bluuebunny/crossref_metadata_2025 huggingface dataset:
Total quality management in the classroom: A personal odyssey
Authors: Ord J. Keith
Published: October 2006

Total Quality Management represents a set of ideas that we are happy to discuss in the classroom but less willing to practice. Personal experiences demonstrate how these concepts can improve an instructor's performance.
Using total quality management tools to improve organizational wellness
Authors: Koberna Sharon , Walter Pam
Published: October 2006

Total Quality Management tools promote understanding of the way things happen.
The role of the quality manager
Authors: Howard Nancy Lee
Published: October 2006

Some institutions appoint an individual to provide quality training and coordination.
Total quality management in word and deed
Authors: Yanckello Robert A. , Flaherty Thomas B.
Published: October 2006

Enthusiasm is no substitute for proper training.
A quality initiative postponed
Authors: Liebmann Jeffrey D.
Published: October 2006

A team designing a Total Quality Management effort during a time of administrative reorganization sees its recommendations for implementation put on hold.
The challenge: Overcoming the pitfalls
Authors: Lozier G. Gregory , Teeter Deborah J.
Published: October 2006

Experiences in the corporate sector demonstrate that there are many recipes for disaster with Total Quality Management.
Measures of resource scarcity in higher education
Authors: Pickens William H.
Published: October 2006

An overview of resources for higher education over the past forty years, with special emphasis on the abundance of the 1980s and the crisis of the 1990s, this chapter pays attention to trends in government support and to ways in which individual institutions can measure the adequacy of their resources for the pursuit of their policy goals.
Using research and theoretical models of graduate student progress
Authors: Baird Leonard L.
Published: October 2006

The implications of current research and theoretical models of graduate student progress for understanding and studying graduate student retention and time to degree are examined.
From facts to action: Expanding the graduate division's educational role
Authors: Nerad Maresi , Cerny Joseph
Published: October 2006

How the University of California at Berkeley's graduate division has used quantitative analysis and qualitative methods to address the issues of time to doctoral degree and student retention is described. The graduate division used this research to develop recommendations and design programmatic outreach activities to improve graduate education.
Enhancing success in doctoral education: From policy to practice
Authors: Lipschutz Susan S.
Published: October 2006

A framework is presented for considering changes in graduate education that will help decrease student frustration. Policy changes are linked to practical considerations.
Quality, excellence, and diversity
Authors: Moses Yolanda T.
Published: October 2006

Diversity and excellence are connected in deep and complex ways and are discussed in relation to assessment, curriculum, teaching, and leadership.
Charting campus progress in promoting ethnic diversity and cultural pluralism
Authors: Ingle Henry T.
Published: October 2006

This chapter presents information on the use of portfolio assessment as a planning and evaluation approach for institutions of higher education. The portfolio methodology involves clustering seven critical performance indicators to guide campus efforts in working more realistically with issues of cultural pluralism and diversity.
Performance indicators and quality assessment in European higher education
Authors: Jongbloed Ben W. A. , Westerheijden Don F.
Published: October 2006

The role of PIs at the national level in European countries appears to be on the decline at the same time that institutions are moving toward more broad‐based quality assessment strategies.
Activity‐based costing model for assessing economic performance
Authors: Dehayes Daniel W. , Lovrinic Joseph G.
Published: October 2006

An economic model is described for evaluating the cost performance of academic and administrative programs. Examples from one university show how the model has been used to control costs and reengineer processes.
Pressures to measure faculty work
Authors: Miller Margaret A.
Published: October 2006

An analysis of the public pressures to measure and describe faculty work is presented, as well as a depiction of the forms those measures and descriptions are taking and how they are likely to evolve.
What we have learned about faculty workload: The best evidence
Authors: Jordan Stephen M.
Published: October 2006

The findings and methodologies from recent faculty workload studies are reviewed and implications for higher education policy are suggested.
Approaches to conducting faculty workload studies: A case study at kent state university
Authors: Glazer Greer , Henry Myron S.
Published: October 2006

Workload initiatives and productivity expectations can be used to help chart future directions.
Defining faculty work
Authors: Gray Peter J. , Diamond Robert M.
Published: October 2006

One major way to respond to internal and external pressure for change in the current faculty culture is with a redefinition of faculty work.
Academic program review in planning, budgeting, and assessment
Authors: Barak Robert J. , Sweeney Janet D.
Published: October 2006

This chapter draws on the results of a national study of public and private two‐ and four‐year higher education institutions to examine the use of program review in institutional planning, budgeting, and student outcomes assessment. We also discuss the reasons for the success or lack of success of program review.
New directions for academic program review at a private, comprehensive college
Authors: Wroblewski Elizabeth
Published: October 2006

This chapter evaluates the first cycle of academic program reviews at a private, comprehensive college, analyzing recommendations resulting from reviews, insights about faculty and review committee perceptions, and new directions for the second cycle.
Arizona state university: Student tracking in a university setting
Authors: Porter John D. , Gebel Melinda A.
Published: October 2006

At Arizona State University, longitudinal files have changed the way institutional researchers can look at students to answer management questions.
Reputational rankings: Background and development
Authors: Stuart Debra L.
Published: October 2006

This chapter discusses the history of and issues surrounding efforts to rate and rank colleges and universities.
Publishers' perspectives: Guidebooks
Authors: Hoeritz Kimberly J. , Corderman Allan B. , Reed Max , Fiske Edward B.
Published: October 2006

College guidebook publishers have come under great scrutiny as the number of such publications has increased. The burden of survey response is felt by the institutions who are called upon to fulfill various requests for information, often involving a number of formats. In this chapter, four major publishers of college guidebooks respond to the issues raised in the previous chapters.
Teaching norms and publication productivity
Authors: Sullivan Anna V. Shaw
Published: October 2006

Critics charge that teaching and research represent incompatible rather than complementary value structures. In this chapter, the relationship between scholarly work and teaching norms held by faculty is examined.
Framing the public policy debate on faculty: What is the role of research?
Authors: Ludwig Meredith Jane
Published: October 2006

