QUANTITATIVE ISOLATION AND ASSAY OF NEUTRAL GLYCERIDE GLYCEROL AND PHOSPHOGLYCERIDE GLYCEROL

1964 ◽  
Vol 42 (2) ◽  
pp. 195-202 ◽  
Author(s):  
A. S. W. DeFreitas ◽  
Florent Depocas
Keyword(s):  
Paper Chromatography ◽  
Specific Activity ◽  
Periodate Oxidation ◽  
Chromotropic Acid ◽  
Sodium Borate ◽  
Carbon 14 ◽  
Acid Catalyzed ◽  
Radioactivity Measurements

Neutral glyceride glycerol and phosphoglyceride glycerol obtained by acid-catalyzed methanolysis of 10-100 mg quantities of mixed lipids are separated by paper chromatography. Quantitative elution of the compounds is followed by a periodate oxidation – chromotropic acid assay of the released formaldehyde. Application of this method to the assay of carbon-14-labelled material permits accurate specific activity determinations by radioactivity measurements on phosphoglycerol and on glycerol complexed with sodium borate.

THE LESS-POLAR METABOLITES PRODUCED BY INCUBATION OF TESTOSTERONE-4-14C WITH RAT AND BOVINE BRAIN

1969 ◽  
Vol 61 (4) ◽  
pp. 641-648 ◽  
Author(s):  
Leon J. Sholiton ◽  
Emile E. Werk
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Paper Chromatography ◽  
Specific Activity ◽  
Bovine Brain ◽  
Polar Fraction ◽  
End Products ◽  
Polar Metabolites ◽  
Layer Chromatography ◽  
Constant Specific Activity

ABSTRACT Rat and bovine brain have been incubated with testosterone-4-14C under standard conditions. With use of paper chromatography, the extracted metabolites were noted to fall into less-polar, iso-polar, and more polar fractions. The components of the less-polar fraction were separated by acetylation and thin-layer chromatography and the major end-products identified by recrystallization to constant specific activity or constant 3H/14C ratios. Androst-4-enedione and 5α-dihydrotestosterone were formed consistently under the conditions utilized. Trace amounts of other less-polar metabolites were noted occasionally.

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 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.

scholarly journals The determination of oestradiol and oestrone in the plasma of the domestic fowl by a method involving the use of labelled derivatives

1968 ◽  
Vol 106 (1) ◽  
pp. 77-86 ◽  
Author(s):  
J. E. O'Grady
Keyword(s):  
Human Plasma ◽  
Paper Chromatography ◽  
Domestic Fowl ◽  
Specific Activity ◽  
High Specific Activity ◽  
Double Labelling ◽  
Plasma Samples ◽  
Labelling Technique ◽  
Preliminary Purification

1. A method involving the use of triple-labelled derivatives has been developed for the determination of total oestrone and oestradiol in the plasma of the domestic fowl. The double-labelling technique devised by Svendsen (1960) for the determination of free oestrogens in human plasma was modified to enable the total oestrogen recovery to be determined for each sample. 2. [6,7−3H2]Oestradiol-17β is added to the plasma samples (1–10ml.), which are hydrolysed with acid and the phenolic steroids then extracted and partially purified. The extract is esterified with iodobenzene-p[35S]-sulphonyl chloride of high specific activity. After addition of standard oestrogen [131I]iodobenzene-p-sulphonates the esters are finally purified by paper chromatography. 3. The oestrogens are determined by comparing the 3H/35S and 131I/35S ratios in the purified esters with similar ratios of appropriate standards. 4. With this procedure the recoveries of oestrone and oestradiol after hydrolysis were 70–85% and 72–84% respectively, and after hydrolysis and preliminary purification 38–53% and 39–51% respectively. With this procedure up to 500ng. of oestradiol can be determined. The sensitivity of the technique for oestrone is 3·0ng. and for oestradiol 2·1ng. 5. The ranges of oestradiol and oestrone concentrations found in six plasma samples were 8·3–21·4ng./ml. and 15·2–31·6ng./ml. respectively.

