Chromatographic Separation of Free Amino Acids in Table Sirups

1971 ◽  
Vol 54 (1) ◽  
pp. 61-65
Author(s):  
Arthur Russell Johnson ◽  
Richard L Corliss ◽  
Enrique Fernandez-Flores
Keyword(s):  
Amino Acids ◽  
Quantitative Analysis ◽  
Amino Acid ◽  
Ion Exchange ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Butyl Esters ◽  
Tlc Analysis

Abstract Qualitative chromatographic methods for the separation of free amino acids in table sirups are presented to aid in the development of chemical indices of composition which may be useful in establishing the identity of sirups and detecting their adulteration. Free amino acids in 2 table sirups were isolated on ion exchange columns and eluted with dilute ammonia. The concentrated amino acid mixture in the eluate was spotted directly on silica gel G plates for TLC analysis, or the amino acids were converted to their N-trifluoroacetyl n-butyl esters for GLC analysis. As many as 16 amino acids were qualitatively separated and identified and a potential for quantitative analysis was demonstrated.

Liver extract and its free amino acids equally stimulate gastric acid secretion

1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Liver Extract ◽  
Amino Acid Mixture ◽  
Acid Mixture

Using intragastric titration in dogs with gastric fistulas, dose-response studies were carried out with liver extract and with a mixture of amino acids that matched the free amino acids found in liver extract. All solutions were adjusted to pH 7.0 and osmolality to 290 mosmol x kg-1. Doses are expressed as the sum of the concentrations of all free amino acids. At each dose studied (free amino acid concentration: 2.8, 5.6, 11, 23, and 45 mM), acid secretion in response to the free amino acid mixture was not significantly different from that of liver extract. The peak response to both liver extract and the free amino acid mixture occurred with the 23-mM dose and represented about 60% of the maximal response to histamine. The serum concentrations of gastrin after liver extract and the amino acid mixture were not significantly different. It is concluded that in dogs with gastric fistula, gastric acid secretion and release of gastrin were not significantly different in response to liver extract and to a mixture of amino acids that simulated the free amino acid content of liver extract.

Effect of Glycylglycine on Absorption from Human Jejunum of an Amino Acid Mixture Simulating Casein and a Partial Enzymic Hydrolysate of Casein Containing Small Peptides

1977 ◽  
Vol 53 (1) ◽  
pp. 27-33
Author(s):  
P. D. Fairclough ◽  
D. B. A. Silk ◽  
M. L. Clark ◽  
D. M. Matthews ◽  
T. C. Marrs ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Acid Uptake ◽  
Amino Acid Residues ◽  
Small Peptides

1. A jejunal perfusion technique has been used in normal volunteer subjects to study jejunal absorption of amino acid residues from a partial enzymic hydrolysate of casein in which about 50% of the amino acids existed as small peptides, and also from an equivalent mixture of free amino acids. 2. The effect of a high concentration of the dipeptide glycylglycine on the absorption of amino acid residues from these preparations was studied to quantify the importance of mucosal uptake of intact peptides during absorption of the partial hydrolysate of casein. 3. The results were unexpected. Glycylglycine significantly inhibited absorption of several amino acid residues (aspartic acid + asparagine, serine, glutamic acid + glutamine, proline, alanine, phenylalanine, threonine and isoleucine) from the free amino acid mixture, whereas it significantly inhibited the absorption of only two (serine, glutamic acid + glutamine) from the peptide-containing partial casein hydrolysate. 4. The effect of glycylglycine on absorption of amino acids from the mixture of free amino acids was apparently due to inhibition of amino acid uptake by free glycine liberated from the dipeptide during perfusion. The reason for the failure of glycylglycine to cause extensive inhibition of absorption from the partial hydrolysate is not clear. It may be due to glycylglycine being only a weak inhibitor of peptide uptake, but the possibility that some peptides are taken up by a system unavailable to glycylglycine has to be considered.

