BIOSYNTHESIS OF MUSTARD OIL GLUCOSIDES: VI. BIOSYNTHESIS OF GLUCOBARBARIN IN RESEDA LUTEOLA L.

1965 ◽  
Vol 43 (2) ◽  
pp. 189-198 ◽  
Author(s):  
E. W. Underhill
Keyword(s):  
Specific Activity ◽  
Mustard Oil ◽  
Keto Acid ◽  
Carbon 14 ◽  
Acid Analogue ◽  
Phenylbutyric Acid ◽  
Carboxyl Carbon

A number of C14-labelled compounds were fed to Reseda luteola L.; after a 24-hour period of metabolism, the thioglucoside aglycone (5-phenyl-2-oxazolidinethione) was isolated and its specific activity determined. In some instances the aglycone was degraded to determine the distribution of C14.DL-γ-Phenylbutyrine (2-amino-4-phenylbutyric acid) was the most efficient precursor of the aglycone, followed by phenylalanine and acetate; the carboxyl carbon of these compounds was not incorporated into the thioglucoside aglycone. Little or no randomization of C14 in the aglycone resulted from feeding DL-γ-phenylbutyrine-2- and -3-C14, DL-phenylalanine-2- and -3-C14, and acetate-2-C14. The conversion of C14 from 10 additional compounds into the aglycone was less than that from D-glucose-G-C14. Isotope competition experiments suggest that β-benzylmalic acid also may be a precursor. It appears that the C6–C3 aglycone is formed from phenylalanine and acetate via C6–C5 and C6–C4 intermediates (including γ-phenylbutyrine or its keto acid analogue) in a manner analogous to the formation of gluconasturtiin in watercress. The carbon-14 and nitrogen-15 of L-phenylalanine-G-C14-N15 and of DL-γ-phenylbutyrine-2-C14-N15 were not incorporated as a unit into the aglycone of glucobarbarin.

STUDIES ON WHEAT PLANTS USING CARBON-14 COMPOUNDS: XV. UTILIZATION OF SERINE-1-C14 AND SERINE-3-C14

1961 ◽  
Vol 39 (7) ◽  
pp. 1107-1111 ◽  
Author(s):  
W. B. McConnell ◽  
A. J. Finlayson
Keyword(s):  
Amino Acids ◽  
Specific Activity ◽  
Protein Fractions ◽  
Carbon 14 ◽  
Stages Of Growth ◽  
Protein Amino Acids ◽  
Late Stages ◽  
Carboxyl Carbon ◽  
Soluble Material ◽  
Preferential Incorporation

Thirty-five per cent and 43% of the carbon-14 from DL-serine-1-C14 and L-serine-3-C14, respectively, were found in the mature kernels of wheat plants to which the above tracers were administered by injection into the stem during late stages of growth. Total recoveries of carbon-14 in upper portions of the plant were 40% and 35% respectively. Radioactivity was extensively distributed among major kernel components with protein fractions having a somewhat greater specific activity than starch and ether-soluble material. Carbon-14 from both tracers was incorporated into all of the protein amino acids isolated, notable features being an extensive labelling of carboxyl carbon of glycine when DL-serine-1-C14 was used and preferential incorporation of serine carbon-3 into histidine. The results are in accord with the view that conversion of serine to glycine occurs largely by loss of serine carbon-3 and that little or no glycine is formed from serine via decarboxylation.

scholarly journals THE REPLACEABILITY OF dl-METHIONINE IN THE DIET OF THE RAT WITH ITS α-KETO ACID ANALOGUE

1942 ◽  
Vol 145 (1) ◽  
pp. 201-205 ◽  
Author(s):  
William M. Cahill ◽  
Guilford G. Rudolph
Keyword(s):  
Keto Acid ◽  
Acid Analogue

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.

Phenylalanine metabolism in control subjects, mental patients, and phenylketonurics

1962 ◽  
Vol 17 (6) ◽  
pp. 985-992 ◽  
Author(s):  
William Sacks
Keyword(s):  
Control Subject ◽  
Whole Blood ◽  
Specific Activity ◽  
Normal Subjects ◽  
Activity Ratios ◽  
Normal Humans ◽  
Phenylalanine Metabolism ◽  
Specific Activities ◽  
A Minor ◽  
Carboxyl Carbon

After injection of dl-phenylalanine-1-C14 or l-phenylalanine-1-C14, C14O2 specific activities in whole blood were frac15–frac13 as high as those after injection of dl-tyrosine-1-C14 or l-tyrosine-1-C14 in normal subjects and chronic psychotic patients. In phenylalanine-C14 studies, tyrosine specific activities were 1/16–1/10 of corresponding phenylalanine specific activities. After injection of l-phenylalanine-1-C14 into two phenylketonuric (PKU) patients, C14O2 activities in one, a child, approximated those in other experiments, whereas they were lower in the adult PKU-patient. Maximal tyrosine specific activity (adult PKU patient) was frac16 the corresponding phenylalanine specific activity. Ratios of specific activities of maximal C14O2 to phenylalanine were similar in the control subject and PKU patient, suggesting that catabolism of phenylalanine proceeds at the same rate in phenylketonuria. Results with l-phenylalanine-U-C14 indicated that more than the carboxyl carbon contributed to blood 14O2. The data suggest that hydroxylation of phenylalanine to form tyrosine may be a minor pathway in intermediary metabolism of phenylalanine in normal humans and in chronic psychotic and phenylketonuric patients. Submitted on April 11, 1962

