of the carboxylic acids by alkaline hydrolysis followed by conversion into the corresponding potassium salts and subsequent methylation with 11CH3I produced the labelled compounds in very good chemical and radiochemical yields (94%).
Preparation of 4‐phenylbutyric [2,3‐2H2]‐, [4,4‐2H2]‐, [2,3,4,4‐2H4]‐, and [2,2,3,3,4,4‐2H6]‐acids by use of crossed kolbe electrolysis as a key reaction
Authors: Tashiro Masashi , Tsuzuki Hirohisa , Goto Hideyuki , Ogasahara Shoji , Mataka Shuntaro 
Published: October 2006

AbstractThe four deuteriated 4‐phenylbutyric [2,3‐2H2]‐, [4,4‐2H2]‐, [2,3,4,4‐2H4]‐, and [2,2,3,3,4,4‐2H6]‐acids have been synthesized in high isotopic purity by utilizing crossed Kolbe electrolysis of methyl hydrogen [2H0]‐, [2,3‐2H2], and [2,3,3,3‐2H4]‐succinates and phenyl acetic [2H0] and [2H2]‐acids as a key reaction.
Synthesis of racemic, R‐ and S‐[1‐11C]‐β‐hydroxybutyric acid
Authors: Thorell Jan‐Olov , Stone‐Elander Sharon , König Wilfried A. , Halldin Christer , Widén Lennart 
Published: October 2006

AbstractRacemic, R‐ and S‐β‐hydroxybutyric acid were labelled with 11C in the carboxylic position by a two‐step stereospecific synthesis starting with carrier‐added [11C]cyanide and R/S, R‐ or S‐propylene oxide. Hydrolysis of the intermediate nitrile with hydrochloric acid gave racemic [1‐11C]‐β‐hydroxybutyric acid and R‐ or S‐[1‐11C]‐β‐hydroxybutyric acid with an enantiomeric excess of 87–97%. The total synthesis time (including HPLC puritication) was 45–50 min from end of trapping. The isolated decay‐corrected radiochemical yield was 20–30% based on [11C]cyanide. The radiochemical purity of the products was > 99%
Radiosynthesis of [11C]‐N‐methylacyclovir
Authors: Wilson Alan A. , Conti Peter S. , Dannals Robert F. , Ravert Hayden T. , Wagner Henry N. 
Published: October 2006

AbstractA selective and potent analogue of the anti‐herpes agent acyclovir has been labelled with 11C in good yield and at high specific activities. 1‐[11C]‐Methyl‐9‐(2‐hydroxyethoxy)methyl)guanine may be useful for detecting HSV encephalitis using positron emission tomography.
An improved synthesis of [15N] labelled acetamide and acetonitrile
Authors: Morgan D. R. , Dorn H. C. 
Published: October 2006

AbstractAn improved synthesis of [15N] labelled acetamide and acetonitrile is described which provides these compounds in yields of 85% and 64%, respectively. The key difference in the present preparation is the use of 2,2,2‐trifluoroethyl acetate for the reaction with 15NH4OH.
Determination of the stereochemistry of tritium label in sulbactam obtained by isotope exchange of penicillanic acid (R)‐sulphoxide benzyl ester
Authors: Gibson Colin L. , Jones John R. , Sharratt Andrew P. , Liss Robert H. 
Published: October 2006

AbstractSulbactam, a β‐lactamase inhibitor, has been prepared in tritiated (170 mCi mmol−1) form by the highly stereospecific isotope exchange procedure involving penicillanic acid (R)‐sulphoxide benzyl ester. The stereochemistry of the tritiation has been established by 3H n.m.r. in conjunction with a 1H NOESY spectrum of sulbactam.
Preparation of the α‐[D]galvinoxyl radical
Authors: Tsiao C. , Wild C. , Gu J. , Dorn H. C. 
Published: October 2006

AbstractThe stable galvinoxyl radical has been prepared with specific deuterium substitution at the methylene carbon bridge between the two aromatic rings. The corresponding EPR spectrum illustrates only the small residual hyperfine coupling with the aromatic ring hydrogens.
Bisphosphonic compounds. I. Preparation of 13C‐ and 14C‐labelled clodronate
Authors: Jouko Vepsäläinen , Heikki Nupponen , Esko Pohjala 
Published: October 2006