The debate about faculty roles is addressed by questioning the debate itself. The author suggests a way to change the public conversation about faculty by changing the descriptions of what faculty do and the research approach to studying it. She argues that a holistic perspective on faculty is necessary as a starting point for policy‐relevant research.
Synthesis of 14C‐labelled 1‐(2,6‐dimethyphenylamino)‐2‐dimethylamino‐propane
Authors: Zólyomi G. , Zubovics Z. , Toldy L.
Published: October 2006

The antiarrhytmic 1‐(2,6‐dimethylphenylamino)‐2‐dimethylamino‐propane (6a) was labelled with 14C for pharmacokinetic study. A convenient synthesis, using 2‐bromopropionyl‐1‐14C chloride as radioactive key intermediate, involving an improved method for the reduction of N‐(2‐dimethylaminopropionyl)‐2,6‐dimethylaniline (8) was elaborated.
Synthesis of (2H5) indole‐3‐pyruvic acid
Authors: Badenoch‐Jones Jane , Summons Roger E. , Letham David S.
Published: October 2006

A method for the synthesis of deuterium‐labelled tryptophan and its enzymatic conversion to indole‐3‐pyruvic acid ((2H5)IPYA) using amino acid oxidase is described. (2H5)IPYA can be used as an internal standard for the quantitation of IPYA by mass spectrometry in plant extracts and for estimating the breakdown of IPYA to indole‐3‐acetic acid (IAA) during sample extraction and purification. When used in conjunction with (2H2) IAA, (2H5) IPYA should allow more accurate quantitation of IAA in plant extracts.
A new synthetic route for preparing 14C‐labelled aminogutethimide
Authors: Askam V. , Eweiss N. , Nicholls P. J.
Published: October 2006

A new route for preparing aminoglutethimide labelled at C5 (Scheme I (10)) with 14C is described, which offers the advantage of introducing 14C at a late stage in the synthesis.
Synthesis of [2‐13C]phenol (1)
Authors: Yuan Sun‐Shine , Ajami Alfred M.
Published: October 2006

[2‐13C]cyclohexanone was synthesized through [13C]cyanation of cyclopentanone followed by acetylation, reduction and ring expansion. Treatment with cupric bromide/lithium bromide and dehydrobromination of the resulting labeled 1,6‐dibromohexanone in a “one pot” procedure gave [2‐13C]phenol.
Ein Verfahren zur Herstellung von Mehrfach mit Tritium Markiertem Thymin BZW. Thymidin
Authors: Pleiß U. , Römer J.
Published: October 2006

After a survey about the preparation of tritium labelled thymine and thymidine a new synthesis for the preparation of manifold labelled thymine respectively thymidine is given. 5‐Formyluracil was reduced to 5‐hydroxymethyluracil (5‐HMU) in a phosphate buffer at pH 7,0 with tritium gas using Pd0/BaSO4 as catalyst. The tritium labelled 5‐HMU was hydrogenated to [4methyl‐3H] thymine with tritium gas using a mixture of Palladium black and Palladiumchloride in dry dioxane. The specific activity was 2550 GBq/mmol. [methyl‐3H] Thymidine was obtained in a usual enzymatic synthesis.
Synthesis of iodine‐125 labelled analogues of metyrapone and metyrapol
Authors: Hays Sheryl J. , Mangner Thomas J.
Published: October 2006

Metyrapone (1) and metyrapol (2) are potent and reversible inhibitors of the 11β‐hydroxylase enzyme system of the adrenal cortex. Iodine‐125‐labelled derivatives of 1 and 2 were required for biodistribution studies. Utilizing a new exchange procedure these radioiodinated analogues were synthesized with radiochemical yields ranging from 24‐100% and specific activities as high as 1.72 Ci/mmol.
Synthesis of deuterated methylenecyclohexanes, methylenedecalins and taraxasterols
Authors: Lee Hsiu‐Pu Daniel , Eichmeier Larry S. , Piatak David M.
Published: October 2006

Taraxasterols specifically labelled at various ring E sites were synthesized as were cyclohexanes and decalins substituted by a methyl group and an exocyclic methylene moiety similar to the ring Esystem of this terpene. Preparation of deuterated analogs in which the deuterium is located beta to the exocyclic double bond was accomplished by catalytic reduction of the corresponding unsaturated ketone, followed by removal of the label at the alpha carbon and introduction of the exocyclic methylene with a Wittig reaction. Compounds labelled on the exocyclic methylene moiety were afforded by a Wittig reaction of the appropriate ketone with (methyl‐d3)triphenylphosphonium bromide. Taraxasterol trideuterated alpha to the double bond was prepared by DC1 exchange of the ketone followed by a Wittig reaction.
Partial synthesis of [6α‐3H]gibberellin‐A3 of high specific activity
Authors: Lischewski M. , Pleiß U.
Published: October 2006

The phytohormone gibberellin‐A3 was tritium‐labelled by a chemical route. The specific activity of the [6α‐3]‐gibberellin‐A3 obtained was 22.5 Ci/mmol.
Synthesis of phenyl‐3H‐sec‐butyl‐35S1‐disulphide
Authors: Ayrey G.
Published: October 2006

Phenyl‐3H‐sec‐butyl disulphide was synthesized via Wilzbach irradiated phenyl benzenethiolsulphonate and phenyl‐sec‐butyl‐35S1‐disulphide was synthesized via elemental sulphur‐35. The two disulphides were mixed to give phenyl‐3H‐sec‐butyl‐35 S1‐disulphide which was assayed by liquid scintillation counting.
Isotopic discrimination between 3H and 14C in vitro during enzymatic phosphorylation of labelled thymidine
Authors: Baugnet‐Mahieu L. , Goutier R. , Semal M.
Published: October 2006

We compare the phosphorylation of 6‐3H‐TdR and 2‐14C‐TdR to TMP, TDP and TTP by tissue extracts and to TMP by purified kinase preparations. The rate of phosphorylation of 6‐3H‐TdR is only 0.6 to 0.8 that of 2‐14C‐TdR. The same isotopic discrimination exists between methyl‐labelled thymidines. In mixtures of 3H‐TdR and 14C‐TdR incubated together with a liver extract, the isotopic ratio is lower in the products than in the substrate. Degradation products of 3H‐TdR do not seem to interfere with enzymatic activity. This isotopic discrimination is tentatively ascribed to an isotopic effect of 3H which is mainly detectable at the high substrate/enzyme ratios prevailing in the in vitro incubation conditions.
Synthesis of L‐ascorbic‐4‐3H acid
Authors: Bell E. M. , Baker E. M. , Tolbert B. M.
Published: October 2006

A method is presented for preparation of L‐xyloascorbic‐4‐3 H acid 9.5μC/mg by the exchange of 8 M dipotassium ascorbate in tritiumlabeled water by heating 20 hours at 100°C The data confirms the assumptions of Brenner (8), that alkaline isomerization of ascorbic acid proceeds through a carbanion on carbon‐4. A study of the radiation stability of crystalline ascorbic acid indicates that it is not unusually radiation sensitive.
Studies on the tritium labelling of some local anaesthetics and amino acids by the microwave discharge modification of the Wilzbach technique
Authors: Gosztonyi T. , Walde N.
Published: October 2006

Some local anaesthetics and amino acids were labelled with tritium by the microwave discharge modification of the Wilzbach technique.

