STUDIES ON WHEAT PLANTS USING CARBON-14 COMPOUNDS: XIX. OBSERVATIONS ON THE METABOLISM OF LYSINE-C14

1963 ◽  
Vol 41 (6) ◽  
pp. 1367-1371 ◽  
Author(s):  
S. N. Nigam ◽  
W. B. McConnell
Keyword(s):  
Glutamic Acid ◽  
Specific Activity ◽  
High Specific Activity ◽  
Water Soluble ◽  
Pipecolic Acid ◽  
Insoluble Residue ◽  
Wheat Seedlings ◽  
Carbon 14 ◽  
Related Substances ◽  
Very High

When generally labelled lysine-C14 or α-aminoadipic acid-6-C14 was administered to wheat seedlings 48% and 57%, respectively, of the carbon-14 was recovered in water-soluble materials. An additional 39% of the lysine carbon-14 was found in the insoluble residue whereas with α-aminoadipic acid-6-C14 only 11% of the carbon-14 was in the residue. When lysine-C14 was administered, lysine, pipecolic acid, and α-aminoadipic acid had high specific activities while glutamic acid and some related substances contained significant amounts of carbon-14. By contrast, when α-aminoadipic acid-6-C14 was used as tracer the lysine and pipecolic acid isolated were weakly labelled, although α-aminoadipic acid of very high specific activity was recovered from the tissues. Appreciable carbon-14 was also found in the glutamic acid, 63% of this being in position-5.The data are taken as evidence that α-aminoadipic acid and pipecolic acid are on the pathway of lysine metabolism, with acetate being a product of further degradation. The results provide no evidence that α-aminoadipic acid can serve as a precursor to lysine.

STUDIES ON WHEAT PLANTS USING CARBON-14 COMPOUNDS: XIX. OBSERVATIONS ON THE METABOLISM OF LYSINE-C14

1963 ◽  
Vol 41 (1) ◽  
pp. 1367-1371 ◽  
Author(s):  
S. N. Nigam ◽  
W. B. McConnell
Keyword(s):  
Glutamic Acid ◽  
Specific Activity ◽  
High Specific Activity ◽  
Water Soluble ◽  
Pipecolic Acid ◽  
Insoluble Residue ◽  
Wheat Seedlings ◽  
Carbon 14 ◽  
Related Substances ◽  
Very High

When generally labelled lysine-C14 or α-aminoadipic acid-6-C14 was administered to wheat seedlings 48% and 57%, respectively, of the carbon-14 was recovered in water-soluble materials. An additional 39% of the lysine carbon-14 was found in the insoluble residue whereas with α-aminoadipic acid-6-C14 only 11% of the carbon-14 was in the residue. When lysine-C14 was administered, lysine, pipecolic acid, and α-aminoadipic acid had high specific activities while glutamic acid and some related substances contained significant amounts of carbon-14. By contrast, when α-aminoadipic acid-6-C14 was used as tracer the lysine and pipecolic acid isolated were weakly labelled, although α-aminoadipic acid of very high specific activity was recovered from the tissues. Appreciable carbon-14 was also found in the glutamic acid, 63% of this being in position-5.The data are taken as evidence that α-aminoadipic acid and pipecolic acid are on the pathway of lysine metabolism, with acetate being a product of further degradation. The results provide no evidence that α-aminoadipic acid can serve as a precursor to lysine.