AbstractTetrakis(1‐methylethyl) (methylene‐13C)bisphosphonate was obtained from 13C‐methyliodide via the Michaelis‐Arbuzov reaction with tris(1‐methylethyl)phosphite followed by condensation with chlorophosphonic acid bis(1‐methylethyl)ester. Tetrakis(1‐methylethyl) (methylene‐14C)bisphosphonate was prepared from 14C‐dibromomethane via the Michaelis‐Arbuzov reaction with excess of tris(1‐methylethyl)phosphite. Both of these labelled tetraesters were chlorinated with NaOCl, hydrolysed with HCl and neutralized with NaOH similarly. The overall yield of 13C‐clodronate, (dichloromethyl one‐13C)bisphosphonic acid disodium salt tetrahydrate, was 71% with 99.5% isotopic and 99.8% chemical purity. The overall radiochemical yield of 14C‐clodronate was 9.8%.
Synthesis of a bis(aminoethanethiol) ligand with an activated ester group for protein conjugation and 99mTc labeling
Authors: Eisenhut M. , Mißfeldt M. , Lehmann W. D. , Karas M. 
Published: October 2006

AbstractThe N‐hydroxysuccinimide (NHS) ester of the bis(aminoethanethiol) (BAT) ligand, 6‐(4″‐(4″‐carboxyphenoxy) butyl)‐2, 10‐dimercap‐to‐2, 10‐dimethyl‐4, 8‐diazaundecane, was synthesized by reacting 7‐ (4′‐bromobutyl) ‐3,3, 11, 11‐tetramethyl‐1, 2‐dithia‐5, 9‐diazacycloundecane with the sodium salt of 4‐hydroxybenzoic acid ethyl ester, followed by ester hydrolysis, reductive disulfide cleavage with dithiothreitol (DTT) and activation of the carboxyl group with NHS and dicyclohexylcarbodiimide (DCC). The resulting NHS‐BAT ester was conjugated to monoclonal antibodies at pH 8.5 with about 40% yield. 2–4 BAT ligands conjugated to the antibody did not change the binding characteristics significantly. Proof of the amount of covalent bound BAT ligands was attained by UV‐laser desorption/ionization (UV‐LD/I) mass spectrometry. Complexation with 99mTc was accomplished by using the tin‐reduction method. The labeling efficiency was >90%.
Synthesis of a labelled terpene synthon, useful in the preparation of metabolites of Δ1‐tetrahydrocannabinol
Authors: Szirmai Maria , Halldin Magnus M , Ohlsson Agneta 
Published: October 2006

AbstractThe synthesis of an isotopically labelled terpene synthon (4) is described. The usefulness of this terpene synthon in the synthesis of Δ1‐THC metabolites is shown by preparation of (±)‐[2H10]‐Δ1‐THC‐7‐oic acid (5) by condensation of 4 with [2H7]‐olivetol. Compound 5 is suitable as internal standard for mass spectrometric assays.
Synthesis of (2‐methyl‐4‐nitro‐1‐[15N1]imidazolyl)acetic acid
Authors: Suwinski Jerzy , Szczepankiewicz Wojciech 
Published: October 2006

Abstract1,4‐Dinitro‐2‐methylimidazole reacts under mild conditions with glycine to yield (2‐methyl‐4‐nitro‐1‐imidazolyl)acetic acid. The use of [15N]glycine gives a product having a labelled nitrogen in 1 position of 4‐nitroimidazole.
Solid phase synthesis of a tetrapeptide labelled with Carbon‐13. Preparation of L‐[U‐13C]lysyl‐L‐[1‐13C]arginyl‐L‐[3‐13C]asparyl‐L‐[1‐13C]serine
Authors: Humbert Thierry , Marsura Alain , Luu‐Duc Cuong 
Published: October 2006