Protein value and amino-acid balance of condensed herring solubles and spontaneously heated herring meal. Chick experiments

1958 ◽  
Vol 51 (2) ◽  
pp. 164-176 ◽  
Author(s):  
B. Laksesvela
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Meal Protein ◽  
Amino Acid Balance ◽  
Microbiological Assays

1. In a series of tests chicks were fed up to 4 weeks of age on a ‘purified’ diet supplemented with 10% of protein from either herring meal or condensed herring solubles.2. The solubles alone appeared of negligible value as a protein source, but certain mixtures of solubles and meal protein proved superior to meal alone, although the levels of the essential amino acids plus cystine and tyrosine were lower in the mixture than in meal alone. The supplementary effect may possibly be due to changes in the aminoacid ratio or balance.3. Only tryptophan improved growth and viability when free amino acids were added singly to the solubles. Simultaneous supply of all 10 essential amino acids elevated growth to about 80% of that on meal alone. A combination of tryptophan, isoleucine, histidine and phenylalanine appeared nearly as effective as the 10. Depressant effects of free amino acids at the low levels used were also met with. The chick results followed closely the predictions made from the results of microbiological assays of the amino-acid composition of the solubles, and these were in conformity with the composition of the ‘ideal’ amino-acid mixture for chicks proposed by Fisher & Johnson (1957).4. The small weight gains of the chicks on solubles alone consisted largely of water rather than true tissue. Appetite appeared to be governed by the balance of amino acids, this appearing to be more important than the absolute levels fed. This applied to diets with heated meal as well as the solubles.

ION EXCHANGE CHROMATOGRAPHY OF THE FREE AMINO ACIDS IN THE PLASMA OF INFANTS UNDER 2,500 GM AT BIRTH

PEDIATRICS ◽  
1970 ◽  
Vol 45 (4) ◽  
pp. 606-613
Author(s):  
Johanne C. Dickinson ◽  
Herman Rosenblum ◽  
Paul B. Hamilton
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ion Exchange ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Sensitivity ◽  
Exchange Chromatography ◽  
Chromatographic Technique ◽  
The Individual ◽  
Amino Acid Concentrations

The free amino acids in the plasma of 46 infants who were under 2,500 gm at birth were determined by an ion exchange chromatographic technique of high sensitivity and resolution. Ninety-two plasma samples were collected from the 46 infants on different days after birth, and the data for 23 amino acids plus taurine and ethanolamine were summarized and compared with newborn, full-term and adult levels. In 16 cases tyrosine levels were high; these values are listed separately. With respect to the remaining amino acids, many showed marked changes during the first few postnatal days; but, by the end of the first week, stable patterns had developed. The decrease or increase of the individual amino acid concentrations in these infants compared to infants with birth weights over 2,500 gm and to the adult was not great and seemed to be characteristic for each amino acid. Attention was drawn to the technical details of preparing and analyzing physiological fluids which would minimize the changes in amino acid concentrations resulting from improper handling.

scholarly journals Splanchnic-bed transfers of amino acids in sheep blood and plasma, as monitored through use of a multiple U-13C-labelled amino acid mixture

1996 ◽  
Vol 75 (2) ◽  
pp. 217-235 ◽  
Author(s):  
G. E. Lobley ◽  
A. Connell ◽  
D. K. Revell ◽  
B. J. Bequette ◽  
D. S. Brown ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Gas Chromatography Mass Spectrometry ◽  
Acid Mixture ◽  
Body Protein ◽  
Hydrolysis Of

AbstractThe response in whole-body and splanchnic tissue mass and isotope amino acid transfers in both plasma and blood has been studied in sheep offered 800 g lucerne (Medicago sutiva) pellets/d. Amino acid mass transfers were quantified over a 4 h period,by arterio-venous procedures, across the portal-drained viscera (PDV) and liver on day 5 of an intravenous infusion of either vehicle or the methylated products, choline (0.5 g/d) plus creatine (10 g/d). Isotopic movements were monitored over the same period during a 10 h infusion of a mixture of U-13C-labelled amino acids obtained from hydrolysis of labelled algal cells. Sixteen amino acids were monitored by gas chromatography-mass spectrometry, with thirteen of these analysed within a single chromatographic analysis. Except for methionine, which is discussed in a previous paper, no significant effects of choline plus creatine infusion were observed on any of the variables reported. Whole-body protein irreversible-loss rates ranged from 158 to 245 g/d for the essential amino acids, based on the relative enrichments (dilution of the U-13C molecules by those unlabelled) of free amino acids in arterial plasma, and 206-519 g/d, when blood free amino acid relative enrichments were used for the calculations. Closer agreement was obtained between lysine, threonine, phenylalanine and the branched-chain amino acids. Plasma relative enrichments always exceeded those in blood (P < 0.001), possibly due to hydrolysis of peptides or degradation of protein within the erythrocyte or slow equilibration between plasma and the erythrocyte. Net absorbed amino acids across the PDV were carried predominantly in the plasma. Little evidence was obtained of any major and general involvement of the erythrocytes in the transport of free amino acids from the liver. Net isotope movements also supported these findings. Estimates of protein synthesis rates across the PDV tissues from [U-13C] leucine kinetics showed good agreement with previous values obtained with single-labelled leucine. Variable rates were obtained between the essential amino acids, probably due to different intracellular dilutions. Isotope dilution across the liver was small and could be attributed predominantly to uni-directional transfer from extracellular sources into the hepatocytes and this probably dominates the turnover of the intracellular hepatic amino acid pools.