MECHANISM OF CITRIC ACID FORMATION FROM GLUCOSE BY ASPERGILLUS NIGER

1954 ◽  
Vol 32 (1) ◽  
pp. 68-80 ◽  
Author(s):  
Ping Shu ◽  
A. Funk ◽  
A. C. Neish
Keyword(s):  
Citric Acid ◽  
Aspergillus Niger ◽  
Dicarboxylic Acid ◽  
Acid Formation ◽  
Carbon 14 ◽  
Steady Rate ◽  
Tertiary Carbon ◽  
Rate Of Oxygen Consumption ◽  
Carboxyl Carbon ◽  
C 78

A medium containing glucose-1-C14 as the sole carbon source was fermented by Aspergillus niger under conditions giving a steady rate of oxygen consumption and a good yield of citric acid (63%). The citric acid was isolated and degraded by chemical methods to determine the carbon-14 concentration of the methylene carbons, the tertiary carbon, the tertiary carboxyl carbon, and the primary carboxyl carbons. These were found to contain, respectively, 35.6, 21.2, 7.25, and 5.99% of the C14 concentration of carbon-1 of the glucose. A mathematical analysis of these data in the light of current theories on citric acid formation suggested following conclusions: (a) 37–40% of the total citric acid was formed from recycled C4-dicarboxylic acid, (b) 40% of the dicarboxylic acid was formed through C2,C2 condensation and 60% through C1,C3 condensation, (c) 78% of the glucose was dissimilated through the Embden–Meyerhof scheme, the remainder being dissimilated through a mechanism involving carboxyl labeled pyruvic acid.

Chain Elongation of Aromatic Amino Acids: the Role of 2-Benzylmalic Acid in the Biosynthesis of a C6C4 Amino Acid and a C6C3 Mustard Oil Glucoside

1974 ◽  
Vol 52 (10) ◽  
pp. 916-921 ◽  
Author(s):  
D. Dörnemann ◽  
W. Löffelhardt ◽  
H. Kindl
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aromatic Amino Acids ◽  
Chain Elongation ◽  
Mustard Oil ◽  
Barbarea Vulgaris ◽  
Nasturtium Officinale ◽  
A Chain ◽  
Phenylbutyric Acid

A chemical synthesis of specifically 14C-labelled 2-benzylmalic acid, hitherto unknown, was developed. 4-Phenylacetoacetate obtained by condensation of phenylacetyl chloride-1-14C with ethyl acetoacetate yielded 2-benzylmalic acid-2-14C after cyanohydrin reaction and hydrolysis.2-Benzylmalic acid-2-14C, administered to shoots of Nasturtium officinale and Barbarea vulgaris, was shown to be an efficient precursor of the aglucone moiety of the mustard oil glucoside gluconasturtiin. The incorporation of radioactivity agreed well with the values reported for incorporation of 3-benzylmalic acid, but was considerably higher than that obtained after application of L-phenylalanine-U-14C. A conversion of 2-benzylmalic acid into 3-benzylmalic acid and 2-amino-4-phenylbutyric acid could also be demonstrated. These findings provide the final evidence for a chain-lengthening mechanism leading to homologous amino acids as proposed by Underbill and Wetter in 1966.

THE CONVERSION OF 2,6-DIAMINOPIMELIC ACID-1,7-C14TO LYSINE-1-C14BY CERTAIN BACTERIA

1961 ◽  
Vol 39 (10) ◽  
pp. 1551-1558 ◽  
Author(s):  
A. J. Finlayson ◽  
F. J. Simpson
Keyword(s):  
Escherichia Coli ◽  
Aspergillus Flavus ◽  
Culture Medium ◽  
Leuconostoc Mesenteroides ◽  
Streptomyces Griseus ◽  
Diaminopimelic Acid ◽  
Proteus Vulgaris ◽  
E Coli ◽  
Carbon 14 ◽  
Carboxyl Carbon

When 2,6-diaminopimelicacid-1,7-C14was added to growing cultures of Bacillus megaterium, Staphlococcus aureus, and Escherichia coli, 8–9% of added carbon-14 appeared in the cellular lysine. Similar experiments with Proteus vulgaris, Streptomyces griseus, Aspergillus flavus, and Lactobacillus arabinosus resulted in less than 0.3% of the added carbon-14 being incorporated into the cellular lysine. Leuconostoc mesenteroides converted 0.6% of the added DAP-1,7-C14to lysine-1-C14.Over 90% of the carbon-14 in cell lysine from B. megaterium and L. mesenteroides was found in the carboxyl carbon. This was interpreted as indicating a direct decarboxylation of DAP-1,7-C14to lysine-1-C14. About 70% of the carbon-14 in the lysine from cells of S. aureus and E. coli was found in the carboxyl carbon, thus suggesting that some lysine comes from sources other than 2,6-diaminopimelic acid.Those organisms that actively decarboxylated DAP-1,7-C14to form lysine-C14also synthesized DAP and excreted it into the culture medium during growth.

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.

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