AbstractSynthesis of a [13C] tetrapeptide L‐[U‐13C]Lysyl‐L‐[1‐13C]Arginyl‐L‐[3‐13C]Aspartyl‐L‐[1‐13C] Serine (KRDS) on ap‐alkoxybenzyl ester polystyrene‐1% divinylbenzene resin support is described by using repetitive nonhydrolytic base cleavage of α‐amino protective groups in Solid Phase Peptide Synthesis (SPPS). Protected [13C] amino acid (AA) used in this SPPS model were prepared with 9‐Fluorenylmethyloxycarbonyl (Fmoc) protecting group and with different acid labile side chain protecting group over AA type as: Fmoc‐Ser(tert‐Bu)‐OH, Fmoc‐Asp(tert‐Bu)‐OH, Fmoc‐Arg(Pmc)‐OH and Fmoc‐Lys(Fmoc)‐OH. All the protected AA were coupled byN,N′‐dicyclohexyl carbodiimide (DCC) procedure, followed by Fmoc group cleavage using 20% piperidine inN,Ndimethylacetamide (DMA). Quantitative deblocking side‐chain AA protection and removal of KRDS from the solid support was effected by treatment with 50% trifluoroacetic acid in methylene chloride in a one pot‐procedure. Homogeneous free [13C] KRDS was obtained in 90% overall yield after HPLC purification. This synthesis schedule offered the advantage over present solid phase method which used acidolysis for repetitive α‐amino group deblocking.
Use of a microwave cavity to reduce reaction times in radiolabelling with [11C]cyanide
Authors: Thorell Jan‐Olov , Stone‐Elander Sharon , Elander Nils 
Published: October 2006

AbstractAdvantages of using a microwave cavity over thermal treatment are demonstrated for radiolabelling reactions with [11C]cyanide. For comparison purposes, two literature syntheses involving typical cyanide chemistry at rather vigorous conditions were investigated: cyano‐de‐halogenation with subsequent hydrolysis of the nitrile and the Bücher‐Strecker synthesis of an aromatic amino acid. Comparable yields were obtained with intensities < 100 W in reaction times that were 1/15 to 1/20th those used in thermal methods. Even rates of slower nucleophilic substitutions could be increased by manipulating the polarity of the medium. For the short‐lived radionuclide carbon‐11, such time gains result in radioactivity gains at the end‐of‐synthesis on the order of 70‐100%.
Synthesis of 14C and 3H labelled 6‐nitro‐7‐sulfamoylbenzo[f]quinoxalin‐2,3‐dione
Authors: Foged Christian , Jacobsen Poul 
Published: October 2006

AbstractA 14C labelled form of 6‐nitro‐7‐sulfamoylbenzo[f]quinoxalin‐2,3‐dione [1] was synthesized in two steps from 1,2‐diamino‐5‐sulfamoylnaphthalene [2] and 30 mCi 14C‐oxalic acid. A total of 5.5 mCi was isolated as a yellow solid with a radiochemical purity > 99%. The specific activity was 99 mCi/mmol.A 3H labelled form of [1] was synthesized in two steps from 10‐bromo‐7‐sulfamoylbenzo‐[f]quinoxalin‐2,3‐dione [4] and tritium gas. The product was isolated with a radiochemical purity of >98% and a specific activity of 10 Ci/mmol.
Preparation of multi‐labelled urocanic acids with 2H, 13C and 15N
Authors: Furuta Takashi , Katayama Motofusa , Shibasaki Hiromi , Kasuya Yasuji 
Published: October 2006

AbstractTwo types of multi‐labelled urocanic acids with stable isotopes, i.e., [3‐2H,1′,3′‐15N2]urocanic acid and [2,3,5′‐2H3,2′‐13C,1′,3′‐15N2]urocanic acid were synthesized by the enzymatic reaction of DL‐[3,3‐2H2,1′,3′‐15N2]histidine or DL‐[2,3,3,5′‐2H4,2′‐13C,1′,3′‐15N2]histidine with histidine ammonia‐lyase (Pseudomonas fluorescens) at pH 9.0. The reaction of DL‐[2,3,3,5′‐2H4,2′‐13C,1′,3′‐15N2]histidine was achieved in D2O buffer system (pD 9.0) to avoid the enzyme‐catalyzed hydrogen exchange at C‐5′ of the imidazole ring. The isotopic purities were demonstrated to be 94 atom%, based upon the ion intensities in the region of the molecular ions of respective gas chromatographic derivatives measured by GC‐MS.
Tritium labelling of two highly selective agonists for CCK‐B receptor: [3H]propionyl‐Tyr(SO3Na)‐gNle‐mGly‐Trp‐(N‐Me)Nle‐Asp‐Phe‐NH2([3H]pBC 264) [3H]propionyl‐γDLys‐Trp‐Nle‐Asp‐Phe‐NH2([3H]pBC 254)
Authors: Corringer P. J. , Durieux C. , Ruiz‐Gayo M. , Roques B. P. 
Published: October 2006