THE METABOLISM OF VALERATE-2-C14 BY UREDOSPORES OF WHEAT STEM RUST

1963 ◽  
Vol 41 (1) ◽  
pp. 1-7 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
High Specific Activity ◽  
Water Soluble ◽  
Buffer Solution ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
Water Soluble Extract

When uredospores of Puccinia graminis var. tritici race 15B were shaken in a medium containing M/30 phosphate buffer, pH 6.2, and valerate-2-C14, about 88% of the radioactivity was removed from the buffer solution in a period of 3 hours. About 40% of the carbon-14 taken from the buffer was found in a water-soluble extract of the spores and about 15% was respired as carbon dioxide. The result is compared with an earlier report that carbon 1 of valerate is more extensively released as carbon dioxide and less extensively incorporated into spore components. Glutamic acid, glutamine, γ-aminobutyric acid, and alanine of high specific activity were isolated. It was estimated from partial degradation that more than one-half of the carbon-14 of glutamic acid occurred in position 4 and that carbon 5 was very weakly labelled. Citric acid was also of high specific activity and was labelled predominantly in the internal carbons.It is concluded that respiring rust spores utilize externally supplied valerate by β-oxidation, which releases carbons 1 and 2 in a form which is metabolized as acetate by the tricarboxylic acid cycle.

STUDIES ON WHEAT PLANTS WITH CARBON-14 COMPOUNDS: XX. THE METABOLISM OF PROPIONIC ACID

1964 ◽  
Vol 42 (2) ◽  
pp. 187-193 ◽  
Author(s):  
W. B. McConnell ◽  
A. J. Finlayson
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Propionic Acid ◽  
Specific Activity ◽  
High Specific Activity ◽  
Similar Data ◽  
Tissue Slices ◽  
Wheat Seedlings ◽  
Carbon 14 ◽  
Kernel Protein

The metabolism of propionic acid by maturing wheat plants was investigated by use of the radioactive tracers propionate-1-C14, -2-C14, and -3-C14. Carbon 2 of propionate was most extensively incorporated into kernel components and yielded kernel protein of high specific activity, glutamic acid being particularly radioactive. Carbon 3 was also preferentially incorporated into glutamic acid but was not as efficient in this regard as was carbon 2. Carbon 1 of propionate was extensively respired as carbon dioxide. It did not label glutamic acid extensively. Partial degradation of glutamic acid from kernel protein hydrolyzates showed that carbon 1 of propionate labelled carbon 1 of glutamate more than it did other glutamate carbons. Carbon 2 of propionate preferentially labelled carbon 4 of glutamate and carbon 3 preferentially labelled carbon 5 of glutamate. Similar data were obtained by examining the carbon-14 distribution in free glutamic acid obtained from wheat seedlings labelled with radioactive propionate-1-C14, -2-C14, and -3-C14.The results are interpreted as evidence that propionate is degraded by conversion of carbon 1 to carbon dioxide and by utilization of carbons 2 and 3 as acetate, with carbon 3 behaving as the carboxyl carbon of acetate. They accord with views on the mode of propionate metabolism derived from studies with plant tissue slices.

THE METABOLISM OF VALERATE-2-C14 BY UREDOSPORES OF WHEAT STEM RUST

1963 ◽  
Vol 41 (1) ◽  
pp. 1-7 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
High Specific Activity ◽  
Water Soluble ◽  
Buffer Solution ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
Water Soluble Extract

When uredospores of Puccinia graminis var. tritici race 15B were shaken in a medium containing M/30 phosphate buffer, pH 6.2, and valerate-2-C14, about 88% of the radioactivity was removed from the buffer solution in a period of 3 hours. About 40% of the carbon-14 taken from the buffer was found in a water-soluble extract of the spores and about 15% was respired as carbon dioxide. The result is compared with an earlier report that carbon 1 of valerate is more extensively released as carbon dioxide and less extensively incorporated into spore components. Glutamic acid, glutamine, γ-aminobutyric acid, and alanine of high specific activity were isolated. It was estimated from partial degradation that more than one-half of the carbon-14 of glutamic acid occurred in position 4 and that carbon 5 was very weakly labelled. Citric acid was also of high specific activity and was labelled predominantly in the internal carbons.It is concluded that respiring rust spores utilize externally supplied valerate by β-oxidation, which releases carbons 1 and 2 in a form which is metabolized as acetate by the tricarboxylic acid cycle.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