The following substances were investigated: local anaesthetics: carbocaine, citanest, l‐cocaine, tetracaine and xylocaine; amino acids: glycine, DL‐α‐alanine, DL‐Leucine, DL‐phenylalanine and DL‐tryptophane.

The range of microwave energy used was 4,000 to 270,000 Wsec. The range of specific activities obtained was from 0.2 to 29.4 mC/mM; and for the most used substance, DL‐leucine, from 0.4 to 27.2 mC/mM.

The effects of some reaction parameters on the labelling were investigated. Results obtained are discussed.
Preparation and analysis of isotopically pure tetratritiated methane
Authors: Ciranni G. , Guarino A.
Published: October 2006

Many difficulties are encountered in the preparation of multilabelled coumpounds, as their purification and analysis for isotopic purity are involved. Another major problem is their self‐radiolysis which can change their composition during storage.

This paper describes the preparation of CT4 and the analyses which were carried out in order to check its purity : i.e. the mass spectrometric assay and a new gas chromatographic technique employing as detector an ionization chamber coupled with a vibrating reed electrometer. These analyses confirmed the isotopic purity of the CT4 prepared, the main impurity being CHT3.
Synthesis of carbon‐14 labelled S‐ethyl hexahydro‐1H‐azepine‐1‐carbothiolate
Authors: Gutman A. D. , Baker D. R. , Brokke M. E.
Published: October 2006

S‐Ethyl hexahydro‐1H‐azepine‐1‐carbothiolate labelled in the ethyl moiety and in the azepine ring with carbon‐14 was prepared to facilitate residue and metabolism studies. The ethyl labeled compound was prepared in 86% yield and 99+% radiochemical purity. The azepine labeled material was prepared in 60% yield and 99+% radiochemical purity.
Spezifische Markierung kristallisierter Leucinaminopeptidase mit Managan‐54
Authors: Fittkau S. , Kettmann U. , Hanson H.
Published: October 2006

Das Protein “Leucinaminopeptidase” kann aus Rinderaugenlinsen kristallisiert werden und ist durch Magnesium‐ und Manganionen aktivierbar. Wird einem Kristallisationsansatz 54MnCI2 zugesetzt, so sind die gewonnenen Enzymkristalle radioaktiv. Bei einem wahrscheinlichen Molekulargewicht der Leucinaminopeptidase von 325.000 findet man einen Gehalt von 4‐5 Atomen Mangan pro Enzymmolekül. Das Metall ist fest gebunden und läβt sich weder durch Fraktionierung an Sephadex G 25 noch durch kontinuierliche Dialyse bei p H 8 gegen Trispu ffer entfernen.

Die Markierung der Leucinaminopeptidase mit 54Mn kann auch durch einfache Inkubation der Enzymlösung mit Manganchlorid erfolgen. Das überschiissige, nicht‐proteingebundene Metall wird an einer Sephadex‐Säule quantitativ abgetrennt.

Weiter wurde die Bindungsfähigkeit der Leucinaminopeptidase für Zn‐ und Co‐lonen in Abhängigkeit vom pH ‐ Wert und der Metallionen‐Konzentration hestimmt.
Tritiations by HTO promoted aluminium chloride. IV. Cyclohexane and n‐heptane
Authors: Mǎntescu C. , Genunche A. , Dutǎ‐Cristu D. , Balaban A. T.
Published: October 2006

Tritium labelling of saturated hydrocarbons (n‐heptane, cyclohexane) is conveniently performed on a small scale by isotopic exchange with tritiated water in the presence of aluminium chloride. The reaction involves hydride ion abstraction but is not accompanied by isomerization, unless the reaction conditions are rather severe. The activities of cyclohexane, and of the methylcyclopentane formed by its isomerization, were found to be comparable.
Preparation of bis‐/2‐chloroethyl‐1,2‐3H/methylamine hydrochloride
Authors: Filip J.
Published: October 2006

Bis‐(2‐chloroethyl‐1,2‐3H) methylamine hydrochloride was prepared. The starting product was acetylene‐1,2‐3H which was selectively hydrogenated to ethylene‐1,2‐3H. It was observed that on reduction with chromium (II) chloride solution in dilute hydrochloric acid the isotopic exchange with acetylene‐1,2‐3H is negligible. Ethylene was converted to ethyleneoxide‐1,2‐3H by the usual method. Ethyleneoxide‐1,2‐3H can be used for synthesis of several labelled halogenalkylamines and as the starting compound for other syntheses.
Tritium labelling of amino‐acids and peptides by the Wilzbach method. II. Racemization of amino‐acids during exposure to tritium gas
Authors: Parmentier J. H.
Published: October 2006

Optically pure amino‐acids were labelled with tritium by the Wilzbach method. The percentage of radioactivity found in the opposite enantiomer was determined by reverse dilution analysis. After tritiation of L‐phenylalanine, D‐phenylalanine, L‐tyrosine, L‐proline, D‐proline, L‐glutamic acid and L‐alanine respectively 2.7, 2.2, ≤ 1.1, 4.6, 4.0, 11.9 and 19.3 of the activities of the radiochemically pure amino‐acids were found in D‐phenylalanine, L‐phenylalanine, D‐tyrosine, D‐proline, L‐proline, D‐glutamic acid and D‐alanine.