AbstractAmong the CCK‐B receptor agonists reported to date, the two modified peptides BC 264 and BC 254 display a high affinity and selectivity for this binding site and are highly protected from enzymatic degradation. Recently, we reported the biological properties of a tritiated analog of this agonist, [3H]pBC 264, which fullfils all the criteria required for in vitro as well as in vivo studies of the CCK‐B receptor. On the other hand, BC 254 displays a high affinity for the CCK‐B binding sites in the guinea‐pig (K1= 0.56 nM) while its affinity in the rat is more than 60‐fold lower, a difference which could be due to the occurrence of CCK‐B receptor subtypes. In the present paper, we report the synthesis of [3H]pBC 264 and of the new tritiated ligand [3H]pBC 254 using [3H] NPS (N‐succinimidyl[2,3‐3H]propionate) as labelling agent. These two probes have high specific activity (70–100 Ci/mmol) and will enable extensive studies of the CCK‐B receptors to be carried out.
The synthesis of 1,3,4‐thiadiazol‐2‐ylcyanamide sodium, a potentially useful anti‐influenza agent and its [5‐14C] and [UL‐13C3] isotopomers
Authors: Wheeler William J. , Blanchard William B. 
Published: October 2006

AbstractAs an aid to the study of the metabolism and disposition of LY217896 in laboratory animals and humans, 14C‐labeled material was prepared utilizing formic‐[14C] acid as the starting material. Uniformly labeled LY217896‐[13C] was also synthesized for use in metabolite identification. Formic acid, cyanogen bromide, and potassium cyanide which were >99% isotopically enriched with 13C were utilized; once the appropriate starting materials were synthesized, the synthesis of the 13C and 14C‐labeled materials were parallel.
Synthesis of carbon‐14 and tritium labeled analogs of Manoalide
Authors: Senderoff S. G. , Shu A. Y. L. , Lawrie K. , Heys J. R. 
Published: October 2006

AbstractSeveral Manoalide analogs, 4‐(1‐acetyloxyalkyl)‐5‐hydroxy‐2(5H)‐furanones labeled with carbon‐14 in the alkyl side chain, were synthesized. The key step in these syntheses was singlet oxygenation of 2‐trialkylsilyl‐4‐alkylfurans to give the corresponding 4‐alkyl‐5‐hydroxy‐2(5H)‐furanones. The carbon‐14 label in the side chain was introduced earlier in the synthesis by reaction of the desired labeled alkyl Grignard reagent with the appropriate 2‐trialkylsilyl‐4‐furancarboxaldehyde and trapping of the resulting magnesium alkoxide with acetic anhydride. Labeled n‐alkyl Grignard reagents were obtained by carbonation of the corresponding nor‐alkyl bromides using ultrapure magnesium metal and barium carbonate‐ 14C followed by reduction of the resulting acid to the alcohol. Bromination followed by metallation gave the desired reagents. Manoalide analogs bearing a carbon‐14 or tritium label in the acetyl moiety of the side chain were synthesized by acetylation of the desired sidechain alcohol with acetyl chloride‐1‐ 14C, and by acetylation of the desired alcohol with dibromoacetic acid‐DCC followed by catalytic halogen‐tritium exchange and completion of the synthesis.
Biosynthetic preparation of the tritium labelled 3α‐hydroxy‐5α‐pregnan‐20‐one, an allosteric modulator of gabaergic neurotransmission
Authors: Jussofie Astrid , Jussofie Ibrahim , Stoppok Martin , Lax E. Rodney 
Published: October 2006