The labeling of brassinosteroids by tritium

RSC Advances ◽  
2015 ◽  
Vol 5 (80) ◽  
pp. 65214-65220 ◽  
Author(s):  
Aleš Marek ◽  
Mahadeo R. Patil ◽  
Tomáš Elbert
Keyword(s):  
Convenient Method ◽  
Specific Activity ◽  
High Specific Activity ◽  
Very High

A convenient method for the synthesis of tritium-labeled brassinosteroids with very high specific activity is reported.

scholarly journals Production of Sm-153 With Very High Specific Activity for Targeted Radionuclide Therapy

2021 ◽  
Vol 8 ◽  
Author(s):  
Michiel Van de Voorde ◽  
Charlotte Duchemin ◽  
Reinhard Heinke ◽  
Laura Lambert ◽  
Eric Chevallay ◽  
...  
Keyword(s):  
Neutron Irradiation ◽  
Radionuclide Therapy ◽  
High Efficiency ◽  
Separation Efficiency ◽  
Specific Activity ◽  
High Specific Activity ◽  
Mass Separation ◽  
Full Potential ◽  
Targeted Radionuclide Therapy ◽  
Very High

Samarium-153 (153Sm) is a highly interesting radionuclide within the field of targeted radionuclide therapy because of its favorable decay characteristics. 153Sm has a half-life of 1.93 d and decays into a stable daughter nuclide (153Eu) whereupon β− particles [E = 705 keV (30%), 635 keV (50%)] are emitted which are suitable for therapy. 153Sm also emits γ photons [103 keV (28%)] allowing for SPECT imaging, which is of value in theranostics. However, the full potential of 153Sm in nuclear medicine is currently not being exploited because of the radionuclide's limited specific activity due to its carrier added production route. In this work a new production method was developed to produce 153Sm with higher specific activity, allowing for its potential use in targeted radionuclide therapy. 153Sm was efficiently produced via neutron irradiation of a highly enriched 152Sm target (98.7% enriched, σth = 206 b) in the BR2 reactor at SCK CEN. Irradiated target materials were shipped to CERN-MEDICIS, where 153Sm was isolated from the 152Sm target via mass separation (MS) in combination with laser resonance enhanced ionization to drastically increase the specific activity. The specific activity obtained was 1.87 TBq/mg (≈ 265 times higher after the end of irradiation in BR2 + cooling). An overall mass separation efficiency of 4.5% was reached on average for all mass separations. Further radiochemical purification steps were developed at SCK CEN to recover the 153Sm from the MS target to yield a solution ready for radiolabeling. Each step of the radiochemical process was fully analyzed and characterized for further optimization resulting in a high efficiency (overall recovery: 84%). The obtained high specific activity (HSA) 153Sm was then used in radiolabeling experiments with different concentrations of 4-isothiocyanatobenzyl-1,4,7,10-tetraazacyclododecane tetraacetic acid (p-SCN-Bn-DOTA). Even at low concentrations of p-SCN-Bn-DOTA, radiolabeling of 0.5 MBq of HSA 153Sm was found to be efficient. In this proof-of-concept study, we demonstrated the potential to combine neutron irradiation with mass separation to supply high specific activity 153Sm. Using this process, 153SmCl3 suitable for radiolabeling, was produced with a very high specific activity allowing application of 153Sm in targeted radionuclide therapy. Further studies to incorporate 153Sm in radiopharmaceuticals for targeted radionuclide therapy are ongoing.