STUDIES ON WHEAT PLANTS USING C14 COMPOUNDS: VIII. FORMATION OF AMYLOSE AND AMYLOPECTIN IN THE WHEAT KERNEL

1958 ◽  
Vol 36 (9) ◽  
pp. 985-991 ◽  
Author(s):  
W. B. McConnell ◽  
A. K. Mitra ◽  
A. S. Perlin
Keyword(s):  
Specific Activity ◽  
Wheat Starch ◽  
Field Conditions ◽  
Conversion Process ◽  
Straight Chain ◽  
Active Growth ◽  
Carbon 14 ◽  
Wheat Kernel ◽  
Tracer Techniques ◽  
A Minor

Tracer techniques have been used to examine the pattern by which the straight-chain and branched components of wheat starch are laid down in the maturing kernel. The starches were isolated from kernels of wheat plants to which had been administered glucose-1-C14, acetate-1-C14, or acetate-2-C14 at different periods of active growth under field conditions. Fractionation of the starches gave amylose and amylopectin and, in addition, a minor fraction of amylopectin, all labelled with carbon-14. Notable differences were found in the specific activity of these starch fractions, and in the distribution of carbon-14 within the monomeric units of samples labelled via glucose-1-C14. These findings indicate that the process of starch deposition in the kernel is not extensively reversible. Amylopectin appears to be formed from amylose, in agreement with current views, and it is suggested that the minor amylopectin component is an intermediate in this conversion process.

Carbon-14 Distribution in Peanut Fruit Parts During Maturation Following 14CO Treatment of Intact Plants1

1974 ◽  
Vol 1 (2) ◽  
pp. 63-67 ◽  
Author(s):  
Harold E. Pattee ◽  
Elizabeth B. Johns ◽  
John A. Singleton ◽  
Timothy H. Sanders
Keyword(s):  
Seed Coat ◽  
Developmental Stages ◽  
Specific Activity ◽  
Total Radioactivity ◽  
Maturity Stage ◽  
Early Maturity ◽  
Early Maturation ◽  
Carbon 14 ◽  
Fruit Part ◽  
Successive Feeding

Abstract Effects of sampling date and developmental stage on the distribution of radioactivity within the crude ethanol, lipid, and starch fractions from fruit, seed coat, and seed of peanut were investigated. Major differences were found between the first and fourth feeding dates in the amount of 14C-labeled photo-synthate translocated to individual peanut fruit parts. Maximum levels of radioactivity in the pericarp, seed coat, and seed were attained at progressively later developmental stages as the respective part became the dominant metabolic sink. Within the fruit, maximum radioactivity in starch was reached during early maturity (stage 3) and total radioactivity generally decreased with successive feeding dates. Thus the level of photosynthate being translocated to a given fruit decreases as more fruit develop on the plant. Observed relationships between level of radioactivity and specific activity of fruit-part components were interpreted as indicating that metabolic reserves are built up in the fruit and seed coat during early maturation and utilized later during seed development and maturation when the level of available translocated photosynthate has diminished.

THE PRODUCTION OF Na22 BY A (H3, n) REACTION IN A NUCLEAR REACTOR

1954 ◽  
Vol 32 (2) ◽  
pp. 94-97 ◽  
Author(s):  
L. G. Cook ◽  
K. D. Shafer
Keyword(s):  
Aluminum Alloy ◽  
Ion Exchange ◽  
Neutron Flux ◽  
Paper Chromatography ◽  
Half Life ◽  
Nuclear Reactor ◽  
Specific Activity ◽  
Separation And Purification

The positron emitting Na22 of 2.6 year half-life has been prepared in a nuclear reactor by the double reaction Li6(n, α)H3, Ne20(H3, n)Na22. The over-all yield was 2.3 × 10−7 atoms of Na22 per atom of tritium formed. Eleven grams of lithium as aluminum alloy turnings in a neon atmosphere at 200 p.s.i. was irradiated for 175 days in a neutron flux of about 4 × 1012 n./cm.2/sec. About 380 μc. of Na22 was obtained in a sodium extract having a specific activity of 10 mc. Na22/gm. of Na23. A specific activity in the curie/gm. level would be expected from a longer irradiation in the highest flux (6 × 1013 n./cm.2/sec.) in the NRX reactor. The separation and purification of the sodium proved practicable by paper chromatography or ion exchange; the analyses for trace Li and Na23 were carried out by radioactivation.

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