AbstractA procedure for the biosynthetic preparation of 3α‐hydroxy‐5α‐[1,2,6,7‐3H]‐pregnan‐20‐one (3H‐HPO) with high specific activity convenient for binding studies was developed. 3H‐HPO was synthesized from [1,2,6,7‐3H]progesterone using a microsomal preparation from rat liver and NADPH. The progesterone metabolite was purified by silica gel 60 and Sephadex LH 20 chromatography. The identity of the product was confirmed by reverse isotopic dilution of chemically synthesized and highly purified 3α‐hydroxy‐5α‐pregnan‐20‐one. The yield for radiolabelled HPO was 60% and its purity was > 98%.
Understanding the mechanism of sweet taste: Synthesis of tritium labeled guanidineacetic acids
Authors: Nagarajan Srinivasan , Kellogg Michael S. , Dubois Grant E. , Williams David S. , Gresk Christopher J. , Markos Charles S. 
Published: October 2006

AbstractSyntheses of tritium labeled guanidineacetic acid sweetener and a tritiated photoaffinty labeling reagent via the catalytic hydrogenation of the dibromo intermediates are described. These labeled compounds were required for the investigation of sweet taste mechanism.
A simple procedure for producing oxygen‐labelled inorganic phosphate from isotopically labelled water that optimizes yield based on the isotope
Authors: Ray William J. 
Published: October 2006

AbstractPhosphorus pentachloride can be treated with stoichiometric amounts of oxygen‐labelled water to produce 80–90 percent yields of labelled inorganic phosphate when the reaction is conducted in dioxane. Any phosphorus‐chlorine bonds remaining at the end of the reaction are eliminated by reaction with diethylamine prior to adding water.
Preparation of di‐(2‐ethylhexyl) adipate and some of its metabolites labelled with deuterium
Authors: Moore Richard B 
Published: October 2006

AbstractThe syntheses of deutero‐labelled di‐(2‐ethylhexyl)adipate (DEHA), mono‐(2‐ethylhexyl) adipate (MEHA), 2‐ethylhexan‐1‐ol, 2‐ethylhexanoic acid, 2‐ethyl‐5‐ketohexanoic acid, 3‐ethyl‐6‐methyltetrahydro‐2H‐pyran‐2‐one and 2‐ethylhexanedioic acid are described. All compounds were perdeutero‐labelled in the ethyl group. The title compound, DEHA, was used in a human dosing study.
Synthesis of 2‐chloroethyl (13C)‐methyl sulfide
Authors: Taber Douglass F. , Meagley Robert P. 
Published: October 2006

AbstractIncorporation of a stable isotope‐labelled methylthio group into the mustard 2‐chloroethyl methyl sulfide 2 was complicated by concomitant reaction with iodide ion, a necessary byproduct from the precursor stable isotope‐labelled iodomethane. A two step procedure was therefore employed, initial displacement with mercaptoethanol 4 being followed by chlorination with thionyl chloride.
Synthesis of 3‐[18F]‐fluoromethyl‐TCP1, A potential tool for pet study of the nmda receptor channel complex
Authors: Ponchant M. , Kamenkaj M. , Crouzel C. 
Published: October 2006

AbstractIn an attempt to visualize the NMDA glutamatergic receptors and after checking the biological activity of the cold 3‐fluoromethyl‐TCP 3, 3‐[18F]‐fluoro‐methyl‐TCP 4 was synthesized by a nucleophilic substitution of 3‐bromomethyl‐TCP 5 with [18F−].
Synthesis of [3H]tert‐butyl 8‐chloro‐5,6‐dihydro‐5‐methyl‐6‐oxo‐4h‐imidazo[1,5‐a][1,4]benzodiazepine 3‐carboxylate, a selective, high affinity ligand for the diazepam insensitive (DI) subtype of the benzodiazepine receptor
Authors: Gu Zi‐Qiang , de Costa Brian R. , Wong Garry , Rice Kenner C. , Skolnick Phil 
Published: October 2006