Wilzbach labelling ol phenylalanine caused the formation of a considerable amount of a radiochemical impurity that was identified as β‐cyclohexylalanine.
The radiopurity of S‐adenosylmethionine and S‐adenosylethionine preparations
Authors: Schlenk F. , Zydek C. R.
Published: October 2006

In the biosynthesis of labeled S‐adenosylmethionine and S‐adeno‐sylethionine from the corresponding 14C‐labeled sulfur amino acids by yeast, some radioimpurity occurred by non‐specific labeling of the sulfonium compounds. This is explained by partial degradation of methionine and ethionine in the yeast cells, followed by utilization of the randomized fragments in the biosynthesis. The degree of mislabeling remains low because endogenous methionine synthesis from metabolic pool constituents is suppressed by the excess of methionine and ethionine supplement in the culture medium. Hydrolysis of the sulfonium compounds and analysis of the fragments showed that the misplaced isotope amounts to approximately 0.5% in the adenine, and 0.2% in the homoserine part compared with the total radioactivity of the sulfonium compounds (100%).
Recent developments in the mechanism of the protection effect of aromatic compounds on the radiolysis of aliphatics
Authors: Ekstrom A. , Garnett J. L.
Published: October 2006

The proposed mechanisms by which aromatic compounds protect aliphatic materials from enhanced radiolytic decomposition are reviewed. Recent developments in this field using the radiolysis of methanol‐benzene as a typical system are discussed. Emphasis has been placed on the identification and isolation of the scavenging products from methanol‐benzene also the chemical fate of the added benzene. Isotope effects have been used to elucidate possible mechanisms of formation of the scavenging products. The application of the results of this study to the problem of self‐destruction of radioactive compounds is discussed. An interpretation of the mechanism of the protection effect in terms of the storage of labelled molecules is made.
Chlorisotopenaustausch bei organischen Verbindungen, I Flüssigkeitsszintillationstechnik und Flüssigkeitszählrohr zur Aktivitätsbestimmung organischer Chlorverbindungen‐(36Cl)
Authors: Kirchhoff Klaus , Boberg Friedrich , Schultze Georg Richard
Published: October 2006

Es werden vergleichende Untersuchungen zur Aktivitätsbestimmung bei Hexachlorpropen‐(36Cl) und Trichloracrylsäure‐(36Cl) mitgeteilt. Die Messungen erfolgen im Geiger‐Müller‐Flüssigkeitszählrohr mit Zählgerät und mit einem Zweikanalflüssigkeitsszintillationsgerät. Die relativen Messfehler betragen ±0,9% beim Flüssigkeitszählrohr und ±0,6% beim Flüssigkeitsszintillationsgerät. Für die Zählrohrmessung werden Eigenabsorption der Substanz und Totzeit mit Hilfe empirischer Korrekturen eliminiert.

Für Messungen mittels Flüssigkeitsszintillationsgerät wird der Löscheffekt empirisch eingeeicht. Für 36Cl ist die Wirkung des Löscheffektes von Hexachlorpropen, Heptachlorpropan, Trichloracrylsäure, Äthylenglykol, Methylalkohol, Tetrachlorkohlenstoff und Tetrachloräthylen durch Verstärkungserhöhung zu kompensieren, wie experimentell gezeigt wird.

Der Löscheffekt vom 4.5‐Dichlor‐1.2‐dithia‐cyclopentenon‐(3) kann aber nicht kompensiert werden. Die Wirkung von Netzspannungsschwankungen, Füllhöhenänderungen und Einwaagefehlern wird untersucht.
Isotopic exchange of active methyl hydrogens. V. (1) Reactivity of α‐ and γ‐methyl groups and β‐hydrogens in pyrylium salts
Authors: Gǎrd Eugenia , Vasilescu Alice , Mateescu G. D. , Balaban A. T.
Published: October 2006

The deuteration and dedeuteration of 2,4,6‐trimethylpyrylium perchlorate in water (D2O and H2O, respectively) was studied by nuclear magnetic resonance using as a quantitative standard for protons tetramethylammonium bromide. γ‐Methyl groups exchange faster than α‐methyl groups; β‐standing hydrogens exchange very slowly. A mechanism involving anhydrobase and pseudobase formation is discussed and theoretical calculations are mentioned. Geminal hydrogen‐deuterium spin‐spin coupling in incompletely deuterated methyl groups is observed.
Versuche zur Synthese von Glutamat‐2‐T
Authors: Wenzel M. , Brühmüller M. , Engels K.
Published: October 2006

Glutaminsäure wurde durch Austauschreaktionen in HTO mit Tritium markiert. Bei der Austauschreaktion nach intermediärer Azlacton‐Bildung mit Essigsäure wird 1‐Glutamat racemisiert. Der Tritium‐Einbau ist gering und erfolgt nicht am C2‐Atom, wie durch enzymatischen Abbau mit Glutamat‐Dehydrogenase bewiesen wurde. Mit Hilfe von Transaminase gelingt es dagegen, spezifisch 1‐Glutaminsäure in Position 2 zu markieren und die spezifische Aktivität des eingesetzten HTO zu erreichen.
Chlorisotopenaustausch bei organischen verbindungen, II(1) hexachlorpropen und alcl3‐36Cl
Authors: Boberg Friedrich , Kirchhoff Klaus , Schultze Georg Richard
Published: October 2006

Es ist der Chloraustausch zwischen Hexachlorpropen und Aluminiumchlorid‐[36Cl] untersucht worden. Austausch ist in 1‐, 2‐und in 3‐Stellung am Chlorolefin möglich, entscheidend sind die Reaktionsbedingungen

1) In Methylenchlorid trilt in homogener Lösung der Austausch in 1‐ und in 3‐Stellung ein. Diese Reaktion verläuft nach einem Carbeniummechanismus, der näher diskutiert wird. In Übereinstimmung mit den gebrachten Vorstellungen wird der Austausch durch Elektronendonatoren behindert. Erste Untersuchungen hierzu mit Furan, Tetrahydrofuran, Dioxan und Tetrahydropyran werden mitgeteilt. Die energetische Bevorzugung des Carbeniumions zeigt sich auch im Massenspektrum.

2) Am festen Aluminiumchloridkristall wird auch das Chlor am Kohlenstoffatom 2 des Chlorolefins ausgetauscht.