Intestinal Absorption of Oligopeptides in Cystinuria

1971 ◽  
Vol 41 (1) ◽  
pp. 23-33 ◽  
Author(s):  
A. M. Asatoor ◽  
M. R. Crouchman ◽  
A. R. Harrison ◽  
F. W. Light ◽  
L. W. Loughridge ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Intestinal Transport ◽  
Tolerance Test ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Test Technique ◽  
Rat Gut

1. The intestinal transport of oligopeptides containing either lysine or arginine has been compared with that of the corresponding free amino acids in six homozygous cystinuric patients and in six normal adult subjects by use of the oral tolerance test technique. 2. No difference was found in the absorption of lysine from l-lysylglycine and an equivalent mixture of free lysine and glycine. 3. In comparisons of serum increments of lysine and arginine after oral casein and an equivalent free amino acid mixture there was no difference in the case of lysine but rise of serum arginine was higher in three cystinuric patients after the whole protein than after the amino acids. 4. Studies of urinary piperidine and pyrrolidine output in a single cystinuric patient supported the results of the tolerance tests. 5. Absorption rates of the dipeptides l-lysylglycine and l-arginyl-l-aspartate from an isolated loop of rat gut are compared with those of an equivalent free amino acid mixture. No difference was found for the former peptide, but in the latter absorption rates of arginine were higher after the amino acid mixture.

Rapid Analysis of Nutritionally Important Free Amino Acids in Serum and Organs (Liver, Brain, and Heart) by Liquid Chromatography of Precolumn Phenylisothiocyanate Derivatives

1990 ◽  
Vol 73 (3) ◽  
pp. 470-475 ◽  
Author(s):  
Ghulam Sarwar ◽  
Herbert G Botting
Keyword(s):  
Amino Acids ◽  
Liquid Chromatography ◽  
Amino Acid ◽  
Ion Exchange ◽  
Free Amino Acids ◽  
Amino Acid Analysis ◽  
Free Amino ◽  
Rapid Analysis ◽  
Protein Hydrolysates ◽  
Modified Method

Abstract An amino acid analysis method for protein hydrolysates, using precolumn phenylisothiocyanate (PITC) derivatlzatlon and liquid chromatography, was modified for its application In rapid analysis of commonly occurring free amino acids in serum and other physiological samples. The modifications Included changes In column temperature (47.5°C compared to 25-35°C used In analyzing protein hydrolysates), method of preparing standard and test samples, and gradient conditions. By using a Waters Pico-Tag amino acid analysis 15 cm long column (which Is also used for analyzing protein hydrolysates), separation of 27 PTC-amino acids in human serum and rat liver, brain, or heart was completed in 20 mln by the modified method. The total time for analysis and equilibration was 30 mln. The modified method was much faster than the traditional ion-exchange methods (2-3 h) or the existing liquid chromatographic methods using PITC derivatlzatlon (66-80 mln) for determining nutritionally Important free amino acids In physiological fluids and tissues. Variability of the method (expressed as coefficients of variation) for the determination (Including deprotelnizatlon, derivatlzatlon, and liquid chromatography) of all amino acids was less than 5%, which compared favorably with the reproducibility of Ion-exchange methods