AbstractThe preparation of [3H]‐labelled tert‐butyl 8‐chloro‐5,6‐dihydro‐5‐methyl‐6‐oxo‐4H‐imidazo[1,5‐a][1,4]benzodiazepine 3‐carboxylate (TCIB, 6), a high affinity ligands for the diazepam insensitive (DI) subtype of the benzodiazepine receptor (BZR) is described. Synthesis of [3H]TCIB was accomplished in 4 steps starting from 5‐chloroisatoic anhydride. Tritium‐label introduction was achieved in the final step by selective catalytic tritiolysis in 62% radiochemical yield with quantitative isotopic incorporation.
Synthesis of radioiodinated 2′‐iodobutyrophenone derivatives
Authors: Nakatsuka Iwao , Shiba Kunio , Saji Hideo , Yoshitake Akira , Yokoyama Akira 
Published: October 2006

AbstractTo develop new radioligands labelled with radioiodine (125I, 131I and 121I) for in vitro and in vivo dopamine receptor studies, three iodinated butyrophenones (2′‐iodospiperone, 2′‐iodotrifluperidol and 2′‐iodohaloperidol) were designed, synthesized and labelled with 125I.
Synthesis of 14C‐labeled eschenmoser's salt: Dimethyl([14C]methylene)ammonium iodide
Authors: Kupczyk‐Subotkowska Lidia , Shine Henry J. 
Published: October 2006

AbstractA six step synthesis of dimethyl([14C]methylene)ammonium iodide (Eschenmoser's salt) is described. Sodium [2‐14C]acetate was used as the starting material. The overall yield of the final product was 30% with specific activity 8 mCi/mol.
123I‐iodobenzoylglucosamines: Glucose analogues for heart imaging
Authors: Lutz T. , Dougan H. , Rihela T. , Vo C. V. , Lyster D. M. 
Published: October 2006

AbstractThe ortho‐, meta‐ and para‐[123I]‐2‐deoxy‐2‐N‐(iodobenzoyl)‐D‐glucosamine (BGA) derivatives were investigated to determine the effect of iodine position and lipophilicity on tissue distribution. There was no correlation between tissue uptake and lipophilicity. Maximum uptake was observed for o‐BGA displaying a heart:blood ratio of 36.0 at 18 hours post injection. Yeast hexokinase phosphorylation studies in vitro and an in vivo insulin experiment were carried out on o‐BGA. No phosphorylation was detected, but the insulin study indicated that o‐BGA uses the glucose transporter. o‐BGA showed maximum tissue uptake in mice at an optimal specific activity of 0.004mg/μCi. Mouse biodistribution studies of o‐[123I]‐iodobenzamide(o‐123IBA) indicated that the glucose moiety of o‐BGA may be involved in the heart accumulation process in mice. Heart tissue extraction studies showed unmetabolized o‐[123I]BGA, recorded at 14 hours post injection, showed significant heart uptake.
Preparation of α–[3‐11C]aminoisobutyric acid from an azadisilolidine derivative of alanine
Authors: Oberdorfer Franz , Zobeley Axel , Weber Klaus , Prenant Christian , Haberkorn Uwe , Maier‐Borst Wolfgang 
Published: October 2006

AbstractAlkylation of ethyl 2‐(2,2,5,5‐tetramethyl‐[1,2,5,]azadisilolidine‐1‐yl)propionate with [11C]CH3I afforded, following acid hydrolysis and chromatographic purification, the non‐physiological α‐[3‐11C]aminoisobutyric acid within 40 min in yields of 5 ‐ 15% (not corrected for decay) related to initially produced [11C]CH3I. Usually 1.2·109 Bq of the tracer molecule were prepared for use in amino acid transport studies. Dilution with a known amount of unlabelled α‐aminoisobutyric acid (10 μmol) provided a constant specific radioactivity of 1.2·108 Bq·μmol−1 for each application. The radiochemical purity of that product was better than 98%, whereas the final carrier‐added solution typically contained 10 ‐ 45 μmol of alanine.
Introduction of tritium into organic compounds by isotope exchange reactions
Authors: Myasoedov N. F. 
Published: October 2006

AbstractVarious isotope exchange reactions for the introduction of tritium into a range of organic compounds have been investigated. The influence of the catalyst, solvent and reaction conditions on the yield and specific activities of a number of steroids, phytohormones and sugars are reported. Heterogeneous hydrogen isotope exchange with gaseous tritium has also been used to label a number of nonpolar compounds. Similarly the potential of solid state hydrogen isotope exchange has been explored. The reaction mechanism is discussed as well as the influence of the reaction conditions on the specific activity and the label distribution.