Bei markierten Hexachlorpropenen wird die Stellung des 36Cl durch Überführung des Chlorolefins‐[36Cl] in Trichloracrylsäure‐[36Cl] festgelegt.

Der Versuchsteil enthält Angaben zur Herstellung von AlCl3‐[36Cl], Hexachlorpropen‐[36Cl], Trichloracrylsäure‐[36Cl]. Die Apparatur zur Gewinnung von AlCl3‐[36Cl] aus Aluminium und HCl‐[36Cl] wird näher beschrieben. Aktivitäten sind mit der Flüssigkeitsscintillations‐Methode und dem Geiger‐Müller‐Flüssigkeits‐zählrohr bestimmt worden.
Radiolysis of binary mixtures. Part VIII. Tritium Labelling by direct radiation synthesis. The methanol‐benzene system
Authors: Ekstrom A. , Garnett J. L.
Published: October 2006

A novel synthesis of tritiated compounds is reported using the direct irradiation of an aromatic‐aliphatic mixture, one of the components of which is labelled with tritium. The irradiation of the methanoltritiated benzene system has been used to illustrate the principle of the technique. The gamma irradiation of methanolic solutions of tritiated benzene yields the following tritiated scavenging products, some of which are specifically labelled under certain conditions : anisole; 1,3 –‐ and 1,4‐cyclohexadienes; 2,5‐phenylcyclohexadiene; 1,3‐ and 1,4‐cyclohexadiene‐methanols. The potential of the method as a general tritium labeling tool is discussed and compared with conventional procedures. Although the absolute yields of the labelled products from direct irradiation are small for relatively large total radiation doses (megarads), scavenging by non‐labelled parent material can be used to give large chemical yields if required. The predominant advantage of the present method is that compounds labelled in specific positions with tritium can be obtained in a one‐step chemical process whereas this synthesis may be difficult by other conventional labelling methods.
Synthesis of 14C‐labeled olefins using the wittig reaction
Authors: Muhs M. A.
Published: October 2006

The Wittig synthesis has been used to prepare conveniently carbon‐14 labeled 1‐olefins in the C5 to C8 range in about 60 % yield. The chemical and radiochemical purities of the products exceeded 99.5 %. The common source of carbon‐14 in these reactions was methyl‐14C‐triphenylphosphonium iodide which was readily and quantitatively prepared from commercially available methyl‐14C iodide.
Spurious isotope effects in enzymatic reactions with tritium labelled substrates
Authors: Oldham K. G.
Published: October 2006

Tritium labelled substrates are commonly used in enzyme assays on account of their high specific activity, cheapness and availability. Because of certain special effects occurring with tritium labelled compounds, isotope effects may erroneously be inferred from rate measurements using these compounds. These special effects, and recommended methods of detecting and eliminating them, are discussed.
Synthèse biologique d'acide quinique 14C uniformément marqué
Authors: Boudet A.
Published: October 2006

Uniformly 14C‐labelled quinic acid has been biosynthesized by exposing young Quercus pedunculata Ehrh leaves to a source of light in a 14CO2 atmosphere. A preliminary study of the change in specific radioactivity of the labelled acid with time has led to a determination of the optimum metabolisation time. After extraction, separation over ion‐exchange resins and purification by preparative chromatography have allowed to obtain from 10 mCi of Ba14CO3 0,26 mCi of quinic acid, the radiochemical purity of which was proved by autoradiography.

L'acide quinique 14C uniformément marqué a été synthétisé en exposant à la lumière, en présence de 14CO2, des jeunes feuilles de Quercus pedunculata Ehrh. L'étude de l'évolution, en fonction du temps, de la radioactivité spécifique de l'acide marqué a conduit à déterminer un temps de métabolisation optimum. Aprés extraction, la séparation sur résines échangeuses d'ions et la chromarographie préparative ont permis d'obtenir à partir de 10 mCi de Ba14CO3, 0,26 mCi d'acide quinique radiochromatographiquement pur.
Self‐radiolysis of tritiated compounds
Authors: Guarino A. , Pizzella R. , Possagno E.
Published: October 2006

The self‐radiolysis of a tritiated organic compound has been studied with particular attention to the determination of its percent decomposition, its G(‐M)value, as well as yields of the radiolysis products.

Reliable figures have been obtained with the use of accurate experimental techniques, in particular the reverse isotopic dilution method coupled to preparative gas‐chromatography.
Preparation of radioisotopically labelled S‐ribosyl‐l‐Homocysteine
Authors: Duerre John A. , Miller H.
Published: October 2006

S‐Ribosyl‐L‐homocysteine radioisotopically labelled in specific moieties has been prepared by enzymatic hydrolysis of the glycosyl bond of sulfur‐35 or tritium‐labelled S‐adenosyl‐L‐homocysteine. Procedures for chromatographic purification and analysis are reported.
Tritium labelling of compounds by exchange in strongly basic media
Authors: Jones J. R.
Published: October 2006

A large body of organic compounds containing carbon‐hydrogen bonds have very feeble acidic properties. In order that these compounds be made to ionise it is necessary to employ highly basic media. Recent developments now result in the use of several such systems, some of which can serve as a convenient source of labelling. The possibilities of the method are outlined together with the limitations, and a number of specific examples illustrating how compounds can be labelled are given.
The preparation of uniformly labeled cyclohexylamine and cyclamate
Authors: Alter A. , Forman J. C.
Published: October 2006

Aniline uniformly labeled with 14C was reduced, in the presence of Rhodium on Alumina catalyst, to cyclohexylamine. The cyclohexylamine was converted to uniformly labeled sodium cyclamate. The overall radiochemical yield was 34 %.
Synthèse de la DL‐Ephedrine (Hydroxyméthylène 14C)
Authors: Nguyen‐Hoang‐Nam  , Herbert M. , Nguyen‐Dat‐Xuong  , Pichat L.
Published: October 2006