Ion-Exchange Chromatography of Free Amino Acids in Human Intraocular Fluids

1971 ◽  
Vol 17 (4) ◽  
pp. 285-289 ◽  
Author(s):  
Davis G Durham ◽  
Johanne C Dickinson ◽  
Paul B Hamilton
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ion Exchange ◽  
Free Amino Acids ◽  
Free Amino ◽  
Subretinal Fluid ◽  
Aqueous Fluid ◽  
Exchange Chromatography ◽  
Chromatographic Technique ◽  
Order Of Magnitude

Abstract Free amino acids were determined in human aqueous, vitreous, and subretinal fluid (50 to 100 µl) from individual eyes by using an ion-exchange chromatographic technique of increased sensitivity. The concentrations of amino acids in aqueous fluid from intraocular malignant melanomas were compared with those found for normal eyes, and some differences were observed. Other pathological conditions investigated were mongolism, intraocular hemangioma, uveitis, Sturge—Weber’s syndrome, and Marfan’s syndrome; only the latter two appeared to have a normal amino acid pattern. Vitreous and subretinal fluid each had a distinctive pattern, with the amino acid concentrations generally lower than in aqueous fluid, except for glutamine, which appeared to be of the same order of magnitude in all intraocular fluids and plasma. Postmortem and eye-bank aqueous fluids were also analyzed, and showed considerable variability from normal. The presence of an additional 28 unknown compounds was demonstrated in aqueous fluid.

AMINO ACID COMPOSITION OF UREDOSPORES OF PUCCINIA GRAMINIS TRITICI

1965 ◽  
Vol 43 (6) ◽  
pp. 695-699 ◽  
Author(s):  
David Stefanye ◽  
Kenneth R. Bromfield
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ion Exchange ◽  
Free Amino Acids ◽  
Free Amino ◽  
Spore Wall ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Puccinia Graminis ◽  
Total Free Amino Acids

Uredospores of Puccinia graminis var. tritici (race 56) were analyzed quantitatively for total free amino acids and ninhydrin-positive substances by ion-exchange chromatography. Extracts of these substances were obtained by leaching the spores and by re-extracting leached spores with boiling water. Thirty-five ninhydrin-positive compounds were found and identified. The leach extract differed quantitatively from the extract obtained by boiling although both contained the same 35 substances. It is proposed that there are easily extractable ninhydrin-positive substances coating the spore wall and ninhydrin-positive substances in the protoplasm that can be extracted only with difficulty.

Metabolism of Intravenously Administered Dipeptides in Rats: Effects on Amino Acid Pools, Glucose Concentration and Insulin and Glucagon Secretion

1977 ◽  
Vol 52 (2) ◽  
pp. 193-204 ◽  
Author(s):  
S. A. Adibi ◽  
B. A. Krzysik ◽  
A. L. Drash
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Intestinal Mucosa ◽  
Intravenous Administration ◽  
Free Amino Acids ◽  
Free Amino ◽  
Renal Cortex ◽  
Plasma Concentrations ◽  
Acid Mixture ◽  
Body Tissues

1. Studies were performed to investigate the metabolic fate of dipeptides when administered intravenously in rats. Glycyl-leucine, glycylglycine or glycylsarcosine was injected into the jugular vein. The plasma disappearance rate after the peak plasma concentrations was most rapid for glycyl-leucine and least rapid for glycylsarcosine. 2. During urine collection for 40 min, trace amounts of glycyl-leucine and glycylglycine and 13% of the injected glycylsarcosine were excreted. 3. Neither glycylglycine nor glycyl-leucine was detected in the liver, muscle, intestinal mucosa or renal cortex, but concentrations of glycine or leucine, or both, in these tissues were increased after each injection. In contrast, glycylsarcosine was recovered in all these tissues with concentrations in the renal cortex being far greater than in any other tissue, but sarcosine was found only in the renal cortex and intestinal mucosa. 4. The changes in plasma concentrations of free amino acids, glucose and glucagon, and tissue concentrations of free amino acids, were similar after the intravenous administration of glycyl-leucine and an equimolar mixture of free glycine and leucine. However, the amount of insulin secreted during the 40 min after glycyl-leucine injection was 1·6 times that produced after the injection of the corresponding amino acid mixture. 5. Results show that, within the present experimental conditions, the intravenous administration of dipeptides is as effective as that of the corresponding free amino acids in enriching the tissue pools of amino acids. It is suggested that efficient hydrolysis by cellular enzymes prohibits accumulation of intact dipeptides in body tissues.

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