STUDIES ON WHEAT PLANTS USING CARBON-14 LABELLED COMPOUNDS: X. THE INCORPORATION OF GLUTAMIC ACID-l-C14

1959 ◽  
Vol 37 (1) ◽  
pp. 933-936 ◽  
Author(s):  
W. B. McConnell
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Wheat Plant ◽  
Protein Fractions ◽  
Appreciable Amount ◽  
Kernel Development ◽  
Carbon 14

Glutamic acid-1-C14 was injected into the top internode of wheat stems at a stage of growth when kernel development was rapid (71 days after seeding). The plants were harvested 31 days later when they had matured and the incorporation of carbon-14 studied. About one-third of the carbon-14 administered was found in the upper portions of the mature plants, much of the remaining radioactivity having apparently been respired. About 85% of the carbon-14 recovered was found in the kernel. The protein fractions of these were most radioactive, but an appreciable amount of carbon-14 also appeared in the starch. Glutamic acid had the highest specific activity of the amino acids isolated from the gluten, but proline and arginine were also strongly labelled. Since these three amino acids were labelled predominantly in carbon-1 their close metabolic relationship in the wheat plant seems probable.

THE METABOLISM OF PROPIONATE BY WHEAT STEM RUST UREDOSPORES

1963 ◽  
Vol 41 (3) ◽  
pp. 737-743 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell ◽  
G. A. Ledingham
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Glutamic Acid ◽  
Stem Rust ◽  
Water Extract ◽  
Hot Water ◽  
Insoluble Residue ◽  
Soluble Carbohydrates ◽  
Wheat Stem Rust ◽  
Carbon 14

When uredospores of wheat stem rust were shaken for 3 hours with phosphate buffer (pH 6.2) containing propionate-1-C14, -2-C14, or -3-C14, about 55% of the carbon-14 was removed from the solution. With propionate-1-C14, most of the carbon-14 taken up was released as carbon dioxide-C14, whereas about 20% and 31% of propionate carbon 2 and carbon 3, respectively, was incorporated into the spores. The specific activity of a fraction consisting of the free amino acids of a hot-alcohol and hot-water extract of the spores increased markedly with increase in the position number of propionate in which the carbon-14 was located. A similar relation was observed for other fractions such as soluble carbohydrates, ether-soluble material, organic acids, and insoluble residue from spores. The most active amino acids isolated were glutamic acid, γ-aminobutyric acid, and alanine. Partial degradations showed that with propionate-2-C14 the carboxyl groups of glutamic acid were especially radioactive, whereas with propionate-3-C14 the internal carbons were most radioactive.It is concluded that propionate metabolism in the rust spores involved conversion of carbon 1 to carbon dioxide, and utilization of carbons 2 and 3 as acetate with carbon 2 behaving as the carboxyl carbon.

Eine Methode zur qualitativen und quantitativen Bestimmung von drei Juvenilhormonen von Insekten

1974 ◽  
Vol 29 (3-4) ◽  
pp. 161-168 ◽  
Author(s):  
K. H. Trautmann ◽  
A. Schuler ◽  
M. Suchý ◽  
H.-K. Wipf
Keyword(s):  
Quantitative Determination ◽  
Specific Activity ◽  
High Specific Activity ◽  
Ether Extract ◽  
Qualitative And Quantitative ◽  
Work Up ◽  
First Time ◽  
Very High ◽  
Tenebrio Molitor Larvae

Abstract A method is presented permitting the qualitative and quantitative determination of all three presently known hormones (JH1-3). The determination is based on the method of radioactive isotope dilution, whereby a very small known amount of tritium-labelled JH-1 is added to the ether extract of the particular species. The addition of radioactive JH-1 permits the isolation of all three hormones, because of their similar behaviour during the chosen work up. The quantitative determination was carried out by gas chromatography and the identification was confirmed with the help of retention-times and GC-MS combination. The method was checked by using an extract of Hyalophora cecropia. For the first time methyl 10,11-epoxy-3,7,11-trimethyl-2-trans-6-trans-dodecadienoate (JH-3) could also be identified as the juvenile hormone of Melo­lontha melolontha. In Vanessa io larvae, Tenebrio molitor larvae and adults and in Musca domestica larvae none of the three known hormones could be detected. The preparation of JH-1 labelled with tritium in the methyl group of the ester was accomplished with very high specific activity (4.34 Ci/mmol) of the tritiated acid with diazomethane.

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