La DL‐éphédrine (hydroxyméthylène 14C) a été synthétisée à partir de Ba14CO3 en 5 stades. Après 2 purifications successives par chromatographie sur colonne de partage‐silicagel et sur résine échangeuse d' AG 50W‐X2, on obtient la DL‐éphédrine (hydroxyméthylène 14C) HCl avec un rendement radioactif de 30 % par rapport à Ba14CO3 (activité spécifique : 17 mCi/mM). L'analyse par électrophorèse sur papier en tampon borate de sodium pH 9,2, associée à la chromatographie sur papier et à la chromatographie en couche mince, permet de contrǒler la pureté radiochimique de la DL‐éphédrine 14C.
Synthese von 14C‐markiertem Polyvinylpyridin‐N‐oxid
Authors: Maul W.
Published: October 2006

Polyvinyl‐pyridin‐N‐oxid ist eine hochmolekulare Verbindung, die eine therapeutische Wirkung auf die experimentelle Silikose hat. Für biologische Untersuchungen wurde 14C‐markiertes Polyvinylpyridin‐N‐oxid hergestellt. Die Synthese verlief über folgende Stufen : 2‐(2′‐Pyridyl)‐essigsäureäthylester‐[1‐14C], 2‐(2′‐Pyridyl)‐äthanol‐[1‐14C] und 2‐Vinylpyridin‐[vinyl‐2‐14C]. Letzteres wurde polymerisiert und oxydiert zu Polyvinylpyridin‐N‐oxid‐[vinyl‐2‐14C]. Eine fraktionierte Fällung dieses Produktes lieferte Präparate mit einem mittleren Molekulargewicht von 7 000 bis 570 000.
Some factors involved in the decomposition of labeled steroids during storage
Authors: Geller Lawrence E. , Silberman Norman
Published: October 2006

Estrone,6‐7‐3H in benzene has been found to exhibit greater decomposition when stored at −5 °C than when stored at +5 °C. The reason is attributed to lack of uniform dispersal of the solute due to solvent crystallization. The non‐distillable residues from commercial solvents have been found to cause rapid destruction of a stored radiochemical if not removed before storage. Data is presented which indicates that the best method for reducing the total amount of decomposition of labeled steroids which are stored for extended periods of time is repurification at regular time intervals.
Synthesis of kryptogenin‐26‐14C and diosgenin‐26‐14C
Authors: Bennett Raymond D. , Sauer Horst H. , Heftmann Erich
Published: October 2006

Kryptogenin‐26‐14C (13) was synthesized from dihydrodiosgenin diacetate (1). The radioactive carbon atom was introduced by the Arndt‐Eistert method, and the extra carbon atom was then removed by a carboxy‐inversion reaction. Diosgenin‐26‐14C (14) was prepared by reduction of kryptogenin‐26‐14C.
Synthese von 14C‐markiertem noxiptilin
Authors: Maul Walter
Published: October 2006

Noxiptilin 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 betrug, in Äthanol im Kühlschrank stieg der Prozentsatz der radioaktiven Verunreinigungen von 0,6 auf 4,2 %.
Validity of tritium tracers. Stability of tritium atoms in purines, pyrimidines, nucleosides and nucleotides
Authors: Anthony Evans E. , Sheppard Hilary C. , Turner John C.
Published: October 2006

The effect of pH and temperature on the stability of tritium atoms at various positions in purines, pyrimidines, nucleosides and nucleotides is discussed. The importance of recognizing several types of instability is stressed.

The formation of a hydrate on storing solutions of tritiated uridine and other results of the self‐radiolysis of tritiated precursors of the nucleic acids are described. Alcohol solutions and low temperatures are recommended for minimising self‐decomposition.
Chemical graphs. IX. Isotope‐isomerism of multiply‐labelled compounds
Authors: Balaban A. T. , Fǎrcasiu D. , Harary F.
Published: October 2006

Generalizations of previous figure‐counting series used in Pólya's enumeration theorem are exploited to enable us to predict the number of isomers of multiply‐labelled compounds. Nomenclature problems for such isotope‐isomers are reviewed.
A study of the stability and radiochemical purity of some radiopharmaceuticals
Authors: Rybakow Z. , Cífka J.
Published: October 2006

The thermal and radiation stability of diiodofluorescein were studied. The decomposition products were separated by paper chromatography. Inorganic iodine, mono‐, tri‐ and tetrafluorescein were found as thermal decomposition products of diiodofluorescein. In addition, fluorescein and two unidentified compounds were separated from gamma‐irradiated solutions of diiodofluorescein. The yields of radiation decomposition of diiodofluorescein and formation of monoiodofluorescein and inorganic iodine were estimated as a function of the concentration of diiodofluorescein.
New possibilities of enzymic synthesis of radioactive nucleotides. III. Preparative synthesis of radioactive 5′‐nucleotides by an unpurified cell‐free extract of mouse leukemic cells
Authors: Nejedlý Z. , Hrušková S. , Hybσ K. , Filip J. , Cihák A. , Veselý J.
Published: October 2006

AKR leukemic mouse cells possess a considerable uridine kinase activity. The ability of unpurified cell‐free extracts prepared from these cells to phosphorylate nucleosides‐14C was investigated. The substrate specificity of the enzyme preparation and the possibility to regulate the course of the enzymatic reactions were examined. The method is convenient for the preparative synthesis of uracil, cytosine and hypoxanthine 5′‐nucleotides‐14C.
Synthesis of olivetol‐4,6−14C2, and its conversion to (–)–δ9‐6a, 10a‐trans‐tetrahydrocannabinol‐2,4−14C2 via (–)–Δ8‐6a, 10a‐trans‐tetrahydrocannabinol‐2,4−14C2
Authors: Liebman A. A. , Malarek D. H. , Dorsky A. M. , Kaegi H. H.
Published: October 2006

Olivetol‐4,6−14C2 (III) was prepared by condensing diethyl‐malonate‐2−14C with 3‐nonen‐2‐one followed by hydrolysis, decar‐boxylation and oxidation. Reaction with (+)‐trans‐p‐menthadien‐2,8‐ol‐l provided (–) — Δ86a, 10a‐trans‐tetrahydrocannabinol‐2,4−14C2 (IV) which was isomerized to (–) — Δ9‐6a, 10a‐trans‐tetrahydrocannabinol‐2,4−14C2 (V). On a scale of 3–5 mmole, malonate‐2−14C yields 45–50% of chromatographically pure olivetol‐4,6−14C2, which on a 2 mmole scale, gave a 56% radiochemical yield of purified tetrahydrocannabinols. Both the (–) — Δ8‐THC‐2,4−14C2 and (–) — Δ9‐THC‐2,4−14C2 had greater [α]D than previously reported.
Synthesis of 15N labelledl alkaloids: Coniine−15N and nicotine‐1′−15N
Authors: Leete E. , Isaacson H. V. , Durst H. D.
Published: October 2006

Coniine−15N was obtained by the reductive amination of 5‐oxcoctanal using sodium cyanoborohydride and ammonium−15N bromide. Nornicotine‐l'−15N resulted from a similar reductive amination of 4‐oxo‐4‐(3′‐pyridyl)butanal. Methylation with formaldehyde and formic acid afforded nicotine‐l'−15N.
Synthesis of tritium labeled isoxsuprine hydrochloride
Authors: Madding G. D.
Published: October 2006

Tritium labeled isoxsuprine hydrochloride was required for drug metabolism studies in these laboratories. This compound was prepared specifically labeled with tritium in the 1‐position by the catalytic reduction of racemic β(R), γ(R)‐ and β(S), γ(S)‐p‐hydroxy‐α‐(1‐phenoxy‐2‐propylamino)‐propiophenone hydrochloride with tritium.
Markierte verbindungen XI. chloraustausch zwischen 3H‐pentachlor‐1‐propen und AlCl3–(36Cl), das tetrachlorpropenylium‐ion
Authors: Boberg Friedrich , Khalaf Hosni
Published: October 2006

The tetrachloropropenylium‐ion is proved as intermediate for the exchange of chlorine between 3H‐pentachloro‐1‐propene and AlCl3–(36Cl). The exchange is preferred on C‐3. Chlorine of trichloroacrolein is exchanged with HCl in H2SO4‐solution. — 36Cl‐labelled C3‐compounds have been synthesized.
Synthesis of caffeine‐2−14C
Authors: Heftmann Erich
Published: October 2006

Xanthine‐2−14C (1) was converted to caffeine‐2−11C (2) by methylation with dimethyl sulfate.
The synthesis of l‐amino acids and their derivatives labelled with 3H
Authors: Brundish D. E. , Elliott D. F. , Wade Roy
Published: October 2006

Methods have been devised for the synthesis of a range of L‐amino acids and of certain of their derivatives and of D‐serine labelled with 3H at their α‐carbon atoms by a racemisation method followed by enzymic resolution. Conditions have been found which allow good recovery of materials of high specific activity for a given outlay of isotope with the added advantage that experimental technique has been maintained to the simplest level possible The stereochemical purity of the labelled amino acids synthesized is in excess of 99.99%.

The 3H‐labelling method for determining C‐terminal residues in peptides developed by Matsuo(1) has been briefly investigated.
Synthesis and characterization of carbon‐14 labelled 4, 4′‐ diaminodiphenyl sulfone (dapsone‐14C; DDS‐14C)
Authors: Blackburn C. E. , Glazko A. J.
Published: October 2006

4, 4′‐Diaminodiphenyl‐14C sulfone

Named as 4, 4′‐sulfonyldianiline in Chemical Abstracts.

(DDS‐14C) was synthesized in four steps. Uniformly carbon‐14 labelled aniline hydrochloride was first acetylated to yield acetanilide (phenyl‐14C). This was coupled with SOCL2 and AlCl3 in a Friedel‐Crafts reaction to yield 4, 4′‐diacetamidodiphenyl‐14C sulfoxide. Oxidation with hydrogen peroxide yielded 4, 4′‐diacetamidodiphenyl‐14C sulfone (DADDS‐14C. Hydrolysis of DADDS‐14C in HCL yielded DDS‐14C. Characterization data are included.
Synthese du methyl‐2 p‐chlorophenyl‐4 pentane diol‐2,4(fenpentadiol) marque AU 14C
Authors: Noël J. P. , Benakis A. , Valette R. , Herbert M. , Pichat L.
Published: October 2006

Methyl‐2 p‐chlorophenyl‐4 pentane diol 2,4 14C‐4 (Rd 292‐Fenpentadiol), a psychotropic drug, was prepared by means of the action of methyl magnesium iodure on p‐chlorophenyl‐3 hydroxy‐3 ethyl butyrate 14C‐3. The latter was obtained by means of the Reformatzri reaction between ethyl bromoacetate and p‐chloroacetophenon 14CO, which was obtained by the action of iodhydric acid on p‐chlorophenyl diazoacetophenon 14CO, resulting from the action of diazomethane on p‐chlorobenzoyl 14C chlorure. The necessary p‐chlorobenzoic carboxyl 14C acid was obtained through carbonatation of p‐chlorphenyl magnesium bromure, free from any isomere a or m. The total yield compared to 14CO3Ba was 31% Specific activity : 25, 3 mCi/mM.
Study on autoradiolysis of tritiated nucleosides
Authors: Kopoldova J. , Dedkova V.
Published: October 2006

The autoradiolytic decomposition of thymidine‐6‐T and uridine‐5‐T in aqueous solution at +2 and −15°C, in ethanol, and on chromatographic paper was studied in dependence on time of storage and specific activity.
A non‐exchange synthesis of tritium‐labelled tetrahydrocannabinols
Authors: Gill E. W. , Jones Gareth
Published: October 2006

Tritium‐labelled (‐) ‐Δ1 (6) and (‐) ‐Δ1 ‐tetrahy irocannabinols at a specific activity of 607 mCi/mmole were synthesized by a non‐exchange method. The tritium was introduced by the catalytic reduction with tritium gas of an unsaturated precursor of dimethyl olivetol in hexafluorobenzene as a non‐exchanging solvent. Specifically labelled olivetol was subsequently used in the synthesis of (‐) ‐Δ1 ‐tetrahydrocannabinol by an established method. The radiochemical purity of the product was shown to be greater than 98% by TLC, GLC, liquid scintillation counting and bioassay.
Specific tritium labelling of α ‐(p‐methoxyphenyl)‐α'‐nitro‐4 [3‐(dimethylamino) propoxy] stilbene (CI‐680) by catalytic deiodination
Authors: Blackburn C. E.
Published: October 2006

In an unusual example of tritium‐labelling by catalytic dehalogenation in the presence of competing groups, an iodinated precursor was selectively deiodinated with tritium gas to yield α‐(4‐methoxyphenyl‐3‐3H) ‐α'‐nitro‐4[3‐ (dimethylamino) propoxy] stilbene (CI‐680‐3H).

The product was labelled specifically at the C‐3 position of the methoxyphenyl moiety with a specific radioactivity of 27.7 Ci/mmole and a net yield of 609 mCi. Characterization of CI‐680‐3H (base) established the chemical purity to be ≥99% and the radiochemical purity to be ≥97.6%. Characterization also included an evaluation of the tritium label stability in water and in aqueous acidic and basic media.
Preparation of some mercuri‐derivatives of iodinated fluorescein labelled with iodine‐131 I
Authors: Kronrád L. , Hladík V.
Published: October 2006

Mercurisation reaction of the iodinated fluorescein‐131I has been studied. Individual products formed in the reaction mixture were isolated with both paper chromatography and chromatography on alumina column. It was found that in contrast to unsubstituted fluorescein the yield of mercuriderivatives is considerably lower in case of iodinated fluorescein‐131I.
Syntheses de sept pyrimidines deuteriees en position specifique
Authors: Hervieu Jacqueline , Lautie‐Mouneyrac Marie‐France , Dagaut Jacques , Dizabo Pierre , Leitch Leonard C. , N‐Renaud Roger
Published: October 2006

The synthesis of seven deuteriopyrimidines of high isotopic purity was effected either by reductive dechlorination of chloropyrimidines with deuterium on a Pd/CaCO3 catalyst, deuterolysis of sulfonylhydrazinopyrimidines with mild base in D2 O or oxidation of hydrazinopyrimidines with silver acetate.
Contribution a l'etude des echanges isotopiques du tritium dans le phenol a haute temperature
Authors: Bettens B. , Dubois E.
Published: October 2006

The experimental determination of the exchange rate, first between the tritium fixed on the OH function and the hydrogen of the nucleus, and then between the tritium specifically fixed on the cycle and the OH function has been studied.

The experimental results are obtained by two different ways, the lyophilisation and the transformation in the corresponding phenolate.

By means of the experimental values we have calculated the activation energy of the exchange. With these values, it is possible to show that : a) due to its stability, the molecule can be use as tracer at high temperature in gazeous phase. b) the compounds with labile hydrogene have a certain catalytic effect on the isotopic exchange.
Synthesis of 1 ‐ deuterioaldehydes from methylene ‐ BIS ‐ pyridinium cations
Authors: Olofson R. A. , Zimmerman D. M. , Schnur Rodney C.
Published: October 2006

A synthesis of 1‐deuterio and 1‐tritioaldehydes, especially arylaldehydes, from precursor gem‐dihalides is described. The scheme is especially useful when high label incorporation is desired.
Markierte verbindungen XIII. Hexachlor‐ 1.3 ‐ cyclopentadien ‐ (36CL)
Authors: Boberg Friedrich , Khalaf Hosni
Published: October 2006

The exchange of chlorine between hexachloro‐1.3‐ cyclopentadiene and AlCl3‐ (36 Cl) is studied. Chlorocyclo‐C3 ‐compounds ‐( 36 Cl) are synthesized.
Synthesis of picolinic‐(carboxyl‐14C) acid and 2‐{(methylsulfinyl) acetyl ‐ (carbonyl ‐14C)} pyridine
Authors: Merril E. J. , Vernice G. G.
Published: October 2006

Picolinic‐ (carboxyl‐14C) acid was prepared by carbonation of the lithio derivative obtatined from n‐butyl lithium and 2‐bromopyridine. This was esterified and allowed to react with the anion generated from dimethyl sulfoxide by sodium hydride to give 2‐[(methylsulfinyl)acetyl‐(carbonyl‐14C)] pyridine.
Preparation of [14C] triethylaluminium
Authors: Ayrey G. , Mazza R. J.
Published: October 2006

A method for the preparation of [14C] triethylaluminium by catalysed exchange of [14C] ethylene with inactive triethylaluminium is described. Novel methods for handling this spontaneously inflammable substance were developed and used for hydrolytic and radiochemical analyses.
Labelled polypeptides, III. Synthesis of α‐melanotropin labelled with tritium on the tyrosine residue
Authors: Medzihradszky K. , Nikolics K. , Teplan I. , Seprodi J. , Fittkau S.
Published: October 2006

The synthesis and purification of α‐melanotropin labelled with tritium on the tyrosine residue is described. The hormone possesses a specific radioactivity of 2.8 Ci/mmole, which enables its application in studying transport processes, metabolism and mechanism of hormone action.
Synthesis of C‐14 labelled methyl sterculate
Authors: Pawlowski Norman E. , Nixon Joseph E. , Lee Donald J. , Sinnhuber Russell O.
Published: October 2006

Methyl sterculate, a cyclopropenoid fatty acid, has been synthesized with carbon‐14 as the methylene carbon in the cyclopropene ring.
Preparation de la D‐Methionine (14C‐3) et de la Methionine (14C‐3)
Authors: Pichat L. , Beaucourt J. P.
Published: October 2006

La carbonatation avec 14CO2 du Mméthylthiométhyllithium a fourni l'acide méthylthio‐2 acétique(14C‐1) avec un rendement de 83%, dont la réduction par LiA1H4 a conduit au méthylthio‐2 éthanol‐1 (14C‐1) qui a été transformé en chlorure correspondant par action de la tri‐n‐octylphosphine et CCl4. Le chlorure condensé sur le sodio acétamicomalonate d'éthyle a fourni le (méthylthio‐2 éthyl) acétamidomalonate d'éthyle (14C03) qui a été saponifié en monoester dont la décarboxylation a produit le DL‐méthylthio‐4 acétamido‐2 butyrate d'éthyle (14C‐3). L'hydrolyse par l'α‐chymotrypsine donne la N‐acétyl‐L‐méthionine (14C‐3) que l'on sépare du méthylthio‐4 acétamido‐2‐D‐butyrate d'éthyle (14C‐3). Par hydrolyse chlorhydrique on aboutit respectivement à la L‐méthionine (14C‐3) et à la D‐méthionine (14C‐3) dactivité spécifique: 54 mCi/mM avec des rendements respectifs globaux de 14 et 11% par rapport a 14CO3Ba.